183 research outputs found
Recruitment of ethnic minority patients to a cardiac rehabilitation trial: The Birmingham Rehabilitation Uptake Maximisation (BRUM) study [ISRCTN72884263]
Background: Concerns have been raised about low participation rates of people from minority ethnic groups
in clinical trials. However, the evidence is unclear as many studies do not report the ethnicity of participants and
there is insufficient information about the reasons for ineligibility by ethnic group. Where there are data, there
remains the key question as to whether ethnic minorities more likely to be ineligible (e.g. due to language) or
decline to participate. We have addressed these questions in relation to the Birmingham Rehabilitation Uptake
Maximisation (BRUM) study, a randomized controlled trial (RCT) comparing a home-based with a hospital-based
cardiac rehabilitation programme in a multi-ethnic population in the UK.
Methods: Analysis of the ethnicity, age and sex of presenting and recruited subjects for a trial of cardiac
rehabilitation in the West-Midlands, UK.
Participants: 1997 patients presenting post-myocardial infarction, percutaneous transluminal coronary angioplasty
or coronary artery bypass graft surgery.
Data collected: exclusion rates, reasons for exclusion and reasons for declining to participate in the trial by ethnic
group.
Results: Significantly more patients of South Asian ethnicity were excluded (52% of 'South Asian' v 36% 'White
European' and 36% 'Other', p < 0.001). This difference in eligibility was primarily due to exclusion on the basis of
language (i.e. the inability to speak English or Punjabi). Of those eligible, similar proportions were recruited from
the different ethnic groups (white, South Asian and other). There was a marked difference in eligibility between
people of Indian, Pakistani or Bangladeshi origin
Dynamical Properties and Plasmon Dispersion of a Weakly Degenerate Correlated One-Component Plasma
Classical Molecular Dynamics (MD) simulations for a one-component plasma
(OCP) are presented. Quantum effects are included in the form of the Kelbg
potential. Results for the dynamical structure factor are compared with the
Vlasov and RPA (random phase approximation) theories. The influence of the
coupling parameter , degeneracy parameter and the form
of the pair interaction on the optical plasmon dispersion is investigated. An
improved analytical approximation for the dispersion of Langmuir waves is
presented.Comment: 23 pages, includes 7 ps/eps-figures and 2 table
Dynamic correlations of the Coulomb Luttinger liquid
The dynamic density response function, form-factor, and spectral function of
a Luttinger liquid with Coulomb electron-electron interaction are studied with
the emphasis on the short-range electron correlations. The Coulomb interaction
changes dramatically the density response function as compared to the case of
the short-ranged interaction. The form of the density response function is
smoothing with time, and the oscillatory structure appears. However, the
spectral functions remain qualitatively the same. The dynamic form-factor
contains the -peak in the long-wave region, corresponding to one-boson
excitations. Besides, the multi-boson-excitations band exists in the
wave-number region near to . The dynamic form-factor diverges at the
edges of this band, while the dielectric function goes to zero there, which
indicates the appearance of a soft mode. We develop a method to analyze the
asymptotics of the spectral functions near to the edges of the
multi-boson-excitations band.Comment: 11 pages, 3 figures, submitted to PR
Recommended from our members
Synthesis, structures, and reactivity of isomers of [RuCp*(1,4- (Me2N)2C6H4)]2
[RuCp*(1,3,5-R3C6H3)]2 {Cp* = η5-pentamethylcyclopentadienyl, R = Me, Et} have previously been found to be moderately air stable, yet highly reducing, with estimated D+/0.5D2 (where D2 and D+ represent the dimer and the corresponding monomeric cation, respectively) redox potentials of ca. −2.0 V vs. FeCp2+/0. These properties have led to their use as n-dopants for organic semiconductors. Use of arenes substituted with π-electron donors is anticipated to lead to even more strongly reducing dimers. [RuCp*(1-(Me2N)-3,5-Me2C6H3)]+PF6− and [RuCp*(1,4-(Me2N)2C6H4)]+PF6− have been synthesized and electrochemically and crystallographically characterized; both exhibit D+/D potentials slightly more cathodic than [RuCp*(1,3,5-R3C6H3)]+. Reduction of [RuCp*(1,4-(Me2N)2C6H4)]+PF6− using silica-supported sodium–potassium alloy leads to a mixture of isomers of [RuCp*(1,4-(Me2N)2C6H4)]2, two of which have been crystallographically characterized. One of these isomers has a similar molecular structure to [RuCp*(1,3,5-Et3C6H3)]2; the central C–C bond is exo,exo, i.e., on the opposite face of both six-membered rings from the metals. A D+/0.5D2 potential of −2.4 V is estimated for this exo,exo dimer, more reducing than that of [RuCp*(1,3,5-R3C6H3)]2 (−2.0 V). This isomer reacts much more rapidly with both air and electron acceptors than [RuCp*(1,3,5-R3C6H3)]2 due to a much more cathodic D2˙+/D2 potential. The other isomer to be crystallographically characterized, along with a third isomer, are both dimerized in an exo,endo fashion, representing the first examples of such dimers. Density functional theory calculations and reactivity studies indicate that the central bonds of these two isomers are weaker than those of the exo,exo isomer, or of [RuCp*(1,3,5-R3C6H3)]2, leading to estimated D+/0.5D2 potentials of −2.5 and −2.6 V vs. FeCp2+/0. At the same time the D2˙+/D2 potentials for the exo,endo dimers are anodically shifted relative to those of [RuCp*(1,3,5-R3C6H3)]2, resulting in much greater air stability than for the exo,exo isomer.
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Polyhydroxy Fullerenes (Fullerols or Fullerenols): Beneficial Effects on Growth and Lifespan in Diverse Biological Models
Recent toxicological studies on carbon nanomaterials, including fullerenes, have led to concerns about their safety. Functionalized fullerenes, such as polyhydroxy fullerenes (PHF, fullerols, or fullerenols), have attracted particular attention due to their water solubility and toxicity. Here, we report surprisingly beneficial and/or specific effects of PHF on model organisms representing four kingdoms, including the green algae Pseudokirchneriella subcapitata, the plant Arabidopsis thaliana, the fungus Aspergillus niger, and the invertebrate Ceriodaphnia dubia. The results showed that PHF had no acute or chronic negative effects on the freshwater organisms. Conversely, PHF could surprisingly increase the algal culture density over controls at higher concentrations (i.e., 72% increase by 1 and 5 mg/L of PHF) and extend the lifespan and stimulate the reproduction of Daphnia (e.g. about 38% by 20 mg/L of PHF). We also show that at certain PHF concentrations fungal growth can be enhanced and Arabidopsis thaliana seedlings exhibit longer hypocotyls, while other complex physiological processes remain unaffected. These findings may open new research fields in the potential applications of PHF, e.g., in biofuel production and aquaculture. These results will form the basis of further research into the mechanisms of growth stimulation and life extension by PHF
Machine Learning Developments in ROOT
© Published under licence by IOP Publishing Ltd. ROOT is a software framework for large-scale data analysis that provides basic and advanced statistical methods used by high-energy physics experiments. It includes machine learning tools from the ROOT-integrated Toolkit for Multivariate Analysis (TMVA). We present several recent developments in TMVA, including a new modular design, new algorithms for pre-processing, cross-validation, hyperparameter-tuning, deep-learning and interfaces to other machine-learning software packages. TMVA is additionally integrated with Jupyter, making it accessible with a browser
Ellis-Van Creveld syndrome
Ellis-van Creveld syndrome (EVC) is a chondral and ectodermal dysplasia characterized by short ribs, polydactyly, growth retardation, and ectodermal and heart defects. It is a rare disease with approximately 150 cases reported worldwide. The exact prevalence is unknown, but the syndrome seems more common among the Amish community. Prenatal abnormalities (that may be detected by ultrasound examination) include narrow thorax, shortening of long bones, hexadactyly and cardiac defects. After birth, cardinal features are short stature, short ribs, polydactyly, and dysplastic fingernails and teeth. Heart defects, especially abnormalities of atrial septation, occur in about 60% of cases. Cognitive and motor development is normal. This rare condition is inherited as an autosomal recessive trait with variable expression. Mutations of the EVC1 and EVC2 genes, located in a head to head configuration on chromosome 4p16, have been identified as causative. EVC belongs to the short rib-polydactyly group (SRP) and these SRPs, especially type III (Verma-Naumoff syndrome), are discussed in the prenatal differential diagnosis. Postnatally, the essential differential diagnoses include Jeune dystrophy, McKusick-Kaufman syndrome and Weyers syndrome. The management of EVC is multidisciplinary. Management during the neonatal period is mostly symptomatic, involving treatment of the respiratory distress due to narrow chest and heart failure. Orthopedic follow-up is required to manage the bones deformities. Professional dental care should be considered for management of the oral manifestations. Prognosis is linked to the respiratory difficulties in the first months of life due to thoracic narrowness and possible heart defects. Prognosis of the final body height is difficult to predict
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