Abstract The impact of forestry practices was evaluated on Eucalyptus’s growth variables and mortality dynamics. An experiment was conducted in Uruguay over sixteen years, sixteen spacing and thinning treatments were compared depending on the genetic material and productive objective. Tree height and diameter at breast height were assessed annually. All variables were analyzed using linear mixed models. Kaplan-Meier survival analysis and the Log Rank test were used to compare tree survival. 460 trees ha-1 from seed material resulted in the highest individual basal area (0.023 m2), while treatments with 2000 trees ha-1, without thinning, generated a greater yield per hectare (1014 m3 ha-1). Variations in mortality were detected in higher-density treatments (above 800 trees ha-1). This study underscores the critical importance of managing spacing, genetic material, and thinning practices to optimize Eucalyptus growth. Eucalyptuss s dynamics years objective annually models KaplanMeier Kaplan Meier 46 ha1 ha 1 ha- 0.023 0023 0 023 (0.02 m2, m2 m , m2) 200 ha1, 1, 1014 (101 ha1. . ha-1) higherdensity higher density above 80 4 0.02 002 02 (0.0 20 101 (10 8 0.0 00 (0. 2 10 (1 0. (0 (

RESUMEN Durante el almacenamiento, los granos de soja pueden ser atacados por insectos, que se controlan preventivamente con insecticidas. La información sobre la disipación de los residuos de insecticidas es crucial para conocer sus concentraciones finales en los alimentos y establecer los períodos de carencia necesarios para su consumo sin riesgos para la salud, así como para cumplir con las normas nacionales e internacionales. Los objetivos de este estudio fueron cuantificar los niveles de residuos de insecticidas organofosforados (diclorvos, clorpirifos-metilo y pirimifos-metilo) en soja almacenada, establecer el efecto de los días de almacenamiento y modelizar la dinámica de disipación. Los residuos de insecticidas en la soja se analizaron a los 2, 30, 60, 90 y 120 días después de la aplicación. Se validó un método analítico basado en la extracción por QuEChERS seguida de la determinación por cromatografía gaseosa acoplada a espectrometría de masas (GC-MS/MS), con recuperaciones medias del 82-105%, dependiendo de los niveles de adición. Los residuos disminuyeron por debajo del 80% de la concentración inicial a los 60 días de la aplicación y por debajo de los niveles cuantificables a los 120 días. Los residuos siguieron una dinámica de disipación de pseudoprimer orden [Ct = C0×exp(-k.t)], siendo la constante de disipación (k) y las vidas medias de 0,538 y 1,3 días para diclorvos, 0,018 y 38,8 días para clorpirifos-metilo, y 0,023 y 30,1 días para pirimifos-metilo, respectivamente. Estos resultados permiten concluir que, a la dosis recomendada, estos insecticidas son seguros para su uso en granos de soja almacenados.

ABSTRACT During storage, soybean kernels can be attacked by insects, which are preventively controlled with insecticides. Information on the dissipation of insecticide residues is crucial to know their final concentrations in food and establish the waiting periods necessary for consumption without health risks, and to determine the minimum waiting period necessary to comply with national and international standards. The aims of this study were to quantify the residue levels of organophosphorus insecticides (dichlorvos, chlorpyrifos-methyl and pirimiphos-methyl) in stored soybean, establish the effect during the storage period, and model the dissipation dynamics. Insecticide residues in soybeans were analyzed at 2, 30, 60, 90 and 120 days after application. An analytical method based on QuEChERS extraction followed by gas chromatography mass spectrometry (GC-MS/MS) determination was validated, with mean recoveries of 82-105%, depending on the spiking levels. Residues decreased below 80% of the initial concentration at 60 days after application and below quantifiable levels at 120 days. Residues followed a pseudo-first-order dissipation dynamics [Ct = C0×exp(-k.t)], with the dissipation constant (k) and half-lives being 0.538 and 1.3 days for dichlorvos, 0.018 and 38.8 days for chlorpyrifos-methyl, and 0.023 and 30.1 days for pirimiphos-methyl, respectively. These results allow concluding that, at the recommended dosage, these insecticides are safe for use on soybean grains stored under standard conditions commonly nowadays used in Argentina.

ABSTRACT Background: The acute phase of COVID-19 infection is associated with cardiovascular involvement, but there is limited information regarding this relationship in the recovery phase from this disease both in patients with or without persistent symptoms. Objectives: The aims of this study were: 1. To analyze cardiovascular involvement by echocardiography in the recovery phase from COVID-19 disease, and 2. To explore its association with: a) the severity of the acute phase and b) the presence of persistent symptoms. Methods: An analytical, observational, prospective and single-center study was carried out, including consecutive patients attending the center for post-COVID-19 evaluation who underwent a transthoracic color Doppler echocardiogram looking for pathological outcomes. Results: A total of 600 patients were included from September 1, 2020 to May 1, 2021, and 29 of these patients (4.8%) presented pathological findings in the echocardiogram. Patients with moderate or severe acute phase COVID-19 infection had a higher prevalence of wall motion disorders (4.3% vs. 0.5%, p=0.02) and pericardial effusion (4.3% vs. 0.24%, p=0.01) compared with those with asymptomatic or mild symptoms; however, after multivariate adjustment, this association did not reach statistical significance. In 28.6% of cases, patients reported persistent symptoms, with no evident association between their presence and pathological echocardiographic results. Conclusion: The prevalence of cardiovascular involvement evaluated by echocardiography was 4.8% in the recovery phase from COVID-19 disease. Patients with more severe initial clinical presentation exhibited more pathological findings, but the significance was not sustained in the multivariate analysis. Persistent symptoms were not associated with greater cardiovascular involvement.

RESUMEN Introducción: La infección por COVID-19 se asocia a compromiso cardiovascular en su etapa aguda. La información sobre el compromiso cardíaco en la etapa de convalecencia de la enfermedad tanto en pacientes con y sin síntomas persistentes es limitada. Objetivos: 1. Analizar el compromiso cardíaco mediante ecocardiograma en la etapa de convalecencia de la enfermedad por COVID-19; 2. Explorar su asociación con: a) gravedad del cuadro agudo y b) persistencia de síntomas. Métodos: Estudio analítico, observacional, prospectivo y unicéntrico. Se incluyeron pacientes consecutivos que consultaron al centro para realizar evaluación post-COVID. Se realizó ecocardiograma Doppler color transtorácico en busca de hallazgos patológicos. Resultados: Se incluyeron 600 pacientes desde el 01/09/2020 al 01/05/2021. Veintinueve (4,8%) presentaron hallazgos patológicos en el ecocardiograma. Los pacientes con cuadros iniciales moderados o graves presentaron mayor prevalencia de trastornos de motilidad parietal (4,3% versus 0,5%, p = 0,02) y derrame pericárdico (4,3% versus 0,24%, p = 0,01) en comparación con aquellos con cuadros asintomáticos o leves. En el ajuste multivariado esta asociación no alcanzó significación estadística. El 28,6% de los pacientes referían síntomas persistentes, no observándose una asociación entre la presencia de los mismos y los hallazgos ecocardiográficos patológicos. Conclusión: La prevalencia de compromiso cardíaco evaluado mediante ecocardiograma en la etapa de convalecencia de la enfermedad por COVID-19 fue de 4,8%. Los pacientes con cuadros iniciales más graves presentaron más hallazgos patológicos. La significancia no se sostuvo en el análisis multivariado. Los síntomas persistentes no se asociaron a mayor compromiso cardíaco.

The aim of this work was to analyze the dissipation dynamics of the insecticides pirimiphos- methyl and dichlorvos in maize (Zea mays L.) grains after post-harvest spray applications. The recommendations for their use for Argentina and the Maximum Residue Limits (MRLs) established by local and international pesticide regulations were considered. Supervised experimental trials were conducted in stored maize grains treated with 10 cc.t-1 of pirimiphos-methyl and 20 cc.t-1 of dichlorvos. Samples were monitored 2, 30, 60, 90 and 120 days after application. The pesticides were extracted from the maize grains using the QuEChERS technique and the residues were determined using high-resolution gas chromatography with mass detector. Residue dissipation percentages and daily dissipation rates differed between active ingredients. At 48 hours after application, pirimiphos-methyl residues were 5.1±0.42 μg.g-1, i.e. below the MRLs established by the Argentine Service for Agrifood Health and Quality (10 μg.g-1), the USA (8 μg.g-1) and the Codex Alimentarius (7 μg.g-1), and close to the MRLs established by the EU (5 μg.g-1). Dichlorvos residues reached 2.97±0.27 μg.g-1, and required at least a 90-day withholding period to be lower than the MRLs of the EU.

El objetivo de este trabajo fue analizar la dinámica de disipación de los insecticidas pirimifós-metil y diclorvós aplicados durante el almacenamiento de granos de maíz (Zea mays L.). Se compararon los niveles de residuos recomendados para Argentina con el Límite Máximo de Residuos (LMR) establecido internacionalmente. Los ensayos fueron realizados en un ambiente controlado. Se aplicaron dosis de 10 cm³.t-1 de pirimifós-metil y 20 cm³.t-1 de diclorvós sobre granos de maíz almacenados. Las muestras se tomaron a los 2, 30, 60, 90 y 120 días desde la aplicación. La extracción de plaguicidas del tejido vegetal se realizó mediante la técnica QuEChERS y la determinación de residuos por cromatografía gaseosa de alta resolución con detector de masa. El porcentaje de disipación de residuos y la tasa diaria de disipación fue diferente para ambos principios activos. Los residuos de pirimifós-metil a las 48 horas de la aplicación fueron de 5,1±0,42 μg.g-1, i.e., estuvieron por debajo de los LMR establecidos por SENASA (10 μg.g-1), EUA (8 μg.g-1), Codex Alimentarius (7 μg.g-1) y cercanos a los LMR de UE (5 μg.g-1). Para diclorvós los residuos a los 30 días alcanzaron valores de 2,97±0,27 μg.g-1 y se requirieron al menos 90 días para alcanzar valores menores a los LMR de la UE.

Abstract Prosopis alba is the most important native species in the semi-arid Chaco for afforestation with multiple objectives. More than 50% of the planted area in Santiago del Estero, Argentina, has been established in areas with very different site quality, generating a heterogeneous growth behavior. It is proposed to evaluate the influence of edaphic factors on the growth of plantations Prosopis alba Griseb (algarrobo) in areas of the semi-arid Chaco, information that will facilitate silvicultural decision making and will allow predicting the quality of sites with forestation potential based on conditions of the soil. The correlation between dasometric and edaphic variables was evaluated in relation to 3 kinds of site quality (CI, CII and CIII). A dominant height projection model expressed as a Site Index with the most correlated edaphic variables was determined, which explains 42% of the variation in growth. The electrical conductivity has a threshold of 10 dS m-1 for the CI and CII with Site Index of 10 and 8 respectively; for higher EC values the growth of the mass decreases. The concentration of soluble cations varies in relation to the site index, the CI and CII have low sodium concentrations, with a critical value of approximately 39 mEq L-1. Growth is conditioned by chemical properties of the soil, the presence of salts would further explain the impact on growth, with a saline threshold from which growth is compromised from a productive approach.

Resumen Prosopis alba Griseb es la especie nativa de mayor importancia en el Chaco semiárido para la forestación con múltiples objetivos. Más de 50% de la superficie plantada en la provincia de Santiago del Estero, Argentina, se ha establecido en áreas con calidades de sitio muy diferentes, generando un comportamiento heterogéneo en el crecimiento. Se propone evaluar la influencia de factores edáficos en el crecimiento de plantaciones de Prosopis alba Griseb (algarrobo blanco), información que facilitará la toma de decisiones silviculturales y permitirá predecir la calidad de sitio con potencial de forestación, con base en características edáficas. Se evalúo la correlación entre variables dasométricas y edáficas en relación con tres clases de calidad de sitio (CI, CII y CIII). Se determinó un modelo de proyección de altura dominante, expresado como índice de sitio con las variables edáficas de mayor correlación, que explica 42% de la variación en el crecimiento. La conductividad eléctrica presentó un umbral de 10 dS m-1 para la CI y CII con índice de sitio de 10 y 8 respectivamente; para valores superiores de CE disminuyó el crecimiento de la masa. La concentración de cationes solubles varió con respecto al índice de sitio, la CI y CII presentaron concentraciones bajas de sodio, con un valor crítico de aproximadamente 39 mEq L-1. El crecimiento estuvo condicionado por propiedades químicas del suelo, la presencia de sales explicaría en mayor medida el impacto en el crecimiento, con un umbral salino a partir del cual el crecimiento se ve comprometido desde un enfoque productivo.

ABSTRACT The classification of sites through curves of Site Index allows to predict the yield of the planted forests at a certain age of the stand and to plan cultural treatments. The goal of this research was to compare linear and non-linear models of fixed effects vs. mixed non-linear models to estimate the site index in plantations of Prosopis alba var Griseb in the irrigated area of the province of Santiago del Estero, Argentina using the guide curve method. The data used comes from temporary plots, permanent plots and growth data from the stem analysis of selected individuals based on their greater growth in height within the sampled areas. The registered variable for the evaluation of the site was the dominant Height (HD), defined as the average height of the 100 thickest trees per hectare. Considering that the source of data from repeated measurements on the same subject implies the presence of correlation and/or heteroscedasticity, it was proposed to evaluate statistical models that allow to properly representing the structure of the variance-covariance matrix, improving the accuracy in the adjustment. From the analysis of the results, it appears that the models non-linear mixed models have had better performance in the adjustment of the Site Index than linear and non-linear models of fixed effects. The most accurate model (smallest AIC and BIC) in the site index estimation was the mixed non-linear regression model of “Gompertz”, with structure of composite symmetry correlation and exponential heteroscedasticity.

Solanum muricatum Aiton is an herbaceous perennial fruit species native to the Andean region of Colombia, Ecuador, and Peru. In Chile, it was probably introduced in pre-Columbian times as a domesticated species and is presently grown in the coastal areas of the north-central regions of Coquimbo and Valparaíso. The species has been bred, but little information is available on its genetic variability in Chile. To characterize the genetic variability in this species, fruits were collected from 14 different ecotypes and seeds were sown to generate approximately 60 segregants from each accession. Segregants were planted at two different locations to characterize their fruits and fruiting habits. Fruit weight ranged from 30 to 485 g, while length was 3.5 to 16.7 cm, equatorial diameter 3.4 to 9.5 cm, pulp firmness 1.7 to 10 N, and soluble solids content 6.3 to 13.5° Brix. Fruit shape ranged from flat to oblong. When analyzing the estimated variance components with a mixed linear model, most of the variability between different ecotypes was in fruit shape, length, and weight, which resulted in a genetic contribution of 34.6%, 29.3%, and 18.1% of the total variability of these traits, respectively. Genetic variability was also found for pulp firmness and soluble solids content. Therefore, enough variability is available in seed-propagated pepinos from Chilean ecotypes to allow genetic improvement of these fruit quality traits. There was also variability from genotype x environment interactions; therefore, selections must be performed for specific environments or stable selections must be found.

The aim of this study was to assess genetic diversity among 40 alfalfa (Medicago sativa L.) genotypes of different non-dormant (FD=8) cultivars. Biomass yield, regrowth speed and reaction to spring black stem, lepto leaf spot, and rust were evaluated. Analyses of variances were performed using a mixed model to examine the agronomic variation among individuals. A principal component analysis on standardized agronomic data was performed. Agronomic data were also used to calculate Gower's distance and UPGMA algorithm. For the molecular analysis, six SSR markers were evaluated and 84 alleles were identified. The genetic distance was estimated using standard Nei's distance. Average standard genetic diversity was 0.843, indicating a high degree of variability among genotypes. Finally, a generalized procrustes analysis was performed to calculate the correlation between molecular and agronomic distance, indicating a 65.4% of consensus. This value is likely related to the low number of individuals included in the study, which might have underestimated the real phenotypic variability among genotypes. Despite the low number of individuals and SSR markers analyzed, this study provides a baseline for future diversity studies to identify genetically distant alfalfa individuals or cultivars.

El objetivo de este trabajo consistió en determinar la diversidad genética en 40 individuos de alfalfa (Medicago sativa L.) de cinco cultivares de grado de reposo 8. Se evaluaron a campo la producción de forraje, la velocidad de rebrote y el comportamiento frente a tallo negro de primavera, mancha ocular y roya. El análisis de la varianza se realizó mediante un modelo lineal mixto para determinar la variación agronómica entre los individuos. El análisis de componentes principales se realizó a partir de los datos agronómicos estandarizados. El dendrograma agronómico se construyó a partir del índice de Gower y el agrupamiento UPGMA. Para la caracterización molecular se analizaron seis marcadores SSR, con los cuales se identificaron un total de 84 alelos. Las distancias genéticas se calcularon con el índice de Nei estándar. La diversidad genética promedio fue de 0,843, indicando una alta variabilidad entre los individuos evaluados. Por último, el análisis de procrustes generalizado detectó un 65,4% de consenso entre el ordenamiento agronómico y el molecular. Este porcentaje probablemente se relacione con el bajo número de individuos y marcadores SSR analizados; sin embargo, este estudio provee una línea de base para estudios futuros de diversidad que permitirán identificar individuos o cultivares genéticamente distantes.

New precision agriculture technologies allow collecting information from several variables at many georeferenced locations within crop fields. The spatial covariation of soil properties and crop yield data can be evaluated by principal component analysis (PCA). Nevertheless, PCA has not been explicitly developed for spatial data as other multivariate descriptive methods. Other multivariate techniques that include spatial autocorrelation among data of neighborhood sites have been recently developed. In this paper, we apply and compare two multivariate analyses, PCA and spatially constrained multivariate analysis methods (MULTISPATI-PCA). The latter incorporates the spatial information into multivariate analysis calculating Moran's index between the data at one location and the mean values of its neighbors. The results showed that MULTISPATI-PCA detected relations in the data that were not detected with PCA. The mapping of spatial variability from the first principal component was similar between PCA and MULTISPATI-PCA, but maps from the second component were different due to the variance correction by spatial autocorrelation. MULTISPATIPCA method represents a crucial tool to map spatial variability within a field, and to identify homogeneous zones in a multivariate sense.

La utilización de nuevas tecnologías asociadas a la agricultura de precisión permite capturar información de múltiples variables en gran cantidad de sitios georreferenciados dentro de lotes en producción. Las covariaciones espaciales de las propiedades del suelo y el rendimiento del cultivo pueden evaluarse a través del análisis de componentes principales clásico (PCA). No obstante, como otros métodos multivariados descriptivos, el PCA no ha sido desarrollado explícitamente para datos espaciales. Nuevas versiones de análisis multivariado permiten contemplar la autocorrelación espacial entre datos de sitios vecinos. En este trabajo se aplican y comparan los resultados de dos técnicas multivariadas, el PCA y MULTISPATI-PCA. Este último incorpora la información espacial a través del cálculo del índice de Moran entre los datos de un sitio y el dato promedio de sus vecinos. Los resultados mostraron que utilizando MULTISPATI-PCA se detectaron correlaciones entre variables que no fueron detectadas con el PCA. Los mapas de variabilidad espacial construidos a partir de la primera componente de ambas técnicas fueron similares; no así los de la segunda componente debido a cambios en la estructura de co-variación identificada, al corregir la variabilidad por la autocorrelación espacial de los datos. El método MULTISPATI-PCA constituye una herramienta importante para el mapeo de la variabilidad espacial y la identificación de zonas homogéneas dentro de lotes.

Measures of agro-ecosystems genetic variability are essential to sustain scientific-based actions and policies tending to protect the ecosystem services they provide. To build the genetic variability datum it is necessary to deal with a large number and different types of variables. Molecular marker data is highly dimensional by nature, and frequently additional types of information are obtained, as morphological and physiological traits. This way, genetic variability studies are usually associated with the measurement of several traits on each entity. Multivariate methods are aimed at finding proximities between entities characterized by multiple traits by summarizing information in few synthetic variables. In this work we discuss and illustrate several multivariate methods used for different purposes to build the datum of genetic variability. We include methods applied in studies for exploring the spatial structure of genetic variability and the association of genetic data to other sources of information. Multivariate techniques allow the pursuit of the genetic variability datum, as a unifying notion that merges concepts of type, abundance and distribution of variability at gene level.

Obtener estimaciones confiables de la diversidad genética en los agroecosistemas es esencial para tomar decisiones basadas en el conocimiento científico que permitan proteger los servicios ecosistémicos que éstos brindan. Para construir el dato de variabilidad genética es necesario trabajar con gran cantidad de variables de distinta naturaleza. Los marcadores moleculares proveen datos multidimensionales que generalmente son complementados con otros tipos de información, por ejemplo datos morfológicos o fisiológicos. Así, los estudios sobre variabilidad genética están frecuentemente asociados a la medición de muchos caracteres en una misma entidad biológica. De especial interés son los métodos multivariados diseñados para analizar similitudes entre entidades caracterizadas por múltiples variables que permiten resumir la información en pocas variables sintéticas informativas de la variabilidad total. En este trabajo se discuten e ilustran distintos métodos multivariados utilizados en la construcción del dato de variabilidad genética. Se incluyen métodos aplicados a la exploración de la estructura espacial de la variabilidad genética y métodos para estudiar la asociación de los datos genéticos con otras fuentes de información. Las técnicas multivariadas en esta revisión permiten abordar el problema de construir al dato de variabilidad genética como un concepto donde convergen mediciones sobre tipo, abundancia y distribución de la variabilidad a nivel de genes.