Comparing Random-based and k-Anonymity-Based Algorithms for Graph Anonymization

Recently, several anonymization algorithms have appeared for privacy preservation on graphs. Some of them are based on random-ization techniques and on k-anonymity concepts. We can use both of them to obtain an anonymized graph with a given k-anonymity value. In this paper we compare algorithms based on both techniques in orderto obtain an anonymized graph with a desired k-anonymity value. We want to analyze the complexity of these methods to generate anonymized graphs and the quality of the resulting graphs.

Multidelayed random walks: Theory and application to the neolithic transition in Europe

We present a model in which particles (or individuals of a biological population) disperse with a rest time between consecutive motions (or migrations) which may take several possible values from a discrete set. Particles (or individuals) may also react (or reproduce). We derive a new equation for the effective rest time T˜ of the random walk. Application to the neolithic transition in Europe makes it possible to derive more realistic theoretical values for its wavefront speed than those following from the single-delayed framework presented previously [J. Fort and V. Méndez, Phys. Rev. Lett. 82, 867 (1999)]. The new results are consistent with the archaeological observations of this important historical process

Summer ozone cycles in the Lisbon metropolitan area and its relation to some meteorological variables

The aim of this work is to study the tropospheric ozone concentrations and daily peak cycles in the Lisbon MetropolitanArea (LMA) during the summer season (June, July and August, JJA) covering the 4-yr study period 2002-2005. Theresults show that all the stations have the same pattern: a minimum in the early morning followed by an increase at 1000UTC reaching to a peak at 1300-1400 UTC, dropped again to minimum values 1800 UTC but with different concentrationsdue to regional and local wind circulations and complex dynamic interactions. We identified in Lisbon city the ozone “weekendeffect”. Finally, we studied an episode of very high levels of tropospheric ozone and related daily ozone concentrationswith some meteorological variables.

Neural networks complemented with genetic algorithms and fuzzy systems for predicting nitrogenous effluent variables in wastewater treatment plants

This work focuses on the prediction of the two main nitrogenous variables that describe the water quality at the effluent of a Wastewater Treatment Plant. We have developed two kind of Neural Networks architectures based on considering only one output or, in the other hand, the usual five effluent variables that define the water quality: suspended solids, biochemical organic matter, chemical organic matter, total nitrogen and total Kjedhal nitrogen. Two learning techniques based on a classical adaptative gradient and a Kalman filter have been implemented. In order to try to improve generalization and performance we have selected variables by means genetic algorithms and fuzzy systems. The training, testing and validation sets show that the final networks are able to learn enough well the simulated available data specially for the total nitrogen

Cambios en los cuidadores informales en cuanto a estilos de vida, relaciones y alteraciones de salud mental

Changes in the informal caregiver life styles, relations and alterations of mental health. Justification.The increase of the population aged 65 years and older in developed countries is generating a proportional increasing of the dependency caused by chronic pathologies. The care of these persons is being carried out by relatives, informal carers, leading to some alterations in diverse areas, among them mental alterations, as a consequence of taking care. Objectives. To develop a profile of the informal carers and to correlate the caregiver burden with the carers disorders. To detect risk factors to allow carrying out premature nursing interventions to diminish the disorders in the informal carers. Design. An observational and cross-sectional study is made in primary care health services area of the city of Girona. Methodology. Random sample of carer of dependent people at their home , assigned to the program of domiciliary attention (ATDOM) of the educational basic areas of health (ABS). A sample size of 269 persons, with a level of precision of 9% was needed. Questionnaire ICUB 97, the test of Barthel, the Philadelphia Geriatric Center scale, and a questionnaire are used as instruments that includes demographic and social variables, and mental and physical carers disorders.Results. A total of 80 participants were interviewed. The most common problems as consequence of taking care were the backache, to feel more tired, to feel impotent and to have less free time. Correlation between the level of dependence of the patient with the number of problems perceived by the caretaker does not exist. Since they are informal carers they eat frequently outside the habitual schedule, took place an increase or loss of weight, experienced more disorders in sexual life and an increasing lack of interest in surroundings. A 33% of the informal carers are being treated for problems related to the mental health.Conclusion. The fact of being informal carer carries important consequences in their health, the lifestyles and the social relations. These can be attenuated if the nursing interventions are able to consider to the well-taken care of subject, and its surroundings in an holistic way. The professionals of infirmary of mental health must contribute to their knowledge and abilities contributing to make an assessment, a diagnosis and an intervention paying special attention to psycho-social aspects mentioned

Cambios en los cuidadores informales en cuanto a estilos de vida, relaciones y alteraciones de salud mental

Changes in the informal caregiver life styles, relations and alterations of mental health. Justification.The increase of the population aged 65 years and older in developed countries is generating a proportional increasing of the dependency caused by chronic pathologies. The care of these persons is being carried out by relatives, informal carers, leading to some alterations in diverse areas, among them mental alterations, as a consequence of taking care. Objectives. To develop a profile of the informal carers and to correlate the caregiver burden with the carers disorders. To detect risk factors to allow carrying out premature nursing interventions to diminish the disorders in the informal carers. Design. An observational and cross-sectional study is made in primary care health services area of the city of Girona. Methodology. Random sample of carer of dependent people at their home , assigned to the program of domiciliary attention (ATDOM) of the educational basic areas of health (ABS). A sample size of 269 persons, with a level of precision of 9% was needed. Questionnaire ICUB 97, the test of Barthel, the Philadelphia Geriatric Center scale, and a questionnaire are used as instruments that includes demographic and social variables, and mental and physical carers disorders.Results. A total of 80 participants were interviewed. The most common problems as consequence of taking care were the backache, to feel more tired, to feel impotent and to have less free time. Correlation between the level of dependence of the patient with the number of problems perceived by the caretaker does not exist. Since they are informal carers they eat frequently outside the habitual schedule, took place an increase or loss of weight, experienced more disorders in sexual life and an increasing lack of interest in surroundings. A 33% of the informal carers are being treated for problems related to the mental health.Conclusion. The fact of being informal carer carries important consequences in their health, the lifestyles and the social relations. These can be attenuated if the nursing interventions are able to consider to the well-taken care of subject, and its surroundings in an holistic way. The professionals of infirmary of mental health must contribute to their knowledge and abilities contributing to make an assessment, a diagnosis and an intervention paying special attention to psycho-social aspects mentioned

Time-delayed fronts from biased random walks

We generalize a previous model of time-delayed reaction–diffusion fronts (Fort and Méndez 1999 Phys. Rev. Lett. 82 867) to allow for a bias in the microscopic random walk of particles or individuals. We also present a second model which takes the time order of events (diffusion and reproduction) into account. As an example, we apply them to the human invasion front across the USA in the 19th century. The corrections relative to the previous model are substantial. Our results are relevant to physical and biological systems with anisotropic fronts, including particle diffusion in disordered lattices, population invasions, the spread of epidemics, etc

Major variables influencing correct antibiotic prescription by primary care physicians in acute pharyngitis: a cross-sectional study

Objectives:To analyse which are the main variables that influence primary care professionals, in the prescription of antibiotics in patients with acute pharyngitis.To analyse which is the diagnosis pattern used by primary care professionals towards cutepharyngitis. To recognize the clinical and analytical criteria that primary care professionals use, to determine antibiotic treatment in acute pharyngitis.To identify the main clinical variables related with the prescription of antibiotics by primary care professionals, in acute pharyngitis treatment. Design: Cross-­‐sectional study Participants:165 primary care professionals from the Sanitary Region of Girona not attending paediatric patients and randomly selected from 29 ABS managed by two of the main health care providers: Insitut Català de la Salut (ICS) and Institut d’Assistència Sanitària (IAS) Main outcome measures: Each participant will fill out a questionnaire with personal and workplace questions, as well as about knowledge and attitude in front of the acute pharyngitis caused by group A streptococci. They will also answer 4 clinical questions about correct treatment and diagnosis of acute pharyngitis caused by group A streptococci

Análisis de la eficacia de los saques de esquina en la copa del mundo de fútbol 2010. Un intento de identificación de variables explicativas

In soccer, dead-ball moves are those in which the ball is returned to play from a stationary position following an interruption of play. The aim of this study was to analyse the effectiveness of one such dead-ball move, namely corner kicks, and to identify the key variables that determine the success of a shot or header following a corner, thereby enabling a model of successful corner kicks to be proposed. We recorded 554 corner kicks performed during the 2010 World Cup in South Africa and carried out a univariate, bivariate and multivariate analysis of the data. The results indicated that corners were of limited effectiveness in terms of the success of subsequent shots or headers. The analysis also revealed a series of variables that were significantly related to one another, and this enabled us to propose an explanatory model. Although this model had limited explanatory power, it nonetheless helps to understand the execution of corner kicks in practical terms.

Monte Carlo study of a kinetic lattice model with random diffusion of disorder

We report Monte Carlo results for a nonequilibrium Ising-like model in two and three dimensions. Nearest-neighbor interactions J change sign randomly with time due to competing kinetics. There follows a fast and random, i.e., spin-configuration-independent diffusion of Js, of the kind that takes place in dilute metallic alloys when magnetic ions diffuse. The system exhibits steady states of the ferromagnetic (antiferromagnetic) type when the probability p that J>0 is large (small) enough. No counterpart to the freezing phenomena found in quenched spin glasses occurs. We compare our results with existing mean-field and exact ones, and obtain information about critical behavior.

Determinació de l’estat de seguretat alimentària de dues zones d’Etiòpia i de les variables socioeconòmiques que les afecten

L’objectiu d’aquest estudi ha sigut generar dades especifiques locals de dos zones agroecològiques diferents d’Etiòpia ( el woreda Wukro i el woreda Abaya), mesurar l’estat de seguretat alimentària de la seva població, i els determinants socioeconòmics que els afecten, així com identificar els principals problemes metodològics, interpretatius que afecten a aquestes mesures i, en conseqüència, les intervencions que se’n poden derivar.

Stratification of the severity of critically ill patients with classification trees

Background: Development of three classification trees (CT) based on the CART (Classification and Regression Trees), CHAID (Chi-Square Automatic Interaction Detection) and C4.5 methodologies for the calculation of probability of hospital mortality; the comparison of the results with the APACHE II, SAPS II and MPM II-24 scores, and with a model based on multiple logistic regression (LR). Methods: Retrospective study of 2864 patients. Random partition (70:30) into a Development Set (DS) n = 1808 and Validation Set (VS) n = 808. Their properties of discrimination are compared with the ROC curve (AUC CI 95%), Percent of correct classification (PCC CI 95%); and the calibration with the Calibration Curve and the Standardized Mortality Ratio (SMR CI 95%). Results: CTs are produced with a different selection of variables and decision rules: CART (5 variables and 8 decision rules), CHAID (7 variables and 15 rules) and C4.5 (6 variables and 10 rules). The common variables were: inotropic therapy, Glasgow, age, (A-a)O2 gradient and antecedent of chronic illness. In VS: all the models achieved acceptable discrimination with AUC above 0.7. CT: CART (0.75(0.71-0.81)), CHAID (0.76(0.72-0.79)) and C4.5 (0.76(0.73-0.80)). PCC: CART (72(69- 75)), CHAID (72(69-75)) and C4.5 (76(73-79)). Calibration (SMR) better in the CT: CART (1.04(0.95-1.31)), CHAID (1.06(0.97-1.15) and C4.5 (1.08(0.98-1.16)). Conclusion: With different methodologies of CTs, trees are generated with different selection of variables and decision rules. The CTs are easy to interpret, and they stratify the risk of hospital mortality. The CTs should be taken into account for the classification of the prognosis of critically ill patients.

Relación entre variables de personalidad e interés por temas morbosos y sexuales en los mass media: réplica del estudio de Zuckerman y Litle en una muestra española

Este trabajo pretende replicar con muestras españolas un estudio americano diseñado para evaluar las relaciones entre el rasgo Búsquesa de Sensaciones, Extraversión, Neuroticismo y Psicoticismo, con el interés por la contemplación o lectura de sucesos violentos, morbosos y sexuales en los medios de comunicación (o reales). El estudio se realizó a partir de inventarios autoinformados de curiosidad morbosa, cuestionarios de personalidad y autopuntuaciones de asistencia a películas pornográficas y de terror. Los resultados obtenidos informan de una relación positiva entre las escalas de Búsqueda de Sensaciones (EBS) y las escalas de Curiosidad Morbosa (CTM-CTS). Ello sugiere como hipótesis que los altos buscadores de sensaciones podrían estar interesados en estímulos que aumentan la actividad del sistema central de catecolaminas. Para ello se parte de hallazgos experimentales previos que apuntan que películas morbosas de terror o sexuales aumentan los niveles de las catecolaminas periféricas.