3,543 research outputs found

    Diabetic retinopathy and socioeconomic deprivation in Gloucestershire

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    Objectives To investigate socioeconomic variations in diabetes prevalence, uptake of screening for diabetic retinopathy, and prevalence of diabetic retinopathy. Methods The County of Gloucestershire formed the setting of the study. A cross-sectional study of people with diabetes was done on a countywide retinopathy-screening database. Diabetes prevalence with odds ratios, uptake of screening, prevalence of any retinopathy and prevalence of sight-threatening retinopathy at screening were compared for different area deprivation quintiles. Logistic regression was used to adjust for confounding. Results With each increasing quintile of deprivation, diabetes prevalence increased (odds ratio 0.84), the probability of having been screened for diabetic retinopathy decreased (odds ratio 1.11), and the prevalence of sight-threatening diabetic retinopathy among screened patients increased (odds ratio of 0.98), while the prevalence of non-sight-threatening diabetic retinopathy remained unchanged with each increasing quintile of deprivation. Conclusion Sight-threatening diabetic retinopathy was associated with socioeconomic deprivation, but non-sight-threatening diabetic retinopathy was not. Uptake of screening was inversely related to socioeconomic deprivation

    Optimized fuzzy control for natural trajectory based FES-swinging motion

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    The use of electrical signals to restore the function of paralyzed muscles is called functional electrical stimulation (FES). FES is a promising ethod to restore mobility to individuals paralyzed due to spinal cord injury (SCI). A crucial issue of FES is the control of motor function by the artificial activation of paralyzed muscles due to the various characteristics of the underlying physiological/biomechanical system. Muscle response characteristics are nonlinear and time-varying. After developing a nonlinear model describing the dynamic behavior of the knee joint and muscles, a closed-loop approach of control strategy to track the reference trajectory is assessed in computer simulations. Then, the controller was validated through experimental work. In this approach only the quadriceps muscle is stimulated to perform the swinging motion by controlling the amount of stimulation pulsewidth. An approach of fuzzy trajectory tracking control of swinging motion optimized with genetic algorithm is presented. The results show the effectiveness of the approach in controlling FES-induced swinging motion in the simulation as well as in the practical environment

    Energy Losses through Unharnessed Biomass in South-Eastern Region of Nigeria

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    The problem of over-dependence on the non-renewable and fastdepleting fossil fuels is one the world of science needs not wink at any longer. In Nigeria, the level of dependence on these fossil fuels has created a great disparity in the sourcing, harnessing, exploration and exploitation of these natural endowments vis-Γ -vis other energy sources. The truth of the matter is that virtually all other sources of energy are neglected, untapped and unutilized/underutilized. This research work was necessitated by the burden to create awareness on the quantity of energy lost as occasioned by this insensitive attitude of the society to these other forms of energy and the possible implications to the environment and economy. It is the view of these writers that diversification of our energy consumption is a potent panacea to the usual power shortages and high cost of energy in Nigeria. The research findings show that about 20.52% of domestic energy requirements of South-eastern region of Nigeria could be met through proper harnessing of biomass (biodegradable materials) for the production of biogas.African Research Review Vol. 2 (3) 2008: pp. 21-3

    Morphological characteristics and egg production of forced-moult layers under different moult induction techniques

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    A study was conducted to investigate the morphological characteristics and egg production of forcedmoult layers. Different feeding patterns designated T1, T2 and T3 representing ad libitum supply of feed and water, no feed but water given ad libitum and no feed or water, respectively, were used to induce moult. T1 served as the control. One hundred and twenty 84-week old layers in their 64 weeks in lay were randomly assigned to each treatment, which was replicated 4 times with 30 hens per replicate.Forced-moult treatments were imposed for 10 days, after which the moulting hens were fed moult diet for 50 days and returned to the same feed as the control. The results of the study revealed that morphological characteristics following moult induction included loss of feathers, dullness of theeyeballs, shriveling and paleness of the comb, wattle and ear lobes. Also the moulting birds emaciated with T2 and T3 losing 18.18 and 25.97%, respectively, of their initial body weights by day 7 of moult induction. The forced-moult groups T2 and T3 stopped egg production by  6 days of moult induction and resumed egg production by day 25. T2 and T3 attained a peak egg production of 71% by the second month following resumption of lay. On the other hand, in the T1 egg production progressively decreased with age

    Plasma progesterone profile and ovarian activity of forced-moult layers

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    Different techniques of moult induction were used to force moult 360 commercial old layers, aged 85 weeks. The techniques were: natural day length with feed and water ad libitum, natural day length with water but no feed, natural day length with no feed and no water, reduced day length with feed and water ad libitum, reduced day length with water but no feed, reduced day length with no feed and no water, designated as T1, T2, T3, T4, T5 and T6, respectively. The T1 served as the control. Sixty hens wererandomly assigned to each treatment which was replicated 3 times. The moult induction period was for 10 days coupled with 50 days of recovery period when the birds were fed low protein moult diet. At day 7, the ovaries of T2, T3, T5, T6 regressed weighing 3.43, 7.03, 5.00, 4.80 g, respectively. These were significantly (P<0.05) lower than the ovarian weights of 34.73 and 35.13 g of T4 and control (T1), respectively. By day 35 of moult induction, the ovaries of T2, T3, T5 showed the greatest recoveryincreasing to 18.53, 20.73, 13.27 g, respectively, while T4 decreased to 13.00 g. The number of large yellow follicles of T2, T3, T5, T6 decreased from 3.33 on day 0 to 0.00 on day 7. By day 21 the large yellow follicles of T2, T3, T5 and T6 started regenerating, ranging between 2.33 and 3.00 and by day 49 were significantly (P<0.05) higher than T4 (1.67). Plasma progesterone levels decreased from between 0.50 and 0.60 ng/ml on day 0 to undetectable levels by days 7 and 14 in T2, T3, T5, T6. By day 21,plasma progesterone levels (ng/ml) started rising in T2 (0.40), T3 (0.33), T5 (0.40), T6 (0.33) although these were significantly (P<0.05) lower than those of T1 (0.77) and T4 (0.81). As the number of large yellow follicles increased, the concentration of progesterone in the plasma increased

    C. trachomatis pgp3 antibody prevalence in young women in England, 1993-2010

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    Seroepidemiology of chlamydia can offer study opportunities and insights into cumulative risk of exposure that may contribute to monitoring the frequency of, and control of, genital chlamydia-the most commonly diagnosed STI in England. We undertook retrospective anonymous population-based cross-sectional surveys using an indirect IgG ELISA for chlamydia Pgp3 antibody. Sera from 4,732 women aged 17-24 years were tested. Samples were taken at 3-yearly intervals between 1993 and 2002, a period during which other data suggest chlamydia transmission may have been increasing, and from each year between 2007 and 2010. Seroprevalence increased in 17-24 year olds over time between 1993 and 2002. Between 2007 and 2010, age-standardised seroprevalence among 17-24 year olds decreased from 20% (95% CI: 17-23) to 15% (95%CI 12-17) (p = 0.0001). The biggest drop was among 20 to 21 year olds, where seroprevalence decreased from 21% in 2007 to 9% in 2010 (p = 0.002). These seroprevalence data reflect some known features of the epidemiology of chlamydia infection, and show that exposure to antibody-inducing chlamydia infection has declined in recent years. This decline was concurrent with increasing rates of screening for asymptomatic chlamydia. Serology should be explored further as a tool for evaluation of chlamydia control, including chlamydia screening programmes

    Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid

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    BACKGROUND: Increased prevalences of diabetes mellitus have been reported among individuals chronically exposed to inorganic arsenic (iAs). However, the mechanisms underlying the diabetogenic effects of iAs have not been characterized. We have previously shown that trivalent metabolites of iAs, arsenite (iAs(III)) and methylarsonous acid (MAs(III)) inhibit insulin-stimulated glucose uptake (ISGU) in 3T3-L1 adipocytes by suppressing the insulin-dependent phosphorylation of protein kinase B (PKB/Akt). OBJECTIVES: Our goal was to identify the molecular mechanisms responsible for the suppression of PKB/Akt phosphorylation by iAs(III) and MAs(III). METHODS: The effects of iAs(III) and MAs(III) on components of the insulin-activated signal transduction pathway that regulate PKB/Akt phosphorylation were examined in 3T3-L1 adipocytes. RESULTS: Subtoxic concentrations of iAs(III) or MAs(III) had little or no effect on the activity of phosphatidylinositol 3-kinase (PI-3K), which synthesizes phosphatidylinositol-3,4,5-triphosphate (PIP(3)), or on phosphorylation of PTEN (phosphatase and tensin homolog deleted on chromosome ten), a PIP(3) phosphatase. Neither iAs(III) nor MAs(III) interfered with the phosphorylation of 3-phosphoinositide-dependent kinase-1 (PDK-1) located downstream from PI-3K. However, PDK-1 activity was inhibited by both iAs(III) and MAs(III). Consistent with these findings, PDK-1-catalyzed phosphorylation of PKB/Akt(Thr308) and PKB/Akt activity were suppressed in exposed cells. In addition, PKB/Akt(Ser473) phosphorylation, which is catalyzed by a putative PDK-2, was also suppressed. Notably, expression of constitutively active PKB/Akt restored the normal ISGU pattern in adipocytes treated with either iAs(III) or MAs(III). CONCLUSIONS: These results suggest that inhibition of the PDK-1/PKB/Akt-mediated transduction step is the key mechanism for the inhibition of ISGU in adipocytes exposed to iAs(III) or MAs(III), and possibly for impaired glucose tolerance associated with human exposures to iAs

    Discovery of a recent, natural whale fall on the continental slope off Anvers Island, western Antarctic Peninsula

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Whale falls provide a substantial, nutrient-rich resource for species in areas of the ocean that may otherwise be largely devoid of food. We report the discovery of a natural whale fall at 1430 m depth in the cold waters of the continental slope off the western Antarctic Peninsula. This is the highest-latitude whale fall reported to date. The section of the carcass we observedβ€”the tail flukeβ€”was more complete than any previously reported natural whale fall from the deep sea and in the early stages of decomposition. We estimate the entire cetacean to measure 5–8 m in length. The flesh remained almost intact on the carcass but the skin was missing from the entire section except for the end of the fluke, clearly exposing blubber and soft tissue. The absence of skin indicates rapid and Homogeneous loss. The dominant macrofauna present were crustaceans, including most prominently the lithodid crab Paralomis birsteini, and zoarcid fish typical of the β€˜mobile-scavenger’ successional stage. The density of mobile macrofauna was greatest on the carcass and declined to background levels within 100 m, indicating that they were attracted to the whale fall. This whale fall offers an important opportunity to examine the decomposition of a carcass under deep-sea conditions at polar latitudes.We are grateful to the captain and crew of the RV Nathaniel B. Palmer, and to the US Antarctic Support Contractor, Lockheed Martin, for their assistance at sea. We thank J.T. Eastman and two anonymous reviewers for helpful comments on the manuscript. Funding was provided by grants from the U.S. National Science Foundation: ANT-1141877 to R.B.A. and ANT-1141896 to J.B.M. This is contribution 122 from the Institute for Research on Global Climate Change at the Florida Institute of Technology

    Is the even distribution of insecticide-treated cattle essential for tsetse control? Modelling the impact of baits in heterogeneous environments

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    Background: Eliminating Rhodesian sleeping sickness, the zoonotic form of Human African Trypanosomiasis, can be achieved only through interventions against the vectors, species of tsetse (Glossina). The use of insecticide-treated cattle is the most cost-effective method of controlling tsetse but its impact might be compromised by the patchy distribution of livestock. A deterministic simulation model was used to analyse the effects of spatial heterogeneities in habitat and baits (insecticide-treated cattle and targets) on the distribution and abundance of tsetse. Methodology/Principal Findings: The simulated area comprised an operational block extending 32 km from an area of good habitat from which tsetse might invade. Within the operational block, habitat comprised good areas mixed with poor ones where survival probabilities and population densities were lower. In good habitat, the natural daily mortalities of adults averaged 6.14% for males and 3.07% for females; the population grew 8.46in a year following a 90% reduction in densities of adults and pupae, but expired when the population density of males was reduced to <0.1/km2; daily movement of adults averaged 249 m for males and 367 m for females. Baits were placed throughout the operational area, or patchily to simulate uneven distributions of cattle and targets. Gaps of 2–3 km between baits were inconsequential provided the average imposed mortality per km2 across the entire operational area was maintained. Leaving gaps 5–7 km wide inside an area where baits killed 10% per day delayed effective control by 4–11 years. Corrective measures that put a few baits within the gaps were more effective than deploying extra baits on the edges. Conclusions/Significance: The uneven distribution of cattle within settled areas is unlikely to compromise the impact of insecticide-treated cattle on tsetse. However, where areas of >3 km wide are cattle-free then insecticide-treated targets should be deployed to compensate for the lack of cattle

    In Vivo Comparative Evaluation of Effects of Artemeter-Lumefantrine, Sulphadoxine-Pyrimetamine and Halofantrine on G6PD Activities, Haemoglobin Concentration and Malaria Parasite Clearance Rate in Malaria Infected Adults

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    Background: The use of antimalaria combination therapy especially regimens containing an artemisin-based compound has been recommended as a good first-line treatment for malaria by WHO. However, limited reports exist on the effects of the ACT and other antimalarial drugs on some vital biological parameters such as G6PD activity and haemoglobin concentration. In this study, we investigated the effects of Artemeter-Lumefantrine, sulphadoxine-pyrimetamine combination therapies and Halofantrine monotherapy on G6PD activity, Haemoglobin level and parasite clearance rate in malaria-infected adults treated with the drugs in Enugu, Nigeria. Methodology: Forty malaria-infected adults aged between 20 and 30 years were used. The subjects were divided into four groups (A, B, C and D). The groups A, B and C were given Artemeter-Lumefantrine, sulphadoxine-pyrimetamine and halofantrine respectively, while group D was a control group (malaria-positive control). Blood samples of the subjects were collected through venepuncture at baseline (Day 0) and after treatment on Day 4, for comparative analysis of G6PD activity, haemoglobin concentration and parasite clearance for each group. Results: The result of this study showed that sulphadoxine-pyrimetamine significantly (p&lt;0.05) lowered haemoglobin concentration as compared with Halofantrine, Artemeter-lumefantrine and control. The haemoglobin concentration of the last three groups did not show any significant difference (p&gt;0.05) between each other. The G6PD activity of the group treated with sulphadoxine-pyrimetamine was significantly (p&lt;0.05) higher as compared with that treated with Artemeter-lumefantrine but non-significant (p&gt;0.05) as compared with halofantrine and control. Parasite clearance rate was significantly (p&lt;0.05) highest with the Halofantrine group (76%, p&lt; 0.05) while Sulphadoxine-pyrimetamine had the lowest (52%) parasite clearance. Conclusion: This study therefore indicated that antimalaria drugs as well as malaria parasite could cause a reduction in haemoglobin concentration with sulphadoxine-pyrimetamine causing significant (p&lt;0.05) increase in G-6-PD activity. Keywords: Antimalarials, Artemether-Lumefantrine, G6PD, sulphadoxine-pyrimetamine, Parasite clearance, Halofantrine, Haemoglobin concentratio
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