Aquatic parameters and life history observations of the Great Basin spadefoot toad in Utah

The distribution and breeding habitats of the Great Basin spadefoot toad ( Scaphiopus intermontanus ) were investigated in the Bonneville Basin of western Utah. The permanent springs and man-made reservoirs used for breeding were largely found below the 1600 m elevation. The pH's ranged between 7.2 and 10.4 and the total dissolved solids between 170 and 4800 mg/l. The springs were less alkaline than the rain-filled reservoirs. The lack of aquatic vegetation was a common feature of the reservoirs and most of the springs. Observations of breeding without rain are noted as well as the lack of breeding with rain. The snout – vent lengths of adult spadefoots are greater in the Bonneville Basin than in other parts of the Great Basin. Utilization of permanent water sources and stimuli for emergence and breeding, as well as the larger adult size of S. intermontanus in the Bonneville Basin, are discussed in relation to the diverse precipitation patterns, the sparseness of the water sources, and the Holocene history of the Great Basin.      

硅钢脱碳工艺研究

通过对硅钢退火原理的分析，研究了影响硅钢退火的因素，指出调整炉内气氛，改进脱碳工艺，可以达到提高产品质量的目的。     

低次烟叶的烘焙技术研究

为探索一种新的处理低次烟叶的加工方法,提升烟叶的使用价值,通过设计低、中、高3种烘焙强度,从过程水分、物理指标、常规化学成分、香味成分及感官质量5个方面系统分析了在3种烘焙强度处理下烟丝的质量状况,同时,研究了单糖施加对低次烟叶烘焙处理的效果。试验结果表明,烤烟烘焙处理强度应低于白肋烟,且单糖能改善烘焙后低次烟叶的质量,低强度条件下烘焙后烟丝的质量较原料样显著提升。     

Deficiency of PORCN, a regulator of Wnt signaling, is associated with focal dermal hypoplasia

Focal dermal hypoplasia (FDH) is an X-linked dominant multisystem birth defect affecting tissues of ectodermal and mesodermal origin. Using a stepwise approach of (i) genetic mapping of FDH, (ii) high-resolution comparative genome hybridization to seek deletions in candidate chromosome areas and (iii) point mutation analysis in candidate genes, we identified PORCN, encoding a putative O-acyltransferase and potentially crucial for cellular export of Wnt signaling proteins, as the gene mutated in FDH. The findings implicate FDH as a developmental disorder caused by a deficiency in PORCN.     

二粒子体系自旋最大纠缠态的类型分析

针对曾谨言等[1]由二体算符ó1αó2β构成自旋力学量完全集的3种基本形式,文章由局域酉变换不变量出发,给出自旋1/2的二粒子体系纯态纠缠态的分类,结果表明有四种基本形式,进一步发现由同一纠缠形式叠加态的纠缠度不变.     

论高等院校足球选项课中的运动损伤与预防

对高等院校足球选项课中运动损伤进行了调查和研究,从运动解剖学、运动生理学、运动医学诸方面分析讨论了运动损伤的原因与规律,提出了预防运动损伤发生的措施和办法。     

X-ray structure of NS1 from a highly pathogenic H5N1 influenza virus

The recent emergence of highly pathogenic avian (H5N1) influenza viruses, their epizootic and panzootic nature, and their association with lethal human infections have raised significant global health concerns. Several studies have underlined the importance of non-structural protein NS1 in the increased pathogenicity and virulence of these strains. NS1, which consists of two domains-a double-stranded RNA (dsRNA) binding domain and the effector domain, separated through a linker-is an antagonist of antiviral type-I interferon response in the host. Here we report the X-ray structure of the full-length NS1 from an H5N1 strain (A/Vietnam/1203/2004) that was associated with 60% of human deaths in an outbreak in Vietnam. Compared to the individually determined structures of the RNA binding domain and the effector domain from non-H5N1 strains, the RNA binding domain within H5N1 NS1 exhibits modest structural changes, while the H5N1 effector domain shows significant alteration, particularly in the dimeric interface. Although both domains in the full-length NS1 individually participate in dimeric interactions, an unexpected finding is that these interactions result in the formation of a chain of NS1 molecules instead of distinct dimeric units. Three such chains in the crystal interact with one another extensively to form a tubular organization of similar dimensions to that observed in the cryo-electron microscopy images of NS1 in the presence of dsRNA. The tubular oligomeric organization of NS1, in which residues implicated in dsRNA binding face a 20-A-wide central tunnel, provides a plausible mechanism for how NS1 sequesters varying lengths of dsRNA, to counter cellular antiviral dsRNA response pathways, while simultaneously interacting with other cellular ligands during an infection.