895 research outputs found
The potential of low-intensity and online interventions for depression in low- and middle-income countries
The World Health Organization (WHO) reports that low- and middle-income countries (LMICs) are confronted with a serious âmental health gapâ, indicating an enormous disparity between the number of individuals in need of mental health care and the availability of professionals to provide such care (WHO in 2010). Traditional forms of mental health services (i.e. face-to-face, individualised assessments and interventions) are therefore not feasible. We propose three strategies for addressing this mental health gap: delivery of evidence-based, low-intensity interventions by non-specialists, the use of transdiagnostic treatment protocols, and strategic deployment of technology to facilitate access and uptake. We urge researchers from all over the world to conduct feasibility studies and randomised controlled studies on the effect of low-intensity interventions and technology supported (e.g. online) interventions in LMICs, preferably using an active control condition as comparison, to ensure we disseminate effective treatments in LMICs
Spectroscopic Analysis of H I Absorption Line Systems in 40 HIRES Quasars
We list and analyze H I absorption lines at redshifts 2 < z < 4 with column
density (12 < log(N_HI) < 19) in 40 high-resolutional (FWHM = 8.0 km/s) quasar
spectra obtained with the Keck+HIRES. We de-blend and fit all H I lines within
1,000 km/s of 86 strong H I lines whose column densities are log(N_HI/[cm^-2])
> 15. Unlike most prior studies, we use not only Lya but also all visible
higher Lyman series lines to improve the fitting accuracy. This reveals
components near to higher column density systems that can not be seen in Lya.
We list the Voigt profile fits to the 1339 H I components that we found. We
examined physical properties of H I lines after separating them into several
sub-samples according to their velocity separation from the quasars, their
redshift, column density and the S/N ratio of the spectrum. We found two
interesting trends for lines with 12 < log(N_HI) < 15 which are within 200-1000
km/s of systems with log(N_HI) > 15. First, their column density distribution
becomes steeper, meaning relatively fewer high column density lines, at z <
2.9. Second, their column density distribution also becomes steeper and their
line width becomes broader by about 2-3 km/s when they are within 5,000 km/s of
their quasar.Comment: 32 pages, 14 figures, accepted for publication in the Astronomical
Journal. A complete version with all tables and figures is available at
http://www.astro.psu.edu/users/misawa/pub/Paper/40hires.ps.g
A High Deuterium Abundance at z=0.7
Of the light elements, the primordial abundance of deuterium, (D/H)_p,
provides the most sensitive diagnostic for the cosmological mass density
parameter Omega_B. Recent high redshift (D/H) measurements are highly
discrepant, although this may reflect observational uncertainties. The larger
(D/H) values, which imply a low Omega_B and require the Universe to be
dominated by non-baryonic matter (dynamical studies indicate a higher total
density parameter), cause problems for galactic chemical evolution models since
they have difficulty in reproducing the large decline down to the lower
present-day (D/H). Conversely, low (D/H) values imply an Omega_B greater than
derived from ^7Li and ^4He abundance measurements, and may require a deuterium
abundance evolution that is too low to easily explain. Here we report the first
measurement at intermediate redshift, where the observational difficulties are
smaller, of a gas cloud with ideal characteristics for this experiment. Our
analysis of the z = 0.7010 absorber toward 1718+4807 indicates (D/H) = 2.0 +/-
0.5 x 10^{-4} which is in the high range. This and other independent
observations suggests there may be a cosmological inhomogeneity in (D/H)_p of
at least a factor of ten.Comment: 6 pages, 1 figur
Impact of microbial activity on the leaching of soluble N forms in soil
The hydrological transport of low-molecular weight organic nitrogen (LMWON) compounds has received little attention in the literature, particularly relative to inorganic nitrogen (N), with less attention given to the decoupling of the carbon (C) and N cycles following rainfall events. We determined the impacts of the soil biota on the transport of N compounds in a loam soil, using 15N and 13C to trace the vertical transport of 15N13C-urea, 15N13C-amino acids, 15NO3, and 15NH4 through the soil profile, following simulated rainfall events. This research has demonstrated that biotic assimilation leads to rapid decoupling of the C and N cycles during leaching, with C transport limited to the soil surface (<â2 cm), whereas N which was stored within the soil profile during a single rainfall event could be remobilised and leached (a further 2â6 cm) following an additional rainfall event
Low Mass Stars and the He3 Problem
The prediction of standard chemical evolution models of higher abundances of
He3 at the solar and present-day epochs than are observed indicates a possible
problem with the yield of He3 for stars in the range of 1-3 solar masses.
Because He3 is one of the nuclei produced in Big Bang Nucleosynthesis (BBN), it
is noted that galactic and stellar evolution uncertainties necessarily relax
constraints based on He3. We incorporate into chemical evolution models which
include outflow, the new yields for He3 of Boothroyd & Malaney (1995) which
predict that low mass stars are net destroyers of He3. Since these yields do
not account for the high \he3/H ratio observed in some planetary nebulae, we
also consider the possibility that some fraction of stars in the 1 - 3 solar
mass range do not destroy their He3 in theirpost main-sequence phase. We also
consider the possibility that the gas expelled by stars in these mass ranges
does not mix with the ISM instantaneously thus delaying the He3 produced in
these stars, according to standard yields, from reaching the ISM. In general,
we find that the Galactic D and He3 abundances can be fit regardless of whether
the primordial D/H value is high (2 x 10^{-4}) or low (2.5 x 10^{-5}).Comment: 20 pages, latex, 9 ps figure
Intergalactic UV Background Radiation Field
We have performed proximity effect analysis of low and high resolution data,
considering detailed frequency and redshift dependence of the AGN spectra
processed through galactic and intergalactic material. We show that such a
background flux, calculated using the observed distribution of AGNs, falls
short of the value required by the proximity effect analysis by a factor of
2.7. We have studied the uncertainty in the value of the required flux
due to its dependence on the resolution, description of column density
distribution, systemic redshifts of QSOs etc. We conclude that in view of these
uncertainties the proximity effect is consistent with the background
contributed by the observed AGNs and that the hypothesized presence of an
additional, dust extinct, population of AGNs may not be necessary.Comment: To be published in the Journal of Astronomy and Astrophysics aasms, 2
figures, 2 tables. Paper replaced to include the figure
Geometrical Effects of Baryon Density Inhomogeneities on Primordial Nucleosynthesis
We discuss effects of fluctuation geometry on primordial nucleosynthesis. For
the first time we consider condensed cylinder and cylindrical-shell fluctuation
geometries in addition to condensed spheres and spherical shells. We find that
a cylindrical shell geometry allows for an appreciably higher baryonic
contribution to be the closure density (\Omega_b h_{50}^2 \la 0.2) than that
allowed in spherical inhomogeneous or standard homogeneous big bang models.
This result, which is contrary to some other recent studies, is due to both
geometry and recently revised estimates of the uncertainties in the
observationally inferred primordial light-element abundances. We also find that
inhomogeneous primordial nucleosynthesis in the cylindrical shell geometry can
lead to significant Be and B production. In particular, a primordial beryllium
abundance as high as [Be] = 12 + log(Be/H) is possible while still
satisfying all of the light-element abundance constraints.Comment: Latex, 20 pages + 11 figures(not included). Entire ps file with
embedded figures available via anonymous ftp at
ftp://genova.mtk.nao.ac.jp/pub/prepri/bbgeomet.ps.g
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