814 research outputs found

    On the number of points in a lattice polytope

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    In this article we will show that for every natural dd and n>1n>1 there exists a natural number tt such that for every dd-dimensional simplicial complex T\mathcal{T} with vertices in Zd\mathbb{Z}^d, the number of lattice points in the ttht^{\mathrm{th}} dilate of T\mathcal{T} is exactly χ(T)\chi(\mathcal{T}) modulo nn, where χ(T)\chi(\mathcal{T}) is the Euler characteristic of T\mathcal{T}.Comment: 3 page

    Asymptotically maximal families of hypersurfaces in toric varieties

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    A real algebraic variety is maximal (with respect to the Smith-Thom inequality) if the sum of the Betti numbers (with Z2\mathbb{Z}_2 coefficients) of the real part of the variety is equal to the sum of Betti numbers of its complex part. We prove that there exist polytopes that are not Newton polytopes of any maximal hypersurface in the corresponding toric variety. On the other hand we show that for any polytope Δ\Delta there are families of hypersurfaces with the Newton polytopes (λΔ)λN(\lambda\Delta)_{\lambda \in \mathbb{N}} that are asymptotically maximal when λ\lambda tends to infinity. We also show that these results generalize to complete intersections.Comment: 18 pages, 1 figur

    A Technological Dream Turned Legal Nightmare

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    The U.S. Global Positioning System (GPS) provides precise positioning information to anyone in the world, regardless of nationality, as long as they have access to an inexpensive receiver. However, in managing and providing the GPS for no charge, the United States may have opened itself to worldwide tort exposure. This Note analyzes U.S. liability for negligently operating the GPS under the Federal Tort Claims Act (FTCA) in four categories. First, this Note examines the transformation of the GPS from its domestic military beginnings to its current role as the foremost radionavigation technique in history and as a vital tool to civilians across the world. Relying on historical data and the GPS\u27s rapid expansion, this Note establishes how negligent GPS operation by the United States could harm a non-American outside of the United States. Second, this Note addresses the applicability of the FTCA\u27s foreign country exception to a lawsuit arising from negligent GPS operation. This second section argues that the foreign country exception should probably not prevent the lawsuit from progressing. Third, this Note surveys and analyzes U.S. Supreme Court and U.S. Courts of Appeals caselaw to determine the applicability of the FTCA\u27s discretionary function exception to this lawsuit. It then reveals the crucial issues relevant to a GPS lawsuit under the FTCA\u27s discretionary function exception. This Note concludes by stating that Congress should exempt the GPS from FTCA liability because of the devastating effect unparalleled global liability would have on the planet\u27s preeminent navigational device

    Work group inclusion : test of a scale and model

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    We develop a theoretically based 10-item measure of work group inclusion comprised of two components (belongingness and uniqueness) and use this measure to empirically test the nomological network of work group inclusion developed by Shore et al. In Phase 1, we use two samples of full-time employees to develop and refine items as well as establish content validity. In Phase 2, we demonstrate convergent, discriminant, and incremental validity with both conceptually related and unrelated constructs. In Phase 3, we use data from an additional sample of employees and supervisors to test criterion-related validity and mediation by examining the multilevel relationships between inclusion and important antecedents and outcomes. Across the three phases of our study, the results demonstrate support not only for the factor structure, reliability, and validity of our work group inclusion measure but also for a theoretical model in which the construct of inclusion has important implications for individuals and organizations

    Mixed-method study of a conceptual model of evidence-based intervention sustainment across multiple public-sector service settings.

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    BackgroundThis study examines sustainment of an EBI implemented in 11 United States service systems across two states, and delivered in 87 counties. The aims are to 1) determine the impact of state and county policies and contracting on EBI provision and sustainment; 2) investigate the role of public, private, and academic relationships and collaboration in long-term EBI sustainment; 3) assess organizational and provider factors that affect EBI reach/penetration, fidelity, and organizational sustainment climate; and 4) integrate findings through a collaborative process involving the investigative team, consultants, and system and community-based organization (CBO) stakeholders in order to further develop and refine a conceptual model of sustainment to guide future research and provide a resource for service systems to prepare for sustainment as the ultimate goal of the implementation process.MethodsA mixed-method prospective and retrospective design will be used. Semi-structured individual and group interviews will be used to collect information regarding influences on EBI sustainment including policies, attitudes, and practices; organizational factors and external policies affecting model implementation; involvement of or collaboration with other stakeholders; and outer- and inner-contextual supports that facilitate ongoing EBI sustainment. Document review (e.g., legislation, executive orders, regulations, monitoring data, annual reports, agendas and meeting minutes) will be used to examine the roles of state, county, and local policies in EBI sustainment. Quantitative measures will be collected via administrative data and web surveys to assess EBI reach/penetration, staff turnover, EBI model fidelity, organizational culture and climate, work attitudes, implementation leadership, sustainment climate, attitudes toward EBIs, program sustainment, and level of institutionalization. Hierarchical linear modeling will be used for quantitative analyses. Qualitative analyses will be tailored to each of the qualitative methods (e.g., document review, interviews). Qualitative and quantitative approaches will be integrated through an inclusive process that values stakeholder perspectives.DiscussionThe study of sustainment is critical to capitalizing on and benefiting from the time and fiscal investments in EBI implementation. Sustainment is also critical to realizing broad public health impact of EBI implementation. The present study takes a comprehensive mixed-method approach to understanding sustainment and refining a conceptual model of sustainment

    Inclusive leadership : realizing positive outcomes through belongingness and being valued for uniqueness

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    We introduce a theoretically-grounded conceptualization of inclusive leadership and present a framework for understanding factors that contribute to and follow from inclusive leadership within work groups. We conceptualize inclusive leadership as a set of positive leader behaviors that facilitate group members perceiving belongingness in the work group while maintaining their uniqueness within the group as they fully contribute to group processes and outcomes. We propose that leader pro-diversity beliefs, humility, and cognitive complexity increase the propensity of inclusive leader behaviors. We identify five categories of inclusive leadership behaviors that facilitate group members' perceptions of inclusion, which in turn lead to member work group identification, psychological empowerment, and behavioral outcomes (creativity, job performance, and reduced turnover) in the pursuit of group goals. This framework provides theoretical grounding for the construct of inclusive leadership while advancing our understanding of how leaders can increase diverse work group effectiveness

    Cervical masses in dogs and cats 1. Investigation and management

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    Abnormalities in the cervical region can be challenging to investigate and manage; however, the area is a common location for disease processes in dogs and cats. The anatomy of this region can make investigations and treatment difficult and a thorough understanding of this is essential before embarking on management and treatment of conditions in this location. Due to the various anatomical structures in the cervical area, there is often a long potential differential diagnoses list for mass lesions in this region. It is important to perform a thorough and logical investigative process in order to manage these masses appropriately. This article discusses investigation and management of cervical masses, while a second article, to be published in a subsequent issue of In Practice, will focus on differential diagnoses

    Leading for the long haul: A mixed-method evaluation of the Sustainment Leadership Scale (SLS)

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    © 2018 The Author(s). Background: Despite our progress in understanding the organizational context for implementation and specifically the role of leadership in implementation, its role in sustainment has received little attention. This paper took a mixed-method approach to examine leadership during the sustainment phase of the Exploration, Preparation, Implementation, Sustainment (EPIS) framework. Utilizing the Implementation Leadership Scale as a foundation, we sought to develop a short, practical measure of sustainment leadership that can be used for both applied and research purposes. Methods: Data for this study were collected as a part of a larger mixed-method study of evidence-based intervention, SafeCare®, sustainment. Quantitative data were collected from 157 providers using web-based surveys. Confirmatory factor analysis was used to examine the factor structure of the Sustainment Leadership Scale (SLS). Qualitative data were collected from 95 providers who participated in one of 15 focus groups. A framework approach guided qualitative data analysis. Mixed-method integration was also utilized to examine convergence of quantitative and qualitative findings. Results: Confirmatory factor analysis supported the a priori higher order factor structure of the SLS with subscales indicating a single higher order sustainment leadership factor. The SLS demonstrated excellent internal consistency reliability. Qualitative analyses offered support for the dimensions of sustainment leadership captured by the quantitative measure, in addition to uncovering a fifth possible factor, available leadership. Conclusions: This study found qualitative and quantitative support for the pragmatic SLS measure. The SLS can be used for assessing leadership of first-level leaders to understand how staff perceive leadership during sustainment and to suggest areas where leaders could direct more attention in order to increase the likelihood that EBIs are institutionalized into the normal functioning of the organization

    Two new submodels for the Modular Earth Submodel System (MESSy): New Aerosol Nucleation (NAN) and small ions (IONS) version 1.0

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    Abstract. Two new submodels for the Modular Earth Submodel System (MESSy) were developed. The New Aerosol Nucleation (NAN) submodel includes new parameterisations of aerosol particle formation rates published in recent years. These parameterisations include ion-induced nucleation and nucleation of pure organic species. NAN calculates the rate of new particle formation based on the aforementioned parameterisations for aerosol submodels in the ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The ion pair production rate, needed to calculate the ion-induced or ion-mediated nucleation, is described using the new submodel IONS, which provides ion pair production rates for other submodels within the MESSy framework. Both new submodels were tested in EMAC simulations. These simulations showed good agreement with ground-based observations. </jats:p

    Diffusion and jump-length distribution in liquid and amorphous Cu33_{33}Zr67_{67}

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    Using molecular dynamics simulation, we calculate the distribution of atomic jum ps in Cu33_{33}Zr67_{67} in the liquid and glassy states. In both states the distribution of jump lengths can be described by a temperature independent exponential of the length and an effective activation energy plus a contribution of elastic displacements at short distances. Upon cooling the contribution of shorter jumps dominates. No indication of an enhanced probability to jump over a nearest neighbor distance was found. We find a smooth transition from flow in the liquid to jumps in the g lass. The correlation factor of the diffusion constant decreases with decreasing temperature, causing a drop of diffusion below the Arrhenius value, despite an apparent Arrhenius law for the jump probability
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