8,927 research outputs found
The mental health of children and adolescents: report on the second Australian child and adolescent survey of mental health and wellbeing
FOREWORD
This report provides compelling reading for everyone interested in the health and wellbeing of Australian children and adolescents. Based on a survey conducted in the homes of over 6,300 families with children and/or adolescents aged 4 to 17 years, the report presents a comprehensive picture of the mental health of young Australians. It documents the prevalence and type of mental health problems, the impact of those problems on families and young people themselves and the role of health and education services in providing assistance. While the primary sources of information were parents and carers, the survey also engaged directly with young people 11 years and older who completed their own survey. This information provides unique insights about aspects of their emotional lives and behaviour that are generally not visible to parents and carers
Dynamics of OH(2Pi)-He collisions in combined electric and magnetic fields
We use accurate quantum mechanical calculations to analyze the effects of
parallel electric and magnetic fields on collision dynamics of OH(2Pi)
molecules. It is demonstrated that spin relaxation in 3He-OH collisions at
temperatures below 0.01 K can be effectively suppressed by moderate electric
fields of order 10 kV/cm. We show that electric fields can be used to
manipulate Feshbach resonances in collisions of cold molecules. Our results can
be verified in experiments with OH molecules in Stark decelerated molecular
beams and electromagnetic traps.Comment: 20 pages, 5 figures, submitted to Faraday Discuss. 142: Cold and
Ultracold Molecule
Cold heteromolecular dipolar collisions
We present the first experimental observation of cold collisions between two
different species of neutral polar molecules, each prepared in a single
internal quantum state. Combining for the first time the techniques of Stark
deceleration, magnetic trapping, and cryogenic buffer gas cooling allows the
enhancement of molecular interaction time by 10. This has enabled an
absolute measurement of the total trap loss cross sections between OH and
ND at a mean collision energy of 3.6 cm (5 K). Due to the dipolar
interaction, the total cross section increases upon application of an external
polarizing electric field. Cross sections computed from \emph{ab initio}
potential energy surfaces are in excellent agreement with the measured value at
zero external electric field. The theory presented here represents the first
such analysis of collisions between a radical and a closed-shell
polyatomic molecule.Comment: 7 pages, 5 figure
Quantum nature of cyclotron harmonics in thermal spectra of neutron stars
Some isolated neutron stars show harmonically spaced absorption features in
their thermal soft X-ray spectra. The interpretation of the features as a
cyclotron line and its harmonics has been suggested, but the usual explanation
of the harmonics as caused by relativistic effects fails because the
relativistic corrections are extremely small in this case. We suggest that the
features correspond to the peaks in the energy dependence of the free-free
opacity in a quantizing magnetic field, known as quantum oscillations. The
peaks arise when the transitions to new Landau levels become allowed with
increasing the photon energy; they are strongly enhanced by the square-root
singularities in the phase-space density of quantum states in the case when the
free (non-quantized) motion is effectively one-dimensional. To explore
observable properties of these quantum oscillations, we calculate models of
hydrogen neutron star atmospheres with B \sim 10^{10} - 10^{11} G (i.e.,
electron cyclotron energy E_{c,e} = 0.1 - 1 keV) and T_{eff} = 1 - 3 MK. Such
conditions are thought to be typical for the so-called central compact objects
in supernova remnants, such as 1E 1207.4-5209 in PKS 1209-51/52. We show that
observable features at the electron cyclotron harmonics form at moderately
large values of the quantization parameter, b_{eff} = E_{c,e}/kT_{eff} = 0.5 -
20. The equivalent widths of the features can reach 100 - 200 eV; they grow
with increasing b_{eff} and are lower for higher harmonics.Comment: 6 pages; shortened, references updated; published in Ap
Key Components of Musical Discourse Analysis
Musical discourse analysis is an interdisciplinary study which is incomplete without consideration of relevant social, linguistic, psychological, visual, gestural, ritual, technical, historical and musicological aspects. In the framework of Critical Discourse Analysis, musical discourse can be interpreted as social practice: it refers to specific means of representing specific aspects of the social (musical) sphere. The article introduces a general view of contemporary musical discourse, and analyses genres from the point of ‘semiosis’, ‘social agents’, ‘social relations’, ‘social context’, and ‘text’. These components of musical discourse analysis, in their various aspects and combinations, should help thoroughly examine the context of contemporary musical art, and determine linguistic features specific to different genres of musical discourse
Two weight inequalities for maximal truncations of dyadic Calderón-Zygmund operators
"Vegeu el resum a l'inici del document del fitxer adjunt"
A characterization of two weight norm inequalities for maximal singular integrals
"Vegeu el resum a l'inici del document del fitxer adjunt"
Mechanism of active targeting in solid tumors with transferrin-containing gold nanoparticles
PEGylated gold nanoparticles are decorated with various amounts of human transferrin (Tf) to give a series of Tf-targeted particles with near-constant size and electrokinetic potential. The effects of Tf content on nanoparticle tumor targeting were investigated in mice bearing s.c. Neuro2A tumors. Quantitative biodistributions of the nanoparticles 24 h after i.v. tail-vein injections show that the nanoparticle accumulations in the tumors and other organs are independent of Tf. However, the nanoparticle localizations within a particular organ are influenced by the Tf content. In tumor tissue, the content of targeting ligands significantly influences the number of nanoparticles localized within the cancer cells. In liver tissue, high Tf content leads to small amounts of the nanoparticles residing in hepatocytes, whereas most nanoparticles remain in nonparenchymal cells. These results suggest that targeted nanoparticles can provide greater intracellular delivery of therapeutic agents to the cancer cells within solid tumors than their nontargeted analogs
Two weight inequalities for discrete positive operators
"Vegeu el resum a l'inici del document del fitxer adjunt"
- …