134 research outputs found

    HR‐pQCT measures of bone microarchitecture predict fracture : systematic review and meta‐analysis

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    HR‐pQCT is a non‐invasive imaging modality for assessing volumetric bone mineral density (vBMD) and microarchitecture of cancellous and cortical bone. The objective was to (i) assess fracture‐associated differences in HR‐pQCT bone parameters and (ii) to determine if HR‐pQCT is sufficiently precise to reliably detect these differences in individuals. We systematically identified 40 studies that used HR‐pQCT (39/40 used XtremeCT scanners) to assess 1291‐3253 and 3389‐10,687 individuals with and without fractures, respectively, ranging in age from 10.9 to 84.7 years with no comorbid conditions. Parameters describing radial and tibial bone density, microarchitecture, and strength were extracted and percentage differences between fracture and control subjects were estimated using a random effects meta‐analysis. An additional meta‐analysis of short‐term in vivo reproducibility of bone parameters assessed by XtremeCT was conducted to determine whether fracture‐associated differences exceeded the least significant change (LSC) required to discern measured differences from precision error. Radial and tibial HR‐pQCT parameters, including failure load, were significantly altered in fracture subjects, with differences ranging from −2.6% (95% CI: −3.4 to −1.9) in radial cortical vBMD to −12.6% (95% CI: −15.0 to −10.3) in radial trabecular vBMD. Fracture‐associated differences reported by prospective studies were consistent with those from retrospective studies, indicating that HR‐pQCT can predict incident fracture. Assessment of study quality, heterogeneity and publication biases verified the validity of these findings. Finally, we demonstrated that fracture‐associated deficits in total and trabecular vBMD, and certain tibial cortical parameters, can be reliably discerned from HR‐pQCT‐related precision error and can be used to detect fracture‐associated differences in individual patients. Although differences in other HR‐pQCT measures, including failure load, were significantly associated with fracture, improved reproducibility is needed to ensure reliable individual cross‐sectional screening and longitudinal monitoring. In conclusion, our study supports the use of HR‐pQCT in clinical fracture prediction

    HEPA respirators and tuberculosis in hospital workers

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    Adal et al. (July 21 issue)1 demonstrate that at the University of Virginia Hospital, where the incidence of tuberculosis is low, the infection controls already instituted may be sufficient and the cost of adding respirators with high-efficiency particulate air filters (HEPA respirators) for their 3852 workers is impressively high. The situation is different at our hospital, Lincoln Medical and Mental Health Center in South Bronx, New York. In contrast to their figure of 11 patients with documented tuberculosis per year, we have over 160 such patients per year, of whom approximately 30 percent have multidrug-resistant tuberculosis

    Many body physics from a quantum information perspective

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    The quantum information approach to many body physics has been very successful in giving new insight and novel numerical methods. In these lecture notes we take a vertical view of the subject, starting from general concepts and at each step delving into applications or consequences of a particular topic. We first review some general quantum information concepts like entanglement and entanglement measures, which leads us to entanglement area laws. We then continue with one of the most famous examples of area-law abiding states: matrix product states, and tensor product states in general. Of these, we choose one example (classical superposition states) to introduce recent developments on a novel quantum many body approach: quantum kinetic Ising models. We conclude with a brief outlook of the field.Comment: Lectures from the Les Houches School on "Modern theories of correlated electron systems". Improved version new references adde

    Reflections on IDEAL: What we have learnt from a unique calf cohort study

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    The year 2020 marks a decade since the final visit was made in the ‘Infectious Diseases of East African Livestock’ (IDEAL) project. However, data generation from samples obtained during this ambitious longitudinal study still continues. As the project launches its extensive open-access database and biobank to the scientific community, we reflect on the challenges overcome, the knowledge gained, and the advantages of such a project. We discuss the legacy of the IDEAL project and how it continues to generate evidence since being adopted by the Centre for Tropical Livestock Genetics and Health (CTLGH). We also examine the impact of the IDEAL project, from the authors perspective, for each of the stakeholders (the animal, the farmer, the consumer, the policy maker, the funding body, and the researcher and their institution) involved in the project and provide recommendations for future researchers who are interested in running longitudinal field studies.The Bill & Melinda Gates Foundation, the UK Government’s Department for International Development and the International Livestock Research Institute.http://www.elsevier.com/locate/prevetmedam2021Veterinary Tropical Disease

    Superstripes and complexity in high-temperature superconductors

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    While for many years the lattice, electronic and magnetic complexity of high-temperature superconductors (HTS) has been considered responsible for hindering the search of the mechanism of HTS now the complexity of HTS is proposed to be essential for the quantum mechanism raising the superconducting critical temperature. The complexity is shown by the lattice heterogeneous architecture: a) heterostructures at atomic limit; b) electronic heterogeneity: multiple components in the normal phase; c) superconducting heterogeneity: multiple superconducting gaps in different points of the real space and of the momentum space. The complex phase separation forms an unconventional granular superconductor in a landscape of nanoscale superconducting striped droplets which is called the "superstripes" scenario. The interplay and competition between magnetic orbital charge and lattice fluctuations seems to be essential for the quantum mechanism that suppresses thermal decoherence effects at an optimum inhomogeneity.Comment: 20 pages, 3 figures; J. Supercon. Nov. Mag. 201

    Dynamic assessment precursors: Soviet ideology, and Vygotsky

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    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

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    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced

    Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice

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    It is often challenging for the clinician interested in cystic fibrosis (CF) to interpret molecular genetic results, and to integrate them in the diagnostic process. The limitations of genotyping technology, the choice of mutations to be tested, and the clinical context in which the test is administered can all influence how genetic information is interpreted. This paper describes the conclusions of a consensus conference to address the use and interpretation of CF mutation analysis in clinical settings

    The Sample Analysis at Mars Investigation and Instrument Suite

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