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2008 2017
Created Date: 2013
Contributors: Manning, Craig E., Shock, Everett, Sverjensky, Dimitri A., et al.
Description: Carbon can be a major constituent of crustal and mantle uids, occurring both as dissolved ionic species (e.g., carbonate ions or organic acids) and molecular species (e.g., CO[subscript 2], CO, CH[subscript 4], and more complex organic compounds). The chemistry of dissolved carbon changes dramatically with pressure (P) and temperature (T). In aqueous uids at low P and T, molecular carbon gas species such as CO[subscript 2] and CH[subscript 4] saturate at low concentration to form a separate phase. With modest increases in P and T, these molecular species become fully miscible with H[subscript 2]O, enabling deep crustal and mantle uids ...

Created Date: 2013-06-04
Contributors: Zhu, Jiangtao, Crozier, Peter, Anderson, James, et al.
Description: The morphology, microstructure, and composition of the submicron fraction of individual light-absorbing carbon (LAC) particles collected by research aircraft during the ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) project above the Yellow Sea at altitudes of 120, 450 and 1500 m are investigated by transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Two types of carbonaceous particles, small spherule soot with graphitic spherules and amorphous carbonaceous spheres (brown carbon), are found at all altitudes in high concentration. For soot particles, emphasis of the study is on the component subparticles (spherules). The nanoscopic structures of the small spherule soot ...

Created Date: 2013-05-04
Contributors: Christoforides, Alexis, Carpten, John D, Weiss, Glen J, et al.
Description: BACKGROUND: The field of cancer genomics has rapidly adopted next-generation sequencing (NGS) in order to study and characterize malignant tumors with unprecedented resolution. In particular for cancer, one is often trying to identify somatic mutations--changes specific to a tumor and not within an individual's germline. However, false positive and false negative detections often result from lack of sufficient variant evidence, contamination of the biopsy by stromal tissue, sequencing errors, and the erroneous classification of germline variation as tumor-specific. RESULTS: We have developed a generalized Bayesian analysis framework for matched tumor/normal samples with the purpose of identifying tumor-specific alterations such as ...

Created Date: 2013-09-22
Contributors: Gerkin, Richard, Nauen, David W, Xu, Fang, et al.
Description: BACKGROUND: During development both Hebbian and homeostatic mechanisms regulate synaptic efficacy, usually working in opposite directions in response to neuronal activity. Homeostatic plasticity has often been investigated by assaying changes in spontaneous synaptic transmission resulting from chronic circuit inactivation. However, effects of inactivation on evoked transmission have been less frequently reported. Importantly, contributions from the effects of circuit inactivation and reactivation on synaptic efficacy have not been individuated. RESULTS: Here we show for developing hippocampal neurons in primary culture that chronic inactivation with TTX results in increased mean amplitude of miniature synaptic currents (mEPSCs), but not evoked synaptic currents (eEPSCs). ...

Created Date: 2013-06-12
Contributors: Pommier, Anne, Evans, Rob L., Key, Kerry, et al.
Description: Our knowledge of magma dynamics would be improved if geophysical data could be used to infer rheological constraints in melt-bearing zones. Geophysical images of the Earth's interior provide frozen snapshots of a dynamical system. However, knowledge of a rheological parameter such as viscosity would constrain the time-dependent dynamics of melt bearing zones. We propose a model that relates melt viscosity to electrical conductivity for naturally occurring melt compositions (including H2O) and temperature. Based on laboratory measurements of melt conductivity and viscosity, our model provides a rheological dimension to the interpretation of electromagnetic anomalies caused by melt and partially molten rocks ...

Created Date: 2013
Contributors: Lim, Merlyna, Arizona State University. Consortium for Science, Policy & Outcomes
Description: In July 2012, the Indonesian Minister of Communication and Information, Tifatul Sembiring, declared that the government had shut down one million websites in view of the Islamic holy month of Ramadhan. This was in addition to another one million sites the ministry claimed to have blocked back in February 2012. Minister Sembiring, a politician from the Islamic-based Partai Keadilan Sejahtera (Prosperous Justice Party, PKS), said that his staff would continue blocking access to online pornography beyond the holy month.

Created Date: 2012
Contributors: Lanchier, Nicolas, Arizona State University. School of Mathematical and Statistical Sciences
Description: Similarly to the popular voter model, the Deffuant model describes opinion dynamics taking place in spatially structured environments represented by a connected graph. Pairs of adjacent vertices interact at a constant rate. If the opinion distance between the interacting vertices is larger than some confidence threshold epsilon > 0, then nothing happens, otherwise, the vertices' opinions get closer to each other. It has been conjectured based on numerical simulations that this process exhibits a phase transition at the critical value epsilon(c) = 1/2. For confidence thresholds larger than one half, the process converges to a global consensus, whereas coexistence occurs ...

Created Date: 2013-05-30
Contributors: McDermott, Jeni, Whipple, Kelin, Hodges, Kip, et al.
Description: The southern Tibetan Plateau margin between ~ 83E and 86.5E is defined by an abrupt change from the low-relief Tibetan Plateau to the rugged topography and deep gorges of the Himalaya. This physiographic transition lies well to the north of active thrusting, and thus, the mechanism responsible for the distinct topographic break remains the focus of much debate. While numerous studies have utilized thermochronology to examine the exhumation history of the Himalaya, few have done so with respect to variations across the Himalaya-Tibetan Plateau transition. In this work, we examine the nature of the transition where it is accessible and ...

Created Date: 2013
Contributors: Alford, Terry, Das, Sayantan, Arizona State University. Department of Chemistry and Biochemistry, et al.
Description: Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The ...

Created Date: 2014-07-21
Contributors: Lunardini, Cecilia, Razzaque, Soebur, Theodoseau, Kristopher, et al.
Description: We discuss the possibility that the IceCube neutrino telescope might be observing the Fermi bubbles. If the bubbles discovered in gamma rays originate from accelerated protons, they should be strong emitters of high energy (≳ GeV) neutrinos. These neutrinos are detectable as showerlike or tracklike events at a Km[superscript 3] neutrino observatory. For a primary cosmic ray flux with spectrum ∝ E[superscript −2.1] and cutoff energy at or above 10 PeV, the Fermi bubble flux substantially exceeds the atmospheric background, and could account for up to ∼4–5 of the 28 events detected above ∼30 TeV at IceCube. Running the detector ...