1,212 research outputs found

    Clinically Silent Alzheimer\u27s and Vascular Pathologies Influence Brain Networks Supporting Executive Function in Healthy Older Adults

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    Aging is associated with declines in executive function. We examined how executive functional brain systems are influenced by clinically silent Alzheimer’s disease (AD) pathology and cerebral white matter hyperintensities (WMHs). Twenty-nine younger adults and thirty-four cognitively normal older adults completed a working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Older adults further underwent lumbar cerebrospinal fluid (CSF) draw for assessment of AD pathology and FLAIR imaging for assessment of WMHs. Accurate working memory performance in both age groups was associated with high fronto-visual functional connectivity (fC). However, in older adults, higher expression of fronto-visual fC was linked with lower levels of clinically silent AD pathology. In addition, AD pathology and WMHs were each independently related to increased fMRI response in the left dorsolateral prefrontal cortex, a pattern associated with slower task performance. Our results suggest that clinically silent AD pathology is related to lower expression of a fronto-visual fC pattern supporting executive task performance. Further, our findings suggest that AD pathology and WMHs appear to be linked with ineffective increases in frontal response in CN older adults

    Urethral Slings for Irradiated Patients With Male Stress Urinary Incontinence: A Meta-analysis

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    ObjectiveTo systematically compare success, cure and complication rates of urethral sling surgeries in stress urinary incontinence patients with and without a history of pelvic radiotherapy (RT).Materials and methodsWe searched PUBMED, EMBASE, and Web of Science to identify relevant articles. The primary outcomes were the success and cure rates. The secondary outcomes included the rates of infection, urethral erosion, total complications, explantation, and satisfaction. Outcomes were analyzed using a random-effects model to calculate the unadjusted odds ratio (OR) in patients with a history of RT compared with those without prior RT.ResultsOn pooled analysis, we found significantly lower odds of success (OR 0.68; 95% confidence interval [CI] 0.53-0.87, P < .001) and cure (OR 0.67; 95% CI 0.55-0.82, P < .001) in radiated patients than in nonirradiated patients. Subgroup analysis by type of sling showed significantly lower odds of success in Advance subgroup (OR 0.66; 95% CI 0.45-0.95, P < .001) and significantly lower odds of cure in Advance (OR 0.59; 95% CI 0.36-0.95, P < .001) and Atoms subgroups (OR 0.70; 95% CI 0.54-0.93, P < .001). We also found significantly greater odds of sling explantation (OR 2.93; 95% CI 1.62-5.29, P < .001) and infection (OR 3.06, 95% CI 1.03-9.07, P < .001) in radiated patients than in nonradiated patients.ConclusionPatients with a history of pelvic RT have lower odds of success and cure and higher odds of infection and sling explantation than those without a history of pelvic RT

    Local Luminous Infrared Galaxies. I. Spatially resolved observations with Spitzer/IRS

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    We present results from the Spitzer/IRS spectral mapping observations of 15 local luminous infrared galaxies (LIRGs). In this paper we investigate the spatial variations of the mid-IR emission which includes: fine structure lines, molecular hydrogen lines, polycyclic aromatic features (PAHs), continuum emission and the 9.7um silicate feature. We also compare the nuclear and integrated spectra. We find that the star formation takes place in extended regions (several kpc) as probed by the PAH emission as well as the [NeII] and [NeIII] emissions. The behavior of the integrated PAH emission and 9.7um silicate feature is similar to that of local starburst galaxies. We also find that the minima of the [NeIII]/[NeII] ratio tends to be located at the nuclei and its value is lower than that of HII regions in our LIRGs and nearby galaxies. It is likely that increased densities in the nuclei of LIRGs are responsible for the smaller nuclear [NeIII]/[NeII] ratios. This includes the possibility that some of the most massive stars in the nuclei are still embedded in ultracompact HII regions. In a large fraction of our sample the 11.3um PAH emission appears more extended than the dust 5.5um continuum emission. We find a dependency of the 11.3um PAH/7.7 um PAH and [NeII]/11.3um PAH ratios with the age of the stellar populations. Smaller and larger ratios respectively indicate recent star formation. The estimated warm (300 K < T < 1000 K) molecular hydrogen masses are of the order of 10^8 M_Sun, which are similar to those found in ULIRGs, local starbursts and Seyfert galaxies. Finally we find that the [NeII] velocity fields for most of the LIRGs in our sample are compatible with a rotating disk at ~kpc scales, and they are in a good agreement with H-alpha velocity fields.Comment: Comments: 52 pages, accepted for publicacion in ApJ

    Genome-to-genome analysis highlights the effect of the human innate and adaptive immune systems on the hepatitis C virus

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    Outcomes of hepatitis C virus (HCV) infection and treatment depend on viral and host genetic factors. Here we use human genome-wide genotyping arrays and new whole-genome HCV viral sequencing technologies to perform a systematic genome-to-genome study of 542 individuals who were chronically infected with HCV, predominantly genotype 3. We show that both alleles of genes encoding human leukocyte antigen molecules and genes encoding components of the interferon lambda innate immune system drive viral polymorphism. Additionally, we show that IFNL4 genotypes determine HCV viral load through a mechanism dependent on a specific amino acid residue in the HCV NS5A protein. These findings highlight the interplay between the innate immune system and the viral genome in HCV control

    Who are the visitors? Characteristics of temporary movers in Australia

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    Comparison of place of enumeration at the Census with place of usual residence provides a unique window on the geography and characteristics of temporary population movements. This paper uses microdata from the 2001 Australian Census in a logistic regression framework to examine the characteristics of temporary movers classified according to distance of travel and purpose of move. We show that the age composition of temporary movers varies according to distance of move. For non-local work-related travel, the most significant predictors are being male, maritally unattached and working either in extractive industries or government and defence. Travel for consumption shows more balanced sex ratios but is selective of older age groups, and of those who are unemployed or outside the labour force. Both types of move are strongly associated with income

    NMR and NQR Fluctuation Effects in Layered Superconductors

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    We study the effect of thermal fluctuations of the s-wave order parameter of a quasi two dimensional superconductor on the nuclear spin relaxation rate near the transition temperature Tc. We consider both the effects of the amplitude fluctuations and the Berezinskii-Kosterlitz-Thouless (BKT) phase fluctuations in weakly coupled layered superconductors. In the treatment of the amplitude fluctuations we employ the Gaussian approximation and evaluate the longitudinal relaxation rate 1/T1 for a clean s-wave superconductor, with and without pair breaking effects, using the static pair fluctuation propagator D. The increase in 1/T1 due to pair breaking in D is overcompensated by the decrease arising from the single particle Green's functions. The result is a strong effect on 1/T1 for even a small amount of pair breaking. The phase fluctuations are described in terms of dynamical BKT excitations in the form of pancake vortex-antivortex (VA) pairs. We calculate the effect of the magnetic field fluctuations caused by the translational motion of VA excitations on 1/T1 and on the transverse relaxation rate 1/T2 on both sides of the BKT transitation temperature T(BKT)<Tc. The results for the NQR relaxation rates depend strongly on the diffusion constant that governs the motion of free and bound vortices as well as the annihilation of VA pairs. We discuss the relaxation rates for real multilayer systems where the diffusion constant can be small and thus increase the lifetime of a VA pair, leading to an enhancement of the rates. We also discuss in some detail the experimental feasibility of observing the effects of amplitude fluctuations in layered s-wave superconductors such as the dichalcogenides and the effects of phase fluctuations in s- or d-wave superconductors such as the layered cuprates.Comment: 38 pages, 12 figure

    Review of genetic factors in intestinal malrotation

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    Intestinal malrotation is well covered in the surgical literature from the point of view of operative management, but few reviews to date have attempted to provide a comprehensive examination of the topic from the point of view of aetiology, in particular genetic aetiology. Following a brief overview of molecular embryology of midgut rotation, we present in this article instances of and case reports and case series of intestinal malrotation in which a genetic aetiology is likely. Autosomal dominant, autosomal recessive, X-linked and chromosomal forms of the disorder are represented. Most occur in syndromic form, that is to say, in association with other malformations. In many instances, recognition of a specific syndrome is possible, one of several examples discussed being the recently described association of intestinal malrotation with alveolar capillary dysplasia, due to mutations in the forkhead box transcription factor FOXF1. New advances in sequencing technology mean that the identification of the genes mutated in these disorders is more accessible than ever, and paediatric surgeons are encouraged to refer to their colleagues in clinical genetics where a genetic aetiology seems likely
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