Albatross:a scalable simulation-based inference pipeline for analysing stellar streams in the Milky Way

Stellar streams are potentially a very sensitive observational probe of galactic astrophysics, as well as the dark matter population in the Milky Way. On the other hand, performing a detailed, high-fidelity statistical analysis of these objects is challenging for a number of key reasons. First, the modelling of streams across their (potentially billions of years old) dynamical age is complex and computationally costly. Secondly, their detection and classification in large surveys such as Gaia renders a robust statistical description regarding e.g. the stellar membership probabilities, challenging. As a result, the majority of current analyses must resort to simplified models that use only subsets or summaries of the high quality data. In this work, we develop a new analysis framework that takes advantage of advances in simulation-based inference techniques to perform complete analysis on complex stream models. To facilitate this, we develop a new, modular dynamical modelling code sstrax for stellar streams that is highly accelerated using jax. We test our analysis pipeline on a mock observation that resembles the GD1 stream, and demonstrate that we can perform robust inference on all relevant parts of the stream model simultaneously. Finally, we present some outlook as to how this approach can be developed further to perform more complete and accurate statistical analyses of current and future data

Sequential simulation-based inference for gravitational wave signals

The current and upcoming generations of gravitational wave experiments represent an exciting step forward in terms of detector sensitivity and performance. For example, key upgrades at the LIGO, Virgo and KAGRA facilities will see the next observing run (O4) probe a spatial volume around four times larger than the previous run (O3), and design implementations for, e.g., the Einstein Telescope, Cosmic Explorer, and LISA experiments are taking shape to explore a wider frequency range and probe cosmic distances. In this context, however, a number of very real data analysis problems face the gravitational wave community. For example, it will be critical to develop tools and strategies to analyze (among other scenarios) signals that arrive coincidentally in detectors, longer signals that are in the presence of nonstationary noise or other shorter transients, as well as noisy, potentially correlated, coherent stochastic backgrounds. With these challenges in mind, we develop peregrine, a new sequential simulation-based inference approach designed to study broad classes of gravitational wave signal. In this work, we describe the method and implementation, before demonstrating its accuracy and robustness through direct comparison with established likelihood-based methods. Specifically, we show that we are able to fully reconstruct the posterior distributions for every parameter of a spinning, precessing compact binary coalescence using one of the most physically detailed and computationally expensive waveform approximants (SEOBNRv4PHM). Crucially, we are able to do this using only 2% of the waveform evaluations that are required in, e.g., nested sampling approaches. Finally, we provide some outlook as to how this level of simulation efficiency and flexibility in the statistical analysis could allow peregrine to tackle these current and future gravitational wave data analysis problems

Trends in Abortion Incidence and Service Availability in North Carolina, 1980-2013

Objectives: Abortion incidence has declined nationally during the last decade. In recent years, many states, including North Carolina, have passed legislation related to the provision of abortion services. Despite the changing political environment, there is no comprehensive analysis on past and current trends related to unintended pregnancy and abortion in North Carolina. Methods: This study is a secondary analysis of vital registration data made publicly available by the North Carolina State Center for Health Statistics. Birth and induced abortion records were obtained for the years 1980 to 2013. We describe abortion incidence and demographic characteristics of women obtaining abortions over time. Results: The number of North Carolina abortions declined 36% between 1980 and 2013. The abortion ratio declined from 26/100 pregnancies (live births and abortions) in 1980 to just 14/100 in 2013. These ratios, however, vary across demographic subgroups. In 2013, the abortion ratio was more than 2 times greater for non-Hispanic black women than non-Hispanic white women (22 and 9, respectively). Among non-Hispanic black and Hispanic women, the abortion ratio is greater among women with a previous pregnancy as compared with women in their first pregnancy. For non-Hispanic white women, the abortion ratios are similar for first and higher-order pregnancies. Conclusions: Trends in North Carolina are similar to national trends; however, detailed analyses by race/ethnicity, age, and parity demonstrate important distinctions among abortion patients over time in the state. We discuss these trends in relation to policy changes and increased access to effective contraceptive

Fifth-grade students’ digital retellings and the Common Core: Modal use and design intentionality

Multimodal composing is part of the Common Core vision of the twenty-first-century student. Two descriptive studies were conducted of fifth-grade students’ digital folktale retellings. Study 1 analyzed 83 retellings in relation to the types and frequencies of modal use, such as image, sound, movement, and written text, as well as their retelling accuracy. Students composed within a scaffolded digital composing environment which comprised the PowerPoint authoring/presentation tool and a researcher-developed story frame. All students’ retellings included writing and visual design, 80% included animation, and 70% included sound. Retelling accuracy scores averaged 54%. Study 2 was conducted with a new group of 14 fifth-grade students who had previous digital retelling experience. The retellings included the same types of modal use, but at a higher level of frequency. In their retrospective design interviews, students expressed design intentionality and a metamodal awareness of how modes work together to create an appealing story

Topology optimization of nonlinear periodically microstructured materials for tailored homogenized constitutive properties

A topology optimization method is presented for the design of periodic microstructured materials with prescribed homogenized nonlinear constitutive properties over finite strain ranges. The mechanical model assumes linear elastic isotropic materials, geometric nonlinearity at finite strain, and a quasi-static response. The optimization problem is solved by a nonlinear programming method and the sensitivities computed via the adjoint method. Two-dimensional structures identified using this optimization method are additively manufactured and their uniaxial tensile strain response compared with the numerically predicted behavior. The optimization approach herein enables the design and development of lattice-like materials with prescribed nonlinear effective properties, for use in myriad potential applications, ranging from stress wave and vibration mitigation to soft robotics

Engaging men to promote and support exclusive breastfeeding: a descriptive review of 28 projects in 20 low- and middle-income countries from 2003 to 2013

Abstract Background Lay support has been associated with improved breastfeeding practices, but studies of programs that engage men in breastfeeding support have shown mixed results and most are from high-income countries. The purpose of our research is to review strategies to engage men in exclusive breastfeeding (EBF) promotion or support in 28 project areas across 20 low- and middle-income countries. This information may be used to inform program implementers and policymakers seeking to increase EBF. Methods We tested the difference between baseline and final EBF proportions using Pearson’s chi-square (a = 0.05) and identified project areas with a significant increase. We categorized male engagement strategies as low- and high-intensity, using information from project reports. We looked for patterns by intensity and geography and described strategies used to engage men in different places. Results Twenty-eight projects were reviewed; 21 (75%) were in areas where a statistically significant increase in EBF was observed between the beginning and end of the project. A variety of high- and low-intensity male engagement strategies was used in areas with an increase in EBF prevalence and in all geographic regions. High-intensity strategies engaged men directly during home or health visits by forming men’s groups and by working with male community leaders or members to promote EBF. Low-intensity strategies included large community meetings that included men, and radio messages, and other behavior change materials directed towards men. Conclusion Male engagement strategies took many forms in these project areas. We did not find consistent associations between the intensities or types of male engagement strategies and increases in EBF proportions. There is a gap in understanding how gender norms might impact male involvement in women’s health behaviors. This review does not support the broad application of male engagement to improve EBF practices, and we recommend considering local gender norms when designing programs to support women to EBF

Engaging men to promote and support exclusive breastfeeding: a descriptive review of 28 projects in 20 low- and middle-income countries from 2003 to 2013

Background: Lay support has been associated with improved breastfeeding practices, but studies of programs that engage men in breastfeeding support have shown mixed results and most are from high-income countries. The purpose of our research is to review strategies to engage men in exclusive breastfeeding (EBF) promotion or support in 28 project areas across 20 low- and middle-income countries. This information may be used to inform program implementers and policymakers seeking to increase EBF. Methods: We tested the difference between baseline and final EBF proportions using Pearson\u2019s chi-square (a = 0.05) and identified project areas with a significant increase. We categorized male engagement strategies as low- and high-intensity, using information from project reports. We looked for patterns by intensity and geography and described strategies used to engage men in different places. Results: Twenty-eight projects were reviewed; 21 (75%) were in areas where a statistically significant increase in EBF was observed between the beginning and end of the project. A variety of high- and low-intensity male engagement strategies was used in areas with an increase in EBF prevalence and in all geographic regions. High-intensity strategies engaged men directly during home or health visits by forming men\u2019s groups and by working with male community leaders or members to promote EBF. Low-intensity strategies included large community meetings that included men, and radio messages, and other behavior change materials directed towards men. Conclusion: Male engagement strategies took many forms in these project areas. We did not find consistent associations between the intensities or types of male engagement strategies and increases in EBF proportions. There is a gap in understanding how gender norms might impact male involvement in women\u2019s health behaviors. This review does not support the broad application of male engagement to improve EBF practices, and we recommend considering local gender norms when designing programs to support women to EBF

Genomic analysis reveals key aspects of prokaryotic symbiosis in the phototrophic consortium "<em>Chlorochromatium aggregatum</em>"

BACKGROUND: ‘Chlorochromatium aggregatum’ is a phototrophic consortium, a symbiosis that may represent the highest degree of mutual interdependence between two unrelated bacteria not associated with a eukaryotic host. ‘Chlorochromatium aggregatum’ is a motile, barrel-shaped aggregate formed from a single cell of ‘Candidatus Symbiobacter mobilis”, a polarly flagellated, non-pigmented, heterotrophic bacterium, which is surrounded by approximately 15 epibiont cells of Chlorobium chlorochromatii, a non-motile photolithoautotrophic green sulfur bacterium. RESULTS: We analyzed the complete genome sequences of both organisms to understand the basis for this symbiosis. Chl. chlorochromatii has acquired relatively few symbiosis-specific genes; most acquired genes are predicted to modify the cell wall or function in cell-cell adhesion. In striking contrast, ‘Ca. S. mobilis’ appears to have undergone massive gene loss, is probably no longer capable of independent growth, and thus may only reproduce when consortia divide. A detailed model for the energetic and metabolic bases of the dependency of ‘Ca. S. mobilis’ on Chl. chlorochromatii is described. CONCLUSIONS: Genomic analyses suggest that three types of interactions lead to a highly sophisticated relationship between these two organisms. Firstly, extensive metabolic exchange, involving carbon, nitrogen, and sulfur sources as well as vitamins, occurs from the epibiont to the central bacterium. Secondly, ‘Ca. S. mobilis’ can sense and move towards light and sulfide, resources that only directly benefit the epibiont. Thirdly, electron cycling mechanisms, particularly those mediated by quinones and potentially involving shared protonmotive force, could provide an important basis for energy exchange in this and other symbiotic relationships

Repurposing a photosynthetic antenna protein as a super-resolution microscopy label

Techniques such as Stochastic Optical Reconstruction Microscopy (STORM) and Structured Illumination Microscopy (SIM) have increased the achievable resolution of optical imaging, but few fluorescent proteins are suitable for super-resolution microscopy, particularly in the far-red and near-infrared emission range. Here we demonstrate the applicability of CpcA, a subunit of the photosynthetic antenna complex in cyanobacteria, for STORM and SIM imaging. The periodicity and width of fabricated nanoarrays of CpcA, with a covalently attached phycoerythrobilin (PEB) or phycocyanobilin (PCB) chromophore, matched the lines in reconstructed STORM images. SIM and STORM reconstructions of Escherichia coli cells harbouring CpcA-labelled cytochrome bd 1 ubiquinol oxidase in the cytoplasmic membrane show that CpcA-PEB and CpcA-PCB are suitable for super-resolution imaging in vivo. The stability, ease of production, small size and brightness of CpcA-PEB and CpcA-PCB demonstrate the potential of this largely unexplored protein family as novel probes for super-resolution microscopy

Genomic diversity of bacteriophages infecting Microbacterium spp

The bacteriophage population is vast, dynamic, old, and genetically diverse. The genomics of phages that infect bacterial hosts in the phylum Actinobacteria show them to not only be diverse but also pervasively mosaic, and replete with genes of unknown function. To further explore this broad group of bacteriophages, we describe here the isolation and genomic characterization of 116 phages that infect Microbacterium spp. Most of the phages are lytic, and can be grouped into twelve clusters according to their overall relatedness; seven of the phages are singletons with no close relatives. Genome sizes vary from 17.3 kbp to 97.7 kbp, and their G+C% content ranges from 51.4% to 71.4%, compared to ~67% for their Microbacterium hosts. The phages were isolated on five different Microbacterium species, but typically do not efficiently infect strains beyond the one on which they were isolated. These Microbacterium phages contain many novel features, including very large viral genes (13.5 kbp) and unusual fusions of structural proteins, including a fusion of VIP2 toxin and a MuF-like protein into a single gene. These phages and their genetic components such as integration systems, recombineering tools, and phage-mediated delivery systems, will be useful resources for advancing Microbacterium genetics