868 research outputs found
Lattice QCD gluon propagators near transition temperature
Landau gauge gluon propagators are studied numerically in the SU(3)
gluodynamics as well as in the full QCD with the number of flavors
using efficient gauge fixing technique. We compare these propagators at
temperatures very close to the transition point in two phases : confinement and
deconfinement. The electric mass has been determined from the momentum
space longitudinal gluon propagator. Gribov copy effects are found to be rather
strong in the gluodynamics, while in the full QCD case they are weak ("Gribov
noise"). Also we analyse finite volume dependence of the transverse and
longitudinal propagators.Comment: 9 pages, 7 figure
Synthesis of OCL Pre-conditions for Graph Transformation Rules
Proceedings of: Third International Conference on Model Transformation (ICMT 2010): Theory and Practice of Model Transformation. MĂĄlaga, Spain, 28 June-02 July, 2010Graph transformation (GT) is being increasingly used in Model Driven Engineering (MDE) to describe in-place transformations like animations and refactorings. For its practical use, rules are often complemented with OCL application conditions. The advancement of rule post-conditions into pre-conditions is a well-known problem in GT, but current techniques do not consider OCL. In this paper we provide an approach to advance post-conditions with arbitrary OCL expressions into pre-conditions. This presents benefits for the practical use of GT in MDE, as it allows: (i) to automatically derive pre-conditions from the meta-model integrity constraints, ensuring rule correctness, (ii) to derive pre-conditions from graph constraints with OCL expressions and (iii) to check applicability of rule sequences with OCL conditions.Work funded by the Spanish Ministry of Science and Innovation through projects âDesign and construction of a Conceptual Modeling Assistantâ (TIN2008-00444/TIN - Grupo Consolidado), âMETEORICâ (TIN2008-02081),mobility grants JC2009-00015 and PR2009-0019, and the R&D program of the Community of Madrid (S2009/TIC-1650, project âe-Madridâ).Publicad
Canonical Derivations with Negative Application Conditions
Using graph transformations to specify the dynamics of distributed systems and networks, we require a precise understanding of concurrency. Negative application conditions (NACs) are an essential means for controlling the application of rules, extending our ability to model complex systems. A classical notion of concurrency in graph transformation is based on shift equivalence and its representation by canonical derivations, i.e., normal forms of the shift operation anticipating independent steps. These concepts are lifted to graph transformation systems with NACs and it is shown that canonical derivations exist for so-called incremental NACs
Soft Covariant Gauges on the Lattice
We present an exploratory study of a one-parameter family of covariant,
non-perturbative lattice gauge-fixing conditions, that can be implemented
through a simple Monte Carlo algorithm. We demonstrate that at the numerical
level the procedure is feasible, and as a first application we examine the
gauge dependence of the gluon propagator.Comment: 11 pages, Latex, epsf.sty included + 5 PostScript picture
âClinics arenât meant for menâ: Sexual health care access and seeking behaviours among men in Gauteng province, South Africa
Men may be key players in the transmission of sexually transmitted infections (STI), and it is important that STI/HIV health services reach men. The objective of this study was to explore sexual health care access and seeking behaviours in men. This study used focus groups to examine sexual health care access and seeking behaviours in men 5 years after implementation of free antiretroviral therapy (ART) in the South African public sector. Six focus groups (N=58) were conducted with men â„18 years in an urban area of Gauteng province. Men were recruited from various locations throughout the community. Men reported several barriers and facilitators to the use of public and private clinics for sexual health services including HIV testing, and many men reported seeking care from traditional healers. Men often viewed public clinics as a place for women and reported experiences with some female nurses who were rude or judgmental of the men. Additionally, some men reported that they sought sexual health care services at public clinics; however, they were not given physical examinations by health care providers to diagnose their STI syndrome. Most men lacked knowledge about ART and avoided HIV testing because of fear of death or being abandoned by their families or friends. Study findings suggest that men still require better access to high-quality, non-judgmental sexual health care services. Future research is needed to determine the most effective method to increase menâs access to sexual health care services.Keywords: sexual health care access, men.Les hommes peuvent ĂȘtre des responsables dans la transmission des infections sexuellement transmissibles (IST), et il est important que les services de santĂ© des IST/VIH les sensibilisent (les hommes). Les objectifs de cette Ă©tude Ă©taient dâexaminer lâaccĂšs aux soins de santĂ© et les comportements sexuels des hommes pendant 5 ans aprĂšs la mise en oeuvre de la thĂ©rapie antirĂ©trovirale (ART) gratuite dans le secteur public Sud-Africain. Six groups dâhommes ĂągĂ©s â„18 ans (N=58) ont menĂ©s des discussions dans la zone urbaine de la province de Gauteng. Ces hommes sont recrutĂ©s dans divers endroits dans toute la communautĂ©. Ils ont dĂ©clarĂ©s rencontrĂ©s des obstacles et facilitateurs Ă lâaccĂšs des cliniques publiques et privĂ©es des services de santĂ© sexuelle, y compris le test du VIH, et beaucoup dâhommes dĂ©clarent ĂȘtre Ă la recherche de soins vers des guĂ©risseurs traditionnels. Les hommes ont souvent vu les cliniques publiques comme des endroits pour les femmes et se sont souvent plaint des expĂ©riences quâils ont eues par rapport aux infirmiĂšres qui ont un mauvais jugement sur eux. Certains dâentre eux ont dĂ©clarĂ© quâils cherchaient des soins de santĂ© dans les cliniques publiques, mais quâils nâĂ©taient pas soumis Ă des examens physiques pour diagnostiquer leurs syndrome dâIST. La plupart dâentre eux nâavaient pas de connaissances de lâART et Ă©vitent le test du VIH parce quâils ont peur de la mort ou dâĂȘtre abandonnĂ© par leurs familles ou leurs amis. Cette Ă©tude suggĂšre que les hommes doivent exiger de meilleures qualitĂ©s de soins, un non-jugement des services de santĂ© sexuelle. Les recherches futures sont nĂ©cessaires pour dĂ©terminer la mĂ©thode la plus efficace dâaccroitre lâaccĂšs des hommes aux services de santĂ© sexuelle
Gluon Propagator in the Infrared Region
The gluon propagator is calculated in quenched QCD for two different lattice
sizes (16^3x48 and 32^3x64) at beta=6.0. The volume dependence of the
propagator in Landau gauge is studied. The smaller lattice is instrumental in
revealing finite volume and anisotropic lattice artefacts. Methods for
minimising these artefacts are developed and applied to the larger lattice
data. New structure seen in the infrared region survives these conservative
cuts to the lattice data. This structure serves to rule out a number of models
that have appeared in the literature. A fit to a simple analytical form
capturing the momentum dependence of the nonperturbative gluon propagator is
also reported.Comment: 13 pages, 9 figures, using RevTeX. Submitted to Phys. Rev. D. This
and related papers can also be obtained from
http://www.physics.adelaide.edu.au/~jskuller/papers
Safety and preliminary activity results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab in patients with refractory solid tumors
Colorectal cancer; Lung cancer; Monoclonal antibodyCĂĄncer colorrectal; CĂĄncer de pulmĂłn; Anticuerpo monoclonalCĂ ncer colorectal; CĂ ncer de pulmĂł; AnticĂČs monoclonalBackground
The phase I GATTO study (NCT03360734) explored the feasibility, tolerability and preliminary activity of combining gatipotuzumab, a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin 1 (TA-MUC1) and an anti-epidermal growth factor receptor (anti-EGFR) antibody in refractory solid tumors.
Patients and methods
Initially the study enrolled primary phase (PP) patients with EGFR-positive metastatic solid tumors, for whom no standard treatment was available. Patients received gatipotuzumab administered at 1400 mg every 2 weeks, 6 weeks after the start of the glyco-optimized anti-EGFR antibody tomuzotuximab at 1200 mg every 2 weeks. As this regimen was proven safe, enrollment continued in an expansion phase (EP) of patients with refractory metastatic colorectal cancer, non-small-cell lung cancer, head and neck cancer and breast cancer. Tomuzotuximab and gatipotuzumab were given at the same doses and gatipotuzumab treatment started 1 week after the first dose of the anti-EGFR antibody. Additionally, investigators could use a commercial anti-EGFR antibody in place of tomuzotuximab.
Results
A total of 52 patients were enrolled, 20 in the PP and 32 in the EP. The combined treatment was well tolerated and no dose-limiting toxicity was observed in the whole study, nor related serious adverse event or death. Preliminary activity of the combination was observed, with one and four RECIST partial responses in the PP and EP, all in colorectal cancer patients. The trial was accompanied by a comprehensive translational research program for identification of biomarkers, including soluble TA-MUC1 (sTA-MUC1) in serum. In the EP, patients with baseline sTA-MUC1 levels above the median appeared to have improved progression-free survival and overall survival.
Conclusions
Combination of a TA-MUC1-targeting antibody and an EGFR-targeting antibody is safe and feasible. Interesting antitumor activity was observed in heavily pretreated patients. Future studies should test this combination together with chemotherapy and explore the potential of sTA-MUC1 as a companion biomarker for further development of the combination.This work was supported by Glycotope GmbH (no grant number)
Satisfiability of constraint specifications on XML documents
Jose Meseguer is one of the earliest contributors in the area of Algebraic Specification. In this paper, which we are happy to dedicate to him on the occasion of his 65th birthday, we use ideas and methods coming from that area with the aim of presenting an approach for the specification of the structure of classes of XML documents and for reasoning about them. More precisely, we specify the structure of documents using sets of constraints that are based on XPath and we present inference rules that are shown to define a sound and complete refutation procedure for checking satisfiability of a given specification using tableaux.Peer ReviewedPostprint (author's final draft
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
Confinement Phenomenology in the Bethe-Salpeter Equation
We consider the solution of the Bethe-Salpeter equation in Euclidean metric
for a qbar-q vector meson in the circumstance where the dressed quark
propagators have time-like complex conjugate mass poles. This approximates
features encountered in recent QCD modeling via the Dyson-Schwinger equations;
the absence of real mass poles simulates quark confinement. The analytic
continuation in the total momentum necessary to reach the mass shell for a
meson sufficiently heavier than 1 GeV leads to the quark poles being within the
integration domain for two variables in the standard approach. Through Feynman
integral techniques, we show how the analytic continuation can be implemented
in a way suitable for a practical numerical solution. We show that the would-be
qbar-q width to the meson generated from one quark pole is exactly cancelled by
the effect of the conjugate partner pole; the meson mass remains real and there
is no spurious qbar-q production threshold. The ladder kernel we employ is
consistent with one-loop perturbative QCD and has a two-parameter infrared
structure found to be successful in recent studies of the light SU(3) meson
sector.Comment: Submitted for publication; 10.5x2-column pages, REVTEX 4, 3
postscript files making 3 fig
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