3,006 research outputs found

    Pauvreté et accÚs à l'eau dans la vallée du Sénégal

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    Water poverty in the Senegal Valley Considering the flood-recession agriculture, the hydraulic history of the valley of the Senegal River is ancient, but knows a deep mutation since the introduction of the irrigation. Can one speak of water poverty, whereas two dams now control the water flow of the Senegal River and ensure a permanent abundance in water ? The answer to this questioning is proposed through the link between poverty, access to funding, access to land, and involvement in resource management.L'histoire hydraulique de la vallée du fleuve Sénégal est ancienne et remonte à la culture de décrue. Mais elle connaßt une profonde mutation depuis l'introduction de l'irrigation. Peut-on parler de « pauvreté hydraulique », alors que deux barrages régulent à présent le régime du fleuve Sénégal et assurent une permanence de l'abondance en eau ? La réponse à cette question est proposée sous l'angle de l'articulation entre la pauvreté, l'accÚs au financement, l'accÚs au foncier, la participation à la gestion de la ressource

    Pauvreté et accÚs à l'eau dans la vallée du Sénégal

    Get PDF
    L'histoire hydraulique de la vallée du fleuve Sénégal est ancienne et remonte à la culture de décrue. Mais elle connaßt une profonde mutation depuis l'introduction de l'irrigation. Peut-on parler de « pauvreté hydraulique », alors que deux barrages régulent à présent le régime du fleuve Sénégal et assurent une permanence de l'abondance en eau ? La réponse à cette question est proposée sous l'angle de l'articulation entre la pauvreté, l'accÚs au financement, l'accÚs au foncier, la participation à la gestion de la ressource.HYDRAULIQUE ; HISTOIRE ; AMENAGEMENT HYDROAGRICOLE ; CULTURE DE DECRUE ; CULTURE IRRIGUEE ; SORGHO ; MIL ; RIZ IRRIGUE ; ACCES A LA TERRE ; RESSOURCES EN EAU ; GESTION DE L'ENVIRONNEMENT ; ACCES AU CREDIT ; TENURE FONCIERE ; ENDETTEMENT ; EXCLUSION SOCIALE ; PAUVRETE ; REVENUS AGRICOLES ; ORGANISATION PAYSANNE ; ACCES A L'EAU ; GESTION DE L'EAU ; SENEGAL ; FLEUVE SENEGAL VALLEE

    Topological semimetal in a fermionic optical lattice

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    Optical lattices play a versatile role in advancing our understanding of correlated quantum matter. The recent implementation of orbital degrees of freedom in chequerboard and hexagonal optical lattices opens up a new thrust towards discovering novel quantum states of matter, which have no prior analogs in solid state electronic materials. Here, we demonstrate that an exotic topological semimetal emerges as a parity-protected gapless state in the orbital bands of a two-dimensional fermionic optical lattice. The new quantum state is characterized by a parabolic band-degeneracy point with Berry flux 2π2\pi, in sharp contrast to the π\pi flux of Dirac points as in graphene. We prove that the appearance of this topological liquid is universal for all lattices with D4_4 point group symmetry as long as orbitals with opposite parities hybridize strongly with each other and the band degeneracy is protected by odd parity. Turning on inter-particle repulsive interactions, the system undergoes a phase transition to a topological insulator whose experimental signature includes chiral gapless domain-wall modes, reminiscent of quantum Hall edge states.Comment: 6 pages, 3 figures and Supplementary Informatio

    Using Three-Dimensional Gait Data for Foot/Ankle Orthopaedic Surgery

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    We present the case of a forty year old male who sustained a torn carotid during strenuous physical activity. This was followed by a right hemispheric stroke due to a clot associated with the carotid. Upon recovery, the patient’s gait was characterized as hemiparetic with a stiff-knee pattern, a fixed flexion deformity of the toe flexors, and a hindfoot varus. Based on clinical exams and radiographs, the surgical treatment plan was established and consisted of correction of the forefoot deformities, possible hamstrings lengthening, and tendon transfer of the posterior tibial tendon to the dorsolateral foot. To aid in surgical planning, a three-dimensional gait analysis was conducted using a state-of-the-art motion capture system. Data from this analysis provided insight into the pathomechanics of the patient’s gait pattern. A forefoot driven hindfoot varus was evident from the presurgical data and the tendon transfer procedure was deemed unnecessary. A computer was used in the OR to provide surgeons with animations of the patient’s gait and graphical results as needed. A second gait analysis was conducted 6 weeks post surgery, shortly after cast removal. Post-surgical gait data showed improved foot segment orientation and position. Motion capture data provides clinicians with detailed information on the multisegment kinematics of foot motion during gait, before and during surgery. Further, treatment effectiveness can be evaluated by repeating gait analyses after recovery

    Osteoarticular Infection in Three Young Thoroughbred Horses Caused by a Novel Gram Negative Cocco-Bacillus

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    © 2020 Bernard J. Hudson et al. We describe three cases of osteoarticular infection (OAI) in young thoroughbred horses in which the causative organism was identified by MALDI-TOF as Kingella species. The pattern of OAI resembled that reported with Kingella infection in humans. Analysis by 16S rRNA PCR enabled construction of a phylogenetic tree that placed the isolates closer to Simonsiella and Alysiella species, rather than Kingella species. Average nucleotide identity (ANI) comparison between the new isolate and Kingella kingae and Alysiella crassa however revealed low probability that the new isolate belonged to either of these species. This preliminary analysis suggests the organism isolated is a previously unrecognised species

    Loneliness, social support and cardiovascular reactivity to laboratory stress

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    Self-reported or explicit loneliness and social support have been inconsistently associated with cardiovascular reactivity (CVR) to stress. The present study aimed to adapt an implicit measure of loneliness, and use it alongside the measures of explicit loneliness and social support, to investigate their correlations with CVR to laboratory stress. Twenty-five female volunteers aged between 18 and 39 years completed self-reported measures of loneliness and social support, and an Implicit Association Test (IAT) of loneliness. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) reactivity indices were measured in response to psychosocial stress induced in the laboratory. Functional support indices of social support were significantly correlated with CVR reactivity to stress. Interestingly, implicit, but not explicit, loneliness was significantly correlated with DBP reactivity after one of the stressors. No associations were found between structural support and CVR indices. Results are discussed in terms of validity of implicit versus explicit measures and possible factors that affect physiological outcomes

    Does oral sodium bicarbonate therapy improve function and quality of life in older patients with chronic kidney disease and low-grade acidosis (the BiCARB trial)? Study protocol for a randomized controlled trial

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    Date of acceptance: 01/07/2015 © 2015 Witham et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements UK NIHR HTA grant 10/71/01. We acknowledge the financial support of NHS Research Scotland in conducting this trial.Peer reviewedPublisher PD

    (De)Constructing a Natural and Flavorful Supersymmetric Standard Model

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    Using the framework of deconstruction, we construct simple, weakly-coupled supersymmetric models that explain the Standard Model flavor hierarchy and produce a flavorful soft spectrum compatible with precision limits. Electroweak symmetry breaking is fully natural; the mu-term is dynamically generated with no B mu-problem and the Higgs mass is easily raised above LEP limits without reliance on large radiative corrections. These models possess the distinctive spectrum of superpartners characteristic of "effective supersymmetry": the third generation superpartners tend to be light, while the rest of the scalars are heavy.Comment: 36 pages, 4 figures ; v2: references added, expanded discussion of FCNC

    Coherent states for exactly solvable potentials

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    A general algebraic procedure for constructing coherent states of a wide class of exactly solvable potentials e.g., Morse and P{\"o}schl-Teller, is given. The method, {\it a priori}, is potential independent and connects with earlier developed ones, including the oscillator based approaches for coherent states and their generalizations. This approach can be straightforwardly extended to construct more general coherent states for the quantum mechanical potential problems, like the nonlinear coherent states for the oscillators. The time evolution properties of some of these coherent states, show revival and fractional revival, as manifested in the autocorrelation functions, as well as, in the quantum carpet structures.Comment: 11 pages, 4 eps figures, uses graphicx packag

    Stochastic population growth in spatially heterogeneous environments

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    Classical ecological theory predicts that environmental stochasticity increases extinction risk by reducing the average per-capita growth rate of populations. To understand the interactive effects of environmental stochasticity, spatial heterogeneity, and dispersal on population growth, we study the following model for population abundances in nn patches: the conditional law of Xt+dtX_{t+dt} given Xt=xX_t=x is such that when dtdt is small the conditional mean of Xt+dti−XtiX_{t+dt}^i-X_t^i is approximately [xiÎŒi+∑j(xjDji−xiDij)]dt[x^i\mu_i+\sum_j(x^j D_{ji}-x^i D_{ij})]dt, where XtiX_t^i and ÎŒi\mu_i are the abundance and per capita growth rate in the ii-th patch respectivly, and DijD_{ij} is the dispersal rate from the ii-th to the jj-th patch, and the conditional covariance of Xt+dti−XtiX_{t+dt}^i-X_t^i and Xt+dtj−XtjX_{t+dt}^j-X_t^j is approximately xixjσijdtx^i x^j \sigma_{ij}dt. We show for such a spatially extended population that if St=(Xt1+...+Xtn)S_t=(X_t^1+...+X_t^n) is the total population abundance, then Yt=Xt/StY_t=X_t/S_t, the vector of patch proportions, converges in law to a random vector Y∞Y_\infty as t→∞t\to\infty, and the stochastic growth rate lim⁥t→∞t−1log⁥St\lim_{t\to\infty}t^{-1}\log S_t equals the space-time average per-capita growth rate \sum_i\mu_i\E[Y_\infty^i] experienced by the population minus half of the space-time average temporal variation \E[\sum_{i,j}\sigma_{ij}Y_\infty^i Y_\infty^j] experienced by the population. We derive analytic results for the law of Y∞Y_\infty, find which choice of the dispersal mechanism DD produces an optimal stochastic growth rate for a freely dispersing population, and investigate the effect on the stochastic growth rate of constraints on dispersal rates. Our results provide fundamental insights into "ideal free" movement in the face of uncertainty, the persistence of coupled sink populations, the evolution of dispersal rates, and the single large or several small (SLOSS) debate in conservation biology.Comment: 47 pages, 4 figure
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