788 research outputs found
The brain drain and the world distribution of income and population
This paper models the evolution of the world distribution of income and shows that
while the distribution of income per capita across economies in the world will be
stable in the long run, the world distribution of population may be divergent. The
paper then uses this model to analyze the impact of the current trend towards
predominantly skilled emigration from poor to rich countries on fertility, human
capital formation, and growth, in both the sending and receiving countries. It shows
that in the long run, brain drain migration patterns may increase world inequality as
relatively poor countries grow large in terms of population. In the short run
however, it is possible for world inequality to fall due to rises in GDP per capita in
large developing economies with low skilled emigration rates
The survival of large dimensional threshold contact processes
We study the threshold contact process on with
infection parameter . We show that the critical point
, defined as the threshold for survival starting from
every site occupied, vanishes as . This implies that the threshold
voter model on has a nondegenerate extremal invariant
measure, when is large.Comment: Published in at http://dx.doi.org/10.1214/08-AOP440 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Contact process under renewals I
Motivated by questions regarding long range percolation, we investigate a
non-Markovian analogue of the Harris contact process in : an
individual is attached to each site , and it can be
infected or healthy; the infection propagates to healthy neighbors just as in
the usual contact process, according to independent exponential times with a
fixed rate ; nevertheless, the possible recovery times for an
individual are given by the points of a renewal process with heavy tail; the
renewal processes are assumed to be independent for different sites. We show
that the resulting processes have a critical value equal to zero.Comment: 13 page
Copy number variation burden does not predict severity of neurodevelopmental phenotype in children with a sex chromosome trisomy
Sex chromosome trisomies (SCTs) (XXX, XXY, and XYY karyotypes) are associated with an elevated risk of neurodevelopmental disorders. The range of severity of the phenotype is substantial. We considered whether this variable outcome was related to the presence of copy number variants (CNVs)—stretches of duplicated or deleted DNA. A sample of 125 children with an SCT were compared with 181 children of normal karyotype who had been given the same assessments. First, we compared the groups on measures of overall CNV burden: number of CNVs, total span of CNVs, and likely functional impact (probability of loss‐of‐function intolerance, pLI, summed over CNVs). Differences between groups were small relative to within‐group variance and not statistically significant on overall test. Next, we considered whether a measure of general neurodevelopmental impairment was predicted by pLI summed score, SCT versus comparison group, or the interaction between them. There was a substantial effect of SCT/comparison status but the pLI score was not predictive of outcomes in either group. We conclude that variable presence of CNVs is not a likely explanation for the wide phenotypic variation in children with SCTs. We discuss methodological challenges of testing whether CNVs are implicated in causing neurodevelopmental problems
Complexity in eating disorders: A case for simple or complex formulation and treatment?
© British Association for Behavioural and Cognitive Psychotherapies 2017. Eating disorders are commonly regarded as complex psychiatric conditions, although this perception might be a product of the high levels of physical and psychological co-morbidity that are present in many such cases, rather than being about complexity in the eating disorder per se. This paper will consider the reasons that eating disorders are seen as complex, and whether or not that perceived complexity should be seen as a genuine reason to deviate from existing evidence-based cognitive behavioural therapy (CBT) protocols. Case examples will be used to illustrate how complex presentations can require clinicians to work skilfully with relatively simple formulations to achieve the best outcome, rather than using unnecessarily complex formulations and treatments. The importance of clear supervision is also stressed, as it can play a role in clinicians' perception of the need for a complex or simple formulation, it can support the clinician in developing a collaborative, focused and efficient formulation, and it can keep the clinician on track with an evidence-based CBT approach
Is \gamma-ray emission from novae affected by interference effects in the 18F(p,\alpha)15O reaction?
The 18F(p,\alpha)15O reaction rate is crucial for constraining model
predictions of the \gamma-ray observable radioisotope 18F produced in novae.
The determination of this rate is challenging due to particular features of the
level scheme of the compound nucleus, 19Ne, which result in interference
effects potentially playing a significant role. The dominant uncertainty in
this rate arises from interference between J\pi=3/2+ states near the proton
threshold (Sp = 6.411 MeV) and a broad J\pi=3/2+ state at 665 keV above
threshold. This unknown interference term results in up to a factor of 40
uncertainty in the astrophysical S-factor at nova temperatures. Here we report
a new measurement of states in this energy region using the 19F(3He,t)19Ne
reaction. In stark contrast with previous assumptions we find at least 3
resonances between the proton threshold and Ecm=50 keV, all with different
angular distributions. None of these are consistent with J\pi= 3/2+ angular
distributions. We find that the main uncertainty now arises from the unknown
proton-width of the 48 keV resonance, not from possible interference effects.
Hydrodynamic nova model calculations performed indicate that this unknown width
affects 18F production by at least a factor of two in the model considered.Comment: 5 pages, 4 figures. Accepted for publication in Phys. Rev. Let
The Extent and Coverage of Current Knowledge of Connected Health: Systematic Mapping Study
Background: This paper examines the development of the Connected Health research landscape with a view on providing a historical perspective on existing Connected Health research. Connected Health has become a rapidly growing research field as our healthcare system is facing pressured to become more proactive and patient centred. Objective: We aimed to identify the extent and coverage of the current body of knowledge in Connected Health. With this, we want to identify which topics have drawn the attention of Connected health researchers, and if there are gaps or interdisciplinary opportunities for further research. Methods: We used a systematic mapping study that combines scientific contributions from research on medicine, business, computer science and engineering. We analyse the papers with seven classification criteria, publication source, publication year, research types, empirical types, contribution types research topic and the condition studied in the paper. Results: Altogether, our search resulted in 208 papers which were analysed by a multidisciplinary group of researchers. Our results indicate a slow start for Connected Health research but a more recent steady upswing since 2013. The majority of papers proposed healthcare solutions (37%) or evaluated Connected Health approaches (23%). Case studies (28%) and experiments (26%) were the most popular forms of scientific validation employed. Diabetes, cancer, multiple sclerosis, and heart conditions are among the most prevalent conditions studied. Conclusions: We conclude that Connected Health research seems to be an established field of research, which has been growing strongly during the last five years. There seems to be more focus on technology driven research with a strong contribution from medicine, but business aspects of Connected health are not as much studied
Genetically altered AMPA-type glutamate receptor kinetics in interneurons disrupt long-range synchrony of gamma oscillation
Gamma oscillations synchronized between distant neuronal populations may be critical for binding together brain regions devoted to common processing tasks. Network modeling predicts that such synchrony depends in part on the fast time course of excitatory postsynaptic potentials (EPSPs) in interneurons, and that even moderate slowing of this time course will disrupt synchrony. We generated mice with slowed interneuron EPSPs by gene targeting, in which the gene encoding the 67-kDa form of glutamic acid decarboxylase (GAD67) was altered to drive expression of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor subunit GluR-B. GluR-B is a determinant of the relatively slow EPSPs in excitatory neurons and is normally expressed at low levels in γ-aminobutyric acid (GABA)ergic interneurons, but at high levels in the GAD-GluR-B mice. In both wild-type and GAD-GluR-B mice, tetanic stimuli evoked gamma oscillations that were indistinguishable in local field potential recordings. Remarkably, however, oscillation synchrony between spatially separated sites was severely disrupted in the mutant, in association with changes in interneuron firing patterns. The congruence between mouse and model suggests that the rapid time course of AMPA receptor-mediated EPSPs in interneurons might serve to allow gamma oscillations to synchronize over distance
Clinicians' concerns about delivering cognitive-behavioural therapy for eating disorders
Despite research supporting the effectiveness of evidence-based interventions in the treatment of eating disorders, those interventions are under-utilised in routine clinical practice, possibly due to clinicians' concerns about delivering the relevant techniques. This study examined what elements of therapy clinicians worry about when delivering cognitive-behavioural therapy (CBT) for the eating disorders, and what clinician variables are associated with such concerns. The participants were 113 clinicians who used individual CBT with eating disorder patients. They completed a novel measure of concerns about delivering elements of CBT, as well as demographic characteristics and a standardised measure of intolerance of uncertainty. Clinicians worried most about body image work and ending treatment, but least about delivering psychoeducation. Their concerns fell into four distinct factors. Older, more experienced clinicians worried less about delivering the CBT techniques, but those with greater levels of prospective and inhibitory anxiety worried more about specific factors in the CBT techniques. Clinicians' capacity to tolerate uncertainty might impair their delivery of evidence-based CBT, and merits consideration as a target in training and supervision of CBT clinicians
Does landscape-scale conservation management enhance the provision of ecosystem services?
Biodiversity conservation approaches are increasingly being implemented at the landscape-scale to support the maintenance
of metapopulations and metacommunities. However, the impact of such interventions on the provision of ecosystem services
is less well defined. Here we examine the potential impacts of landscape-scale conservation initiatives on ecosystem
services, through analysis of five case study areas in England and Wales. The provision of multiple ecosystem services was
projected according to current management plans and compared with a baseline scenario. Multicriteria analysis indicated
that in most cases landscape-scale approaches lead to an overall increase in service provision. Consistent increases were
projected in carbon storage, recreation and aesthetic value, as well as biodiversity value. However, most study areas
provided evidence of trade-offs, particularly between provisioning services and other types of service. Results differed
markedly between study areas, highlighting the importance of local context. These results suggest that landscape-scale
conservation approaches are likely to be effective in increasing ecosystem service provision, but also indicate that associated
costs can be significant, particularly in lowland areas
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