190 research outputs found

    Cytokinin induces genome-wide binding of the type-B response regulator ARR10 to regulate growth and development in Arabidopsis

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    Cytokinins, like other plant hormones, affect a diverse array of plant growth and development processes and responses to the environment. How a signaling molecule mediates such a diverse array of outputs and how these response pathways are integrated with other inputs remain fundamental questions in plant biology. An integrated set of approaches was used to define the targets of the type-B response regulators, a key set of transcription factors that control cytokinin-dependent gene expression. Results shed light on the physiological role of the type-B ARRs in regulating the cytokinin response, mechanism of type-B ARR activation, and basis by which cytokinin regulates diverse aspects of growth and development as well as responses to biotic and abiotic factors

    “In the Beginning, It Was Little Whispers...Now, We’re Almost a Roar”: Conceptualizing a Model for Community and Self in LGBTQ+ Health Information Practices

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    Although LGBTQ+ populations experience significant health challenges, little research exists that investigates their health from an informational perspective. Our study addresses this gap by exploring the health information practices of LGBTQ+ communities in South Carolina, focusing on how sociocultural context shapes these practices. Thirty semi-structured interviews with South Carolina LGBTQ+ community leaders analyzed using open qualitative coding informed the development of a conceptual framework describing their information practices. Findings show that participants engaged in two broad types of practices – protective and defensive – as responses to risks and barriers experienced, which are in turn produced by social and structural factors. Findings advance information practices and marginalization approaches and offer ways for medical professionals to improve service to LGBTQ+ populations

    The JWST Early-Release Science Program for Direct Observations of Exoplanetary Systems Ii: A 1 To 20 Μm Spectrum of the Planetary-Mass Companion Vhs 1256-1257 B

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    We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a (∼8″, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color-magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256 b with JWST\u27s NIRSpec IFU and MIRI MRS modes for coverage from 1 to 20 μm at resolutions of ∼1000-3700. Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are observed in several portions of the JWST spectrum based on comparisons from template brown dwarf spectra, molecular opacities, and atmospheric models. The spectral shape of VHS 1256 b is influenced by disequilibrium chemistry and clouds. We directly detect silicate clouds, the first such detection reported for a planetary-mass companion

    Participation, knowledge production, and evaluative research: participation by different actors in a mental health study

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    This article reflects on the interrelations between participation, knowledge production, and public policy evaluation in light of issues from our own experience with evaluative research on a municipal network of Psychosocial Care Centers (CAPS) in Brazil. The article discusses the coordination of the complex process and the potentials and limits of partnerships for conducting qualitative evaluative studies in mental health with participation by different social actors. The authors conclude that qualitative evaluative research aligned with the perspective of including different points of view representing various segments is the best approach for understanding the numerous spin-offs from the implementation of services linked to the Brazilian psychiatric reform movement, given the inherent specificities of the mental health field.No presente texto apresentamos considerações sobre pesquisa avaliativa qualitativa e participativa com base em investigação desta natureza realizada junto a uma rede municipal de Centros de Atenção Psicossocial (CAPS) ligados ao Sistema Único de Saúde (SUS). A coordenação do complexo processo, bem como as potencialidades e limites do estabelecimento de parcerias para a realização de trabalhos de investigação avaliativa qualitativa em saúde mental, com a inclusão de diferentes atores sociais, são aqui discutidas. Concluímos que a pesquisa avaliativa qualitativa aliada à perspectiva de inclusão de distintos pontos de vista dos vários segmentos envolvidos é a que melhor se adequa à compreensão dos muitos desdobramentos oriundos da implementação de serviços ligados ao movimento de reforma psiquiátrica brasileira, dado as especificidades inerentes ao campo da saúde mental.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP)Universidade Estadual de Campinas FCMUNIFESPSciEL

    Altered Metabolism and Persistent Starvation Behaviors Caused by Reduced AMPK Function in Drosophila

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    Organisms must utilize multiple mechanisms to maintain energetic homeostasis in the face of limited nutrient availability. One mechanism involves activation of the heterotrimeric AMP-activated protein kinase (AMPK), a cell-autonomous sensor to energetic changes regulated by ATP to AMP ratios. We examined the phenotypic consequences of reduced AMPK function, both through RNAi knockdown of the gamma subunit (AMPKγ) and through expression of a dominant negative alpha (AMPKα) variant in Drosophila melanogaster. Reduced AMPK signaling leads to hypersensitivity to starvation conditions as measured by lifespan and locomotor activity. Locomotor levels in flies with reduced AMPK function were lower during unstressed conditions, but starvation-induced hyperactivity, an adaptive response to encourage foraging, was significantly higher than in wild type. Unexpectedly, total dietary intake was greater in animals with reduced AMPK function yet total triglyceride levels were lower. AMPK mutant animals displayed starvation-like lipid accumulation patterns in metabolically key liver-like cells, oenocytes, even under fed conditions, consistent with a persistent starved state. Measurements of O2 consumption reveal that metabolic rates are greater in animals with reduced AMPK function. Lastly, rapamycin treatment tempers the starvation sensitivity and lethality associated with reduced AMPK function. Collectively, these results are consistent with models that AMPK shifts energy usage away from expenditures into a conservation mode during nutrient-limited conditions at a cellular level. The highly conserved AMPK subunits throughout the Metazoa, suggest such findings may provide significant insight for pharmaceutical strategies to manipulate AMPK function in humans

    The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b

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    We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a <<20 MJup_\mathrm{Jup} widely separated (\sim8\arcsec, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799 c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color-magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256~b with \textit{JWST}'s NIRSpec IFU and MIRI MRS modes for coverage from 1 μ\mum to 20 μ\mum at resolutions of \sim1,000 - 3,700. Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are observed in several portions of the \textit{JWST} spectrum based on comparisons from template brown dwarf spectra, molecular opacities, and atmospheric models. The spectral shape of VHS 1256 b is influenced by disequilibrium chemistry and clouds. We directly detect silicate clouds, the first such detection reported for a planetary-mass companion.Comment: Accepted ApJL Iterations of spectra reduced by the ERS team are hosted at this link: https://github.com/bemiles/JWST_VHS1256b_Reduction/tree/main/reduced_spectr

    The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems IV: NIRISS Aperture Masking Interferometry Performance and Lessons Learned

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    We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same dataset to explore the random, static, and calibration errors of NIRISS AMI observables. We compare the observed noise properties and achievable contrast to theoretical predictions. We explore possible sources of calibration errors, and show that differences in charge migration between the observations of HIP 65426 and point-spread function calibration stars can account for the achieved contrast curves. Lastly, we use self-calibration tests to demonstrate that with adequate calibration, NIRISS AMI can reach contrast levels of 910\sim9-10 mag. These tests lead us to observation planning recommendations and strongly motivate future studies aimed at producing sophisticated calibration strategies taking these systematic effects into account. This will unlock the unprecedented capabilities of JWST/NIRISS AMI, with sensitivity to significantly colder, lower mass exoplanets than ground-based setups at orbital separations inaccessible to JWST coronagraphy.Comment: 20 pages, 12 figures, submitted to AAS Journal
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