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Astronomically, there are viable mechanisms for distributing organic material throughout the Milky Way. Biologically, the destructive effects of ultraviolet light and cosmic rays means that the majority of organisms arrive broken and dead on a new world. The likelihood of conventional forms of panspermia must therefore be considered low. However, the information content of damaged biological molecules might serve to seed new life (necropanspermia).

Background Observational studies have found that youth civic engagement is associated with positive mental health, education, and socioeconomic outcomes. However, access to civic opportunities is not evenly distributed. Many classrooms in the United States of America (USA) do not have access to high-quality civics education. Action civics approaches to civic education prepare students for civic engagement by developing the necessary civic skills, knowledge, and character. Through action civics, classes take action on a real-world issue students choose together. Some evidence suggests that action civics may positively affect participants’ wellbeing through the feelings of civic connection and empowerment. The aim of this study is to investigate, through a randomized controlled trial, the impact of a school-based action civics education intervention on civic and wellbeing outcomes, and the mechanisms of any impact observed, among middle and high school students in the USA. Methods This study uses a cluster-randomized trial with a waitlist-control design. We are randomizing at the school level, implementing the intervention at the teacher/classroom level, and measuring outcomes at the student level. We are recruiting social studies, civics, government, and related subject teachers, across both middle and high schools, from across the USA, leveraging network ties and referrals to invite teachers/schools to participate. We aim to recruit a sample of around 1,500 students. Intervention group teachers will receive action civics curricular resources they can incorporate into their regular teaching, while the control group will not receive the curricular resources until 12 months later and will continue with their teaching as planned. Students will fill out surveys at the beginning and end of the semester, and will be invited to complete a survey six months later. Surveys will assess civic, wellbeing, demographic, and other related variables. Discussion This study is one of the first randomized controlled trials to assess the impacts of action civics curricular materials on civic and wellbeing outcomes. The study will strengthen our understanding of the impacts of action civics education, with implications for the quality and adoption of civic curricula nationwide. Trial registration NCT04514133 (date of registration September 25, 2020).

Despite increasing political will to achieve Universal Health Coverage (UHC), there is a paucity of empiric data describing what health system indicators are useful surrogates of country-level progress towards UHC. We sought to determine what public health interventions were useful tracers of country-level UHC progress. Across 183 countries we evaluated the extent to which 16 service delivery indicators explained variability in the UHC Service Coverage Index, (UHC SCI) a WHO-validated indicator of country-level health coverage. Dominance analyses, stratifying countries by World Bank income criteria, were used to determine which indicators were most important in in predicting UHC SCI scores. Health workforce density ranked first overall, provision of basic sanitation and access to clean water ranked second, and provision of basic antenatal services ranked third. In analysis stratified by World Bank income criteria, health workforce density ranked first in Lower Middle Income-Countries (LMICs) (n = 45) and third in Upper Middle Income-Countries (UMICs) (n = 51). While each country will have a different approach to achieving UHC, strengthening the health workforce will need to be a key priority if they are to be successful in achieving UHC.

Worldwide, the HIV epidemic is concentrated among hidden populations (i.e., female sex workers, men who have sex with men, and people who inject drugs). To understand the true scope and scale of the HIV epidemic, estimates of the sizes of these populations are needed. Various methods are available to enumerate hidden populations, but the degree of agreement between these methods has not been formally evaluated. We systematically reviewed the peer-reviewed literature to assess the extent to which different population size estimation methods provide the same estimate of a target population. Of the 341 studies identified from our search, 25 met our eligibility criteria. Twenty-one unique methods were documented. The service multiplier method was the most common in the review. Eighty target populations were estimated, covering 16 countries. We observed variable population size estimates, with little agreement between methods. We note trends in the relative performance of individual methods.

There is a paucity of empiric data evaluating whether Tuberculosis (TB) is a useful surrogate measure for Universal Health Coverage (UHC), despite recognition of the importance of TB control efforts as part of the broader UHC agenda. We hypothesized that indicators of TB burden and coverage are sensitive tracers of UHC, when compared to other disease-specific indicators of service provision. Linear regression models were used to determine the extent to which variability in UHC Service Coverage Index (SCI) was accounted for by (1) TB incidence rates and (2) TB mortality rates across 183 countries. Dominance analyses, stratifying countries by World Bank income criteria and TB burden, were used to determine the importance of TB treatment coverage in predicting UHC SCI scores, relative to other disease-specific indicators of service provision. Across 183 countries, TB incidence rate and TB mortality rate were negatively correlated, with UHC SCI score, (r = -0.67 and r = -0.74, respectively). In linear regression models including all 183 countries, TB incidence rates explained 45% of the variability in SCI scores; TB mortality rate explained 55% of variability. Restricting models to the 30 highest TB burden countries, both incidence and mortality explained less of the variability in SCI score (16% and 36%, respectively). In dominance analysis, comparing 13 disease-specific indicators of service provision, TB effective treatment coverage, ranked ninth overall. In dominance analysis stratified by TB burden, the TB treatment coverage estimate was ranked ninth in the 30 high burden countries and sixth in the 153 non-high burden countries. In separate analyses stratified by world bank income status, TB coverage ranked as third most important variable in LICs and fifth in LMICs and UMICs, but was less important in analysis restricted HICs (ranked seventh). Compared to other disease-specific indicators of service provision, TB coverage was an important indicator of overall UHC service coverage, especially in low-income countries. These findings highlight that national-level inequities in TB-coverage may be an important tracer of universal health coverage.

Background Trans women experience high rates of gender-based violence (GBV)—a risk factor for adverse health outcomes. Transphobic hate crimes are one such form of GBV that affect trans women. However, little is understood about factors that shape transphobic hate crimes and racial/ethnic variation in these experiences. To contextualize GBV risk and police reporting, we examined self-reported types and correlates of transphobic hate crimes by racial/ethnic group of trans women in the San Francisco Bay Area. Methods From 2016 to 2018, trans women participated in a longitudinal cohort study of HIV. Secondary data analyses ( N  = 629) examined self-reported experiences of transphobic hate crimes (i.e., robbery, physical assault, sexual assault, and battery with weapon) by race/ethnicity, and whether hate crimes were reported to the police. Chi-square tests and simple logistic regression examined demographic, sociocultural, and gender identity factors associated with transphobic violence experiences and police reporting. Results About half (45.8%) of participants reported ever experiencing a transphobic hate crime; only 51.1% of these were reported to the police. Among those who reported a hate crime experience, Black (47.9%) and Latina (49.0%) trans women reported a higher prevalence of battery with a weapon; White (26.7%) and trans women of “other” race/ethnicities (25.0%) reported a higher prevalence of sexual assault ( p  = 0.001). Having one’s gender questioned, history of sex work, homelessness as a child and adult, and a history incarceration were associated with higher odds of experiencing a transphobic hate crime. Trans women who felt their gender identity questioned had lower odds of reporting a hate crime to the police compared to those did not feel questioned. Conclusions A high proportion of trans women experienced a transphobic hate crime, with significant socio-structural risk factors and racial differences by crime type. However, crimes were underreported to the police. Interventions that address structural factors, especially among trans women of color, can yield violence prevention benefits.

Inequitable gender norms and beliefs contribute to increased sexual risk behavior, and, among adolescent girls and young women (AGYW), risk of HIV acquisition. We investigated the longitudinal measurement properties of the Gender Equitable Men’s Scale (GEMS) when applied to a cohort of AGYW in rural South Africa (2011–2015). We used item response theory [Person-Item maps, Differential Item Functioning (DIF)] and measurement invariance confirmatory factor analysis models to assess the validity and reliability of the GEMS instrument. Item difficulty and endorsement of gender equitable beliefs both shifted over time. DIF analysis identified item bias for over half of the items; influenced by age, pregnancy, sexual debut, and intimate partner violence. Measurement invariance models revealed strong longitudinal invariance properties. GEMS is a reliable longitudinal measurement of gender equitable beliefs, with notable bias for specific items when administered to subgroups. Additional items specific to the adolescent experience are warranted for a more stable assessment of gender equitable beliefs in a population facing shifting norms as they mature.

Mapping and population size estimates of people who inject drugs (PWID) provide information needed for monitoring coverage of programs and planning interventions. The objectives of this study were to provide the locations and numbers of PWID in eight cities in Afghanistan and extrapolate estimates for the country as a whole. Multiple population size estimation methods were used, including key informant interviews for mapping and enumeration with reverse tracking, unique object and service multipliers, capture-recapture, and wisdom of the crowds. The results of the several methods were synthesized using the Anchored Multiplier-a Bayesian approach to produce point estimates and 95% credible intervals (CI). Using the prevalence of PWID in the eight cities and their correlation with proxy indicators, we extrapolated the PWID population size for all of Afghanistan. Key informants and field mapping identified 374 hotspots across the eight cities from December 29, 2018 to March 20, 2019. Synthesizing results of the multiple methods, the number of male PWID in the eight study cities was estimated to be 11,506 (95% CI 8,449-15,093), corresponding to 0.69% (95% CI 0.50-0.90) of the adult male population age 15-64 years. The total number of women who injected drugs was estimated at 484 (95% CI 356-633), corresponding to 0.03% (95% CI 0.02-0.04) of the adult female population. Extrapolating by proxy indicators, the total number of PWID in Afghanistan was estimated to be 54,782 (95% CI 40,250-71,837), men and 2,457 (95% CI 1,823-3,210) women. The total number of PWID in Afghanistan was estimated to be 57,207 (95% CI 42,049-75,005), which corresponds to 0.37% (95% CI 0.27-0.48) of the adult population age 15 to 64 years. This study provided estimates for the number of PWID in Afghanistan. These estimates can be used for advocating and planning services for this vulnerable at-risk population.

Switchable nanomaterials—materials that can change their properties and/or function in response to external stimuli—have potential applications in electronics, sensing and catalysis. Previous efforts to develop such materials have predominately used molecular switches that can modulate their properties by means of conformational changes. Here, we show that electrical conductance through films of gold nanoparticles coated with a monolayer of charged ligands can be controlled by dynamic, long-range gradients of both mobile counterions surrounding the nanoparticles and conduction electrons on the nanoparticle cores. The internal gradients and the electric fields they create are easily reconfigurable, and can be set up in such a way that electric currents through the nanoparticles can be modulated, blocked or even deflected so that they only pass through select regions of the material. The nanoion/counterion hybrids combine the properties of electronic conductors with those of ionic gels/polymers, are easy to process by solution-casting and, by controlling the internal gradients, can be reconfigured into different electronic elements (current rectifiers, switches and diodes). Dynamic internal gradients of ions and electrons can be used to direct electric currents through films of charged metal nanoparticles, and allows current rectifiers, switches and diodes to be created.