| 2006 |
151. Jahrgang
|
| Rohrer, Heinrich |
Was ich mir von einem jungen Wissenschafter wünschte |
151/1-2: 1-3 |
| Schaik, van Carel |
In search of the roots of human nature |
151/1-2: 5-12 |
| Schlagwörter: Evolution
- Fortpftanzungsbiologie - Infantizid - intellektuelle Fähigkeiten
- Kultur - natürliche Selektion - Orang-Utans - post partum Amenorrhöe
- soziales Lernen - Werkzeuggebrauch |
Who are we, and where do we come from? These
are two age-old questions I try to answer here. Charles Darwin claimed
that we evolved by natural selection from ape-like ancestors. But we are
not mere naked apes and were only made human by our language, morality,
art and culture. By studying great apes we are surprisingly still finding
out new things about humans. Infanticide by males is not pathological.
Instead, we can find its origins in reproductive biology. Infanticide is
adaptive, in the cruel logic of natural selection, to the males committing
it. Females developed counterstrategies to protect their offspring efficiently.
The unusual forms of tool use we found among the orangutans
is a socially transmitted behavioral innovation and therefore a kind of
culture, whose dispersal can be stopped by unsuitable habitat. Populations
with higher association time had larger skill repertoires than the more
solitary ones. Intellectual performance is a function of both the inherent
potential and of inputs provided by individual and social learning. Evolution
of increased intellectual performance is most likely when animals have
culture. Culture and intelligence have co-evolved. |
| Boutellier, Roman |
How much innovation will Homo Faber tolerate? |
151/1-2: 13-19 |
| Schlagwörter: Gesetzgebung - Miniaturisierung
- Nebenwirkungen - Risiko - Technologieakzeptanz - Wachstum |
Politicians, academics and industrial leaders
do agree on one thing: Innovation is the way out of today's growth problem.
Indeed, we can expect a wave of innovations, of such a dimension humanity
has never seen in its whole history.
The trigger is miniaturization that is behind the simple
combinations of existing modules into new products. Whether these innovations
will increase GDP growth substantially is to be questioned:
Today's innovation-euphoria may quickly change into bans
on new technologies, if the speed of technology development and introduction
of new laws are poles apart. Man has a limited appetite for risk and new
technologies need time until their side effects show up. Many technologies
are already tightly controlled. We have a dilemma: On the one hand we want
the positive effects of new technologies as quickly as possible, on the
other hand we have to protect ourselves against its side effects. The legislature,
but as well every individual is asked to strike the right balance and to
take responsibility. Max Frisch's Homo Faber has not lost its relevance. |
| Lohmann, Ulrike |
Aerosols and climate |
151/1-2: 21-28 |
| Schlagwörter: Aerosole - Feinstaub Klima - direkter
und indirekter Aerosoleffekt |
Aerosols affect the climate system
in different ways. They can scatter and absorb solar radiation (direct
aerosol effect). They also act as condensation nuclei for cloud droplet
and ice crystal formation and so influence the physical and optical properties
of clouds as well as their precipitation formation (indirect aerosol effects).
The net result of these aerosol radiative effects is a cooling that partly
offsets the greenhouse gas warming. The magnitude of these effects is,
however, still very uncertain. This article addresses the main sources
and sinks of aerosols as well as their radiative effects. |
| Burga, Conradin A. |
Monitoring of weeds 2001-2005 and the hot summer 2003
A case study of a stone pavement area of Andeer (Rhine vaIley/GR) |
151/1-2: 29-34 |
| Schlagwörter: Holzpflanzen - Pflasterritzen-Ruderalvegetation
- Samenbank – wärmeliebende/trockentolerante submediterrane Pflanzen |
The hot summer 2003 is characterized by the
occurrence of more plant species compared with former years. Especially
thermophilous and drought-tolerant plant species show a higher abundance
and inereasing numbers of saplings of woody plants could be recorded. During
2003, a significant higher amount of diaspores of the seed bank could germinate,
mainly new woody plant species. Especially the sub Mediterranean Soft-foliaged
Asparagus (Asparagus tenuifolius) must be mentioned. lt's a characteristic
species of the herbaceous layer of manna ash-hop hornbeam (Fraxino orni-Ostryetum)
and sweet chestnut-forests of Southern Ticino and Misox valley. Moreover,
some typical weeds like Conyza canadensis, Arenaria serpylifolia s.str.,
Cardamine hirsuta show a mass occurrence during summer 2003. They are dryness
tolerant, heavy nutrient consuming and displacement producing weeds. Some
of these new plant invaders of summer 2003 were able to survive the following
winter, but not the winter 2004/2005. The seed bank of the investigated
area has been nourished intensively with diaspores. Given a future continuously
global warming, a mass invasion of certain serious weeds may be expected,
and this would mean an increasing weed control. |
| Stauffer, Felix |
Jugendpreis 2005 der Naturforschenden Gesellschaft in Zürich |
151/1-2: 35-37 |
| Burga, C., F. Klötzli und M.Gloor |
Internationale Balzan-Stiftung, Balzan-Preis 2005 |
151/1-2: 39-40 |
|
Die beiden Preisträger aus dem Gebiet
der Geisteswissenschaften sind Lothar Ledderose (D, Kunsthistoriker Japan
und China), Peter Hall (GB, Sozial- und Kulturgeschichte, Stadtplanung).
Die Auszeichnung im Bereich der Naturwissenschaften ging
an Peter und Rosmary Grant (GB/USA) sowie Russel J. Hemley und Ho-kwang
Mao (USA). |
| Zingg, Andreas |
Dauerwald - ein neues altes Thema der Waldwachstumsforschung |
151/1-2: 42-45 |
| Thees, Oliver, Fritz Frutig, Edgar Kaufmann |
Energiepotenzial im Schweizer Wald |
151/1-2: 46-48 |
| Schiestl, Florian Paul |
On honesty and deception: pollinator attraction and floral
evolution in plants |
151/3: 51-58 |
| Auskreuzung - Bestäubung - Mimikry - Orchideen
– Täuschblumen |
A standing enigma
in pollination ecology is the evolution of pollinator attraction without
offering reward in about one third of all orchid species. Deceptive orchids
may mimic floral signals of rewarding plants (food deception) or mating
signals of receptive females (sexual deception) to attract pollen vectors.
In some «food deceptive» orchids, similarities in the spectral
reflectance visible to the pollinator in a model plant and its mimic have
been demonstrated. Other species do not mimic specific model plants but
attract pollinators with general attractive floral signals. In «sexually
deceptive» orchids, floral odor is thc key trait for pollinator attraction,
and behaviorally active compounds in the orchids arc identical to the sex
pheromone of the pollinator species. Deceptive orchids often show high
variability in floral signals, that may be avoid learning and subsequently
avoiding of deceptive plants by the pollinators The evolution of obligate
deception in orchids seems paradoxical in the light of the typically lower
fruit set than in rewarding species. Pollination by deception, however,
can reduce self pollination and encourage pollen flow over longer distances,
thus promoting outbreeding. |
| Hall, Heike |
Bioartificial 3D fibrin scaffolds: wound healing as good as with Mother
Nature? |
151/3: 59-66 |
| Angiogenese - Endothelzellen - Fibrinmatrices
- Tissue Engineering - Wundheilung |
Efficient blood supply
is essential for all tissues as each individual cell needs to be located
in dose proximity to the next blood vessel to guarantee nutrient- and gas
exchange. Many diseases are induced by the reduction of blood perfusion
such that the tissues gradually loose their ability to function properly.
Therefore, therapeutic angiogenesis aims to increase blood perfusion in
ischemic tissues by stimulating the patient's endogenous capacity to develop
new blood vessels. These studies include application of angiogenic growth
factors and adhesion sequences as well as local gene therapy.
Our approach is to design bioartificial 3D-fibrin matrices
that have very defined characteristics and apply them at the desired place
in the body. These 3D-matrices serve as provisional scaffolds for invading
cells and induce very specific tissue responses. During healing, cells
infiltrate the scaffold and degrade it with the speed of tissue regeneration
such that it is completely removed when tissue healing is completed. These
3D-matrices can be pre-seeded with autologous cells, however, they can
also be designed to encourage endogenous endothelial- or progenitor cells
to attach and form tight cell-to matrix contacts. These cells enable vascularization
of the 3D-matrix and therefore promote better healing and tissue regeneration. |
| Letsch, Dominik |
The Wulp-gravel from Küsnachter Tobel |
151/3: 67-72 |
| Glazialschotter - Gossau-Interstadial - Relative
Warmphase - Schlamm- und Schuttströme - Seeablagerungen |
The well consolidated,
quarternary gravel outcropping in the upper part of the valley of Küsnacht
near Zurich (Wulp-Schotter) have been known for more than a hundred years
but have not been studied in detail yet. The article gives a short overview
on distribution and structure of the gravel and tries to explain their
origin as debris- and mudflow deposit near a glacier. The mapping of the
gravel and the measurement of drag-marks at the base of it, suggest that
the often proposed hypothesis of the gravel being deposited in an ancient
river valley is not very probable. Furthermore the gravel bears evidence
of a relative warming-phase during and shortly after their deposition.
A discussion of their age leads to the Gossau-Interstadial in the middle
of the last (Wurm) glaciation, which is considered to be likely. |
| Burga, Conradin A. |
The lignite profile of Gossau (Zurich): Vegetation history
and Mid-Würmian palaeoecology |
151/4: 91-100 |
|
The lignite profile of Gossau/ZU reveals
good evidence to the Mid-Würmian vegetation and dimate history of
the Zurich Oberland. The main lignite layer represents mainly the Mid-Würmian
period whereas the above located smaller lignite layer shows the Mid-Würmian
termination. With the help of pollen analyses two spruce periods (Mid-Würmian
interstadials) and three pine periods (mainly Mid-Würmian stadials)
could be recognized. During the interstadials the Gossau/ZU area was covered
at least partly by open boreal coniferous forests (spruce, Serbian spruce,
pine, Swiss stone pine, larch, birch) whereas during the poor or treeless
pine stadials only locally small tree stands of birch and pine could exist.
During the stadials herbs and shrubs of open arctic alpine steppe or tundra
vegetation dominated.
The lignite analyses of plant remains revealed a silting-up
plant succession of a former early Mid- Würmian Gossau/ZH lake to
a peat bog dominated by sedges.
Based on finds of wood remains and warm water demanding
water plants (Najas flexilis) one can conclude that the first spruce interstadial
at the beginning of the Mid-Würmian reflects the warmest climate conditions
compared with the following younger Mid-Würmian interstadials which
show an increasing wetter and colder climate. |
| Brandes, Andrea and Helmut Brandl |
Historical cases of animal anthrax in Switzerland: Incidents in the
canton of Zurich between 1878 and 1919 |
151/4: 101-106 |
| Anthrax - Bacillus anthracis - tanneries- horsehair and -wool processing |
Anthrax is a well-known infectious disease
occurring in wild animals and livestock. The causing agent is the spore-forming,
Gram-positive bacterium Bacillus anthracis. Anthrax might occur in horses,
cattle, sheep, goats, pigs, buffaloes, camels, antelopes, other herbivores,
and even in ostriches and elephants. lt has been assumed that anthrax incidents
are related to climatic as well as particular soil conditions because cases
occurred always after long periods of ram or floodings. Additionally, carcass
disposal sites have been identified as possible infection source. Historical
records reporting cases of animal anthrax in the canton of Zurich between
1878 and 1919 were analysed on the level of political communities regarding
occurrence and number of cases, animals affected, and number of municipalities
affected. Data were correlated with industrial activities (tanning, wool
and horse hair processing) in a community and to the prevailing meteorological
conditions. A total of 675 cases of animal anthrax have been recorded showing
a maximum in 1894. Most of cases involved cattle. Only 6 goats (0.9%),
16 pigs (2.3%) and 21 horses (3.1%) were affected. Cases occurred in 131
of the 171 communities over the 41 years of records. Occurrence correlated
with industrial activities in a community. The investigation of relevant
industrial activities (companies handling potentially contaminated materials,
such as hides, fur, wool, hair, meat, or bone meal) showed that there is
a correlation between the occurrence of cases in a community and local
companies. The influence of wool processing companies (P--0.004) and tanneries
(P= 0.032) is significant whereas horse hair processing showed no significance.
In the communities reporting the highest numbers of cases, tanneries or
wool processing industries were localized. However, a statistical relationship
between the number of cases reported and meteorological data (rainfall,
mean temperature) was not found. |
| Hoop, Richard und Martin Schwyzer |
Avian influenza an update |
151/4:107-111 |
|
In the previous issue of this journal (3/2006),
we reprinted an artide entitled «Die Vielfalt der Influenzaviren»
(diversity of the influenza viruses) by Griot, Eynard, Hoop, Mathys, Matter,
Steffen, and Wunder-Ii, providing background information on the current
epizootic of avian influenza (GRIOT et al., 2006). That artide had originally
appeared in publication #71 of the Swiss society «Forschung für
Leben» and reflected the situation at the end of 2005. Recent developments
in Switzerland and abroad are covered until the end of August 2006 in the
following update. First, we describe the worldwide spread of avian influenza
as an animal disease and the current status of surveillance and prevention
in Switzerland. Then we examine the role of H5N1 influenza viruses (particularly
genotype Z) as infectious agents of zoonosis and the preparedness of this
country for a potential pandemic. |
| Köhler, Claudia |
Reproductive biology in plants -with and without Mendel |
151/4:113-119 |
| |
Seed development in flowering plants is initiated
by the fusion of two male gametes with two female gametes, the egg cell
and the central cell, leading to the formation of embryo and endosperm,
respectively. In most plant species double fertilization is necessary for
the initiation of seed development and autonomous development of egg and
central cell are actively suppressed. In contrast, apomictic species can
form viable seeds without fertilization of the egg cell. Genetic studies
using the model plant Arabidopsis identified an evolutionary conserved
protein complex repressing autonomous division of egg and central cell.
Mutants defective in subunits of this complex can form seed like structures
without fertilization, containing endosperm but no viable embryos. The
molecular basis inhibiting autonomous cell divisions is currently intensively
investigated and will be subject of this overview. |
| 2005 |
150. Year
|
| Christian Stauffer |
The reintroduction of the Przewalski's horse
in the Gobi B-National Park in Mongolia. |
(2005) 150/1-2: 1-9 |
| |
The Przewalski's horse
was extinct in the wild in the late l960ties of the last century. But it
survived in captivity, in zoos and animal parks. The successful breeding
between 1950 and 1980 allowed the reintroduction to the wild after 1990.
Different sites were checked in Mongolia, and the Gobi B-strictly protected
area turned out to be the most suitable habitat. Between 1992 and 2004
89 Przewalski's horses were transported to the Gobi and 93 foals were born.
91 animals survived until now. Especially during winter 2000/2001 severe
losses were registrated. By 2004 four harem-groups and one stallion-group
were established in the wild. Since 1998 a substantial scientific program
was established, which was helpful for the monitoring of the Przewalski-population
and different habitat factors. Since 2002 the focus has changed; the Przewalski's
horse is not the first goal of the project anymore, but the umbrella species
for the development of the Gobi B-strictly protected area into a biosphere
reserve. |
| Stefan Brönnimann |
Climatic variations in the first half of the
20th century |
(2005) 150/1-2: 11-17 |
| |
Studying past climate
variability is a key to understanding and assessing climate change. While
the second half of the 20th century is well studied, relatively little
is known about the first half of the century. Yet, there were large climatic
variations in that half with extreme environmental and economical effects
such as the Arctic warming 1920-1945, the «Dust Bowl» droughts
in the USA during the 1930s or the global climate anomalies of the early
1940s. In this contribution, the ongoing discussion is sketched on behalf
of existing studies on these three examples as well as data analyses. Only
by combining observational data and model results, the complex mechanisms
behind these climatic variations can be understood. Many questions remain
open, though. There is a lack of observation-based data in order to validate
model-derived hypotheses. Future work will focus on this point. |
| Oskar Keller und Edgar Krayss |
The Rhine-Linth glacier in the last Glacial
Maximum
Part 1: introduction. Building-up and retreat of the Rhine-Linth glacier
during the Upper Würm |
(2005) 150/1-2: 19-32 |
| |
The Würm glaciation
of the Alpine foreland has been reconstructed in different phases as a
result of investigations in the Rhine-Lake Bodan region as well as in the
Linth glacier area. Moreover, it will be related with the glaciological,
hydrographical and climatological environment. The methodical basis is
the definition of ice marginal positions by using ice marginal relicts
and the levels of glacial drainage paths. To understand the three-dimensional
geometry of the ice bodies and the glacial processes it is necessary to
construct contour charts with isohypses of the ice surface.
The building-up and the retreat of the Rhine-Linth glacial
system can be divided into four main phases:
(1) Ice advance into the piedmont basins
(2) Building-up of the foreland glaciation
(3) Stages of the last glacial maximum (LGM)
(4) Wasting in the Alpine foreland and in the outlet
valleys.
The real glacier advance supposedly begins at about 29
000 calendar years before present and ensued out of a base position near
Chur at Domat-Ems. In the Bodan foreland in the region of Constance-Ravensburg
an ice-marginal stage was found and named «Obersee-Stage».
The greatest extension was reached near Schaffhausen before 24 000 years
BP. The following high glacial stages as well as the ice retreat into the
outlet channels consists of periods of wasting and of stabilisation or
re-advance respectively, the so-called ice marginal complexes. One can
distinguish Würm Maximum W/M (Schaffhausen/Killwangen), Feuerthalen/Schlieren
W/F, Stein am Rhein/Zürich W/S, Konstanz/Hurden W/K and Weissbad-Koblach
W/W. After 17 000 years BP the glaciers finally melted back rapidly into
the inner Alpine valleys. |
| Frank Klötzli |
Unifying elements in vegetation: Convergence
- coevolution – synevolution |
(2005) 150/1-2: 33-45 |
| |
1. «Synevolution»
signifies convergent evolution of morpho- and physiological structures
in vegetation of similar sites. Therefore synevolution determines that
similar picture which prevails in a given biome and incorporates all compartments
of an ecosystem.
2. Synevolution enables certain predictability on the
evolution of disturbed ecosystems. The destabilization of decisive site
factors leads to the modification of certain structures of the system.
Examples: accumulation of nutrients leads to «macrophorbisation»
favouring large forbs, acidification gives way to heath-like structures,
and desiccation to step-like structures (most important results see table
2!).
Browsing and shadowing or opening of strata give way
to combined influences.
3. Synevolution enables us to draw conclusions from changes
in site conditions to a change in vegetation structures without considering
the taxa. |
| Roland Psenner (Innsbruck) |
The secret life of Lake Vostok. |
150/3-4: 57-67 |
| Antarctic - ice ecosystems - life in ice - micororganisms
- |
One of the most remarkable Antarctic
ice cores, spanning the last 420 000 years of climate history, comes from
a 14000 km² large and approximately 1000 m deep lake, called Vostok
after the Russian station in East Antarctica. The core with a length of
3623 m has answered many questions regarding climate oscillations, at the
same time, however, it has raised a number of enigmas which will not be
solved soon. One of them regards the origin of the lake several million
years ago, another one the question whether there is life in Lake Vostok,
and, if so, which forms it may have adopted and which way the evolution
might have gone. Since life does exist at any place where there is liquid
water and since micro organisms have been found also in the accreted ice
of the lake, we can assume that Lake Vostok does harbour life. An unsolved
technical problem, however, prevents us from finding reliable answers,
and this is how to sample the lake, for we do not have a method to collect
water without the risk of contamination. So Lake Vostok remains at the
center of research and – necessarily - of speculations about life in extreme
environments. At the same time it provides inspiration for the exploration
of extraterrestrial bodies which show similar conditions, such as low temperatures
and oceans covered by several km of ice. |
| Oskar Keller (Eggersriet SG), Edgar Krayss (St. Gallen) |
The Rhine-Linth glacier during the last Glacial Maximum Part 2: Dating
and models of the Rhine-Linth glaciation. Climate reconstructions |
150/3-4: 69-85 |
| |
All available 14C-data of the Rhine-Linth
glacier during the last High Glacial are compiled in a special space-time
diagram. The established chronology comprises a period of 29 000 to 24
000 calendar years before present for the building-up of the glaciation
starting in the area of Chur and ending with the maximal extension. The
ice wasting and the retreat back into the inner Alps took place between
23 000 and 16 500 years BP. Calculated by a model the building-up of the
ice masses needed a medium net balance of 0.13 m of ice per year. During
the first period the rate of advance reached 60 m per year in the outlet
valleys, later on 15-20 m/year in the foreland basins. For the retreat
after the Würm Maximum calculations provide melting rates of 0.05
m/year in the phase of the ice high stages and 0.15-0.18 m/year in the
main phase of wasting.
During the period of the glacial maximal stages the climate
in the glacier foreland is characterized by an average year temperature
of -6 °C, that means about 14-15 °C lower than today (2.nd part
of 20th century). Average temperatures of +7 °C must be supposed for
July and -20 °C nearly for January. The precipitations seem to have
decreased to 20% compared with today. Finally, a diagram of the period
between the last interglacial and present time provides an overview of
the supposed course of the average year temperature (depression to recent)
in the Lake Bodan (Lake Constance) and Lake of Zurich region. |
| Pascal Beer (Bäretswil) |
Naturalness of forests and their alien plants - Investigations near
Zurich and in the Canton of Aargau |
150/3-4: 87-93 |
| Keywords: evaluation methods - Beech-forests - Hemeroby - Neophytes
- Phyto-Diversity – potencial natural vegetation |
In two beech forest areas near Zurich and
Zofingen AG (Swiss Central Plateau), a partly new method to quantify the
degree of their naturalness has been investigated with the help of 41 plots.
The assessment is based on vegetation records according to Braun-Blanquet
and on the comparison between the actual and the potential natural vegetation.
The method can be used with a reasonable time budget. Furthermore, the
plant diversity has been calculated. On eight additional plots the appearance
of invasive alien plants and their influence on plant diversity in the
forest was investigated. 51% of the plots reach nearly their natural state,
while 10% show a strong anthropogenic influence. Forest areas with invasive
alien species show lightly lower plant diversity than similar areas with
a natural vegetation. Between the two test areas of Zurich and Zofingen
very few differences were recorded. While foresters are mainly responsible
for the improvement of the state of forests, much can also be contributed
by every person living around the forest areas. |
| Karl-Heinz Altmann (Zürich) |
Nature as drug producer and as a source of inspiration for the chemist:
The importance of natural products in drug discovery. |
150/3-4: 97-105 |
Keywords
Antibiotics - Biogene Arzneistoffe - Epothilone - Leitstrukturen -
Lovastatin - Naturstoffforschung - Statine - Taxol |
Natural products represent an immeasurable
reservoir of lead structures for the development of new drugs. Today, more
than 50% of drugs in clinical use are substances, which are produced, e.
g., by plants, fungi, or bacteria or which are structurally derived from
such compounds. The first part of this article will highlight the importance
of natural product leads for drug discovery based on two specific examples
of drugs (or groups of drugs) which are currently in clinical use. The
second part of the paper will then deal with a new class of natural products,
which are called epothilones, and which in the recent past have attracted
considerable attention as new lead structures for anticancer drug discovery.
The elucidation of the relationship between structure and biological activity
of these molecules through the synthesis of appropriate analogs represents
one of the major topics in the author's research group at the Institute
of Pharmaceutical Sciences at the ETH Zurich. The understanding of structure-activity-relationships
provides the necessary basis for the development of new drugs, which exhibit
an improved overall profile over the original natural product leads. Currently
6 compounds of the epothilone structural class are undergoing clinical
evaluation in humans. |
| 2004 |
149. Year
|
|
| Eric Kubli (Zürich) |
Einführung in das Themenheft «Was
ist Leben?» |
149/1: 1-2 |
| Peter Walde (Zürich) |
What is life? - Thoughts of a chemist |
149/1: 3-14 |
| Keywords: AIDS-Virus - Autopoiese - minimale
Zellen - RNS (Ribonukleinsäure) - Selbstorganisation -Selbstreproduktion
- Ursprung des Lebens - Vesikel - Wasser |
It is difficult to define life and
to provide a generally accepted definition of a living system (of a «creature»).
From a chemical point of view, cellular life can be viewed as nothing else
than a particular form of matter. A living system is a highly complex organization
and interaction of a large number of very complex as well as rather simple
chemical compounds within individual compartments (cells) or within defined
assembles of compartments, and in exchange with the environment. This entirely
materialistic consideration of living systems is based on different hypotheses.
These hypotheses include the evolutionary relationship among all living
systems, the postulate that all living systems have a common ancestor,
and the assumption that the origin of life was a spontaneous process in
which non-living matter transformed into living matter. The question «What
is life?» contains at last the question about the origin of life.
It is assumed that the first living systems formed about 4 billion years
ago as a direct consequence of a pre-biological increase in molecular complexity,
in a process in which the principles of molecular self-organization most
likely played an important role, although the entire process is rather
difficult to comprehend at the moment. |
| Gottfried Schatz (Reinach) |
The human genome, dignity of life, and the wonderful
mistakes of evolution |
149/1: 15-22 |
| Keywords: Entstehung des Lebens - Individualität
- Komplexität - menschliches Genom |
Our individuality is based on the
enormous molecular complexity of our body and the virtually limitless possibilities
of combining its constituents. As a result, each of us is molecularly unique.
The history of life is recounted from the simplest organisms up to the
(present) «pinnade» of evolution, Homo sapiens. |
| Klaus Peter Rippe |
From «Robo-Roach» to «RoboCop»?
Cyborg technology from an ethical point of view |
149/1: 23-28 |
| Keywords: Ethik - Instrumentalisierung - Perfektionierung
- Technikfolgenabschätzung - Wissenschafts-Ethik - Würde |
Research projects in the field of
cyborg-technology are currently conducted at several universities all over
the world. Thus, science enters an area which has so far been reserved
for science fiction writers. Starting with the example of one of these
projects, the roboroach, this article examines cyborg technology from an
ethical point of view. The author comes to the following conclusion: In
the non-human domain, cyborg technology is no threat for an animal itself,
but scientists may show a morally suspicious attitude of instrumentalising
the non-human world. This attitude is potentially harmful for human beings,
animals or the environment. In the human domain, cyborg technology has
a high potential to help and benefit people. In particular, it can be expected
to lead to the development of better
prostheses or artificial organs for handicapped persons. But besides
the danger of abuse, there is a risk to follow a simplistic approach. |
| Christoph Rehmann-Sutter (Basel) |
A discussion of the objectivity of «life» |
149/1: 29-37 |
| Keywords: Aristoteles - Leben - ökologische
Ethik - organische Praxis - Relationalität lntrinsic Sense. |
In the common way of asking «What
is life?» it is presupposed that life is something like an object
at all. This article analyses the underlying philosophical controversy:
it is about substantivism (not «substantialism»). This controversy
is closely related to ethics and opens the question of alternatives. One
alternative approach is the theory of organic practice. This approach leads
to a relational idea of life, starting from the assumption that all living
processes have their sense in themselves: as sensible performances. When
we say that something is «living», we ascribe to it a space
of sense. Life is reinterpreted as a basic term for an ethics of nature,
a term that expresses moral recognition. |
| F. Klötzli |
BRÜGGER, R. und VASSELLA, A. 2003. Pflanzen
im Wandel der Jahreszeiten. Anleitung für phänologische Beobachtungen.
287 Seiten zweisprachig: d./f.) 8 Phototafeln 6 graphische Darstellungen,
36 Zeichnungen und 5 Tabellen. Arbeitsgemeinschaft Geographica Bernensia,
Bern, Fr. 29.80. |
149/1: 38 |
| Christoph P. E. Zollikofer und Marcia
S. Ponce de León |
Paleoanthropology: new methods, new insights |
149/2-3: 39-50 |
|
Over past decades,
paleoanthropology has undergone significant changes, both with respect
to the kind of questions asked to the fossil record, and the tools used
to analyze hominid fossils. Given the scarcity and fragmentary state of
conservation of most hominid remains, there is a need for non-invasive
methods providing a maximum of information about the precious specimens.
Computer-assisted paleoanthropology unites various methods and technologies
to achieve this goal: Computed Tomography (CT) provides insights into hidden
internal structures of fossil specimens. Processing CT data with computer
graphics methods permits touch-free preparation, three-dimensional reconstruction
and morphometric analysis of virtual fossils. Geometric Morphometry aims
at comprehensive measurement of the three-dimensional form of organismic
structures, thus giving detailed insights into complex spatial patterns
of form variability in a sample. This analytical toolkit can be used to
address «evo-devo» questions, for example, to investigate the
role of ontogenetic modifications during the evolutionary diversification
of archaic Homo into Neanderthals and modern humans. Besides analytical
innovations, new fossil finds play a key role in generating new questions
and new answers in paleoanthropology. Fossil hominids recovered in recent
years from sites in the Republic of Georgia and the Republic of Chad re-shapes
our ideas about the Out-of-Africa movement of early Homo, and about the
origin of hominids. |
| Raoul J. Mutter |
Fossil fishes from the Triassic of the Canadian Rocky Mountains |
149/2-3: 51-58 |
|
The search for fossils
in the Early Triassic of the Sulphur Mountain Formation (Vega-Phroso Member)
in the vicinity of Wapiti Lake (eastern British Columbia) has yielded a
wealth of new finds. In spite of the fossils' generally poor preservation,
a number of exciting remains has been recovered, representing fairly complete
and/or scientifically valuable specimens:
chondrichthyans, ray-finned fishes and coelacanths.
The Early Triassic fauna of the Canadian Rockies is very
important for palaeoichthyology because it serves as a reference fauna
showing outstanding diversity. There are several rock-units in the Vega-Phroso
Member where a concentration of associated and well-preserved fossils can
be found. Clams retrieved from certain horizons, and possibly also microfossils,
may help reconfirm the relative age of faunal assemblages since the fauna
appears rather primitive when compared with other Early Triassic faunas. |
| Fabian Egloff und Edwin Urmi |
Water plants in the Canton of Zurich (Switzerland): Cryptogamic Macrophytes |
149/2-3: 59-73 |
|
The present paper
deals with the distribution and frequency of aquatic pteridophytes, bryophytes
and stoneworts (charophytes) of the Canton of Zurich and the threats to
them. It is focussed on bryophytes collected in the years 1971 until 1974.
The results are presented as lists and in the form of distribution maps.
Only one (Equisetum fluviatile) out of five pteridophyte
species is a native water plant in the narrow sense. Bryophytes show a
considerable diversity with 64 species of which, however, only 16 are real
aquatic plants. One species of peat moss (Sphagnum teres) is new to the
survey area. Charophytes are represented by 11 species.
Aiming to assess changes in the species spectra, we undertook
reinvestigations in 2003 at 38 sites with the most remarkable species.
Decline was found as well as increase. Some species might possibly have
vanished since the first survey.
Shall the water plant diversity be maintained at the
present level, more conservation effort is needed. |
| Peter Staubli |
Regeneration of raised bogs in the Canton of Zoug |
149/2-3: 75-81 |
|
The total expanse
of raised bogs in Switzerland comprises around 1500 hectares, which corresponds
to about 14% of the original area. Of this, only 150 hectares have been
left in their natural state. The two federal acts on bog conservation require
of cantonal governments to reverse as far as possible existing impairment
of bogs at any given opportunity.
Compared to its total expanse the Canton of Zoug is the
most copiously covered in bogs of all Swiss Cantons. Since 1990 several
projects for the regeneration of raised bogs have been successfully carried
out. Next to tried and tested regeneration methods the department for area
planning of Zoug has developed a new method, which has come to be known
as the Zouger Method. Hereby sawdust is used in combination with wooden
boards rammed into the soil to replace peat as filling material for drainage
ditches.
Five more or less completed projects have shown considerable
success after already five to ten years:
Ground-water levels are rising significantly, bog areas
are increasing, (peat-) moss is spreading, bush land is receding and new
contracts on areas of extensification have been set up.An overview shows
the state of various regeneration projects in Switzerland. |
| Gerhart Wagner |
Das Mittelmoränen-Modell – aus wissenschaftlicher Sicht; Duplik
von Wagner auf die Replik von Graf et al.
in der "Vierteljahrsschrift" 148 (3) (German only) |
149/2-3: 83-86 |
| Müller,L. und Fraefel,C. |
More than just fever blisters: therapeutic applications
of herpes simplex viruses |
149/4: 87-94 |
|
Of the numerous herpes
viruses in nature, eight are known human pathogens. One of these is herpes
simplex virus type 1 (HSV-1), which causes the sometimes-cumbersome fever
blisters and more dangerous conditions such as keratitis and encephalitis.
Currently, great efforts are under way to exploit selected members of the
herpes virus family for therapeutic uses. Potential applications of genetically
modified herpes viruses include somatic gene therapy and cancer therapy
using oncolytic herpes. viruses. Numerous pre-clinical studies and some
clinical trials underline the great potential herpes viruses hold in these
areas. |
| Suter, St. und Hölzle, M. |
Cold glaciers as a paleo-temperature archive - a study from the Mont-Blanc
and Monte-Rosa areas |
149/4: 95-104 |
|
Little knowledge has
existed until today on the thermal characteristics of high-elevation Alpine
glaciers. In the framework of an international research project a systematic
investigation on the thermal conditions of so-called cold glaciers and
their relation to climate was carried out for the Mont-Blanc and Monte-Rosa
areas. «Cold» means that the firn shows below-freezing temperatures
throughout the year. Especially the occurrence of cold firn, the interaction
between cold firn and microclimate and the characteristics as a paleo-temperature
archive were investigated in the study. The occurrence of cold firn follows
a complex microclimatic pattern and is characterized by a large variability.
Besides altitude and slope aspect, melt water infiltration during the summer
months plays an important part whether cold firn is formed and how cold
it is. This could be shown with an energy-balance study and be supported
with model calculations. The observed warming in Central Europe since the
1990s could as well be confirmed for high-alpine sites based on observed
englacial borehole-temperature profiles. Due to the high sensitivity of
cold firn areas especially to high summer temperatures, these areas might
be subject to a rapid warming in the near future with serious consequences
for the role of Alpine glaciers as a climate archive. |
| Haab, R. und Jutz, X. |
Bog Regeneration Program for the Canton of Zurich |
149/4: 105-115 |
|
For six years, the
Canton of Zurich's Conservation Unit has been running a bog restoration
program, which aims to regenerate the Canton's most significant 10 to 15
bogs. On five of these sites, measures based on this restoration program
have already been implemented. This paper describes the planning and implementation
procedures applied to the individual projects as well as the program's
core features. Monitoring results so far indicate that the relevant bogs
develop as desired. |
| Kuhn, N. |
Frahm, J.-P. und Frey,W. 2004
Moosflora |
149/4: 116 |
|
No abstract |
| Kuhn, N. |
Benkova, V.E. und Schweingruber, F.H. 2004
Anatomy of Russian Woods |
149/4: 117 |
|
|
| Gilgen, R. |
Pressemitteilung der SANW zur Abschiedsvorlesung von Prof. Dr. Dr.h.c.
Peter Baccini
Kupfer, Holz und Honig - Drei Stoffe und eine Geschichte |
149/4: 118 |
|
|
| 2003 |
148. Year |
|
| Heinz Böker |
Is depression a psychosomatic disorder? |
1: 1-16 |
|
Depressive disorders
are very frequent and often very severe psychiatric diseases. The great
variety of biological, psychological, and sociological results of the depression
research requires an attempt at an integration. For this purpose the «psychosomatic
paradigm», which focuses on the circular connection between factors
on different dimensions, is applied to the spectrum of depressive disorders.
A selection of empirical results of the different areas of depression research
(epidemiology, life-event- and social-support-research neurobiology, cognitive
science, therapy evaluation) is used as building-stones of a circular model
of depression. The complexity of the research questions underlines the
importance of an idiographic perspective and an adequate qualitative research
design. implications of the suggested circular model of depression for
depression research and treatment are discussed. |
| Heinz Bachmann |
A homogenization of the temperature series of Zurich |
1: 17-26 |
|
Indispensable
for studying the climatic change is the availability of very long and homogenous
temperature series. Homogenizing such a series can he achieved in different
ways, all being somehow hypothetical. The homogenization of the temperature
series of Zurich (monthly means) is here, in opposition to the often used
method of comparison with other series assumed to he homogenous, produced
(as far as possible) by own simultaneous measurements in the Zurich station
(METEO Schweiz), arranged in the times of discontinuities in the measurements. |
| Heinz Furrer , Thomas Reichlin and Andre Grundmann |
Fossilized tree trunks in the Lower Freshwater Molasse
(Late Oligocene) in the Goldau Landslide area, Central Switzerland |
1: 27-34 |
|
In the spectacular
outcrop in the upper part of the landslide area we discovered four fossilized
tree trunks (or rather stumps) embedded in situ in a marl layer and covered
by sandstone beds. Most likely the trees were growing on an Oligocene alluvial
fan-complex north of the rising Alps and later were covered by sandy sediment
during flooding events. These very remarkable fossil remains would certainly
he worth preserving a full-sized replica of one of the tree trunks could
he presented for instance in a museum or in the local wildlife nature park |
| Conradin A. Burga und Giuseppe Sampietro |
Pollen analytical investigations of the Robenhausen bog (Lake of Pfäffikon
ZH) A contribution to the Late-Würmian and Holocene vegetation history
of the Zurich Oberland (Switzerland). Part 1: lntroduction, survey and
Late-Glacial vegetation history |
2: 35-44 |
|
Flora, Vegetation
and climate history since the Late Würmian have been investigated
with the help of pollen analyses of limnic sediments and peat layers of
the Rohenhausen bog.
The main goal is the reconstruction of the locale and
regional Vegetation history since ca. 14 000 y BP Late Würmian Vegetation
development started with pioneer steppe and grass Vegetation and changed
during the end of older Dryas to shrub associations, nurse crops and first
stocks of birch. During Bölling and Alleröd interstadial established
first Late-Glacial birch and Scots pine forests. The cold phase of Younger
Dryas caused an opening of the forests and increasing amounts of non arboreal
pollen which represent typical Late-Glacial tundra and steppe Vegetation. |
| Friso van der Veen |
The Swiss Light Source, a new light for research on matter |
2: 47-54 |
|
During the past years
synchrotron radiation sources have become of increasing importance for
the natural sciences. These extremely brilliant sources deliver electromagnetic
radiation with wavelengths ranging from the infrared to the hard X-ray
regime. The Swiss Light Source (SLS), in operation since August 2001, provides
new opportunities for research on condensed matter. The main applications
are to be found in structural biology, in materials science, and in the
research into the electronic bonding properties of surfaces and interfaces. |
| Dieter Steiner |
Human ecology and sustainable development |
2: 55-64 |
|
Present-day human
ecology is concerned with the problems of the human-environment relation
and, in this regard, tries to develop an interdisciplinary and integrative
perspective. This contribution demonstrates how we can apply this kind
of view to the currently interesting topic of sustainable development.
We start by introducing the conventional model which is built on the three
pillars of ecology, society (s.str. and economy and makes use of the idea
of capital stocks. We also discuss the related issues of weak vs. strong
sustainability and efficiency vs. sufficiency. Here the critique as generated
by a human ecological view point sets in. It identifies three types of
short comings: 1. The area of culture (s.str:), understood as basic mindset,
is missing; 2. within the area of society (s.str. the political system
is exempt from consideration, although it would he the tool to initiate
sustainable development, and 3. it is claimed that the areas considered
are of equal value, whereas it should he obvious that ecology is of primary
and culture of secondary importance. |
| Gerhart Wagner |
Pleistocene medial moraines in the Canton of Zurich
Part 2: The glacier of Linth/Rhine in the Glatt valley, glaciers of
Reuss and Thur/Rhine |
3: 67-77 |
| |
As a continuation of WAGNER (2002),
the paradigm of medial moraines is applied to the glacier of Linth/Rhine
in the Glatt-valley and to the Zurich and neighbouring areas of the glaciers
of Reuss and Thur/Rhine.
1. Drumlins. The sediments forming mainly the drum/ins
arc thought to he transported originally as surface-moraine. Their hill
character is given primarily by sedimentation (ridges of the medial moraines,
«hummocky moraines», evtl. topographic inversion). Following
Heim (1919, p. 262), they can he specified as «surface-moraine drum/ins».
Many of them arc modified and covered with ground moraine by subsequent
ice advancement
2. The Deckenschotter. Following the «medial moraines
model», the building material of the «Deckenschotter»
has also been transported upon the ice by medial moraines ending locally
on elevated parts of the ground relief A great part of their debris has
been washed out and sedimented near the ice. Therefore, the Deckenschotters
do not reflect the basis, but the ice surface of the corresponding glaciers.
The conception of former generalized high relief-grounds is given up. The
hypothesis of tectonic movements during the Iceage becomes also unnecessary.
3. Interrelations between drumlin fields and Deckenschotter.
In every cold period, the same medial moraine pattern has been built up
upon the highly composed glaciers («re-iteration» of the medial
moraines). Therefore, the medial moraine-tracks, identified for the Würm-glaciation,
can be correlated in many cases with occurrences of Deckenschotter or «Riss»-sediments. |
| Martin Frank |
Radiogenic isotope systems in ferromanganese crusts: Tracers for circulation
and weathering inputs in the ocean |
3: 89-96 |
| |
The radiogenic isotope compositions
of certain dissolved trace metals in seawater (neodymium, lead, hafnium)
can he used as tracers in oceanographic and paleooceanographic research.
These metals have oceanic residence times on the order of or shorter than
the time required to renew all the water of the global ocean once (approx.
1500 years). Thus the isotopic signatures of distinct water masses remain
preserved over long distances (thousands of kilometers). The isotope composition
of these metals in sea water changes on time scales of few 10s of years
to millions of years as a function of changes in circulation and water
mass mixing, source provenance of the eroded continental material, style
and intensity of weathering, or geographic changes such as the opening
and closing of oceanic seaways or orogenies. The effects of these processes
arc superimposed on each other and have to he isolated in order to derive
reliable conclusions on paleocirculation or weathering inputs in the past
from time series of radiogenic isotope signals. Deep-sea ferromanganese
crusts arc chemical seawater precipitates, which have incorporated the
radiogenic isotope composition of deep water during their very slow growth
(few mm per million years). They represent ideal archives to reconstruct
the evolution of radiogenic isotopes in the ocean over the past up to 60
million years. |
| Pascal Vittoz, Antoine Guisan, Martine Rebetez, Alexandre
Buttler und Frank Klötzli |
Vegetation permanent plots as indicators for changing environment The
project PERMANENT.PLOT.CH needs your help |
3: 97-99 |
| |
A new project has been launched
this year at the University of Lausanne. It aims to create a vegetation
databank of both historic and recent permanent plots in Switzerland (relevés
of floristic inventories which can be geographically pinpointed). This
project will ensure long-term access to floristic inventories of georeferenced
surfaces in Switzerland and will provide important information for future
Swiss botanical research in relation to a changing environment. If you
know of such permanent plots in Switzerland, please contact us. |
| Conradin A. Burga und Giuseppe Sampietro |
Pollen analytical investigations of the Robenhausen bog
(Lake of Pfäffikon ZH). A contribution to the Late Würmian and
Holocene vegetation history of the Zurich Oberland (Switzerland)
Part 2: Holocene flora and vegetation history, human
settlement |
4: 103-112 |
|
During the early Holocene,
thermophilic deciduous tree species (oak; elm, lime tree, maple, ash [mixed
oak forest], hornbeam, hazel, beech) and conifers (silver fir spruce) immigrated
and spread out in the area of the Lake of Pfaffikon, whereas the late glacial
colonists Scotspine and birch recessed during the Older Atlantic the mixed
oak forest reached its optimal spread. At 6400y BP beech and silver fir
(and later spruce) spread quickly in the Pfäffikon-Robenhausen area.
During 5700 y BP (beginning of the Neolithic) occur the first signals of
human impact on Vegetation (culture pollen, forest clearing during 5000
y BP lowest amounts of beech and silver fir pollen, more culture indicators).
After the immigration of hornbeam during the beginning of the Subboreal,
an intensified human presence has been recorded from the Bronze Age to
Roman times: increasing amounts of pollen indicators which reveal farming,
forest clearings. pasturing and trim of deciduous trees). At 3000 y BP
started peat growth together with the locale silting-up of the Lake of
Pfäffikon; later on started the development to a raised bog. During
Roman times, sweet chestnut and walnut were introduced. From 1715 to about
1960 peat was used as fuel. At the drilling site ca. 1.5 m peat were removed;
this corresponds to ca. 1300 years peat bog growth. |
| Hilbi, Hubert |
Eat and be eaten -
On the interaction between pathogenic bacteria and phagocytes |
4: 113-121 |
|
Phagocytes («cells
that devour») take up inert particles and bacteria in a process called
phagocytosis. Bacteria are engulfed by immune phagocytes (macrophages and
neutrophilic granulocytes) and killed and degraded in the phagolysosome,
a membrane-bound compartment. Phagolysosomes form continuously from phagosomes
by fusing with endosomes and lysosomes.
Various pathogenic bacteria can interrupt or modify basically
every step during the maturation of phagolysosomes. Thus, the bacteria
not only avoid their own death but eventually kill the phagocytic cell
instead. Pathogenic strategies include cytotoxicity, antiphagocytosis,
pathogen-induced phagocytosis and intracellular replication. Many pathogens
replicate in macrophages either in a custom-tailored vacuole, or in the
host cell cytoplasm after escaping from the phagolysosome. The interaction
with phagocytes is crucial for the success of a pathogen's virulence strategy.
Free-living amoebae such as Acanthamoeba castellanii
or Dictyostelium discoideum are primordial phagocytes that feed on bacteria.
Some bacteria, including Legionella pneumophila, replicate in these amoebae
in a specific vacuole and ultimately kill the host cell. If Legionellae
are inhaled via aerosols, they may replicate in the alveolar macrophages
of the human lung and cause Legionnaires' disease. Intracellular replication
of Legionella within amoebae and macrophages is mechanistically similar
Therefore, amoebae are a valid model system to study cellular aspects of
Legionnaires' disease. |
| Panke, Sven |
Bioprocess engineering in the «-omics» age |
4: 123-132 |
|
Bioprocess engineering
is concerned with the design and the analysis of processes that employ
biocatalysts to produce valuable products from inexpensive starting materials.
Typical modern products are advanced chemical compounds and biopharmaceuticals.
Traditionally, bioprocess engineering played a role in supporting the exploitation
of difficult-to-develop biocatalysts by adapting equipment to rather demanding
specifications. The successes in enzyme technology and molecular biology
all the way to systems biology have changed the field. Today, biocatalysts
are adapted to process requirements and the process of obtaining a suitable
biocatalyst in the first place has been accelerated and facilitated dramatically.
Modern bioprocess engineering has to find its place between the options
of process engineering and biotechnology. While being required to adopt
the tools of molecular biology; bioprocess engineering can contribute engineering
analysis to the current art of biocatalyst design. |
| 2002 |
147. Year |
|
| Frank Klötzli |
Editorial |
1:1-2 |
| Christoph Lippuner |
Leishmania and leishmaniasis -Little
known scourge of developing countries |
1: 3-12 |
| Keywords: Impfung - Infektionskrankheit
- Lebenszyklus der Leishmanien - LPG (Lipophosphoglycan) -Krankheitsformen
- Makrophagen - Mausmodell - Parasit - Sandfliege - T-Helferzellen -Verbreitung
- Zytokine |
Leishmania is aprotozoic
parasite that causes various forms of leishmaniasis. Sandflies are the
carriers of the parasite. The symptoms of leishmaniasis are not specific.
Macrophages and dendritic cells are the primary infected cells in mammals.
This article presents a short overview of the distribution
and the life-cycle of leishmania and the three main groups of leishmaniasis
- the cutaneous, mucosal and visceral form.
Morphology of parasite and the influence of surface molecules
on the infection process of the macrophages is further described. Lipophosphoglycan
belongs to the surface molecules. The influence of this molecule on the
infection process of macrophages is shown.
The influence of the susceptibility confering cytokine
IL-4 and protective IFN-y on the progression of the leishmania infection
in the mouse model is described. The T-helper cells are essential for the
secretion of these cytokines. The progress of the disease: recovery or
fatal, is determined by the kind of differentiation. Depending on the differentiation
stage, the infection heals or becomes lethal.
This is the reason why this mouse model lends itself
so well to unravelling the complex immune system.
The necessity of new therapy strategies and vaccine development
is discussed. |
| Sebastian Brandner |
From stem cells to mice: Model
systems of neurological diseases |
1: 13-22 |
| Key words: Alzheimer - Demenz
- Neurodegeneration - Parkinson - Stammzellen - transgene Maus -Transplantation |
For the understanding
of development and progression, but also for the design of rational therapies
of neurodegenerative diseases, it is of fundamental importance to gain
insight into their mechanisms. Here, we will shed light on the pathomechanisms
and potential therapies of typical neurodegenerative diseases - Alzheimer
5' and Parkinson 5' disease - which affect substantial parts of the ageing
population. Several experimental approaches, most of them involving transgenic
mice have greatly contributed to our current understanding of these neurodegenerative
diseases. Although all model system have specific limitations, they are
invaluable not only for the study of disease mechanisms but also for the
development of rational therapies. |
| Ursula Kües |
Sexual and asexual reproduction
of a fungus with 12000 sexes |
1: 23-34 |
| Key words: Basidiosporen - Coprinus
cinereus - Fruchtkörper - Kreuzungstypen - Meiose - Mitose - Oidien
-Pheromone - Rezeptoren - Transkriptionsfaktoren |
The mushroom Coprinus
cinereus has an enormous number of different mating type specificities
(«sexes»). These control the fusion of monokaryons, mycelia
with one type of nuclei, to dikaryons having two types of genetically distinct
nuclei and sexual and asexual reproduction on the latter. In terms of adaptation
to the environment, the dikaryon with the two types of nuclei together
with the high numbers of mating type specificities gives a genetic flexibility
to the fungus, not found in other eukaryotes. Molecular analysis revealed
the cellular functions of the products of the mating type genes, the interactions
between these products, and the molecular basis of the high number of mating
type specficities. |
| Christian Monn |
Luftschadstoffe und Allergene:
ein ungesundes Zusammenwirken |
1: 35-36 |
| |
kein Abstract |
|
| Anton Fischer |
Klötzli, F. und Walther,
G.R. (Hrsg.) 1999: Conference on recent shifts in vegetation boundaries
of deciduous forest, esp. due to global warming, 342. S. Birkhäuser
Basel |
|
| Erik C. Böttger |
The frightening foreign - molecular
aspects of pathogens causing infectious disease |
2::41-49 |
| Key words: Antibiotika - Bakterien
- Impfstoff- Mykobakterien - Rekombination - Ribosom -ribosomale RNA -
Toxizität |
The microbial world
is enormously diverse, only a small fraction of which represents human
pathogens the subject of medical microbiology. Central in the constant
fight against pathogenic microbes are antibiotic drugs and vaccines. The
principle of selective toxicity forms the theoretical basis for drugs endowed
with antibacterial activity, but it is only recently that we are beginning
to understand the molecular basis for this specificity The vaccine against
tuberculosis is a live vaccine which represents the vaccine being used
most frequently but also discussed most controversial -the protective efficacy
of this vaccine varies between 0 to 85½0o. Molecular investigations
suggest that mechanisms of genetic instability play a major role in the
variable protective efficacy of this vaccine. |
| Dennis C. Turner |
The behaviour of dogs and cats.
Points of contact between man and animal |
2: 51-61 |
| Key words: Domestikation - Ethologie
- Mensch-Tier-Beziehung - Psychologie - Zucht |
Various reasons for
the domestication of the ancestors of dogs and cats have been proposed
and those ancestors exhibit(ed) a number of pre-adaptations making them
attractive for domestication. After reviewing these, the results of breeding,
in particular, breed differences in the character traits of dogs and cats,
are examined, which in turn are shown to affect the human-companion animal
relationship. Lastly, evidence is presented concerning the role of attachment
to, and social support by, cats in the interactive behaviour between people
and their cats. |
| Konstantin Siegmann |
Fire and man. From the stone age
to the "Global Change" |
2: 63-71 |
| Key words: Aerosol - Abgase -
Albedo - Kohlenstoff- Luftreinhaltung - Lungenkrebs - Partikel - Russ -Treibhauseffekt
- Verbrennung |
Only the use of fire
made today's technologic society possible. There are, however, several
dangers associated with the use of fossil fuels for energy production.
On the one hand certain combustion by-products are a threat to human health
(e.g. soot particles), on the other hand other combustion products (e.g.
carbon dioxide) alter the climate of the earth and lead to global warming.
Own research results for the formation of soot in combustion are presented
and a general picture of soot formation is developed |
| Georg Benz |
Coevolution of insects and plants |
3: 77-91 |
| |
Coevolution means
common evolution of two or more species or populations leading to mutual
adaptation and mutual advantage. The paper deals with coevolution of higher
plants and insects concerning herbivory, and with entomogamous angiosperme
plants and their pollinator. In an introductory chapter a short survey
is given on evolution in general, and of higher plants and insects in particular.
In the second chapter the problems of herbivory and mutual adaptations
are described as well as insect induced resistance or defence on demand.
The subalpine larch/budmoth-system with its cyclic defoliations, leading
to pure larch forests without natural succession, is treated as a unique
example of coevolution between an insect and a specific ecosystem. In the
third chapter the much easier to understand coevolution of entomogamous
Angiospermae and their insect pollinators are discussed in general and
the example of the American Yucca filamentosa and its specific pollinating
moth in more detail In the fourth chapter herbivory and entomogamous pollination
are finally discussed. |
| Paul I. Ward |
Coevolution of the sexes |
3: 93-97 |
| |
Reproduction has traditionally
been viewed as a co-operative act between the sexes. A more recent viewpoint
is that there are extensive elements of conflict at every level of the
interaction. For example, in many species copulation has costs for females,
especially in a reduced life expectancy. These costs can have wide-reaching
consequences for the evolution of many physiological and morphological
characters of males and females. This new viewpoint and the adaptations
which can now be better understood, particularly in behaviour and at the
molecular level, are presented and discussed, principally using two insect
examples, Drosophila melanogaster and the yellow dung fly Scathophaga stereoraria. |
| Wolf U. Blanckenhorn |
The evolution of body size and
sexual size dimorphism |
3: 99-106 |
| |
Body size is one of
the most important quantitative traits under evolutionary scrutiny and
varies tremendously among and within organisms. The majority of animals
has two sexes, and females and males often differ in size (sexual size
dimorphism: SSD). The concept of natural selection is introduced first,
one of the two mechanisms promoting evolutionary change. Then the main
genetic and ecological factors (temperature, food availability, season
length) influencing body size within and among species are discussed. Several
classic evolutionary «rules» relating to body size (e.g. Bergmann
's rule, Rensch s' rule), the causes of some of which are disputed or unclear
are presented next. Finally, the evolutionary causes of SSD are discussed.
SSD is believed to be the net evolutionary result of sex-specific selection
pressures - sexual selection in males, fecundity selection in females,
and viability selection in both sexes - within the limits set by phylogenetic,
genetic, developmental and physiological constraints. |
| Paul Schmid-Hempel |
Coevolution and the Red Queen |
3: 107-114 |
| |
What is responsible
for the maintenance of genetic variation in natural populations? Recent
results suggest that the rapidly progressing coevolution between hosts
and their parasites is one such important evolutionary process. The genotypes
of hosts and parasites thereby interact closely and such that negative
frequency-dependent selection emerges. This process is presumably also
one of the reasons for the evolution and maintenance of sexual reproduction. |
| Jürg Helbling |
Coevolution and the social sciences |
3: 115-124 |
| |
The Darwinian research
program can contribute to solve some important theoretical problems in
social science such as Cupertino, conflict, strategies and group competition
and social change. However, an evolutionary social science will only be
successful if the Darwinian research program is reformulated and adjusted
for the analysis of social and cultural phenomena. A biological-genetic
theory put forward by sociobiology in order to explain human social behaviour
has not produced any convincing results. This is shown by referring to
hunter-and-gatherer- as well as to tribal societies. |
| Eduard Kaeser |
Man: The animal, the automaton
- The «coevolution» of man and machine |
3: 125-132 |
| |
Man is a «toolmaking
animal», as Benjamin Franklin held it. Since the invention of the
hand axe he coevolves with his tools. In the course of this evolution the
tools manifest the propensity to become more and more autonomous. The triumph
of modern technology seems to open the prospect of a «coevolution»
of man and machine - even more: of«post-biological» generations
of machines evolving independently of mankind. Such a scene gives rise
to ambivalent emotions in view of the newest technologies, the ambivalence
of blessing and curse, temptation and fear. On the one hand, there is the
temptation to improve human capabilities, to enlarge and «delegate»
them to artefacts and automata. On the other hand, there is the concomitant
anxiety about a future in which the machine will have emancipated from
its creator, turning itself into a potential enemy of man. The more human
capability and power are delegated to machines the more we are urged to
questions like these:
Where is the place of man in the coevolution of man and-machine?
will the inventor adapt or even submit to the progeny of his new inventions? |
| Heinz Sulser |
The scallop of the pilgrims of St James |
4: 137-140 |
|
In the Middle Ages the pilgrims
of St. James brought the shells of scallop back home. This was the visible
sign of having endured the pilgrimage right to its destination, Santiago
de Compostela in north-western Spain. From the taxonomic standpoint the
scallop of the pilgrims is Pecten maximus and not Pecten jacobaeus, as
the name would imply. P. maximus occurs in the Atlantic, P. jacobaeus is
living in the Mediterranean Sea. The reasons for this confusion are discussed.
New outcomes of molecular-biological research suggest that the Atlantic
and the Mediterranean Pecten are two morphologically differing, geographically
separated forms of the same species. |
| Andreas Schaller |
Herbivore resistance: Self-defence in the plant kingdom |
4: 141-150 |
| |
Plants are the most prevalent
organisms on this planet, despite the abundance of insect species, half
of which feed on living plant tissue. Plant resistance is due to a multitude
of characteristics that evolved in millions of years of reciprocal adaptation.
Plant anatomical features constitute structural barriers that prevent access
of the predator Toxic secondary compounds contribute to resistance as do
the natural enemies of insect herbivores. Many determinants of resistance
are induced only after insect attack. The wound response in Solanaceae
is the one system that has been investigated in more detail. Wounding by
insect herbivores results in the release of systemin, a signal molecule
that induces systemic resistance of the plant. Hallmark of the wound response
is a dramatic change in gene expression resulting in the accumulation of
defense proteins in the plant leaves. Upon consumption of the leaves these
proteins are taken up by the insect and, as a consequence, insect growth
and development is retarded. In this article, a synopsis is attempted of
the diversity and fascinating complexity of the factors contributing to
plant resistance against herbivores |
| Gerhart Wagner |
Pleistocene medial moraines in the Canton of Zurich - Part
1: Valley of Zurich and Knonauer Amt |
4: 151-163 |
| |
During Pleistocene glaciations,
most of primary lateral moraines of the Alpine Glaciers joined to medial
moraines. Those became the most important feeder lines for alpine debris
and built up many prealpine Quaternary walls and hills. Gravels near the
glacier margins were also formed from medial moraines detritus at any location
that ever was covered by ice. Therefore, the elevation of gravels above
sea level cannot serve as indicator for their age.
The main stream of the Linth-glacier in the valley of
the Lake of Zurich carried on his left side a large track of a composite
medial moraine which built up during the maximum stage of Würm-glaciation
the high Quaternary wall of Hirzel - Zimmerberg. During later stages, the
same track formed the morainic landscape in the KnonauerAmt. During the
stages of Zurich, it became a large secondary lateral moraine accumulating
the walls between the Sihl and the Lake of Zurich.
Several small medial moraines accumulated hills in the
region of Zurich, as well as along the right slope of the main valley and
at the bottom of the lake.
Even during Prewürmian glaciations, the similar
individuals of medial moraines must have existed. The Hirzel track built,
in one or two of the former glaciations, the elevated old gravels between
Albishorn and Uetliberg. |
| 2001 |
146th Year
|
|
| Gallandat, J.-D., Hainard, P., Hegg, O. und Klözli,
F. |
La recherche sur la végetation en Suisse
No Abstract |
1: 3-6
|
| Mutter, R.J. |
"Colobodus", a Potpourri of Larger Fishes from the Triassic
of Europe |
1: 7-14
|
| |
Numerous remains of bony fishes,
some of them exceptionally well preserved. from the middle Triassic of
Monte San Giorgio, which have been provisionally labelled "Colobodus",
are stored in large part at the ((Paläontologisehes Institut und Museum
der University Zurich". This group of extinct large perleidiform fishes
is especially interesting, because it represents an intermediate evolutionary
stage between basal and derived fishes.
The genus Colobodus has originally been erected on a
dentition fragment. The morphology and taxonomy of these remains are here
studied with respect to systematics and the phylogenetic relationships.
In terms of taxonomy, the scales have proven to he extraordinarily useful
in providing data. Histological investigations document the growth of these
primitive actinopterygian ganoid scales. The initial results are here briefly
summarized. |
| Weggler, M. und Widmer, M. |
Breeding birds in the Canton of Zurich - Status and population
trends between 1986/88 and 1999/00 |
1: 15-28
|
| |
We evaluate the status of all
breeding birds in the Canton of Zurich and document changes in distribution
and population sizes between 1986l88 and 1999l00. Our evaluation is based
on a recensus of all breeding birds in 154 representative study plots (40-60
ha) in 1999 after a first census conducted in the years 1986l88. For rare
species and wetland birds we used data from a continuous bird monitoring
project carried out since 1993. Since the last extensive survey in the
years 1986/88 a total of 142 breeding bird species were detected in the
Canton of Zurich. Seven species (Black-necked Grebe, Ruddy Shelduck, Goosander
Peregrine Falcon, Common Tern, Meadow Pipit and Stonechat) have recently
colonised or recolonised our study area while five species (Eagle owl Water
Pipit, Northern Wheatear Lesser Grey Shrike, Woodchat Shrike) disappeared.
A total of 117 species bred regularly and another 18 do so irregularly.
Between 1986l88 and 1999 20 out of 57 widespread and common species showed
a positive population trend in at least one out of three main habitats
(arable land, human settlements, forest). Another 19 species decreased
in number; 17 species remained stable and one species showed different
trends in different habitats. |
| Möller, A. |
On the relationship between nature philosophy and psychiatry
according to Eugen Bleuler |
1: 29-34
|
| |
Documents by Eugen Bleuler from
different periods, that go into general psychological topics of meaning
of consciousness, formation of motive and will are presented. An effort
towards integration of seemingly incompatible, side by side standing, unrelated
biological and psychological concepts that probably is most likely explainable
by the contemporary background of ideas, is recognizable. In this context
Eugen Bleuler refers to an already (especially by RICHARD SEMON) systematically
developed theory called 'Mnemism 'that he interpreted and applied to the
psychological circumstances mentioned above. That theory of 'mnemism 'that
can he most adequately described as a biogenetic-vitalistic theory, is
assuming, that all organic life independent of the possibility of a self-reflecting
consciousness is able to learn experiences made by analysis of environment
and to pass it on following generations. It represents the benchmark for
Bleuler's standpoints, for example for the question of determination of
human acting, that as itselves are already known from his earlier documents,
but here have found a more theoretically based explanation. The text focuses
also on BLEULER 'S work about a scientifically based ethic, published in
1936. The anti-religious and anti-philosophical position, already demonstrable
in different preceding works of Bleuler; will be shown. According to that
concept, the idea of social suitability is of utmost importance, which
is also recognisable in the animal world as a general principle 0$ nature.
Bleuler perceives the ethical 'instinct 'as inherent; its absence characterises
the image of a 'moral idiot' which was already a theme in his earlier works.
Statements from Bleuler about matters concerning euthanasia will he presented.
Also, concerning these matters about ethical issues, it can he shown once
more that the elder Bleuler was hardly influenced by psychoanalytical perspectives. |
| Elias Landolt |
Orchid meadows in Wollishofen (Zurich) - an astonishing
relict from the beginning of the 20th century |
2-3: 41-51
|
| |
Since 1914 the flat roofs of
the filtration plant ((Moos" in Wollishofen (Zurich), have developed into
meadows that are surprisingly rich in plant species and flowers. The area
covers 3 ha and contains 175 species, including nine orchids and many species
that are endangered or rare in the eastern Swiss Plateau. Most impressive
are the ca. 6000 individuals of Orchis morio, a species otherwise
extinct in the surroundings of Zurich. The meadows reflect the species
richness of an agricultural region at the beginning of the 20th century.
It has been proposed that the Canton takes measures to protect the rich
vegetation on the roofs, as well as in several neighbouring areas. |
| Keller, W. |
In search of ancient woodland indicators |
2-3: 53-63
|
| |
Are ancient woodland areas richer
in plant species than recent ones and do exist ancient-forest plants? The
question is evaluated for the small spatial formation of Switzerland by
vegetation relevés in the cantone of Schaffhausen. Woodland plants
do colonize recent forests within few decades. There is no significant
difference in species of ancient and recent woodland. |
| Conradin A. Burga, Roger Perret and Heinrich Zoller |
Swiss localities of early recognized Holocene climate oscillations
- Characterization and significance |
2-3: 65-74
|
| Key words: Holocene climate oscillations
- climate signals - pollen analysis - Vegetation change -Hypsithermal -
Swiss Alps |
This contribution gives an overview
of Swiss Alpine localities of early recognized Holocene climate oscillations.
For the period before measuring instruments and even written or pictorial
evidence exist, information about climate must be obtained from other sources.
The main sources of proxy data are natural archives of palaeoenvironments
(peat bogs, lake sediments), which provide information of varying quality
(climate signals) and for different time scales and time windows. During
the fifties and sixties of the 20th century, first Holocene climate oscillations
have been detected mainly with the help of pollen and macrofossil analyses.
The climate oscillations are expressed in most cases by an opening of the
subalpine forests (recession of Abies alba, Picea abies, Pinus cembra,
Larix decidua, Pinus mugo) and/or by a replacement by shrub vegetation
(Juniperus communis, Hippophae rhamnoides, Salix spec., Alnus viridis,
Ericaceae, Calluna vulgaris, Empetrum nigrum) or by increasing NAP-values
(Poaceae, Cyperaceae, Rosaceae, Caryophyllaceae, Artemisia, Rumex/Oxyria-type,
Plantago alpina, Epilobium etc.).
After the characterization of each locally recognized
climate oscillation, a critical valuation of the sites is given of the
following aspects:
· Relationship of stratigraphic evidence to glacier
oscillations
· Signals and their quality of palaeoclimatic
change
· Magnitude of changes in the vegetation belts
· Mid-Holocene climate optimum ("Hypsithermal")
in the Swiss Alps |
| Heinz Joss |
350 years of slide rule history and the contributions made
by the Zurich region |
2-3: 75-82
|
| |
The slide rule - in straight,
circular and cylindrical form - was the most widespread calculating device
for some 350 years, before being abruptly superseded in the 1970s by the
electronic calculator. This article begins by outlining the slide rules'
development, its different forms, scale systems and geographical dissemination
during this period. The second section then examines the role played by
the Zurich region in the slide rules' evolution.
Little is known about either the general development
of the slide rule or the significance of Zurich-based manufacturers, specially
in the market niche for cylindrical and circular slide rules. Research
and writing in this fields are a passionate hobby of the author, who would
appreciate any information that might help him add to his knowledge. |
| Heinrich Bührer |
Natural Science Society of Zurich on the
World Wide Web |
4: 85-86
|
| |
Under the address www.ngzh.ch,
NGZ is present on the internet since April 2000. The society presents its
program and abstracts of its publications. The content is mainly in German,
as this is the local language, but the abstracts of publications are available
also in English. |
| Jean-Pierre Burg |
The tall, rising Goddess of the Tibet Himalaya:
the Namche-Barwa massive |
4: 87-93
|
| |
Geological observations at the
eastern termination of the Himalaya reveal the folding of the suture between
the Indian and Eurasian plates. Indian continent metamorphic rocks are
buried under the suture and form a large antiform. Radiometric and fission-track
analyses document the cooling (i. e. uplift and exhumation) of these rocks
from 30 km depth during the last 4 Ma. This very fast exhumation at 10
mm/year is still today accompanied by crustal scale folding and surface
erosion. For comparison, in the Alps the actual exhumation rate amounts
only ca. 1 mm/year. |
| Hanspeter Holzhauser |
The advance of the Gorner glacier from 1791
until its maximum extension in 1859, reconstructed with the help of historical
visual records and written documents |
4: 95-104
|
| |
The study of historical material
such as visual records and written documents is one of the important methods
to reconstruct glacier fluctuations during modern times. The high quality
of the historical material allows the reconstruction of the more or less
continuous advance of the Gorner glacier during the 19th century. By 1820
the Gorner glacier as opposed to most of the other Alpine glaciers with
maximum extension at that time, was comparatively small. The glacier did
not reach its maximum extension until 1859. During a time span of 60 years
the tongue of the Gorner glacier advanced about 600 m destroying many farm
buildings and houses as well as valuable farmland. The dendrochronological
analysis of wood from a stable shows that it was built in the glacier forefield
in 1696/97 This means that the Gorner glacier was small from this time
up unto the early 19th century. |
| André Grundmann |
Guide to the vegetation in the area of the
Goldau landslide mass, Central Switzerland |
4: 105-114
|
| |
In the area of the Goldau landslide
mass various vegetation complexes can be found. The forest stands span
from open pine woodlands to mature deciduous forests. On block surfaces
a mosaic of phanerogamous plants and moss communities has developed Wetland
communities are also present. This guide should give a short overview of
species and vegetation types to a visitor coming to this landslide area. |
| 2000 |
145th Year |
|
| Hölzle,M.
Dischl, M. & R. Frauenfelder |
World-wide glacier monitoring as an indicator
of global climate change |
5-12 (1) |
| Observed glacier fluctuations
contribute important in- formation about rates of change in energy fluxes
at the earth/atmosphere-interface, possible acceleration trends in the
development and the range of pre-industrial variability. In view of climate
change detection, mass balance as the direct undelayed signal and the cumulative
length change as a clear but indirect delayed, filtered and strongly enhanced
signal are suitable indicators. These two variables are observed on different
glaciers world-wide within international programmes. The data are regularly
analysed and published by the World Glacier Monitoring Service in Zurich.
The mean annual mass loss of the directly observed glaciers resuIts in
a value of around 0.3 m water equivalent per year for the period 1980-1995.
The mass loss of the years 1996 and 1997 was again remarkably higher than
the mean of the period 1980-1995, with a value of 0.4 m water equivalent
per year. This value is also higher than the 0.25 m water equivalent per
year for the period of 1900 to today, calculated on the basis of length
change data. |
| Wyssling, G & J.
Eikenberg |
The Höllgrotten caves near Baar (Kanton
Zug) Development and age termination on tufaceous freshwater limestone |
13-30 (1) |
| |
The Höllgrotten,
located in the lower part of the Lorze Valley, Baar/Zug, are one of the
most frequently visited caves in Switzerland. The Höllgrotten caves
lie in a massive tufaceous limestone complex which began to be formed at
the beginning oft he Holocene period. New hydrogeological data, supported
by precise chronometer dating using the 230Th/234U
and 226Raex/234U-decay series, makes it
possible to reconstruct the formation of the tufaceous freshwater limestone-complex
and the accompanying caves, as a result of the post-glacial evolution of
the climate. The freshwater precipitates consist mainly of porous tufaceous
limestone, formed continuously at the surface and facilitated by plant
assimilation (mosses and algae).
The genesis of the tufaceous limestone complex and the
formation of the caves occurred during optimal climatic conditions in the
Holocene period between 8500 and 5500 years ago (Hypsithermal). This is
directly related to the evolution of the mire (fen) in the aqueous recharge
area of the very productive springs which caused the build-up of the tufaceous
limestone of the Höllgrotten. During the late Atlantic and the early
Subboreal the production of tufaceous limestone decreased dramatically.
However, since the late Subboreal, very little precipitation of limestone
has occurred at the surface or in the closed cavities.
The Höllgrotten caves were formed between 6000 and
5000 years ago in areas of overhanging cliffs and niche-like cavities.
In these areas, "tuff curtains" were formed around suspended free roots
and moss cushions, finally resulting in the formation of the caves. After
the caves finally closed as a result of further growth of the tuff curtains,
extensive precipitation of crystalline travertine occurred, coating the
inside walls of the cavities therein. In some cases, this process sealed
the base of some of the caves, leading to the formation of lakes inside
them. The upper caves (Zauberschloss, Nadelgrotte, Bärengrotte and
Wurzelgrotte) were formed in areas with overhanging cliffs consisting of
gravel formations (Lorze Schotter). The lower caves (Feengrotte, Korallenschlucht,
Adlergrotte, Dom and Traubengrotte) at the base of the Lorze Valley were
generated in an overhanging cliff from tufaceous limestone, arising from
erosion by the Lorze River some 6000 years ago. |
| Stössel, Iwan |
Early tetrapods: trackways as controversial
contribution |
31-40 (1) |
| |
The conquest of/and
by vertebrates is considered to be one of the key events in the history
of life. During the last decade, new discoveries have seriously challenged
older models which were largely based on the famous fossil Ichthyostega,
which was found almost seventy years ago in Greenland. Instead of a linear
transition from an aquatic fish to a terrestrial tetrapod, we are now confronted
with a complex mosaic of evolutionary experiments. Temporal or even causal
relationships are difficult to recognize. Trace fossils make a controversial
contribution to this discussion. This paper aims to discuss these controversies
by documenting the most extensive Devonian trackways known so far. This
385 Ma old finding from SW Ireland appears to indicate that the ability
for tetrapod-type locomotion predates the oldest tetrapod fossils by several
million years. Moreover the trackways suggest that the trackmaker was able
to walk at least in a semi-terrestrial environment, a mode of locomotion
for which the earliest known tetrapods were not able according the latest
models of tetrapod evolution. |
| Straumann, N. |
The mystery of the cosmic vacuum energy density
and the accelerated expansion of the Universe |
49-56 (2/3) |
| |
Since the introduction
of the cosmological term by Einstein and its later rejection by him after
the discovery of the Hubble expansion, this term - now interpreted as a
property of the physical vacuum - has been revived several times for reasons
which later turned out to be premature. Recent astronomical observations
now provide for the first time rather strong evidence for a positive cosmological
constant and thus for an accelerated expansion of the universe. this should
become an established fact, elementary particle physicists and astronomers
are confronted with different aspects of a deep mystery. |
| |
Key words: Anisotropien
- Big Bang - Friedmann-Lemaitre-Modelle - kosmologische Konstante - kosmologisches
Glied - Hubble-Diagramm - Hubble-Expansion - Magnitude-Rotverschiebungs-Beziehung
- Typ-la Supernovae - «Quintessenz» |
| Schipper, I. |
Refractive Surgery: Life without Eyeglasses
The Wish and the Reality |
57-63 (2/3) |
| |
The goal of refractive
surgery is to enable good visual acuity either entirely without eyeglasses,
or at the very least, with a need for much weaker corrective lenses. The
operative procedures can be carried out either on the cornea itself or
within the eye using artificial lenses.
At the present time, Lasik (Laser-in-situ-Keratomileusis)
is the most commonly used procedure. The procedure involves the creation
of a superficial corneal flap, which is then turned to one side, exposing
the corneal tissue below. This tissue is then ablated by the Excimer-Laser
to achieve the visual acuity correction. Finally the superficial corneal
flap is replaced.
Artificial lenses are utilized for the correction of
severe refractive errors. The lenses may be implanted either behind or
in front of the iris. The simultaneous removal of the original lens is
indicated in certain cases. For the correction of slight myopia, the insertion
of a plastic ring into the cornea is a good alternative to laser treatment.
Minor amounts of far-sightedness can be treated using
Holmium-Laser-Coagulation of the corneal periphery. |
| |
Key words: Astigmatismus
- Excimer-Laser - Kurzsichtigkeit - Intraokularlinse - Lasik - Weitsichtigkeit |
| Hantke, R.,
Wagner, G., Schatz, W. and Seitter, H. |
Possible Tertiary relict species in the Rigi
and Brienzer Rothorn area |
65-85 (2/3) |
During the cold periods
of the Pleistocene the highest south-exposed slopes in the Rigi and Brienzer
Rothorn areas were snow-free, thus offering cold-resistent plants a chance
to persist. Recent species which have probably uninterruptedly colonized
the area since the Late Tertiary are denominated preglacial relicts. Two
species with an isolated occurrence on the Brienzergrat area - Ranunculus
seguicri VILL. and Papaver occidentale (MARKGRAF) HESS & LANDOLT- are
almost certainly such relicts.
In order to search for further species which might be
considered as preglacial relicts, a complete inventory of the present flora
was made during numerous excursions. The lists of species were completed
with the species given for both areas in the atlas of recent plant distribution
by WELTEN & SUTTER (1982). The highest present-day occurrence for each
species was determined in the literature, For those presently occurring
above 2400m - in the Central Alps even far above 3000 m -it was assumed
that, in the study areas, they persisted in sunny, south-exposed areas
during cold periods and that they were not displaced by recurring forests
during the warm periods. 286(70%) out of a total of412 species occurring
above 1800 m(i. e. above the pleistocene valley glaciers) in the Brienzer
Rothorn area, and 168 (56%) out of a total of 298 species occurring above
1400 m in the Rigi area, may be considered as preglacial relicts. |
| |
Key words: Brienzer
Rothorn - Florenrelikte - Giswiler klippen - Landschaftsgeschichte - Miozän
- Pleistozän -Pliozän - Rigi - Subalpine Molasse |
| Geissbühler, S. |
Rewetting and scrub and woodland clearance as
measures for the rehabilitation of a cut-over raised bog in the central
plateau of Switzerland |
87-109 (2/3) |
| |
The aim of a mire-rehabilitation
project which started in Hagenmoos 10 years ago was to preserve a mountain
pine bog and to initiate mire-rehabilitation in two peat cutting pits.
To achieve this, encroaching scrub and woodland was cleared in the larger
of the two pits. Afterwards both pits were rewetted by blocking two large
drainage ditches.
To observe the ecological and vegetational development,
115 permanent plots of 1 m2 were established before the rewetting
started. Subsequently, vascular plants and the bryophytes were recorded
each year in 33 permanent plots.
Most changes regarding ecology and vegetation were observed
in the peat cutting pits. The vegetation on these plots indicates that
over time there was an increase in humidity light and humus. The vegetation
of the smaller pit developed towards transitional mire and raised bog.
Reed-bed and bottle sedge swamp vegetation increased in the larger pit.
Probability of occurrence proved to be a suitable tool
to predict the occurrence of species. Vascular plants and bryophytes of
the observed plots showed rather similar indicator values for the site
conditions. However, changes which happened in a thin layer near the surface
were better indicated by the bryophytes than by the vascular plants. |
| |
Key words: Bergföhrenhochmoor
- Hagenmoos - Moorregeneration - Schweiz - Zeigerwerte |
| Gassmann, Fritz |
Remarks and Corrigenda to N.Straumann (pg.49-56) |
116-117 (4) |
| Thöny, Beat |
Gene Therapy: a Consequence of Molecular Biology
for the Medicine of the Future |
119-128 (4) |
| |
Molecular biology
describes the physico-chemical relationship of all processes in living
organisms, including storage and transmission of genetic information. The
genome is the total genetic material of an organism and is contained in
the cell nucleus as a double-stranded DNA helix. Gene technology was developed
to analyze the complex genomic information and to isolate or clone each
gene. Of great consequence in clinical application are molecular diagnostics
and gene therapy; the latter defined as the correction of inherited or
acquired mutations in the DNA. In theory, gene therapy enables to correct
all inherited diseases. The molecular or inheritable metabolic diseases
are apparent after birth and are thus a discipline of pediatrics. Depending
on the type of disease, different gene therapeutic methods are applied:
gene augmentation for deficiency of gene function, directed inhibition
of pathogenic genes or specific killing of cells for cancerous diseases,
and precise correction of DNA mutations. A therapeutic gene can be directly
administered to the body, or can be transferred in vitro into cells and
subsequently returned to the patient. The delivery systems for gene transfer
are mainly viral vectors based on retroviruses or adenoviruses. Despite
the great potential and intensive investigations in the field of gene therapy
it will be decades before routine applications in daily medicine will be
become practice. |
| KlötzIi, Patrick
and Matthias Rosenmayr |
Field study on a local population of Podarcis
sicula ruin lizard (Rafinesque-Schmaltz, 1810) in Rapperswil (SG) |
129-142 (4) |
| |
On the area of the
station of Rapperswil (SG) a large population of Podarcis sicula (ruin
lizard) has developped, unique for an area north of the Alps. Some minor
groups have been sighted near Basle (BS) and near Remigen (AG) and also
near Chiasso (TI) on the southern border of Switzerland. Investigations
in the frame of a small research project in animal ecology at the technical
college of Rapperswil (SG) have shown that this local population is most
likely belonging to the northern italian subspecies Podarcis sicula campestris
(ruin lizard). They might have been transported from the south in a train
wagon, presumably with plant material, or than set free by some reptile
holders. In 1996 the population counted around seventy animals. As a sympatric
lizard population of autochthonous Lacerta agilis (sand lizard) existed,
the only other species, a microhabitat analysis was undertaken to investigate
a possible interspecific competition. Both species occurred in the same
types of habitats but had different specific niches. A displacement of
the indigenous by the introduced species is highly improbable in this case.
Rather the question arises for how long this small isolated Podarcis-population
may survive in a situation without any possibility for genetic transfer.
The same time is questionable if an introduced species actually disturbing
the indigenous fauna without, so far; any losses for the local herpetofauna
should be protected with special measures. |
| Boller, Beat |
History and development of the Swiss «Mattenklee»,
a persistent form of cultivated red clover |
143-151 (4) |
| |
«Mattenklee»,
a Swiss form of cultivated red clover (Trifolium pratense L.), has developed
from red clover which had originally been imported into Switzerland from
the Netherlands. In the ley farming systems which were mainly practised
in the Canton of Berne, farmers used to harvest their own red clover seed
from stands which had previously been utilized for forage for at least
three years. More or less unconsciously, they thus improved the persistency
of their particular farm variety. This type of red clover has long been
known as «Mattenklee». Since 1900 it has been systematically
bred in Switzerland, first in Lausanne, later also at the Swiss Federal
Research Station for Agroecologv and Agriculture in Zurich-Reckenholz where
it is being bred exclusively since 1976. By focussing on selection for
disease resistance, and by artificially induced doubling of chromosomes,
several cultivars were developed which are significantly more persistent
than comparable varieties from abroad. Particular Mattenklee-grass mixtures
were developed which are highly appreciated by Swiss farmers because they
perform very well for three full years. Seven Mattenklee cultivars from
the breeding programme of Zurich-Reckenholz are currently listed on the
common catalogue of the European Union. They constantly proved to be superior
yielding in the third year of stand in official variety trials of several
countries. The tradition of harvesting Mattenklee seed on the own farm
has been almost completely abandoned in the early 70ies. Therefore, genetic
resources exist only in the collections and in the breeding material of
Zurich-Reckenholz. The only exception is the farm variety LEISI which is
being conserved «on farm» on the original farm at Oberembrach
(Canton of Zurich), and is multiplied therefrom for the Swiss market. |
| Keller, Hugo |
Magnetic Flux Lines in High-Temperature Superconductors |
153-160 (4) |
| |
An external magnetic
field may penetrate a superconductor in the form of quantized magnetic
flux lines. When these flux lines are strongly pinned on defects in the
material, an electrical current can flow without dissipation. In the novel
high-temperature superconductors (HTSC) the flux lines exhibit an unusual
behavior Due to the pronounced layered structure and the extremely short
coherence length of the HTSC, the flux lines in these materials are exposed
to large thermal fluctuations, already well below the superconducting transition
temperature, so that they become detached from the pinning centers. The
flux lines can then move freely like the molecules in a liquid, and the
electrical resistance does not vanish completely By introducing artificial
pinning centers into the superconductor this problem which is important
for technical applications may be overcome. |
| 1999 |
144th Year |
|
| Endress Peter K |
Plant diversity world wide - the
Botanic Garden of the University and the Herbarium of the University and
the ETH in Zurich. |
3-13,1 |
|
Plant
systematics investigates the diversity of plants on our planet, it attempts
the phylogenetic reconstruction of the evolutionary history of plants and
it tries to understand the evolution and diversity of the biological features
of plants. In addition to research in the natural habitat and in the laboratory,
plant collections in the form of botanical gardens and herbaria are essential.
They are part of all major centres of plant systematics. With new techniques
for electronic data processing and for molecular biology the possibilities
of biological systematics have greatly expanded in the last few years.
The University of Zurich has large plant collections, which have been substantially
enlarged by the addition of the herbarium of the ETH in 1991. The botanic
collections, however, are of a far greater significance than merely for
research purposes. The Botanical Garden is an important showcase of the
University. The history and present status of the plant collections and
of plant systematic research in Zurich is outlined. |
| Schubiger P August |
Radiopharmaceuticals for tumortherapy
- Fiction or reality? |
15-23,1 |
|
The treatment
of tumor metastasis is up to now mainly a domain covered by chemotherapy
and in special cases only as for instance in some thyroid cancers radionuclide
therapy is being used. However only one of eight patients diagnosed with
metastatic disease can be cured at the present time and targeted radionuclide
therapy has the potential to improve on this number. It took many years
of intensive radiopharmaceutical research in the development of radioiodinated
antibodies directed against lymphoma, which are now on the step of becoming
clinical routine. New interesting therapeutic radionuclides are presented,
as well as specific tumourseeking molecules (peptides, antibodies). The
influence of the parameter variations to the biological behaviour of the
whole radioconjugate is discussed and possibilities of improved radiotherapeutics
presented. |
| Müller Peter |
The other side of the salad head
perspective: Snails from Bachs and Weiach in the focus of the modern nature
protection. |
25-36, 1 |
|
Between
1996 and 1998 73 snail species have been found in 13 sites of the communities
of Bachs and Weiach (Canton of Zurich, Switzerland). Among them, nine species
belong to the categories 1-3 of the Red list of Switzerland. Two species
are reported for the first time in the canton of Zurich, and one species,
Columella aspera, is reported to the first time in Switzerland. Starting
on the basis of the local situation the conservation measures are discussed
in a greater context. |
| Thallmair Michaela |
...and they do grow! Nerve growth
after CNS lesions. |
37-47,1 |
|
After
lesions in the adult central nervous system (CNS) fibers have only a very
limited capacity to regrow. Studies investigating CNS lesions showed that
in areas known for their inherent plasticity and growth potential high
levels of the growth-associated protein GAP-43 are retained throughout
life. In addition, these regions regularly show a low content of myelin.
Because myelin contains specific neurite growth inhibitors, we investigated
the growth capacity of lesioned CNS fibers in animals where these inhibitory
proteins were experimentally suppressed, e.g. by neonatal X-irradiation
or by application of a neutralizing monoclonal antibody (IN-1). The present
report gives an overview of experiments showing that compensatory fiber
growth (structural plasticity) occurs in the adult CNS after suppression
of the myelin-associated inhibitory components. The new fiber growth is
paralleled by a high degree of functional recovery. |
| Odermatt Bernhard |
The basement membrane - junction
and barrier between cells and connective tissue. |
59-71, 2 |
|
Basement
membranes are specialized structures of the extracellular matrix, separating
cell sheets or single cells from connective tissue. One of the main components
of basement membranes is type IV collagen. In contrast to the fiber forming
collagens, type IV collagen molecules assemble into three dimensional networks
forming the scaffold of the basement membrane. During invasion and metastasis,
malignant tumors are able to break through basement membranes. To accomplish
this, they need adhesion receptors (integrins) for the attachment onto
type IV collagen. In order to dissolve the type IV collagen network, they
produce the enzyme type IV collagenase. Finally, the tumor cells migrate
through the hole generated in the basement membrane. On the molecular level
many details are known about these processes. Alport syndrome is an X-chromosome
linked inherited disease associated with hypoacousis and progressive failure
of the renal function. The morphology of the glomerular basement membranes
in the kidney is changed and their filtration capacity severely hampered.
Mutations in the gene encoding the a5(IV) chain of type IV collagen are
responsible for this disease. Today, the molecular mechanisms leading from
the defective gene to the disease symptoms are increasingly understood. |
| Boletzky Sigurd v |
Systematic morphology and phylogenetics
- on the significance of the work of Adolf Naef (1883-1949). |
73-82, 2 |
|
The comprehensive
work of the zoologist Adolf Naef is briefly reviewed in relation to its
historical role in zoology (especially Cephalopoda and other Mollusca,
Vertebrata and other Chordata) and in the development of phylogenetic systematics.
The variable reception of the theoretical approaches of Naefs systematic
morphology and phylogenetics reflects the versatility of morphological
views of biology in our century. The evident necessity of incorporating
Naefs special studies in modern research revives interest in his theoretical
writing which continues to raise relevant questions about morphological
research in an evolutionist context. |
| Scharfetter, Christian |
Models of mental disorders - Paradigmas
of psychiatry 1800-2000 |
101-112, 3 |
|
In this
historical essay some of the prominent models and paradigmas of psychiatry
between 1800 and 2000 are discussed. Most of them follow the medical paradigma:
the acceptance of the reality of mental disorders. They may be interpreted
by cerebral pathology, hereditary determination or in psycho- and sociodynamic
models, combined in George Engel's bio-psychosocial model. Antipsychiatry
represented the opposition: denial of mental disorders and alternative
interpretation as a healthy reaction against the mad normality. A review
of concurrent, sometimes complementary disease- and illness-concepts is
given. |
| Hergersberg, Martin |
The human genome project deciphering
the sequence of the hereditary material |
113-127,3 |
|
The ambitious
plan of the determination of the DNA sequence of the human genome is known
as the human genome project (HGP). Since its start in 1991, it has yielded
significant results. Until recently, the work has focused on the establishment
of high-resolution genetic and physical maps. The genome sequences of many
prokaryotes and of several eukaryotes have been completely determined.
Approximately 17% of the human genome sequence are already known, and recent
technological developments will lead to the determination of the complete
human genome sequence by the years 2000-2003. At the moment, the genomic
location and at least partial sequence of 30000 human genes are known,
corresponding to approximately 30% of all human genes. These results are
relevant for the localisation and isolation of disease genes and disease
susceptibility alleles. The knowledge of a large part of all human genes
allows the determination of the activity of many thousands of genes in
parallel The information from the HGP makes the search for frequent predisposition
alleles for common diseases (cancer; heart disease, psychiatric diseases)
possible, in particular through the identification of linkage disequilibria.
These studies require the clinical and genetic analysis of large human
populations in hitherto unknown detail, thereby raising new questions regarding
the ownership and the privacy of genetic data. |
| Nievergelt, Bernhard |
Cooperation between theoretical
and applied ecology is to the advantage of both disciplines |
137-146, 4 |
|
Today,
different approaches within ecological sciences have an important role.
In this paper it is stressed that on the one side the top down approach
in pure ecology has supplied nature conservation practice with valuable
concepts such as the theory of insular biogeogragphy, the concepts of patch
dynamics and of minimum viable population size. On the other side, actual
problems in nature conservation are of ten complex and require interdisciplinary
research. In these approaches, the treated area respectively the problem
being in focus determines the programme. Thus, in a bottom up procedure
all researcher perform their contribution in order to serve to the common
goal. A close cooperation between researchers of the two approaches is
to the advantage of both. |
| Graf, Kurt |
Conceptional reflections on landscape
ecology in Switzerland |
147-158, 4 |
|
The present
study is based on empirical investigations to landscape changes in Switzerland.
It intends to analyze the multifarious aspects and processes within geo-,
pedo-, hydro-, bio- and climate ecology'. Moreover, methodically it implies
the realisation of the corresponding maps, lists and evaluations. Certainly
the proposed methods cannot be implemented in a standard way but must be
adapted to the specific situation and subject. For this purpose, it is
principally necessary to consider the demands of landscape ecology' and
aesthetics. The interrelations and mechanisms are illustrated by graphs
that reflect different levels of abstraction. |
| Halliday, Alex N. |
Excited atoms, planetary collisions
and differences between Earth and Mars |
159-168, 4 |
|
Determining
the timing of events associated with the birth of our solar system is a
major technical and scientific challenge. The variations in isotopic composition
produced by the decay of short-lived radioactive nuclides that are long
since extinct provides us with tools to attack these problems. The decay
of hafnium-182 to tungsten-182 is particularly powerful and shows that
large asteroidal bodies formed and differentiated into a silicate rich
mantle and iron metal core within the first 10 Myrs of the solar system.
However the earths' development was more protracted. The W isotopic composition
of the earth is best explained by a protracted growth history from giant
impacts such as that which formed the moon 50 million years after the start
of the solar system. Mars in contrast exhibits no sign of this late giant
impact history and appears to have stopped growing within 20 million years
after the start of the solar system, presumably in response to the growth
of Jupiter As such, Mars provides us with a unique window through which
to view the earliest development of our own planet. |
| 1998 |
143th Year |
|
| Holderegger Rolf |
Habitat, decline, and conservation
biology of the prealpine plant species Saxifraga mutata L. in the Canton
of Zurich, Switzerland. |
3-11, 1 |
|
Saxifraga
mutata is a characteristic prealpine pioneer plant species of the Swiss
Plateau. A review of several investigations on its population biology shows
that a repeated formation of open sites due to erosion is necessary for
the maintenance of the population dynamics of this species. In contrast
to this, genetic factors are of minor importance for its local survival.
During this century, several strongly isolated populations of S. mutata
of the Plateau of the Canton of Zurich disappeared. Those remaining are
often quite small and strongly isolated. A floristic analysis of the species'
stations shows that many other plant species of the Swiss red list would
also benefit from the protection of the habitats of S. mutata. General
conclusions with respect to nature conservation in the Canton of Zurich
are given in accordance with these results. |
| Woggon Brigitte |
Anxiety. |
25-28,1 |
|
Anxiety
can be a symptom of another illness or it can be a distinct disorder. Lifetime
prevalence is 25% (phobias, generalized anxiety panic). Anxiety can be
treated successfully with behaviour therapy and psychotropic drugs. |
| Satz Norbert |
Lyme-Borreliosis. |
29-38, 1 |
|
Lyme Borreliosis
is worldwide and especially in Switzerland the most frequent tick borne
disease. For a greater understanding first the life of our ticks and the
causative agent Borrelia burgdorferi are described. The involvement of
a multitude of organs induces a bright variety of clinical manifestations
which are presented as an overview. Furthermore the great diagnostic difficulties,
the controversy in therapy and the prophylaxis are discussed. |
| Koenig Barbara |
The importance of behavioural ecology
for conservation. |
49-55, 2 |
|
We currently
have to witness a worldwide and dramatic decrease in species diversity
that no longer causes deep concern only among biologists and conservationists.
This loss in biodiversity is mainly caused by increasing habitat destruction
through modern man. Besides protection of their habitat, a good knowledge
of the ecology and biology of a species or population is necessary to save
it from going extinct. In the following I will use several examples to
illustrate the importance and the role of behavioural ecology for the conservation
of endangered species. |
| Eckert Johannes |
The "small fox tapeworm" (Echinococcus
multilocularis): A persisting threat for humans? |
tica">57-66, 2 |
|
The "small
fox tapeworm" (Echinococcus multilocularis) is the causative agent of alveolar
echinococcosis (AE) in humans which primarily affects almost exclusively
the liver and which is lethal in approximately 90% of untreated patients
within 10 years after diagnosis. After early detection of the infection
cure is possible by complete surgical removal of the parasite. In later
phases of the disease prospects for cure are unfavourable, but long-term
chemotherapy can inhibit parasite proliferation and prolong survival periods
of patients significantly. AE is a rare disease with an average incidence
rate in Switzerland (1984-1992) of 0.1 new cases per year and 100 000 inhabitants.
However, in view of the severity of the infection and a persisting infection
risk it has principally to be regarded as a serious threat for humans.
In Switzerland E. multilocularis has been detected in foxes from 21 of
the 26 cantons (including half-cantons) during recent years. The average
prevalence rates in the various cantons range between 2.7% and 53%. Less
frequently, the parasite also occurs in dogs and cats. According to the
present knowledge, E. multilocularis has a wider range of geographic distribution
in central Europe than previously anticipated, including 10 countries.
In view of growing fox populations, the increasing immigration of foxes
to residential areas and many open epidemiological questions, it is recommended
to establish systems for continuous surveillance using the available new
methods (caproantigen detection and PCR) for diagnosing the infection in
carnivores (foxes, dogs, cats) and in humans (immunodiagnosis, ultrasound
examination), respectively. |
| Matile Philippe |
Unsolved mysteries. |
67-75, 2 |
|
no abstract |
|
| Steiner Pascale , Turner Hans |
The mollusca of Lake Greifensee:
Inventory and abundance of species in relation to site factors. |
85-96, 3 |
|
Lake Greifensee,
canton Zurich, Switzerland, is a medium-sized lake measuring up to 6400
m long, by 1750 m wide, and reaching 32 m depth. Subfossil and modern molluscan
material collected in 1916, 1928, 1936 and for the present study shows
that accelerated eutrophication has taken place since c. 1900. Between
May and August 1996 samples were taken regularly at seven points at 2 m
and 5 m depth, and at a further nine locations from the littoral zone down
to 14 m depth. 15 species of gastropod and 13 species of bivalve could
be found in shallower water down to 5 m depth, though only a few species
were present in significant numbers. At one location four species, all
bivalves (Psidium casertanum, R. henslowanum, R. hibernicum and P. nitidum),
were still present at 11.8 m depth, but below c. 13 m depth, within the
hypolimnion, molluscs are presently entirely absent due to oxygen deficiency
and elevated amounts of soluble phosphate-iron compounds. Of the 28 species
recorded, four are new to the Greifensee since 1928 and/or 1936: Potamopyrgus
antipodarum, Physella acuta, Dreissena polymorpha, and Psidium nitidum.
15 species and one subspecies (V. piscinalis alpestris) collected by former
authors could no longer be found, though some of these species might still
be living among water plants near the lake margin or in supralittoral marshes
as the present study did not focus on such habitats. At least six of these
species and one subspecies appear to have become extinct in the lake: Bithynia
leachii, Valvata piscinalis alpestris, Physa fontinalis, Hippeutis complanatus,
Planorbarius corneus, Psidium amnicum and Psidium conventus. |
| Binggeli, Bruno |
Ein Blick in die kosmische Frühzeit
mit dem Hubble-Teleskop |
97-108,3 |
|
|
|
| Beck-Sickinger Annette G |
G-protein coupled receptors: The molecular acceptors of light and colour,
odour and pain. |
109-116, 3 |
|
G-Protein
coupled proteins constitute a super-family of integral membrane proteins
encompassing hundreds of receptors for all types of chemical messengers
as well as, for example, the key molecules of our light- and smell sensory
systems, bioactive amines, peptide hormones, neurotransmitter or even proteins.
Due to their complicated organization with the characteristic seven transmembrane
segments (7TM) it has as yet been almost impossible to structurally characterize
these proteins by crystallography or magnetic resonance. However, a number
of indirect methods were used to study the structure, the ligand binding
and the signal transduction capacity of these proteins and are summarized
in this review. |
| Pletscher, Alfred |
Janusgesicht der Wissenschaft in
der Oeffentlichkeit |
117-125,3 |
|
|
|
| Schaefer Beat W |
Molecular principles of tumor development: Basis for new therapeutic
approaches. |
133-141, 4 |
|
The distinct
properties of tumor cells are based on genetic changes which accumulate
over time in several steps. On the molecular level, these properties can
be summarized into a few basic concepts which will be discussed using a
pediatric tumor, rhabdomyosarcoma, as a model system: the first group of
changes can be found in oncogenes which are components of the signal transduction
pathways stimulation cell proliferation. During the last couple of years,
suppressor genes were identified as a second group. Their normal task is
to slow proliferation and hence they must be inactivated by tumor cells.
Only recently then, a third group of genes has been identified which regulate
the cellular suicide program that normally eliminates damaged cells. These
findings are the basis for developing new therapeutic concepts based on
critical target genes. Possible therapies included the synthesis of specific
blocking agents, somatic gene therapy or the use of antisense molecules.
Several of these approaches are now in first clinical trials. |
| Arnold Susi |
From the wolf to the domestic dog:
History of selection and its consequences. |
143-155,4 |
|
Molecular
genetic analyses have shown that the domestic dog originated solely from
the wolf, and most likely from two maternal lineages. Inbreeding was therefore
present from the beginning of the history of the dog. Inbreeding itself
cannot be the only reason for the serious health problems affecting the
various breeds. These health problems are rather a consequence of the increased
intensity of inbreeding. As long as dogs were bred as working dogs the
degree of inbreeding was limited. Since the beginning of the 20th century
the beauty of the dog has become more important. This goal was easily achieved
by the intensification of inbreeding. This, in turn led to an increase
in homozygosity causing an increase in the frequency of inherited diseases.
The future of our breeds is now dependent upon how skilfully we handle
the situation. Only by well coordinated action, involving breeders, veterinarians
and molecular geneticists, is it possible to improve the health and life
span of pure bred dogs. |
| Brandl Helmut |
Useful things from microbes: Bacteria
as producers of industrial materials. |
157-164, 4 |
|
A broad
range of industrial application in the field of environmental biotechnology
is based on the organismic diversity of microorganisms. This potential
is illustrated by two case studies. (i) Many microorganisms are known for
its ability to form intracellular storage materials. These materials can
be extracted and processed by plastic-manufacturing industries to produce
bulk products. The unique feature of this material is its biodegradability
which can be used for applications where biodegradability poses a selective
advantage over traditional petrochemical-based plastics. In addition, its
production is based on renewable resources and contributes to sustainable
future. (ii) Metals can be mobilized from solids by the capability of many
microorganisms to produce organic and inorganic acids as well as by the
ability to catalyze redox processes. These metals can be recovered. The
technique has been successfully applied in copper and gold mining. It is
also possible to adapt the technique for the treatment of metal-containing
waste materials. The application of bioleaching technologies as well as
the development of biodegradable plastics must be seen in the context of
a future in which industrial technologies have to be increasingly in harmony
with the global material cycles of the biosphere. |
| Brinkmann Winand |
Ichthyosaurs (Reptilia) from the
"Grenzbitumenzone" (Middle Triassic) of Monte San Giorgio (Ticino, Switzerland):
New results. |
165-177, 4 |
|
The 240
Mio. years old marine basin sediments of the Middle Triassic "Grenzbitumenzone"
or Besano Formation (Anisian/Ladinian) of the Ticino calcareous alps, have
yielded abundant ichthyosaur material from Monte San Giorgio (Switzerland)
and Besano (Italy), which has been reported in this magazine already in
1997. At that time only representatives of the genera Cymbospondylus and
Besanosaurus (Shastasauridae) and of the general Mixosaurus and Phalarodon
(Mixosauridae) were known from the "Grenzbitumenzone". The occurrence of
the genus Phalrodon with anterio-posterior elongated crushing teeth in
the posterior part of the upper and lower jaw was reported for the first
time from southern Ticino. Recently, two further ichthyosaurs, Mikadocephalus
gracilirostris and Wimanius odontopalatus, have been erected on the ichthyosaur
skull material from Monte San Giorgio kept in Tuebingen (Germany), which
cannot be assigned to a family at present. Moreover, additional Tuebingen
material of the "Grenzbitumenzone" was mentioned as Mixosaurus cf. nordenskioeldii,
which shows similarities with certain mixosaur remains from Spitzbergen
(Norway). Corresponding material is also present in the Zurich collection.
Meanwhile, the skeleton of a second mixosaur, Mixosarus (Sangiorgiosaurus)
kuhnschnyderi, with anterio-posterior elongated crushing teeth has been
found among the Zurich ichthyosaur material of Monte San Giorgio. In contrast
to Phalarodon the crushing teeth of Mixosaurus kuhnschnyderi are smaller
and restricted to the posterior part of the lower jaw. A further skull
of Mixosaurus kuhnschnyderi with a well developed sagittal crest has been
added to the collection of the natural history Museum of Lugano, Switzerland,
at the beginning of this year. |