Search results for "barrier"
showing 10 items of 678 documents
Le simbiosi in ambiente marino
2011
L’adattamento e la conseguente selezione naturale ha prodotto un’infinita varietà di organismi viventi, ciascuno dotato di peculiari caratteristiche, per consentire ad ogni specie di utilizzare l’ambiente in cui vive. I membri che formano le comunità naturali creano tra di essi dei complessi sistemi fatti di rapporti di competizione e di cooperazione. Questi, contribuiscono ad assicurare l’evoluzione delle specie nell’efficace opera di utilizzazione dell’ambiente. Nell’ambito delle relazioni tra individui di specie diverse esistono alcune singolari associazioni che si evolvono insieme, stabilendo un legame intimo e duraturo che comporta un elevato grado di specializzazione da parte dei cont…
2019
These days, the important role of retinoids in adult brain functionality and homeostasis is well accepted and has been proven by genomic as well as non-genomic mechanisms. In the healthy brain, numerous biological processes, e.g., cell proliferation, neurogenesis, dendritic spine formation as well as modulation of the immune system, have been attributed to retinoid signaling. This, together with the finding that retinoid metabolism is impaired in Alzheimer's disease (AD), led to preclinical and early clinical testing of natural and synthetic retinoids as innovative pharmaceuticals with multifactorial properties. Acitretin, an aromatic retinoid, was found to exert an anti-amyloidogenic effec…
Electrical Characterization of CdTe pixel detectors with Al Schottky anode
2014
Abstract Pixelated Schottky Al/p-CdTe/Pt detectors are very attractive devices for high-resolution X-ray spectroscopic imaging, even though they suffer from bias-induced time instability (polarization). In this work, we present the results of the electrical characterization of a (4×4) pixelated Schottky Al/p-CdTe/Pt detector. Current–voltage ( I–V ) characteristics and current transients were investigated at different temperatures. The results show deep levels that play a dominant role in the charge transport mechanism. The conduction mechanism is dominated by the space charge limited current (SCLC) both under forward bias and at high reverse bias. Schottky barrier height of the Al/CdTe con…
Impact of landscape on spatial genetic structure and diversity ofCoenagrion mercuriale(Zygoptera:Coenagrionidae) in northern France
2015
AbstractLoss and fragmentation of habitat is a current main cause of biodiversity loss in freshwater habitats. Odonates (dragonflies and damselflies) depend on these habitats to complete their development. Fragmentation may be a particular threat for odonates because it generates a network of small habitat patches within which populations could suffer from isolation and loss of genetic diversity. The southern damselfly Coenagrion mercuriale is categorized on the IUCN red list as Near Threatened, largely because of population fragmentation and demographic declines associated with changes in land use. Small populations at the margin of this species’ range are of particular concern because the…
Volatile Anesthetics Influence Blood-Brain Barrier Integrity by Modulation of Tight Junction Protein Expression in Traumatic Brain Injury
2012
Disruption of the blood-brain barrier (BBB) results in cerebral edema formation, which is a major cause for high mortality after traumatic brain injury (TBI). As anesthetic care is mandatory in patients suffering from severe TBI it may be important to elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ) such as zonula occludens-1 (ZO-1) and claudin-5 (cl5) play a central role for BBB stability. First, the influence of the volatile anesthetics sevoflurane and isoflurane on in-vitro BBB integrity was investigated by quantification of the electrical resistance (TEER) in murine brain endothelial monolayers and neurovascular co-cultures of the B…
Correlation of Metabolic Syndrome with Redox Homeostasis Biomarkers: Evidence from High-Fat Diet Model in Wistar Rats
2022
Metabolic Syndrome (MetS) is an extremely complex disease. A non-balanced diet such as high-fat diet (HFD) induces metabolic dysfunction that could modify redox homeostasis. We here aimed at exploring redox homeostasis in male Wistar rats, following 8 weeks of HFD, correlating the eventual modification of selected biomarkers that could be associated with the clinical manifestations of MetS. Therefore, we selected parameters relative to both the glucose tolerance and lipid altered metabolism, but also oxidative pattern. We assessed some biomarkers of oxidative stress i.e., thiols balance, lipid peroxidation and antioxidant barriers, via the use of specific biochemical assays, individuating e…
Amino acid transport across each side of the blood-brain barrier.
2011
Valuation of Barrier Options in a Black-Scholes Setup with Jump Risk
1999
This paper discusses the pitfalls in the pricing of barrier options approximations of the underlying continuous processes via discrete lattice models. These problems are studied first in a Black-Scholes model. Improvements result from a trinomial model and a further modified model where price changes occur at the jump times of a Poisson process. After the numerical difficulties have been resolved in the Black-Scholes model, unpredictable discontinuous price movements are incorporated.
Electric Vehicles and Psychology, Part 2
2021
This paper presents the main psychological attitudes influencing the transition from conventional ICEV to BEV, and it is the continuance of Electric vehicles and psychology, part 1, [1]. This part faces the range anxiety problem, the risk of explosion of batteries, the autonomous silver vehicles and the experience of driving electric vehicles. If the reader is looking for simple answers, the author does not recommend the subsequent reading, since few paradoxes will be solved.