4,501 research outputs found
Cross-Cultural Content Validity of the Autism Program Environment Rating Scale in Sweden
Increasing rates of autism spectrum disorder (ASD) and younger age at diagnosis pose a challenge to preschool intervention systems. In Sweden, most young autistic children receive intervention service in community-based preschool programs, but no tool is yet available to assess the quality of the preschool learning environment. This study adapted the Autism Program Environment Rating Scale Preschool/Elementary to Swedish community context (APERS-P-SE). Following translation and a multistep modification process, independent experts rated the content validity of the adaptation. Findings indicate high cross-cultural validity of the adapted APERS-P-SE. The cultural adaption process of the APERS-P-SE highlights similarities and differences between the American and Swedish preschool systems and their impact on early ASD intervention
A Positive-Weight Next-to-Leading-Order Monte Carlo for Z Pair Hadroproduction
We present a first application of a previously published method for the
computation of QCD processes that is accurate at next-to-leading order, and
that can be interfaced consistently to standard shower Monte Carlo programs. We
have considered Z pair production in hadron-hadron collisions, a process whose
complexity is sufficient to test the general applicability of the method. We
have interfaced our result to the HERWIG and PYTHIA shower Monte Carlo
programs. Previous work on next-to-leading order corrections in a shower Monte
Carlo (the MC@NLO program) may involve the generation of events with negative
weights, that are avoided with the present method. We have compared our results
with those obtained with MC@NLO, and found remarkable consistency. Our method
can also be used as a standalone, alternative implementation of QCD
corrections, with the advantage of positivity, improved convergence, and
next-to-leading logarithmic accuracy in the region of small transverse momentum
of the radiated parton.Comment: 33 pages, 10 figure
Collision Dynamics and Solvation of Water Molecules in a Liquid Methanol Film
Environmental molecular beam experiments are used to examine water
interactions with liquid methanol films at temperatures from 170 K to 190 K. We
find that water molecules with 0.32 eV incident kinetic energy are efficiently
trapped by the liquid methanol. The scattering process is characterized by an
efficient loss of energy to surface modes with a minor component of the
incident beam that is inelastically scattered. Thermal desorption of water
molecules has a well characterized Arrhenius form with an activation energy of
0.47{\pm}0.11 eV and pre-exponential factor of 4.6 {\times} 10^(15{\pm}3)
s^(-1). We also observe a temperature dependent incorporation of incident water
into the methanol layer. The implication for fundamental studies and
environmental applications is that even an alcohol as simple as methanol can
exhibit complex and temperature dependent surfactant behavior.Comment: 8 pages, 5 figure
Is there a female protective effect against ADHD? Evidence from two representative twin samples
OBJECTIVE: Attention-deficit/hyperactivity disorder (ADHD) is more frequent in males than females. The ‘female protective effect’ posits that females undergo greater exposure to etiological factors than males in order to develop ADHD, leading to the prediction that relatives of females with ADHD will display more ADHD behaviors. We thus tested whether co-twins of females displaying extreme ADHD traits would display more ADHD traits than co-twins of males displaying extreme ADHD traits.
METHOD: Parents of approximately 7,000 pairs of non-identical twins in Sweden, and around 4,000 pairs of twins in England and Wales, completed dimensional assessments of ADHD traits. Probands were selected on the basis of scoring within the highest 10% of the distribution in each sample. Dimensional scores of co-twins of probands, as well as the categorical recurrence rate, were investigated by proband sex.
RESULTS: Co-twins of female probands displayed higher mean ADHD trait scores (x ̅=0.62-0.79) than co-twins of male probands (x ̅=0.38-0.55) in both samples. This trend was significant in the Swedish sample (p<.01) and when the two samples were merged into a single, larger sample (p<.001). When the samples were merged, there was also a significant association between proband sex and co-twin’s categorical status, with more co-twins of female probands also being probands than co-twins of male probands.
CONCLUSIONS: These findings support a female protective effect against ADHD behaviors, suggesting that females require greater exposure to genetic and environmental factors associated with ADHD in order to develop the condition
Color structure for soft gluon resummation - a general recipe
A strategy for calculating the color structure needed for soft gluon
resummation for processes with any number of colored partons is introduced
using a N_c --> infinity inspired basis. In this basis a general formalism can
be found at the same time as the calculations are simplified.
The advantages are illustrated by recalculating the soft anomalous dimension
matrix for the processes gg --> gg, q\qbar --> q \qbar g and q\qbar --> ggg.Comment: 16 page
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