2,537 research outputs found
Scalar GW detection with a hollow spherical antenna
We study the response and cross sections for the absorption of GW energy in a
Jordan-Brans-Dicke theory by a resonant mass detector shaped as a hollow
sphere.Comment: latex file, 9 page
Sensitivity of spherical gravitational-wave detectors to a stochastic background of non-relativistic scalar radiation
We analyze the signal-to-noise ratio for a relic background of scalar
gravitational radiation composed of massive, non-relativistic particles,
interacting with the monopole mode of two resonant spherical detectors. We find
that the possible signal is enhanced with respect to the differential mode of
the interferometric detectors. This enhancement is due to: {\rm (a)} the
absence of the signal suppression, for non-relativistic scalars, with respect
to a background of massless particles, and {\rm (b)} for flat enough spectra, a
growth of the signal with the observation time faster than for a massless
stochastic background.Comment: four pages, late
Trait mindfulness at baseline predicts increases in telomerase activity over time
Introduction
Preliminary investigations of cross-sectional samples have linked trait mindfulness with measures related to the hypothalamic–pituitary–adrenal (HPA)-mediated stress response and to the inflammatory system, suggesting that this is one potential pathway linking mindfulness based interventions and health. However, no previous studies explored the association between the trait mindfulness construct and markers of cellular ageing.
Methods
In the current study we examined in a sample of healthy mothers (n = 92) of a child with Autism Spectrum Disorder (i.e. women showing high levels of chronic psychological stress) the prospective associations between a multidimensional scale of trait mindfulness, the Five Facet Mindfulness Questionnaire (FFMQ), and telomerase activity (TA), a marker of cellular ageing and telomere homeostasis. Participants’ trait mindfulness and TA were assessed at baseline as well as 9 and 18 month follow-up.
Results
Analysis showed that higher levels of baseline mindfulness on FFMQ observation and describe subscales were related to increase in TA from baseline to 9 month (r = 0.27, P = 0.03 and r = 0.24, P = .04, respectively). Additionally, the FFMQ Describe subscale was related to increase in TA from baseline to 18 month (r = .30, P = .02). Results are reported following covariate adjustment of age, BMI, ethnicity, and education.
Discussion
Our results showed that higher levels of baseline mindfulness are associated with higher increases in TA after 9 months and 18 months, with increased TA reportedly being associated with decreased oxidative damage, increased telomere length and overall more functional cellular physiology. These findings support a role of mindfulness-related interventions to increase general and mental health
Microdistribution of macroinvertebrates in a temporary pond of Central Italy: Taxonomic and functional analyses
Spatial distribution of physical and chemical variables and macroinvertebrate composition, structure and functional aspects were investigated in five microhabitats available (Ranunculus acquatilis+ Ranunculus sardous, Spirogyra sp., Juncus effusus, and unvegetated littoral sediments and central sediments) in a temporary pond near Rome during spring 2004. The central sediments were found to differ greatly from the other substrates. They were characterized by higher nutrient contents (total P, total N), organic matter and organic C, and silt and clay in the sediments, and lower dissolved oxygen content and lower pH in the water. Species richness and densities of total macrofauna showed the lowest values in central sediments and the highest ones in submerged macrophytes (Ranunculus spp.) and emergent vegetation (Juncus effusus). Oligochaeta Tubificidae, some Nematoda (Dorylaimus spp.), and Chironomidae Tanypodinae (Procladius sp. and Psectrotanypus varius) and Chironominae (Chironomus plumosus group) characterized the central sediments, whereas Ephemeroptera and most of the Odonata and Coleoptera species were commonly found in submerged macrophyte beds. Some species of Coleoptera and Hemiptera (Hygrobia hermanni, Helochares lividus, Berosus signaticollis and Gerris maculatus) were mainly found in the algal substratum, and some Nematoda species (Tobrilus spp. and Aporcelaimellus obtusicaudatus), Oligochaeta Enchytraeidae, young larvae of Sympetrum and Diptera Ceratopogonidae in littoral sediments. Juncus effusus appeared to be mainly colonized by Chironomidae Orthocladiinae (Psectrocladius sordidellus group and Cotynoneura scutellata) and Tanytarsini (Paratanytarsus sp.). Central sediments also favoured high abundances of collector-gatherers, burrowers and drought resistant forms with passive dispersal, whereas Ranunculus spp. hosted mainly scrapers, shredders, swimmers+divers and active dispersal forms without any resistant stages to desiccation. Juncus plants were mostly colonized by collector-filterers and by organisms capable of both active dispersal and surviving desiccation. Littoral sediments and algae showed similar functional organization and intermediate features between central sediments and submerged macrophyte beds. All these results demonstrate that microhabitat characteristics play a crucial role in selecting macroinvertebrate taxa according to their environmental requirement, feeding mechanism, movement and resistance to drought. Moreover, our study confirms the role of submerged and emergent vegetation in maintaining high biodiversity and suggests that all microhabitats should be considered to provide both an exhaustive collection of species for pond management and conservation and basic insights into the functioning of pond communities. (C) 2009 Elsevier GmbH. All rights reserved
Bosonic Helium droplets with cationic impurities: onset of electrostriction and snowball effects from quantum calculations
Variational MonteCarlo and Diffusion MonteCarlo calculations have been
carried out for cations like Li, Na and K as dopants of small
helium clusters over a range of cluster sizes up to about 12 solvent atoms. The
interaction has been modelled through a sum-of-potential picture that
disregards higher order effects beyond atom-atom and atom-ion contributions.
The latter were obtained from highly correlated ab-initio calculations over a
broad range of interatomic distances.
This study focuses on two of the most striking features of the microsolvation
in a quantum solvent of a cationic dopant: electrostriction and snowball
effects. They are here discussed in detail and in relation with the nanoscopic
properties of the interaction forces at play within a fully quantum picture of
the clusters features
Temperate climate - Innovative outputs nexus
Technological change is a vital human activity that interacts with geographic factors and environment. The purpose of the study here is to analyse the relationship between geo-climate zones of the globe and technological outputs in order to detect favourable areas that spur higher technological change and, as a consequence, human development. The main finding is that innovative outputs are higher in geographical areas with a temperate climate (latitudes). In fact, warm temperate climates are favourable environments for human societies that, by a long-run process of adaptation and learning, create platforms of institutions and communications systems, infrastructures, legal systems, economic governance and socio-economic networks that support inventions and diffusion of innovations. The linkages between observed facts show the vital geo-climate sources of fruitful patterns of the technological innovation and economic growth
Technology & environment : some possible damaging effects of technological change in advanced and opulent societies
An interesting problem is the analysis of effects of the predominant impact of technological change on the health of societies. This study considers technological change as the human activity that generates a huge impact on societies and causes environmental disorders affecting the health of population. In particular, technical innovations support the industrialisation and human development, which by a social change based on population growth, mass production and consumption, and resources depletion, engenders pollution and several environmental carcinogens. This study shows that a main effect of the critical impact of technological change on societies is the high cancer incidence of population living in industrialised areas of opulent and advanced countries. Vital empirical evidence and linkages between observed facts endeavour to explain the major relationships concerning the interactions among technology, ecosystems and the health of societies
Gravitational Wave Radiation from Compact Binary Systems in the Jordan-Brans-Dicke Theory
In this paper we analyze the signal emitted by a compact binary system in the Jordan-Brans-Dicke theory. We compute the scalar and tensor components of the power radiated by the source and study the scalar waveform. Eventually we consider the detectability of the scalar component of the radiation by interferometers and resonant-mass detectors
Gravitational-Wave Stochastic Background Detection with Resonant-Mass Detectors
In this paper we discuss how the standard optimal Wiener filter theory can be
applied, within a linear approximation, to the detection of an isotropic
stochastic gravitational-wave background with two or more detectors. We apply
then the method to the AURIGA-NAUTILUS pair of ultra low temperature bar
detectors, near to operate in coincidence in Italy, obtaining an estimate for
the sensitivity to the background spectral density of $\simeq 10^{-49}\
Hz^{-1}\simeq 8\times10^{-5}\times\rho_c\rho_c\simeq1.9 \times 10^{-26}\
kg/m^3\simeq 6
\times10^{-5}\times\rho_c\simeq 2\times10^{-5}\times
\rho_c\simeq 2 \times10^{-6}\rho_c$.Comment: 32 pages, postscript file, also available at
http://axln01.lnl.infn.it/reports/stoch.htm
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