Dynamique de la teneur en carbone et en azote des sols dans les systèmes d’exploitation du Ferlo : cas du CRZ de Dahra

Objectif : Cette étude, réalisée au Centre de Recherches Zootechniques (CRZ) de Dahra situé en Région sylvopastorale du Sénégal, a pour objectif d’apprécier l’évolution de la teneur en carbone, en azote et le stock de carbone du sol dans ses différents systèmes d’exploitation.Méthodologie et résultats : En 2011, des échantillons de sols (à 0-20 cm et 20 – 40 cm) ont été prélevés au niveau des mêmes sites que ceux qui ont fait l’objet d’analyse de sols en 1962, afin de déterminer la teneur en carbone et azote du sol. Le nombre d’échantillons est fonction de la superficie des différents types de sols rencontrés. L’utilisation de la cartographie nous a permis de déterminer le nombre d’échantillon prélevé sur chaque système d’exploitation. Au niveau du CRZ de Dahra, l’analyse des paramètres pédologiques (teneur en carbone, en azote et rapport C/N) de l’horizon 0-20 cm, n’a pas révélé de différence significative entre 1962 et 2011. Par contre, dans l’horizon 20-40 cm, seule la teneur en azote présente une hausse significative entre ces deux périodes. S’agissant des systèmes d’exploitation du CRZ de Dahra, l’analyse de la teneur en carbone, en azote et du rapport C/N de l’horizon 0-20 cm, n’a pas révélé de différence significative aussi bien pour l’année 1962 que celle de 2011. Au niveau de l’horizon 20-40 cm, parmi les paramètres étudiés, seul la teneur en carbone de 1962 présentait une différence significative (au seuil de 5%) entre les systèmes de cultures et les pâturages. Le stock de carbone du centre est en moyenne de 0,08±0,03 et 0,06±0,02 t/ha respectivement pour les horizons 0-20 et 20-40 cm. Celui-ci est plus important au niveau des gommiers et plus faibles dans les systèmes de culture et les pâturages.Conclusion et application des résultats : Cette étude a permis de montrer qu’au niveau du CRZ de Dahra à vocation essentiellement pastorale, le carbone et l’azote du sol, présente une certaine stabilité dans les différents systèmes d’exploitation. Toutefois, les gommiers présentent les teneurs en carbone et en azote du sol les plus importantes. Ces résultats peuvent servir de données d’entrée aux modèles de prévision de la séquestration du carbone et de l’azote du sol des écosystèmes sahéliens pastoraux, être valorisés en aménagement pastoral et agro-sylvopastoral en vue d’une meilleure préservation de l’environnement et de la gestion de la fertilité du sol.Mots clés : carbone, l'azote, le contenu, les sol

Genome of the carbapenemase-producing clinical isolate Elizabethkingia miricola EM_CHUV and comparative genomics with Elizabethkingia meningoseptica and Elizabethkingia anophelis: evidence for intrinsic multidrug resistance trait of emerging pathogens.

Elizabethkingia miricola is a Gram-negative non-fermenting rod emerging as a life-threatening human pathogen. The multidrug-resistant (MDR) carbapenemase-producing clinical isolate E. miricola EM_CHUV was recovered in the setting of severe nosocomial pneumonia. In this study, the genome of E. miricola EM_CHUV was sequenced and a functional analysis was performed, including a comparative genomic study with Elizabethkingia meningoseptica and Elizabethkingia anophelis. The resistome of EM_CHUV revealed the presence of a high number of resistance genes, including the presence of the blaGOB-13 and blaB-9 carbapenemase-encoding genes. Twelve mobility genes, with only two of them located in the proximity of resistance genes, and four potential genomic islands were identified in the genome of EM_CHUV, but no prophages or CRISPR sequences. Ten restriction-modification system (RMS) genes were also identified. In addition, we report the presence of a putative conjugative plasmid (pEM_CHUV) that does not encode any antibiotic resistance genes. Altogether, these findings point towards a limited number of DNA exchanges with other bacteria and suggest that multidrug resistance is an intrinsic trait of E. miricola owing to the presence of a high number of resistance genes within the bacterial core genome

Flexible and reliable operation of a photovoltaic system through a back-to-back converter

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.Photovoltaic systems, despite their 40 % annual growing over the 10 last years, have yet high initial installations costs. There are oversizing problems and storage difficulties inherent of isolated systems. For interconnected systems, the islanding is still the main challenge. This work proposes the use of a "backto- back" converter that allows the improvement of the sun's energy, especially in localities where the distribution network is intermittent. The proposed configuration enables the operation of photovoltaic systems in three different operation modes at the point of maximum power and a smooth transition between modes without the need of batteries for storage. Simulation results in PSCAD/EMTDC are presented to prove all the functionality of the proposed configuration.dc201

Pathogenesis of adolescent idiopathic scoliosis in girls - a double neuro-osseous theory involving disharmony between two nervous systems, somatic and autonomic expressed in the spine and trunk: possible dependency on sympathetic nervous system and hormones with implications for medical therapy

Anthropometric data from three groups of adolescent girls - preoperative adolescent idiopathic scoliosis (AIS), screened for scoliosis and normals were analysed by comparing skeletal data between higher and lower body mass index subsets. Unexpected findings for each of skeletal maturation, asymmetries and overgrowth are not explained by prevailing theories of AIS pathogenesis. A speculative pathogenetic theory for girls is formulated after surveying evidence including: (1) the thoracospinal concept for right thoracic AIS in girls; (2) the new neuroskeletal biology relating the sympathetic nervous system to bone formation/resorption and bone growth; (3) white adipose tissue storing triglycerides and the adiposity hormone leptin which functions as satiety hormone and sentinel of energy balance to the hypothalamus for long-term adiposity; and (4) central leptin resistance in obesity and possibly in healthy females. The new theory states that AIS in girls results from developmental disharmony expressed in spine and trunk between autonomic and somatic nervous systems. The autonomic component of this double neuro-osseous theory for AIS pathogenesis in girls involves selectively increased sensitivity of the hypothalamus to circulating leptin (genetically-determined up-regulation possibly involving inhibitory or sensitizing intracellular molecules, such as SOC3, PTP-1B and SH2B1 respectively), with asymmetry as an adverse response (hormesis); this asymmetry is routed bilaterally via the sympathetic nervous system to the growing axial skeleton where it may initiate the scoliosis deformity (leptin-hypothalamic-sympathetic nervous system concept = LHS concept). In some younger preoperative AIS girls, the hypothalamic up-regulation to circulating leptin also involves the somatotropic (growth hormone/IGF) axis which exaggerates the sympathetically-induced asymmetric skeletal effects and contributes to curve progression, a concept with therapeutic implications. In the somatic nervous system, dysfunction of a postural mechanism involving the CNS body schema fails to control, or may induce, the spinal deformity of AIS in girls (escalator concept). Biomechanical factors affecting ribs and/or vertebrae and spinal cord during growth may localize AIS to the thoracic spine and contribute to sagittal spinal shape alterations. The developmental disharmony in spine and trunk is compounded by any osteopenia, biomechanical spinal growth modulation, disc degeneration and platelet calmodulin dysfunction. Methods for testing the theory are outlined. Implications are discussed for neuroendocrine dysfunctions, osteopontin, sympathoactivation, medical therapy, Rett and Prader-Willi syndromes, infantile idiopathic scoliosis, and human evolution. AIS pathogenesis in girls is predicated on two putative normal mechanisms involved in trunk growth, each acquired in evolution and unique to humans

Sistemas de justiça e a vitimização secundária de crianças e ou adolescentes acometidas de violência sexual intrafamiliar

Este artigo aponta resultados de pesquisa realizada junto aos juízes de direito, sobre a inquirição de crianças e/ou adolescentes, vítimas de violência sexual, no sistema de justiça. Referencial teórico centrado na visão do contexto ecológico do desenvolvimento humano. O método foi de natureza qualitativa, com entrevista semiestruturada e observação livre, em Comarcas do Judiciário Brasileiro. O tratamento dos dados deu-se a partir da técnica de análise de conteúdo temática, que aponta “Impotências e Limites” e “Violência Secundária”. Na primeira, o juiz, desprovido de preparo, socorre-se à hora da inquirição da vítima, de modelo cujas bases estão na prática, experiência de vida, sem apropriar-se das estruturas necessárias ao procedimento. A didática utilizada é de senso comum. “Violência Secundária” evidencia que os modos de intervenção do lugar do judiciário podem ser vistos como aspectos de revitimização de crianças e adolescentes, quando apenas ouve tais pessoas em sucessivos momentos para obtenção de materialidade da prova para incriminação do agressor, em discordância entre a prioridade imediata e a absoluta assegurada legalmente pela Constituição Federal Brasileira. O Sistema Judicial não demonstra estar organizado para priorizar questões envolvendo crianças e adolescentes. Seja como suporte para lidar com as possíveis implicações da inquirição, seja na discussão para se formular abordagens que evitem a violência secundária de vítimas de violência sexual. O campo da saúde poderá trazer contribuições para a área judiciária desde que o problema seja visto a partir de uma dimensão interdisciplinar, ainda que caiba ao judiciário a palavra final para a sua solução

The structural evolution of the Dialé-Dalérna basin, Kédougou-Kéniéba Inlier, eastern Senegal

The Diale-Dalema group is located in the eastern part of the Kedougou-Kenieba Inlier (KKI) and is essentially composed of Paleoproterozoic rock formations. Lithostructural studies in this area, hassuggested, often controversial, deformational regimes and geodynamic evolution models. In this study, we suggest the existence of an initial tangential D-1 deformation and transpressional D-2 deformational phases. D-1 is characterized by an initial metamorphic schistosity denoted as S-1 and by F-1 folds with the main shortening stress direction generally oriented in NW-SE direction. D-2 in the study area is divided into two stages. The first stage designated as D-2a is coaxial and compressive in nature. It is characterized by a N-S to NNE-SSW trending metamorphic schistosity termed 5(2a). The D-2a phase evolves gradually to a transcurrent phase connoted as D-2b and characterized by a NNE-SSW S-2b metamorphic schistosity which is axial planar to the F-2b folds with subvertical fold axes. During the D-2 phase, the main shortening stress direction rotates gradually in a clockwise motion from an E-W to a NW-SE direction within a continuum of deformation. The third deformation phase D-3 in the Diale-Dalerna basin, is also divided into two stages, thus D-3a and D-3b. D-3a is transcurrent and transtensive in nature and is characterized by NE-SW sinistral shear corridors with local extensional jogs. During this deformation stage, the maximum shortening stress (sigma(1)) direction acts in a N-S direction and rotate to a NE-SW direction, thereby creating a N-S transcurrent dextral shear corridors. D-3b component of the D-3 deformation is compressive in nature with a weak sinistral shear component. The D-4 corresponds to a N-S extensional phase which is characterized by E-W directed normal faults. D-4 in the study area denotes the final stage of the evolution of the Eburnean orogeny in the KM

Phenotypic and genotypic characterization of clinical carbapenem-resistant Enterobacteriaceae isolates from Sokoto, northwest Nigeria

Emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) are two of the major problems currently threatening global public health. In Nigeria, interest in CPE is recent. In Sokoto, northwest Nigeria, there are no data on the prevalence and mechanism underlying carbapenem resistance. In this study, we aimed to investigate the presence of clinical carbapenems-resistant Enterobacteriaceae isolates in two leading hospitals in Sokoto, northwest Nigeria. A total of 292 non-duplicate Enterobacteriaceae isolated from clinical specimens processed in the diagnostic laboratories of two hospitals between January and June 2019 were collected. Of these, 129 (44.2 %) and 19 (6.5%) were resistant to third-generation cephalosporin and carbapenems, respectively. RT-PCR revealed that 10 (7.8%), 19 (14.7%) and 46 (35.7%) of the third-generation cephalosporin-resistant isolates harboured bla(SHV), bla(TEM) and bla(CTX-M) genes, respectively. The modified Carba NP test result showed that only 7 (36.8 %) of the 19 carbapenem-resistant isolates were carbapenemase producing; among them, bla(NDM-5) and bla(OXA-181) genes were identified in five and two isolates, respectively. However, none of the carbapenemase genes investigated, including bla(VIM), bla(KPC) and bla(IMP), was detected in the remaining carbapenem-resistant isolates, suggesting a non-enzymatic mechanism. This study reports for the first time, the emergence of CPE in Sokoto state and the detection of NDM-producing Citrobacter freundii in Nigeria. The observed CPE in this study is a concern in a country where alternative antibiotics are rarely available. (C) 2020 The Authors. Published by Elsevier Ltd