1,191 research outputs found

    Software quality assurance plan for GCS

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    The software quality assurance (SQA) function for the Guidance and Control Software (GCS) project which is part of a software error studies research program is described. The SQA plan outlines all of the procedures, controls, and audits to be carried out by the SQA organization to ensure adherence to the policies, procedures, and standards for the GCS project

    Melatonin Alters Age-Related Changes in Transcription Factors and Kinase Activation

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    Male mice were fed 40 ppm melatonin for 2 months prior to sacrifice at age 26 months, and compared with both 26 and 4 month-old untreated controls. The nuclear translocation of NF-κB increased with age in both brain and spleen and this was reversed by melatonin only in brain. Another transcription factor, AP-1 was increased with age in the spleen and not in brain and this could be blocked by melatonin treatment. The fraction of the active relative to the inactive form of several enabling kinases was compared. The proportion of activated ERK was elevated with age in brain and spleen but this change was unresponsive to melatonin. A similar age-related increase in glial fibrillary acidic protein (GFAP) was also refractory to melatonin treatment. The cerebral melatonin M1 receptor decreased with age in brain but increased in spleen. The potentially beneficial nature of melatonin for the preservation of brain function with aging was suggested by the finding that an age-related decline in cortical synaptophysin levels was prevented by dietary melatonin

    Principal Component Analysis with Noisy and/or Missing Data

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    We present a method for performing Principal Component Analysis (PCA) on noisy datasets with missing values. Estimates of the measurement error are used to weight the input data such that compared to classic PCA, the resulting eigenvectors are more sensitive to the true underlying signal variations rather than being pulled by heteroskedastic measurement noise. Missing data is simply the limiting case of weight=0. The underlying algorithm is a noise weighted Expectation Maximization (EM) PCA, which has additional benefits of implementation speed and flexibility for smoothing eigenvectors to reduce the noise contribution. We present applications of this method on simulated data and QSO spectra from the Sloan Digital Sky Survey.Comment: Accepted for publication in PASP; v2 with minor updates, mostly to bibliograph

    Reinterpretation and Long-Term Preservation of Data and Code

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    Careful preservation of experimental data, simulations, analysis products, and theoretical work maximizes their long-term scientific return on investment by enabling new analyses and reinterpretation of the results in the future. Key infrastructure and technical developments needed for some high-value science targets are not in scope for the operations program of the large experiments and are often not effectively funded. Increasingly, the science goals of our projects require contributions that span the boundaries between individual experiments and surveys, and between the theoretical and experimental communities. Furthermore, the computational requirements and technical sophistication of this work is increasing. As a result, it is imperative that the funding agencies create programs that can devote significant resources to these efforts outside of the context of the operations of individual major experiments, including smaller experiments and theory/simulation work. In this Snowmass 2021 Computational Frontier topical group report (CompF7: Reinterpretation and long-term preservation of data and code), we summarize the current state of the field and make recommendations for the future.Comment: Snowmass 2021 Computational Frontier CompF7 Reinterpretation and long-term preservation of data and code topical group repor

    Upper limb prostheses: bridging the sensory gap

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    Replacing human hand function with prostheses goes far beyond only recreating muscle movement with feedforward motor control. Natural sensory feedback is pivotal for fine dexterous control and finding both engineering and surgical solutions to replace this complex biological function is imperative to achieve prosthetic hand function that matches the human hand. This review outlines the nature of the problems underlying sensory restitution, the engineering methods that attempt to address this deficit and the surgical techniques that have been developed to integrate advanced neural interfaces with biological systems. Currently, there is no single solution to restore sensory feedback. Rather, encouraging animal models and early human studies have demonstrated that some elements of sensation can be restored to improve prosthetic control. However, these techniques are limited to highly specialized institutions and much further work is required to reproduce the results achieved, with the goal of increasing availability of advanced closed loop prostheses that allow sensory feedback to inform more precise feedforward control movements and increase functionality

    Programma

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    Programma scientifico della nuova rivista pubblicata sul portale della Sorbonne Université, diretta da L. Cugny, V. Caporaletti e F. Araújo Costa, la "Revue d'études du Jazz et des Musiques Audiotactiles"

    Model-Independent Global Constraints on New Physics

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    Using effective-lagrangian techniques we perform a systematic survey of the lowest-dimension effective interactions through which heavy physics might manifest itself in present experiments. We do not restrict ourselves to special classes of effective interactions (such as `oblique' corrections). We compute the effects of these operators on all currently well-measured electroweak observables, both at low energies and at the ZZ resonance, and perform a global fit to their coefficients. Despite the fact that a great many operators arise in our survey, we find that most are quite strongly bounded by the current data. We use our survey to systematically identify those effective interactions which are {\it not} well-bounded by the data -- these could very well include large new-physics contributions. Our results may also be used to efficiently confront specific models for new physics with the data, as we illustrate with an example.Comment: plain TeX, 68 pages, 2 figures (postscript files appended), McGill-93/12, NEIPH-93-008, OCIP/C-93-6, UQAM-PHE-93/08, UdeM-LPN-TH-93-15

    Discrete physiological effects of beetroot juice and potassium nitrate supplementation following 4 weeks sprint interval training

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    The physiological and exercise performance adaptations to sprint interval training (SIT) may be modified by dietary nitrate (NO3-) supplementation. However, it is possible that different types of NO3- supplementation evoke divergent physiological and performance adaptations to SIT. The purpose of this study was to compare the effects of 4 weeks SIT with and without concurrent dietary NO3- supplementation administered as either NO3--rich beetroot juice (BR) or potassium NO3- (KNO3). Thirty recreationally-active subjects completed a battery of exercise tests before and after a 4 week intervention in which they were allocated to one of three groups: 1) SIT undertaken without dietary NO3- supplementation (SIT); 2) SIT accompanied by concurrent BR supplementation (SIT+BR); or 3) SIT accompanied by concurrent KNO3 supplementation (SIT+KNO3). During severe-intensity exercise, VO2peak and time to task failure were improved to a greater extent with SIT+BR than SIT and SIT+KNO3 (P0.05). These findings indicate that 4 weeks SIT with concurrent BR supplementation results in greater exercise capacity adaptations compared to SIT alone and SIT with concurrent KNO3 supplementation. This may be the result of greater NO-mediated signalling in SIT+BR compared to SIT+KNO3
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