1,184 research outputs found
Conflicts of National Security Interests in East Asia and the Pacific: At the Turn of the Twenty-First Century
Introduction. With Korea, Vietnam and the Gull War as bloody memories of the past, East Asia and the Pacific enters a new era of international relations with the turn to the 21st Century. The entire region, and the rest of the world, breathes more freely because the cold war in its passing has taken with it the imminent danger of a nuclear holocaust. Never has the time been more propitious for a reexamination of conflicts of national security interests in East Asia, with special attention to the role of the United States. It is the purpose of this study to analyze successively the strategic situation in Northeast Asia, China, Southeast Asia and the Southwest Pacific with a view to finding more effective policies and strategies for peace, stability and prosperity
Green Function on the q-Symmetric Space SU_q(2)/U(1)
Following the introduction of the invariant distance on the non-commutative
C-algebra of the quantum group SU_q(2), the Green function and the Kernel on
the q-homogeneous space M=SU(2)_q/U(1) are derived. A path integration is
formulated. Green function for the free massive scalar field on the
non-commutative Einstein space R^1xM is presented.Comment: Plain Latex, 19
Gluon mass generation in the PT-BFM scheme
In this article we study the general structure and special properties of the
Schwinger-Dyson equation for the gluon propagator constructed with the pinch
technique, together with the question of how to obtain infrared finite
solutions, associated with the generation of an effective gluon mass.
Exploiting the known all-order correspondence between the pinch technique and
the background field method, we demonstrate that, contrary to the standard
formulation, the non-perturbative gluon self-energy is transverse
order-by-order in the dressed loop expansion, and separately for gluonic and
ghost contributions. We next present a comprehensive review of several subtle
issues relevant to the search of infrared finite solutions, paying particular
attention to the role of the seagull graph in enforcing transversality, the
necessity of introducing massless poles in the three-gluon vertex, and the
incorporation of the correct renormalization group properties. In addition, we
present a method for regulating the seagull-type contributions based on
dimensional regularization; its applicability depends crucially on the
asymptotic behavior of the solutions in the deep ultraviolet, and in particular
on the anomalous dimension of the dynamically generated gluon mass. A
linearized version of the truncated Schwinger-Dyson equation is derived, using
a vertex that satisfies the required Ward identity and contains massless poles
belonging to different Lorentz structures. The resulting integral equation is
then solved numerically, the infrared and ultraviolet properties of the
obtained solutions are examined in detail, and the allowed range for the
effective gluon mass is determined. Various open questions and possible
connections with different approaches in the literature are discussed.Comment: 54 pages, 24 figure
Alternating Kinetics of Annihilating Random Walks Near a Free Interface
The kinetics of annihilating random walks in one dimension, with the
half-line x>0 initially filled, is investigated. The survival probability of
the nth particle from the interface exhibits power-law decay,
S_n(t)~t^{-alpha_n}, with alpha_n approximately equal to 0.225 for n=1 and all
odd values of n; for all n even, a faster decay with alpha_n approximately
equal to 0.865 is observed. From consideration of the eventual survival
probability in a finite cluster of particles, the rigorous bound alpha_1<1/4 is
derived, while a heuristic argument gives alpha_1 approximately equal to 3
sqrt{3}/8 = 0.2067.... Numerically, this latter value appears to be a stringent
lower bound for alpha_1. The average position of the first particle moves to
the right approximately as 1.7 t^{1/2}, with a relatively sharp and asymmetric
probability distribution.Comment: 6 pages, RevTeX, 5 eps figures include
Suono e Spettacolo. Athanasius Kircher, un percorso nelle Immagini sonore.
The Society of Jesus made great propaganda efforts throughout the seventeenth century and chose the images and the play as a privileged means to communicate and persuade. Athanasius Kircher, a key figure of the seventeenth century, he decided to dominate the wild nature of sound through Phonurgia Nova, which includes a gallery of powerful symbolic images for Baroque aesthetics. The essay, through the grant of the images from the Library of the Department of Mathematics "Guido Castelnuovo" Sapienza University of Rome, aims to understand, through the pictures offered by Kircher, the sound phenomenon and the spectacle that this produces. In Phonurgia Nova a process of dramatization sound effects takes place, often through machines and "visions" applied to the theatrical reality, as experimental and astonishing environment beloved in baroque. Kircher illustrates the sound through explanatory figures, so to dominate the sound through the eyes. Sound is seen, admired and represented: its spectacle not only takes place through the implementation of sound machines or the "wonders" applied to the theater, but even through images, creating create a sense of wonder in in the erudite person of the seventeenth century
D-Instantons and asymptotic geometries
The large N limit of D3-branes is expected to correspond to a superconformal
field theory living on the boundary of the anti-de Sitter space appearing in
the near-horizon geometry. Dualizing the D3-brane to a D-instanton, we show
that this limit is equivalent to a type IIB S-duality. In both cases one
effectively reaches the near-horizon geometry. This provides an alternative
approach to an earlier derivation of the same result that makes use of the
properties of a gravitational wave instead of the D-instanton.Comment: 17 pages, LaTeX, 1 figure, minor corrections and refs adde
The emergence of international food safety standards and guidelines: understanding the current landscape through a historical approach
Following the Second World War, the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) teamed up to construct an International Codex Alimentarius (or 'food code') which emerged in 1963. The Codex Committee on Food Hygiene (CCFH) was charged with the task of developing microbial hygiene standards, although it found itself embroiled in debate with the WHO over the nature these standards should take. The WHO was increasingly relying upon the input of biometricians and especially the International Commission on Microbial Specifications for Foods (ICMSF) which had developed statistical sampling plans for determining the microbial counts in the final end products. The CCFH, however, was initially more focused on a qualitative approach which looked at the entire food production system and developed codes of practice as well as more descriptive end-product specifications which the WHO argued were 'not scientifically correct'. Drawing upon historical archival material (correspondence and reports) from the WHO and FAO, this article examines this debate over microbial hygiene standards and suggests that there are many lessons from history which could shed light upon current debates and efforts in international food safety management systems and approaches
Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review
A critical review on signatures of Quark-Gluon-Plasma formation is given and
the current (1998) experimental status is discussed. After giving an
introduction to the properties of QCD matter in both, equilibrium- and
non-equilibrium theories, we focus on observables which may yield experimental
evidence for QGP formation. For each individual observable the discussion is
divided into three sections: first the connection between the respective
observable and QGP formation in terms of the underlying theoretical concepts is
given, then the relevant experimental results are reviewed and finally the
current status concerning the interpretation of both, theory and experiment, is
discussed. A comprehensive summary including an outlook towards RHIC is given
in the final section.Comment: Topical review, submitted to Journal of Physics G: 68 pages,
including 39 figures (revised version: only minor modifications, some
references added
From Marginalized to Maximized Opportunities for Diverse Youths With Disabilities: A Position Paper of the Division on Career Development and Transition
Current secondary education and transition practices have created differential education and employment outcomes by gender, race and ethnicity, socioeconomic status, and disability classifications. These differential outcomes result in economic and social marginalization of far too many students with disabilities. Transition education practices need to respond to these differential outcomes and provide targeted, systematic, and long-term opportunities for all students to attain individually and family-determined postschool goals. This position paper recommends an ecological framework for considering the multiple systems that influence transition education and postschool outcomes for diverse youths with disabilities. The authors argue for educators, researchers, and policy makers to attend to social, political, economic, educational, and cultural contexts in developing effective interventions and improving postschool outcomes.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
The American Association for the Surgery of Trauma renal injury grading scale: Implications of the 2018 revisions for injury reclassification and predicting bleeding interventions.
BackgroundIn 2018, the American Association for the Surgery of Trauma (AAST) published revisions to the renal injury grading system to reflect the increased reliance on computed tomography scans and non-operative management of high-grade renal trauma (HGRT). We aimed to evaluate how these revisions will change the grading of HGRT and if it outperforms the original 1989 grading in predicting bleeding control interventions.MethodsData on HGRT were collected from 14 Level-1 trauma centers from 2014 to 2017. Patients with initial computed tomography scans were included. Two radiologists reviewed the scans to regrade the injuries according to the 1989 and 2018 AAST grading systems. Descriptive statistics were used to assess grade reclassifications. Mixed-effect multivariable logistic regression was used to measure the predictive ability of each grading system. The areas under the curves were compared.ResultsOf the 322 injuries included, 27.0% were upgraded, 3.4% were downgraded, and 69.5% remained unchanged. Of the injuries graded as III or lower using the 1989 AAST, 33.5% were upgraded to grade IV using the 2018 AAST. Of the grade V injuries, 58.8% were downgraded using the 2018 AAST. There was no statistically significant difference in the overall areas under the curves between the 2018 and 1989 AAST grading system for predicting bleeding interventions (0.72 vs. 0.68, p = 0.34).ConclusionAbout one third of the injuries previously classified as grade III will be upgraded to grade IV using the 2018 AAST, which adds to the heterogeneity of grade IV injuries. Although the 2018 AAST grading provides more anatomic details on injury patterns and includes important radiologic findings, it did not outperform the 1989 AAST grading in predicting bleeding interventions.Level of evidencePrognostic and Epidemiological Study, level III
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