73 research outputs found

    The Rigidly Rotating Magnetosphere of Sigma Ori E

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    We attempt to characterize the observed variability of the magnetic helium-strong star sigma Ori E in terms of a recently developed rigidly rotating magnetosphere model. This model predicts the accumulation of circumstellar plasma in two co-rotating clouds, situated in magnetohydrostatic equilibrium at the intersection between magnetic and rotational equators. We find that the model can reproduce well the periodic modulations observed in the star's light curve, H alpha emission-line profile, and longitudinal field strength, confirming that it furnishes an essentially correct, quantitative description of the star's magnetically controlled circumstellar environment.Comment: 4 pages, 3 figures, accepted by Ap

    Effect of the Friendship Bench Intervention on Antiretroviral Therapy Outcomes and Mental Health Symptoms in Rural Zimbabwe: A Cluster Randomized Trial.

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    IMPORTANCE Common mental disorders (CMD), which include depression and anxiety, are prevalent among people living with HIV and are associated with suboptimal antiretroviral therapy (ART) adherence. OBJECTIVE To assess the effect of a lay health worker-led psychological intervention on ART adherence, virologic suppression, and mental health symptoms. DESIGN, SETTING, AND PARTICIPANTS Open-label pragmatic cluster trial with 1:1 block randomization of 16 health facilities in rural Bikita, Zimbabwe. Recruitment occurred from October 2018 to December 2019, and participants were followed up for 12 months, ending in December 2020. Participants were adults aged 18 years and older, who spoke English or Shona, screened positive for CMD (Shona Symptoms Questionnaire [SSQ]-14 score ≥9), received first-line ART for 6 or more months, had no World Health Organization stage 4 disease, no psychosis, were not pregnant, and provided informed consent. Data were analyzed from March 2021 to February 2022. INTERVENTION The Friendship Bench, consisting of 6 lay health worker-led weekly problem-solving therapy sessions and optional peer-led group support. MAIN OUTCOMES AND MEASURES The primary outcome was mean adherence during 2 to 6 months of follow-up, and the secondary outcomes were mean adherence during 1 to 12 months of follow-up, change in SSQ-14 and Patient Health Questionnaire (PHQ-9) scores (3, 6, 9, and 12 months), and viral load suppression (6 and 12 months). RESULTS A total of 516 participants were recruited (244 in Friendship Bench and 272 in enhanced standard care facilities); 438 (84.9%) were female and the mean (SD) age was 45.6 (10.9) years. Mean (SD) adherence between 2 to 6 months was 89.9% (18.4%) in the Friendship Bench group and 87.2% (20.1%) in the control group. The intervention had no statistically significant effect on adherence between 2 to 6 months (unadjusted mean difference, 1.93 percentage points; 95% CI, -1.20 to 5.06 percentage points; P = .23), between months 1 to 12 (mean difference 0.79 percentage points; 95% CI, -2.14 to 3.71 percentage points; P = .60), or viral suppression. Declines in SSQ-14 scores from baseline to 3 months (difference, -1.65; 95% CI, -3.07 to -0.24), 6 months (difference, -1.57; 95% CI, -2.98 to -0.15), and 9 months (difference, -1.63; 95% CI, -3.05 to -0.22) were greater in the Friendship Bench than the standard care group (P < .05). There were no differences in the decline in the SSQ-14 scores from baseline to 12 months and in declines in PHQ-9 scores from baseline to 3, 6, 9, and 12 months. CONCLUSIONS AND RELEVANCE In this randomized trial of HIV-positive participants with CMD, the Friendship Bench intervention had no effect on adherence and viral suppression, possibly due to the absence of skill-based adherence training and a ceiling effect. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT03704805

    Diastolic dysfunction in diabetes and the metabolic syndrome: promising potential for diagnosis and prognosis

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    Cardiac disease in diabetes mellitus and in the metabolic syndrome consists of both vascular and myocardial abnormalities. The latter are characterised predominantly by diastolic dysfunction, which has been difficult to evaluate in spite of its prevalence. While traditional Doppler echocardiographic parameters enable only semiquantitative assessment of diastolic function and cannot reliably distinguish perturbations in loading conditions from altered diastolic functions, new technologies enable detailed quantification of global and regional diastolic function. The most readily available technique for the quantification of subclinical diastolic dysfunction is tissue Doppler imaging, which has been integrated into routine contemporary clinical practice, whereas cine magnetic resonance imaging (CMR) remains a promising complementary research tool for investigating the molecular mechanisms of the disease. Diastolic function is reported to vary linearly with age in normal persons, decreasing by 0.16 cm/s each year. Diastolic function in diabetes and the metabolic syndrome is determined by cardiovascular risk factors that alter myocardial stiffness and myocardial energy availability/bioenergetics. The latter is corroborated by the improvement in diastolic function with improvement in metabolic control of diabetes by specific medical therapy or lifestyle modification. Accordingly, diastolic dysfunction reflects the structural and metabolic milieu in the myocardium, and may allow targeted therapeutic interventions to modulate cardiac metabolism to prevent heart failure in insulin resistance and diabetes

    BMJ Open

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    Purpose The objectives of the International epidemiology databases to evaluate AIDS (IeDEA) are to (i) evaluate the delivery of combination antiretroviral therapy (ART) in children, adolescents and adults in sub-Saharan Africa, (ii) to describe ART regimen effectiveness, durability and tolerability, (iii) to examine HIV-related comorbidities and coinfections and (iv) to examine the pregnancy-related and HIV-related outcomes of women on ART and their infants exposed to HIV or ART in utero or via breast milk. Participants IeDEA is organised in four regions (Central, East, Southern and West Africa), with 240 treatment and care sites, six data centres at African, European and US universities, and almost 1.4 million children, adolescents and adult people living with HIV (PLWHIV) enrolled. Findings to date The data include socio-demographic characteristics, clinical outcomes, opportunistic events, treatment regimens, clinic visits and laboratory measurements. They have been used to analyse outcomes in PLWHIV-1 or PLWHIV-2 who initiate ART, including determinants of mortality, of switching to second-line and third-line ART, drug resistance, loss to follow-up and the immunological and virological response to different ART regimens. Programme-level estimates of mortality have been corrected for loss to follow-up. We examined the impact of coinfection with hepatitis B and C, and the epidemiology of different cancers and of (multidrug resistant) tuberculosis, renal disease and of mental illness. The adoption of ‘Treat All’, making ART available to all PLWHIV regardless of CD4+ cell count or clinical stage was another important research topic. Future plans IeDEA has formulated several research priorities for the ‘Treat All’ era in sub-Saharan Africa. It recently obtained funding to set up sentinel sites where additional data are prospectively collected on cardiometabolic risks factors as well as mental health and liver diseases, and is planning to create a drug resistance database

    Phenotypic and Genome-Wide Analysis of an Antibiotic-Resistant Small Colony Variant (SCV) of Pseudomonas aeruginosa

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    Small colony variants (SCVs) are slow-growing bacteria, which often show increased resistance to antibiotics and cause latent or recurrent infections. It is therefore important to understand the mechanisms at the basis of this phenotypic switch.One SCV (termed PAO-SCV) was isolated, showing high resistance to gentamicin and to the cephalosporine cefotaxime. PAO-SCV was prone to reversion as evidenced by emergence of large colonies with a frequency of 10(-5) on media without antibiotics while it was stably maintained in presence of gentamicin. PAO-SCV showed a delayed growth, defective motility, and strongly reduced levels of the quorum sensing Pseudomonas quinolone signal (PQS). Whole genome expression analysis further suggested a multi-layered antibiotic resistance mechanism, including simultaneous over-expression of two drug efflux pumps (MexAB-OprM, MexXY-OprM), the LPS modification operon arnBCADTEF, and the PhoP-PhoQ two-component system. Conversely, the genes for the synthesis of PQS were strongly down-regulated in PAO-SCV. Finally, genomic analysis revealed the presence of mutations in phoP and phoQ genes as well as in the mexZ gene encoding a repressor of the mexXY and mexAB-oprM genes. Only one mutation occurred only in REV, at nucleotide 1020 of the tufA gene, a paralog of tufB, both encoding the elongation factor Tu, causing a change of the rarely used aspartic acid codon GAU to the more common GAC, possibly causing an increase of tufA mRNA translation. High expression of phoP and phoQ was confirmed for the SCV variant while the revertant showed expression levels reduced to wild-type levels.By combining data coming from phenotypic, gene expression and proteome analysis, we could demonstrate that resistance to aminoglycosides in one SCV mutant is multifactorial including overexpression of efflux mechanisms, LPS modification and is accompanied by a drastic down-regulation of the Pseudomonas quinolone signal quorum sensing system

    Double J/ψJ/\psi production in pion-nucleon scattering at COMPASS

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    We present the study of the production of double J/ψJ/\psi mesons using COMPASS data collected with a 190 GeV/cc π\pi^- beam scattering off NH3_{3}, Al and W targets. Kinematic distributions of the collected double J/ψJ/\psi events are analysed, and the double J/ψJ/\psi production cross section is estimated for each of the COMPASS targets. The results are compared to predictions from single- and double-parton scattering models as well as the pion intrinsic charm and the tetraquark exotic resonance hypotheses. It is demonstrated that the single parton scattering production mechanism gives the dominant contribution that is sufficient to describe the data. An upper limit on the double intrinsic charm content of pion is evaluated. No significant signatures that could be associated with exotic tetraquarks are found in the double J/ψJ/\psi mass spectrum.Comment: 12 pages, 4 figure

    Epistasis among Presynaptic Serotonergic System Components

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    Epistatic interactions among regulatory components of the serotonin (5-HT) neurotransmitter system may be an important aspect of 5-HT function. Because 5-HT dysregulation is associated with several common psychiatric disorders, the potential for epistasis among genetic variants in the 5-HT transporter (SERT), 5-HT 1B terminal autoreceptor and the 5-HT 1A somatodendritic autoreceptor should be examined. In this study, output from a dynamic minimal model of 5-HT function was compared to empirical results in the literature. Parameters representing extracellular 5-HT clearance rates (SERT), 5-HT release levels (5-HT 1B ) and inhibitory thresholds (the amount of extracellular 5-HT above which cell firing is inhibited, an indication of 5-HT 1A autoreceptor sensitivity) were varied to simulate genetic deletion (i.e. knockout) of each component singly, and in combination. Simulated knockout effects on extracellular 5-HT level and presynaptic neural firing rates were in the same direction and of similar relative magnitude as studies in the literature. Epistasis among presynaptic components appears to be important in the 5-HT system’s regulation of extracellular 5-HT levels, but not of firing rates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44113/1/10519_2004_Article_1019.pd

    Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

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    &lt;p&gt;Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.&lt;/p&gt; &lt;p&gt;Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate &#60;60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.&lt;/p&gt; &lt;p&gt;Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.&lt;/p&gt

    EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

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    More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369
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