3,738 research outputs found

    Evolutionary Robotics: a new scientific tool for studying cognition

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    We survey developments in Artificial Neural Networks, in Behaviour-based Robotics and Evolutionary Algorithms that set the stage for Evolutionary Robotics in the 1990s. We examine the motivations for using ER as a scientific tool for studying minimal models of cognition, with the advantage of being capable of generating integrated sensorimotor systems with minimal (or controllable) prejudices. These systems must act as a whole in close coupling with their environments which is an essential aspect of real cognition that is often either bypassed or modelled poorly in other disciplines. We demonstrate with three example studies: homeostasis under visual inversion; the origins of learning; and the ontogenetic acquisition of entrainment

    Growing Pains or Opportunities? A Customer Survey of Three Farmers\u27 Markets in One Rural Community

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    The continued growth of farmers\u27 markets is presenting new challenges to Extension. As the number of markets expands, how can Extension help those in the same community work together for mutual benefit? The study reported here examined similarities and differences among customers attending three different farmers\u27 markets within a single locality in Gettysburg, Pennsylvania. Based on 370 customer surveys, study results underscore the diversity of markets operating within the same community and provide insights into ways Extension might assist markets to work together to expand their shared customer base, increase revenues, and better serve local residents

    Tivozanib in the treatment of renal cell carcinoma

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    Mehmet Hepgur, Sarmad Sadeghi, Tanya B Dorff, David I Quinn Division of Medical Oncology, University of Southern California Norris Comprehensive Cancer Center, Keck School of Medicine, Los Angeles, CA, USA Abstract: Renal cell carcinoma (RCC) is an aggressive malignancy compared to other urological malignancies and has been associated with poor responses to conventional cytotoxic chemotherapy. Interferon-a and interleukin-2 were previously utilized in a limited number of patients with good performance status due to toxicity and safety issues. Over the last decade, through advances in the understanding of the biology and pathology of RCC, the important role of vascular endothelial growth factor (VEGF) in RCC has been identified. Data from randomized trials have led to the approval of first-generation tyrosine kinase inhibitors (TKIs) sorafenib, sunitinib, and pazopanib; however, these agents inhibit a wide variety of kinase targets and are associated with a range of adverse effects. More recently, a new generation TKI, axitinib, has been approved by the US Food and Drug Administration. Tivozanib is a novel TKI, which is a potent inhibitor of VEGF-1, VEGF-2, VEGF-3, c-kit, and PDGR kinases, with a more restricted target spectrum. Phase II and III studies have demonstrated significant activity and a favorable safety profile as an initial targeted treatment for advanced RCC. This review examines the emerging data with tivozanib for the treatment of advanced RCC. Preclinical investigations as well as Phase I, II, and III data are examined; data on the comparative benefits of tivozanib are reviewed. Finally, we discuss the future potential of tivozanib in combination, biomarkers associated with tivozanib response, and acquisition of resistance and nonkidney cancer indications. Keywords: targeted therapy, renal cell cancer, tyrosine kinase inhibitor, tivozani

    Direct test of time-reversal symmetry in the entangled neutral kaon system at a ϕ\phi-factory

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    We present a novel method to perform a direct T (time reversal) symmetry test in the neutral kaon system, independent of any CP and/or CPT symmetry tests. This is based on the comparison of suitable transition probabilities, where the required interchange of in out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a ϕ\phi-factory. In the time distribution between the two decays, we compare a reference transition like the one defined by the time ordered decays (,ππ)(\ell^-,\pi\pi) with the T -conjugated one defined by (3π0,+)(3\pi^0, \ell^+). With the use of this and other T conjugated comparisons, the KLOE-2 experiment at DAΦ\PhiNE could make a significant test

    Current oscillations in Vanadium Dioxide: evidence for electrically triggered percolation avalanches

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    In this work, we experimentally and theoretically explore voltage controlled oscillations occurring in micro-beams of vanadium dioxide. These oscillations are a result of the reversible insulator to metal phase transition in vanadium dioxide. Examining the structure of the observed oscillations in detail, we propose a modified percolative-avalanche model which allows for voltage-triggering. This model captures the periodicity and waveshape of the oscillations as well as several other key features. Importantly, our modeling shows that while temperature plays a critical role in the vanadium dioxide phase transition, electrically induced heating cannot act as the primary instigator of the oscillations in this configuration. This realization leads us to identify electric field as the most likely candidate for driving the phase transition

    T and CPT Symmetries in Entangled Neutral Meson Systems

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    Genuine tests of an asymmetry under T and/or CPT transformations imply the interchange between in-states and out-states. I explain a methodology to perform model-indepedent separate measurements of the three CP, T and CPT symmetry violations for transitions involving the decay of the neutral meson systems in B- and {\Phi}-factories. It makes use of the quantum-mechanical entanglement only, for which the individual state of each neutral meson is not defined before the decay of its orthogonal partner. The final proof of the independence of the three asymmetries is that no other theoretical ingredient is involved and that the event sample corresponding to each case is different from the other two. The experimental analysis for the measurements of these three asymmetries as function of the time interval {\Delta}t > 0 between the first and second decays is discussed, as well as the significance of the expected results. In particular, one may advance a first observation of true, direct, evidence of Time-Reserval-Violation in B-factories by many standard deviations from zero, without any reference to, and independent of, CP-Violation. In some quantum gravity framework the CPT-transformation is ill-defined, so there is a resulting loss of particle-antiparticle identity. This mechanism induces a breaking of the EPR correlation in the entanglement imposed by Bose statistics to the neutral meson system, the so-called {\omega}-effect. I present results and prospects for the {\omega}-parameter in the correlated neutral meson-antimeson states.Comment: Proc. DISCRETE 2010, Symposium on Prospects in the Physics of Discrete Symmetries, December 2010, Rom

    Generation of rotationally dominated galaxies by mergers of pressure-supported progenitors

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    Through the analysis of a set of numerical simulations of major mergers between initially non-rotating, pressure supported progenitor galaxies with a range of central mass concentrations, we have shown that: (1) it is possible to generate elliptical-like galaxies, with v/sigma > 1 outside one effective radius, as a result of the conversion of orbital- into internal-angular momentum; (2) the outer regions acquire part of the angular momentum first; (3) both the baryonic and the dark matter components of the remnant galaxy acquire part of the angular momentum, the relative fractions depend on the initial concentration of the merging galaxies. For this conversion to occur the initial baryonic component must be sufficiently dense and/or the encounter should take place on a orbit with high angular momentum. Systems with these hybrid properties have been recently observed through a combination of stellar absorption lines and planetary nebulae for kinematic studies of early-type galaxies. Our results are in qualitative agreement with such observations and demonstrate that even mergers composed of non-rotating, pressure-supported progenitor galaxies can produce early-type galaxies with significant rotation at large radii.Comment: 5 pages, 6 figures, 2 tables. Accepted for publication in A&A Letter

    Randomized phase III KEYNOTE-045 trial of pembrolizumab versus paclitaxel, docetaxel, or vinflunine in recurrent advanced urothelial cancer: results of >2 years of follow-up.

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    BackgroundNovel second-line treatments are needed for patients with advanced urothelial cancer (UC). Interim analysis of the phase III KEYNOTE-045 study showed a superior overall survival (OS) benefit of pembrolizumab, a programmed death 1 inhibitor, versus chemotherapy in patients with advanced UC that progressed on platinum-based chemotherapy. Here we report the long-term safety and efficacy outcomes of KEYNOTE-045.Patients and methodsAdult patients with histologically/cytologically confirmed UC whose disease progressed after first-line, platinum-containing chemotherapy were enrolled. Patients were randomly assigned 1 : 1 to receive pembrolizumab [200 mg every 3 weeks (Q3W)] or investigator's choice of paclitaxel (175 mg/m2 Q3W), docetaxel (75 mg/m2 Q3W), or vinflunine (320 mg/m2 Q3W). Primary end points were OS and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1) by blinded independent central radiology review (BICR). A key secondary end point was objective response rate per RECIST v1.1 by BICR.ResultsA total of 542 patients were enrolled (pembrolizumab, n = 270; chemotherapy, n = 272). Median follow-up as of 26 October 2017 was 27.7 months. Median 1- and 2-year OS rates were higher with pembrolizumab (44.2% and 26.9%, respectively) than chemotherapy (29.8% and 14.3%, respectively). PFS rates did not differ between treatment arms; however, 1- and 2-year PFS rates were higher with pembrolizumab. The objective response rate was also higher with pembrolizumab (21.1% versus 11.0%). Median duration of response to pembrolizumab was not reached (range 1.6+ to 30.0+ months) versus chemotherapy (4.4 months; range 1.4+ to 29.9+ months). Pembrolizumab had lower rates of any grade (62.0% versus 90.6%) and grade ≥3 (16.5% versus 50.2%) treatment-related adverse events than chemotherapy.ConclusionsLong-term results (>2 years' follow-up) were consistent with those of previously reported analyses, demonstrating continued clinical benefit of pembrolizumab over chemotherapy for efficacy and safety for treatment of locally advanced/metastatic, platinum-refractory UC.Trial registrationClinicalTrials.gov: NCT02256436

    Farmers Markets and the Local Food System: The Case of Gettysburg, Pennsylvania

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    In order to examine and obtain a better understanding of the local food system within Adams County, Pennsylvania, this study explores the characteristics and perspectives of the customers and vendors at the farmers markets in Gettysburg, Pennsylvania. Survey findings from the Gettysburg Farmers Market and the three Adams County Farmers Markets include customer demographic information, perspectives and shopping behavior as well as vendor product information, farm size and location and preference for market management. Introductory background information on the Farm Bill and the influence of agricultural practices on the environment, human health and nutrition and the relationship between farmers markets and the local economy are offered in order to emphasize the value of a well-managed local food system. Conclusions provide evidence that lower income and lower education levels are not sufficiently represented at all the markets and food stamp programs are being underutilized. This study suggests employing additional marketing to target underrepresented demographic groups, public transportation to potentially inaccessible market locations and increased advertisement and encouragement of food stamp programs at all markets in order to expand the customer base and increase access to healthy, local foods for less advantaged citizens. The results from this study are intended to offer evidence that will promote and facilitate market management, strengthen customer/vendor relationships and encourage better ties between the local community and local food systems at the farmers markets within Gettysburg in Adams County, Pennsylvania

    The JCMT Gould Belt survey: Dense core clusters in Orion B

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    The James Clerk Maxwell Telescope Gould Belt Legacy Survey obtained SCUBA-2 observations of dense cores within three sub-regions of OrionB: LDN1622, NGC2023/2024, and NGC2068/2071, all of which contain clusters of cores. We present an analysis of the clustering properties of these cores, including the two-point correlation function and Cartwright’s Q parameter. We identify individual clusters of dense cores across all three regions using a minimal spanning tree technique, and find that in each cluster, the most massive cores tend to be centrally located. We also apply the independent M–Σ technique and find a strong correlation between core mass and the local surface density of cores. These two lines of evidence jointly suggest that some amount of mass segregation in clusters has happened already at the dense core stage
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