1,181 research outputs found

    Tissue of origin dictates branched-chain amino acid metabolism in mutant Kras-driven cancers

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    Tumor genetics guides patient selection for many new therapies, and cell culture studies have demonstrated that specific mutations can promote metabolic phenotypes. However, whether tissue context defines cancer dependence on specific metabolic pathways is unknown. Kras activation and Trp53 deletion in the pancreas or the lung result in pancreatic ductal adenocarinoma (PDAC) or non-small cell lung carcinoma (NSCLC), respectively, but despite the same initiating events, these tumors use branched-chain amino acids (BCAAs) differently. NSCLC tumors incorporate free BCAAs into tissue protein and use BCAAs as a nitrogen source, whereas PDAC tumors have decreased BCAA uptake. These differences are reflected in expression levels of BCAA catabolic enzymes in both mice and humans. Loss of Bcat1 and Bcat2, the enzymes responsible for BCAA use, impairs NSCLC tumor formation, but these enzymes are not required for PDAC tumor formation, arguing that tissue of origin is an important determinant of how cancers satisfy their metabolic requirements.National Institutes of Health (U.S.) (Grant F30CA183474)National Institutes of Health (U.S.) (Grant T32GM007753

    The Many Uses of Matā on Rapa Nui

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    Obsidian tools with a stem or tang attached to a blade and known as matā have been recovered from a broad range of archaeological contexts on Rapa Nui. Their highly variable morphology suggests that this class of artifact had multiple, but too few analyses of their use-wear have been conducted to be confident about the relationships between form and use. A sample of 22 matā from sealed archaeological deposits in a cave on the southern coast of Rapa Nui and ranging in age from ca. A.D. 1300–1800 were analyzed using high power magnification. The patterns of use-wear scarring, striations, polishes, and residues demonstrate that the tools were all hafted and were used in a broad range of activities including fish processing and the manufacture and/or decoration of wooden, bone, and shell artifacts. The results demonstrate the importance of additional comprehensive usewear and residue studies for understanding the multiple roles of matā within ancient Rapa Nui society

    Validation practices for satellite based earth observation data across communities

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    Assessing the inherent uncertainties in satellite data products is a challenging task. Different technical approaches have been developed in the Earth Observation (EO) communities to address the validation problem which results in a large variety of methods as well as terminology. This paper reviews state-of-the-art methods of satellite validation and documents their similarities and differences. First the overall validation objectives and terminologies are specified, followed by a generic mathematical formulation of the validation problem. Metrics currently used as well as more advanced EO validation approaches are introduced thereafter. An outlook on the applicability and requirements of current EO validation approaches and targets is given

    The Grizzly, October 23, 2014

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    Website Launching • Homecoming Kicking Off This Weekend • Board to Discuss New President • Good Neighbors Debuting This Week • Grizzly Gala Returning • American Class Style Can be Surprising • Throop Researches Medieval Europe • U-Innovate Competition Returns • Don\u27t Forget About Small Majors • Opinion: The Problem With Capital Punishment; Extraterrestrial Existence: Reason to Believe? • Football Team Preparing for Homecoming • Serving Up Success • Field Hockey Dashes to 11-2 Starthttps://digitalcommons.ursinus.edu/grizzlynews/1913/thumbnail.jp

    The Grizzly, November 6, 2014

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    Dr. Peter Small Appointed as Interim Dean • Berman Receives Large Grant • Graduates Granted Campus Housing • Campus Safety Handles Thefts • Senate Changes Organization • Learning to Embrace American Foods • Watson Fellowship Nominees Announced • Myrin Undergoes Renovations • Dr. Jennifer Fleeger Writes Book on Mismatched Female Voices in Film • Opinion: The Francis Effect Alters Public Perception of Roman Catholic Church; How Proactive is Rape Prevention Nail Polish? • Men\u27s Swim Hoping to Make a Splash • Pinning Down Success • Field Hockey to Host Centennial Playoffshttps://digitalcommons.ursinus.edu/grizzlynews/1915/thumbnail.jp

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    The Forward Physics Facility at the High-Luminosity LHC

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    Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at √s = 13 TeV

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    Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb−1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterising the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and Otq(8), where the limits on the latter are the most stringent to date. [Figure not available: see fulltext.]

    Two-particle azimuthal correlations in photonuclear ultraperipheral Pb plus Pb collisions at 5.02 TeV with ATLAS

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    Two-particle long-range azimuthal correlations are measured in photonuclear collisions using 1.7 nb − 1 of 5.02 TeV Pb + Pb collision data collected by the ATLAS experiment at the CERN Large Hadron Collider. Candidate events are selected using a dedicated high-multiplicity photonuclear event trigger, a combination of information from the zero-degree calorimeters and forward calorimeters, and from pseudorapidity gaps constructed using calorimeter energy clusters and charged-particle tracks. Distributions of event properties are compared between data and Monte Carlo simulations of photonuclear processes. Two-particle correlation functions are formed using charged-particle tracks in the selected events, and a template-fitting method is employed to subtract the nonflow contribution to the correlation. Significant nonzero values of the second- and third-order flow coefficients are observed and presented as a function of charged-particle multiplicity and transverse momentum. The results are compared with flow coefficients obtained in proton-proton and proton-lead collisions in similar multiplicity ranges, and with theoretical expectations. The unique initial conditions present in this measurement provide a new way to probe the origin of the collective signatures previously observed only in hadronic collision
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