4,010 research outputs found

    Structure and genetic diversity in wild and cultivated populations of Zapote mamey (Pouteria sapota, Sapotaceae) from southeastern Mexico: its putative domestication center

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    Tropical fruit trees are an important component of the human diet; however, little is known about their genetic diversity levels. Zapote mamey (Pouteria sapota) is a tree native to southeastern Mexico and Central America, and Mexico is the leading producer in the world. Studies of the genetic diversity of Zapote mamey have been based on cultivated materials using morphological and biochemical characterization or dominant molecular markers. To gain a deeper understanding about the conservation status of Zapote mamey in its center of origin and domestication, we collected 188 individuals from eight wild and five cultivated populations in southeastern Mexico and characterized them using eight microsatellite loci. STRUCTURE, 3D-PCoA, and neighbor-joining analyses showed three groups in the wild gene pool and one group in the cultivated gene pool. FST values were significant between wild and cultivated gene pools, among the four groups observed and among the 13 populations collected (0.13, 0.25, and 0.36, respectively). Overall, we found low levels of genetic diversity (A = 2.77, HO = 0.29, HE = 0.39), permutation tests did not show significant differences between wild and cultivated gene pools. The Garza–Williamson index showed low values in both gene pools (wild = 0.16, cultivated = 0.11) and the Bottleneck program indicated a decrease in genetic diversity in both gene pools (wild, P = 0.027; cultivated, P = 0.054); both analyses suggest a potential genetic bottleneck within this species. This study can help to generate adequate sampling techniques and to develop effective management strategies for Zapote mamey of southeastern Mexico

    Análisis dogmático del derecho penal ambiental chileno, a la luz del derecho comparado y las obligaciones contraídas por Chile en el ámbito del derecho internacional. Conclusiones y propuesta legislativa

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    Indexación: ScieloEl presente artículo corresponde al Informe Final del Proyecto FONDECYT 1010206­2001, sobre tratamiento penal de los delitos contra el medio ambiente en Chile. Sus conclusiones se exponen en siete partes: la primera aborda la cuestión de la necesidad de un derecho penal protector del medio ambiente, ante los riesgos a que se encuentra sometido en las sociedades contemporáneas; la segunda, la necesidad de su regulación desde el punto de vista del Derecho Internacional y las obligaciones contraídas en la materia; la tercera, una descripción sucinta de los modelos de regulación de la protección penal del medio ambiente en el derecho comparado; la cuarta, una explicación acerca de las normas de derecho penal ambiental vigentes en Chile; la quinta, el por qué de la insuficiencia legislativa penal para la protección del medio ambiente, a la luz de las obligaciones internacionales contraídas en la materia, el estado del derecho comparado y la necesidad de evitar la burla del Sistema de Evaluación de Impacto Ambiental; la sexta, una reseña y crítica científica de los proyectos de ley en materia penal ambiental presentados al Congreso Nacional; y la séptima, las ideas matrices de las soluciones de lege ferenda que se ofrecen a los problemas de las insuficiencias del Derecho nacional en la materia y el texto de la propuesta de Proyecto de Ley elaborado, producto final de nuestras investigaciones.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-00122003000200002&nrm=is

    Aportación al conocimiento del ciclo biológico de Chromulina nevadensis

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    In this paper we present data about enlargement of the original description of Chromulina nevadensis. This study has been carried out on an oligotrophic high mountain lake (La Caldera) close to the lake where it was described (Aguas Verdes). Also we make some consideration about the mixotrophy, a nutritional behavior previously knew for other chrysophyceae taza. Finally we study, by the first time, the morfology of its statospores with SEM.En este trabajo se amplía y se comenta la descripción de Chromulina nevadensis P.M. Sánchez. El estudio se realiza en una laguna oligotrófica de alta montaña (La Caldera), próxima a la laguna de Aguas Verdes, donde se obtuvo el material para su descripción original. Igualmente realizamos algunas consideraciones sobre el comportamiento mixotrófico de este taxon, ya conocido para otros miembros de las crisofíceas. Para finalizar describimos, por primera vez, la morfología a MEB de su estatospora

    Nitric oxide deficiency decreases C-repeat binding factor-dependent and -independent induction of cold acclimation

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    [EN] Plant tolerance to freezing temperatures is governed by endogenous components and environmental factors. Exposure to low non-freezing temperatures is a key factor in the induction of freezing tolerance in the process called cold acclimation. The role of nitric oxide (NO) in cold acclimation was explored in Arabidopsis using triple nia1nia2noa1-2 mutants that are impaired in the nitrate-dependent and nitrate-independent pathways of NO production, and are thus NO deficient. Here, we demonstrate that cold-induced NO accumulation is required to promote the full cold acclimation response through C-repeat Binding Factor (CBF)-dependent gene expression, as well as the CBF-independent expression of other cold-responsive genes such as Oxidation-Related Zinc Finger 2 (ZF/OZF2). NO deficiency also altered abscisic acid perception and signaling and the cold-induced production of anthocyanins, which are additional factors involved in cold acclimation.We thank Isabel Lopez-Diaz and Esther Carrera for the hormone quantification carried out at the Plant Hormone Quantification Service, IBMCP, Valencia, Spain. This work was supported by grants from MINECO of Spain Government and FEDER EU funds [BIO2014-56067-P, BIO2017-82945-P to JL and BIO2016-79187-R to JS].Costa-Broseta, Á.; Perea-Resa, C.; Castillo, M.; Ruíz, MF.; Salinas, J.; Leon Ramos, J. (2019). Nitric oxide deficiency decreases C-repeat binding factor-dependent and -independent induction of cold acclimation. Journal of Experimental Botany. 70(12):3283-3296. https://doi.org/10.1093/jxb/erz115S328332967012Adams, S., & Carré, I. A. (2011). Downstream of the plant circadian clock: output pathways for the control of physiology and development. 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Identification of a Plant Nitric Oxide Synthase Gene Involved in Hormonal Signaling. Science, 302(5642), 100-103. doi:10.1126/science.1086770Hannah, M. A., Heyer, A. G., & Hincha, D. K. (2005). A Global Survey of Gene Regulation during Cold Acclimation in Arabidopsis thaliana. PLoS Genetics, 1(2), e26. doi:10.1371/journal.pgen.0010026Igamberdiev, A. U., Ratcliffe, R. G., & Gupta, K. J. (2014). Plant mitochondria: Source and target for nitric oxide. Mitochondrion, 19, 329-333. doi:10.1016/j.mito.2014.02.003Jensen, M. K., Lindemose, S., de Masi, F., Reimer, J. J., Nielsen, M., Perera, V., … Skriver, K. (2013). ATAF1 transcription factor directly regulates abscisic acid biosynthetic gene NCED3 in Arabidopsis thaliana. FEBS Open Bio, 3(1), 321-327. doi:10.1016/j.fob.2013.07.006Jeon, J., Kim, N. Y., Kim, S., Kang, N. Y., Novák, O., Ku, S.-J., … Kim, J. (2010). A Subset of Cytokinin Two-component Signaling System Plays a Role in Cold Temperature Stress Response in Arabidopsis. Journal of Biological Chemistry, 285(30), 23371-23386. doi:10.1074/jbc.m109.096644Kakei, Y., & Shimada, Y. (2014). AtCAST3.0 Update: A Web-Based Tool for Analysis of Transcriptome Data by Searching Similarities in Gene Expression Profiles. Plant and Cell Physiology, 56(1), e7-e7. doi:10.1093/pcp/pcu174Krol, M., Gray, G. R., Huner, N. P. A., Hurry, V. M., Öquist, G., & Malek, L. (1995). Low-temperature stress and photoperiod affect an increased tolerance to photoinhibition in Pinus banksiana seedlings. Canadian Journal of Botany, 73(8), 1119-1127. doi:10.1139/b95-122Lee, H. G., & Seo, P. J. (2015). The MYB 96– HHP module integrates cold and abscisic acid signaling to activate the CBF – COR pathway in Arabidopsis. The Plant Journal, 82(6), 962-977. doi:10.1111/tpj.12866León, J., Castillo, M. C., Coego, A., Lozano-Juste, J., & Mir, R. (2013). Diverse functional interactions between nitric oxide and abscisic acid in plant development and responses to stress. Journal of Experimental Botany, 65(4), 907-921. doi:10.1093/jxb/ert454Li, D., Li, Y., Zhang, L., Wang, X., Zhao, Z., Tao, Z., … Yang, Y. (2014). Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44. International Journal of Molecular Sciences, 15(5), 8473-8490. doi:10.3390/ijms15058473Lozano-Juste, J., Colom-Moreno, R., & León, J. (2011). In vivo protein tyrosine nitration in Arabidopsis thaliana. Journal of Experimental Botany, 62(10), 3501-3517. doi:10.1093/jxb/err042Lozano-Juste, J., & León, J. (2009). Enhanced Abscisic Acid-Mediated Responses in nia1nia2noa1-2 Triple Mutant Impaired in NIA/NR- and AtNOA1-Dependent Nitric Oxide Biosynthesis in Arabidopsis. Plant Physiology, 152(2), 891-903. doi:10.1104/pp.109.148023Morishita, T., Kojima, Y., Maruta, T., Nishizawa-Yokoi, A., Yabuta, Y., & Shigeoka, S. (2009). Arabidopsis NAC Transcription Factor, ANAC078, Regulates Flavonoid Biosynthesis under High-light. 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    Relationship between the isometric force of the dominant hand and the Body Mass Index of university students

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    INTRODUCTION: Strength is the neuromuscular capacity to overcome or counter resistances through muscular activity and is closely linked to all the motor actions that the human being develops, and to his body mass index. OBJECTIVE: To determine the level of correlation between body mass index (BMI) and the isometric strength of the dominant hand of university students. METHOD: The strength was evaluated with a TAKEI SCIENTIFIC INSTRUMENT 5401 dynamometer to 70 university students using a random sampling method using a descriptive transactional design. We obtained data that were processed with a bivariate correlation obtaining the Pearson coefficient. We used SPSS ver. 15. RESULTS: The studied age was 23 ± 1.9 years, with a length of 165.6 cm. ± 7.72 for women and 173.7 cm. ± 7.95 men, as well as a weight in women of 64.1 ± 14.82 kg and men 82.3 ± 14.72 kg, which results in a BMI for women of 25.01 ± 4.405 m2/kg and 25.06 with ± 4.398 m2/kg for men. On the other hand, the female isometry strength was 3.08. ± 0.613 Kg and for men was 3.68 ± 0.839 Kg. In females, there was not correlation between the BMI and isometric strength (Sig = .192). Contrary, in males, there was a significant and negative correlation grade between the BMI and isometric strength (r = -0,452; Sig. = 0.035). CONCLUSIONS: In this study, it was observed that as BMI increases, strength does not grow. Therefore, other variables should be evaluated to understand what is related to the overweight or obesity of students

    DIVERSIDAD DE AVES DE SOTOBOSQUE EN BOSQUES TROPICALES, ÁREAS DE REGENERACIÓN NATURAL Y CULTIVOS DE PALMA AFRICANA EN HUMEDALES DEL LAGO DE IZABAL, GUATEMALA

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    Diversity of understory birds in tropical forests, natural recovery areas, and African oil palm crops in wetlands of the Izabal Lake, Guatemala. – African oil palm (Elaeis guineensis) crops have been identified as one of the most important threats to biodiversity of tropical forests. By mean of mist nets, species richness, diversity and structure of understory bird communities were studied in three vegetation types of a Neotropical wetland: humid tropical forest remnants, natural regeneration sites (“guamiles”), and African oil palm plantations. We captured a total of 734 birds of 106 species, belonging to 22 families. The habitat with highest diversity was forest (63 species and 329 individuals), followed by guamiles (62 species and 368 individuals) and finally oil palm plantations (11 species and 37 individuals). As expected, statistical differences were found among the studied habitats. Only 11% of species and 5% of the total captured birds were recorded in the African oil palm plantations. Our data show that oil palm cultivation represents a serious threat to biological diversity, making it a priority to generate guidelines based on scientific and conservation criteria

    Multiclasificadores basados en aprendizaje automático como herramienta para la evaluación del perfil neurotóxico de líquidos iónicos

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    Los líquidos iónicos poseen un perfil fisicoquímico único, el cual los provee de un amplio rango de aplicaciones. Su variabilidad estructural casi ilimitada permite su diseño para tareas específicas. Sin embargo, su sustentabilidad, específicamente su seguridad desde el punto de vista toxicológico, ha sido frecuentemente cuestionada. Este último aspecto limita significativamente el cumplimiento de las regulaciones establecidas por la Unión Europea para el registro, evaluación, autorización y restricción de compuestosquímicos (REACH), así como su aplicación final. Debido a que la mayoría de los líquidos iónicos no han sido sintetizados, se hace evidente la importancia del desarrollo de herramientas quimioinformáticas que, de forma eficiente, permitan evaluar el potencial toxicológico de estos compuestos. En este sentido, el uso combinado de múltiples clasificadores ha demostrado superar las limitaciones de desempeño asociadas al uso de clasificadores individuales. En el presente trabajo fueron evaluadas varias estrategias alternativas de multiclasificadores basados en técnicas de aprendizaje automático supervisado, como herramientas para la evaluación del perfil neurotóxico de líquidos iónicos basado en la inhibición de la enzima acetilcolinesterasa, como indicador de neurotoxicidad. Se obtuvieron dos multiclasificadores con una alta capacidad predictiva sobre un conjunto de validación externa (no utilizado en el proceso de aprendizaje de los modelos). De acuerdo a los resultados obtenidos el 96% de un conjunto de nuevos líquidos iónicos podrá ser correctamente clasificado con la utilizaciónde estos multiclasificadores, los cuales constituyen herramientas de toma de decisión útiles en el campo del diseño y desarrollo de nuevos líquidos iónicos sustentables

    ZnO (Ag-N) Nanorods Films Optimized for Photocatalytic Water Purification

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    ZnO nanorods (NRs) films, nitrogen-doped (ZnO:N), and ZnO doped with nitrogen and decorated with silver nanostructures (ZnO:N-Ag) NRs films were vertically supported on undoped and N doped ZnO seed layers by a wet chemical method. The obtained films were characterized structurally by X-ray diffraction. Morphological and elemental analysis was performed by scanning electron microscopy, including an energy dispersive X-ray spectroscopy facility and their optical properties by Ultraviolet-Visible Spectroscopy. Analysis performed in the NRs films showed that the nitrogen content in the seed layer strongly affected their structure and morphology. The mean diameter of ZnO NRs ranged from 70 to 190 nm. As the nitrogen content in the seed layer increased, the mean diameter of ZnO:N NRs increased from 132 to 250 nm and the diameter dispersion decreased. This diameter increase occurs simultaneously with the incorporation of nitrogen into the ZnO crystal lattice and the increase in the volume of the unit cell, calculated using the X-ray diffraction patterns and confirmed by a slight shift in the XRD angle. The diffractograms indicated that the NRs have a hexagonal wurtzite structure, with preferential growth direction along the c axis. The SEM images confirmed the presence of metallic silver in the form of nanoparticles dispersed on the NRs films. Finally, the degradation of methyl orange (MO) in an aqueous solution was studied by UV-vis irradiation of NRs films contained in the bulk of aqueous MO solutions. We found a significant enhancement of the photocatalytic degradation efficiency, with ZnO:N-Ag NRs film being more efficient than ZnO:N NRs film, and the latter better than the ZnO NRs film. View Full-Text
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