277 research outputs found

    Juvenile idiopathic arthritis: a review of novel diagnostic and monitoring technologies

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    Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease of childhood and is characterized by an often insidious onset and a chronic relapsing−remitting course, once diagnosed. With successive flares of joint inflammation, joint damage accrues, often associated with pain and functional disability. The progressive nature and potential for chronic damage and disability caused by JIA emphasizes the critical need for a prompt and accurate diagnosis. This article provides a review of recent studies related to diagnosis, monitoring and management of JIA and outlines recent novel tools and techniques (infrared thermal imaging, three-dimensional imaging, accelerometry, artificial neural networks and fuzzy logic) which have demonstrated potential value in assessment and monitoring of JIA. The emergence of novel techniques to assist clinicians’ assessments for diagnosis and monitoring of JIA has demonstrated promise; however, further research is required to confirm their clinical utility

    The Submillimeter Polarization of Sgr A*

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    We report on the submillimeter properties of Sagittarius A* derived from observations with the Submillimeter Array and its polarimeter. We find that the spectrum of Sgr A* between 230 and 690 GHz is slightly decreasing when measured simultaneously, indicating a transition to optically thin emission around 300-400 GHz. We also present very sensitive and well calibrated measurements of the polarization of Sgr A* at 230 and 345 GHz. With these data we are able to show for the first time that the polarization of Sgr A* varies on hour timescales, as has been observed for the total intensity. On one night we find variability that may arise from a polarized "blob" orbiting the black hole. Finally, we use the ensemble of observations to determine the rotation measure. This represents the first statistically significant rotation measure determination and the only one made without resorting to comparing position angles measured at separate epochs. We find a rotation measure of (-5.6+/-0.7)x10^5 rad/m^2, with no evidence for variability on inter-day timescales at the level of the measurement error. The stability constrains interday fluctuations in the accretion rate to 8%. The mean intrinsic polarization position angle is 167+/-7 degrees and we detect variations of 31+18/-9 degrees. This separation of intrinsic polarization changes and possible rotation measure fluctuations is now possible because of the frequency coverage and sensitivity of our data. The observable rotation measure restricts the accretion rate to the range 2x10^{-7} Msun/yr to 2x10^{-9} Msun/yr, if the magnetic field is near equipartition and ordered.Comment: v2: Minor change to orbital calculation. Invited contribution to the proceedings of the Galactic Center Workshop 200

    Dynamics of Accretion Flows Irradiated by a Quasar

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    We present the results from axisymmetric time-dependent HD calculations of gas flows which are under the influence of gravity of a black hole in quasars. We assume that the flows are non-rotating and exposed to quasar radiation. We take into account X-ray heating and the radiation force due to electron scattering and spectral lines. To compute the radiation field, we consider a standard accretion disk as a source of UV photons and a spherical central object as a source of X-rays. The gas temperature and ionization state in the flow are calculated self-consistently from the photoionization and heating rate of the central object. We find that for a 10e8 MSUN black hole with an accretion luminosity of 0.6 of the Eddington luminosity the flow settles into a steady state and has two components: (1) an equatorial inflow and (2) a bipolar inflow/outflow with the outflow leaving the system along the disk rotational axis. The inflow is a realization of a Bondi-like accretion flow. The second component is an example of a non-radial accretion flow which becomes an outflow once it is pushed close to the rotational axis where thermal expansion and the radiation pressure accelerate it outward. Our main result is that the existence of the above two flow components is robust to the outer boundary conditions and the geometry and spectral energy distribution of the radiation field. However, the flow properties are not robust. In particular, the outflow power and collimation is higher for the radiation dominated by the UV/disk emission than for the radiation dominated by the X-ray/central engine emission. Our most intriguing result is that a very narrow outflow driven by radiation pressure on lines can carry more energy and mass than a broad outflow driven by thermal expansion

    Accretion of low angular momentum material onto black holes: 2D hydrodynamical inviscid case

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    We report on the first phase of our study of slightly rotating accretion flows onto black holes. We consider inviscid accretion flows with a spherically symmetric density distribution at the outer boundary, but with spherical symmetry broken by the introduction of a small, latitude-dependent angular momentum. We study accretion flows by means of numerical 2D, axisymmetric, hydrodynamical simulations. Our main result is that the properties of the accretion flow do not depend as much on the outer boundary conditions (i.e., the amount as well as distribution of the angular momentum) as on the geometry of the non-accreting matter. The material that has too much angular momentum to be accreted forms a thick torus near the equator. Consequently, the geometry of the polar region, where material is accreted (the funnel), and the mass accretion rate through it are constrained by the size and shape of the torus. Our results show one way in which the mass accretion rate of slightly rotating gas can be significantly reduced compared to the accretion of non-rotating gas (i.e., the Bondi rate), and set the stage for calculations that will take into account the transport of angular momentum and energy.Comment: LaTeX,to appear in Ap

    Earth incorporated: centralization and variegation in the global company network

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    Over the past 20 years, a widening gulf has appeared between the increasingly internationalized financing arrangements of the world’s leading corporations, and the persistence of nationally compartmentalized approaches to the study of corporate control. In lieu of direct empirical evidence on corporate control at the global level, the most widespread assumption is that the globalization of ownership has taken the form of an expansion of arms-length, market-based arrangements traditionally prevailing in the Anglo-American economies. Here, however, we challenge this assumption, both empirically and conceptually. Empirically, we show that three quarters of the world’s 205 largest firms by sales are linked to a single global company network of concentrated (5%) ownership ties. This network has a hierarchically centralized organization, with a dominant “global network core” of US fund managers ringed by a more geographically diverse “state capitalist periphery.” Conceptually, we argue that the this architecture can be broadly explained through a Polanyian “variegated capitalist” model of contradictory market institutionalization, with the formation of the global company network actually a counterintuitive product of global financial marketization. In order to understand this process of network formation, however, it is necessary to extend Polanyi’s model of a double movement mediated through political interventions in the market, to incorporate Veblenian processes of evolutionary institutional change mediated through the market

    The ethics of uncertainty for data subjects

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    Modern health data practices come with many practical uncertainties. In this paper, I argue that data subjects’ trust in the institutions and organizations that control their data, and their ability to know their own moral obligations in relation to their data, are undermined by significant uncertainties regarding the what, how, and who of mass data collection and analysis. I conclude by considering how proposals for managing situations of high uncertainty might be applied to this problem. These emphasize increasing organizational flexibility, knowledge, and capacity, and reducing hazard

    Conjoint Analysis Versus Rating and Ranking for Values Elicitation and Clarification in Colorectal Cancer Screening

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    PURPOSE: To compare two techniques for eliciting and clarifying patient values for decision making about colorectal cancer (CRC) screening: choice-based conjoint analysis and a rating and ranking task. METHODS: Using our decision lab registry and university e-mail lists, we recruited average risk adults ages 48-75 for a written, mailed survey. Eligible participants were given basic information about CRC screening and six attributes of CRC screening tests, then randomized to complete either a choice-based conjoint analysis with 16 discrete choice tasks or a rating and ranking task. The main outcome was the most important attribute, as determined from conjoint analysis or participant ranking. Conjoint analysis-based most important attribute was determined from individual patient-level utilities generated using multinomial logistic regression and hierarchical Bayesian modeling. RESULTS: Of the 114 eligible participants, 104 completed and returned questionnaires. Mean age was 57 (range 48-73), 70% were female, 88% were white, 71% were college graduates, and 62% were up to date with CRC screening. Ability to reduce CRC incidence and mortality was the most frequent most important attribute for both the conjoint analysis (56% of respondents) and rating/ranking (76% of respondents) groups, and these proportions differed significantly between groups (absolute difference 20%, 95% CI 3%, 37%, p =0.03). There were no significant differences between groups in proportion with clear values (p = 0.352), intent to be screened (p = 0.226) or unlabelled test preference (p = 0.521) CONCLUSIONS: Choice-based conjoint analysis produced somewhat different patterns of attribute importance than a rating and ranking task, but had little effect on other outcomes

    Associations between cardiorespiratory fitness, physical activity and clustered cardiometabolic risk in children and adolescents: the HAPPY study

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    Clustering of cardiometabolic risk factors can occur during childhood and predisposes individuals to cardiometabolic disease. This study calculated clustered cardiometabolic risk in 100 children and adolescents aged 10-14 years (59 girls) and explored differences according to cardiorespiratory fitness (CRF) levels and time spent at different physical activity (PA) intensities. CRF was determined using a maximal cycle ergometer test, and PA was assessed using accelerometry. A cardiometabolic risk score was computed as the sum of the standardised scores for waist circumference, blood pressure, total cholesterol/high-density lipoprotein ratio, triglycerides and glucose. Differences in clustered cardiometabolic risk between fit and unfit participants, according to previously proposed health-related threshold values, and between tertiles for PA subcomponents were assessed using ANCOVA. Clustered risk was significantly lower (p < 0.001) in the fit group (mean 1.21 ± 3.42) compared to the unfit group (mean -0.74 ± 2.22), while no differences existed between tertiles for any subcomponent of PA. Conclusion These findings suggest that CRF may have an important cardioprotective role in children and adolescents and highlights the importance of promoting CRF in youth

    AKAP350, a Multiply Spliced Protein Kinase A-anchoring Protein Associated with Centrosomes

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    Protein kinase A-anchoring proteins (AKAPs) localize the second messenger response to particular subcellular domains by sequestration of the type II protein kinase A. Previously, AKAP120 was identified from a rabbit gastric parietal cell cDNA library; however, a monoclonal antibody raised against AKAP120 labeled a 350-kDa band in Western blots of parietal cell cytosol. Recloning has now revealed that AKAP120 is a segment of a larger protein, AKAP350. We have now obtained a complete sequence of human gastric AKAP350 as well as partial cDNA sequences from human lung and rabbit parietal cells. The genomic region containing AKAP350 is found on chromosome 7q21 and is multiply spliced, producing at least three distinct AKAP350 isoforms as well as yotiao, a protein associated with the N-methyl-D-aspartate receptor. Rabbit parietal cell AKAP350 is missing a sequence corresponding to a single exon in the middle of the molecule located just after the yotiao homology region. Two carboxyl-terminal splice variants were also identified. Both of the major splice variants showed tissue- and cell-specific expression patterns. Immunofluorescence microscopy demonstrated that AKAP350 was associated with centrosomes in many cell types. In polarized Madin-Darby canine kidney cells, AKAP350 localized asymmetrically to one pole of the centrosome, and nocodazole did not alter its localization. During the cell cycle, AKAP350 was associated with the centrosomes as well as with the cleavage furrow during anaphase and telophase. Several epithelial cell types also demonstrated noncentrosomal pools of AKAP350, especially parietal cells, which contained multiple cytosolic immunoreactive foci throughout the cells. The localization of AKAP350 suggests that it may regulate centrosomal and noncentrosomal cytoskeletal systems in many different cell types
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