445 research outputs found
Renormalization group analysis of the three-dimensional Gross-Neveu model at finite temperature and density
The Renormalization Group flow equations obtained by means of a proper time
regulator are used to analyze the restoration of the discrete chiral symmetry
at non-zero density and temperature in the Gross-Neveu model in d=2+1
dimensions. The effects of the wave function renormalization of the auxiliary
scalar field on the transition have been studied. The analysis is performed for
a number of fermion flavors N_f=12 and the limit of large N_f is also
considered. The results are compared with those coming from lattice
simulations.Comment: Latex file, 12 pages, 2 eps figures, minor changes, added references,
published versio
Extended radio emission in BL Lac objects - I: the images
We have observed 28 sources selected from the 1Jy sample of BL Lac objects
(Stickel et al. 1991) with the Very Large Array (VLA) in A, B and D
configurations at 1.36, 1.66 and 4.85 GHz, and/or with the Westerbork Synthesis
Radio Telescope (WSRT) at 1.40 GHz. In this paper we present high sensitivity
images at arcsecond resolution of the 18 objects showing extended structure in
our images, and of another source from the FIRST (Faint Images of the Radio Sky
at Twenty-cm) survey (Becker et al. 1995). In general our high sensitivity
images reveal an amount of extended emission larger than previously reported.
In some objects the luminosity of the extended structure is comparable with
that of FR~II radio sources. A future paper will be devoted to the
interpretation of these results.Comment: 12 pages, 35 figures, to appear on A&A Supp. Ser., postscript file
with figures included available at
http://www.ira.noto.cnr.it/staff/carlo/ds1030.ps.g
Motivations for volunteerism, satisfaction, and emotional exhaustion: The moderating effect of volunteers' age
This investigation aims to explore the moderating role of volunteers' age in the relation between motivations for volunteering and, respectively, satisfaction with volunteerism and emotional exhaustion. A longitudinal study was conducted with a sample of 241 Spanish healthcare volunteers. Results show that volunteers' age moderates the relations between social motivations and satisfaction, and social motivations and volunteers' emotional exhaustion, and also between growth motivations and satisfaction, and volunteers' emotional exhaustion. The relationships between security motivations and satisfaction and emotional exhaustion are not moderated by age. Our findings underline that, for younger volunteers, satisfaction decreases when social motives are high, rather than low, and, in the opposite, emotional exhaustion increases when growth motives are high, rather than low. For older volunteers, instead, the only significant effect concern satisfaction, which is higher when social motives are high, rather than low
Detection of Contact Binaries Using Sparse High Phase Angle Lightcurves
We show that candidate contact binary asteroids can be efficiently identified
from sparsely sampled photometry taken at phase angles >60deg. At high phase
angle, close/contact binary systems produce distinctive lightcurves that spend
most of the time at maximum or minimum (typically >1mag apart) brightness with
relatively fast transitions between the two. This means that a few (~5) sparse
observations will suffice to measure the large range of variation and identify
candidate contact binary systems. This finding can be used in the context of
all-sky surveys to constrain the fraction of contact binary near-Earth objects.
High phase angle lightcurve data can also reveal the absolute sense of the
spin.Comment: 4 pages, 4 figures, 1 table. Accepted for publication in ApJ
Are Botanical Biopesticides Safe for Bees (Hymenoptera, Apoidea)?
The recent global decline in insect populations is of particular concern for pollinators. Wild and managed bees (Hymenoptera, Apoidea) are of primary environmental and economic importance because of their role in pollinating cultivated and wild plants, and synthetic pesticides are among the major factors contributing to their decline. Botanical biopesticides may be a viable alternative to synthetic pesticides in plant defence due to their high selectivity and short environmental persistence. In recent years, scientific progress has been made to improve the development and effectiveness of these products. However, knowledge regarding their adverse effects on the environment and non-target species is still scarce, especially when compared to that of synthetic products. Here, we summarize the studies concerning the toxicity of botanical biopesticides on the different groups of social and solitary bees. We highlight the lethal and sublethal effects of these products on bees, the lack of a uniform protocol to assess the risks of biopesticides on pollinators, and the scarcity of studies on specific groups of bees, such as the large and diverse group of solitary bees. Results show that botanical biopesticides cause lethal effects and a large number of sublethal effects on bees. However, the toxicity is limited when comparing the effects of these compounds with those of synthetic compounds
SiPM and front-end electronics development for Cherenkov light detection
The Italian Institute of Nuclear Physics (INFN) is involved in the
development of a demonstrator for a SiPM-based camera for the Cherenkov
Telescope Array (CTA) experiment, with a pixel size of 66 mm. The
camera houses about two thousands electronics channels and is both light and
compact. In this framework, a R&D program for the development of SiPMs suitable
for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different
photosensors have been produced at Fondazione Bruno Kessler (FBK), with
different micro-cell dimensions and fill factors, in different geometrical
arrangements. At the same time, INFN is developing front-end electronics based
on the waveform sampling technique optimized for the new NUV SiPM. Measurements
on 11 mm, 33 mm, and 66 mm NUV SiPMs
coupled to the front-end electronics are presentedComment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Current Approaches, Typologies and Predictors of Deviant Work Behaviors: A Scoping Review of Reviews
This study provides a scoping review of the recent conceptual developments about the deviant work behavior and counterproductive work behavior constructs. It also examines the specific types of deviant work behavior that have been more consistently investigated in the last decade, and whether they cover the interpersonal or organizational type of deviant behavior. In addition, individual, group, and organizational predictors of deviant work behaviors are examined. A scoping review of reviews was conducted on Scopus and Web of Science databases and 54 studies published from 2010 to June 2021 were taken into account. Results show that more recent conceptualizations are based on well established models in the literature and consider the hierarchical structure of these two constructs. Recent reviews examine the relationships of deviant work behavior with job performance and ethical behavior constructs, the multilevel nature of deviant work behavior, and the consequences for the actor of the deviance. The specific types of deviant work behavior more frequently reviewed in the last decade are workplace abuse, incivility, ostracism, bullying and sexual harassment, and abusive and destructive leadership; this evidence suggests a much greater attention to interpersonal, rather than organizational, forms of deviant work behavior. Regarding antecedents, results show the continuing prevalence of personality factors antecedents. Limitations of the study and theoretical and practical implications for the field are also provided
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