642 research outputs found

    Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks

    Get PDF
    Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.This work is partially supported by the Spanish Ministry of Science and Innovation through the Continuity of Service, Security and QoS for Transportation Systems (CONSEQUENCE) (TEC2010-20572-C02-01/02) and INcident monitoRing In Smart COmmunities (INRISCO) (TEC2014-54335-C4-2-R) projects. We thank the editor and anonymous reviewers for their constructive comments, which helped us to improve our manuscript

    Relationship between consumers’ perceptions about goat kid meat and meat sensory appraisal

    Get PDF
    The goat meat preferred by consumers in Spain comes from suckling goat kids, slaughtered at a live weight of 8–10 kg. However, consumption of this meat is very uncommon, so it is necessary to show its value. To achieve this, we planned to investigate consumers’ perceptions about goat kid meat and to study whether their perceptions are related to their sensory appraisal of the meat, measured by the mean of the consumers’ home tests. The experiment was conducted with 30 volunteer families (from two cities with different consumption patterns), who were surveyed regarding their sociodemographic parameters, purchasing and eating habits, and the importance of the meat’s attributes. As a result, four clusters were obtained, which were labeled “negative,” “idealistic,” “positive,” and “concerned about fat content”. The parameters of the animal production system were valued differently by the clusters. Meat tenderness, taste, and amount of fat were considered very decisive factors by most respondents. When the goat kid meat was valued, tenderness was considered more important than taste among older people (“negative” cluster), whereas there was not so much difference between the appraisal of all parameters for the other three clusters. We conclude that it is necessary to improve the information received by consumers about goat production systems and meat quality parameters. There is certainly potential for creating new markets, especially targeted toward young consumers and considering specific strategies for the different groups of consumers, depending on the region and habits of consumption

    Effect of including whole linseed and vitamin E in the diet of young bulls slaughtered at two fat covers on the sensory quality of beef packaged in two different packaging systems

    Get PDF
    Background: Forty-six Pirenaica young bulls, slaughtered at two levels of fatness (3 and 4 mm), were used to evaluate the effect of the inclusion of 50 g kg-1 linseed alone or with 200 IU vitamin E kg-1 in the concentrate and of the meat packaging system (vacuum or modified atmosphere packaging (MAP)) on the beef sensory quality. Results: the inclusion of linseed or supplementation with vitamin E in the concentrate induced no significant differences in the main meat sensory scores and overall appraisal except under MAP, where small differences due to concentrate ingredients were found in juiciness and metallic flavor intensity. Extending the display time up to 4 or 8 days in high-oxygen MAP had detrimental effects on sensory attributes. Meat from animals with 4 mm fat cover depth were rated more tender and juicy, less fibrous and with a higher intensity of beef flavor and rancid odor than meat from 3 mm fat cover bulls when both samples were vacuum packaged. Conclusion: The inclusion of 50 g kg-1 linseed in the concentrate fed to bulls had no detrimental effect on the beef sensory quality. The vacuum-packaged meat of bulls slaughtered at 4 mm fat cover was rated higher on sensory analysis than that at 3 mm fat cover

    PAH occurrence during combustion of biodiesel from various feedstocks

    Get PDF
    PAHs are pollutants of concern since they are known carcinogenic compounds. Their occurrence is mainly related to combustion or pyrolysis of organic matter such as fossil fuels. In the current scenario where biofuels are growingly important, it is also necessary to characterize PAH emissions due to their combustion. There are a number of works concerning PAH emissions from biodiesel combustion in Diesel engines, however, there are few regarding the difference between them depending on the feedstock and type of alcohol used in the transesterification. The authors have processed and characterized biodiesel from several feedstocks (Le. tallow, palm, rapeseed, soy-bean, coconut, peanut and linseed oils) to obtain FAME and FAEE and they have developed a method to measure the PAHs originated during their combustion in a bomb calorimeter. The tests have been carried out under different oxygen pressure conditions, and samples have been c1eaned from the bomb after each one of these tests. The samples have been prepared for GC-MS analysis, where PAH quantities among some other combustion products have been assessed. This work shows statistical relations obtained between the measured amounts of 18 PAHs of concern and the composition (oil and type of alcohol) used to obtain the biodiesel, and also the oxygen pressure during combustion

    Presence of multiple group I introns closely related to bacteria and fungi in plastid 23S rRNAs of lichen-forming Trebouxia

    Get PDF
    The chloroplast-encoded large subunit ribosomal RNA gene of several free-living green algae contains group I introns at Escherichia coli genic positions 1917, 1931, 1951, and 2449. Herein we report the presence of group I introns at these positions within the chloroplast-encoded large subunit ribosomal RNA gene of several lichen-forming green algae belonging to the Trebouxia genus. In contrast to the introns inserted at position 2449, all introns inserted at positions 1917, 1931, and 1951 contained LAGLIDADG homing endonuclease genes. Phylogenetic analyses show that: (i) introns inserted at positions 1917, 1931, and 1951 are closely related to introns located at homologous insertion sites in bacterial rDNA genes; and (ii) introns inserted at position 2449 are closely related to fungal introns located at homologous insertion sites in mitochondrial rDNA genes. The symbiogenetic thalli of some lichens are proposed as the likely setting of horizontal transfer of genetic material among distantly related organisms such as bacteria, fungi, and green [email protected]; [email protected]

    Effect of the intake of lean Red-Meat from beef-(Pirenaica Breed) versus lean White-Meat on body composition, fatty acids profile and cardiovascular risk indicators: a randomized cross-over study in healthy young adults

    Get PDF
    The main dietary guidelines recommended a restriction of total and saturated fat intake in the management of cardiovascular risk. These recommendations are overgeneralized, and all red meats should be limited and replaced by white meat. The aim is to assess the effect of the consumption of beef (from the Pirenaica breed) or chicken-based diets on body composition, fatty acid profile and cardiovascular (CV) risk indicators in healthy adults. A randomized cross-over study was carried out in three University accommodation halls. Participants consumed either the Pirenaica breed beef or chicken three times per week for 8-week periods with their usual diet. Body composition, clinical, biochemical and dietary variables were evaluated at baseline and at the end of each period. A validated diet questionnaire was used to assess nutrient intake and monitor compliance. Intervention and control group comparisons were done with the general linear regression model for repeated measures. Forty-seven healthy adults were included (51.6% males, mean age 19.9 ± 1.75 years). No significant differences were found in body composition, fatty acid profile or CV risk indicators from baseline in either diet group. Consumption of lean red meat (Pirenaica breed) or lean white meat (chicken) as part of the usual diet is associated with a similar response. Clinical Trial Registration: NCT 04832217 (accessed on 6 September 2022)

    Percepciones del consumidor sobre la carne de caprino en España

    Get PDF
    Se ha realizado una encuesta a consumidores (n=119) con el fin de conocer la percepción que tenían de la carne de caprino frente a la carne de ovino en función de diversos aspectos relacionados con la intención de compra y la percepción de su calidad. El cuestionario constó de 11 enunciados afirmativos, respondidos hedónicamente mediante una escala categórica de 7 puntos (1: “totalmente en desacuerdo”, 7: “totalmente de acuerdo”). El análisis de las respuestas se realizó mediante frecuencias. Los resultados obtenidos han demostrado, globalmente, una sensibilidad positiva hacia la carne de caprino tanto en parámetros decisivos a la hora de la intención de compra como en parámetros de calidad sensorial de la carne. Esto ha sucedido en contra de lo que podría pensarse dado, en nuestro país, el alto consumo y consideración de calidad que tiene la especie ovina.Comisión Interministerial de Ciencia y Tecnología AGL2005-05777- C02-01/GA

    Spanish facilities and fisrst results in measuring thermodynamic temperature using the radiance method

    Get PDF
    Newport Pagnell, Buckinghamshire, May 18-19 2015; https://royalsociety.org/science-events-and-lectures/2015/05/new-kelvin/Currently, the dissemination of the kelvin, according to the International Temperature Scale (ITS-90), at high temperatures is realised at the Centro Español de Metrología (CEM) by using the fixed points of Ag and Cu and a standard radiation thermometer. Recently, absolute radiometry has been proposed by the CCT Working Group 5 [1] to be included in future revisions of the Mise-en-Practique for the kelvin (MeP-K). The Centro Español de Metrologia (CEM) in collaboration with the Instituto de Óptica of the Consejo Superior de Investigaciones Científicas (IO-CSIC) has been working in the following lines linked to this new alternative to disseminate the kelvin: ¿ Absolute calibration, i.e., calibration in terms of the thermodynamic temperature, of commercial radiation thermometers, by using a facility based on a monochromator and a high stability lamp [2]. At present, the uncertainties of these measurements, obtained with a KE-LP2 radiation thermometer, are about the ones obtained with the ITS-90 method, i. e. from 0,3 K to 1,1 K (from 1084,62 °C to 2474 °C, k = 2). Some improvements in the facilities described in [2] have been implemented in order to reduce uncertainty. ¿ Development of a filter radiometer to measure the thermodynamic temperature. It has been designed by CEM based in NPL previous work [3]. This filter radiometer can be calibrated with a laser based experimental setup, which improves the above measurement uncertainty [4]: from 0,2 K to 0,7 K (from 1084,62 °C to 2474 °C, k = 2). Because of some problems with the radiometer stability at 2500 °C, some changes in the design have been done. The facilities used in [2] and [4] are currently been developed at CEM site as the transportation of the instruments for calibration has caused significant drifts. A complete description of IO-CSIC and new CEM facilities will be presented, together with the results obtained on the determination of the WP1 InK cells thermodynamic temperatures by using both, a radiation thermometer with an absolute calibration, and a filter radiometer.Peer Reviewe
    corecore