728 research outputs found

    Asymmetric Conflicts with Endogenous Dimensionality

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    This article examines a two-stage model of asymmetric conflict based on the classic Colonel Blotto game in which players have, in the first stage, the ability to increase the number of battlefields contested. It thereby endogenizes the “dimensionality” of conflict. In equilibrium, if the asymmetry in the players’ resource endowments exceeds a threshold, the weak player chooses to add battlefields, while the strong player never does. Adding battlefields spreads the strong player’s forces more thinly, increasing the incidence of favorable strategic mismatches for the weak player.Asymmetric Conflict, Multi-battle Conflict, Colonel Blotto Game, Stochastic Guerilla Warfare, Endogenous Dimensionality

    Fractional Zero Forcing via Three-color Forcing Games

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    An rr-fold analogue of the positive semidefinite zero forcing process that is carried out on the rr-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup when colored with a fractional positive semidefinite forcing set are examined and used to define a three-color forcing game that directly computes the fractional positive semidefinite forcing number of a graph. We develop a fractional parameter based on the standard zero forcing process and it is shown that this parameter is exactly the skew zero forcing number with a three-color approach. This approach and an algorithm are used to characterize graphs whose skew zero forcing number equals zero.Comment: 24 page

    Evaluation of an ATP Assay to Quantify Bacterial Attachment to Surfaces in Reduced Gravity

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    Aim: To develop an assay to quantify the biomass of attached cells and biofilm formed on wetted surfaces in variable-gravity environments. Methods and Results: Liquid cultures of Pseudomonas aeruginosa were exposed to 30-35 brief cycles of hypergravity (< 2-g) followed by free fall (i.e., reduced gravity) equivalent to either lunar-g (i.e., 0.17 normal Earth gravity) or micro-g (i.e., < 0.001 normal Earth gravity) in an aircraft flying a series of parabolas. Over the course of two days of parabolic flight testing, 504 polymer or metal coupons were exposed to a stationary-phase population of P. aeruginosa strain ERC1 at a concentration of 1.0 x 10(exp 5) cells per milliliter. After the final parabola on each flight test day, half of the material coupon samples were treated with either 400 micro-g/L ionic silver fluoride (microgravity-exposed cultures) or 1% formalin (lunar-gravity-exposed cultures). The remaining sample coupons from each flight test day were not treated with a fixative. All samples were returned to the laboratory for analysis within 2 hours of landing, and all biochemical assays were completed within 8 hours of exposure to variable gravity. The intracellular ATP luminescent assay accurately reflected cell physiology compared to both cultivation-based and direct-count microscopy analyses. Cells exposed to variable gravity had more than twice as much intracellular ATP as control cells exposed only to normal Earth gravity

    Prognostic and predictive value of circulating tumor cells and CXCR4 expression as biomarkers for a CXCR4 peptide antagonist in combination with carboplatin-etoposide in small cell lung cancer: exploratory analysis of a phase II study.

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    Background Circulating tumor cells (CTCs) and chemokine (C-X-C motif) receptor 4 (CXCR4) expression in CTCs and tumor tissue were evaluated as prognostic or predictive markers of CXCR4 peptide antagonist LY2510924 plus carboplatin-etoposide (CE) versus CE in extensive-stage disease small cell lung cancer (ED-SCLC). Methods This exploratory analysis of a phase II study evaluated CXCR4 expression in baseline tumor tissue and peripheral blood CTCs and in post-treatment CTCs. Optimum cutoff values were determined for CTC counts and CXCR4 expression in tumors and CTCs as predictors of survival outcome. Kaplan-Meier estimates and hazard ratios were used to determine biomarker prognostic and predictive values. Results There was weak positive correlation at baseline between CXCR4 expression in tumor tissue and CTCs. Optimum cutoff values were H-score ≥ 210 for CXCR4+ tumor, ≥7% CTCs with CXCR4 expression (CXCR4+ CTCs), and ≥6 CTCs/7.5 mL blood. Baseline H-score for CXCR4+ tumor was not prognostic of progression-free survival (PFS) or overall survival (OS). Baseline CXCR4+ CTCs ≥7% was prognostic of shorter PFS. CTCs ≥6 at baseline and cycle 2, day 1 were prognostic of shorter PFS and OS. None of the biomarkers at their respective optimum cutoffs was predictive of treatment response of LY2510924 plus CE versus CE. Conclusions In patients with ED-SCLC, baseline CXCR4 expression in tumor tissue was not prognostic of survival or predictive of LY2510924 treatment response. Baseline CXCR4+ CTCs ≥7% was prognostic of shorter PFS. CTC count ≥6 at baseline and after 1 cycle of treatment were prognostic of shorter PFS and OS

    Exploring the Utility of Mindfulness and Self-regulation Assignments for Business Students

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    There are a number of personal habits, disciplines, and activities that are associated with success for both college students and business professionals. Goal-setting, concentration and focus, and the ability to delay gratification have long been known to be key factors. More recent research has shown that mindfulness, self-assessment, and self-regulation are also important to success. However, today’s world poses serious, new challenges to the student or professional who wishes to think and learn effectively and to achieve his/her goals. Previously, a Learning Academy was created to lead volunteer students through a series of self-assessments, worksheet exercises, personal reflections, and group discussions aimed at promoting the habits, disciplines, and activities mentioned above (Roberson, 2017; Polin and Roberson, 2016). The Academy was a success, but the number of students impacted was limited. The purpose of this study is to determine if there is utility in assigning selected Learning Academy content within a business course in order to reach a wider group of students

    Safety review of the Governor\u27s Highway Safety Office Sign Grant Program

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    The Governor\u27s Highway Safety Office Sign Grant Program attempts to improve safety in small communities throughout the state of Tennessee. The Sign Grant Program provides funding to upgrade regulatory and warning signs on the locally maintained roads of recipients. A measurable and significant reduction in accidents is one of the desired outcomes of the grant. The purpose of this study was to attempt to take quantitative and qualitative measure of the safety benefits of the Sign Grant Program. A before-and-after accident study in selected grant-receiving communities and a comprehensive survey of previous recipient communities were the chosen analysis techniques. It was found that the Sign Grant Program induced a reduction in certain types of accidents. Grant recipients expressed a belief that the program had many safety and non-safety benefits within their communities

    Improving Student Effort on a Learning Outcome Assessment: Benchmarks, Options, and Results

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    Mission-driven accreditation standards were established by AACSB in 2003 and updated in 2013, and these standards required accredited business and accounting programs to establish and assess student learning outcomes. This approach was a major change for AACSB accreditation, so beginning in 2003 universities were given a few years to design and implement their Assurance of Learning (AoL) programs. The result has been an array of measures to assess student learning outcomes. All too often, however, the AoL programs were stand-alone efforts to comply with the standards for assessment and were not linked to meaningful continuous improvement processes. Assessing basic business content knowledge gained by students continues to constitute an important element for AACSB accreditation. The challenge for universities is how best to measure content knowledge. While there are a variety of alternative approaches, many universities use the Educational Testing Service’s Major Field Test of Business (MFTB) as a component of their AoL programs. Between September 2013 and June 2015, 563 domestic institutions administered the MFTB to a total of 68,594 students (Educational Testing Service, 2015). The MFTB is a nationally-normed assessment instrument that enables business schools to compare their students’ content knowledge with that of students at other universities. Despite widespread use of the MFTB, concerns are sometimes expressed regarding the validity of the MFTB data. At issue is the extent to which students taking the test are sufficiently engaged and serious about doing their best, because if not, the test results cannot provide a reasonable estimate of students’ true knowledge and have little or no value as an assessment tool. Question: Is it possible to increase student motivation on a learning outcome assessment test and get results that are closer to each student’s true score
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