Resumen El maíz de calidad proteínica (MCP) combina la calidad proteínica de la mutante opaco-2 (o2) con un endospermo vítreo. Estas características han permitido a los programas de mejoramiento alrededor del mundo producir genotipos MCP que ayudan a aliviar la malnutrición de la gente en países en desarrollo de África, Asia y América Latina con una dieta basada en cereales. Sin embargo, el desarrollo de estos materiales ha sido poco eficiente debido al limitado conocimiento acerca de las bases moleculares de la conversión del endospermo suave o2 en un fenotipo vítreo en MCP. Esta conversión se ha asociado con el incremento en cuerpos proteínicos pequeños ricos en γ-zeína de 27 kDa, la síntesis de almidón con una mayor proporción de amilosa y ramificaciones de amilopectina cortas-intermedias que favorece la compactación de los gránulos de almidón, así como alteraciones en la envoltura de los amiloplastos que favorece la interacción entre gránulos de almidón y cuerpos proteínicos. Estudios adicionales sobre los mecanismos involucrados en la modificación del endospermo en MCP contribuirán a producir materiales con buenas características agronómicas y buena calidad proteínica.

Abstract Quality protein maize (QPM) combines the protein quality of the opaque-2 (o2) mutant with a vitreous endosperm. These characteristics have allowed breeding programs worldwide to produce QPM genotypes that help alleviate malnutrition of people in developing countries from Africa, Asia and Latin America with a cereal-based diet. However, the development of these materials has been inefficient due to the limited knowledge about the molecular basis of the soft o2 endosperm conversion into a vitreous phenotype in QPM. This conversion has been associated with an increase in small protein bodies rich in 27 kDa γ-zein, the synthesis of starch with a higher proportion of amylose and short-intermediate amylopectin chain branches that favors the compaction of the starch granules, as well as alterations in the amyloplast envelope that favors the interaction between starch granules and protein bodies. Additional studies about the mechanisms involved in the modification of the endosperm in QPM will contribute to produce materials with good agronomic characteristics and protein quality.

RESUMO Este trabalho descreve os resultados do programa Extension for Community Healthcare Outcomes para eliminação do câncer do colo do útero nas Américas (ECHO ELA), desenvolvido na forma de cooperação trilateral entre a Organização Pan-Americana da Saúde (OPAS), o Instituto Nacional do Câncer dos Estados Unidos (NCI) e o MD Anderson Cancer Center da Universidade do Texas (MD Anderson). O programa visa a disseminar estratégias para a prevenção do câncer do colo do útero e está estruturado em torno dos três pilares da estratégia de eliminação do câncer do colo do útero da Organização Mundial da Saúde (OMS) e das Metas 90-70-90 associadas. O público-alvo inclui autoridades sanitárias de países da América Latina e do Caribe, bem como os pontos focais de doenças não transmissíveis nas representações da OPAS nos países, além de colaboradores clínicos e de saúde pública. Todos os meses, são realizadas sessões virtuais de uma hora e meia em espanhol usando o formato ECHO®. No período de maio de 2020 a junho de 2021, foram realizadas 14 sessões do ECHO, com uma média de 74 participantes por sessão (variação: 46 a 142). Foram realizadas duas enquetes anônimas (linha de base e acompanhamento) e dois grupos focais. Os entrevistados afirmaram que os tópicos sobre os quais mais aprenderam foram a situação da vacinação contra o HPV na região e as estratégias para implementar a vacinação contra o HPV. As necessidades identificadas incluíam apoio entre as sessões do ECHO e assistência técnica específica para o país. O programa ECHO ELA oferece um fórum para aumentar a colaboração entre os países da América Latina e do Caribe e difundir melhores práticas para atingir as metas de eliminação do câncer do colo do útero da OMS.

RESUMEN Se describen los resultados del programa ECHO® (Extension for Community Healthcare Outcomes) para la eliminación del cáncer cervicouterino en las Américas (ECHO-ELA), que se concibió como una cooperación trilateral entre la Organización Panamericana de la Salud (OPS), el Instituto Nacional del Cáncer de los Estados Unidos (NCI) y el centro contra el cáncer MD Anderson (MD Anderson) de la Universidad de Texas. La finalidad del programa es difundir las estrategias para la prevención del cáncer cervicouterino, y está estructurado en torno a los tres pilares de la estrategia para la eliminación del cáncer cervicouterino de la Organización Mundial de la Salud (OMS) y los objetivos 90-70-90 conexos. El público destinatario comprende autoridades de salud de países de América Latina y el Caribe, así como los puntos focales de la OPS para las enfermedades no transmisibles en las Representaciones en los países, además de colaboradores en el ámbito clínico y de la salud pública. Las sesiones virtuales se llevan a cabo en español, durante 1,5 horas cada mes, utilizando el formato ECHO®. De mayo del 2020 a junio del 2021 se celebraron 14 sesiones de ECHO, con un promedio de 74 participantes por sesión (límites: 46-142). Se realizaron dos encuestas anónimas (al inicio y de seguimiento) y dos grupos de opinión. Los encuestados declararon que los temas sobre los que más aprendieron fueron la situación de la vacunación contra el VPH en la región y las estrategias para poner en marcha la vacunación contra el VPH. Entre las necesidades mencionadas figuraban el apoyo entre las sesiones de ECHO y la asistencia técnica específica para cada país. El programa ECHO-ELA brinda un foro para una mayor colaboración entre los países de América Latina y el Caribe y para difundir las estrategias sobre las mejores prácticas, a fin de alcanzar los objetivos de la OMS de eliminación del cáncer cervicouterino.

ABSTRACT We describe the outcomes of The Extension for Community Healthcare Outcomes-Elimination of Cervical Cancer in The Americas (ECHO-ELA) program, which was developed as a tri-lateral cooperation between Pan American Health Organization (PAHO), the U.S. National Cancer Institute (NCI) and The University of Texas MD Anderson Cancer Center (MD Anderson). The program’s purpose is to disseminate strategies for cervical cancer prevention and is structured around the three pillars of the World Health Organization’s (WHO) Cervical Cancer Elimination Strategy and the associated 90-70-90 target goals. The target audience includes health authorities from Latin American and Caribbean countries, as well as PAHO’s non-communicable disease Focal Points in country offices as well as clinical and public health collaborators. The virtual sessions are held in Spanish for 1.5 hours every month using the ECHO® format. From May 2020 to June 2021, 14 ECHO sessions were held with an average of 74 participants per session (range: 46 – 142). We conducted two anonymous surveys (baseline and follow up) and two focus groups. Respondents stated that the topics they learned the most about included the state of HPV vaccination in the region and strategies for implementing HPV vaccination. Identified needs included support between ECHO sessions and country-specific technical assistance. The ECHO-ELA program provides a forum for increased collaboration between countries in Latin America/Caribbean and the dissemination of best-practice strategies to reach the WHO Cervical Cancer Elimination target goals.

Abstract Preterm birth (PTB) is the main condition related to perinatal morbimortality worldwide. The aim of this study was to identify gene-environment interactions associated with spontaneous PTB or its predictors. We carried out a retrospective case-control study including parental sociodemographic and obstetric data as well as newborn genetic variants of 69 preterm and 61 at term newborns born at a maternity hospital from Tucumán, Argentina, between 2005 and 2010. A data-driven Bayesian network including the main PTB predictors was created where we identified gene-environment interactions. We used logistic regressions to calculate the odds ratios and confidence intervals of the interactions. From the main PTB predictors (nine exposures and six genetic variants) we identified an interaction between low neighbourhood socioeconomic status and rs2074351 (PON1, genotype GG) variant that was associated with an increased risk of toxoplasmosis (odds ratio 12.51, confidence interval 95%: 1.71 - 91.36). The results of this exploratory study suggest that structural social disparities could influence the PTB risk by increasing the frequency of exposures that potentiate the risk associated with individual characteristics such as genetic traits. Future studies with larger sample sizes are necessary to confirm these findings.

Abstract This work aimed to identify ecophysiological and biochemical indicators to characterize tomato genotypes tolerant to salt stress. Four varieties (Amalia, Vyta, Campbell-28 and Claudia) were studied under semi-controlled conditions, a salinized medium based on NaCl at electrical conductivity (EC) of 6 dS m-1 with their respective control at EC=0.36 dS m-1. Proline content, glycine betaine, total soluble proteins, chlorophyll and carotenoids, water potential in leaves and roots, leaf osmotic potential and osmotic adjustment (AO) were the evaluated variables. A principal component analysis (PCA) was carried out to determine the indicators that most contribute to salinity tolerance variability. There was a significant variability response in the evaluated indicators between the saline medium and the control medium. Proline increased between 3 and 9 mg g-1 mf in roots and between 8 and 23 mg g-1 mf in leaves, demonstrating the ability to osmoregulation in function of organic solutes. The Amalia and Vyta varieties presented the highest increases in glycine betaine (18 mg g-1 ms). All the varieties reduced their water potential under salinity conditions to values lower than -0.9 MPa, consequently there was a significant OA among the varieties, with Vita and Amalia being the ones with the highest OA. Starting from the PCA analysis, it was found that the variables root and leaf water potential, osmotic potential, osmotic adjustment and proline content were the ones with the greatest contribution to the total variability found among varieties. Vyta and Amalia were tolerant varieties while Claudia and Campbell-28 classified as susceptible.

Resumen El presente trabajo tiene como objetivo identificar indicadores fisiológicos y bioquímicos para caracterizar genotipos de tomate tolerantes al estrés salino. Se estudiaron cuatro variedades (Amalia, Vyta, Campbell-28 y Claudia) en condiciones semicontroladas, un medio salinizado a base de NaCl a conductividad eléctrica (CE) de 6 dS m-1 con su respectivo control a CE=0.36 dS m-1. Se evaluaron indicadores: contenido de prolina, glicina betaína, proteínas solubles totales, clorofila a y carotenoides, potencial hídrico en hojas y raíces, potencial osmótico foliar y ajuste osmótico (AO). Se realizó un análisis de componentes principales (ACP) para determinar los indicadores que más contribuyen a la tolerancia a la salinidad. Existió variabilidad de respuesta en los indicadores evaluados entre el medio salino y el medio control. La prolina se incrementó entre 3 y 9 mf g-1 ms en raíces y entre 8 y 23 mg g-1 mf en hojas, demostrando la capacidad de osmorregular en función de solutos orgánicos. Las variedades Amalia y Vyta presentaron los mayores incrementos de glicina betaína (18 mg g-1 ms). Todas las variedades redujeron su potencial hídrico en condiciones de salinidad a valores menores de -0.9 MPa, en consecuencia existió un AO significativo entre las variedades, siendo Vyta y Amalia las de mayor AO. Partiendo del ACP se encontró que las variables potencial hídrico radicular y foliar, potencial osmótico, ajuste osmótico y el contenido de prolina fueron las de mayor contribución a la variabilidad total encontrada entre variedades. Vyta y Amalia resultaron las tolerantes mientras que Claudia y Campbell-28 clasificaron como susceptibles.

ABSTRACT Little is known about how Brazilian dentists’ treatment decisions for proximal carious lesions are compared to current evidence-based recommendations, so better understanding is needed to close any potential evidence-practice gap. Objectives: This cross-sectional study aimed to quantify the evidence-practice gap about proximal carious lesions treatment and identify dentist factors associated with this evidence-practice gap. Methods: Brazilian dentists (n=214) from Araraquara, São Paulo State, “completed a questionnaire about their dentist and practice characteristics and a translated version of the “Assessment of Caries Diagnosis and Caries Treatment” from the U.S. National Dental Practice-Based Research Network. Five radiographic images of proximal carious lesions in low-risk and high-risk patient scenarios were used. Associations between treatment recommendations and lesion, dentist, and practice characteristics were tested for statistical significance (p<0.05). Results: Lesions confined to the enamel would be restored by 35% and 71% of dentists in the low-risk and high-risk patient scenarios, respectively, suggesting a substantial evidence-practice gap given that surgical intervention of enamel lesions is not consistent with current evidence. The lesion depth threshold to recommend a permanent restoration differed between the low-risk and high-risk patient scenarios (p<0.001). Specific dentist/practice characteristics (dentist gender, graduate of a public dental school, postgraduate training, use of caries risk assessment) were significantly associated with the evidence-practice gap, but the magnitude of these differences was not major Conclusion: A substantial evidence-practice gap in treatment of proximal carious lesions was found for the sample overall, even when clinical scenarios presented low-risk patients. Global strategies are needed to close this substantial evidence-practice gap.

RESUMO Pouco se sabe se as decisões de tratamento dos dentistas brasileiros para lesões cariosas proximais são comparadas às recomendações atuais baseadas em evidências, portanto, é necessário um melhor entendimento para fechar qualquer potencial lacuna entre a evidência e a prática. Purpose: Este estudo transversal teve como objetivo quantificar a lacuna entre a evidência e a prática na decisão de tratamento das lesões cariosas proximais e identificar os fatores associados a essa lacuna entre a evidência e a prática. Methods: Cirurgiões-dentistas brasileiros (n=214) de Araraquara, Estado de São Paulo, preencheram um questionário sobre suas características odontológicas e clínicas e uma versão traduzida do “Assessment of Caries Diagnosis and Caries Treatment” da U.S. National Dental Practice-Based Research Network. Cinco imagens radiográficas de lesões cariosas proximais em cenários de pacientes de baixo risco e alto risco foram usadas. Associações entre recomendações de tratamento e lesão, dentista e características da prática foram testadas (p<0,05). Results: As lesões confinadas ao esmalte seriam restauradas por 35% e 71% dos dentistas nos cenários de pacientes de baixo risco e alto risco, respectivamente, sugerindo uma lacuna entre a evidência e a prática substancial, dado que a intervenção cirúrgica das lesões do esmalte não é consistente com as evidências atuais. O limiar de profundidade da lesão para recomendar uma restauração permanente diferiu entre os cenários de pacientes de baixo risco e alto risco (p<0,001). Características específicas do dentista/prática (sexo do dentista, graduado em uma faculdade pública, pós-graduação, uso da avaliação de risco de cárie) foram significativamente associadas à lacuna entre a evidência e a prática, mas a magnitude dessas diferenças não foi importante. Conclusions: uma lacuna entre a evidência e a prática substancial na decisão de tratamento de lesões cariosas proximais foi encontrada para a amostra como um todo, mesmo quando os cenários clínicos apresentavam pacientes de baixo risco. Estratégias globais são necessárias para fechar essa lacuna entre a evidência e a prática.

Resumen La extracción minera tiene un fuerte impacto sobre el suelo y la cobertura vegetal. Sin embargo, poco se conoce sobre el efecto de esta actividad en la flora y los microrganismos asociados a este tipo de ambientes, los cuales son fundamentales para la cadena trófica de muchos organismos. Los hongos formadores de micorrizas arbusculares (HFMA) forman asociaciones con las plantas y pueden ayudar a mejorar su desarrollo en ambientes contaminados con metales pesados, entre otros beneficios. Las plantas nativas y los HFMA de los suelos degradados por la minería tienen un papel importante en el establecimiento de programas de recuperación de áreas influenciadas por estas actividades; por lo tanto, el objetivo de este estudio fue caracterizar la abundancia y diversidad de la vegetación y HFMA en una zona afectada por la minería de oro. La vegetación se evaluó en dos áreas: una adyacente a depósitos mineros y con vegetación nativa (SI-N) y otra intermedia con desechos mineros e inicio de sucesión vegetal natural (SI-SV) y los HFMA en el área SI-N y el área de desechos de minería (SI-M). La vegetación se cuantificó mediante el método de RAP y los HFMA por medio de tamizado en húmedo a partir de suelo directo y cultivos trampa. En las plantas, se identificaron 605 individuos, pertenecientes a 29 familias, 46 géneros y 54 especies vegetales y de HFMA, 13 especies y 11 géneros; la diversidad, se determinó mediante los números de Hills, donde el área SI-N fue mayor en la vegetación (Q1: 11,94) y el área SI-M en los HFMA (Q1: 3.07). Los metales pesados y la vegetación fueron factores que disminuyeron la diversidad y abundancia de HFMA en SI-M. Se destacan las especies vegetales de los géneros Agrostis, Baccharis y Miconia y el HFMA Glomus microcarpum como las especies más frecuentes y con potencial para la recuperación de áreas degradadas.

Abstract Mining extraction has a substantial impact on soil and vegetation cover. However, little is known about its effect on the flora and microorganisms associated with these environments. Arbuscular Mycorrhizal Fungi (AMF) form associations with plants, improving their development in environments contaminated with heavy metals, among other benefits. Native plants and AMF found in the soil degraded by mining play an essential role in establishing programs dealing with recovering areas influenced by these activities. Therefore, this study aimed to characterize vegetation and AMF abundance and diversity in an area affected by gold mining in Colombia. Vegetation was evaluated in two areas, one adjacent to mining deposits with native vegetation (SI-N) and the other in an intermediate area with mining waste and initial natural plant successions (SI-SV). AMF was assessed in the SI-N and the mining waste area (SI-M). Vegetation was quantified using the RAP method, and AMF was assessed using wet sieving from direct soil samples and trap crops. Vegetation evaluations identified 605 individuals belonging to 29 families, 46 genera, and 54 species, and AMF assessment identified 11 species and five genera. Diversity was established using Hill numbers, finding that SI-N was more diverse for vegetation (Q1: 11.94) and SI-M for AMF (Q1: 3.07). Heavy metals and vegetation decreased the diversity and abundance of AMF in the SI-M. Plant species of the genera Baccharis, Agrostis, Miconia, and the AMF Glomus microcarpum were the most frequent species with potential for recovery in degraded areas.

RESUMEN Objetivos. Determinar los cambios en las características clínicas y desenlaces intrahospitalarios de los pacientes hospitalizados por COVID-19 en un hospital privado de Caracas durante dos años de pandemia. Materiales y métodos. Estudio retrospectivo, observacional, de pacientes hospitalizados por COVID-19. Se investigó la correspondencia entre las olas de ingresos hospitalarios con las variantes circulantes del SARS-CoV-2 en la población general del Distrito Capital y estado Miranda. Resultados. Se incluyeron 1025 pacientes (569 hombres y 456 mujeres), con edad promedio de 62,9 DE: 16,2 años. Cuatro olas de ingresos hospitalarios fueron identificadas: primera (marzo-noviembre 2020) 150/1025 (14,6%) casos; segunda (diciembre-2020 a mayo-2021) 415/1025 (40,5%) casos; tercera (junio-diciembre 2021) 344/1025 (33,6%) casos; cuarta (enero-febrero 2022) 116/1025 (11,3%) casos. La edad promedio fue mayor en la cuarta ola (primera 64,0±15,7, segunda 61,4±15,8, tercera 62,1±16,5, y cuarta ola 68,5±16,4), mientras que la proporción de pacientes masculinos (primera 66,7%, segunda 58,8%, tercera 50,3%, y cuarta 44,8%), los pacientes con enfermedad grave-crítica (primera 65,3%, segunda 57%, tercera 51,7% y cuarta 44,8%), la estadía intrahospitalaria (primera 9,1±6,0, segunda 9,0±7,3, tercera 8,8±7,7, y cuarta 6,9±5,0 días), los ingresos a la UCI (primera 23,3%, segunda 15,7%, tercera 14,0%, y cuarta 11,2%; p=0,027) y la mortalidad (primera 21.8%, segunda 10,7%, tercera 9,1%, y cuarta 7,1%; p<0,001) disminuyeron progresivamente con el tiempo. Conclusiones. Los resultados muestran menor frecuencia de casos severos y mejoría de los desenlaces intrahospitalarios en dos años de pandemia. Es probable que los cambios en las variantes circulantes, las mejoras del manejo de la enfermedad y la vacunación hayan influido sobre estos resultados.

ABSTRACT Objectives. To determine changes in the clinical characteristics and in-hospital outcomes of patients hospitalized for COVID-19 in a private hospital in Caracas during two years of the pandemic. Materials and Methods. Retrospective, observational study of patients hospitalized for COVID-19. We evaluated the correspondence between waves of hospital admissions and circulating variants of SARS-CoV-2 in the general population of the Capital District and Miranda state. Results. A total of 1025 patients (569 men and 456 women) were included, with a mean age of 62.9 SD: 16.2 years. Four waves of hospital admissions were identified: first (March-November 2020) 150/1025 (14.6%) cases; second (December 2020 to May 2021) 415/1025 (40.5%) cases; third (June-December 2021) 344/1025 (33.6%) cases; fourth (January-February 2022) 116/1025 (11.3%) cases. The mean age was higher in the fourth wave (first: 64.0±15.7, second: 61.4±15.8, third: 62.1±16.5, and fourth wave: 68.5±16.4), while the proportion of male patients (first: 66.7%, second: 58.8%, third: 50.3%, and fourth wave: 44.8%), patients with severe-critical illness (first: 65.3%, second: 57%, third: 51.7%, and fourth wave: 44.8%), in-hospital stay (first: 9.1±6.0, second: 9.0±7.3, third: 8.8±7.7, and fourth wave: 6.9±5.0 days), ICU admissions (first: 23.3%, second: 15.7%, third: 14.0%, and fourth wave: 11.2%; p=0.027) and mortality (first: 21. 8%, second: 10.7%, third: 9.1%, and fourth wave: 7.1%; p<0.001) progressively decreased over time. Conclusions. The results show lower frequency of severe cases and improvement of in-hospital outcomes in two years of the pandemic. Changes in circulating variants, improvements in disease management and vaccination are likely to have influenced these results.

ABSTRACT Objectives. To determine changes in the clinical characteristics and in-hospital outcomes of patients hospitalized for COVID-19 in a private hospital in Caracas during two years of the pandemic. Materials and Methods. Retrospective, observational study of patients hospitalized for COVID-19. We evaluated the correspondence between waves of hospital admissions and circulating variants of SARS-CoV-2 in the general population of the Capital District and Miranda state. Results. A total of 1025 patients (569 men and 456 women) were included, with a mean age of 62.9 SD: 16.2 years. Four waves of hospital admissions were identified: first (March-November 2020) 150/1025 (14.6%) cases; second (December 2020 to May 2021) 415/1025 (40.5%) cases; third (June-December 2021) 344/1025 (33.6%) cases; fourth (January-February 2022) 116/1025 (11.3%) cases. The mean age was higher in the fourth wave (first: 64.0±15.7, second: 61.4±15.8, third: 62.1±16.5, and fourth wave: 68.5±16.4), while the proportion of male patients (first: 66.7%, second: 58.8%, third: 50.3%, and fourth wave: 44.8%), patients with severe-critical illness (first: 65.3%, second: 57%, third: 51.7%, and fourth wave: 44.8%), in-hospital stay (first: 9.1±6.0, second: 9.0±7.3, third: 8.8±7.7, and fourth wave: 6.9±5.0 days), ICU admissions (first: 23.3%, second: 15.7%, third: 14.0%, and fourth wave: 11.2%; p=0.027) and mortality (first: 21. 8%, second: 10.7%, third: 9.1%, and fourth wave: 7.1%; p<0.001) progressively decreased over time. Conclusions. The results show lower frequency of severe cases and improvement of in-hospital outcomes in two years of the pandemic. Changes in circulating variants, improvements in disease management and vaccination are likely to have influenced these results.

RESUMEN Objetivos. Determinar los cambios en las características clínicas y desenlaces intrahospitalarios de los pacientes hospitalizados por COVID-19 en un hospital privado de Caracas durante dos años de pandemia. Materiales y métodos. Estudio retrospectivo, observacional, de pacientes hospitalizados por COVID-19. Se investigó la correspondencia entre las olas de ingresos hospitalarios con las variantes circulantes del SARS-CoV-2 en la población general del Distrito Capital y estado Miranda. Resultados. Se incluyeron 1025 pacientes (569 hombres y 456 mujeres), con edad promedio de 62,9 DE: 16,2 años. Cuatro olas de ingresos hospitalarios fueron identificadas: primera (marzo-noviembre 2020) 150/1025 (14,6%) casos; segunda (diciembre-2020 a mayo-2021) 415/1025 (40,5%) casos; tercera (junio-diciembre 2021) 344/1025 (33,6%) casos; cuarta (enero-febrero 2022) 116/1025 (11,3%) casos. La edad promedio fue mayor en la cuarta ola (primera 64,0±15,7, segunda 61,4±15,8, tercera 62,1±16,5, y cuarta ola 68,5±16,4), mientras que la proporción de pacientes masculinos (primera 66,7%, segunda 58,8%, tercera 50,3%, y cuarta 44,8%), los pacientes con enfermedad grave-crítica (primera 65,3%, segunda 57%, tercera 51,7% y cuarta 44,8%), la estadía intrahospitalaria (primera 9,1±6,0, segunda 9,0±7,3, tercera 8,8±7,7, y cuarta 6,9±5,0 días), los ingresos a la UCI (primera 23,3%, segunda 15,7%, tercera 14,0%, y cuarta 11,2%; p=0,027) y la mortalidad (primera 21.8%, segunda 10,7%, tercera 9,1%, y cuarta 7,1%; p<0,001) disminuyeron progresivamente con el tiempo. Conclusiones. Los resultados muestran menor frecuencia de casos severos y mejoría de los desenlaces intrahospitalarios en dos años de pandemia. Es probable que los cambios en las variantes circulantes, las mejoras del manejo de la enfermedad y la vacunación hayan influido sobre estos resultados.

Abstract The litterfall that accumulates in the forest soil and its further decomposition play an important roll in the maintenance of productivity in different terrestrial ecosystems since its constitute the main flow of nutrients to the soil. The objective of this study was to evaluate the production of litterfall, its nutrient return thru litterfall deposition and macronutrient use efficiency. The study was conducted in Linares, Crucitas and Los Ramones, state of Nuevo León, México. Average litterfall deposition was 5 800, 5 270 and 6 596 kg ha−1 year−1 for Linares, Crucitas and Los Ramones, respectively. Total nutrient return thru litterfall followed the sequence: Linares > Crucitas > Los Ramones, with value of 135, 122 and 101 kg ha−1 year−1, respectively. Even though the return of P thru litterfall was the lowest, P nutrient use efficiency was higher with respect to Ca, Mg and K. Greatest nutrient use efficiency in terms of Ca and Mg was observed in Los Ramones, K in Crucitas and P in Linares. The results showed that there exist spatial and temporal variation in the production of litterfall, nutrient return and nutrient use efficiency between studied sites. Thus, litterfall deposition, nutrient return and nutrient use efficiency between sites depend on stand composition and richness, edaphic properties, litterfall quality, and plant phenology.

Resumen La hojarasca que se acumula sobre el piso forestal y su posterior descomposición juegan un papel importante en el mantenimiento de la productividad de los diferentes ecosistemas terrestres al constituir el principal flujo de nutrientes al suelo. El objetivo del estudio fue evaluar la producción de hojarasca y retorno de nutrientes a través de la caída de la hojarasca y la eficiencia en el uso de macro-nutrientes. El estudio se realizó en los sitios de Linares, Crucitas y Los Ramones, en el Estado de Nuevo León, México. El promedio de caída de hojarasca fue de 5 800, 5 270 a 6 596 kg ha−1 año−1 para Linares, Crucitas y Los Ramones, respectivamente. El retorno total de nutrientes siguió la secuencia: Linares > Crucitas > Los Ramones con valores de 135, 122 y 101 kg ha−1 año−1, respectivamente. A pesar de que el retorno de P en la hojarasca fue menor, la eficiencia del uso de este nutriente fue mayor que la presentada por el Ca, Mg ó K. La mayor eficiencia de uso de nutrientes en términos de Ca y Mg se observó en Los Ramones, el K en Crucitas y el P en linares. Existe variación espacial y temporal en la producción de hojarasca, retorno de nutrientes y la eficiencia en su uso entre los sitios evaluados. Por tanto, la caída de hojarasca, retorno de nutrientes y uso eficiente en estos sitios dependen de la riqueza de especies, diferencias edáficas, calidad de la hojarasca y fenología de las diferentes especies.

Lack of diversity regarding genetic and environmental backgrounds weakens the generalization and clinical applicability of research findings on psychotic disorders. Notably, Latin Americans have been generally neglected in genetic studies, comprising less than 2% of genome-wide association study samples. But Latin American populations represent a unique opportunity for research, given the exceptionally high ethnic admixture of this group. Increasing genetic diversity is essential to improve the fine mapping of known regions associated with psychotic disorders, discover novel genetic associations, and replicate studies. Additionally, Latin America is characterized by massive social, political, and economic inequalities, all known risk factors for mental health issues, including psychotic disorders. This article aims to 1) discuss the challenges and advantages of studying Latin America’s particular genetic makeup and environmental context; 2) review previous studies conducted in the region; and 3) describe three Latin American research initiatives in progress: the Neuropsychiatric Genetics of Psychosis in Mexican Populations (NeuroMEX), the Paisa, and the Latin American Network for the Study of Early Psychosis (ANDES) studies.

ABSTRACT Aims: Assess the incidence of COVID-19 during the first wave of the pandemic in 40 hemodialysis units in Spain. Material and methods: We analyzed 396 Rt-PCR performed March 14th to April 28th, 2020 in a cohort of 2398 hemodialysis (HD) patients corresponding to 19 hospital units and 21 satellite centers. Results: We performed Rt-PCR in 14% of the patients, with a marked variability depending on the location. The overall COVID-19 incidence was 3.2% (range 0-15.9%). It was significantly higher in the hospital units (4.5%) than in the satellite units (1.9%) (p=0.0003). There was a positive and significant correlation between the COVID-19 incidence in the units and their proximity to Madrid (R2=0.6235, p=0.0013), which was the main epidemic focus. Conclusion: Our study showed a low incidence of COVID-19 in HD, higher in hospital units and closer to Madrid.

Abstract Pimenta dioica L. Merrill, known as pimienta gorda, xocoxochitl (in Nahuatl) or allspice, is native to Mesoamerica. In Mexico, it has been used since pre-Hispanic times due to its medicinal properties and as a condiment for the preparation of “tamales” and “moles”. The dried fruits have a high economic value due to their flavor and aroma: a combination of cinnamon, nutmeg and clove. For this reason, it is known as allspice in English. Xocoxochitl is a dioecious tree. The fruiting, female trees, have a greater economic importance, while non-fruiting trees, or male trees, function to some extent as pollinators. However, leaves and fruits present similar volatile organic compounds (VOCs) responsible for the already mentioned properties. In order to evaluate the VOCs in leaves at different developmental stages, leaves were collected from: 2-years-old sexually undifferentiated trees and 14-years-old female and male differentiated trees. VOCs were collected and evaluated using SPME-GC-MS. Data obtained show a great diversity of VOCs at all leaf developmental stages, regardless of the tree analyzed. The dried fruit essential oil is highly valued by the international industry, but the leaves have minor use. However, leaves showed a great VOCs richness containing most of the dried fruit compounds. The VOCs profile in female and male trees were also evaluated. Individual VOCs displayed a different relative amount in each leaf developmental stage, as well as specific compounds for each type of tree were identified.

Resumen Pimenta dioica L. Merrill, conocida como pimienta gorda, xocoxochitl (en náhuatl) o como allspice, es originaria de Mesoamérica. En México, se ha usado desde la época prehispánica debido a sus propiedades medicinales, así como condimento para la preparación de tamales y moles. Los frutos secos tienen un alto valor económico debido a su sabor y aroma: una combinación de canela, nuez moscada y clavo. Por esta razón, en inglés se le llama allspice. Xocoxochitl es un árbol dioico. Los árboles que fructifican, árboles hembra, presentan una mayor importancia económica mientras que los árboles que no fructifican, árboles macho, funcionan en forma limitada como polinizadores. Sin embargo, las hojas y los frutos presentan compuestos orgánicos volátiles (COVs) similares responsables de las características mencionadas. Con el fin de evaluar los COVs presentes en hojas de diferentes estados de desarrollo, se colectaron hojas de árboles no diferenciados de 2 años de edad, así como de árboles diferenciados, hembra y macho, de 14 años de edad. Los COVs fueron colectados y analizados mediante SPME-GC-MS. Los datos obtenidos muestran una riqueza de COVs en todos los estados de desarrollo de la hoja, independientemente del árbol analizado. El aceite esencial del fruto seco es altamente apreciado en la industria internacional, sin embargo, las hojas presentan un menor uso. Además, también se evaluó el perfil de COVs de árboles hembra y macho. Ciertos COVs mostraron una cantidad relativa diferente en cada estado de desarrollo de la hoja, así mismo, se identificaron compuestos específicos para cada tipo de árbol.

ABSTRACT Mortality due to SARS-CoV-2 is high compared to that caused by other respiratory viruses. This article aims to define the comorbidities associated with high mortality rates or complications that require ventilatory support in intensive care units. A bibliographic search has been performed with respect to comorbidities and/or alterations in laboratory tests and radiographic exams that have been associated with mortality, especially those described in China.

RESUMEN La infección por COVID-19 presenta una elevada mortalidad respecto a otros virus respiratorios. En este artículo buscamos definir las comorbilidades que están asociadas a la elevada mortalidad o a las complicaciones que requieren mayor soporte ventilatorio en unidades de cuidados intensivos. Se ha diseñado una búsqueda bibliográfica con respecto a las comorbilidades y/o alteraciones en los exámenes de laboratorio y los estudios radiológicos que se han asociado a la presencia de mortalidad, especialmente en los casos descritos en China.

Abstract Chagas Disease is caused by Trypanosoma cruzi. This infection is endemic in the Americas region. Neurological Chagas reactivation is diagnosed through the visualization of the parasite in the cerebrospinal fluid, blood, or tissue samples. Herein, we report the visualization of trypomastigotes by direct microscopic observation of a brain biopsy specimen and its preservation fluid (PF) in a paitient infected with VIH and T. cruzi. This easy and simple diagnostic method coupled with quantitative polymerase chain reaction can be used in all tissue biopsies and PF of T. cruzi seropositive patients, suspected of Chagas disease reactivation.

Abstract Conyza species are important weeds in global agriculture, especially due to their capacity to evolve resistance to multiple herbicide mechanisms of action. We aimed to evaluate the frequency and distribution of resistance to glyphosate and chlorimuron-ethyl in Conyza spp. populations from Brazil. Seed samples were collected from grain production areas across nine Brazilian states over five consecutive years (2014 to 2018). Prior to resistance monitoring trials, dose-response assays were conducted to determine a single dose of glyphosate or chlorimuron-ethyl to discriminate resistant and susceptible populations. Resistance monitoring based on plant responses to the application of discriminatory doses of glyphosate (960 g ha-1) or chlorimuron-ethyl (20 g ha-1). Populations were classified as resistant, moderately resistant, or susceptible to either herbicide. While glyphosate resistance was highly frequent (71.2%) in all the five years, chlorimuron-ethyl resistant populations occurred at 39.8% of the total. The frequency of multiple resistance to both herbicides (35.3%) was proportional to the occurrence of chlorimuron-ethyl resistance (39.6%). Resistance to glyphosate and to chlorimuron-ethyl were found across all states evaluated.