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In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed. 相似文献
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Trindade WG Hoareau W Megiatto JD Razera IA Castellan A Frollini E 《Biomacromolecules》2005,6(5):2485-2496
Composites based on phenolic matrices and unmodified and chemically modified sugar cane bagasse and curaua fibers were prepared. The fibers were oxidized by chlorine dioxide, mainly phenolic syringyl and guaiacyl units of the lignin polymer, followed by grafting furfuryl alcohol (FA), which is a chemical obtained from a renewable source. The fibers were widely characterized by chemical composition analysis, crystallinity, UV-vis diffuse reflectance spectroscopy, SEM, DSC, TG, tensile strength, and 13C CP-MAS NMR. The composites were analyzed by SEM, impact strength, and DMA. The SEM images and DMA results showed that the oxidation of sugar cane bagasse fibers followed by reaction with FA favored the fiber/matrix interaction at the interface. The same chemical modification was less effective for curaua fibers, probably due to its lower lignin content, since the reaction considered touches mainly the lignin moiety. The tensile strength results obtained showed that the fibers were partially degraded by the chemical treatment, decreasing then the impact strength of the composites reinforced with them. In the continuity of the present project, efforts has been addressed to the optimization of fiber surface modification, looking for reagents preferably obtained from renewable resources and for chemical modifications that intensify the fiber/matrix interaction without loss of mechanical properties. 相似文献
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TANATIN BI 《Mikrobiologiia》1951,20(6):506-511
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ANDRÉIA SILVA FLORES RÉA M. CORRÊA ELIANA R. FORNI-MARTINS ANA M. G. AZEVEDO TOZZI 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(2):271-277
Chromosome numbers were counted for 23 species of Crotalaria native to Brazil. Among these data there were new counts for 15 taxa, and some confirmed previous reports or represented numbers that were different from those cited previously. The chromosome numbers most frequently found were 2 n = 16 and 2 n = 32. Only C. incana L. had 2 n = 14 and C. tweediana Benth. had 2 n = 54. The counts 2 n = 32 and 54 were found in species of section Calycinae and 2 n = 16 and 14 in species of section Chrysocalycinae . The data revealed the importance of chromosomal parameters in the characterization of sections Calycinae and Chrysocalycinae in Brazil. We discuss the systematic significance and evolutionary aspects for the genus, comparing the results with the two sections that are native in Brazil. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 271–277. 相似文献
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Fernanda Aparecida Nieri-Bastos Marcos Gomes Lopes Paulo Henrique Duarte Can?ado Giselle Ayres Razera Rossa Jo?o Luiz Horácio Faccini Solange Maria Gennari Marcelo Bahia Labruna 《Memórias do Instituto Oswaldo Cruz》2014,109(2):259-261
Adult ticks of the species Amblyomma parvum were collected from the
vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the
Cerrado biome (state of Piauí) in Brazil. The ticks were
individually tested for rickettsial infection via polymerase chain reaction (PCR)
targeting three rickettsial genes, gltA, ompA and
ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A.
parvum ticks from Pantanal and Cerrado, respectively, contained
rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to
the corresponding fragments of the gltA, ompA and
ompB genes of Candidatus Rickettsia andeanae.
This report is the first to describe Ca. R. andeanae in Brazil. 相似文献
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Ricci GC De Souza-Kaneshima AM Felismino MF Mendes-Bonato AB Pagliarini MS Do Valle CB 《Journal of genetics》2011,90(2):289-294
A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them,
15 accessions presented 2n = 18; 27 accessions, 2n = 36; and 2 accessions, 2n = 45 chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In
the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities
were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low
frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number
and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce
interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions. 相似文献
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The genetic variability at six cloned minisatellite loci was analyzed in
minke whale populations from the North Atlantic, North Pacific, and
Antarctic Oceans. Three loci displayed only a few different alleles in each
of the three populations, with heterozygosity ranging from 0.00 to 0.47,
and three loci revealed many different alleles in at least two fo the three
populations, with heterozygosity ranging up to 0.98. Using small sample
sizes, samples from two adjacent Antarctic Management Areas were not found
to differ significantly in allele frequencies at any of the six loci. The
use of principal coordinate analysis to detect multilocus disequilibria was
explored. No significant evidence was found of intrapopulation
heterogeneity within the pooled Antarctic sample. Pronounced interoceanic
differences were observed at every locus, confirming the existence of
genetic isolation found earlier using more conventional marker systems. The
populations from the three oceans appear to have diverged to such a degree
that the hypervariable loci have had time to evolve independently and
arrive at different evolutionary stages in different populations. The
frequency of undetected "null" alleles is remarkably high in minke whale
populations compared to human populations and is probably a result of the
cloning protocol used. Minisatellite loci are shown to provide a powerful
population genetic tool, supplying levels of resolution appropriate to
different degrees of evolutionary divergence.
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