Tensile strained InxGa1−xPIn_{x}Ga_{1-x}P membranes for cavity optomechanics

We investigate the optomechanical properties of tensile-strained ternary InGaP nanomembranes grown on GaAs. This material system combines the benefits of highly strained membranes based on stoichiometric silicon nitride, with the unique properties of thin-film semiconductor single crystals, as previously demonstrated with suspended GaAs. Here we employ lattice mismatch in epitaxial growth to impart an intrinsic tensile strain to a monocrystalline thin film (approximately 30 nm thick). These structures exhibit mechanical quality factors of 2*10^6 or beyond at room temperature and 17 K for eigenfrequencies up to 1 MHz, yielding Q*f products of 2*10^12 Hz for a tensile stress of ~170 MPa. Incorporating such membranes in a high finesse Fabry-Perot cavity, we extract an upper limit to the total optical loss (including both absorption and scatter) of 40 ppm at 1064 nm and room temperature. Further reductions of the In content of this alloy will enable tensile stress levels of 1 GPa, with the potential for a significant increase in the Q*f product, assuming no deterioration in the mechanical loss at this composition and strain level. This materials system is a promising candidate for the integration of strained semiconductor membrane structures with low-loss semiconductor mirrors and for realizing stacks of membranes for enhanced optomechanical coupling.Comment: 10 pages, 3 figure

QuantiFERON®-TB gold in-tube performance for diagnosing active tuberculosis in children and adults in a high burden setting.

To determine whether QuantiFERON®-TB Gold In-Tube (QFT) can contribute to the diagnosis of active tuberculosis (TB) in children in a high-burden setting and to assess the performance of QFT and tuberculin skin test (TST) in a prospective cohort of TB suspect children compared to adults with confirmed TB in Tanzania. Sensitivity and specificity of QFT and TST for diagnosing active TB as well as indeterminate QFT rates and IFN-γ levels were assessed in 211 TB suspect children in a Tanzanian district hospital and contrasted in 90 adults with confirmed pulmonary TB. Sensitivity of QFT and TST in children with confirmed TB was 19% (5/27) and 6% (2/31) respectively. In adults sensitivity of QFT and TST was 84% (73/87) and 85% (63/74). The QFT indeterminate rate in children and adults was 27% and 3%. Median levels of IFN-γ were lower in children than adults, particularly children <2 years and HIV infected. An indeterminate result was associated with age <2 years but not malnutrition or HIV status. Overall childhood mortality was 19% and associated with an indeterminate QFT result at baseline. QFT and TST showed poor performance and a surprisingly low sensitivity in children. In contrast the performance in Tanzanian adults was good and comparable to performance in high-income countries. Indeterminate results in children were associated with young age and increased mortality. Neither test can be recommended for diagnosing active TB in children with immature or impaired immunity in a high-burden setting

jpHMM: Improving the reliability of recombination prediction in HIV-1

Previously, we developed jumping profile hidden Markov model (jpHMM), a new method to detect recombinations in HIV-1 genomes. The jpHMM predicts recombination breakpoints in a query sequence and assigns to each position of the sequence one of the major HIV-1 subtypes. Since incorrect subtype assignment or recombination prediction may lead to wrong conclusions in epidemiological or vaccine research, information about the reliability of the predicted parental subtypes and breakpoint positions is valuable. For this reason, we extended the output of jpHMM to include such information in terms of ‘uncertainty’ regions in the recombination prediction and an interval estimate of the breakpoint. Both types of information are computed based on the posterior probabilities of the subtypes at each query sequence position. Our results show that this extension strongly improves the reliability of the jpHMM recombination prediction. The jpHMM is available online at http://jphmm.gobics.de/

Mycobacterium tuberculosis lineage 4 comprises globally distributed and geographically restricted sublineages

Generalist and specialist species differ in the breadth of their ecological niches. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that, whereas the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration.We thank S. Lecher, S. Li and J. Zallet for technical support. Calculations were performed at the sciCORE scientific computing core facility at the University of Basel. This work was supported by the Swiss National Science Foundation (grants 310030_166687 (S.G.) and 320030_153442 (M.E.) and Swiss HIV Cohort Study grant 740 to L.F.), the European Research Council (309540-EVODRTB to S.G.), TB-PAN-NET (FP7-223681 to S.N.), PathoNgenTrace projects (FP7-278864-2 to S.N.), SystemsX.ch (S.G.), the German Center for Infection Research (DZIF; S.N.), the Novartis Foundation (S.G.), the Natural Science Foundation of China (91631301 to Q.G.), and the National Institute of Allergy and Infectious Diseases (5U01-AI069924-05) of the US National Institutes of Health (M.E.)

The effect of botulinum toxin A in children with non-neurogenic therapy-refractory dysfunctional voiding – A systematic review

Introduction:Dysfunctional voiding (DV) is a habitual voiding disorder caused by involuntary contraction or non-relaxation of the external urethral sphincter (EUS) during voiding. This contraction causes high post-void residuals (PVR), urinary incontinence and urinary tract infections (UTIs). Various treatments for DV are available, but some children do not respond. Intersphincteric botulinum toxin-A (BTX-A) may be a possible treatment for therapy-refractory children with DV.Objective: The aim of this systematic review is to summarize the effects and safety of intersphincteric BTX-A as a treatment for therapy-refractory DV in children. Methods: A systematic search in Embase, MEDLINE, Cochrane, and Web of Science databases was performed. Studies reporting on the usage of intersphincteric BTX-A as a treatment for DV in children were included. Data on PVR, maximum flow rate (Qmax), repeat injections and complications were extracted. Results: From a total of 277 articles, five cohort studies were identified, reporting on 78 children with DV of whom 53 were female (68 %) and 25 were male (32 %). Sample sizes ranged from ten to twenty patients. Mean or median age at the time of intervention ranged from 8 to 10.5 years. Meta-analysis could not be performed due to lack of data. The narrative synthesis approach was therefore used to summarize the results. All studies showed significant decrease in PVR after BTX-A injection. Three studies showed a 33–69 % improvement on incontinence after BTX-A injection. Less UTIs were reported after treatment. A temporary increase in incontinence, UTIs and transitory numbness to the gluteus muscle were reported as side-effects. Conclusions: BTX-A could be a safe and effective treatment option for therapy-refractory DV in children by reducing PVR, UTIs and incontinence. Hereby, the synergistic effect of BTX-A and urotherapy should be emphasized in future management. Furthermore, this study identified gaps in current knowledge that are of interest for future research.</p

Physical Activity and Sedentary Time Among U.S. Adolescents Before and During COVID-19: Findings From a Large Cohort Study

INTRODUCTION: Evidence suggests that adolescents engage in less physical activity during the summer break. Less is known regarding physical activity during the summer months of the COVID-19 pandemic. METHODS: Utilizing data from the Adolescent Brain Cognitive Development study, the authors examined daily activity measured by Fitbit Charge 2 devices before and after the onset of the COVID-19 pandemic during school and summer months. Linear models estimated activity during pre-COVID-19 school, pre-COVID-19 summer, COVID-19 school, and COVID-19 summer. RESULTS: Participants (N=7,179, aged 11.96 years, 51% female, 51% White) accumulated 8,671.0 (95% CI=8,544.7; 8,797.3) steps, 32.5 (95% CI=30.8, 32.3) minutes of moderate-to-vigorous physical activity, and 507.2 (95% CI=504.2, 510.2) minutes of sedentary time. During COVID-19 school, adolescents accumulated fewer daily steps and minutes of moderate-to-vigorous physical activity (-1,782.3 steps [95% CI= -2,052.7; -1,511.8] and -6.2 minutes [95% CI= -8.4, -4.0], respectively). Adolescents accumulated more minutes of daily sedentary time (29.6 minutes [95% CI=18.9, 40.3]) during COVID-19 school months than during the pre-COVID-19 school months. During pre-COVID-19 summer months, adolescents accumulated 1,255.1 (95% CI=745.3; 1,765.0) more daily steps than during COVID-19 months. Boys accumulated more daily steps and moderate-to-vigorous physical activity (2,011.5 steps [95% CI=1,271.9; 2,751.0] and 7.9 minutes [95% CI=1.4, 14.4], respectively) during the summer before COVID-19 than in summer during COVID-19. Both girls and boys accumulated more minutes of sedentary time during COVID-19 school months (47.4 [95% CI=27.5, 67.3] and 51.2 [95% CI=22.8, 79.7], respectively) than during COVID-19 summer months. CONCLUSIONS: Societal restrictions during COVID-19 negatively impacted activity levels in the U.S., particularly during the summer months during COVID-19

A novel method for detecting Lipoarabinomannan in urine with the promise of meeting the WHO target product profile for the diagnosis of tuberculosis

The diagnosis of tuberculosis largely relies on the detection of Mycobacterium tuberculosis (M. tuberculosis) via pathogen-specific DNA or bacterial culture from sputum samples. As the only point-of-care test so far, urinary lipoarabinomannan (LAM) has been endorsed by the World Health Organization for the diagnosis of tuberculosis in people living with HIV.In this study, the electrochemiluminescence LAM research assay (EclLAM) was used to measure LAM in the urine of HIV-sero-negative individuals with pulmonary tuberculosis and to monitor anti-tuberculosis treatment. Urine samples from 18 patients with microbiologically confirmed tuberculosis were analyzed before and after the initiation of anti-tuberculosis therapy and 17 healthy controls via the S4-20/A194-01 antibody pair.The assay identified 13/18 (72.2 %) patients with tuberculosis and was negative in 17/17 (100.0 %) controls (AUC 0.88). The results of the reactive urine LAM tests correlated with the detection of M. tuberculosis growth in culture (r = 0.94, p In conclusion, the LAM-specific antibody assay is promising to fulfill the WHO target product profile for the diagnosis of tuberculosis