1,804 research outputs found

    Proposing new variables for the identification of strategic groups in franchising

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    The identification of strategic groups in the Spanish franchising area is the main aim of this study. The authors have added some new strategic variables (not used before) to the study and have classified franchisors between sectors and distribution strategy. The results reveal the existence of four perfectly differentiated strategic groups (types of franchisors). One of the major implications of this study is that the variables that build a strategic group vary depending on the respective sector the network operates in and its distribution strategy. This fact indicates that including sector and distribution strategy is absolutely necessary to achieve good classifications of franchisor type

    MRI radiomic features are independently associated with overall survival in soft tissue sarcoma

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    Purpose: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. Methods and Materials: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell\u27s concordance index. Results: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; Conclusions: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS

    Frequency-Reconfigurable Dipole Antenna Using Liquid-Metal Pixels

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    A frequency-tunable half-wavelength dipole antenna is realized using an array of electrically actuated liquid-metal pixels. The liquid-metal pixelated dipole antenna demonstrates frequency reconfigurability by switching between resonances at 2.51 GHz, 2.12 GHz, 1.85 GHz, and 1.68 GHz

    Performance in franchising: the effects of different management styles

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    Various theoretical approaches uphold the relevance of the relationship between the form of management and performance. Different management styles influence the relationships of agencies [Jensen, M.C. (1998). Foundations of organizational strategy. Cambridge, MA: Harvard University Press], the cost of governing transactions [Williamson, O.E. (1985). The economics institutions of capitalism: Firms, markets, relational contracting. New York, NY: Free Press], and the allocation of resources between the exploitation and exploration of activities [March, J.G. (1991). Exploration and exploitation in organizational learning. Organization Science, 2(1), 71-87], and this is manifested in firm performance. In light of these assumptions, this article presents an empirical verification of the relationship between the management of franchises and their performance, examining how different styles of management on the part of franchisers over their franchisees have significant effects on the growth and profits of franchiser firms.Peris-Ortiz, M.; Willoughby, MC.; Rueda Armengot, C. (2012). Performance in franchising: the effects of different management styles. Service Industries Journal. 32(16):2507-2525. doi:10.1080/02642069.2011.594876S250725253216Altinay, L., & Okumus, F. (2010). Franchise partner selection decision making. The Service Industries Journal, 30(6), 929-946. doi:10.1080/02642060802322275Child, J. (1972). Organizational Structure, Environment and Performance: The Role of Strategic Choice. Sociology, 6(1), 1-22. doi:10.1177/003803857200600101Combs, J. G., & Ketchen, D. J. (1999). CAN CAPITAL SCARCITY HELP AGENCY THEORY EXPLAIN FRANCHISING? REVISITING THE CAPITAL SCARCITY HYPOTHESIS. Academy of Management Journal, 42(2), 196-207. doi:10.2307/257092Combs, J. (2003). Why Do Firms Use Franchising as an Entrepreneurial Strategy?: A Meta-Analysis. Journal of Management, 29(3), 443-465. doi:10.1016/s0149-2063(03)00019-9COMBS, J. G., KETCHEN, D. J., & IRELAND, R. D. (2006). Effectively managing service chain organizations. Organizational Dynamics, 35(4), 357-371. doi:10.1016/j.orgdyn.2006.08.006Combs, J. G., Michael, S. C., & Castrogiovanni, G. J. (2009). Institutional Influences on the Choice of Organizational Form: The Case of Franchising. Journal of Management, 35(5), 1268-1290. doi:10.1177/0149206309336883Crook, T. R., Shook, C. L., Madden, T. M., & Morris, M. L. (2009). A review of current construct measurement in entrepreneurship. International Entrepreneurship and Management Journal, 6(4), 387-398. doi:10.1007/s11365-009-0114-7Fama, E. F., & Jensen, M. C. (1983). Agency Problems and Residual Claims. The Journal of Law and Economics, 26(2), 327-349. doi:10.1086/467038Fama, E. F., & Jensen, M. C. (1983). Separation of Ownership and Control. The Journal of Law and Economics, 26(2), 301-325. doi:10.1086/467037Gillis, W. E., & Combs, J. G. (2009). Franchisor strategy and firm performance: Making the most of strategic resource investments. Business Horizons, 52(6), 553-561. doi:10.1016/j.bushor.2009.07.001Gouldner, A. W. (1960). The Norm of Reciprocity: A Preliminary Statement. American Sociological Review, 25(2), 161. doi:10.2307/2092623Gupta, A. K., Smith, K. G., & Shalley, C. E. (2006). The Interplay Between Exploration and Exploitation. Academy of Management Journal, 49(4), 693-706. doi:10.5465/amj.2006.22083026Hambrick, D. C. (2007). Upper Echelons Theory: An Update. Academy of Management Review, 32(2), 334-343. doi:10.5465/amr.2007.24345254Hambrick, D. C., & Mason, P. A. (1984). Upper Echelons: The Organization as a Reflection of Its Top Managers. The Academy of Management Review, 9(2), 193. doi:10.2307/258434Hindle, K., & Moroz, P. (2009). Indigenous entrepreneurship as a research field: developing a definitional framework from the emerging canon. International Entrepreneurship and Management Journal, 6(4), 357-385. doi:10.1007/s11365-009-0111-xJensen, M. C., & Meckling, W. H. (1976). Theory of the firm: Managerial behavior, agency costs and ownership structure. Journal of Financial Economics, 3(4), 305-360. doi:10.1016/0304-405x(76)90026-xJensen, M. C., & Heckling, W. H. (1995). SPECIFIC AND GENERAL KNOWLEDGE, AND ORGANIZATIONAL STRUCTURE. Journal of Applied Corporate Finance, 8(2), 4-18. doi:10.1111/j.1745-6622.1995.tb00283.xKlein, B., Crawford, R. G., & Alchian, A. A. (1978). Vertical Integration, Appropriable Rents, and the Competitive Contracting Process. The Journal of Law and Economics, 21(2), 297-326. doi:10.1086/466922Liu, W., Lepak, D. P., Takeuchi, R., & Sims, H. P. (2003). 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    Deterministic mechanical model of T-killer cell polarization reproduces the wandering of aim between simultaneously engaged targets

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    T-killer cells of the immune system eliminate virus-infected and tumorous cells through direct cell-cell interactions. Reorientation of the killing apparatus inside the T cell to the T-cell interface with the target cell ensures specificity of the immune response. The killing apparatus can also oscillate next to the cell-cell interface. When two target cells are engaged by the T cell simultaneously, the killing apparatus can oscillate between the two interface areas. This oscillation is one of the most striking examples of cell movements that give the microscopist an unmechanistic impression of the cell's fidgety indecision. We have constructed a three-dimensional, numerical biomechanical model of the molecular-motor-driven microtubule cytoskeleton that positions the killing apparatus. The model demonstrates that the cortical pulling mechanism is indeed capable of orienting the killing apparatus into the functional position under a range of conditions. The model also predicts experimentally testable limitations of this commonly hypothesized mechanism of T-cell polarization. After the reorientation, the numerical solution exhibits complex, multidirectional, multiperiodic, and sustained oscillations in the absence of any external guidance or stochasticity. These computational results demonstrate that the strikingly animate wandering of aim in T-killer cells has a purely mechanical and deterministic explanation. © 2009 Kim, Maly

    Prognostic significance of IDH-1 and MGMT in patients with glioblastoma: One step forward, and one step back?

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    A group of 160 patients with primary glioblastoma treated with radiotherapy and temozolomide was analyzed for the impact of O6-methly-guanly-methyl-transferase (MGMT)-promoter methylation as well as isocitrate dehydrogenase (IDH)1-mutational status. Unexpectedly, overall survival or progression-free survival were not longer in the group with methylated MGMT-promoter as compared to patients without that methylation. IDH-1 mutations were significantly associated with increased overall survival

    The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

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    The {\sc Majorana} collaboration is searching for neutrinoless double beta decay using 76^{76}Ge, which has been shown to have a number of advantages in terms of sensitivities and backgrounds. The observation of neutrinoless double-beta decay would show that lepton number is violated and that neutrinos are Majorana particles and would simultaneously provide information on neutrino mass. Attaining sensitivities for neutrino masses in the inverted hierarchy region, 155015 - 50 meV, will require large, tonne-scale detectors with extremely low backgrounds, at the level of \sim1 count/t-y or lower in the region of the signal. The {\sc Majorana} collaboration, with funding support from DOE Office of Nuclear Physics and NSF Particle Astrophysics, is constructing the {\sc Demonstrator}, an array consisting of 40 kg of p-type point-contact high-purity germanium (HPGe) detectors, of which \sim30 kg will be enriched to 87% in 76^{76}Ge. The {\sc Demonstrator} is being constructed in a clean room laboratory facility at the 4850' level (4300 m.w.e.) of the Sanford Underground Research Facility (SURF) in Lead, SD. It utilizes a compact graded shield approach with the inner portion consisting of ultra-clean Cu that is being electroformed and machined underground. The primary aim of the {\sc Demonstrator} is to show the feasibility of a future tonne-scale measurement in terms of backgrounds and scalability.Comment: Proceedings for the MEDEX 2013 Conferenc
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