Search results for " Barrier"
showing 10 items of 540 documents
The importance of tight junctions in the blood-brain barrier
2021
There are two barriers in the central nervous system (CNS) responsible for maintaining the homeostatic balance of the human body’s internal environment in relation to external conditions: the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). The blood-brain barrier is a physical barrier with a fixed location between the blood and the nervous tissue. Its basic structural elements include endothelial cells of the brain capillaries, astrocytes and pericytes. The blood-brain barrier is the barrier between the blood and neurons which isolates the central nervous system from the rest of the body in a unique manner. The blood-brain barrier is formed by astrocytes and per…
Who uses intermediaries in international trade? Evidence from firm-level survey data
2011
The present paper uses data from the World Bank Enterprise Survey conducted in Turkey in 2005 to shed light on the firms which use intermediaries in international trade. It lends robust empirical support to recent theories which suggest that indirect exporters are mostly small firms which are not profitable enough to cover the high fixed costs of building their own distribution network abroad. Manufacturers which introduce entirely new products to foreign markets are more likely to use trade intermediaries, as are firms which produce low quality goods. In contrast, neither foreign ownership nor credit constraints are correlated with the choice of export mode. Moreover, firms which rely on t…
Improving Institutional Efficiency in the Spanish Higher Education System
2002
* There have been changes in the internal management, better internal efficiency in the use of the resources, and changes in the organisation and the structure of the government. The changes in the different institutions are directly linked to the external pressure to which they are subjected. The universities that are under greater pressure in terms of restrictions in their budgets or control of their results show greater initiative to adopt these changes. But the magnitude of the changes depends on the capacity of the universities to carry them out. The existence of legal, institutional or structural barriers can sometimes cause problems in the adoption of necessary changes or can modify …
On Subsidies in Trade Agreements
2008
When terms of trade externalities are the only source of cross-border inefficiencies, trade negotiators must negotiate market access only. Based on this principle, Bagwell and Staiger (2006) argue against the WTO subsidy rules. The present paper shows that their argument fails when trade agreements are required to be self-enforceable. By affecting output, subsidies impact the self-enforcement constraints, which, in turn, determine the policies of trade agreements. Consequently, trade agreements must include subsidy rules. In realistic scenarios, banning production subsidies is efficient while negotiating market access only is inefficient. In this sense, this paper makes a strong case for th…
Na+-dependent Glutamate Transporters (EAAT1, EAAT2, and EAAT3) of the Blood-Brain Barrier
1999
Na(+)-dependent transporters for glutamate exist on astrocytes (EAAT1 and EAAT2) and neurons (EAAT3). These transporters presumably assist in keeping the glutamate concentration low in the extracellular fluid of brain. Recently, Na(+)-dependent glutamate transport was described on the abluminal membrane of the blood-brain barrier. To determine whether the above-mentioned transporters participate in glutamate transport of the blood-brain barrier, total RNA was extracted from bovine cerebral capillaries. cDNA for EAAT1, EAAT2, and EAAT3 was observed, indicating that mRNA was present. Western blot analysis demonstrated all three transporters were expressed on abluminal membranes, but none was …
How can knowledge sharing reduce barriers for entering the Chinese market? : A study on Business Region Kristiansand China Forum
2018
Master's thesis Business Administration BE501 - University of Agder 2018 Konfidensiell til / confidential until 01.07.2023
Sintesi, caratterizzazione e nuove strategie formulative per la somministrazione di nuovi derivati dopaminici nella terapia della malattia di Parkins…
2014
Lo Stagnone di Marsala: un monumento naturale
2015
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Isolation of T Cells from the Gut
2014
The lymphocytes of epithelial and lamina proprial compartments of the intestine are phenotypically and functionally distinct and serve a wide range of functions in the intestinal mucosa like regulating intestinal homeostasis, maintaining epithelial barrier function as well as regulating adaptive and innate immune responses. To analyze the role of these cells in different disease states, it is necessary to isolate pure cell populations of the intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL) of the gut. In this protocol we describe a method to isolate T cells from IEL and LPL, which can be used for further investigations like comparative studies of mRNA expression, cell …
An affine scaling method using a class of differential barrier functions: primal approach
2020
International audience; In this paper we propose a family of affine scaling interior point algorithms, called galpv4, using a primal approach, based on a large class of differential barrier functions. We show that these algorithms are in fact an extension and generalization of the classical affine scaling algorithm based on the well-known log barrier function. After carrying out a complete convergence analysis, we select some of these algorithms for comparison with the classical affine scaling algorithm, performed with the help of the familiar Netlib test set.