462 research outputs found

    The 11 Year History of Starspots on V1149 Ori=HD 37824

    Get PDF
    All available radial-velocity measures, published and unpublished, yield an improved period and a new (assumed circular) solution. The period is 53.58 d +/- 0.02 d, and conjunction (K1 giant in front) was at 2 444 325.93 +/- 0.12 d. Eleven years of V-band photometry, published and unpublished, between 1978-1979 and 1989-1990 are analyzed. Eighteen data groups are fit with a two-spot light-curve-modeling technique. Six spots existing sometime during the 11 years are identified, and the 4-percent range of their rotation periods is used to estimate a differential rotation coefficient of k = 0.08 +/- 0.02. Observed lifetimes of those six spots are consistent with times calculated on the assumption that large spots are disrupted by the shear of differential rotation. The two best observed spots each lasted about five years

    Interfirm Structure and Buyer-Salesperson Behavior Impact on Relationship Outcomes

    Get PDF
    The individual level interaction between the buyer and salesperson can best be understood in the broader framework provided by the inter-firm relationship. Very little research has been conducted that examines both firm level and interpersonal level constructs in the context of business relationships. The primary purpose of this study is to design and test a theoretical model that examines the effect of inter-firm structure and buyer-salesperson behaviors on relationship outcomes. The results suggest that in established relationships, the external environment plays a role in determining the how buyer-seller firms structure their relationships. The way in which the relationship is structured plays an important role in determining how the buyer and salesperson interact. Both inter-firm structure and buyer-salesperson behaviors, in turn, influence buyer satisfaction

    Afferent specific role of NMDA receptors for the circuit integration of hippocampal neurogliaform cells.

    Get PDF
    This is the final version of the article. Available from Nature Publishing Group via the DOI in this record.Appropriate integration of GABAergic interneurons into nascent cortical circuits is critical for ensuring normal information processing within the brain. Network and cognitive deficits associated with neurological disorders, such as schizophrenia, that result from NMDA receptor-hypofunction have been mainly attributed to dysfunction of parvalbumin-expressing interneurons that paradoxically express low levels of synaptic NMDA receptors. Here, we reveal that throughout postnatal development, thalamic, and entorhinal cortical inputs onto hippocampal neurogliaform cells are characterized by a large NMDA receptor-mediated component. This NMDA receptor-signaling is prerequisite for developmental programs ultimately responsible for the appropriate long-range AMPAR-mediated recruitment of neurogliaform cells. In contrast, AMPAR-mediated input at local Schaffer-collateral synapses on neurogliaform cells remains normal following NMDA receptor-ablation. These afferent specific deficits potentially impact neurogliaform cell mediated inhibition within the hippocampus and our findings reveal circuit loci implicating this relatively understudied interneuron subtype in the etiology of neurodevelopmental disorders characterized by NMDA receptor-hypofunction.Proper brain function depends on the correct assembly of excitatory and inhibitory neurons into neural circuits. Here the authors show that during early postnatal development in mice, NMDAR signaling via activity of long-range synaptic inputs onto neurogliaform cells is required for their appropriate integration into the hippocampal circuitry.We thank Daniel Abebe for mouse colony maintenance and Kurt Auville for additional assistance with confocal imaging. We thank UNC Vector Core and Ed Boyden, MIT, Cambridge, MA, USA for generously providing AAV9-syn-Chrimson-TdTomato and AAV9-syn-Chronos-GFP. This work was supported by an intramural award to C.J.M. from the Eunice Kennedy–Shriver National Institute of Child Health and Human Development and a Competitive Fellowship Award to J.C.W. from the National Institute of Neurological Disorders and Strok

    The Two Variables in The Triple System HR 6469=V819 Her: One Eclipsing, One Spotted

    Get PDF
    A complete BV light curve, from 14 nights of good data obtained with the Vanderbilt University-Tennessee State University (VU-TSU) automatic telescope, are presented and solved with the Wilson-Devinney program. Third light is evaluated, with the companion star brighter by 0.58m in V and 0.11m in B. The eclipses are partial. Inferred color indices yield F2 V and F8 V for the eclipsing pair and G8 IV-III for the distant companion star. After removing the variability due to eclipses, we study the residual variability of the G8 IV-III star over the ten years 1982 to 1992. Each yearly light curve is fit with a two-spot model. Three relatively long-lived spots are identified, with rotation periods of 85.9d, 85.9d, and 86.1d. The weak and intermittent variability is understood because the G8 IV-III star has a Rossby number at the threshold for the onset of heavy spottedness

    Site-specific prolapse surgery. I. Reliability and durability of native tissue paravaginal repair

    Get PDF
    Introduction and hypothesis: This study aims to compare native tissue abdominal and vaginal paravaginal repair, and to investigate whether surgical outcome was independent of operative route. Methods: Retrospective comparison of 111 displacement cysto-urethrocoeles, repaired between 1997 and 2007. Treatment was by surgeon assignment, 52 women having abdominal (APVR) and 59 vaginal paravaginal repairs. Main outcome measures were same-site prolapse recurrence, time to failure and surgical complications. Initial reliability was evaluated by chi-square test, 10-year durability by Kaplan-Meier survival analysis and Cox proportional hazards model. Results: When examined in the Cox proportional hazards model, anatomic results of APVR were more durable than a mechanically analogous transvaginal operation done [95% CI=1.029-2.708 (p value=0.038)]. Kaplan-Meier curves plateaued within 38 months. Symptom resolution was broadly equivalent. Surgical complication rate was 3.6%. Conclusions: Site-specific re-suture of torn native tissue has genuine curative potential. Most of the long-term success was attributable to site-specific repair, rather than nonspecific scar formation.9 page(s

    A Minimal Model for Multiple Epidemics and Immunity Spreading

    Get PDF
    Pathogens and parasites are ubiquitous in the living world, being limited only by availability of suitable hosts. The ability to transmit a particular disease depends on competing infections as well as on the status of host immunity. Multiple diseases compete for the same resource and their fate is coupled to each other. Such couplings have many facets, for example cross-immunization between related influenza strains, mutual inhibition by killing the host, or possible even a mutual catalytic effect if host immunity is impaired. We here introduce a minimal model for an unlimited number of unrelated pathogens whose interaction is simplified to simple mutual exclusion. The model incorporates an ongoing development of host immunity to past diseases, while leaving the system open for emergence of new diseases. The model exhibits a rich dynamical behavior with interacting infection waves, leaving broad trails of immunization in the host population. This obtained immunization pattern depends only on the system size and on the mutation rate that initiates new diseases

    Congenital tumors: imaging when life just begins

    Get PDF
    BACKGROUND: The technical developments of imaging methods over the last 2 decades are changing our knowledge of perinatal oncology. Fetal ultrasound is usually the first imaging method used and thus constitutes the reference prenatal study, but MRI seems to be an excellent complementary method for evaluating the fetus. The widespread use of both techniques has increased the diagnosis rates of congenital tumors. During pregnancy and after birth, an accurate knowledge of the possibilities and limits of the different imaging techniques available would improve the information obtainable, thus helping the medical team to make the most appropriate decisions about therapy and to inform the family about the prognosis. CONCLUSION: In this review article, we describe the main congenital neoplasms, their prognosis and their imaging characteristics with the different pre- and postnatal imaging methods available

    Functional outcome after sacrospinous hysteropexy for uterine descensus

    Get PDF
    The study aimed to evaluate urogenital symptoms, defecatory symptoms and quality of life before and after a sacrospinous hysteropexy for uterovaginal prolapse. Seventy-two women with symptomatic uterovaginal prolapse were treated with sacrospinous hysteropexy. Before and after surgery, urogenital and defecatory symptoms and quality of life were assessed with a validated questionnaire. Anatomical outcome was assessed by means of pelvic examination before and after surgery. The mean follow-up time was 12.7 months. Scores on all domains of urogenital symptoms and defecatory symptoms, except for the pain and fecal incontinence domain, improved significantly. Also, quality of life improved on all domains. No major complications were encountered
    corecore