687 research outputs found
The flight robotics laboratory
The Flight Robotics Laboratory of the Marshall Space Flight Center is described in detail. This facility, containing an eight degree of freedom manipulator, precision air bearing floor, teleoperated motion base, reconfigurable operator's console, and VAX 11/750 computer system, provides simulation capability to study human/system interactions of remote systems. The facility hardware, software and subsequent integration of these components into a real time man-in-the-loop simulation for the evaluation of spacecraft contact proximity and dynamics are described
Evaluasi Kesesuaian Lahan Tanaman Kacang Tanah (Arachis Hipogeae L.) di Desa Werwaru Kecamatan Pulau Moa
Penelitian ini bertujuan untuk menentukan factor-faktor pembatas untuk tanaman kacang tanah yang terdapat di lapangan dan menetapkan kelas kesesuaian lahan untuk tanaman kacang tanah di desa Werwaru Kecamatan Pulau Moa Kabupaten Maluku Barat Daya. Metode yang digunakan dalam penelitian ini adalah metode survey. Jarak observasi yang digunakan adalah free survey, dengan menggunakan tipe pengamatan identifikasi (boring), dan profil pit. Berdasarkan hasil penilaiaan kesesuaian lahan aktual diketahui bahwa pada lokasi penelitian terdapat beberapa faktor karakteristik dan kualitas lahan yang menjadi faktor pembatas terhadap pertumbuhan tanaman kacang tanah yakni: faktor curah hujan pada masa pertumbuhan (wa), kedalaman efektif (r), C-organik (nr), Kemiringan lereng (s). Berdasarkan tindakan perbaikan satuan lahan yang direkomendasikan untuk tanaman kacang tanah yaitu pada kelas S2 dan kelas S3. Satuan lahan yang direkomendasikan untuk tanaman kacang tanah yakni: Untuk kelas S2: L0a1D, L0a3A, L0a3B, L0a3C, L0a3D, L1a1D, L1a3B, L2a1D, L2a3B dengan luas 1942,13 ha atau 36,1 persen dan S3: L0a2E, L1a2E, L2a2E dengan luas 219,12 ha atau 4,1 persen.
Kata kunci: evaluasi kesesuaian lahan, kacang tanah, Werwaru Pulau Mo
Approche semi-quantitative de la minĂ©ralisation des aquifĂšres schisteux en zone Ă©quatoriale de transition : Cas de la rĂ©gion Sikensi-Agboville (CĂŽte dâIvoire)
LâaquifĂšre des schistes (Sikensi-Agboville) compte dâimportants ouvrages permettant lâapprovisionnement en eau potable des populations locales. Toute fois, la couleur et le goĂ»t inhabituels, par endroit, des eaux prĂ©levĂ©es sont quelques peu inquiĂ©tants, bien quâaucun risque sanitaire grave nâest jusquâĂ prĂ©sent dĂ©celĂ©. Pour tenter dâapporter un Ă©lĂ©ment de comprĂ©hension Ă cette question, nous utilisons la gĂ©ochimie des roches, laminĂ©ralogie et lâhydrochimie pour Ă©tudier les interactions entre lâeau et son aquifĂšre. Les rĂ©sultats montrent que les schistes en question sont constituĂ©s dâalbite, de chlorites, de micas noirs, dâĂ©pidotes, du sphĂšne et de lâapatite, susceptibles de fournir leurs cations majeurs Ă la nappe. La dissolution incongruente de ces minĂ©raux au contact de lâeau Ă pH 6 et Ă ~26 °C, montre que le Na+ provient majoritairement de lâalbite et le Mg2+ des chlorites, qui sont en proportion considĂ©rable dans les schistes, avec des concentrations respectives de ~0,463 mmol.L-1 et de ~0,171 mmol.L-1. Un faible taux de 0,025 mmol.L-1 de Mg2+ est fourni par la biotite tandis que le K+, avec une concentration de ~0,018 mmol.L-1, provient Ă la fois de la biotite et de lâannite. La principale source du Ca2+ concerne les Ă©pidotes, avec un taux de ~0,188 mmol.L-1 puis viennent lâapatite et le sphĂšne, avec des taux moyens respectifs de 0,251 mmol.L-1 et de ~0,090 mmol.L-1.Mots clĂ©s: Nappe, silicates, hydrolyse, interaction, concentration, cations majeurs
Use of multiple covariates in assessing treatment-effect modifiers: A methodological review of individual participant data meta-analyses
Individual participant data (IPD) meta-analyses of randomised trials are considered a reliable way to assess participant-level treatment effect modifiers but may not make the best use of the available data. Traditionally, effect modifiers are explored one covariate at a time, which gives rise to the possibility that evidence of treatment-covariate interaction may be due to confounding from a different, related covariate. We aimed to evaluate current practice when estimating treatment-covariate interactions in IPD meta-analysis, specifically focusing on involvement of additional covariates in the models. We reviewed 100 IPD meta-analyses of randomised trials, published between 2015 and 2020, that assessed at least one treatment-covariate interaction. We identified four approaches to handling additional covariates: (1) Single interaction model (unadjusted): No additional covariates included (57/100 IPD meta-analyses); (2) Single interaction model (adjusted): Adjustment for the main effect of at least one additional covariate (35/100); (3) Multiple interactions model: Adjustment for at least one two-way interaction between treatment and an additional covariate (3/100); and (4) Three-way interaction model: Three-way interaction formed between treatment, the additional covariate and the potential effect modifier (5/100). IPD is not being utilised to its fullest extent. In an exemplar dataset, we demonstrate how these approaches lead to different conclusions. Researchers should adjust for additional covariates when estimating interactions in IPD meta-analysis providing they adjust their main effects, which is already widely recommended. Further, they should consider whether more complex approaches could provide better information on who might benefit most from treatments, improving patient choice and treatment policy and practice
Methods and apparatus for switching a transponder to an active state, and asset management systems employing same
A transponder that may be used as an RFID tag includes a passive circuit to eliminate the need for an "always on" active RF receiving element to anticipate a wake-up signal for the balance of the transponder electronics. This solution allows the entire active transponder to have all circuit elements in a sleep (standby) state, thus drastically extending battery life or other charge storage device life. Also, a wake-up solution that reduces total energy consumption of an active transponder system by allowing all non-addressed transponders to remain in a sleep (standby) state, thereby reducing total system or collection energy. Also, the transponder and wake-up solution are employed in an asset tracking system
Interpretable Subgroup Discovery in Treatment Effect Estimation with Application to Opioid Prescribing Guidelines
The dearth of prescribing guidelines for physicians is one key driver of the
current opioid epidemic in the United States. In this work, we analyze medical
and pharmaceutical claims data to draw insights on characteristics of patients
who are more prone to adverse outcomes after an initial synthetic opioid
prescription. Toward this end, we propose a generative model that allows
discovery from observational data of subgroups that demonstrate an enhanced or
diminished causal effect due to treatment. Our approach models these
sub-populations as a mixture distribution, using sparsity to enhance
interpretability, while jointly learning nonlinear predictors of the potential
outcomes to better adjust for confounding. The approach leads to
human-interpretable insights on discovered subgroups, improving the practical
utility for decision suppor
Molecular structures of gasâphase polyatomic molecules determined by spectroscopic methods
Spectroscopic data related to the structures of polyatomic molecules in the gas phase have been reviewed, critically evaluated, and compiled. All reported bond distances and angles have been classified as equilibrium (re), average (rz), substitution (rs), or effective (ro) parameters, and have been given a quality rating which is a measure of the parameter uncertainty. The surveyed literature includes work from all of the areas of gasâphase spectroscopy from which precise quantitative structural information can be derived. Introductory material includes definitions of the various types of parameters and a description of the evaluation procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87746/2/619_1.pd
Effects of air pollution and the introduction of the London Low Emission Zone on the prevalence of respiratory and allergic symptoms in schoolchildren in East London: a sequential cross-sectional study
The adverse effects of traffic-related air pollution on childrenâs respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8â9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00â1.02), NO2 (1.03, 1.00â1.06), PM10 (1.16, 1.04â1.28) and PM2.5 (1.38, 1.08â1.78), all per ÎŒg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions
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