Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

O-glicosilación incompleta en células cancerígenas y parásitos: Importancia biomédica

Durante la carcinogénesis ocurren modificaciones importantes en la glicosilación, entre ellas la elongación incompleta de las cadenas sacarídicas con uniones de tipo O y la exposición de antígenos que en condiciones normales estaban ocultos, los cuales son reconocidos por componentes de la respuesta inmune que promueven o limitan el crecimiento tumoral. Diversos estudios reportan que estructuras asociadas a tumor tales como los antígenos Tn y sialil- Tn se expresan en algunos parásitos protozoarios y helmintos, planteando numerosas interrogantes a nivel de la interacción parásito-hospedador. Considerando que existe una correlación negativa entre ciertas infecciones parasitarias y el desarrollo de cáncer, los antígenos de O-glicosilación incompleta obtenidos de parásitos podrían ser potenciales blancos en la inmunoterapia del cáncer

Potencial papelero de la fibra de sisal (Agave sisalana).

CONTENIDO Editorial. La extensión rural: desiderato para la Facultad de Ciencias Forestales y Ambientales de la Universidad de Los Andes, Venezuela.Rodríguez P., Luis E. Artículos Agroforestería en fincas sobre planicie inundable en el área de influencia de la Reserva Forestal Caparo. Pezo, Margarita y Plonczak Ratschiller, Miguel Andrés Potencial papelero de la fibra de sisal (Agave sisalana). Santiago A., Daniel I.; Rodríguez de G., Nora y Mogollón, Gladys M. Empleo de maderas no comerciales de alta densidad de los llanos occidentales, Barinas, Venezuela, para el establecimiento de un programa masivo de estructuras para viviendas de clase media. Contreras Miranda, Wilver; Owen de Contreras, Mary E. y Vargas, Julio Producción de apio andino en respuesta al suministro de fertilizantes. Añez, Bruno; Espinoza, Wilmer y Vásquez Chávez, Jorge A. Fertilización química y orgánica.¿Efectos interactivos o independientes sobre la producción de zanahoria? Añez, Bruno y Espinoza, Wilmer Análisis del crecimiento en altura de árboles bajo un sistema de selección mediante cortas cíclicas, usando modelos lineales mixtos. Duran, Mariano J.; Donoso H., Pablo J. y Quintero M., Maria Alejandra Productividad del bosque natural en varias zonas de vida de Venezuela y su relación con algunas variables climáticas y edaficas. Torres Lezama, Armando; Bello, N. y Ramírez Angulo, Hirma C. El conocimiento técnico-forestal y sus efectos en la política forestal en Venezuela. Aicher, Christoph Durabilidad natural e inducida en tableros de partículas de pino caribe con urea formaldehído.Moreno P., Pablo A.; Durán P., Jorge A. y Garay J., Dario A. Tesis. Caracterización autoecológica de siete especies arbóreas usadas por la etnia Piaroa en la Amazonia venezolana.Sánchez P., Domingo A. Evaluación de la variación del diámetro del fuste en plantaciones de Teca (Tectona grandis L.) con análisis de mediciones repetidas y curvas de perfil en la unidad experimental Reserva Forestal de Caparo.Mora de Pinto, Elba Marina Modelo para la selección y priorización de áreas a reforestar en los alrededores de la ciudad de Mérida, Venezuela, utilizando sistemas de información geográfica.Gutiérrez, Julián19-27dsantiago@cante [email protected] analíticosemestra

Cuestionario de efectividad de la psicoterapia Outcome Questionnaire. Validación en muestra clínica colombiana

To establish the structural and psychometric properties of the OQ-45.2 and identify sensitivity to change and differences by gender. Method: It was done in clinical population included 214 consultants (111 men and 103 women) Instrument: Outcome Questionnaire (OQ-45.2). Results: The AFC showed low rates of kindness adjustment and RMSEA value of 0.071. It was recommended that the AFE, and this structure included 20 items, explaining 58.8% of the total variance: worry, problems performing the social role, overall dissatisfaction, alcohol / drugs, relationship difficulties and dissatisfaction with relationships. For the original scale, the coefficients were found between 0.52 and 0.92; no gender difference appeared in any of the factors but sensitivity to change in therapy in all dimensions. For the structure found throughout the AFE with 20 items, the coefficients were between 0.47 and 0.75. The rates for this new structure adjustments were very suitable (CFI = 0.920, TLI = 0.902 and NFI = 0.790) and RMSEA value of 0.046. Gender-related differences in size (higher in women) overall dissatisfaction and Alcohol / drug (higher scores in man) were reported. The test reported sensitivity to change in the original scale Stress, Performance and negative interpersonal relations, and the abbreviated scale Worry, Problems of the social role and Dissatisfaction in relationships. Conclusions: 45.2 OQ did not provide a suitable structure through the AFC. The AFE reported six factors and 20 items, appropriate indexes setup, but not all factors with a high level of reliability.Establecer las propiedades estructurales y psicométricas del OQ-45.2 e identificar la sensibilidad al cambio y diferencias según género. Método: se realizó en población clínica, participaron 214 consultantes (111 hombres y 103 mujeres), Instrumento: Outcome Questionnaire (OQ-45.2). Resultados: El AFC mostró índices de bondad de ajuste bajos y valor de RMSEA de 0.071. Se recomendó realizar el AFE, y esta estructura incluyó 20 ítems y explicó el 58,8 % de la varianza total: preocupación, problemas del desempeño del rol social, insatisfacción global, alcohol/drogas, dificultades en las relaciones e insatisfacción en las relaciones afectivas. Para la escala original, los coeficientes se encontraron entre 0.52 y 0.92; no se presentaron diferencias según género en ninguno de los factores pero sí sensibilidad al cambio en la terapia en todas las dimensiones. Para la estructura encontrada a través del AFE con 20 ítems, los coeficientes se encontraron entre 0.47 y 0.75. Los índices de ajustes para esta nueva estructura fueron muy favorables (CFI=0,920, TLI=0,902 y NFI=0,790) y valor de RMSEA de 0.046. Se reportaron diferencias con relación al género en las dimensiones Insatisfacción global (más elevadas en mujeres) y Alcohol/droga (puntuaciones más elevadas en hombre). La prueba reportó sensibilidad al cambio en la escala original en Estrés, Desempeño y Relaciones interpersonales negativas, y en la escala abreviada en Preocupación, Problemas del rol social e Insatisfacción en las relaciones afectivas. Conclusiones: el OQ 45.2 no presentó una estructura adecuada a través del AFC. El AFE reportó 6 factores y 20 ítems, adecuados índices de ajustes, pero no todos los factores con buen nivel de confiabilidad

ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA) and C-reactive protein serum levels (CRP) in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35), II (n = 29), and III (n = 18). A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease.Introdução e objetivo . A Doença de Chagas é um problema de saúde pública mundial. A disponibilidade de ferramentas diagnósticas para prever o desenvolvimento de miocardiopatia chagásica crônica é fundamental para reduzir a morbidade e a mortalidade. Aqui estudamos o valor prognóstico da atividade sérica da adenosina deaminase (ADA) e dos níveis de proteína C reativa (PCR) em indivíduos chagásicos. Métodos : 110 indivíduos: 28 saudáveis e 82 pacientes chagásicos foram divididos de acordo com a gravidade da doença em fase I (n = 35), II (n = 29) e III (n = 18). Para cada indivíduo foram feitos uma história médica, eletrocardiograma, radiografia de tórax e ecocardiografía transtorácica. O diagnóstico de Chagas foi confirmado por ELISA e MABA utilizando antígenos recombinantes, a atividade sérica da enzima ADA foi determinada por espectrofotometria, e os níveis séricos de PCR por ELISA. Resultados : os níveis de PCR e da atividade da ADA aumentaram linearmente em relação à fase da doença, sendo a PCR significativamente maior na fase III, e a ADA em todas as fases. Além disso, PCR e ADA foram correlacionados positivamente com parâmetros ecocardiográficos de remodelamento cardíaco e alterações eletrocardiográficas, e negativamente com a fração de ejeção. PCR e ADA foram mais elevadas em pacientes com índice cardiotorácico ≥ 50%, enquanto que a ADA foi maior em pacientes com alterações da repolarização ventricular. Finalmente, os níveis de PCR foram correlacionados positivamente com a atividade da ADA. Conclusão : ADA e PCR são marcadores prognósticos de disfunção e remodelamento cardíaco na Doença de Chagas, e devem ser incluídos na avaliação e acompanhamento dos pacientes

Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population.

Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean) in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers), Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations

Dirichlet distributions of the ancestral components of the study population.

<p>The European component had a normal distribution and consisted of 40–60% of the study population. The African component had a non-normal distribution and consisted of less than 30% of the study population. The Native American (Amerindian) component had a non-normal distribution and consisted of 20% of the study population.</p

Comparison of medians of ancestral components according to the geographical origin of the population, Andean vs. Atlantic regions (Mann-Whitney U-test).

<p>Comparison of medians of ancestral components according to the geographical origin of the population, Andean vs. Atlantic regions (Mann-Whitney U-test).</p