950 research outputs found

    Suboptimal blood pressure control in chronic kidney disease stage 3: baseline data from a cohort study in primary care

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    Background: poorly controlled hypertension is independently associated with mortality, cardiovascular risk and disease progression in chronic kidney disease (CKD). In the UK, CKD stage 3 is principally managed in primary care, including blood pressure (BP) management. Controlling BP is key to improving outcomes in CKD. This study aimed to investigate associations of BP control in people with CKD stage 3.Methods: 1,741 patients with CKD 3 recruited from 32 general practices for the Renal Risk in Derby Study underwent medical history, clinical assessment and biochemistry testing. BP control was assessed by three standards: National Institute for Health and Clinical Excellence (NICE), National Kidney Foundation Kidney Disease Outcome Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Descriptive statistics were used to compare characteristics of people achieving and not achieving BP control. Univariate and multivariate logistic regression was used to identify factors associated with BP control.Results: the prevalence of hypertension was 88%. Among people with hypertension, 829/1426 (58.1%) achieved NICE BP targets, 512/1426 (35.9%) KDOQI targets and 859/1426 (60.2%) KDIGO targets. Smaller proportions of people with diabetes and/or albuminuria achieved hypertension targets. 615/1426 (43.1%) were only taking one antihypertensive agent. On multivariable analysis, BP control (NICE and KDIGO) was negatively associated with age (NICE odds ratio (OR) 0.27; 95% confidence interval (95% CI) 0.17-0.43) 70–79 compared to &lt;60), diabetes (OR 0.32; 95% CI 0.25-0.43)), and albuminuria (OR 0.56; 95% CI 0.42-0.74)). For the KDOQI target, there was also association with males (OR 0.76; 95% CI 0.60-0.96)) but not diabetes (target not diabetes specific). Older people were less likely to achieve systolic targets (NICE target OR 0.17 (95% CI 0.09,0.32) p?&lt;?0.001) and more likely to achieve diastolic targets (OR 2.35 (95% CI 1.11,4.96) p?&lt;?0.001) for people &gt;80 compared to?&lt;?60).Conclusions: suboptimal BP control was common in CKD patients with hypertension in this study, particularly those at highest risk of adverse outcomes due to diabetes and or albuminuria. This study suggests there is scope for improving BP control in people with CKD by using more antihypertensive agents in combination while considering issues of adherence and potential side effects.<br/

    A scalar invariant and the local geometry of a class of static spacetimes

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    The scalar invariant, I, constructed from the "square" of the first covariant derivative of the curvature tensor is used to probe the local geometry of static spacetimes which are also Einstein spaces. We obtain an explicit form of this invariant, exploiting the local warp-product structure of a 4-dimensional static spacetime,  (3)Σ×fR~^{(3)}\Sigma \times_{f} \reals, where (3)Σ^{(3)}\Sigma is the Riemannian hypersurface orthogonal to a timelike Killing vector field with norm given by a positive function, ff on (3)Σ^{(3)}\Sigma . For a static spacetime which is an Einstein space, it is shown that the locally measurable scalar, I, contains a term which vanishes if and only if (3)Σ^{(3)}\Sigma is conformally flat; also, the vanishing of this term implies (a)  (3)Σ~^{(3)}\Sigma is locally foliated by level surfaces of ff, (2)S^{(2)}S, which are totally umbilic spaces of constant curvature, and (b) (3)Σ^{(3)}\Sigma is locally a warp-product space. Futhermore, if (3)Σ^{(3)}\Sigma is conformally flat it follows that every non-trivial static solution of the vacuum Einstein equation with a cosmological constant, is either Nariai-type or Kottler-type - the classes of spacetimes relevant to quantum aspects of gravity.Comment: LaTeX, 13 pages, JHEP3.cls; The paper is completely rewritten with a new title and introduction as well as additional results and reference

    Quantum trajectory approach to stochastically-induced quantum interference effects in coherently-driven two-level atoms

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    Stochastic perturbation of two-level atoms strongly driven by a coherent light field is analyzed by the quantum trajectory method. A new method is developed for calculating the resonance fluorescence spectra from numerical simulations. It is shown that in the case of dominant incoherent perturbation, the stochastic noise can unexpectedly create phase correlation between the neighboring atomic dressed states. This phase correlation is responsible for quantum interference between the related transitions resulting in anomalous modifications of the resonance fluorescence spectra.Comment: paper accepted for publicatio

    Mucin gene expression during differentiation of human airway epithelia in vitro MUC4 and MUC5b are strongly induced

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    Mucus hypersecretion is characteristic of chronic airway diseases. However, regulatory mechanisms are poorly understood. Human airway epithelial cells grown on permeable supports at the air-liquid interface (ALI) develop a mucociliary morphology resembling that found in vivo. Such cultures provide a model for studying secretory cell lineage, differentiation, and function, and may provide insight regarding events leading to mucus hypersecretion. The mucin gene expression profile of well-differentiated human airway epithelial cells in culture has not yet been established. We compared expression of all the currently described mucin genes in poorly differentiated (conventional cultures on plastic) and well-differentiated (ALI) human nasal and bronchial epithelial cells. Differentiation-dependent upregulation of MUC3, MUC5AC, MUC5B, and MUC6 messenger RNA (mRNA) was demonstrated using reverse transcriptase-polymerase chain reaction (RT-PCR). Northern blot analysis showed a similar increase for MUC4 and demonstrated that induction of MUC4 and MUC5B expression depended on retinoic acid. MUC1, MUC2, MUC7, and MUC8 mRNAs were also detected by RT-PCR, but these genes did not appear to be strongly regulated as a function of differentiation. Mucin gene expression was similar in bronchial and nasal cells. Thus, mucociliary differentiation of human airway epithelia in vitro entails upregulation of several mucin genes

    Data Mining Approaches to Diffuse Large B–Cell Lymphoma Gene Expression Data Interpretation

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    This paper presents a comprehensive study of gene expression patterns originating from a diffuse large B–cell lymphoma (DLBCL) database. It focuses on the implementation of feature selection and classification techniques. Thus, it firstly tackles the identification of relevant genes for the prediction of DLBCL types. It also allows the determination of key biomarkers to differentiate two subtypes of DLBCL samples: Activated B–Like and Germinal Centre B–Like DLBCL. Decision trees provide knowledge–based models to predict types and subtypes of DLBCL. This research suggests that the data may be insufficient to accurately predict DLBCL types or even detect functionally relevant genes. However, these methods represent reliable and understandable tools to start thinking about possible interesting non–linear interdependencies

    The Centurion 18 telescope of the Wise Observatory

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    We describe the second telescope of the Wise Observatory, a 0.46-m Centurion 18 (C18) installed in 2005, which enhances significantly the observing possibilities. The telescope operates from a small dome and is equipped with a large-format CCD camera. In the last two years this telescope was intensively used in a variety of monitoring projects. The operation of the C18 is now automatic, requiring only start-up at the beginning of a night and close-down at dawn. The observations are mostly performed remotely from the Tel Aviv campus or even from the observer's home. The entire facility was erected for a component cost of about 70k$ and a labor investment of a total of one man-year. We describe three types of projects undertaken with this new facility: the measurement of asteroid light variability with the purpose of determining physical parameters and binarity, the following-up of transiting extrasolar planets, and the study of AGN variability. The successful implementation of the C18 demonstrates the viability of small telescopes in an age of huge light-collectors, provided the operation of such facilities is very efficient.Comment: 16 pages, 13 figures, some figures quality was degraded, accepted for publication in Astrophysics and Space Scienc

    A Gravitational Aharonov-Bohm Effect, and its Connection to Parametric Oscillators and Gravitational Radiation

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    A thought experiment is proposed to demonstrate the existence of a gravitational, vector Aharonov-Bohm effect. A connection is made between the gravitational, vector Aharonov-Bohm effect and the principle of local gauge invariance for nonrelativistic quantum matter interacting with weak gravitational fields. The compensating vector fields that are necessitated by this local gauge principle are shown to be incorporated by the DeWitt minimal coupling rule. The nonrelativistic Hamiltonian for weak, time-independent fields interacting with quantum matter is then extended to time-dependent fields, and applied to problem of the interaction of radiation with macroscopically coherent quantum systems, including the problem of gravitational radiation interacting with superconductors. But first we examine the interaction of EM radiation with superconductors in a parametric oscillator consisting of a superconducting wire placed at the center of a high Q superconducting cavity driven by pump microwaves. We find that the threshold for parametric oscillation for EM microwave generation is much lower for the separated configuration than the unseparated one, which then leads to an observable dynamical Casimir effect. We speculate that a separated parametric oscillator for generating coherent GR microwaves could also be built.Comment: 25 pages, 5 figures, YA80 conference (Chapman University, 2012

    Shadowing Effects on Vector Boson Production

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    We explore how nuclear modifications to the nucleon structure functions, shadowing, affect massive gauge boson production in heavy ion collisions at different impact parameters. We calculate the dependence of Z0Z^0, W+W^+ and W−W^- production on rapidity and impact parameter to next-to-leading order in Pb+Pb collisions at 5.5 TeV/nucleon to study quark shadowing at high Q2Q^2. We also compare our Pb+Pb results to the pppp rapidity distributions at 14 TeV.Comment: 25 pages ReVTeX, 12 .eps figures, NLO included, version accepted for publication in Physical Review

    A multi-component, community-engaged intervention to reduce cardiovascular disease risk in perimenopausal Latinas: pilot study protocol

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    Background: Cardiovascular disease (CVD) risk increases substantially during perimenopause. Latinas have a significantly worse CVD risk factor profile than non-Hispanic White women, potentially due to multiple sociocultural and environmental factors. To date, interdisciplinary interventions have not focused on improving nutrition, physical activity, stress management, and biologic CVD risk in perimenopausal Latinas. The purpose of this study is to examine the feasibility and initial efficacy of a multi-component intervention to reduce CVD risk in perimenopausal Latinas. Methods: This is a two-group, repeated measures experimental study. Eighty perimenopausal Latinas (age 40–55 years) from two community groups will be randomized: one group will complete the intervention; the other will be a wait-list control. The intervention consists of 12-weekly sessions (education, physical activity, stress management, coping skills training), followed by 3 months of continued support, and 6 months of skill maintenance on their own. The primary outcomes include arterial stiffness, blood pressure, lipids, and blood glucose. Secondary outcomes are health behaviors (nutrition, physical activity, sleep, coping strategies), self-efficacy, and other biological factors related to CVD risk (adiposity, C-reactive protein, hair cortisol, vasomotor symptoms). We will assess changes in outcomes from Time 1 (baseline) to Time 2 (6 months) and Time 3 (12 months) using general linear mixed models to test the hypotheses. We will also evaluate the feasibility of the intervention by assessing enrollment and retention rates, barriers, and facilitators to enrollment, intervention fidelity, the suitability of study procedures, and participant satisfaction with the intervention and study protocol. We hypothesize the intervention group will decrease biologic CVD risk and improve health behaviors and self-efficacy significantly more than the wait-list control. Discussion: Results from this study will contribute to knowledge on the feasibility of behavioral interventions, including stress management and coping skills training, which could reduce CVD burden among perimenopausal Latinas. Because Hispanic/Latinos are the largest ethnic minority in the United States (US), progress regarding CVD risk among perimenopausal Latinas may lead to significant improvement in the overall CVD burden in the US. Trial registration: Prospectively registered, NCT04313751 (03/19/2020), Protocol version 1.

    Non-Equilibrium Statistical Physics of Currents in Queuing Networks

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    We consider a stable open queuing network as a steady non-equilibrium system of interacting particles. The network is completely specified by its underlying graphical structure, type of interaction at each node, and the Markovian transition rates between nodes. For such systems, we ask the question ``What is the most likely way for large currents to accumulate over time in a network ?'', where time is large compared to the system correlation time scale. We identify two interesting regimes. In the first regime, in which the accumulation of currents over time exceeds the expected value by a small to moderate amount (moderate large deviation), we find that the large-deviation distribution of currents is universal (independent of the interaction details), and there is no long-time and averaged over time accumulation of particles (condensation) at any nodes. In the second regime, in which the accumulation of currents over time exceeds the expected value by a large amount (severe large deviation), we find that the large-deviation current distribution is sensitive to interaction details, and there is a long-time accumulation of particles (condensation) at some nodes. The transition between the two regimes can be described as a dynamical second order phase transition. We illustrate these ideas using the simple, yet non-trivial, example of a single node with feedback.Comment: 26 pages, 5 figure
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