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1.
PLoS One ; 19(3): e0295368, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38507347

RESUMEN

The World Health Organization has recommended a range of social and health measures to mitigate the spread of coronavirus disease 2019 (COVID-19), including strategies such as quarantines, border closures, social distancing, and mask usage, among others. Specifically, the Chilean authorities implemented the "step-by-step" plan, built on the concept of dynamic quarantine. Numerous studies have examined the effectiveness of these quarantines in Chile during the pandemic, utilizing data published by the Chilean Ministry of Health. This study's primary aim was to enhance our understanding of quarantine effectiveness in Chile during the pandemic. We accomplished this by analyzing the distributional behavior of the time until the COVID-19 pandemic was deemed under control or not. In our study, we defined an event with two potential outcomes related to the instantaneous reproductive number (Rt), which signifies the time until a change in the event outcome occurs. Importantly, we did not predefine a specific temporal observation unit. These findings allowed us to complement the concept of effective quarantine by considering the dynamics generated by the protocols, such as phase 1 of the quarantine, in achieving natural herd immunity in response to the number of COVID-19 cases and Rt. We assessed the behavior of the mean and median residual lifetime until the initiation of controlled/uncontrolled episodes of the COVID-19 pandemic based on Rt in all regions of Chile. Despite variations in the distribution of residual times for controlled/uncontrolled episodes in different regions, there was a similar observation during the period considered (between March 2020 and March 2021): the mitigation measures did not produce a clear positive effect for controlling the epidemic. The residual times of episodes with Rr,t > 1 were not different from those episodes with Rr,t ≤ 1.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Cuarentena , Pandemias/prevención & control , Chile/epidemiología , SARS-CoV-2
2.
Forensic Sci Int Genet ; 45: 102226, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31884178

RESUMEN

A molecular genetic protocol for distinguishing pure and hybrid South American camelids was developed to provide strong, quantifiable, and unbiased species identification. We detail the application of the approach in the context of a criminal case in the Andes Mountains of central Chile where the defendants were alleged to have illegally hunted three wild guanacos (Lama guanicoe), as opposed to hybrid domestic llama (Lama glama)/wild guanaco crosses, which are unregulated. We describe a workflow that differentiates among wild, domestic and hybrid South American camelids (Lama versus Vicugna) based on mitochondrial cytochrome b genetic variation (to distinguish between Lama and Vicugna), and MC1R and exon 4 variation of the ASIP gene (to differentiate wild from domestic species). Additionally, we infer the population origin and sex of each of the three individuals from a panel of 15 autosomal microsatellite loci and the presence or absence of the SRY gene. Our analyses strongly supported the inference that the confiscated carcasses corresponded with 2 male and 1 female guanacos that were hunted illegally. Statistical power analyses suggested that there was an extremely low probability of misidentifying domestic camelids as wild camelids (an estimated 0 % Type I error rate), or using more conservative approached a 1.17 % chance of misidentification of wild species as domestic camelids (Type II error). Our case report and methodological and analytical protocols demonstrate the power of genetic variation in coat color genes to identify hybrids between wild and domestic camelid species and highlight the utility of the approach to help combat illegal wildlife hunting and trafficking.


Asunto(s)
Pelaje de Animal , Animales Domésticos/genética , Animales Salvajes/genética , Camelidae/genética , Genética Forense/métodos , Variación Genética , Proteína de Señalización Agouti/genética , Animales , Conservación de los Recursos Naturales/legislación & jurisprudencia , Crimen/legislación & jurisprudencia , Citocromos b/genética , ADN Mitocondrial/genética , Exones , Femenino , Genes sry , Masculino , Repeticiones de Microsatélite , Receptor de Melanocortina Tipo 1/genética , Análisis para Determinación del Sexo , América del Sur
3.
Artículo en Español | PAHO-IRIS | ID: phr-34939

RESUMEN

[RESUMEN]. Objetivos. Exponer las ventajas de la utilización del alfa ordinal para situaciones en que no se cumplan los supuestos del alfa de Cronbach y mostrar la utilidad del alfa ordinal con la versión chilena del AUDIT, así como proporcionar los comandos en el lenguaje de programación R para realizar los cálculos respectivos. Métodos. Se compararon el alfa de Cronbach y el alfa ordinal en el caso del cuestionario AUDIT aplicado a 419 estudiantes de una universidad chilena. Resultados. En todos los dominios, el alfa ordinal resultó ser mayor que el alfa de Cronbach, lo que es congruente con lo encontrado en la bibliografía. Al considerar el alfa ordinal se acepta la confiabilidad de cada uno de los dominios y de la encuesta completa, lo que no ocurre completamente al trabajar con el alfa de Cronbach. Conclusiones. Para tomar decisiones sobre la confiabilidad de una dimensión se debe considerar un índice que cumpla los supuestos necesarios para su utilización, ya que no hacerlo puede desembocar en conclusiones erróneas y afectar de manera notable el desarrollo de una investigación. Los valores del alfa de Cronbach subestiman la confiabilidad de un instrumento al trabajar con escalas ordinales.


[ABSTRACT]. Objectives. Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach’s alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. Methods. Cronbach’s alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. Results. In all domains, the result using ordinal alpha was greater than with Cronbach’s alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach’s alpha. Conclusions. In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach’s alpha underestimate the reliability of an instrument when working with ordinal scales.


[RESUMO]. Objetivos. Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. Métodos. Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. Resultados. Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. Conclusões. Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.


Asunto(s)
Consumo de Bebidas Alcohólicas , Estudio de Validación , Reproducibilidad de los Resultados , Chile , Consumo de Bebidas Alcohólicas , Estudio de Validación , Reproducibilidad de los Resultados , Consumo de Bebidas Alcohólicas , Estudio de Validación , Reproducibilidad de los Resultados
4.
Rev Panam Salud Publica ; 42: e65, 2018.
Artículo en Español | MEDLINE | ID: mdl-31093093

RESUMEN

OBJECTIVES: Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach's alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. METHODS: Cronbach's alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. RESULTS: In all domains, the result using ordinal alpha was greater than with Cronbach's alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach's alpha. CONCLUSIONS: In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach's alpha underestimate the reliability of an instrument when working with ordinal scales.


OBJETIVOS: Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. MÉTODOS: Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. RESULTADOS: Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. CONCLUSÕES: Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.

5.
Rev. panam. salud pública ; 42: e65, 2018. tab
Artículo en Español | LILACS | ID: biblio-961816

RESUMEN

RESUMEN Objetivos Exponer las ventajas de la utilización del alfa ordinal para situaciones en que no se cumplan los supuestos del alfa de Cronbach y mostrar la utilidad del alfa ordinal con la versión chilena del AUDIT, así como proporcionar los comandos en el lenguaje de programación R para realizar los cálculos respectivos. Métodos Se compararon el alfa de Cronbach y el alfa ordinal en el caso del cuestionario AUDIT aplicado a 419 estudiantes de una universidad chilena. Resultados En todos los dominios, el alfa ordinal resultó ser mayor que el alfa de Cronbach, lo que es congruente con lo encontrado en la bibliografía. Al considerar el alfa ordinal se acepta la confiabilidad de cada uno de los dominios y de la encuesta completa, lo que no ocurre completamente al trabajar con el alfa de Cronbach. Conclusiones Para tomar decisiones sobre la confiabilidad de una dimensión se debe considerar un índice que cumpla los supuestos necesarios para su utilización, ya que no hacerlo puede desembocar en conclusiones erróneas y afectar de manera notable el desarrollo de una investigación. Los valores del alfa de Cronbach subestiman la confiabilidad de un instrumento al trabajar con escalas ordinales.


ABSTRACT Objectives Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach's alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. Methods Cronbach's alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. Results In all domains, the result using ordinal alpha was greater than with Cronbach's alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach's alpha. Conclusions In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach's alpha underestimate the reliability of an instrument when working with ordinal scales.


RESUMO Objetivos Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. Métodos Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. Resultados Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. Conclusões Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.


Asunto(s)
Humanos , Consumo de Bebidas Alcohólicas , Estudio de Validación , Chile , Reproducibilidad de los Resultados
6.
J Therm Biol ; 69: 110-117, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29037370

RESUMEN

Global climate change will have a greater impact on ectotherms in tropical and subtropical communities than at higher latitudes, because ambient temperatures are closer to the upper thermal limits of species. Amphibian species are highly dependent on external weather conditions, and the effect of global warming on these has been evaluated recently. The Great Chilean frog (Calyptocephalella gayi) is an endemic, monotypic species and genus whose conservation status is considered Vulnerable because of high extraction pressure for human consumption, lack of regulatory measures and comprehension by its consumers. Their populations have also declined due to the loss and destruction of their habitats. C. gayi has not been considered as an object of physiological study, so this large species is not known as one that can adapt to current environmental changes. In this study we analyze the thermoregulatory capacity and thermal efficiency of C. gayi to determine its potential for climatic adaptation. The results indicate that this species is strictly a thermal-conformer; its thermal efficiency and its ability to withstand high temperatures allow it to sustain itself under a climate change scenario, however, it has thermal constraints that do not allow it to withstand temperatures greater than 30°C. By modeling its ontogenetic conditions mathematically, we project that the larvae are not in danger, although there is a group of around 4% which is very close to 30°C, which is the highest temperature recorded for the species. However, about 40% of subadults and approximately 47% of adult frogs will not survive the change of ~7°C projected for the following 85 years, which will affect future generations.


Asunto(s)
Anuros/fisiología , Extinción Biológica , Fósiles , Calentamiento Global , Termotolerancia , Animales , Cambio Climático , Simulación por Computador , Ecosistema , Modelos Biológicos
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