Aumento de la conducta operante tras la presentación de estímulos condicionados asociados al efecto del etanol

Previous studies have shown that stimuli associated with drugs canacquire motivational proprieties, which allow them to control operantbehavior for drug consumption/seeking and other types of reward.The current research investigated whether a conditioned stimulus(CS) that has been paired with ethanol is able to disrupt the rate ofresponding for a reward. A Pavlovian instrumental transfer experimentwas conducted with albino rats. The experimental group receivedpaired presentations of the CS (i.e, tone) and the unconditionedstimulus (US) (i.e., the effects of ethanol). Subjects in the controlgroup received random presentations of the US and the CS. The rateof operant behavior for food seeking in both the presence and theabsence of the CS was determined for the subjects. The results showthat a CS associated with ethanol increased the rate of responding forfood.    Estudios previos señalan que estímulos externos asociados a drogas adquieren propiedades motivacionales que llegan a controlar la respuesta operante de búsqueda/consumo de droga y otro tipo de recompensas. La presente investigación tiene como objetivo demostrar que los ECs asociados al efecto del etanol adquieren propiedades motivacionales modificando la tasa de respuesta operante para la obtención de comida. Para ello se realizó un experimento de transferencia de control con ratas albinas. Al grupo experimental se le hicieron presentaciones contingentes del EC (tono) y el estímulo incondicionado (EI) (i.e., efecto del etanol). Los sujetos del grupo control tuvieron exposiciones aleatorias EC/EI. Posteriormente se comparó la tasa de respuesta operante para la búsqueda de comida frente al EC al etanol en el grupo experimental y control. Los resultados indican que los ECs asociados al efecto del etanol aumentan la respuesta operante frente a reforzadores naturales

Reconstructing Native American population history

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call First American. However, speakers of Eskimog-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America. © 2012 Macmillan Publishers Limited. All rights reserved.Fil: Reich, David. Harvard Medical School; Estados Unidos. Massachusetts Institute of Technology; Estados UnidosFil: Patterson, Nick. Massachusetts Institute of Technology; Estados UnidosFil: Campbell, Desmond. Colegio Universitario de Londres; Reino Unido. The University Of Hong Kong; Hong KongFil: Tandon, Arti. Harvard Medical School; Estados Unidos. Massachusetts Institute of Technology; Estados UnidosFil: Mazieres, Stéphane. Colegio Universitario de Londres; Reino UnidoFil: Ray, Nicolas. Universidad de Ginebra; SuizaFil: Parra, Maria V.. Colegio Universitario de Londres; Reino Unido. Universidad de Antioquia; ColombiaFil: Rojas, Winston. Colegio Universitario de Londres; Reino Unido. Universidad de Antioquia; ColombiaFil: Duque, Constanza. Universidad de Antioquia; Colombia. Colegio Universitario de Londres; Reino UnidoFil: Mesa, Natalia. Universidad de Antioquia; Colombia. Colegio Universitario de Londres; Reino UnidoFil: García, Luis F.. Universidad de Antioquia; ColombiaFil: Triana, Omar. Universidad de Antioquia; ColombiaFil: Blair, Silvia. Universidad de Antioquia; ColombiaFil: Maestre, Amanda. Universidad de Antioquia; ColombiaFil: Dib, Juan C.. Fundación Salud Para El Tró Pico; ColombiaFil: Bravi, Claudio Marcelo. Colegio Universitario de Londres; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Bailliet, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Corach, Daniel. Universidad de Buenos Aires; ArgentinaFil: Hünemeier, Tábita. Colegio Universitario de Londres; Reino Unido. Universidade Federal do Rio Grande do Sul; BrasilFil: Bortolini, Maria Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Salzano, Francisco M.. Universidade Federal do Rio Grande do Sul; BrasilFil: Petzl Erler, María Luiza. Universidade Federal do Paraná; BrasilFil: Acuña Alonzo, Victor. National Institute Of Anthropology And History; MéxicoFil: Aguilar Salinas, Carlos. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Canizales-Quinteros, Samuel. Universidad Nacional Autónoma de México; MéxicoFil: Tusié Luna, Teresa. Universidad Nacional Autónoma de México; MéxicoFil: Riba, Laura. Universidad Nacional Autónoma de México; MéxicoFil: Rodríguez Cruz, Maricela. Umae Hospital de Pediatría Centro Medico Nacional Siglo Xxi; MéxicoFil: Lopez Alarcón, Mardia. Umae Hospital de Pediatría Centro Medico Nacional Siglo Xxi; MéxicoFil: Coral Vazquez, Ramón. Instituto Politécnico Nacional; Méxic

Reconstructing Native American Population History

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America

Aumento de la conducta operante tras la presentación de estímulos condicionados asociados al efecto del etanol

Previous studies have shown that stimuli associated with drugs canacquire motivational proprieties, which allow them to control operantbehavior for drug consumption/seeking and other types of reward.The current research investigated whether a conditioned stimulus(CS) that has been paired with ethanol is able to disrupt the rate ofresponding for a reward. A Pavlovian instrumental transfer experimentwas conducted with albino rats. The experimental group receivedpaired presentations of the CS (i.e, tone) and the unconditionedstimulus (US) (i.e., the effects of ethanol). Subjects in the controlgroup received random presentations of the US and the CS. The rateof operant behavior for food seeking in both the presence and theabsence of the CS was determined for the subjects. The results showthat a CS associated with ethanol increased the rate of responding forfood.    Estudios previos señalan que estímulos externos asociados a drogas adquieren propiedades motivacionales que llegan a controlar la respuesta operante de búsqueda/consumo de droga y otro tipo de recompensas. La presente investigación tiene como objetivo demostrar que los ECs asociados al efecto del etanol adquieren propiedades motivacionales modificando la tasa de respuesta operante para la obtención de comida. Para ello se realizó un experimento de transferencia de control con ratas albinas. Al grupo experimental se le hicieron presentaciones contingentes del EC (tono) y el estímulo incondicionado (EI) (i.e., efecto del etanol). Los sujetos del grupo control tuvieron exposiciones aleatorias EC/EI. Posteriormente se comparó la tasa de respuesta operante para la búsqueda de comida frente al EC al etanol en el grupo experimental y control. Los resultados indican que los ECs asociados al efecto del etanol aumentan la respuesta operante frente a reforzadores naturales

Aumento de la conducta operante tras la presentación de estímulos condicionados asociados al efecto del etanol

Estudios previos señalan que estímulos externos asociados a drogas adquieren propiedades motivacionales que llegan a controlar la respuesta operante de búsqueda/consumo de droga y otro tipo de recompensas. La presente investigación tiene como objetivo demostrar que los ECs asociados al efecto del etanol adquieren propiedades motivacionales modificando la tasa de respuesta operante para la obtención de comida. Para ello se realizó un experimento de transferencia de control con ratas albinas. Al grupo experimental se le hicieron presentaciones contingentes del EC (tono) y el estímulo incondicionado (EI) (i.e., efecto del etanol). Los sujetos del grupo control tuvieron exposiciones aleatorias EC/EI. Posteriormente se comparó la tasa de respuesta operante para la búsqueda de comida frente al EC al etanol en el grupo experimental y control. Los resultados indican que los ECs asociados al efecto del etanol aumentan la respuesta operante frente a reforzadores naturales

The Comparative Analysis of Two RT-qPCR Kits for Detecting SARS-CoV-2 Reveals a Higher Risk of False-Negative Diagnosis in Samples with High Quantification Cycles for Viral and Internal Genes

The early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the real-time quantitative polymerase chain reaction (RT-qPCR) as a gold-standard molecular tool has allowed to test and trace the viral spread and the isolation of COVID-19-infected patients. The detection capacity of viral and internal genes is an essential parameter to consider and analyze during the assay. In this study, we analyze the performance of the two commercial RT-qPCR kits used in Chile, TaqMan™ 2019-nCoV Control Kit v1 (Thermo Fisher) and MaxCov19 (TAAG Genetics), for the COVID-19 diagnosis from nasopharyngeal swab samples (NPSs). Our results show a lower sensitivity of the TAAG kit compared to the Thermo Fisher kit, even in the detection of SARS-CoV-2 mutations associated with its variants. This study reinforces the relevance of evaluating the performance of RT-qPCR kits before being used massively since those with lower sensitivity can generate false negatives and produce outbreaks of local infections

Corrigendum: Reconstructing Native American population history

No abstract available

Reconstructing Native American population history.

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America