Consejo Nacional De Ciencia Y Tecnologia Research Articles

Seroepidemiology of SARS-CoV-2 in Healthcare Personnel Working at the Largest Tertiary COVID-19 Referral Hospitals in Mexico City

Background: We performed a longitudinal SARS-CoV-2 seroepidemiologic study in healthcare personnel of the two largest tertiary referral hospitals in Mexico City. Methods: Participants answered a computer-assisted self-administered interview and donated blood samples for antibody testing every three weeks from October 2020 to June 2021. Findings: 290/883 participants had a positive result in any of the antibody tests, yielding an overall adjusted prevalence in the study period of 33·5%. 235 positive tests were identified at baseline (prevalent cases), the remaining 55 positive tests were incident cases. Prevalent cases showed associations with both occupational (institution 2 vs. 1: adjusted odds ratio [aOR]=2·24, 95% confidence interval [CI]: 1·54, 3·25; laboratory technician vs. medical doctor: aOR=4·38, 95% CI: 1·75, 10·93) and community risk (municipality of residence Xochimilco vs. Tlalpan: aOR=2·03, 95% CI: 1·09, 3·79). The incidence rate was 3·0 cases per 100 person-months. Incident cases were mainly associated with community-acquired risk, due to contact with suspect/confirmed COVID-19 cases (HR=2·45, 95% CI: 1·21, 5·00).Interpretation: We observed similar level of exposure to SARS-CoV-2 in healthcare workers of the two largest tertiary COVID-19 referral centers in Mexico City to the general population. Most variables associated with exposure in this setting pointed toward community rather than occupational risk.Funding: Consejo Nacional de Ciencia y Tecnología (CONACyT) (Fondo FORDECYT-PRONACES) and the Mexican Government (Programa Presupuestal P016; Anexo 13 del Decreto del Presupuesto de Egresos de la Federación).Declaration of Interest: None to declare. Ethical Approval: The study was reviewed and approved by the Institutional Review Boards of both participating institutions.

Power Efficient Simple Technique to Convert a Reset-and-Hold Into a True-Sample-and-Hold Using an Auxiliary Output Stage

This work was supported by a Grant TEC2016-80396-C2 (AEI/FEDER). The work of Hector Daniel Rico-Aniles was supported by the Mexican Consejo Nacional de Ciencia y Tecnologia (CONACYT) through an academic scholarship under Grant 408946.

Effect of Dry Heat Puffing on Nutritional Composition, Fatty Acid, Amino Acid and Phenolic Profiles of Pseudocereals Grains

This work was supported by the Ministry of Economy and Competitiveness (MINECO, Spain) and FEDER programme from the European Commission (grant number AGL2013–43247-R). E. P. acknowledges the MINECO and European Social Fund for her “Ramon y Cajal” grant. L. P-M. acknowledges the Consejo Nacional de Ciencia y Tecnologia (CONCYTEC, Peru) for fi nancial support.

Variants in ARID5B Gene Are Associated with the Development of Acute Lymphoblastic Leukemia in Mexican Children

Introduction: Acute lymphoblastic leukemia (ALL) is the most common subtype of leukemia diagnosed in children under 18 years. According to the statistics of the Popular Medical Insurance Program in Mexico, the ALL incidence is 79.8 cases per million per year, and it is significantly increasing. Recently, several SNPs of ARID5B gene have been associated with ALL susceptibility and are more strongly related with ALL risk in Hispanics. However, these observations are not necessarily representative of the situation in Mexico, since the proportion of Mexican patients included in these studies is unknown. It is essential for us to know if the genetic variants of ARID5B confer susceptibility to the development of the disease in our population and if these variants contribute to the higher incidence of childhood ALL in Mexico.Aim: The purpose of this study was to determine the association between the SNPs rs10821936, rs10994982, rs7089424, rs2393732, rs2393782, rs2893881, and rs4948488 of ARID5B gene with the susceptibility to develop ALL in Mexican children.Methods: The study included 384 controls and 298 children with ALL recruited at Instituto Nacional de Pediatria in Mexico city and Hospital de Especialidades Pediatricas de Tuxtla Gutierrez, Chiapas, Mexico. This study was reviewed and approved by the Institutional Research and Ethics Committees from both participant Institutions in accordance to the ethical principles of the Declaration of Helsinki. Volunteers, parents, or legal tutors of patients were previously informed about the study, and before the biological samples were collected, they provided a signed, written informed consent letter to participate. Genomic DNA was extracted from peripheral blood and saliva samples. Genotyping analysis was performed by real-time polymerase chain reaction (RT-PCR) using a pre-designed TaqMan assay for 7 SNPs (rs10821936, rs10994982, rs7089424, rs2393732, rs2393782, rs2893881, and rs4948488) of ARID5B. Genotypic and allelic frequencies were calculated to compare the differences between controls and patients (Fisher's exact test). The odds ratio (OR) was calculated to determine the association between SNPs and ALL susceptibility. Ancestry analysis was conducted for controls and patients (STRUCTURE program), and Haplotype analysis (Haploview program).Results: The estimated proportion of Native American and European ancestry was not statistically different between controls and patients; all SNPs in ARID5B were in Hardy-Weinberg equilibrium. The frequency of the risk alleles was higher in patients than in controls, but only 3 SNPs showed statistically significant differences (p<0.05). The SNPs rs10821936, rs10994982, and rs7089424 were associated with ALL and pre-B ALL susceptibility, and rs2393732 was specifically associated with pre-B ALL. No association betwwen SNPs of ARID5B gene and T-ALL was found. The CAG haplotype (rs10821936, rs10994982, and rs7089424) was strongly associated with ALL risk in our population. The SNPs rs10821936, rs10994982, rs7089424, and rs2393732 were significantly associated with an increased risk for developing childhood ALL, specifically pre-B ALL.Conslusions: The frequency of the risk alleles was higher than in Hispanic children with ALL.Each SNP of ARID5B confers an individual effect on the risk for developing the disease, and the CAG haplotype was strongly associated with ALL susceptibility.The genetic background of our population could be positively influencing the susceptibility to ALL development, specifically pre-B ALL.The SNPs rs10821936, rs10994982, rs7089424 and rs2393732 of ARID5B gene are significantly associated with an increased risk to develop childhood ALL and this could also explain in part the high incidence of childhood ALL in Mexico.Acknowledgments: This work was supported by the grants from Fondos del Presupuesto Federal para la Investigación (project 085/2012), Consejo Nacional de Ciencia y Tecnologia (CONACyT) - Desarrollo Cientifico para Atender Problemas Nacionales (project 216163), and in part by the Intramural Program of the National Cancer Institute.Conflict-of-interest disclosure: The authors state that there are no conflicts of interest. DisclosuresNo relevant conflicts of interest to declare.

Orange juice processing using a continuous flow ultrasound-assisted supercritical CO 2 system: Microbiota inactivation and product quality

This work was supported by the PROMETEOII\2014\005 project financed by the Generalitat Valenciana (Conselleria d'Educacio, Cultura i Esport, Valencia, Spain). The authors acknowledge the Consejo Nacional de Ciencia y Tecnologia (CONACyT) for the scholarship awarded to PhD Student Paniagua-Martinez, I.

Historical biogeography of Florestina (Asteraceae: Bahieae) of dry environments in Mexico: evaluating models and uncertainty in low-diversity clades

F.S.-T. wishes to thank the Posgrado en Ciencias Biologicas and the Programa de Becas Posdoctorales both at UNAM for continuous support throughout this research. This work was also supported by Consejo Nacional de Ciencia y Tecnologia (CONACYT) through a Doctoral Dissertation grant (171389). N.J.M. was supported by the National Institute for Mathematical and Biological Synthesis, an Institute sponsored by the National Science Foundation, the U.S. Department of Homeland Security and the U.S. Department of Agriculture through NSF Award #EFJ0832858, with additional support from The University of Tennessee, Knoxville. N.J.M. was also funded by the Australian Research Council’s Discovery Early Career Researcher Award #DE150101773, and by The Australian National University. F.S.T. was supported by two Short-Term Visitor grants from NIMBioS in 2014 and 2015. K.A.M. was supported by the National Institutes of Health Program for Excellence and Equity in Research Grant [R25 5R25GM086761-06] and the Ecology and Evolutionary Biology Department at the University of Tennessee, Knoxville.

ChemInform Abstract: First Practical and Efficient Synthesis of 3‐Phosphorylated β‐Carboline Derivatives Using the Pictet—Spengler Reaction.

The authors are thankful for financial support by the Mexican Consejo Nacional de Ciencia y Tecnologia (CONACYT) for financial support via project 181816, by the Spanish Ministerio de Ciencia e Innovacion (MICINN), FEDER (grant number CTQ2010- 17436) and by the Gobierno de Aragon-FSE (research group E40). J. L. V.-C. also thank CONACYT for graduate scholarships.

DNA Barcoding of Mammals in Mexico: Implications for Biodiversity

The Mexican Barcode of Life (MEXBOL) project started as an initiative by researchers who wanted Mexico to join the international DNA barcoding (iBOL) collaboration to establish a genetic system of species identification and discovery. MEXBOL has three main nodes associated with different research institutions in the northern, central, and southern parts of the country. At the beginning of 2009, the laboratories of the three nodes began to operate with support from the University of Guelph in Canada where DNA barcoding began in 2003. By the end of 2011, the laboratories in Mexico will be completely equipped and fully operational. The project is funded by the Consejo Nacional de Ciencia y Tecnologia (CONACyT). In addition, the steering committee of MEXBOL supports the Comision Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO) initiative to offer grants to any university and research center for barcoding collections of Mexican specimens. We present preliminary results of projects dealing with barcoding Mexican mammals. The aims of these analyses are to evaluate the importance of the DNA barcoding (using cytochrome c oxidase subunit I gene; COI) for the identification of species, study of genetic diversity, and taxonomic review. Our preliminary data suggest that DNA barcodes can be used for the discovery of cryptic species and have important implications to the understanding of the mega-diversity of mammals in Mexico.

Toward a Mexican eddy covariance network for carbon cycle science

First Annual MexFlux Principal Investigators Meeting; Hermosillo, Sonora, Mexico, 4–8 May 2011; The carbon cycle science community has organized a global network, called FLUXNET, to measure the exchange of energy, water, and carbon dioxide (CO2) between the ecosystems and the atmosphere using the eddy covariance technique. This network has provided unprecedented information for carbon cycle science and global climate change but is mostly represented by study sites in the United States and Europe. Thus, there is an important gap in measurements and understanding of ecosystem dynamics in other regions of the world that are seeing a rapid change in land use. Researchers met under the sponsorship of Red Temática de Ecosistemas and Consejo Nacional de Ciencia y Tecnologia (CONACYT) to discuss strategies to establish a Mexican eddy covariance network (MexFlux) by identifying researchers, study sites, and scientific goals. During the meeting, attendees noted that 10 study sites have been established in Mexico with more than 30 combined years of information. Study sites span from new sites installed during 2011 to others with 9 to 6 years of measurements. Sites with the longest span measurements are located in Baja California Sur (established by Walter Oechel in 2002) and Sonora (established by Christopher Watts in 2005); both are semiarid ecosystems. MexFlux sites represent a variety of ecosystem types, including Mediterranean and sarcocaulescent shrublands in Baja California; oak woodland, subtropical shrubland, tropical dry forest, and a grassland in Sonora; tropical dry forests in Jalisco and Yucatan; a managed grassland in San Luis Potosi; and a managed pine forest in Hidalgo. Sites are maintained with an individual researcher's funds from Mexican government agencies (e.g., CONACYT) and international collaborations, but no coordinated funding exists for a long‐term program.

A SIMPLE TEST OF NORMALITY FOR TIME SERIES

This paper considers testing for normality for correlated data. The proposed test procedure employs the skewness-kurtosis test statistic, but studentized by standard error estimators that are consistent under serial dependence of the observations. The standard error estimators are sample versions of the asymptotic quantities that do not incorporate any downweighting, and, hence, no smoothing parameter is needed. Therefore, the main feature of our proposed test is its simplicity, because it does not require the selection of any user-chosen parameter such as a smoothing number or the order of an approximating model.We are very grateful to Don Andrews and two referees for useful comments and suggestions. We are especially thankful to a referee who provided a FORTRAN code. Lobato acknowledges financial support from Asociacion Mexicana de Cultura and from Consejo Nacional de Ciencia y Tecnologia (CONACYT) under project grant 41893-S. Velasco acknowledges financial support from Spanish Direccion General de Ensenanza Superior, BEC 2001-1270.

Influence of Feed Intake Fluctuation, Feeding Frequency, Time of Feeding, and Rate of Gain on Performance by Limit-Fed Steers11The authors gratefully acknowledge the support of the New Mexico State Univ. Agric. Exp. Stn., Las Cruces, NM 88003. S. A. Soto-Navarro was sponsored by CONSEJO NACIONAL DE CIENCIA y TECNOLOGIA (CONACyT), Mexico, DF. Appreciation is also expressed to Elanco Animal Health,

Abstract Four experiments were conducted to determine the effects of feed intake fluctuation, feeding frequency, time of feeding, and rate of gain on performance by limit-fed steers. Mean initial BW for steers in Experiments 1, 2, 3, and 4 were 378 ± 43, 225 ± 19, 227 ± 20, and 249 ± 17 kg, respectively. All experiments were complete random designs, and pen was the experimental unit. In Experiment 1, 10% daily variation in feed intake resulted in decreased (P 0.10) ADG or G/F. Average daily gain and G/F by steers programed to gain 1.25 kg/d were not affected (P>0.10) by 10% fluctuation in feed intake or twice daily feeding in Experiment 3. Treatments used in Experiment 4 consisted of 1) steers fed to gain 0.9 kg/d, 2) steers fed to gain 0.9 kg/d with 10% daily feed intake fluctuation, 3) steers fed to gain 1.25 kg/d, and 4) steers fed to gain 1.25 kg/d with 10% daily feed intake fluctuation. Fluctuation in feed intake did not affect (P>0.10) ADG at either rate of gain. Results suggest that feed intake fluctuation in limit-fed cattle might decrease performance early in the feeding period; however, cattle seem to adapt to fluctuating feed intake as the feeding period progresses. Time and frequency of feeding did not affect performance by limit-fed steers.