The Orion Nebula Cluster (ONC) is the nearest site of ongoing massive star formation, which allows us to study the kinematics and dynamics of the region in detail and constrain star formation ...theories. Using HST ACS/WFPC2/WFC3IR and Keck II NIRC2 data, we have measured the proper motions of 701 stars within an ∼6′ × 6′ field of view around the center of the ONC. We have found more than 10 escaping star candidates, concentrated predominantly at the core of the cluster. The proper motions of the bound stars are consistent with a normal distribution, albeit elongated north-south along the Orion filament, with proper-motion dispersions of mas yr−1 or intrinsic velocity dispersions of km s−1 assuming a distance of 400 pc to the ONC. The cluster shows no evidence for tangential-to-radial anisotropy. Our velocity dispersion profile agrees with the prediction from the observed stellar + gas density profile from Da Rio et al., indicating that the ONC is in virial equilibrium. This finding suggests that the cluster was formed with a low star formation efficiency per dynamical timescale based on comparisons with current star formation theories. Our survey also recovered high-velocity IR sources BN, x and n in the BN/KL region. The estimated location of the first two sources ∼500 yr ago agrees with that of the radio source I, consistent with their proposed common origin from a multistellar disintegration. However, source n appears to have a small proper motion and is unlikely to have been involved in the event.
We report the beginning of activity for comet C/2015 ER61 (PANSTARRS), the first instance of watching a long-period comet turn on. Pre-discovery observations and observations from the NEOWISE space ...telescope suggest that the nucleus is large, with a radius of RN ∼ 9 km, assuming an albedo of 0.025. Our photometric data follows the comet from r = 8.9 to 4.8 au as it moved into solar conjunction in 2016 July. Our sublimation model shows that activity began near r = 8.8 au (true anomaly, TA = −139°) in early 2015, driven by CO2 sublimation, which peaked in 2016 April at r = 5.1 au (TA = −127°). Appreciable water sublimation began around r = 5.0 au. Our sublimation model is consistent with an active water sublimation area of 1% of the surface (equivalent to 10.2 km2), and an active surface area for CO2 sublimation of 0.029% (0.3 km2). The CO2 production rate at r = 4.66 au as measured by NEOWISE is (8.4 2) × 1025 s−1. If CO2-ice had been present on the surface, dust dragged from the surface by sublimation would have been observed much farther out-as far as 20 au. Our thermal models suggest that the CO2 ice was present at a depth of 0.4 m. The comet came out of solar conjunction in 2016 December and, unless it brightens significantly, is unlikely to have water production rates much higher than a few ×1028 s−1.
We report the detection of several absorption lines of neutral phosphorus (P, Z = 15) in archival near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble ...Space Telescope. We derive phosphoms abundances or interesting upper limits in 14 late-type stars with metallicities spanning -3.8 < Fe/H < -0.1. Previously, phosphorus had only been studied in Galactic stars with -1.0 < Fe/H < +0.3. Iron lines reveal abundance offsets between the optical and ultraviolet regions, and we discuss and apply a correction factor to account for this offset. In stars with Fe/H > -1.0, the P/Fe ratio decreases toward the solar value with increasing metallicity, in agreement with previous observational studies. In stars with Fe/H < -1.0, left angle bracketP/Feright angle bracket = +0.04 + or - 0.10, which overlaps with the P/Fe ratios found in several high-redshift damped Lyman- alpha systems. This behavior hints at a primary origin in massive stars.
The Orion Nebula Cluster (ONC) is the nearest site of ongoing massive star formation, which allows us to study the kinematics and dynamics of the region in detail and constrain star formation ...theories. Using HST ACS/WFPC2/WFC3IR and Keck II NIRC2 data, we have measured the proper motions of 701 stars within an \(\sim6'\times6'\) field of view around the center of the ONC. We have found more than 10 escaping star candidates, concentrated predominantly at the core of the cluster. The proper motions of the bound stars are consistent with a normal distribution, albeit elongated North-South along the Orion filament, with proper motion dispersions of \((\sigma_{\mu,\alpha^*}, \sigma_{\mu,\delta}) = (0.83\pm0.02,\,1.12\pm0.03)\) mas yr\(^{-1}\) or intrinsic velocity dispersions of \((\sigma_{v,\alpha^*}, \sigma_{v,\delta}) = (1.57\pm0.04,\,2.12\pm0.06)\) km s\(^{-1}\) assuming a distance of 400 pc to the ONC. The cluster shows no evidence for tangential-to-radial anisotropy. Our velocity dispersion profile agrees with the prediction from the observed stellar + gas density profile from Da Rio et al. (2014), indicating that the ONC is in virial equilibrium. This finding suggests that the cluster was formed with a low star formation efficiency per dynamical timescale based on comparisons with current star formation theories. Our survey also recovered high-velocity IR sources BN, x, and n in the BN/KL region. The estimated location of the first two sources \(\sim500\) years ago agrees with that of the radio source I, consistent with their proposed common origin from a multi-stellar disintegration. However, source n appears to have a small proper motion and is unlikely to have been involved in the event.
In this follow-up to our earlier study (Toller, Suter, & Trautman, Gender role identity & attitudes towards feminism, Sex Roles, 51, 85-90, 2004) we examine the interrelationships among gender role, ...support for feminism, & willingness to self-label as feminist. Ten percent of college students previously surveyed participated in qualitative interviews, which elicited characterizations of feminists, whether students self-identified as feminist, suggestions for garnering support for feminism, & for interpretation of the initial study's findings. Students were asked to speculate why we found that highly masculine men & highly feminine women were neither likely to self-identify as feminist nor to support the feminist movement & why more feminine men & more masculine women were found to be more willing to self-label as feminist & more likely to support the feminist movement. References. Adapted from the source document.
We report the detection of several absorption lines of neutral phosphorus (P, Z=15) in archival near ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble ...Space Telescope. We derive phosphorus abundances or interesting upper limits in 14 late-type stars with metallicities spanning -3.8<Fe/H<-0.1. Previously, phosphorus had only been studied in Galactic stars with -1.0<Fe/H<+0.3. Iron lines reveal abundance offsets between the optical and ultraviolet regions, and we discuss and apply a correction factor to account for this offset. In stars with Fe/H>-1.0, the P/Fe ratio decreases toward the solar value with increasing metallicity, in agreement with previous observational studies. In stars with Fe/H<-1.0, <P/Fe>=+0.04+/-0.10, which overlaps with the P/Fe ratios found in several high-redshift damped Lyman-alpha systems. This behavior hints at a primary origin in massive stars.
Abstract
Background
There is limited evidence to date about changes to sexual and reproductive health (SRH) during the initial wave of coronavirus disease 2019 (COVID-19). To address this gap, our ...team organized a multicountry, cross-sectional online survey as part of a global consortium.
Methods
Consortium research teams conducted online surveys in 30 countries. Sampling methods included convenience, online panels, and population-representative. Primary outcomes included sexual behaviors, partner violence, and SRH service use, and we compared 3 months prior to and during policy measures to mitigate COVID-19. We conducted meta-analyses for primary outcomes and graded the certainty of the evidence.
Results
Among 4546 respondents with casual partners, condom use stayed the same for 3374 (74.4%), and 640 (14.1%) reported a decline. Fewer respondents reported physical or sexual partner violence during COVID-19 measures (1063 of 15 144, 7.0%) compared to before COVID-19 measures (1469 of 15 887, 9.3%). COVID-19 measures impeded access to condoms (933 of 10 790, 8.7%), contraceptives (610 of 8175, 7.5%), and human immunodeficiency virus/sexually transmitted infection (HIV/STI) testing (750 of 1965, 30.7%). Pooled estimates from meta-analysis indicate that during COVID-19 measures, 32.3% (95% confidence interval CI, 23.9%–42.1%) of people needing HIV/STI testing had hindered access, 4.4% (95% CI, 3.4%–5.4%) experienced partner violence, and 5.8% (95% CI, 5.4%–8.2%) decreased casual partner condom use (moderate certainty of evidence for each outcome). Meta-analysis findings were robust in sensitivity analyses that examined country income level, sample size, and sampling strategy.
Conclusions
Open science methods are feasible to organize research studies as part of emergency responses. The initial COVID-19 wave impacted SRH behaviors and access to services across diverse global settings.
The I-SHARE-1 study in 30 countries assessed sexual and reproductive health outcomes among adults. During COVID-19 measures, 32.3% of people needing HIV/STI testing had hindered access, 4.4% experienced partner violence, and 5.8% decreased casual partner condom use.
Research suggests experiences with police are related to human immunodeficiency virus (HIV) sexual risk among women working as sex workers. However, little is known about the links between specific ...police-related behaviors and HIV vulnerability. We examine whether 5 police-related experiences are associated with measures of HIV risk and violence among a sample of female sex workers (FSWs) in Andhra Pradesh, India, and consider the implications for HIV prevention. FSWs at least 18 years of age (n = 835) were recruited through respondent-driven sampling for a cross-sectional survey conducted as part of Avahan, the India AIDS Initiative. Using logistic regression models adjusted for age, age at start of sex work, and sex work venue, we assessed police-related experiences reported by FSWs in relation to HIV risk behaviors and violence. Results showed having sex with police to avoid trouble, giving gifts to police to avoid trouble, having police take condoms away, experiencing a workplace raid, and being arrested were associated with sexually transmitted infection symptoms, inconsistent condom use, acceptance of more money for sex without a condom, and experience of client violence. These findings suggest a need for interventions targeting police-FSW interactions to reduce HIV vulnerability among FSWs.
Rapid rise of population migration is a defining feature of the 21st century due to the impact of climate change, political instability, and socioeconomic downturn. Over the last decade, an ...increasing number of migrant peoples travel across the Americas to reach the United States seeking asylum or cross the border undocumented in search of economic opportunities. In this journey, migrant people experience violations of their human rights, hunger, illness, violence and have limited access to medical care. In the ‘Divine Comedy’, the Italian poet Dante Alighieri depicts his allegorical pilgrimage across Hell and Purgatory to reach Paradise. More than 700 years after its publication, Dante's poem speaks to the present time and the perilious journey of migrant peoples to reach safehavens. By exploring the depths and heights of the human condition, Dante's struggles resonate with the multiple barriers and the unfathomable experiences faced by migrant peoples in transit across South, Central, and North America to reach the United States. Ensuring the safety of migrant peoples across the Americas and elsewhere, and attending to their health needs during their migratory paths represent modern priorities to reduce social injustices and achieving health equity.
Little is known about the effectiveness of intervening to change interactions between female sex workers (FSWs) and police in order to reduce HIV risk. Using data collected in the context of a HIV ...prevention intervention that included components to change policing practices (
n
= 1,680), we examine the association of FSWs’ reports of negative police interactions and HIV risk behaviors and whether these associations varied over time. Results show negative police interactions declined significantly over time. FSWs who had more than one negative police interaction were more likely to experience STI symptoms (AOR 2.97 95 % CI 2.27–3.89), inconsistently use condoms with their clients (AOR 1.36 95 % CI 1.03–1.79), and accept more money for condomless sex (AOR 2.37 95 % CI 1.76–3.21). Over time, these associations were stable or increased. Even where interventions have reduced the number of police incidents experienced by FSWs, stakeholders in HIV prevention must remain vigilant in challenging these incidents.
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