813 research outputs found

    Using the entomological inoculation rate to assess the impact of vector control on malaria parasite transmission and elimination

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    Prior studies have shown that annual entomological inoculation rates (EIRs) must be reduced to less than one to substantially reduce the prevalence of malaria infection. In this study, EIR values were used to quantify the impact of insecticide-treated bed nets (ITNs), indoor residual spraying (IRS), and source reduction (SR) on malaria transmission. The analysis of EIR was extended through determining whether available vector control tools can ultimately eradicate malaria. The analysis is based primarily on a review of all controlled studies that used ITN, IRS, and/or SR and reported their effects on the EIR. To compare EIRs between studies, the percent difference in EIR between the intervention and control groups was calculated. Eight vector control intervention studies that measured EIR were found: four ITN studies, one IRS study, one SR study, and two studies with separate ITN and IRS intervention groups. In both the Tanzania study and the Solomon Islands study, one community received ITNs and one received IRS. In the second year of the Tanzania study, EIR was 90% lower in the ITN community and 93% lower in the IRS community, relative to the community without intervention; the ITN and IRS effects were not significantly different. In contrast, in the Solomon Islands study, EIR was 94% lower in the ITN community and 56% lower in the IRS community. The one SR study, in Dar es Salaam, reported a lower EIR reduction (47%) than the ITN and IRS studies. All of these vector control interventions reduced EIR, but none reduced it to zero. These studies indicate that current vector control methods alone cannot ultimately eradicate malaria because no intervention sustained an annual EIR less than one. While researchers develop new tools, integrated vector management may make the greatest impact on malaria transmission. There are many gaps in the entomological malaria literature and recommendations for future research are provided

    T-cell subpopulations αβ and γδ in cord blood of very preterm infants : The influence of intrauterine infection

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    Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPreterm infants are very susceptible to infections. Immune response mechanisms in this group of patients and factors that influence cord blood mononuclear cell populations remain poorly understood and are considered insufficient. However, competent immune functions of the cord blood mononuclear cells are also described. The aim of this work was to evaluate the T-cell population (CD3+) with its subpopulations bearing T-cell receptor (TCR) αβ or TCR γδ in the cord blood of preterm infants born before 32 weeks of gestation by mothers with or without an intrauterine infection. Being a pilot study, it also aimed at feasibility check and assessment of an expected effect size. The cord blood samples of 46 infants age were subjected to direct immunofluorescent staining with monoclonal antibodies and then analyzed by flow cytometry. The percentage of CD3+ cells in neonates born by mothers with diagnosis of intrauterine infection was significantly lower than in neonates born by mothers without infection (p = 0.005; Mann-Whitney U test). The number of cells did not differ between groups. Infection present in the mother did not have an influence on the TCR αβ or TCR γδ subpopulations. Our study contributes to a better understanding of preterm infants' immune mechanisms, and sets the stage for further investigations.Peer reviewedFinal Published versio

    Filipina American women's breast cancer knowledge, attitudes, and screening behaviors

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    BACKGROUND: Filipino Americans are the fastest growing Asian minority group in the United States. There is limited knowledge about their breast cancer knowledge, screening practices and attitudes. METHODS: As part of the evaluation of the Asian Grocery Store-Based Cancer Education Program, 248 Filipino American women completed baseline and follow-up surveys, while an additional 58 took part in focus groups. RESULTS: Compliance with annual clinical breast exam guidelines among women 40 to 49 years old was 43%, and annual mammography use among women 50 and over was 56%. The Asian Grocery Store-Based Cancer Education Program and complementary focus group study identified multiple barriers that hindered women from attending education programs, with time as the most frequently reported barrier. CONCLUSION: The Asian Grocery Store-Based Cancer Education Program was reported to be a culturally acceptable and effective way of disseminating breast cancer information and one that addressed the women's most frequently reported barrier, lack of time

    Fluctuations in granular gases

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    A driven granular material, e.g. a vibrated box full of sand, is a stationary system which may be very far from equilibrium. The standard equilibrium statistical mechanics is therefore inadequate to describe fluctuations in such a system. Here we present numerical and analytical results concerning energy and injected power fluctuations. In the first part we explain how the study of the probability density function (pdf) of the fluctuations of total energy is related to the characterization of velocity correlations. Two different regimes are addressed: the gas driven at the boundaries and the homogeneously driven gas. In a granular gas, due to non-Gaussianity of the velocity pdf or lack of homogeneity in hydrodynamics profiles, even in the absence of velocity correlations, the fluctuations of total energy are non-trivial and may lead to erroneous conclusions about the role of correlations. In the second part of the chapter we take into consideration the fluctuations of injected power in driven granular gas models. Recently, real and numerical experiments have been interpreted as evidence that the fluctuations of power injection seem to satisfy the Gallavotti-Cohen Fluctuation Relation. We will discuss an alternative interpretation of such results which invalidates the Gallavotti-Cohen symmetry. Moreover, starting from the Liouville equation and using techniques from large deviation theory, the general validity of a Fluctuation Relation for power injection in driven granular gases is questioned. Finally a functional is defined using the Lebowitz-Spohn approach for Markov processes applied to the linear inelastic Boltzmann equation relevant to describe the motion of a tracer particle. Such a functional results to be different from injected power and to satisfy a Fluctuation Relation.Comment: 40 pages, 18 figure

    Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae s.s.

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    <p>Abstract</p> <p>Background</p> <p>Carbon dioxide (CO<sub>2</sub>) plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector <it>Anopheles gambiae sensu stricto </it>is attracted to human volatiles augmented by CO<sub>2</sub>. This study investigated whether CO<sub>2</sub>, usually supplied from gas cylinders acquired from commercial industry, could be replaced by CO<sub>2 </sub>derived from fermenting yeast (yeast-produced CO<sub>2</sub>).</p> <p>Methods</p> <p>Trapping experiments were conducted in the laboratory, semi-field and field, with <it>An. gambiae s.s</it>. as the target species. MM-X traps were baited with volatiles produced by mixtures of yeast, sugar and water, prepared in 1.5, 5 or 25 L bottles. Catches were compared with traps baited with industrial CO<sub>2</sub>. The additional effect of human odours was also examined. In the laboratory and semi-field facility dual-choice experiments were conducted. The effect of traps baited with yeast-produced CO<sub>2 </sub>on the number of mosquitoes entering an African house was studied in the MalariaSphere. Carbon dioxide baited traps, placed outside human dwellings, were also tested in an African village setting. The laboratory and semi-field data were analysed by a χ<sup>2</sup>-test, the field data by GLM. In addition, CO<sub>2 </sub>concentrations produced by yeast-sugar solutions were measured over time.</p> <p>Results</p> <p>Traps baited with yeast-produced CO<sub>2 </sub>caught significantly more mosquitoes than unbaited traps (up to 34 h post mixing the ingredients) and also significantly more than traps baited with industrial CO<sub>2</sub>, both in the laboratory and semi-field. Adding yeast-produced CO<sub>2 </sub>to traps baited with human odour significantly increased trap catches. In the MalariaSphere, outdoor traps baited with yeast-produced or industrial CO<sub>2 </sub>+ human odour reduced house entry of mosquitoes with a human host sleeping under a bed net indoors. <it>Anopheles gambiae s.s</it>. was not caught during the field trials. However, traps baited with yeast-produced CO<sub>2 </sub>caught similar numbers of <it>Anopheles arabiensis </it>as traps baited with industrial CO<sub>2</sub>. Addition of human odour increased trap catches.</p> <p>Conclusions</p> <p>Yeast-produced CO<sub>2 </sub>can effectively replace industrial CO<sub>2 </sub>for sampling of <it>An. gambiae s.s</it>.. This will significantly reduce costs and allow sustainable mass-application of odour-baited devices for mosquito sampling in remote areas.</p

    Neuronal circuitry for pain processing in the dorsal horn

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    Neurons in the spinal dorsal horn process sensory information, which is then transmitted to several brain regions, including those responsible for pain perception. The dorsal horn provides numerous potential targets for the development of novel analgesics and is thought to undergo changes that contribute to the exaggerated pain felt after nerve injury and inflammation. Despite its obvious importance, we still know little about the neuronal circuits that process sensory information, mainly because of the heterogeneity of the various neuronal components that make up these circuits. Recent studies have begun to shed light on the neuronal organization and circuitry of this complex region

    Hostility, Physical Aggression and Trait Anger as Predictors for Suicidal Behavior in Chinese Adolescents: A School-Based Study

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    Purpose: This study explored the extent to which trait aggression is associated with suicidal behavior in a nationwide school-based sample of adolescents. Methods: A nationwide sample of 14,537 high school students in urban areas of China was recruited. Information concerning suicide ideation, plans, attempts, trait aggression and other risk factors was collected by a self-reported questionnaire. Multivariate regression analyses were employed to predict suicidal behavior. Results: Approximately 18.5 % of students reported suicide ideation, 8.7 % reported suicide plans, and 4.1 % reported attempts during the past one year. Hostility and trait anger had a significant positive association with suicidal ideation. Hostility and physical aggression were positively related to suicide plans. Hostility had a positive correlation with suicide attempts, while trait anger was inversely associated with suicide attempts. Conclusions: This study suggests that hostility, physical aggression and trait anger may be able to be used to predict suicidal behavior among adolescents. Suicide prevention programs should target at attenuating the severity of hostility, anger and physical aggression. But teachers and parents should also give close attention to students with low trait anger

    Staging the city: London at the fin de siècle and the crisis of representation

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    Staging the city: London at the fin de siècle and the crisis of representatio
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