Search results for "access"

The solvent-excluding surface as a descriptor of ionic channels: Gramicidin-A

1998

Abstract We have set out a methodology for checking the performance of the methods used to compute the Solvent-Excluding Surface. The method consists of computing the area of the Solvent-Excluding Surface of a model of channel, with a fixed pore size, for several values of the solvent radius. The graphical representation of the value of the area versus the radius of the solvent sphere shows a sharp change just at the radius of the pore. With this model we may analyze the ability of each method to describe small changes of the surface. We made the study with GEPOL93, older versions of GEPOL and MSDOT. The study is applied to a natural protein channel, as is Gramicidin-A, showing that this ty…

GEPOL: An improved description of molecular surfaces. III. A new algorithm for the computation of a solvent-excluding surface

1994

To understand and calculate the interactions of a solute with a solvent, a good method of computing the molecular surface is needed. Three kinds of surfaces may be used: the van der Waals Surface, the Accessible Surface, and the Molecular Surface. The latter is redefined in this article as the Solvent-Excluding Surface. The new algorithm for computing the Solvent-Excluding Surface included in the GEPOL93 program is described. GEPOL93 follows the same concept as former versions of GEPOL but with a full new algorithm. Thus, it computes the Solvent-Excluding Surface by filling the spaces not accessible to the solvent with a set of new spheres. The computation is controlled by three parameters:…

Molecular surface area and hydrophobic effect.

1992

Packing meterials with surface barriers, controlled distribution and topography of ligands for sample clean-up and analysis of biologically active so…

1991

Various types of, so-called, restricted access packings have been developed for sample clean-up and analysis of biologically active solutes by means of HPLC. The unique feature of these packings is that they prevent the access of matrix components such as protein whilst selectively retaining the drug components and their metabolites. This results from the fact that the particles of the packings possess a surface barrier for large solutes at the external or internal surface area and exhibit a controlled gradient in the chemical surface composition. They are grouped, according to their particle structures, into internal-surface reversed phases (ISRP), shielded hydrophobic phases (SHP), semi-p…

Towards a Sustainable Use of Architectural Heritage: How to Assess Accessibility and the User’s Role

2022

Scientific communities and institutional bodies are supporting many shared efforts towards improving accessibility to architectural heritage, in the awareness that it provides the basis for inclusion and enhancement. Accessibility is related to the wider tendency toward a conscious and sustainable use of the architectural heritage, considered as a multifaceted tool for its conservation. This has also highlighted the user’s role, which is paramount in order to reach and increase sustainable processes in the field of architectural heritage, as well as in all the technological processes. The user should be active in his/her relationships with the built heritage, in a multi-sensorial way and in…

The Differences in Values Between Managers of the European Founding Countries, the New Members and the Applicant Countries:

2007

Advocates for a social Europe are worried that the accession of ex-Eastern Bloc countries into the European Community would lead European corporations to emphasize a financial orientation rather than a societal orientation. We examined this question in a study of the values orientations of 3,836 managers in 16 countries representing established EU, new EU, and candidate EU country groups. Within-Europe managerial values convergence was found in a relatively high openness to change and low self-enhancement values. However, we found divergent values such that managers in established EU countries were more self-transcendent and less conservative than their counterparts in new EU and candidate …

Exploiting programmable architectures for WiFi/ZigBee inter-technology cooperation

2014

The increasing complexity of wireless standards has shown that protocols cannot be designed once for all possible deployments, especially when unpredictable and mutating interference situations are present due to the coexistence of heterogeneous technologies. As such, flexibility and (re)programmability of wireless devices is crucial in the emerging scenarios of technology proliferation and unpredictable interference conditions. In this paper, we focus on the possibility to improve coexistence performance of WiFi and ZigBee networks by exploiting novel programmable architectures of wireless devices able to support run-time modifications of medium access operations. Differently from software…

40 years of time geography: from the conceptual framework to the GI Science contributions

2011

International audience; Social scientists studying the effects of space on human behavior usually consider the time dimension as an external factor. Activities are analyzed in an aggregate sense such that the process of individual decision-making is depicted as the single case of "the average individual." In order to link efficiently space and time dimensions, Torsten Hägerstrand defined in 1970's the concept of Time Geography and thereby founded the school of Swedish geography. His conceptual framework was destined to change the course of history in the social sciences. After 40 years, this success has transcended scientific boundaries. In this paper, we propose to review the evolution of …

Docència i lliure accés: l'Open Course Ware de la Universitat de València

2008

En este artículo presentamos la Oficina OCW de la Universitat de València atendiendo al contexto general de aparición y sus características específicas. En primer lugar, contextualizamos el Open Course Ware en el ámbito de los movimientos Open y repasamos algunas de sus iniciativas. Después nos centramos en la caracterización de los usuarios/destinatarios prototípicos del OCW como “nativos digitales”, atendiendo a la distinción de dos modelos epistemológicos: la inteligencia colectiva (nativos) y el paradigma del experto (inmigrantes digitales), algunas de cuyas premisas básicas se explican solamente por la aparición de las tecnologías digitales. Tras esta contextualización teórica, exponem…

Access to Secondary Education in Albania: Incentives, Obstacles, and Policy Spillovers

2006

When judged either by educational attainment of adult population or by secondary and tertiary enrollment rates, by 2002 Albania compared very unfavorably to most European countries, including its neighbors. This study examines the determinants of secondary enrollment applying unobserved family effect probit model to data from Living Standards Measurement Survey 2002- 2003. The focus of the paper is to investigate the importance of access to school and to further education for enrollment. We find that both absence of a secondary school in the community and the distance from the residence location to a secondary school have strong negative effect on enrollment, controlling for family backgrou…