10 research outputs found
Estudio de procesos y herramientas aplicables a la generalización vectorial de entidades lineales.
Se presenta un estudio de algoritmos que ofrecen resultados óptimos en cuanto a lo que a la generalización
vectorial de entidades lineales se refiere. Este estudio se encuentra dentro del marco del proyecto CENIT España
Virtual para la investigación de nuevos algoritmos de procesado cartográfico.
La generalización constituye uno de los procesos cartográficos más complejos, cobrando su mayor importancia a
la hora de confeccionar mapas derivados a partir de otros a mayores escalas. La necesidad de una generalización se
hace patente ante la imposibilidad de representar la realidad en su totalidad, teniendo ésta que ser limitada o
reducida para la posterior elaboración del mapa, manteniendo, eso sí, las características esenciales del espacio
geográfico cartografiado. La finalidad, por tanto, es obtener una imagen simplificada pero representativa de la
realidad.
Debido a que casi el ochenta por ciento de la cartografía vectorial está compuesta por elementos lineales, la
investigación se centra en aquellos algoritmos capaces de procesar y actuar sobre éstos, demostrando además que
su aplicación puede extenderse al tratamiento de elementos superficiales ya que son tratados a partir de la línea
cerrada que los define.
El estudio, además, profundiza en los procesos englobados dentro de la exageración lineal que pretenden
destacar o enfatizar aquellos rasgos de entidades lineales sin los que la representatividad de nuestro mapa se vería
mermada. Estas herramientas, acompañadas de otras más conocidas como la simplificación y el suavizado de
líneas, pueden ofrecer resultados satisfactorios dentro de un proceso de generalización.
Abstract:
A study of algorithms that provide optimal results in vector generalization is presented. This study is within the
CENIT project framework of the España Virtual for research of new cartographic processing algorithms.
The generalization is one of the more complex mapping processes, taking its greatest importance when preparing
maps derived from other at larger scales. The need for generalization is evident given the impossibility of
representing whole real world, taking it to be limited or reduced for the subsequent preparation of the map, keeping
main features of the geographical space. Therefore, the goal is to obtain a simplified but representative image of the reality.
Due to nearly eighty percent of the mapping vector is composed of linear elements, the research focuses on
those algorithms that can process them, proving that its application can also be extended to the treatment of
surface elements as they are treated from the closed line that defines them.
Moreover, the study focussed into the processes involved within the linear exaggeration intended to highlight or
emphasize those features of linear entities that increase the representativeness of our map. These tools, together
with others known as the simplification and smoothing of lines, can provide satisfactory results in a process of
generalization
Estado del arte de algoritmos de generalización vectorial de núcleos urbanos.
Se presenta este artículo con el ánimo de enumerar y estudiar diferentes algoritmos que tratan la generalización de datos cartográficos vectoriales de zonas urbanas, debido a que en ellas se concentran la mayoría de los conflictos que se pueden encontrar en los procesos de generalización cartográfica. A pesar de que la generalización es uno de los procedimientos más difíciles de automatizar, existen herramientas que implementan estos algoritmos y ofrecen resultados satisfactorios, aunque ninguna de ellas es capaz de automatizar por completo el proceso de generalización. A continuación, se incluyen las pruebas realizadas al respecto, describiendo y analizando los resultados obtenidos, estableciendo una comparativa con trabajos realizados por diferentes autores. Se concluye el documento valorando los posibles trabajos futuros para solventar la problemática de la generalización cartográfica. Este estudio se encuentra en el marco del proyecto CENIT España Virtual.
Abstract: This article is focused in studying different algorithms about generalization of vector map data from urban areas, because most of the conflicts in the processes of cartographic generalization are concentrated in these areas. Although generalization is one of the most difficult processes to automate, there are tools that implement these algorithms and provide satisfactory results. However,none of them can automate the process of generalization completely. Then tests in describing and analyzing the results are included, establishing a comparison with works of various authors. The document concludes by assessing the possible future works to solve the problem of cartographic generalization. This study is within the CENIT project España Virtual
Estado del arte de algoritmo de generalización vectorial de núcleos urbanos
La generalización de núcleos urbanos es uno de los procesos más complejos dentro de la generalización
vectorial. Debido a los numerosos conflictos que se pueden dar en el tratamiento de cartografía urbana, se requiere
del establecimiento de una pauta a seguir mediante la actuación conjunta de diferentes operadores. El objetivo final
de este proceso es la obtención de cartografía representativa de la zona a tratar, manteniendo en la medida de lo
posible las relaciones entre los elementos que conforman y definen el núcleo urbano.
La generalización de núcleos urbanos adquiere especial relevancia debido a la necesidad de tener en cuenta la
geometría de las edificaciones, así como la del entramado viario, aspecto poco notable cuando se trata de
cartografía de zonas rústicas.
Además, ha sido objeto de diversas investigaciones por englobar una gran variedad de procesos de gran utilidad y
aplicación en otros apartados incluidos en la automatización de procesos de generalización vectorial.
El estudio de la bibliografía existente al respecto permite agrupar los algoritmos atendiendo a los operadores que
intervienen en el proceso de generalización. Estos operadores permitirán reducir el número de edificios, garantizar la
legibilidad entre ellos y mantener las relaciones existentes entre los mismos. Este estudio se encuentra en el marco del proyecto CENIT España Virtual.The generalization of urban areas is one of the most complex processes within the vector generalization. Due to
the numerous conflicts that may occur in the treatment of urban maps, establishing a pattern is required to follow
through joint action by different operators. The final target of this process is to obtain representative mapping of the
treated area, keeping, as far as possible, the relationships between the elements that define the urban area.
The generalization of urban areas is especially relevant because of the need to take in account the geometry of
buildings, as well as the road network, which is poorly marked in rural areas cartography.
Moreover, it has been goal of several investigations because it involves a wide variety of useful processes
included in the automation of vector generalization.
The study of the literature about the algorithms can group them in terms of the operators involved in the process
of generalization. These operators will reduce the number of buildings, keeping legibility and existing relationships
between them.
This study is within the CENIT project España Virtual
Nuevo algoritmo de generalización lineal y ortogonalización de construcciones en un entorno urbano.
Resumen: La generalización cartográfica es el proceso que permite la obtención de cartografía derivada a partir de la generada mediante el registro de información geográfica. Normalmente, la generalización implica una reducción de escala, aunque podría ser una reducción de la cantidad de información sin reducir la escala, debido a un cambio de objetivo de la cartografía. La dificultad de la generalización aumenta cuanto menor es la escala destino y mayor la diferencia entre ésta y la escala origen. Estas dificultades se concentran en aquellas entidades que representan objetos modificados por el hombre, es decir, principalmente en los núcleos urbanos, ya que deben preservar ciertas propiedades en su geometría una vez generalizados.
En este artículo, se propone un algoritmo para la generalización lineal de núcleos urbanos, basándose en las características constructivas y relacionales de las edificaciones que los conforman.
Abstract: Mapping generalization is the process which derived maps are obtained from others generated by recording geographic information. Usually, generalization involves a reduction of scale, although it could be a reduction in the amount of information without reducing the scale, due to a change in target mapping. The smaller target scale, the more difficult is the generalization. Also, the more difference between origin scale and target scale, the more difficult is the generalization. The difficulties are concentrated in entities that represent objects modified by man, mainly in urban areas, as they must preserve certain geometry properties once generalized.
In this paper, an algorithm is proposed for linear generalization of urban areas, based on constructive and relational characteristics of the buildings that shape them
Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study
Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection
Ahora / Ara
La cinquena edició del microrelatari per l’eradicació de la violència contra les dones de l’Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume I vol ser una declaració d’esperança. Aquest és el moment en el qual les dones (i els homes) hem de fer un pas endavant i eliminar la violència sistèmica contra les dones. Ara és el moment de denunciar el masclisme i els micromasclismes començant a construir una societat més igualitària.
Cadascun dels relats del llibre és una denúncia i una declaració que ens encamina cap a un món millor
Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study
Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe
Long-term effect of a practice-based intervention (HAPPY AUDIT) aimed at reducing antibiotic prescribing in patients with respiratory tract infections
Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study
10.1371/journal.pone.0139981PLoS ONE1010e013998
Interleukin-2 therapy in patients with HIV infection
Collaboratore per la suddetta ricerca multicentrica in quanto membro del INSIGHT-ESPRIT Study Grou