399 research outputs found

    When viruses play team sports : mixed infections in plants

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    Altres ajuts: Generalitat de Catalunya/CERCA ProgrammeThe pathological importance of mixed viral infections in plants might be underestimated except for a few well-characterized synergistic combinations in certain crops. Considering that the host ranges of many viruses often overlap and that most plant species can be infected by several unrelated viruses, it is not surprising to find more than one virus simultaneously in the same plant. Furthermore, dispersal of the majority of plant viruses relies on efficient transmission mechanisms mediated by vector organisms, mainly but not exclusively insects, which can contribute to the occurrence of multiple infections in the same plant. Recent work using different experimental approaches has shown that mixed viral infections can be remarkably frequent, up to the point that they could be considered the rule more than the exception. The purpose of this review is to describe the impact of multiple infections not only on the participating viruses themselves but also on their vectors and on the common host. From this standpoint, mixed infections arise as complex events that involve several cross-interacting players, and they consequently require a more general perspective than the analysis of single-virus/single-host approaches for a full understanding of their relevance

    AMISEC: Leveraging Redundancy and Adaptability to Secure AmI Applications

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    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

    Detecting false testimonies in reputation systems using self-organizing maps

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    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

    Nutritive Value of Wheat Bran Diets Supplemented With Fresh Carrots and Wet Brewers' Grains in Yellow Mealworm

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    [EN] We evaluated the effect of supplementation of a wheat bran (WB) diet with fresh carrots (FC) or wet brewer's grains (WBG) on the growth performance and chemical composition of Tenebrio molitor larvae. Additionally, a digestibility trial was performed to determine the nutritional value of the raw materials used. The control diet was based on WB-only. Two other diets were formulated in which WB was supplemented with FC (FC diet) or with WBG (WBG diet). The experiment was conducted in trays (12 per treatment) and lasted 90 d. Larval weight, feed intake, and excreted feces were controlled in each tray the experiment. The digestibility trial was performed from 48 to 62 d post-hatch. Results showed digestibility coefficients of ashes, crude protein, and gross energy were significantly higher in FC diet compared with the other diets. Consequently, both digestible energy (DE) and digestible protein (DP) contents of FC were also significantly higher than those obtained for WB and WBG diets (on av. +1.12 megajoule [MJ] DE and +9.15 g DP per kg dry matter [DM]; P < 0.003). Mealworms fed FC diet showed significantly higher final weight and average daily gain than those fed the WBG diet (+12.4%), being higher in WBG than in WB diet (+3.5%). Dietary treatment did not affect DM, ashes, ether extract, and crude protein content of mealworms obtained. Some dietary effects on amino acid and fatty acid composition were observed. This study provides novel data and a unique experimental approach to assess the nutritional value of raw materials in mealwormsWe thank Juan Cañamero (Production Manager of Feedect) for his contribution maintaining the colony and collaborating in data collection. Dr. Enrique Blas (Universitat Politècnica de València) is also thanked for contributing with his ideas, opinions, and support during the design of the experiment.Fasce, B.; Ródenas Martínez, L.; López Luján, MDC.; Moya, V.; Pascual Amorós, JJ.; Cambra López, M. (2022). Nutritive Value of Wheat Bran Diets Supplemented With Fresh Carrots and Wet Brewers' Grains in Yellow Mealworm. Journal of Insect Science. 22(3):1-9. https://doi.org/10.1093/jisesa/ieac0221922

    Assessing the impact on virus transmission and insect vector behavior of a viral mixed infection in melon

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    Altres ajuts: Generalitat de Catalunya/CERCA ProgrammeMixed viral infections in plants are common, and can result in synergistic or antagonistic interactions. Except in complex diseases with severe symptoms, mixed infections frequently remain unnoticed, and their impact on insect vector transmission is largely unknown. In this study, we considered mixed infections of two unrelated viruses commonly found in melon plants, the crinivirus cucurbit yellow stunting disorder virus (CYSDV) and the potyvirus watermelon mosaic virus (WMV), and evaluated their vector transmission by whiteflies and aphids, respectively. Their dynamics of accumulation was analyzed until 60 days postinoculation (dpi) in mixed-infected plants, documenting reduced titers of WMV and much higher titers of CYSDV compared with single infections. At 24 dpi, corresponding to the peak of CYSDV accumulation, similar whitefly transmission rates were obtained when comparing either individual or mixed-infected plants as CYSDV sources, although its secondary dissemination was slightly biased toward plants previously infected with WMV, regardless of the source plant. However, at later time points, mixed-infected plants partially recovered from the initially severe symptoms, and CYSDV transmission became significantly higher. Interestingly, aphid transmission rates both at early and late time points were unaltered when WMV was acquired from mixed-infected plants despite its reduced accumulation. This lack of correlation between WMV accumulation and transmission could result from compensatory effects observed in the analysis of the aphid feeding behavior by electrical penetration graphs. Thus, our results showed that mixed-infected plants could provide advantages for both viruses, directly favoring CYSDV dissemination while maintaining WMV transmission

    IAA : Información y actualidad astronómica (24)

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    Sumario : Máseres en el espacio.-- Venus Express.-- El complejo cinturón de asteroides.-- DECONSTRUCCIÓN Y otros ENSAYOS : Rotación diferencial y oscilaciones estelares.-- ACTUALIDAD.-- ENTRE BASTIDORES .-- HISTORIAS DE ASTRONOMÍA: El astrónomo de vista prodigiosa.-- CIENCIA: PILARES E INCERTIDUMBRES : Ondas gravitatorias.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

    Narrow Diameter Dental Implants as an Alternative Treatment for Atrophic Alveolar Ridges. Systematic Review and Meta-Analysis

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    To determine the marginal bone loss and the survival, success and failure rates of narrow dental implants, a systematic literature search was carried out in the MEDLINE (Pubmed), Cochrane, Scopus, and Scielo databases for articles published between 2010 and 2021. The exclusion criteria were: systematic reviews, case reports, expert opinions; animal studies; samples of less than 10 subjects; follow-up periods of less than 36 months; smokers of minimum 10 cigarettes/day; and articles about mini-implants for orthodontic anchorage. Meta-analyses were performed to assess marginal bone loss and implant survival, success, and failure rates. Fifteen studies were included: 7 clinical trials, 3 randomized clinical trials, 3 cohort studies, and 2 case series. The total number of subjects was 773, in whom 1245 implants were placed. The survival rate for the narrow diameter implants was 97%, the success rate 96.8%, and the failure rate 3%. Marginal bone loss was 0.821 mm. All these data were evaluated at 36 months. Based on the literature, it can be considered that there is sufficient evidence to consider small diameter implants a predictable treatment option. These show favorable survival and success rates and marginal bone loss. All of them are comparable to those of standard diameter dental implants

    La espiritualidad de la educación integral como factor de bienestar bioético y sostenible

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    The evident remoteness between the religious postulates and the secular activity has led us to spiritual disorder and the oblivion of the authentic needs and aspirations of the human being. The current mentality and practice, towards what is considered merely useful or verifiable, has led us to this antinomy of polarized extremes, either towards an anthropocentrism that survives in a paradoxical happiness, disproportionate in the search for the strictly tangible, or towards an economic or ecological discourse that forgets the ontological idea, and the authentic value and meaning of the human being. From a positive and normative analysis, this study aims to emphasize the importance of the so-called 'Integral Training’, taught by some university centers, as a promoter of the psychological and spiritual well-being, as well as the attitudes of sustainable entrepreneurship, in an ethical way and responsible.El evidente alejamiento entre los postulados religiosos y la actividad secular nos ha llevado al desorden espiritual y al olvido de las necesidades y aspiraciones auténticas del ser humano. La mentalidad y la praxis actuales, hacia lo que se considera meramente útil o verificable, nos ha llevado a esta antinomia de extremos polarizados, ya sea hacia un antropocentrismo que sobrevive en una felicidad paradójica, desproporcionada en la búsqueda de lo estrictamente tangible, o hacia un discurso económico o ecológico que olvida la idea ontológica, y el auténtico valor y significado del ser humano. Desde un análisis positivo y normativo, este estudio pretende enfatizar la importancia de la llamada 'Educación Integral', impartida por algunos centros universitarios, como promotora del bienestar psicológico y espiritual, así como de las actitudes de emprendimiento sostenible, de forma ética y responsable
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