1,437 research outputs found

    A comparison of location of acute symptomatic vs. 'silent' small vessel lesions

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    Background: Acute lacunar ischaemic stroke, white matter hyperintensities, and lacunes are all features of cerebral small vessel disease. It is unclear why some small vessel disease lesions present with acute stroke symptoms, whereas others typically do not. Aim: To test if lesion location could be one reason why some small vessel disease lesions present with acute stroke, whereas others accumulate covertly. Methods: We identified prospectively patients who presented with acute lacunar stroke symptoms with a recent small subcortical infarct confirmed on magnetic resonance diffusion imaging. We compared the distribution of the acute infarcts with that of white matter hyperintensity and lacunes using computational image mapping methods. Results: In 188 patients, mean age 67 ± standard deviation 12 years, the lesions that presented with acute lacunar ischaemic stroke were located in or near the main motor and sensory tracts in (descending order): posterior limb of the internal capsule (probability density 0·2/mm3), centrum semiovale (probability density = 0·15/mm3), medial lentiform nucleus/lateral thalamus (probability density = 0·09/mm3), and pons (probability density = 0·02/mm3). Most lacunes were in the lentiform nucleus (probability density = 0·01–0·04/mm3) or external capsule (probability density = 0·05/mm3). Most white matter hyperintensities were in centrum semiovale (except for the area affected by the acute symptomatic infarcts), external capsules, basal ganglia, and brainstem, with little overlap with the acute symptomatic infarcts (analysis of variance, P < 0·01). Conclusions: Lesions that present with acute lacunar ischaemic stroke symptoms may be more likely noticed by the patient through affecting the main motor and sensory tracts, whereas white matter hyperintensity and asymptomatic lacunes mainly affect other areas. Brain location could at least partly explain the symptomatic vs. covert development of small vessel disease

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Network Modeling Sex Differences in Brain Integrity and Metabolic Health

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    Hypothesis-driven studies have demonstrated that sex moderates many of the relationships between brain health and cardiometabolic disease, which impacts risk for later-life cognitive decline. In the present study, we sought to further our understanding of the associations between multiple markers of brain integrity and cardiovascular risk in a midlife sample of 266 individuals by using network analysis, a technique specifically designed to examine complex associations among multiple systems at once. Separate network models were constructed for male and female participants to investigate sex differences in the biomarkers of interest, selected based on evidence linking them with risk for late-life cognitive decline: all components of metabolic syndrome (obesity, hypertension, dyslipidemia, and hyperglycemia); neuroimaging-derived brain-predicted age minus chronological age; ratio of white matter hyperintensities to whole brain volume; seed-based resting state functional connectivity in the Default Mode Network, and ratios of N-acetyl aspartate, glutamate and myo-inositol to creatine, measured through proton magnetic resonance spectroscopy. Males had a sparse network (87.2% edges = 0) relative to females (69.2% edges = 0), indicating fewer relationships between measures of cardiometabolic risk and brain integrity. The edges in the female network provide meaningful information about potential mechanisms between brain integrity and cardiometabolic health. Additionally, Apolipoprotein ϵ4 (ApoE ϵ4) status and waist circumference emerged as central nodes in the female model. Our study demonstrates that network analysis is a promising technique for examining relationships between risk factors for cognitive decline in a midlife population and that investigating sex differences may help optimize risk prediction and tailor individualized treatments in the future

    Properties of local interactions and their potential value in complementing genome-wide association studies

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    Local interactions between neighbouring SNPs are hypothesized to be able to capture variants missing from genome-wide association studies (GWAS) via haplotype effects but have not been thoroughly explored. We have used a new high-throughput analysis tool to probe this underexplored area through full pair-wise genome scans and conventional GWAS in diastolic and systolic blood pressure and six metabolic traits in the Northern Finland Birth Cohort 1966 (NFBC1966) and the Atherosclerosis Risk in Communities study cohort (ARIC). Genome-wide significant interactions were detected in ARIC for systolic blood pressure between PLEKHA7 (a known GWAS locus for blood pressure) and GPR180 (which plays a role in vascular remodelling), and also for triglycerides as local interactions within the 11q23.3 region (replicated significantly in NFBC1966), which notably harbours several loci (BUD13, ZNF259 and APOA5) contributing to triglyceride levels. Tests of the local interactions within the 11q23.3 region conditional on the top GWAS signal suggested the presence of two independent functional variants, each with supportive evidence for their roles in gene regulation. Local interactions captured 9 additional GWAS loci identified in this study (3 significantly replicated) and 73 from previous GWAS (24 in the eight traits and 49 in related traits). We conclude that the detection of local interactions requires adequate SNP coverage of the genome and that such interactions are only likely to be detectable between SNPs in low linkage disequilibrium. Analysing local interactions is a potentially valuable complement to GWAS and can provide new insights into the biology underlying variation in complex traits

    Measurement of the top quark mass using the matrix element technique in dilepton final states

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    We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7  fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84  GeV

    Dietary Saturated Fat Intake Moderates the Effect of Plasma Triglycerides on Memory Performance in Middle-Aged Adults

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    Isabelle Gallagher,1 Yanrong Li,1 Cherry Youn,1 Hirofumi Tanaka,2 Jaimie N Davis,3 Andreana P Haley1 1Department of Psychology, University of Texas at Austin, Austin, TX, USA; 2Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA; 3Department of Nutritional Sciences, The University of Texas at Austin, Austin, TX, USACorrespondence: Andreana P Haley, Department of Psychology, The University of Texas at Austin, SEA 3.130E, 108 E Dean Keeton St, Austin, TX, 78712, USA, Tel +1 512 232 0863, Fax +1 512 471-6175, Email [email protected]: With Alzheimer’s disease and related dementias are projected to triple by 2050, addressing modifiable health and lifestyle factors is crucial to prevention and reducing the associated public health burden. This study investigates the interaction between triglyceride levels and dietary fat intake and diet quality on memory performance in middle-aged adults at heightened risk for metabolic health issues.Patients and Methods: Community-dwelling adults aged 40– 65 with cardiometabolic health risks participated in this cross-sectional study. Participants with a history of neurological or psychiatric conditions were excluded. Dietary intake was self-reported through a 3-day food record, and serum triglyceride levels were measured. Neuropsychological testing assessed memory performance. Cross-sectional regression analyses examined how dietary fat intake and quality interact with triglyceride levels to affect memory performance in 146 adults.Results: The analysis revealed a significant interaction between triglyceride levels and the ratio of dietary saturated fat to total caloric intake on memory performance (β = − 0.087, p = 0.022). The relationship between triglyceride levels and memory performance was modified by the ratio of saturated fat to total caloric intake. At higher levels of saturated fat intake, higher triglycerides were associated with worse memory performance. However, at lower levels of saturated fat intake, the association between triglycerides and memory performance was not statistically significant. Better adherence to USDA dietary guidelines, reflected by higher Healthy Eating Index 2020 scores, was associated with better memory performance (β = 0.018, p < 0.002), regardless of triglyceride levels.Conclusion: Diet quality, as indicated by adherence to dietary guidelines, supports cognitive health. Elevated triglycerides combined with a high ratio of dietary saturated fat intake were associated with poorer memory performance. Precision nutrition strategies aimed at reducing saturated fat intake in midlife adults with elevated triglyceride levels may help mitigate memory-related cognitive decline and enhance brain health.Plain Language Summary: This study explored how diet and triglyceride levels (a type of fat in the blood) might influence memory and the risk of Alzheimer’s disease and other dementias in adults at higher risk. We focused on middle-aged adults (ages 40-65) who had cardiometabolic health issues, such as obesity, high blood pressure, high cholesterol, or diabetes. We worked with 146 adults from the community who reported their eating habits over three days and took tests to measure triglyceride levels and memory performance. The study found that higher triglyceride levels combined with a diet high in saturated fats (common in many Western diets) were linked to poorer memory performance. However, adults with high triglycerides who ate less saturated fat performed better on memory tests than those with higher saturated fat intake. Overall, following a healthier diet was associated with better memory, regardless of triglyceride levels. These findings suggest that improving diet quality—by adhering to dietary guidelines—could help protect brain health and reduce memory problems. For people with high triglycerides, cutting back on saturated fat may help improve memory and protect against cognitive decline. These results point to the importance of personalized nutrition strategies to support brain health and potentially reduce the risk of memory loss as we age.Keywords: cardiometabolic, Western diet, cognition, midlif

    Measurement of the cross section for inclusive isolated-photon production in pp collisions at √s=13TeV using the ATLAS detector

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    Inclusive isolated-photon production in pp collisions at a centre-of-mass energy of 13TeVis studied with the ATLAS detector at the LHC using a data set with an integrated luminosity of 3.2fb−1. The cross section is measured as a function of the photon transverse energy above 125GeVin different regions of photon pseudorapidity. Next-to-leading-order perturbative QCD and Monte Carlo event-generator predictions are compared to the cross-section measurements and provide an adequate description of the data

    Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

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    Operation and performance of the ATLAS Tile Calorimeter in Run 1

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    The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report

    Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

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    This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing
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