67 research outputs found

    Remarks on affine variations on the ellipsoid

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    We extend a variational result of Blaschke and give some further stability results

    Affine Bibliography 1998

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    Intrinsic and Extrinsic Geometry of Ovaloids and Rigidity

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    Our main result is that an ovaloid with nowhere dense umbilics and prescribed Weingarten operator and spherical volume form is rigid in Euclidean 3-space. In case of an ovaloid of revolution we can drop the assumption on the volume form

    Generating higher order Codazzi tensors by functions

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    We study higher order Codazzi tensors on constant curvature spaces and show how they can be generated by functions. We give applications in Riemannian geometry and hypersurface theory; in particular we characterize ellipsoids in terms of second order spherical harmonics

    Acceptance of HIV Testing for Children Ages 18 Months to 13 Years Identified Through Voluntary, Home-Based HIV Counseling and Testing in Western Kenya

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    Background Home-based, voluntary counseling and testing (HCT) presents a novel approach to early diagnosis. We sought to describe uptake of pediatric HIV testing, associated factors, and HIV prevalence among children offered HCT in Kenya. Methods The USAID-AMPATH Partnership conducted HCT in western Kenya in 2008. Children 18 months to 13 years were offered HCT if their mother was known to be dead, her living status was unknown, mother was HIV-infected or of unknown HIV status. This retrospective analysis describes the cohort of children encountered and tested. Results HCT was offered to 2,289 children and accepted for 1,294 (57%). Children were more likely to be tested if more information was available about a suspected or confirmed maternal HIV-infection (for HIV-infected, living mothers OR=3.20, 95% CI: 1.64–6.23), if parents were not in household (OR=1.50, 95% CI: 1.40–1.63), if they were grandchildren of head of household (OR=4.02, 95% CI: 3.06–5.28), or if their father was not in household (OR=1.41, 95% CI: 1.24–1.56). Of the eligible children tested, 60 (4.6%) were HIV-infected. Conclusions HCT provides an opportunity to identify HIV among high-risk children; however, acceptance of HCT for children was limited. Further investigation is needed to identify and overcome barriers to testing uptake

    Provider perspectives on shared decision-making regarding hypospadias surgery

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    Introduction: Many parents experience decisional conflict and decisional regret around hypospadias surgery. The utilization of a shared decision-making (SDM) process may mitigate these issues, however addressing the principal components of the SDM process is a complex task that requires the investment of providers. Objective: The purpose of this study was to facilitate a discussion about SDM anchored on hypospadias with pediatric urology and general pediatric providers to explore perspectives, clinical applications and barriers to adopting SDM in clinical practice. Study design: We conducted two focus groups in order to engage pediatric urology and general pediatric providers in guided discussions about SDM anchored on hypospadias. All activities were audio recorded and professionally transcribed. The transcripts were analyzed by three coders using directed qualitative content analysis techniques to identify themes and relationships between themes to inform the development of an affinity diagram (Extended Summary Figure). Results: Two focus groups were held; one with seven pediatric urology providers in November 2018 and one with ten general pediatric providers in January 2019 (median age 51 years, 88.2% Caucasian, 58.8% female, 70.6% physicians and 29.4% nurse practitioners). Both groups identified some of the key components of SDM including engaging families in decision-making, informing them about treatment options and clarifying values/preferences (Extended Summary Figure). They thought that SDM was useful for discussing preference-sensitive conditions (e.g. hypospadias) and addressing parental compliance. General pediatric providers also suggested that SDM helped them avoid unnecessary referrals to specialists. Both groups identified parental, provider and systemic barriers to the adoption of SDM: a) desire for paternalism, b) misperceptions about medical evidence, c) completion of parental decision-making prior to the clinical visit, d) provider bias/lack of interest and e) time constraints/productivity pressures. Discussion: Providers who care for hypospadias patients are knowledgeable about SDM and its potential clinical applications. They identified several potentially modifiable barriers to the adoption of a SDM process about hypospadias surgery in a pediatric clinical setting. Conclusions: Based on feedback from providers, we plan to implement a hypospadias decision aid early in the parental decision-making process about hypospadias such as in the postpartum unit and at well-child visits in the newborn period and provide a provider training session about SDM to address the identified knowledge gaps

    Crosslinking of a CD4 Mimetic Miniprotein with HIV-1 Env gp140 Alters Kinetics and Specificities of Antibody Responses against HIV-1 Env in Macaques

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    Evaluation of the epitope specificities, location (systemic, mucosal) and effector function of antibodies elicited by novel HIV-1 immunogens engineered to improve exposure of specific epitopes is critical for HIV-1 vaccine development. Utilizing an array of humoral assays, we evaluated the magnitude, epitope specificity, avidity and function of systemic and mucosal immune responses elicited by a vaccine regimen containing Env cross-linked to a CD4 mimetic miniprotein (gp140-M64U1) in rhesus macaques. Crosslinking of gp140 Env with M64U1 resulted in an earlier increase in both the magnitude and avidity of the IgG binding response compared to Env protein alone. Notably, binding IgG responses at an early time point correlated with Antibody Dependent Cellular Cytotoxicity (ADCC) function at the peak immunity time point, which was higher for the crosslinked Env group compared to the Env group alone. In addition, the crosslinked Env group developed higher IgG responses against a linear epitope in the C1 gp120 region of the HIV-1 envelope glycoprotein. These data demonstrate that structural modification of the HIV-1 envelope immunogen by crosslinking gp140 with the CD4 mimetic M64U1 elicited an earlier increase of binding antibody responses and altered the specificity of the IgG responses that correlated with the rise of subsequent antibody-mediated antiviral functions.IMPORTANCE The development of an efficacious HIV-1 vaccine remains a global priority to prevent new cases of HIV-1 infection. Of the six HIV-1 efficacy trials to date, only one has demonstrated partial efficacy, and the immune correlates analysis of this trial revealed a role for binding antibodies and antibody Fc mediated effector functions. New HIV-1 envelope immunogens are being engineered to selectively expose the most vulnerable and conserved sites on the HIV-1 envelope with the goal of eliciting antiviral antibodies. Evaluation of the humoral responses elicited by these novel immunogen designs in nonhuman primates is critical for understanding how to improve upon immunogen design to inform further testing in human clinical trials. Our results demonstrate that Env structural modifications that aim to mimic the CD4 bound conformation can result in earlier antibody elicitation, altered epitope specificity and increased antiviral function post immunization.This work was supported by the National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID) grants, Center for HIV/AIDS Vaccine Immunology (CHAVI)/ HIV Vaccine Trials Network (HVTN) Early Stage Investigator (ESI) Award (U19AI067854, UM1AI068618), (HHSN27201100016C), 1P01AI120756 and the NIH NIAID Duke Center for AIDS Research Immunology Core P30 AI 64518. The NHP study was funded by NIH PO1 AI066287-02

    The ABC130 barrel module prototyping programme for the ATLAS strip tracker

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    For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

    The determinants of genetic diversity in butterflies

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    This is the final version. Available on open access from Nature Research via the DOI in this recordUnder the neutral theory, genetic diversity is expected to increase with population size. While comparative analyses have consistently failed to find strong relationships between census population size and genetic diversity, a recent study across animals identified a strong correlation between propagule size and genetic diversity, suggesting that r-strategists that produce many small offspring, have greater long-term population sizes. Here we compare genome-wide genetic diversity across 38 species of European butterflies (Papilionoidea), a group that shows little variation in reproductive strategy. We show that genetic diversity across butterflies varies over an order of magnitude and that this variation cannot be explained by differences in current abundance, propagule size, host or geographic range. Instead, neutral genetic diversity is negatively correlated with body size and positively with the length of the genetic map. This suggests that genetic diversity is determined both by differences in long-term population size and the elect of selection on linked sites.Biotechnology & Biological Sciences Research Council (BBSRC)European Research CouncilNatural Environmental Research Council (NERC)Institute of Evolutionary Biology at Edinburgh Universit
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