ABSTRACT Public procurement is crucial for the proper functioning of a country, but unfortunately, it can face problems that undermine its efficiency and transparency. For this reason, this research analyzes the top 23 companies that sold over $2.21 billion to the Ecuadorian government between 2015 and 2020. A descriptive methodology and a quantitative approach were used to classify the companies based on their origin, economic activity, and financial situation. The results reveal that 67% of these companies are of Ecuadorian origin. In terms of their financial situation, although they have a strong liquidity position, financing expenses completely dilute their profits, resulting in a negative net profit margin. This finding suggests the need to establish public policies that promote the diversification of economic sectors and the implementation of effective financial management strategies in contracting companies to improve their profitability and long-term financial sustainability.

RESUMEN La contratación pública es crucial para el buen funcionamiento de un país, pero desafortunadamente puede enfrentar problemas que perjudican su eficiencia y transparencia. Por este motivo, esta investigación analiza las 23 principales empresas que entre 2015 y 2020 vendieron más de 2.21 mil millones de dólares con el Estado ecuatoriano. Se utilizó una metodología descriptiva y un enfoque cuantitativo para clasificar a las empresas según su origen, actividad económica y situación financiera. Los resultados revelan que el 67% de estas empresas son de origen ecuatoriano. En cuanto a su situación financiera, aunque tienen una posición sólida en términos de liquidez, los gastos del financiamiento diluyen en su totalidad las utilidades, generando una rentabilidad neta de ventas negativa. Este hallazgo sugiere la necesidad de establecer políticas públicas que promuevan la diversificación de los sectores económicos y la implementación de estrategias de gestión financiera efectivas en las empresas contratistas para mejorar su rentabilidad y sostenibilidad financiera en el largo plazo.

Resumen El objetivo de este estudio es determinar las potencialidades de los pastos más utilizados en los sistemas de producción familiar en la provincia de Los Ríos, Ecuador, durante el verano. El estudio se realizó en áreas de investigación y en el Laboratorio de Ruminología y Metabolismo Nutricional de la Universidad Técnica Estatal de Quevedo. Las especies más utilizadas en los sistemas ganaderos fueron seleccionadas para realizar estudios de comportamiento productivo (biomasa total, RMS total, hojas y tallos) calidad (MS, PB, cenizas, MO, P, Ca, FDN, FDA, LAD, Cel, Hcel, CC, TT, FT, TCT, DIVMS, DISMS, DMO, EM y ENL), a las que se les realizaron análisis de conglomerados para agrupar especies con similitud. Para la producción y composición química se obtuvieron tres componentes principales con valores propios superiores a uno y que explican 87.27 % de la variabilidad entre las variedades. En el componente uno se mostraron 11 indicadores relacionados con proteína, energía y los componentes estructurales de la célula con valores de preponderancia mayor de 0.75. Para el análisis de conglomerados se formaron cinco grupos, con los mejores resultados para el tercer grupo, lo integró el M. maximus con valores altos en la PB, relación hoja/tallo, DISMS y EM. Toda esta información contribuiría al diseño de alternativas tecnológicas para siembra, establecimiento, manejo y uso de su biomasa como fuente de alimento donde se minimiza la productividad y la sostenibilidad del ecosistema.

Abstract The aim of this study is to determine the potentialities of the most used grasses in family production systems in Los Ríos province, Ecuador, during the summer. The study was carried out in research areas and in the Ruminology and Nutritional Metabolism Laboratory of the Quevedo State Technical University. The species most used in livestock systems were selected to carry out studies of productive behavior (total biomass, total DMY, leaves and stems) and quality (DM, CP, ashes, OM, P, Ca, NDF, ADF, Lignin, Cel, Hcel, CC, IVDMD, ISDMD, OMD, ME and NLE), which underwent cluster analysis to group species with similarity. For production and chemical composition, three main components were obtained with eigenvalues greater than one and that explain 87.27 % of the variability between varieties. In component one, 11 indicators related to protein, energy and the structural components of the cell were shown with values of preponderance greater than 0.75. For the cluster analysis, five groups were formed, with the best results for the third group, made up of M. maximus with high values in CP, leaf/stem ratio, ISDMD and ME. All this information would contribute to the design of technological alternatives for sowing, establishment, management, and use of its biomass as a food source where the productivity and sustainability of the ecosystem are minimized.

Resumen: A partir de una experiencia en común, se intenta resaltar alguna característica personal descollante de Carlos Castilla del Pino que le permitió resistir la atonía socio-cultural y profesional del franquismo y desarrollar, a pesar de todo, una vida profesional y teórica relevante. Tuvo que resistir esa atonía y amordazamiento de la larga noche de piedra y argamasa del franquismo en una ciudad de provincias duramente represaliada durante la guerra y posguerra civil española, dominada por tanto durante decenios por el fascismo institucional e ideológico. A pesar de ello, Carlos Castilla logró desarrollar una obra teórica (en especial en psicopatología, antropología e ideología) sumamente avanzada, coherente y arriesgada, para cuya compresión propongo un marco pragmático. El lema republicano, resistir es vencer, podría ser un buen resumen de su vida profesional y teórica, aunque es más dudoso que tal afirmación pueda tener el mismo valor para su vida personal.

Abstract: Based on a common experience, we try to highlight some outstanding personal characteristic of Carlos Castilla del Pino that allowed him to resist the socio-cultural and professional lethargy of Francoism and develop, despite everything, a relevant professional and theoretical life. To do so, he had to resist that lethargy and gagging of the long night of stone and mortar of Francoism and, on top of that, in a provincial city harshly retaliated during and after the Spanish civil war; therefore dominated for decades by institutional and ideological fascism. Despite this, Castilla del Pino managed to develop a highly advanced, coherent and risky theoretical work, especially in psychopathology, anthropology and ideology, for whose understanding I propose a pragmatic framework. The Republican motto, “to resist is to win”, could be a good summary of his professional and theoretical life, although it is more doubtful that such statement can have the same value for his personal life.

La mortalidad y formas graves atribuibles al COVID-19 en población pediátrica han sido bajas en comparación con los adultos. No obstante, los niños, niñas y adolescentes (NNA) constituyen un universo especialmente afectado por la pandemia, en cuanto a restricción y limitación de sus derechos. La Subcomisión de Derechos de la Niñez y Adolescencia y el Comité de Pediatría Social de la Sociedad Argentina de Pediatría entendieron trascendente recolectar sus voces para relevar el impacto que la transición de la situación de pandemia por COVID-19 a la actual "nueva normalidad" ha producido en los sentimientos, emociones y deseos de los NNA en Argentina. Realizamos un estudio cualitativo, descriptivo, basado en encuesta anónima, entre NNA argentinos de 6 a 18 años residentes en Argentina. El análisis incluyó 1537 entrevistas efectivas. Los resultados permitieron sugerir recomendaciones para desarrollar estrategias de afrontamiento, contención y acompañamiento de los NNA en la pospandemia.

Resumen Antecedentes: El síndrome de Down es la anomalía cromosómica más frecuente y se asocia con defectos cardiacos congénitos, elementos clínicos de una alta morbilidad y mortalidad infantil. Objetivo: Describir los desenlaces clínicos de los pacientes con síndrome de Down sometidos a cirugía e intervencionismo como tratamiento de las cardiopatías congénitas en esta institución. Material y métodos: Estudio retrospectivo que incluyó pacientes menores de 18 años con síndrome de Down y patología cardiaca asociada durante los últimos 10 años. Las variables estudiadas fueron: peso, talla, sexo, edad, tipo de cardiopatía, procedimiento correctivo, tiempo de estancia intrahospitalaria y en unidad de terapia intensiva, morbilidad y mortalidad. Resultados: 368 pacientes pediátricos fueron llevados a corrección quirúrgica o intervencionista, de los cuales 197 (54%) pertenecían al sexo femenino, la mediana de edad fue de 24 meses (rango intercuartílico [RIQ]: 14-48) en el grupo quirúrgico y de 36 meses (RIQ: 17-85) en el intervencionista. Las cardiopatías congénitas más frecuentes fueron: persistencia del conducto arterioso (31%), comunicación interventricular (28%), canal atrioventricular (CAV) (20%), comunicación interauricular (16%) y tetralogía de Fallot con el 4% respectivamente. La estancia hospitalaria fue de 9 días (RIQ: 7-15) en el grupo quirúrgico y de 3 días (RIQ: 2-5) en el hemodinámico. Las morbilidades fueron infección postoperatoria en 30 pacientes (14%) y en 19 pacientes (9%) bloqueo atrioventricular completo. La mortalidad global incluyendo tanto el quirúrgico como el intervencionista fue del 2%. Conclusiones: Los resultados terapéuticos, quirúrgicos e intervencionistas, en los niños con síndrome de Down y cardiopatías congénitas han mejorado en forma muy satisfactoria. Es de destacar la menor prevalencia del CAV en la población mexicana. Es indispensable realizar evaluación cardiológica a los niños con síndrome de Down y aquellos con cardiopatías congénitas llevarlos a corrección de manera oportuna para favorecer la sobrevida y calidad de vida.

Abstract Background: Down syndrome is the most common chromosomal abnormality, it is associated with a wide variety of congenital heart defects, being considered as clinical elements of high infant morbidity and mortality. Objective: To describe the clinical outcomes of patients with Down syndrome undergoing surgery and interventionism as treatment for congenital heart disease at this Institution. Material and methods: 368 patients with Down syndrome and associated congenital heart disease were diagnosed. The variables studied were weight, stature, sex, age, type of heart disease, corrective procedure, length of stay in the hospital and intensive care unit, morbidity and mortality. Results: 368 pediatric patients underwent surgical or interventional correction. Of which 197 (54%) were female, the median age was 24 months (interquartile range [IQR]: 14-48) in the surgical group and 36 months (IQR: 17-85) in the interventional group. The most frequent congenital heart diseases were: PCA (31%), IVC (28%), CAV (20%), ASD (16%) and tetralogy of Fallot with 4% respectively. Hospital stay was 9 days (IQR: 7-15) in the surgical group and 3 days (IQR: 2-5) in the hemodynamic group. Morbidities were postoperative infection in 30 patients (14%) and complete atrioventricular block in 19 patients (9%). Overall mortality including both surgical and interventional was 2%. Conclusions: The therapeutic, surgical and interventional results in children with Down syndrome and congenital heart disease have improved very satisfactorily. The lower prevalence of the atrioventricular canal in the Mexican population is noteworthy. It is essential to carry out a cardiological evaluation of children with Down syndrome and those with congenital heart disease to correct them in a timely manner to promote survival and quality of life.

Resumen El comportamiento de los componentes de las plantas proteicas es de vital importancia para los animales que los consumen en su dieta. La presente investigación tiene como objetivo evaluar algoritmos de regresión para determinar la conducta de las expresiones que mejor se adaptan a los procedimientos de un laboratorio tradicional y estimar los componentes químicos de plantas proteicas, en este sentido, se ha utilizado la biblioteca MULAN de java, que contiene algoritmos de aprendizaje automático capaces de adaptarse a disímiles problemas. Para ello, se crearon tres conjuntos de datos para cada especie estudiada en este trabajo; cada uno de estos incluye los elementos principales a ser evaluados en cada experimento, que están delimitados por: Metabolitos secundarios, componentes de la pared celular y digestibilidad para los ficheros de entrenamiento uno, dos y tres, respectivamente. Posteriormente, fueron evaluados por medio del aprendizaje supervisado y una validación cruzada de cada uno para determinar el mejor ajuste por aRMSE (Error cuadrático medio de la raíz). Los resultados del aprendizaje fueron comparados con experimentos anteriores, donde se tenía una variante de aprendizaje que contenía en un solo dataset todos los componentes a evaluar en una sola predicción. El resultado de la comparación muestra que los algoritmos vagos basados en instancias tienen un mejor comportamiento en el aprendizaje que los otros evaluados.

Abstract The behavior of components of protein plant is of vital importance for animals that consume them in their diet. The objective of this research is to evaluate regression algorithms, to determine the behavior of the expressions that best adapt to the procedures of a traditional laboratory and to estimate the chemical components of protein plants, in this sense the MULAN library of java has been used, that contain automatic learning algorithms capable of adapting to dissimilar problems. Three data set were created for each species treated in this study; each of these include the main elements to be evaluate in each experiment, these are delimitings by: secondary metabolites, cell wall components and digestibility element for training files one, two and three, respectively; subsequently, they were evaluated through learning supervised and cross-validation of each to determine the best fit by aRMSE (Average Root Mean Square Error). The learning results were compare with previous experiments, where there was a learning variant that contained in a single dataset all the components to be evaluates in a single prediction. The result of the comparison shows that the lazy algorithms based on instances have a better learning behavior than the others evaluate.

ABSTRACT Introduction. Hip fractures are a group of frequent pathologies in frail older adults, with a negative impact on functionality. Objective. To determine the clinical, functional, mental, and social characteristics based on the comprehensive geriatric assessment. Methods. 445 patients were evaluated, comorbidity was measured with the Charlson index, baseline functional state with the Barthel index and the Lawton and Brody scale, mental state with the Pfeiffer questionnaire, delirium using the Confusion Assessment Method and social assessment with the Gijón Socio-Family Scale. Categorical variables were presented as absolute value and percentage and continuous variables as mean and standard deviation. Results. The female sex represented 71.5%, the average age in women was 81.58 years and in men 82.58 years. Visual impairment was 48.8% and hearing impairment 46.1%. 46% had more than one comorbidity. 30.3% were independent for basic activities, as well as 90.3% of women and 64.3% of men were dependent for instrumental activities. Cognitive impairment was present in 53.5% and delirium developed in 20.4%. In the second week, 30.5% were operated and in the third, 21.6%. Mortality was 2.7% during hospitalization. Conclusion. the most frequent characteristics were of an octogenarian, with visual / auditory deterioration, without comorbidity, but multipathological, with slight dependence for basic activities of daily living and cognitive deterioration in a risky social environment.

RESUMEN Introducción. Las fracturas de cadera son un conjunto de patologías frecuentes en los adultos mayores frágiles, con impacto negativo sobre la funcionalidad. Objetivo. Determinar las características clínicas, funcionales, mentales y sociales basados en la evaluación geriátrica integral. Métodos. Se evaluó a 445 pacientes, la comorbilidad se midió con el índice de Charlson, el estado funcional basal con el índice de Barthel y la escala de Lawton y Brody, el estado mental con el cuestionario de Pfeiffer, el delirio mediante el Confusion Assessment Method y la evaluación social con la Escala Sociofamiliar de Gijón. Las variables categóricas se presentaron como valor absoluto y porcentaje, y las continuas como media y desviación estándar. Resultados. El sexo femenino representó el 71,5%, el promedio de edad en mujeres fue de 81,58 años y en varones de 82,58 años. El deterioro visual fue 48,8% y el auditivo fue 46,1%. El 46,0% tuvieron más de una comorbilidad. 30,3% era independiente para actividades básicas, así como 90,3% de mujeres y 64,3% de hombres fueron dependientes para actividades instrumentales. El deterioro cognitivo estuvo presente en el 53,5% de los pacientes y delirio el 20,4%. En la segunda semana fueron operados 30,5% y en la tercera 21,6%. La mortalidad fue de 2,7% durante la hospitalización. Conclusión. Las características más frecuentes fueron de una octogenaria, con deterioro visual/auditivo, sin comorbilidad, pero pluripatológica, con dependencia leve para actividades básicas de vida diaria y deterioro cognitivo en entorno social de riesgo.

ABSTRACT The behavior of marine currents in the Florida Straits was sampled by seven oceanographic moorings between 2012 and 2018. Using data from one of these moorings, the behavior of the Florida Current during said period was analyzed. The statistical parameters used in the research were: minimum, maximum, mean, standard deviation, anomalous values, and Pearson's correlation coefficient. Current roses were obtained at different depths from the filtered data with a cut frequency of 48 hr-1. The maximum magnitude values of the Florida Current reached up to 2 m/s, with a movement towards the east-northeast or east. Absolute values of the anomalies in the study period 2012 -2018 did not exceed 0.15 m/s, and those of monthly anomalies alternated their sign in a biannual or triannual period. An extremely low linear correlation was detected between annual series for all depths of the analysis, with absolute Pearson correlation values lower than 0.31. Particularly, between August-2013 and August-2014, the Florida Current showed a slight tendency to slow down; and in the period August-2015 // August-2016, a predominance in its proximity to Cuba. No evidence was found of anomalous behavior of the Florida Current with respect to its historical behavior.

RESUMEN Entre 2012 y 2018 se monitoreó el comportamiento de las corrientes marinas en el Estrecho de La Florida mediante mediciones directas en siete anclajes oceanográficos. Con los datos de uno de estos anclajes se analizó el comportamiento de la Corriente de La Florida durante dicho periodo. Los estadígrafos empleados en el estudio fueron: mínimo, máximo, media, desviación estándar, valores anómalos y coeficiente de correlación de Pearson. Se obtuvieron rosas de corrientes en diferentes profundidades con los datos filtrados con frecuencia de corte de 48 h-1. Los valores máximos de magnitud de la Corriente de La Florida alcanzaron hasta 2 m/s, predominando el movimiento hacia el estenoreste o el este. Los valores absolutos de las anomalías en el periodo de estudio 2012 -2018 no superaron 0,15 m/s y los de las anomalías mensuales alternaron su signo en un periodo bianual o trianual. Se detectó una muy baja correlación lineal entre series anuales para todas las profundidades de análisis, con valores absolutos de correlación de Pearson inferiores a 0,31. Particularmente, entre agosto-2013 y agosto-2014, la Corriente de La Florida mostró una ligera tendencia a su ralentización; y en el lapso agosto-2015//agosto-2016, un predominio en su acercamiento a Cuba. No se encontró evidencia de un comportamiento anómalo de la Corriente de La Florida con respecto a su comportamiento histórico.

RESUMEN Los pacientes con COVID-19 tienen un amplio espectro de presentación clínica y las tasas de mortalidad en los casos graves son relativamente altas. La identificación tem prana de los factores de riesgo que se relacionan con la gravedad de la enfermedad es de vital importancia. Con el objetivo de correlacionar los síntomas iniciales de COVID-19 con la gravedad de la enfermedad, se realizó el presente estudio de cohorte transversal retrospectivo y observacional de 413 pacientes con diagnóstico de COVID-19 entre enero y marzo 2021. De todos los síntomas iniciales estudiados, la disnea (p < 001), fiebre (p 0,001), tos (p 0,002), odinofagia (p 0,01), cefalea (p 0,01) y síntomas gastrointestinales (p 0,03), se asociaron con el desarrollo de una enfermedad grave. Las comorbilidades que se asociaron con peor pronóstico fueron: hipertensión arterial (p < 0,001), obesidad (p < 0,001), EPOC (p < 0,001), extabaquismo (p < 0,001), diabetes (p 0,01), enfermedad cardiovascular previa (p 0,03), y enfermedad oncológica activa (p 0,04). En conclusión, los pacientes con diagnóstico de COVID-19, cuya manifestación inicial es disnea, fiebre, tos, odinofagia, cefalea y síntomas gastrointestinales, deben ser monitoreados de cerca para prevenir el deterioro de la enfermedad.

ABSTRACT Patients with COVID-19 have a broad spectrum of clinical presentations, and mortal ity rates are relatively high in severe cases. Early identification of risk factors that are related to the severity of the disease is of vital importance. In order to correlate the initial symptoms of COVID-19 with disease severity, the present retrospective, cross-sectional, observational cohort study was conducted, including 413 patients diagnosed with COVID-19 between January and March, 2021. Of all the initial symptoms that were studied, dyspnea (p < 001), fever (p 0.001), cough (p 0.002), odynophagia (p 0.01), headache (p 0.01), and gastrointestinal symptoms (p 0.03) were associated with the development of severe illness. The comorbidities that were associated with the worst prognoses were: arterial hypertension (p < 0.001), obesity (p < 0.001), COPD (chronic obstructive pulmonary disease) (p < 0.001), former smoking (p < 0.001), diabetes (p 0.01), previous cardiovascular disease (p 0.03), and active oncological disease (p 0.04). In conclusion, patients diagnosed with COVID-19 whose initial manifestations include dyspnea, fever, cough, odynophagia, headache, and gastrointestinal symptoms should be closely monitored to prevent disease deterioration.

RESUMEN Los pacientes con COVID-19 tienen un amplio espectro de presentación clínica y las tasas de mortalidad en los casos graves son relativamente altas. La identificación tem prana de los factores de riesgo que se relacionan con la gravedad de la enfermedad es de vital importancia. Con el objetivo de correlacionar los síntomas iniciales de COVID-19 con la gravedad de la enfermedad, se realizó el presente estudio de cohorte transversal retrospectivo y observacional de 413 pacientes con diagnóstico de COVID-19 entre enero y marzo 2021. De todos los síntomas iniciales estudiados, la disnea (p < 001), fiebre (p 0.001), tos (p 0.002), odinofagia (p 0.01), cefalea (p 0.01) y síntomas gastrointestinales (p 0.03), se asociaron con el desarrollo de una enfermedad grave. Las comorbilidades que se asociaron con peor pronóstico fueron: hipertensión arterial (p < 0.001), obesidad (p <0.001), EPOC (p < 0.001), ex tabaquismo (p < 0.001), diabetes (p 0.01), enfermedad cardiovascular previa (p 0.03), y enfermedad oncológica activa (p 0.04). En conclusión, los pacientes con diagnóstico de COVID-19, cuya manifestación inicial es disnea, fiebre, tos, odinofagia, cefalea y síntomas gastrointestinales, deben ser monitoreados de cerca para prevenir el deterioro de la enfermedad.

ABSTRACT Patients with COVID-19 have a broad spectrum of clinical presentations, and mortal ity rates are relatively high in severe cases. Early identification of risk factors that are related to the severity of the disease is of vital importance. In order to correlate the initial symptoms of COVID-19 with disease severity, the pres ent retrospective, cross-sectional, observational cohort study was conducted, including 413 patients diagnosed with COVID-19 between January and March, 2021. Of all the initial symptoms that were studied, dyspnea (p < 001), fever (p 0.001), cough (p 0.002), odynophagia (p 0.01), headache (p 0.01), and gastrointestinal symptoms (p 0.03) were associated with the development of severe illness. The comorbidities that were associated with the worst prognoses were: arterial hypertension (p < 0.001), obesity (p < 0.001), COPD (chronic obstructive pulmonary disease) (p < 0.001), former smok ing (p < 0.001), diabetes (p 0.01), previous cardiovascular disease (p 0.03), and active oncological disease (p 0.04). In conclusion, patients diagnosed with COVID-19 whose initial manifestations include dyspnea, fever, cough, odynophagia, headache, and gastrointestinal symptoms should be closely monitored to prevent disease deterioration.

Abstract Alcohol Use Disorder (AUD) is a highly prevalent condition worldwide that produces a wide range of pathophysiological consequences, with a critical impact on health and social issues. Alcohol influences gene expression through epigenetic changes mainly through DNA methylation. In this sense, levels of 5-methylcytosine (5-mC), namely Global DNA methylation (GMe), which can be influenced by environmental and hormonal effects, represent a putative biological mechanism underlying alcohol effects. Our aim was to investigate the influence of AUD diagnosis and alcohol patterns (i.e., years of addiction, use in the last 30 days, and alcohol severity) on GMe levels. The sample consisted of 256 men diagnosed with AUD and 361 men without AUD. DNA samples from peripheral blood were used to assess GMe levels, measured through the levels of 5-mC using high-performance liquid chromatography. Results from multiple linear regression analysis indicated that the presence of AUD was associated with lower GMe levels (beta=-0.155, p=0.011). Other alcohol-related outcomes were not associated with DNA methylation. Our findings are consistent with the hypothesis that the impact of chronic and heavy alcohol use in GMe could be a potential mechanism mediating the multiple organ damages related to AUD.

Abstract The Yarinacocha lake is an emblematic ecosystem of the Peruvian Amazon, representing the main point of fish landing and a tourist attraction in the city of Pucallpa. The wide fauna diversity in this area has made it the target of various studies, although for fish species most of them were focused on commercial species. In this work, we carried out the first ichthyofauna species inventory of the Yarinacocha lake, sampling throughout the entire lake during the rainy and dry seasons and considering also all previously recorded species deposited in the Ichthyological Collection of the MUSM with the same locality. A total of 164 fish species were recorded, representing 10 orders (plus Eupercaria), 34 families and 116 genera. Characiformes was the order with more species (68 spp., 41.5%) followed by Siluriformes (59 spp., 36%), Cichliformes (17 spp., 10.5%), and Gymnotiformes (8 spp., 4.9%). The most highly represented families, including almost 55.5% of the total diversity obtained, were Characidae (23 spp., 14%), followed by Cichlidae (17 spp., 10.4%), Loricariidae (14 spp., 8.5%), Pimelodidae (13 spp., 7.9%), Doradidae (13 spp., 7.4%) and Anostomidae (12 spp., 7.3%). From the total fish species recorded in this study, only 22 are considered protected species following the IUCN criteria and 109 species have commercial importance, including 90 ornamental species (54.8%). Our results contribute to the knowledge of the ichthyofauna of the Yarinacocha lake and can be used as a starting point for its conservation and sustainable management over time.

Resumo O lago Yarinacocha é um ecossistema emblemático da Amazônia peruana, representando o principal ponto de desembarque de peixes e também uma atração turística da cidade de Pucallpa. A grande diversidade faunística nesta área a tornou alvo de vários estudos, embora para as espécies de peixes a maioria deles tenha sido focada em espécies comerciais. Neste trabalho, realizamos o primeiro inventário da ictiofauna do lago Yarinacocha, amostrando todo o lago durante as estações chuvosa e seca, e também considerando todas as espécies depositadas na Coleção Ictiológica do MUSM dessa localidade. Um total de 164 espécies de peixes foram registradas, representando 10 ordens (mais Eupercaria), 34 famílias e 116 gêneros. Characiformes foi a ordem com mais espécies (68 espécies, 41,5%), seguida por Siluriformes (59 espécies, 36%), Cichliformes (17 espécies, 10,5%) e Gymnotiformes (8 espécies, 4,9%). As famílias mais representadas, incluindo quase 55,5% da diversidade total obtida, foram Characidae (23 spp., 14%), seguido por Cichlidae (17 spp., 10,4%), Loricariidae (14 spp., 8,5%), Pimelodidae (13 spp., 7,9%), Doradidae (13 spp., 7,4%) e Anostomidae (12 spp., 7,3%). Do total de espécies de peixes registradas neste estudo, apenas 22 são consideradas espécies protegidas seguindo os critérios da IUCN e 109 espécies têm importância comercial, incluindo 90 espécies ornamentais (54,8%). Nossos resultados contribuem para o conhecimento da ictiofauna do lago Yarinacocha e podem ser utilizados como ponto de partida para sua conservação e manejo sustentável ao longo do tempo.

ABSTRACT: The aim was to describe the incidence and lesions caused by metazoan and protozoan parasites in Didelphis virginiana opossums in Mexico. From 2019 to 2021, twenty D. virginiana were collected from the state of Colima, Mexico. Post mortem, parasitological, and histopathological studies were performed to identify and describe their lesions and findings. All opossums(20/20) presented at least one type of parasite of the twelve found; the most abundant were nematodes 58.33% (7/12) Didelphostrongylus hayesi, Turgida turgida, Cruzia sp., Viannaia sp., Trichuris didelphis, Trichostrongylidae and Gnathostoma sp. Protozoa 25% (3/12), including Sarcocystis sp., Besnoitia sp., and Sarcocystis sp. A single specimen of Mathevotaenia sp., 8.3% (1/12), and Paragonimus mexicanus 8.3%, were identified (1/12). The most affected systems were the digestive, respiratory, and musculoskeletal. The most abundant parasites were Turgida turgida (20/20) 100%, Cruzia sp., (16/20) 80%, and Viannaia sp. (6/20) 30%, followed by Sarcocystis sp. cysts, (6/20) 30%. The associated parasitic lesions were: D. hayesi produce eosinophilic granulomatous bronchopneumonia, P. mexicanus eosinophilic focal granulomatous pneumonia, and Besnoitia sp., focal eosinophilic lymphoplasmacytic interstitial pneumonia. Gnathostoma and T. turgida caused severe eosinophilic granulomatous focal gastritis. Viannaia sp., Sarcocystis sp., Mathevotaenia sp., and Trichostrongylidae; caused diffuse eosinophilic mucosal enteritis. Cruzia sp., and T. didelphis, induced diffuse eosinophilic mucosal typhlitis. Sarcocystis sp. cysts were detected in the cytoplasm of muscle fibers without histological changes.

RESUMO: O objetivo deste artigo foi descrever a frequência e as lesões causadas por parasitas metazoários e protozoários em gambás (Didelphis virginiana) no México. De 2019 a 2021, vinte Gambás (D. virginiana) foram coletados no estado de Colima, México. Estudos post mortem, parasitológicos e histopatológicos foram realizados para identificar e descrever suas lesões. Todos os gambás (20/20) apresentaram pelo menos um tipo de parasita dos doze encontrados, os mais abundantes foram os nematóides 58,33% (7/12) Didelphostrongylus hayesi, Turgida turgida, Cruzia sp., Viannaia sp., Trichuris didelphis, Trichostrongylidae e Gnathostoma sp. Protozoários 25% (3/12) Sarcocystis sp., Besnoitia sp. e Sarcocystis sp. Só uma única espécie de Mathevotaenia sp., 8,3% (1/12) e Paragonimus mexicanus 8,3% (1/12). Os sistemas mais acometidos foram o digestivo, respiratório e musculoesquelético. Os parasitas mais abundantes foram T. turgida (20/20) 100%, Cruzia sp., 80% (16/20), e Viannaia sp., 30% (6/20), seguidos pelos cistos de Sarcocystis sp., 30% (6/20). As lesões observadas causadas pelos vários tipos de parasitas foram: D. hayesi produziu broncopneumonia granulomatosa eosinofílica, P. mexicanus gerou pneumonia granulomatosa focal eosinofílica e Besnoitia sp. produziu pneumonia intersticial linfoplasmocítica eosinofílica focal. Ganthostoma e T. turgida geraram uma gastrite focal granulomatosa eosinofílica grave. Viannaia sp., Sarcocystis sp., Mathevotaenia sp. e Trichostrongylidae causaram enterite mucosa eosinofílica difusa. Cruzia sp. e Trichuris didelphis causaram tiflite mucosa eosinofílica difusa. Cistos de Sarcocystis spp. foram detectados no citoplasma das fibras musculares, sem alterações histológicas.

Abstract We compared sampling techniques in a managed native forest in Paragominas, Pará, Brazil. Our goal in this study was to evaluate the feasibility of using Double Sampling (DS) and Sampling with Partial Replacement (SPR), when compared to Continuous Forest Inventory (CFI), to estimate the wood stock for trees with DBH ≥ 20 cm in a managed forest. In our results, DS had the best volume prediction, generating a sampling error of 5.20% (11.48 m³ ha-1) on the second occasion 3.86% (8.78 m³ ha-1). The average volume increment, estimated for the forest in the monitored period (2014-2016) was 6.88 m³ ha-1, with a relative sampling error of 63.09%. Therefore, as an alternative and of low cost, we suggest using DS in successive forest inventories in monitoring areas of forest resources in the Brazilian Amazon.