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Se evaluaron los efectos toxicos que produce un suelo contaminado con petroleo fresco sobre plantas de Phaseolus vulgaris . Para ello se genero un indice absoluto de fitotoxicidad que integra siete parametros, medidos a traves de indices relativos de fitotoxicidad para las variables: altura, longitud radical, numero de nodulos y biomasa seca (foliar, radical, del fruto y total). Asimismo, se calcularon los coeficientes de determinacion (R 2 ). El bioensayo se realizo bajo condiciones de tunel de plastico y se evaluo los efectos toxicos del petroleo en plantas de frijol negro ( P. vulgaris L.) al cabo de 100 dias. Se establecio un diseno experimental de bloques al azar en condiciones semicontroladas, con seis tratamientos con tres repeticiones por tratamiento. Las concentraciones de hidrocarburos fueron: 1500, 3000, 4500, 6000, 7500 y 9000 mg/kg de hidrocarburos totales del petroleo (HTP) y un tratamiento testigo (0 mg/kg).Al dia 100, el detrimento fisiologico [emergencia (R 2 = 0.89; b = -3.427); altura(R 2 = 0.84; b = -0.0029); longitud radical (R 2 = 0.62; b = -0.001); numero de nodulos (R 2 = 0.68; b = -0.0092) y biomasa total (R 2 = 0.77; b = -0.0014)] de las plantas mostro una correlacion negativa con la concentracion de los HTP en el suelo, con diferencias entre los tratamientos (Tukey p≤ 0.05). Al dia 68 del ensayo se observo marchitez de las plantas a concentraciones mayores de 3000 mg/kg HTP.

The oil industry has generated chronic spills and its accumulation in the mangrove forest located on the southeast coast of Mexico. The evaluation of the impact of oil on the soil-root interaction of Languncularia racemosa (Lr) is basic to determine the changes in microbial activity and its biotechnological potential for land remediation. Lr is a tree that grows in these areas contaminated with weathered oil. The objective of this study was to evaluate the spatial distribution in soil of total petroleum hydrocarbons (TPH), the population of plant growth promoting bacteria, microbial respiration in the rhizoplane (RI), rhizosphere (RZ) and non-rhizospheric soil. (SNR) of Lr. For this study, an area of ​​8,000 m2 of a Histosol affected by chronic oil spill and drilling mud from the La Venta 248 oil well was used. Fifteen Lr trees were selected and samples were taken from the RI (secondary roots), from the RZ (secondary and tertiary roots with adhered soil) and SNR (organic matter). The results show differences in the amount of HTP accumulated in the organic soil. The spatial distribution of the HTP defined four study floor (S): S1: 1797, S2: 3294, S3: 5249, and S4: 10389 mg kg-1. The PHT were higher in RI of S1 and 2, but in RZ and SNR in S2 and 3. In RI of Soil 4 the population of N-fixing and P-solubilizing bacteria were stimulated in greater quantity, but Azotobacter was inhibited and Azospirillum. For the RZ of Lr Azospirillum it was favored but in the soil 2 and 4. The microbial respiration at 7, 14, 21, 42 and 63 days was stimulated by the IR followed by the RZ in the four evaluated soils, however the respiration microbial was negatively affected by oil in the RI, RZ and SNR. The results suggest that Lr is sustainable in soils with hydrocarbon contamination, and is a biostimulator of microbial activity that can be used for the natural attenuation of hydrocarbons, with a high population of N-fixing bacteria and solubilizers of P in RI with 10389 mg kg-1 of HTP derived from weathered petroleum. However, soils containing HTP higher than 4158 mg kg-1 in RI, RZ and SNR require previous treatment to remove the oil and put it in contact with the RZ of the white mangrove. La evaluación del impacto del petróleo en la interacción suelo-raíz de la planta de mangle blanco, Laguncularia racemosa, es básica para identificar los cambios en la actividad microbiana y en el potencial biotecnológico para la remediación de histosoles contaminados. El objetivo de la investigación fue evaluar la distribución espacial de los hidrocarburos totales del petróleo (HTP) en el suelo orgánico, la densidad poblacional de bacterias promotoras del crecimiento vegetal, así como la respiración microbiana en el rizoplano (RI) en la rizósfera (RZ) y en suelo no rizosférico (SNR) de L. racemosa. Una superficie de 8 000 m2 de un histosol afectado desde 1967 y 1968 se evaluó por derrame crónico de petróleo y lodos de perforación provenientes del pozo petrolero La Venta 248. Se seleccionaron 15 árboles de L. racemosa y se extrajeron muestras del RI, RZ y SNR. Los HTP se extrajeron en equipo soxhlet con diclorometano durante ocho horas y se cuantificaron por gravimetría. La cantidad promedio extraída de HTP permitió la diferenciación de cuatro suelos (S) en el área evaluada, con valor promedio para el S1 de 1 797 mg kg-1 (no contaminado para la normativa mexicana) y tres suelos contaminados: S2 con 3 294, S3: 5 249 y S4: 10 389 mg kg-1. Los resultados evidencian diferencias estadísticas (Duncan, P ≤ 0.05) entre medias de las variables evaluadas. La mayor acumulación de HTP fue 22 962 mg kg-1, se extrajo del SNR en el S4. Las mayores densidades de bacterias fijadoras de N, solubilizadoras de P, Azospirillum y Azotobacter fueron bioestimuladas por la presencia de niveles altos de HTP en el suelo, sin embargo la respiración microbiana fue inhibida. Los resultados sugieren que L. racemosa es sostenible en suelos con petróleo intemperizado, y es un bioestimulador de la actividad microbiana para la atenuación natural. n el RZ del mangle blanco.

In Costa Rica, sugarcane plants with symptoms similar to those described for yellow leaf syndrome (YLS) (1,2) were first observed in 1994 in research plots of imported material in the midland areas of San Carlos and Turrialba. Recently, the same symptoms have been observed in commercial plantations in Turrialba. Symptomatic plants were characterized by yellowing of the leaves and central veins, the yellowing being more intense near the leaf tips. In severe cases, veins became reddish, and necrosis developed along the leaf edges, beginning at the leaf tip and extending to the base of the leaf. Growth of stems and roots was also reduced in infected plants. Minipurifications of six plants of four different varieties were examined by immunospecific electron microscopy (ISEM) using polyclonal antibodies (1). They were: one symptomatic plant each of the varieties H782313 and H608521; two symptomatic plants of H657052, and one asymptomatic plant each of H608521 and H827318. Isometric particles of approximately 28 nm were observed in the asymptomatic H827318 plant and in all symptomatic plants, with the exception of one plant of H657052. The size and morphology of the particles was similar to those reported for Sugarcane yellow leaf virus (ScYLV) (2). The presence of ScYLV was verified by indirect enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies (1). Twenty-two of 24 symptomatic plants and five of 13 asymptomatic plants were positive for ScYLV. These findings confirm the association of ScYLV with the yellows syndrome of sugarcane observed in Costa Rica. However, as was also reported by Scaglusi and Lockhart (1), ScYLV was not detected in several symptomatic plants, and research is continuing to determine whether other pathogens are associated with this syndrome in Costa Rica. References: (1) S. Scagliusi and B. E. L. Lockhart. Phytopathology 90:120, 2000; (2) J. Vega et al. Plant Dis. 81:21, 1997.

In 1995, severe symptoms were observed on ‘Caturra’ and ‘Catuaí’ coffee (Coffea arabica L.) varieties in farms in the southern part of the Central Valley in Costa Rica. Symptoms were reduced leaf size, malformation of leaves, curling of leaf edges, shortening of internodes, and severe leaf chlorotic mosaic, which sometimes became necrotic. Abortion of flowers and young beans was also observed, with a reduction in yield. Plants also showed irregular growth with an atypical curling appearance that gave rise to the Spanish name “crespera.” Ten and three healthy plants were inoculated by grafting in the greenhouse, using infected and healthy budwoods, respectively. Approximately 6 months after inoculation, 3 of 10 grafted plants with infected budwoods showed symptoms of leaf chlorosis, curling, and malformation of leaves and bunched new flushes. Samples of 39 symptomatic plants collected from the field and samples of 3 healthy plants maintained in the greenhouse were tested by enzyme-linked immunosorbent assay (ELISA). All (100%) analyzed symptomatic samples were positive for X. fastidiosa, and all healthy controls were negative. The symptoms observed in Costa Rica are different from those described for coffee leaf scorch in Brazil (1,2), but the climatological conditions and soil type present in Costa Rica are also very different from the areas where X. fastidiosa occurs in Brazil. Leafhoppers were collected randomly in one of the most affected regions. Graphocephala permagna and Erythrogonia sonora were the most frequent insect species found associated with coffee. In ELISA, 34.5% (10 of 29) and 23.8% (5 of 21) of the collected specimens belonging to G. permagna and E. sonora, respectively, tested positive for X. fastidiosa. These positive ELISAs do not necessarily mean that the insect is a vector. The results presented here extend the known geographic distribution of X. fastidiosa. To our knowledge, this is the first report of X. fastidiosa in coffee in Costa Rica. Universidad de Costa Rica/[801-A2-528]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

copyright 2002 The American Phytopathological Society (APS) Journals. Datos y artículo incluido por Lisela Moreira Carmona, responsable de depósitos de publicaciones del área de Patógenos y Plagas del CIBCM Powdery scab of potatoes, caused by Spongospora subterranea (Wallr.) Lagerheim f. sp. subterranea Tomlinson, is important worldwide due to its effect on tuber quality and transmission of Potato mop-top virus. Although powdery scab-like lesions have been observed on potato in Costa Rica (1), the presence of the pathogen has not been confirmed. During a survey in 2001, powdery scab-on was observed from a field and a greenhouse in the high elevation zone of the main potato-producing area of Costa Rica. Commercial potatoes with scab-like lesions were also obtained at a farmers' market. Scraping the lesions, and observing spore balls or cystosori with a honey-comb-like structure under light microscopy confirmed the identity of S. subterranea. The identity of the pathogen was also confirmed by enzyme-linked immunosorbent assay using monoclonal antibodies specific for S. subterranea (BioReba Ag, Reinach, Switzerland). Pathogenicity of S. subterranea was confirmed by a bioassay on tomato plants grown in nutrient solution culture (2). Tomato cv. Supermarmande plants were grown from seed in pots filled with quartz and watered with nutrient solution. Three weeks after planting, the roots were trimmed to 60 mm, and the plants were transferred to the nutrient solution for additional growth. After growing for 1 week in the nutrient solution, tomato seedlings were inoculated by replacing the nutrient solution with nutrient solution containing cystosori (20 mg/liter, wt/vol) that were scraped from the scab lesions. Zoosporangia of S. subterranea were observed in root hairs and epidermal cells of the seedlings 2 weeks after inoculation. To our knowledge, this is the first report that confirms the presence of S. subterranea on potato in Costa Rica. Universidad de Costa Rica/[801-A2-506]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM) UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiología

Bioremediation is an environmentally sound and cost-effective strategy to restore soils contaminated with petroleum oil. In this study, native bio-surfactant-producing bacteria able to use polycyclic aromatic hydrocarbons (PAHs: anthracene [ANT] or phenanthrene [PHE]) as their sole carbon source were isolated from soil contaminated with weathered petroleum oil (WPO) collected near “La Venta” gas processing complex, in Tabasco, Mexico. Bacteria able to grow in 200 ppm of ANT or PHE and having high bio-surfactant activity were selected. Included were bacteria identified as Sphingobium sp., Bosea sp., Pseudomonas sp., Rhodococcus sp. and Phenylobacterium sp. Different consortia of these bacteria ± bio-stimulation with glucose, ammonium nitrate, or both, were examined for their capacity to degrade either WPO or fresh crude petroleum oil (FCPO) in soil microcosms. No efficient short-term (24 days) degradation of WPO using bio-augmentation and bio-stimulation strategies was possible using two bacterial consortia conformed by combinations of these bacterial isolates. Best results were obtained with a consortium composed of Pseudomonas cloritidismutans and Rhodococcus qingshengii, identified by 16S rRNA sequencing, which led to an 86% reduction of FCPO contaminants in soil microcosms, 90 days after treatment. However, the bioremediation efficiency of this consortium was significantly reduced by moderate salinity levels in the soil. Although promising, these results highlight the adverse effect that weathering and/or salinity may have on the remediation of petroleum oil-contaminated soils.

Copyright 2008 American Phytopathology Society Journals. Since the late 1990s, chlorotic mottling, marginal scorch, deformation of leaves, defoliation, shortening of internodes, and branch dieback have been observed in avocado trees (Persea americana Mill.) in Costa Rica. The symptoms are not uniformly distributed in the tree, so some branches are symptomatic while others are not. These symptoms are similar to several leaf scorch diseases caused by the bacterium Xylella fastidiosa Wells (2,4). This bacterium has been detected in coffee and citrus plants in Costa Rica. Of 227 avocado trees tested by double-antibody sandwich (DAS)-ELISA with X. fastidiosa specific antiserum (Agdia Inc., Elkhart, IN) from 2000–2004, 188 were positive. Results of ELISA tests of individual trees varied with the season and branches tested. Fifteen greenhouse-grown, ELISA-negative avocado seedlings were grafted with budwood from an ELISA-positive tree. Eight of these developed scorch symptoms and one also showed chlorotic mottling and deformation, showing that the disease is graft transmitted. All of these features are characteristic of diseases caused by X. fastidiosa (2,4). Transmission electron microscopy of leaf petioles from three field trees positive by ELISA, revealed rod-shaped bacilli approximately 1.6 to 2.0 μm long and 0.3 μm in diameter with a rippled cell wall inside xylem vessels and embedded in a matrix; morphology and measurements that are consistent with those reported for X. fastidiosa (2). DNA extraction and PCR attempts have been limited by mucilaginous sap from avocado. Positive PCR results (approximately 472-bp band) were obtained from two of the grafted seedlings and seven field trees from two distinct geographical locations (Alajuela and San José provinces) with DNA extractions from the plant sap using DNeasy Plant Mini Kit (Qiagen GmbH, Hilden, Germany) following a modified protocol (1) and nested PCR (3). Four of the PCR products, including one from the grafted seedlings, were cloned and sequenced in duplicate. GenBank sequences EU021997 to EU022000 present 99 to 100% sequence identity to a Pierce's disease strain from California (Temecula1) and 94 to 95% to a citrus variegated chlorosis strain from Brazil (Found-5). Several attempts have been made to isolate the bacterium in ‘periwinkle wilt’ and buffered cysteine-yeast extract media with negative results, probably because of the rapid production of mucilaginous sap when the avocado tissues were sampled. To our knowledge, this is the first report of X. fastidiosa in avocado trees. Fundación CRUSA Universidad de Costa Rica/[801-A2-528]/UCR/Costa Rica Universidad de Costa Rica/[801-A1-801]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

Copyright © 2008, Plant Disease, American Phytopathological Society Datos incluidos por Lisela Moreira Carmona, responsable de depósitos para el área de Patógenos y plagas de plantas del CIBCM A survey was conducted in 39 potato (Solanum tuberosum) fields in Costa Rica to determine incidence and association of Spongospora subterranean f. sp. subterranea and Potato mop-top pomovirus (PMTV). The fields were located in Costa Rica’s two major potato-production regions and were further characterized by their altitude. In all, 633 paired samples of leaf tissue and corresponding tubers were collected, assessed visually for disease, and subsequently assayed by enzyme-linked immunosorbent assay (ELISA). S. subterranea presence in tuber tissue was tested by double-antibody sandwich (DAS)-ELISA and PMTV presence in leaf and tuber tissues was tested by triple-antibody sandwich (TAS)-ELISA. Moreover, soil samples were collected from 10 fields surveyed and were evaluated for both pathogens via ELISA and bioassay. The incidence of both diseases ranged from 0 to 100% within individual fields, with incidences lower than 40% occurring in more than 70% of the fields. Higher incidences were found in fields located at higher altitudes. Of the 633 paired samples, 179 and 146 were positive for PMTV and S. subterranea, respectively, according to ELISA in either the foliage or tubers. A low correlation was found for PMTV visual symptoms and ELISA test results. Only 14 of the 81 foliar samples testing positive for PMTV had visual symptoms; the remaining 67 samples were asymptomatic. Conversely, comparison of visual evaluation with detection of S. subterranea by ELISA on tubers showed that 70% of the results were coincident. S. subterranea was detected in 4 of 10 soil samples tested by ELISA. Soilborne PMTV was detected by ELISA in roots of bait plants sown in these soil samples. Co-occurrence of both pathogens was detected in 64 samples. A significant but low degree of association for vector and virus was determined, and data suggests that S. subterranea is participating in the transmission of PMTV in Costa Rica in low frequency Universidad de Costa Rica/[801-94-905]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

Potentially life-threatening interoceptive sensations easily engage the behavioral defensive system. Resulting fear and anxiety toward interoceptive threat are functionally distinct states that are hypothesized to play a prominent role in the etiology of panic disorder. The present study aimed to investigate whether fear- and anxiety-potentiated startle responses occur to predictable and unpredictable interoceptive threat, respectively. Therefore, we modified the NPU threat test (Schmitz & Grillon, ) and replaced the aversive electrocutaneous stimulus with an aversive interoceptive stimulus (a breathing occlusion, making it briefly impossible to breathe). Healthy participants (N = 48) underwent three instructed conditions. A visual cue signaled the occlusion in the predictable condition (P), whereas another cue was unrelated to the occurrence of the occlusion in the unpredictable condition (U). The safe condition (N) also had a visual cue, but no occlusion. Both fear- and anxiety-potentiated startle blink responses were observed in response to predictable and unpredictable respiratory threat, respectively. The current study presents and validates the NPU respiratory threat test (NPUr) as an ecologically valid paradigm to study both anxiety and fear in response to a panic-relevant interoceptive threat. The paradigm allows future testing of contextual generalization, investigation of different clinical groups, and more explicit comparisons of defensive responding to interoceptive versus exteroceptive threats.

Natural hosts of four melon viruses (cucumber mosaie virus o CMV, papaya ringspot virus o PRSV, watermelon virus 2 o WMV -2 and zuechini yellow mosaic virus o ZYMV) were identified in two commereial melon farms in Costa Rica. The farms differed in management practices. Farm A had a long history of melon production in rotation with corn, sorghum and lice. Weed control was poor. Farm B was previously used as pastureland, had a shorter history of melon production, and was frequently plowed for weed control. Plant species diversity was monitored in 100 m' quadrants on each fanu over a one year periodo In addition to the eultivated areas, four distinet plant communities (improved pasture field, drainage ditehes. secondary forest and fallow field) in farm A, and ihree (spontaneus mixed species pasture field, fallow field and secondary forest) in farm B were included in the study. The number of quadrants sampled was dependent on the total eultivated area on eaeh farm. Five sampling dates were selected during rainy and dry ,easons and transition periods between ,easons. Plants of each species represented in the quadrants were colleeted at each sampling date and identified using referenee collections. Four plants of each species showing virus-like symptoms in the field were tested for the presence of the four viruses by ELlSA. The total number of plant species, and the pereent ground cover of eaeh species infected at least with one of the viruses were reeorded on eaeh of the five sampling dates. A total of 86 and 72 plant species were identified in sites A and B. respectively. Fourteen plant species. 16% of the total plant species represented in site A. and six species in site B (8%) were found to be infected with at least one of the four melon viruses at different times throughout the year. AII tour viruses were deteeted in each location at each of the five sampling dates, indicating that weed species naturally oecurring in and around areas 01' eommercial melon production serve as reservoirs for the melon viruses and ensure the survival oflhe vifllses from one production season 10 the next. Several new host species of three of the melon viruses (PRSV, WMV -2 and ZYMV) were identified. Previously unreported hosts of PRSV included Tridax procumbens. Cleome viscosa. Cleome spiiiosa. Molvoviscus arboreus and Sida rhombif()/ia. New hosts of WMV-2 included C. viscosa, Crofum ari;el1leus. Musa I'ardisiaca and POJl.'eria heterol'hylla. New hosts of ZYMV included Guazuma ulmifolia, Rauvo!fia rerral'hylla, Malochra alceifolia, Boerhavia d!ffusa, p, heterophylla and C. viscosa.

In the present project, the previous knowledge of the social manager of knowledge based on the regulations of the Institutions of Higher Education is defined, the representation of the same in the context of the locality as a relevant scenario that the teacher-manager needs to know, since the work is in situ, vital for the conjuncture of the work that it carries out in its approach to the community. The methodology is participatory, with a bibliographic design. The theoretical nuclei are: guidelines for thedesign of projects of social responsibility, regulations of functions of the managers of Social Knowledge Management, resource management, instructions for the management of reporting matrices and monitoring matrices and monitoring of the implementation of the projects in the practices of connection with the community. The perspective of the functions of the manager are intertwined with the substantive functions such as: Research, Social Knowledge Management and Postgraduate. The objective is to characterize the monitoring and monitoring functions of the social responsibility project manager as a linkage manager within the glocal functions, its perspective and projection being to carry out a relevant and participatory social work with the community. En el presente proyecto, se definen los conocimientos previos que tiene el gestor social del conocimiento basado en la normativa de las Instituciones de Educación Superior, la representación de la misma en el contexto de la localidad como escenario pertinente que necesita conocer el docente-gestor, ya que el trabajo es in situ, vital para la coyuntura del trabajo que realiza en su acercamiento a la comunidad. La metodología es participativa, con un diseño bibliográfico. Los núcleos teóricos son: lineamientos para el diseño de proyectos de responsabilidad social, reglamentos de funciones de los gestores de Gestión Social del Conocimiento, gestión de recursos, instructivos para el manejo de matrices de informes y matrices de seguimiento y monitoreo de la implementación de los proyectos en las prácticas de vinculación con la colectividad. La perspectiva de las funciones del gestor se entrelazan con las funciones sustantivas como: Investigación, Gestión Social del Conocimiento y Posgrado. El objetivo, es caracterizar las funciones de seguimiento y monitoreo del gestor de proyectos de responsabilidad social como gestor de vinculación dentro de las funciones glocales siendo su perspectiva y proyección el efectuar un trabajo social relevante y participativo con la comunidad.

The oil industry has generated chronic oil spills and their accumulation in wetlands of the state of Tabasco, in Southeastern Mexico. Waterlogging is a factor that limits the use of remediation technologies because of its high cost and low levels of oil degradation. However, Leersia hexandra is a grass that grows in these contaminated areas with weathered oil. The aim of the study was to evaluate the bacteria density, plant biomass production and phytoremediation of L. hexandra in contaminated soil. For this, two experiments in plastic tunnel were performed with fresh (E1) and weathered petroleum (E2) under waterlogging experimental conditions. The E1 was based on eight doses: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 and 180 000 mg.kg-1 dry basis (d. b.) of total petroleum hydrocarbons fresh (TPH-F), and the E2, that evaluated five doses: 14 173, 28 400, 50 598, 75 492 and 112 142 mg. kg-1 d. b. of total petroleum hydrocarbons weathered (TPH-W); a control treatment with 2 607 mg.kg-1 d. b. was used. Each experiment, with eight replicates per treatment, evaluated after three and six months: a) microbial density of total free-living nitrogen-fixing bacteria (NFB) of Azospirillum (AZP) and Azotobacter group (AZT), for viable count in serial plate; b) dry matter production (DMP), quantified gravimetrically as dry weight of L. hexandra; and c) the decontamination percentage of hydrocarbons (PDH) by Soxhlet extraction. In soil with TPH-F, the NFB, AZP y AZT populations were stimulated five times more than the control both at the three and six months; however, concentrations of 150 000 and 180 000 mg.kg-1 d. b. inhibited the bacterial density between 70 and 89 %. Likewise, in soil with TPH-W, the FNB, AZP and AZT inhibitions were 90 %, with the exception of the 14 173 mg.kg-1 d. b. treatment, which stimulated the NFB and AZT in 2 and 0.10 times more than the control, respectively. The DMP was continued at the six months in the experiments, with values of 63 and 89 g in fresh and weathered petroleum, respectively; had no significant differences with the control (p≤0.05). The PDH reached values of 66 to 87 % both TPH-F and TPH-W at six months, respectively. These results demonstrated the ability the L. hexandra rhizosphere to stimulate the high NFB density, vegetal biomass production and phytoremediation of contaminated soils (with fresh and weathered petroleum), in a tropical waterlogging environment.

Ser educador actualmente exige del perfil docente un alto nivel de dominio de la competencia comunicativa, herramienta clave para acceder al conocimiento. Su escaso desarrollo constituye una barrera para su aprehensión. Por su importancia para el desempeño profesional, se realizó una investigación a los futuros docentes del último curso de la Carrera de Sistemas Multimedia/ Facultad de Filosofía/UG, durante al año lectivo 2016 – 2017, cuyo objetivo fue establecer el nivel de desarrollo alcanzado durante su formación académica. Se diseñó la misma con una metodología mixta al combinar componentes cualitativos y cuantitativos para disponer de mayor riqueza interpretativa. Los resultados permiten inferir que el nivel de dominio de la competencia comunicativa en la población investigada, dista considerablemente del esperado y de las expectativas socioeducativas actuales; por tanto, urge optimizar su desarrollo desde el inicio de la carrera ya sea trasversalmente a través de malla curricular , como con capacitaciones específicas continuas para el entrenamiento sistemático de habilidades comunicativas que aseguren calidad comunicativa a la hora de gestionar el conocimiento.

ResumenLa industria petrolera ha generado derrames crónicos de petróleo y su acumulación en Gleysoles en zonas anegadas en el estado de Tabasco, en el sureste de México. El anegamiento es un factor que limita el uso de tecnologías de remediación por el alto costo y los bajos niveles de degradación del petróleo, sin embargo, Leersia hexandra Sw. es un pasto que crece en estas zonas contaminadas con petróleo intemperizado. El objetivo del estudio fue evaluar la densidad de bacterias, producción de biomasa vegetal y fitorremediación de L.hexandra en suelo contaminado con petróleos fresco e intemperizado, bajo condiciones experimentales de anegamiento. Se realizaron dos experimentos (E1 y E2) en un túnel de plástico. El E1 se basó en ocho dosis: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 y 180 000 mg kg-1 base seca (b.s.) de hidrocarburos totales de petróleo fresco (HTPF), y en el E2 se evaluaron cinco dosis: 14 173, 28 400, 50 598, 75 492 y 112 142 mg kg-1 b. s. de hidrocarburos totales de petróleo intemperizado (HTPI), con ocho repeticiones en cada experimento, además se utilizó un testigo con 2 607 mg kg-1 b. s. de HTP de origen biogénico. Las variables evaluadas a los tres y seis meses fueron 1) densidad microbiana de las bacterias fijadoras de nitrógeno de vida libre totales (BFN), del grupo Azospirillum (AZP) y Azotobacter (AZT), por cuenta viable en placa seriada; 2) producción de materia seca total (MS), se cuantificó por el peso seco por gravimetría, y 3) el porcentaje de descontaminación de los hidrocarburos (DSC) por extracción en equipo soxhlet. En suelos con HTPF, la población de BFN, AZP y AZT se estimuló hasta cinco veces más que el tratamiento testigo a los tres y seis meses; sin embargo, concentraciones de 150 000 y 180 000 mg kg-1 b. s. inhibieron entre un 70 y 89 % la densidad bacteriana. A su vez, en suelos con PI, la inhibición se registró hasta en un 90 %, a excepción del tratamiento con 14 173 mg kg-1 b. s., el cual estimuló las BNF y AZT en 2 y 0.10 veces más que testigo, respectivamente. La producción de MS fue continua en los experimentos hasta los seis meses, con valores de 63 y 89 g en PF y PI, respectivamente; sin diferencias significativas con el testigo (p ≤ 0.05). El DSC alcanzó valores del 66 % al 87 % en HTPF como HTPI a los seis meses, respectivamente. Estos resultados demuestran la habilidad del L. hexandra para desarrollar una rizósfera con alta densidad de BFN, producir biomasa vegetal y fitorremediar Gleysoles con petróleo fresco e intemperizado en ambientes tropicales inundados. Abstract:The oil industry has generated chronic oil spills and their accumulation in wetlands of the state of Tabasco, in Southeastern Mexico. Waterlogging is a factor that limits the use of remediation technologies because of its high cost and low levels of oil degradation. However, Leersia hexandra is a grass that grows in these contaminated areas with weathered oil. The aim of the study was to evaluate the bacteria density, plant biomass production and phytoremediation of L. hexandra in contaminated soil. For this, two experiments in plastic tunnel were performed with fresh (E1) and weathered petroleum (E2) under waterlogging experimental conditions. The E1 was based on eight doses: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 and 180 000 mg.kg-1 dry basis (d. b.) of total petroleum hydrocarbons fresh (TPH-F), and the E2, that evaluated five doses: 14 173, 28 400, 50 598, 75 492 and 112 142 mg. kg-1 d. b. of total petroleum hydrocarbons weathered (TPH-W); a control treatment with 2 607 mg.kg-1 d. b. was used. Each experiment, with eight replicates per treatment, evaluated after three and six months: a) microbial density of total free-living nitrogen-fixing bacteria (NFB) of Azospirillum (AZP) and Azotobacter group (AZT), for viable count in serial plate; b) dry matter production (DMP), quantified gravimetrically as dry weight of L. hexandra; and c) the decontamination percentage of hydrocarbons (PDH) by Soxhlet extraction. In soil with TPH-F, the NFB, AZP y AZT populations were stimulated five times more than the control both at the three and six months; however, concentrations of 150 000 and 180 000 mg.kg-1 d. b. inhibited the bacterial density between 70 and 89 %. Likewise, in soil with TPH-W, the FNB, AZP and AZT inhibitions were 90 %, with the exception of the 14 173 mg.kg-1 d. b. treatment, which stimulated the NFB and AZT in 2 and 0.10 times more than the control, respectively. The DMP was continued at the six months in the experiments, with values of 63 and 89 g in fresh and weathered petroleum, respectively; had no significant differences with the control (p≤0.05). The PDH reached values of 66 to 87 % both TPH-F and TPH-W at six months, respectively. These results demonstrated the ability the L. hexandra rhizosphere to stimulate the high NFB density, vegetal biomass production and phytoremediation of contaminated soils (with fresh and weathered petroleum), in a tropical waterlogging environment. Rev. Biol. Trop. 65 (1): 21-30. Epub 2017 March 01.

El objetivo de este trabajo fue identificar parámetros de la microflora rizosférica, la fauna del suelo y de la planta de rábano para medir la eficacia de la descontaminación de un Fluvisol afectado por petróleo crudo. En 0.85 ha de suelo restaurado y en 0.377 ha de suelo testigo aledaño, localizados en Cunduacán, estado de Tabasco, México, se establecieron bioensayos con plantas de rábano (Raphanus sativus L.) en tres épocas climáticas del año: nortes (noviembre a febrero), sures o sequía (marzo a mayo) y lluvias (junio a octubre). El diseño fue completamente al azar con arreglo factorial (tipo de suelo y época del año) y con cuatro repeticiones. Se evaluaron cinco variables de la microflora, la diversidad de la fauna del suelo y siete variables de la planta. Los datos se analizaron con contrastes ortogonales, ANDEVA y correlaciones múltiples, además se calcularon índices de impacto ecotoxicológico (IIE). El suelo superficial restaurado aún tiene 6 480 a 11 210 mg kg-1 de hidrocarburos totales del petróleo (HTP) que causó necrosis y hasta 92 % de mortalidad de las plantas. No se formó el bulbo (-0.658**) y en consecuencia disminuyó la biomasa vegetal (-0.691**), ambos fueron los parámetros más sensibles en la época de sures. La variable más afectada (p ≤ 0.01) en las épocas de nortes y de lluvias fue la densidad de la fauna del suelo (-0.729**). El IIE propuesto aporta valores que permite identificar parámetros sensibles de bioindicadores utilizados en la evaluación de la calidad de la restauración de Fluvisoles contaminados con petróleo crudo

Tomato fruit is rich in antioxidant compounds such as lycopene and &beta, carotene. The beneficial effects of the bioactive compounds of tomato fruit have been documented as anticancer activities. The objective of this research was to determine whether arsenic (As) causes changes in the content of antioxidant compounds in tomato fruits and whether Silicon nanoparticles (SiO2 NPs) positively influence them. The effects on fruit quality and non-enzymatic antioxidant compounds were determined. The results showed that As decreased the oxide-reduction potential (ORP), while lycopene and &beta, carotene were increased by exposure to As at a low dose (0.2 mg L&minus, 1), and proteins and vitamin C decreased due to high doses of As in the interaction with SiO2 NPs. A dose of 250 mg L&minus, 1 of SiO2 NPs increased glutathione and hydrogen peroxide (H2O2), and phenols decreased with low doses of As and when they interacted with the NPs. As for the flavonoids, they increased with exposure to As and SiO2 NPs. The total antioxidant capacity, determined by the ABTS (2,2&acute, azino-bis[3-ethylbenzthiazolin-6-sulfonic acid]) test, showed an increase with the highest dose of As in the interaction with SiO2 NPs. The application of As at low doses induced a greater accumulation of bioactive compounds in tomato fruit, however, these compounds decreased in high doses as well as via interaction with SiO2 NPs, indicating that there was an oxidative burst.

This study evaluated the effect of crude oil on the intraradical structures and morphospecies of arbuscular mycorrhizal fungi (AMF) and on the aerial and root dry matter of the grass Leersia hexandra Swartz in order to propose indicators of toxicity. An experiment was conducted in a microtunnel for 180 days. The concentrations (g kg−1) of crude oil in the Gleysol were 0.693 (control), 3, 10, 30, 60, 90, 120, 150, and 180. The growth of intraradical hyphae, arbuscules, vesicles, and spores in soil was stimulated by crude oil concentrations of 3, 10, 30 and 60 g, but concentrations of 90, 120, 150, and 180 g kg−1 inhibited it. Eight morphospecies of AMF were identified. The number of spores of Rhizophagus fasciculatus, Rhizophagus intraradices, Funneliformis geosporum, Diversispora eburnea, and Ambispora gerdemannii showed sensitivity to the concentration of crude oil (index values were lower than one). The number of spores of Diversispora sp. was stimulated by exposure to crude oil, with non-toxic values for the eight concentrations. The index based on the aerial dry matter of L. hexandra showed toxicity values lower than one with crude oil concentrations of 60, 90, 120, 150, and 180 g kg−1, but the root dry matter showed non-toxic values with the eight concentrations. We suggest using the number of spores and morphospecies as an index of toxicity of crude oil and recommend using Diversispora sp. and L. hexandra for the phytoremediation of Gleysol contaminated with crude oil in the Mexican humid tropics.

espanolLa calidad diagnostica es el resultado de integrar el conocimiento medico y reconocimiento de los errores clinicos, se alcanza unicamente con la identificacion de las causas de muerte; es la correlacion clinico patologica la herramienta principal para dicha accion. El objetivo general de la investigacion fue determinar la discrepancia clinico-patologica y su relacion con otras variables en las autopsias realizadas en la institucion. Se revisaron 159 protocolos de autopsia del periodo comprendido entre enero 2012 y junio 2016, elaborados por el Servicio de Patologia del Hospital Escuela Universitario de Tegucigalpa, Honduras. Se excluyeron 36 por no cumplir los criterios de inclusion. Se utilizaron la CIE-10 y la clasificacion de Goldman et al. para clasificar las patologias y establecer las discrepancias diagnosticas, respectivamente. El sexo predominante fue el femenino (2,96:1), la edad media fue de 38 anos; prevalecieron los diagnosticos de embarazo/parto/puerperio y enfermedades infecciosas y parasitarias. Concluimos que en 46% de los casos existe discrepancia diagnostica y la glomerulonefritis fue la principal causa de error, seguida de bronconeumonia. Se recomienda estandarizar el protocolo de autopsias y promover sesiones clinico-patologicas periodicas e integrales. EnglishDiagnostic quality is the result of the integration of medical knowledge and recognition of clinical error, achieved only by identifying the cause of death; clinical pathological correlation is the primary tool for this action. The overall objective of this research was to determine clinical pathological discrepancy and its relationship with other variables within the autopsies performed at the institution. 159 autopsy protocols, elaborated by the Department of Pathology of Hospital Escuela Universitario in Tegucigalpa, Honduras, from January 2012 to June 2016, were reviewed. 36 were excluded for not meeting the inclusion criteria. ICD-10 and Goldman et al. modified by Battle criteria were used to classify diseases and establish diagnostic discrepancies, respectively. The majority of patients were female (2.96:1), the mean age was 38 years old; diagnoses of pregnancy/birth/puerperium and infectious and parasitic diseases prevailed. We conclude that diagnostic discrepancies exist in 46% of all cases and glomerulonephritis was the leading cause of error, followed by bronchopneumonia. It is recommended that autopsy protocols be standardized, and integrative clinical pathological sessions are promoted and integral.

The aim of this study was to evaluate the spatial distribution of total petroleum hydrocarbons (TPH) in rhizoplane and non-rhizosphere of Leersia hexandra, known as Japanese grass, the effect of oil on the aerial biomass of L. hexandra, the population of plant growth-regulating bacteria, and microbial respiration in rhizosphere and non-rhizospheric soil. Samples of rhizosphere and soil were collected at 14 points across a surface of 2.3 ha, layer 1 (0–15-cm depth), layer 2 (15–30 cm), and layer 3 (30–70 cm), to measure TPH (mg kg−1). The spatial distribution of TPH defined four study zones (Z): Z1: 1393, Z2: 3455, Z3: 5574, and Z4: 7544. TPH were higher in underlying layers in the four zones. Zone 2 produced the largest amount of aerial biomass; oil induced hormesis in the grass, but inhibited it at doses ≥5574. For the rhizosphere of L. hexandra, it was cut with a sterilized knife, stimulated the population of N-fixing and phosphorus solubilizing, heterotrophic bacteria, as well as microbial respiration (day 1, 14, 21, 42, and 63 after incubation) in the four zones. The population of the three groups of bacteria was more stimulated by weathered oil in rhizosphere soil, compared to non-rhizosphere soil and with control treatment, suggesting that the rhizosphere system of L. hexandra has the potential to bioestimulate beneficial microbial activity in unpolluted and polluted areas compared to non-rhizosphere soil. We recommend the use of L. hexandra to recover soils degraded by weathered oil in farms located in the Mexican humid tropics.

An experiment was conducted in field for three years to assess the sustainability of aquatic plants Leersia hexandra, Cyperus articulatus, and Eleocharis palustris for use in the removal of total hydrocarbons of weathered oil in four areas contaminated with 60916-119373 mg/kg of hydrocarbons. The variables evaluated were coverage of plant, dry matter, density of plant growth-promoting rhizobacteria, and the removal of total weathered oil. The variables showed statistical differences (p = 0.05) due to the effects of time and the amount of oil in the soil. The three aquatic plants survived on the farm during the 36-month evaluation. The grass L. hexandra yielded the greatest coverage of plant but was inhibited by the toxicity of the oil, which, in contrast, stimulated the coverage of C. articulatus. The rhizosphere of L. hexandra in control soil was more densely colonized by N-fixing bacteria, while the density of phosphate and potassium solubilizing rhizobacteria was stimulated by exposure to oil. C. articulatus coverage showed positive relationship with the removal of weathered oil; positive effect between rhizosphere and L. hexandra grass coverage was also identified. These results contributed to the removal of weathered oil in Gleysols flooded and affected by chronic discharges of crude oil.

This study compared individual (I) to group (G) formats of cognitive-behavioral therapy (CBT) and interpersonal psychotherapy (IPT) for the treatment of depression in adolescents. One hundred and 12 Puerto Rican adolescents were randomized to four conditions (CBT-I, CBT-G, IPT-I, IPT-G). Participants were assessed at pretreatment and posttreatment with structured interviews to establish diagnosis and with self-report measures to assess treatment outcome. The results suggest that CBT and IPT are robust treatments in both group and individual formats. However, CBT produced significantly greater decreases in depressive symptoms and improved self-concept than IPT. The implications of these findings are discussed.

Español. Se estudian un total de 206 taxones identificados durante el estudio del ciclo anual realizado en las costas de Andalucía a lo largo del año 2000. Destacan, entre las diatomeas céntricas, la subclase Coscinodiscophycidae con 27 taxones y la subclase Chaetocerotophycidae con 28. Entre las pennadas destaca la clase Bacillariophyceae con 76 species. Los géneros que mostraron un mayor número de taxones fueron Chaetoceros, Thalassiosira y Rhizosolenia en el grupo de diatomeas céntricas, mientras que entre las pennadas destacaron los géneros Lyrella, Gyrosigma y Pseudonitzschia. Respecto a su distribución espacial, se han detectado 12 especies exclusivamente atlánticas, mientras que 69 fueron mediterráneas. El resto de taxones presentó una distribución más amplia tanto mediterránea como atlántica. En cuanto a la abundancia celular hemos considerado 119 taxones en la categoría de raros, 57 de habituales y 29 como taxones mayoritarios. Entre los últimos destacaron Hemiaulus sinensis y Eucampia cornuta con carácter marcadamente atlántico, y en la zona mediterránea Cerataulina pelagica y Proboscia alata f. inermes. Las especies más abundantes de todo el litoral andaluz fueron Leptocylindrus minimus, Leptocylindrus danicus, Pseudonitzschia fraudulenta, Skeletonema costatum, Thalassionema nitzschioides, Guinardia striata, Guinardia delicatula y Dactyliosolen phuketensis.English. In this paper we study 206 taxa found during the annual cycle conducted off the coast of Andalusia during 2000. The most representatives centric diatoms were the subclass Coscinodiscophycidae with 27 taxa and the subclass Chaetocerotophycidae with 28. Among the pennate diatom stand out Bacillariophyceae with 76 species. The Genera that showing the bigger number of taxa were Chaetoceros, Thalassiosira and Rhizosolenia in centric diatoms, whereas in pennate diatoms the Genera Lyrella, Gyrosigma and Pseudonitzschia were dominant. Regarding spatial distribution, 12 species were found exclusively Atlantic, while 69 were Mediterranean. The remaining taxa had a wider distribution both Mediterranean and Atlantic. In terms of cell abundance we considered 119 taxa in the category of rare, 57 taxa in the category of common and 29 as abundant taxa. In the Atlantic area Hemiaulus sinensis and Eucampia cornuta dominated whereas Cerataulina pelagica and Proboscia alata f. inermis characterized the Mediterranean zone. Leptocylindrus minimus, Leptocylindrus danicus, Pseudonitzschia fraudulenta, Skeletonema costatum, Thalassionema nitzschioides, Guinardia striata, Guinardia delicatula, and Dactyliosolen phuketensis were the most representative taxa in the whole Andalusian littoral.

The current concept and measures of self-efficacy for depression in adolescents do not consider developmental and cultural aspects essential to understand and assess this construct in Latino youth. We examined the factor structure of the Escala de Autoeficacia para la Depresión en Adolescentes (EADA), a Spanish instrument designed to assess this construct as experienced by this population. Participants were 116 Puerto Rican adolescents aged 13 to 17 years who completed the EADA and two other self-report measures. An exploratory factor analysis yielded a two-factor solution (Personal Self-Efficacy for Depression and Interpersonal Self-Efficacy for Depression) accounting for 37.57% of the total variance. Results revealed that EADA factors have excellent internal consistency as well as concurrent and construct validity, supporting its adequacy to assess Latino adolescents’ self-efficacy for depression. The conceptual meaning of the factors was consistent with the distinction between aspects of this construct hypothesized to be important among Latino youth.

We report a laboratory confirmed case of vertical transmission of dengue in a mother-child pair in the eastern part of Puerto Rico. The clinical course of the pregnant female suggested a GBS infection, but laboratory tests confirmed it was dengue infection, one week after delivery. The male infant was healthy at birth, but one week after birth developed clinical complications related to vertical transmission of dengue. This report targets physicians in dengue endemic countries like Puerto Rico to be aware of the possibility of vertical transmission of dengue in symptomatic pregnant patients, especially around the time of delivery.

The aims of our study were to compare the effectiveness of poultry manure (PM) and banana waste (BW), with regard to their use as inoculant carriers of a bacterial consortium constituted by strains of Azospirillum, Azotobacter and P-solubiliser bacteria and to establish the most efficient dose of biofertilizer for a soil cultivated with banana (Musa paradisiaca AAA Simmonds), with respect to improving plant performance and soil physical and microbiological properties. Six months after planting, plant growth had increased with increase in dose of the biofertilizers applied. The biofertilizer prepared on BW enhanced the density of P-solubiliser bacteria, the concentrations of available P and foliar P to a greater extent than with the biofertilizer prepared on PM. The increases produced by the biofertilizer prepared on PM for the soil aggregate stability, enzymatic activities and the labile carbon fractions were highly correlated to the dose applied. Both biofertilizers can be considered potentially useful as inoculant carriers of PGPR but the usefulness of BW appears to be restricted to moderate doses of application (� 3%). 2008 Elsevier Ltd. All rights reserved. The banana (Musa paradisiaca AAA Simmonds) c.v. ‘Dwarf Cavendish’ is an important food crop in tropical areas of Mexico, with a cultivated area of 76,313 ha and an annual production of 2,196,155 Tm (SIAP-SAGARPA, 2006). In particular, about 19% of surface cultivated with banana is located in the state of Tabasco (SE Mexico). The system production is based on intensive use of inorganic fertilizers and pesticides that yields 7–70 Mg ha � 1 of banana

Copyright The Microbiological Society of Korea and Springer-Verlag Berlin Heidelber GmbH 2008. / . Datos incluidos por Lisela Moreira Carmona. Coffee plants exhibiting a range of symptoms including mild to severe curling of leaf margins, chlorosis and deformation of leaves, stunting of plants, shortening of internodes, and dieback of branches have been reported since 1995 in several regions of Costa Rica's Central Valley. The symptoms are referred to by coffee producers in Costa Rica as "crespera" disease and have been associated with the presence of the bacterium Xylella fastidiosa. Coffee plants determined to be infected by the bacterium by enzyme linked immunosorbent assay (ELISA), were used for both transmission electron microscopy (TEM) and for isolation of the bacterium in PW broth or agar. Petioles examined by TEM contained rod-shaped bacteria inside the xylem vessels. The bacteria measured 0.3 to 0.5 μm in width and 1.5 to 3.0 μm in length, and had rippled cell walls 10 to 40 nm in thickness, typical of X. fastidiosa. Small, circular, dome-shaped colonies were observed 7 to 26 days after plating of plant extracts on PW agar. The colonies were comprised of Gram-negative rods of variable length and a characteristic slight longitudinal bending. TEM of the isolated bacteria showed characteristic rippled cell walls, similar to those observed in plant tissue. ELISA and PCR with specific primer pairs 272-l-int/272-2-int and RST31/RST33 confirmed the identity of the isolated bacteria as X. fastidiosa. RFLP analysis of the amplification products revealed diversity within X. fastidiosa strains from Costa Rica and suggest closer genetic proximity to strains from the United States of America than to other coffee or citrus strains from Brazil. Fundación CR-USA Universidad de Costa Rica/[801-A2-528]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

En un estudio realizado durante los años 1999 y 2000, en un vivero de orquídeas ubicado en el Valle Central (Costa Rica), se determinó que el género Potyvirus ocupa el segundo lugar en frecuencia de las infecciones virales detectadas, mediante la prueba de ELISA realizada a 148 plantas de diferentes especies de orquídeas nativas, que mostraban síntomas de posi- ble etiología viral. Durante el año 2002, se evaluaron nuevamente para potyvirus, 33 plantas de orquídeas pertenecientes a nueve géneros, en el vivero men- cionado, de las cuales cinco fueron positivas. En un estudio realizado durante los años 1999 y 2000, en un vivero de orquídeas ubicado en el Valle Central (Costa Rica), se determinó que el género Potyvirus ocupa el segundo lugar en frecuencia de las infecciones virales detectadas, mediante la prueba de ELISA realizada a 148 plantas de diferentes especies de orquídeas nativas, que mostraban síntomas de posi- ble etiología viral. Durante el año 2002, se evaluaron nuevamente para potyvirus, 33 plantas de orquídeas pertenecientes a nueve géneros, en el vivero men- cionado, de las cuales cinco fueron positivas.