饲用酸化剂对1～63日龄黄羽肉鸡生长性能的影响

本试验旨在评估饲用酸化剂对1~63日龄黄羽肉鸡生长性能、肠道损伤和盲肠微生物菌群变化的影响,同时探讨壳寡糖对饲用酸化剂的增效作用。试验采用单因素完全随机区组设计,设对照组(Con.)、饲用酸化剂(Trt.1)和饲用酸化剂+壳寡糖(Trt.2)共3个处理。每个处理5个重复,每个重复50羽。饲养周期为63天。试验结果表明,从零日龄开始持续在黄羽肉鸡日粮中添加饲用酸化剂、饲用酸化剂+壳寡糖后,对1~21d和22~42d阶段黄羽肉鸡生长性能的影响未达显著(P0.05)水平;但在43~63d阶段时,与对照组相比,添加饲用酸化剂、饲用酸化剂+壳寡糖组的耗料增重比分别降低0.11和0.14,具有极大的生产意义;且饲用酸化剂添加组盲肠大肠杆菌/乳酸杆菌值显著(P0.05)低于对照组,饲用酸化剂+壳寡糖添加组盲肠大肠杆菌/乳酸杆菌值显著(P0.05)低于对照组和饲用酸化剂添加组。说明饲用酸化剂可通过维持肠道健康,促进养分消化吸收,从而提高饲料利用率;而壳寡糖在平衡肠道菌群、维持肠道健康方面对饲用酸化剂有增效作用。     

Nutrient starvation affects expression of LC3 family at the feto-maternal interface during murine placentation

LC3 − the mammalian homolog of Atg8 − was found as autophagosome membrane binding protein in mammals and widely used as an autophagosomal marker. LC3A, B and C show different expression patterns in each tissue. The aim of this study was to reveal the differences of expression patterns among LC3 families in mouse placenta under normal condition and nutrient starving condition. LC3A and B were highly expressed in decidual cells. LC3A and B were increased in D14 compared with D12 and D16 in mouse placenta, while LC3C was decreased. Starvation induced increase in LC3B expression specifically. Immunohistochemistry showed different expression patterns among LC3A, B and C. LC3A expression in syncytiotrophoblast was vanished by starvation. The results of real time RT-PCR suggested differences between D12 and D16 in autophagic cascade induced by starvation. Taken together, this study suggests that autophagy could play a role in placental invasion system and that nutrient starvation affects LC3B expression.     

哀牢山保护区景东片区中山湿性常绿阔叶林特点研究

哀牢山位于云南省中部,保护区分布在哀牢山的中上部,其中景东片区面积为11 812hm2,位于哀牢山西坡北段。此次我们在哀牢山保护区主要保护对象之一的中山湿性常绿阔叶林中设置了样地,开展详细调查,并对调查数据进行了计算、统计、分析。通过各个样本乔木层、灌木层、草本层的H’值比较,发现乔木层﹥灌木层﹥草本层,表明乔木层的信息量大于灌木层,而草本层是该结构中相对较低的。     

Localization of putative pituitary stem/progenitor cells in female dairy cattle

Research on sex-determining region Y-box 2 (SOX2)-positive pituitary stem/progenitor cells, as a source of hormone-producing cells, is progressing rapidly in rodents. However, the stem/progenitor cells supplying hormone-producing cells that are essential for growth, reproduction, and lactation in bovines have not yet been identified. In this study, we characterized SOX2-positive cells in the pituitary gland of dairy cattle (Holstein heifers) after sexual maturity. Immunofluorescence analysis revealed that the localization pattern of SOX2-positive cells in the dairy cattle pituitary gland was similar to that observed in the rodent pituitary gland; the marginal cell layer (MCL), dense cell clusters, and single cells scattered in the parenchyma of the anterior lobe. Furthermore, most of the SOX2-positive cells were positive for the pituitary stem/progenitor cell niche markers E-cadherin and cytokeratin 8+18, which have been reported in rodents. In addition, in the MCL of the anterior lobe, there was a subpopulation of SOX2-positive cells positive for paired-related homeobox 1 and 2, whereas negative for S100β. Moreover, in the parenchyma of the anterior lobe, co-localization of SOX2 and pituitary hormones was infrequent. In summary, this study reveals the localization of putative pituitary stem/progenitor cells positive for SOX2 in dairy cattle. These results provide valuable information to support further investigation of cell supply in the dairy cattle pituitary gland.     

Status of Biological Studies and Aquaculture Development of the Mud Crab, <Emphasis Type="Italic">Scylla serrata</Emphasis>, in China: An Experimental Ecological Studies

This is an initial paper in a series of overviews of biological research and aquaculture development of the mud crab, Scylla serrata, in China. Results of experimental ecological studies on mud crabs are reported here. As a result of these experimental studies, results that are important for mud crab culture were also discovered and these include, methods to condition and manage broodstock, determination of ecological conditions that are suitable for embryonic development, and the influence of temperature, salinity, diet and larval density on development and survival of larvae. Results of this work will be useful in establishing a good method for artificial mass culture of larvae.     

华山松腐烂病发生危害与相关因子的初步研究

 调查研究表明:华山松腐烂病的发生危害与树龄、混交比、郁闭度等11方面的因子有关,将有助于华山松腐烂病发生、发展规律的研究和防治工作的开展。     

科尔沁沙地小叶杨和杂交杨一些生理生态特性的比较研究

采用ＡＰ４气孔计和ＰＶ曲线研究了小叶杨和杂交杨气孔导率和水分状况在不同季节的变化特征，结果表明：（１）在干旱的５、６月份，小叶杨的气孔导率远远高于杂交杨；在湿润的７月又低于杂交场；在生长近结束的８月底二者气地度近等；（２）小叶杨和杂交杨各在干旱的５月渗透调节抗旱能力相差不多，以后各月杂交杨则高于小叶杨，６月最明显；随着植物枝条木质化程度的提高，二者渗透调节能力和抗旱性均呈上升趋势。     

文化意象的传递和翻译

文化意象的差异往往导致传递过程中的语义缺省和冲突.本文就文化意象的传递和翻译问题进行了探讨,强调译者应提高跨文化意识,结合异化和归化两种互惠互补的翻译策略,实现文化传真.