Use of comparative proteomics to identify the effects of creatine pyruvate on lipid and protein metabolism in broiler chickens

Four hundred male chickens were selected to study the effects of pyruvate (Pyr), creatine pyruvate (CrPyr) and creatine (Cr) on the expression of hepatic mitochondrial and cytoplasm proteins associated with lipid and protein metabolism. Mitochondrial purification was accomplished using the two-step differential centrifugation and density gradient method, and the activities of organelle-specific marker enzymes were determined to assess the purity of the mitochondria. Proteins were extracted and fractionated by two-dimensional electrophoresis and the differential protein spots were assessed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. CrPyr reduced fatty acid accumulation by down-regulating adipose differentiation-related protein, inhibited ATP synthase expression, and reduced cholesteryl ester transfer protein (CETP) expression, thus reducing the levels of high density lipoprotein and triglycerol (TG) levels (thereby lowering fat and cholesterol deposition). CrPyr increased the expression of eukaryotic translation initiation factor (eIF) 2B, calreticulin (CRT) and eIF3a, thus promoting protein synthesis. CrPyr up-regulated the expression of fatty acid-binding proteins, CETP and apolipoprotein A-IV in cytoplasmic extracts, and these proteins accelerated the decomposition of fatty acids and TG, thus reducing fat deposition. In conclusion, CrPyr plays an important role in lipolysis and protein synthesis, and this effect was more pronounced than was the effect of Pyr and Cr.     

Distribution of red-spotted grouper nervous necrosis virus (RGNNV) antigens in nervous and non-nervous organs of European seabass (Dicentrarchus labrax) during the course of an experimental challenge

The distribution of red-spotted grouper nervous necrosis virus (RGNNV) antigens was examined by immunohistochemistry in the nervous and non-nervous organs of juvenile European seabass (Dicentrarchus labrax) during the course of an intramuscular infection. Histological changes resulting from the infection were evaluated from 3 days to 2 months post-infection. The specific antibody response was also studied 2 months post-challenge. Viral proteins were present throughout the experimental period in the retina (inner nuclear layer, ganglion layer, outer limiting membrane, and outer plexiform layer), brain (cerebellum and tectum opticum), and liver (hepatocytes and endothelial cells). These proteins were also observed in the renal tubular cells, white pulp of spleen, and in fibroblasts and cartilage of caudal fin. This is the first report of RGNNV proteins appearing in these organs, where the immunostaining was only detected at certain sampling times after the onset of mortality. Brain and retina of virus-exposed fish showed high levels of vacuolation, while accumulation of fat vacuoles was observed in the liver. RGNNV infection also induced a specific antibody response as measured by an ELISA. In summary, this is the first study demonstrating the presence of viral proteins in cells of caudal fin, kidney and spleen of European seabass.     

Density-Dependent Ecohydrological Effects of Piñon–Juniper Woody Canopy Cover on Soil Microclimate and Potential Soil Evaporation

Many rangeland processes are driven by microclimate and associated ecohydrological dynamics. Most rangelands occur in drylands where evapotranspiration normally dominates the water budget. In these water-limited environments plants can influence abiotic and biotic processes by modifying microclimate factors such as soil temperature and potential soil evaporation. Previous studies have assessed spatial variation in microclimate and associated ecohydrological attributes within an ecosystem (e.g., under vs. between woody canopies) or across ecosystems (e.g., with differing amounts of woody canopy cover), but generally lacking are assessments accounting systematically for both, particularly for evergreen woody plants. Building on recently quantified trends in near-ground solar radiation associated with a piñon–juniper gradient spanning 5% to 65% woody canopy cover, we evaluated trends in soil temperature and associated estimates of potential soil evaporation as a function of amount of woody canopy cover for sites overall and for associated canopy vs. intercanopy locations. Quantified soil temperature trends decreased linearly with increasing woody canopy cover for intercanopy as well as canopy patches, indicating the coalescing influence of individual canopies on their neighboring areas. Notably, intercanopy locations within high-density (65%) woody canopy cover could be as much as ～10°C cooler than intercanopy locations within low-density (5%) cover. Corresponding potential soil evaporation rates in intercanopies within high-density woody canopy cover was less than half that for intercanopies within low density. Our results highlight ecohydrological consequences of density-dependent shading by evergreen woody plants on soil temperature and potential soil evaporation and enable managers to rapidly estimate and compare approximate site microclimates after assessing amounts of woody canopy cover. Such predictions of microclimate have general utility for improving management of rangelands because they are a fundamental driver of many key processes, whether related to understory forage and herbaceous species or to wildlife habitat quality for game or nongame species.     

大溪河鸭江镇河段综合治理工程对当地水环境的影响研究

指出了大溪河受到喀斯特地貌的影响,存在着水资源短缺问题,分析了大溪河鸭江镇河段综合治理工程的目的、意义和工程的背景,并探讨了该工程对当地水环境保护的影响。     

不同温度条件对蠋蝽生长发育的影响

在室内环境下,对不同温度条件下蠋蝽的各项生长发育指标进行了测试,结果表明:不同温度处理对蠋蝽卵的孵化率、幼虫存活率以及雌虫产卵量都没有显著影响,但对蠋蝽发育历期以及成虫存活率等影响显著,其中蠋蝽发育历期在20℃时需要42.3 d,而在30℃时只需29.0 d。     

内蒙古柴河林业局森林资源现状及分布特点

文章分析了柴河林业局森林资源现状及其特点。     

DDGS对麻黄肉鸡生长性能的影响

试验选取32日龄的麻黄肉鸡1200只,随机分成4组,每组5个重复,每个重复60只鸡。饲粮分别添加0%,2%,4%,6%的DDGS,试验期为36 d。试验结果表明,日粮中添加0%、4%、6%、8%的DDGS对黄羽肉鸡的生长性能均无显著影响(P>0.05)。但4%添加组料肉比最低。综合考虑饲料成本及经济效益等因素,本试验条件下,以DDGS添加量为4%的效益最好。     

Effect of human disturbance on the structure and regeneration of forests in the Nevado de Toluca National Park, Mexico

Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those dominated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnus jorullensis forests were increasing due to the disturbance of Pinus and Quercus forests, as well abandoned crop lands within the park. A combination of logging, uncontrolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early successional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised.     

Comparison of P and cation cycling in two contrasting seasonally dry forest ecosystems

Context

Interactions of N and P cycles and those of other macro-elements in forests are scarcely known.

Aim

This study compares the P cycle in two very different forest ecosystems where soil P availability is low (tropical dry forest in Mexico and Mediterranean forest in Spain) in relation to Ca, K, and Mg cycles.

Methods

Compiled data belonging to these two forest sites are discussed, comparing the P and base cation budgets and exploring relationships among P and base cation cycles.

Results

Broad differences between input and output of base cations were observed. Analysis of the P budget indicates P retention inside both forest ecosystems. The tropical dry forest has higher nutrient contents than those found in the Mediterranean temperate forest. Chemical composition of forest leaves and litters, and base cation?CP ratios varied according to soil P availability and cation concentrations. However, P resorption is higher in the tropical dry forest than in the temperate one.

Conclusion

This study reveals the existence of P retention at the ecosystem level in both forests, but suggested P limitation at the Mediterranean forest seems to be stronger than that occurring at the tropical forest.     

钨酸钠-磷钼酸比色分光光度法测定饲料中的单宁

试验研究了用丙酮溶液提取饲料中单宁,溶液经过滤后,取滤液加钨酸钠-磷钼酸混合溶液,显色后,在760 nm波长处测定吸光度值,标准曲线法测定饲料中单宁含量。单宁在0.50～6.00 mg/l浓度范围内与吸光度值呈良好的线性关系,线性回归方程为A=0.056 48×C+0.001 08,相关系数为0.999 7,方法的检出限为17.5 mg/kg。该方法操作简便、快速、结果准确,应用于饲料中单宁的测定,结果满意。