2,324 research outputs found

    Thalamic inflammation after brain trauma is associated with thalamo-cortical white matter damage

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    Background Traumatic brain injury can trigger chronic neuroinflammation, which may predispose to neurodegeneration. Animal models and human pathological studies demonstrate persistent inflammation in the thalamus associated with axonal injury, but this relationship has never been shown in vivo. Findings Using [11C]-PK11195 positron emission tomography, a marker of microglial activation, we previously demonstrated thalamic inflammation up to 17 years after traumatic brain injury. Here, we use diffusion MRI to estimate axonal injury and show that thalamic inflammation is correlated with thalamo-cortical tract damage. Conclusions These findings support a link between axonal damage and persistent inflammation after brain injury

    Potent induction of antibody-secreting B-cells by human dermal-derived CD14+ dendritic cells triggered by dual toll-like receptor ligation

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    Targeting CD14(+) dermal-derived dendritic cells (DDCs) is a rational approach for vaccination strategies aimed at improving humoral immune responses, because of their natural ability to stimulate naïve B-cells. Here, we show that CD14(+) DDCs express mRNA for TLRs 1–9, but respond differentially to single or paired TLR ligands. Compared to single ligands, some combinations were particularly effective at activating CD14(+) DDCs, as shown by enhanced expression of B-cell stimulatory cytokines (IL-6, IL-10 and TNF-α) and more pronounced phenotypic maturation. These combinations were Resiquimod (R-848) plus Polyinosinic:polycytidylic acid (Poly(I:C)); R-848 plus LPS; Pam3CSK4 plus Poly(I:C); LPS plus Poly(I:C). We also found that selected TLR ligand pairs (R-848 plus either LPS or Poly(I:C)) were superior to individual agents at boosting the inherent capacity of CD14(+) DDCs to induce naïve B-cells to proliferate and differentiate into CD27(+) CD38(+) B-cells that secrete high levels of IgG and IgA. When treated with the same TLR ligand combinations, CD14(+) DDCs also promoted the differentiation of Th1 (IFN-γ-secreting) CD4(+) T-cells, but not of Th2 or Th17 CD4(+) T-cells. These observations may help to identify adjuvant strategies aimed at inducing protective immune responses to various pathogens, including but not limited to HIV-1

    Why lose weight? Reasons for seeking weight loss by overweight but otherwise healthy men

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    OBJECTIVE: To identify the reasons for seeking weight loss in overweight or obese but otherwise healthy men. DESIGN: Interviews, prior to intervention, with subjects who had volunteered to participate in a work-site-based weight loss study. SUBJECTS: Ninety-one overweight=obese male workers. Mean age 41, range 18 – 55 y, mean body mass index (BMI) 31.0, range 26.2 – 41.6 kg=m2. MEASUREMENTS: Anthropometric measurements; body weight and height. Body mass index calculated. A short interview using open questions to determine the individuals reason for seeking weight loss. RESULTS: The message that weight loss is beneficial to health for the overweight was recognized by all subjects regardless of BMI, and was reported as the main factor for attempting weight loss. Improved fitness and effects on appearance and well-being were reported half as often as the primary reason for weight loss. CONCLUSION: Overweight lay members of the public have accepted the health education message that weight loss can improve health. Overweight but otherwise healthy men who responded, of their own accord, to an electronic mail message offering help to lose weight did not regard obesity and overweight as primarily a cosmetic issue. This is still, however, important, especially to younger people

    High-resolution laboratory lysimeter for automated sampling of tracers through a 0.5m soil block

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    A computer-controlled, automated sample collection from a 0.5-m lysimeter, designed to give superior temporal and spatial resolution for monitoring the movement of chemical tracers through a large undisturbed soil block, is described. The soil block, 0.520.520.5 m, was monitored for saturation using eight time domain reflectometry probes. Rainfall was applied at approximately 1600 ml hm1 using a 12212 array of 23-gauge (0.318 mm internal diameter) hypodermic needles. Soil leachates were collected at the base of the soil block using a machined aluminium collection plate with a 10210 grid of funnels that passed leachates to sample collection palettes. Sample collection was automated using a personal computer equipped with National Instruments LabVIEW™ software and linked to sensors for palette tracking. The automation of the lysimeter allowed sample collection and storage over a user-defined period with no human interaction. As an example of the use of the automated lysimeter, results show the distribution of phosphate within the soil. The eluted phosphate showed an initial and secondary peak, and only emerged from preferential flow channels

    Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas

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    Neglected tropical diseases (NTDs) have\ud been recently identified as significant public\ud health problems in Texas and elsewhere in\ud the American South. A one-day forum on the\ud landscape of research and development and\ud the hidden burden of NTDs in Texas\ud explored the next steps to coordinate advocacy,\ud public health, and research into a\ud cogent health policy framework for the\ud American NTDs. It also highlighted how\ud U.S.-funded global health research can serve\ud to combat these health disparities in the\ud United States, in addition to benefiting\ud communities abroad

    On the experimental verification of quantum complexity in linear optics

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    The first quantum technologies to solve computational problems that are beyond the capabilities of classical computers are likely to be devices that exploit characteristics inherent to a particular physical system, to tackle a bespoke problem suited to those characteristics. Evidence implies that the detection of ensembles of photons, which have propagated through a linear optical circuit, is equivalent to sampling from a probability distribution that is intractable to classical simulation. However, it is probable that the complexity of this type of sampling problem means that its solution is classically unverifiable within a feasible number of trials, and the task of establishing correct operation becomes one of gathering sufficiently convincing circumstantial evidence. Here, we develop scalable methods to experimentally establish correct operation for this class of sampling algorithm, which we implement with two different types of optical circuits for 3, 4, and 5 photons, on Hilbert spaces of up to 50,000 dimensions. With only a small number of trials, we establish a confidence >99% that we are not sampling from a uniform distribution or a classical distribution, and we demonstrate a unitary specific witness that functions robustly for small amounts of data. Like the algorithmic operations they endorse, our methods exploit the characteristics native to the quantum system in question. Here we observe and make an application of a "bosonic clouding" phenomenon, interesting in its own right, where photons are found in local groups of modes superposed across two locations. Our broad approach is likely to be practical for all architectures for quantum technologies where formal verification methods for quantum algorithms are either intractable or unknown.Comment: Comments welcom

    Intimate partner violence in early adolescence : the role of gender, socio-economic factors and the school

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    Background: Intimate partner violence (IPV) among adolescents is common worldwide, but our understanding of perpetration, gender differences and the role of social-ecological factors remains limited. Objectives: To explore the prevalence of physical and sexual IPV perpetration and victimisation by gender, and associated risk and protective factors. Methods: Young adolescents (N=2 839) from 41 randomly selected public high schools in the Western Cape region of South Africa (SA), participating in the PREPARE study, completed a self-administered questionnaire. Results: The participants’ mean age was 13.65 years (standard deviation 1.01), with 19.1% (541/2 839) reporting being victims/survivors of IPV and 13.0% (370/2 839) reporting perpetrating IPV. Girls were less likely to report being a victim/survivor of physical IPV (odds ratio (OR) 0.72; 95% confidence interval (CI) 0.57 - 0.92) and less likely to be a perpetrator of sexual IPV than boys (OR 0.33; 95% CI 0.21 - 0.52). Factors associated with perpetration of physical and sexual IPV were similar and included being a victim/survivor (physical IPV: OR 12.42; 95% CI 8.89 - 17.36, sexual IPV: OR 20.76; 95% CI 11.67 - 36.93), being older (physical IPV: OR 1.26; 95% CI 1.08 - 1.47, sexual IPV: OR 1.36; 95% CI 1.14 - 1.62 ), having lower scores on school connectedness (physical IPV: OR 0.59; 95% CI 0.46 - 0.75, sexual IPV: OR 0.56; 95% CI 0.42 - 0.76) and scoring lower on feelings of school safety (physical IPV: OR 0.66; 95% CI 0.57 - 0.77, sexual IPV: OR 0.50; 95% CI 0.40 - 0.62). Conclusions: Physical and sexual IPV was commonly reported among young adolescents in SA. Further qualitative exploration of the role of reciprocal violence by gender is needed, and the role of ‘school climate’-related factors should be taken into account when developing preventive interventions

    Relationships between retinal layer thickness and brain volumes in the UK Biobank cohort

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    BACKGROUND: Current methods to diagnose neurodegenerative diseases are costly and invasive. Retinal neuroanatomy may be a biomarker for more neurodegenerative processes and can be quantified in vivo using optical coherence tomography (OCT), which is inexpensive and noninvasive. We examined the association of neuroretinal morphology with brain MRI image derived phenotypes (IDPs) in a large cohort of healthy older people. METHODS: UK Biobank participants aged 40 to 69 years old underwent comprehensive examinations including ophthalmic and brain imaging assessments. Macular retinal nerve fibre layer (mRNFL), ganglion cell-inner plexiform layer (mGCIPL), ganglion cell complex (mGCC) and total macular thicknesses were obtained from OCT. MRI IDPs assessed included total brain, grey-matter, white-matter and hippocampal volume. Multivariable linear regression models were used to evaluate associations between retinal layers thickness and brain MRI IDPs, adjusting for demographic factors and vascular risk factors. RESULTS: A total of 2,131 participants (mean age 55 years; 51% women) with both gradable OCT images and brain imaging assessments were included. In multivariable regression analysis, thinner mGCIPL, mGCC, and total macular thickness were all significantly associated with smaller total brain (p<0.001), grey-matter and white-matter volumes (p<0.01), and grey-matter volume in the occipital pole (p<0.05). Thinner mGCC and total macular thicknesses were associated with smaller hippocampal volume (p<0.02). No association was found between mRNFL and the MRI IDPs. CONCLUSION: Markers of retinal neurodegeneration are associated with smaller brain volumes. Our findings suggest that retinal structures may be a biomarker providing information about important brain structures in healthy, older adults
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