1,126 research outputs found

    LEAF AREA INDEX RELATED TO WEED SUPPRESSION IN UPLAND TARO

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    LEAF AREA INDEX RELATED TO WEED SUPPRESSION IN UPLAND TAR

    Phosphorylation of MAP Kinases crucially controls the response to environmental stress in Dunaliella viridis

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    The green unicellular microalga Dunaliella viridis has the ability to cope with a wide variety of environmental stressful conditions, such as thermal and osmotic shocks, high PAR, UV radiation and nitrogen deficiency. The lack of a rigid cell wall makes D. viridis an excellent model organism to study stress signaling in eukaryotic unicellular organisms. Mitogen-activated protein kinases (MAPKs) are highly conserved serine/threonine kinases that convert extracellular stimuli into a wide range of responses at both cellular and nuclear levels. In eukaryotic cells, MAPKs are involved in both cell proliferation and differentiation (ERK pathway) and stress responses (JNK and p38 pathways), through protein kinase cascades. Significantly lesser phosphorylation levels of ERK-like protein were observed in D. viridis cultures acclimated to high salinity (3-4 M NaCl). In contrast, JNK-like and p38-like proteins phosphorylation levels increased in stressed cells. Likewise, the efficacy of specific commercial inhibitors of the phosphorylation of ERK (PD98059), JNK (SP600125) and p38 (SB203580) revealed the importance of JNK-like proteins in the maintenance of cell viability, the highlighted participation of p38-like proteins and the non-direct implication of the ERK-like proteins in the acclimatization process. In summary, specific blockade of JNK- and p38-like cascades in stressed cells led to rapid cell death. The behavior of MAPK-like proteins in algae is not known in depth, so the analysis of their mechanism of action, as well as their function in this model microalga, will allow to estimate the fate of unicellular eukaryotic organisms in aquatic ecosystems subjected to environmental stress derived from the conditions prevailing within a framework of global climate change.Peer reviewe

    Consensus on the Clinical Approach to Moderate-to-Severe Atopic Dermatitis in Spain: A Delphi Survey

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    Background. The purpose of this study was to gather information on the current assessment and management of patients with moderate-to-severe AD in routine daily practice. Methods. A cross-sectional two-round Delphi survey with the participation of dermatologists and allergologists throughout Spain was conducted. They completed a 46-item questionnaire, and consensus was defined when responses of >= 80% of participants coincided in the categories of a 5-point Likert scale for that item. Results. A total of 105 specialists (aged 40-59 years) completed the two rounds. Participants agreed regarding the consideration of AD as a multifaceted disease and the differences in clinical presentation of AD according to the patient's age. It is recommendable to perform a skin biopsy to exclude early stage T-cell cutaneous lymphoma, psoriasis, or dermatitis herpetiformis, among others (99.1%). Also, consensus was reached regarding the use of the SCORAD index to quantify the severity of the disease (86.7%), the use of wet wraps to increase the effect of topical corticosteroids (90.4%), the usefulness of proactive treatment during follow-up (85.6%) and tacrolimus ointment (91.2%) to reduce new flares, and the fact that crisaborole is not the treatment of choice for severe AD (92.4%). AD was not considered a contraindication for immunotherapy in patients with allergic respiratory diseases (92.4%). In patients with severe AD, the use of immune response modifier drugs (97.6%) or phototherapy (92.8%) does not sufficiently cover their treatment needs. Consensus was also obtained regarding the role of the new biologic drugs (93.6%) targeting cytokines involved in the Th2 inflammatory pathway (92.0%) and the potential role of dupilumab as first-line treatment (90.4%) in moderate-to-severe AD patients. Conclusion. This study contributes a reference framework to the care of AD patients. There is no diagnostic test or biomarkers to direct treatment or to assess the severity of the disease, and many therapeutic challenges remain

    Material herpetológico colectado por Roberto Donoso Barros en Venezuela (excepto geckos) en el Museo de Zoologia de la Universidad de Concepción, Chile

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    The material collected by Roberto Donoso Barros in Venezuela between 1963 and 1964 deposited at the Universidad de Concepción in Chile is catalogued and commented. Species are ordered following current systematic; specimens and species of interest are commented, especially those type material described by RDB.Se revisa el material herpetológico recolectado por Roberto Donoso Barros en Venezuela entre los años 1963 y 1964, el cual se encuentra depositado en la colección de vertebrados de la Universidad de Concepción, Chile. Se ordena taxonómicamente respetando los conceptos actualmente establecidos. Por último, cuando es necesario se hacen comentarios de los ejemplares y especies con confusión taxonómica, haciendo énfasis en el material tipo descrito por este autor

    Optimal Reconfiguration of a Limited Parallel Robot for Forward Singularities Avoidance

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    [EN] The positioning of the anchoring points of a Parallel Kinematic Manipulator has an important impact on its later performance. This paper presents an optimization problem to deal with the reconfiguration of a Parallel Kinematic manipulator with four degrees of freedom and the corresponding algorithms to address such problem, with the subsequent test on an actual robot. The cost function minimizes the forces applied by the actuators along the trajectory and considers singular positions and the feasibility of the active generalized coordinates. Results are compared among different algorithms, including evolutionary, heuristics, multi-strategy and gradient-based optimizers.This work was supported by the Spanish Ministry of Education, Culture and Sports through the Project for Research and Technological Development with Ref. DPI2017-84201-RLlopis-Albert, C.; Valero, F.; Mata, V.; Escarabajal, RJ.; Zamora-Ortiz, P.; Pulloquinga, JL. (2020). Optimal Reconfiguration of a Limited Parallel Robot for Forward Singularities Avoidance. Multidisciplinary Journal for Education, Social and Technological Sciences. 7(1):113-127. https://doi.org/10.4995/muse.2020.13352OJS11312771Arakelian, V., Briot, S., & Glazunov, V. (2008). Increase of singularity-free zones in the workspace of parallel manipulators using mechanisms of variable structure. Mechanism and Machine Theory, 43(9), 1129-1140. https://doi.org/10.1016/J.MECHMACHTHEORY.2007.09.005Araujo-Gómez, P., Díaz-Rodríguez, M., Mata, V., & González-Estrada, O. A. (2019). Kinematic analysis and dimensional optimization of a 2R2T parallel manipulator. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 41(10), 425. https://doi.org/10.1007/s40430-019-1934-1Araujo-Gómez, P., Mata, V., Díaz-Rodríguez, M., Valera, A., & Page, A. (2017). Design and kinematic analysis of a novel 3UPS/RPU parallel kinematic mechanism with 2T2R motion for knee diagnosis and rehabilitation tasks. Journal of Mechanisms and Robotics, 9(6), 061004. https://doi.org/10.1115/1.4037800Beiranvand, V., Hare, W., & Lucet, Y. (2017). Best practices for comparing optimization algorithms. Optimization and Engineering, 18(4), 815-848. https://doi.org/10.1007/s11081-017-9366-1Dash, A. K., Chen, I. M., Yeo, S. H., & Yang, G. (2005). Workspace generation and planning singularity-free path for parallel manipulators. Mechanism and Machine Theory, 40(7), 776-805. https://doi.org/10.1016/j.mechmachtheory.2005.01.001Gosselin, C., & Angeles, J. (1990). Singularity Analysis of Closed-Loop Kinematic Chains. IEEE Transactions on Robotics and Automation, 6(3), 281-290. https://doi.org/10.1109/70.56660Llopis-Albert, C., Rubio, F., & Valero, F. (2018). Optimization approaches for robot trajectory planning. Multidisciplinary Journal for Education, Social and Technological Sciences, 5(1), 1. https://doi.org/10.4995/muse.2018.9867Patel, Y. D., & George, P. M. (2012). Parallel Manipulators Applications-A Survey. Modern Mechanical Engineering, 02(03), 57-64. https://doi.org/10.4236/mme.2012.23008Rubio, F., Llopis-Albert, C., Valero, F., & Suñer, J. L. (2016). Industrial robot efficient trajectory generation without collision through the evolution of the optimal trajectory. Robotics and Autonomous Systems, 86, 106-112. https://doi.org/10.1016/j.robot.2016.09.008Rubio, F., Valero, F., & Llopis-Albert, C. (2019). A review of mobile robots: Concepts, methods, theoretical framework, and applications. International Journal of Advanced Robotic Systems, 16(2), 172988141983959. https://doi.org/10.1177/1729881419839596Tsai, L.-W. (1999). Robot Analysis and Design. John Wiley & Sons, Inc. New York, NY, USA ©1999.Valero, F., Rubio, F., & Llopis-Albert, C. (2019). Assessment of the Effect of Energy Consumption on Trajectory Improvement for a Car-like Robot. Robotica, 37(11), 1998-2009. https://doi.org/10.1017/S0263574719000407Vallés, M., Araujo-Gómez, P., Mata, V., Valera, A., Díaz-Rodríguez, M., Page, Á., & Farhat, N. M. (2018). Mechatronic design, experimental setup, and control architecture design of a novel 4 DoF parallel manipulator. Mechanics Based Design of Structures and Machines, 46(4), 425-439. https://doi.org/10.1080/15397734.2017.1355249Wehage, K. T., Wehage, R. A., & Ravani, B. (2015). Generalized coordinate partitioning for complex mechanisms based on kinematic substructuring. Mechanism and Machine Theory, 92, 464-483. https://doi.org/10.1016/j.mechmachtheory.2015.06.006www.esteco.com. (n.d.). Retrieved June 10, 2019, from https://www.esteco.com/Xianwen Kong, B., & Gosselin, C. M. (2002). Kinematics and singularity analysis of a novel type of 3-CRR 3-DOF translational parallel manipulator. International Journal of Robotics Research, 21(9), 791-798. https://doi.org/10.1177/02783649020210090501Yang, X. (2017). Optimization Algorithms Optimization and Metaheuristic Algorithms in Engineering. (March). https://doi.org/10.1007/978-3-642-20859-

    Conocimientos, prácticas y aspectos entomológicos del dengue en Medellín, Colombia: un estudio comparativo entre barrios con alta y baja incidencia

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    Introduction: Dengue, mainly transmitted by Aedes aegypti, is a very important viral disease in terms of public health. Colombia is an endemoepidemic country for dengue and, in cities like Medellín, there are neighborhoods with high and low incidence. The disease dynamics in the neighborhoods might be determined by differences in the knowledge, practices and entomological aspects of the vector among the communities.Objective: To identify the knowledge and practices of residents of neighborhoods with high and low incidence of dengue, and to explore the entomological aspects related to the presence of the vector.Materials and methods: We conducted a cross-sectional study comparing two neighborhoods with high incidence and two with low incidence during the triennium of 2013-2015. A random sample of 100 houses per neighborhood was selected in order to evaluate the knowledge, practices and entomological aspects related to dengue. In addition, descriptive, bivariate and multivariate analyses (logistic regression) were performed.Results: In neighborhoods with high incidence, participants had not attended school or had only a primary school level of education (OR=1.69; 95% CI: 1.09-2.63). Additionally, they did not have health coverage or belonged to the subsidized regime (OR=2.16; 95% CI: 1.41-3.32). In contrast, they had a greater knowledge of the vector (OR=1.53; 95% CI: 1.00-2.35). In terms of practices, there was a greater chance of finding houses where water was stored (OR=1.69; 95% CI: 1.11-2.57) and regarding the entomological aspects, more houses with adult mosquitoes were found (OR=2.13 95% CI: 1.29-3.50).Conclusions: We found important differences among the neighborhoods regarding knowledge, practices, and the presence of adult stages of the vector, which helps to explain the epidemiology of dengue in these sites.Introducción. El dengue, transmitido principalmente por Aedes aegypti, es una enfermedad viral de gran importancia en salud pública. Colombia es un país endemoepidémico para el dengue y, en ciudades como Medellín, hay barrios con alta y baja incidencia. Las diferencias en cuanto a los conocimientos, las prácticas y los aspectos entomológicos podrían estar determinando la dinámica de la enfermedad en los barrios.Objetivo. Determinar los conocimientos y prácticas en torno al dengue de los habitantes de barrios con alta y baja incidencia y explorar los aspectos entomológicos relacionados con la presencia del vector.Materiales y métodos. Se hizo un estudio transversal y se compararon dos barrios con alta incidencia y dos con baja incidencia durante el trienio de 2013 a 2015. Se seleccionó una muestra aleatoria de 100 viviendas por barrio para evaluar los conocimientos, las prácticas y los aspectos entomológicos. Se hicieron el análisis descriptivo, el bivariado y el multivariado (regresión logística).Resultados. En los barrios con alta incidencia, los participantes se caracterizaron por no haber realizado estudios o haber cursado únicamente primaria (odds ratio, OR=1,69; IC95%=1,09-2,63), así como por pertenecer al régimen subsidiado del sistema de seguridad social en salud o no estar afiliado (OR=2,16; IC95% 1,41-3,32) y, además, presentaron un mayor conocimiento del vector (OR=1,53; IC95% 1,00-2,35). En cuanto a las prácticas, la posibilidad de encontrar viviendas en donde se almacenaba el agua fue mayor (OR=1,69; IC95% 1,11-2,57) y, en lo relacionado con los aspectos entomológicos, se encontraron más viviendas con mosquitos adultos (OR=2,13; IC95% 1,29-3,50).Conclusiones. En este estudio se encontraron diferencias importantes entre los barrios en cuanto a los conocimientos, las prácticas y la presencia de estados adultos del vector, lo cual contribuye a explicar la epidemiología del dengue en estos lugares

    Comunidades de peces del atolón de Clipperton (Pacífico oriental tropical) y su relación con la cobertura de corales

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    Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m) around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level). We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages.El atolón de Clipperton, uno de los arrecifes de coral más aislados del mundo, presenta un gran interés científico por su geomorfología y endemismo. Este estudio analizó la estructura de las comunidades de peces de arrecife de este atolón y su relación con la cobertura de coral vivo. Para ello se muestrearon nueve estaciones alrededor del arrecife en tres sitios a tres profundidades (6, 12, 20 m), registrando, la riqueza y biomasa de peces, así como la cobertura de coral hermatípico a nivel de género. Se evaluó la variación de la riqueza, biomasa y diversidad de peces entre sitios y profundidades, así como la relación de la composición y biomasa de peces con la cobertura de coral vivo. Los resultados mostraron que la riqueza y biomasa fueron similares entre los sitios, pero diferentes entre profundidades, ya que incrementan con la profundidad. En contraste, la diversidad difirió entre sitios pero no entre profundidades. Los análisis multidimensionales indicaron que la comunidad de peces fue diferente entre sitios y profundidades, relacionándolo con la cobertura de coral de los géneros Pocillopora, Porites, Pavona y Leptoseris, que dominan a distinta profundidad. Los resultados evidenciaron una baja riqueza y diversidad de peces arrecifales en el atolón de Clipperton. En arrecifes de coral aislados, con baja heterogeneidad de hábitats y poca perturbación humana, la cobertura de coral vivo influye en la variación espacial de las comunidades de peces arrecifales. Este estudio resalta la importancia de la estructura del hábitat de coral en la conformación de las comunidades de peces arrecifales

    Type-Specific Identification of Genital Human Papillomavirus Infection in Women with Cytological Abnormality

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    Objectives: To estimate the frequency of human papillomavirus (HPV) infection and the genotype distribution of HPV among women with a Pap smear showing atypical squamous cells of undetermined significance (ASC-US) attending the Program for the Detection and Control of Cervical Cancer in Bogotá, Colombia. Study Design: Cervical samples from 200 women with an ASC-US Pap smear were analyzed for the presence of HPV DNA and genotype distribution using a commercial molecular technique (Linear Array®; Roche Molecular Systems, USA). Results: HPV infection was found in 140 women (70%). High-risk HPV types were present in 46.4% of the samples; 16.4% showed a low-risk HPV type, and 37.1% showed both. Of the positive samples, 42.9% were infected with a single viral genotype, whereas 57.1% exhibited multiple HPV infections. The most common HPV genotypes were HPV 16, 53, and 52 with a prevalence of 26.4, 16.4, and 13.6%, respectively. Conclusion: The epidemiological characterization of HPV infections described in this study might guide actions for epidemiological surveillance to strengthen the program in Bogotá and to develop appropriate HPV vaccination programs.Instituto de Genética Veterinari

    Occupational Health and Safety Prevention Plan in Water Treatment Plant

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    The research was carried out at the "El Guarumo" drinking water plant located in Santa Ana, province of Manabí, Ecuador. The objective of the investigation was the proposal of a plan of prevention of occupational risks that allows the management of the labor risks in said plant. The main tools used were: survey, interview, checklist, LEST questionnaire for the diagnosis of the current situation in terms of working conditions, the risk identification matrix and the binary method of risk assessment. The main results obtained were the identification of the risks in their different categories, observing that the critical risk factors are related to the physical overexertion, the uncomfortable postures and the manual lifting of the load. Among the important risks are falling objects, skin contact with toxic substances and mental overwork, closely related to work pressures and job security? It was possible to carry out the proposal of preventive and corrective measures in order to properly manage the risks and contribute to the safety and health of the workers
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