378 research outputs found

    The effect of sepsis on cerebral microvascular blood flow

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    Background: Sepsis is a dysregulated host response to infection that affects 18 000 000 people worldwide, and over 325 000 000 dollars are spent treating sepsis in Canada every year. One of the symptoms of severe sepsis is an altered mental state, which is accompanied with a measured decrease in oxygen levels in the skeletal muscle microvasculature. It is hypothesized that his altered mental state is due to a lack of oxygenated blood reaching the brain. Hypothesis: After the onset of sepsis, microvascular cerebral blood flow and oxygen levels in the blood will decrease. Onset of decreased blood flow in the brain is expected to occur later than in skeletal muscle. Methods: Data will be collected rom Sprague Dawley rats. Rats will undergo a sepsis inducing procedure, and one of the right leg muscles will be exposed. Data will be collected from this muscle via intravital video microscopy, and from the left leg and the brain via near infrared spectroscopy. Results: Expected results include a decrease in microvascular blood flow in both legs and the brain, with a later onset of decreased flow in the brain compared to the leg. Discussion: It is known that sepsis causes changes in skeletal muscle microvasculature. If we see these same changes in the cerebral microvasculature, it may be an indication that there isn\u27t enough oxygen reaching the brain. This could be a cause of a decreased mental state, and would be worth further exploration

    Epidemiology of malaria in the Taabo health and demographic surveillance system, south-central CĂŽte d'Ivoire

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    A deep understanding of the local epidemiology of malaria is essential for the design and implementation of setting-specific control and elimination efforts. In CĂŽte d'Ivoire, new initiatives are underway to reduce the burden of malaria, which requires high-quality longitudinal data. The epidemiology of malaria was studied in the Taabo health and demographic surveillance system (HDSS) in south-central CĂŽte d'Ivoire and implications for control are discussed.; Two cross-sectional surveys were carried out in the rainy season of June/July in 2010 and 2011. Inhabitants of approximately 7 % of randomly selected households in the Taabo HDSS were invited to participate. People were clinically examined, ear temperature was measured and spleen size determined. Finger-prick blood samples were collected and subjected to a rapid diagnostic test (RDT). Additionally, thick and thin blood films were prepared on microscope slides and diagnosed under a microscope for Plasmodium infection and parasitaemia. Haemoglobin (Hb) level was determined using a HemoCue device.; A total of 1187 and 1264 people in 2010 and 2011, respectively, had complete data records. The prevalence of Plasmodium infection was 46.0 % in 2010 and 56.6 % in 2011, owing to a statistically significant difference (p < 0.05). Males showed a higher Plasmodium infection prevalence than females (49.6 and 62.8 % versus 42.6 and 51.2 %; respectively, in 2010 and 2011; both p < 0.05). The highest malaria prevalence was observed among infants and young children (aged ≀9 years). The risk of Plasmodium infection was significantly higher in villages compared to small hamlets and urban settings (p < 0.05). Fever, Hb level and splenomegaly were associated with parasitaemia.; Malaria is highly endemic in the Taabo HDSS in south-central CĂŽte d'Ivoire with considerable spatial heterogeneity of Plasmodium infection. There is a pressing need to scale-up control interventions against malaria

    Compressible primitive equation: formal derivation and stability of weak solutions

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    We present a formal derivation of a simplified version of Compressible Primitive Equations (CPEs) for atmosphere modeling. They are obtained from 33-D compressible Navier-Stokes equations with an \emph{anisotropic viscous stress tensor} where viscosity depends on the density. We then study the stability of the weak solutions of this model by using an intermediate model, called model problem, which is more simple and practical, to achieve the main result

    Impacts des rejets accidentels sur la qualitĂ© environnementale des sĂ©diments de la rade portuaire d’Abidjan (lagune EbriĂ© ; CĂŽte d’Ivoire)

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    La densitĂ© du trafic maritime s’est intensifiĂ© depuis la crĂ©ation du port d’Abidjan situĂ© dans l’estuaire de la lagune EbriĂ© en CĂŽte d’Ivoire. En outre sa rade portuaire est le lieu de rejets industriels et urbains. Les sĂ©diments de la rade portuaire d’Abidjan, ont Ă©tĂ© analysĂ©s par spectromĂ©trie d’adsorption en vue de dĂ©terminer les teneurs en Ă©lĂ©ments traces mĂ©talliques (ETM), afin d’évaluer le facteur d’enrichissement et la qualitĂ© du sĂ©diment. Les sĂ©diments de ce fond lagunaire ne sont pas polluĂ©s en Cd, et sont de bonne qualité environnementale. Leur teneur en Pb ne constitue pas de danger pour le biota. La pollution en Cr, Ni et Cu est modĂ©rĂ© et les sĂ©diments sont de mauvaises qualitĂ©. Concernant l’arsenic et le zinc, les Ă©chantillons dont le facteur d’enrichissement est infĂ©rieur Ă  1,3 ne constituent pas de danger pour l’environnement. Pour le reste des échantillons, l’arsenic (As) fortement enrichis, prĂ©sente un danger pour les sĂ©diments. Il en est de mĂȘme pour Pb.Mots clĂ©s : ETM; Facteur d’enrichissement, qualitĂ© environnementale, rade portuaire, Abidjan, CĂŽte d’Ivoir

    Evaluation de l’efficacitĂ© d’un bio-fongicide Ă  base de Lecanicillium lecanii (Zimmerm) sur les cercosporioses de l’arachide (Arachis hypogaea L.) en milieu rĂ©el

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    La lutte biologique est une mĂ©thode alternative Ă  la lutte chimique ayant des effets nĂ©fastes sur la santĂ© des producteurs, des consommateurs et de l’environnement. Les maladies foliaires, en l’occurrence les cercosporioses causĂ©es par Cercospora arachidicola et Phaeoisariopsis personata handicapent la production arachidiĂšre dans le monde en gĂ©nĂ©ral, et particuliĂšrement au Burkina Faso. Cette Ă©tude a consistĂ© Ă  utiliser une souche A de Lecanicillium lecanii, Ă  des traitements diffĂ©rents contre le dĂ©veloppement des cercosporioses. Pour ce faire, quatre traitements, T1, T2, T3 et T4, ont Ă©tĂ© appliquĂ©s sur deux variĂ©tĂ©s, la TS32-1 et la PC79-79 respectivement chaque deux jour, chaque semaine, chaque dix jour et chaque deux semaine. Le dispositif expĂ©rimental est un bloc de Fisher complĂštement randomisĂ© Ă  trois rĂ©pĂ©titions, constituĂ©e chacune de 5 blocs dont 4 blocs correspondant chacun Ă  un traitement et un bloc constituant le tĂ©moin. L’étude, conduite Ă  GampĂšla, au Burkina Faso a permis de mesurer les paramĂštres tels que la levĂ©e au 21Ăšme JAS, la densitĂ© de peuplement au 32Ăšme JAS, l’incidence des cercosporioses et l’envahissement foliaire, le taux de survie, le pourcentage de dĂ©foliation et les composantes de rendement. L’étude a permis de montrer que les traitements ont eu un effet rĂ©ductif sur le dĂ©veloppement des cercosporioses au niveau des deux variĂ©tĂ©s, surtout sur la variĂ©tĂ© sensible TS32-1. Le traitement effectuĂ© chaque deux jour a donnĂ© le meilleur contrĂŽle des cercosporioses avec une note moyenne de 3,5 sur TS32- 1 et de 2,75 sur PC79-79. Sur les composantes du rendement, les traitements ont Ă©galement permis d’obtenir de bons rĂ©sultats comparĂ©s aux rĂ©sultats du tĂ©moin pour les deux variĂ©tĂ©s. En effet, le tĂ©moin a enregistrĂ© de 318,7 et 402,3 kg/ha respectivement pour les variĂ©tĂ©s TS32-1 et PC79-79 et les autres traitements ont obtenu des rendements compris entre 507,7 et 1656,7 kg/ha. Biological control is an alternative method to chemical control, which has adverse effects on the health of producers, consumers and the environment. Foliar diseases, in this case cercosporioses caused by Cercospora arachidicola and Phaeoisariopsis personata, handicap peanut production in the world in general, and particularly in Burkina Faso. This study consisted in using a Lecanicillium lecanii strain A, with different treatments against the development of cercosporioses. To do this, four treatments, T1, T2, T3 and T4, were applied to two varieties, TS32-1 and PC79-79 respectively every two days, every week, every ten days and every two weeks. The experimental set-up was a completely randomised Fisher block with three replicates, each consisting of five blocks, four of which corresponded to a treatment and one to a control. The study, conducted in GampĂšla, Burkina Faso, measured parameters such as emergence at 21 days after planting, stand density at 32 days after planting, incidence of cercosporiosis and leaf invasion, survival rate, defoliation percentage and yield components. The study showed that the treatments had a reducing effect on cercosporium development in both varieties, especially in the susceptible variety TS32-1. The treatment applied every second day gave the best cercospora control with an average score of 3.5 on TS32-1 and 2.75 on PC79- 79. On the output components, the treatments also performed well compared to the control for both varieties. Indeed, the control recorded 318.7 and 402.3 kg/ha for TS32-1 and PC79-79 respectively and the other treatments obtained yields between 507.7 and 1656.7 kg/ha

    Assessing the presence of Wuchereria bancrofti in vector and human populations from urban communities in Conakry, Guinea

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    The Global Programme to Eliminate Lymphatic Filariasis was launched in 2000 with the goal of interrupting transmission of lymphatic filariasis (LF) through multiple rounds of mass drug administration (MDA). In Guinea, there is evidence of ongoing LF transmission, but little is known about the most densely populated parts of the country, including the capital Conakry. In order to guide the LF control and elimination efforts, serological and entomological surveys were carried out to determine whether or not LF transmission occurs in Conakry.; The prevalence of circulating filarial antigen (CFA) of Wuchereria bancrofti was assessed by an immuno-chromatography test (ICT) in people recruited from all five districts of Conakry. Mosquitoes were collected over a 1-year period, in 195 households in 15 communities. A proportion of mosquitoes were analysed for W. bancrofti, using dissection, loop-mediated isothermal amplification (LAMP) assay and conventional polymerase chain reaction (PCR).; CFA test revealed no infection in the 611 individuals examined. A total of 14,334 mosquitoes were collected; 14,135 Culex (98.6 %), 161 Anopheles (1.1 %) and a few other species. Out of 1,312 Culex spp. (9.3 %) and 51 An. gambiae (31.7 %) dissected, none was infected with any stage of the W. bancrofti parasite. However, the LAMP assay revealed that 1.8 % of An. gambiae and 0.31 % of Culex spp. were positive, while PCR determined respective prevalences of 0 % and 0.19 %.; This study revealed the presence of W. bancrofti DNA in mosquitoes, despite the apparent absence of infection in the human population. Although MDA interventions are not recommended where the prevalence of ICT is below 1 %, the entomological results are suggestive of the circulation of the parasite in the population of Conakry. Therefore, rigorous surveillance is still warranted so that LF transmission in Conakry would be identified rapidly and adequate responses being implemented

    Malaria knowledge and long-lasting insecticidal net use in rural communities of central CĂŽte d'Ivoire

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    ABSTRACT: BACKGROUND: To improve effectiveness of malaria control interventions, it is essential to deepen the knowledge of contextual factors that govern people's practice for preventive and curative measures. The aim of this study was to determine factors that influence the use of long-lasting insecticidal nets (LLINs) in three rural communities of Cote d'Ivoire, two of which benefited from recent interventions. METHODS: The study was carried out in 957 households in three villages (Bozi, N'Dakonankro and Yoho) located in central Cote d'Ivoire. Indicators of socioeconomic position (SEP), malaria knowledge and practice, placing special emphasis on LLINs, were investigated during a cross-sectional questionnaire survey. Principal component analysis was used to calculate the SEP of households by means of a list of household assets ownership. The concentration index was used to assess the direction of the association between SEP and a given variable. To compare groups or means, Fisher's exact test, chi2 and Kruskal-Wallis test were used, as appropriate. RESULTS: Significant differences were found between SEP and reported malaria symptoms, such as fever or hot body, convulsion, anaemia and jaundice (yellow eyes). Individuals from the least poor group cited more often the use of bed nets and insecticide-treated nets (ITNs) compared to poorer groups. The mean number of individuals reporting the use of bed nets and LLINs was different between groups with different educational level. Moreover, the mean number of LLINs in a household was influenced by the presence of children below five years of age. CONCLUSION: The study not only confirmed that education and SEP play important roles in the prevention and control of malaria and promotion of health in general, but pointed at the basic essential knowledge and the key behavioural elements that should guide education and learning processes among the poorer segments of the population. In turn, such knowledge may change behaviour and lead to an increased utilization of LLIN

    Dynamics of Anemia in Relation to Parasitic Infections, Micronutrient Status, and Increasing Age in South-Central CĂŽte d'Ivoire

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    Background. Parasitic diseases (eg, malaria and helminthiases) exert enormous burdens on public health and social well-being. Moreover, parasitic infections are important causes of anemia in tropical Africa, exacerbated by lack of a diversified diet and inflammatory and genetic diseases. There is a paucity of longitudinal studies monitoring the dynamics of anemia in relation to the aforementioned parameters. Methods. We designed a 14-month prospective longitudinal study in 3 cohorts (ie, infants aged 6-23 months, children aged 6-8 years, and women aged 15-25 years) in the Taabo health demographic surveillance system located in south-central Cîte d'Ivoire. Parasitological, hematological, and micronutrient data were obtained from repeated cross-sectional surveys, utilizing standardized, quality-controlled methods. Results. We found that young age, Plasmodium and Schistosoma infections, cellular iron deficiency, and stunting were significantly negatively associated with hemoglobin concentration. Moreover, iron status biomarkers (ie, ferritin and soluble transferrin receptor) were significantly associated with inflammatory parameters. Conclusions. Based on our results, effective prevention and control measures that target parasitic diseases and iron deficiency are needed. These measures might include the distribution of long-lasting insecticidal nets, intermittent preventive treatment for malaria, regular anthelmintic drug administration, and improved intake of bioavailable iron, coupled with health and nutritional education and improved hygiene, water, and sanitatio

    Dynamic tracking of microvascular hemoglobin content for continuous perfusion monitoring in the intensive care unit: pilot feasibility study

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    Purpose: There is a need for bedside methods to monitor oxygen delivery in the microcirculation. Near-infrared spectroscopy commonly measures tissue oxygen saturation, but does not reflect the time-dependent variability of microvascular hemoglobin content (MHC) that attempts to match oxygen supply with demand. The objective of this study is to determine the feasibility of MHC monitoring in critically ill patients using high-resolution near-infrared spectroscopy to assess perfusion in the peripheral microcirculation. Methods: Prospective observational cohort of 36 patients admitted within 48 h at a tertiary intensive care unit. Perfusion was measured on the quadriceps, biceps, and/or deltoid, using the temporal change in optical density at the isosbestic wavelength of hemoglobin (798 nm). Continuous wavelet transform was applied to the hemoglobin signal to delineate frequency ranges corresponding to physiological oscillations in the cardiovascular system. Results: 31/36 patients had adequate signal quality for analysis, most commonly affected by motion artifacts. MHC signal demonstrates inter-subject heterogeneity in the cohort, indicated by different patterns of variability and frequency composition. Signal characteristics were concordant between muscle groups in the same patient, and correlated with systemic hemoglobin levels and oxygen saturation. Signal power was lower for patients receiving vasopressors, but not correlated with mean arterial pressure. Mechanical ventilation directly impacts MHC in peripheral tissue. Conclusion: MHC can be measured continuously in the ICU with high-resolution near-infrared spectroscopy, and reflects the dynamic variability of hemoglobin distribution in the microcirculation. Results suggest this novel hemodynamic metric should be further evaluated for diagnosing microvascular dysfunction and monitoring peripheral perfusion
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