Spatial beam self-cleaning and supercontinuum generation with Yb-doped multimode graded-index fiber taper based on accelerating self-imaging and dissipative landscape

We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index profile when 1064 nm pulsed beams propagate from wider (122 µm) into smaller (37 µm) diameter. In the passive mode, increasing the input beam peak power above 20 kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self-cleaning with supercontinuum generation between 520-2600 nm. By taper cut-back, we observed that the dissipative landscape, i.e., a non-monotonic variation of the average beam power along the MMF, leads to modal transitions of self-cleaned beams along the taper length

Une typologie d'exploitations agropastorales au Siné-Saloum, Sénégal

Les auteurs ont utilisé des méthodes d'analyse multidimensionnelle (analyse factorielle des correspondances, classification hiérarchique) pour réaliser une typologie d'exploitations agropastorales sur la base d'une enquête menée au Siné-Saloum, Sénégal, sur 245 exploitations. Les variables retenues concernent principalement la taille de l'exploitation (nombre d'actifs, surfaces cultivées), le cheptel de traction, le troupeau bovin extensif et les petits ruminants. A partir des 4 groupes de la typologie, une interprétation est donnée des principaux modes de fonctionnement des exploitations et des hypothèses sont discutées quant à la dynamique de ces exploitations, en relation notamment avec les modes de capitalisation et avec la traction bovin

Prise en charge du priapisme à Dakar

Résumé Objectif Évaluer la prise en charge des patients présentant un priapisme. Patients et méthodes Il s’agit d’une étude rétrospective sur quatre ans, du 1er août 2002 au 31 juillet 2006, portant sur 35 patients. Les cadres d’étude ont été les trois grands services d’urologie du Sénégal qui sont tous à Dakar. Les paramètres suivants ont été étudiés: l’âge, le temps d’évolution du priapisme, les données anamnestiques, le type hémodynamique du priapisme, les résultats du bilan paraclinique, le traitement chirurgical (la technique chirurgicale, la technique d’anesthésie), la durée d’hospitalisation, le traitement associé, les complications per- et postopératoires, les résultats immédiats et à long terme. Résultats L’âge moyen des patients était de 21,2 ans. Le groupe d’âge le plus représenté était celui de 20 à 30 ans. La majorité des patients (43 %) avaient une notion de drépanocytose connue. La plupart des patients (65 %) ont été pris en charge avant 24 heures d’évolution. Chez tous nos patients, le priapisme était de bas débit. Dans 50 % des cas, les patients drépanocytaires avaient une forme SS. Dans près de la moitié des cas (62 %), la technique d’anesthésie choisie a été le bloc pénien. La ponction des corps caverneux a été le moyen thérapeutique le plus utilisé (63 %). Aucune complication postopératoire majeure n’a été déplorée dans la prise en charge des patients dans notre série. Chez presque tous les patients (95 %), la détumescence durable a été notée le jour même du début du traitement ou le lendemain. Conclusion: Le priapisme, bien que rare en Afrique, est caractérisé par la prédominance de la drépanocytose comme étiologie et le délai particulièrement long de la prise en charge. </jats:sec

Development of a PbWO4 Detector for Single-Shot Positron Annihilation Lifetime Spectroscopy at the GBAR Experiment

We have developed a PbWO4 (PWO) detector with a large dynamic range to measure the intensity of a positron beam and the absolute density of the ortho-positronium (o-Ps) cloud it creates. A simulation study shows that a setup based on such detectors may be used to determine the angular distribution of the emission and reflection of o-Ps to reduce part of the uncertainties of the measurement. These will allow to improve the precision in the measurement of the cross-section for the (anti)hydrogen formation by (anti)proton-positronium charge exchange and to optimize the yield of antihydrogen ion which is an essential parameter in the GBAR experiment

Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

Combined Inflammatory and Metabolic Defects Reflected by Reduced Serum Protein Levels in Patients with Buruli Ulcer Disease

Buruli ulcer is a skin disease caused by Mycobacterium ulcerans that is spreading in tropical countries, with major public health and economic implications in West Africa. Multi-analyte profiling of serum proteins in patients and endemic controls revealed that Buruli ulcer disease down-regulates the circulating levels of a large array of inflammatory mediators, without impacting on the leukocyte composition of peripheral blood. Notably, several proteins contributing to acute phase reaction, lipid metabolism, coagulation and tissue remodelling were also impacted. Their down-regulation was selective and persisted after the elimination of bacteria with antibiotic therapy. It involved proteins with various functions and origins, suggesting that M. ulcerans infection causes global and chronic defects in the host’s protein metabolism. Accordingly, patients had reduced levels of total serum proteins and blood urea, in the absence of signs of malnutrition, or functional failure of liver or kidney. Interestingly, slow healers had deeper metabolic and coagulation defects at the start of antibiotic therapy. In addition to providing novel insight into Buruli ulcer pathogenesis, our study therefore identifies a unique proteomic signature for this disease

Immune Response in Lambs Naturally Infected With Mycoplasma Species

During the past several years, an ovine coughing syndrome characterized by paroxysmal cough leading to rectal prolapses has been observed in Iowa and neighboring states. Preliminary studies conducted by Kaeberle and Eness (1) several years ago indicated the presence of relatively high levels of M. ovipneumoniae (MO) antibody in lambs from affected flocks. In the present study, serum samples obtained from six flocks around the state of Iowa, at various stages of the clinical disease, were compared by ELISA for antibody to MO and M. arginini (MA). Results indicated low antibody levels to MO in flocks sampled at the early stages of infection whereas increased levels of antibody were evident in lambs from flocks that had apparently recovered from the disease. On the other hand, antibody levels to MA were more likely to increase earlier in the disease process. Our results suggest that the chronic nature of this disease may result from the failure of the immune system to produce antibodies that are protective against MO infection. At such a time that appreciable levels of specific antibodies appear in the serum (several weeks following infection) lambs seem to recover from the clinical disease. In addition, this lack of circulating antibody levels against MO would not be inconsistent with a predominant IgE response during early stages of the clinical disease as we have suggested in another entry in this issue of Sheep Research Reports

Modulation of Immune Response in Lambs

Experiments using different types of antigen-adjuvant preparations were conducted in outbred sheep to compare effects of adjuvants on immune responses. Trinitrophenyl-ovalbumin (TNP-ovalbumin) incorporated in a preparation with nonionic block copolymers elicited high antibody titers to both ovalbumin and TNP. Different humoral immune responses were observed when Pasteurella haemolytica lipopolysaccharide (LPS) was added to the preparations. Responses to ovalbumin and TNP were reduced when Pasteurella haemolytica LPS was added to copolymer L121. The antibody titers to ovalbumin or TNP were not affected by the addition of LPS to the preparation containing copolymer L180.5. Lymphocyte proliferation assays demonstrated high stimulation indices at day 17 to ovalbumin by lymphocytes from lambs receiving preparations containing copolymers without Pasteurella haemolytica LPS

Type I Hypersensitivity in Lambs With Coughing Syndrome

Lambs from two flocks with a chronic respiratory disease characterized by paroxysmal cough and rectal prolapses were tested for their skin reactivity to Mycoplasma ovipneumoniae (MO) and M. arginini (MA) antigens (Ags). There was a marked, immediate skin reaction to intradermal injection of MO Ag in many of the tested lambs. Some of these positive lambs also reacted to MA Ag. Phosphate buffered saline (PBS) used as a negative control gave no skin reaction in any of the tested animals. In addition, simultaneous serological tests revealed low antibody levels against MO and MA. However, both agents could be routinely isolated from nasal swabs of the affected lambs. There is reason to suspect that an immediate type hypersensitivity to MO Ag and perhaps to other allergens that develops in association with the mycoplasmal infection contributes to this coughing syndrome

Dérivation du haut appareil urinaire par une sonde JJ: indications et résultatsdansuneétude rétrospective et monocentrique

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