A pilot search for mm-wavelength recombination lines from emerging ionized winds in pre-planetary nebulae candidates

We report the results from a pilot search for radio recombination line (RRL) emission at millimeter wavelengths in a small sample of pre-planetary nebulae (pPNe) and young PNe (yPNe) with emerging central ionized regions. Observations of the H30\alpha, H31a, H39a, H41a, H48b, H49b, H51b, and H55g lines at 1 and 3mm have been performed with the IRAM 30 m radio telescope. These lines are excellent probes of the dense inner (<~150 au) and heavily obscured regions of these objects, where the yet unknown agents for PN-shaping originate. We detected mm-RRLs in three objects: CRL 618, MWC 922, and M 2-9. For CRL 618, the only pPN with previous published detections of H41a, H35a, and H30a emission, we find significant changes in the line profiles indicating that current observations are probing regions of the ionized wind with larger expansion velocities and mass-loss rate than ~29 years ago. In the case of MWC 922, we observe a drastic transition from single-peaked profiles at 3mm to double-peaked profiles at 1mm, which is consistent with maser amplification of the highest frequency lines; the observed line profiles are compatible with rotation and expansion of the ionized gas, probably arranged in a disk+wind system around a ~5-10 Msun central mass. In M 2-9, the mm-RRL emission appears to be tracing a recent mass outburst by one of the stars of the central binary system. We present the results from non-LTE line and continuum radiative transfer models, which enables us to constrain the structure, kinematics, and physical conditions (electron temperature and density) of the ionized cores of our sample. (abridged). We deduce mass-loss rates of ~1e-6-1e-7 Msun/yr, which are significantly higher than the values adopted by stellar evolution models currently in use and would result in a transition from the asymptotic giant branch to the PN phase faster than hitherto assumed.Comment: Accepted by Astronomy and Astrophysics. 28 pages, including figure

Seasonal fluctuations of cosmopolitan inversion frequencies in a natural population of Drosophila melanogaster

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Bayesian analysis of a disability model for lung cancer survival

Bayesian reasoning, survival analysis and multi-state models are used to assess survival times for Stage IV non-small-cell lung cancer patients and the evolution of the disease over time. Bayesian estimation is done using minimum informative priors for the Weibull regression survival model, leading to an automatic inferential procedure. Markov chain Monte Carlo methods have been used for approximating posterior distributions and the Bayesian information criterion has been considered for covariate selection. In particular, the posterior distribution of the transition probabilities, resulting from the multi-state model, constitutes a very interesting tool which could be useful to help oncologists and patients make efficient and effective decisions.This study has been partially supported by the Ministerio de Ciencia e Innovación [grant number MTM2010- 19528], Mutua Madrileña [grant AP75942010], Ministero dell'Istruzione, dell'Universitá e della Ricerca of Italy and the visiting professor program of the Regione Autonoma della Sardegna

Fluxtube model atmospheres and Stokes V zero-crossing wavelengths

First results of the inversion of Stokes I and V profiles from plage regions near disk center are presented. Both low and high spatial resolution spectra of FeI 6301.5 and FeI 6302.5 A obtained with the Advanced Stokes Polarimeter (ASP) have been considered for analysis. The thin flux tube approximation, implemented in an LTE inversion code based on response functions, is used to describe unresolved magnetic elements. The code allows the simultaneous and consistent inference of all atmospheric quantities determining the radiative transfer with the sole assumption of hydrostatic equilibrium. By considering velocity gradients within the tubes we are able to match the full ASP Stokes profiles. The magnetic atmospheres derived from the inversion are characterized by the absence of significant motions in high layers and strong velocity gradients in deeper layers. These are essential to reproduce the asymmetries of the observed profiles. Our scenario predicts a shift of the Stokes V zero-crossing wavelengths which is indeed present in observations made with the Fourier Transform Spectrometer.Comment: To appear in ApJ Letters (1997) (in press

Twin studies of subjective sleep quality and sleep duration, and their behavioral correlates: Systematic review and meta-analysis of heritability estimates

Twin studies have shown that a substantial proportion of the variance for sleep variables is due to genetic factors. However, there is still considerable heterogeneity among research reports. Our main objectives were to: 1) Review the twin literature regarding sleep quality and duration, as well as their behavioural correlates; 2) Estimate the mean heritability of subjective sleep quality and sleep duration; 3) Assess heterogeneity among studies on these topics; and 4) Search for moderator variables. Two parallel meta-analyses were carried out for sleep quality and sleep duration. Seventeen articles were included in the meta-analysis. Mean MZ correlations were consistently higher than DZ correlations. A mean heritability of 0.31 (95% CI: 0.20, 0.41) was found for subjective sleep quality (range: 0-0.43) and 0.38 (95% CI: 0.16, 0.56) for sleep duration (range: 0-1). Heterogeneity indexes were significant for both sleep quality (I2 = 98.77, p < .001) and sleep duration (I2 = 99.73, p < .001). The high heterogeneity warrants further research considering possible moderators that may affect heritability

CHK1 expression in gastric cancer is modulated by p53 and RB1/E2F1: Implications in chemo/radiotherapy response

Radiation has a limited but relevant role in the adjuvant therapy of gastric cancer (GC) patients. Since Chk1 plays a critical function in cellular response to genotoxic agents, we aimed to analyze the role of Chk1 in GC as a biomarker for radiotherapy resistance. We analyzed Chk1 expression in AGS and MKN45 human GC cell lines by RT-QPCR and WB and in a small cohort of human patient’s samples. We demonstrated that Chk1 overexpression specifically increases resistance to radiation in GC cells. Accordingly, abrogation of Chk1 activity with UCN-01 and its expression with shChk1 increased sensitivity to bleomycin and radiation. Furthermore, when we assessed Chk1 expression in human samples, we found a correlation between nuclear Chk1 accumulation and a decrease in progression free survival. Moreover, using a luciferase assay we found that Chk1’s expression is controlled by p53 and RB/E2F1 at the transcriptional level. Additionally, we present preliminary data suggesting a posttranscriptional regulation mechanism, involving miR-195 and miR-503, which are inversely correlated with expression of Chk1 in radioresistant cells. In conclusion, Chk1/microRNA axis is involved in resistance to radiation in GC, and suggests Chk1 as a potential tool for optimal stratification of patients susceptible to receive adjuvant radiotherapy after surgeryThis work was supported by Instituto de Salud Carlos III–Fondo de Investigación Sanitaria (PS09/1988 to ISP; PI11-00949, pI014-1495 and Feder Funds to RP); Comunidad Autónoma de Madrid-Universidad Autónoma de Madrid (CCG10-UAM/BIO-5871 to ISP); Fundación Leticia Castillejo Castillo and Ministerio de Ciencia e Innovación (SAF2012-30862 to RSP), Spain

Keeping it organ-ized: multicompartment constructs to mimic tissue heterogeneity

Tissue engineering aims at replicating tissues and organs to develop applications in vivo and in vitro. In vivo, by engineering artificial constructs using functional materials and cells to provide both physiological form and function. In vitro, by engineering 3D models to support drug discovery and enable understanding of fundamental biology. 3D culture constructs mimic cell-cell and cell-matrix interactions and use biomaterials seeking to increase the resemblance of engineered tissues with its in vivo homologues. Native tissues, however, include complex architectures, with compartmentalized regions of different properties containing different types of cells that can be captured by multicompartment constructs. Recent advances in fabrication technologies, such as micropatterning, microfluidics or 3D bioprinting, have enabled compartmentalized structures with defined compositions and properties that are essential in creating 3D cell-laden multiphasic complex architectures. This review focuses on advances in engineered multicompartment constructs that mimic tissue heterogeneity. It included multiphasic 3D implantable scaffolds and in vitro models, including systems that incorporate different regions emulating in vivo tissues, highlighting the emergence and relevance of 3D bioprinting in the future of biological research and medicine