Abstract Introduction: the GA haplotype of polymorphisms rs1554483 and rs4864548 has been associated with components of the metabolic syndrome such as high blood pressure and triglyceride levels; its carriers have a risk of obesity, 1.5 times higher than the rest of the population. Methodology: SNP rs1554483 and rs4864548 were obtained from 2504 individuals from the “1000genomes phase 3” database. Data were grouped into five macro populations (Africa, East Asia, South Asia, Europe and Latin America) covering a total of 26 populations. Differences in haplotype frequency between macro populations and populations were analyzed, for which Fisher's F statistic was used. Results: the macro population of Africa presented the lowest frequency (17.9 %) and that of East Asia the highest (57.4 %). Within the populations there is a relative homogeneity in the frequencies, except in the case of those that make up the macro population of Latin America where the Peruvian population of Lima and the Puerto Rican population present much higher frequencies than the rest. Conclusions: the GA haplotype presents heterogeneity between macro populations, which suggests highly differentiated micro evolutionary processes between continents. We propose to study the association of the GA haplotype with other polymorphisms such as rs3749474, rs11932595 and rs6859524 that have also been associated with risk of obesity and factors associated with metabolic syndrome.

Resumen Introducción: el haplotipo GA de los polimorfismos rs1554483 y rs4864548 se ha asociado con componentes del síndrome metabólico como la hipertensión arterial y los niveles de triglicéridos. Sus portadores presentan un riesgo de obesidad 1,5 veces mayor que el resto de la población. Metodología: se obtuvieron los SNP rs1554483 y rs4864548 de 2504 individuos desde la base de datos “1000genomes phase 3”. Los datos se agruparon en cinco macropoblaciones (África, Asia Oriental, Asia Meridional, Europa y Latinoamérica) cubriendo un total de 26 poblaciones. Se analizaron las diferencias en la frecuencia del haplotipo entre las macropoblaciones y las poblaciones, para lo cual se utilizó el estadístico F de Fisher. Resultados: la macropoblación de África presentó la menor frecuencia (17,9 %) y la del Este de Asia la mayor (57,4 %). Dentro de las poblaciones existe una relativa homogeneidad en las frecuencias, excepto en el caso de las que componen la macropoblación de Latinoamérica, donde la población peruana de Lima y la puertorriqueña presentan frecuencias mucho mayores que el resto. Conclusiones: el haplotipo GA presenta heterogeneidad entre las macropoblaciones, lo que sugiere procesos microevolutivos altamente diferenciados entre los continentes. Se propone estudiar la asociación del haplotipo GA con otros polimorfismos, como rs3749474, rs11932595 y rs6859524, que también se han asociado con el riesgo de obesidad y factores asociados al síndrome metabólico.

Resumen Introducción: los ritmos circadianos influyen en la conducta alimentaria, siendo el gen CLOCK uno de los encargados de su regulación. El rs3749474T/C del gen CLOCK ha sido asociado a un mayor riesgo de obesidad y quienes portan el alelo T presentan una mayor pérdida de peso ante una dieta baja en carbohidratos y lípidos que quienes poseen la forma CC. Material y métodos: usando la base de datos 1000 Genomes se obtuvo el genotipo del polimorfismo de nucleótido único (SNP) rs3749474 de 2.504 individuos, abarcando cinco macropoblaciones (África, Este Asiático, Sur Asiático, Europa y Latinoamérica) y 26 poblaciones. CT y TT fueron tratados como genotipos de no riesgo y CC, como de riesgo. Se utilizó la prueba exacta de Fisher para comparar las frecuencias de los genotipos de riesgo y no riesgo. Resultados: existe una alta diferenciación para la frecuencia de genotipos portadores del alelo T entre las macropoblaciones: África alcanzó solo el 31,47 %; Europa, un 56,86 %; Latinoamérica, un 66,28 %; el Sur Asiático, un 68,3 %; y el Este Asiático, un 81,15 %, con diferencias significativas (pFisher < 0,05) en todas las comparaciones, excepto entre Latinoamérica y Sur Asiático. Se observó una baja heterogeneidad entre poblaciones dentro de cada macropoblación. Conclusiones: la alta heterogeneidad para las frecuencias genotípicas de CLOCK rs3749474 en las macropoblaciones estudiadas indica que la disminución del consumo de carbohidratos y lípidos tendrá un impacto heterogéneo desde el punto de vista epidemiológico. Esto sugiere incluir la ancestría genética en posteriores estudios de asociación entre ciclos circadianos, conducta alimentaria y obesidad, con el objeto de desarrollar pruebas clínicas personalizadas.

Abstract Introduction: circadian rhythms influence eating behavior, with the CLOCK gene being one of those responsible for its regulation. The rs3749474T/C of the CLOCK gene has been associated with an increased risk of obesity. Those who carry the T allele have greater weight loss on a diet low in carbohydrates and lipids than those who have the CC form. Methodology: using the 1000 Genomes database, the genotype of the single nucleotide polymorphism (SNP) rs3749474 was obtained from 2,504 individuals, covering five macro-populations (Africa, East Asia, South Asia, Europe and Latin America) and 26 populations. CT and TT were treated as non-risk genotypes and CC as risk. Fisher's exact test was used to compare the frequencies of risk and non-risk genotypes among the five macro populations. Results: there is a high differentiation for the frequency of genotypes carrying the T allele among the macro-populations: Africa reached only 31.47 %, Europe 56.86 %; Latin America 66.28 %; South Asia 68.3 % and East Asia 81.15 %, with significant differences (pFisher < 0.05) in all comparisons, except between Latin America and South Asia. Low heterogeneity was observed between populations within each macro population. Conclusions: the high heterogeneity for the genotypic frequencies of CLOCK rs3749474 in the studied macro-populations indicates that the decrease in the consumption of carbohydrates and lipids will have a heterogeneous impact, from the epidemiological point of view. This suggests including the genetic ancestry in later studies of association between circadian cycles, eating behavior and obesity, in order to develop personalized clinical tests.

Abstract The properties of fibre reinforced concrete were studied under monotonic loads according to Japanese, North American and European codes. Two different types of SIKA polypropylene fibre were with different dosages. One hundred and eighty tests were performed, obtaining resistance to compression, tension, bending, toughness, and energy absorption in the hardened state. The results show that the addition of fibres affects the workability of the concrete mix. The increase in fibre dosage does not affect compressive, tensile, or flexural strength. However, the failure changes from brittle to more ductile, allowing it to reach residual strengths of 50% of the maximum reached and 200% deformation. The dissipated energy increased with increasing fibre dosage. The performance achieved by both fibres was similar, although the optimal dosage was 6 kg/m3 for type A fibres and 8 kg /m3 for type B. Therefore, the replacement of flexural reinforcing steel in the foundation slabs of one-story buildings can be performed if adequate dosages are used in compliance with established analytical procedures for industrial floor design.

Abstract A proposal of a semi-rigid self-centering connection for the seismic protection of wooden structures is studied. An analytical model for the characterization of the response of the connection is developed. Quasi-static tests of a wooden column with the proposed connection allowed to validate the model and calibrate its parameters, obtaining errors smaller than 6% between analytical prediction and experimental results. The self-centering capacity and the effectiveness of the connection to limit the loads transmitted to the connected elements were evidenced. Damped free vibration tests evidenced the capacity of the connection to reduce structural vibrations. It was verified that the resistance and dissipation capacity of the connection can be modified by two design parameters that can be adjusted at the assembly. The proposed connection has desirable characteristics for its use in the protection of structural wooden frames, is versatile, and its design is simple, with explicit physical parameters.