Newly identified loci that influence lipid concentrations and risk of coronary artery disease

To identify genetic variants influencing plasma lipid concentrations, we first used genotype imputation and meta-analysis to combine three genome-wide scans totaling 8,816 individuals and comprising 6,068 individuals specific to our study (1,874 individuals from the FUSION study of type 2 diabetes and 4,184 individuals from the SardiNIA study of aging-associated variables) and 2,758 individuals from the Diabetes Genetics Initiative, reported in a companion study in this issue. We subsequently examined promising signals in 11,569 additional individuals. Overall, we identify strongly associated variants in eleven loci previously implicated in lipid metabolism (ABCA1, the APOA5-APOA4-APOC3-APOA1 and APOE-APOC clusters, APOB, CETP, GCKR, LDLR, LPL, LIPC, LIPG and PCSK9) and also in several newly identified loci (near MVK-MMAB and GALNT2, with variants primarily associated with high-density lipoprotein (HDL) cholesterol; near SORT1, with variants primarily associated with low-density lipoprotein (LDL) cholesterol; near TRIB1, MLXIPL and ANGPTL3, with variants primarily associated with triglycerides; and a locus encompassing several genes near NCAN, with variants strongly associated with both triglycerides and LDL cholesterol). Notably, the 11 independent variants associated with increased LDL cholesterol concentrations in our study also showed increased frequency in a sample of coronary artery disease cases versus controls.     

In situ Os isotopes in abyssal peridotites bridge the isotopic gap between MORBs and their source mantle

Abyssal peridotites are assumed to represent the mantle residue of mid-ocean-ridge basalts (MORBs). However, the osmium isotopic compositions of abyssal peridotites and MORB do not appear to be in equilibrium, raising questions about the cogenetic relationship between those two reservoirs. However, the cause of this isotopic mismatch is mainly due to a drastic filtering of the data based on the possibility of osmium contamination by sea water. Here we present a detailed study of magmatic sulphides (the main carrier of osmium) in abyssal peridotites and show that the 187Os/188Os ratio of these sulphides is of primary mantle origin and can reach radiogenic values suggesting equilibrium with MORB. Thus, the effect of sea water on the osmium systematics of abyssal peridotites has been overestimated and consequently there is no true osmium isotopic gap between MORBs and abyssal peridotites.     

Quantitative mapping of amplicon structure by array CGH identifies CYP24 as a candidate oncogene

We show here that quantitative measurement of DNA copy number across amplified regions using array comparative genomic hybridization (CGH) may facilitate oncogene identification by providing precise information on the locations of both amplicon boundaries and amplification maxima. Using this analytical capability, we resolved two regions of amplification within an approximately 2-Mb region of recurrent aberration at 20q13.2 in breast cancer. The putative oncogene ZNF217 (ref. 5) mapped to one peak, and CYP24 (encoding vitamin D 24 hydroxylase), whose overexpression is likely to lead to abrogation of growth control mediated by vitamin D, mapped to the other.     

纪念爱因斯坦的"奇迹年"(1905)100周年--2005世界物理学年(WYP)

在庆祝爱因斯坦的"奇迹年"(1905)100周年之际,2005年已被欧洲物理学会等机构称为"世界物理学年"(WYP).2005世界物理学年的一系列重大活动的目的在于提高公众的物理学意识并广泛普及物理学的知识.本文对2005世界物理学年进行了描述,讨论了1905年在科学史上的重要性,也简要介绍了2005世界物理学年的国际方案、美国物理学会与美国物理教师协会的国家目标及活动计划等.     

三原子准分子激光

本文描述了两种新的三原子稀有气体卤化物激光,即中心波长为520毫微米的Xe_2Cl激光和中心波长为436毫微米的Kr_2F激光.还给出了高气压Ar/Xe/CCl_4和Ar/Kr/NF_3混合气体的荧光和激光发射数据.     

Detection of polarization in the cosmic microwave background using DASI. Degree Angular Scale Interferometer

The past several years have seen the emergence of a standard cosmological model, in which small temperature differences in the cosmic microwave background (CMB) radiation on angular scales of the order of a degree are understood to arise from acoustic oscillations in the hot plasma of the early Universe, arising from primordial density fluctuations. Within the context of this model, recent measurements of the temperature fluctuations have led to profound conclusions about the origin, evolution and composition of the Universe. Using the measured temperature fluctuations, the theoretical framework predicts the level of polarization of the CMB with essentially no free parameters. Therefore, a measurement of the polarization is a critical test of the theory and thus of the validity of the cosmological parameters derived from the CMB measurements. Here we report the detection of polarization of the CMB with the Degree Angular Scale Interferometer (DASI). The polarization is deteced with high confidence, and its level and spatial distribution are in excellent agreement with the predictions of the standard theory.     

Rapid regulation of steroidogenesis by mitochondrial protein import

Most mitochondrial proteins are synthesized on cytoplasmic ribosomes and imported into mitochondria. The imported proteins are directed to one of four submitochondrial compartments--the outer mitochondrial membrane, the inner mitochondrial membrane, the intramembraneous space, or the matrix--where the protein then functions. Here we show that the steroidogenic acute regulatory protein (StAR), a mitochondrial protein required for stress responses, reproduction, and sexual differentiation of male fetuses, exerts its activity transiently at the outer mitochondrial membrane rather than at its final resting place in the matrix. We also show that its residence time at this outer membrane and its activity are regulated by its speed of mitochondrial import. This may be the first example of a mitochondrial protein exerting its biological activity in a compartment other than that to which it is finally targeted. This system enables steroidogenic cells to initiate and terminate massive levels of steroidogenesis within a few minutes, permitting the rapid regulation of serum steroid hormone concentrations.     

连续波强激光传输的研究

进行了千瓦级连续波ＣＯ２强激光传输的实验研究，传输距离分别为５０ｍ，８０ｍ和１００ｍ，接收到的远场花样中衍射次极大出现了不连续分布。通过远场强度分布的数值模拟对实验结果进行了定性的解释。研究结果为进一步深入研究提供了有益的资料。     

Surface plasmon subwavelength optics

Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.