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A new coupled global NCEP Reanalysis for the period 1979-present is now available, at much higher temporal and spatial resolution, for climate studies. T he first reanalysis at NCEP (all acronyms are defined in the appendix), conducted in the 1990s, resulted in the NCEP-NCAR reanalysis (Kalnay et al. 1996), or R1 for brevity, and ultimately covered many years, from 1948 to the present (Kistler et al. 2001). It is still being executed at NCEP, to the benefit of countless users for monthly, and even daily, updates of the current state of the atmosphere. At the same time, other reanalyses were being conducted, namely, ERA-15 (Gibson et al. 1997) was executed for a more limited period (1979-93) at the ECMWF, COLA conducted a short reanalysis covering the May 1982-November 1983 period (Paolino et al. 1995), and NASA GSFC conducted a reanalysis covering the 1980-94 period (Schubert et al. 1997). The general purpose of conducting reanalyses is to produce multiyear global state-of-the-art gridded representations of atmospheric states, generated by a constant model and a constant data assimilation system. To use the same model and data assimilation over a very long period was the great advance during the 1990s, because gridded datasets available before 1995 had been created in real time by ever-changing models and analysis methods, even by hand analyses prior to about 1965. The hope was that a reanalysis,

The genome is extensively transcribed into long intergenic noncoding RNAs (lincRNAs), many of which are implicated in gene silencing1,2. Potential roles of lincRNAs in gene activation are much less understood3,4,5. Development and homeostasis require coordinate regulation of neighboring genes through a process termed locus control6. Some locus control elements and enhancers transcribe lincRNAs7,8,9,10, hinting at possible roles in long range control. In vertebrates, 39 Hox genes, encoding homeodomain transcription factors critical for positional identity, are clustered in four chromosomal loci; the Hox genes are expressed in nested anterior-posterior and proximal-distal patterns co-linear with their genomic position from 3′ to 5′of the cluster11. Here we identify HOTTIP, a lincRNA transcribed from the 5′ tip of the HOXA locus that coordinates the activation of multiple 5′ HOXA genes in vivo. Chromosomal looping brings HOTTIP into close proximity to its target genes. HOTTIP directly binds the adaptor protein WDR5 and targets WDR5/MLL complexes across HOXA, driving histone H3 lysine 4 trimethylation and gene transcription. Induced proximity is necessary and sufficient for HOTTIP activation of its target genes. Thus, by serving as key intermediates that transmit information from higher order chromosomal looping into chromatin modifications, lincRNAs may organize chromatin domains to coordinate long-range gene activation.

Residents of the Tibetan Plateau show heritable adaptations to extreme altitude. We sequenced 50 exomes of ethnic Tibetans, encompassing coding sequences of 92% of human genes, with an average coverage of 18X per individual. Genes showing population-specific allele frequency changes, which represent strong candidates for altitude adaptation, were identified. The strongest signal of natural selection came from EPAS1, a transcription factor involved in response to hypoxia. One SNP at EPAS1 shows a 78% frequency difference between Tibetan and Han samples, representing the fastest allele frequency change observed at any human gene to date. This SNP’s association with erythrocyte abundance supports the role of EPAS1 in adaptation to hypoxia. Thus, a population genomic survey has revealed a functionally important locus in genetic adaptation to high altitude.

We report a surface segregation approach to synthesize high quality graphenes on Ni under ambient pressure. Graphenes were segregated from Ni surfaces by carbon dissolving at high temperature and cooling down with various cooling rates. Different segregation behaviors were identified, allowing us to control the thickness and defects of graphene films. Electron microscopy and Raman spectroscopy studies indicated that these graphenes have high quality crystalline structure and controllable thickness. Graphenes were transferred to insulating substrates by wet etching and were found to maintain their high quality.

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A thermal light-emitting source, such as a black body or the incandescent filament of a light bulb, is often presented as a typical example of an incoherent source and is in marked contrast to a laser. Whereas a laser is highly monochromatic and very directional, a thermal source has a broad spectrum and is usually quasi-isotropic. However, as is the case with many systems, different behaviour can be expected on a microscopic scale. It has been shown recently that the field emitted by a thermal source made of a polar material is enhanced by more than four orders of magnitude and is partially coherent at a distance of the order of 10 to 100nm. Here we demonstrate that by introducing a periodic microstructure into such a polar material (SiC) a thermal infrared source can be fabricated that is coherent over large distances (many wavelengths) and radiates in well defined directions. Narrow angular emission lobes similar to antenna lobes are observed and the emission spectra of the source depends on the observation angle--the so-called Wolf effect. The origin of the coherent emission lies in the diffraction of surface-phonon polaritons by the grating.

The cell division axis determines the future positions of daughter cells and is therefore critical for cell fate. The positioning of the division axis has been mostly studied in systems such as embryos or yeasts, in which cell shape is well defined. In these cases, cell shape anisotropy and cell polarity affect spindle orientation. It remains unclear whether cell geometry or cortical cues are determinants for spindle orientation in mammalian cultured cells. The cell environment is composed of an extracellular matrix (ECM), which is connected to the intracellular actin cytoskeleton via transmembrane proteins. We used micro-contact printing to control the spatial distribution of the ECM on the substrate and demonstrated that it has a role in determining the orientation of the division axis of HeLa cells. On the basis of our analysis of the average distributions of actin-binding proteins in interphase and mitosis, we propose that the ECM controls the location of actin dynamics at the membrane, and thus the segregation of cortical components in interphase. This segregation is further maintained on the cortex of mitotic cells and used for spindle orientation.