29 research outputs found

    Arkansas Cotton Variety and Strain Tests 1991

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    Varieties and advanced strains of cotton were evaluated in 1991 by the Arkansas Agricultural Experiment Station. Varieties and some advanced breeding lines were evaluated in the 1991 Arkansas Cotton Variety Test. Entries in the 1991 Commercial Cotton Strain Test included both released varieties that have not been evaluated in Arkansas and advanced breeding lines that may soon be available to producers

    The Giant Accreting Protoplanet Survey (GAPlanetS) -- Results from a Six Year Campaign to Image Accreting Protoplanets

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    Accreting protoplanets represent a window into planet formation processes. We report H{\alpha} differential imaging results from the deepest and most comprehensive accreting protoplanet survey to date, acquired with the Magellan Adaptive Optics (MagAO) system's VisAO camera. The fourteen transitional disks targeted are ideal candidates for protoplanet discovery due to their wide, heavily depleted central cavities, wealth of non-axisymmetric circumstellar disk features evocative of ongoing planet formation, and ongoing stellar accretion. To address the twin challenges of morphological complexity in the target systems and PSF instability, we develop novel approaches for frame selection and optimization of the Karhounen-Loeve Image Processing algorithm pyKLIP. We detect one new candidate protoplanet, CS Cha "c", at a separation of 75mas and a {\Delta}mag of 5.1 and robustly recover the HD142527 B and HD100453 B low mass stellar companions across multiple epochs. Though we cannot rule out a substantial scattered light contribution to its emission, we also recover LkCa 15 b. Its presence inside of the cleared disk cavity and consistency with a forward-modeled point source suggest that it remains a viable protoplanet candidate. The protoplanet PDS 70 c was marginally recovered under our conservative general methodology. However, through targeted optimization in H{\alpha} imagery, we tentatively recover PDS 70 c in three epochs and PDS 70 b in one epoch. Of the many other previously-reported companions and companion candidates around objects in the sample, we do not recover any additional robust candidates. However, lack of recovery at moderate H{\alpha} contrast does not rule out the presence of protoplanets at these locations, and we report limiting H{\alpha} contrasts in such cases.Comment: Accepted for publication in A

    The Comprehensive Archive of Substellar and Planetary Accretion Rates

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    Accretion rates ( MĖ™\dot{M} ) of young stars show a strong correlation with object mass ( M ); however, extension of the \dot{M}\mbox{--}M relation into the substellar regime is less certain. Here, we present the Comprehensive Archive of Substellar and Planetary Accretion Rates (CASPAR), the largest compilation to date of substellar accretion diagnostics. CASPAR includes: 658 stars, 130 brown dwarfs, and 10 bound planetary mass companions. In this work, we investigate the contribution of methodological systematics to scatter in the \dot{M}\mbox{--}M relation and compare brown dwarfs to stars. In our analysis, we rederive all quantities using self-consistent models, distances, and empirical line flux to accretion luminosity scaling relations to reduce methodological systematics. This treatment decreases the original 1 Ļƒ scatter in the \mathrm{log}\dot{M}\mbox{--}\mathrm{log}M relation by āˆ¼17%, suggesting that it makes only a small contribution to the dispersion. The CASPAR rederived values are best fit by MĖ™āˆM2.02Ā±0.06\dot{M}\propto {M}^{2.02\pm 0.06} from 10 M _J to 2 M _āŠ™ , confirming previous results. However, we argue that the brown-dwarf and stellar populations are better described separately and by accounting for both mass and age. Therefore, we derive separate age-dependent \dot{M}\mbox{--}M relations for these regions and find a steepening in the brown-dwarf \dot{M}\mbox{--}M slope with age. Within this mass regime, the scatter decreases from 1.36 dex to 0.94 dex, a change of āˆ¼44%. This result highlights the significant role that evolution plays in the overall spread of accretion rates, and suggests that brown dwarfs evolve faster than stars, potentially as a result of different accretion mechanisms

    HTPN 078: an enhanced case management study to achieve viral suppression among viremic HIV-positive men who have sex with men in the United States.

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    OBJECTIVES: After identifying and recruiting men who have sex with men living with HIV and virally unsuppressed, this study attempted to enhance treatment and care via case management to increase the proportion who achieved viral suppression. DESIGN: Participants were randomized into one of two study arms: standard of care (SOC) or enhanced case management (CM) intervention. Participants were followed for 12ā€Šmonths with quarterly study assessments, with blood collected for CD4+ cell count testing, HIV viral load testing (primary prespecified outcome), and plasma storage. METHODS: Participants identified via respondent-driven sampling and direct recruitment and were invited to participate in the randomized controlled trial. The CM intervention provided a wide range of support services including, health education, clinical care coordination, medication adherence support, and social service assistance. The month-12 assessment included questions about healthcare utilization, stigma, substance use, and mental health. RESULTS: Among the 144 participants virally unsuppressed at baseline, most had had a previous positive HIV test result; were Black, non-Hispanic, gay and bisexual men, aged 22-50. Among the 128 participants at the last study visit, 68 were virally suppressed, with no statistically significant difference between the CM and SOC arms (viral suppression 42% and 53%, respectively; adjusted odds ratio = 0.62 [Pā€Š=ā€Š0.15; 95% confidence interval: 0.32, 1.2]). CONCLUSIONS: Reaching targets of at least 90% sustained viral suppression among all people with HIV will likely require more than an individual-level CM approach that addresses barriers to optimal care and treatment at multiple levels
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