3,438 research outputs found
The association between family and community social capital and health risk behaviours in young people: an integrative review
Background:
Health risk behaviours known to result in poorer outcomes in adulthood are generally established in late childhood and adolescence. These ‘risky’ behaviours include smoking, alcohol and illicit drug use and sexual risk taking. While the role of social capital in the establishment of health risk behaviours in young people has been explored, to date, no attempt has been made to consolidate the evidence in the form of a review. Thus, this integrative review was undertaken to identify and synthesise research findings on the role and impact of family and community social capital on health risk behaviours in young people and provide a consolidated evidence base to inform multi-sectorial policy and practice.<p></p>
Methods:
Key electronic databases were searched (i.e. ASSIA, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, Embase, Medline, PsycINFO, Sociological Abstracts) for relevant studies and this was complemented by hand searching. Inclusion/exclusion criteria were applied and data was extracted from the included studies. Heterogeneity in study design and the outcomes assessed precluded meta-analysis/meta-synthesis; the results are therefore presented in narrative form.<p></p>
Results:
Thirty-four papers satisfied the review inclusion criteria; most were cross-sectional surveys. The majority of the studies were conducted in North America (n=25), with three being conducted in the UK. Sample sizes ranged from 61 to 98,340. The synthesised evidence demonstrates that social capital is an important construct for understanding the establishment of health risk behaviours in young people. The different elements of family and community social capital varied in terms of their saliency within each behavioural domain, with positive parent–child relations, parental monitoring, religiosity and school quality being particularly important in reducing risk.<p></p>
Conclusions:
This review is the first to systematically synthesise research findings about the association between social capital and health risk behaviours in young people. While providing evidence that may inform the development of interventions framed around social capital, the review also highlights key areas where further research is required to provide a fuller account of the nature and role of social capital in influencing the uptake of health risk behaviours.<p></p>
COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses VIII. Deconvolution of high resolution near-IR images and simple mass models for 7 gravitationally lensed quasars
We apply the iterative MCS deconvolution method (ISMCS) to near-IR HST
archives data of seven gravitationally lensed quasars currently monitored by
the COSMOGRAIL collaboration: HE 0047-1756, RX J1131-1231, SDSS J1138+0314,
SDSS J1155+6346, SDSS J1226-0006, WFI J2026-4536 and HS 2209+1914. In doing so,
we obtain relative positions for the lensed images and shape parameters for the
light distribution of the lensing galaxy in each system. The lensed image
positions are derived with 1-2 mas accuracy. To predict time delays and to test
the ability of simple mass models to reproduce the observed configuration,
isothermal and de Vaucouleurs mass models are calculated for the whole sample
using state-of-the-art modeling techniques. The effect of the lens environment
on the lens mass models is taken into account with a shear term. Doubly imaged
quasars are equally well fitted by each of these models. A large amount of
shear is necessary to reproduce SDSS J1155+6346 and SDSS J1226-006. In the
latter case, we identify a nearby galaxy as the dominant source of shear. The
quadruply imaged quasar SDSS J1138+0314 is well reproduced by simple lens
models, which is not the case for the two other quads, RX J1131-1231 and WFI
J2026-4536. This might be the signature of astrometric perturbations due to
massive substructures in the lensing galaxy unaccounted for by the models.
Other possible explanations are also presented.Comment: 14 pages, 1 figure (with 28 frames), 5 tables, accepted for
publication in Astronomy & Astrophysics (08/07/2010
One needs positive signatures for detection of Dark Matter
One believes there is huge amount of Dark Matter particles in our Galaxy
which manifest themselves only gravitationally. There is a big challenge to
prove their existence in a laboratory experiment. To this end it is not
sufficient to fight only for the best exclusion curve, one has to see an annual
recoil spectrum modulation --- the only available positive direct dark matter
detection signature. A necessity to measure the recoil spectra is stressed.Comment: 16 pages, 1 figure. arXiv admin note: substantial Appendix text
overlap with arXiv:0806.3917; missed acknowledge is added onl
The VLT-FLAMES Tarantula Survey I: Introduction and observational overview
The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has
obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30
Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our
scientific motivations and give an overview of the survey targets, including
optical and near-infrared photometry and comprehensive details of the data
reduction. One of the principal objectives was to detect massive binary systems
via variations in their radial velocities, thus shaping the multi-epoch
observing strategy. Spectral classifications are given for the massive
emission-line stars observed by the survey, including the discovery of a new
Wolf-Rayet star (VFTS 682, classified as WN5h), 2' to the northeast of R136. To
illustrate the diversity of objects encompassed by the survey, we investigate
the spectral properties of sixteen targets identified by Gruendl & Chu from
Spitzer photometry as candidate young stellar objects or stars with notable
mid-infrared excesses. Detailed spectral classification and quantitative
analysis of the O- and B-type stars in the VFTS sample, paying particular
attention to the effects of rotational mixing and binarity, will be presented
in a series of future articles to address fundamental questions in both stellar
and cluster evolution.Comment: Accepted by A&A, 52 pages (main body: 19 pages, supplementary tables:
33 pages), v3: two classifications updated to match a parallel pape
A coupled channel analysis of the centrally produced K+K- and pi+pi- final states in pp interactions at 450 GeV/c
A coupled channel analysis of the centrally produced K+K- and pi+pi- final
states has been performed in pp collisions at an incident beam momentum of 450
GeV/c. The pole positions and branching ratios to pipi and KK of the f0(980),
f0(1370), f0(1500) and f0(1710) have been determined. A systematic study of the
production properties of all the resonances observed in the pi+pi- and K+K-
channels has been performed.Comment: 16 pages, Latex, 5 Figure
Beings in their own right? Exploring Children and young people's sibling and twin relationships in the Minority World
This paper examines the contributions that the sociological study of sibship and twinship in the Minority World can make to childhood studies. It argues that, in providing one forum within which to explore children and young people's social relationships, we can add to our understanding of children and young people's interdependence and develop a more nuanced understanding of agency. As emergent subjects, children, young people and adults are in a process of ‘becoming’. However, this does not mean that they can ‘become’ anything they choose to. The notion of negotiated interdependence (Punch 2002) is useful in helping us to grasp the contingent nature of children and young people's agency
Substructure revealed by RR Lyraes in SDSS Stripe 82
We present an analysis of the substructure revealed by 407 RR Lyraes in Sloan
Digital Sky Survey (SDSS) Stripe 82. Period estimates are determined to high
accuracy using a string-length method. A subset of 178 RR Lyraes with
spectrally derived metallicities are employed to derive
metallicity-period-amplitude relations, which are then used to find
metallicities and distances for the entire sample. The RR Lyraes lie between 5
and 115 kpc from the Galactic center. They are divided into subsets of 316 RRab
types and 91 RRc types based on their period, colour and metallicity. The
density distribution is not smooth, but dominated by clumps and substructure.
Samples of 55 and 237 RR Lyraes associated with the Sagittarius Stream and the
Hercules-Aquila Cloud respectively are identified. Hence, ~ 70 % of the RR
Lyraes in Stripe 82 belong to known substructure. There is a sharp break in the
density distribution at Galactocentric radii of 40 kpc, reflecting the fact
that the dominant substructure in Stripe 82 - the Hercules-Aquila Cloud and the
Sagittarius Stream - lies within 40 kpc. In fact, almost 60 % of all the RR
Lyraes in Stripe 82 are associated with the Hercules-Aquila Cloud alone, which
emphasises its pre-eminence. Additionally, evidence of a new and distant
substructure - the Pisces Overdensity - is found, consisting of 28 faint RR
Lyraes centered on Galactic coordinates (80 deg, -55 deg) and with distances of
~ 80 kpc. The total stellar mass in the Pisces Overdensity is ~10000 solar
masses and its metallicity is [Fe/H] ~ -1.5.Comment: 15 pages, submitted to MNRA
The Orbital Solution and Spectral Classification of the High-Mass X-Ray Binary IGR J01054-7253 in the Small Magellanic Cloud
We present X-ray and optical data on the Be/X-ray binary (BeXRB) pulsar IGR
J01054-7253 = SXP11.5 in the Small Magellanic Cloud (SMC). Rossi X-ray Timing
Explorer (RXTE) observations of this source in a large X-ray outburst reveal an
11.483 +/- 0.002s pulse period and show both the accretion driven spin-up of
the neutron star and the motion of the neutron star around the companion
through Doppler shifting of the spin period. Model fits to these data suggest
an orbital period of 36.3 +/- 0.4d and Pdot of (4.7 +/- 0.3) x 10^{-10}
ss^{-1}. We present an orbital solution for this system, making it one of the
best described BeXRB systems in the SMC. The observed pulse period, spin-up and
X-ray luminosity of SXP11.5 in this outburst are found to agree with the
predictions of neutron star accretion theory. Timing analysis of the long-term
optical light curve reveals a periodicity of 36.70 +/- 0.03d, in agreement with
the orbital period found from the model fit to the X-ray data. Using blue-end
spectroscopic observations we determine the spectral type of the counterpart to
be O9.5-B0 IV-V. This luminosity class is supported by the observed V-band
magnitude. Using optical and near-infrared photometry and spectroscopy, we
study the circumstellar environment of the counterpart in the months after the
X-ray outburst.Comment: 12 pages, 13 figures and 3 tables. This paper has been accepted for
publication in MNRA
On the structure of phase transition maps for three or more coexisting phases
This paper is partly based on a lecture delivered by the author at the ERC
workshop "Geometric Partial Differential Equations" held in Pisa in September
2012. What is presented here is an expanded version of that lecture.Comment: 23 pages, 6 figure
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