327 research outputs found
Dynamics in Attention to Environmental Problems: Patterns in Four EU Member States
The politics and administration of institutional chang
Mesh inlay, mesh kit or native tissue repair for women having repeat anterior or posterior prolapse surgery: randomised controlled trial (PROSPECT)
Funding The project was funded by the National Institute for Health Research Health Technology Assessment Programme (Project Number 07/60/18). The Health Services Research Unit and the Health Economics Research Unit are funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. Acknowledgements The authors wish to thank the women who participated in the PROSPECT study. We also thank Margaret MacNeil for her secretarial support and data management; Dawn McRae and Lynda Constable for their trial management support; the programming team in CHaRT, led by Gladys McPherson; members of the Project Management Group for their ongoing advice and support of the study; and the staff at the recruitment sites who facilitated the recruitment, treatment and follow up of study participants.Peer reviewedPublisher PD
Self-diffusion of adatoms, dimers, and vacancies on Cu(100)
We use ab initio static relaxation methods and semi-empirical
molecular-dynamics simulations to investigate the energetics and dynamics of
the diffusion of adatoms, dimers, and vacancies on Cu(100). It is found that
the dynamical energy barriers for diffusion are well approximated by the
static, 0 K barriers and that prefactors do not depend sensitively on the
species undergoing diffusion. The ab initio barriers are observed to be
significantly lower when calculated within the generalized-gradient
approximation (GGA) rather than in the local-density approximation (LDA). Our
calculations predict that surface diffusion should proceed primarily via the
diffusion of vacancies. Adatoms are found to migrate most easily via a jump
mechanism. This is the case, also, of dimers, even though the corresponding
barrier is slightly larger than it is for adatoms. We observe, further, that
dimers diffuse more readily than they can dissociate. Our results are discussed
in the context of recent submonolayer growth experiments of Cu(100).Comment: Submitted to the Physical Review B; 15 pages including postscript
figures; see also http://www.centrcn.umontreal.ca/~lewi
Infant regulatory problems, parenting quality and childhood attention problems
Background and aims
To determine the combined impact of infant multiple/persistent regulatory problems (RPs), parenting quality and maternal mental health on childhood attention problems.
Study design
A prospective, population-based cohort study including 16 paediatric hospitals in Southern Bavaria (Germany).
Subjects
1459 infants were followed from birth to 8âŻyears of age.
Outcome measures
RPs were assessed at 5 and 20âŻmonths using interviews by trained paediatricians; parenting quality was assessed between birth and 5âŻmonths using parent interviews and nurses' observations; maternal mental health was assessed at birth and 5âŻmonths using standardized parents' interviews; childhood data on attention problems were collected at 8âŻyears, using parent reports and expert behaviour observation ratings.
Results
After correction for gestational age, sex, and socioeconomic status, early RPs (βâŻ=âŻ0.079) and low parenting quality (βâŻ=âŻ0.175) predicted later attention problems (R2âŻ=âŻ0.272). Their impact was additive, such that infants with both multiple/persistent RPs and poor parenting quality showed the highest attention problems 8âŻyears later. However, the impact of RPs on attention was strongest for preterm children. Maternal mental health was a significant moderator of the relationship between parenting quality and attention problems. With adequate maternal mental health, good parenting quality was related to lower attention problems, yet with mental health problems present, the effect of good parenting on attention problems diminished.
Conclusions
Guidance and support for parents of infants with multiple/persistent crying, sleeping or feeding problems may be essential to prevent the development of childhood attention problems, especially when maternal mental health problems are present
Mood and anxiety disorders in very preterm/very low-birth weight individuals from 6 to 26 years
Background
Very preterm (<32 weeksâ gestational age; VP) or very lowâbirth weight (<1,500 g; VLBW) birth has been associated with increased risk for anxiety and mood disorders and less partnering in adulthood. The aim was to test whether (a) VP/VLBW are at increased risk of any anxiety or mood disorders from 6 to 26 years compared with term-born individuals; (b) social support from romantic partners is associated with protection from anxiety and mood disorders; and (c) VP/VLBW adultsâ lower social support mediates their risk for any anxiety and mood disorders.
Methods
Data are from a prospective geographically defined longitudinal whole-population study in South Bavaria (Germany). Two hundred VP/VLBW and 197 term individuals were studied from birth to adulthood. Anxiety and mood disorders were assessed at 6, 8, and 26 years with standardized diagnostic interviews and social support via self-report at age 26.
Results
At age 6, VP/VLBW children were not at increased risk of any anxiety or mood disorder. At age 8, VP/VLBW more often had any anxiety disorder than term comparisons (11.8% vs. 6.6%, OR = 2.10, 95% CI [1.08â4.10]). VP/VLBW adults had an increased risk for any mood (27.5% vs. 18.8%, OR = 1.65 [1.02â2.67]) but not for any anxiety disorder (33.0% vs. 28.4%, OR = 1.27 [0.82â1.96]). None of the significant differences survived correction for multiple testing. Social support was associated with a lower risk of anxiety or mood disorders in both groups (OR = 0.81 [0.68â0.96]) and mediated the association of VP/VLBW birth with any anxiety or any mood disorders at age 26.
Conclusions
This study does not show a persistently increased risk for any anxiety or mood disorder after VP/VLBW birth. Low social support from a romantic partner mediates the risk for anxiety or mood disorders after VP/VLBW birth
Island nucleation in the presence of step edge barriers: Theory and applications
We develop a theory of nucleation on top of two-dimensional islands bordered
by steps with an additional energy barrier for descending atoms.
The theory is based on the concept of the residence time of an adatom on the
island,and yields an expression for the nucleation rate which becomes exact in
the limit of strong step edge barriers. This expression differs qualitatively
and quantitatively from that obtained using the conventional rate equation
approach to nucleation [J. Tersoff et al., Phys. Rev. Lett.72, 266 (1994)]. We
argue that rate equation theory fails because nucleation is dominated by the
rare instances when two atoms are present on the island simultaneously. The
theory is applied to two distinct problems: The onset of second layer
nucleation in submonolayer growth, and the distribution of the sizes of top
terraces of multilayer mounds under conditions of strong step edge barriers.
Application to homoepitaxial growth on Pt(111) yields the estimate eV for the additional energy barrier at CO-decorated steps.Comment: 13 pages, 3 figure
Early regulatory problems and parenting: life-long risk, vulnerability or susceptibility for attention, internalizing and externalizing outcomes?
Multiple or persistent crying, sleeping, or feeding problems in early childhood (regulatory problems, RPs) predict increased risk for self-regulation difficulties. Sensitive parenting may protect children from trajectories of dysregulation. Considering self-regulation from a life-course perspective, are children with early multiple and/or persistent RPs affected similarly by parenting as those without (main effects model, ME), or are they more vulnerable (diathesis-stress, DIA-S), or more susceptible (differential susceptibility theory, DST) to variations in sensitive parenting at age 6 years? Participants (Nâ=â302) were studied prospectively from birth to 28 years. RPs were assessed from 5 to 56 months. Sensitive parenting was observed at 6 years. Attention regulation was observed at 8 and 28 years. Internalizing and externalizing problems were rated by parents at 8 years, and by adults at 28 years. Confirmatory-comparative modelling tested whether associations of sensitive parenting with outcomes at 8 and 28 years among individuals with early multiple and/or persistent RPs (nâ=â74) versus those without (nâ=â228) were best explained by ME, DIA-S, or DST models. Best fitting models differed according to age at assessment. For childhood attention regulation, the statistically parsimonious DIA-S provided the best fit to the data. At age 28, two additive main effects (ME, RP group and sensitive parenting) fit best. DIA-S and ME explained internalizing and externalizing problems. Using a comprehensive life-span approach, DIA-S and ME models but not DST explained how early RPs and sensitive parenting predicted attention, internalizing, and externalizing outcomes. Individuals with early RPs are vulnerable to insensitive parenting
Decay of isolated surface features driven by the Gibbs-Thomson effect in analytic model and simulation
A theory based on the thermodynamic Gibbs-Thomson relation is presented which
provides the framework for understanding the time evolution of isolated
nanoscale features (i.e., islands and pits) on surfaces. Two limiting cases are
predicted, in which either diffusion or interface transfer is the limiting
process. These cases correspond to similar regimes considered in previous works
addressing the Ostwald ripening of ensembles of features. A third possible
limiting case is noted for the special geometry of "stacked" islands. In these
limiting cases, isolated features are predicted to decay in size with a power
law scaling in time: A is proportional to (t0-t)^n, where A is the area of the
feature, t0 is the time at which the feature disappears, and n=2/3 or 1. The
constant of proportionality is related to parameters describing both the
kinetic and equilibrium properties of the surface. A continuous time Monte
Carlo simulation is used to test the application of this theory to generic
surfaces with atomic scale features. A new method is described to obtain
macroscopic kinetic parameters describing interfaces in such simulations.
Simulation and analytic theory are compared directly, using measurements of the
simulation to determine the constants of the analytic theory. Agreement between
the two is very good over a range of surface parameters, suggesting that the
analytic theory properly captures the necessary physics. It is anticipated that
the simulation will be useful in modeling complex surface geometries often seen
in experiments on physical surfaces, for which application of the analytic
model is not straightforward.Comment: RevTeX (with .bbl file), 25 pages, 7 figures from 9 Postscript files
embedded using epsf. Submitted to Phys. Rev. B A few minor changes made on
9/24/9
Deep-water macroalgae from the Canary Islands: new records and biogeographical relationships
Due to the geographical location and paleobiogeography of the Canary Islands, the
seaweed flora contains macroalgae with different distributional patterns. In this contribution, the biogeographical relations of several new records of deep-water macroalgae recently collected around the Canarian archipelago are discussed. These are Bryopsidella neglecta (Berthotd) Rietema,Discosporangium mesarthrocarpum (Meneghini) Hauck, Hincksia onslowensis (Amsler et Kapraun)P.C. Silva, Syringoderma floridana Henry, Peyssonnelia harveyana J. Agardh, Cryptonemia seminervis(C. Agardh) J. Agardh, Botryodadia wynnei Ballantine, Gloiocladia blomquistii (Searles) R. E.Norris, PIahchrysis peltata (W. R. Taylor) P. Huv4 et H. Huv4, Leptofauchea brasiliensis Joly, and Sarcodiotheca divaricata W. R. Taylor. These new records, especially those in the Florideophyceae,support the strong affinity of the Canary Islands seaweed flora with the warm-temperate Mediterranean-Atlantic region. Some species are recorded for the first time from the east coast of the Atlantic Ocean, enhancing the biogeographic relations of the Canarian marine flora with that of the western Atlantic regions
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