A Killing Disease Epidemic Among Displaced Sudanese Population Identified as Visceral Leishmaniasis.

A fatal disease epidemic affected the Bentiu area in southern Sudan and led to a mass migration of the Nuer tribe searching for treatment. The initially available information revealed a high mortality rate due to a possible occurrence of tuberculosis, malaria, enteric fever or visceral leishmaniasis (VL). Serological screening of 53 of the most severely affected patients in an enzyme-linked immunosorbent assay (ELISA) or an improved direct agglutination test (DAT) revealed positivity for VL. In 39 of those patients, diagnosis was confirmed by identification of Leishmania donovani amastigotes in lymph node or bone-marrow aspirates. In a total of 2714 patients observed, 1195 (44.0%) had clinical symptoms suggesting VL: DAT positive titers (1:3200-greater than or equal to 1:12800) were obtained in 654 (24.1%), of whom 325 were confirmed parasitologically. Forty-two VL cases died before or during treatment, giving a mortality rate of 6.4%. Among the intercurrent infections diagnosed in the VL population (654), respiratory involvements (31.7%) and malaria (10.7%) were most prevalent. With the exception of four (0.6%), all other VL patients (509) responded readily to sodium stibogluconate. The factors initiating the outbreak are discussed. Malnutrition and nomadic movements to potential VL endemic areas appeared to be the most important. HIV infection as a possible predisposition seemed remote considering the clinical and epidemiological similarity to VL occurring in East Africa, adequate humoral response in DAT, and immediate positive response to specific anti-Leishmania chemotherapy

Crystallization Mechanism of Hard Sphere Glasses

In supercooled liquids, vitrification generally suppresses crystallization. Yet some glasses can still crystallize despite the arrest of diffusive motion. This ill-understood process may limit the stability of glasses, but its microscopic mechanism is not yet known. Here we present extensive computer simulations addressing the crystallization of monodisperse hard-sphere glasses at constant volume (as in a colloid experiment). Multiple crystalline patches appear without particles having to diffuse more than one diameter. As these patches grow, the mobility in neighbouring areas is enhanced, creating dynamic heterogeneity with positive feedback. The future crystallization pattern cannot be predicted from the coordinates alone: crystallization proceeds by a sequence of stochastic micro-nucleation events, correlated in space by emergent dynamic heterogeneity.Comment: 4 pages 4 figures Accepted for publication in Phys. Rev. Lett., April 201

Modelling and validation of synthesis of poly lactic acid using an alternative energy source through a continuous reactive extrusion process

PLA is one of the most promising bio-compostable and bio-degradable thermoplastic polymers made from renewable sources. PLA is generally produced by ring opening polymerization (ROP) of lactide using the metallic/bimetallic catalyst (Sn, Zn, and Al) or other organic catalysts in a suitable solvent. In this work, reactive extrusion experiments using stannous octoate Sn(Oct)2 and tri-phenyl phosphine (PPh)3 were considered to perform ROP of lactide. Ultrasound energy source was used for activating and/or boosting the polymerization as an alternative energy (AE) source. Ludovic® software, designed for simulation of the extrusion process, had to be modified in order to simulate the reactive extrusion of lactide and for the application of an AE source in an extruder. A mathematical model for the ROP of lactide reaction was developed to estimate the kinetics of the polymerization process. The isothermal curves generated through this model were then used by Ludovic software to simulate the “reactive” extrusion process of ROP of lactide. Results from the experiments and simulations were compared to validate the simulation methodology. It was observed that the application of an AE source boosts the polymerization of lactide monomers. However, it was also observed that the predicted residence time was shorter than the experimental one. There is potentially a case for reducing the residence time distribution (RTD) in Ludovic® due to the ‘liquid’ monomer flow in the extruder. Although this change in parameters resulted in validation of the simulation, it was concluded that further research is needed to validate this assumption

Controlled Delivery of Sdf-1 Alpha and Igf-1: Cxcr4(+) Cell Recruitment and Functional Skeletal Muscle Recovery

Therapeutic delivery of regeneration-promoting biological factors directly to the site of injury has demonstrated its efficacy in various injury models. Several reports describe improved tissue regeneration following local injection of tissue specific growth factors, cytokines and chemokines. Evidence exists that combined cytokine/growth factor treatment is superior for optimizing tissue repair by targeting different aspects of the regeneration response. The purpose of this study was to evaluate the therapeutic potential of the controlled delivery of stromal cell-derived factor-1alpha (SDF-1 alpha) alone or in combination with insulin-like growth factor-I (SDF-1 alpha/IGF-I) for the treatment of tourniquet-induced ischemia/reperfusion injury (TK-I/R) of skeletal muscle. We hypothesized that SDF-1 alpha will promote sustained stem cell recruitment to the site of muscle injury, while IGF-I will induce progenitor cell differentiation to effectively restore muscle contractile function after TK-I/R injury while concurrently reducing apoptosis. Utilizing a novel poly-ethylene glycol PEGylated fibrin gel matrix (PEG-Fib), we incorporated SDF-1 alpha alone (PEG-Fib/SDF-1 alpha) or in combination with IGF-I (PEG-Fib/SDF-1 alpha/IGF-I) for controlled release at the site of acute muscle injury. Despite enhanced cell recruitment and revascularization of the regenerating muscle after SDF-1 alpha treatment, functional analysis showed no benefit from PEG-Fib/SDF-1 alpha therapy, while dual delivery of PEG-Fib/SDF-1 alpha/IGF-I resulted in IGF-I-mediated improvement of maximal force recovery and SDF-1 alpha-driven in vivo neovasculogenesis. Histological data supported functional data, as well as highlighted the important differences in the regeneration process among treatment groups. This study provides evidence that while revascularization may be necessary for maximizing muscle force recovery, without modulation of other effects of inflammation it is insufficient.Kinesiology and Health Educatio

Online, interactive user guidance for high-dimensional, constrained motion planning

We consider the problem of planning a collision-free path for a high-dimensional robot. Specifically, we suggest a planning framework where a motion-planning algorithm can obtain guidance from a user. In contrast to existing approaches that try to speed up planning by incorporating experiences or demonstrations ahead of planning, we suggest to seek user guidance only when the planner identifies that it ceases to make significant progress towards the goal. Guidance is provided in the form of an intermediate configuration $\hat{q}$, which is used to bias the planner to go through $\hat{q}$. We demonstrate our approach for the case where the planning algorithm is Multi-Heuristic A* (MHA*) and the robot is a 34-DOF humanoid. We show that our approach allows to compute highly-constrained paths with little domain knowledge. Without our approach, solving such problems requires carefully-crafting domain-dependent heuristics

LCF Life of NiCr-Y Coated Disk Alloys After Shot Peening, Oxidation and Hot Corrosion

In a prior companion study (Ref. 1), three different Ni-Cr coating compositions (29, 35.5, 45 wt% Cr) were applied at two thicknesses by Plasma Enhanced Magnetron Sputtering (PEMS) to two similar Ni-based disk alloys. One coating also received a thin ZrO2 overcoat. The low cycle fatigue (LCF) life of each coating was determined at 760 C and was less than that of the uncoated specimens. In this followon effort, shot peening was examined as a means to improve the as-deposited coating morphology as well as impart a residual compressive stress in the near-surface region. After evaluating the effect of the shot peening on the LCF life, the effectiveness of the shot-peened coating in protecting the disk alloy from oxidation and hot corrosion attack was evaluated. This evaluation was accomplished by exposing coated and shot-peened specimens to 500 h of oxidation followed by 50 h of hot corrosion, both at 760 C in air. These exposed specimens were then tested in fatigue and compared to similarly treated and exposed uncoated specimens. For all cases, shot peening improved the LCF life of the coated specimens. More specifically, the highest Cr coating showed the best LCF life of the coated specimens after shot peening, as well as after the environmental exposures. Characterization of the coatings after shot peening, oxidation, hot corrosion and LCF testing is presented and discussed

Kinematics of CO2 fluxes in the tropical Atlantic ocean during the 1983 northern summer

CO2 evasion within the Atlantic equatorial belt (5°N-5°S) increases from the East to the West (Andrié et al., 1986). Many factors contribute the variations of pCO2 in the equatorial surface waters. To assess their relative importance, a kinematic box model is developed. A 2° x 2° box whose depth is defined by the 24.90 °/°° isopcynal level flows westward from 4°W to 38°W within the Equator-2°S band with the south equatorial current. Time (zonal) evolution of nitrate, total CO2, total alkalinity and mass, and of the corresponding water pCO2, are simulated taking into account advection, meridional divergence, diffusion, biological activity and gas exchange. Initial and boundary conditions are taken from the FOCAL 4 (July-August 1983) data se

The bile duct ligated rat : a relevant model to study muscle mass loss in cirrhosis

Muscle mass loss and hepatic encephalopathy (complex neuropsychiatric disorder) are serious complications of chronic liver disease (cirrhosis) which impact negatively on clinical outcome and quality of life and increase mortality. Liver disease leads to hyperammonemia and ammonia toxicity is believed to play a major role in the pathogenesis of hepatic encephalopathy. However, the effects of ammonia are not brain-specific and therefore may also affect other organs and tissues including muscle. The precise pathophysiological mechanisms underlying muscle wasting in chronic liver disease remains to be elucidated. In the present study, we characterized body composition as well as muscle protein synthesis in cirrhotic rats with hepatic encephalopathy using the 6-week bile duct ligation (BDL) model which recapitulates the main features of cirrhosis. Compared to sham-operated control animals, BDL rats display significant decreased gain in body weight, altered body composition, decreased gastrocnemius muscle mass and circumference as well as altered muscle morphology. Muscle protein synthesis was also significantly reduced in BDL rats compared to control animals. These findings demonstrate that the 6-week BDL experimental rat is a relevant model to study liver disease-induced muscle mass loss