The Evolution of K* and the Halo Occupation Distribution since z=1.5: Observations vs. Simulations

We study the evolution of the K-band luminosity function (LF) and the Halo Occupation Distribution (HOD) using Subaru observations of 15 X-ray clusters at z=0.8-1.5 and compare the results with mock clusters (0<z<1.3) extracted from the Millennium Simulation and populated with galaxies using the semi-analytic model (SAM) of Bower et al., matched in mass to our observed sample. We find that the characteristic luminosity K* defined by a Shechter LF is consistent with SAM predictions, which mimic well the evolution of K* in z>1 rich clusters. However, we cannot distinguish between this model and a simple stellar population synthesis model invoking passive evolution with a formation redshift z~5 - consistent with the presence of an old red galaxy population ubiquitous in rich clusters at z=1.5. We also see a small difference (\Delta K*~0.5) between our clusters and studies of the field population at similar redshifts, suggesting only a weak dependence of the luminous (L>L*) part of the LF on environment. Turning to our HOD study, we find that within R_{500}, high-z clusters tend to host smaller numbers of galaxies to a magnitude K*+2 compared to their low-z counterparts. This behavior is also seen in the mock samples and is relatively insensitive to the average mass of the cluster haloes. In particular, we find significant correlations of the observed number of member cluster galaxies (N) with both z and cluster mass: $N(M,z)=(53\pm1)(1+z)^{-0.61^{+0.18}_{-0.20}}(M/10^{14.3})^{0.86\pm0.05}$. Finally, we examine the spatial distribution of galaxies and provide a new estimate of the concentration parameter for clusters at high z ($c_{g}=2.8^{+1.0}_{-0.8}$). Our result is consistent with predictions from both our SAM mock clusters and literature's predictions for dark matter haloes. The mock sample predictions rise slowly with decreasing redshift reaching $c_{g}=6.3^{+0.39}_{-0.36}$ at z=0.Comment: 17 pages, 3 tables, 12 Figures. Accepted for publications in MNRAS. Version 2: modified Figs. 4, 8 and 1

Evolution of the Red Sequence Giant to Dwarf Ratio in Galaxy Clusters out to z ~ 0.5

We analyze deep g' and r' band data of 97 galaxy clusters imaged with MegaCam on the Canada-France-Hawaii telescope. We compute the number of luminous (giant) and faint (dwarf) galaxies using criteria based on the definitions of de Lucia et al. (2007). Due to excellent image quality and uniformity of the data and analysis, we probe the giant-to-dwarf ratio (GDR) out to z ~ 0.55. With X-ray temperature (Tx) information for the majority of our clusters, we constrain, for the first time, the Tx-corrected giant and dwarf evolution separately. Our measurements support an evolving GDR over the redshift range 0.05 < z < 0.55. We show that modifying the (g'-r'), m_r' and K-correction used to define dwarf and giant selection do not alter the conclusion regarding the presence of evolution. We parameterize the GDR evolution using a linear function of redshift (GDR = alpha * z + beta) with a best fit slope of alpha = 0.88 +/- 0.15 and normalization beta = 0.44 +/- 0.03. Contrary to claims of a large intrinsic scatter, we find that the GDR data can be fully accounted for using observational errors alone. Consistently, we find no evidence for a correlation between GDR and cluster mass (via Tx or weak lensing). Lastly, the data suggest that the evolution of the GDR at z < 0.2 is driven primarily by dry merging of the massive giant galaxies, which when considered with previous results at higher redshift, suggests a change in the dominant mechanism that mediates the GDR.Comment: 20 pages, 15 figures. Accepted to MNRA

The XMM Cluster Survey: The Stellar Mass Assembly of Fossil Galaxies

This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and stellar populations of their fossil galaxies. In total, 17 groups and clusters are identified at z < 0.25 with large magnitude gaps between the first and fourth brightest galaxies. All the information necessary to classify these systems as fossils is provided. For both groups and clusters, the total and fractional luminosity of the brightest galaxy is positively correlated with the magnitude gap. The brightest galaxies in FSs (called fossil galaxies) have stellar populations and star formation histories which are similar to normal brightest cluster galaxies (BCGs). However, at fixed group/cluster mass, the stellar masses of the fossil galaxies are larger compared to normal BCGs, a fact that holds true over a wide range of group/cluster masses. Moreover, the fossil galaxies are found to contain a significant fraction of the total optical luminosity of the group/cluster within 0.5R200, as much as 85%, compared to the non-fossils, which can have as little as 10%. Our results suggest that FSs formed early and in the highest density regions of the universe and that fossil galaxies represent the end products of galaxy mergers in groups and clusters. The online FS catalog can be found at http://www.astro.ljmu.ac.uk/~xcs/Harrison2012/XCSFSCat.html.Comment: 30 pages, 50 figures. ApJ published version, online FS catalog added: http://www.astro.ljmu.ac.uk/~xcs/Harrison2012/XCSFSCat.htm

ONS : an ontology for a standardized description of interventions and observational studies in nutrition

Background: The multidisciplinary nature of nutrition research is one of its main strengths. At the same time, however, it presents a major obstacle to integrate data analysis, especially for the terminological and semantic interpretations that specific research fields or communities are used to. To date, a proper ontology to structure and formalize the concepts used for the description of nutritional studies is still lacking. Results: We have developed the Ontology for Nutritional Studies (ONS) by harmonizing selected pre-existing de facto ontologies with novel health and nutritional terminology classifications. The ONS is the result of a scholarly consensus of 51 research centers in nine European countries. The ontology classes and relations are commonly encountered while conducting, storing, harmonizing, integrating, describing, and searching nutritional studies. The ONS facilitates the description and specification of complex nutritional studies as demonstrated with two application scenarios. Conclusions: The ONS is the first systematic effort to provide a solid and extensible formal ontology framework for nutritional studies. Integration of new information can be easily achieved by the addition of extra modules (i.e., nutrigenomics, metabolomics, nutrikinetics, and quality appraisal). The ONS provides a unified and standardized terminology for nutritional studies as a resource for nutrition researchers who might not necessarily be familiar with ontologies and standardization concepts

The red-sequence of 72 WINGS local galaxy clusters

We study the color-magnitude red sequence and blue fraction of 72 X-ray selected galaxy clusters at z=0.04-0.07 from the WINGS survey, searching for correlations between the characteristics of the red sequence and the environment. We consider the slope and scatter of the red sequence, the number ratio of red luminous-to-faint galaxies, the blue fraction and the fractions of ellipticals, S0s and spirals that compose the red sequence. None of these quantities correlate with the cluster velocity dispersion, X-ray luminosity, number of cluster substructures, BCG prevalence over next brightest galaxies and spatial concentration of ellipticals. Instead, the properties of the red sequence depend strongly on local galaxy density. Higher density regions have a lower RS scatter, a higher luminous-to-faint ratio, a lower blue fraction, and a lower spiral fraction on the RS. Our results highlight the prominent effect of the local density in setting the epoch when galaxies become passive and join the red sequence, as opposed to the mass of the galaxy host structure.Comment: Accepted for publication in A&

Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the emission line galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\% and 68\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong emission line. We find a mean redshift of 0.8 and 0.87, with 15 and 13\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6<z<1.2, for the most secure spectroscopic redshifts, the mean redshift for the bright and faint sample is 0.85 and 0.9 respectively. Star contamination is lower than 2\%. We measure a galaxy bias averaged on scales of 1 and 10~Mpc/h of 1.72 \pm 0.1 for the bright sample and of 1.78 \pm 0.12 for the faint sample. The error on the galaxy bias have been obtained propagating the errors in the correlation function to the fitted parameters. This redshift evolution for the galaxy bias is in agreement with theoretical expectations for a galaxy population with MB-5\log h < -21.0. We note that biasing is derived from the galaxy clustering relative to a model for the mass fluctuations. We investigate the quality of the DES photometric redshifts and find that the outlier fraction can be reduced using a comparison between template fitting and neural network, or using a random forest algorithm

Impact of social determinants on antiretroviral therapy access and outcomes entering the era of universal treatment for people living with HIV in Italy

Background: Social determinants are known to be a driving force of health inequalities, even in high income countries. Aim of our study was to determine if these factors can limit antiretroviral therapy (ART) access, outcome and retention in care of people living with HIV (PLHIV) in Italy. Methods: All ART naïve HIV+ patients (pts) of Italian nationality enrolled in the ICONA Cohort from 2002 to 2016 were included. The association of socio-demographic characteristics (age, sex, risk factor for HIV infection, educational level, occupational status and residency area) with time to: ART initiation (from the first positive anti-HIV test), ART regimen discontinuation, and first HIV-RNA &lt; 50 cp/mL, were evaluated by Cox regression analysis, Kaplan Meier method and log-rank test. Results: A total of 8023 HIV+ pts (82% males, median age at first pos anti-HIV test 36 years, IQR: 29-44) were included: 6214 (77.5%) started ART during the study period. Women, people who inject drugs (PWID) and residents in Southern Italy presented the lowest levels of education and the highest rate of unemployment compared to other groups. Females, pts aged &gt; 50 yrs., unemployed vs employed, and people with lower educational levels presented the lowest CD4 count at ART initiation compared to other groups. The overall median time to ART initiation was 0.6 years (yrs) (IQR 0.1-3.7), with a significant decrease over time [2002-2006 = 3.3 yrs. (0.2-9.4); 2007-2011 = 1.0 yrs. (0.1-3.9); 2012-2016 = 0.2 yrs. (0.1-2.1), p &lt; 0.001]. By multivariate analysis, females (p &lt; 0.01) and PWID (p &lt; 0.001), presented a longer time to ART initiation, while older people (p &lt; 0.001), people with higher educational levels (p &lt; 0.001), unemployed (p = 0.02) and students (p &lt; 0.001) were more likely to initiate ART. Moreover, PWID, unemployed vs stable employed, and pts. with lower educational levels showed a lower 1-year probability of achieving HIV-RNA suppression, while females, older patients, men who have sex with men (MSM), unemployed had higher 1-year risk of first-line ART discontinuation. Conclusions: Despite median time to ART start decreased from 2002 to 2016, socio-demographic factors still contribute to disparities in ART initiation, outcome and durability

Flavor violating leptonic decays of τ and μ leptons in the Standard Model with massive neutrinos

We have revisited the computations of the flavor violating leptonic decays of the τ and μ leptons into three lighter charged leptons in the Standard Model with massive neutrinos. We were driven by a claimed unnaturally large branching ratio predicted for the τ − → μ − l + l − (l = μ, e) decays (Pham, Eur Phys J C 8:513 1999), which was at odds with the corresponding predictions for the μ − → e−e−e+ processes (Petcov, Sov J Nucl Phys 25:340 1977). In contrast with the prediction in [17], our results are strongly suppressed and in good agreement with the approximationmade in Ref. [15], where masses and momenta of the external particles were neglected in order to deal with the loop integrals. However -as a result of keeping external momenta and masses in the computation of the dominant penguin and box diagrams- we even find slightly smaller branching fractions. Therefore, we confirm that any future observation of such processes would be an unambiguous manifestation of new physics beyond the Standard Model.Finally, we also acknowledge support from Conacyt through projects FOINS-296-2016 (Fronteras de la Ciencia), and 236394 and 250628 (Ciencia Básica)

Combining traditional dietary assessment methods with novel metabolomics techniques: present efforts by the Food Biomarker Alliance

FFQ, food diaries and 24 h recall methods represent the most commonly used dietary assessment tools in human studies on nutrition and health, but food intake biomarkers are assumed to provide a more objective reflection of intake. Unfortunately, very few of these biomarkers are sufficiently validated. This review provides an overview of food intake biomarker research and highlights present research efforts of the Joint Programming Initiative 'A Healthy Diet for a Healthy Life' (JPI-HDHL) Food Biomarkers Alliance (FoodBAll). In order to identify novel food intake biomarkers, the focus is on new food metabolomics techniques that allow the quantification of up to thousands of metabolites simultaneously, which may be applied in intervention and observational studies. As biomarkers are often influenced by various other factors than the food under investigation, FoodBAll developed a food intake biomarker quality and validity score aiming to assist the systematic evaluation of novel biomarkers. Moreover, to evaluate the applicability of nutritional biomarkers, studies are presently also focusing on associations between food intake biomarkers and diet-related disease risk. In order to be successful in these metabolomics studies, knowledge about available electronic metabolomics resources is necessary and further developments of these resources are essential. Ultimately, present efforts in this research area aim to advance quality control of traditional dietary assessment methods, advance compliance evaluation in nutritional intervention studies, and increase the significance of observational studies by investigating associations between nutrition and health. Keywords: Dietary assessment; Food intake biomarkers; Food metabolome; Metabolomics