306 research outputs found
Association of Urinary Bisphenol A Concentration with Heart Disease: Evidence from NHANES 2003/06
BACKGROUND: Bisphenol A (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years. METHODOLOGY AND FINDINGS: A cross-sectional analysis of NHANES: subjects were n = 1455 (2003/04) and n = 1493 (2005/06) adults aged 18-74 years, representative of the general adult population of the United States. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, BMI, waist circumference, and urinary creatinine concentration. Main outcomes were reported diagnoses of heart attack, coronary heart disease, angina and diabetes and serum liver enzyme levels. Urinary BPA concentrations in 2005/06 (geometric mean 1.79 ng/ml, 95% CI: 1.64 to 1.96) were lower than in 2003/04 (2.49 ng/ml, CI: 2.20 to 2.83, difference p-value = 0.00002). Higher BPA concentrations were associated with coronary heart disease in 2005/06 (OR per z-score increase in BPA = 1.33, 95%CI: 1.01 to 1.75, p = 0.043) and in pooled data (OR = 1.42, CI: 1.17 to 1.72, p = 0.001). Associations with diabetes did not reach significance in 2005/06, but pooled estimates remained significant (OR = 1.24, CI: 1.10 to 1.40, p = 0.001). There was no overall association with gamma glutamyl transferase concentrations, but pooled associations with alkaline phosphatase and lactate dehydrogenase remained significant. CONCLUSIONS: Higher BPA exposure, reflected in higher urinary concentrations of BPA, is consistently associated with reported heart disease in the general adult population of the USA. Studies to clarify the mechanisms of these associations are urgently needed
50 Years of Test (Un)fairness: Lessons for Machine Learning
Quantitative definitions of what is unfair and what is fair have been
introduced in multiple disciplines for well over 50 years, including in
education, hiring, and machine learning. We trace how the notion of fairness
has been defined within the testing communities of education and hiring over
the past half century, exploring the cultural and social context in which
different fairness definitions have emerged. In some cases, earlier definitions
of fairness are similar or identical to definitions of fairness in current
machine learning research, and foreshadow current formal work. In other cases,
insights into what fairness means and how to measure it have largely gone
overlooked. We compare past and current notions of fairness along several
dimensions, including the fairness criteria, the focus of the criteria (e.g., a
test, a model, or its use), the relationship of fairness to individuals,
groups, and subgroups, and the mathematical method for measuring fairness
(e.g., classification, regression). This work points the way towards future
research and measurement of (un)fairness that builds from our modern
understanding of fairness while incorporating insights from the past.Comment: FAT* '19: Conference on Fairness, Accountability, and Transparency
(FAT* '19), January 29--31, 2019, Atlanta, GA, US
Spectral Typing of Late Type Stellar Companions to Young Stars from Low Dispersion Near-Infrared Integral Field Unit Data
We used the Project 1640 near-infrared coronagraph and integral field
spectrograph to observe 19 young solar type stars. Five of these stars are
known binary stars and we detected the late-type secondaries and were able to
measure their JH spectra with a resolution of R\sim30. The reduced, extracted,
and calibrated spectra were compared to template spectra from the IRTF spectral
library. With this comparison we test the accuracy and consistency of spectral
type determination with the low-resolution near-infrared spectra from P1640.
Additionally, we determine effective temperature and surface gravity of the
companions by fitting synthetic spectra calculated with the PHOENIX model
atmosphere code. We also present several new epochs of astrometry of each of
the systems. Together these data increase our knowledge and understanding of
the stellar make up of these systems. In addition to the astronomical results,
the analysis presented helps validate the Project 1640 data reduction and
spectral extraction processes and the utility of low-resolution, near-infrared
spectra for characterizing late-type companions in multiple systems.Comment: Accepted to Astronomical Journal, 25 pages, 8 figure
Electric Field Conjugation with the Project 1640 coronagraph
The Project 1640 instrument on the 200-inch Hale telescope at Palomar
Observatory is a coronagraphic instrument with an integral field spectrograph
at the back end, designed to find young, self-luminous planets around nearby
stars. To reach the necessary contrast for this, the PALM-3000 adaptive optics
system corrects for fast atmospheric speckles, while CAL, a phase-shifting
interferometer in a Mach-Zehnder configuration, measures the quasistatic
components of the complex electric field in the pupil plane following the
coronagraphic stop. Two additional sensors measure and control low-order modes.
These field measurements may then be combined with a system model and data
taken separately using a white-light source internal to the AO system to
correct for both phase and amplitude aberrations. Here, we discuss and
demonstrate the procedure to maintain a half-plane dark hole in the image plane
while the spectrograph is taking data, including initial on-sky performance.Comment: 9 pages, 7 figures, in Proceedings of SPIE, 8864-19 (2013
Association between Serum Perfluorooctanoic Acid (PFOA) and Thyroid Disease in the U.S. National Health and Nutrition Examination Survey
addresses: Epidemiology and Public Health Group, eninsula Medical School, Exeter, United Kingdom.notes: PMCID: PMC2866686types: Journal Article'Reproduced with permission from Environmental Health Perspectives'Copyright © 2010 National Institute of Environmental Health SciencesPerfluorooctanoic acid (PFOA, also known as C8) and perfluorooctane sulfonate (PFOS) are stable compounds with many industrial and consumer uses. Their persistence in the environment plus toxicity in animal models has raised concern over low-level chronic exposure effects on human health
Ottawa 2020 consensus statements for programmatic assessment 2: Implementation and practice
INTRODUCTION: Programmatic assessment is a longitudinal, developmental approach that fosters and harnesses the learning function of assessment. Yet the implementation, a critical step to translate theory into practice, can be challenging. As part of the Ottawa 2020 consensus statement on programmatic assessment, we sought to provide descriptions of the implementation of the 12 principles of programmatic assessment and to gain insight into enablers and barriers across different institutions and contexts. METHODS: After the 2020 Ottawa conference, we surveyed 15 Health Profession Education programmes from six different countries about the implementation of the 12 principles of programmatic assessment. Survey responses were analysed using a deductive thematic analysis. RESULTS AND DISCUSSION: A wide range of implementations were reported although the principles remained, for the most part, faithful to the original enunciation and rationale. Enablers included strong leadership support, ongoing faculty development, providing students with clear expectations about assessment, simultaneous curriculum renewal and organisational commitment to change. Most barriers were related to the need for a paradigm shift in the culture of assessment. Descriptions of implementations in relation to the theoretical principles, across multiple educational contexts, coupled with explanations of enablers and barriers, provided new insights and a clearer understanding of the strategic and operational considerations in the implementation of programmatic assessment. Future research is needed to further explore how contextual and cultural factors affect implementation
Telomeric expression sites are highly conserved in trypanosoma brucei
Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs) of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs). The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs) were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology
Project 1640: the world's first ExAO coronagraphic hyperspectral imager for comparative planetary science
Project 1640, a high-contrast spectral-imaging effort involving a coordinated set of instrumentation and software, built at AMNH, JPL, Cambridge and Caltech, has been commissioned and is fully operational. This novel suite of instrumentation includes a 3388+241-actuator adaptive optics system, an optimized apodized pupil Lyot coronagraph, an integral field spectrograph, and an interferometric calibration wave front sensor. Project 1640 is the first of its kind of instrumentation, designed to image and characterize planetary systems around nearby stars, employing a variety of techniques to break the speckle-noise barrier. It is operational roughly one year before any similar project, with the goal of reaching a contrast of 10^(-7) at 1 arcsecond separation. We describe the instrument, highlight recent results, and document on-sky performance at the start of a 3-year, 99-night survey at the Palomar 5-m Hale telescope
A multispecies tree ring reconstruction of Potomac River streamflow (950-2001)
Millennial length reconstruction of Potomac River StreamflowInstrumental record does represent the past milleniumImprovement upon the previous reconstructio
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