2,305 research outputs found

    Metabolic effects of a high-fat diet post-weaning after low maternal dietary folate during pregnancy and lactation

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    Scope Investigate the influence of low-folate supply during pregnancy and lactation on obesity and markers of the metabolic syndrome in offspring, and how provision of a high-fat diet post weaning may exacerbate the resultant phenotype. Methods and results Female C57Bl/6 mice were randomized to low or normal folate diets (0.4 or 2 mg folic acid/kg diet) prior to and during pregnancy and lactation. At 4 wk of age, offspring were randomized to high- or low-fat diets, weighed weekly and food intake assessed at 9 and 18 wk old. Adiposity was measured at 3 and 6 months. Plasma glucose and triacylglycerol (TAG) concentrations were measured at 6 months. Maternal folate supply did not influence adult offspring body weight or adiposity. High-fat feeding post weaning increased body weight and adiposity at 3 and 6 months (p > 0.001). Maternal low folate lowered plasma glucose (p = 0.010) but increased plasma TAG (p = 0.048). High-fat feeding post weaning increased plasma glucose and TAG (p = 0.023, p = 0.049 respectively). Offspring from folate-depleted (but not folate-adequate) dams had 30% higher TAG concentration when fed the high-fat diet from weaning (p = 0.005 for interaction). Conclusion Inadequate maternal folate intake has long-term effects on offspring metabolism, manifested as increased circulating TAG, particularly in offspring with high-fat intake post weaning

    The Impact of Environmental Turbulence on Product Innovation in Small to Medium Enterprises in Harare, Zimbabwe

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    The purpose of the research was to examine the impact of environmental turbulence on product innovations in small to medium enterprises (SMEs). In the study environmental turbulence consisted of five dimensions namely, supplier turbulence, technological turbulence, market turbulence, regulatory turbulence and competitive intensity. A cross-sectional quantitative research design was adopted in the study. The study sample was drawn from a pool of 3,000 SMEs both unregistered and registered with the Ministry of Small and Medium Enterprises in Harare, Zimbabwe. In the study, a total of 200 completed surveys were obtained and analysed. To analyse the research data SPSS23 was utilised. Regression analysis was carried out to establish the cause-and-effect relationship between the independent and dependent variables in the study. The findings of the study showed that technology turbulence and competitive intensity had a statistically significant positive impact on product innovation. Market turbulence was noted as having a statistically significant negative impact on product innovativeness. The main implications established in the study were that SMEs should introduce mechanisms to manage and mitigate market, supplier and regulatory turbulence to ensure that their levels of product innovativeness remain positive

    Evaluation of the Long-Lasting Insecticidal Net Interceptor LN: Laboratory and Experimental Hut Studies against Anopheline and Culicine Mosquitoes in Northeastern Tanzania

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    Long lasting insecticidal nets (LN) are a primary method of malaria prevention. Before new types of LN are approved they need to meet quality and efficacy standards set by the WHO Pesticide Evaluation Scheme. The process of evaluation has three phases. In Phase I the candidate LN must meet threshold bioassay criteria after 20 standardized washes. In Phase II washed and unwashed LNs are evaluated in experimental huts against wild, free flying anopheline mosquitoes. In Phase III the LN are distributed to households in malaria endemic areas, sampled over three years of use and tested for continuing insecticidal efficacy. Interceptor® LN (BASF Corporation, Germany) is made of polyester netting coated with a wash resistant formulation of alpha-cypermethrin. Interceptor LN was subjected to bioassay evaluation and then to experimental hut trial against pyrethroid-susceptible Anopheles gambiae and An. funestus and resistant Culex quinquefasciatus. Mosquito mortality, blood feeding inhibition and personal protection were compared between untreated nets, conventional alpha-cypermethrin treated nets (CTN) washed 20 times and LNs washed 0, 20 and 30 times. In Phase I Interceptor LN demonstrated superior wash resistance and efficacy to the CTN. In the Phase II hut trial the LN killed 92% of female An. gambiae when unwashed and 76% when washed 20 times; the CTN washed 20 times killed 44%. The LN out-performed the CTN in personal protection and blood-feeding inhibition. The trend for An. funestus was similar to An. gambiae for all outcomes. Few pyrethroid-resistant Cx. quinquefasciatus were killed and yet the level of personal protection (75-90%) against Culex was similar to that of susceptible An. gambiae (76-80%) even after 20 washes. This protection is relevant because Cx. quinquefasciatus is a vector of lymphatic filariasis in East Africa. After 20 washes and 60 nights’ use the LN retained 27% of its initial insecticide dose. Interceptor LN meets the approval criteria set by WHO and is recommended for use in disease control against East African vectors of malaria and filariasis. Some constraints associated with the phase II evaluation criteria, in particular the washing procedure, are critically reviewed

    Equity and coverage of insecticide-treated bed nets in an area of intense transmission of Plasmodium falciparum in Tanzania

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    BACKGROUND: There is no clear consensus on the most sustainable and effective distribution strategy for insecticide treated bed nets (ITNs). Tanzania has been a leader in social marketing but it is still not clear if this can result in high and equitable levels of coverage. METHODS: A cluster-randomized survey of ITN and bed net ownership and use was conducted in a rural area exposed to intense Plasmodium falciparum transmission in NE Tanzania where ITN distribution had been subject to routine delivery of national strategies and episodic free distribution through local clinics. Data were collected on household assets to assess equity of ITN coverage and a rapid diagnostic test for malaria (RDT) was performed in all ages. RESULTS: Among 598 households in four villages the use of any or insecticidal bed nets in children less than five years of age was 71% and 54% respectively. However there was a 19.8% increase in the number of bed nets per person (p < 0.001) and a 13.4% increase in the number of insecticidal nets per person (p < 0.001) for each quintile increase in household asset score. The odds of being RDT-positive were reduced by more than half in the least poor compared to the poorest households (OR 0.49, 95% CI 0.35-0.70). Poorer households had paid less for their nets and acquired them more recently, particularly from non-commercial sources, and bed nets in the least poor households were less likely to be insecticidal compared to nets in the poorest households (OR 0.44, 95% CI 0.26-0.74). CONCLUSION: Marked inequity persists with the poorest households still experiencing the highest risk of malaria and the lowest ITN coverage. Abolition of this inequity within the foreseeable future is likely to require mass or targeted free distribution, but risks damaging what is otherwise an effective commercial market

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    SUMMARY We isolated step-to-step transitions from other contributors to walking mechanics using a cyclical rocking task and then examined the contribution of individual joints to the total work required to redirect the velocity of the center of mass (COM). Nine participants were instructed to rock backward and forward in the sagittal plane, eliminating the need to swing the legs and progress forward. To systematically increase the required work, we increased step length from 60 to 100% of leg length, keeping rocking frequency constant. The individual limbs method quantified the COM work and the joint power method apportioned the COM work among its various sources. As predicted by a physics-based model, we found that work in rocking was performed mainly during the step-to-step transitions and increased strongly with step length. We also found that increases in the average COM work rate exacted a proportional metabolic cost. The similar patterns of COM work and COM work rate during rocking and walking support the use of rocking to isolate the mechanics of step-to-step transitions. We found that the ankle was the main joint contributing to the positive work required to redirect the COM velocity during forward rocking. At the longest length, it accounted for 88% of the work performed by the trailing leg joints. Interestingly, the summed contribution of ankle, knee and hip joint work accounted for only 39% of the front leg negative COM work during the forward transition, suggesting that most of the collision work is performed by passive tissue

    Variation of malaria transmission and morbidity with altitude in Tanzania and with introduction of alphacypermethrin treated nets

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    BACKGROUND: Highland areas with naturally less intense malaria transmission may provide models of how lowland areas might become if transmission was permanently reduced by sustained vector control. It has been argued that vector control should not be attempted in areas of intense transmission. METHODS: Mosquitoes were sampled with light traps, pyrethrum spray and window exit traps. They were tested by ELISA for sporozoites. Incidence of malaria infection was measured by clearing existing infections from children with chlorproguanil-dapsone and then taking weekly blood samples. Prevalence of malaria infection and fever, anaemia and splenomegaly were measured in children of different age groups. All these measurements were made in highland and lowland areas of Tanzania before and after provision of bednets treated with alphacypermethrin. RESULTS: Entomological inoculation rates (EIR) were about 17 times greater in a lowland than a highland area, but incidence of infection only differed by about 2.5 times. Malaria morbidity was significantly less prevalent in the highlands than the lowlands. Treated nets in the highlands and lowlands led to 69–75% reduction in EIR. Malaria morbidity showed significant decline in younger children at both altitudes after introduction of treated nets. In children aged 6–12 the decline was only significant in the highlands CONCLUSIONS: There was no evidence that the health benefits to young children due to the nets in the lowlands were "paid for" by poorer health later in life. Our data support the idea of universal provision of treated nets, not a focus on areas of natural hypo-endemicity

    Measurement Properties of Visual Analogue Scale, Numeric Rating Scale, and Pain Severity Subscale of the Brief Pain Inventory in Patients With Low Back Pain:A Systematic Review

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    Visual Analogue Scale (VAS), Numeric Rating Scale (NRS), and Pain Severity subscale of the Brief Pain Inventory (BPI-PS)] are the most frequently used instruments to measure pain intensity in low back pain (LBP). However, their measurement properties in this population have not been systematically reviewed. The goal of this study was to provide such systematic evidence synthesis. Six electronic sources (MEDLINE, EMBASE, CINAHL, PsycINFO, SportDiscus, Google Scholar) were searched (July 2017). Studies assessing any measurement property in patients with non-specific LBP were included. Two reviewers independently screened articles and assessed risk of bias using the COSMIN checklist. For each measurement property: evidence quality was rated as high, moderate, low, or very low (GRADE approach); results were classified as sufficient, insufficient or inconsistent. Ten studies assessed the VAS, 13 the NRS, four the BPI-PS. The three instruments displayed low or very low quality evidence for content validity. High quality evidence was only available for NRS insufficient measurement error. Moderate evidence was available for: NRS inconsistent responsiveness, BPI-PS sufficient structural validity and internal consistency, and BPI-PS inconsistent construct validity. All VAS measurement properties were underpinned by no, low or very low quality evidence, likewise the other measurement properties of NRS and BPI-PS

    Spin transport in as-grown and annealed thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy

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    We characterize the spin Hall magnetoresistance (SMR), spin Seebeck effect (SSE), and dampinglike spin-orbit torque (SOT) in thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy by using harmonic Hall effect measurements. By consecutive annealing steps followed by measurements on a single device, we reveal that the spin-dependent effects gradually decrease in amplitude as the annealing temperature increases. We attribute this behavior primarily to the changes in the spin-mixing conductance, which sensitively depends on the interface quality. However, further analysis demonstrates that although the SSE scales closely with the SMR, the dampinglike SOT shows a significantly different trend upon annealing, contrary to theoretical expectations. By comparing the dampinglike SOT with the field-induced Hall effect, we found evidence that scattering from Fe impurities in the Pt at the interface might be responsible for the distinct annealing temperature dependence of the dampinglike SOT.Deutsche ForschungsgemeinschaftUnited States. Defense Advanced Research Projects Agency (C-SPIN, a SRC STARnet Center)Microelectronics Advanced Research Corporation (MARCO) (C-SPIN, a SRC STARnet Center

    Is Housing Quality Associated with Malaria Incidence among Young Children and Mosquito Vector Numbers? Evidence from Korogwe, Tanzania

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    Background Several studies conducted in Northeast Tanzania have documented declines in malaria transmission even before interventions were scaled up. One explanation for these reductions may be the changes in socio-environmental conditions associated with economic development, and in particular improvements in housing construction. Objective This analysis seeks to identify (1) risk factors for malaria incidence among young children and (2) household and environmental factors associated with mosquito vector numbers collected in the child’s sleeping area. Both analyses focus on housing construction quality as a key determinant. Methodology For 435 children enrolled in a larger trial of intermittent preventive treatment for malaria in infants in the Korogwe District in Tanga, Northeastern Tanzania, detailed information on their dwelling characteristics were collected in the last year of the trial. Principal components analysis was used to construct an index of housing structure quality and converted to quintile units for regression analysis. Univariate and multivariate random effects negative binomial regressions were used to predict risk factors for child malaria incidence and the mean total number of indoor female Anopheles gambiae and funestus mosquitoes collected per household across three occasions. Findings Building materials have substantially improved in Korogwe over time. Multivariate regressions showed that residing in rural areas (versus urban) increased malaria incidence rates by over three-fold and mean indoor female A. gambiae and funestus numbers by nearly two-fold. Compared to those residing in the lowest quality houses, children residing in the highest quality houses had one-third lower malaria incidence rates, even when wealth and rural residence were controlled for. Living in the highest quality houses reduced vector numbers while having cattle near the house significantly increased them. Conclusions Results corroborate findings from other studies that show associations between malaria incidence and housing quality; associations were concentrated amongst the highest quality houses
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