525 research outputs found

    A framework for automated anomaly detection in high frequency water-quality data from in situ sensors

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    River water-quality monitoring is increasingly conducted using automated in situ sensors, enabling timelier identification of unexpected values. However, anomalies caused by technical issues confound these data, while the volume and velocity of data prevent manual detection. We present a framework for automated anomaly detection in high-frequency water-quality data from in situ sensors, using turbidity, conductivity and river level data. After identifying end-user needs and defining anomalies, we ranked their importance and selected suitable detection methods. High priority anomalies included sudden isolated spikes and level shifts, most of which were classified correctly by regression-based methods such as autoregressive integrated moving average models. However, using other water-quality variables as covariates reduced performance due to complex relationships among variables. Classification of drift and periods of anomalously low or high variability improved when we applied replaced anomalous measurements with forecasts, but this inflated false positive rates. Feature-based methods also performed well on high priority anomalies, but were also less proficient at detecting lower priority anomalies, resulting in high false negative rates. Unlike regression-based methods, all feature-based methods produced low false positive rates, but did not and require training or optimization. Rule-based methods successfully detected impossible values and missing observations. Thus, we recommend using a combination of methods to improve anomaly detection performance, whilst minimizing false detection rates. Furthermore, our framework emphasizes the importance of communication between end-users and analysts for optimal outcomes with respect to both detection performance and end-user needs. Our framework is applicable to other types of high frequency time-series data and anomaly detection applications

    Assessing Psychological Well-Being: Self-Report Instruments for the NIH Toolbox

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    Objective— Psychological well-being (PWB) has a significant relationship with physical and mental health. As part of the NIH Toolbox for the Assessment of Neurological and Behavioral Function, we developed self-report item banks and short forms to assess PWB. Study Design and Setting— Expert feedback and literature review informed the selection of PWB concepts and the development of item pools for Positive Affect, Life Satisfaction, and Meaning and Purpose. Items were tested with a community-dwelling U.S. internet panel sample of adults aged 18 and above (N=552). Classical and item response theory (IRT) approaches were used to evaluate unidimensionality, fit of items to the overall measure, and calibrations of those items, including differential item function (DIF). Results— IRT-calibrated item banks were produced for Positive Affect (34 items), Life Satisfaction (16 items), and Meaning and Purpose (18 items). Their psychometric properties were supported based on results of factor analysis, fit statistics, and DIF evaluation. All banks measured the concepts precisely (reliability ≄0.90) for more than 98% of participants. Conclusion— These adult scales and item banks for PWB provide the flexibility, efficiency, and precision necessary to promote future epidemiological, observational, and intervention research on the relationship of PWB with physical and mental health

    Optical Monitoring of the Broad-Line Radio Galaxy 3C390.3

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    We have undertaken a new ground-based monitoring campaign on the BLRG 3C390.3 to improve the measurement of the size of the BLR and to estimate the black hole mass. Optical spectra and g-band images were observed in 2005 using the 2.4m telescope at MDM Observatory. Integrated emission-line flux variations were measured for Ha, Hb, Hg, and for HeII4686, as well as g-band fluxes and the optical AGN continuum at 5100A. The g-band fluxes and the AGN continuum vary simultaneously within the uncertainties, tau=(0.2+-1.1)days. We find that the emission-line variations are delayed with respect to the variable g-band continuum by tau(Ha)=56.3(+2.4-6.6)days, tau(Hb)=44.3(+3.0_-3.3)days, tau(Hg)=58.1(+4.3-6.1)days, and tau(HeII4686)=22.3(+6.5-3.8)days. The blue and red peak in the double peaked line profiles, as well as the blue and red outer profile wings, vary simultaneously within +-3 days. This provides strong support for gravitationally bound orbital motion of the dominant part of the line emitting gas. Combining the time delay of Ha and Hb and the separation of the blue and red peak in the broad double-peaked profiles in their rms spectra, we determine Mbh_vir=1.77(+0.29-0.31)x10^8Msol and using sigma_line of the rms spectra Mbh_vir=2.60(+0.23-0.31)x10^8Msol for the central black hole of 3C390.3, respectively. Using the inclination angle of the line emitting region the mass of the black hole amounts to Mbh=0.86(+0.19-0.18)x10^9 Msol (peak-separation) and Mbh=1.26(+0.21-0.16)x10^9 Msol (sigma_line), respectively. This result is consistent with the black hole masses indicated by simple accretion disk models to describe the observed double-peaked profiles, derived from the stellar dynamics of 3C390.3, and with the AGN radius-luminosity relation. Thus, 3C390.3 as a radio-loud AGN with a low Eddington ratio, Ledd/Lbol=0.02, follows the same AGN radius-luminosity relation as radio-quiet AGN.Comment: accepted, scheduled for September 20, 2012, ApJ 75

    On the variability of quasars: a link between Eddington ratio and optical variability?

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    Repeat scans by the Sloan Digital Sky Survey (SDSS) of a 278 square degree stripe along the Celestial equator have yielded an average of over 10 observations each for nearly 8,000 spectroscopically confirmed quasars. Over 2500 of these quasars are in the redshift range such that the CIV emission line is visible in the SDSS spectrum. Utilising the width of these CIV lines and the luminosity of the nearby continuum, we estimate black hole masses for these objects. In an effort to isolate the effects of black hole mass and luminosity on the photometric variability of our dataset, we create several subsamples by binning in these two physical parameters. By comparing the ensemble structure functions of the quasars in these bins, we are able to reproduce the well-known anticorrelation between luminosity and variability, now showing that this anticorrelation is independent of the black hole mass. In addition, we find a correlation between variability and the mass of the central black hole. By combining these two relations, we identify the Eddington ratio as a possible driver of quasar variability, most likely due to differences in accretion efficiency.Comment: 13 pages, 5 figures, Accepted for publication in MNRA

    Childhood cancer incidence and survival in Thailand: A comprehensive population‐based registry analysis, 1990–2011

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    BackgroundSoutheast Asia is undergoing a transition from infectious to chronic diseases, including a dramatic increase in adult cancers. Childhood cancer research in Thailand has focused predominantly on leukemias and lymphomas or only examined children for a short period of time. This comprehensive multisite study examined childhood cancer incidence and survival rates in Thailand across all International Classification of Childhood Cancer (ICCC) groups over a 20‐year period.MethodsCancer cases diagnosed in children ages 0‐19 years (n = 3574) from 1990 to 2011 were extracted from five provincial population‐based Thai registries, covering approximately 10% of the population. Descriptive statistics of the quality of the registries were evaluated. Age‐standardized incidence rates (ASRs) were calculated using the Segi world standard population, and relative survival was computed using the Kaplan‐Meier method. Changes in incidence and survival were analyzed using Joinpoint Regression and reported as annual percent changes (APC).ResultsThe ASR of all childhood cancers during the study period was 98.5 per million person‐years with 91.0 per million person‐years in 1990–2000 and 106.2 per million person‐years in 2001–2011. Incidence of all childhood cancers increased significantly (APC = 1.2%, P < 0.01). The top three cancer groups were leukemias, brain tumors, and lymphomas. The 5‐year survival for all childhood cancers significantly improved from 39.4% in 1990–2000 to 47.2% in 2001–2011 (P < 0.01).ConclusionsBoth childhood cancer incidence and survival rates have increased, suggesting improvement in the health care system as more cases are identified and treated. Analyzing childhood cancer trends in low‐ and middle‐income countries can improve understanding of cancer etiology and pediatric health care disparities.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146559/1/pbc27428_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146559/2/pbc27428.pd

    Subjective and Objective Binge Eating in Relation to Eating Disorder Symptomatology, Depressive Symptoms, and Self-Esteem among Treatment-Seeking Adolescents with Bulimia Nervosa: Subjective and Objective Binge Eating

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    This study investigated the importance of the distinction between objective (OBE) and subjective binge eating (SBE) among 80 treatment-seeking adolescents with bulimia nervosa (BN). We explored relationships among OBEs, SBEs, eating disorder (ED) symptomatology, depression, and self-esteem using two approaches. Group comparisons showed that OBE and SBE groups did not differ on ED symptoms or self-esteem; however, the SBE group had significantly greater depression. Examining continuous variables, OBEs (not SBEs) accounted for significant unique variance in global ED pathology, vomiting, and self-esteem. SBEs (not OBEs) accounted for significant unique variance in restraint and depression. Both OBEs and SBEs accounted for significant unique variance in eating concern; neither accounted for unique variance in weight/shape concern, laxative use, diuretic use, or driven exercise. Loss of control, rather than amount of food, may be most important in defining binge eating. Additionally, OBEs may indicate broader ED pathology while SBEs may indicate restrictive/depressive symptomatology

    Radiation-induced brachial plexopathy in patients with breast cancer treated with comprehensive adjuvant radiation therapy

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    Purpose: Our purpose was to describe the risk of radiation-induced brachial plexopathy (RIBP) in patients with breast cancer who received comprehensive adjuvant radiation therapy (RT). Methods and Materials: Records for 498 patients who received comprehensive adjuvant RT (treatment of any residual breast tissue, the underlying chest wall, and regional nodes) between 2004 and 2012 were retrospectively reviewed. All patients were treated with conventional 3 to 5 field technique (CRT) until 2008, after which intensity modulated RT (IMRT) was introduced. RIBP events were determined by reviewing follow-up documentation from oncologic care providers. Patients with RIBP were matched (1:2) with a control group of patients who received CRT and a group of patients who received IMRT. Dosimetric analyses were performed in these patients to determine whether there were differences in ipsilateral brachial plexus dose distribution between RIBP and control groups. Results: Median study follow-up was 88 months for the overall cohort and 92 months for the IMRT cohort. RIBP occurred in 4 CRT patients (1.6%) and 1 IMRT patient (0.4%) ( Conclusions: RIBP remains a rare complication of comprehensive adjuvant breast radiation and no clear dosimetric predictors for RIBP were identified in this study. The IMRT technique does not appear to adversely affect the development of this late toxicity

    Non-pharmacological interventions to reduce psychological distress in patients undergoing diagnostic cardiac catheterization: a rapid review

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    Abstract Background: Cardiac catheterization is the standard procedure for the diagnosis of coronary heart disease. The threat physically and emotionally from this procedure can effect the patient’s perception of their health. The heightened psychological distress associated with this diagnostic procedure can cause adverse patient outcomes. Non-pharmacologic interventions have been implemented to reduce psychological distress associated with cardiac catheterization. Aims: The objective of this rapid review is to assess the efficacy of non-pharmacologic interventions (procedural education, relaxation techniques, psychological preparation) on psychological distress experienced by patients as they undergo a cardiac catheterization. Methods: Published, peer-reviewed, English-language intervention studies from 1981 to 2014 were identified in a search of CINAHL, Medline, and Cochrane Library. Eligible studies included adults undergoing cardiac catheterization. Studies included in this review used experimental and quasi-experimental designs and assessed at least one primary outcome: anxiety, depression, and pain to test non-pharmacologic interventions pre and post-cardiac catheterization. Researchers independently extracted data from included studies and completed a quality assessment using a published tool. Data was synthesised as a narrative. Results: There were 29 eligible experimental and quasi-experimental studies that tested the 3 interventions (n=2504). Findings suggest that non-pharmacologic interventions were able to effectively reduce psychological distress in some patients undergoing cardiac catheterization. Conclusion: Evidence is stronger in recent studies that non-pharmacologic interventions of procedural education and psychological preparation can reduce psychological distress in patients undergoing cardiac catheterization. Further research is needed to define the various relaxation techniques that can be effectively implemented for patients undergoing cardiac catheterization

    RELICS: High-Resolution Constraints on the Inner Mass Distribution of the z=0.83 Merging Cluster RXJ0152.7-1357 from strong lensing

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    Strong gravitational lensing (SL) is a powerful means to map the distribution of dark matter. In this work, we perform a SL analysis of the prominent X-ray cluster RXJ0152.7-1357 (z=0.83, also known as CL 0152.7-1357) in \textit{Hubble Space Telescope} images, taken in the framework of the Reionization Lensing Cluster Survey (RELICS). On top of a previously known z=3.93z=3.93 galaxy multiply imaged by RXJ0152.7-1357, for which we identify an additional multiple image, guided by a light-traces-mass approach we identify seven new sets of multiply imaged background sources lensed by this cluster, spanning the redshift range [1.79-3.93]. A total of 25 multiple images are seen over a small area of ~0.4 arcmin2arcmin^2, allowing us to put relatively high-resolution constraints on the inner matter distribution. Although modestly massive, the high degree of substructure together with its very elongated shape make RXJ0152.7-1357 a very efficient lens for its size. This cluster also comprises the third-largest sample of z~6-7 candidates in the RELICS survey. Finally, we present a comparison of our resulting mass distribution and magnification estimates with those from a Lenstool model. These models are made publicly available through the MAST archive.Comment: 15 Pages, 7 Figures, 4 Tables Accepted for publication in Ap
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