278 research outputs found
“Youth as accessories”:Stakeholder Perspectives on Youth Participation in Mental Health Policymaking [Part II]
PURPOSE: To elicit stakeholder perspectives on the findings from our scoping review on youth participation in mental health policymaking, we conducted a global consultation with young people and adults directly involved in mental health policymaking. METHOD: Forty-four stakeholders from 16 countries, including 15 young people, 9 policymakers and 20 facilitators of youth participation, took part in individual interviews and/or focus groups. They were asked about how the review findings contrasted with their own experiences in mental health policymaking. The transcribed data were thematically analyzed. RESULTS: All participants viewed lived experience as valuable in identifying policy gaps. Youth pointed out that children and youth with disabilities, diverse sexual orientations, and/or gender identities were often excluded, and spoke about feelings of being an “accessory”, illustrating a lack of power-sharing in a tokenized policymaking process. Adult participants’ accounts highlighted the challenges inherent in policymaking such as the need for political knowledge and institutional time constraints. A range of cultural, socio-economic, and political barriers to youth participation, that were often context-specific, were identified. CONCLUSIONS: The diverse perspectives of stakeholders extended the review results. Based on our findings, we recommend that adults and institutions: (1) recognize lived experience as expertise in shaping mental health policies; (2) include diverse groups; (3) reduce tokenistic relationships through the creation of safer spaces, adult feedback, co-production, and social accountability; and (4) adopt an intersectional approach to address cultural, socio-economic, and political barriers to participation. Methodologically, our work demonstrates why stakeholder consultations are an essential component of scoping reviews
Photodesorption of water ice: a molecular dynamics study
Absorption of ultraviolet radiation by water ice coating interstellar grains
can lead to dissociation and desorption of the ice molecules. These processes
are thought to be important in the gas-grain chemistry in molecular clouds and
protoplanetary disks, but very few quantitative studies exist. We compute the
photodesorption efficiencies of amorphous water ice and elucidate the
mechanisms by which desorption occurs. Classical molecular dynamics
calculations were performed for a compact amorphous ice surface at 10 K thought
to be representative of interstellar ice. Dissociation and desorption of H2O
molecules in the top six monolayers are considered following absorption into
the first excited electronic state with photons in the 1300-1500 Angstrom
range. The trajectories of the H and OH photofragments are followed until they
escape or become trapped in the ice. The probability for H2O desorption per
absorbed UV photon is 0.5-1% in the top three monolayers, then decreases to
0.03% in the next two monolayers, and is negligible deeper into the ice. The
main H2O removal mechanism in the top two monolayers is through separate
desorption of H and OH fragments. Removal of H2O molecules from the ice, either
as H2O itself or its products, has a total probability of 2-3% per absorbed UV
photon in the top two monolayers. In the third monolayer the probability is
about 1% and deeper into the ice the probability of photodesorption falling to
insignificant numbers. The probability of any removal of H2O per incident
photon is estimated to be 3.7x10^-4, with the probability for photodesorption
of intact H2O molecules being 1.4x10^-4 per incident photon. When no desorption
occurs, the H and OH products can travel up to 70 and 60 Angstroms inside or on
top of the surface during which they can react with other species.Comment: 12 pages, 10 figures, A&A, in pres
Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches
The LUX-ZEPLIN (LZ) experiment will search for dark matter particle
interactions with a detector containing a total of 10 tonnes of liquid xenon
within a double-vessel cryostat. The large mass and proximity of the cryostat
to the active detector volume demand the use of material with extremely low
intrinsic radioactivity. We report on the radioassay campaign conducted to
identify suitable metals, the determination of factors limiting radiopure
production, and the selection of titanium for construction of the LZ cryostat
and other detector components. This titanium has been measured with activities
of U~1.6~mBq/kg, U~0.09~mBq/kg,
Th~~mBq/kg, Th~~mBq/kg, K~0.54~mBq/kg, and Co~0.02~mBq/kg (68\% CL).
Such low intrinsic activities, which are some of the lowest ever reported for
titanium, enable its use for future dark matter and other rare event searches.
Monte Carlo simulations have been performed to assess the expected background
contribution from the LZ cryostat with this radioactivity. In 1,000 days of
WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute
only a mean background of (stat)(sys) counts.Comment: 13 pages, 3 figures, accepted for publication in Astroparticle
Physic
Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA
The multiplicity structure of the hadronic system X produced in
deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic
system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY
vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant
mass M_X of the system X. Results are presented on multiplicity distributions
and multiplicity moments, rapidity spectra and forward-backward correlations in
the centre-of-mass system of X. The data are compared to results in e+e-
annihilation, fixed-target lepton-nucleon collisions, hadro-produced
diffractive final states and to non-diffractive hadron-hadron collisions. The
comparison suggests a production mechanism of virtual photon dissociation which
involves a mixture of partonic states and a significant gluon content. The data
are well described by a model, based on a QCD-Regge analysis of the diffractive
structure function, which assumes a large hard gluonic component of the
colourless exchange at low Q^2. A model with soft colour interactions is also
successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first
submission - omitted bibliograph
Differential (2+1) Jet Event Rates and Determination of alpha_s in Deep Inelastic Scattering at HERA
Events with a (2+1) jet topology in deep-inelastic scattering at HERA are
studied in the kinematic range 200 < Q^2< 10,000 GeV^2. The rate of (2+1) jet
events has been determined with the modified JADE jet algorithm as a function
of the jet resolution parameter and is compared with the predictions of Monte
Carlo models. In addition, the event rate is corrected for both hadronization
and detector effects and is compared with next-to-leading order QCD
calculations. A value of the strong coupling constant of alpha_s(M_Z^2)=
0.118+- 0.002 (stat.)^(+0.007)_(-0.008) (syst.)^(+0.007)_(-0.006) (theory) is
extracted. The systematic error includes uncertainties in the calorimeter
energy calibration, in the description of the data by current Monte Carlo
models, and in the knowledge of the parton densities. The theoretical error is
dominated by the renormalization scale ambiguity.Comment: 25 pages, 6 figures, 3 tables, submitted to Eur. Phys.
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