The Adoption and Management of Soil Conservation Practices in Haiti: The Case of Rock Walls

Farmers are usually reluctant to adopt measures to reduce the toll of soil erosion; and even when soil conservation structures are adopted, farmers fail to manage them. This study investigates factors that influence adoption and management of soil conservation structures in Fort-Jacques, Haiti. The results show that personal characteristics of farmers, institutional factors, such as local group membership, training in soil conservation, per capita income and size of farm influence soil conservation adoption in Forte-Jacques. Age, education, per capita household income, participation in local groups, the interaction of per capita household income and farmers’ age influence rock wall management.Resource /Energy Economics and Policy,

Speech of the Hon. James A. Bayard, in the Senate of the United States

Full title: Speech of the Hon. James A. Bayard, in the Senate of the United States, upon his motion made on the 16th of June, to postpone the further consideration of the bill declaring war against Great Britain, to the 31st of October

Algorithms for Maneuvering Spacecraft Around Small Bodies

A document describes mathematical derivations and applications of autonomous guidance algorithms for maneuvering spacecraft in the vicinities of small astronomical bodies like comets or asteroids. These algorithms compute fuel- or energy-optimal trajectories for typical maneuvers by solving the associated optimal-control problems with relevant control and state constraints. In the derivations, these problems are converted from their original continuous (infinite-dimensional) forms to finite-dimensional forms through (1) discretization of the time axis and (2) spectral discretization of control inputs via a finite number of Chebyshev basis functions. In these doubly discretized problems, the Chebyshev coefficients are the variables. These problems are, variously, either convex programming problems or programming problems that can be convexified. The resulting discrete problems are convex parameter-optimization problems; this is desirable because one can take advantage of very efficient and robust algorithms that have been developed previously and are well established for solving such problems. These algorithms are fast, do not require initial guesses, and always converge to global optima. Following the derivations, the algorithms are demonstrated by applying them to numerical examples of flyby, descent-to-hover, and ascent-from-hover maneuvers

Etude pilote sur la pertinence de la détermination du calcium dans la sueur

Le calcium est un électrolyte fréquemment mesuré en médecine, que ce soit dans les contrôles de routine, chez les insuffisants rénaux, en gastro-entérologie, en oncologie ou chez les patients ayant subi une opération de la thyroïde ou des glandes parathyroïdes. En endocrinologie par exemple, une méta-analyse1 montre qu’entre 7% et 50% des patients présentent une hypoparathyroïdie transitoire après une thyroïdectomie dans le cadre d’un cancer thyroïdien et environ 1.2% des patients vont souffrir d’une hypoparathyroïdie postopératoire permanente. Dans ce contexte, des suivis réguliers avec de nombreuses prises de sang doivent être effectués jusqu’à la normalisation de la calcémie, ce qui est chronophage, coûteux et contraignant pour le patient tout comme pour le médecin et le système de santé. Il parait alors pertinent d’envisager d’autres méthodes pour rendre le suivi de la calcémie plus facile et moins invasif pour le patient, avec par exemple de nouveaux dispositifs de monitoring en continu. Ceci permettrait dans le futur d’intervenir plus précocement lors de déviation de la norme en ce qui concerne la calcémie, d’ajuster au mieux les traitements, de possiblement diminuer les coûts liés aux prises de sang ainsi que de réduire le temps et le stress lié au séjour hospitalier des patients. La sueur est déjà utilisée pour le dépistage de la fibrose kystique, grâce au test à la pilocarpine. En effet le dosage quantitatif du chlore dans la sueur est considéré comme le « Gold Standard » pour le diagnostic de la dysfonction du récepteur CFTR responsable de la mucoviscidose. En outre ce test est également utilisé pour documenter la bonne réponse des traitements modulateurs du CFTR, comme l’Ivacaftor. Bien que les techniques de stimulation de la sueur par iontophorèse à la pilocarpine, mises au point par Gibson et Cooke2, existent depuis la fin des années 50, ce n’est que récemment, et grâce aux avancées technologiques dans le domaine de la nanotechnologie, que des études, notamment en néphrologie, en médecine du sport etc., s’intéressent à ce fluide corporel qui a longtemps été́ laissé pour compte. Que ce soit en ce qui concerne le sodium pour l’insuffisance rénale ou en ce qui concerne le chlore ou le potassium, des études ont démontré́ des corrélations, plus ou moins fortes suivant les électrolytes, entre leur concentration dans la sueur et celle dans le sang. Néanmoins, ces études3, ne comportant que peu de participants, ne permettent pas pour l’instant de tirer de conclusions définitives. En ce qui concerne le calcium, la recherche de littérature a montré́ qu’il n’y avait pas d’études qui s’étaient intéressées à la corrélation entre la concentration de calcium plasmatique et sudoral. Seules des études4,5 concernant les conditions de récoltes du calcium ont été́ réalisées. Elles ont démontré́ qu’il n’y avait pas de différence significative (moins de 10% de différence) en fonction de la partie du corps choisie pour la récolte. En raison du manque d’études sur le sujet et le potentiel que la sueur représente pour le suivi de la calcémie, il parait important que des recherches soient effectuées sur ce sujet, c’est pourquoi cette étude s’y intéresse

Neural Connectivity with Hidden Gaussian Graphical State-Model

The noninvasive procedures for neural connectivity are under questioning. Theoretical models sustain that the electromagnetic field registered at external sensors is elicited by currents at neural space. Nevertheless, what we observe at the sensor space is a superposition of projected fields, from the whole gray-matter. This is the reason for a major pitfall of noninvasive Electrophysiology methods: distorted reconstruction of neural activity and its connectivity or leakage. It has been proven that current methods produce incorrect connectomes. Somewhat related to the incorrect connectivity modelling, they disregard either Systems Theory and Bayesian Information Theory. We introduce a new formalism that attains for it, Hidden Gaussian Graphical State-Model (HIGGS). A neural Gaussian Graphical Model (GGM) hidden by the observation equation of Magneto-encephalographic (MEEG) signals. HIGGS is equivalent to a frequency domain Linear State Space Model (LSSM) but with sparse connectivity prior. The mathematical contribution here is the theory for high-dimensional and frequency-domain HIGGS solvers. We demonstrate that HIGGS can attenuate the leakage effect in the most critical case: the distortion EEG signal due to head volume conduction heterogeneities. Its application in EEG is illustrated with retrieved connectivity patterns from human Steady State Visual Evoked Potentials (SSVEP). We provide for the first time confirmatory evidence for noninvasive procedures of neural connectivity: concurrent EEG and Electrocorticography (ECoG) recordings on monkey. Open source packages are freely available online, to reproduce the results presented in this paper and to analyze external MEEG databases

Zero-dispersion Wavelength Mapping in Short Single-Mode Optical Fibers Using Parametric Amplification

We demonstrate a novel convenient nondestructive method based on optical parametric amplification that allows retrieval of the zero-dispersion wavelength map along a short optical fiber span with a high-spatial resolution. The improved resolution relies on the high sensitivity to the local longitudinal dispersion fluctuations of the parametric high-gain spectrum.Comment: 3 page

Numerical Analysis on the Optimisation of Thermal Comfort Levels in an Office Located inside a Historical Building

The present study examines the possibility of thermal comfort optimisation inside an office room where, due to historical heritage, it is possible to modify neither the energetic characteristic of the envelope nor the position of the inlet air vents. The distribution of global and local thermal comfort indices is evaluated in both heating and cooling conditions by establishing a computational fluid dynamics (CFD) model validated against experimental data. The obtained results demonstrate a striking asymmetry of the air velocity and temperature distribution due to the low energy efficiency of the building. In heating mode, the predicted mean vote (PMV) values were improved if the discharged air from the fan coil was at its maximal velocity. However, at the same time, the vertical air temperature gradient increased by around 0.5 C in each working station. In the cooling condition, in the absence of the solar radiation, the minimal air-flow rate satisfied the acceptable range of the draught rate (DR), whereas in the presence of a solar load, it could not meet the required cooling load in all positions, leading to higher floor temperature. The findings of this study allow for identifying and rearranging the optimal position of working stations in terms of thermal comfort

A qualitative study on the impacts of COVID-19 on the delivery of randomised controlled trials evaluating lay-delivered psychological interventions in five countries

COVID-19 is having substantial impacts on research conduct, including clinical trials. However, there is limited research investigating the impact of the pandemic on the conduct of clinical trials and barriers to the delivery of interventions. The current study contributes to filling this gap by investigating the impacts of COVID-19 and related mitigation strategies in the context of five randomised controlled trials (RCTs) of lay-delivered psychological interventions for Syrian refugees in Jordan, Lebanon, the Netherlands, Switzerland, and Turkey. We conducted semi-structured interviews with purposively selected researchers (N = 14) across all five countries. Data were analysed using codebook thematic analysis. The trial researchers highlighted how COVID-19 has had pervasive impacts across different components of the trial including recruitment, assessment, intervention delivery, and supervision. These impacts were considered to influence the external and internal scientific validity of these trials, as well as some aspects of trial administration such as budgeting and the workforce. Various mitigation strategies to adapt to constraints imposed by pandemic responses were described by researchers, such as shifting to a remote intervention delivery and evaluation or adding COVID-19 measures to better understand the impacts of COVID-19 on outcome data. The current piece provides an account of the impacts of COVID-19 on the conduct of trials of lay-delivered psychological interventions for refugees in five countries. Our findings will be valuable for researchers testing similar interventions during COVID-19 and other public health emergencies