A Novel Route to Calculate the Length Scale for the Glass Transition in Polymers

The occurrence of glass transition is believed to be associated to cooperative motion with a growing length scale with decreasing temperature. We provide a novel route to calculate the size of cooperatively rearranging regions CRR of glass-forming polymers combining the Adam-Gibbs theory of the glass transition with the self-concentration concept. To do so we explore the dynamics of glass-forming polymers in different environments. The material specific parameter $\alpha$ connecting the size of the CRR to the configurational entropy is obtained in this way. Thereby, the size of CRR can be precisely quantified in absolute values. This size results to be in the range 1 $\div$ 3 nm at the glass transition temperature depending on the glass-forming polymer

The Spin Glass Transition : Exponents and Dynamics

Numerical simulations on Ising Spin Glasses show that spin glass transitions do not obey the usual universality rules which hold at canonical second order transitions. On the other hand the dynamics at the approach to the transition appear to take up a universal form for all spin glasses. The implications for the fundamental physics of transitions in complex systems are addressed.Comment: 4 pages (Latex) with 3 figures (postscript), accepted for publication in Physica

A not so massive cluster hosting a very massive star

We present the first physical characterization of the young open cluster VVV CL041. We spectroscopically observed the cluster main-sequence stellar population and a very-massive star candidate: WR62-2. CMFGEN modeling to our near-infrared spectra indicates that WR62-2 is a very luminous (10$^{6.4\pm0.2} L_{\odot}$) and massive ($\sim80 M_{\odot}$) star.Comment: 1 page, 1 figure, to be published in the "International Workshop on Wolf-Rayet Stars conference proceedings" by Universit\"atsverlag Potsdam (editors: W.-R. Hamann, A. Sander, and H. Todt

New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

© 2017 The American Astronomical Society. All rights reserved.It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color-magnitude diagrams. We provide their coordinates as well as their near-IR color-magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color-magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A Ks < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color-magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.Peer reviewedFinal Accepted Versio

Open cluster candidates in the VVVX area: VVVX CL 076 and CL 077

We are reporting some basic parameters of two newly discovered clusters, VVVX CL 076 and CL 077, recently discovered in the galactic disk area covered by the VISTA Variables in the Via Lactea eXtended (VVVX) ESO Public Survey. The preliminary analysis shows that both clusters are young and relatively close to the Sun.Peer reviewedFinal Published versio

Epigenetics and lifestyle

The concept of 'lifestyle' includes different factors such as nutrition, behavior, stress, physical activity, working habits, smoking and alcohol consumption. Increasing evidence shows that environmental and lifestyle factors may influence epigenetic mechanisms, such as DNA methylation, histone acetylation and miRNA expression. It has been identified that several lifestyle factors such as diet, obesity, physical activity, tobacco smoking, alcohol consumption, environmental pollutants, psychological stress and working on night shifts might modify epigenetic patterns. Most of the studies conducted so far have been centered on DNA methylation, whereas only a few investigations have studied lifestyle factors in relation to histone modifications and miRNAs. This article reviews current evidence indicating that lifestyle factors might affect human health via epigenetic mechanisms

Adaptive changes in geranylgeranyl pyrophosphate synthase gene expression level under ethanol stress conditions in Oenococcus oeni.

Aims: The aim of this study was to investigate the effect of ethanol exposure on the expression level of geranylgeranyl pyrophosphate synthase gene involved in the metabolism of Oenococcus oeni to probe the mechanisms of ethanol tolerance correlated with adaptive changes. Methods and Results: The evaluation of ten potential internal control genes and the comparative study of their stability were performed to select the most stable internal controls for the normalization of expression data. The expression level analysis by qPCR and changes after exposure to ethanol stresses highlighted a significant increase in the presence of higher ethanol concentrations. Conclusions: The analysis of results suggest that O. oeni adjusts the expression of genes to adapt to stress conditions and the high expression level of ggpps would allow a flow of isoprenoid precursors towards the carotenoids and related pathways to stabilize bacterial cell membranes, improving the cell membrane disturbances and preventing cell death induced by ethanol. Significance and Impact of the Study: The involvement of ggpps gene in physiological changes of bacterial behaviour confirmed the exposure to stress requires the activation of defence mechanism to be more tolerant to adverse conditions. Improving the knowledge of stress tolerance and adaptation mechanisms of O. oeni is essential to enhance the efficiency of the malolactic starter in wine and to obtain the development of starters able to survive to direct inoculation with a large benefit for wine technology

Interacting adaptation constraints in the Caribbean highlight the importance of sustained adaptation finance

Adaptation to ever intensifying climate change is of paramount importance to reduce its impacts, in particular for those at the frontlines of climate change such as the Caribbean Small Island Developing States (SIDS). However, a range of constraints make it harder to plan and implement adaptation and thus hinder adaptation progress. Here, we provide an assessment on regional perceptions of adaptation constraints and avenues to overcome them based on a mixed-method approach, combining an online survey and semi-structured interviews with adaptation experts from Caribbean SIDS. We find that finance is the largest constraint being faced which closely interacts with information, human capacity and governance constraints throughout the entire adaptation process. Such interacting constraints can lead to vicious cycles profoundly hindering adaptation and therefore need to be addressed in parallel. Our results highlight how adaptation actors at the national level, in particular national governments, have a key role to play when overcoming constraints for the implementation of adaptation projects at the local level, alongside regional and international organisations.Peer Reviewe

New Galactic Star Clusters Discovered in the Disk Area of the VVVX Survey

The ‘VISTA Variables in the Vía Láctea eXtended (VVVX)’ ESO Public Survey is a near-infrared photometric sky survey that covers nearly 1700 deg2 towards the Galactic disc and bulge. It is well-suited to search for new open clusters, hidden behind dust and gas. The pipeline processed and calibrated KS-band tile images of 40 per cent of the disc area covered by VVVX was visually inspected for stellar overdensities. Then, we identified cluster candidates by examination of the composite JHKS colour images. The colour-magnitude diagrams of the cluster candidates are constructed. Whenever possible the Gaia DR2 parameters are used to calculate the mean proper motions, radial velocities, reddening and distances. We report the discovery of 120 new infrared clusters and stellar groups. Approximately half of them (47 per cent) are faint, compact, highly reddened, and they seem to be associated with other indicators of recent star formation, such as nearby Young Stellar Objects, Masers, H II regions or bubbles. The preliminary distance determinations allow us to trace the clusters up to 4.5 kpc, but most of the cluster candidates are centred at 2.2 kpc. The mean proper motions of the clusters show that in general they follow the disc motion of the Galaxy