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At least 19 recordsLinked to original sources
PubMed2005

[Characteristics of changes in respiratory function of humans after a long stay in Antarctic region].

Fifteen participants of the Antarctic expedition (men, 27-51 years old) have been investigated after their return from a one-year stay there. All subjects have signs of latent hypoxia. Compensation of hypoxic reactions depended on the initial state of organism oxygen regimen as well as on the features of a genotype. It was supposed that, after a long stay by a person in the coastal Antarctic conditions, the latent form of hypoxia could develop. The latter was accompanied by reorganizations of oxygen regimen and determined by specific features of a genotype.

Adaptation, Physiological↗
PubMed2003

[Medical and biological studies of Ukrainian scientists in Antarctic region].

People adaptation problem in Antarctic conditions, prophylactics of the desinchronostic disturbances, destability of psycho-emotion state, pathological manifestation of the heart-vessel system, tasks of regional waste influences on the people organism are not insolvable up to now and is the base of medical-biological researches. In accordance with the peculiarities of the geographical positions of Academician Vernadsky station and long period of staying in extremely conditions of Antarctic the medical-physiological researches will executed on the each stage. During the selection of candidates for the work at Ukrainian Antarctic station we studied new medico-biological criteria including genetic markers with aim to forecast antagonism functional state during wintering. At the period of staying in Antarctic in the conditions of season inversions and hour belts removals it will executed the researches of biorhythmological peculiarities of the psychophysiological function and heart-vessel system states, outer system of breathing and biochemistry indexes of people fluids. It was shown that the biggest part of disturbances in organisms functional system at the period of Antarctic winter has an ability to restoration after returning to homeland. However, disturbances in immunology system state are prolonged, harmful influence of solar radiation are revealed on the people sight, especially, when one use the not recommended lighting filters. With the purpose of prophylactic of desynchronic disturbances, which was find after wintering at the more then 90% expedition personnel, it was worked out an non invasion methods of correction by using the individual polychromatic influence on organism. It is studied the teleconnection results of long period staying of expedition staff in Antarctic. It was established, that Ukrainian members of expedition have the fixed number of radionuclids of Cesium in organism. After staying in Antarctic radionuclids of Cesium in organism do not reveal.

Adaptation, Physiological↗
PubMed2002

Fallout radiocesium in an Antarctic region: deposition history, activity densities and vertical transport in soils.

To improve the knowledge about the (137)Cs spatial distribution and vertical migration in soils of the Southern Hemisphere, the total areal activity density and the vertical transport parameters of this radionuclide were measured in an Antarctic region. For this purpose vegetation and incremental soil samples were collected at 21 representative sites located at 4 islands of the South Shetland Archipelago: King George, Robert, Greenwich and Snow (62-63 degrees S and 58-62 degrees W). The total (137)Cs activity density varied considerably from 118 to 662 Bq m(-2) (median 384 Bq m(-2), reference date 1995), with a high percentage of the total activity retained in the vegetation cover (5-98% in moss, 3-20% in lichen and 4-12% in grass). At most sites, the maximum activity density in soil was observed in the top layer from where it decreased continuously. To evaluate the transport parameters of (137)Cs from the activity-depth profiles, the classical convection-diffusion model was used based on the time-course of the annual deposition density of (137)Cs at the studied region. The values for the diffusion coefficient D(s) (median 0.043 cm(2) year(-1)) and the convection velocity v(s) (median -0.012 cm year(-1)) of radiocesium observed under a polar climate are small compared to the transport parameters determined in temperate zones. The data also indicate that at these sites the convectional transport of (137)Cs is almost negligible compared to the transport by diffusion. The high vulnerability of the Antarctic soils to (137)Cs deposition, as a consequence of its very slow transport due to the extreme climatic conditions at these latitudes, has been confirmed.

Antarctic Regions↗
PubMed2006

Isolation and molecular identification of free-living amoebae of the genus Naegleria from Arctic and sub-Antarctic regions.

Twenty-three freshwater samples with sediment taken from two regions in the Arctic, Spitzbergen and Greenland, and one region in sub-Antarctica, Ile de la Possession, were cultured for amoebae at 37 degrees C and room temperature (RT). Only two samples yielded amoebae at 37 degrees C and the two isolates were identified from their morphological features to belong to the genus Acanthamoeba. Vahlkampfiid amoebae were isolated from 11 samples at RT. Morphological analysis of the cysts identified all 11 isolates as belonging to the genus Naegleria, although only about half of them (45%) transformed into flagellates. Ribosomal DNA sequence analysis demonstrated that these isolates represent novel species and that N. antarctica, N. dobsoni and N. chilensis are their closest relatives. Not surprisingly, these three species also grow at lower temperatures (<37 degrees C) than the majority of described Naegleria spp. Two of the eight new species were found in both Arctic and sub-Antarctic regions, and other new species from the Arctic are closely related to new species from the sub-Antarctic. Therefore, it seems the Naegleria gene pool present in the polar regions is different from that found in temperate and tropical regions.

Animals↗
PubMed1978

[Effect of the extreme factors of antarctic regions on the composition of serum in polar explorers].

Extreme conditions of the Antarctic continent caused adaptive changes in the protein composition of human blood, expressed in the increased level of blood globulin fraction. The detected reduction in the Beta1A-gloubulins in the blood indicated a reduction of the infection immunity level. An increase of blood transferrin content of polar explorers served as a response of the organism to the influence of hypoxic hypoxia.

Antarctic Regions↗
PubMed1990

[Dynamics of morphometric indicators of rat testes during adaptation to high-altitude in the Antarctic regions with subsequent dysadaptation].

In the experiments performed on 100 white non-inbred male rats (some of them have been kept at the altitude of 3.488 m in the station Vostok, and others--at the coastal level in the station Mirny) testes have been studied, as well as morphometric analysis of convoluted seminiferous tubules and estimation of spermatogenesis activity. During the first month of living at the altitude the section area of the convoluted seminiferous tubules decreases, while the area of their lumen increases. During subsequent periods in the animals, living at the altitude, differences in the parameters, in comparison with the control, disappear. During the first 6 months of their living at the altitude a sharp decrease in spermatogenesis activity is observed. A month of life at the coastal level (after 10 months of hypoxic effect) does not result in normalization of the spermatogenesis activity.

Acclimatization↗
PubMed2000

Risks, especially for the eye, emanating from the rise of solar UV-radiation in the Arctic and Antarctic regions.

Physical and biological characteristics of solar UV-radiation wavebands A, B, and C are explained and information is provided on UV-levels in particular environments and ocular tissues. The question whether or not the rise in circumpolar UV of the last 20 years or so can be regarded as a threat is briefly addressed and it is concluded that even if no threat to photosynthetic productivity of crops and vegetation exists, there is a danger regarding the status of health of human skin and eyes (in particular the lens). The nature of the UV-induced damage to cornea, lens, and even the retina with its photo-receptive cells and pigment epithelium is assessed and a word of caution is sounded with regard to possible injury-potentiating effects of certain chemicals as seen, for instance, in the recent and alarming rise of cataract in Scottish salmon. Finally, because of the multifaceted effects of UV (e.g. at molecular, cellular, tissue, individual, population, and ecosystem level), a plea is made for a concerted, well-funded, international effort to tackle the many remaining problems at all fronts and from all possible angles.

Antarctic Regions↗
PubMed2003

You are what you eat: describing the foraging ecology of southern elephant seals (Mirounga leonina) using blubber fatty acids.

Understanding the trophodynamics of marine ecosystems requires data on the temporal and spatial variation in predator diet but, particularly for wide-ranging species, these data are often unavailable. The southern elephant seal (Mirounga leonina) consumes large quantities of fish and squid prey in the Southern Ocean relative to other marine mammals; however, how diet varies relative to seasonal and spatial foraging behaviour is unknown. We used fatty acid (FA) signature analysis of 63 blubber cores from adult female M. leonina over three seasons (winter 1999, summer 2000 and winter 2001) to determine diet structure. We detected significant differences between seasons and between the main foraging regions (Antarctic continental shelf versus pelagic). We used the FA profiles from 53 fish, squid and krill species to construct a discriminant function that would classify each seal, from its blubber sample as having a fish- or squid-FA profile. We determined that a higher proportion of M. leonina had fish-dominated diets during the winter and when foraging around the Antarctic continental shelf, and the majority had more squid-dominated diets during the summer when foraging pelagically. Thus, we were able to measure the coarse-scale diet structure of a major marine predator using FA profiles, and estimate its associated seasonal and temporal variation.

Adipose Tissue↗
PubMed2000

Nervous and sensory system correlates of an epibenthic evolutionary radiation in antarctic notothenioid fishes, genus Trematomus (Perciformes; Nototheniidae).

The perciform suborder Notothenioidei consists of 120 species, with 94 confined to the Antarctic Region of the Southern Ocean. On the Antarctic shelf, this phyletic radiation has been accompanied by a substantial morphological and ecological diversification towards a pelagic existence. For example, the primarily benthic genus Trematomus contains an epibenthic radiation that includes T. loennbergii, T. lepidorhinus, and T. eulepidotus. By comparing these epibenthic species with three congeneric benthic species (T. scotti, T. pennellii, and T. bernacchii) we tested three null hypotheses regarding brain variation in Antarctic trematomids: 1) that there is no difference in brain morphology among the six species; 2) that phylogenetic and ecological factors do not influence brain morphology; and 3) that peripheral sensory structures do not influence brain morphology. We rejected each of these hypotheses, leading us to conclude that Trematomus brains vary interspecifically, between benthic and epibenthic species, and with a species' depth distribution. Further, we conclude that brain variation is correlated with differences in peripheral sensory systems and motor activity. Specifically, epibenthic Trematomus have larger percentages of their brain volume devoted to lateral line mechanoreceptive and motor (cerebellar) structures. Species living at greater depths have low ratios of cones:rods in the retina and larger olfactory structures.

Animals↗