188 research outputs found

    Examining geodetic glacier mass balance in the eastern Pamir transition zone

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    This research was supported by the Key Research Program of Frontier Sciences CAS [QYZDY-SSW-DQC026] and the National Natural Science Foundation of China [41590853]. SRTM DEM and NASA HMA DEM data were sourced from NASA Earthdata (https://earthdata.nasa.gov/), and the ALOS Global Digital Surface Model (AW3D30) was sourced from JAXA (https://www.eorc.jaxa.jp/ALOS/en/aw3d30/index.htm). ALOS PRISM level-1B1 products were ordered from http://en.alos-pasco.com/alos/prism/ under a 4th ALOS RA data grant awarded to Quincey (PI No. 1008). Landsat-7 and Landsat-8 images can be freely downloaded from http://glovis.usgs.gov. Randolph Glacier Inventory data were acquired from Global Land Ice Measurements from Space (GLIMS) (RGI Consortium, 2017). Lv acknowledges program B for outstanding PhD candidates of Nanjing University and the support from the Chinese Scholarship Council (CSC) for studying at the University of Leeds.Glaciers in the eastern Pamir have reportedly been gaining mass during recent decades, even though glaciers in most other regions in High Mountain Asia have been in recession. Questions still remain about whether the trend is strengthening or weakening, and how far the positive balances extend into the eastern Pamir. To address these gaps, we use three different digital elevation models to reconstruct glacier surface elevation changes over two periods (2000–09 and 2000–15/16). We characterize the eastern Pamir as a zone of transition from positive to negative mass balance with the boundary lying at the northern end of Kongur Tagh, and find that glaciers situated at higher elevations are those with the most positive balances. Most (67% of 55) glaciers displayed a net mass gain since the 21st century. This led to an increasing regional geodetic glacier mass balance from −0.06 ± 0.16 m w.e. a−1 in 2000–09 to 0.06 ± 0.04 m w.e. a−1 in 2000–15/16. Surge-type glaciers, which are prevalent in the eastern Pamir, showed fluctuations in mass balance on an individual scale during and after surges, but no statistical difference compared to non-surge-type glaciers when aggregated across the region.Publisher PDFPeer reviewe

    Clock controls timing of mouse pancreatic differentiation through regulation of Wnt- and Notch-based and cell division components

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    The oscillations of circadian genes control the daily circadian clock, regulating a diverse array of physiologies with the 24-hour light/dark cue across a wide variety of organisms. Here we first show that before embryonic circadian rhythms occur, the oscillation (nucleocytoplasmic shuttling) of core circadian gene Clock is tissue-specific and correlated with the state of differentiation during both early development and later pancreas organogenesis. Disruption of Clock as well as Timeless in the embryonic pancreas does not block pancreatic differentiation but alters the balance and maturity of endocrine and exocrine cells. Molecular analysis indicates that inhibition of Clock or Timeless expression disturbs not only cell cycle regulators, but also Wnt- and Notch-signaling components, whose oscillations establish the timing mechanism in somitogenesis. Thus, our results provide new insights about circadian genes' function in control of the timing of differentiation during embryonic development. (c) 2007 Elsevier Inc. All rights reserved

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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    Search for anomalous couplings in boosted WW/WZ -> l nu q(q)over-bar production in proton-proton collisions at root s=8TeV

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    Analysis of SIR epidemic models with nonlinear incidence rate and treatment

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    ► Nonlinear dynamics of a SIR epidemic model is considered. ► Nonlinear incidence rate, vertical transmission, vaccination were included. ► Capacity of treatment was modeled and analyzed. ► Backward bifurcation occurs in the model. ► Existence and stability of multiple endemic equilibria was studied. This paper deals with the nonlinear dynamics of a susceptible-infectious-recovered (SIR) epidemic model with nonlinear incidence rate, vertical transmission, vaccination for the newborns of susceptible and recovered individuals, and the capacity of treatment. It is assumed that the treatment rate is proportional to the number of infectives when it is below the capacity and constant when the number of infectives reaches the capacity. Under some conditions, it is shown that there exists a backward bifurcation from an endemic equilibrium, which implies that the disease-free equilibrium coexists with an endemic equilibrium. In such a case, reducing the basic reproduction number less than unity is not enough to control and eradicate the disease, extra measures are needed to ensure that the solutions approach the disease-free equilibrium. When the basic reproduction number is greater than unity, the model can have multiple endemic equilibria due to the effect of treatment, vaccination and other parameters. The existence and stability of the endemic equilibria of the model are analyzed and sufficient conditions on the existence and stability of a limit cycle are obtained. Numerical simulations are presented to illustrate the analytical results
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