999 resultados para Data Accessibility


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Accessibility has become a serious issue to be considered by various sectors of the society. However, what are the differences between the perception of accessibility by academy, government and industry? In this paper, we present an analysis of this issue based on a large survey carried out with 613 participants involved with Web development, from all of the 27 Brazilian states. The paper presents results from the data analysis for each sector, along with statistical tests regarding the main different issues related to each of the sectors, such as: government and law, industry and techniques, academy and education. The concern about accessibility law is poor even amongst people from government sector. The analyses have also pointed out that the academy has not been addressing accessibility training accordingly. The knowledge about proper techniques to produce accessible contents is better than other sectors`, but still limited in industry. Stronger investments in training and in the promotion of consciousness about the law may be pointed as the most important tools to help a more effective policy on Web accessibility in Brazil.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The interaction of bovine serum albumin (BSA) with the ionic surfactants sodium dodecylsulfate (SDS, anionic), cetyltrimethylammonium chloride (CTAC, cationic) and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS, zwitterionic) was studied by electron paramagnetic resonance (EPR) spectroscopy of spin label covalently bound to the single free thiol group of the protein. EPR spectra simulation allows to monitor the protein dynamics at the labeling site and to estimate the changes in standard Gibbs free energy, enthalpy and entropy for transferring the nitroxide side chain from the more motionally restricted to the less restricted component. Whereas SDS and CTAC showed similar increases in the dynamics of the protein backbone for all measured concentrations. HPS presented a smaller effect at concentrations above 1.5 mM. At 10 mM of surfactants and 0.15 mM BSA, the standard Gibbs free energy change was consistent with protein backbone conformations more expanded and exposed to the solvent as compared to the native protein, but with a less pronounced effect for HPS. In the presence of the surfactants, the enthalpy change, related to the energy required to dissociate the nitroxide side chain from the protein, was greater, suggesting a lower water activity. The nitroxide side chain also detected a higher viscosity environment in the vicinity of the paramagnetic probe induced by the addition of the surfactants. The results suggest that the surfactant-BSA interaction, at higher surfactant concentration, is affected by the affinities of the surfactant to its own micelles and micelle-like aggregates. Complementary DLS data suggests that the temperature induced changes monitored by the nitroxide probe reflects local changes in the vicinity of the single thiol group of Cys-34 BSA residue. (C) 2011 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We estimate the effect of employment density on wages in Sweden in a large geocoded data set on individuals and workplaces. Employment density is measured in four circular zones around each individual’s place of living. The data contains a rich set of control variables that we use in an instrumental variables framework. Results show a relatively strong but rather local positive effect of employment density on wages. Beyond 5 kilometers the effect becomes negative. This might indicate that the effect of agglomeration economies falls faster with distance than the effects of congestion.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

An administrative border might hinder the optimal allocation of a given set of resources by restricting the flow of goods, services, and people. In this paper we address the question: Do administrative borders lead to poor accessibility to public service such as hospitals? In answering the question, we have examined the case of Sweden and its regional borders. We have used detailed data on the Swedish road network, its hospitals, and its geo-coded population. We have assessed the population’s spatial accessibility to Swedish hospitals by computing the inhabitants’ distance to the nearest hospital. We have also elaborated several scenarios ranging from strongly confining regional borders to no confinements of borders and recomputed the accessibility. Our findings imply that administrative borders are only marginally worsening the accessibility.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Delineation of commuting regions has always been based on statistical units, often municipalities or wards. However, using these units has certain disadvantages as their land areas differ considerably. Much information is lost in the larger spatial base units and distortions in self-containment values, the main criterion in rule-based delineation procedures, occur. Alternatively, one can start from relatively small standard size units such as hexagons. In this way, much greater detail in spatial patterns is obtained. In this paper, regions are built by means of intrazonal maximization (Intramax) on the basis of hexagons. The use of geoprocessing tools, specifically developed for the processing ofcommuting data, speeds up processing time considerably. The results of the Intramax analysis are evaluated with travel-to-work area constraints, and comparisons are made with commuting fields, accessibility to employment, commuting flow density and network commuting flow size. From selected steps in the regionalization process, a hierarchy of nested commuting regions emerges, revealing the complexity of commuting patterns.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aimee Guidera, Director of the National Data Quality Campaign, delivered the second annual Lee Gurel '48 Lecture in Education, "From Dartboards to Dashboards: The Imperative of Using Data to Improve Student Outcomes." Aimee Rogstad Guidera is the Founding Executive Director of the Data Quality Campaign. She manages a growing partnership among national organizations collaborating to improve the quality, accessibility and use of education data to improve student achievement. Working with 10 Founding Partners, Aimee launched the DQC in 2005 with the goal of every state having a robust longitudinal data system in place by 2009. The Campaign is now in the midst of its second phase focusing on State Actions to ensure effective data use. Aimee joined the National Center for Educational Accountability as Director of the Washington, DC office in 2003. During her eight previous years in various roles at the National Alliance of Business, Aimee supported the corporate community's efforts to increase achievement at all levels of learning. As NAB Vice President of Programs, she managed the Business Coalition Network, comprised of over 1,000 business led coalitions focused on improving education in communities across the country. Prior to joining the Alliance, Aimee focused on school readiness, academic standards, education goals and accountability systems while in the Center for Best Practices at the National Governors Association. She taught for the Japanese Ministry of Education in five Hiroshima high schools where she interviewed educators and studied the Japanese education system immediately after receiving her AB from Princeton University’s Woodrow Wilson School of Public & International Affairs. Aimee also holds a Masters Degree in Public Policy from Harvard’s John F. Kennedy School of Government.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Rates of suicide by jumping show large regional differences. Barriers on bridges may prevent suicides but also may lead to a substitution of jumping site or method. The aim of our study was to compare suicide data from regions with and without suicide bridges and to estimate the effects on method and site substitution if bridges were to be secured. In a national survey, suicide data for the years 1990 to 2003 were collected. Regions with high rates of bridge suicides were identified and compared with regions with low rates, and the analysis revealed that only about one third of the individuals would be expected to jump from buildings or other structures if no bridge was available. The results suggest no method substitution for women. For men, a trend of a substituting jumping by overdosing in regions without suicide bridges was found. We conclude that restricted access to suicide bridges will not automatically lead suicidal individuals to choose another jumping site or suicide method. The results support the notion that securing bridges may save lives.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

- Resumen La hipótesis que anima esta tesis doctoral es que algunas de las características del entorno urbano, en particular las que describen la accesibilidad de su red de espacio público, podrían estar relacionadas con la proporción de viajes a pie o reparto modal, que tiene cada zona o barrio de Madrid. Uno de los puntos de partida de dicha hipótesis que el entorno urbano tiene una mayor influencia sobre los viaje a pie que en sobre otros modos de transporte, por ejemplo que en los viajes de bicicleta o en transporte público; y es que parece razonable suponer que estos últimos van a estar más condicionadas por ejemplo por la disponibilidad de vías ciclistas, en el primer caso, o por la existencia de un servicio fiable y de calidad, en el segundo. Otra de las motivaciones del trabajo es que la investigación en este campo de la accesibilidad del espacio público, en concreto la denominada “Space Syntax”, ha probado en repetidas ocasiones la influencia de la red de espacio público en cómo se distribuye la intensidad del tráfico peatonal por la trama urbana, pero no se han encontrado referencias de la influencia de dicho elemento sobre el reparto modal. De acuerdo con la hipótesis y con otros trabajos anteriores se propone una metodología basada en el análisis empírico y cuantitativo. Su objetivo es comprobar si la red de espacio público, independientemente de otras variables como los usos del suelo, incluso de las variables de ajenas entorno no construido, como las socioeconómicas, está o no relacionada estadísticamente con la proporción de peatones viajes en las zonas urbanas. Las técnicas estadísticas se utilizan para comprobar sistemáticamente la asociación de las variables del entorno urbano, denominadas variables independientes, con el porcentaje de viajes a pie, la variable dependiente. En términos generales, la metodología es similar a la usada en otros trabajos en este campo como los de CERVERÓ y KOCKLEMAN (1997), CERVERÓ y DUNCAN (2003), o para los que se utilizan principalmente en la revisión general de TRB (2005) o, más recientemente, en ZEGRAS (2006) o CHATMAN (2009). Otras opciones metodológicas, como los métodos de preferencias declaradas (ver LOUVIERE, HENSHER y SWAIT, 2000) o el análisis basado en agentes (PENN & TURNER, 2004) fueron descartados, debido a una serie de razones, demasiado extensas para ser descritas aquí. El caso de estudio utilizado es la zona metropolitana de Madrid, abarcándola hasta la M-50, es decir en su mayor parte, con un tamaño aproximado de 31x34 Km y una población de 4.132.820 habitantes (aproximadamente el 80% de la población de la región). Las principales fuentes de datos son la Encuesta Domiciliaria de Movilidad de 2004 (EDM04), del Consorcio Regional de Transportes de Madrid que es la última disponible (muestra: > 35.000 familias,> 95.000 personas), y un modelo espacial del área metropolitana, integrando el modelo para calcular los índices de Space Syntax y un Sistema de Información Geográfica (SIG). La unidad de análisis, en este caso las unidades espaciales, son las zonas de transporte (con una población media de 7.063 personas) y los barrios (con una población media de 26.466 personas). Las variables del entorno urbano son claramente el centro del estudio. Un total de 20 índices (de 21) se seleccionan de entre los más relevantes encontrados en la revisión de la producción científica en este campo siendo que, al mismo tiempo, fueran accesibles. Nueve de ellos se utilizan para describir las características de los usos del suelo, mientras que otros once se usan para describir la red de espacios públicos. Estos últimos incluyen las variables de accesibilidad configuracional, que son, como se desprende de su título, el centro del estudio propuesto. La accesibilidad configuracional es un tipo especial de accesibilidad que se basa en la configuración de la trama urbana, según esta fue definida por HILLIER (1996), el autor de referencia dentro de esta línea de investigación de Space Syntax. Además se incluyen otras variables de la red de espacio público más habituales en los estudios de movilidad, y que aquí se denominan características geométricas de los elementos de la red, tales como su longitud, tipo de intersección, conectividad, etc. Por último se incluye además una variable socioeconómica, es decir ajena al entorno urbano, para evaluar la influencia de los factores externos, pues son varios los que pueden tener un impacto en la decisión de caminar (edad, género, nivel de estudios, ingresos, tasa de motorización, etc.). La asociación entre las variables se han establecido usando análisis de correlación (bivariante) y modelos de análisis multivariante. Las primeras se calculan entre por pares entre cada una de las 21 variables independientes y la dependiente, el porcentaje de viajes a pie. En cuanto a los segundos, se han realizado tres tipos de estudios: modelo multivariante general lineal, modelo multivariante general curvilíneo y análisis discriminante. Todos ellos son capaces de generar modelos de asociación entre diversas variables, pudiéndose de esta manera evaluar con bastante precisión en qué medida cada modelo reproduce el comportamiento de la variable dependiente, y además, el peso o influencia de cada variable en el modelo respecto a las otras. Los resultados fundamentales del estudio se expresan en dos modelos finales alternativos, que demuestran tener una significativa asociación con el porcentaje de viajes a pie (R2 = 0,6789, p <0,0001), al explicar las dos terceras partes de su variabilidad. En ellos, y en general en todo el estudio realizado, se da una influencia constante de tres índices en particular, que quedan como los principales. Dos de ellos, de acuerdo con muchos de los estudios previos, corresponden a la densidad y la mezcla de usos del suelo. Pero lo más novedoso de los resultados obtenidos es que el tercero es una medida de la accesibilidad de la red de espacio público, algo de lo que no había referencias hasta ahora. Pero, ¿cuál es la definición precisa y el peso relativo de cada uno en el modelo, es decir, en la variable independiente? El de mayor peso en la mayor parte de los análisis realizados es el índice de densidad total (n º residentes + n º puestos de trabajo + n º alumnos / Ha). Es decir, una densidad no sólo de población, sino que incluye algunas de las actividades más importantes que pueden darse una zona para generar movilidad a pie. El segundo que mayor peso adquiere, llegando a ser el primero en alguno de los análisis estadísticos efecturados, es el índice de accesibuilidad configuracional denominado integración de radio 5. Se trata de una medida de la accesibilidad de la zona, de su centralidad, a la escala de, más un menor, un distrito o comarca. En cuanto al tercero, obtiene una importancia bastante menor que los anteriores, y es que representa la mezcla de usos. En concreto es una medida del equilibrio entre los comercios especializados de venta al por menor y el número de residentes (n º de tiendas especializadas en alimentación, bebidas y tabaco / n º de habitantes). Por lo tanto, estos resultados confirman buena parte de los de estudios anteriores, especialmente los relativas a los usos del suelo, pero al mismo tiempo, apuntan a que la red de espacio público podría tener una influir mayor de la comprobada hasta ahora en la proporción de peatones sobre el resto de modos de transportes. Las razones de por qué esto puede ser así, se discuten ampliamente en las conclusiones. Finalmente se puede precisar que dicha conclusión principal se refiere a viajes de una sola etapa (no multimodales) que se dan en los barrios y zonas del área metropolitana de Madrid. Por supuesto, esta conclusión tiene en la actualidad, una validez limitada, ya que es el resultado de un solo caso — Abstract The research hypothesis for this Ph.D. Thesis is that some characteristics of the built environment, particularly those describing the accessibility of the public space network, could be associated with the proportion of pedestrians in all trips (modal split), found in the different parts of a city. The underlying idea is that walking trips are more sensitive to built environment than those by other transport modes, such as for example those by bicycle or by public transport, which could be more conditioned by, e.g. infrastructure availability or service frequency and quality. On the other hand, it has to be noted that the previously research on this field, in particular within Space Syntax’s where this study can be referred, have tested similar hypothesis using pedestrian volumes as the dependent variable, but never against modal split. According to such hypothesis, research methodology is based primarily on empirical quantitative analysis, and it is meant to be able to assess whether public space network, no matter other built environment and non-built environment variables, could have a relationship with the proportion of pedestrian trips in urban areas. Statistical techniques are used to check the association of independent variables with the percentage of walking in all trips, the dependent one. Broadly speaking this methodology is similar to that of previous studies in the field such as CERVERO&KOCKLEMAN (1997), CERVERO & DUNCAN (2003), or to those used mainly in the general review of T.R.B. (2005) or, more recently in ZEGRAS (2006) or CHATMAN (2009). Other methodological options such as stated choice methods (see LOUVIERE, HENSHER & SWAIT, 2000) or agent based analysis (PENN & TURNER, 2004), were discarded, due to a number of reasons, too long to be described here. The case study is not the entire Madrid’s metropolitan area, but almost (4.132.820 inhabitants, about 80% of region´s population). Main data sources are the Regional Mobility Home Based Survey 2004 (EDM04), which is the last available (sample: >35.000 families, > 95.000 individuals), and a spatial model of the metropolitan area, developed using Space Syntax and G.I.S. techniques. The analysis unit, in this case spatial units, are both transport zones (mean population = 7.063) and neighborhoods (mean population = 26.466). The variables of the built environment are clearly the core of the study. A total of 20 (out of 21) are selected from among those found in the literature while, at the same time, being accessible. Nine out of them are used to describe land use characteristics while another eleven describe the network of public spaces. Latter ones include configurational accessibility or Space Syntax variables. This is a particular sort of accessibility related with the concept of configuration, by HILLIER (1996), one of the main authors of Space Syntax, But it also include more customary variables used in mobility research to describe the urban design or spatial structure (here public space network), which here are called geometric characteristics of the such as its length, type of intersection, conectivity, density, etc. Finally a single socioeconomic variable was included in order to assess the influence non built environment factors that also may have an impact on walking (age, income, motorization rate, etc.). The association among variables is worked out using bi-variate correlation analysis and multivariate-analysis. Correlations are calculated among the 21 independent variables and the dependent one, the percentage of walking trips. Then, three types of multi-variate studies are run: general linear, curvilinear and discriminant multi-variate analysis. The latter are fully capable of generating complex association models among several variables, assessing quite precisely to what extent each model reproduces the behavior of the dependent variable, and also the weight or influence of each variable in the model. This study’s results show a consistent influence of three particular indexes in the two final alternative models of the multi-variate study (best, R2=0,6789, p<0,0000). Not surprisingly, two of them correspond to density and mix of land uses. But perhaps more interesting is that the third one is a measure of the accessibility of the public space network, a variable less important in the literature up to now. Additional precisions about them and their relative weight could also be of some interest. The density index is not only about population but includes most important activities in an area (nº residents + nº jobs+ nº students/Ha). The configurational index (radius 5 integration) is a measure of the accessibility of the area, i.e. centrality, at the scale of, more a less, a district. Regarding the mix of land uses index, this one is a measure of the balance between retail, in fact local basic retail, and the number of residents (nº of convenience shops / nº of residents). Referring to their weights, configurational index (radius 5 integration) gets the higher standardized coefficient of the final equation. However, in the final equations, there are a higher number of indexes coming from the density or land use mix categories than from public space network enter. Therefore, these findings seem to support part of the field’s knowledge, especially those concerning land uses, but at the same time they seem to bring in the idea that the configuration of the urban grid could have an influence in the proportion of walkers (as a part of total trips on any transport mode) that do single journey trips in the neighborhoods of Madrid, Spain. Of course this conclusion has, at present, a limited validity since it’s the result of a single case. The reasons of why this can be so, are discussed in the last part of the thesis.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

La web ha sufrido una drástica transformación en los últimos años, debido principalmente a su popularización y a la enorme cantidad de información que alberga. Debido a estos factores se ha dado el salto de la denominada Web de Documentos, a la Web Semántica, donde toda la información está relacionada con otra. Las principales ventajas de la información enlazada estriban en la facilidad de reutilización, accesibilidad y disponibilidad para ser encontrada por el usuario. En este trabajo se pretende poner de manifiesto la utilidad de los datos enlazados aplicados al ámbito geográfico y mostrar como pueden ser empleados hoy en día. Para ello se han explotado datos enlazados de carácter espacial provenientes de diferentes fuentes, a través de servidores externos o endpoints SPARQL. Además de eso se ha trabajado con un servidor privado capaz de proporcionar información enlazada almacenada en un equipo personal. La explotación de información enlazada se ha implementado en una aplicación web en lenguaje JavaScript, tratando de abstraer totalmente al usuario del tratamiento de los datos a nivel interno de la aplicación. Esta aplicación cuenta además con algunos módulos y opciones capaces de interactuar con las consultas realizadas a los servidores, consiguiendo un entorno más intuitivo y agradable para el usuario. ABSTRACT: In recent years the web has suffered a drastic transformation because of the popularization and the huge amount of stored information. Due to these factors it has gone from Documents web to Semantic web, where the data are linked. The main advantages of Linked Data lie in the ease of his reuse, accessibility and availability to be located by users. The aim of this research is to highlight the usefulness of the geographic linked data and show how can be used at present time. To get this, the spatial linked data coming from several sources have been managed through external servers or also called endpoints. Besides, it has been worked with a private server able to provide linked data stored in a personal computer. The use of linked data has been implemented in a JavaScript web application, trying completely to abstract the internally data treatment of the application to make the user ignore it. This application has some modules and options that are able to interact with the queries made to the servers, getting a more intuitive and kind environment for users.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: To determine whether mental illness is associated with accessibility and remoteness. Design: A cross-sectional, population-based, computer-assisted telephone interview survey, stratified by Accessibility and Remoteness Index of Australia (ARIA) categories. Setting: Secondary analysis of data collected from 2545 South Australian adults in October and November 2000. Outcome measures: Psychological distress and depression as determined by the Kessler 10 Psychological Distress Scale, the SF-12 measure of health status, and self-reported mental illness diagnosed by a doctor in the previous 12 months. Results: Overall, mental illness prevalence estimates were similar using the three measures of psychological distress (10.5%), clinical depression (12.9%) and self-reported mental health problem (12.7%). For each measure, there was no statistically significant variation in prevalence across ARIA categories, except for a lower than expected prevalence of depression (7.7%) in the accessible category. There was no trend suggesting higher levels of mental illness among residents of rural and remote regions. Conclusions: The prevalence rates of psychological distress, depression and self-reported mental illness are high. However, we found no evidence that the prevalence of these conditions varies substantially across ARIA categories in South Australia. This finding may challenge existing stereotypes about higher levels of mental illness outside metropolitan Australia.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this study, we propose a novel method to predict the solvent accessible surface areas of transmembrane residues. For both transmembrane alpha-helix and beta-barrel residues, the correlation coefficients between the predicted and observed accessible surface areas are around 0.65. On the basis of predicted accessible surface areas, residues exposed to the lipid environment or buried inside a protein can be identified by using certain cutoff thresholds. We have extensively examined our approach based on different definitions of accessible surface areas and a variety of sets of control parameters. Given that experimentally determining the structures of membrane proteins is very difficult and membrane proteins are actually abundant in nature, our approach is useful for theoretically modeling membrane protein tertiary structures, particularly for modeling the assembly of transmembrane domains. This approach can be used to annotate the membrane proteins in proteomes to provide extra structural and functional information.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Since the Second World War a range of policies have been implemented by central and local government agencies, with a view to improving accessibility to facilities, housing and employment opportunities within rural areas. It has been suggested that a lack of reasonable access to a range of such facilities and opportunities constitutes a key aspect of deprivation or disadvantage for rural residents. Despite considerable interest, very few attempts have been made to assess the nature and incidence of this disadvantage or the reaction of different sections of the population of rural areas to it. Moreover, almost all previous assessments have relied on so-called 'objective' measures of accessibility and disadvantage and failed to consider the relationship between such measures and 'subjective' measures such as individual perceptions. It is this gap in knowledge that the research described in this thesis has addressed. Following a critical review of relevant literature the thesis describes the way in which data on 'objective' and 'subjective' indicators of accessibility and behavioural responses to accessibility problems was collected, in six case study areas in Shropshire. Analysis of this data indicates that planning and other government policies have failed to significantly improve rural resident's accessibility to their basic requirements, and may in some cases have exacerbated it, and that as a result certain sections of the rural population are relatively disadvantaged. Moreover, analysis shows that .certain aspects of individual subjective' assessments of such accessibility disadvantage are significantly associated with more easily-obtained 'objective' measures. By using discriminant analysis the research demonstrates that it is possible to predict the likely levels of satisfaction with access to facilities from a range of 'objective' measures. The research concludes by highlighting the potential practical applications of such indicators in policy formulation, policy appraisal and policy evaluation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Forests play a pivotal role in timber production, maintenance and development of biodiversity and in carbon sequestration and storage in the context of the Kyoto Protocol. Policy makers and forest experts therefore require reliable information on forest extent, type and change for management, planning and modeling purposes. It is becoming increasingly clear that such forest information is frequently inconsistent and unharmonised between countries and continents. This research paper presents a forest information portal that has been developed in line with the GEOSS and INSPIRE frameworks. The web portal provides access to forest resources data at a variety of spatial scales, from global through to regional and local, as well as providing analytical capabilities for monitoring and validating forest change. The system also allows for the utilisation of forest data and processing services within other thematic areas. The web portal has been developed using open standards to facilitate accessibility, interoperability and data transfer.