Crude incidence in two-phase designs in the presence of competing risks.

BackgroundIn many studies, some information might not be available for the whole cohort, some covariates, or even the outcome, might be ascertained in selected subsamples. These studies are part of a broad category termed two-phase studies. Common examples include the nested case-control and the case-cohort designs. For two-phase studies, appropriate weighted survival estimates have been derived; however, no estimator of cumulative incidence accounting for competing events has been proposed. This is relevant in the presence of multiple types of events, where estimation of event type specific quantities are needed for evaluating outcome.MethodsWe develop a non parametric estimator of the cumulative incidence function of events accounting for possible competing events. It handles a general sampling design by weights derived from the sampling probabilities. The variance is derived from the influence function of the subdistribution hazard.ResultsThe proposed method shows good performance in simulations. It is applied to estimate the crude incidence of relapse in childhood acute lymphoblastic leukemia in groups defined by a genotype not available for everyone in a cohort of nearly 2000 patients, where death due to toxicity acted as a competing event. In a second example the aim was to estimate engagement in care of a cohort of HIV patients in resource limited setting, where for some patients the outcome itself was missing due to lost to follow-up. A sampling based approach was used to identify outcome in a subsample of lost patients and to obtain a valid estimate of connection to care.ConclusionsA valid estimator for cumulative incidence of events accounting for competing risks under a general sampling design from an infinite target population is derived

Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults

This document is the Accepted Manuscript version of the following article: Binoy Kumaran, Anthony Herbland and Tim Watson, ‘Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults’, European Journal of Physiotheraphy, first published online 20 April 2017. The version of record is available online at doi: http://dx.doi.org/10.1080/21679169.2017.1316310. © 2017 Informa UK Limited, trading as Taylor & Francis Group.Aims: Radiofrequency-based electrophysical agents (EPAs) have been used in therapy practice over several decades (e.g. shortwave therapies). Currently, there is insufficient evidence supporting such EPAs operating below shortwave frequencies. This laboratory-based study investigated the deep physiological effects of 448 kHz capacitive resistive monopolar radiofrequency (CRMRF) and compared them to pulsed shortwave therapy (PSWT). Methods: In a randomized crossover study, 17 healthy volunteers initially received four treatment conditions: high, low and placebo dose conditions receiving 15-min CRMRF treatment and a control condition receiving no intervention. Fifteen participants additionally received high-dose PSWT as fifth condition, for comparison. Pre- and post-treatment measurements of deep blood flow and tissue extensibility were obtained using Doppler ultrasound and sonoelastography. Group data were compared using analysis of variance model. Statistical significance was set at p ≤ .05, 0.8 power, and 95% confidence interval. Results: Significant increases in volume and intensity of deep blood flow were obtained with CRMRF over placebo, control (p = .003) and PSWT (p < .001). No significant changes in blood flow velocity or tissue extensibility were noted for any condition. Conclusions: Deep blood flow changes with CRMRF were more pronounced than that with PSWT, placebo or control. Potential greater therapeutic benefits need to be confirmed with comparative clinical studies.Peer reviewe

Dynamics and nucleation of dislocations in crystals

Hydrogen-poor superluminous supernovae (SLSNe-I) have been predominantly found in low-metallicity, star-forming dwarf galaxies. Here we identify Gaia17biu/SN 2017egm as an SLSN-I occurring in a "normal" spiral galaxy (NGC 3191) in terms of stellar mass (several times 10^10 M_sun) and metallicity (roughly Solar). At redshift z=0.031, Gaia17biu is also the lowest redshift SLSN-I to date, and the absence of a larger population of SLSNe-I in dwarf galaxies of similar redshift suggests that metallicity is likely less important to the production of SLSNe-I than previously believed. With the smallest distance and highest apparent brightness for an SLSN-I, we are able to study Gaia17biu in unprecedented detail. Its pre-peak near-ultraviolet to optical color is similar to that of Gaia16apd and among the bluest observed for an SLSN-I while its peak luminosity (M_g = -21 mag) is substantially lower than Gaia16apd. Thanks to the high signal-to-noise ratios of our spectra, we identify several new spectroscopic features that may help to probe the properties of these enigmatic explosions. We detect polarization at the ~0.5% level that is not strongly dependent on wavelength, suggesting a modest, global departure from spherical symmetry. In addition, we put the tightest upper limit yet on the radio luminosity of an SLSN-I with <5.4x10^26 erg/s/Hz (at 10 GHz), which is almost a factor of 40 better than previous upper limits and one of the few measured at an early stage in the evolution of an SLSN-I. This limit largely rules out an association of this SLSNe-I with known populations of gamma-ray burst (GRB) like central engines.Comment: Accepted for publication in ApJ. Ancillary ASCII tables added: TRL.txt -- blackbody temperature, radius and luminosity; uvw2uvm2uvw1uvu.txt -- UV photometry; BgVri.txt -- optical photometry; zJHK.txt -- NIR photometr

Cultural experience tourist motives dimensionality : a cross-cultural study

This empirical research of tourists&rsquo; cultural experiences aims to advance theory by developing a measurement model of tourists&rsquo; motives towards attending cultural experiences for samples of Western and Asian tourists visiting Melbourne, Australia. Drawing upon Iso-Ahola&rsquo;s (1989) seeking/avoiding dichotomy theory for tourist motivation dimensions, the hypothesized dimensions primarily included escape and seeking-related dimensions, and some hedonic dimensions because of their relevance to aesthetic products (Hirschman &amp; Holbrook, 1982; Holbrook &amp; Hirschman, 1982), which are the context for this study. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to crossvalidate the underlying dimensionality structure of cultural experience motives. A four-factor model was extracted from the EFA consistent with some theoretical formulations and was retained in the CFA. Specific cultural language group differences for the motive dimensions were also hypothesized between Western and Asian tourist samples, and within the Chinese- and Japanese-speaking Asian tourist samples, but not within the different cultural groups of English-speaking Western tourists. These cross-cultural hypotheses were tested for the motive dimension measurement model using invariance testing in CFA. The findings for the motive dimensions differing by cultural group were not as expected. Significant cultural differences between Western and Asian tourists were not found, but a new finding of this study was significant differences between English-speaking tourists in their motives for attending cultural experiences. Marketing implications of these findings are also presented.<br /

Theory and practice of social norms interventions: eight common pitfalls.

BACKGROUND: Recently, Global Health practitioners, scholars, and donors have expressed increased interest in "changing social norms" as a strategy to promote health and well-being in low and mid-income countries (LMIC). Despite this burgeoning interest, the ability of practitioners to use social norm theory to inform health interventions varies widely. MAIN BODY: Here, we identify eight pitfalls that practitioners must avoid as they plan to integrate a social norms perspective in their interventions, as well as eight learnings. These learnings are: 1) Social norms and attitudes are different; 2) Social norms and attitudes can coincide; 3) Protective norms can offer important resources for achieving effective social improvement in people's health-related practices; 4) Harmful practices are sustained by a matrix of factors that need to be understood in their interactions; 5) The prevalence of a norm is not necessarily a sign of its strength; 6) Social norms can exert both direct and indirect influence; 7) Publicising the prevalence of a harmful practice can make things worse; 8) People-led social norm change is both the right and the smart thing to do. CONCLUSIONS: As the understanding of how norms evolve in LMIC advances, practitioners will develop greater understanding of what works to help people lead change in harmful norms within their contexts. Awareness of these pitfalls has helped several of them increase the effectiveness of their interventions addressing social norms in the field. We are confident that others will benefit from these reflections as well

Infrastructure for Semantic Annotation in the Genomics Domain

We describe a novel super-infrastructure for biomedical text mining which incorporates an end-to-end pipeline for the collection, annotation, storage, retrieval and analysis of biomedical and life sciences literature, combining NLP and corpus linguistics methods. The infrastructure permits extreme-scale research on the open access PubMed Central archive. It combines an updatable Gene Ontology Semantic Tagger (GOST) for entity identification and semantic markup in the literature, with a NLP pipeline scheduler (Buster) to collect and process the corpus, and a bespoke columnar corpus database (LexiDB) for indexing. The corpus database is distributed to permit fast indexing, and provides a simple web front-end with corpus linguistics methods for sub-corpus comparison and retrieval. GOST is also connected as a service in the Language Application (LAPPS) Grid, in which context it is interoperable with other NLP tools and data in the Grid and can be combined with them in more complex workflows. In a literature based discovery setting, we have created an annotated corpus of 9,776 papers with 5,481,543 words

The Imbibing Idiot Bias: Consuming Alcohol Can be Hazardous to Your (Perceived) Intelligence

Alcohol consumption and cognitive impairment frequently co-occur. We propose that the relationship is so familiar that exposure to alcohol cues primes expectations of cognitive impairment. Across five studies, we find that in the absence of any evidence of reduced cognitive performance, people who hold an alcoholic beverage are perceived to be less intelligent than those who do not, a mistake we term the imbibing idiot bias. In fact, merely priming observers with alcohol cues causes them to judge targets who hold no beverage at all as less intelligent. The bias is not driven by a belief that less intelligent people are more likely to consume alcohol. We find that the bias may be costly in professional settings. Job candidates who ordered wine during an interview held over dinner were viewed as less intelligent and less hireable than candidates who ordered soda. However, prospective candidates believe that ordering wine rather than soda will help them appear more intelligent

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Pruning the regulatory tree

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62897/1/457534a.pd

Analysis of matched case–control data with multiple ordered disease states: possible choices and comparisons

In an individually matched case–control study, effects of potential risk factors are ascertained through conditional logistic regression (CLR). Extension of CLR to situations with multiple disease or reference categories has been made through polychotomous CLR and is shown to be more efficient than carrying out separate CLRs for each subgroup. In this paper, we consider matched case–control studies where there is one control group, but there are multiple disease states with a natural ordering among themselves. This scenario can be observed when the cases can be further classified in terms of the seriousness or progression of the disease, for example, according to different stages of cancer. We explore several popular models for ordered categorical data in this context. We first adopt a cumulative logit or equivalently, a proportional-odds model to account for the ordinal nature of the data. The important distinction of this model from a stratified dichotomous and polychotomous logistic regression model is that the stratum-specific nuisance parameters cannot be eliminated in this model via the conditional-likelihood approach. We discuss a Mantel–Haenszel approach for analysing such data. We point out possible difficulties with standard likelihood-based approaches with the cumulative logit model when applied to case–control data. We then consider an alternative conditional adjacent-category logit model. We illustrate the methods by analysing data from a matched case–control study on low birthweight in newborns where infants are classified according to low and very low birthweight and a child with normal birthweight serves as a control. A simulation study compares the different ordinal methods with methods ignoring sub-classification of the ordered disease states. Copyright © 2007 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56068/1/2790_ftp.pd