3,157 research outputs found
Deconfinement vs. chiral symmetry and higher representation matter
The interplay of deconfinement and chiral symmetry restoration are considered
in terms of effective theories. We generalize the earlier model studies by
considering fermions in higher representations, and study the finite
temperature phase diagrams of SU(2) and SU(3) gauge theories with two fermion
flavors in fundamental, adjoint or two-index symmetric representations. We
discuss our results in relation to recent lattice simulations on these theories
and outline possible applications in the context of dynamical electroweak
symmetry breaking.Comment: 13 pages, 6 figure
Hot Quark Matter with an Axial Chemical Potential
We analyze the phase diagram of hot quark matter in presence of an axial
chemical potential, . The latter is introduced to mimic the chirality
transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron
configurations. In particular, we study the curvature of the critical line at
small , the effects of a finite quark mass and of a vector interaction.
Moreover, we build the mixed phase at the first order phase transition line,
and draw the phase diagram in the chiral density and temperature plane. We
finally compute the full topological susceptibility in presence of a background
of topological charge.Comment: 12 pages, 7 figures. Few references added, short discussion included.
Final version appearing on Phys. Rev.
A clinical review on megalencephaly: A large brain as a possible sign of cerebral impairment.
Megalencephaly and macrocephaly present with a head circumference measurement 2 standard deviations above the age-related mean. However, even if pathologic events resulting in both megalencephaly and macrocephaly may coexist, a distinction between these two entities is appropriate, as they represent clinical expression of different disorders with a different approach in clinical work-up, overall prognosis, and treatment. Megalencephaly defines an increased growth of cerebral structures related to dysfunctional anomalies during the various steps of brain development in the neuronal proliferation and/or migration phases or as a consequence of postnatal abnormal events. The disorders associated with megalencephaly are classically defined into 3 groups: idiopathic or benign, metabolic, and anatomic. In this article, we seek to underline the clinical aspect of megalencephaly, emphasizing the main disorders that manifest with this anomaly in an attempt to properly categorize these disorders within the megalencephaly group
Congenital muscular dystrophy: from muscle to brain.
Congenital muscular dystrophies (CMDs) are a wide group of muscular disorders that manifest with very early onset of muscular weakness, sometime associated to severe brain involvement.The histologic pattern of muscle anomalies is typical of dystrophic lesions but quite variable depending on the different stages and on the severity of the disorder.Recent classification of CMDs have been reported most of which based on the combination of clinical, biochemical, molecular and genetic findings, but genotype/phenotype correlation are in constant progression due to more diffuse utilization of the molecular analysis.In this article, the Authors report on CMDs belonging to the group of dystroglycanopathies and in particular on the most severe forms represented by the Fukuyama CMD, Muscle-Eye-Brain disease and Walker Walburg syndrome.Clinical diagnosis of infantile hypotonia is particularly difficult considering the different etiologic factors causing the lesions, the difficulty in localizing the involved CNS area (central vs. peripheral) and the limited role of the diagnostic procedures at this early age.The diagnostic evaluation is not easy mainly in differentiating the various types of CMDs, and represents a challenge for the neonatologists and pediatricians. Suggestions are reported on the way to reach a correct diagnosis with the appropriate use of the diagnostic means
Handover procedures in integrated satellite and terrestrial mobile systems
The integration of satellite and terrestrial mobile systems is investigated in terms of the strategies for handover across the integrated cellular coverage. The handover procedure is subdivided into an initialization phase, where the need for issuing a handover request must be identified, and an execution phase, where the request must be satisfied, if possible, according to a certain channel assignment strategy. A modeling approach that allows the design of the parameters that influence the performance of the overall handover procedure is presented, along with a few numerical results
A Monte-Carlo Implementation of the SAGE Algorithm for Joint Soft Multiuser and Channel Parameter Estimation
An efficient, joint transmission delay and channel parameter estimation
algorithm is proposed for uplink asynchronous direct-sequence code-division
multiple access (DS-CDMA) systems based on the space-alternating generalized
expectation maximization (SAGE) framework. The marginal likelihood of the
unknown parameters, averaged over the data sequence, as well as the expectation
and maximization steps of the SAGE algorithm are derived analytically. To
implement the proposed algorithm, a Markov Chain Monte Carlo (MCMC) technique,
called Gibbs sampling, is employed to compute the {\em a posteriori}
probabilities of data symbols in a computationally efficient way. Computer
simulations show that the proposed algorithm has excellent estimation
performance. This so-called MCMC-SAGE receiver is guaranteed to converge in
likelihood.Comment: 5 pages, 3 figures, 10th IEEE International Workshop on Signal
Processing Advances in Wireless Communications (SPAWC) 200
Embolisation for Vascular Injuries Complicating Elective Orthopaedic Surgery
AbstractObjectivesThe study aims to present the indications and emphasise the role of embolisation for vascular injuries in orthopaedic surgery.MethodsThirty-one patients with vascular injuries complicating elective orthopaedic surgery had embolisation from 2003 to 2010. N-2-butyl cyano-acrylate (NBCA) was used as embolic agent in 28 patients, gelatin sponge in three and coil embolisation in addition to NBCA or gelatin sponge in two patients. The mean follow-up period was 37 months (range, 4–96 months).ResultsThe most common orthopaedic operations associated with vascular injuries amenable to embolisation were hip-joint procedures; and the most common injuries were arterial tears of branch vessels or non-critical axial vessels, most commonly of the superior glutaeal artery. In all cases, angiography showed the bleeding point, and a single embolisation session effectively stopped bleeding. Embolisation-related complications were not observed.ConclusionsEmbolisation should be considered the treatment of choice for vascular injuries of branch vessels or non-critical axial vessels following elective orthopaedic surgery because of the advantages of minimally invasive therapy and the lack of complications
- …