17 research outputs found

    The Zwicky Transient Facility: Data Processing, Products, and Archive

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    The Zwicky Transient Facility (ZTF) is a new robotic time-domain survey currently in progress using the Palomar 48-inch Schmidt Telescope. ZTF uses a 47 square degree field with a 600 megapixel camera to scan the entire northern visible sky at rates of ~3760 square degrees/hour to median depths of g ~ 20.8 and r ~ 20.6 mag (AB, 5sigma in 30 sec). We describe the Science Data System that is housed at IPAC, Caltech. This comprises the data-processing pipelines, alert production system, data archive, and user interfaces for accessing and analyzing the products. The realtime pipeline employs a novel image-differencing algorithm, optimized for the detection of point source transient events. These events are vetted for reliability using a machine-learned classifier and combined with contextual information to generate data-rich alert packets. The packets become available for distribution typically within 13 minutes (95th percentile) of observation. Detected events are also linked to generate candidate moving-object tracks using a novel algorithm. Objects that move fast enough to streak in the individual exposures are also extracted and vetted. The reconstructed astrometric accuracy per science image with respect to Gaia is typically 45 to 85 milliarcsec. This is the RMS per axis on the sky for sources extracted with photometric S/N >= 10. The derived photometric precision (repeatability) at bright unsaturated fluxes varies between 8 and 25 millimag. Photometric calibration accuracy with respect to Pan-STARRS1 is generally better than 2%. The products support a broad range of scientific applications: fast and young supernovae, rare flux transients, variable stars, eclipsing binaries, variability from active galactic nuclei, counterparts to gravitational wave sources, a more complete census of Type Ia supernovae, and Solar System objects.Comment: 30 pages, 16 figures, Published in PASP Focus Issue on the Zwicky Transient Facility (doi: 10.1088/1538-3873/aae8ac

    Debating Survey Approaches

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    Examining the role of patient experience surveys in measuring health care quality.

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    Patient care experience surveys evaluate the degree to which care is patient-centered. This article reviews the literature on the association between patient experiences and other measures of health care quality. Research indicates that better patient care experiences are associated with higher levels of adherence to recommended prevention and treatment processes, better clinical outcomes, better patient safety within hospitals, and less health care utilization. Patient experience measures that are collected using psychometrically sound instruments, employing recommended sample sizes and adjustment procedures, and implemented according to standard protocols are intrinsically meaningful and are appropriate complements for clinical process and outcome measures in public reporting and pay-for-performance programs

    Drug-induced acute myocardial infarction: identifying 'prime suspects' from electronic healthcare records-based surveillance system.

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    BACKGROUND: Drug-related adverse events remain an important cause of morbidity and mortality and impose huge burden on healthcare costs. Routinely collected electronic healthcare data give a good snapshot of how drugs are being used in 'real-world' settings. OBJECTIVE: To describe a strategy that identifies potentially drug-induced acute myocardial infarction (AMI) from a large international healthcare data network. METHODS: Post-marketing safety surveillance was conducted in seven population-based healthcare databases in three countries (Denmark, Italy, and the Netherlands) using anonymised demographic, clinical, and prescription/dispensing data representing 21,171,291 individuals with 154,474,063 person-years of follow-up in the period 1996-2010. Primary care physicians' medical records and administrative claims containing reimbursements for filled prescriptions, laboratory tests, and hospitalisations were evaluated using a three-tier triage system of detection, filtering, and substantiation that generated a list of drugs potentially associated with AMI. Outcome of interest was statistically significant increased risk of AMI during drug exposure that has not been previously described in current literature and is biologically plausible. RESULTS: Overall, 163 drugs were identified to be associated with increased risk of AMI during preliminary screening. Of these, 124 drugs were eliminated after adjustment for possible bias and confounding. With subsequent application of criteria for novelty and biological plausibility, association with AMI remained for nine drugs ('prime suspects'): azithromycin; erythromycin; roxithromycin; metoclopramide; cisapride; domperidone; betamethasone; fluconazole; and megestrol acetate. LIMITATIONS: Although global health status, co-morbidities, and time-invariant factors were adjusted for, residual confounding cannot be ruled out. CONCLUSION: A strategy to identify potentially drug-induced AMI from electronic healthcare data has been proposed that takes into account not only statistical association, but also public health relevance, novelty, and biological plausibility. Although this strategy needs to be further evaluated using other healthcare data sources, the list of 'prime suspects' makes a good starting point for further clinical, laboratory, and epidemiologic investigation

    RACK1 inhibits TRPM6 activity via phosphorylation of the fused alpha-kinase domain.

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    Contains fulltext : 71290.pdf (publisher's version ) (Closed access)BACKGROUND: The maintenance of the body's Mg(2+) balance is of great importance because of its involvement in numerous enzymatic systems and its intervention in neuromuscular excitability, protein synthesis, and nucleic acid stability. Recently, the transient receptor potential melastatin 6 (TRPM6) was identified as the gatekeeper of active Mg(2+) transport and therefore plays a crucial role in the regulation of Mg(2+) homeostasis. Remarkably, TRPM6 combines a Mg(2+) channel with an alpha-kinase domain whose function remains elusive. RESULTS: Here, we identify the receptor for activated C-kinase 1 (RACK1) as the first regulatory protein of TRPM6 that associates with the alpha-kinase domain. RACK1 and TRPM6 are both present in renal Mg(2+)-transporting distal convoluted tubules. We demonstrate that RACK1 inhibits channel activity in an alpha-kinase activity-dependent manner, whereas small interference (si) RNA-mediated knockdown of RACK1 increases the current. Moreover, threonine(1851) in the alpha-kinase domain was identified as an autophosphorylation site of which the phosphorylation state is essential for the inhibitory effect of RACK1. Importantly, threonine(1851) was crucial for the Mg(2+) sensitivity of TRPM6 autophosphorylation and channel activity. TRPM6 channel activity was less sensitive to Mg(2+) when RACK1 was knocked down by siRNA. Finally, activation of protein kinase C by phorbol 12-myristate 13-acetate-PMA prohibited the inhibitory effect of RACK1 on TRPM6 channel activity. CONCLUSIONS: We propose a unique mode of TRPM6 regulation in which the Mg(2+) influx is controlled by RACK1 through its interaction with the alpha-kinase and the phosphorylation state of the threonine(1851) residue
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