On the radioecological issues of natural radionuclides in water and sediment of a highly contaminated lagoon from Mexico

Se han determinado las concentraciones de actividad de radionucleidos naturales en el agua y los sedimentos de la laguna El Pedernalillo, Zacatecas, México

Áreas potenciales para plantaciones de Agave angustifolia Haw en Guerrero, México

Objective: To determine optimum and suboptimal areas for the establishment of plantations of Agave angustifolia Haw. in the state of Guerrero. Design/methodology/approach: A collection of 139 specimens of A. angustifolia was carried out, obtaining for each specimen phenotypic, agroclimatic and agroecological data. The information of 30 specimens of herbarium was consulted. Interviews were conducted with the representatives of the state council of mezcal in Guerrero, the company Sanzekan Tinemi and Mezcalli del Sur, to complement the information of the areas. A database was created where the information of each copy was included, as well as the information obtained from the interviews. Criteria for selecting potential areas of A. angustifoliawere defined, after which a Geographic Information Systems (GIS) was constructed, generating mapping areas with agroclimatic and agro potential, wherein the optimal suboptimal and marginal areas for the establishment of A. angustifolia were delineated. For the validation of the information, field visits were made to specific sites to verify the agroecological conditions of the potential areas obtained in this research. Results: There are approximately 1,020,998.27 ha with optimum aptitude and 618,015.87 ha with suboptimal aptitude. Limitations on study/implications: We suggest to incorporate information referring to the physiology, productivity and genetic diversity of the native populations of A. angustifolia. Findings/conclusions: The regions with the highest and suboptimal potential for the plantations of A. angustifolia are Norte, Tierra Caliente and Centro, where the largest production of mezcal in the state occurs.  Objetivo: Determinar áreas optimas y subóptimas para establecer plantaciones de Agave angustifolia Haw. en el estado de Guerrero, México. Diseño/metodología/aproximación: Se recolectaron 139 ejemplares de A. angustifolia, para cada ejemplar se registraron datos fenotípicos, agroclimáticos y agroecológicos. Se consultó la información de 30 ejemplares de herbario; además se entrevistaron a los representantes del Consejo Estatal del Mezcal en Guerrero, la empresa Sanzekan Tinemi y la empresa Mezcalli del Sur, para complementar la información de las áreas. Se generó una base de datos donde se incluyó la información de cada ejemplar, así como la obtenida de entrevistas. Se definieron criterios para la selección de áreas potenciales de A. angustifolia, después de lo cual se construyó un Sistema de Información Geográfica (SIG),generando la cartografía de las áreas con potencial agroclimático y agroecológico, donde se delimitaron las áreas optimas, subóptimas y marginales, para el establecimiento de A. angustifolia. Para la validación de la información, se realizaron visitas de campo a sitios específicos para verificar las condiciones agroecológicas de las áreas potenciales obtenidas en el presente trabajo. Resultados: Los resultados indican que existen aproximadamente 1,020,998.27 ha con aptitud óptima y 618,015.87 ha con aptitud subóptima. Limitaciones del estudio/implicaciones: se sugiere incorporar información referente a la fisiología, productividad y diversidad genética de las poblaciones nativas de A. angustifolia. Hallazgos/conclusiones: Las regiones con mayor potencial optimo y subóptimo para las plantaciones de A. angustifolia son Norte, Tierra Caliente y Centro, donde además se presenta la mayor producción de mezcal en el estado

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

Measurement of activity concentration of polonium-210 in species of the phylum Mollusca, Tabasco, Mexico

The activity concentration of polonium-210 in the soft tissue of several species of mollusks of coastal areas from Tabasco, Mexico, has been determined. Polonium-210 is a natural radionuclide that may be bioaccumulated by flora and fauna, particularly by mollusks. Radioecological evaluation of polonium-210 in mollusks is of particular interest for environmental radioactivity surveillance and to understand the mechanisms of migration of this radionuclide from the environment to humans. In this work, an analysis of the levels of polonium-210 in mollusks from Mexico is presented. Methods include the use of alpha-particle spectrometry to measure polonium-210 in the soft tissue of the studied mollusks. Results show an average value of 158 Bq/kg in mollusks from Tabasco, Mexico. Mollusks from the taxonomic class Bivalvia bioaccumulate more polonium-210 than Gastropods. The activity concentration values of polonium-210 in mollusks from Mexico are of the same order as those reported internationally. A further work on the mechanisms of migration and bioaccumulation of polonium in these organisms is necessary.Consejo Nacional de Ciencia y Tecnología (Scholarship: 454803; CVU: 269695

383 A/C tumor necrosis factor receptor 1 polymorphism and ankylosing spondylitis in Mexicans: A preliminary study

The objective of this study was to evaluate the differences in allele and genotype frequencies of -383 tumor necrosis factor receptor 1 (TNFR1) polymorphism between ankylosing spondylitis (AS) and controls. Mexican Mestizos with AS were matched by gender, age, and ethnicity with healthy controls and compared in allele and genotype frequencies of the -383 TNFR1 polymorphism. Polymorphisms were genotyped using PCR-RFLP. The AA genotype occurred at a higher frequency in the AS group (92%) compared with controls (79%, P = 0.03). A allele was increased in AS (96% vs. 88%, P = 0.015) and was associated with genetic susceptibility for AS (odds ratio = 3.48, 95% CI = 1.23-10.61). This preliminary study is the first assessing the association of the -383 A/C TNFR1 polymorphism with AS, although it has the limitation of a small sample size. These data are of interest for the genetic epidemiology of AS in the Mexican population, requiring further investigation in other countries. © Springer-Verlag 2011

<em>De novo</em> and inherited pathogenic variants in <em>KDM3B</em> cause intellectual disability, short stature, and facial dysmorphism.

By using exome sequencing and a gene matching approach, we identified de novo and inherited pathogenic variants in KDM3B in 14 unrelated individuals and three affected parents with varying degrees of intellectual disability (ID) or developmental delay (DD) and short stature. The individuals share additional phenotypic features that include feeding difficulties in infancy, joint hypermobility, and characteristic facial features such as a wide mouth, a pointed chin, long ears, and a low columella. Notably, two individuals developed cancer, acute myeloid leukemia and Hodgkin lymphoma, in childhood. KDM3B encodes for a histone demethylase and is involved in H3K9 demethylation, a crucial part of chromatin modification required for transcriptional regulation. We identified missense and truncating variants, suggesting that KDM3B haploinsufficiency is the underlying mechanism for this syndrome. By using a hybrid facial-recognition model, we show that individuals with a pathogenic variant in KDM3B have a facial gestalt, and that they show significant facial similarity compared to control individuals with ID. In conclusion, pathogenic variants in KDM3B cause a syndrome characterized by ID, short stature, and facial dysmorphism