1,262 research outputs found

    Charge Conjugation from Space-Time Inversion

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    We show that the CPT group of the Dirac field emerges naturally from the PT and P (or T) subgroups of the Lorentz group.Comment: 4 pages, no figure

    Seven steps to successful change: How a large academic medical center prepared patients for organizational change

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    Vanderbilt University Medical Center (VUMC) launched a new electronic health record (EHR) in a “big bang” implementation that saw the new software go live across multiple hospitals, clinics and geographic locations in a single morning. The organization rightly focused most of its energy on preparing its nearly 25,000 employees for the impacts of the transition, but it also considered the effects that would be felt by its patients and families. Survey data indicate that patient satisfaction scores demonstrably dip before, during and after an EHR implementation, and take approximately a year to recover. A team at DMC employed a seven-step approach to preparing patients for the impacts of the transition, which led to a return to pre-implementation patient satisfaction scores in about half the time of its peer institutions. The article explores these seven steps in detail and offers recommendations for how healthcare organizations facing large-scale change can use a similar structured approach to mitigate negative impacts to patients. Experience Framework This article is associated with the Culture & Leadership lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this len

    Structural and functional characterisation of the fork head transcription factor-encoding gene, Hc-daf-16, from the parasitic nematode Haemonchus contortus (Strongylida)

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    Despite their phylogenetic diversity, parasitic nematodes share attributes of longevity and developmental arrest (=hypobiosis) with free-living nematodes at key points in their life cycles, particularly in larval stages responsible for establishing infection in the host. Insulin-like signalling plays crucial roles in the regulation of life span and arrest (=dauer formation) in the free-living nematode, Caenorhabditis elegans. Insulin-like signalling in C. elegans negatively regulates the fork head boxO (FoxO) transcription factor encoded by daf-16, which is linked to initiating a dauer-specific pattern of gene expression. Orthologues of daf-16 have been identified in several species of parasitic nematode. Although function has been demonstrated for an orthologue from the parasitic nematode Strongyloides stercoralis (Rhabditida), the functional capabilities of homologues/orthologues in bursate nematodes (Strongylida) are unknown. In the present study, we used a genomic approach to determine the structures of two complete daf-16 orthologues (designated Hc-daf-16.1 and Hc-daf-16.2) and their transcripts in the parasitic nematode Haemonchus contortus, and assessed their function(s) using C. elegans as a genetic surrogate. Unlike the multiple isoforms of Ce-DAF-16 and Ss-DAF-16, which are encoded by a single gene and produced by alternative splicing, mRNAs encoding the proteins Hc-DAF-16.1 and Hc-DAF-16.2 are transcribed from separate and distinct loci. Both orthologues are transcribed in all developmental stages and both sexes of H. contortus, and the inferred proteins (603 and 556 amino acids) each contain a characteristic, highly conserved fork head domain. In spite of distinct differences in genomic organisation compared with orthologues in C. elegans and S. stercoralis, genetic complementation studies demonstrated here that Hc-daf-16.2, but not Hc-daf-16.1, could restore daf-16 function to a C. elegans strain carrying a null mutation at this locus. These findings are consistent with previous results for S. stercoralis and demonstrate functional conservation of the daf-16b orthologue between key parasitic nematodes from two different taxonomic orders and C. elegans. We conclude from these experiments that the fork head transcription factor DAF-16 and, by inference, other insulin-like signalling elements, are conserved in H. contortus, a parasitic nematode of paramount economic importance. We demonstrate that functionality is sufficiently conserved in Hc-DAF-16.2 that it can replace Ce-DAF-16 in promoting dauer arrest in C. elegans

    The Ursinus Weekly, October 15, 1951

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    Henning W. Prentis slated as speaker at Founders\u27 Day program, October 24 • Chaplain first Forum speaker on October 31 • Curtain Club adds sixty new members at annual party • New preceptress in charge of 646 Main • 300 books added to Library collection • Piano recital date moved to Nov. 8 • Cub and Key honor given to Jay Kern • Y plans weekend trip, arranges fireside chats • Date announced for civil service exam • WAA to sell socks, Christmas cards • Soph class plans year; Informal dance Nov. 3 • French Club discusses plans • Rev. Creager to speak • Juniors to sponsor G. E. House of Magic • German Club schedules trips and welcomes Inge Rudloff • 12 students become psychology majors • Spirit Committee fans campus enthusiasm • Editorials: No complaints; British voters go to polls; McCarthy vs. free speech • Letter to the editor • Dorm initiations give jokers a release • So the frosh love customs? Scribes of 1955 reveal all • Dr. Miller\u27s family hits high spots in European tour • Four teams open intradorm football • Hockey and soccer are overshadowed, but fortunately have excellent leaders • Dickinson hands Ursinus season\u27s second defeat • Dr. Roelofs keeps athletes in shape • Garnet eleven will play host to Bears Saturday • Alumnae team is undefeated; Faces Owlettes on Saturday • Harry Spangler succeeds Gerry Seeders as head coach of Ursinus court team • Bears defeated by Stevens Tech • Rittenhouse, Feldt to manage girls intramural program • Beardwood Chemical Society hears lecture on narcotics • Lit reading givenhttps://digitalcommons.ursinus.edu/weekly/1523/thumbnail.jp

    Carboxy-Terminal Truncation Activates glp-1 Protein to Specify Vulval Fates in Caenorhabditis elegans

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    The glp-1 and lin-12 genes encode homologous transmembrane proteins that may act as receptors for cell interactions during development. The glp-1 product is required for induction of germ-line proliferation and for embryogenesis. By contrast, lin-12 mediates somatic cell interactions, including those between the precursor cells that form the vulval hypodermis (VPCs). Here we analyse an unusual allele of glp-1, glp-1(q35), which displays a semidominant multivulva phenotype (Muv), as well as the typical recessive, loss-of-function Glp phenotypes (sterility and embryonic lethality). We find that the effects of glp-1(q35) on VPC development mimic those of dominant lin-12 mutations, even in the absence of lin-12 activity. The glp-1(q35) gene bears a nonsense mutation predicted to eliminate the 122 C-terminal amino acids, including a ProGluSerThr (PEST) sequence thought to destabilize proteins. We suggest that the carboxy terminus bears a negative regulatory domain which normally inactivates glp-1 in the VPCs. We propose that inappropriate glp-1(q35) activity can substitute for lin-12 to determine vulval fate, perhaps by driving the VPCs to proliferate

    Extended supersymmetric sigma models in AdS_4 from projective superspace

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    There exist two superspace approaches to describe N=2 supersymmetric nonlinear sigma models in four-dimensional anti-de Sitter (AdS_4) space: (i) in terms of N=1 AdS chiral superfields, as developed in arXiv:1105.3111 and arXiv:1108.5290; and (ii) in terms of N=2 polar supermultiplets using the AdS projective-superspace techniques developed in arXiv:0807.3368. The virtue of the approach (i) is that it makes manifest the geometric properties of the N=2 supersymmetric sigma-models in AdS_4. The target space must be a non-compact hyperkahler manifold endowed with a Killing vector field which generates an SO(2) group of rotations on the two-sphere of complex structures. The power of the approach (ii) is that it allows us, in principle, to generate hyperkahler metrics as well as to address the problem of deformations of such metrics. Here we show how to relate the formulation (ii) to (i) by integrating out an infinite number of N=1 AdS auxiliary superfields and performing a superfield duality transformation. We also develop a novel description of the most general N=2 supersymmetric nonlinear sigma-model in AdS_4 in terms of chiral superfields on three-dimensional N=2 flat superspace without central charge. This superspace naturally originates from a conformally flat realization for the four-dimensional N=2 AdS superspace that makes use of Poincare coordinates for AdS_4. This novel formulation allows us to uncover several interesting geometric results.Comment: 88 pages; v3: typos corrected, version published in JHE

    The mass-to-light ratio of rich star clusters

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    We point out a strong time-evolution of the mass-to-light conversion factor eta commonly used to estimate masses of unresolved star clusters from observed cluster spectro-photometric measures. We present a series of gas-dynamical models coupled with the Cambridge stellar evolution tracks to compute line-of-sight velocity dispersions and half-light radii weighted by the luminosity. We explore a range of initial conditions, varying in turn the cluster mass and/or density, and the stellar population's IMF. We find that eta, and hence the estimated cluster mass, may increase by factors as large as 3 over time-scales of 50 million years. We apply these results to an hypothetic cluster mass distribution function (d.f.) and show that the d.f. shape may be strongly affected at the low-mass end by this effect. Fitting truncated isothermal (Michie-King) models to the projected light profile leads to over-estimates of the concentration parameter c of delta c ~ 0.3 compared to the same functional fit applied to the projected mass density.Comment: 6 pages, 2 figures, to appear in the proceedings of the "Young massive star clusters", Granada, Spain, September 200

    Genetic Covariance Structure of Reading, Intelligence and Memory in Children

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    This study investigates the genetic relationship among reading performance, IQ, verbal and visuospatial working memory (WM) and short-term memory (STM) in a sample of 112, 9-year-old twin pairs and their older siblings. The relationship between reading performance and the other traits was explained by a common genetic factor for reading performance, IQ, WM and STM and a genetic factor that only influenced reading performance and verbal memory. Genetic variation explained 83% of the variation in reading performance; most of this genetic variance was explained by variation in IQ and memory performance. We hypothesize, based on these results, that children with reading problems possibly can be divided into three groups: (1) children low in IQ and with reading problems; (2) children with average IQ but a STM deficit and with reading problems; (3) children with low IQ and STM deficits; this group may experience more reading problems than the other two
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