X-ray and gamma ray shielding behavior of concrete blocks

Hernandez-Murillo Christian Geovanni,Molina Contreras J. Rafael,Escalera-Velasco Luis Alberto,de Leon-Martínez Héctor Asael,Rodriguez-Rodriguez José Antonio,Vega-Carrillo Héctor Rene 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8

The shielding characteristics of two concrete blocks, widely used in the building industry in Mexico have been determined. These characteristics include the mass interaction coefficients, the linear attenuation coefficients and the half-value layers. The energy-dispersed X-ray fluorescence shows that the percentage mass content of each atom in the sample, and the atomic volume of the constituent elements of a material, plays an important role in its shielding capabilities. The total linear attenuation coefficients and the half-value layers were analyzed for a set of photon energies related to X-rays for diagnosis and cancer treatment with linear accelerators. Our results show that the concrete blocks have similar photon attenuation coefficients than the Portland concrete and better features than gypsum

Genome and chromosome wide association studies for growth traits in Simmental and Simbrah cattle

Calderón-Chagoya René,Vega-Murillo Vicente Eliezer,García-Ruiz Adriana,Ríos-Utrera Ángel,Martínez-Velázquez Guillermo,Montaño-Bermúdez Moisés 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.1

Objective: The objective of this study was to perform genome (genome wide association studies [GWAS]) and chromosome (CWAS) wide association analyses to identify single nucleotide polymorphisms (SNPs) associated with growth traits in registered Simmental and Simbrah cattle. Methods: The phenotypes were deregressed BLUP EBVs for birth weight, weaning weight direct, weaning weight maternal, and yearling weight. The genotyping was performed with the GGP Bovine 150k chip. After the quality control analysis, 105,129 autosomal SNP from 967 animals (473 Simmental and 494 Simbrah) were used to carry out genotype association tests. The two association analyses were performed per breed and using combined information of the two breeds. The SNP associated with growth traits were mapped to their corresponding genes at 100 kb on either side. Results: A difference in magnitude of posterior probabilities was found across breeds between genome and chromosome wide association analyses. A total of 110, 143, and 302 SNP were associated with GWAS and CWAS for growth traits in the Simmental-, Simbrahand joint -data analyses, respectively. It stands out from the enrichment analysis of the pathways for RNA polymerase (POLR2G, POLR3E) and GABAergic synapse (GABRR1, GABRR3) for Simmental cattle and p53 signaling pathway (BID, SERPINB5) for Simbrah cattle. Conclusion: Only 6,265% of the markers associated with growth traits were found using CWAS and GWAS. The associated markers using the CWAS analysis, which were not associated using the GWAS, represents information that due to the model and priors was not associated with the traits.

Genetic diversity evolution in the Mexican Charolais cattle population

Rios-Utrera, Angel,Montano-Bermudez, Moises,Vega-Murillo, Vicente Eliezer,Martinez-Velazquez, Guillermo,Baeza-Rodriguez, Juan Jose,Roman-Ponce, Sergio Ivan Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.7

Objective: The aim was to characterize the genetic diversity evolution of the registered Mexican Charolais cattle population by pedigree analysis. Methods: Data consisted of 331,390 pedigree records of animals born from 1934 to 2018. Average complete generation equivalent, generation interval, effective population size (N_e), and effective numbers of founders (f_e), ancestors (f_a), and founder genomes (N_g) were calculated for seven five-year periods. The inbreeding coefficient was calculated per year of birth, from 1984 to 2018, whereas the gene contribution of the most influential ancestors was calculated for the latter period. Results: Average complete generation equivalent consistently increased across periods, from 4.76, for the first period (1984 through 1988), to 7.86, for the last period (2014 through 2018). The inbreeding coefficient showed a relative steadiness across the last seventeen years, oscillating from 0.0110 to 0.0145. During the last period, the average generation interval for the father-offspring pathways was nearly 1 yr. longer than that of the mother-offspring pathways. The effective population size increased steadily since 1984 (105.0) and until 2013 (237.1), but showed a minor decline from 2013 to 2018 (233.2). The population displayed an increase in the f_a since 1984 and until 2008; however, showed a small decrease during the last decade. The effective number of founder genomes increased from 1984 to 2003, but revealed loss of genetic variability during the last fifteen years (from 136.4 to 127.7). The f_a:f_e ratio suggests that the genetic diversity loss was partially caused by formation of genetic bottlenecks in the pedigree; in addition, the N_g:f_a ratio indicates loss of founder alleles due to genetic drift. The most influential ancestor explained 1.8% of the total genetic variability in the progeny born from 2014 to 2018. Conclusion: Inbreeding, N_e, f_a, and N_g are rather beyond critical levels; therefore, the current genetic status of the population is not at risk.

Expression of heat shock protein genes in Simmental cattle exposed to heat stress

Guzmán Luis Felipe,Martínez-Velázquez Guillermo,Villaseñor-González Fernando,Vega-Murillo Vicente Eliezer,Palacios-Fránquez José Antonio,Ríos-Utrera Ángel,Montaño-Bermúdez Moisés 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.5

Objective: In tropical, subtropical and arid zones, heat stress is the main cause of productivity reduction in cattle. When climate stressors occur, animals become thermal adapted through differential expression of some genes, including heat shock proteins (HSP) family. The aim of this study was to determine levels of expression of HSP60, HSP70, and HSP90 genes in Simmental cattle raised in tropical environments of Mexico. Methods: In this study, expression of HSP60, HSP70, and HSP90 genes was analyzed in 116 Simmental cattle from three farms with tropical climate located in western Mexico. Animals were sampled twice a day, in the morning and noon. Gene expression was evaluated by quantitative polymerase chain reaction using probes marked with fluorescence. The MIXED procedure of SAS with repeated measures was used for all statistical analysis. Results: HSP60 gene expression differences were found for sex (p = 0.0349). HSP70 gene differences were detected for sampling hour (p = 0.0042), farm (p<0.0001), sex (p = 0.0476), and the interaction sampling hour×farm (p = 0.0002). Gene expression differences for HSP90 were observed for farm (p<0.0001) and year (p = 0.0521). HSP70 gene showed to be a better marker of heat stress than HSP60 and HSP90 genes. Conclusion: Expression of HSP70 gene in Simmental herds of the tropical region of western México was different during early morning and noon, but the expression of the HSP60 and HSP90 genes was similar. Identification of resilient animals to heat stress will be useful in the genetic improvement of the Simmental breed.

Effect of stress during slaughter on carcass characteristics and meat quality in tropical beef cattle

Carrasco-García Apolo A.,Pardío-Sedas Violeta T.,León-Banda Gloria G.,Ahuja-Aguirre Concepción,Paredes-Ramos Pedro,Hernández-Cruz Bertha C.,Murillo Vicente Vega 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.10

Objective: This study aimed to determine the effects of stress during slaughter of beef cattle on physiological parameters, carcass, and meat quality at a Federal Inspection Type slaughterhouse located in the southeast of Mexico. Methods: A total of 448 carcasses of male Zebu×European steers with an average age of 36 months were included. Carcass assessment of presence of bruises and bruise characteristics was carried out on each half-carcass. Blood variable indicators of stress (packed cell volume, neutrophil to lymphocyte ratio, glucose, cortisol concentration) and meat quality parameters (pH, color, shear force, drip loss) were evaluated. Results: Of the 448 carcasses evaluated, 81% of the carcasses showed at least one bruise; one bruise was detected in 36.6% and two bruises in 27.0% of animals. Of the 775 bruises found, 69.2% of the bruises were grade 1 in region 3. Of the 448 carcasses studied, 69.6% showed hyperglycemia (6.91 mmol/L); 44.3% and 22.7% showed high (74.7 ng/mL) and extremely high (108.8 ng/mL) cortisol levels, respectively, indicative of inadequate handling of animals during preslaughter and slaughter. Of the carcasses evaluated, 90.4% had a pH ≥5.8 with an average of pH 6.3. In both pH groups, meat samples showed L* values >37.0 (81.6%) and a shear force >54.3 N; meat pH≥5.8 group showed a drip loss of 2.5%. These findings were indicative of dark, firm, and dry (DFD) meat. According to principal component analysis, grades 1 and 2 bruises in region 3 and grade 1 bruises in region 5 were highly associated with cortisol, drip loss, and color parameters b* and h* and were negatively associated with L*, a*, and C*. Conclusion: The bruises probably caused by stress-inducing situations triggered DFD meat. Appropriate changes in handling routines in operating conditions should be made to minimize stress to animals during the slaughter process to improve animal welfare and meat quality.