The size of components in continuum nearest-neighbor graphs

We study the size of connected components of random nearest-neighbor graphs with vertex set the points of a homogeneous Poisson point process in ${\mathbb{R}}^d$. The connectivity function is shown to decay superexponentially, and we identify the exact exponent. From this we also obtain the decay rate of the maximal number of points of a path through the origin. We define the generation number of a point in a component and establish its asymptotic distribution as the dimension $d$ tends to infinity.Comment: Published at http://dx.doi.org/10.1214/009117905000000729 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

THE LIFE QUALITY OF FAMILIES WITH A MEMBER WITH A MENTAL DISABILITY

This paper focuses on the quality of life of a family taking care of a mentally disabled member. In order to be able to provide families taking care of a disabled member with high-quality special-education care and support, it is at first necessary to learn about their needs in as complex a way as possible. This paper presents a selected summary of the results of a survey carried out by means of a questionnaire and a standardized questionnaire SEIQoL, in order to compare the quality of life of parents taking care of a mentally disabled child/children and the quality of life of parents taking care of a child/children without mental disability, and thus to ascertain those areas that would be desirable for further focus in the future

Diabetes Mellitus, Arterial Wall, and Cardiovascular Risk Assessment

Diabetes mellitus is an independent risk factor for atherothrombotic cardiovascular disease. Adults with diabetes are two to four times more likely to develop heart disease or stroke than adults without diabetes. The two major features of diabetes, i.e., hyperglycemia and insulin-resistance, trigger arterial stiffening and increase the susceptibility of the arterial wall to atherosclerosis at any given age. These pathological changes in the arterial wall may provide a functional and structural background for cardiovascular events. The present paper provides a critical overview of the clinical evidence linking diabetes-related metabolic abnormalities to cardiovascular risk, debates the pathophysiologic mechanisms through which insulin resistance and hyperglycemia may affect the arterial wall, and discusses the associations between vascular biomarkers, metabolic abnormalities and cardiovascular events

Lipids and Cardiovascular Organ Damage in Type 2 Diabetes Mellitus

One of the mechanisms underlying increased cardiovascular (CV) risk in patients with type 2 diabetes mellitus is atherogenic dyslipidemia, that is characterized by elevated triglycerides and free fatty acids (FFAs) levels, low levels of high-density lipoprotein cholesterol (HDL) and an excess of small dense low-density lipoprotein particles (sdLDLs). Each component of atherogenic dyslipidemia is associated with CV events and triggers alterations at different levels of CV system through different pathways. FFAs and sdLDLs induce endothelial dysfunction, intima-media thickening, plaque formation and arterial stiffening through increase in oxidative stress and inflammation and promoting lipid accumulation and smooth muscle cells (SMCs) proliferation in vascular wall. In contrast, HDL exerts protective effect on arterial wall by increasing nitric oxide availability, by reverse cholesterol transport and by suppression of SMCs proliferation and migration. FFAs overload results in a switch in myocardial substrate utilization, causing changes in myocardial energy metabolism and an increase in baseline oxygen consumption. Accumulation of toxic lipid intermediates in myocardium provokes damage of cellular membrane integrity, organelle dysfunction and apoptosis with consequent decrease in myocardial performance. The structural and functional changes in myocardium can be reversed by therapy with reconstructed HDL. Therefore, the impact of atherogenic dyslipidemia on CV system is not limited on accelerated atherosclerosis, but causes different organ damages that must be considered in their complexity

Vascular ultrasound and cardiovascular risk assessment

Vascular ultrasound is able to detect endothelial dysfunction, arterial structural remodeling and increased arterial stiffness. These alterations have been shown to be associated with established and emerging cardiovascular risk factors and with incident cardiovascular events. Therefore, vascular ultrasound has been proposed to evaluate the role of different risk factors in the initiation and progression of atherosclerotic process, to study vascular aging and the relationship between arterial stiffness and atherosclerosis, to assess the efficacy of life-style and therapeutic interventions, and to improve the estimation of individual cardiovascular risk. The present paper provides a critical overview of the clinical evidence appraising the association of flow-mediated dilation, carotid and femoral intima-media thickness and plaque presence as well as local arterial stiffness with cardiovascular risk factors and cardiovascular events

Increased carotid IMT in patients with type 2 diabetes free of cardiovascular complications appears to be an adaptive mechanism to an increased wall stress more than atheromasic degeneration

Type 2 diabetes (DM2) and poor glycemic control adversely affect common carotid intima media thickness (IMT), considered marker of preclinical atherosclerosis. However, studies evaluating the effect of DM2 and glucose levels on IMT did not consider carotid diameter, known to affect IMT. A certain IMT increase could reflect a mutual adjustment between diameter and wall thickness aimed to maintain constant wall tensile stress (WTS). Aim: To compare carotid IMT, luminal diameter, WTS and local wave speed (WS) between patients with uncomplicated DM2 and healthy controls. Methods: Eighty-four patients with well controlled DM2 (HbA1c <7.8%) and 84 controls matched for sex, age and BMI. were studied by radiofrequencybased carotid ultrasound (QIMT and QAS, Esaote). Results: DM2 against controls had higher (p<0.0001) IMT (720131 vs. 62076 mm), luminal diameter (6.60.6 vs. 6.00.7 mm), WS (8.3.61.7 vs. 6.51.2 m/s) and pulse pressure (5813 vs. 478 mmHg), but comparable WTS (498 vs. 5014 kPa; pZ0.82). In the entire population, fasting glucose was not independently related to IMT, but was related to carotid diameter (together with male sex and waist), pulse pressure and local WS (together with age and antihypertensive treatment). In DM2, HbA1c was independently related to carotid diameter, pulse pressure and WS. Conclusions: Chronically increased plasma glucose levels may induce intrinsic stiffening of large artery and widening of pulse pressure. Increased pulsatile load in stiff arteries causes luminal dilatation and increases WTS, triggering an increase in arterial wall thickness. Hyperglycaemia affects arterial wall, but through a “sclerotic” more than “atherogenic” mechanism

Utilisation of the High Speed Camera for the Pin-hole Discharge Diagnostics

The high speed camera was utilised for plasma diagnostics of the DC pin-hole discharge in electrolyte solutions. Two discharge modes were determined. Plasma channels were observed either in the bubble or outside the bubble in the bulk solution, which confirms both thermal and electron theory of the discharge ignition in liquid. In the diaphragm discharge, plasma streamers were better visible on the cathode side of the dielectric barrier because they formed significantly longer channels

Impact of glycemic control on aortic stiffness, left ventricular mass and diastolic longitudinal function in type 2 diabetes mellitus

Poor glycemic control is associated with impaired left ventricular (LV) diastolic function in patients with type 2 diabetes mellitus (T2DM). Inappropriate LV mass increase and accelerated aortic stiffening were suggested to participate on deterioration of diastolic function. The present study investigated the inter-relationships between glycemic control, early diastolic and systolic longitudinal velocity of mitral annulus, LV mass and aortic stiffness in T2DM patients free of cardiovascular disease and with preserved LV ejection fraction, and compared them with those observed in healthy volunteers of similar age and sex distribution