Stellar hydrodynamics caught in the act: Asteroseismology with CoRoT and Kepler

Asteroseismic investigations, particularly based on data on stellar oscillations from the CoRoT and Kepler space missions, are providing unique possibilities for investigating the properties of stellar interiors. This constitutes entirely new ways to study the effects of dynamic phenomena on stellar structure and evolution. Important examples are the extent of convection zones and the associated mixing and the direct and indirect effects of stellar rotation. In addition, the stellar oscillations themselves show very interesting dynamic behaviour. Here we discuss examples of the results obtained from such investigations, across the Hertzsprung-Russell diagram.Comment: Proc. IAU Symposium 271, Astrophysical Dynamics: From stars to galaxies, eds N. Brummell, A. S. Brun, M. S. Miesch, Y. Ponty, IAU and Cambridge University Press, in the pres

A lyophilized open-source RT-LAMP assay for molecular diagnostics in resource-limited settings

A critical bottleneck for equitable access to population-scale molecular diagnostics is the limited availability of rapid, inexpensive point-of-care tests especially in low- and middle-income countries. Here, we developed an open-source Reverse transcription loop-mediated isothermal amplification (RT-LAMP) molecular assay for the detection of respiratory RNA virus infections. It is based on non-proprietary enzymes, namely HIV-1 reverse transcriptase, Bst LF DNA polymerase and UDG BMTU thermolabile uracil DNA glycosylase. Formulated as liquid or lyophilized reaction mixtures, these reagents enable sensitive colorimetric detection of respiratory samples without the need for prior nucleic acid isolation. We evaluated our open-source lyophilized RT-LAMP assay on clinical samples with suspected COVID-19 infection, demonstrating high sensitivity and 100% specificity compared to the gold standard Reverse transcription quantitative polymerase chain reaction (RT-qPCR). Reaction performance was unaffected by prolonged storage of lyophilized reagents at ambient or elevated temperatures. As a proof of concept, we evaluated the robustness and ease-of-use of lyophilized RT-LAMP reaction mixes through independent laboratory testing of COVID-19 samples in Ghana. Overall, our open-source RT-LAMP assay provides a flexible and scalable point-of-care test that can be adapted for rapid detection of various pathogens in resource-limited settings.M.M. and M.J.K. were supported by the Vienna Science and Technology Fund (WWTF) through project COV20-031. This project received funding from the VW foundation (grant # 9A027) given to TReND in Africa, as well as funding from the "Mila Charitable Organisation". The IMP receives generous institutional funding from Boehringer Ingelheim and the Austrian Research Promotion Agency (Headquarter grant FFG852936), and IMBA is generously supported by the Austrian Academy of Sciences. Research in the lab of A.P. was supported by the Austrian Science Fund (START Projekt Y 1031-B28, SFB “RNA-Deco” F 80). Research in the lab of J.B. was supported by the European Research Council (ERC2015-CoG - 682181). F.A and G.A.A. were supported by a Science for Africa Foundation (SFA)/Wellcome Developing Excellence in Leadership Training and Science (DELTAS) in Africa grant (DEL-22-014: Awandare, G). Work in the L.M.-A. laboratory was supported by grant PID2019104176RBI00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation, and an institutional grant of the Fundación Ramón Areces. The laboratory of J.M.P. at IMBA received funding from the Austrian Academy of Sciences, the Medical University of Vienna, the Swedish Research Council (2018- 05766), the T. von Zastrow foundation, and the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 101005026. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA.N

Long-wavelength observations of debris discs around sun-like stars

[Abridged] We present two deep surveys of circumstellar discs around solar-type stars at different ages carried out at 350 micron with the CSO and at 1.2 mm with the IRAM 30-m telescope. The aim of this study is to understand the evolution timescale of circumstellar debris discs, and the physical mechanisms responsible for such evolution around solar-type stars. In addition, we perform a detailed characterisation of the detected debris discs. Theoretically, the mass of the disc is expected to decrease with time. In order to test this hypothesis, we performed the generalised Kendall's tau correlation and three different two-sample tests. A characterisation of the detected debris discs has been obtained by computing the collision and Poynting-Robertson timescales and by modelling the spectral energy distribution. The Kendall's tau correlation yields a probability of 76% that the mass of debris discs and their age are correlated. Similarly, the three two-sample tests give a probability between 70 and 83% that younger and older debris systems belong to different parent populations in terms of dust mass. We detected submillimetre/millimetre emission from six debris discs, enabling a detailed SED modelling. Our results on the correlation and evolution of dust mass as a function of age are conditioned by the sensitivity limit of our survey. Deeper millimetre observations are needed to confirm the evolution of debris material around solar-like stars. In the case of the detected discs, the comparison between collision and Poynting-Robertson timescales supports the hypothesis that these discs are collision dominated. All detected debris disc systems show the inner part evacuated from small micron-sized grains.Comment: Accepted by A&

A genome-scale shRNA resource for transgenic RNAi in Drosophila

Existing transgenic RNAi resources in Drosophila melanogaster based on long double-stranded hairpin RNAs are powerful tools for functional studies, but they are ineffective in gene knockdown during oogenesis, an important model system for the study of many biological questions. We show that shRNAs, modeled on an endogenous microRNA, are extremely effective at silencing gene expression during oogenesis. We also describe our progress toward building a genome-wide shRNA resource. © 2011 Nature America, Inc. All rights reserved

Systematic Identification Tudor-domain containing proteins acting in the Drosophila germline piRNA pathway

vorgelegt von: Dominik HandlerZusammenfassung in deutscher und englischer SpracheMolecular BiotechnologyMasterarbeit FH Campus Wien 201

The Rhino-Deadlock-Cutoff Complex Licenses Noncanonical Transcription of Dual-Strand piRNA Clusters in Drosophila

SummaryArgonaute proteins of the PIWI clade are central to transposon silencing in animal gonads. Their target specificity is defined by 23–30 nt PIWI interacting RNAs (piRNAs), which mostly originate from discrete genomic loci termed piRNA clusters. Here, we show that a complex composed of Rhino, Deadlock, and Cutoff (RDC) defines dual-strand piRNA clusters genome-wide in Drosophila ovaries. The RDC is anchored to H3K9me3-marked chromatin in part via Rhino’s chromodomain. Depletion of Piwi results in loss of the RDC and small RNAs at a subset of piRNA clusters, demonstrating a feedback loop between Piwi and piRNA source loci. Intriguingly, profiles of RNA polymerase II occupancy, nascent transcription, and steady-state RNA levels reveal that the RDC licenses noncanonical transcription of dual-strand piRNA clusters. Likely, this process involves 5′ end protection of nascent RNAs and suppression of transcription termination. Our data provide key insight into the regulation and evolution of piRNA clusters

The Drosophila ZAD zinc finger protein Kipferl guides Rhino to piRNA clusters

SUMMARYRNA interference systems depend on the synthesis of small RNA precursors whose sequences define the target spectrum of these silencing pathways. The Drosophila Heterochromatin Protein 1 (HP1) variant Rhino permits transcription of PIWI-interacting RNA (piRNA) precursors within transposon-rich heterochromatic loci in germline cells. Current models propose that Rhino’s specific chromatin occupancy at piRNA source loci is determined by histone marks and maternally inherited piRNAs, but also imply the existence of other, undiscovered specificity cues. Here, we identify a member of the diverse family of zinc finger associated domain (ZAD)-C2H2 proteins, Kipferl, as critical Rhino cofactor in ovaries. By binding to guanosine-rich DNA motifs and interacting with the Rhino chromodomain, Kipferl recruits Rhino to specific loci and stabilizes it on chromatin. In kipferl mutant flies, Rhino is lost from most of its target chromatin loci and instead accumulates on pericentromeric satellite arrays, resulting in decreased levels of transposon targeting piRNAs and impaired fertility. Our findings reveal that DNA sequence, in addition to the H3K9me3 mark, determines the identity of piRNA source loci and provide insight into how Rhino might be caught in the crossfire of genetic conflicts.</jats:p

Persisting Gaps in Coverage and Services of Illinois Women Who Acquired Insurance After Implementation of the Affordable Care Act

Objectives: Before implementation of the Affordable Care Act, many uninsured women in Illinois received care through safety-net programs. The new law allowed them to acquire health insurance through Medicaid or the Illinois Health Exchange. We examined (1) the health care experiences of such women who previously used a safety-net program and acquired this new coverage and (2) persisting gaps in coverage for breast and cervical cancer services and other health care services. Methods: We interviewed a stratified random sample of 400 women aged 34-64 in Illinois each year during 2015-2017 (total N = 1200). We used multivariable logistic regression models to determine the association between health insurance status (Illinois Health Exchange vs Medicaid) and past 12-month gaps in coverage (ie, delaying care, not having a recent mammogram, having a medical cost, and having a medical cost not covered) for the 360 women who were former participants of the Illinois Breast and Cervical Cancer Program. We calculated odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for race/ethnicity, age, income, and education. Results: We found no significant differences by health insurance status in the prevalence of delaying preventive, chronic, or sick care; timeliness of the most recent mammogram; and having a major medical cost. However, of women who reported a major medical cost, women with health insurance through the Illinois Health Exchange had a higher prevalence of not having a cost covered than women with Medicaid (adjusted OR = 4.86; 95% CI, 1.48-16.03). Conclusions: The results of this study suggest that many women who gained health insurance lacked adequate coverage and services. Safety-net programs will likely continue to play an essential role in supporting women as they navigate a complex system. </jats:sec