1,778 research outputs found

    Delayed mortality effects cut the malaria transmission potential of insecticide resistant mosquitoes

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    Malaria transmission has been substantially reduced across Africa through the distribution of long-lasting insecticidal nets (LLINs). However, the emergence of insecticide resistance within mosquito vectors risks jeopardizing the future efficacy of this control strategy. The severity of this threat is uncertain because the consequences of resistance for mosquito fitness are poorly understood: while resistant mosquitoes are no longer immediately killed upon contact with LLINs, their transmission potential may be curtailed because of longer-term fitness costs that persist beyond the first 24 h after exposure. Here, we used a Bayesian state-space model to quantify the immediate (within 24 h of exposure) and delayed (>24 h after exposure) impact of insecticides on daily survival and malaria transmission potential of moderately and highly resistant laboratory populations of the major African malaria vector Anopheles gambiae. Contact with LLINs reduced the immediate survival of moderately and highly resistant An. gambiae strains by 60–100% and 3–61%, respectively, and delayed mortality impacts occurring beyond the first 24 h after exposure further reduced their overall life spans by nearly one-half. In total, insecticide exposure was predicted to reduce the lifetime malaria transmission potential of insecticide-resistant vectors by two-thirds, with delayed effects accounting for at least one-half of this reduction. The existence of substantial, previously unreported, delayed mortality effects within highly resistant malaria vectors following exposure to insecticides does not diminish the threat of growing resistance, but posits an explanation for the apparent paradox of continued LLIN effectiveness in the presence of high insecticide resistance

    Malnutrition, poor food intake, and adverse healthcare outcomes in non-critically ill obese acute care hospital patients

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    Obesity, defined as a BMI\ua0≥\ua030\ua0kg/m, has demonstrated protective associations with mortality in some diseases. However, recent evidence demonstrates that poor nutritional status in critically ill obese patients confounds this relationship. The purpose of this paper is to evaluate if poor nutritional status, poor food intake and adverse health-related outcomes have a demonstrated association in non-critically ill obese acute care hospital patients.This is a secondary analysis of the Australasian Nutrition Care Day Survey dataset (N\ua0=\ua03122), a prospective cohort study conducted in hospitals from Australia and New Zealand in 2010. At baseline, hospital dietitians recorded participants' BMI, evaluated nutritional status using Subjective Global Assessment (SGA), and recorded 24-h\ua0food intake (as 0%, 25%, 50%, 75%, and 100% of the offered food). Post-three months, participants' length of stay (LOS), readmissions, and in-hospital mortality data were collected. Bivariate and regression analyses were conducted to investigate if there were an association between BMI, nutritional status, poor food intake, and health-related outcomes.Of the 3122 participants, 2889 (93%) had eligible data. Obesity was prevalent in 26% of the cohort (n\ua0=\ua0750; 75% females; 61\ua0±\ua015 years; 37\ua0±\ua07\ua0kg/m). Fourteen percent (n\ua0=\ua0105) of the obese patients were malnourished. Over a quarter of the malnourished obese patients (N\ua0=\ua030/105, 28%) consumed ≤25% of the offered meals. Most malnourished obese patients (74/105, 70%) received standard diets without additional nutritional support. After controlling for confounders (age, disease type and severity), malnutrition and intake ≤25% of the offered meals independently trebled the odds of in-hospital mortality within 90 days of hospital admission in obese patients.Although malnourished obese experienced significantly adverse health-related outcomes they were least likely to receive additional nutritional support. This study demonstrates that BMI alone cannot be used as a surrogate measure for nutritional status and warrants routine nutritional screening for all hospital patients, and subsequent nutritional assessment and support for malnourished patients

    Using Conditioned Food Aversion (CFA) to reduce Pied Crow (Corbus albus) predation of plover nests

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    Nest predation is one of the principle constraints on bird breeding success, accounting for 20 to 80% of all nest failures. It can be exacerbated by anthropogenic factors and the resultant increased predation pressure has caused the decline of numerous bird species worldwide. Identifying management strategies to reduce nest predation is consequently a priority for biodiversity conservation. Many lethal and non-lethal methods of predator control can be ineffective, unethical, time-consuming and expensive to implement. An alternative is the use of Conditioned Food Aversion (CFA), a method by which animals are deliberately induced to avoid nests following consumption of eggs treated with an illness-inducing toxin. Previous studies suggest that this technique is effective but many have been subject to several methodological flaws that limit their applicability. Here I employ an improved experimental design that uses both spatial and temporal controls and incorporates quantification of predator identity and abundance. By so doing the resultant effects can be attributed to CFA treatment with higher certainty. In the Berg River Estuary, South Africa, nest losses of the Kittlitz's Plover (Charadrius pecuarius) are high due to Pied Crow (Corvus albus) nest predation. I used this common plover as a model species to test whether CFA can be used as a conservation management tool to reduce nest predation. I used a field experiment to assess whether provisioning quail eggs treated with carbachol, an illness-inducing chemical, resulted in reduced nest predation. To assess the effects of treatment, nest survival data for both artificial plover nests containing quail eggs and natural Kittlitz's plover nests, as well as predator abundance were compared across three experimental phases (pre-treatment, treatment and post-treatment) and according to treatment type (carbachol versus water)

    Microstructural Correlates of Resilience against Major Depressive Disorder: Epigenetic Mechanisms?

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    Mental disorders are a major cause of long-term disability and are a direct cause of mortality, with approximately 800.000 individuals dying from suicide every year worldwide - a high proportion of them related to major depressive disorder (MDD)^1^. Healthy relatives of patients with major depressive disorder (MDD) are at risk to develop the disease. This higher vulnerability is associated with structural^2-4^ and functional brain changes^5^. However, we found using high angular resolution diffusion imaging (HARDI) with 61 diffusion directions that neuron tracts between frontal cortices and limbic as well as temporal and parietal brain regions are characterized by better diffusion coefficients in unaffected relatives (UHR), who managed to stay healthy, compared to healthy volunteers without any family history for a psychiatric disease (HC). Moreover, those UHR with stronger fibre connections better managed incidences of adversity in early life without later developing depression, while in HC axonal connections were found to be decreased when they had early-life adversity. Altogether these findings indicate the presence of stronger neural fibre connections in UHR, which seem to be associated with resilience against environmental stressors, which we suggest occur through epigenetic mechanisms

    Development of a Capillary Blood Mail-in Kit for the Measurement of Hemoglobin A1c

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    Biomedical Tissue Engineering, Biomaterials and Medical Devices Poster SessionIt is estimated that in the United States diabetes affects 25 million children and adults, and is a major cause of morbidity and mortality. Cost of diabetes in the United States is over $175 billion a year. To optimize insulin dose diabetic patients regularly measure their blood glucose. Random glucose measurement does not provide indication of long-term glucose control. The long-term indicator of glucose control is the hemoglobin A1c (HbA1c). It provides average blood glucose level of the previous 2 to 3 months. In most cases, for HbA1c testing, patients come to clinical laboratories for blood draw. It is time consuming and inconvenient. In recent years efforts have been made to develop sample mail-in kit where the blood sample can be collected at home and mailed to a testing laboratory. We present the development of a stabilizing solution (SS) and mail-in kit for Hb A1c testing. With this kit, after a simple finger prick, a patient collects blood using a capillary tube. The blood-containing capillary tube is dropped in a tube containing SS, and is mailed to the laboratory in a pre-stamped box in a regular mail. Validation of the kit included 1) Comparing HbA1c levels in the whole blood to hemolysate and SS immediately after preparation of the samples, 2) Stability of HbA1c in SS for 4 and 7 days at 4oC, room temperature and 37oC, 3) mailing the samples in the regular mail and comparing the values of HbA1c in mailed-in samples to the whole blood samples. The data for some of these comparisons are shown in the Table below. No significant difference was found in the values of HbA1c in various test groups. In conclusion, we have developed a convenient mail-in kit for the measurement of HbA1c. The advantages of mail-in kit for HbA1c measurement include patients' satisfaction as it negates the need for venipuncture and laboratory visit for sample collection, and the availability of results to a physician before the patient's visit for optimal care

    Analyzing an Urban University\u27s Diversity Dilemma

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    Lack of diversity in the teaching force is proving to be a grievous problem for our country. Across the nation the percentage of teachers of color in our schools remains stagnant as the percentage of students of color increases (Gay, Dingus & Jackson, 2003; Gordon, 2000; Gursky, 1999). Councils have been convened and conferences held to confront the issue (National Collaborative on Diversity in the Teaching Force, 2004). This disparity between the supply and demand for a diverse teaching force not only violates our standards of equity, it also appears to have a deleterious effect on achievement of students, particularly those of color (Gay, Dingus & Jackson, 2003; Hurtado, 1996). Growing awareness of this problem is strengthening the resolve of many educators to find ways to recruit persons of color to the teaching force in their region or community. The problem proves to be more complex than meets the eye, however. The causes are deeply rooted, requiring careful analysis of the cultural character of each specific community (Gordon, 2000). An additional complication stems from the fact that the majority of the United States teachers and administrators are of European descent, and may have little insight into the reasons young people of color don\u27t select teaching as a career. Without that understanding, it is difficult for them to create successful programs to recruit people of color
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