32 research outputs found

    Collisional removal of HI from the inner disks of Virgo cluster galaxies

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    There is sufficient observational evidence to show that many Virgo Cluster spirals are HI deficient in their inner disks (in addition to being HI deficient globally, as previously established). It is shown here that collisions between galaxies in a cluster can lead to the removal of HI gas from these galaxies while leaving the H2 gas, undisturbed. This follows directly from the application of the Spitzer-Baade collisional gas removal mechanism to galaxies consisting of stars and a two-component interstellar medium (ISM) consisting of HI and H2, with HI having the largest filling factor. This can account for both the observed HI deficiency in the inner regions and the normal H2 content of these galaxies. The frequency of galaxy collisions in the Virgo Cluster is shown to be large enough to make collisional gas removal a viable mechanism

    Influence of the Physicomechanical Properties of Starches on Their Tabletability—A Multivariate Analysis

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    Purpose The goal of this study was to identify correlations between the physicomechanical properties of different grades of starches with their tabletability. Methods Corn-starch grades (PURE-DENT® B700, PURE-DENT® B810, and PURE-DENT® B830) and pregelatinized corn-starch grades (SPRESS® B818, SPRESS® B820, and SPRESS® B825) were studied for physicomechanical properties, dynamic sorption isotherm, moisture content [MC] (% w/w), dehydration enthalpy (J/g) [ΔHd], and percent crystallinity (%). Tablets (6 mm) were compressed from hand-weighed powders (constant true volume) using Gamlen Tablet Press (Compression pressure-100 MPa; Compression speed- 5mm/s, 50 mm/s). Tablet mechanical strength (TMS) and Heckel parameters were evaluated. Correlation between physicomechanical properties and compression descriptors was evaluated by multivariate method. Results All starches followed Type-III sorption isotherm with open hysteresis loop indicating their large amorphous content. High amorphous content was further confirmed with hollow diffraction peaks of starches in the powder X-ray diffraction studies. Glass transition temperature of all starches was about 101°C. The moisture content and percent crystallinity of all starches was found statistically insignificant. However, PURE-DENT® B830 and SPRESS® B818 showed significantly low ΔHd values. Principle component analysis (PCA) loadings plot calculated with measured physicomechanical properties and TMS showed positive correlation between high Heckel Yield pressure values of plastic and elastic deformation and negative correlation with percent crystallinity, ΔHd, and MC along PC1. These relationships confirmed expected phenomenon in PCA score plots that Starches (PURE-DENT® B830 and SPRESS® B818) with plastic deformation followed by low elastic recovery in the decompression phase shows better tabletability. Furthermore, positive correlation of low ΔHd with TMS might indicate that starches with easy availability of associated water (low ΔHd) might have better tabletability due to water induced material plasticization. Conclusion Out of the six different grades of starches studied PURE-DENT® B830 and SPRESS® B818 showed better tabletability regardless of similar MC and amorphous nature. The better tabletability of these two starches might be attributed to their better plasticization due to loosely bound associated water, and low elastic recovery in the decompression phase

    Participation in adherence clubs and on-time drug pickup among HIV-infected adults in Zambia: a matched-pair cluster randomized trial

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    Background: Current models of HIV service delivery, with frequent facility visits, have led to facility congestion, patient and healthcare provider dissatisfaction, and suboptimal quality of services and retention in care. The Zambian urban adherence club (AC) is a health service innovation designed to improve on-time drug pickup and retention in HIV care through off-hours facility access and pharmacist-led group drug distribution. Similar models of differentiated service delivery (DSD) have shown promise in South Africa, but observational analyses of these models are prone to bias and confounding. We sought to evaluate the effectiveness and implementation of ACs in Zambia using a more rigorous study design. Methods and findings: Using a matched-pair cluster randomized study design (ClinicalTrials.gov: NCT02776254), 10 clinics were randomized to intervention (5 clinics) or control (5 clinics). At each clinic, between May 19 and October 27, 2016, a systematic random sample was assessed for eligibility (HIV+, age ≥ 14 years, on ART >6 months, not acutely ill, CD4 count not 7 days late). Intervention effect was estimated using unadjusted Kaplan–Meier survival curves and a Cox proportional hazards model to derive an adjusted hazard ratio (aHR). Medication possession ratio (MPR) and implementation outcomes (adoption, acceptability, appropriateness, feasibility, and fidelity) were additionally evaluated as secondary outcomes. Baseline characteristics were similar between 571 intervention and 489 control participants with respect to median age (42 versus 41 years), sex (62% versus 66% female), median time since ART initiation (4.8 versus 5.0 years), median CD4 count at study enrollment (506 versus 533 cells/mm3), and baseline retention (53% versus 55% with at least 1 late drug pickup in previous 12 months). The rate of late drug pickup was lower in intervention participants compared to control participants (aHR 0.26, 95% CI 0.15–0.45, p < 0.001). Median MPR was 100% in intervention participants compared to 96% in control participants (p < 0.001). Although 18% (683/3,734) of AC group meeting visits were missed, on-time drug pickup (within 7 days) still occurred in 51% (350/683) of these missed visits through alternate means (use of buddy pickup or early return to the facility). Qualitative evaluation suggests that the intervention was acceptable to both patients and providers. While patients embraced the convenience and patient-centeredness of the model, preference for traditional adherence counseling and need for greater human resources influenced intervention appropriateness and feasibility from the provider perspective. The main limitations of this study were the small number of clusters, lack of viral load data, and relatively short follow-up period. Conclusions: ACs were found to be an effective model of service delivery for reducing late ART drug pickup among HIV-infected adults in Zambia. Drug pickup outside of group meetings was relatively common and underscores the need for DSD models to be flexible and patient-centered if they are to be effective

    Differentiated care preferences of stable patients on ART in Zambia: a discrete choice experiment

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    Background: Although differentiated service delivery (DSD) models for stable patients on antiretroviral therapy (ART) offer a range of health systems innovations, their comparative desirability to patients remains unknown. We conducted a discrete choice experiment to quantify service attributes most desired by patients to inform model prioritization Methods: Between July and December 2016 a sample of HIV-positive adults on ART at 12 clinics in Zambia were asked to choose between two hypothetical facilities which differed across six DSD attributes. We used mixed logit models to explore preferences, heterogeneity and trade-offs Results: Of 486 respondents, 59% were female and 85% resided in urban locations. Patients strongly preferred infrequent clinic visits (3 vs. 1-month visits: β (i.e. relative utility) =2.84; p <0.001). Milder preferences were observed for: waiting time for ART pick-up (1 vs. 6 hrs.; β=-0.67; p<0.001) or provider (1 vs. 3 hrs.; β=-0.41; p=0.002); ‘buddy’ ART collection (β=0.84; p <0.001); and ART pick-up location (clinic vs. community: β=0.35; p=0.028). Urban patients demonstrated a preference for collecting ART at a clinic (β=1.32, p<0.001), and although the majority of rural patients preferred community ART pick-up (β=-0.74, p=0.049), 40% of rural patients still preferred facility ART collection. Conclusions: Stable patients on ART primarily want to attend clinic infrequently, supporting a focus in Zambia on optimizing multi-month prescribing over other DSD features - particularly in urban areas. Substantial preference heterogeneity highlights the need for DSD models to be flexible, and accommodate both setting features and patient choice in their design

    Report on the Challenges of Air Transportation Experienced by People with Disabilities

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    Boarding an airplane is difficult for persons with mobility impairments and increases the risk of injury to both passengers and employees. Airplane seats are uncomfortable and lack the necessary support for many individuals with disabilities. Additionally, airplane restrooms can be inaccessible to wheelchair users. Potential solutions for these issues include the use of detachable plane seats or personal wheelchairs on board and an airplane redesign to provide additional restroom space. The number of service and emotional support animals being brought on airplanes have also increased substantially over the past few years. Passengers that travel with their service animals must contend with having to follow different rules for different airlines carriers and not having sufficient space for animals to be safe and comfortable

    Report of the Topical Group on Cosmic Probes of Dark Matter for Snowmass 2021

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    Cosmological and astrophysical observations currently provide the only robust, positive evidence for dark matter. Cosmic probes of dark matter, which seek to determine the fundamental properties of dark matter through observations of the cosmos, have emerged as a promising means to reveal the nature of dark matter. This report summarizes the current status and future potential of cosmic probes to inform our understanding of the fundamental nature of dark matter in the coming decade.Comment: Report of the CF3 Topical Group for Snowmass 2021; 35 pages, 10 figures, many references. V3 updates Fig 3-2 and the author lis

    Astro2020 Must Issue Actionable Recommendations Regarding Diversity, Inclusion, and Harassment

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    The 2010 Decadal survey failed to issue any recommendations on diversity and inclusion.Astro2020 cannot make the same mistake. Findings can be ignored by funding agencies;recommendations cannot. In the past decade, multiple groups have assembled detailed actionplans to fix a broken climate within our profession. Astro2020 should play a key role, bysynthesizing this work to produce actionable recommendations to support diversity andinclusion and stop harassment within our profession

    The global burden of injury: Incidence, mortality, disability-adjusted life years and time trends from the global burden of disease study 2013

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    Background The Global Burden of Diseases (GBD), Injuries, and Risk Factors study used the disabilityadjusted life year (DALY) to quantify the burden of diseases, injuries, and risk factors. This paper provides an overview of injury estimates from the 2013 update of GBD, with detailed information on incidence, mortality, DALYs and rates of change from 1990 to 2013 for 26 causes of injury, globally, by region and by country. Methods Injury mortality was estimated using the extensive GBD mortality database, corrections for illdefined cause of death and the cause of death ensemble modelling tool. Morbidity estimation was based on inpatient and outpatient data sets, 26 cause-of-injury and 47 nature-of-injury categories, and seven follow-up studies with patient-reported long-term outcome measures. Results In 2013, 973 million (uncertainty interval (UI) 942 to 993) people sustained injuries that warranted some type of healthcare and 4.8 million (UI 4.5 to 5.1) people died from injuries. Between 1990 and 2013 the global age-standardised injury DALY rate decreased by 31% (UI 26% to 35%). The rate of decline in DALY rates was significant for 22 cause-of-injury categories, including all the major injuries. Conclusions Injuries continue to be an important cause of morbidity and mortality in the developed and developing world. The decline in rates for almost all injuries is so prominent that it warrants a general statement that the world is becoming a safer place to live in. However, the patterns vary widely by cause, age, sex, region and time and there are still large improvements that need to be made

    The Role Of CD90 in Breast Cancer Tumor Progression

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    Breast cancer is the most common cancer among women, with effective treatments if the disease stays local. However, if the tumor metastasizes, patient outcomes are significantly reduced. Mesenchymal stem cells (MSC) have been shown to enhance metastasis by facilitating invasion and tumor outgrowth. MCF10A Ca1h cells, a mesenchymal-like cell line, have been shown to promote metastasis in a murine model and enhance the survival and proliferation of their epithelial counterpart (Ca1a) in coculture. We have established the presence of the classic MSC markers, CD90, CD105, and CD73, on the Ca1h cells and observe a decrease in the CD90+ population in the Ca1a and fibronectin knockdown Ca1h cells. To examine the effects of this decreased expression, a CD90 knockdown of Ca1h cells was created using lenti-viral transduction. A decrease in fibronectin levels was seen in the CD90 knockdowns, along with a change in morphological characteristics of the cells. To investigate the influence of a 3D microenvironment on cell phenotype, they were also cultured on fibronectin coated scaffolds and evaluated for CD44/CD24 expression. Lastly, the knockdowns were cocultured with the Ca1a cells in a 3D hydrogel to assess the impact of coculture on survival and proliferation. We found that the CD90 knockdowns take on epithelial-like characteristics and decrease survival of Ca1a cells in coculture. These findings suggest that CD90 is necessary to maintain a mesenchymal phenotype and could be used as a target for therapies to prevent metastasis

    H I deficiency in cluster spiral galaxies: dependence on galaxy size

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    From the available H I data on spiral galaxies in three rich Abell clusters and the Virgo Cluster, it is shown that galaxies with medium to large optical sizes tend to be more severely deficient in atomic hydrogen than the small galaxies. This is so both in terms of the fractional number of galaxies that are deficient and the amount of gas lost by a galaxy. The fraction of H l-deficient galaxies increases with size over most of the size range, saturating or dropping only for the largest galaxies. We make a comparative study of various currently accepted gas removal mechanisms, namely those which are a result of galaxy-intracluster medium interactions, e.g., ram pressure stripping, as well as those due to galaxy-galaxy interactions, i.e., collisions and tidal interactions. We show that with the exception of tidal interactions, all of these mechanisms would produce a size dependence in H I deficiency that is the opposite of that observed. That is, the gas in the largest galaxies would be the least affected by these mechanisms. However, if there is significant mass segregation, these processes may give the trends observed in the size dependence of H I deficiency. We propose that tidal encounters between galaxies in subclumps or groups, which then merged to form clusters or were subsequently accreted by them, could have led to significant gas removal from these galaxies at early epochs. This could qualitatively explain the dependence of H I deficiency on galaxy size. Since all the gas removal mechanisms known are less effective on the galaxies of the largest sizes, the drop in the fraction of deficient galaxies for these sizes is accounted for
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