6,831 research outputs found

    Autism, surge in the prevalence and linkage with childhood vaccination - A Review

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    Autism a neurodegenerative disorder characterised by an abnormal child behaviour likeisolation, learning difficulties, general abnormality in communication and social reciprocity, inability to maintain eye contact or point at something, looking at thing with the peripheral vision and many other neurological disorders, the aetiology of autism is multifactorial including among other social, environmental, genetics, epigenetics andneurological factors, in recent years vaccines have drawn large interest of scientific community for its asserted role in the development of autism, this is largely due to the presence in higher concentration of a mercury containing compound thimerosal in many vaccines, and due to some evidence which link some vaccines including measles, mumps and rubella vaccines with autism, moreover several authentic scientific studies wereundertaken to falsified those findings. Here we critically review those assertion, examined some implicating component of vaccine and relate them with neurobiology of autism

    The transient response of global-mean precipitation to increasing carbon dioxide levels

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    The transient response of global-mean precipitation to an increase in atmospheric carbon dioxide levels of 1% yr(-1) is investigated in 13 fully coupled atmosphere-ocean general circulation models (AOGCMs) and compared to a period of stabilization. During the period of stabilization, when carbon dioxide levels are held constant at twice their unperturbed level and the climate left to warm, precipitation increases at a rate of similar to 2.4% per unit of global-mean surface-air-temperature change in the AOGCMs. However, when carbon dioxide levels are increasing, precipitation increases at a smaller rate of similar to 1.5% per unit of global-mean surface-air-temperature change. This difference can be understood by decomposing the precipitation response into an increase from the response to the global surface-temperature increase (and the climate feedbacks it induces), and a fast atmospheric response to the carbon dioxide radiative forcing that acts to decrease precipitation. According to the multi-model mean, stabilizing atmospheric levels of carbon dioxide would lead to a greater rate of precipitation change per unit of global surface-temperature change

    Strategic Network Formation with Attack and Immunization

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    Strategic network formation arises where agents receive benefit from connections to other agents, but also incur costs for forming links. We consider a new network formation game that incorporates an adversarial attack, as well as immunization against attack. An agent's benefit is the expected size of her connected component post-attack, and agents may also choose to immunize themselves from attack at some additional cost. Our framework is a stylized model of settings where reachability rather than centrality is the primary concern and vertices vulnerable to attacks may reduce risk via costly measures. In the reachability benefit model without attack or immunization, the set of equilibria is the empty graph and any tree. The introduction of attack and immunization changes the game dramatically; new equilibrium topologies emerge, some more sparse and some more dense than trees. We show that, under a mild assumption on the adversary, every equilibrium network with nn agents contains at most 2n42n-4 edges for n4n\geq 4. So despite permitting topologies denser than trees, the amount of overbuilding is limited. We also show that attack and immunization don't significantly erode social welfare: every non-trivial equilibrium with respect to several adversaries has welfare at least as that of any equilibrium in the attack-free model. We complement our theory with simulations demonstrating fast convergence of a new bounded rationality dynamic which generalizes linkstable best response but is considerably more powerful in our game. The simulations further elucidate the wide variety of asymmetric equilibria and demonstrate topological consequences of the dynamics e.g. heavy-tailed degree distributions. Finally, we report on a behavioral experiment on our game with over 100 participants, where despite the complexity of the game, the resulting network was surprisingly close to equilibrium.Comment: The short version of this paper appears in the proceedings of WINE-1

    Co-evolution of strategy and structure in complex networks with dynamical linking

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    Here we introduce a model in which individuals differ in the rate at which they seek new interactions with others, making rational decisions modeled as general symmetric two-player games. Once a link between two individuals has formed, the productivity of this link is evaluated. Links can be broken off at different rates. We provide analytic results for the limiting cases where linking dynamics is much faster than evolutionary dynamics and vice-versa, and show how the individual capacity of forming new links or severing inconvenient ones maps into the problem of strategy evolution in a well-mixed population under a different game. For intermediate ranges, we investigate numerically the detailed interplay determined by these two time-scales and show that the scope of validity of the analytical results extends to a much wider ratio of time scales than expected

    Parameter scaling in the decoherent quantum-classical transition for chaotic systems

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    The quantum to classical transition has been shown to depend on a number of parameters. Key among these are a scale length for the action, \hbar, a measure of the coupling between a system and its environment, DD, and, for chaotic systems, the classical Lyapunov exponent, λ\lambda. We propose computing a measure, reflecting the proximity of quantum and classical evolutions, as a multivariate function of (,λ,D)(\hbar,\lambda,D) and searching for transformations that collapse this hyper-surface into a function of a composite parameter ζ=αλβDγ\zeta = \hbar^{\alpha}\lambda^{\beta}D^{\gamma}. We report results for the quantum Cat Map, showing extremely accurate scaling behavior over a wide range of parameters and suggest that, in general, the technique may be effective in constructing universality classes in this transition.Comment: Submitte

    Isolation and characterisation of microorganisms contaminating herbal infusion sold in Minna, Nigeria

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    The microbiological assessment of ten herbal infusion samples from ten different locations in Minna, Niger State was investigated. The assessment of the microbial contamination on the herbal products was carried out, using standard methods. Pour plate method was used to cultivate serially diluted portions of the medicinal plant infusion samples. The results revealed that all the herbal preparations had the presence of microbial contaminants. The total heterotrophic counts of the different herbal samples ranged from 0 cfu/mL to 25.0 × 108cfu/mL while the total fungal counts ranged from 3.0×106cfu/mL to 3.5×108cfu/mL. The total viable bacteria counts showed that the highest counts of 25.0 × 108cfu/mL was recorded in the sample from Bosso and the least counts of 0 cfu/mL from Kasuwan-Gwari while the total fungal counts showed that the highest count of 3.5×108cfu/mL was found in the sample obtained from FUT campus and the least counts of 3.0×106cfu/mL in the sample from Mai-Kunkele. One way analysis of variance (ANOVA) showed that there was significant difference (p<0.05) in the microbial load of the herbal infusions from each location. The microbial isolates identified were E. coli, Staphylococcus aureus, Shigella sp, Klebsiella sp, Pseudomonas sp, Micrococcus sp, Salmonella sp, Aspergillus sp, Penicillium sp and Saccharomyces cerevisaie. Members of the genus Aspergillus were found to be predominant. This suggests that the herbal infusion harbors microorganisms that could be hazardous to human health and hence producers should maintain the highest possible level of hygiene during the processing and packaging of the products in order to ensure safety of the products

    Increased systemic inflammation is associated with cardiac and vascular dysfunction over the first 12 weeks of antiretroviral therapy among undernourished, HIV-infected adults in Southern Africa.

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.INTRODUCTION: Persistent systemic inflammation is associated with mortality among undernourished, HIV-infected adults starting antiretroviral therapy (ART) in sub-Saharan Africa, but the etiology of these deaths is not well understood. We hypothesized that greater systemic inflammation is accompanied by cardiovascular dysfunction over the first 12 weeks of ART. METHODS: In a prospective cohort of 33 undernourished (body mass index <18.5 kg/m2) Zambian adults starting ART, we measured C-reactive protein (CRP), tumor necrosis factor-α receptor 1 (TNF-α R1), and soluble CD163 and CD14 at baseline and 12 weeks. An EndoPAT device measured the reactive hyperemia index (LnRHI; a measure of endothelial responsiveness), peripheral augmentation index (AI; a measure of arterial stiffness), and heart rate variability (HRV; a general marker of autonomic tone and cardiovascular health) at the same time points. We assessed paired changes in inflammation and cardiovascular parameters, and relationships independent of time point (adjusted for age, sex, and CD4+ T-cell count) using linear mixed models. RESULTS: Serum CRP decreased (median change -3.5 mg/l, p=0.02), as did TNF-α R1 (-0.31 ng/ml, p<0.01), over the first 12 weeks of ART. A reduction in TNF-α R1 over 12 weeks was associated with an increase in LnRHI (p=0.03), and a similar inverse relationship was observed for CRP and LnRHI (p=0.07). AI increased in the cohort as a whole over 12 weeks, and a reduction in sCD163 was associated with a rise in the AI score (p=0.04). In the pooled analysis of baseline and 12 week data, high CRP was associated with lower HRV parameters (RMSSD, p=0.01; triangular index, p<0.01), and higher TNF- α R1 accompanied lower HRV (RMSSD, p=0.07; triangular index, p=0.06). CONCLUSIONS: Persistent inflammation was associated with impaired cardiovascular health over the first 12 weeks of HIV treatment among undernourished adults in Africa, suggesting cardiac events may contribute to high mortality in this population.This work was supported by the Vanderbilt Meharry Center for AIDS Research (NIH grant number P30 AI54999); the NIH Fogarty International Center, Office of the Director, National Institutes of Health, National Heart, Blood, and Lung Institute, and National Institute of Mental Health, through the Vanderbilt-Emory-Cornell-Duke Consortium for Global Health Fellows (grant number R25 TW009337); the National Center for Advancing Translational Sciences (CTSA award number UL1TR000445) and the European and Developing Countries Clinical Trials Partnership (grant IP.2009.33011.004)

    Gender differences in Achievement Goals and Performances in English Language and Mathematics of Senior Secondary Schools students in Borno State, Nigeria

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    The paper investigated gender difference in achievement goals and performance in English Language and Mathematics of senior secondary schools students in Borno State, Nigeria.  The study specifically sought to determine gender differences in students’ academic performances in English Language, Mathematics and overall academic performance as well as the effects of gender on these differences in performance if any.  The study was based on the ‘A Hierarchical Model of Approach and Avoidance Achievement Goals Motivation’ propounded by Elliot and Church (1997).   The study used Correlational design with a sample of 827 (414 boys and 413) students selected via stratified random sampling form 18 schools across the state.  “A Hierarchical Model of Approach and Avoidance Achievement Goals Motivation” Scale was used to measure achievement goals, tests in English and  Mathematics were used to measure achievement measures in the two subjects domains while  the aggregate of average scores in the two  tests  was used to measure overall academic performance.  The instruments were administered to the participants in a classroom seating position and collected on the sport and the data was analyzed using MANAVA. The results revealed that males performed significantly better than females in English Language and overall academic performance but there is no gender difference in Mathematics performance; and there is significant effect of gender on students’ learning goal orientation in faviour of males, whereas there are no gender effects on performance –approach and performance-avoidance goals orientation of students. The implications of the study for education and research were highlighted. Keywords: Gender, differences, achievement goals, performance, English language, Mathematics, senior secondary schools students.  Nigeri

    Peran Komunikasi Keluarga Dalam Mencegah Perilaku Merokok Bagi Remaja Di Kelurahan Winangun Kecamatan Malalayang Kota Manado

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    The background of this research problem is the phenomenon of smoking among adolescents are high enough to make researchers interested in studying. In this study defined each of understanding Role in Preventing Family Communication for Adolescent Smoking Behavior. As for the supporting theories applied that Theory of Interpersonal Communication and Stimulus Response Theory. The research methodology is descriptive method with a single variable. The population is 1149 with a sample of 20 respondents. Data collection techniques drawn consist of primary data and secondary data using descriptive statistical data analysis techniques. The results showed that the role of family communication is very important in preventing smoking behavior for adolescents. Communication is able to build a harmonious relationship between parents and children, making it easier for parents to influence and deliver all the advice, guidance, motivation and expectations of families included in preventing smoking behavior is not good for children
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