1,870 research outputs found
Using chlorhexidine varnish to prevent early childhood caries in American Indian children
Objectives: To test the efficacy of 10% chlorhexidine (CHX) dental varnish applied to the mothers' dentition in preventing caries in American Indian children. Methods: This was a placebo‐controlled, double‐blind, randomized clinical trial. Mother–child pairs were enrolled when the child was 4.5‐6.0 months. Mothers received 4 weekly applications of the study treatment (CHX or placebo) followed by single applications when her child was age 12 and 18 months. Children received caries examinations at enrollment, 12, 18 and 24 months. Analyses were limited to the intent‐to‐treat (ITT) group: children whose mothers received the first study treatment and who received at least one post‐baseline exam. The outcome variable was the number of new carious surfaces (NNCS) at the child's last visit. Wilcoxon nonparametric and Fisher's exact tests were used to test differences between the active and placebo groups. Results: We randomized 414 mother–child pairs, with 367 (88.6%) included in the ITT group (active = 188, placebo = 179). The proportion of children caries‐free at their final exam was 51.1% and 50.8% for the active and placebo groups ( P > 0.99). The mean NNCS for the active and placebo groups was 3.82 (standard deviation [SD] = 8.18) and 3.80 (SD = 6.08), respectively ( P = 0.54). The proportion with NNCS > 6 was 18.1% for active children versus 27.9% for placebo (relative risk [RR] = 0.65, P = 0.03). The number needed to treat to shift one child from NNCS > 6 to a lower severity was 10.2. Conclusions: In this population CHX varnish did not reduce the mean NNCS or proportion of children with caries, but did reduce the proportion with severe caries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96744/1/jphd348.pd
Starlight Demonstration of the Dragonfly Instrument: an Integrated Photonic Pupil Remapping Interferometer for High Contrast Imaging
In the two decades since the first extra-solar planet was discovered, the
detection and characterization of extra-solar planets has become one of the key
endeavors in all of modern science. Recently direct detection techniques such
as interferometry or coronography have received growing attention because they
reveal the population of exoplanets inaccessible to Doppler or transit
techniques, and moreover they allow the faint signal from the planet itself to
be investigated. Next-generation stellar interferometers are increasingly
incorporating photonic technologies due to the increase in fidelity of the data
generated. Here, we report the design, construction and commissioning of a new
high contrast imager; the integrated pupil-remapping interferometer; an
instrument we expect will find application in the detection of young faint
companions in the nearest star-forming regions. The laboratory characterisation
of the instrument demonstrated high visibility fringes on all interferometer
baselines in addition to stable closure phase signals. We also report the first
successful on-sky experiments with the prototype instrument at the 3.9-m
Anglo-Australian Telescope. Performance metrics recovered were consistent with
ideal device behaviour after accounting for expected levels of decoherence and
signal loss from the uncompensated seeing. The prospect of complete
Fourier-coverage coupled with the current performance metrics means that this
photonically-enhanced instrument is well positioned to contribute to the
science of high contrast companions.Comment: 10 pages, 7 figures, accepted to Mon. Not. of Roy. Ast. Soc., 201
The hydration state of HO(aq)
The HO(aq) ion participates in myriad aqueous phase chemical processes of
biological and chemical interest. A molecularly valid description of its
hydration state, currently poorly understood, is a natural prerequisite to
modeling chemical transformations involving HO(aq). Here it is shown that
the statistical mechanical quasi-chemical theory of solutions predicts that
is the dominant inner shell coordination
structure for HO(aq) under standard conditions. Experimental observations
and other theoretical calculations are adduced to support this conclusion.
Hydration free energies of neutral combinations of simple cations with
HO(aq) are evaluated and agree well with experimental values.Comment: 10 pages, 1 figur
Performance of a 1200m long suspended Fabry-Perot cavity
Using one arm of the Michelson interferometer and the power recycling mirror
of the interferometric gravitational wave detector GEO600, we created a
Fabry-Perot cavity with a length of 1200 m. The main purpose of this experiment
was to gather first experience with the main optics, its suspensions and the
corresponding control systems. The residual displacement of a main mirror is
about 150 nm rms. By stabilising the length of the 1200 m long cavity to the
pre-stabilised laser beam we achieved an error point frequency noise of 0.1
mHz/sqrt(Hz) at 100 Hz Fourier frequency. In addition we demonstrated the
reliable performance of all included subsystems by several 10-hour-periods of
continuous stable operation. Thus the full frequency stabilisation scheme for
GEO600 was successfully tested.Comment: Amaldi 4 (Perth 2001) conference proceedings, 10 pages, 8 figure
Bayesian Centroid Estimation for Motif Discovery
Biological sequences may contain patterns that are signal important
biomolecular functions; a classical example is regulation of gene expression by
transcription factors that bind to specific patterns in genomic promoter
regions. In motif discovery we are given a set of sequences that share a common
motif and aim to identify not only the motif composition, but also the binding
sites in each sequence of the set. We present a Bayesian model that is an
extended version of the model adopted by the Gibbs motif sampler, and propose a
new centroid estimator that arises from a refined and meaningful loss function
for binding site inference. We discuss the main advantages of centroid
estimation for motif discovery, including computational convenience, and how
its principled derivation offers further insights about the posterior
distribution of binding site configurations. We also illustrate, using
simulated and real datasets, that the centroid estimator can differ from the
maximum a posteriori estimator.Comment: 24 pages, 9 figure
‘Blindness to the obvious’?: Treatment experiences and feminist approaches to eating disorders
Eating disorders (EDs) are now often approached as biopsychosocial problems, but the social or cultural aspects of the equation are often marginalised in treatment - relegated to mere contributory or facilitating factors. In contrast, feminist and socio-cultural approaches are primarily concerned with the relationship between EDs and the social/ cultural construction of gender. Yet although such approaches emerged directly from the work of feminist therapists, the feminist scholarship has increasingly observed, critiqued and challenged the biomedical model from a scholarly distance. As such, this article draws upon data from 15 semi-structured interviews with women in the UK context who have experience of anorexia and/or bulimia in order to explore a series of interlocking themes concerning the relationship between gender identity and treatment. In engaging the women in debate about the feminist approaches (something which has been absent from previous feminist work), the article explores how gender featured in their own understandings of their problem, and the ways in which it was - or rather wasn’t - addressed in treatment. The article also explores the women’s evaluations of the feminist discourse, and their discussions of how it might be implemented within therapeutic and clinical contexts
Persistent starspot signals on M dwarfs: multi-wavelength Doppler observations with the Habitable-zone Planet Finder and Keck/HIRES
Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create
quasiperiodic signals in their photometric and Doppler spectroscopic
measurements. The periodic Doppler signals can mimic radial velocity (RV)
changes expected from orbiting exoplanets. Exoplanets can be distinguished from
activity-induced false positives by the chromaticity and long-term incoherence
of starspot signals, but these qualities are poorly constrained for
fully-convective M stars. Coherent photometric starspot signals on M dwarfs may
persist for hundreds of rotations, and the wavelength dependence of starspot RV
signals may not be consistent between stars due to differences in their
magnetic fields and active regions. We obtained precise multi-wavelength RVs of
four rapidly-rotating M dwarfs (AD Leo, G 227-22, GJ 1245B, GJ 3959) using the
near-infrared (NIR) Habitable-zone Planet Finder, and the optical Keck/HIRES
spectrometer. Our RVs are complemented by photometry from Kepler, TESS, and the
Las Cumbres Observatory (LCO) network of telescopes. We found that all four
stars exhibit large spot-induced Doppler signals at their rotation periods, and
investigated the longevity and optical-to-NIR chromaticity for these signals.
The phase curves remain coherent much longer than is typical for Sunlike stars.
Their chromaticity varies, and one star (GJ 3959) exhibits optical and NIR RV
modulation consistent in both phase and amplitude. In general, though, we find
that the NIR amplitudes are lower than their optical counterparts. We conclude
that starspot modulation for rapidly-rotating M stars frequently remains
coherent for hundreds of stellar rotations, and gives rise to Doppler signals
that, due to this coherence, may be mistaken for exoplanets.Comment: Accepted for publication in the Astrophysical Journa
Plasma Electronics
Contains reports on twelve research projects.U. S. Atomic Energy Commission under Contract AT(30-1)-3285National Science Foundation (Grant GK-524
Behavioral health coaching for rural-living older adults with diabetes and depression: an open pilot of the HOPE Study
BACKGROUND: Patients with diabetes are at increased risk for depression, compounding the burden of disease. When comorbid with diabetes, depression leads to poorer health outcomes and often complicates diabetes self-management. Unfortunately, treatment options for these complex patients are limited and comprehensive services are rarely available for patients in rural settings. METHODS: A small open trial was conducted to test the acceptability, feasibility and preliminary outcomes of a telephone-delivered coaching intervention for rural-dwelling older adults with uncontrolled diabetes and comorbid, clinically significant depressive symptoms. A total of eight older adults were enrolled in Healthy Outcomes through Patient Empowerment (HOPE), a 10-session (12-week), telephone-based coaching intervention. Primary study constructs included measures of diabetes control (Hemoglobin [Hb] A1c), depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]), and diabetes-related distress (Problem Areas in Diabetes Scale [PAID]). Assessments were conducted at baseline, post-intervention, and 6-month follow-up. Acceptability and feasibility were evaluated using patient surveys, focused exit interviews, and session attendance data. RESULTS: Clinically significant improvements were realized post-intervention and at 6-month follow-up for outcomes related to diabetes and depression. Effect sizes using Cohen's d were determined post-intervention and at 6-month follow-up, respectively, for HbA1c (d=0.36; d=0.28), PHQ-9 (d=1.48; d=1.67, and PAID (d=1.50; d=1.06) scores. Among study participants, HbA1c improved from baseline by a mean (M) of 1.13 (SD=1.70) post-intervention and M=0.84 (SD=1.62) at 6 months. Depression scores, measured by the PHQ-9, improved from baseline by M=5.14 (SD=2.27) post-intervention and M=7.03 (SD=4.43) at 6-month follow-up. PAID scores also improved by M=17.68 (SD=10.7) post-intervention and M=20.42 (SD=20.66) from baseline to 6-month follow-up. Case examples are provided for additional context and to more fully articulate salient intervention concepts. CONCLUSION: Although preliminary, data from this small open trial suggest that HOPE holds the potential to improve both physical (diabetes) and emotional (diabetes distress, depression) health outcomes and that changes can be maintained over a 6-month time period. As envisioned by the authors, HOPE may function as an extension of traditional primary care for rural-dwelling older adults with multiple comorbidities. A future randomized clinical trial will test HOPE’s broader effectiveness with rural-dwelling older adults. TRIAL REGISTRATION: NCT0127471
A comparison of measurement methods of hippocampal atrophy rate for predicting Alzheimer's dementia in the Aberdeen Birth Cohort of 1936
Acknowledgments The authors would like to thank all radiographers and doctors involved in gathering the data. A special thanks is given to the participants from the Aberdeen 1936 Birth Cohort studies for their voluntary contribution to these projects. R.T.S. receives funding from TauRx. A.D.M. provides brain imaging advice to TauRx but receives no remuneration for this. She has previously received honoraria from GE Healthcare for educational lectures on brain imaging in dementia and parkinsonian disorders. The other authors report no disclosures. Data collection was funded by grants from the Alzheimer's Research Trust (now Alzheimer's Research UK, grant reference ART/SPG2003B), Alzheimer's Research UK (grant reference ARUK-SB2012B-2), and the University of Aberdeen Development Trust.DG002 RGB3109. L.J.W., R.T.S., and A.D.M. acquired funding for the study and are steering committee members and guarantors of the imaging data. L.J.W. recruited participants. A.D.M. supervised all imaging acquisitions. Conflicts of interest: None declared Statistical analyses completed by Dr Arnab Rana, Aberdeen Biomedical Imaging Center Industry sponsorship: None.Peer reviewedPublisher PD
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