1,537 research outputs found

    A Chink in the Armor: How a Uniform Approach to Proportionality Analysis Can End the Use of Human Shields

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    The appropriate response to human shields is a recurring issue in modern warfare. Technological asymmetry, disparate obligations, and doctrinal divergence between state and nonstate adversaries combine to make civilians account for 84 percent of combat deaths. Just as a slot machine entices a gambler though he rarely wins, the international community\u27s inconsistent response to human shields has placed shield users on an intermittent reinforcement schedule, thereby ensuring that this tactic remains part of insurgent strategy. Long-term protection of civilians requires eliminating this tactic. Principles of behavior science indicate that an effective way to do so is to uniformly remove its desired consequence--combatants must never allow the presence of shields to impede access to the shielded military objective. This approach is supported by a broader, more forward-thinking conception of the principle of proportionality as reflected in current treaty and customary international law

    Quantum Group Invariant Supersymmetric t-J Model with periodic boundary conditions

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    An integrable version of the supersymmetric t-J model which is quantum group invariant as well as periodic is introduced and analysed in detail. The model is solved through the algebraic nested Bethe ansatz method.Comment: 11 pages, LaTe

    La tumba hipogea de Bolores (Torres Vedras): una aproximación interdisciplinar a la comprensión del paisaje social del Neolítico Final/Edad del Cobre de la Península Ibérica

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    To better understand the sociopolitical landscape of the Portuguese Estremadura during the Late Neolithic/Copper Age, interdisciplinary excavations were conducted at Bolores (Torres Vedras), in the Sizandro River Valley. Following a test season in 1986, a University of Iowa team conducted four campaigns between 2007 and 2012. Bolores is a rock-cut tomb used primarily between 2800-2600 cal BC for the burial of adults, adolescents, and children (MNI=36). The architectural, material cultural, and bioarchaeological evidence suggests that Bolores housed the remains of a distinctive group of local individuals who marked their difference from other burial populations in the Sizandro and Estremadura through material culture and tomb architecture. Social differences were denoted spatially and through offerings of material goods. No social stratification is evident, however, that would suggest a state-level society: there are no wealthy child burials and no significant health or dietary disparities within this population or between it and others in the region.Para comprender mejor el paisaje sociopolítico de la Extremadura portuguesa durante el Neolítico Final/Edad del Cobre se han llevado a cabo excavaciones interdisciplinares en Bolores (Torres Vedras), en el valle del río Sizandro. Tras una campaña de prueba en 1986, un equipo de la Universidad de Iowa realizó cuatro campañas entre 2007 y 2012. Bolores es una tumba hipogea que fue utilizada principalmente entre 2800 y 2600 cal BCE como enterramiento colectivo para adultos, adolescentes y niños (NMI=36). Los datos arquitectónicos, bioarqueológicos y de cultura material analizados hasta la fecha sugieren que Bolores albergó los restos de un grupo social distintivo compuesto de individuos locales que marcaban sus diferencias con otras poblaciones funerarias del Sizandro y Extremadura portuguesa mediante la cultura material y la arquitectura funeraria. Las diferencias sociales en la población de Bolores fueron señaladas espacialmente y marcadas mediante las ofrendas de bienes materiales. Sin embargo, no se aprecia una estratificación social significativa que sugiera una sociedad de nivel estatal: no hay enterramientos infantiles ricos, ni disparidades en la salud o dieta de esta población funeraria o entre esta población y otras en la región de Torres Vedras

    International VLBI Service for Geodesy and Astrometry: Delivering high-quality products and embarking on observations of the next generation

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    © 2016 Springer-Verlag Berlin HeidelbergThe International VLBI Service for Geodesy and Astrometry (IVS) regularly produces high-quality Earth orientation parameters from observing sessions employing extensive networks or individual baselines. The master schedule is designed according to the telescope days committed by the stations and by the need for dense sampling of the Earth orientation parameters (EOP). In the pre-2011 era, the network constellations with their number of telescopes participating were limited by the playback and baseline capabilities of the hardware (Mark4) correlators. This limitation was overcome by the advent of software correlators, which can now accommodate many more playback units in a flexible configuration. In this paper, we describe the current operations of the IVS with special emphasis on the quality of the polar motion results since these are the only EOP components which can be validated against independent benchmarks. The polar motion results provided by the IVS have improved continuously over the years, now providing an agreement with IGS results at the level of 20–25 (Formula presented.)as in a WRMS sense. At the end of the paper, an outlook is given for the realization of the VLBI Global Observing System

    Exact solution and surface critical behaviour of open cyclic SOS lattice models

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    We consider the LL-state cyclic solid-on-solid lattice models under a class of open boundary conditions. The integrable boundary face weights are obtained by solving the reflection equations. Functional relations for the fused transfer matrices are presented for both periodic and open boundary conditions. The eigen-spectra of the unfused transfer matrix is obtained from the functional relations using the analytic Bethe ansatz. For a special case of crossing parameter λ=π/L\lambda=\pi/L, the finite-size corrections to the eigen-spectra of the critical models are obtained, from which the corresponding conformal dimensions follow. The calculation of the surface free energy away from criticality yields two surface specific heat exponents, αs=2L/2\alpha_s=2-L/2\ell and α1=1L/\alpha_1=1-L/\ell, where =1,2,,L1\ell=1,2,\cdots,L-1 coprime to LL. These results are in agreement with the scaling relations αs=αb+ν\alpha_s=\alpha_b+\nu and α1=αb1\alpha_1=\alpha_b-1.Comment: 13 pages, LaTeX, to appear in J. Phys.

    Effectiveness of physiotherapy exercise following total knee replacement: Systematic review and meta-analysis

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    Background: Rehabilitation, with an emphasis on physiotherapy and exercise, is widely promoted after total knee replacement. However, provision of services varies in content and duration. The aim of this study is to update the review of Minns Lowe and colleagues 2007 using systematic review and meta-analysis to evaluate the effectiveness of post-discharge physiotherapy exercise in patients with primary total knee replacement. Methods: We searched MEDLINE, Embase, PsycInfo, CINAHL and Cochrane CENTRAL to October 4th 2013 for randomised evaluations of physiotherapy exercise in adults with recent primary knee replacement. Outcomes were: patient-reported pain and function, knee range of motion, and functional performance. Authors were contacted for missing data and outcomes. Risk of bias and heterogeneity were assessed. Data was combined using random effects meta-analysis and reported as standardised mean differences (SMD) or mean differences (MD). Results: Searches identified 18 randomised trials including 1,739 patients with total knee replacement. Interventions compared: physiotherapy exercise and no provision; home and outpatient provision; pool and gym-based provision; walking skills and more general physiotherapy; and general physiotherapy exercise with and without additional balance exercises or ergometer cycling. Compared with controls receiving minimal physiotherapy, patients receiving physiotherapy exercise had improved physical function at 3-4 months, SMD -0.37 (95% CI -0.62, -0.12), and pain, SMD -0.45 (95% CI -0.85, -0.06). Benefit up to 6 months was apparent when considering only higher quality studies. There were no differences for outpatient physiotherapy exercise compared with home-based provision in physical function or pain outcomes. There was a short-term benefit favouring home-based physiotherapy exercise for range of motion flexion. There were no differences in outcomes when the comparator was hydrotherapy, or when additional balancing or cycling components were included. In one study, a walking skills intervention was associated with a long-term improvement in walking performance. However, for all these evaluations studies were under-powered individually and in combination. Conclusion: After recent primary total knee replacement, interventions including physiotherapy and exercise show short-term improvements in physical function. However this conclusion is based on meta-analysis of a few small studies and no long-term benefits of physiotherapy exercise interventions were identified. Future research should target improvements to long-term function, pain and performance outcomes in appropriately powered trials

    Phase transition in an asymmetric generalization of the zero-temperature q-state Potts model

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    An asymmetric generalization of the zero-temperature q-state Potts model on a one dimensional lattice, with and without boundaries, has been studied. The dynamics of the particle number, and specially the large time behavior of the system has been analyzed. In the thermodynamic limit, the system exhibits two kinds of phase transitions, a static and a dynamic phase transition.Comment: 11 pages, LaTeX2

    Quantum spin chain with "soliton non-preserving" boundary conditions

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    We consider the case of an integrable quantum spin chain with "soliton non-peserving" boundary conditions. This is the first time that such boundary conditions have been considered in the spin chain framework. We construct the transfer matrix of the model, we study its symmetry and we find explicit expressions for its eigenvalues. Moreover, we derive a new set of Bethe ansatz equations by means of the analytical Bethe ansatz method.Comment: 12 pages, LaTeX, two appendices added, minor correction
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