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91.
Alfonso Suárez Guadalupe Williams-Linera Carlos Trejo Juan Ignacio Valdez-Hernández Víctor Manuel Cetina-Alcalá Heike Vibrans 《Agroforestry Systems》2012,85(1):35-55
Species for restoration forestry on degraded lands in the tropics are often restricted to a few well-known exotic timber species. This selection frequently leads to failed projects, as local people expect trees to cover a number of uses, not only timber. We studied local knowledge of the usefulness, scarcity and importance for wildlife of native tree species in central Veracruz, Mexico, a region with mainly secondary vegetation and remnants of tropical dry forest. Data were obtained from several workshops, in depth interviews of 40 key informants, field walks with informants, and botanical collections. Analysis included indices for cultural importance, scarcity and wildlife relevance. We documented 76 species in one or more of the categories, from primary, secondary, agroforestry and riparian habitats. Fabaceae was the most important family. All of the species were useful for humans, mainly for rural construction, food, fence posts and fuel. Two-thirds of the species were considered scarce though they were not necessarily rare??some were highly useful, overexploited species with populations insufficient for demand; this category included five of the ten most important species culturally. Also, two-thirds of the tree taxa were considered important for wildlife, especially species of Moraceae. The study shows that the local population is highly aware of the varying functions of trees in the landscape. However, few of the important species are available from regional nurseries. We propose a number of species for restoration forestry, agroforestry systems and enrichment plantings that would be valued by landowners. 相似文献
92.
Hund A Gollnick N Sauter-Louis C Neubauer-Juric A Lahm H Büttner M 《Veterinary microbiology》2012,154(3-4):247-256
The compulsory vaccination campaign against Bluetongue virus serotype eight (BTV-8) in Germany was exercised in the state of Bavaria using three commercial monovalent inactivated vaccines given provisional marketing authorisation for emergency use. In eleven Bavarian farms representing a cross sectional area of the state the immune reactions of sheep and cattle were followed over a two year period (2008-2009) using cELISA, a serum neutralisation test (SNT) and interferon gamma (IFN-γ) ELISPOT. For molecular diagnostics of BTV genome presence two recommended real time quantitative RT-PCR protocols were applied. The recommended vaccination scheme led to low or even undetectable antibody titers (ELISA) in serum samples of both cattle and sheep. A fourfold increase of the vaccine dose in cattle, however, induced higher ELISA titers and virus neutralising antibodies. Accordingly, repeated vaccination in sheep caused an increase in ELISA-antibody titers. BTV-8 neutralising antibodies occurred in most animals only after multiple vaccinations in the second year of the campaign. The secretion of interferon gamma (IFN-γ) in ELISPOT after in vitro re-stimulation of PBMC of BTV-8 vaccinated animals with BTV was evaluated in the field for the first time. Sera of BTV-8 infected or vaccinated animals neutralising BTV-8 could also neutralise an Italian BTV serotype 1 cell culture adapted strain and PBMC of such animals secreted IFN-γ when stimulated with BTV-1. 相似文献
93.
Fessler AT Kaspar H Lindeman CJ Stegemann MR Peters T Mankertz J Watts JL Schwarz S 《Veterinary microbiology》2012,157(1-2):226-231
The correct assessment of mastitis pathogens for their susceptibility/resistance to cefoperazone is currently hampered by the lack of harmonized test conditions and interpretive criteria. The aim of this study was to provide a proposal for clinical breakpoints of cefoperazone which are applicable to Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis from cases of bovine mastitis and better reflect the situation in the bovine udder than breakpoints adopted from human medicine. For this, pharmacological data and clinical efficacy data of the documents submitted for approval of cefoperazone have been revisited. In addition, 1086 bacterial pathogens of the aforementioned six species/groups collected in Germany and in the USA during recent years were tested in parallel for their cefoperazone MICs and the zone diameters using a 75 μg disk. Subsequently, MICs were plotted against zone diameters. Based on the pharmacological data, the clinical efficacy and the microbiological data, a proposal was made for veterinary-specific breakpoints which classify members of the aforementioned species/groups as (a) susceptible to cefoperazone when their MIC is ≤ 2 μg/ml and their zone diameters are ≥ 27 mm (staphylococci or E. coli) or ≥ 21 mm (streptococci), (b) intermediate when their MIC is 4 μg/ml and their zone diameters are 22-26 mm (staphylococci or E. coli) or 16-20mm (streptococci), and (c) resistant when their MIC is ≥ 8 μg/ml and their zone diameters are ≤ 21 mm (staphylococci or E. coli) or ≤ 15 mm (streptococci). 相似文献
94.
95.
The filter paper method was used to establish the retentivity curves of single aggregates. Aggregates (diameter 3-4 cm) from an Alfisol (sandy loam) and a Mollisol (sandy clay) were used. The aggregates had different water contents. Whatman No. 42 filter paper, attached to a conical plastic tube on the end of a rod, was inserted into a hole made in the aggregate. The hole was made using a small corer. The aggregates were sealed in wax, put into a plastic bag and stored in a thermo-constant room to equilibrate. After seven days the water content of the aggregates and of the filter papers were determined at 105°C. Retentivity curves for the aggregates are presented and sources of error are discussed. 相似文献
96.
Fernández García A Butz P Trierweiler B Zöller H Stärke J Pfaff E Tauscher B 《Journal of agricultural and food chemistry》2003,51(27):8093-8097
Peptides containing the cyclic product of glutamine at the N terminus are usually biologically active. If the cyclization of glutamine was associated with a volume reduction, pressure should displace the equilibrium in the direction of the lower volume. Here, results in model solutions and in whey are discussed, showing that the theorized cyclization of glutamine in Gln-His-ProNH(2) or Gln-Leu-ProNH(2) is significantly accelerated during the application of heat and even more strongly when elevated temperature and pressure combinations are used. The reaction rate depended on the intensity of the pressure treatment, the pH, and the nature of the amino acids adjacent to glutamine. The products of the reaction were identified as thyrotropin-releasing hormone (TRH) and [Leu(2)]TRH. The reported reactions could affect the naturally balanced concentration of short-chain peptides in foods and therefore induce unpredictable biological effects. 相似文献
97.
Gross T Siepmann A Sturm D Windgassen M Scarcelli JJ Seedorf M Cole CN Krebber H 《Science (New York, N.Y.)》2007,315(5812):646-649
In eukaryotes, termination of messenger RNA (mRNA) translation is mediated by the release factors eRF1 and eRF3. Using Saccharomyces cerevisiae as a model organism, we have identified a member of the DEAD-box protein (DBP) family, the DEAD-box RNA helicase and mRNA export factor Dbp5, as a player in translation termination. Dbp5 interacts genetically with both release factors and the polyadenlyate-binding protein Pab1. A physical interaction was specifically detected with eRF1. Moreover, we show that the helicase activity of Dbp5 is required for efficient stop-codon recognition, and intact Dbp5 is essential for recruitment of eRF3 into termination complexes. Therefore, Dbp5 controls the eRF3-eRF1 interaction and thus eRF3-mediated downstream events. 相似文献
98.
Rüdiger Fründ Georg Guggenberger Konrad Haider Heike Knicker Ingrid Kgel-Knabner Hans-Dietrich Lüdemann Jrg Luster Wolfgang Zech Michael Spiteller 《植物养料与土壤学杂志》1994,157(3):175-186
Non destructive spectroscopic methods such as 13C- and 15N-NMR provide new insights into the structure of humic substances. Solid state NMR is capable of studying complete native soils by the CPMAS-technique. By means of nitrogen 15-enriched composts it is suggested that nitrogen in soil organic matter is mainly located in amide and peptide structures. Most probable assignments are given. The investigation of humification processes in forest soils is possible via an approach which uses several fractionation techniques in combination with degradative and non-degradative analytical techniques. Besides structure analysis, the 13C-NMR-spectroscopy provides important information about the functions of humic substances. By using 13C-enriched xenobiotics the binding mechanism to organic matter can be elucidated on a molecular basis. Molecular fluorescence spectrometry, a non-invasive method, is a powerful tool for the quantitative characterization of metal ion complexation by dissolved organic matter in aqueous leaf litter extracts in terms of conditional stability constants and metal binding capacities. 相似文献
99.
100.
Heike Hoffmann Michael Schloter Berndt-Michael Wilke 《Biology and Fertility of Soils》2007,44(2):411-413
To improve our knowledge about the effect of soil structure on potential nitrification (PN) rates in different soil aggregate
fractions, we adapted and validated the standard method based on International Organization of Standardization (ISO) 15685
to small sample volumes. This assay was used to determine the distribution of PN in soil aggregates obtained from three different
sites (natural grassland, agricultural land and forest). Overall, the external surface layers of the aggregates showed higher
PN rates than the interior fractions of the aggregates. These differences were more clear in clayey than in sandy soils. 相似文献