3,607 research outputs found

    Search for Lorentz Invariance and CPT Violation with the MINOS Far Detector

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    We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of 20–510 over the current best limits found by using the MINOS near detector

    Improved Measurement of Muon Antineutrino Disappearance in MINOS

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    We report an improved measurement of ν̅_μ disappearance over a distance of 735 km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a ν̅_μ-enhanced configuration. From a total exposure of 2.95×10^20 protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of Δm̅^2=[2.62_(-0.28)^(+0.31)(stat)±0.09(syst)]×10^(-3)  eV^2 and constrain the ν_μ mixing angle sin^(2)(2θ̅)>0.75 (90% C.L.). These values are in agreement with Δm^2 and sin^(2)(2θ) measured for νμ, removing the tension reported in [ P. Adamson et al. Phys. Rev. Lett. 107 021801 (2011)]

    A Method for Evaluating Storm-Damaged Cotton for Extension County Agents and Specialists

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    Extension county agents and specialists are often asked to provide unbiased crop damage assessments when storms occur. There is generally no published methodology on which to base damage assessments. The objectives of the project described here were to (a) provide an unbiased database to producers and crop insurance representatives and (b) develop an unbiased, in-field method for damage evaluations for cotton. This method proved to be effective in allowing Extension personnel to monitor crop damage over time as a result of the storm. It provided an unbiased database for use by Extension and USDA workers, producers, and crop insurance personnel

    An Open-Source Plate Reader

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    Microplate readers are foundational instruments in experimental biology and bioengineering that enable multiplexed spectrophotometric measurements. To enhance their accessibility, we here report the design, construction, validation, and benchmarking of an open-source microplate reader. The system features full-spectrum absorbance and fluorescence emission detection, in situ optogenetic stimulation, and stand-alone touch screen programming of automated assay protocols. The total system cost

    Cortisol patterns are associated with T cell activation in HIV.

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    ObjectiveThe level of T cell activation in untreated HIV disease is strongly and independently associated with risk of immunologic and clinical progression. The factors that influence the level of activation, however, are not fully defined. Since endogenous glucocorticoids are important in regulating inflammation, we sought to determine whether less optimal diurnal cortisol patterns are associated with greater T cell activation.MethodsWe studied 128 HIV-infected adults who were not on treatment and had a CD4(+) T cell count above 250 cells/µl. We assessed T cell activation by CD38 expression using flow cytometry, and diurnal cortisol was assessed with salivary measurements.ResultsLower waking cortisol levels correlated with greater T cell immune activation, measured by CD38 mean fluorescent intensity, on CD4(+) T cells (r = -0.26, p = 0.006). Participants with lower waking cortisol also showed a trend toward greater activation on CD8(+) T cells (r = -0.17, p = 0.08). A greater diurnal decline in cortisol, usually considered a healthy pattern, correlated with less CD4(+) (r = 0.24, p = 0.018) and CD8(+) (r = 0.24, p = 0.017) activation.ConclusionsThese data suggest that the hypothalamic-pituitary-adrenal (HPA) axis contributes to the regulation of T cell activation in HIV. This may represent an important pathway through which psychological states and the HPA axis influence progression of HIV

    An Experimental Approach to a Rapid Propulsion and Aeronautics Concepts Testbed

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    Modern aircraft design tools have limitations for predicting complex propulsion-airframe interactions. The demand for new tools and methods addressing these limitations is high based on the many recent Distributed Electric Propulsion (DEP) Vertical Take-Off and Landing (VTOL) concepts being developed for Urban Air Mobility (UAM) markets. We propose that low cost electronics and additive manufacturing can support the conceptual design of advanced autonomy-enabled concepts, by facilitating rapid prototyping for experimentally driven design cycles. This approach has the potential to reduce complex aircraft concept development costs, minimize unique risks associated with the conceptual design, and shorten development schedule by enabling the determination of many "unknown unknowns" earlier in the design process and providing verification of the results from aircraft design tools. A modular testbed was designed and built to evaluate this rapid design-build-test approach and to support aeronautics and autonomy research targeting UAM applications utilizing a complex, transitioning-VTOL aircraft configuration. The testbed is a modular wind tunnel and flight model. The testbed airframe is approximately 80% printed, with labor required for assembly. This paper describes the design process, fabrication process, ground testing, and initial wind tunnel structural and thermal loading of a proof-of-concept aircraft, the Langley Aerodrome 8 (LA-8)

    The NuMI neutrino beam

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    This paper describes the hardware and operations of the Neutrinos at the Main Injector (NuMI) beam at Fermilab. It elaborates on the design considerations for the beam as a whole and for individual elements. The most important design details of individual components are described. Beam monitoring systems and procedures, including the tuning and alignment of the beam and NuMI long-term performance, are also discussed

    Type I D-branes in an H-flux and twisted KO-theory

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    Witten has argued that charges of Type I D-branes in the presence of an H-flux, take values in twisted KO-theory. We begin with the study of real bundle gerbes and their holonomy. We then introduce the notion of real bundle gerbe KO-theory which we establish is a geometric realization of twisted KO-theory. We examine the relation with twisted K-theory, the Chern character and provide some examples. We conclude with some open problems.Comment: 23 pages, Latex2e, 2 new references adde
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