Reputation based selfishness prevention techniques for mobile ad-hoc networks

Mobile ad-hoc networks require nodes to cooperate in the relaying of data from source to destination. However, due to their limited resources, selfish nodes may be unwilling to forward packets, which can deteriorate the multi-hop connectivity. Different reputation-based protocols have been proposed to cope with selfishness in mobile ad-hoc networks. These protocols utilize the watchdog detection mechanism to observe the correct relaying of packets, and to compile information about potential selfish nodes. This information is used to prevent the participation of selfish nodes in the establishment of multi-hop routes. Despite its wide use, watchdog tends to overestimate the selfish behavior of nodes due to the effects of radio transmission errors or packet collisions that can be mistaken for intentional packet drops. As a result, the availability of valid multi-hop routes is reduced, and the overall performance deteriorates. This paper proposes and evaluates three detection techniques that improve the ability of selfishness prevention protocols to detect selfish nodes and to increase the number of valid routes.Ingeniería, Industria y Construcció

Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy.

BACKGROUND: The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials. METHODS: In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up. RESULTS: Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17-6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03-5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12-2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface. CONCLUSIONS: Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials

Reputation based selfishness prevention techniques for mobile ad-hoc networks

Mobile ad-hoc networks require nodes to cooperate in the relaying of data from source to destination. However, due to their limited resources, selfish nodes may be unwilling to forward packets, which can deteriorate the multi-hop connectivity. Different reputation-based protocols have been proposed to cope with selfishness in mobile ad-hoc networks. These protocols utilize the watchdog detection mechanism to observe the correct relaying of packets, and to compile information about potential selfish nodes. This information is used to prevent the participation of selfish nodes in the establishment of multi-hop routes. Despite its wide use, watchdog tends to overestimate the selfish behavior of nodes due to the effects of radio transmission errors or packet collisions that can be mistaken for intentional packet drops. As a result, the availability of valid multi-hop routes is reduced, and the overall performance deteriorates. This paper proposes and evaluates three detection techniques that improve the ability of selfishness prevention protocols to detect selfish nodes and to increase the number of valid routes.Ingeniería, Industria y Construcció

Multilingual soil database

The FAO-ISRIC-CSIC Multilingual Soil Database (SDBm) is a multilingual (English/French/Spanish) system designed to store and manipulate morphological and analytical soil data. It is a collection of programs written in CLIPPER 5.2 and C languages which constitutes a user-friendly tool for an efficient and systematic organization of soil profile data. Data storage is greatly facilitated by the multilingual function which provides "assist menus" in the selected language. Decoding tables in English, French and Spanish for the automatic translation of codes are available.SDBm is the result of cooperation between experts from the Soil Resources, Management and Information Service, Land and Water Development Division of FAO (AGLS), the International Soil Reference and Information Centre (ISRIC) and the Institute of Natural Resources and Agro-Biology (CSIC).Peer reviewe

FCCas. Sistema automatizado para evaluar la fertilidad natural de los suelos. Modelo Marisma

47 páginas, 28 figuras, 2 tablas, 11 referencias.-- MicroLEIS.com. Software y Documentación. Versión bilingüe: Inglés/Español. 1990-2004. El sistema MicroLEIS.com se compone de un software interactivo y documentación explicativa que puede ser de utilidad a investigadores, educadores y técnicos interesados en el uso y manejo sostenibles de los suelos, con especial referencia a la región Mediterránea. Dicho sistema proporciona un conjunto de herramientas informatizadas para el almacenamiento y gestión de datos básicos, así como para su interpretación práctica desde un punto de vista agro-ecológico. Sus principales características son: ingeniería de datos y conocimientos mediante el uso de un conjunto de técnicas en bases de datos, modelos de evaluación de tierras, aplicación automática y visualización; extrapolación de conocimientos desde una escala local a otra escala regional, nacional o continental; evaluación agro-ecológica de tierras a través de las siguientes unidades de estudio: lugar (clima), suelo (sitio+suelo), tierra (clima+sitio+suelo) y campo (clima+sitio+suelo+manejo); uso de datos agro-meteorológicos mensuales e información estandar facilitada por los reconocimientos de suelos y otros relacionados; análisis integrado mediante combinación de datos biofísicos con experiencia sobre uso y manejo agrícola; incorporación de los conceptos de ‘calidad del suelo’ y ‘agricultura sostenible’, a modo de sistema de apoyo a la decisión para la protección de los suelos; y desarrollo informático en versiones para ordenadores PC, Web y SIG.-- Propiedad intelectual del CSIC, derechos de explotación cedidos a Evenor-Tech, Spin-off del CSIC.En los últimos años, el grupo de investigación MicroLEIS del Instituto de Recursos Naturales y Agrobiología del CSIC viene desarrollando una serie de sistemas informáticos a fin de facilitar la exploración de los límites agro-ecológicos de la sostenibilidad. A su vez, estas actividades se encuentran muy próximas a las prioridades de investigación establecidas por la División de Fomento de Tierras y Aguas de FAO. En ambos casos, el principal objetivo radica en conseguir instrumentos informatizados de fácil uso que permita la difusión de los resultados científicos hacia los agricultores. A través de una Carta de Acuerdo firmada entre FAO y el CSIC, se llevó a cabo el trabajo de colaboración cuyos resultados se recogen en esta publicación. El trabajo representó, básicamente, el desarrollo de un sistema de evaluación en forma de programa de ordenador, llamado FCCas, capaz de transformar la información procedente de los reconocimientos de suelos en indicadores de la fertilidad natural de los propios suelos. Para ello se siguió el Fertility Capability System (FCC; Sanchez et al., 1982) al considerarse el procedimiento de mayor aceptación internacional.Comunidad Europea. FAO. Comisión Interministerial de Ciencia y TecnologíaPeer reviewe

Global parental leave in surgical careers: differences according to gender, geographical regions and surgical career stages

BACKGROUND: There is a lack of information regarding the provision of parental leave for surgical careers. This survey study aims to evaluate the experience of maternity/paternity leave and views on work-life balance globally. METHODS: A 55-item online survey in 24 languages was distributed via social media as per CHERRIES guideline from February to March 2020. It explored parental leave entitlements, attitude towards leave taking, financial impact, time spent with children and compatibility of parenthood with surgical career. RESULTS: Of the 1393 (male : female, 514 : 829) respondents from 65 countries, there were 479 medical students, 349 surgical trainees and 513 consultants. Consultants had less than the recommended duration of maternity leave (43.8 versus 29.1 per cent), no paid maternity (8.3 versus 3.2 per cent) or paternity leave (19.3 versus 11.0 per cent) compared with trainees. Females were less likely to have children than males (36.8 versus 45.6 per cent, P = 0.010) and were more often told surgery is incompatible with parenthood (80.2 versus 59.5 per cent, P < 0.001). Males spent less than 20 per cent of their salary on childcare and fewer than 30 hours/week with their children. More than half (59.2 per cent) of medical students did not believe a surgical career allowed work-life balance. CONCLUSION: Surgeons across the globe had inadequate parental leave. Significant gender disparity was seen in multiple aspects.RD&E staff can access the full-text of this article by clicking on the 'Additional Link' above and logging in with NHS OpenAthens if prompted.Published version, accepted version (12 month embargo), submitted versio

Global parental leave in surgical careers: differences according to gender, geographical regions and surgical career stages

Background: There is a lack of information regarding the provision of parental leave for surgical careers. This survey study aims to evaluate the experience of maternity/paternity leave and views on work-life balance globally. Methods: A 55-item online survey in 24 languages was distributed via social media as per CHERRIES guideline from February to March 2020. It explored parental leave entitlements, attitude towards leave taking, financial impact, time spent with children and compatibility of parenthood with surgical career. Results: Of the 1393 (male : female, 514 : 829) respondents from 65 countries, there were 479 medical students, 349 surgical trainees and 513 consultants. Consultants had less than the recommended duration of maternity leave (43.8 versus 29.1 per cent), no paid maternity (8.3 versus 3.2 per cent) or paternity leave (19.3 versus 11.0 per cent) compared with trainees. Females were less likely to have children than males (36.8 versus 45.6 per cent, P = 0.010) and were more often told surgery is incompatible with parenthood (80.2 versus 59.5 per cent, P &lt; 0.001). Males spent less than 20 per cent of their salary on childcare and fewer than 30 hours/week with their children. More than half (59.2 per cent) of medical students did not believe a surgical career allowed work-life balance. Conclusion: Surgeons across the globe had inadequate parental leave. Significant gender disparity was seen in multiple aspect

Virological outcome among HIV infected patients transferred from pediatric care to adult units in Madrid, Spain (1997–2017)

The aim of this transversal study was to describe the virological and immunological features of HIV-infected youths transferred from pediatric to adult care units since 1997 vs. the non-transferred patients from the Madrid Cohort of HIV-infected children and adolescents in Spain. We included 106 non-transferred and 184 transferred patients under clinical follow-up in 17 public hospitals in Madrid by the end of December 2017. Virological and immunological outcomes were compared in transferred vs. non-transferred patients. ART drug resistance mutations and HIV-variants were analyzed in all subjects with available resistance pol genotypes and/or genotypic resistance profiles. Among the study cohort, 133 (72.3%) of 184 transferred and 75 (70.7%) of 106 non-transferred patients had available resistance genotypes. Most (88.9%) of transferred had ART experience at sampling. A third (33.3%) had had a triple-class experience. Acquired drug resistance (ADR) prevalence was significantly higher in pretreated transferred than non-transferred patients (71.8% vs. 44%; p = 0.0009), mainly to NRTI (72.8% vs. 31.1%; p < 0.0001) and PI (29.1% vs. 12%; p = 0.0262). HIV-1 non-B variants were less frequent in transferred vs. non-transferred (6.9% vs. 32%; p < 0.0001). In conclusion, the frequent resistant genotypes found in transferred youths justifies the reinforcement of HIV resistance monitoring after the transition to avoid future therapeutic failures

BJS commission on surgery and perioperative care post-COVID-19

Background: Coronavirus disease 2019 (COVID-19) was declared a pandemic by the WHO on 11 March 2020 and global surgical practice was compromised. This Commission aimed to document and reflect on the changes seen in the surgical environment during the pandemic, by reviewing colleagues experiences and published evidence. Methods: In late 2020, BJS contacted colleagues across the global surgical community and asked them to describe how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had affected their practice. In addition to this, the Commission undertook a literature review on the impact of COVID-19 on surgery and perioperative care. A thematic analysis was performed to identify the issues most frequently encountered by the correspondents, as well as the solutions and ideas suggested to address them. Results: BJS received communications for this Commission from leading clinicians and academics across a variety of surgical specialties in every inhabited continent. The responses from all over the world provided insights into multiple facets of surgical practice from a governmental level to individual clinical practice and training. Conclusion: The COVID-19 pandemic has uncovered a variety of problems in healthcare systems, including negative impacts on surgical practice. Global surgical multidisciplinary teams are working collaboratively to address research questions about the future of surgery in the post-COVID-19 era. The COVID-19 pandemic is severely damaging surgical training. The establishment of a multidisciplinary ethics committee should be encouraged at all surgical oncology centres. Innovative leadership and collaboration is vital in the post-COVID-19 era