Cryptanalysis of a group key establishment protocol

In this paper, we analyze the security of a group key establishment scheme proposed by López-Ramos et al. This proposal aims at allowing a group of users to agree on a common key. We present several attacks against the security of the proposed protocol. In particular, an active attack is presented, and it is also proved that the protocol does not provide forward secrecy

Estimation of pre-exercise hydration status of Mexican college athletes

INTRODUCTION: The state of hydration is a very important aspect for athletes and coaches. According to NATA and ACSM athletes must be educated to maintain a good state of hydration and thus obtain better results. PURPOSE: To determine the state of hydration, before the sport practice of athletes (males) that belong to representative sports. METHODS: Seventy-five males college athletes, physically active and apparently healthy, were voluntarily recruited. They had an average height of 174.8 ± 7.4cm, weight 87.2 ± 24.0kg and age 21.3 ± 2.4 years. The athletes attended the study on a single spontaneous occasion, prior to the training session. Were given a questionnaire of hydration habits and a urine container (to collect a urine sample of their own). The urine gravity (UG) was determined by a urinary refractometer (ATAGO, Master-Sur/Na). RESULTS: Athletes had a urine gravity of 1.024 ± 0.006UG, finding maximum values up to 1.033 UG. Only 2.6% of the study population was well hydrated (1.030UG), which means a loss of fluid of 2%, 4% and more than 5% of total body weight for hypohydration conditions. Athletes mentioned that during and one hour after exercise they drink 762.3 ± 560.2mL and 644.4 ± 362.2mL respectively, either water or isotonic drink. However, these liquid volume did not compensated the water deficiency with which they begin the practice of the exercise. CONCLUSION: Before the training, 97.4% of the subjects presented different level of hypohydration, including very severe hypohydration state. The fluid ingested after the training session did not disappear the hydration deficiency with which they begin the exercise

Cryptanalysis of a Group Key Establishment Protocol

[EN] In this paper, we analyze the security of a group key establishment scheme proposed by López-Ramos et al. This proposal aims at allowing a group of users to agree on a common key. We present several attacks against the security of the proposed protocol. In particular, an active attack is presented, and it is also proved that the protocol does not provide forward secrecy.SIMinisterio de Ciencia, Innovación y Universidade

“Métodos de remoción y degradación de antibióticos en medio acuoso”

En los últimos años, los antibióticos han sido considerados contaminantes emergentes debido a su aporte continuo y su persistente aparición en los ecosiste concentraciones. Estos contaminantes se han detectado en todos los cuerpos acuáticos del mundo, lo que indica su eliminación tratamiento convencionale

Is English important in your life? : A collaborative experience in a secondary school

In this chapter, we describe a collaborative action-research project involving an ethnographer, an English teacher and secondary school students in the production of videos about the role of English in the youths' lives. Building on the principles of language socialisation and imagined communities, the analysis of the videos produced by the students foregrounds the connections between their socialisation into English, their sense of present and future investment in English learning activities and their engagement with imagined communities of YouTubers and Instagrammers. Social media, digital platforms and private after- school language colleges emerge as central in young people's English language learning trajectories, alongside their formal education. We conclude that collaborative action- research initiatives might provide teachers, researchers and students with opportunities to connect youths' in- and out- of- school practices and engage them in more meaningful English learning experiences

Physical and recreational activities to promote community environmental education

Through a diagnosis made in the distribution "Carlos Manuel de Céspedes" of Bayamon municipality, Granma province, it was determined that there were limitations regarding the needs, tastes, and recreational preferences in the adolescent population that responded to the development of an environmental culture , Which was the starting point for the programming of physical and recreational activities with this objective. For this, theoretical and empirical methods as well as statistical-mathematical methods were applied. After its application, the high level of knowledge and satisfaction of this population was corroborated, evidenced in the behavioral change experienced

PROYECTO FÍSICO-RECREATIVO PARA JÓVENES DESDE UNA PERSPECTIVA MEDIO AMBIENTAL COMUNITARIA

En el reparto “Carlos Manuel de Céspedes” del municipio Bayamo se desarrolla la presente investigación con el objetivo de aplicar un proyecto recreativo desde una perspectiva medioambiental dirigida a los jóvenes de 16 a 19 años de edad, Esta investigación muestra los sustentos teóricos acerca de la recreación y el medio ambiente, posibilitando esto que la autora implementara el proyecto “Los jóvenes se recrean” con el propósito de satisfacer las necesidades recreativas de la población juvenil, además de promover el conocimiento medioambiental, mediante el diagnóstico efectuado se determinaron las regularidades en relación con las necesidades, gustos, preferencias recreativas y la cultura medioambiental, teniendo en cuenta las expectativas de los jóvenes y sus limitaciones en relación con la educación ambiental. Para ello se aplicaron métodos teóricos, empíricos y estadísticos.PALABRAS CLAVE: proyecto recreativo; jóvenes; medioambiental.PHYSICAL-RECREATIONAL PROJECT FOR YOUNG PEOPLE FROM A COMMUNITY ENVIRONMENTAL PERSPECTIVEABSTRACTIn Carlos Manuel de Céspedes neighborhood in Bayamo city, takes place the present research which is aimed to the making of recreational project from an environmental point of and lead to the young people between 16 and 19 years old. This research is supported with the theoretical basement of recreation and environment, what makes possible that the author be able to apply the project entitled Young People Have Fun which, at great extent, supply the recreational needs of these juvenile population.KEYWORDS: recreational project; young people; environmental

Opuntia ficus-indica (Nopal Extract) as Green Inhibitor for Corrosion Protection in Industrial Steels

Soluble extract from Opuntia ficus-indica (Nopal extract) has been proposed in this chapter as a green inhibitor due to its component called mucilage, which has the ability to retain water; for this reason, it has been used as metal corrosion protection in machinery pieces, tools and other metallic components that need to be stored for short periods. In this way, three industrial carbon steels (AISI 1018, 1045 and 4140) have been exposed in sulfuric acid (H2SO4) to evaluate the corrosion behavior with or without Nopal extract (NE). Some electrochemical techniques have been implemented to evaluate the corrosion inhibition efficiency (IE) such as DC linear polarization resistance (LPR) and AC electrochemical impedance spectroscopy (EIS). Results indicated a considerable superficial modification of steel in terms of dielectric constant and ion charge capacity. When the NE was added, the corrosion mechanism changed from localized to general attack, decreasing the corrosion rate in all cases. More susceptibility to fail by corrosion was observed in the 1045 carbon steel in comparison with the other two studied steels; these results were confirmed by the percentage of inhibitor’s efficiency of about 95%

Flora y microflora de 3 hábitats de caracoles hospederos intermediarios de fasciola hepática en Tulancingo, Hgo.

De octubre de 1982 a octubre de 1983 se hicieron visitas mensuales a tres diferentes canales de riego, en los que se localizan las diferentes especies de caracole