Search results for "CLASSIFICATION"
showing 10 items of 29475 documents
The Female Handball Player
2018
Female hormones fluctuate in concentrations during the menstrual cycle. This has triggered speculations among athletes, coaches, as well as researchers about the hormonal changes that lead to variations in athletic performance and adaptation to training. Many athletes, as in the general population, use oral contraceptives. This has raised questions concerning the suppression of the endogenous circulating female hormones and if the administration of synthetic hormones may have negative impact on athletic performance and training adaptations – or the opposite.
Preliminary health screening and possible pathogen determination in aBufo bufo(Linnaeus, 1758) (Amphibia: Bufonidae) population
2010
The population of the common toad, Bufo bufo, on Jersey (Channel Islands, UK) has undergone a marked decline over recent years. Hypothesized causes for this decline include land use change, pollution, climate change and predation. We examined the carcasses of 97 wild adult common toads for gastrointestinal and pulmonary helminths. In addition, 31 adult toad carcasses were examined for the presence of ranavirus infection, and 212 wild common toads were examined for the presence of infection with the fungus Batrachochytrium dendrobatidis. Three nematode species Rhabdias bufonis, Aplectana macintoshii and Oswaldocruzia filiformis, and one species of cestode, Nematotaenia dispar, were identifie…
Population size estimation of larval coregonids in large lakes: Stratified sampling design with a simple prediction model for vertical distribution
2009
Abstract The lake-specific vertical distribution of larval coregonids was assessed annually in Finnish lakes by bongo net sampling. The effect of inter-annual and inter-lake variation in vertical distributions on population estimates of larval coregonids were analysed in 1999–2008. The vertical distribution of newly hatched vendace ( Coregonus albula (L.)) and European whitefish ( Coregonus lavaretus L. s.l.) larvae was analysed and high inter-annual and lake-specific variation in the larval vertical distribution was found. Generally, in both littoral and pelagic areas, larvae were aggregated near the water surface, mostly in the top 30 cm layer. We compared observed and predicted density e…
Taxonomic clarification in W-Mediterranean Androcymbium (Colchicaceae): A. wyssianum sunk in the synonymy of A.gramineum and A.europaeum restored
2010
Abstract Hoyo A. del & Pedrola-Monfort J.: Taxonomic clarification in W Mediterranean Androcymbium (Colchicaceae): A. wyssianum sunk in the synonymy of A. gramineum and A. europaeum restored. — Willdenowia 40: 47–53. — Online ISSN 1868-6397. — © 2010 BGBM Berlin-Dahlem. doi:10.3372/wi.40.40103 (available via http://dx.doi.org/) Capsule dehiscence has been used as a diagnostic character for W Mediterranean species of Androcymbium. Depending on the state of capsule maturity, the character, however, can be ambiguous in herbarium material. Based on morphological, phenological and cpDNA characters it is shown that misinterpretation of the capsule as indehiscent in the type material of A. gramine…
Small Scale Geographical Variation in Plumage Colour of Pied Flycatcher Males
1997
Ecology -94". A cruise report. Swedish Polar Research Secretariat, Stockholm, pp. 311-316. Lundgren, B., Hedenstr6m, A. and Pettersson, J. 1995. Correlation between some body components and visible fat index in the Willow Warbler Phylloscopus trochilus (L.). Ornis Svecica 5: 75-79. Pettersson, J. and Hasselquist, D. 1985. Fat deposition and migration capacity of Robins Erithacus rubecula and Goldcrests Regulus regulus at Ottenby, Sweden. Ring. & Migr. 6: 66-76. Piersma, T., Bruinzeel, L., Drent, R., Kersten, M., Van der Meer, J. and Wiersma, P. 1996. Variability in basal metabolic rate of a long-distance migrant shorebird (Red Knot, Calidris canutus), reflects shifts in organ sizes. Physiol…
Frequency-dependent flight activity in the colour polymorphic wood tiger moth
2015
Abstract Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms unexpected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwing coloration across Europe. Previous studies indicate that yellow males are better defended from predators, while white males have a positively frequency-dependent mating advantage. However, the potential frequency-dependent behavioural differences in flight between the morphs, as well as the role of male-male interactions in inducing flying activity, have not been previously considered. We ran an outdoor cage experiment where proportions of both male morphs were manipul…
Modelling drift of pelagic offspring: the importance of egg surveys in providing a realistic model initialization
2015
Abstract Having valid information about the location and dynamics of biological processes is important for coastal management. In this context modelling, the pelagic drift of early life stages has been shown to be an important tool for understanding the spatial scale of population dynamics in marine systems. Often simulated particles are released in hypothetical quantities at assumed spawning grounds with no or few field data to guide the model parametrization. In this study, we combine high-resolution field data and state-of-the-art oceanographic modelling and use a probabilistic approach to construct kernel density distributions of the dispersal of pelagic fish eggs. Specifically, the pot…
Numerical response of predators to large variations of grassland vole abundance, long-term community change and prey switches
2020
AbstractVoles can reach high densities with multi-annual population fluctuations of large amplitude, and they are at the base of large and rich communities of predators in temperate and arctic food webs. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues. Here, a 20-year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts. Our results show how the predator community responds to prey variations of large amplitude and how it reorganized with the increase in a domina…
Population dynamics of fossorial water vole (Arvicola terrestris scherman): a land use and landscape perspective
1997
Abstract This study investigates the effect of land use, and landscape composition and structure on the population dynamics of fossorial water vole (Arvicola terrestris scherman Shaw). Water vole populations were monitored from 1989 to 1994 in the Doubs department, France, by using index methods. Land use patterns were studied based on agriculture and forestry data from the French Ministry of Agriculture collected in 1956, 1970, 1979 and 1988. Grassland quality and landscape structure were studied based on field transects, combined with the assessment of landscape structure from maps at 1:25,000 scale. Outbreaks of water vole populations occurred as a wave, spreading from epicentres over mo…
Habitat Preferences for Territory Selection by the Endangered Eastern Iberian Reed BuntingEmberiza Schoeniclus witherbyi
2014
Summary. Given the 80% decline of the eastern Iberian reed bunting Emberiza schoeniclus witherbyi breeding population in recent decades, our aim was to identify the habitat components selected during territory establishment and to characterise the vegetation features that are positively or negatively selected at the territory scale. GLMM were used to explain the occurrence of territories in 11 wetlands. Fourteen variables with four vegetation dominance categories were analysed with respect to habitat composition, while occupancy of seven vegetation classes and 12 reed structural parameters were analysed with respect to habitat structure. The proportion of reed-cattails (Typha) measured by t…