Search results for "STRESS"

Vanhemmuustyylien, vanhemmuuden stressin ja lasten ongelmakäyttäytymisen väliset yhteydet

2010

A Numerical Method for the Analysis of Plane-Strain Forming Processes with Unilateral Constraints

1983

The Authors propose a numerical model for the solution of plane-strain forming processes, based on the linearization of the yield surface. This allows to employ the linear programming technique for the solution of the variational problem derived from the application of the upper-bound theorem. Such a model permits to take into account the unilateral constraints in a very simple way. Therefore it is well suited to solve a large class of problems, such as sheet forming, in which the unilateral constraints are often present.

Treatment of bilateral vocal cord paralysis following permanent recurrent laryngeal nerve injury.

2012

Bilateral vocal cord paralysis is a serious illness requiring emergency intervention to resolve the potentially life-threatening respiratory distress. Several surgical procedures were proposed to help improve the airway and to eliminate the tracheostoma in those patients with permanent paralysis. All the procedures have their own advantages and disadvantages. We conducted a retrospective study of 30 patients affected by bilateral vocal cord paralysis following total thyroidectomy. All the patients underwent total thyroidectomy for benign thyroid pathology. In 26 patients (86.6%), cord paralysis occurred during the perioperative stage; and in the remaining 4 cases (13.3%), it occurred within…

Leading Edge Erosion of Wind Turbine Blades: Effects of Environmental Parameters on Impact Velocities and Erosion Damage Rate

2021

Abstract Leading edge erosion (LEE) of a wind turbine blade (WTB) is a complex phenomenon that contributes to high operation and maintenance costs. The impact between rain droplets and rotating blades exerts cyclic fatigue stresses on the leading edge — causing progressive material loss and reduced aerodynamic performance. One of the most important parameters for erosion modelling and damage prediction is the relative impact velocity between rain droplets and rotating blade and depends upon the environmental conditions. The environmental condition, in general, could vary for onshore and offshore wind turbines (OWTs) — for instance, the presence of wave-induced loads along with less turbulen…

Junction Dynamics in Telechelic Hydrogen Bonded Polyisobutylene Networks

1996

4-Urazoylbenzoic acid groups are attached to the chain ends of polyisobutylene. The cooperative assembling process of these polar groups is studied by DSC and dielectric and dynamic mechanical spectroscopy. The melting of the ordered clusters occurs in the temperature range 380-390 K. Distortions within the U4A clusters (Σ process) are monitored below the melting temperature T m with dielectric spectroscopy. On a larger length scale, these distortions also lead to stress relaxation which can be probed by dynamic mechanical measurements. Near T m , the relaxation ofU4A multiplets (α* relaxation) is detected with dielectric spectroscopy. In this temperature range, dynamic mechanical measureme…

Residual Stresses in Glasses

2013

The history dependence of the glasses formed from flow-melted steady states by a sudden cessation of the shear rate $\dot\gamma$ is studied in colloidal suspensions, by molecular dynamics simulations, and mode-coupling theory. In an ideal glass, stresses relax only partially, leaving behind a finite persistent residual stress. For intermediate times, relaxation curves scale as a function of $\dot\gamma t$, even though no flow is present. The macroscopic stress evolution is connected to a length scale of residual liquefaction displayed by microscopic mean-squared displacements. The theory describes this history dependence of glasses sharing the same thermodynamic state variables, but differi…

MODULATION OF FOOD REWARD BY ADIPOSITY SIGNALS

2006

Extensive historical evidence from the drug abuse literature has provided support for the concept that there is functional communication between central nervous system (CNS) circuitries which subserve reward/motivation, and the regulation of energy homeostasis. This concept is substantiated by recent studies that map anatomical pathways, or which demonstrate that hormones and neurotransmitters associated with energy homeostasis regulation can directly modulate reward and motivation behaviors. Studies from our laboratory have focused specifically on the candidate adiposity hormones, insulin and leptin, and show that these hormones can decrease performance in behavioral paradigms that assess …

Chronic social stress lessens the metabolic effects induced by a high-fat diet

2021

Stress has a major impact on the modulation of metabolism, as previously evidenced by hyperglycemia following chronic social defeat (CSD) stress in mice. Although CSD-triggered metabolic dysregulation might predispose to pre-diabetic conditions, insulin sensitivity remained intact, and obesity did not develop, when animals were fed with a standard diet (SD). Here, we investigated whether a nutritional challenge, a high-fat diet (HFD), aggravates the metabolic phenotype and whether there are particularly sensitive time windows for the negative consequences of HFD exposure. Chronically stressed male mice and controls (CTRL) were kept under (i) SD-conditions, (ii) with HFD commencing post-CSD,…

Changes of inflammatory mediators in obese patients after laparoscopic cholecystectomy.

2010

Background Obesity is associated with the impairment of immunological functions. The aim of this study was to analyze some inflammatory mediators in obese subjects who underwent laparoscopic cholecystectomy. Methods Seventeen consecutive female patients with a BMI ranging from 35 to 45 kg/m2 (obese) and 17 consecutive female patients with BMI ranging from 20 to 25 kg/m2 (nonobese) were included in the study. All patients were affected by symptomatic gallbladder stone disease and underwent laparoscopic cholecystectomy. Changes in levels of leukocytes, neutrophils, IL-6, IL-10, leptin, and adiponectin were evaluated. Results We observed a significant increase in leukocyte and neutrophil level…

Data from: Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest i…

2012

Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affect…