Construcción de un densímetro operado magnéticamente

Se diseñó y construyó un densímetro operado magnéticamente, el cual permite determinar la densidad de una solución con precisión hasta la quinta cifra decimal. En el diseno se tuvo en cuenta la posibilidad de poder armar y desarmar fácilmente las diferentes piezas que constituyen el densímetro, con el objeto de cambiar la bobina principal y asi aumentar el rango de las densidades que se pueden medir. La calibración del densímetro se realizó mediante anillos de platino y soluciones de cloruro de sodio. Igualmente, se diseñó, construyó y montó un sistema para el control de temperatura, el cual no presentó desviaciones mayores de 10,006°C a 25°C

Extrapolación a dilución infinita del volumen molar aparente de sales de amonio cuaternario en soluciones acuosas diluidas

Se midieron las densidades a 25,000 ± 0,006°C de soluciones acuosas diluidas de los yoduros de bencil trimetll amonio y dimetil dibencil amonio, e mpleando un densímetro de flotación magnética. Se calcularon los volúmenes molares aparentes 0v S^ obtuvieron volúmenes molares parciales a dilución infinita, extrapolando los valores de 0 ^ mediante la ecuación de Redlich y Meyer yj—°y + S^y^c-Fb^c,sin el término bvc. El cambio progresivo de un grupo metilo por un grupo bencilo en el yoduro de tetrametll amonio produce un incremento en el volumen parcial molar a dilución infinita de 64,4 ml/mol para las sales estudiadas

Population structure and connectivity of the mountainous star coral, Orbicella faveolata , throughout the wider Caribbean region

As coral reefs continue to decline worldwide, it becomes ever more necessary to understand the connectivity between coral populations to develop efficient management strategies facilitating survival and adaptation of coral reefs in the future. Orbicella faveolata is one of the most important reef-building corals in the Caribbean and has recently experienced severe population reductions. Here, we utilize a panel of nine microsatellite loci to evaluate the genetic structure of O. faveolata and to infer connectivity across ten sites spanning the wider Caribbean region. Populations are generally well-mixed throughout the basin (FST = 0.038), although notable patterns of substructure arise at local and regional scales. Eastern and western populations appear segregated with a genetic break around the Mona Passage in the north, as has been shown previously in other species; however, we find evidence for significant connectivity between Curaçao and Mexico, suggesting that the southern margin of this barrier is permeable to dispersal. Our results also identify a strong genetic break within the Mesoamerican Barrier Reef System associated with complex oceanographic patterns that promote larval retention in southern Belize. Additionally, the diverse genetic signature at Flower Garden Banks suggests its possible function as a downstream genetic sink. The findings reported here are relevant to the ongoing conservation efforts for this important and threatened species, and contribute to the growing understanding of large-scale coral reef connectivity throughout the wider Caribbean

Population structure and connectivity of the mountainous star coral, Orbicella faveolata , throughout the wider Caribbean region

As coral reefs continue to decline worldwide, it becomes ever more necessary to understand the connectivity between coral populations to develop efficient management strategies facilitating survival and adaptation of coral reefs in the future. Orbicella faveolata is one of the most important reef-building corals in the Caribbean and has recently experienced severe population reductions. Here, we utilize a panel of nine microsatellite loci to evaluate the genetic structure of O. faveolata and to infer connectivity across ten sites spanning the wider Caribbean region. Populations are generally well-mixed throughout the basin (FST = 0.038), although notable patterns of substructure arise at local and regional scales. Eastern and western populations appear segregated with a genetic break around the Mona Passage in the north, as has been shown previously in other species; however, we find evidence for significant connectivity between Curaçao and Mexico, suggesting that the southern margin of this barrier is permeable to dispersal. Our results also identify a strong genetic break within the Mesoamerican Barrier Reef System associated with complex oceanographic patterns that promote larval retention in southern Belize. Additionally, the diverse genetic signature at Flower Garden Banks suggests its possible function as a downstream genetic sink. The findings reported here are relevant to the ongoing conservation efforts for this important and threatened species, and contribute to the growing understanding of large-scale coral reef connectivity throughout the wider Caribbean

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Data from: Species delimitation of common reef corals in the genus Pocillopora using nucleotide sequence phylogenies, population genetics, and symbiosis ecology

No description availabl

Síntesis de los yoduros trimetilbencilamonio-amonio y dibencilamonio

Se sintetizó el yoduro de trimetilbencilamono por metllaclón exhastiva de la amina primarla. La dimetilbencilamina se preparó mediante la reacción de la amina primarla con formaldehído y ácido acético. La reacción entre la dimetilbencilamina y el cloruro de bencllo produjo el cloruro de dimetilbencilamonio, cuyo ion cloruro fue Intercambiado por el ion yoduro empleando una resina de Intercambio Iónico. Las sales fueron caracterizadas por espectroscopia de resonancia magnética nuclear, punto de fusión y titulación potenclométrica del Ion yoduro con nitrato de plata

psbA_miniCircle_Pocillopora_Sym

Nexus file with the alignment of the psbA minicircle sequences from Symbiodinium found in association with Pocillopora corals in the Eastern Pacific

Construcción de un densímetro operado magnéticamente

<span style="font-size: xx-small; font-family: Arial;"><span style="font-size: xx-small; font-family: Arial;"><p align="left">Se diseñó y construyó un densímetro operado magnéticamente, el cual permite determinar la densidad de una solución con precisión hasta la quinta cifra decimal. En el diseno se tuvo en cuenta la posibilidad de poder armar y desarmar fácilmente las diferentes piezas que constituyen el densímetro, con el objeto de cambiar la bobina principal y asi aumentar el rango de las densidades que se pueden medir. La calibración del densímetro se realizó mediante anillos de platino y soluciones de cloruro de sodio. Igualmente, se diseñó, construyó y montó un sistema para el control de temperatura, el cual no presentó desviaciones mayores de 10,006°C a 25°C.</p></span></span