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881.
Although there is much research showing a strong negative effect of habitat fragmentation and deterioration on the viability of different insect populations and on species richness, the effect of fragmentation is modified by other local and landscape factors. One of the most substantial gaps in knowledge is whether species are similar in their response to the same environmental factors and if their response mirrors response of the entire community. From the conservation point of view this knowledge is of primary importance in planning conservation actions, yet these studies are rare. In this paper we test the relative effects of habitat patch and landscape characteristics on butterflies inhabiting calcareous grasslands in southern Poland. Butterfly species richness and abundance were positively affected by patch size and wind shelter. In the case of species richness there was also a positive effect of plant species richness. Butterfly diversity was enhanced in wind sheltered patches, and commonness (non-rarity) enhanced by distance to buildings and by shorter vegetation. Multivariate analysis suggested differences in the responses of individual species to the examined environmental variables, with some species more responsive to patch size and shelter and others to sward height. The conservation of butterfly communities requires sensible and complex management to ensure high habitat diversity. The most important challenge for future studies on calcareous grasslands is to formulate a model of management that guarantees high species richness and conservation of each individual species.  相似文献   
882.
883.
In a moss sample collected in Costa Rica, 63 specimens and 13 eggs of the new species were found. Mesobiotus pseudopatiens sp. nov. belongs to the harmsworthi group and is most similar to Mesobiotus patiens, but it differs from it mainly by smaller eggs, longer flexible portions of egg processes and certain morphometric characters of adults. In addition, after re-examination of specimens of the genus Milnesium collected in Costa Rica, a new record of Milnesium kogui may be added to Costa Rican fauna. The paper also discusses taxonomical problems and the zoogeography of Costa Rican tardigrades, which partially agree with hypotheses of Great American Biotic Interchange and Mexican Transition Zone. A large number of so-called ‘Costa Rican species’ are doubtful taxa with ‘cosmopolitan’ distribution; the largest number of species, however, have tropical/subtropical or neotropical distribution. Certain species from colder regions are also present in the mountains of Costa Rica.

http://zoobank.org/urn:lsid:zoobank.org:pub:F6F6195E-0888-4279-A3AF-422642F8B40  相似文献   

884.
885.
Rhodococcus equi is an important bacterial pathogen in foals up to 6 months old, widespread in horse farms all over the world. It was found that only virulent R. equi strains expressing 15–17 kDa virulence-associated protein (VapA) and having large virulence plasmid of 85–90 kb containing vapA gene are pathogenic for horses. To date, 12 plasmid types have been reported in VapA positive strains from horses. There are no data concerning plasmid types of Polish field R. equi strains isolated from horses and horse farm environment. The aim of the study is to determine plasmid profiles of virulent R. equi strains isolated in Poland from dead foals as well as from soil samples taken from horse breeding farms. Plasmid profiles of 10 clinical strains derived from 8 farms and 11 environmental strains from 3 farms, confirmed as virulent by PCR, were compared with 12 reference strains containing the known plasmid size and type. Plasmid DNAs were analysed by digestion with the restriction endonucleases BamHI, EcoRI, EcoT22I, and HindIII for detailed comparison and estimation of plasmid sizes. The results of RFLP analysis revealed that all except one isolates used in the study are classified as VapA 85 kb type I plasmid. One strain harboured VapA 87 kb type I plasmid. This is the first report of plasmid types of Polish field R. equi strains. The results of our preliminary investigations on horse farms located in central and eastern Poland indicate that the virulent R. equi strains thus far isolated from diseased foals and horse farms environment represent a highly uniform plasmid pattern.  相似文献   
886.
The aim of the study was to create and evaluate models for predicting high levels of daily pollen concentration of Corylus, Alnus, and Betula using a spatiotemporal correlation of pollen count. For each taxon, a high pollen count level was established according to the first allergy symptoms during exposure. The dataset was divided into a training set and a test set, using a stratified random split. For each taxon and city, the model was built using a random forest method. Corylus models performed poorly. However, the study revealed the possibility of predicting with substantial accuracy the occurrence of days with high pollen concentrations of Alnus and Betula using past pollen count data from monitoring sites. These results can be used for building (1) simpler models, which require data only from aerobiological monitoring sites, and (2) combined meteorological and aerobiological models for predicting high levels of pollen concentration.  相似文献   
887.
Novel 1-(1,3-disubstituted-imidazolidyn-2-ylidene)-3-ethoxycarbonylmethylurea derivatives (3a3j) were obtained from appropriate 1-aryl-3-arylsulfonyl-1H-imidazolidine-2-imines (1a–1j) and ethyl isocyanatoacetate (2), which were subjected to condensation. Seven compounds were tested for their antiviral activity against HSV-1 and CVB3 viruses. Among the tested compounds, 3c was found to be active against HSV-1, proving that 4-methoxy substituent as R and 4-methyl substituent as R1 are most beneficial for activity against this virus. Furthermore, 3e and 3g were active against CVB3, which demonstrated that both 4-methyl and 4-chloro substitution is tolerated as R1, whereas 4-chloro and 2-methoxy substituents are best as R. It was also shown that the active compounds are characterized by relatively big surface area, small ovality, and greatest HOMO and LUMO energies in comparison to the rest of the compounds.  相似文献   
888.
Novel 1-(1-aryl-4,5dihydro-1H-imidazoline)-3-chlorosulfonylourea derivatives 3a3f were synthesized in the reaction of 1-aryl-4,5-dihydro-1H-imidazol-2-amines with chlorosulfonyl isocyanate. The second series of compounds 4a4f was prepared from the respective 1-(1-aryl-4,5-dihydro-1H-imidazoline)-3-chlorsulfonylureas 3a3f and 1,1′-carbonyldiimidazole (CDI). The selected compounds were tested for their activity against Herpes simplex virus and coxsackievirus B3 (CVB3). It was determined that three derivatives, i.e 3d, 4a and 4d are active against Herpes simplex virus (HSV-1). Compounds 3d and 4c are active against CVB3. Their favorable activity can be primarily attributed to their low lipophilicity values. Moreover, the lack of substituent in the phenyl moiety or 4-methoxy substitution can be considered as the most beneficial for the antiviral activity.  相似文献   
889.
The research was aimed to elaborate a method for selection of male plants (XY, YY) and female ones (XX) as well as for identification of supermale genotypes (YY) among male phenotypes. The population obtained by self-pollination of andromonoecious plants was analysed. In order to identify the bands differentiating the male from the female genotypes, Bulk Segregant Analysis (BSA) was carried out. Primers identified by BSA analysis were used for RAPD amplification on the template of the male and female individuals. Among the products obtained by the use of primer OPB-20, some bands were linked with sex. A band of about 700 bp was found in all female plants, and in 4 phenotypically male specimens. In the male plants, the band showed a much lower intensity, compared with the female specimens. It seems that this fragment can be linked to the X chromosome in the investigated specimens. In the female specimens with XX karyotype, template duplication occurs and hence the band intensity is twice as high as in the XY karyotype. Three male plants did not include the OPB-20-700 fragment so they could potentially have the supermale (YY) karyotype. If the obtained marker proved its usefulness for identification of supermale plants, it could become a valuable tool facilitating breeding work.  相似文献   
890.
Novel water-soluble polymeric photosensitizers based on the natural polymer chitosan were synthesized and studied. The modified chitosans contain covalently attached Rose Bengal. The polymers absorb light from the visible spectral region and generate singlet oxygen. They can serve as environmentally friendly, biodegradable polymeric photosensitizers, which can use light from a visible spectral region to initiate photooxidation of organic compounds in water.  相似文献   
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