47,233 research outputs found

    The bacillary and macrophage response to hypoxia in tuberculosis and the consequences for T cell antigen recognition

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    M. tuberculosis is a facultative anaerobe and its characteristic pathological hallmark, the granuloma, exhibits hypoxia in humans and in most experimental models. Thus the host and bacillary adaptation to hypoxia is of central importance in understanding pathogenesis and thereby to derive new drug treatments and vaccines

    The effect of a multi-component intervention on disrespect and abuse during childbirth in Kenya

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    Background Disrespect and abuse (D & A) during labor and delivery are important issues correlated with human rights, equity, and public health that also affect women’s decisions to deliver in facilities, which provide appropriate management of maternal and neonatal complications. Little is known about interventions aimed at lowering the frequency of disrespectful and abusive behaviors. Methods Between 2011 and 2014, a pre-and-post study measured D & A levels in a three-tiered intervention at 13 facilities in Kenya under the Heshima project. The intervention involved working with policymakers to encourage greater focus on D & A, training providers on respectful maternity care, and strengthening linkages between the facility and community for accountability and governance. At participating facilities, postpartum women were approached at discharge and asked to participate in the study; those who consented were administered a questionnaire on D & A in general as well as six typologies, including physical and verbal abuse, violations of confidentiality and privacy, detainment for non-payment, and abandonment. Observation of provider-patient interaction during labor was also conducted in the same facilities. In both exit interview and observational studies, multivariate analyses of risk factors for D & A controlled for differences in socio-demographic and facility characteristics between baseline and endline surveys. Results Overall D & A decreased from 20–13 % (p < 0.004) and among four of the six typologies D & A decreased from 40–50 %. Night shift deliveries were associated with greater verbal and physical abuse. Patient and infant detainment declined dramatically from 8.0–0.8 %, though this was partially attributable to the 2013 national free delivery care policy. Conclusion Although a number of contextual factors may have influenced these findings, the magnitude and consistency of the observed decreases suggest that the multi-component intervention may have the potential to reduce the frequency of D & A. Greater efforts are needed to develop stronger evaluation methods for assessing D & A in other settings

    Bayesian Optimisation for Safe Navigation under Localisation Uncertainty

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    In outdoor environments, mobile robots are required to navigate through terrain with varying characteristics, some of which might significantly affect the integrity of the platform. Ideally, the robot should be able to identify areas that are safe for navigation based on its own percepts about the environment while avoiding damage to itself. Bayesian optimisation (BO) has been successfully applied to the task of learning a model of terrain traversability while guiding the robot through more traversable areas. An issue, however, is that localisation uncertainty can end up guiding the robot to unsafe areas and distort the model being learnt. In this paper, we address this problem and present a novel method that allows BO to consider localisation uncertainty by applying a Gaussian process model for uncertain inputs as a prior. We evaluate the proposed method in simulation and in experiments with a real robot navigating over rough terrain and compare it against standard BO methods.Comment: To appear in the proceedings of the 18th International Symposium on Robotics Research (ISRR 2017

    Computational neurorehabilitation: modeling plasticity and learning to predict recovery

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    Despite progress in using computational approaches to inform medicine and neuroscience in the last 30 years, there have been few attempts to model the mechanisms underlying sensorimotor rehabilitation. We argue that a fundamental understanding of neurologic recovery, and as a result accurate predictions at the individual level, will be facilitated by developing computational models of the salient neural processes, including plasticity and learning systems of the brain, and integrating them into a context specific to rehabilitation. Here, we therefore discuss Computational Neurorehabilitation, a newly emerging field aimed at modeling plasticity and motor learning to understand and improve movement recovery of individuals with neurologic impairment. We first explain how the emergence of robotics and wearable sensors for rehabilitation is providing data that make development and testing of such models increasingly feasible. We then review key aspects of plasticity and motor learning that such models will incorporate. We proceed by discussing how computational neurorehabilitation models relate to the current benchmark in rehabilitation modeling – regression-based, prognostic modeling. We then critically discuss the first computational neurorehabilitation models, which have primarily focused on modeling rehabilitation of the upper extremity after stroke, and show how even simple models have produced novel ideas for future investigation. Finally, we conclude with key directions for future research, anticipating that soon we will see the emergence of mechanistic models of motor recovery that are informed by clinical imaging results and driven by the actual movement content of rehabilitation therapy as well as wearable sensor-based records of daily activity

    GRADE QUALITY OF PARBOILED MILLED DOMESTIC AND IMPORTED RICE VARIETIES SOLD IN SOUTH-EAST NIGERIA

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    The objective of this work was to grade the domestic rice varieties and classify them according to Recommended Model Grading System for Marketing Rice in International Trade. Eighteen (18) domestic rice varieties were collected from Enugu (4), Ebonyi (7) and Anambra State (7). Three (3) imported rice varieties coded Ip1, Ip2, and Ip3 were purchased from Ogige market in Nsukka LGA of Enugu state, Nigeria and served as controls. The rice varieties were cleaned manually by winnowing, graded and classified according to Recommended Model Grading System for Marketing Rice in International Trade. Domestic rice varieties from Enugu state were of grade 1 quality excluding Fortin 16 (old variety). Faro 40 (72.33) and Taraba rice (77.33) from Anambra state were of grade 2 quality while R-Bus (81.33), Igboukwu rice (86.67), Aguleri rice (83.67) and B-G (84.67) were of grade 1 quality. Geshua (68.33) from Ebonyi state was of grade 2 quality while Afikpo-Mas (87.33), Abakiliki-Mas (84.33), R-8 (89.33) and 306 (82.67) were of grade 1 quality. All the imported rice varieties (control samples) were of premium quality.  Omor-Mas (95.33), Akpujie (95.67), kpurukpuru (98.00), and Fortin 16 (old variety) (95.00) were of premium quality and did not differ from the imported rice varieties in grade quality

    Clinical Evaluation of the Efficacy of Arthocare Forte, A Chondro-Protective and Anti-Arthritic Drug in the Management of Bacterial Plaque-Induced Chronic Periodontitis

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    Background: Arthocare forte medication is made up of different  constituents and the advantages offered by this disposition have not been explored in the management of chronic periodontitis. Aim: The aim was to assess the clinical response of bacterial  plaque.induced generalized chronic periodontitis to arthocare medication, and the relationship of age and gender to the prevalence of chronic  periodontal disease. Subjects and Methods: This study was done at the Dental Surgery Clinic of the University of Calabar Teaching Hospital, Nigeria. It was a Prospective randomized  controlled trial evaluating the effect of arthocare treatment on 81/162  patients with teeth mobility over a period of 5 years. All the patients (162) underwent root planing, and 81/162 (50%) were treated with arthocare for comparative analysis. The variables recorded were patientfs age, gender, and degree of tooth mobility, periodontal pocket, and bleeding from the pocket after treatment. Statistical analysis was done using EPI INFO 7. Results: Majority of the patients were between 46 and 75 years in both control (n = 59/81, 72.8%) and experimental groups (n = 52/81, 64.2%). There were 86/162 (53.1%) males and 76/162 (46.9%) females, giving a male.to.female ratio of 1.1:1. Seventy.seven patients (95.1%) in the experimental group had total remission in comparison to 32/81 (39.5%) in control group which was statistically significant (P &lt; 0.001). Conclusion: The arthocare administered to patients in the experimental group speeds up the regenerative capacity and stability of the periodontium when compared with the control. Multicentre clinical trials are recommended to validate the use of arthocare forte in the treatment of generalized chronic periodontitis.Keywords: Arthocare, Bacterial plaque, Chronic periodontiti

    Tailoring Gold Nanoparticle Characteristics and the Impact on Aqueous-Phase Oxidation of Glycerol

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    Poly(vinyl alcohol) (PVA)-stabilized Au nanoparticles (NPs) were synthesized by colloidal methods in which temperature variations (−75 to 75 °C) and mixed H2O/EtOH solvent ratios (0, 50, and 100 vol/vol) were used. The resulting Au NPs were immobilized on TiO2 (P25), and their catalytic performance was investigated for the liquid phase oxidation of glycerol. For each unique solvent system, there was a systematic increase in the average Au particle diameter as the temperature of the colloidal preparation increased. Generation of the Au NPs in H2O at 1 °C resulted in a high observed activity compared with current Au/TiO2 catalysts (turnover frequency = 915 h–1). Interestingly, Au catalysts with similar average particle sizes but prepared under different conditions had contrasting catalytic performance. For the most active catalyst, aberration-corrected high angle annular dark field scanning transmission electron microscopy analysis identified the presence of isolated Au clusters (from 1 to 5 atoms) for the first time using a modified colloidal method, which was supported by experimental and computational CO adsorption studies. It is proposed that the variations in the populations of these species, in combination with other solvent/PVA effects, is responsible for the contrasting catalytic properties

    Light attenuation characteristics of glacially-fed lakes

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    Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400–700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems
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