Redshift Weights for Baryon Acoustic Oscillations : Application to Mock Galaxy Catalogs

Large redshift surveys capable of measuring the Baryon Acoustic Oscillation (BAO) signal have proven to be an effective way of measuring the distance-redshift relation in cosmology. Building off the work in Zhu et al. (2015), we develop a technique to directly constrain the distance-redshift relation from BAO measurements without splitting the sample into redshift bins. We parametrize the distance-redshift relation, relative to a fiducial model, as a quadratic expansion. We measure its coefficients and reconstruct the distance-redshift relation from the expansion. We apply the redshift weighting technique in Zhu et al. (2015) to the clustering of galaxies from 1000 QuickPM (QPM) mock simulations after reconstruction and achieve a 0.75% measurement of the angular diameter distance $D_A$ at $z=0.64$ and the same precision for Hubble parameter H at $z=0.29$. These QPM mock catalogs are designed to mimic the clustering and noise level of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12). We compress the correlation functions in the redshift direction onto a set of weighted correlation functions. These estimators give unbiased $D_A$ and $H$ measurements at all redshifts within the range of the combined sample. We demonstrate the effectiveness of redshift weighting in improving the distance and Hubble parameter estimates. Instead of measuring at a single 'effective' redshift as in traditional analyses, we report our $D_A$ and $H$ measurements at all redshifts. The measured fractional error of $D_A$ ranges from 1.53% at $z=0.2$ to 0.75% at $z=0.64$. The fractional error of $H$ ranges from 0.75% at $z=0.29$ to 2.45% at $z = 0.7$. Our measurements are consistent with a Fisher forecast to within 10% to 20% depending on the pivot redshift. We further show the results are robust against the choice of fiducial cosmologies, galaxy bias models, and RSD streaming parameters.Comment: 13 pages, 8 figures, submitted to MNRA

Improved primordial non-gaussianity constraints from measurements of galaxy clustering and the integrated Sachs-Wolfe effect

We present the strongest robust constraints on primordial non-Gaussianity (PNG) from currently available galaxy surveys, combining large-scale clustering measurements and their cross-correlations with the cosmic microwave background. We update the data sets used by Giannantonio et al. (2012), and broaden that analysis to include the full set of two-point correlation functions between all surveys. In order to obtain the most reliable constraints on PNG, we advocate the use of the cross-correlations between the catalogs as a robust estimator and we perform an extended analysis of the possible systematics to reduce their impact on the results. To minimize the impact of stellar contamination in our luminous red galaxy (LRG) sample, we use the recent Baryon Oscillations Spectroscopic Survey catalog of Ross et al. (2011). We also find evidence for a new systematic in the NVSS radio galaxy survey similar to, but smaller than, the known declination-dependent issue; this is difficult to remove without affecting the inferred PNG signal, and thus we do not include the NVSS auto-correlation function in our analyses. We find no evidence of primordial non-Gaussianity; for the local-type configuration we obtain for the skewness parameter $-36 < f_{\mathrm{NL}} < 45$ at 95 % c.l. ($5 \pm 21$ at $1\sigma$) when using the most conservative part of our data set, improving previous results; we also find no evidence for significant kurtosis, parameterized by $g_{\mathrm{NL}}$. In addition to PNG, we simultaneously constrain dark energy and find that it is required with a form consistent with a cosmological constant.Comment: 24 pages, 16 figures. More conservative treatment of the NVSS data, version accepted by Phys. Rev.

Effect of Restrictions on Television Food Advertising to Children on Exposure to Advertisements for ‘Less Healthy’ Foods: Repeat Cross-Sectional Study

<div><h3>Background</h3><p>In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to “reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising”. We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions.</p> <h3>Methods</h3><p>We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods – the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods.</p> <h3>Results</h3><p>1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions.</p> <h3>Conclusions</h3><p>Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods.</p> </div

A repeat cross-sectional study examining the equitable impact of nutritional standards for school lunches in England in 2008 on the diets of 4-7y olds across the socio-economic spectrum

BACKGROUND: The 2008 nutritional standards for primary school lunch in England improved nutritional content. The impact on socio-economic inequalities is unknown. We examine the impact of the nutritional standards on children’s nutrient intake at lunchtime and in total diet by level of deprivation. METHODS: We conducted cross-sectional studies in 12 English primary schools before and after legislation. Dietary intake was recorded for 4-7y olds using a validated, prospective four-day food diary. Socio-economic status was estimated using the Index of Multiple Deprivation; three groups of approximately equal sizes were created. Linear, mixed-effect models explored the effect of year, lunch type (school or home-packed lunch), level of deprivation and the interaction(s) between these factors on children’s diets. RESULTS: 368 and 624 children participated in 2003–4 and 2008–9 respectively. At lunchtime, between 2003–4 and 2008–9, the increase in non-starch polysaccharide (NSP) intake was larger in the least compared to the most deprived group (difference in mean change 0.8 mg; 95% CI 0.4, 1.3). There were similar differences in mean changes for iron (0.3 mg; 0.2, 0.4) and zinc (0.3 mg; 0.1, 0.5). In total diet, differential effects were observed for NSP, iron and zinc; we found no evidence these changes were associated with lunch type. Lunch type was associated with changes in per cent energy from non-milk-extrinsic sugars (NMES) and vitamin C. Per cent energy from NMES was lower and vitamin C intake higher in school lunches in 2008–9 compared with 2003–4. The corresponding differences in home-packed lunches were not as marked and there were subtle but statistically significant effects of the level of deprivation. CONCLUSIONS: By 2008–9, NMES at lunchtime and in total diet was lower for children consuming a school lunch; this change was equitable across the deprivation groups. Vitamin C intake increased more for children in the most deprived group, narrowing the socio-economic inequality. A range of significant differential effects of the nutritional standards were observed and important socio-economic inequalities in dietary intake remain. Additional interventions to promote equitable nutrition in children are needed to support legislative measures and maximise their impact

Spatial variation in the composition of motile macroinvertebrate assemblages associated with two bed types of the seagrass Posidonia oceanica

The influence of continuous (non-fragmented) and reticulate (fragmented) bed type and plant architecture on the species richness, abundance and assemblage composition of motile macroinvertebrates associated with the seagrass Posidonia oceanica was investigated at 3 different spatial scales (10s of metres [‘small’], 100s of metres [‘medium’] and kilometres [‘large’]). Univariate and multivariate analyses did not identify significant differences in the attributes of macroinverte- brate assemblages between the 2 P. oceanica bed types over the 3 spatial scales considered. On the other hand, significant spatial variation in macroinvertebrate attributes was detected at the large spa- tial scale. Results of univariate regression and multivariate correlation analysis consistently indicated significant relationships between attributes of the macroinvertebrate assemblages and epiphyte bio- mass at the large spatial scale. Although less consistent, significant relationships were also detected between attributes of the macroinvertebrate assemblages, and mean sediment grain size, total organic carbon in sediment and shoot biomass at the large and medium spatial scales. The findings indicate that naturally fragmented and non-fragmented P. oceanica beds have similar habitat charac- teristics for the associated macroinvertebrates and that local factors, which influence seagrass bed architecture and particularly epiphyte load, have greater influence on the seagrass fauna. Data from the present study support the notion that fragmented seagrass beds should receive the same attention as non-fragmented ones with regard to habitat conservation and protection.peer-reviewe

Occurrence and distribution of different bed types of seagrass Posidonia oceanica around the Maltese Islands

The small-scale distribution of Posidonia oceanica bed types were mapped at four locations off the northern coast of the Maltese Islands, using aerial photography supplemented by surveys using SCUBA diving. Results showed a similar pattern of occurrence of the seagrass at all locations surveyed. In shallow waters (2 m – 4 m), P. oceanicaoccurred as patches of variable size on a rocky and/or sandy substratum. In deeper waters (5 m – 10 m), the patches of seagrass were often replaced by reticulate beds consisting of P. oceanicainterspersed with areas of bare sand. Deeper still (11 m – 13 m), a transition from reticulate to continuous beds occurred. Continuous beds extended to depths of around 25 - 30 m and eventually became reticulate or patchy in deeper waters (>25 m). Values of total seagrass percentage cover increased, while the ratio of fragmented:continuous bed cover decreased for the four study locations on moving southwards (Ramla Bay to St Thomas Bay), indicating that P. oceanica habitat was more abundant and less fragmented in the south-eastern parts of the Maltese Islands. However, values calculated using an exposure index did not did indicate a relationship between exposure and the observed decease in fragmentation of seagrass beds on moving northwest to southwest along the north-eastern coast. Data from the four sites surveyed, together with data from other surveys, were used to show the large-scale distribution of P. oceanica beds around the Maltese Islands. The implications of the study findings for the conservation and management of P. oceanica habitat around the Maltese Islands are discussed.peer-reviewe

Pathways to recovery among homeless people with mental illness: Is impulsiveness getting in the way?

Objective: This study investigates the association between impulsiveness and six dimensions of recovery among homeless people with mental illness. Method: The sample was composed of 418 participants of a randomized controlled trial of Housing First, a recovery-oriented program that provides immediate access to permanent housing. The reliable change index method was used to provide an estimate of the statistical and clinical significance of the change from baseline to 24 months (i.e., clinically meaningful improvement), on outcomes that pertain to recovery dimensions: psychiatric symptoms (clinical), physical health and substance use problems (physical), residential stability (functional), arrests (criminological), community integration (social), and hope and personal confidence (existential). We tested for the effect of impulsiveness, assessed with the Barratt Impulsiveness Scale–11, on clinically meaningful improvement on each specific outcome, adjusting for age, gender and intervention assignment, as both intervention arms were included in the analysis. Results: For every increase in total impulsiveness score by one standard deviation, the odds of experiencing clinically meaningful improvement decreased by 29% (OR = 0.71, 95% CI, 0.55 to 0.91) on the clinical dimension and by 53% (OR = 0.47, 95% CI, 0.32 to 0.68) on the existential dimension. However, changes in outcomes pertaining to physical, functional, criminological, and social dimensions were not significantly influenced by impulsiveness. Conclusions: Findings highlight the importance of addressing impulsiveness in the context of recovery-oriented interventions for homeless people with mental illness. Further research may be required to improve interventions that are responsive to unique needs of impulsive individuals to support clinical and existential recovery.Objectif : La présente étude porte sur l’association entre l’impulsivité et six dimensions du rétablissement chez des personnes en situation d’itinérance vivant avec une maladie mentale. Méthode : L’échantillon est composé de 418 participants à un essai randomisé contrôlé de l’approche Logement d’abord, un programme axé sur le rétablissement qui offre un accès immédiat à un logement permanent. La méthode de l’indicateur de changement fiable a été utilisée afin de fournir une estimation de la signification statistique et clinique du changement de l’entrée dans l’étude à 24 mois (c.-à-d., une amélioration cliniquement significative) pour les mesures qui ont trait aux dimensions du rétablissement: symptômes psychiatriques (clinique), santé physique et problèmes liés à l’utilisation de substances (physique), stabilité résidentielle (fonctionnelle), arrestations (criminologique), intégration communautaire (social) et espoir et confiance en soi (existentiel). Nous avons testé l’effet de l’impulsivité, évaluée à l’aide de l’échelle d’impulsivité de Barratt, sur l’amélioration cliniquement significative pour chaque mesure, en ajustant pour l’âge, le genre et l’assignation à une intervention, les deux volets de l’intervention étant inclus dans l’analyse. Résultats : Pour chaque augmentation du score total d’impulsivité d’un écart-type, les probabilités de connaître une amélioration cliniquement significative diminuaient de 29% (RC = 0,71; IC à 95% 0,55 à 0,91) pour la dimension clinique et de 53% (RC = 0,47; IC à 95% 0,32 à 0,68) pour la dimension existentielle. Toutefois, les dimensions physique, fonctionnelle, criminologique et sociale n’étaient pas influencées significativement par l’impulsivité. Conclusions : Les résultats soulignent l’importance de prendre en compte l’impulsivité dans le contexte d’interventions axées sur le rétablissement pour les personnes en situation d’itinérance vivant avec une maladie mentale. Des recherches futures pourraient être nécessaires pour améliorer les interventions afin qu’elles soutiennent mieux le rétablissement clinique et existentiel en répondant aux besoins uniques des personnes impulsives

A rate-based approach to cleaning-in-place

Fouling is a major problem in the food industry. In cases where allergens are involved, excessive cleaning of food processing equipment often takes place to ensure allergen levels are reduced to acceptable levels. Experimental trials were conducted in a pilot scale cleaning rig to assess the effect of fluid flow rate and temperature on the removal rate of milk paste during cleaning-in-place. Conductivity measurements taken during trials were analysed to produce an equation enabling calculation of the cleaning rate with water temperature, flow rate, initial deposit mass, and time. The rate of cleaning with detergent was also investigated. This methodology produces a rate based expression for cleaning which can be applied to other products, and can be used to determine the time when cleaning is complete, the extent of a cleaning process, or when the pre-rinse should be replaced with a detergent rinse. This prevents over-cleaning and therefore reduces the costs associated with over-cleaning through energy, material and loss of production time