72 research outputs found
The stellar spectroscopy laboratory and curriculum counselling for secondary-school students
The stellar spectroscopy laboratory is the flagship of a wide-ranging work of curriculum counselling fostered by the Dipartimento di Fisica of the UniversitĂ degli Studi di Milano and the high school âG. Pariniâ in Milan. In time,
valuable results were gained in setting up a new way of collaboration between the high school and university worlds and in spurring secondary-school students to embark in a scientific, and more specifically physical, career. The present work briefly discusses the contents of the laboratory, its didactical value, its role of curriculum
counselling and its effectiveness in directing students to take into consideration the physical sciences as a possible university choice
Reproductive success of a marine teleost was correlated with proactive and reactive stressâcoping styles
The present study investigated the relationship between reproductive success and stressâcoping styles in gilthead seabream Sparus aurata in captivity. To characterise stressâcoping styles, a total of 22 breeders were submitted to three different individualâbased tests, one groupâbased test and postâhandling glucocorticoid quantification. To assess spawning participation, a microsatellite analysis was performed on a total of 2698 larvae, which allowed each offspring to be assigned unambiguously to a single parental couple. Overall, S. aurata showed defined proactive and reactive behavioural traits. Proactive breeders exhibited higher levels of activity and risk taking and lower glucocorticoid blood levels than reactive breeders. The stressâcoping style traits were consistent over time and context (different tests). Breeders that contributed to a higher number of progeny exhibited proactive behaviours, while those showing low progeny contribution exhibited reactive behaviour. Therefore, breeders with a high proportion of progeny (> 20%) had significantly higher activity and risk taking and lower cortisol than breeders with low progeny contribution (< 20%). In addition, males were more proactive than females and males exhibited significantly higher activity, risk taking and lower cortisol than females. This study is the first to establish in S. aurata breeders: (a) a relationship between stressâcoping styles and spawning success; (b) a relationship between stressâcoping styles and gender; and (c) the existence of proactive and reactive traits at the adult stage.info:eu-repo/semantics/acceptedVersio
Mode identification in the high-amplitude {\delta} Scuti star V2367 Cyg
We report on a multi-site photometric campaign on the high-amplitude
Scuti star V2367 Cyg in order to determine the pulsation modes. We also used
high-dispersion spectroscopy to estimate the stellar parameters and projected
rotational velocity. Time series multicolour photometry was obtained during a
98-d interval from five different sites. These data were used together with
model atmospheres and non-adiabatic pulsation models to identify the spherical
harmonic degree of the three independent frequencies of highest amplitude as
well as the first two harmonics of the dominant mode. This was accomplished by
matching the observed relative light amplitudes and phases in different
wavebands with those computed by the models. In general, our results support
the assumed mode identifications in a previous analysis of Kepler data.Comment: 9 pages, 5 figures, 4 tables. Accepted for publication in MNRA
The APACHE survey hardware and software design: Tools for an automatic search of small-size transiting exoplanets
Small-size ground-based telescopes can effectively be used to look for transiting rocky planets around nearby low-mass M stars using the photometric transit method, as recently demonstrated for example by the MEarth project. Since 2008 at the Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA), we have been preparing for the long-term photometric survey APACHE, aimed at finding transiting small-size planets around thousands of nearby early and mid-M dwarfs. APACHE (A PAthway toward the Characterization of Habitable Earths) is designed to use an array of five dedicated and identical 40-cm Ritchey-Chretien telescopes and its observations started at the beginning of summer 2012. The main characteristics of the survey final set up and the preliminary results from the first weeks of observations will be discussed
New Variable Stars Discovered by the APACHE Survey. II. Results After the Second Observing Season
Routinely operating since July 2012, the APACHE survey has celebrated its
second birthday. While the main goal of the Project is the detection of
transiting planets around a large sample of bright, nearby M dwarfs in the
northern hemisphere, the APACHE large photometric database for hundreds of
different fields represents a relevant resource to search for and provide a
first characterization of new variable stars. We celebrate here the conclusion
of the second year of observations by reporting the discovery of 14 new
variables.Comment: 25 pages, accepted for publication on The Journal of the American
Association of Variable Star Observers (JAVVSO
Identification of genomic regions associated with total and progressive sperm motility in Italian Holstein bulls
Sperm motility is directly related to the ability of sperm to move through the female reproductive tract to reach the ovum. Sperm motility is a complex trait that is influenced by environmental and genetic factors and is associated with male fertility, oocyte penetration rate, and reproductive success of cattle. In this study we carried out a GWAS in Italian Holstein bulls to identify candidate regions and genes associated with variations in progressive and total motility (PM and TM, respectively). After quality control, the final data set consisted of 5,960 records from 949 bulls having semen collected in 10 artificial insemination stations and genotyped at 412,737 SNPs (call rate >95%; minor allele frequency >5%). (Co)variance components were estimated using single trait mixed models, and associations between SNPs and phenotypes were assessed using a genomic BLUP approach. Ten windows that explained the greatest percentage of genetic variance were located on Bos taurus autosomes 1, 2, 4, 6, 7, 23, and 26 for TM and Bos taurus autosomes 1, 2, 4, 6, 8, 16, 23, and 26 for PM. A total of 150 genes for TM and 72 genes for PM were identified within these genomic regions. Gene Ontology enrichment analyses identified significant Gene Ontology terms involved with energy homeostasis, membrane functions, sperm-egg interactions, protection against oxidative stress, olfactory receptors, and immune system. There was significant enrichment of quantitative trait loci for fertility, calving ease, immune response, feed intake, and carcass weight within the candidate windows. These results contribute to understanding the architecture of the genetic control of sperm motility and may aid in the development of strategies to identify subfertile bulls and improve reproductive success
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