Mutations in WDR62, encoding a centrosome-associated protein, cause microcephaly with simplified gyri and abnormal cortical architecture

Genes associated with human microcephaly, a condition characterized by a small brain, include critical regulators of proliferation, cell fate and DNA repair. We describe a syndrome of congenital microcephaly and diverse defects in cerebral cortical architecture. Genome-wide linkage analysis in two families identified a 7.5-Mb locus on chromosome 19q13.12 containing 148 genes. Targeted high throughput sequence analysis of linked genes in each family yielded > 4,000 DNA variants and implicated a single gene, WDR62, as harboring potentially deleterious changes. We subsequently identified additional WDR62 mutations in four other families. Magnetic resonance imaging and postmortem brain analysis supports important roles for WDR62 in the proliferation and migration of neuronal precursors. WDR62 is a WD40 repeat-containing protein expressed in neuronal precursors as well as in postmitotic neurons in the developing brain and localizes to the spindle poles of dividing cells. The diverse phenotypes of WDR62 suggest it has central roles in many aspects of cerebral cortical development.     

基于图像质量控制的视频转码技术

为了满足数字视频广播传输过程中对视频质量稳定性的要求,提出一种使视频质量保持在所需范围,并且满足带宽限制的应用方案。该方法使用离散余弦变换系数的均方差来评价图像质量损失,并建立二次量化参数与图像质量损失之间的对应关系模型,动态选择二次量化参数。该方法将视频质量作为主要控制对象,在转码过程中实时评估和控制图像质量损失,使得转码输出的视频质量保持平稳。与传统的像素域质量评估方法相比,全部操作可在频域完成,因而计算量小,调整速度快。仿真实验表明:该方法可有效地控制转码视频的质量损失。     

The DNA sequence and biological annotation of human chromosome 1

The reference sequence for each human chromosome provides the framework for understanding genome function, variation and evolution. Here we report the finished sequence and biological annotation of human chromosome 1. Chromosome 1 is gene-dense, with 3,141 genes and 991 pseudogenes, and many coding sequences overlap. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Fine-scale recombination occurs in hotspots of varying intensity along the sequence, and is enriched near genes. These and other studies of human biology and disease encoded within chromosome 1 are made possible with the highly accurate annotated sequence, as part of the completed set of chromosome sequences that comprise the reference human genome.     

Symbos cavifrons (Artiodactyla: Bovidae) from Delta County, Colorado

A partial cranium belonging to the extinct woodland musk - ox, Symbos cavifrons, is reported from the headwaters of Oak Creek, Delta County, Colorado. This is the first cranium of the genus Symbos to be described from the Colorado Plateau, and it helps to define the southwest boundary of the known range of the genus.         

论民族师专大学生人格“成人”教育

民族地区的师范专科学校教育在我国教育事业和民族地区社会经济、文化教育的发展中承担着重要的任务。民族地区的地理条件、经济发展状况、人民的生产和生活水平等均影响着学生的发展，同时每一个学生又现实地面临着就业的竞争压力，民族地区的师范专科学校教育必须正确认识到学生在人格形成和发展过程中存在的特殊性和差异性，从而符合实际地提升学生人格的境界，塑造学生健全的人格，加快受教育者社会化的进程，才能提高学生的竞争力．才能为每一个受教育者的尽可能全面的发展做好必须的准备。     

飞行仿真转台模糊神经网络补偿的复合控制

针对飞行仿真转台系统的非线性和不确定性,提出了基于模糊神经网络补偿的复合控制器,该控制器由前馈控制器、闭环控制器及模糊神经网络补偿环节组成。前馈环节由零相差跟踪控制器及FIR滤波器构成,闭环控制器由PD控制及干扰观测器构成,补偿环节由一动态模糊神经网络实现,给出了基于Lyapunov函数的稳定性证明。该控制方法突出优点在于兼顾考虑了系统中的结构化不确定性和非结构化不确定性,能够在外部干扰与参数摄动并存的情况下,保证系统的稳定性和跟踪性能。     

New protein fold revealed by a 2.3-A resolution crystal structure of nerve growth factor

Nerve growth factor (NGF) is a member of an expanding family of neurotrophic factors (including brain-derived neurotrophic factor and the neurotrophins) that control the development and survival of certain neuronal populations both in the peripheral and in the central nervous systems. Its biological effects are mediated by a high-affinity ligand-receptor interaction and a tyrosine kinase signalling pathway. A potential use for NGF and its relatives in the treatment of neurological disorders such as Alzheimer's disease and Parkinson's disease requires an understanding of the structure-function relationships of NGF. NGF is a dimeric molecule, with 118 amino acids per protomer. We report the crystal structure of the murine NGF dimer at 2.3-A resolution, which reveals a novel protomer structure consisting of three antiparallel pairs of beta strands, together forming a flat surface. Two subunits associate through this surface, thus burying a total of 2,332 A. Four loop regions, which contain many of the variable residues observed between different NGF-related molecules, may determine the different receptor specificities. A clustering of positively charged side chains may provide a complementary interaction with the acidic low-affinity NGF receptor. The structure provides a model for rational design of analogues of NGF and its relatives and for testing the NGF-receptor recognition determinants critical for signal transduction.     

The peritoneal fluid cytology of the adult female rhesus monkey

Résumé Le % de distribution des cellules de fluide péritonéal d'une femelle adulte de singe rhésus fut enregistré dans des échantillons de fluide cytologique extraits par la paratomie. Les données sond comparées à celles qui ont obtenues précédemment chez la femme.