916 research outputs found

    Structural insights into the role of the Smoothened cysteine-rich domain in Hedgehog signalling.

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    Smoothened (Smo) is a member of the Frizzled (FzD) class of G-protein-coupled receptors (GPCRs), and functions as the key transducer in the Hedgehog (Hh) signalling pathway. Smo has an extracellular cysteine-rich domain (CRD), indispensable for its function and downstream Hh signalling. Despite its essential role, the functional contribution of the CRD to Smo signalling has not been clearly elucidated. However, given that the FzD CRD binds to the endogenous Wnt ligand, it has been proposed that the Smo CRD may bind its own endogenous ligand. Here we present the NMR solution structure of the Drosophila Smo CRD, and describe interactions between the glucocorticoid budesonide (Bud) and the Smo CRDs from both Drosophila and human. Our results highlight a function of the Smo CRD, demonstrating its role in binding to small-molecule modulators

    Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

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    There is increasing interest in developing abattoir-based welfare measures for pigs.The primary aim of this study was to determine the most appropriate place on theslaughter line to conduct assessments of welfare-related lesions, namely apparentaggression-related skin lesions (hereafter referred to as 'skin lesions'), loin bruising andapparent tail biting damage. The study also lent itself to an assessment of theprevalence of these lesions, and the extent to which they were linked with productionparameters. Finishing pigs processed at two abattoirs on the Island of Ireland (n =1950 in abattoir A, and n = 1939 in abattoir B) were used. Data were collected over 6days in each abattoir in July 2014. Lesion scoring took place at two points on theslaughter line: (1) at exsanguination (Slaughter Stage 1 [SS1]), and (2) followingscalding and dehairing of carcasses (Slaughter Stage 2 [SS2]). At both points, eachcarcass was assigned a skin and tail lesion score ranging from 0 (lesion absent) to 3 or4 (severe lesions), respectively. Loin bruising was recorded as present or absent.Differences in the percentage of pigs with observable lesions of each type werecompared between SS1 and SS2 using McNemar/McNemar-Bowker tests. Theassociations between each lesion type, and both cold carcass weight andcondemnations, were examined at batch level using Pearson's correlations. Batch wasdefined as the group of animals with a particular farm identification code on a givenday. The overall percentage of pigs with a visible skin lesion (i.e. score > 0) decreasedbetween SS1 and SS2 (P<0.001). However, the percentage of pigs with a severe skinlesion increased numerically from SS1 to SS2. The percentage of pigs with a visible taillesion and with loin bruising also increased between SS1 and SS2 (P<0.001). Therewas a positive correlation between the percentage of carcasses that were partiallycondemned, and the percentage of pigs with skin lesions, tail lesions and loin bruising(P<0.05). Additionally, as the batch-level frequency of each lesion type increased,average cold carcass weight decreased (P<0.001). These findings suggest that severeskin lesions, tail lesions and loin bruising are more visible on pig carcasses after theyhave been scalded and dehaired, and that this is when abattoir-based lesion scoringshould take place. The high prevalence of all three lesion types, and the links witheconomically important production parameters, suggests more research into identifying key risk factors is warranted

    Implications of Electronics Constraints for Solid-State Quantum Error Correction and Quantum Circuit Failure Probability

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    In this paper we present the impact of classical electronics constraints on a solid-state quantum dot logical qubit architecture. Constraints due to routing density, bandwidth allocation, signal timing, and thermally aware placement of classical supporting electronics significantly affect the quantum error correction circuit's error rate. We analyze one level of a quantum error correction circuit using nine data qubits in a Bacon-Shor code configured as a quantum memory. A hypothetical silicon double quantum dot quantum bit (qubit) is used as the fundamental element. A pessimistic estimate of the error probability of the quantum circuit is calculated using the total number of gates and idle time using a provably optimal schedule for the circuit operations obtained with an integer program methodology. The micro-architecture analysis provides insight about the different ways the electronics impact the circuit performance (e.g., extra idle time in the schedule), which can significantly limit the ultimate performance of any quantum circuit and therefore is a critical foundation for any future larger scale architecture analysis.Comment: 10 pages, 7 figures, 3 table

    Optimized pulses for the control of uncertain qubits

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    Constructing high-fidelity control fields that are robust to control, system, and/or surrounding environment uncertainties is a crucial objective for quantum information processing. Using the two-state Landau-Zener model for illustrative simulations of a controlled qubit, we generate optimal controls for \pi/2- and \pi-pulses, and investigate their inherent robustness to uncertainty in the magnitude of the drift Hamiltonian. Next, we construct a quantum-control protocol to improve system-drift robustness by combining environment-decoupling pulse criteria and optimal control theory for unitary operations. By perturbatively expanding the unitary time-evolution operator for an open quantum system, previous analysis of environment-decoupling control pulses has calculated explicit control-field criteria to suppress environment-induced errors up to (but not including) third order from \pi/2- and \pi-pulses. We systematically integrate this criteria with optimal control theory, incorporating an estimate of the uncertain parameter, to produce improvements in gate fidelity and robustness, demonstrated via a numerical example based on double quantum dot qubits. For the qubit model used in this work, post facto analysis of the resulting controls suggests that realistic control-field fluctuations and noise may contribute just as significantly to gate errors as system and environment fluctuations.Comment: 38 pages, 15 figures, RevTeX 4.1, minor modifications to the previous versio

    The Anonymous Truth: Honesty and Hostility in Public and Private Online Settings

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    Three studies were conducted to understand the relationship between honesty and hostility in public and private online settings. Study one analyzed a college’s public and private online forums and examined post frequency. Related to study one, study two examined the usage of these forums, and current and past social and political issues. Study one found the public forum comprised of general announcements, while the private forum hosted random jokes/statements, negative posts targeting specific people, and personal reflections. Study two’s results indicated the private forum was used more often than the public forum and race was the prevailing social and political issue across time. The third study was developed with a survey where participants had to label 30 statements about race as conservative, liberal, or unclear. Six statements emerged, three as liberal and three as conservative, and were implemented into study three. In study three, participants were told they would be partaking in a speech chat about race with another participant. The chat setting and political condition were manipulated. These results suggested participants were more agreeable in the liberal condition, more agreeable in the public condition, and more hostile in the private condition

    Incorporating Study Abroad Experiences into the High School Classroom Using Practices Informed by Cognitive Research

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    This senior thesis project is a Unit Plan designed for at-risk high school students that incorporates literature from places where I have studied abroad and employs classroom practices that are based upon research in the fields of cognition, motivation, and pedagogy. The accompanying paper addresses the rationale behind choices made for each lesson and the research that supports it

    Perspectives on enhancing physical activity and diet for health promotion among at-risk urban UK South Asian communities: a qualitative study

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    Objectives To explore perspectives on enhancing physical activity and diet among South Asians in urban deprived communities at high risk of chronic disease and to inform development of culturally appropriate health promotion intervention. Design Qualitative study using semistructured one-to-one and family group interviews with thematic analysis of data. Setting Urban disadvantaged communities in the East Midlands of the UK. Participants 45 respondents, including 34 people of South Asian origin (16 at-risk individuals, six family groups involving 18 relatives), of mainly Pakistani and Indian origin, including 16 non-English speakers; and 11 health professionals working locally with communities of concern. Results South Asian participants underlined the challenges of requiring family members across generations to engage in modifying dietary behaviours, and the central role of communal eating of traditional ‘Asian’ food in their cultural lives. Barriers to increasing physical activity included cost, personal safety and lack of time outside of long working hours and carer commitments. However, increasing walking activity was regarded as feasible by both community and health professional participants. Respondents emphasised using a social approach for potential interventions, undertaking activity with family or friends and with bilingual community peers to facilitate engagement, motivation and support. Spoken content and delivery of interventions was favoured, including personal stories and multilingual audio–visual information; within local informal rather than provider settings, including the home; and aided by pedometers for self-monitoring. Conclusions Focusing on physical activity by increasing walking may hold promise as health promotion in this deprived South Asian community context. Further intervention development, with exploration of feasibility and acceptability of the social approach and elements suggested, is merited

    Progesterone receptor modulates ERα action in breast cancer.

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    Progesterone receptor (PR) expression is used as a biomarker of oestrogen receptor-α (ERα) function and breast cancer prognosis. Here we show that PR is not merely an ERα-induced gene target, but is also an ERα-associated protein that modulates its behaviour. In the presence of agonist ligands, PR associates with ERα to direct ERα chromatin binding events within breast cancer cells, resulting in a unique gene expression programme that is associated with good clinical outcome. Progesterone inhibited oestrogen-mediated growth of ERα(+) cell line xenografts and primary ERα(+) breast tumour explants, and had increased anti-proliferative effects when coupled with an ERα antagonist. Copy number loss of PGR, the gene coding for PR, is a common feature in ERα(+) breast cancers, explaining lower PR levels in a subset of cases. Our findings indicate that PR functions as a molecular rheostat to control ERα chromatin binding and transcriptional activity, which has important implications for prognosis and therapeutic interventions.We would like to acknowledge the support of the University of Cambridge, Cancer Research UK and Hutchison Whampoa Limited. Research reported in this manuscript was supported by the National Cancer Institute of the National Institutes of Health under award number 5P30CA142543 (to UT Southwestern) and Department of Defense grants W81XWH-12-1-0288-03 (GVR). W.D.T. is supported by grants from the National Health and Medical Research Council of Australia (ID 1008349; ID 1084416) and Cancer Australia (ID 627229) T.E.H held a Fellowship Award from the US Department of Defense Breast Cancer Research Program (BCRP; #W81XWH-11-1-0592) and currently is supported by a Florey Fellowship from the Royal Adelaide Hospital Research Foundation. J.S.C is supported by an ERC starting grant and an EMBO Young investigator award.This is the accepted manuscript. The final version is available at www.nature.com/nature/journal/v523/n7560/full/nature14583.htm
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