Varietal data from 27 crop species from five continents were drawn together to determine overall trends in crop varietal diversity on farm. Measurements of richness, evenness, and divergence showed that considerable crop genetic diversity continues to be maintained on farm, in the form of traditional crop varieties. Major staples had higher richness and evenness than nonstaples. Variety richness for clonal species was much higher than that of other breeding systems. A close linear relationship between traditional variety richness and evenness (both transformed), empirically derived from data spanning a wide range of crops and countries, was found both at household and community levels. Fitting a neutral “function” to traditional variety diversity relationships, comparable to a species abundance distribution of “neutral ecology,” provided a benchmark to assess the standing diversity on farm. In some cases, high dominance occurred, with much of the variety richness held at low frequencies. This suggested that diversity may be maintained as an insurance to meet future environmental changes or social and economic needs. In other cases, a more even frequency distribution of varieties was found, possibly implying that farmers are selecting varieties to service a diversity of current needs and purposes. Divergence estimates, measured as the proportion of community evenness displayed among farmers, underscore the importance of a large number of small farms adopting distinctly diverse varietal strategies as a major force that maintains crop genetic diversity on farm.

The main objective of this work was to know the types diversity and uses of the pepper, selection criteria and to get samples samples of the landraces. The studied system was a multi-cropping system with corn, beans, pepper and pumpkin (milpa), established in two stages: a) a survey on 60 land-owners from the community, in order to gather information of the crop and their croppin systems applied in the ‘milpa’, pach pakal (land useful for gardening) and back-yards. b) An etnobotanical exploration to collect genetic material and to conduct an in situ assessment of the morphological characters of the plant, fruit and flower. Eight regional pepper types are grown in the community, seven belong to the Capsicum annuum such (yaax ic, xcat’ic, cha’hua, chile dulce, sucurre, pico paloma and maax, the latter C. annuum var. aviculare and one C. chinense (habanero). The yaax ic pepper is the most widely accepted in the community. The farmers base their germplasm selection on the fruit size, taste, pests and disease tolerance and culinary uses. The regional peppers are planted in association with other crops in the “milpas” as well as in the back-yards.

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Introduction: Lichen diversity, community structure, composition and species abundance have been used as indicators of the integrity and ecological continuity of tropical forest ecosystems. Objectives: To assess corticolous lichen species composition, diversity, and ecological importance of three forested stands differing in time of abandonment as indicators of how passive restoration influences the lichen community assemblage. Methods: We surveyed individual lichens on tree stems of a reference old secondary forest and a young secondary forest (50 and 14-year-old natural regeneration after pasture abandonment, respectively), and in a 35-year-old exotic cypress tree plantation, in the oriental Central Valley, in Orosí, Costa Rica. Standard diversity, similarity indexes, and the importance value index were calculated. An NMDS analysis was performed on the community structure parameters and in a presence-absence matrix. Results: We found 64 lichen species in 25 families with 42, 21, and 23 species, and 20, 10, and 15 families, in the young and old secondary forests, and the cypress plantation, respectively. Cryptothecia sp. possessed the highest importance across sites. More than 87 % of the species are rare. The combined IVI of the top three families were: 36, 48.5, and 74.8 % in the young and old forests and the Cypress plantation sites, respectively. Overall, Arthoniaceae is in the top three families. The young forest had the highest species richness, but the old forest presented the best evenness. Similarity and diversity indexes suggest a particularly low resemblance in the lichen communities but a smooth gradient differentiation between the three forests, which was confirmed by the NMDS test. The homogeneity test identified great differences in ecological importance and composition. Conclusions: This region contains a distinctive assemblage of species resulting in a strong community differentiation by site, reflecting the influence of ecophysiological and microclimatic factors that define lichen establishment and survival and suggesting a great regional beta diversity, within a fragmented landscape. Greater connectivity and passive restoration strategies resulted in greater diversity and a more heterogeneous community structure on both forests than the corticolous community of the abandoned plantation. Protection of forest fragments will maximize the integrity of future forests.

ANTECEDENTES: La acumulación de aire en la cavidad pleural sin una patología aparente se denomina Neumotórax Espontáneo Primario (NEP), su causa principal es ruptura de bulas subpleurales (BS). Se presenta sobre todo en adolescentes, pero tiene baja incidencia de 3.4:100,000, por lo que el tratamiento se basa en guías con recomendaciones internacionales en adultos, series de casos o revisiones sistemáticas. OBJETIVO: Describir el manejo, experiencia quirúrgica, evolución y estancia hospitalaria en los pacientes con NEP por bulas en nuestro centro. CASO CLÍNICO: Se describe el manejo en 7 pacientes pediátricos, con edad promedio entre los 12 y 16 años, quienes presentaron neumotórax mayores. Se realizó manejo conservador con drenaje pleural con persistencia de fuga a las 48-72 horas, por lo que se decidió realizar resección de BS con engrapadora lineal por toracoscopia video-asistida (TVA), no se realizó pleurodesis mecánica o química por el riesgo de las complicaciones propias. A las 48 horas postquirúrgicas se retiró el drenaje pleural con remisión de la enfermedad y los pacientes se egresaron a las 72 horas postquirúrgicas. A los 8 meses de evolución persisten sin recaída. CONCLUSIÓN: El uso de manejo conservador en pacientes pediátricos sin importar el tamaño del neumotórax, no debe sobrepasar las 24-48 horas para el manejo quirúrgico, con ello se disminuye el tiempo de estancia hospitalaria y comorbilidades asociadas, además la resección de BS con engrapadora lineal mecánica sin pleurodesis es un tratamiento seguro hasta el momento sin datos de recidiva, como se comprueba en esta serie de casos. PALABRAS CLAVE: Neumotórax espontáneo primario, bulas subpleurales, toracoscopía video asistida