Lithium abundances in CEMP stars

Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the observed abundance of Li should deviate in these stars from the standard Spite lithium plateau. We study here a sample of 11 metal-poor stars and a double-lined spectroscopic binary with -1.8 <[Fe/H]< -3.3 observed with VLT/UVES spectrograph. Among these 12 metal-poor stars, there are 8 CEMP stars for which we measure or constrain the Li abundance. In contrast to previous arguments, we demonstrate that an appropriate regime of dilution permits the existence of "Li-Spite plateau and C-rich" stars, whereas some of the "Li-depleted and C-rich" stars call for an unidentified additional depletion mechanism that cannot be explained by dilution alone. We find evidence that rotation is related to the Li depletion in some CEMP stars. Additionally, we report on a newly recognized double-lined spectroscopic binary star in our sample. For this star, we develop a new technique from which estimates of stellar parameters and luminosity ratios can be derived based on a high-resolution spectrum alone, without the need for input from evolutionary models.Comment: 62 pages, 16 figures, accepted for publication in Ap

The Ursinus Weekly, March 13, 1944

Girls grab gobs for gala gathering as leap-year Lorelei looms at last • Y will entertain at spring reception • Students sell $13,744.70 in war bond drive as Eileen Smith wins second individual prize • Dr. W. Fuller explains CED work after war • Rex Gregor is awarded silver star for bravery • Chaplain tells students progress is inevitable • Senators to direct Red Cross drive here • Curtain Club to give three one-act plays • Marian Martin becomes IRC secretary-treasurer • Freshmen to receive colors in ceremony on Thursday • World Student Service Fund helps Chinese students solve problems • Delegates to be chosen for Penn State conference • Coeds to hear Mrs. Mooney • Carpenters, painters give new face to rec center • Dr. Oppenheimer speaks to pre-medical society • Lt. Norris A. Johnson \u2736, Navy radioman, writes from southwest Pacific about Air Corps duties • Frosh end sorority blues • Loyal Irish to praise St. Patrick on Friday • Improved girls\u27 team upsets Beaver after deadlocking for three periods • J.V.\u27s take Jenkintown six; Mid Halbruegge sets pace • Baseball team practices indoors under Heffernan • One-act play will be given at Women\u27s Club session • Betty Tyson reviews poetryhttps://digitalcommons.ursinus.edu/weekly/1726/thumbnail.jp

‘We were not allowed to gather even for Christmas.’ Impact of COVID-19 on South African young people: Exploring messaging and support

COVID-19 prevention measures including lockdowns, school closures, and restricted movement disrupted young people’s lives. This longitudinal qualitative study conducted in Soweto, South Africa aimed to explore young people’s knowledge and perceptions of COVID-19, vaccination, and the impact of infections. A convenience sample of 30 young black people (n = 15 men; n = 15 women, aged 16–21 years) from Soweto participated in 24 focus group discussions (FGDs), conducted in six phases – each phase had four FGDs stratified by gender and age. Young people’s understanding of COVID-19 deepened throughout the study, however, did not always translate into adherence (following the government’s COVID-19 prevention measures). Although deemed inadequate, TV and radio were preferred over internet COVID-19 information. Parents, teachers, and schools were trusted sources of information. Vaccines and limited access to information attributed to low-risk perception, while new COVID-19 variants attributed to high-risk perception. A low-risk perception and conspiracy theories contributed to non-adherence (disregarding COVID-19 preventative measures provided by the government), particularly among young men. Accessing reliable information that considers young people’s lives and their living context is important. Communities, scientists, and policymakers must learn from the COVID-19 experience and implement localised preventive strategies for education, awareness, and economic support in future emergencies

Radial distribution of the multiple stellar populations in omega Centauri

We present a detailed study of the radial distribution of the multiple populations identified in the Galactic globular cluster omega Cen. We used both space-based images (ACS/WFC and WFPC2) and ground-based images (FORS1@VLT and [email protected] ESO telescopes) to map the cluster from the inner core to the outskirts (~20 arcmin). These data sets have been used to extract high-accuracy photometry for the construction of color-magnitude diagrams and astrometric positions of ~900 000 stars. We find that in the inner ~2 core radii the blue main sequence (bMS) stars slightly dominate the red main sequence (rMS) in number. At greater distances from the cluster center, the relative numbers of bMS stars with respect to rMS drop steeply, out to ~8 arcmin, and then remain constant out to the limit of our observations. We also find that the dispersion of the Gaussian that best fits the color distribution within the bMS is significantly greater than the dispersion of the Gaussian that best fits the color distribution within the rMS. In addition, the relative number of intermediate-metallicity red-giant-branch stars which includes the progeny of the bMS) with respect to the metal-poor component (the progeny of the rMS) follows a trend similar to that of the main-sequence star-count ratio N_bMS/N_rMS. The most metal-rich component of the red-giant branch follows the same distribution as the intermediate-metallicity component. We briefly discuss the possible implications of the observed radial distribution of the different stellar components in omega Cen.Comment: 16 pages, 14 figures (6 in low resolution), 3 tables. Accepted for publication in Astronomy and Astrophysics on 23 September 200

New HST WFC3/UVIS observations augment the stellar-population complexity of omega Centauri

We used archival multi-band Hubble Space Telescope observations obtained with the Wide-Field Camera 3 in the UV-optical channel to present new important observational findings on the color-magnitude diagram (CMD) of the Galactic globular cluster omega Centauri. The ultraviolet WFC3 data have been coupled with available WFC/ACS optical-band data. The new CMDs, obtained from the combination of colors coming from eight different bands, disclose an even more complex stellar population than previously identified. This paper discusses the detailed morphology of the CMDs.Comment: 17 pages, 14 figures (11 in low res), 3 tables. Accepted for publication in AJ on June 19, 201

CS 30322-023: an ultra metal-poor TP-AGB star?

With [Fe/H] = -3.5, CS 30322-023 is the most metal-poor star to exhibit a clear s-process signature and the most metal-poor ``lead star'' known. CS 30322-023 is also remarkable in having the lowest surface gravity (log g <= -0.3) among the metal-poor stars studied to date. The available evidence indicates that this star is presently a thermally-pulsing asymptotic giant branch (TP-AGB) star, with no strong indication of binarity thus far (although a signal of period 192 d is clearly present in the radial-velocity data, this is likely due to pulsation of the stellar envelope). We show that low-mass TP-AGB stars are not expected to be exceedingly rare in a magnitude-limited sample such as the HK survey, because their high luminosities make it possible to sample them over a very large volume. The strong N overabundance and the low 12C/13C ratio (4) in this star is typical of the operation of the CN cycle. Coupled with a Na overabundance and the absence of a strong C overabundance, this pattern seems to imply that hot-bottom burning operated in this star, which should then have a mass of at least 2 Msun. However, the luminosity associated with this mass would put the star at a distance of about 50 kpc, in the outskirts of the galactic halo. We explore alternative scenarios in which the observed abundance pattern results from some mixing mechanism yet to be identified occurring in a single low-metallicity 0.8 Msun AGB star, or from pollution by matter from an intermediate-mass AGB companion which has undergone hot-bottom burning. We stress, however, that our abundances may be subject to uncertainties due to NLTE or 3D granulation effects which were not taken into consideration.Comment: 17 pages, Astronomy & Astrophysics, in press; also available at http://www.astro.ulb.ac.be/Html/ps.html#PR

In urban South Africa, 16 year old adolescents experience greater health equality than children

Despite the strongly established link between socio-economic status (SES) and health across most stages of the life-course, the evidence for a socio-economic gradient in adolescent health outcomes is less consistent. This paper examines associations between household, school, and neighbourhood SES measures with body composition outcomes in 16 year old South African Black urban adolescents from the 1990 born Birth to Twenty (Bt20) cohort. Multiple regression analyses were applied to data from a sub-sample of the Bt20 cohort (n=346, 53% male) with measures taken at birth and 16 years of age to establish socio-economic, biological and demographic predictors of fat mass, lean mass, and body mass index (BMI). Results were compared with earlier published evidence of health inequality at ages 9-10 years in Bt20. Consistent predictors of higher fat mass and BMI in fully adjusted models were being female, born post term, having a mother with post secondary school education, and having an obese mother. Most measures of SES were only weakly associated with body composition, with an inconsistent direction of association. This is in contrast to earlier findings with Bt20 9-10 year olds where SES inequalities in body composition were observed. Findings suggest targeting obesity interventions at females in households where a mother has a high BMI

NMRFx Processor: a cross-platform NMR data processing program

NMRFx Processor is a new program for the processing of NMR data. Written in the Java programming language, NMRFx Processor is a cross-platform application and runs on Linux, Mac OS X and Windows operating systems. The application can be run in both a graphical user interface (GUI) mode and from the command line. Processing scripts are written in the Python programming language and executed so that the low-level Java commands are automatically run in parallel on computers with multiple cores or CPUs. Processing scripts can be generated automatically from the parameters of NMR experiments or interactively constructed in the GUI. A wide variety of processing operations are provided, including methods for processing of non-uniformly sampled datasets using iterative soft thresholding. The interactive GUI also enables the use of the program as an educational tool for teaching basic and advanced techniques in NMR data analysis

Assessing the public acceptability of proposed policy interventions to reduce the misuse of antibiotics in Australia: A report on two community juries

Objective To elicit the views of well-informed community members on the acceptability of proposed policy interventions designed to improve community use of antibiotics in Australia. Design Two community juries held in 2016. Setting and participants Western Sydney and Dubbo communities in NSW, Australia. Twenty-nine participants of diverse social and cultural backgrounds, mixed genders and ages recruited via public advertising: one jury was drawn from a large metropolitan setting; the other from a regional/rural setting. Main outcome measure Jury verdict and rationale in response to a prioritization task and structured questions. Results Both juries concluded that potential policy interventions to curb antibiotic misuse in the community should be directed towards: (i) ensuring that the public and prescribers were better educated about the dangers of antibiotic resistance; (ii) making community-based human and animal health-care practitioners accountable for their prescribing decisions. Patient-centred approaches such as delayed prescribing were seen as less acceptable than prescriber-centred approaches; both juries completely rejected any proposal to decrease consumer demand by increasing antibiotic prices. Conclusion These informed citizens acknowledged the importance of raising public awareness of the risks, impacts and costs of antibiotic resistance and placed a high priority on increasing social and professional accountability through restrictive measures. Their overarching aim was that policy interventions should be directed towards creating collective actions and broad social support for changing antibiotic use through establishing and explaining the need for mechanisms to control and support better prescribing by practitioners, while not transferring the burdens, costs and risks of interventions to consumers.This work was supported by a seed grant from the Marie Bashir Institute for Infectious Disease and Biosecurity and NHMRC CRE 1102962. CD, JJ and GLG received funding support from a NHMRC Project grant (#1083079). SMC is funded through NHMRC Career Development Fellowship (#1032963)