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1.
Pollution of the marginal Arctic seas and rising of toxic contaminants are extremely dangerous for marine and coastal ecosystems and for marine mammals as representatives of a high level of fodder chains in the ocean. Ecology of ice-associated forms of marine mammals, population health and animal welfare are strongly depended from the different environmental processes and phenomena. Operational assessment of the level of this impact is very important for marine biology, marine fisheries and other. Many new problems create a global warming. In order to investigate ice covered Arctic Ocean and charting the number of seals were performed annual inspections onboard research aircraft PINRO Arktika. Multi-spectral airborne and satellite observations were fulfilled regularly from Barents and White Sea to the Bering and Okhotsk Sea. A contemporary status of different group of sea mammals was evaluated, where number and health of adults and pups were checked separately. In situ observations were provided with using helicopter and icebreaker for gathering a water samples, ice cores and specimens of meat and fatty matter (with following biochemical and toxicological analysis in laboratory). A prevailing part of life cycle of Greenland seals (Pagophillus groenladicus) is strongly depended from winter hydrology (water masses arrangement and water exchange, stable currents, meandering fronts, stationary spiraling eddies) and closely connected with type of ice (pack, fast ice) and other parameters of ice (age, origin, salinity, ice edge). First-year ice floes which has a specific properties and distinctive features are used by harp seals for pupping, lactation, molting, pairing and resting. Ringed seals, inversely, use for corresponding purposes only fast-ice. Different aspects of ecology, and migration features of harp seals were analyzed in frame of verification study. It was revealed a scale of influence of winter severity and wind regime (even a cases of ecological catastrophe of harp seal were fixed), but stationary eddies in the White Sea is most effective governing factor (novelty). The results of study of the following relationship of the problem eddies – self-cleaning processes – climate change – ecology of Greenland seal White Sea population will be presented: A) regularities of eddies formation and their spatial arrangement, temporal (seasonal and annual) modification; B) stationary eddy as zone of concentration of polluted waters and toxically hazard, self-cleaning processes and climate change; C) eddies displacement and parameters modification (type of eddy, intensity and sign of rotation) as result of climate change; D) relationship between eddies location and whelping rookeries arrangement, climate change and variety of the type of migration E) spiraling eddies and pollution dynamics, forecast of future modification of marine animal welfare. A further develop a strategy of multi-level ecomonitoring of the polluted Arctic should be discussed and recommendations for conservation and management of ice-associated forms of seals in presence of global warming will be done.  相似文献   

2.
Single zircons from two orthogneiss complexes, the Grey Gneiss and Red Gneiss, the lowermost tectonic units in the Erzgebirge, were dated. The grey Freiberg Gneiss is of igneous origin and has a 207Pb/206Pb emplacement age of 550±7 Ma. A quartz monzonite from Lauenstein contains idiomorphic zircons with a mean 207Pb/206Pb age of 555±7 Ma as well as xenocrysts ranging in age between 850 and 1910 Ma. Red gneisses from the central Erzgebirge contain complex zircon populations, including numerous xenocrysts up to 2464 Ma in age. The youngest, idiomorphic, zircons in all samples yielded uniform 207Pb/206Pb ages between 550±9 and 554±10 Ma. Nd isotopic data support the interpretation of crustal anatexis for the origin of both units. Nd(t) values for the grey gneisses are –7.5 and –6.0 respectively, (mean crustal residence ages of 1.7–1.8 Ga). The red gneisses have a wider range in Nd(t) values from –7.7 to –2.8 (T DM ages of 1.4–1.8 Ga). The zircon ages document a distinct late Proterozoic phase of granitoid magmatism, similar in age to granitoids in the Lusatian block farther north-east. However, Palaeozoic deformation as well as medium pressure metamorphism ( 8 kbar/600–650° C) are identical in both gneiss units and distinguish these rocks from the Lusatian granitoids. The grey and red gneisses were overthrust by units with abundant high-pressure relicts and a contrasting P-T evolution. Zircon xenocryst and Nd model ages in the range 1000–1700 Ma are similar to those in granitoid rocks of Lusatia and the West-Sudetes, and document a pre-Cadomian basement in parts of east-central Europe that, chronologically, has similarities with the Sveconorwegian domain in the Baltic Shield.  相似文献   

3.
Resins of Hymenaea, an angiosperm tree genus known to be a copious resin producer and a major source of amber since the Oligo-Miocene, were collected from a wide range of tropical environments from Latin America and Africa, and analyzed for their carbon, hydrogen, and oxygen stable isotope composition. The average value for 13C in the resins was found to be –27.0±1.3, which is very similar to the values reported for resins in other studies. 18 values for the Hymenaea resins averaged +11.2±1.6, or about 20 more depleted than normal plant cellulose. D values of the resins ranged from –196 to –319, with an average of –243±30. Rough estimates suggest a fractionation of –200 to –210 between the resins and the environmental water. This value is similar to the –200 value observed for the fractionation between other plant lipids and environmental water. The present study suggests that the stable isotope composition of fossil resins (amber) has the potential to provide information on ancient environmental waters.  相似文献   

4.
Movements and corridors of African elephants in relation to protected areas   总被引:1,自引:0,他引:1  
Understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. Using state-of-the-art global positioning system (GPS) technology we tracked 11 focal African elephants (Loxodonta africana) in Kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. Our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. The actual ranges of the tracked elephants are smaller than usually represented. Moreover, the ranges in our sample were complex and not confined to officially designated protected areas, except where fenced. All the unfenced elephants in our sample had distinct home sectors linked by travel corridors. Within each home sector the elephants concentrated in favourite core zones. Such core zones tended to lie in protected areas whereas corridors typically crossed unprotected range. Elephants moved significantly faster along corridors than elsewhere in their range, which suggests awareness of danger outside the protected area. We conclude that understanding the complex use of an animals range is crucial for conservation planning aiming to balance animal interests with those of human beings that co-habit in their range.The revised version was published online in April 2005 with correction to figure 1a and b.  相似文献   

5.
Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called dauer pheromone, produced by all worms. We suggest that the production of dauer pheromone has no fitness advantage for an individual worm and therefore we propose that dauer pheromone is not a signal, but a cue. Thus, it should not be called a pheromone.  相似文献   

6.
This study was supported by the Bundesministerium für Forschung und Technologie (BMFT), core program Einsatz neuer Technologien in den Geisteswissenschaften.  相似文献   

7.
This study was supported by the Bundesministerium für Förschung und Technologie (BMFT), core program Einsatz neuer Technologien in den Geisteswissenschaften.  相似文献   

8.
Ansprache vor dem Wissenschaftlichen Rat der Max-Planck-Gesellschaft am 8.2.1995. Adolf Butenandt war Ehrenprasident der MPG und von 1960 bis 1983 Mitglied des Beirats der Naturwissenschaften.  相似文献   

9.
Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing 15N and 13C values. An experiment using Nile tilapia [Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on 15N and 13C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. 15N and 13C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5 to 4 and for C in the lipid-free body from 4 to 2.5. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results.  相似文献   

10.
Microbial populations in tetra-distilled water collapsed when cultured in a permalloy chamber shielding the populations from the suns and earths electromagnetic field, but thrived when cultured in an ordinary thermostat open to the electromagnetic field. Theoretically, protons in liquid water can be excited at their natural resonance frequencies through Langmuir oscillations and obtain enough kinetic energy to charge the transmembrane potential of a cell. Microbes may be capable of converting this energy into chemical energy to supplement their energy needs.  相似文献   

11.
This study was supported by the Bundesministerium für Forschung und Technologie (BMFT), core program Einsatz neuer Technologien in den Geisteswissenschaften.  相似文献   

12.
The Mariánské Lázn complex (MLC) is located in the Bohemian Massif along the north-western margin of the Teplá-Barrandian microplate and consists of metagabbro, amphibolite and eclogite, with subordinate amounts of serpentinite, felsic gneiss and calcsilicate rocks. The MLC is interpreted as a metaophiolite complex that marks the suture zone between the Saxothuringian rocks to the north-west and the Teplá-Barrandian microplate to the south-east. Sm-Nd geochronology of garnet-omphacite pairs from two eclogite samples yields ages of 377±7, and 367±4 Ma. Samples of eclogite and amphibolite do not define a whole rock Sm-Nd isochron, even though there is a large range in Sm/Nd ratio, implying that the suite of samples may not be cogenetic. Eclogites do not have correlated Nd values and initial 87Sr/86Sr ratios. Five of the eight eclogite samples have high Nd values (+10.2 to +7.1) consistent with derivation from a MORB-like source, but variable 87Sr/86Sr ratios (0.7033 to 0.7059) which probably reflect hydrothermal seawater alteration. Three other eclogite samples have lower Nd values (+ 5.4 to –0.8) and widely variable 87Sr/86Sr ratios (0.7033 to 0.7096). Such low Nd values are inconsistent with derivation from a MORB, source and may reflect a subduction or oceanic island basalt component in their source. The MLC is an important petrotectonic element in the Bohemian Massif, providing evidence for Cambro-Ordovician formation of oceanic crust and interaction with seawater, Late Devonian (Frasnian-Famennian) high- and medium-pressure metamorphism related to closure of a Saxothuringian ocean basin, Early Carboniferous (Viséan) thrusting of the Teplá terrane over Saxothuringian rocks and Late Viséan extension.  相似文献   

13.
The modern theory of biological evolution: an expanded synthesis   总被引:12,自引:2,他引:12  
In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwins Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwins perspective. Weismanns neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwins dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the modern synthesis is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution of digital organisms). In addition, we discuss the expansion of the modern synthesis, embracing all branches of scientific disciplines. It is concluded that the basic tenets of the synthetic theory have survived, but in modified form. These sub-theories require continued elaboration, particularly in light of molecular biology, to answer open-ended questions concerning the mechanisms of evolution in all five kingdoms of life.Dedicated to Prof. Dr. Dr. hc mult. Ernst Mayr on the occasion of his 100th birthdayThis revised version was published online in March 2004, with corrections to the caption of Figure 6.  相似文献   

14.
Water,Climate, and Development Issues in the Amu Darya Basin   总被引:1,自引:0,他引:1  
Before 1960, the Aral Sea was the fourth-largest body of water on Earth. Today, it is on the edge of extinction. The Sea is fed by Central Asias two major rivers, the Amu Darya and the Syr Darya, with a flow, respectively, of about 70 and 35 cubic kilometers per year on average. Today, the Aral story is quite well known to environmental groups within and outside the region. The Amu Daryas watercourse serves as an international border between Tajikistan and Afghanistan and between Uzbekistan and Afghanistan. The Amu Darya crisscrosses Turkmenistan and, for the most part, traverses the length of Uzbekistan and its subregion known as Karakalpakstan. Although an upstream riparian country, Afghanistan has been at war for a couple of decades and in-country conflict remains. As a result, it has had little opportunity to lay claim to its legitimate share of Amu Darya water. With an end to the Russo-Afghan war, an end to the Taliban regime, and with international involvement to bring a semblance of peace and stability to the country in the conflict-laden post-Taliban period, the new Afghan government will surely lay claim to a significant share of Amu Darya water as it reconstructs the nations agricultural sector. This paper discusses issues related to the problems and prospects for sustainable development in the Amu Darya basin.The National Center for Atmospheric Research is sponsored by the National Science Foundation and managed by the University Corporation for Atmospheric Research.  相似文献   

15.
A lek is a clump of male territories that females visit only for mating; it is quite a rare mating system among mammals. As we wanted to investigate the role of past male mating success on their fidelity to lek territories, we displaced fallow deer females by a lek (Lek A), i.e. we removed the resources for rutting males. They moved to a new area followed by some of the territorial males (mobile males) where they established a new lek (Lek B). Other males (faithful males) stayed on Lek A. The former had lower mating success and dominance ranking in the early, undisturbed part of the rut. After disturbance, the MS of faithful males was much reduced, while that of mobile males was higher on Lek B than it had been on Lek A. We then disturbed Lek B. Females returned to Lek A, and the mating success of faithful males reverted to its original level. Past mating success was the main factor predicting whether a male was faithful or mobile. We illustrated for the first time the importance of past experience in promoting lek fidelity; this experiment gives an insight into the mechanisms leading to the traditional use of leks.  相似文献   

16.
Dominance behavior in Polistes wasps is a composite trait consisting of various discrete behaviors such as darts, lunges, bites, and mounts. The majority of these behaviors are considered aggressive, and these aggressive behaviors are considered to form a continuum from mild (e.g., darts) to severe (e.g., falling fights). In this paper we focus on darts, the most common of the dominance behaviors, and investigate their function in un-manipulated post-emergent colonies of the primitively eusocial wasp P. fuscatus. Here we show that darts are correlated with the more severe dominance behaviors, and that dominance ranks do not change with the addition or exclusion of darts. We find no correlation, however, between receiving darts and receiving more severe dominance behaviors. This result suggests that darts are not indicative of aggressive reinforcement of dominance, but rather may serve a different function. Our data suggest that the function of darts is to regulate activity on nests. Both foundresses and workers dart inactive workers significantly more often than by chance, and workers respond to a foundresss (but not a workers) dart by becoming less inactive. We also found that active workers who receive a dart from either a foundress or worker respond mostly by switching from one activity to another. Thus, our data suggest that darts are not aggressive behaviors, that foundresses use this signal to initiate activity, and that foundresses and workers both use the signal to regulate worker activity.  相似文献   

17.
Deception is a crucial yet incompletely understood strategy of social parasites. In central Europe, the Mountain Alcon Blue, Maculinea rebeli, a highly endangered butterfly, parasitises several Myrmica ant species. Caterpillars gain access to host nests probably by faking the ants odour. We analysed gas chromatography–mass spectrometry data of body surface hydrocarbons of pre-adoption and hibernated larvae of Maculinea rebeli and of their host species Myrmica sabuleti and M. schencki. Data were ordinated by different methods, based on similarities in the relative quantities of compounds between chromatograms. The two Myrmica species exhibit species-specific profiles. The Maculinea rebeli pre-adoption larva has a complex profile that simultaneously contains species-specific substances of the two investigated host species. This evidence leads to the interpretation that, in central Europe, Maculinea rebeli is predisposed for multi-host use by the chemical signature of its pre-adoption larva. The Maculinea rebeli larva clearly does not rely on an intersection-odour of compounds common to all host ant species, but synthesises an aggregate-odour containing specific compounds of each of the investigated hosts. We term this previously unknown chemical strategy aggregate-odour multi-host mimicry.B.C. Schlick-Steiner and F.M. Steiner contributed equally to this work.  相似文献   

18.
In species with more than one male reproductive morph, there typically exists a larger morph with exaggerated secondary sexual characters, and a smaller morph with reduced secondary sexual characters. These exaggerated and reduced morphologies are commonly thought to represent specializations to alternative behavioral reproductive tactics—large body size and exaggerated secondary sexual characters should both facilitate territoriality, courtship, and pair-spawning; while small body size and reduced secondary sexual characters should facilitate sneaky cuckoldry. Given this postulated relationship between morphology and behavior, we examined the relationship between the morphology of exaggerated males and cuckoldry. In a field and aquarium study of the midshipman fish, a fish with both exaggerated and reduced morphs, we demonstrated cuckoldry in some males of the exaggerated morph. Since the reduced morphology is thought to be an adaptation towards sneaky cuckoldry, we predicted that, of males with the exaggerated morph, less-exaggerated (smaller) males would be better able to gain proximity to the spawning pair during cuckoldry. In contrast to that prediction, access to the spawning pair during cuckoldry increased with the body size of the cuckolding exaggerated-morph males. This may be related to our observation that exaggerated males often cuckolded aggressively. Thus the exaggerated morphology need not preclude adaptive plasticity to cuckoldry, and may even aid it.  相似文献   

19.
Die Autoren danken der Deutschen Forschungsgemeinschaft für die Förderung dieser Arbeit im Sonderforschungsbereich 237 Unordnung und große Fluktuationen. T. Dittrich dankt der Abteilung für Kernphysik am Weizmann Institut, Rehovot, Israel, insbesondere Prof. U. Smilansky, für Gastfreundschaft während der Fertigstellung des Manuskripts.  相似文献   

20.
The radical pair model of magnetoreception predicts that magnetic compass orientation can be disrupted by high frequency magnetic fields in the Megahertz range. European robins, Erithacus rubecula, were tested under monochromatic 565 nm green light in 1.315 MHz fields of 0.48 T during spring and autumn migration, with 1.315 MHz being the frequency that matches the energetic splitting induced by the local geomagnetic field. The birds responses depended on the alignment of the oscillating field with respect to the static geomagnetic field: when the 1.315 MHz field was aligned parallel with the field lines, birds significantly preferred northerly directions in spring and southerly directions in autumn. These preferences reflect normal migratory orientation, with the variance slightly increased compared to control tests in the geomagnetic field alone or to tests in a 7.0 MHz field. However, in the 1.315 MHz field aligned at a 24° angle to the field lines, the birds were disoriented in both seasons, indicating that the high frequency field interfered with magnetoreception. These finding are in agreement with theoretical predictions and support the assumption of a radical-pair mechanism underlying the processes mediating magnetic compass information in birds.  相似文献   

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