The landscape of cancer genes and mutational processes in breast cancer

All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease.     

模拟结果为什么比实际更暖:简化气候模型结果（英文）

设计了一个非专业人士能够使用、最简化的气候敏感模型,用来研究人类活动所导致的全球变暖的幅度问题.在1990年的第一次IPCC评估报告中,IPCC对其报告中预测的未来全球变暖幅度很有信心,但是随后的观测结果显示全球的变暖幅度只有预测的一半.而自2001年起,全球变暖出现停滞,但是仅仅考虑到二氧化碳浓度的增加,很少有模型能够模拟出这一变化.在已出版的IPCC第五次评估报告的草稿中,IPCC大幅度削减了近期变暖的幅度,并以专家评估代替了模型预测.但是报告中关于未来气候长期变化的预测仍被保留.如果把IPCC模型的总反馈从1.9 W m–2 K–1调整到1.5 W m–2 K–1,气候敏感模型中模拟的温度将从3.2 K降至2.2 K.同时由于反馈很可能是净负反馈,更合适的估计应该是1.0 K.1.0 K是一个能够实现的增幅,21世纪的实际变暖将会小于1 K.即使燃烧所有可开采的化石燃料也不会使全球变暖的幅度超过2.2 K,这一增加幅度也将趋于平稳.本文认为解决IPCC第四、五次报告中评估方法的差异非常关键.一旦这些差异得到解决,人类活动导致的全球变暖在22世纪以及几个世纪以后的平稳态将有可能不会超过IPCC当前模型预测的1/3~1/2.     

Resistance to positional noise in human vision

Human eyes are in constant and rapid motion even when observers try to maintain steady fixation. Also, the visual system has a sluggish temporal response. In combination, these two factors would be expected to blur stimuli and reduce spatial sensitivity. But observers are able to detect a difference in separation of a few seconds of arc between two closely spaced parallel lines. Here we report that even very large amounts of positional jitter of the line pair has minimal impact on this ability. This result is in marked contrast to the deterioration observed when targets are swept linearly across the retina, but is consistent with a system that must ignore oculomotor jitter. To explain these results will require a re-evaluation of current models of position coding in human vision.     

GABAA responses in hippocampal neurons are potentiated by glutamate

In the mammalian cortex, glutamate and gamma-aminobutyric acid (GABA) are the principal transmitters mediating excitatory and inhibitory synaptic events. Glutamate activates cation conductances that lead to membrane depolarization whereas GABA controls chloride conductances that produce hyperpolarization. Here we report that the GABAA-activated conductance in hippocampal pyramidal cells is enhanced by glutamate at concentrations below that required for its excitatory action. The GABA-potentiating effect can be induced, with comparable potency, by several glutamate analogues such as quisqualate, N-methyl-D-aspartate (NMDA), kainate and, surprisingly, by D-2-amino-5-phosphonovalerate (APV), an antagonist for NMDA receptors. Data from dose-response curves show that glutamate enhances the GABAA conductance without significantly changing GABA binding affinity. The low concentration of glutamate needed to enhance GABAA responses raises the possibility that glutamate modulates the strength of GABA-mediated transmission in the cortex.     

Gene polymorphism in Netherton and common atopic disease.

Atopic dermatitis (AD) and asthma are characterized by IgE-mediated atopic (allergic) responses to common proteins (allergens), many of which are proteinases. Loci influencing atopy have been localized to a number of chromosomal regions, including the chromosome 5q31 cytokine cluster. Netherton disease is a rare recessive skin disorder in which atopy is a universal accompaniment. The gene underlying Netherton disease (SPINK5) encodes a 15-domain serine proteinase inhibitor (LEKTI) which is expressed in epithelial and mucosal surfaces and in the thymus. We have identified six coding polymorphisms in SPINK5 (Table 1) and found that a Glu420-->Lys variant shows significant association with atopy and AD in two independent panels of families. Our results implicate a previously unrecognized pathway for the development of common allergic illnesses.