Medium Lethal Dose of Gamma Rays to Induce Mutations in Caribgrass (Eriochloa polystachya Kunth)

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción AnimalLos rayos gamma se pueden utilizar para el mejoramiento genético de las plantas y generar mutaciones que puedan ser útiles. La investigación se realizó con el objetivo de determinar la dosis letal media (DL50) para inducir mutaciones, con radiación gamma, en pasto janeiro (Eriochloa polystachya Kunth). Métodos: Se irradiaron 8 600 estolones de 8 cm de largo con un nudo, cortados de plantas maduras de más de seis meses de edad con dosis de 0; 25; 50; 75 y 100 Gray de rayos gamma Co60. Se evaluó el porcentaje de establecimiento, altura de planta y mortalidad de los estolones. Los datos fueron analizados a través del análisis de regresión lineal probabilística. Resultados: De acuerdo con la variable porcentaje de establecimiento, la DL50, es igual a 52,60 Gy para el genotipo estudiado, con R2 de 57,73. Conclusiones: Se concluye que la dosis media letal para inducir mutaciones en el pasto Janeiro (Eriochloa polystachya Kunth) se obtuvo con 52,60 Gy con R2 de 57,73.Gamma radiation can be used for genetic breeding of plants, and to produce useful mutations. This research was performed in order to determine the medium lethal dose (LD50) of gamma radiation in Caribgrass (Eriochloa polystachya Kunth). Methods: Overall, 8 600 stolons measuring 8 cm long, bearing a node, were cut from mature plants (over six month old), and were radiated with doses of 0, 25, 50, 75, and 100 Gray of gamma rays Co60. The establishment percentage, plant height, and stolon mortality were evaluated. The data were analyzed by probabilistic linear regression analysis. Results: According to variable percentage of establishment, LD50 was equal to 52.60 Gy, in the genotype studied, with an R2 of 57.73. Conclusions: The medium lethal dose to induce mutations of Caribgrass (Eriochloa polystachya Kunth) was achieved with 52.60 Gy

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Cross-cultural invariance of the Spanish version of the COVID-19 Assessment Scorecard to measure the perception of government actions against COVID-19 in Latin America

Objectives: The present study aimed to evaluate the measurement invariance of a general measure of the perception of governmental responses to COVID-|19 (COVID-SCORE-10) in the general population of 13 Latin American countries. Methods: A total of 5780 individuals from 13 Latin American and Caribbean countries selected by non-probabilistic snowball sampling participated. A confirmatory factor analysis was performed and the alignment method was used to evaluate invariance. Additionally, a graded response model was used for the assessment of item characteristics. Results: The results indicate that there is approximate measurement invariance of the COVID-SCORE-10 among the participating countries. Furthermore, IRT results suggest that the COVID-SCORE-10 measures with good psychometric ability a broad spectrum of the construct assessed, especially around average levels. Comparison of COVID-SCORE-10 scores indicated that participants from Cuba, Uruguay and El Salvador had the most positive perceptions of government actions to address the pandemic. Thus, the underlying construct of perception of government actions was equivalent in all countries. Conclusion: The results show the importance of initially establishing the fundamental measurement properties and MI before inferring the cross-cultural universality of the construct to be measured

Test of invariance of the anomie brief scale with the alignment method in 12 Latin American countries

The Social Anomie Brief Scale (SAS10) is a self-report measure of social anomie against new social standards implemented during the current COVID-19 pandemic. The main objective of this study was to evaluate the invariance of the cross-cultural measurement of the SAS10 in a sample of 12 Latin American countries. Additionally, the difficulty and discrimination characteristics of the items were evaluated using the IRT and social anomie was compared between the participating countries. A total of 4,911 people from 12 Latin American countries (Argentina, Bolivia, Chile, Colombia, Cuba, Ecuador, Guatemala, Mexico, Paraguay, Peru, Uruguay, and Venezuela) selected by non-probabilistic snowball sampling participated. The results indicated that the original two-factor model of the SAS10 shows estimation problems and low fit indices in several countries. However, a model of two related dimensions (behavioral and affective) of nine items (SAS-9) presented adequate fit indices in all countries. This model presents adequate estimation of reliability and approximate cross-cultural measurement invariance. Peru was the country with the highest score in the behavioral dimension of social anomie; while Venezuela and Bolivia presented the highest scores in the affective dimension. Mexico was one of the countries with the lowest anomie scores. The results of the IRT would indicate that the characteristics of the SAS-9 items were appropriate. It is concluded that the SAS-9 has shown good psychometric propertiesUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Network Analysis of Posttraumatic Growth Dimensions: A Cross-Sectional Study in People Who Experienced the Death of a Loved One from COVID-19 in 16 Latin American Countries

The present study aimed to apply a network analysis model to provide an exploratory empirical conceptualization of dynamic networks of posttraumatic growth (PTG) symptoms in 7,434 people who experienced the death of a loved one from COVID-19 in 16 Latin American countries. The Post-Traumatic Growth Inventory: Short Form of Eight Items was used. A non-regularized network with partial correlation coefficients was estimated through the ggmModSelect algorithm. The network architecture was analyzed for each country through its local properties and global properties. The results indicated that the networks differed significantly between countries. The core dimensions in the networks were relating to others, personal strength, and life value and opportunities, which were more related dimensions that reinforce the emergence of PTG in all countries. The findings may be useful to motivate researchers and mental health professionals to consider the importance of the individual dimensions of PTG in groups of people who experienced the death of a loved one from COVID-19 in 16 Latin American countries, as well as their interrelationships.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Relationship between fear of COVID-19, conspiracy beliefs about vaccines and intention to vaccinate against COVID-19: a cross-national indirect effect model in 13 latin american countries

The present study explored the predictive capacity of fear of COVID-19 on the intention to be vaccinated against COVID-19 and the influence in this relationship of conspiracy beliefs as a possible mediating psychological variable, in 13 Latin American countries. A total of 5779 people recruited through non-probabilistic convenience sampling participated. To collect information, we used the Fear of COVID-19 Scale, Vaccine conspiracy beliefs Scale-COVID-19 and a single item of intention to vaccinate. A full a priori Structural Equation Model was used; whereas, cross-country invariance was performed from increasingly restricted structural models. The results indicated that, fear of COVID-19 positively predicts intention to vaccinate and the presence of conspiracy beliefs about COVID-19 vaccines. The latter negatively predicted intention to vaccinate against COVID-19. Besides, conspiracy beliefs about COVID-19 vaccines had an indirect effect on the relationship between fear of COVID-19 and intention to vaccinate against COVID-19 in the 13 countries assessed. Finally, the cross-national similarities of the mediational model among the 13 participating countries are strongly supported. The study is the first to test a cross-national mediational model across variables in a large number of Latin American countries. However, further studies with other countries in other regions of the world are needed.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Assessment of Obsessive Thoughts About COVID-19 in 7 Latin American Countries: Structure and Measurement Invariance of the Obsession With COVID-19 Scale

The present study aimed to evaluate the measurement invariance of the Obsession with COVID-19 Scale (OCS) among seven Latin American countries: Bolivia, Brazil, Cuba, El Salvador, Guatemala, Paraguay, and Uruguay. Although the OCS has been used in several countries and languages, there is a need for approaches that better integrate the cross-cultural equivalence of the scale. A total of 3185 people participated in the study. The results indicated the presence of a unidimensional structure and good reliability indices for the OCS in each country. The alignmentmethod indicated that the OCS is an invariant measure of COVID-19 obsession among the populations of seven Latin American countries. The findings based on IRT analysis indicated that all OCS items had adequate discrimination and difficulty parameters. The findings contribute to the understanding of the internal structure of the scale in different countries at the same time, something that has been pending evaluation.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Pandemic Grief and Suicidal Ideation in Latin American Countries: A Network Analysis

This study aimed to characterize the network structure of pandemic grief symptoms and suicidal ideation in 2174 people from eight Latin American countries. Pandemic grief and suicidal ideation were measured using the Pandemic Grief Scale and a single item, respectively. Network analysis provides an in-depth characterization of symptom-symptom interactions within mental disorders. The results indicated that, “desire to die,” “apathy” and “absence of sense of life” are the most central symptoms in a pandemic grief symptom network; therefore, these symptoms could be focal elements for preventive and treatment efforts. Suicidal ideation, the wish to die, and the absence of meaning in life had the strongest relationship. In general, the network structure did not differ among the participating countries. It identifies specific symptoms within the network that may increase the likelihood of their co-occurrence and is useful at the therapeutic level.Revisión por pare