Age spreads in clusters and associations: the lithium test

We report the evidence that several low-mass stars (<~0.4 Msun) of the Orion and Upper Scorpius clusters have lithium abundances well below the interstellar value. Due to time-dependent depletion, our result implies stellar ages greater than ~5 Myr, suggesting that star formation has been proceeding for a long time in these systems.Comment: to appear in IMF@50: The Initial Mass Function 50 years later, eds. E. Corbelli et al. (Kluwer Acad. Press), 2004, in pres

Response to “Comment on ‘Elasticity of flexible and semiflexible polymers with extensible bonds in the Gibbs and Helmholtz ensembles”’ [J. Chem. Phys. 138, 157101 (2013)]

No abstract: this is a "response" to a Comment

Monte Carlo simulations of single polymer force-extension relations

We present Monte Carlo simulations for studying the statistical mechanics of arbitrarily long single molecules under stretching. In many cases in which the thermodynamic limit is not satisfied, different statistical ensembles yield different macroscopic force-displacement curves. In this work we provide a description of the Monte Carlo simulations and discuss in details the assumptions adopted

NGC 3603 - a Local Template for Massive Young Clusters

We present a study of the star cluster associated with the massive Galactic HII region NGC3603 based on near-IR broad-- and narrowband observations taken with ISAAC/VLT under excellent seeing conditions (<0.4''). We discuss color-color diagrams and address the impact of the high UV flux on the disk evolution of the low-mass stars.Comment: 3 pages, 3 figures. To appear in the Proceedings of IAU Symposium 207 "Extragalactic Star Clusters", eds. E. Grebel, D. Geisler and D. Minitt

Study of BsB_{s} oscillations

This document contains two ALEPH Reports on three different analyses of $B_{s}$ oscillations, based on the statistics collected by the ALEPH experiment during 1991-1995. $B_{s}$ mesons are fully reconstructed in several hadronic decay channels, yielding a small sample of candidates with excellent decay length and momentum reconstruction. Semileptonic decays with a fully recontructed $D_{s}$ meson yield larger statistics with equally high $B_{s}$ purity, but somewhat degraded momentum resolution. Inclusive semileptonic decays of b hadrons yield the highest sensitivity to $B_{s}$ oscillations, due to the much higher statistics. The combination of the above three with the other ALEPH analyses gives a limit of $\Delta m_{s} > 10.7$ ps$^{-1}$ at 95% C.L. with a sensitivity equal to $13.1$ ps$^{-1}$

Kepler observations of A-F pre-main sequence stars in Upper Scorpius: Discovery of six new δ\delta~Scuti and one γ\gamma~Doradus stars

We present light curves and periodograms for 27 stars in the young Upper Scorpius association (age=$11 \pm 1$\,Myr) obtained with the Kepler spacecraft. This association is only the second stellar grouping to host several pulsating pre-main sequence (PMS) stars which have been observed from space. From an analysis of the periodograms, we identify six $\delta$~Scuti variables and one $\gamma$~Doradus star. These are most likely PMS stars or else very close to the zero-age main sequence. Four of the $\delta$~Scuti variables were observed in short-cadence mode, which allows us to resolve the entire frequency spectrum. For these four stars, we are able to infer some qualitative information concerning their ages. For the remaining two $\delta$~Scuti stars, only long-cadence data are available, which means that some of the frequencies are likely to be aliases. One of the stars appears to be a rotational variable in a hierarchical triple system. This is a particularly important object, as it allows the possibility of an accurate mass determination when radial velocity observations become available. We also report on new high-resolution echelle spectra obtained for some of the stars of our sample.Comment: 19 pages, 9 figures. Accepted for publication on MNRA

Plant Essential Oils as Biocides in Sustainable Strategies for the Conservation of Cultural Heritage

Biodeterioration is a complex network of interactions between macro/micro-biological systems and organic/inorganic substrates involving physical and chemical alterations, strictly related to their metabolic activities. Concerning microbial deterioration, finding a correct approach to counteract this process is often difficult, requiring an understanding of the kind of alterations and the use of methods that respect artwork and human and environmental health. Specific conservative and remedial methods are used for this aim. They comprise physical, mechanical, and chemical methods, as well as, frequently, synthetic chemical biocides, which have obvious limitations because of their toxicity to operators or because they contain polluting substances that persist in the natural environment. New and alternative research has strongly focused on strategies to replace the use of toxic methods with natural products that do not have undesired effects, as well as implementing safe, novel compounds. Several plants contain natural chemical compounds such as oils, phenols, flavonoids, alkaloids, coumarins, tannins, etc., commonly used as drugs, bioactive molecules, and nutrients. Essential oils extracted from plants can be the correct way to prevent the biodeterioration of cultural heritage in a safe manner. This review aims to summarize the latest research on the use of natural essential oils in restoration procedures for cultural heritage considering them sustainable means with respect to the environment and human health

Conservation of forest biodiversity in Sicily: contribution of the University of Palermo Germplasm Bank (Italy)

Germplasm Banks dedicated to the wild plants seeds conservation play a unique role in integrating the in situ conservation of endemic, rare or endangered plant species. One of the missions of the Seed Bank of the University of Palermo (HBP-Bank) is to support the conservation of biodiversity with particular attention to the spectrum of genetic diversity of plants belonging to Mediterranean habitat. Abies nebrodensis (Lojac.) Mattei is an relict species, consisted of 30 natural individuals, gathered in a small area of the Madonie Natural Park in Sicily (1500 -1600 m above s.l.), recorded on the checklist \u201cTOP 50 Mediterranean Island Plants\u201d. It is also one of eight conifers species critically endangered because of reproductive biology issues. A. nebrodensis species has been monitored in situ in order to evaluate the state of conservation of natural population and to implement the number of individuals. Its preservation has been integrated since 1994 with ex situ conservation of 83 accessions in the HBP-Bank in the long-term conservation conditions. The scientific strength of HBP germplasm collection is supported by the results of several studies on taxonomy, seed biology and genetic diversity. The embryonic loss observed into the seeds produced in natural environment can reduce the genetic variability of germplasm collection. This study, carried out on the A. nebrodensis population, demonstrates that a five-year planning is needed to collect enough seed to represent the genetic variability intra-population. This seed collection scheme can represent a useful tool to apply on other forest endangered species spread in Sicily and in the Mediterranean area