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Zaburzenia neuropsychiatryczne w COVID-19

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In promiscuous species in which females mate with more than one male during oestrus, males may increase their sperm expenditure or change their copulatory behaviour in response to the risk of sperm competition. I used an experimental approach to investigate the pattern of copulatory behaviour of the bank voleMyodes glareolus Schreber, 1780 depending on whether the female mated with one or two males. The work showed that the copulatory period of the bank vole lasted about 80 minutes and consisted of 4–5 ejaculatory series, with multiple intromissions preceding ejaculation. There were no significant changes in number of intromissions across the first four ejaculatory series, but I did find a relationship between number of intromissions and first ejaculation latency; also, ejaculation latencies grew shorter as the ejaculatory series proceeded. Litter size did not differ significantly between females that mated with one male and those mating with two, nor did the reproductive success of males that mated with the same female. Mating with an oestrus female appears to be advantageous for bank vole males even if they mate as the second one, and the risk of sperm competition did not trigger changes in male copulatory behaviour. The similar durations of the copulatory period and patterns of change of ejaculation latencies during copulations with one and two males point to the role of the female in temporal copulatory behaviour of the bank vole.
One of the major challenges in population biology is the identification of barriers to gene flow and/or secondary contacts between differentiated entities. The level of genetic differentiation among eight populations of the common voleMicrotus arvalis (Pallas, 1779) around the Biebrza Wetlands, NE Poland was examined by analyzing seven microsatellite loci for 140 voles and testing for the presence of barriers to gene flow. Overall population differentiation was moderate and significant (F ST = 0.081,p < 0.001) and there was no correlation between geographical and genetic distances among populations. We found a relatively high level of genetic variability within the populations studied. This could be explained by male bias in dispersal, a phenomenon recently found inM. arvalis. Patterns of genetic structure visualized in synthetic genetic maps showed clear gradients along a southeast-northwest axis across the study area, as well as the presence of a potential barrier to dispersal. The position of a barrier to gene flow identified using Monmonier’s maximum difference algorithm likely corresponds to humid habitats of the Biebrza Wetlands. These results suggest that the presence of environmental barriers to gene flow and drift may be responsible for the observed spatial genetic structure ofM. arvalis in the Biebrza Valley. Institute of Biology, University of Białystok, OEwierkowa 20 B, 15-950 Białystok, Poland,
The role of exogenous silicon in enhancing plant resistance to various abiotic stressors: salinity, drought, metal toxicities and ultraviolet radiation are presented. The data on possible involvement of silicon in reducing the reactive oxygen species generation, intensity of lipid peroxidation, and in some cases, increasing the activity of enzymes of the reactive oxygen species detoxificators: superoxide dismutase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase and catalase are analyzed.
W doświadczeniu przeprowadzonym w latach 2006-2007 oceniano kwitnienie i plon oraz jakość kłączy pustynników, gatunku E. bungei oraz 2 odmian ‘Cleopatra’ i ‘Pinokkio’ Kłącza sadzono wiosną 2006 r. na wzniesione zagony w polu. Połowę roślin uprawiano na zagonie z dodatkowo zastosowanym obornikiem. Podczas wegetacji połowę roślin na każdym zagonie nawożono Azofoską: na początku wegetacji (połowa kwietnia) oraz na początku kwitnienia (koniec maja). W czasie kwitnienia mierzono liczbę kwiatostanów, długość pędów i kwiatostanów. Jesienią 2008 r. kłącza wykopano, zważono, policzono wytworzone kłącza z każdej rośliny oraz zmierzono ich średnicę. Nawożenie mineralne oraz zastosowanie obornika wpłynęło korzystnie na długość szypuł kwiatostanowych oraz ich średnicę. Liczba kwiatostanów odmian ‘Cleopatra’ i ‘Pinokkio’ zwiększyła się pod wpływem nawożenia mineralnego. Wykazano również korzystny wpływ nawożenia organicznego na średnice kłączy oraz korzystny wpływ nawożenia organicznego i mineralnego na masę kłączy pustynników. Nawożenie organiczne i mineralne nie wpływało natomiast na liczbę uzyskanych kłączy.
Utilization of browse supply and moose Aices alces Linnaeus, 1758 browsing intensity in relation to tree height (0.5-3.0 m) were estimated for Scots pine in thickets and willow in willow-birch shrubs. The thickets examined provided different browse resources (0.5, 2.0 and 3.2 t dry wt/ha) and the highest utilization (about 50%) was found in the poorest one (thicket 1). In the willow-birch shrubs the use of browse was high and amounted to 85% of total production in both the winter periods studied. The number and increase of biomass of browsed twigs per stem (or plot} was generally associated with the increase of tree height. Browsing intensity depended on the tree height. Pines of 1.5-1.99 m height were characterized by the greatest browse utiliza­tion (76.3%). Moose removed significantly more biomass and twigs from pines growing in the central zone of the thicket 1 than from those growing in the marginal zone. However, in the wiilow-birch shrubs the utilization of all tree height classes was above 70% of the production and moose browsed not only the last year's growth of shoots but also that of earlier years.
We studied enzyme polymorphisms in a striped field mouse Apodemus agrarius (Pallas, 1771) population from NE Poland and the relationships between hetero­zygosity and length and mass of the digestive tract organs, and the mucosal surface area of the small intestine. _Most of 38 loci studied were found monomorphic (pro­portion of polymorphic loci P = 0.053, observed average heterozygosity H0 = 0.021). Heterozygotes were found for Acy, Pgm-1, Mdh-2, Est-D, Pgi, Sdh and Trf. Hetero­zygous males had longer large intestines and ceca and smaller liver wet mass than their homozygous conterparts. However, in females there were no significant inter­actions between heterozygosity and gut parameters. We suggest that the low level of polymorphism, the particular set of the loci examined and sex have an effect on detection of differences between heterozygous and homozygous individuals.
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