251 research outputs found

    Staging and stratifying cognitive dysfunction in multiple sclerosis

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    BACKGROUND: The sequence in which cognitive domains become impaired in multiple sclerosis (MS) is yet to be formally demonstrated. It is unclear whether processing speed dysfunction temporally precedes other cognitive impairments, such as memory and executive function. OBJECTIVE: Determine the order in which different cognitive domains become impaired in MS and validate these findings using clinical and vocational outcomes. METHODS: In a longitudinal sample of 1073 MS patients and 306 healthy controls, we measured performance on multiple, consensus-standard, neurocognitive tests. We used an event-based staging approach to model the sequence in which cognitive domains become impaired. Linear and logistic mixed-effects models were used to explore associations between stages of impairment, neurological disability, and employment status. RESULTS: Our model suggested that the order of impairments was as follows: processing speed, visual learning, verbal learning, working memory/attention, and executive function. Stage of cognitive impairment predicted greater neurological disability, ÎČ = 0.16, SE = 0.02, p < 0.001, and probability of unemployment, ÎČ = 1.14, SE = 0.001, p < 0.001. CONCLUSION: This is the first study to introduce a cognitive staging and stratification system for MS. Findings underscore the importance of using the Symbol Digit Modalities Test in routine screening for cognitive impairment and memory testing to assess patients later in disease evolution

    Evidence for Impaired CARD15 Signalling in Crohn's Disease without Disease Linked Variants

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    BACKGROUND:Sensing of muramyl dipeptide (MDP) is impaired in Crohn's disease (CD) patients with disease-linked variants of the CARD15 (caspase activation and recruitment domain 15) gene. Animal studies suggest that normal CARD15 signalling prevents inflammatory bowel disease, and may be important for disease development in CD. However, only a small fraction of CD patients carry the disease linked CARD15 variants. The aim of this study was thus to investigate if changes could be found in CARD15 signalling in patients without disease associated CARD15 variants. METHODOLOGY/PRINCIPAL FINDINGS:By mapping the response to MDP in peripheral monocytes obtained from CD patients in remission not receiving immunosuppresives, an impaired response to MDP was found in patients without disease linked CARD15 variants compared to control monocytes. This impairment was accompanied by a decreased activation of IkappaB kinase alpha/beta (IKKalpha/beta), the initial step in the nuclear factor kappaB (NFkappaB) pathway, whereas activation of mitogen-activated protein (MAP)-kinases was unaffected. MDP additionally stimulates the inflammasome which is of importance for processing of cytokines. The inflammasome was constitutively activated in CD, but unresponsive to MDP both in CD and control monocytes. CONCLUSIONS/SIGNIFICANCE:These results suggest that inhibited MDP-dependent pathways in CD patients not carrying the disease-associated CARD15 variants might be of importance for the pathogenesis of CD. The results reveal a dysfunctional immune response in CD patients, not able to sense relevant stimuli on the one hand, and on the other hand possessing constitutively active cytokine processing

    Accurate masses and radii of normal stars: modern results and applications

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    This paper presents and discusses a critical compilation of accurate, fundamental determinations of stellar masses and radii. We have identified 95 detached binary systems containing 190 stars (94 eclipsing systems, and alpha Centauri) that satisfy our criterion that the mass and radius of both stars be known to 3% or better. To these we add interstellar reddening, effective temperature, metal abundance, rotational velocity and apsidal motion determinations when available, and we compute a number of other physical parameters, notably luminosity and distance. We discuss the use of this information for testing models of stellar evolution. The amount and quality of the data also allow us to analyse the tidal evolution of the systems in considerable depth, testing prescriptions of rotational synchronisation and orbital circularisation in greater detail than possible before. The new data also enable us to derive empirical calibrations of M and R for single (post-) main-sequence stars above 0.6 M(Sun). Simple, polynomial functions of T(eff), log g and [Fe/H] yield M and R with errors of 6% and 3%, respectively. Excellent agreement is found with independent determinations for host stars of transiting extrasolar planets, and good agreement with determinations of M and R from stellar models as constrained by trigonometric parallaxes and spectroscopic values of T(eff) and [Fe/H]. Finally, we list a set of 23 interferometric binaries with masses known to better than 3%, but without fundamental radius determinations (except alpha Aur). We discuss the prospects for improving these and other stellar parameters in the near future.Comment: 56 pages including figures and tables. To appear in The Astronomy and Astrophysics Review. Ascii versions of the tables will appear in the online version of the articl

    The Hubble Constant

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    I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H0H_0 values of around 72-74km/s/Mpc , with typical errors of 2-3km/s/Mpc. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68km/s/Mpc and typical errors of 1-2km/s/Mpc. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.Comment: Extensively revised and updated since the 2007 version: accepted by Living Reviews in Relativity as a major (2014) update of LRR 10, 4, 200

    Prediction of progression in pTa and pT1 bladder carcinomas with p53, p16 and pRb

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    Currently available prognostic tools appear unable to adequately predict recurrence and progression in non muscle-invasive bladder carcinomas. We aimed to assess the prognostic value of immunohistochemical evaluation of the cell cycle markers p53, p16 and pRb. Paraffin blocks were obtained from 78 cases of pTa and pT1 transitional cell carcinomas, for which long-term follow-up was available. Representative sections were stained using antibodies against p53, p16 and pRb. Altered marker expression was found in 45, 17 and 30% of cases, respectively. Concurrent alteration of two or three markers occurred in 19% of cases, and was significantly associated with grade and stage. In univariate survival analysis, the concurrent alteration of any two markers was significantly associated with progression. The greatest risk was produced by alteration of both p53 and p16, which increased the risk of progression by 14.45 times (95% confidence interval (CI) 3.10-67.35). After adjusting for grade and stage, this risk was 7.73 (CI 1.13-52.70). The markers did not generally predict tumour recurrence, except in the 25 pT1 tumours. In these, p16 alteration was associated with a univariate risk of 2.83 (CI 1.01-7.91), and concurrent p53 and p16 alteration with a risk of 9.29 (CI 1.24-69.50). Overall, we conclude that the immunohistochemical evaluation of p53 and p16 may have independent prognostic value for disease progression, and may help guide management decisions in these tumours

    Foster Care Placement, Poor Parenting, and Negative Outcomes Among Homeless Young Adults

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    Although homeless youth with and without foster care histories both face adverse life circumstances, little is known about how these two groups compare in terms of their early histories and whether they face similar outcomes. As such, we compared those with and without a history of foster care placement to determine if the associations between a history of poor parenting and negative outcomes including depression, delinquency, physical and sexual victimization, and substance use, are similar for these two groups. The sample consisted of 172 homeless young adults from the Midwestern United States. Multivariate results revealed that among those previously in foster care, a history of physical abuse and neglect were positively associated with more depressive symptoms whereas sexual abuse and neglect were related to delinquency and physical victimization. Additionally, lower caretaker monitoring was linked to greater delinquent participation. Among those without a history of foster care, physical abuse was related to more depressive symptoms whereas sexual abuse was positively correlated with delinquency, sexual victimization, and substance use. Furthermore, lower monitoring was related to more substance use. Our findings are discussed in terms of a social stress framework and we review the implications of foster care placement for homeless young adults

    Effectiveness of a computer assisted learning (CAL) package to raise awareness of autism

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    <p>Abstract</p> <p>Background</p> <p>Promoting awareness of autism in populations who work with children may result in an earlier diagnosis of the condition. In this study, a computer assisted learning (CAL) package, containing educationally appropriate knowledge about autism was developed; and the effectiveness of this CAL package was evaluated.</p> <p>Methods</p> <p>The CAL package was developed using computer software, "Xerte" and "Flash Macromedia". The effectiveness of the CAL package was evaluated in 32 childcare students in the UK, who were randomised to watch the CAL package or to read the information leaflet containing the same information (n = 16 in each group). Retention performance, level of enjoyment, and level of confidence to identify a child with autism, after the interventions, were evaluated. The data obtained from two studied groups was analysed using unpaired Student's t-test, 95% confidence interval, and effect size.</p> <p>Results</p> <p>Students who watched the CAL package had superior retention performance percentage scores (p = 0.02, 95% CI = 0.83–12.19, effect size = 0.8) and level of enjoyment (p = 0.04, 95% CI = 0.03–2.75, effect size = 0.7) compared with students who read the information leaflet. However, there was no significant difference in level of confidence to identify a child with autism (p = 0.39, 95% CI = -1.80–0.72, effect size = -0.3).</p> <p>Conclusion</p> <p>The CAL package developed was an effective method of educating people who work with children about autism.</p

    Detection of a Single Identical Cytomegalovirus (CMV) Strain in Recently Seroconverted Young Women

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    Infection with multiple CMV strains is common in immunocompromised hosts, but its occurrence in normal hosts has not been well-studied.We analyzed CMV strains longitudinally in women who acquired CMV while enrolled in a CMV glycoprotein B (gB) vaccine trial. Sequencing of four variable genes was performed in samples collected from seroconversion and up to 34 months thereafter.199 cultured isolates from 53 women and 65 original fluids from a subset of 19 women were sequenced. 51 women were infected with one strain each without evidence for genetic drift; only two women shed multiple strains. Genetic variability among strains increased with the number of sequenced genetic loci. Nevertheless, 13 of 53 women proved to be infected with an identical CMV strain based on sequencing at all four variable genes. CMV vaccine did not alter the degree of genetic diversity amongst strains.Primary CMV infection in healthy women nearly always involves shedding of one strain that remains stable over time. Immunization with CMVgB-1 vaccine strain is not selective against specific strains. Although 75% of women harbored their unique strain, or a strain shared with only one other woman, 25% shared a single common strain, suggesting that this predominant strain with a particular combination of genetic loci is advantageous in this large urban area

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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