2,655 research outputs found

    DIET OF OILBIRDS (STEATORNIS CARIPENSIS) IN CUEVA DE LOS GUÁCHAROS NATIONAL PARK (COLOMBIA): TEMPORAL VARIATION IN FRUIT CONSUMPTION, DISPERSAL, AND SEED MORPHOLOGY

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    Abstract  ∙ Oilbirds (Steatornis caripensis) are specialized nocturnal frugivores that inhabit Neotropical forests and have the potential to play key ecological roles as seed dispersers. In this study, we focused on type and quantity of seeds dispersed by a population of Oilbirds in Cueva de Los Guácharos National Park (Colombia). We assessed temporal variation in diet composition, fruit nutrient composition and measured seed morphology. To do this, we used 5–10 seed traps in a cave from 2011 to 2016, conducting a 5‐day census 1–4 times each year. In 2015, we performed a census in all 12 months to document within year variation. We found seeds of 52 species (including 17 named species, 12 identified just to family, and 23 morphospecies). We found a clear dominance of Arecaceae and Lauraceae families. Intra‐annual variation in species richness reflects the fact that more biomass and higher seed numbers are deposited in the cave in periods of nesting (January–June), as well as during seasonal fruiting patterns in the region. Data on fruit contents from published literature indicated that oilbird diet includes a high representation of lipid‐rich fruits. Consumed seed size varied enormously (range: 0.01–5.99 g dry mass), the largest seeds being up to 29 mm wide and 54 mm long. Regurgitated seeds showed a negative allometric relationship between width and length. Overall, we found a diverse diet and that Oilbirds provide efficient seed dispersal in terms of seed quantity; however, many aspects of dispersal quality remain to be determined. Resumen ∙ Dieta de los Guácharos (Steatornis caripensis) en el parque nacional Cueva de Los Guácharos (Colombia): variación temporal en la cantidad de la dispersión y morfología de semillas Los guácharos (Steatornis caripensis) son aves nocturnas frugívoras especializadas que habitan bosques neotropicales y que tienen el potencial de desempeñar roles ecológicos claves como dispersoras de semillas. En este trabajo, estudiamos la dieta y la cantidad de semillas dispersadas por una población de guácharos en el Parque Nacional Natural Cueva de los Guácharos (Colombia). Para ello, evaluamos la variación temporal, comparamos la composición de lípidos y medimos la morfología de las semillas. De 2011 a 2016 dispusimos 5–10 trampas de semillas en la cueva principal del parque y llevamos a cabo censos de usualmente 5 días, 1–4 veces cada año. Adicionalmente, en 2015 hicimos censos mensuales durante todo el año. En la dieta de los guácharos encontramos semillas de 52 especies de plantas (incluyendo 17 especies, 12 taxones identificados hasta familia y 23 morfoespecies), en las cuales se reflejó una clara dominancia de las familias Arecaceae y Lauraceae. La variación intranual en la riqueza de especies de las semillas depositadas en la cueva mostró que en los periodos de anidación de los guácharos (enero a junio) se presentó el mayor número de semillas y la mayor biomasa, además una alta riqueza de especies en el primer semestre es coherente con los patrones de fructificación en la región. La dieta del guácharo incluyó una alta representación de frutos ricos en lípidos, lo cual fue inferido de la literatura publicada. Los tamaños de las semillas dispersadas variaron enormemente (peso seco entre 0.01 y 5.99 g), siendo las semillas más grandes de 29 mm de ancho y 54 mm de largo. Las semillas que fueron dispersadas mostraron una relación alométrica negativa entre el ancho y el largo. Aunque, nosotros reportamos que los guácharos tienen una dieta diversa y proveen una eficiente dispersión de semillas en términos de la cantidad, aún deben determinarse muchos aspectos de la calidad de la dispersión

    Understanding the neurological implications of acute and long COVID using brain organoids

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    As early as in the acute phase of the coronavirus disease 2019 about the long-term implications of infection. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), like many other viruses, can trigger chronic disorders that last months or even years. Long COVID, the chronic and persistent disorder lasting more than 12 weeks after the primary infection with SARS-CoV-2, involves a variable number of neurological manifestations, ranging from mild to severe and even fatal. In vitro and in vivo modeling suggest that SARS-CoV-2 infection drives changes within neurons, glia and the brain vasculature. In this Review, we summarize the current understanding of the neuropathology of acute and long COVID, with particular emphasis on the knowledge derived from brain organoid models. We highlight the advantages and main limitations of brain organoids, leveraging their humanoerived origin, their similarity in cellular and tissue architecture to human tissues, and their potential to decipher the pathophysiology of long COVID

    Small farmers' perception of factors influencing regional chemical control of Diaphorina citri

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    Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs.Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs

    Purification and characterization of patagonfibrase, a metalloproteinase showing α-fibrinogenolytic and hemorrhagic activities, from Philodryas patagoniensis snake venom

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    Venoms of Colubridae snakes are a rich source of novel compounds, which may have applications in medicine and biochemistry. In the present study, we describe the purification and characterization of a metalloproteinase (patagonfibrase), the first protein to be isolated fromPhilodryas patagoniensis (Colubridae) snake venom. Patagonfibrase is a single-chain protein, showing a molecular mass of 53,224 Da and an acidic isoelectric point (5.8). It hydrolyzed selectively the Aá-chain of fibrinogen and when incubated with fibrinogen or plasma, the thrombin clotting time was prolonged. Prominent hemorrhage developed in mouse skin after intradermal injection of patagonfibrase. When administered into mouse gastrocnemius muscle, it induced local hemorrhage and necrosis, and systemic bleeding in lungs. Patagonfibrase showed proteolytic activity toward azocasein, which was enhanced by Ca 2+ and inhibited by Zn2+, cysteine, dithiothreitol and Na2EDTA. Patagonfibrase impaired platelet aggregation induced by collagen and ADP. Thus, patagonfibrase may play a key role in the pathogenesis of disturbances that occur in P. patagoniensis envenomation, and may be used as a biological tool to explore many facets of hemostasis.Fil: Peichoto, María Elisa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Teibler, Pamela. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Mackessy, S.. Univeristy Of Northem Colorado. School Of Biological Sciences; Estados UnidosFil: Leiva, Laura Cristina Ana. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Acosta, Ofelia Cristina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Gonçalves, L. R. C.. Governo Do Estado de Sao Paulo. Secretaria Da Saude. Instituto Butantan. Laboratorio de Fisiopatologia; BrasilFil: Tanaka Azevedo, A.. Governo Do Estado de Sao Paulo. Secretaria Da Saude. Instituto Butantan. Laboratorio de Fisiopatologia; BrasilFil: Santoro, M.. Governo Do Estado de Sao Paulo. Secretaria Da Saude. Instituto Butantan. Laboratorio de Fisiopatologia; Brasi

    Effect of venom of Bothrops diporus from northeast Argentina on hemostatic system in different mammals

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    Fil: Maruñak, S. L. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.Fil: Nuñez, Sandra. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.Fil: Fernandez, C. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.Fil: Leiva, Laura Cristina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina.Fil: Acosta, Ofelia Cristina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.Los venenos de serpientes inducen gran variedad de efectos sobre la coagulación sanguínea debido a sus componentes coagulantes y anticoagulantes. En este trabajo se estudió el efecto del veneno de Bothrops diporus de Argentina sobre el sistema hemostático en diferentes especies de mamíferos, determinándose las actividades coagulante, fibrinolítica y letal. Se pudo comprobar que el veneno de esta serpiente genera desórdenes de la coagulación sanguínea atribuibles a enzimas de tipo trombinas que inducen la transformación del fibrinógeno a fibrina, registrándose mayor susceptibilidad en las especies ovina y humana. La dosis coagulante mínima se comparó con venenos de víboras centroamericanas, surgiendo que las serpientes de zonas más cálidas poseen menor actividad coagulante.Snake venoms induce a wide variety of disorders, some of them on blood coagulation, since they contain both coagulant and anticoagulant components. In this assay we present the effects of venom of Bothrops diporus from Argentina on the hemostatic system of different mammal species, in order to estimate blood–clotting, fibrinolytic, and lethal activities. From our results, it can be stated that this venom has trombin– like enzymes that produced coagulation of plasma, being ovine and human the most sensitive species. Minimum coagulant dose for this venom was compared to those from Central America (Bothrops asper, Costa Rica), suggesting that venom of snakes from warmer areas have less coagulant activity

    Concordancia entre las pruebas de ELISA avidez IgG desarrollados en el Instituto de Investigaciones en Ciencias de la Salud y un ELISA avidez comercial

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    La infección aguda de toxoplasmosis en la mujer durante el embarazo en su mayor parte es asintomática y detectable solo por anticuerpos lo que podría afectar severamente al feto si no es diagnosticada y tratada precozmente. En este estudio observacional analítico de corte transverso se comparó la prueba de ELISA Avidez IgG para toxoplasmosis desarrollado en el Instituto de Investigaciones en Ciencias de la Salud(IICS) con un test comercial de avidez InmunoLISA Organics USA. Para la concordancia se utilizó 41 sueros mantenidos a -20 ºC procedentes de la seroteca del Departamento de Producción-Bioquímica seleccionados al azar. La concordancia obtenida fue de 92.7% y un índice de Kappa de 0.820 con IC95% (0.6-1) y p<0.0001. El índice bajo de avidez sugiere una infección aguda pero para el diagnóstico debería estar acompañado de otras pruebas serológicas y la clínica del paciente. En cambio un índice alto es diagnóstico de una infección crónica

    3-Hydroxy Kynurenine Treatment Controls T. cruzi Replication and the Inflammatory Pathology Preventing the Clinical Symptoms of Chronic Chagas Disease

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    BACKGROUND: 3-Hydroxy Kynurenine (3-HK) administration during the acute phase of Trypanosoma. cruzi infection decreases the parasitemia of lethally infected mice and improves their survival. However, due to the fact that the treatment with 3-HK is unable to eradicate the parasite, together with the known proapoptotic and immunoregulatory properties of 3-HK and their downstream catabolites, it is possible that the 3-HK treatment is effective during the acute phase of the infection by controlling the parasite replication, but at the same time suppressed the protective T cell response before pathogen clearance worsening the chronic phase of the infection. Therefore, in the present study, we investigated the effect of 3-HK treatment on the development of chronic Chagas' disease. PRINCIPAL FINDINGS: In the present study, we treated mice infected with T. cruzi with 3-HK at day five post infection during 5 consecutive days and investigated the effect of this treatment on the development of chronic Chagas disease. Cardiac functional (electrocardiogram) and histopathological studies were done at 60 dpi. 3-HK treatment markedly reduced the incidence and the severity of the electrocardiogram alterations and the inflammatory infiltrates and fibrosis in heart and skeletal muscle. 3-HK treatment modulated the immune response at the acute phase of the infection impairing the Th1- and Th2-type specific response and inducing TGF-β-secreting cells promoting the emergence of regulatory T cells and long-term specific IFN-γ secreting cells. 3-HK in vitro induced regulatory phenotype in T cells from T. cruzi acutely infected mice. CONCLUSIONS: Our results show that the early 3-HK treatment was effective in reducing the cardiac lesions as well as altering the pattern of the immune response in experimental Chagas' disease. Thus, we propose 3-HK as a novel therapeutic treatment able to control both the parasite replication and the inflammatory response

    Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study

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    A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected

    Presence of an epigenetic signature of prenatal cigarette smoke exposure in childhood

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    Prenatal exposure to tobacco smoke has lifelong health consequences. Epigenetic signatures such as differences in DNA methylation (DNAm) may be a biomarker of exposure and, further, might have functional significance for how in utero tobacco exposure may influence disease risk. Differences in infant DNAm associated with maternal smoking during pregnancy have been identified. Here we assessed whether these infant DNAm patterns are detectible in early childhood, whether they are specific to smoking, and whether childhood DNAm can classify prenatal smoke exposure status. Using the Infinium 450 K array, we measured methylation at 26 CpG loci that were previously associated with prenatal smoking in infant cord blood from 572 children, aged 3–5, with differing prenatal exposure to cigarette smoke in the Study to Explore Early Development (SEED). Striking concordance was found between the pattern of prenatal smoking associated DNAm among preschool aged children in SEED and those observed at birth in other studies. These DNAm changes appear to be tobacco-specific. Support vector machine classification models and 10-fold cross-validation were applied to show classification accuracy for childhood DNAm at these 26 sites as a biomarker of prenatal smoking exposure. Classification models showed prenatal exposure to smoking can be assigned with 81% accuracy using childhood DNAm patterns at these 26 loci. These findings support the potential for blood-derived DNAm measurements to serve as biomarkers for prenatal exposure
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