55 research outputs found
Role of heavy-meson exchange in pion production near threshold
Recent calculations of -wave pion production have severely underestimated
the accurately known \ total cross section near
threshold. In these calculations, only the single-nucleon axial-charge operator
is considered. We have calculated, in addition to the one-body term, the
two-body contributions to this reaction that arise from the exchange of mesons.
We find that the inclusion of the scalar -meson exchange current (and
lesser contributions from other mesons) increases the cross section by about a
factor of five, and leads to excellent agreement with the data. The results are
neither very sensitive to changes in the distorting potential that generates
the wave function, nor to different choices for the meson-nucleon form
factors. We argue that \ data provide direct
experimental evidence for meson-exchange contributions to the axial current.Comment: 28 Pages, IU-NTC #93-0
Virtual-pion and two-photon production in pp scattering
Two-photon production in pp scattering is proposed as a means of studying
virtual-pion emission. Such a process is complementary to real-pion emission in
pp scattering. The virtual-pion signal is embedded in a background of
double-photon bremsstrahlung. We have developed a model to describe this
background process and show that in certain parts of phase space the
virtual-pion signal gives significant contribution. In addition, through
interference with the two-photon bremsstrahlung background, one can determine
the relative phase of the virtual-pion process
A Network Analysis of the Human T-Cell Activation Gene Network Identifies Jagged1 as a Therapeutic Target for Autoimmune Diseases
Understanding complex diseases will benefit the recognition of the properties of the gene networks that control biological functions. Here, we set out to model the gene network that controls T-cell activation in humans, which is critical for the development of autoimmune diseases such as Multiple Sclerosis (MS). The network was established on the basis of the quantitative expression from 104 individuals of 20 genes of the immune system, as well as on biological information from the Ingenuity database and Bayesian inference. Of the 31 links (gene interactions) identified in the network, 18 were identified in the Ingenuity database and 13 were new and we validated 7 of 8 interactions experimentally. In the MS patients network, we found an increase in the weight of gene interactions related to Th1 function and a decrease in those related to Treg and Th2 function. Indeed, we found that IFN-Ă therapy induces changes in gene interactions related to T cell proliferation and adhesion, although these gene interactions were not restored to levels similar to controls. Finally, we identify JAG1 as a new therapeutic target whose differential behaviour in the MS network was not modified by immunomodulatory therapy. In vitro treatment with a Jagged1 agonist peptide modulated the T-cell activation network in PBMCs from patients with MS. Moreover, treatment of mice with experimental autoimmune encephalomyelitis with the Jagged1 agonist ameliorated the disease course, and modulated Th2, Th1 and Treg function. This study illustrates how network analysis can predict therapeutic targets for immune intervention and identified the immunomodulatory properties of Jagged1 making it a new therapeutic target for MS and other autoimmune diseases
Criminalizing protests about animal abuse. Recent Irish experience in global context
"Supporters of the Animal Enterprise Terrorism Act (2006) label as âterroristsâ mainstream animal welfare corporations such as the Humane Society of the United States (HSUS) and People for the Ethical Treatment of Animals (PeTA). Animal advocates fear that conventional forms of protest, such as boycotts and street demonstrations, are being redefined within such legislation as potential âacts of terrorâ. Meanwhile, in Ireland, peaceful grassroots animal rights campaigners have begun to be arrested and jailed for standing outside fur shops with an information table. Is Ireland next in line in terms of the apparent global criminalisation of animal advocacy?" [author's abstract
Addison's disease symptoms - a cross sectional study in urban South Africa
BACKGROUND: Addison's disease is a potentially life-threatening disorder, and prompt diagnosis, and introduction of steroid replacement has resulted in near normal life-expectancy. There are limited data describing the clinical presentation of Addison's disease in South Africa. It is hypothesised that patients may present in advanced state of ill-health, compared to Western countries. Patients A national database of patients was compiled from primary care, referral centres and private practices. 148 patients were enrolled (97 white, 34 mixed ancestry, 5 Asian and 12 black). METHODS: Demographic and clinical data were elicited using questionnaires. Biochemical data were obtained from folder reviews and laboratory archived results. RESULTS: The majority of the cohort was women (62%). The median and inter-quartile age range (IQR) of patients at enrolment was 46.0 (32.0-61.0) years, with a wide range from 2.8-88.0 years. The median and IQR age at initial diagnosis was 34.0 (20.0-45.0) years (range 0.02-77.0) years, indicating that at the time of enrolment, the patients, on average, were diagnosed with Addison's disease 12 years previously. Hyperpigmentation was observed in 76%, nausea and vomiting occurred in more than 40%, and weight loss was noted in 25%. Loss of consciousness as a presenting feature was recorded in 20 %. with a 95% confidence interval [CI] of (14-28%) and shock occurred in 5% CI (1.5-8.5%). Case-finding was recorded at 3.1 per million. CONCLUSIONS: The usual constellation of hyperpigmentation, nausea, vomiting and weight loss suggests Addison's disease, but a significant proportion present with an advanced state of ill-health and Addisonian crises. A lower prevalence rate, compared to Western countries is suggested
Isolation and characterization of Acidicaldus organovorus, gen.nov., sp. nov; a novel sulfur-oxidizing, ferric iron-reducing thermo-acidophilic heterotrophic Proteobacterium.
Thermo-acidophilic prokaryotes isolated from geothermal sites in Yellowstone National Park were identified as novel α-Proteobacteria, distantly related (~93% 16S rRNA gene identity) to the mesophilic acidophile Acidisphaera rubrifaciens. One of these isolates (Y008) was shown to be more thermophilic than all previously characterized acidophilic proteobacteria, with a temperature optimum for growth between 50 and 55°C and a temperature maximum of 65°C. Growth was observed in media maintained at pH between 1.75 and 3.0 and was fastest at pH between 2.5 and 3.0. The G + C content of Y008 was 71.8±0.9 mol%. The acidophile was able to grow heterotrophically on a range of organic substrates, including various monosaccharides, alcohols and amino acids and phenol, though growth on single organic compounds required the provision of one or more growth factors. The isolate oxidized sulfur to sulfuric acid in media containing yeast extract, but was not capable of autotrophic growth with sulfur as energy source. Growth occurred under aerobic conditions and also in the absence of oxygen via anaerobic respiration using ferric iron as terminal electron acceptor. Based on these genotypic and phenotypic traits, it is proposed that Y008 represents the type species of Acidicaldus organivorus, gen. nov., sp. nov
COVID-19 vaccine hesitancy in Africa: a scoping review
Background
Vaccination against the novel coronavirus is one of the most effective strategies for combating the global Coronavirus disease (COVID-19) pandemic. However, vaccine hesitancy has emerged as a major obstacle in several regions of the world, including Africa. The objective of this rapid review was to summarize the literature on COVID-19 vaccine hesitancy in Africa.
Methods
We searched Scopus, Web of Science, African Index Medicus, and OVID Medline for studies published from January 1, 2020, to March 8, 2022, examining acceptance or hesitancy towards the COVID-19 vaccine in Africa. Study characteristics and reasons for COVID-19 vaccine acceptance were extracted from the included articles.
Results
A total of 71 articles met the eligibility criteria and were included in the review. Majority (nâ=â25, 35%) of the studies were conducted in Ethiopia. Studies conducted in Botswana, Cameroun, Cote DâIvoire, DR Congo, Ghana, Kenya, Morocco, Mozambique, Nigeria, Somalia, South Africa, Sudan, Togo, Uganda, Zambia, Zimbabwe were also included in the review. The vaccine acceptance rate ranged from 6.9 to 97.9%. The major reasons for vaccine hesitancy were concerns with vaccine safety and side effects, lack of trust for pharmaceutical industries and misinformation or conflicting information from the media. Factors associated with positive attitudes towards the vaccine included being male, having a higher level of education, and fear of contracting the virus.
Conclusions
Our review demonstrated the contextualized and multifaceted reasons inhibiting or encouraging vaccine uptake in African countries. This evidence is key to operationalizing interventions based on facts as opposed to assumptions. Our paper provided important considerations for addressing the challenge of COVID-19 vaccine hesitancy and blunting the impact of the pandemic in Africa.Medicine, Faculty ofNon UBCPopulation and Public Health (SPPH), School ofReviewedFacultyResearche
Comparative mesocosm study of biostimulation efficiency in two different oil-amended sub-antarctic soils
Biological treatment has become increasingly popular as a remediation method for soils and groundwater contaminated with petroleum hydrocarbon, chlorinated solvents, and pesticides. Bioremediation has been considered for application in cold regions such as Arctic and sub-Arctic climates and Antarctica. Studies to date suggest that indigenous microbes suitable for bioremediation exist in soils in these regions. This paper reports on two case studies at the sub-Antarctic Kerguelen Island, in which indigenous bacteria were found that were capable of mineralizing petroleum hydrocarbons in soil contaminated with crude oil and diesel fuel. All results demonstrate a serious influence of the soil properties on the biostimulation efficiency. Both temperature elevation and fertilizer addition have a more significant impact on the microbial assemblages in the mineral soil than in the organic one. Analysis of the hydrocarbons remaining at the end of the experiments confirmed the bacterial observations. Optimum temperature seems to be around 10°C in organic soil while it was higher in mineral soil. The benefit of adding nutrient was much stronger in mineral than in the organic soil. Overall, this study suggests on the basis of microbiological and physicochemical parameters, that biostimulation treatments were driven by soil properties and that ex-situ bioremediation for treatment of cold contaminated soils will allow greater control over soil temperature, a limiting factor in cold climates.French Polar Institute (IPEV) and EU project FaceiT (Fast Advanced Cellular and Ecosystems Information Technologies [STREP grant no 018391 (COGE)
Core set of outcomes for adolescents with major depressive disorder: A tool of standardized outcomes for clinical research
Major depressive disorder (MDD) is a common and serious mental disorder in adolescents. Although advancements in core outcome set (COS) development for adult depression is underway, the type of outcomes measured in MDD trials for adolescents differ from those in adult populations. Currently, there is no core outcome set for effectiveness trials in the treatment of adolescent major depressive disorder
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