3,429 research outputs found
Action-selection perseveration in young children:Advances of a dynamic model
This study presents an empirical test and dynamic model of perseverative limb selection in children of 14-, 24-, and 36-months old (N = 66 in total). In the experiment, children repeatedly grasped a spoon with a single hand. In two separate conditions, the spoon was presented either four times on their right side or four times on their left side. In both conditions, following this training, the spoon was presented on midline for two more trials. This setup enabled us to determine whether children's limb selection was influenced by their prior choices in the task (i.e., perseveration). Individual children's handedness was determined in a third condition consisting of nine object presentations (laterally or on midline). A dynamic model for limb selection is presented combining external input, motor memory, and preferences. The model was used to simulate the experiment and reproduced the results, including the age-related changes
Protodeboronation of Heteroaromatic, Vinyl, and Cyclopropyl Boronic Acids: pH-Rate Profiles, Autocatalysis, and Disproportionation
pH–rate profiles for aqueous–organic protodeboronation of 18 boronic acids, many widely viewed as unstable, have been studied by NMR and DFT. Rates were pH-dependent, and varied substantially between the boronic acids, with rate maxima that varied over 6 orders of magnitude. A mechanistic model containing five general pathways (k1–k5) has been developed, and together with input of [B]tot, KW, Ka, and KaH, the protodeboronation kinetics can be correlated as a function of pH (1–13) for all 18 species. Cyclopropyl and vinyl boronic acids undergo very slow protodeboronation, as do 3- and 4-pyridyl boronic acids (t0.5 > 1 week, pH 12, 70 °C). In contrast, 2-pyridyl and 5-thiazolyl boronic acids undergo rapid protodeboronation (t0.5 ≈ 25–50 s, pH 7, 70 °C), via fragmentation of zwitterionic intermediates. Lewis acid additives (e.g., Cu, Zn salts) can attenuate (2-pyridyl) or accelerate (5-thiazolyl and 5-pyrazolyl) fragmentation. Two additional processes compete when the boronic acid and the boronate are present in sufficient proportions (pH = pKa ± 1.6): (i) self-/autocatalysis and (ii) sequential disproportionations of boronic acid to borinic acid and borane
Costs of early detection systems for epidemic malaria in highland areas of Kenya and Uganda
BACKGROUND: Malaria epidemics cause substantial morbidity and mortality in highland areas of Africa. The costs of detecting and controlling these epidemics have not been explored adequately in the past. This study presents the costs of establishing and running an early detection system (EDS) for epidemic malaria in four districts in the highlands of Kenya and Uganda. METHODS: An economic costing was carried out from the health service provider's perspective in both countries. Staff time for data entry and processing, as well as supervising and coordinating EDS activities at district and national levels was recorded and associated opportunity costs estimated. A threshold analysis was carried out to determine the number of DALYs or deaths that would need to be averted in order for the EDS to be considered cost-effective. RESULTS: The total costs of the EDS per district per year ranged between US$ 14,439 and 15,512. Salaries were identified as major cost-drivers, although their relative contribution to overall costs varied by country. Costs of relaying surveillance data between facilities and district offices (typically by hand) were also substantial. Data from Uganda indicated that 4% or more of overall costs could potentially be saved by switching to data transfer via mobile phones. Based on commonly used thresholds, 96 DALYs in Uganda and 103 DALYs in Kenya would need to be averted annually in each district for the EDS to be considered cost-effective. CONCLUSION: Results from this analysis suggest that EDS are likely to be cost-effective. Further studies that include the costs and effects of the health systems' reaction prompted by EDS will need to be undertaken in order to obtain comprehensive cost-effectiveness estimates
Protocol for the 'e-Nudge trial' : a randomised controlled trial of electronic feedback to reduce the cardiovascular risk of individuals in general practice [ISRCTN64828380]
Background: Cardiovascular disease (including coronary heart disease and stroke) is a major
cause of death and disability in the United Kingdom, and is to a large extent preventable, by lifestyle
modification and drug therapy. The recent standardisation of electronic codes for cardiovascular
risk variables through the United Kingdom's new General Practice contract provides an
opportunity for the application of risk algorithms to identify high risk individuals. This randomised
controlled trial will test the benefits of an automated system of alert messages and practice
searches to identify those at highest risk of cardiovascular disease in primary care databases.
Design: Patients over 50 years old in practice databases will be randomised to the intervention
group that will receive the alert messages and searches, and a control group who will continue to
receive usual care. In addition to those at high estimated risk, potentially high risk patients will be
identified who have insufficient data to allow a risk estimate to be made. Further groups identified
will be those with possible undiagnosed diabetes, based either on elevated past recorded blood
glucose measurements, or an absence of recent blood glucose measurement in those with
established cardiovascular disease.
Outcome measures: The intervention will be applied for two years, and outcome data will be
collected for a further year. The primary outcome measure will be the annual rate of cardiovascular
events in the intervention and control arms of the study. Secondary measures include the
proportion of patients at high estimated cardiovascular risk, the proportion of patients with missing
data for a risk estimate, and the proportion with undefined diabetes status at the end of the trial
Goldstones in Diphotons
We study the conditions for a new scalar resonance to be observed first in
diphotons at the LHC Run-2. We focus on scenarios where the scalar arises
either from an internal or spacetime symmetry broken spontaneously, for which
the mass is naturally below the cutoff and the low-energy interactions are
fixed by the couplings to the broken currents, UV anomalies, and selection
rules. We discuss the recent excess in diphoton resonance searches observed by
ATLAS and CMS at 750 GeV, and explore its compatibility with other searches at
Run-1 and its interpretation as Goldstone bosons in supersymmetry and composite
Higgs models. We show that two candidates naturally emerge: a Goldstone boson
from an internal symmetry with electromagnetic anomalies, and the scalar
partner of the Goldstone of supersymmetry breaking: the sgoldstino. The dilaton
from conformal symmetry breaking is instead disfavoured by present data, in its
minimal natural realization.Comment: 18 pages + refs, 2 figures. v2: typos corrected, references added,
discussions extended and three new plots. Conclusion unchanged. v3: published
versio
Metabolomics and microbial composition increase insight into the impact of dietary differences in cirrhosis.
BACKGROUND & AIMS: Dietary changes can modulate gut microbiota and interact with cirrhosis. Our prior study demonstrated that microbial diversity was higher in Turkish versus USA cirrhotics, which was associated with lower risk of 90-day hospitalizations. We aimed to define gut microbial functional and metabolomic changes to increase insight into benefits of the Mediterranean compared to Western diets. METHODS: 139 Turkish (46 controls/50 compensated/43 decompensated) and 157 American subjects (48 controls/59 compensated/50 decompensated) were studied. Turkish subjects consumed a modified Mediterranean diet with daily fermented milk intake while Americans consumed a Western diet. Predicted gut microbial functionalities and plasma metabolomics were compared between/within countries. Correlation network differences between microbiota and metabolites in cirrhotics from Turkey versus USA were evaluated. RESULTS: Predicted microbial function showed lower amino acid, bioenergetics and lipid pathways, with functions related to vitamin B, glycan, xenobiotic metabolism, DNA/RNA synthesis, in Turkey compared to USA cirrhotics. Plasma metabolomics demonstrated higher relative lactate levels in Turkey versus USA. The metabolite changes in decompensated cirrhosis, compared to controls, showed similar trends in Turkey and USA, with reduced lipids and phosphocholines. Phosphocholines were significantly lower in patients hospitalized in 90 days (p=0.03). Correlation networks in cirrhotics demonstrated linkage differences between beneficial taxa, Blautia and Oscillispira, and lactate and unsaturated lipids, in Turkey compared to American patients. CONCLUSIONS: A modified Mediterranean diet was associated with altered plasma metabolomics and beneficially alters microbiota functionality and correlations compared to Western diet in cirrhosis. These altered diet-microbial interactions could potentially affect the 90-day hospitalization risk
Six-Month Mortality among HIV-Infected Adults Presenting for Antiretroviral Therapy with Unexplained Weight Loss, Chronic Fever or Chronic Diarrhea in Malawi.
In sub-Saharan Africa, early mortality is high following initiation of antiretroviral therapy (ART). We investigated 6-month outcomes and factors associated with mortality in HIV-infected adults being assessed for ART initiation and presenting with weight loss, chronic fever or diarrhea, and with negative TB sputum microscopy
Gender differences in the association between adiposity and probable major depression: a cross-sectional study of 140,564 UK Biobank participants
<b>Background</b><p></p>
Previous studies on the association between adiposity and mood disorder have produced contradictory results, and few have used measurements other than body mass index (BMI). We examined the association between probable major depression and several measurements of adiposity: BMI, waist circumference (WC), waist-hip-ratio (WHR), and body fat percentage (BF%).<p></p>
<b>Methods</b><p></p>
We conducted a cross-sectional study using baseline data on the sub-group of UK Biobank participants who were assessed for mood disorder. Multivariate logistic regression models were used, adjusting for potential confounders including: demographic and life-style factors, comorbidity and psychotropic medication.<p></p>
<b>Results</b><p></p>
Of the 140,564 eligible participants, evidence of probable major depression was reported by 30,145 (21.5%). The fully adjusted odds ratios (OR) for obese participants were 1.16 (95% confidence interval (CI) 1.12, 1.20) using BMI, 1.15 (95% CI 1.11, 1.19) using WC, 1.09 (95% CI 1.05, 1.13) using WHR and 1.18 (95% CI 1.12, 1.25) using BF% (all p <0.001). There was a significant interaction between adiposity and gender (p = 0.001). Overweight women were at increased risk of depression with a dose response relationship across the overweight (25.0-29.9 kg/m2), obese I (30.0-34.9 kg/m2), II (35.0-39.9 kg/m2) and III (≥40.0 kg/m2) categories; fully adjusted ORs 1.14, 1.20, 1.29 and 1.48, respectively (all p < 0.001). In contrast, only obese III men had significantly increased risk of depression (OR 1.29, 95% CI 1.08, 1.54, p = 0.006).<p></p>
<b>Conclusion</b><p></p>
Adiposity was associated with probable major depression, irrespective of the measurement used. The association was stronger in women than men. Physicians managing overweight and obese women should be alert to this increased risk
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