Search results for "System a"
showing 10 items of 111 documents
Hypertonic Stress and Amino Acid Deprivation Both Increase Expression of mRNA for Amino Acid Transport System A
2004
The activity of amino acid transport system A ([Oxender and Christensen, 1963][1]) is regulated in a variety of different ways, the best studied being the increases of its activity caused by starving cells of amino acids or by exposing them to hypertonicity (for review see [McGivan and Pastor-
Stabilization of hsp70 mRNA on prolonged cell exposure to hypertonicity
2002
AbstractProlonged exposure of 3T3 cells to 0.5 osM hypertonic medium induced the accumulation of hsp70 mRNAs. This increase in mRNA levels required active protein synthesis. A weak and transient activation of heat shock factor 1 (HSF1) was noted, but it was temporally uncoupled to the accumulation of the hsp70 mRNAs. Nuclear run-on assay and transfection experiments showed that hsp70 gene transcription was not affected by hypertonicity. ActD chase experiments showed that during hypertonic treatment, degradation of hsp70 mRNAs was markedly reduced. This effect did not appear to be a general phenomenon since the increase in mRNA level of another gene induced by hypertonicity (ATA2 transporter…
Solar models with accretion. I.
2013
We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. The status of the solar abundance problem is discussed. We investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate this problem. We examine a broad range of models, analyzing metal-enriched and metal-depleted accretion and three scenarios for the timing of accretion. Only partial solutions are found. For metal-rich accreted material (Z_ac_>~0.018) there exist combinations of accreted mass and metallicity that bring the depth of the convective zone into agreement with the helioseism…
On the Borana Calendrical System: A Preliminary Field Report
1988
This article addresses the astronomical functioning of the lunar calendar of the Oromo Borana (Ethiopia and Kenya). It is based on the participant observation method, observing the night sky over a time of about one year with Bante Abbagala, a Borana expert in time reckoning. Differently from previous ethnographic accounts and hypotheses, the author suggests that the Borana implicitly add an intercalary month that allows keeping correspondence between season and the name of the lunar month, even if they do not acknowledge it. They do not consider the declination of the moon, sun or stars. They rather apply a complex devise that allows the direct evaluation of the relative right ascension po…
Assessing sediment connectivity in dendritic and parallel calanchi systems
2019
Abstract Calanchi, a type of Italian badlands created by a combination of water erosion processes and environmental constraints controlling their development, is a striking example of long-term landscape evolution. Sediment connectivity can be defined as the degree to which a system facilitates the fluxes of sediments through itself. The goal of this research is testing the use of simple morphometric variables for assessing sediment connectivity of calanchi landforms distinguishing between dendritic and parallel systems. For detecting the morphological characteristics controlling the sediment connectivity of calanchi basins, literature data (146 calanchi basins) and measurements carried out…
In silico prediction of central nervous system activity of compounds. Identification of potential pharmacophores by the TOPS–MODE approach
2004
The central nervous system (CNS) activity has been investigated by using a topological substructural molecular approach (TOPS-MODE). A discriminant analysis to classify CNS and non-CNS drugs was developed on a data set (302 compounds) of great structural variability where more than 81% (247/302) were well classified. Randic's orthogonalization procedures was carried out to allow the interpretation of the model and to avoid the collinearity among descriptors. The discriminant model was assessed by a leave-n-out (when n varies from 2 to 20) cross-validation procedure (79.94% of correct classification), an external prediction set composed by 78 CNS/non-CNS drugs (80.77% of correct classificati…
Space, scale and accents : constructing migrant identity in Beijing
2007
Credit risk and efficiency in the European banking system: A three-stage analysis
2002
Increased competition and the attempts of European banks to increase their presence in other markets may have affected the efficiency and credit risk in the banking system. The first aspect is the incentive in reducing costs in order to gain in competitiveness. The second is associated with their lack of knowledge of such markets and/ or acceptance of a higher risk in order to increase their market share. Despite the importance of these aspects, banking literature has usually analysed the effects of competition on the efficiency of banking systems without considering these aspects. The few studies that attempt to obtain risk adjusted efficiency measures do not consider that part of the risk…
The pharmacological and non-pharmacological treatment of attention deficit hyperactivity disorder in children and adolescents: protocol for a systema…
2015
[Background] Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of children and adolescents, with a significant impact on health services and the community in terms of economic and social burdens. The objective of this systematic review will be to evaluate the comparative efficacy and safety of pharmacological and non-pharmacological treatments in children and adolescents with ADHD.
Off-line Programming and simulation for automatic robot control software generation
2007
In this paper an off-line programming approach for welding robots is presented. The approach is based on the integration of a software tool for robot simulation and an user-friendly interface for automatic generation of the control program. The user can graphically arrange the components in a robotic work-cell and simulate the movements and operations of robotic arms before converting motions and operating sequences in controller-specific tasks. This methodology guarantees high level of flexibility of the robotic system when high variety of work-pieces needs to be welded. The approach has been implemented and tested in a real welding work-cell.