Model for screening of resonant magnetic perturbations by plasma in a realistic tokamak geometry and its impact on divertor strike points

This work addresses the question of the relation between strike-point splitting and magnetic stochasticity at the edge of a poloidally diverted tokamak in the presence of externally imposed magnetic perturbations. More specifically, ad-hoc helical current sheets are introduced in order to mimic a hypothetical screening of the external resonant magnetic perturbations by the plasma. These current sheets, which suppress magnetic islands, are found to reduce the amount of splitting expected at the target, which suggests that screening effects should be observable experimentally. Multiple screening current sheets reinforce each other, i.e. less current relative to the case of only one current sheet is required to screen the perturbation.Comment: Accepted in the Proceedings of the 19th International Conference on Plasma Surface Interactions, to be published in Journal of Nuclear Materials. Version 2: minor formatting and text improvements, more results mentioned in the conclusion and abstrac

El turismo en México. Apreciaciones sobre el turismo en espacio litoral

México es uno de los líderes del turismo internacional receptivo, con más de veinte millones de turistas ingresados por año a partir de los inicios del siglo XXI. Esta posición de privilegio se fundamenta en una variada oferta de productos turísticos, desde el clásico turismo de sol y playa en varios centros vacacionales localizados en ambas costas del país, el turismo arqueológico revalorizando el patrimonio que testimonian el devenir de avanzadas civilizaciones precolombinas; el turismo cultural que refleja la impronta de la conquista española manifiesta en sus ciudades coloniales y las obras del hombre contemporáneo, el turismo alternativo con fuerte vinculación con la naturaleza, el turismo de compras localizado a lo largo de la frontera norte, o bien el turismo de cruceros con puertos sobre las costas del Mar Caribe y Océano Pacífico. A partir de 1960 el Estado se abocó a la planificación del turismo creando centros turísticos integralmente planificados. Elaboró el primer Plan Nacional de Desarrollo Turístico y ejerció un rol central en la evolución de la actividad, buscando una respuesta favorable a su balanza comercial y paliar las deficiencias en la economía como consecuencia de aplicar una política de sustitución de importaciones. La importancia del turismo, así como la variedad de sus recursos, determinaron zonas con gran vocación turística, pero al mismo tiempo se generó una marcada dualidad territorial debido a la presencia de concentraciones y grandes vacíos poblacionales. Para abordar el tema del Turismo en México se presenta una breve descripción de los principales rasgos geográficos del país, luego se realiza una síntesis del devenir de la actividad turística, haciendo referencia a la planificación turística originada a fines de la década de los años sesenta. Se analiza la dicotomía entre centros turísticos tradicionales y centros turísticos integralmente planificados, brindando ejemplos en ambos casos. Se reflexiona sobre el accionar de los organismos oficiales de turismo que contribuyen con el desarrollo de centros turísticos y se concluye analizando la situación del turismo en la actualidad.Mexico is one of the leaders of receptive international tourism, receiving more than twenty million tourists a year since the beginning of the XXI century. This position of privilege is based on a varied offer of tourist products, from the typical sun and beach tourism in several vacation centres located on both coasts of the country, as well as archaeological tourism which aims at a reassessment of the heritage that testifies to the future of advanced pre-Columbian civilizations. Equally important is cultural tourism that reflects the mark of the Spanish conquest in its colonial cities and the Works of contemporary men; and also alternative tourism with a strong link with nature, and shopping tourism located along the northern border; and finally cruiser tourism with harbours on the coasts of the Caribbean Sea and the Pacific Ocean. From 1960 onwards the State devoted to the planning of tourism creating tourist centres planned comprehensively. It drew up the first National Plan of Tourist Development and exerted a leading role in the evolution of the activity, by searching for a favourable answer to its commercial balance and aiming at alleviating the economic problems present as a consequence of the application of a policy of substitution of imports. The importance of tourism, as well as the variety of its resources, determined areas with great tourist potential, but at the same time there was a marked territorial division generated due to the presence of concentrations and big population gaps. In order to deal with the topic of tourism in Mexico we present a brief description of the main geographical features of the country, then a synthesis of the future of tourist activity there, making reference to tourist planning originated at the end of the 1960s. The dichotomy between traditional tourist centres and those comprehensively planned was analysed, providing examples in both cases. There is a reflexion on the action of official tourism offices that contribute to the development of tourist centres and the study concludes with an analysis of the present situation of tourism.Fil: Benseny, Graciela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

Tissue Factor Is Induced by Resistin in Human Coronary Artery Endothelial Cells by the NF-?B-Dependent Pathway

Objective: Atherosclerosis is characterized by endothelial inflammation and dysfunction. Adipose tissue has increasingly been recognized as an active endocrine organ secreting so-called adipokines. Among these, resistin – recently described, but not yet extensively studied – has been defined as a novel inflammatory marker in atherosclerosis. The pathophysiology underlying this interplay, however, remains to be fully characterized. The aim of the study is to determine whether resistin might affect prothrombotic characteristics of human coronary artery endothelial cells (HCAECs). Methods and Results: Incubation of HCAECs with resistin caused upregulation of tissue factor (TF) expression as demonstrated by FACS analysis. Moreover, TF activity was induced in a dose-dependent manner, as shown by real-time PCR and colorimetric assay. Resistin-induced TF expression was mediated by oxygen free radicals through the activation of the transcription factor nuclear factor-ĸB (NF-ĸB), as demonstrated by electrophoretic mobility shift assay and by suppression of TF expression by superoxide dismutase, catalase, and the NF-ĸB inhibitors PDTC and BAY 11-7082. Conclusions: These data confirm the hypothesis that resistin may contribute to atherothrombosis, exerting direct effects on HCAECs by promoting TF expression; thus, it represents an effector molecule able to induce a prothrombotic phenotype in cells present in the vessel wall

[A new echocardiographic approach to evaluate myocardial function in congenital cardiopathies: strain and strain rate imaging]

Based on color Doppler methodology, regional myocardial strain rates and strain can now be calculated by comparing local myocardial velocity profiles. These deformation data sets may be an important new approach to quantifying regional function of the left or right ventricle in congenital heart disease. This review will give an introduction to the principles behind the technique and how data are acquired and processed. It will also discuss the findings of clinical studies based on this new technique

The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population

P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the possible correlation between atrial preference pacing algorithm, P-wave dispersion and AF burden in DM1 patients with normal cardiac function underwent permanent dual-chamber pacemaker implantation. We enrolled 50 patients with DM1 (age 50.3 \ub1 7.3; 11 F) underwent dual-chamber pacemaker implantation for various degree of atrioventricula block. The study population was randomized following 1 months stabilization period to APP algorithm features programmed OFF or ON. Patients were assessed every 3 months for the first year, and every 6 months thereafter up to 3 years. At each follow-up visit, we counted: the number of premature atrial beats, the number and the mean duration of AF episodes, AF burden and the percentage of atrial and ventricular pacing. APP ON Group showed lower number of AF episodes (117 \ub1 25 vs. 143 \ub1 37; p = 0.03) and AF burden (3059 \ub1 275 vs. 9010 \ub1 630 min; p < 0.04) than APP OFF Group. Atrial premature beats count (44903 \ub1 30689 vs. 13720 \ub1 7717 beats; p = 0.005) and Pwave dispersion values (42,1 \ub1 11 ms vs. 29,1 \ub1 4,2 ms, p = 0,003) were decreased in APP ON Group. We found a significant positive correlation between PD and AF burden (R = 0,8, p = 0.007). Atrial preference pacing algorithm, decreasing the number of atrial premature beats and the P-wave dispersion, reduces the onset and perpetuator factors of AF episodes and decreases the AF burden in DM1 patients underwent dual chamber pacemaker implantation for various degree of atrioventricular blocks and documented atrial fibrillation

Atrial fibrillation burden in Myotonic Dystrophy type 1 patients implanted with dual chamber pacemaker: the efficacy of the overdrive atrial algorithm at 2 year follow-up

The role that atrial pacing therapy plays on the atrial fibrillation (AF) burden is still unclear. Aim of the study was to evaluate the effect of the atrial preference pacing algorithm on AF burden in patients affected by Myotonic Dystrophy type 1 (DM1) followed for a long follow up period. Sixty DM1 patients were -implanted with a dual chamber pacemaker (PM) for first degree or symptomatic type 1/type 2 second degree atrio-ventricular blocks- were followed for 2-years after implantation, by periodical examination. After 1 month of stabilization, they were randomized into two groups: 1) Patients implanted with conventional dual-chamber pacing mode (DDDR group) and 2) Patients implanted with DDDR plus Atrial Preference Pacing (APP) algorithm (APP ON group). The results showed that atrial tachycardia (AT)/AF burden was significantly reduced at 1 year follow up in the APP ON group (2122 \ub1 428 minutes vs 4127 \ub1 388 minutes, P = 0.03), with a further reduction at the end of the 2 year follow up period (4652 \ub1 348 minutes vs 7564 \ub1 638 minutes, P = 0.005). The data here reported show that the APP is an efficient algorithm to reduce AT/AF burden in DM1 patients implanted with dual chamber pacemaker

Role of neurodevelopment involved genes in psychiatric comorbidities and modulation of inflammatory processes in Alzheimer's disease

Introduction With the increase of the population's average age, Alzheimer's disease (AD) is becoming one of the most disabling diseases worldwide. Recently, neurodevelopment processes have been involved in the AD etiopathogenesis. Genetic studies in this field could contribute to our knowledge and suggest new molecular targets for possible treatments. Methods Our primary aim was to investigate the associations among single nucleotide polymorphisms (SNPs) within neurodevelopment related genes (BDNF, ST8SIA2, C15orf32, NCAPG2, ESYT2, WDR60, LOC154822, VIPR2, GSK3B, NR1I2, ZNF804A, SP4) and AD. A number of exploratory analyses was also performed to evaluate the associations with the presence of behavioral and psychiatric symptoms of dementia (BPSD), as well as with variations in hematological parameters. Two independent samples were investigated, one of 228 Greek subjects and one sample of 229 Italian subjects, including 156\uc2\ua0Alzheimer's Disease patients CE patients and 301 healthy controls. All patients were affected by late onset AD (LOAD). Results None of the analyzed SNPs was associated with AD in our samples. In the exploratory analyses, several genetic variants were associated with inflammation parameters in the Greek sample and in the merged one, suggesting a relationship among these genes and the modulation of inflammation and the immune response. Other exploratory analyses showed associations among several SNPs and psychiatric symptomatology in the Greek sample, suggesting a possible modulation of these variants on psychiatric comorbidities in AD. Conclusions Although we failed to find a direct relationship between AD and the genetic variants investigated, possible connections with inflammation and psychiatric symptoms were suggested

The left atrial appendage: from embryology to prevention of thromboembolism

The left atrial appendage (LAA) is the main source of thromboembolism in patients with non-valvular atrial fibrillation (AF). As such, the LAA can be the target of specific occluding device therapies. Optimal management of patients with AF includes a comprehensive knowledge of the many aspects related to LAA structure and thrombosis. Here we provide baseline notions on the anatomy and function of the LAA, and then focus on current imaging tools for the identification of anatomical varieties. We also describe pathogenetic mechanisms of LAA thrombosis in AF patients, and examine the available evidence on treatment strategies for LAA thrombosis, including the use of non-vitamin K antagonist oral anticoagulants and interventional approaches