781 research outputs found
Electromagnetic corrections to light hadron masses
At the precision reached in current lattice QCD calculations, electromagnetic
effects are becoming numerically relevant. We will present preliminary results
for electromagnetic corrections to light hadron masses, based on simulations in
which a degree of freedom is superimposed on QCD
configurations from the BMW collaboration.Comment: 7 pages, 2 figures, The XXVIII International Symposium on Lattice
Field Theory, June 14-19,2010, Villasimius, Sardinia Ital
Global Programs: A New Vision in Agricultural Research
Issues in Agriculture no. 12 from the series "Issues in Agriculture" published by the CGIAR Secretariat
Experimental quantum tossing of a single coin
The cryptographic protocol of coin tossing consists of two parties, Alice and
Bob, that do not trust each other, but want to generate a random bit. If the
parties use a classical communication channel and have unlimited computational
resources, one of them can always cheat perfectly. Here we analyze in detail
how the performance of a quantum coin tossing experiment should be compared to
classical protocols, taking into account the inevitable experimental
imperfections. We then report an all-optical fiber experiment in which a single
coin is tossed whose randomness is higher than achievable by any classical
protocol and present some easily realisable cheating strategies by Alice and
Bob.Comment: 13 page
Urban agriculture: a global analysis of the space constraint to meet urban vegetable demand
Urban agriculture (UA) has been drawing a lot of attention recently for several reasons: the majority of the world population has shifted from living in rural to urban areas; the environmental impact of agriculture is a matter of rising concern; and food insecurity, especially the accessibility of food, remains a major challenge. UA has often been proposed as a solution to some of these issues, for example by producing food in places where population density is highest, reducing transportation costs, connecting people directly to food systems and using urban areas efficiently. However, to date no study has examined how much food could actually be produced in urban areas at the global scale. Here we use a simple approach, based on different global-scale datasets, to assess to what extent UA is constrained by the existing amount of urban space. Our results suggest that UA would require roughly one third of the total global urban area to meet the global vegetable consumption of urban dwellers. This estimate does not consider how much urban area may actually be suitable and available for UA, which likely varies substantially around the world and according to the type of UA performed. Further, this global average value masks variations of more than two orders of magnitude among individual countries. The variations in the space required across countries derive mostly from variations in urban population density, and much less from variations in yields or per capita consumption. Overall, the space required is regrettably the highest where UA is most needed, i.e., in more food insecure countries. We also show that smaller urban clusters (i.e., <100 km2 each) together represent about two thirds of the global urban extent; thus UA discourse and policies should not focus on large cities exclusively, but should also target smaller urban areas that offer the greatest potential in terms of physical space
Hidden charm molecules in finite volume
In the present paper we address the interaction of pairs of charmed mesons with hidden charm in a finite box. We use the interaction from a recent model based on heavy-quark spin symmetry that predicts molecules of hidden charm in the infinite volume. The energy levels in the box are generated within this model, and from them some synthetic data are generated. These data are then employed to study the inverse problem of getting the energies of the bound states and phase shifts for D (D) over bar or D*(D) over bar*. Different strategies are investigated using the lowest two levels for different values of the box size, and the errors produced are studied. Starting from the upper level, fits to the synthetic data are carried out to determine the scattering length and effective range plus the binding energy of the ground state. A similar strategy using the effective range formula is considered with a simultaneous fit to the two levels-one above and the other one below the threshold. This method turns out to be more efficient than the previous one. Finally, a method based on the fit to the data by means of a potential and a conveniently regularized loop function, turns out to be very efficient and allows us to produce accurate results in the infinite volume starting from levels of the box with errors far larger than the uncertainties obtained in the final results. A regularization method based on Gaussian wave functions turns out to be rather efficient in the analysis and as a byproduct a practical and fast method to calculate the Luscher function with high precision is presented
The Effect of Assistive Technology on the Writing Proficiency of Junior High Students with Significant Learning Needs
The purpose of the present study was twofold: to examine the impact of assistive technology (AT) on the writing proficiency of junior high students and to explore the utility of a writing assessment for students with significant learning needs. Writing skills included productivity, sentence complexity, word complexity, spelling, overall quality, and genre-specific skills (e.g., engage and orient reader, state an opinion). Participants were 10 students with a range of learning needs (Mild Cognitive Disability, Learning Disability, Communication Disability, Physical/Medical Disability) enrolled in Grades 5 to 7 within a segregated classroom. Four writing samples were collected from each participant: (1) unassisted narrative, (2) assisted narrative, (3) unassisted persuasive and (4) assisted persuasive, and coded using a writing assessment developed for this study. Results indicated that the use of AT lead to statistically significant improvements in spelling in persuasive and narrative genres, in narrative overall writing quality, and providing reasons in the persuasive genre. In general, students achieved higher proficiency in the narrative genre than in the persuasive genre. However, there was great variation in writing among the students, and only 50% demonstrated higher quality narrative writing with the use of AT. Two case analyses of student writing explored the extremes of writing variability and the utility of the writing assessment. Analyses revealed that, despite the modest gains realized with AT, the writing assessment allowed for a clear understanding of writing skill and demonstrated promising utility as a teacher friendly measure for targeting writing goals for students with significant learning needs. Discussion explores the importance of providing students with significant learning needs with AT that meets their writing needs and the provision of quality writing instruction across writing genres
STAAR: a randomised controlled trial of electronic adherence monitoring with reminder alarms and feedback to improve clinical outcomes for children with asthma
Background Suboptimal adherence to inhaled steroids
is common in children with asthma and is associated
with poor disease control, reduced quality of life and
even death. Previous studies using feedback of
electronically monitored adherence data have
demonstrated improved adherence, but have not
demonstrated a significant impact on clinical outcomes.
The aim of this study was to determine whether
introduction of this approach into routine practice would
result in improved clinical outcomes.
Methods Children with asthma aged 6–16 years were
randomised to the active intervention consisting of
electronic adherence monitoring with daily reminder
alarms together with feedback in the clinic regarding
their inhaled corticosteroid (ICS) use or to the usual care
arm with adherence monitoring alone. All children had
poorly controlled asthma at baseline, taking ICS and
long-acting β-agonists. Subjects were seen in routine
clinics every 3 months for 1 year. The primary outcome
was the Asthma Control Questionnaire (ACQ) score.
Secondary outcomes included adherence and markers of
asthma morbidity.
Results 77 of 90 children completed the study
(39 interventions, 38 controls). Adherence in the
intervention group was 70% vs 49% in the control
group (p≤0.001). There was no significant difference in
the change in ACQ, but children in the intervention
group required significantly fewer courses of oral
steroids (p=0.008) and fewer hospital admissions
(p≤0.001).
Conclusions The results indicate that electronic
adherence monitoring with feedback is likely to be of
significant benefit in the routine management of poorly
controlled asthmatic subjects
Gender differences in the associations between age trends of social media interaction and well-being among 10-15 year olds in the UK
Background Adolescents are among the highest consumers of social media while research has shown that their well-being decreases with age. The temporal relationship between social media interaction and well-being is not well established. The aim of this study was to examine whether the changes in social media interaction and two well-being measures are related across ages using parallel growth models. Methods Data come from five waves of the youth questionnaire, 10-15 years, of the Understanding Society, the UK Household Longitudinal Study (pooled n =9859). Social media interaction was assessed through daily frequency of chatting on social websites. Well-being was measured by happiness with six domains of life and the Strengths and Difficulties Questionnaire. Results Findings suggest gender differences in the relationship between interacting on social media and well-being. There were significant correlations between interacting on social media and well-being intercepts and between social media interaction and well-being slopes among females. Additionally higher social media interaction at age 10 was associated with declines in well-being thereafter for females, but not for males. Results were similar for both measures of well-being. Conclusions High levels of social media interaction in early adolescence have implications for well-being in later adolescence, particularly for females. The lack of an association among males suggests other factors might be associated with their reduction in well-being with age. These findings contribute to the debate on causality and may inform future policy and interventions
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Effect of telehealth on glycaemic control: analysis of patients with type 2 diabetes in the Whole Systems Demonstrator cluster randomised trial
Background: The Whole Systems Demonstrator was a large, pragmatic, cluster randomised trial that compared telehealth with usual care among 3,230 patients with long-term conditions in three areas of England. Telehealth involved the regular transmission of physiological information such as blood glucose to health professionals working remotely. We examined whether telehealth led to changes in glycosylated haemoglobin (HbA1c) among the subset of patients with type 2 diabetes.
Methods: The general practice electronic medical record was used as the source of information on HbA1c. Effects on HbA1c were assessed using a repeated measures model that included all HbA1c readings recorded during the 12-month trial period, and adjusted for differences in HbA1c readings recorded before recruitment. Secondary analysis averaged multiple HbA1c readings recorded for each individual during the trial period.
Results: 513 of the 3,230 participants were identified as having type 2 diabetes and thus were included in the study. Telehealth was associated with lower HbA1c than usual care during the trial period (difference 0.21% or 2.3 mmol/mol, 95% CI, 0.04% to 0.38%, p = 0.013). Among the 457 patients in the secondary analysis, mean HbA1c showed little change for controls following recruitment, but fell for intervention patients from 8.38% to 8.15% (68 to 66 mmol/mol). A higher proportion of intervention patients than controls had HbA1c below the 7.5% (58 mmol/mol) threshold that was targeted by general practices (30.4% vs. 38.0%). This difference, however, did not quite reach statistical significance (adjusted odds ratio 1.63, 95% CI, 0.99 to 2.68, p = 0.053).
Conclusions: Telehealth modestly improved glycaemic control in patients with type 2 diabetes over 12 months. The scale of the improvements is consistent with previous meta-analyses, but was relatively modest and seems unlikely to produce significant patient benefit
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