978 research outputs found
Large Scale Earth's Bow Shock with Northern IMF as simulated by PIC code in parallel with MHD model
In this paper, we propose a 3D kinetic model (Particle-in-Cell PIC ) for the
description of the large scale Earth's bow shock. The proposed version is
stable and does not require huge or extensive computer resources. Because PIC
simulations work with scaled plasma and field parameters, we also propose to
validate our code by comparing its results with the available MHD simulations
under same scaled Solar wind ( SW ) and ( IMF ) conditions. We report new
results from the two models. In both codes the Earth's bow shock position is
found to be ~14.8 RE along the Sun-Earth line, and ~ 29 RE on the dusk side.
Those findings are consistent with past in situ observations. Both simulations
reproduce the theoretical jump conditions at the shock. However, the PIC code
density and temperature distributions are inflated and slightly shifted sunward
when compared to the MHD results. Kinetic electron motions and reflected ions
upstream may cause this sunward shift. Species distributions in the foreshock
region are depicted within the transition of the shock (measured ~2
c/{\omega}pi for {\Theta}Bn =90o and MMS =4.7 ) and in the downstream. The size
of the foot jump in the magnetic field at the shock is measured to be (1.7
c/{\omega}pi ). In the foreshocked region, the thermal velocity is found equal
to 213 km.sec-1 at 15 RE and is equal to 63 km.sec-1at 12 RE (Magnetosheath
region). Despite the large cell size of the current version of the PIC code, it
is powerful to retain macrostructure of planets magnetospheres in very short
time, thus it can be used for a pedagogical test purposes. It is also likely
complementary with MHD to deepen our understanding of the large scale
magnetosphereComment: 26 pages, 8 figures, 1 table , 66 references, JOAA-D-16-00005/201
Susceptibility of staphylococal biofilms to multiple combination of antimicrobials
Scientific supervisor: A.G. Dyachenk
Personalization framework for adaptive robotic feeding assistance
The final publication is available at link.springer.comThe deployment of robots at home must involve robots with pre-defined skills and the capability of
personalizing their behavior by non-expert users. A framework to tackle this personalization is presented and applied
to an automatic feeding task. The personalization involves the caregiver providing several examples of feeding using
Learning-by- Demostration, and a ProMP formalism to compute an overall trajectory and the variance along the path.
Experiments show the validity of the approach in generating different feeding motions to adapt to user’s preferences,
automatically extracting the relevant task parameters. The importance of the nature of the demonstrations is also
assessed, and two training strategies are compared. © Springer International Publishing AG 2016.Peer ReviewedPostprint (author's final draft
Health System Factors Associated With Correct use of Artemether-Lumefantrine for Management of Uncomplicated Malaria in Rural Tanzania
Poor adherence to and inappropriate use of antimalarials leads to ineffective cure and promote development of drug resistance. We assessed quality of malaria case management in two areas with health and demographic surveillance systems in rural Tanzania to ascertain health worker and facility factors that influence correct prescription and correct dosing of an artemisinin based combination therapy (ACT); Artemether-Lumefantrine (ALu). Exit interviews were conducted to all patients attending for initial illness consultation at health facilities. We collected information about health worker’s training, supervision visits and inventoried facility capacity and availability of medical products related to care of malaria patients. Data were double entered in EPI data and analyzed in STATA version 10 We used logistic regression to assess association of different health system factors to correct use of ALu. The outcomes variables were correct treatment, correct dosing and receiving counselling messages, and the predictors were a range of health worker, health facility and patient factors. Total of 1471 patients were included in this analysis. Majority of patients were seen in dispensaries 70.5 %; (95% confidence interval (95%CI): 57.6-80.8) and in public health facilities 80.2% (95%CI: 72.4-86.1). Work experience seems to be a significant predictor of health workers’ compliance to treatment recommendation. Availability of medical products at health facility and patient characteristics are shown to influence correct use of treatment recommendations. The need to develop targeted interventions to address health system bottlenecks that affect quality of care; such as in-availability of medical products is becoming more apparent
Increased use of malaria rapid diagnostic tests improves targeting of anti-malarial treatment in rural Tanzania: implications for nationwide rollout of malaria rapid diagnostic tests.
ABSTRACT: BACKGROUND: The World Health Organization recommends parasitological confirmation of all malaria cases. Tanzania is implementing a phased rollout of malaria rapid diagnostic tests (RDTs) for routine use in all levels of care as one strategy to increase parasitological confirmation of malaria diagnosis. This study was carried out to evaluated artemisinin combination therapy (ACT) prescribing patterns in febrile patients with and without uncomplicated malaria in one pre-RDT implementation and one post-RDT implementation area. METHODS: A cross-sectional health facility surveys was conducted during high and low malaria transmission seasons in 2010 in both areas. Clinical information and a reference blood film on all patients presenting for an initial illness consultation were collected. Malaria was defined as a history of fever in the past 48 hours and microscopically confirmed parasitaemia. Routine diagnostic testing was defined as RDT or microscopy ordered by the health worker and performed at the health facility as part of the health worker-patient consultation. Correct diagnostic testing was defined as febrile patient tested with RDT or microscopy. Over-testing was defined as a febrile patient tested with RDT or microscopy. Correct treatment was defined as patient with malaria prescribed ACT. Over-treatment was defined as patient without malaria prescribed ACT. RESULTS: A total of 1,247 febrile patients (627 from pre-implementation area and 620 from post-implementation area) were included in the analysis. In the post-RDT implementation area, 80.9% (95% CI, 68.2-89.3) of patients with malaria received recommended treatment with ACT compared to 70.3% (95% CI, 54.7-82.2) of patients in the pre-RDT implementation area. Correct treatment was significantly higher in the post-implementation area during high transmission season (85.9% (95%CI, 72.0-93.6) compared to 58.3% (95%CI, 39.4-75.1) in pre-implementation area (p=0.01). Over-treatment with ACT of patients without malaria was less common in the post-RDT implementation area (20.9%; 95% CI, 14.7-28.8) compared to the pre-RDT implementation area (45.8%; 95% CI, 37.2-54.6) (p<0.01) in high transmission. The odds of overtreatment was significantly lower in post- RDT area (adjusted Odds Ratio (OR: 95%CI) 0.57(0.36-0.89); and much higher with clinical diagnosis adjusted OR (95%CI) 2.24(1.37-3.67) CONCLUSION: Implementation of RDTs increased use of RDTs for parasitological confirmation and reduced over-treatment with ACT during high malaria transmission season in one area in Tanzania. Continued monitoring of the national RDT rollout will be needed to assess whether these changes in case management practices will be replicated in other areas and sustained over time. Additional measures (such as refresher trainings, closer supervisions, etc) may be needed to improve ACT targeting during low transmission seasons
Susceptibility of staphylococal biofilms to multiple combination of antimicrobials
Scientific supervisor: A.G. Dyachenk
Pioglitazone Prevents Capillary Rarefaction in Streptozotocin-Diabetic Rats Independently of Glucose Control and Vascular Endothelial Growth Factor Expression
Background/Aims: Reduction of capillary network density occurs early in the development of metabolic syndrome and may be relevant for the precipitation of diabetes. Agonists of the peroxisome proliferator-activated receptor (PPAR)-gamma transcription factor are vasculoprotective, but their capacity for structural preservation of the microcirculation is unclear. Methods: Male Wistar rats were rendered diabetic by streptozotocin and treated with pioglitazone in chow for up to 12 weeks. Capillary density was determined in heart and skeletal muscle after platelet endothelial cell adhesion molecule-1 (PECAM-1) immunostaining. Hallmarks of apoptosis and angiogenesis were determined. Results: Capillary density deteriorated progressively in the presence of hyperglycemia (from 971/mm(2) to 475/mm(2) in quadriceps muscle during 13 weeks). Pioglitazone did not influence plasma glucose, left ventricular weight, or body weight but nearly doubled absolute and relative capillary densities compared to untreated controls (1.2 vs. 0.6 capillaries/myocyte in heart and 1.5 vs. 0.9 capillaries/myocyte in quadriceps muscle) after 13 weeks of diabetes. No antiapoptotic or angiogenic influence of pioglitazone was detected while a reduced expression of hypoxia-inducible factor-3 alpha and PPAR coactivator-1 alpha (PGC-1 alpha) mRNA as well as vascular endothelial growth factor (VEGF) protein possibly occurred as a consequence of improved vascularization. Conclusion: Pioglitazone preserves microvascular structure in diabetes independently of improvements in glycemic control and by a mechanism unrelated to VEGF-mediated angiogenesis. Copyright (C) 2012 S. Karger AG, Base
Effects of Foreign Aid on Developing Countries: Case of Turkana County, Kenya
Despite substantial foreign aid investments in road construction projects in Turkana County, Kenya, anticipated benefits of improved access to social facilities, economic development, and rural and urban growth have not been fully realized. This study involved assessing the impact of foreign aid for road construction in Turkana County. Grounded in the social constructivism perspective, the research acknowledges subjective realities shaped by individual and societal experiences. The agency theory served as the theoretical foundation, framing the donor-recipient relationship as one where donors act as principals imposing conditions on recipient communities as agents. The study addressed the central research question: What is the impact of foreign aid investments for road construction on economic development and access to social services in Turkana County, Kenya? Using a general qualitative design, data were collected through interviews, observations, and document analysis. Thematic analysis was employed to process and interpret data, facilitated by MaxQDA software. Findings highlight while foreign aid has contributed to road infrastructure development, significant challenges persist. Recommendations emphasize the need for strategic reforms, ethical leadership, and ongoing civic education. The study underscores the importance of aligning donor objectives with local priorities to maximize the potential of foreign aid. The study also offers actionable insights for policymakers to redefine foreign aid’s role in infrastructure development, fostering positive social change by improving livelihoods, empowering disadvantaged groups, and promoting sustainable development in Turkana County
Skin flora: Differences Between People Affected by Albinism and Those with Normally Pigmented Skin in Northern Tanzania - Cross Sectional Study.
Skin flora varies from one site of the body to another. Individual's health, age and gender determine the type and the density of skin flora. A 1 cm² of the skin on the sternum was rubbed with sterile cotton swab socked in 0.9% normal saline and plated on blood agar. This was cultured at 35 °C. The bacteria were identified by culturing on MacConkey agar, coagulase test, catalase test and gram staining. Swabs were obtained from 66 individuals affected by albinism and 31 individuals with normal skin pigmentation. Those with normal skin were either relatives or staying with the individuals affected by albinism who were recruited for the study. The mean age of the 97 recruited individuals was 30.6 (SD ± 14.9) years. The mean of the colony forming units was 1580.5 per cm2. Those affected by albinism had a significantly higher mean colony forming units (1680 CFU per cm²) as compared with 453.5 CFU per cm² in those with normally pigmented skin (p = 0.023). The skin type and the severity of sun- damaged skin was significantly associated with a higher number of colony forming units (p = 0.038). Individuals affected by albinism have a higher number of colony forming units which is associated with sun- damaged skin
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