700 research outputs found

    Reversing Blood Flows Act through klf2a to Ensure Normal Valvulogenesis in the Developing Heart

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    Heart valve anomalies are some of the most common congenital heart defects, yet neither the genetic nor the epigenetic forces guiding heart valve development are well understood. When functioning normally, mature heart valves prevent intracardiac retrograde blood flow; before valves develop, there is considerable regurgitation, resulting in reversing (or oscillatory) flows between the atrium and ventricle. As reversing flows are particularly strong stimuli to endothelial cells in culture, an attractive hypothesis is that heart valves form as a developmental response to retrograde blood flows through the maturing heart. Here, we exploit the relationship between oscillatory flow and heart rate to manipulate the amount of retrograde flow in the atrioventricular (AV) canal before and during valvulogenesis, and find that this leads to arrested valve growth. Using this manipulation, we determined that klf2a is normally expressed in the valve precursors in response to reversing flows, and is dramatically reduced by treatments that decrease such flows. Experimentally knocking down the expression of this shear-responsive gene with morpholine antisense oligonucleotides (MOs) results in dysfunctional valves. Thus, klf2a expression appears to be necessary for normal valve formation. This, together with its dependence on intracardiac hemodynamic forces, makes klf2a expression an early and reliable indicator of proper valve development. Together, these results demonstrate a critical role for reversing flows during valvulogenesis and show how relatively subtle perturbations of normal hemodynamic patterns can lead to both major alterations in gene expression and severe valve dysgenesis

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    PD-1 Inhibitory Receptor Downregulates Asparaginyl Endopeptidase and Maintains Foxp3 Transcription Factor Stability in Induced Regulatory T Cells

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    CD4+ T cell differentiation into multiple T helper (Th) cell lineages is critical for optimal adaptive immune responses. This report identifies an intrinsic mechanism by which programmed death-1 receptor (PD-1) signaling imparted regulatory phenotype to Foxp3+ Th1 cells (denoted as Tbet+iTregPDL1 cells) and inducible regulatory T (iTreg) cells. Tbet+iTregPDL1 cells prevented inflammation in murine models of experimental colitis and experimental graft versus host disease (GvHD). Programmed death ligand-1 (PDL-1) binding to PD-1 imparted regulatory function to Tbet+iTregPDL1 cells and iTreg cells by specifically downregulating endo-lysosomal protease asparaginyl endopeptidase (AEP). AEP regulated Foxp3 stability and blocking AEP imparted regulatory function in Tbet+iTreg cells. Also, Aep−/− iTreg cells significantly inhibited GvHD and maintained Foxp3 expression. PD-1-mediated Foxp3 maintenance in Tbet+ Th1 cells occurred both in tumor infiltrating lymphocytes (TILs) and during chronic viral infection. Collectively, this report has identified an intrinsic function for PD-1 in maintaining Foxp3 through proteolytic pathway.Bio-organic Synthesi

    Constitutive expression of NF-κB inducing kinase in regulatory T cells impairs suppressive function and promotes instability and pro-inflammatory cytokine production

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    CD4+Foxp3+ regulatory T cells (Tregs) are indispensable negative regulators of immune responses. To understand Treg biology in health and disease, it is critical to elucidate factors that affect Treg homeostasis and suppressive function. Tregs express several costimulatory TNF receptor family members that activate non-canonical NF-κB via accumulation of NF-κB inducing kinase (NIK). We previously showed that constitutive NIK expression in all T cells causes fatal multi-organ autoimmunity associated with hyperactive conventional T cell responses and poor Treg-mediated suppression. Here, we show that constitutive NIK expression that is restricted to Tregs via a Cre-inducible transgene causes an autoimmune syndrome. We found that constitutive NIK expression decreased expression of numerous Treg signature genes and microRNAs involved in Treg homeostasis and suppressive phenotype. NIK transgenic Tregs competed poorly with WT Tregs in vivo and produced proinflammatory cytokines upon stimulation. Lineage tracing experiments revealed accumulation of ex- Foxp3+ T cells in mice expressing NIK constitutively in Tregs, and these former Tregs produced copious IFNγ and IL-2. Our data indicate that under inflammatory conditions in which NIK is activated, Tregs may lose suppressive function and may actively contribute to inflammation

    Are publicly available internet resources enabling women to make informed fertility preservation decisions before starting cancer treatment: an environmental scan?

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    Background To identify publicly available internet resources and assess their likelihood to support women making informed decisions about, and between, fertility preservation procedures before starting their cancer treatment. Methods A survey of publically available internet resources utilising an environmental scan method. Inclusion criteria were applied to hits from searches of three data sources (November 2015; repeated June 2017): Google (Chrome) for patient resources; repositories for clinical guidelines and projects; distribution email lists to contact patient decision aid experts. The Data Extraction Sheet applied to eligible resources elicited: resource characteristics; informed and shared decision making components; engagement health services. Results Four thousand eight hundred fifty one records were identified; 24 patient resources and 0 clinical guidelines met scan inclusion criteria. Most resources aimed to inform women with cancer about fertility preservation procedures and infertility treatment options, but not decision making between options. There was a lack of consistency about how health conditions, decision problems and treatment options were described, and resources were difficult to understand. Conclusions Unless developed as part of a patient decision aid project, resources did not include components to support proactively women’s fertility preservation decisions. Current guidelines help people deliver information relevant to treatment options within a single disease pathway; we identified five additional components for patient decision aid checklists to support more effectively people’s treatment decision making across health pathways, linking current with future health problems

    Fine and hyperfine interactions in 171^{171}YbOH and 173^{173}YbOH

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    The odd isotopologues of ytterbium monohydroxide, 171,173^{171,173}YbOH, have been identified as promising molecules in which to measure parity (P) and time reversal (T) violating physics. Here we characterize the A~2Π1/2(0,0,0)X~2Σ+(0,0,0)\tilde{A}^{2}\Pi_{1/2}(0,0,0)-\tilde{X}^2\Sigma^+(0,0,0) band near 577 nm for these odd isotopologues. Both laser-induced fluorescence (LIF) excitation spectra of a supersonic molecular beam sample and absorption spectra of a cryogenic buffer-gas cooled sample were recorded. Additionally, a novel spectroscopic technique based on laser-enhanced chemical reactions is demonstrated and utilized in the absorption measurements. This technique is especially powerful for disentangling congested spectra. An effective Hamiltonian model is used to extract the fine and hyperfine parameters for the A~2Π1/2(0,0,0)\tilde{A}^{2}\Pi_{1/2}(0,0,0) and X~2Σ+(0,0,0)\tilde{X}^2\Sigma^+(0,0,0) states. A comparison of the determined X~2Σ+(0,0,0)\tilde{X}^2\Sigma^+(0,0,0) hyperfine parameters with recently predicted values (M. Denis, et al., J. Chem. Phys. 152\bf{152}, 084303 (2020), K. Gaul and R. Berger, Phys. Rev. A 101\bf{101}, 012508 (2020), J. Liu et al., J. Chem. Phys. 154\bf{154}, 064110 (2021)) is made. The measured hyperfine parameters provide experimental confirmation of the computational methods used to compute the P,T-violating coupling constants WdW_d and WMW_M, which correlate P,T-violating physics to P,T-violating energy shifts in the molecule. The dependence of the fine and hyperfine parameters of the A~2Π1/2(0,0,0)\tilde{A}^{2}\Pi_{1/2}(0,0,0) and X~2Σ+(0,0,0)\tilde{X}^2\Sigma^+(0,0,0) states for all isotopologues of YbOH are discussed and a comparison to isoelectronic YbF is made.Comment: 54 pages, 7 figure

    Optical cycling in polyatomic molecules with complex hyperfine structure

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    We have developed and demonstrated a scheme to achieve rotationally-closed photon cycling in polyatomic molecules with complex hyperfine structure and sensitivity to hadronic symmetry violation, specifically 171^{171}YbOH and 173^{173}YbOH. We calculate rotational branching ratios for spontaneous decay and identify repumping schemes which use electro-optical modulators (EOMs) to address the hyperfine structure. We demonstrate our scheme by cycling photons in a molecular beam and verify that we have achieved rotationally-closed cycling by measuring optical pumping into unaddressed vibrational states. Our work makes progress along the path toward utilizing photon cycling for state preparation, readout, and laser cooling in precision measurements of polyatomic molecules with complex hyperfine structure.Comment: 10 pages, 7 figure

    The Elephant (Head) in the Room: A Critical Look at Trophy Hunting

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    Trophy hunting has occupied a prominent position in recent scholarly literature and popular media. In the scientific conservation literature, researchers are generally supportive of or sympathetic to its usage as a source of monetary support for conservation. Although authors at times acknowledge that trophy hunting faces strong opposition from many members of the public, often for unspecified reasons associated with ethics, neither the nature nor the implications of these ethical concerns have been substantively addressed. We identify the central act of wildlife “trophy” taking as a potential source of ethical discomfort and public opposition. We highlight that trophy hunting entails a hunter paying a fee to kill an animal and claim its body or body parts as a trophy of conquest. Situating this practice in a Western cultural narrative of chauvinism, colonialism, and anthropocentrism, we argue trophy hunting is morally inappropriate. We suggest alternative strategies for conservation and community development should be explored and decisively ruled out as viable sources of support before the conservation community endorses trophy hunting. If wildlife conservation is broadly and inescapably dependent on the institution of trophy hunting, conservationists should accept the practice only with a due appreciation of tragedy, and proper remorse

    Designing (with) AI for Wellbeing

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    Designing with data and Artificial Intelligence (AI) can bring significant value to the development of systems and technologies that promote personal wellbeing. However, there are also unaddressed challenges and risks connected to designing (with) AI for wellbeing, such as the difficulties in ensuring that the generated feedback or proposed interventions are relevant considering the large interpersonal variations between the current, desired and achievable level of physical and mental wellbeing of different individuals. In this one-day hybrid workshop, we aim to bring together design and HCI researchers and practitioners interested in the intersection of design, AI, and wellbeing beyond clinical applications. We will discuss challenges in designing with AI for wellbeing originating from a) the domains of design and b) general issues in developing AI systems, and uncover new potential directions that emerge when coupling design, AI and wellbeing. Our aim is to bring together researchers and practitioners from various fields and backgrounds who use data and AI when designing for wellbeing. Through this workshop, we aim to create a conceptual framework that enables the emergence of rich, meaningful, and ethical solutions for designing (with) AI for wellbeing, while also providing handles to mitigate the emergence of negative consequences
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