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11.
A review of extracellular virulence product of Vibrio species important in diseases of cultivated shrimp 总被引:2,自引:0,他引:2
Gabriel Aguirre-Guzmán Humberto Mejia Ruíz & Felipe Ascencio 《Aquaculture Research》2004,35(15):1395-1404
Shrimp aquaculture is an important industry that experiences significant losses from Vibrio species, especially at the larval and juvenile stages. Proteinaceous virulence factors, including alkaline proteases, metalloproteases, cysteine proteases and alkaline serine proteases, have been identified as important elements in Vibrio pathogenesis. This review summarizes current knowledge regarding the principal pathogenic Vibrio species in shrimp, with emphasis on relevant exotoxins and their modes of action, principal characteristics and molecular database. This pathogenic factors and their relation with other molecules produced by microorganisms may be help to understand the virulence mechanisms present in Vibrio strain. 相似文献
12.
Silvana Nisgoski Mayara E Carneiro Elaine C Lengowski Felipe Z Schardosin Graciela I Bolzon de Muñiz 《Southern Forests》2015,77(4):243-247
The correct identification of pine species is necessary for proper application of wood in forest?based industries, since the quality of each species’ wood depends on factors intrinsic to the material. The aim of this study was to evaluate the potential use of near?infrared and visible spectroscopy in the discrimination of pine species planted in southern Brazil. Needles of Pinus clausa, P. glabra, P. kesiya, P. oocarpa, P. palustris, P. pseudostrobus, P. rigida, P. roxburghii and P. serotina were collected from experimental plantations located in the region of Rio Negro, Paraná, Brazil. The needles were dried and milled for analysis. The evaluation was performed with a spectral range of 400–750?nm (visible) and 1 000–2 500?nm (near?infrared). Analysis using the visible spectra resulted in two principal components explaining 95% of the variation between the needle samples. In the near?infrared analysis, it was possible to discriminate between all nine pine species studied using only two principal components, where the first explained 99% of the variation between species. Spectroscopy based on needles can be used for pine species discrimination, using the original data without mathematical treatment, in southern Brazil. 相似文献
13.
Miren del Río Hans Pretzsch Iciar Alberdi Kamil Bielak Felipe Bravo Andreas Brunner Sonia Condés Mark J. Ducey Teresa Fonseca Nikolas von Lüpke Maciej Pach Sanja Peric Thomas Perot Zahera Souidi Peter Spathelf Hubert Sterba Martina Tijardovic Margarida Tomé Patrick Vallet Andrés Bravo-Oviedo 《European Journal of Forest Research》2016,135(1):23-49
14.
The North American long-term soil productivity experiment: Findings from the first decade of research 总被引:1,自引:0,他引:1
Robert F. Powers D. Andrew Scott Felipe G. Sanchez Richard A. Voldseth Deborah Page-Dumroese John D. Elioff Douglas M. Stone 《Forest Ecology and Management》2005,220(1-3):31-50
First decade findings on the impacts of organic matter removal and soil compaction are reported for the 26 oldest installations in the nation-wide network of long-term soil productivity sites. Complete removal of surface organic matter led to declines in soil C concentration to 20 cm depth and to reduced nutrient availability. The effect is attributed mainly to the loss of the forest floor. Soil C storage seemed undiminished, but could be explained by bulk density changes following disturbance and to decomposition inputs of organic C from roots remaining from the harvested forest. Biomass removal during harvesting had no influence on forest growth through 10 years. Soil compaction effects depended upon initial bulk density. Soils with densities greater than 1.4 Mg m−3 resisted compaction. Density recovery was slow, particularly on soils with frigid temperature regimes. Forest productivity response to soil compaction depended both on soil texture and the degree of understory competition. Production declined on compacted clay soils, increased on sands, and generally was unaffected if an understory was absent. 相似文献
15.
Castro Liliane Araújo Andrade-Porto Sanny Maria Oliveira Rebeca Guimarães Batista Yasmin Luzeiro Silva Felipe Moura Araújo Oliveira Christiane Patrícia Feitosa Affonso Elizabeth Gusmão Cruz Claudinei Tavares-Dias Marcos 《Aquaculture International》2021,29(6):2477-2488
Aquaculture International - This study investigated the efficacy of trichlorfon against Neoechinorhynchus buttnerae, as well as its palatability, residue analysis, and the blood parameters of... 相似文献
16.
Lorenza Pacini Felipe Yunta Arwyn Jones Luca Montanarella Pierre Barrè Sergio Saia Songchao Chen Calogero Schillaci 《European Journal of Soil Science》2023,74(4):e13391
Soil Bulk Density (BD) is an extremely important variable because it is an important site characterization parameter, and it is highly relevant for policy development because it is mandatory for calculating soil nutrient stocks. BD can influence soil chemical properties, land-use planning and agronomic management. The 2018 Land Use and Coverage Area Frame Survey (LUCAS) saw the unprecedented collection of BD core analysis in a subset of the locations in Europe and the United Kingdom where soil physical and chemical properties were analysed in the 2009 and the 2015 sampling campaigns. Here, we integrated the LUCAS 2018 BD sampling campaign with the mass fraction of coarse fragments previously determined in LUCAS 2009–2015 in order to provide a dataset of the volume fraction of coarse fragments and the BD of the fine earth and improve soil organic carbon (SOC) stock estimation accuracy for topsoil. BD data sampled at 0–10 and 10–20 cm were averaged to harmonize the BD with the mass fraction of coarse fragments measured in 2009, 2012 and 2015. Samples were from cropland, grassland and woodland soils, which accounted for 41%, 21% and 30%, respectively, of the total number of selected sites (n = 6059); ‘bareland’, and ‘shrubland’ accounted for 3% of the sites each, whereas ‘artificial land’ accounted for <1%. Only six samples were classified as ‘wetland’. The dataset was produced assuming the mass density of the coarse fraction to be constant across all LUCAS soil samples. We also estimated the SOC stocks associated with LUCAS 2018 BD and SOC content measurements and showed that correcting the BD by the coarse mass fraction instead of the coarse volume fraction generates SOC stock underestimation. We found the highest deviations in woodlands and shrublands. We showed that, when SOC stock is computed with coarse mass fraction, the error compared with the computation by volume may vary depending on the SOC and coarse mass fraction. This may imply a SOC stock underestimation for European soils. This dataset fits into the big framework of LUCAS soil properties monitoring and contributes both to soil awareness and soil research and assessments, which are two important objectives of the Soil Strategy and the European Soil Observatory (EUSO). 相似文献
17.
18.
Morphohistological features of the tubular organs of the Myocastor coypus (coypu) female reproductive tract were studied. Specimens came from breeding farms with yard breeding systems. The analysis of the organs was made by histological methods and by macro and microscopic measurement techniques. The animals showed oviducts with macro and microscopically differentiable regions. Their mucosa showed primary branched folds in the ampullar sector. In the rest of the oviduct tract these folds were only of the primary type. The double uterus showed regional variations in the lumen, endometrial glands along the whole surface and a wide fibromuscular cervix with pseudoglands. The endocervical mucosa made clear a complex system of folds covered by a mucus-secreting epithelium. In the long vagina of the coypu a folded, rugose and irregular mucosa was observed. 相似文献
19.
20.
Encarna Rodríguez-García Libertad Juez Felipe Bravo 《European Journal of Forest Research》2010,129(6):1119-1128
Research on natural regeneration is crucial for the development of sustainable forestry practices, in light of the global
climate changes taking place. In this study, 151 plots were sampled in six Pinus pinaster stands that were naturally regenerated by the seed-tree method in Mediterranean forests in central Spain. The objectives
of the survey were to study the suitability of different forest stands designated for natural regeneration as well as to analyse
seedling establishment and the relationship between regeneration and different site factors. Analysis of variance and multivariate
analysis with canonical ordination techniques were employed. Full and partial redundancy analyses on a correlation matrix
were used to carry out a direct gradient analysis of regeneration density as a function of site factors. Nearly all stands
presented seedling densities over 2,000 seedlings ha−1 and were thus found to be suitable for natural regeneration of Pinus pinaster by the seed-tree selection method. Significant variables that best explained total seedling and viable seedling density were
spring and autumn precipitation of the year prior to establishment, spring and summer precipitation of the year of establishment
and percentage cover of litter. There were no signs of competition between shrubs and seedlings, but a negative significant
correlation with grass cover was observed. Pinus pinaster natural regeneration was successful with the seed-tree method, although it appeared to be highly dependent on climate and
stand conditions. 相似文献