472 research outputs found

    Encrypted CDMA audio network

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    We present a secure LAN using sound as the physical layer for low speed applications. In particular, we show a real implementation of a point-to-point or point-to-multipoint secure acoustic network, having a short range, consuming a negligible amount of power, and requiring no specific hardware on mobile clients. The present acoustic network provides VPN-like private channels to multiple users sharing the same medium. It is based on Time-hopping CDMA, and makes use of an encrypted Bloom filter. An asymmetrical error-correction is used to supply data integrity, even in the presence of strong interference. Simulations and real experiments show its feasibility. We also provide some theoretical analysis on the principle of operation.Fil: Ortega, Alfredo A.. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Bettachini, Victor. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fierens, Pablo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Alvarez Hamelin, Jose Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Can the Vaquita Be Saved From Extinction?

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    The vaquita (Phocoena sinus) is considered the world’s most endangered marine mammal. It is the smallest member of the porpoise family endemic to the upper part of the Gulf of California. The current population is estimated at less than 30 individuals. The primary reasons for the species decline includes limited habitat and incidental mortalities associated with illegal gillnet fishing activities. Since 2008, the Mexican government has taken environmental and economic actions to protect the vaquita’s focusing in reducing by-catch deaths to zero. In 2015, a federal Agreement decreed by the Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación (SAGARPA in Spanish) prohibited the use of any fishing gillnets for two years, affecting severely the local human communities because in the region the coastal fisheries represent 40% of the regional PIB, besides that 50% of the local inhabitants are devoted to this activity. Recently, an economical compensation is giving to the fishing permits owners if they do not continue with their fishing activities. However none of this actions and agreements have considered social and economic solutions for the local inhabitants of this region, which includes three communities: San Felipe, Golfo de Santa Clara and Puerto Peñasco. If there is not enacted a change of paradigm of the conservation programs, focusing in the wellbeing of the local fishing communities then the vaquita could be the second marine mammal species to disappear due to human activities

    Fisheries and Biodiversity in the Upper Gulf of California, Mexico

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    The Upper Gulf of California (UGC) has been recognized by its high primary productivity and abundant fishing (Aragon-Noriega & Calderon-Aguilera, 2000). Sediments and nutrients from the Colorado River, and complex hydrodynamics render this as an Important site for spawning, mating and nursing for numerous species of commercial and ecological importance (Cudney & Turk, 1998; Ramirez-Rojo & Aragón-Noriega 2006). Temperature, salinity and abundance of nutrients in this region vary depending on fresh water runoff from the Colorado River (Alvarez-Borrego et al., 1975; Hernández-Ayón et al., 1993; Lavín & Sánchez, 1999). Commercial fishing of high market value resources such as shrimp takes place in the UGC by artisanal or small scale, and industrial fishing. Artisanal fishing is done on relatively small (30 feet) fiber glass boats or artisanal boats with outboard motors, usually operated by two fishers; their primary fishing gear is drift gillnets, which they use to catch croakers, Spanish mackerel and even shrimp. This type of fishing is carried out by cooperatives and individual fishers from the three ports of the UGC: Puerto Peñasco and El Golfo de Santa Clara, in the State of Sonora, and San Felipe, in Baja California. Because marine resources in the region are migratory, fisheries are seasonal generating bursts of accumulated fishing effort over a few months depending on availability of species (see Cudney & Turk 1998). Increasing demand of economically important species has motivated a steady rise in fishing effort and use of gear and fishing practices jeopardizing critical species such as totoaba, Totoaba macdonaldi, an endemic croaker declared under risk of extinction (Cisneros-Mata et al., 1995), and the rare vaquita, Phocoena sinus. Vaquita are accidentally caught in all kinds of gillnets used in the Upper Gulf (D’Agrosa et al., 1995; Blanco 2002)

    Small farmers' perception of factors influencing regional chemical control of Diaphorina citri

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    Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs.Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs

    Obesity, adipokines and their relationship with insulin resistance

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    La obesidad es uno de los principales problemas de salud a nivel mundial. Es una enfermedad que se asocia con un consumo excesivo de alimentos, aunque también se asocia con un proceso de inflamación crónica y con un grupo de trastornos conocidos como síndrome metabólico. Algunas de las características más distintivas de la obesidad son que los adipocitos del individuo están hipertrofiados, tienen un perfil de secreción de adipoquinas irregular, tienen un mayor reclutamiento de células inflamatorias y una homeostasis metabólica alterada; lo que eventualmente resulta en el desarrollo de varias patologías o condiciones importantes, como la resistencia a la insulina y la disfunción mitocondrial. Esta revisión tiene como objetivo presentar el conocimiento actual sobre la inflamación del tejido adiposo asociada a la obesidad.Obesity is one of the main health problems worldwide. It is a disease that is associated with excessive food consumption, although it is also associated with a process of chronic inflammation and with a group of disorders known as metabolic syndrome. Some of the most distinctive characteristics of obesity are that the individual's adipocytes are hypertrophied, have an irregular adipokine secretion profile, have increased recruitment of inflammatory cells, and altered metabolic homeostasis; which eventually results in the development of various important pathologies or conditions, such as insulin resistance and mitochondrial dysfunction. This review aims to present the current knowledge on inflammation of adipose tissue associated with obesity

    Transcriptomics and molecular evolutionary rate analysis of the bladderwort (Utricularia), a carnivorous plant with a minimal genome

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    <p>Abstract</p> <p>Background</p> <p>The carnivorous plant <it>Utricularia gibba </it>(bladderwort) is remarkable in having a minute genome, which at ca. 80 megabases is approximately half that of <it>Arabidopsis</it>. Bladderworts show an incredible diversity of forms surrounding a defined theme: tiny, bladder-like suction traps on terrestrial, epiphytic, or aquatic plants with a diversity of unusual vegetative forms. <it>Utricularia </it>plants, which are rootless, are also anomalous in physiological features (respiration and carbon distribution), and highly enhanced molecular evolutionary rates in chloroplast, mitochondrial and nuclear ribosomal sequences. Despite great interest in the genus, no genomic resources exist for <it>Utricularia</it>, and the substitution rate increase has received limited study.</p> <p>Results</p> <p>Here we describe the sequencing and analysis of the <it>Utricularia gibba </it>transcriptome. Three different organs were surveyed, the traps, the vegetative shoot bodies, and the inflorescence stems. We also examined the bladderwort transcriptome under diverse stress conditions. We detail aspects of functional classification, tissue similarity, nitrogen and phosphorus metabolism, respiration, DNA repair, and detoxification of reactive oxygen species (ROS). Long contigs of plastid and mitochondrial genomes, as well as sequences for 100 individual nuclear genes, were compared with those of other plants to better establish information on molecular evolutionary rates.</p> <p>Conclusion</p> <p>The <it>Utricularia </it>transcriptome provides a detailed genomic window into processes occurring in a carnivorous plant. It contains a deep representation of the complex metabolic pathways that characterize a putative minimal plant genome, permitting its use as a source of genomic information to explore the structural, functional, and evolutionary diversity of the genus. Vegetative shoots and traps are the most similar organs by functional classification of their transcriptome, the traps expressing hydrolytic enzymes for prey digestion that were previously thought to be encoded by bacteria. Supporting physiological data, global gene expression analysis shows that traps significantly over-express genes involved in respiration and that phosphate uptake might occur mainly in traps, whereas nitrogen uptake could in part take place in vegetative parts. Expression of DNA repair and ROS detoxification enzymes may be indicative of a response to increased respiration. Finally, evidence from the bladderwort transcriptome, direct measurement of ROS <it>in situ</it>, and cross-species comparisons of organellar genomes and multiple nuclear genes supports the hypothesis that increased nucleotide substitution rates throughout the plant may be due to the mutagenic action of amplified ROS production.</p

    Las cuevas de la Sierra de Atapuerca y el uso humano del paisaje kárstico durante el Pleistoceno (Burgos, España)

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    El karst de la Sierra de Atapuerca representa un interesante sistema multinivel, inactivo y heredado de antiguos niveles de base plio-pleistocenos, que alberga los enclaves prehistóricos más importantes para el conocimiento del poblamiento antiguo en Eurasia, y que fue declarado Patrimonio de la Humanidad en 2000 por la UNESCO. Estas cuevas se originan a partir de conductos subhorizontales con paleodrenajes en sentido SN, localizándose la zona de descarga en la cabecera del río Pico. Los conductos están organizados en tres niveles principales que aparecen colgados entre 90 y 60 m sobre el actual cauce del río Arlanzón, coincidiendo con los niveles de base generados por sus terrazas fluviales T2, T3 y T5. La incisión fluvial liberó de las aguas los conductos superiores mientras se excavaban los niveles inferiores del karst. Las cuevas que iban quedando accesibles fueron utilizadas por la fauna y los homininos, conservando un registro arqueo-paleontológico de más de 1,2 Ma

    Atopic Dermatitis and Erythrodermia Associated With Systemic Lupus Erythematosus: A Case Report

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    La eritrodermia es una dermatosis inflamatoria que involucra capas parciales o totales de la piel. La mortalidad es del 16%. Los síntomas sistémicos incluyen fiebre, taquicardia, hinchazón de las extremidades, adenomegalia y hepatomegalia. Las causas infecciosas son las más frecuentes, estando presentes hasta en un 40%, seguidas de ictiosis y dermatitis en el 15% de los casos

    Birth weight and blood lipid levels in Spanish adolescents: Influence of selected APOE, APOC3 and PPARgamma2 gene polymorphisms. The AVENA Study

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    Es reproducción del documento publicado en http://dx.doi.org/10.1186/1471-2350-9-98Background: There is increasing evidence indicating that genes involved in certain metabolic processes of cardiovascular diseases may be of particular influence in people with low body weight at birth. We examined whether the apolipoprotein (APO) E, APOC3 and the peroxisome proliferator-activated receptor-gamma-2 (PPAR gamma 2) polymorphisms influence the association between low birth weight and blood lipid levels in healthy adolescents aged 13-18.5 years. Methods: A cross-sectional study of 502 Spanish adolescents born at term was conducted. Total (TC) and high density lipoprotein cholesterol (HDLc), triglycerides (TG), apolipoprotein (apo) A and B, and lipoprotein(a) [ Lp(a)] were measured. Low density lipoprotein cholesterol (LDLc), TC-HDLc, TC/HDLc and apoB/apoA were calculated. Results: Low birth weight was associated with higher levels of TC, LDLc, apoB, Lp(a), TC-HDLc, TC/HDLc and apoB/apoA in males with the APOE epsilon 3 epsilon 4 genotype, whereas in females, it was associated with lower HDLc and higher TG levels. In males with the APOC3 S1/S2 genotype, low birth weight was associated with lower apoA and higher Lp(a), yet this association was not observed in females. There were no associations between low birth weight and blood lipids in any of the PPAR gamma 2 genotypes. Conclusion: The results indicate that low birth weight has a deleterious influence on lipid profile particularly in adolescents with the APOE epsilon 3/epsilon 4 genotype. These findings suggest that intrauterine environment interact with the genetic background affecting the lipid profile in later life.Instituto de Salud Carlos III (FIS PI021830), the Spanish Ministry of Health, FEDER-FSE funds FIS n 00/0015, CSD grants 05/UPB32/0, 109/UPB31/03 and 13/UPB20/04, Ministerio de Educación (AP-2004-2745; EX2007-1124
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