Testing for double inflation with WMAP

With the WMAP data we can now begin to test realistic models of inflation involving multiple scalar fields. These naturally lead to correlated adiabatic and isocurvature (entropy) perturbations with a running spectral index. We present the first full (9 parameter) likelihood analysis of double inflation with WMAP data and find that despite the extra freedom, supersymmetric hybrid potentials are strongly constrained with less than 7% correlated isocurvature component allowed when standard priors are imposed on the cosomological parameters. As a result we also find that Akaike & Bayesian model selection criteria rather strongly prefer single-field inflation, just as equivalent analysis prefers a cosmological constant over dynamical dark energy in the late universe. It appears that simplicity is the best guide to our universe.Comment: 7 pages, 6 figure

Involving Students in a Collaborative Project To Help Discover Inexpensive, Stable Materials for Solar Photoelectrolysis

In general, laboratory experiments focus on traditional chemical disciplines. While this approach allows students the ability to learn and explore fundamental concepts in a specific area, it does not always encourage students to explore interdisciplinary science. Often little transfer of knowledge from one area to another is observed, as students are given step-by-step instructions on how to complete their task with little involvement or problem solving. Herein, we provide an example of a real-time research laboratory experiment that is aimed at individual’s exploration and development, with the scientific goal of discovering inexpensive, stable oxide semiconductors that can efficiently photoelectrolyze water to a useable fuel, hydrogen. Students create unique metal oxide semiconductors combinations, scan the samples for photoactivity using a purchased scan station, and report their findings to a collaborative database. A distinctive feature of the project is its ability to be implemented in a variety of educational levels with a breadth and depth of material covered accordingly. Currently, kits are being used in secondary education classrooms, at undergraduate institutions, or as outreach activities. The project provides students and scientists from different disciplines the opportunity to collaborate in research pertaining to clean energy and the global energy crisis

Low back pain risk factors in a large rural Australian Aboriginal community. An opportunity for managing co-morbidities?

BACKGROUND: Low back pain (LBP) is the most prevalent musculo-skeletal condition in rural and remote Australian Aboriginal communities. Smoking, physical inactivity and obesity are also prevalent amongst Indigenous people contributing to lifestyle diseases and concurrently to the high burden of low back pain. OBJECTIVES: This paper aims to examine the association between LBP and modifiable risk factors in a large rural Indigenous community as a basis for informing a musculo-skeletal and related health promotion program. METHODS: A community Advisory Group (CAG) comprising Elders, Aboriginal Health Workers, academics, nurses, a general practitioner and chiropractors assisted in the development of measures to assess self-reported musculo-skeletal conditions including LBP risk factors. The Kempsey survey included a community-based survey administered by Aboriginal Health Workers followed by a clinical assessment conducted by chiropractors. RESULTS: Age and gender characteristics of this Indigenous sample (n = 189) were comparable to those reported in previous Australian Bureau of Statistics (ABS) studies of the broader Indigenous population. A history of traumatic events was highly prevalent in the community, as were occupational risk factors. Thirty-four percent of participants reported a previous history of LBP. Sporting injuries were associated with multiple musculo-skeletal conditions, including LBP. Those reporting high levels of pain were often overweight or obese and obesity was associated with self-reported low back strain. Common barriers to medical management of LBP included an attitude of being able to cope with pain, poor health, and the lack of affordable and appropriate health care services. Though many of the modifiable risk factors known to be associated with LBP were highly prevalent in this study, none of these were statistically associated with LBP. CONCLUSION: Addressing particular modifiable risk factors associated with LBP such as smoking, physical inactivity and obesity may also present a wider opportunity to prevent and manage the high burden of illness imposed by co-morbidities such as heart disease and type-2 diabetes

Optimizing baryon acoustic oscillation surveys II: curvature, redshifts, and external datasets

We extend our study of the optimization of large baryon acoustic oscillation (BAO) surveys to return the best constraints on the dark energy, building on Paper I of this series (Parkinson et al. 2007). The survey galaxies are assumed to be pre-selected active, star-forming galaxies observed by their line emission with a constant number density across the redshift bin. Star-forming galaxies have a redshift desert in the region 1.6 < z < 2, and so this redshift range was excluded from the analysis. We use the Seo & Eisenstein (2007) fitting formula for the accuracies of the BAO measurements, using only the information for the oscillatory part of the power spectrum as distance and expansion rate rulers. We go beyond our earlier analysis by examining the effect of including curvature on the optimal survey configuration and updating the expected `prior' constraints from Planck and SDSS. We once again find that the optimal survey strategy involves minimizing the exposure time and maximizing the survey area (within the instrumental constraints), and that all time should be spent observing in the low-redshift range (z<1.6) rather than beyond the redshift desert, z>2. We find that when assuming a flat universe the optimal survey makes measurements in the redshift range 0.1 < z <0.7, but that including curvature as a nuisance parameter requires us to push the maximum redshift to 1.35, to remove the degeneracy between curvature and evolving dark energy. The inclusion of expected other data sets (such as WiggleZ, BOSS and a stage III SN-Ia survey) removes the necessity of measurements below redshift 0.9, and pushes the maximum redshift up to 1.5. We discuss considerations in determining the best survey strategy in light of uncertainty in the true underlying cosmological model.Comment: 15 pages, revised in response to referees remarks, accepted for publication in MNRAS. 2nd paper in a series. Paper 1 is at http://arxiv.org/abs/astro-ph/070204

Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics.

OBJECTIVE:To evaluate if mid-pregnancy immune and growth-related molecular factors predict preterm birth (PTB) with and without (±) preeclampsia. STUDY DESIGN:Included were 400 women with singleton deliveries in California in 2009-2010 (200 PTB and 200 term) divided into training and testing samples at a 2:1 ratio. Sixty-three markers were tested in 15-20 serum samples using multiplex technology. Linear discriminate analysis was used to create a discriminate function. Model performance was assessed using area under the receiver operating characteristic curve (AUC). RESULTS:Twenty-five serum biomarkers along with maternal age &lt;34 years and poverty status identified &gt;80% of women with PTB ± preeclampsia with best performance in women with preterm preeclampsia (AUC = 0.889, 95% confidence interval (0.822-0.959) training; 0.883 (0.804-0.963) testing). CONCLUSION:Together with maternal age and poverty status, mid-pregnancy immune and growth factors reliably identified most women who went on to have a PTB ± preeclampsia

Fisher Matrix Preloaded -- Fisher4Cast

The Fisher Matrix is the backbone of modern cosmological forecasting. We describe the Fisher4Cast software: a general-purpose, easy-to-use, Fisher Matrix framework. It is open source, rigorously designed and tested and includes a Graphical User Interface (GUI) with automated LATEX file creation capability and point-and-click Fisher ellipse generation. Fisher4Cast was designed for ease of extension and, although written in Matlab, is easily portable to open-source alternatives such as Octave and Scilab. Here we use Fisher4Cast to present new 3-D and 4-D visualisations of the forecasting landscape and to investigate the effects of growth and curvature on future cosmological surveys. Early releases have been available at http://www.cosmology.org.za since May 2008 with 750 downloads in the first year. Version 2.2 is made public with this paper and includes a Quick Start guide and the code used to produce the figures in this paper, in the hope that it will be useful to the cosmology and wider scientific communities.Comment: 30 Pages, 15 figures. Minor revisions to match published version, with some additional functionality described to match the current version (2.2) of the code. Software available at http://www.cosmology.org.za. Usage, structure and flow of the software, as well as tests performed are described in the accompanying Users' Manua

People of the British Isles: preliminary analysis of genotypes and surnames in a UK control population

There is a great deal of interest in fine scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to play a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. Here we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK control population that can be used as a resource by the research community as well as providing fine scale genetic information on the British population. So far, some 4,000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3,865 samples that have been geocoded indicates that 75% have a mean distance between grandparental places of birth of 37.3km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1,057 samples demonstrates the value of these samples for investigating fine scale population structure within the UK, and shows how this can be enhanced by the use of surnames

Radiative constraints on brane quintessence

We investigate the constraints on quintessence arising from both renormalisable and non-renormalisable couplings where the 5d Planck mass is around the TeV scale. The quintessence field vacuum expectation value is typically of order the 4d Planck mass while non-renormalisable operators are expected to be suppressed by the 5d Planck mass. Non-renormalisable operators are therefore important in computing the 4d effective quintessence potential. We then study the quantum corrections to the quintessence potential due to fermion and graviton loops. The tower of Kaluza-Klein modes competes with the TeV-scale cut-off, altering the graviton contribution to the vacuum polarization of quintessence. Nevertheless we show that, as in four dimensions, the classical potential is stable to such radiative corrections.Comment: 20 pages, 4 figures, uses iopart.cls, graphicx, bm.sty, slashed.sty; submitted to JCAP. Replaced with revised version accepted by JCAP, journal reference supplie

Don’t make me angry, you wouldn’t like me when I’m angry: volitional choices to act or inhibit are modulated by subliminal perception of emotional faces

Volitional action and self-control—feelings of acting according to one’s own intentions and in being control of one’s own actions—are fundamental aspects of human conscious experience. However, it is unknown whether high-level cognitive control mechanisms are affected by socially salient but nonconscious emotional cues. In this study, we manipulated free choice decisions to act or withhold an action by subliminally presenting emotional faces: In a novel version of the Go/NoGo paradigm, participants made speeded button-press responses to Go targets, withheld responses to NoGo targets, and made spontaneous, free choices to execute or withhold the response for Choice targets. Before each target, we presented emotional faces, backwards masked to render them nonconscious. In Intentional trials, subliminal angry faces made participants more likely to voluntarily withhold the action, whereas fearful and happy faces had no effects. In a second experiment, the faces were made supraliminal, which eliminated the effects of angry faces on volitional choices. A third experiment measured neural correlates of the effects of subliminal angry faces on intentional choice using EEG. After replicating the behavioural results found in Experiment 1, we identified a frontal-midline theta component—associated with cognitive control processes—which is present for volitional decisions, and is modulated by subliminal angry faces. This suggests a mechanism whereby subliminally presented “threat” stimuli affect conscious control processes. In summary, nonconscious perception of angry faces increases choices to inhibit, and subliminal influences on volitional action are deep seated and ecologically embedded