1,814 research outputs found

    Evidence for a black-hole in the X-ray transient XTE J1859+226

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    We present the results of time-resolved optical photometry and spectroscopy of the X-ray transient XTE J1859+226 (V406 Vul). Photometric observations taken during 2000 and 2008 reveals the presence of the secondary star's ellipsoidal modulation. Further photometry obtained in 2010 shows the system ~1 mag brighter than its quiescence level and the ellipsoidal modulation diluted by strong flaring activity. Spectroscopic data obtained with the 10.4-m GTC in 2010 reveals radial velocity variations of ~500 km/s over 3 h. A simultaneous fit to the photometry and spectroscopy using sinusoids to represent the secondary star's ellipsoidal and radial velocity variations, yields an orbital period of 6.58+-0.05 h and a secondary star's radial velocity semi-amplitude of K_2= 541+-70 km/s. The implied mass function is f(M)=4.5+-0.6 Msun, significantly lower than previously reported but consistent with the presence of a black hole in XTE J1859+226. The lack of eclipses sets an upper limit to the inclination of 70 degrees which yields a lower limit to the black hole mass of 5.42 Msun.Comment: Accepted for publication in MNRAS. Contains 5 pages and 4 figure

    Rural School District Leadership and Governance: Eating Your Veggies to Stay on the Balcony

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    School board trustees and superintendents must navigate overlapping roles and intersectional identities when engaging in rural school district governance work. If these individuals are not clear about the scope of their role and do not have a common understanding about the importance of high expectations for all, lack of coherent governance can negatively impact their district. Recently, one school district in rural Idaho has experienced phenomenal success. The district is in a very different place than it was just a little over five years ago. In this article insights are shared about the governance practices of trustees and the superintendent that supported their improvement

    Using Focus Groups to Understand What New Residents Want and Need in a Community

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    Materials Characterization Using Acoustic Nonlinearity Parameters and Harmonic Generation: Effects of Crystalline and Amorphous Structures

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    The importance of nonlinearity in the description of material behavior is gaining widespread attention. Nonlinearity plays a major, if not dominating, role in a number of material properties. For example, properties that are important in engineering design such as thermal expansion or the pressure dependence of optical refraction are inherently nonlinear [1]. New assembley techniques such as the use of ultrasonic gauges to determine the loading of critical fasteners depend upon nonlinear properties of the fasteners [2]. Areas of considerable fundamental interest in nonlinearity include lattice dynamics [3], radiation stress in solids [4,5], and nonlinear optics [6

    Synthetic Mudscapes: Human Interventions in Deltaic Land Building

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    In order to defend infrastructure, economy, and settlement in Southeast Louisiana, we must construct new land to mitigate increasing risk. Links between urban environments and economic drivers have constrained the dynamic delta landscape for generations, now threatening to undermine the ecological fitness of the entire region. Static methods of measuring, controlling, and valuing land fail in an environment that is constantly in flux; change and indeterminacy are denied by traditional inhabitation. Multiple land building practices reintroduce deltaic fluctuation and strategic deposition of fertile material to form the foundations of a multi-layered defence strategy. Manufactured marshlands reduce exposure to storm surge further inland. Virtual monitoring and communication networks inform design decisions and land use becomes determined by its ecological health. Mudscapes at the threshold of land and water place new value on former wastelands. The social, economic, and ecological evolution of the region are defended by an expanded web of growing land

    Phosphoinositide 3-Kinase p110 Delta Differentially Restrains and Directs Naïve Versus Effector CD8<sup>+</sup> T Cell Transcriptional Programs

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    Phosphoinositide 3-kinase p110 delta (PI3K p110δ) is pivotal for CD8+ T cell immune responses. The current study explores PI3K p110δ induction and repression of antigen receptor and cytokine regulated programs to inform how PI3K p110δ directs CD8+ T cell fate. The studies force a revision of the concept that PI3K p110δ controls metabolic pathways in T cells and reveal major differences in PI3K p110δ regulated transcriptional programs between naïve and effector cytotoxic T cells (CTL). These differences include differential control of the expression of cytolytic effector molecules and costimulatory receptors. Key insights from the work include that PI3K p110δ signalling pathways repress expression of the critical inhibitory receptors CTLA4 and SLAMF6 in CTL. Moreover, in both naïve and effector T cells the dominant role for PI3K p110δ is to restrain the production of the chemokines that orchestrate communication between adaptive and innate immune cells. The study provides a comprehensive resource for understanding how PI3K p110δ uses multiple processes mediated by Protein Kinase B/AKT, FOXO1 dependent and independent mechanisms and mitogen-activated protein kinases (MAPK) to direct CD8+ T cell fate

    The state of the art in non-pharmacological interventions for developmental stuttering. Part 2: qualitative evidence synthesis of views and experiences.

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    BACKGROUND: A range of interventions have been developed to treat stuttering in recent years. The effectiveness of these interventions has largely been assessed in studies focusing on the impact of specific types of therapy on patient outcomes. Relatively little is known about the factors that influence how the delivery and impact of different types of intervention may be experienced from the perspective of both people who deliver as well as those who receive interventions. AIMS: To synthesize the available evidence in relation to factors that might enhance or mitigate against successful outcomes following interventions for stuttering by identifying and synthesizing relevant qualitative research that explored the experiences of people delivering and receiving interventions that aim to improve fluency. METHODS & PROCEDURES: We carried out a systematic review including research that had used in-depth interviews and focus groups and conducted a substantive qualitative analysis of the data collected. Included study populations were either adults or children affected by a diagnosed stutter and/or providers of therapy for stuttering. An iterative approach was used to search for published qualitative evidence in relevant databases from 1990 to 2014. Retrieved citations were sifted for relevance and the data from articles that met the inclusion criteria were extracted. Each included paper was assessed for quality and a thematic analysis and synthesis of findings was carried out. MAIN CONTRIBUTION: Synthesized qualitative evidence highlights the changing experiences for people who stutter both historically and, for individuals, over the life course. Barriers and facilitators to the implementation of interventions for stuttering are encountered at the individual, intervention, interpersonal and social levels. Interventions may be particularly pertinent at certain transition points in the life course. Attention to emotional as well as practical aspects of stuttering is valued by people receiving therapy. The client-therapist relationship and support from others are also key factors in achieving successful outcomes. CONCLUSIONS & IMPLICATIONS: A synthesis of qualitative findings from published papers has added to the effectiveness data reported in an accompanying paper in understanding how stuttering impacts on people across the life course. Evidence suggests that a client-centred and individually tailored approach enhances the likelihood of successful intervention outcomes through attention to emotional, situational and practical needs
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