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<正>近期伊利诺伊大学的J.A.Almeida博士、 Hans H.Stein博士以及Carsten Pedersen博士联手展开体重对于标准化回肠蛋白质和氨基酸吸收率的影响试验,结论证明,20 kg以下的仔猪回肠对于粗蛋白和氨基酸的吸收率比20~50 kg的育成猪和50~110 kg的育肥猪低。而且同一猪群的不同猪只也表现出吸收率的差异性。例如,在测定的300只仔猪中粗蛋白和氨基酸的吸收率 相似文献
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Hidden allergens are a common problem in food safety that has been known for many years. This is why the European Parliament adopted Directive 2003/89/EC amending 2000/13/EC. In addition to specific ingredients, Directive 2003/89/EC also requests the declaration of specific products that were used in the production and could be a risk for allergic individuals. This also includes the declaration of fining agents and lysozyme used in wines. In fact, it could be assumed that fining agents would be almost completely removed during the manufacturing process; however, until now there has been no necessity to analyze wine for these fining agents. By applying enzyme-linked immunosorbent assay (ELISA), residuals of fining agent proteins and the stabilizer lysozyme were investigated in various German wines. The results showed no detectable amounts of fining agents in wines, except for dried egg white and lysozyme, both derived from hen's egg white. For those products, adverse reactions against treated wines could not be excluded. 相似文献
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Effects of forest management (thinning) on gross ammonification, net ammonification, net nitrification, microbial biomass, and N2O production were studied in the forest floor of adjacent untreated control (“C”) and thinned (“T”) plots in three beech (Fagus sylvatica L.) stands in the Swabian Jura (Southern Germany) during three intensive field campaigns in the year 2004. The investigated sites are located less than 1 km apart on the slopes of a narrow valley. Due to different exposure (southwest, northeast, northwest), the three sites are characterized by warm‐dry microclimate (southwest site, SW) and cool‐moist microclimate (northeast site, NE; and northwest site, NW). Measurements at the NW site covered the second year (13 to 20 months) after thinning, and measurements at the SW and NE sites covered the sixth year (61 to 68 months) after thinning. Mean gross ammonification varied insignificantly across the six plots (range: 37.5 ? 31.2 to 51.0 ? 10.5 mg N (kg dry soil)–1 d–1). The SW site was characterized by very low net nitrification and nitrate (NO ) concentrations that were not significantly different between control and thinned plot. In contrast, for the thinned plot at the NE site (NET), significantly increased mean net nitrification (2.3 ? 1.2 mg N (kg dry soil)–1 d–1 at the NET plot vs. 0.4 ? 0.2 mg N (kg dry soil)–1 d–1 at the NEC plot) and mean extractable NO concentrations (43.9 ? 22.8 mg N (kg dry soil)–1 at the NET plot vs. 4.1 ? 0.8 mg N (kg dry soil)–1 at the NEC plot) were observed. The differences in net nitrification and NO concentrations across the research plots were related to differences in the forest‐floor C : N ratios: net nitrification increased exponentially below a threshold C : N value of about 25. The results of this study indicate that the forest floor of the warm‐dry SW site is very resistant to N loss triggered by thinning due to high C : N ratios around 30. Under the cool‐moist microclimate of the NE site, a significantly lower C : N ratio of 22.1 at the thinned plot (control plot: 26.7) coincided with significantly increased net nitrification. Thus, different responses of net nitrification to thinning under different microclimate appear to be triggered by different C : N ratios. Nitrous oxide production was mainly governed by forest‐floor water content, and since differences in water content at adjacent control and thinned plots were low, N2O production was not significantly different between adjacent control and thinned plots. 相似文献
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Schmucker Julia Uhl Enno Steckel Mathias Pretzsch Hans 《European Journal of Forest Research》2022,141(4):587-604
European Journal of Forest Research - Rare domestic tree species are increasingly being viewed as promising alternatives and additions to current main tree species in forests facing climate change.... 相似文献
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Pretzsch Hans Poschenrieder Werner Uhl Enno Brazaitis Gediminas Makrickiene Ekaterina Calama Rafael 《European Journal of Forest Research》2021,140(5):1295-1296
European Journal of Forest Research - 相似文献
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Thermal stratification negatively affects water quality, and thus is a threatto fish culture in deep water ponds and reservoirs. To prevent and controlit, a device based on an underwater propeller that vertically transportsoxygen rich warm water from the epilimnion down to the anoxic and colderhypolimnion was assembled. The empirical results so far obtained in Israelidual purpose reservoirs for field crop irrigation and fish culture aresummarized herein, and a mathematical model of the device's effect onreservoir thermal structure is presented. 相似文献