Searching for chemical inhomogeneities in Open Clusters: Analysis of the CN and CH Molecular Band Strengths in NGC 2158, NGC 2420, NGC 2682, NGC 7789 and Berkeley 29

Context: The total mass of a cluster, being the main parameter determining its ability to host more than one stellar generation, may constitute a threshold below which the cluster is able to form only a single stellar population. AIms: Our goal is to investigate the existence of star-to-star variations of CN and CH band strengths, related to the N and C abundances, respectively, among the stars in five open cluster (NGC 2158, NGC 2420, NGC 2682, NGC 7789 and Berkeley 29) similar to those observed in globular clusters and linked with the existence of multiple populations therein. Since these systems are less massive than globulars, our results may allow us to constrain the lower mass necessary to form more than one stellar population. Methods: We measured the strength of the CN and CH bands, which correlate with the C and N abundances, using four molecular indices in low-resolution SDSS/SEGUE spectra. Results: We found that for four of the open clusters (NGC 2158, NGC 2420, NGC 2682 and Berkeley 29) all the stars studied in each of them have similar CN and CH band strengths within the uncertainties since neither anomalous spreads nor bimodalities have been detected in their CN and CH distributions. In contrast, for NGC 7789 we found an anomalous spread in the strength of the CN molecular band at 3839 \AA which is larger than the uncertainties. However, the small number of stars studied in this cluster implies that further analysis is needed to confirm the existence of chemical inhomogeneities in this cluster.Comment: 11 pages, 9 figures, Accepted for publication in A&A, Tables 7, 8 and 9 will be publish onlin

The battle of the sexes starts in the oviduct: modulation of oviductal transcriptome by X and Y-bearing spermatozoa

BACKGROUND:Sex allocation of offspring in mammals is usually considered as a matter of chance, being dependent on whether an X- or a Y-chromosome-bearing spermatozoon reaches the oocyte first. Here we investigated the alternative possibility, namely that the oviducts can recognise X- and Y- spermatozoa, and may thus be able to bias the offspring sex ratio. RESULTS:By introducing X- or Y-sperm populations into the two separate oviducts of single female pigs using bilateral laparoscopic insemination we found that the spermatozoa did indeed elicit sex-specific transcriptomic responses. Microarray analysis revealed that 501 were consistently altered (P-value <0.05) in the oviduct in the presence of Y-chromosome-bearing spermatozoa compared to the presence of X-chromosome-bearing spermatozoa. From these 501 transcripts, 271 transcripts (54.1%) were down-regulated and 230 transcripts (45.9%) were up-regulated when the Y- chromosome-bearing spermatozoa was present in the oviduct. Our data showed that local immune responses specific to each sperm type were elicited within the oviduct. In addition, either type of spermatozoa elicits sex-specific signal transduction signalling by oviductal cells. CONCLUSIONS:Our data suggest that the oviduct functions as a biological sensor that screens the spermatozoon, and then responds by modifying the oviductal environment. We hypothesize that there might exist a gender biasing mechanism controlled by the female

Impact of distance determinations on Galactic structure. II. Old tracers

Here we review the efforts of a number of recent results that use old tracers to understand the build up of the Galaxy. Details that lead directly to using these old tracers to measure distances are discussed. We concentrate on the following: (1) the structure and evolution of the Galactic bulge and inner Galaxy constrained from the dynamics of individual stars residing therein; (2) the spatial structure of the old Galactic bulge through photometric observations of RR Lyrae-type stars; (3) the three\--dimensional structure, stellar density, mass, chemical composition, and age of the Milky Way bulge as traced by its old stellar populations; (4) an overview of RR Lyrae stars known in the ultra-faint dwarfs and their relation to the Galactic halo; and (5) different approaches for estimating absolute and relative cluster ages.Comment: Review article, 80 pages (25 figures); Space Science Reviews, in press (chapter of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Age

The ISLAndS project II: The Lifetime Star Formation Histories of Six Andromeda dSphs

The Initial Star formation and Lifetimes of Andromeda Satellites (ISLAndS) project uses Hubble Space Telescope imaging to study a representative sample of six Andromeda dSph satellite companion galaxies. The main goal of the program is to determine whether the star formation histories (SFHs) of the Andromeda dSph satellites demonstrate significant statistical differences from those of the Milky Way, which may be attributable to the different properties of their local environments. Our observations reach the oldest main sequence turn-offs, allowing a time resolution at the oldest ages of ~ 1 Gyr, which is comparable to the best achievable resolution in the MW satellites. We find that the six dSphs present a variety of SFHs that are not strictly correlated with luminosity or present distance from M31. Specifically, we find a significant range in quenching times (lookback times from 9 to 6 Gyr), but with all quenching times more than ~ 6 Gyr ago. In agreement with observations of Milky Way companions of similar mass, there is no evidence of complete quenching of star formation by the cosmic UV background responsible for reionization, but the possibility of a degree of quenching at reionization cannot be ruled out. We do not find significant differences between the SFHs of the three members of the vast, thin plane of satellites and the three off-plane dSphs. The primary difference between the SFHs of the ISLAndS dSphs and Milky Way dSph companions of similar luminosities and host distances is the absence of very late quenching (< 5 Gyr ago) dSphs in the ISLAndS sample. Thus, models that can reproduce satellite populations with and without late quenching satellites will be of extreme interest.Comment: 24 pages, 11 figures, 3 tables, submitted to the Ap

Egg consumption and dyslipidemia in a Mediterranean cohort

Introduction and objectives: Our aim was to prospectively evaluate the association between egg consumption and dyslipidemia in a Mediterranean cohort. Methods: We followed-up 13,104 Spanish university graduates for a mean period of 8 years. Dietary habits at baseline were assessed using a validated semi-quantitative 136-item food-frequency questionnaire. Self-reported blood concentrations of total cholesterol, high-density lipoproteins cholesterol (HDL-c) and triglycerides were evaluated according to categories of egg consumption after 6 and 8 years of follow-up. We also assessed the association between baseline egg consumption and the incidence of hypercholesterolemia, low HDL-c concentrations and hypertriglyceridemia during follow-up. Results: We observed a significant inverse association for intermediate levels of egg consumption (2 to 4 eggs/week vs. less than 1 egg/week) and hypertriglyceridemia with OR = 0.71 (95% confidence interval [CI]: 0.54 to 0.93, p < 0.05) in the multivariable-adjusted model. Using HDL-c values after 8-year follow-up, we found an association between higher egg consumption and lower HDL-c levels (p for trend = 0.02) with an adjusted difference of –4.01 mg/dl (-7.42 to -0.61) for > 4 vs. < 1 egg/week. Lower means of triglycerides were found in each of the three upper categories of egg consumption compared to the lowest category (< 1 egg/week) with significant results for some of these categories both after 6 and 8 year follow-up. Conclusions: Our data do not support that higher egg consumption was associated with abnormal blood levels of total cholesterol or triglycerides; an inverse association with HDL-c as a quantitative variable was found only in one of our analyses.Introducción y objetivos: evaluar prospectivamente la asociación entre el consumo de huevo y el riesgo de dislipidemia en una cohorte mediterránea. Métodos: se siguieron 13.104 graduados universitarios españoles durante un periodo medio de 8 años. La dieta se evaluó al inicio utilizando un cuestionario semicuantitativo de frecuencia de consumo de alimentos repetidamente validado. Las concentraciones sanguíneas de colesterol total, lipoproteínas de alta densidad (HDL-c) y triglicéridos autorreferidas fueron evaluadas según categorías de consumo de huevo tras 6 y 8 años de seguimiento. También se evaluó la asociación entre el consumo basal de huevo y la incidencia de hipercolesterolemia, concentraciones bajas de HDL-c e hipertrigliceridemia durante el seguimiento. Resultados: se observó una asociación entre los niveles intermedios de consumo de huevo (2-4 unidades/semana frente a < 1 unidad/semana) y menor riesgo de hipertrigliceridemia con OR = 0,71 (intervalo de confianza del 95% [IC]: 0,54 a 0,93, p < 0,05) en el modelo más ajustado. Tras 8 años de seguimiento, encontramos una asociación entre un mayor consumo de huevo y menores niveles de HDL-c (p tendencia lineal = 0,02) con una diferencia ajustada de -4,01 mg/dl (-7,42 a -0,61) para > 4 vs. < 1 unidad/semana. Se encontraron menores concentraciones de triglicéridos en las tres categorías superiores de consumo de huevo en comparación con la inferior con resultados significativos para algunas de estas categorías después de 6 y 8 años de seguimiento. Conclusiones: un mayor consumo de huevo no se asoció con niveles anormales de colesterol total o triglicéridos; se encontró una asociación inversa con HDL-c como variable cuantitativa solo en uno de nuestros análisis

Surgical treatment for colorectal cancer: Analysis of the influence of an enhanced recovery programme on long-term oncological outcomes-a study protocol for a prospective, multicentre, observational cohort study

Introduction The evidence currently available from enhanced recovery after surgery (ERAS) programmes concerns their benefits in the immediate postoperative period, but there is still very little evidence as to whether their correct implementation benefits patients in the long term. The working hypothesis here is that, due to the lower response to surgical aggression and lower rates of postoperative complications, ERAS protocols can reduce colorectal cancer-related mortality. The main objective of this study is to analyse the impact of an ERAS programme for colorectal cancer on 5-year survival. As secondary objectives, we propose to analyse the weight of each of the predefined items in the oncological results as well as the quality of life. Methods and analysis A multicentre prospective cohort study was conducted in patients older than 18 years of age who are scheduled to undergo surgery for colorectal cancer. The study involved 12 hospitals with an implemented enhanced recovery protocol according to the guidelines published by the Spanish National Health Service. The intervention group includes patients with a minimum implementation level of 70%, and the control group includes those who fail to reach this level. Compliance will be studied using 18 key performance indicators, and the results will be analysed using cancer survival indicators, including overall survival, cancer-specific survival and relapse-free survival. The time to recurrence, perioperative morbidity and mortality, hospital stay and quality of life will also be studied, the latter using the validated EuroQol Five questionnaire. The propensity index method will be used to create comparable treatment and control groups, and a multivariate regression will be used to study each variable. The Kaplan-Meier estimator will be used to estimate survival and the log-rank test to make comparisons. A p value of less than 0.05 (two-tailed) will be considered to be significant. Ethics and dissemination Ethical approval for this study was obtained from the Aragon Ethical Committee (C.P.-C.I. PI20/086) on 4 March 2020. The findings of this study will be submitted to peer-reviewed journals (BMJ Open, JAMA Surgery, Annals of Surgery, British Journal of Surgery). Abstracts will be submitted to relevant national and international meetings. Trial registration number NCT04305314