On differential rotation and overshooting in solar-like stars

This is the author accepted manuscript. The final version is available from American Astronomical Society via the DOI in this record.We seek to characterize how the change of global rotation rate influences the overall dynamics and large scale flows arising in the convective envelopes of stars covering stellar spectral types from early G to late K. We do so through numerical simulations with the ASH code, where we consider stellar convective envelopes coupled to a radiative interior with various global properties. As solar-like stars spin down over the course of their main sequence evolution, such change must have a direct impact on their dynamics and rotation state. We indeed find that three main states of rotation may exist for a given star: anti-solar-like (fast poles, slow equator), solar-like (fast equator, slow poles), or a cylindrical rotation profile. Under increasingly strict rotational constraints, the latter profile can further evolve into a Jupiter-like profile, with alternating prograde and retrograde zonal jets. We have further assessed how far the convection and meridional flows overshoot into the radiative zone and investigated the morphology of the established tachocline. Using simple mixing length arguments, we are able to construct a scaling of the fluid Rossby number $R_{of} = \tilde{\omega}/2\Omega_* \sim \tilde{v}/2\Omega_* R_*$, which we calibrate based on our 3-D ASH simulations. We can use this scaling to map the behavior of differential rotation versus the global parameters of stellar mass and rotation rate. Finally, we isolate a region on this map ($R_{of} \gtrsim 1.5-2$) where we posit that stars with an anti-solar differential rotation may exist in order to encourage observers to hunt for such targets.We acknowledge funding by ERC STARS2 207430 grant, ANR Blanc Toupies SIMI5-6 020 01, INSU/PNST, CNES SolarOrbiter, PLATO and GOLF grants, FP7 SpaceInn 312844 grant, and NASA grants NNX11AJ36G, NNX13AG18G and NNX16AC92G. K. C. Augustson is funded through the ERC SPIRE 647383 grant. A. Strugarek acknowledges support from the Canadian Institute of Theoretical Astrophysics (National Fellow), from Canadas Natural Sciences and Engineering Research Council and from CNES postdoctoral fellowship

Extensive transmission of isoniazid resistant M. tuberculosis and its association with increased multidrug-resistant TB in two rural counties of eastern China: A molecular epidemiological study

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the molecular characteristics of isoniazid resistant <it>Mycobacterium tuberculosis </it>(MTB), as well as its contribution to the dissemination of multi-drug resistant TB (MDR-TB) in rural areas of eastern China.</p> <p>Methods</p> <p>A population-based epidemiological study was conducted in two rural counties of eastern China from 2004 to 2005. In total, 131 isoniazid resistant MTB isolates were molecularly characterized by DNA sequencing and genotyped by IS<it>6110 </it>restriction fragment length polymorphism (RFLP) and spoligotyping.</p> <p>Results</p> <p>The <it>katG</it>315Thr mutation was observed in 74 of 131 isoniazid resistant isolates and more likely to be MDR-TB (48.6%) and have mutations in <it>rpoB </it>gene (47.3%). Spoligotyping identified 80.2% of isoniazid resistant MTB isolates as belonging to the Beijing family. Cluster analysis by genotyping based on IS<it>6110 </it>RFLP, showed that 48.1% isoniazid resistant isolates were grouped into 26 clusters and <it>katG</it>315Thr mutants had a significantly higher clustering proportion compared to those with <it>katG </it>wild type (73%.vs.18%; OR, 12.70; 95%CI, 6.357-14.80). Thirty-one of the 53 MDR-TB isolates were observed in 19 clusters. Of these clusters, isoniazid resistance in MDR-TB isolates was all due to the <it>katG</it>315Thr mutation; 18 clusters also contained mono-isoniazid resistant and other isoniazid resistant isolates.</p> <p>Conclusions</p> <p>These results highlighted that isoniazid resistant MTB especially with <it>katG</it>315Thr is likely to be clustered in a community, develop extra resistance to rifampicin and become MDR-TB in Chinese rural settings.</p

Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model

Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions

Combining scanning probe microscopy and x-ray spectroscopy

A new versatile tool, combining Shear Force Microscopy and X-Ray Spectroscopy was designed and constructed to obtain simultaneously surface topography and chemical mapping. Using a sharp optical fiber as microscope probe, it is possible to collect locally the visible luminescence of the sample. Results of tests on ZnO and on ZnWO4 thin layers are in perfect agreement with that obtained with other conventional techniques. Twin images obtained by simultaneous acquisition in near field of surface topography and of local visible light emitted by the sample under X-Ray irradiation in synchrotron environment are shown. Replacing the optical fibre by an X-ray capillary, it is possible to collect local X-ray fluorescence of the sample. Preliminary results on Co-Ti sample analysis are presented

Activation of PI3K/mTOR pathway occurs in most adult low-grade gliomas and predicts patient survival

Recent evidence suggests the Akt-mTOR pathway may play a role in development of low-grade gliomas (LGG). We sought to evaluate whether activation of this pathway correlates with survival in LGG by examining expression patterns of proteins within this pathway. Forty-five LGG tumor specimens from newly diagnosed patients were analyzed for methylation of the putative 5′-promoter region of PTEN using methylation-specific PCR as well as phosphorylation of S6 and PRAS40 and expression of PTEN protein using immunohistochemistry. Relationships between molecular markers and overall survival (OS) were assessed using Kaplan-Meier methods and exact log-rank test. Correlation between molecular markers was determined using the Mann-Whitney U and Spearman Rank Correlation tests. Eight of the 26 patients with methylated PTEN died, as compared to 1 of 19 without methylation. There was a trend towards statistical significance, with PTEN methylated patients having decreased survival (P = 0.128). Eight of 29 patients that expressed phospho-S6 died, whereas all 9 patients lacking p-S6 expression were alive at last follow-up. There was an inverse relationship between expression of phospho-S6 and survival (P = 0.029). There was a trend towards decreased survival in patients expressing phospho-PRAS40 (P = 0.077). Analyses of relationships between molecular markers demonstrated a statistically significant positive correlation between expression of p-S6(235) and p-PRAS40 (P = 0.04); expression of p-S6(240) correlated positively with PTEN methylation (P = 0.04) and negatively with PTEN expression (P = 0.03). Survival of LGG patients correlates with phosphorylation of S6 protein. This relationship supports the use of selective mTOR inhibitors in the treatment of low grade glioma

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO