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Dimitris Tsaparis Yorgos Mertzanis Alexander Triantafyllidis 《Journal of Natural History》2015,49(5-8):393-410
The brown bear (Ursus arctos) in Greece is considered endangered but little is known about the genetic status and the exact size of local populations. Non-invasive genetic sampling was used in this study to investigate the genetic diversity and genetic structure of the brown bear population in the Kastoria region (northwest Macedonia, Greece) and to estimate its population size. Estimation of demographic parameters was based on innovative, well-evaluated methods that can provide estimates from a single sampling session. DNA was extracted from hairs, scat and blood samples and subsequent amplification of 10 microsatellite loci allowed the identification of a minimum number of 75 living bears in the study area while the mark–recapture-based analysis resulted in a point estimation of 219 individuals. Relatively high diversity values, lack of heterozygosity deficiency as well as estimated effective population size, support the Kastoria bear population having good conservation status. 相似文献
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In this paper we primarily study the difficulties in the application of the thermodynamical approach to the phenomenon of superconductivity, resulting from a specific interpretation of the low temperature behavior of the Maxwell equations. An attempt is made to elucidate the situation during the first period of the development of superconductivity theory and to render explicit prejudiced attitudes reminiscent of Feyerabend's natural interpretations. 相似文献
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In this paper we attempt to investigate the historical and methodological aspects of the developments related to superfluid helium, concentrating on the period between 1941 and 1955. During this period, the various developments constituted a series of steps towards redefining and refining the two-fluid concept devised to explain the unexpected macroscopic behaviour of superfluid helium. The idea that superfluids are essentially ‘quantum structures on a macroscopic scale’ functioned as a heuristic principle which guided the theoretical physicists engaged in the above research programme. 相似文献
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Theodore Christidis Yorgos Goudaroulis Maria Mikou 《Archive for History of Exact Sciences》1987,37(2):183-191
During the first twenty-four years after the discovery of superconductivity many attempts to derive an adequate theory failed, mainly because the problem was not formulated quite correctly. In this paper we investigate certain questions related to the heuristic role of mathematics in the appropriate formulation of the problem that had to be solved and the development of a theory which was hindered by theoretical superstitions. 相似文献
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Stamatis Zogaris James Maclaine Nicholas Koutsikos Yorgos Chatzinikolaou 《Journal of Natural History》2015,49(5-8):347-357
The river blenny (Salaria fluviatilis) is rarely mentioned in the natural history literature of Cyprus. This has led to doubts about its existence there. Mistakes with mismatched fish collections have occurred in the past, so it is worth asking whether the recorded specimens are actually from Cyprus and whether the species survives there today. Archived correspondence from the original specimen collector confirms that the record of S. fluviatilis on Cyprus is genuine, yet our extensive surveys there during the last 4 years have failed to locate the fish. A review of the species’ Mediterranean island distribution shows that it exists on 10 islands that are either close to the mainland or are relatively very large in areal extent. Although the mystery of S. fluviatilis survival on Cyprus lingers, efforts must be made to survey all potential habitats and consider planning a re-introduction project if the population is confirmed as extinct. 相似文献
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