Detecting false testimonies in reputation systems using self-organizing maps

It has been demonstrated that rating trust and reputation of individual nodes is an effective approach in distributed environments in order to improve security, support decision-making and promote node collaboration. Nevertheless, these systems are vulnerable to deliberate false or unfair testimonies. In one scenario, the attackers collude to give negative feedback on the victim in order to lower or destroy its reputation. This attack is known as bad mouthing attack. In another scenario, a number of entities agree to give positive feedback on an entity (often with adversarial intentions). This attack is known as ballot stuffing. Both attack types can significantly deteriorate the performances of the network. The existing solutions for coping with these attacks are mainly concentrated on prevention techniques. In this work, we propose a solution that detects and isolates the abovementioned attackers, impeding them in this way to further spread their malicious activity. The approach is based on detecting outliers using clustering, in this case self-organizing maps. An important advantage of this approach is that we have no restrictions on training data, and thus there is no need for any data pre-processing. Testing results demonstrate the capability of the approach in detecting both bad mouthing and ballot stuffing attack in various scenarios

AMISEC: Leveraging Redundancy and Adaptability to Secure AmI Applications

Security in Ambient Intelligence (AmI) poses too many challenges due to the inherently insecure nature of wireless sensor nodes. However, there are two characteristics of these environments that can be used effectively to prevent, detect, and confine attacks: redundancy and continuous adaptation. In this article we propose a global strategy and a system architecture to cope with security issues in AmI applications at different levels. Unlike in previous approaches, we assume an individual wireless node is vulnerable. We present an agent-based architecture with supporting services that is proven to be adequate to detect and confine common attacks. Decisions at different levels are supported by a trust-based framework with good and bad reputation feedback while maintaining resistance to bad-mouthing attacks. We also propose a set of services that can be used to handle identification, authentication, and authorization in intelligent ambients. The resulting approach takes into account practical issues, such as resource limitation, bandwidth optimization, and scalability

Predicción de fallo en laminados no convencionales: Estudio experimental

XI CONGRESO NACIONAL DE MATERIALES COMPUESTOS. Celebrado en Móstoles los días 6, 7 y 8 de julio de 2015Desde el inicio del uso de los materiales compuestos, han ido surgiendo distintas teorías para predecir su comportamiento y lo que es más importante, el fallo del material. Mientras que las predicciones parecen fiables en fallos dominados por la fibra no son tanto en fallos dominados por la matriz. En este trabajo se analiza el comportamiento experimental de laminados en los que el fallo dominante es el fallo por la matriz y se comparan los resultados con las predicciones, tanto en fallo a primera como a última lámina, que generan los criterios de fallo más utilizados. En todos los casos se ha incluido el estudio del efecto del espesor de las láminas, conocido como efecto escala, para ver su incidencia en la rotura de los laminados y en las correspondientes predicciones. Se ha constatado que en laminados dominados por el fallo de la matriz, las predicciones no son buenas, existiendo además una significativa incidencia del efecto escala, con una clara interacción entre láminas. Ambos problemas se mitigan cuando se usa un laminado cuyo fallo está dominado por la rotura de la fibra

HispaVeg: a new online vegetation plot database for Spain

We describe a new online database, named HispaVeg, which currently holds data from 2663 vegetation plots of Spanish woodlands, scrublands and grasslands. Unlike other similar databases, a detailed description of the structure is stored with the floristic data of each plot (i.e., number and physiognomy of the vertical layers, cover values for each layer).Most of the vegetation plots are large rectangles (400 to 2000 square meters) with an average of 34 species per plot. The survey dates range from 1956 to present, with most of the records between 1964 and 1994. The elevation of the plots ranges from 0 to 2880, with most of the plots between 300 and 1500 m. HispaVeg is freely available to the scientific community. Users can query the online database, view printable reports for each plot and download spreadsheet-like raw data for subsets of vegetation plots

Extensor Hallucis Capsularis o Tendón Accesorio del Extensor Hallucis Longus: Estudio anatómico y funcional, frecuencia y mediciones

The purpose of this study was to look closely at the anatomy of the extensor hallucis longus, ligament or tendon capsularis Accessory Extensor hallucis longus muscle; defi ne its occurrence frequency, it is a muscle that is not present in all feet and raises controversy in the reviewed literature. The ligament is a ligament capsularis dorsalis pedis group that accompanies the extensor hallucis longus muscle medial to it forever. We intend to demonstrate by our dissections, a ligament more common than it seems and where is its origin and insertion as well as their function, presentation and location by using photographs of cadaver feet and its width measures and characteristics. To achieve our object of study in this article, fi rst 50 dissected human cadaver fi ngers, making the relevant measurements.El objeto de éste estudio fue observar detenidamente la anatomía del Extensor Hallucis Longus, Ligamento Capsularis o Tendón Accesorio del músculo Extensor Hallucis Longus; definir su su frecuencia de aparición, pues es un músculo que no está presente en todos los pies y suscita controversia en la bibliografía consultada.El Ligamento Capsularis es un ligamento del grupo dorsal del pie, que acompaña al músculo Extensor Hallucis Longus siempre medial a él.Pretendemos demostrar con nuestras disecciones, que es un ligamento más habitual de lo que parece y, dónde está su origen e inserción, así como su función, presentación y ubicación mediante fotografías en pies de cadáver, así como medidas sobre su anchura y características particulares.Para conseguir nuestro objeto de estudio en éste artículo, se diseccionan 50 primeros dedos de cadáver humano, realizando las pertinentes mediciones

Anatomic relationship of the proximal nail matrix to the extensor hallucis longus tendon insertion

[Abstract] Background The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the great toe. Material and methods Fifty fresh-frozen human cadaver great toes with no evidence of trauma (average age, 62.5 years; 29 males and 21 females) were used for this study. Under 25X magnification, the proximal limit of the nail matrix and the terminal bony insertion of the extensor hallucis longus tendons were identified. The distance from the terminal tendon insertion to the nail matrix was ascertained using precision calipers, an optical microscope, and autocad® software for windows. Twenty-five great toes were placed in a neutral formalin solution and further analysed by histological longitudinal-sections. The specimens were stained with haematoxylin and eosin and examined microscopically to determine the presence of the extensor hallucis longus tendon along the dorsal aspect of the distal phalanx of each great toe. Results The main result we found in great toes was that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx in all, 100%, specimens. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of the distal phalanx as is the case for fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Conclusions We have found that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of distal phalanx as is the case in fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Our anatomic study demonstrates that the proximal limit of the matrix and nail bed of the human great toe are dorsal and overlapping the terminal extensor hallucis longus tendon until its distal bony insertion in all specimens

Initial clinical and treatment patterns of advanced differentiated thyroid cancer: ERUDIT study

Advanced differentiated thyroid cancer; Epidemiological study; Survival prognostic factorsCáncer de tiroides diferenciado avanzado; Estudio epidemiológico; Factores pronósticos de supervivenciaCàncer de tiroide diferenciat avançat; Estudi epidemiològic; Factors pronòstics de supervivènciaBackground Up to 30% of differentiated thyroid cancer (DTC) will develop advanced-stage disease (aDTC) with reduced overall survival (OS). Objective The aim of this study is to characterize initial diagnosis of aDTC, its therapeutic management, and prognosis in Spain and Portugal. Methods A multicentre, longitudinal, retrospective study of adult patients diagnosed with aDTC in the Iberian Peninsula was conducted between January 2007 and December 2012. Analyses of baseline characteristics and results of initial treatments, relapse- or progression-free survival ((RP)FS) from first DTC diagnosis, OS, and prognostic factors impacting the evolution of advanced disease were evaluated. Results Two hundred and thirteen patients (median age: 63 years; 57% female) were eligible from 23 hospitals. Advanced disease presented at first diagnosis (de novo aDTC) included 54% of patients, while 46% had relapsed from early disease (recurrent/progressive eDTC). At initial stage, most patients received surgery (98%) and/or radioiodine (RAI) (89%), with no differences seen between median OS (95% CI) (10.4 (7.3–15.3) years) and median disease-specific-survival (95% CI) (11.1 (8.7–16.2) years; log-rank test P = 0.4737). Age at diagnosis being <55 years was associated with a lower risk of death (Wald chi-square (Wc-s) P < 0.0001), while a poor response to RAI to a higher risk of death ((Wc-s) P < 0.05). In the eDTC cohort, median (RP)FS (95% CI) was of 1.7 (1.0–2.0) years after RAI, with R0/R1 surgeries being the only common significant favourable factor for longer (RP)FS and time to aDTC ((Wc-s) P < 0.05). Conclusion Identification of early treatment-dependent prognostic factors for an unfavourable course of advanced disease is possible. An intensified therapeutic attitude may reverse this trend and should be considered in poor-performing patients. Prospective studies are required to confirm these findings.ERUDIT study was sponsored and funded by Eisai Farmacéutica S.A. (Madrid, Spain)

The implications of diabetic foot health-related with quality of life: A retrospective case control investigation

[Abstract] The diabetes people show a significant presence of foot health problems are usually all over the world, causing in big economic effects for these persons, their families and world population OBJECTIVE: The purpose of this research is to evaluate and relate the impact of foot health associated with the quality of life (QoL) in a group of people with and without diabetes MATERIAL AND METHODS: A total of 150 persons of a mean age of 71.45 ± 11.93 years came to a foot and ankle specialist outpatient center. Self-reported data were medical records where persons'with and without diabetes was evaluated. All findings obtained was compared with scores quality of life using the tool Foot Health Status Questionnaire, spanish version RESULTS: The diabetes group revealed a reduction of QoL linked to overall health and to foot health in particular. Differences among both groups were analyzed by means of a independent Student's t-test samples, displaying a p-value lower than 0.05 statistically significant for the domains of foot pain, foot function footwear and social capacity CONCLUSIONS: Diabetes people recorded a negative influence on the QoL related with foot health, that seems to be linked with the presence of chronic disease in diabetes people

Geocronología de los megadeslizamientos de Tenerife del último millón de años. Parte II. Nuevas aportaciones al conocimiento de los deslizamientos de los deslizamientos

La revisión de las dataciones disponibles en la bibliografía relacionadas con los megadeslizamientos de la isla de Tenerifeocurridos en el último millón de años, y las nuevas dataciones Ar/Ar realizadas por los autores para acotar la edad de losmismos, han permitido proponer las siguientes edades para los deslizamientos de Icod: ~170 ka; La Orotava: ~560, ~530 y~500(?) ka; Güímar: ~830 ka; y Micheque: 810-830 ka (Ferrer et al., 2020-este volumen). En esta publicación se presentan lasrelaciones entre las evidencias geológicas y geomorfológicas indicadoras de los procesos de inestabilidad de los flancos,observadas tanto en superficie como en el interior de galerías que atraviesan los rellenos de los valles, y las edades de losdeslizamientos. Se refuerza la hipótesis de la ocurrencia de varios deslizamientos de flanco superpuestos o solapados, espaciados en el tiempo, al menos, varias decenas de miles de años, descartándose la hipótesis de procesos únicos de rotura masiva e instantánea del flanco insular; así, en el caso del valle de La Orotava, se confirma una edad en torno a los 530ka para un gran deslizamiento, y la ocurrencia de otros hacia los 560 ka y 500 ka. Se estudia también la relación y causalidad entre el deslizamiento de Icod, el último ocurrido en Tenerife, y la gran erupción explosiva del final del ciclo Cañadas, cuestión controvertida, y se demuestra que la explosión fue consecuencia del deslizamiento, desencadenada por éste hace ~170 ka. Se presentan nuevas evidencias del deslizamiento de Micheque, y se aportan nuevos datos que indican una edad pliocena para el sustrato profundo de los deslizamientos de La Orotava y Micheque