123 research outputs found
Pesticides Reaching the Environment as a Consequence of Inappropriate Agricultural Practices in Argentina
Mitogenome and Nuclear-encoded Fungicide-target Genes of Thecaphora frezii - Causal Agent of Peanut Smut
Background: Thecaphora frezii Carranza and Lindquist causes smut disease in peanut (Arachis hypogaea L.) resulting in up to 35% yield losses. Fungicides have shown ineffective in controlling the disease; whereas research on the molecular basis of that fungicide resistance has been hindered because of the lack of genetic information about T. frezii. The goal of this work was to provide molecular information about fungicide-target loci in T. frezii, including its mitochondrial genome (mitogenome) and critical nuclear-encoded genes.
Results: Here we report the complete annotated mitogenome of T. frezii, a 123,773 bp molecule containing the standard 14 genes that form part of mitochondrial complexes I, III, IV and V, 22 transfer RNAs, small and large subunits of ribosomal RNA, DNA polymerase, ribonuclease P, GII-reverse transcriptase/maturase, nine hypothetical open-reading frames and homing endonucleases (LAGLIDADG, GIY-YIG, HEG). In addition, we report the full-length cDNA sequence of T. frezii cytochrome b (cob) and cytochrome oxidase 1 (cox1) genes; as well as partial sequences of T. frezii succinate dehydrogenase (sdhb), ergosterol biosynthesis (Erg4), cytochrome P450 (cyp51), and beta tubulin (β-tubulin) genes, which are respective targets of strobilurins, quinone oxidation inhibitors, triazoles and beta-tubulin inhibitor fungicides commonly used in the peanut crop. Translation of cob and sdhb genes in this particular T. frezii isolate suggests potential resistance to strobilurin and carboxamide fungicides.
Conclusion: The mitogenome and nuclear-encoded gene sequences presented here provide the molecular tools to research T. frezii fungicide-target loci
Análisis de fuentes y toxicidad equivalente de sedimentos contaminados con PAHs en el estuario de Bahía Blanca, Argentina
This paper presents a comprehensive survey of PAHs in coastal sediments of Bahia Blanca, Argentina and provides useful information of their levels of concentration, sources, ecotoxicological assessment and carcinogenic PAHs profile of local emissions. Sediments were analyzed following Environmental Protection Agency (EPA, USA) protocols by means of Gas Chromatography-Mass Spectrometry, showing total concentrations of PAHs in a range from 103 to more than 2,000 ng.g-1 (mean: 527 ± 114 ng.g-1; median: 507 ng.g-1). A dynamic state of PAHs pollution was demonstrated for the area which was defined by widespread low to moderate levels, but including punctual zones with high pollution processes. Molecular ratios calculations determined a generalized overimposition of pyrolitic PAHs over the petrogenic input. The pyrolitic pattern moved to a biomass burning origin during summer, the period of highest recorded fires. In addition, the ecotoxicological guidelines approach for PAHs chemical concentrations in sediment defined a rare occurrence of biological effects for the majority of sampled sites; however, frequent effects were expected for punctual locations. Further, Total Benzo-a-pyrene equivalents from several sampling stations were found to be above international regulations. Finally, the PAHs carcinogenic dose was calculated using the BaP equivalent factors approach and compared with other worldwide coastal studies by means of Hierarchical Cluster Analysis.Se presenta un estudio exhaustivo de sedimentos del estuario de Bahía Blanca (Argentina) para determinar su impacto por Hidrocarburos Aromáticos Policíclicos (PAHs). Los sedimentos fueron procesados siguiendo protocolos de la Environmental Protection Agency (EPA, USA) y analizados por Cromatografía Gaseosa-Espectrometría de Masas, hallándose un rango de concentraciones total, desde 103 a más de 2,000 ng.g-1 p.s. (p.s.= peso seco; Total PAHs = sumatoria de 17 PAHs), una concentración media de 527 ± 114 ng.g-1 y una mediana de 507 ng.g-1. Se demostró la existencia de un nivel dinámico de contaminación por PAHs, definido por valores bajos a moderados que incluyeron zonas puntuales con altos niveles. El análisis de origen mediante el uso de índices moleculares determinó un predominio de deposiciones pirolíticas sobre las de origen petrogénico, siendo dominantes las emisiones provenientes de la quema de biomasa durante los meses más cálidos. La calidad ecotoxicológica de los sedimentos se abordó utilizando el enfoque de niveles guía, hallándose para la mayoría de los sitios muestreados una predicción de efectos adversos infrecuentes sobre la biota adyacente, con sitios puntuales para los cuales se predijo la aparición frecuente de efectos. Utilizando el concepto de equivalentes de Benzo-a-pireno se calculó su carga total, la cual se halló en ocasiones por sobre los valores indicados en diversas regulaciones internacionales. Finalmente se evaluó la dosis carcinogénica aportada por los 7 PAHs carcinogénicos y su perfil de concentraciones se contrastó estadísticamente con otros sitios costeros del mundo utilizando análisis de grupos jerarquizados
Comparison of CT and CMR for detection and quantification of carotid artery calcification:the Rotterdam Study
Background: Carotid artery atherosclerosis is an important risk factor for stroke. As such, quantitative imaging of carotid artery calcification, as a proxy of atherosclerosis, has become a cornerstone of current stroke research. Yet, population-based data comparing the computed tomography (CT) and cardiovascular magnetic resonance (CMR) for the detection and quantification of calcification remain scarce. Methods: A total of 684 participants from the population-based Rotterdam Study underwent both a CT and CMR of the carotid artery bifurcation to quantify the amount of carotid artery calcification (mean interscan interval: 4.9 ± 1.2 years). We investigated the correlation between the amount of calcification measured on CT and CMR using Spearman’s correlation coefficient, Bland-Altman plots, and linear regression. In addition, using logistic regression modeling, we assessed the association of CT and CMR based calcification volumes with a history of stroke. Results: We found a strong correlation between CT and CMR based calcification volumes (Spearman’s correlation coefficient:0.86, p-value ≤0.01). Bland-Altman analyses showed a good agreement, though CT based calcification volumes were systematically larger. Finally, calcification volume assessed with either imaging modality was associated with a history of stroke with similar effect estimates (odds ratio (OR) per 1-SD increase in calcification volume: 1.52 (95% CI:1.00;2.30) for CT, and 1.47 (95% CI:1.01;2.14) for CMR. Conclusion: CT based and CMR based volumes of carotid artery calcification are highly correlated, but CMR based calcification is systematically smaller than those obtained with CT. Despite this difference, both provide comparable information with regard to a history of stroke. Electronic supplementary material The online version of this article (doi:10.1186/s12968-017-0340-z) contains supplementary material, which is available to authorized users
Casos de enseñanza como estrategia pedagógica en programas empresariales
Los estudios de caso se destacan como una metodología de pedagogía activa en la cual los estudiantes, si son orientados de manera adecuada, pueden tener un aprendizaje experiencial y significativo. El objetivo del presente artículo discute la importancia del método de caso como estrategia pedagógica para la formación gerencial e incluye una serie de pautas acerca de cómo escribir el material y como desarrollarlo dentro de un contexto de clase. Por último, se concluye que la casuística es una posibilidad pedagógica para que los estudiantes aprendan y comprendan de mejor forma las enseñanzas gerenciales frente a las tradicionales y dogmáticas que aún persisten en algunas escuelas de negocios
Origen de la mutación G736A del gen Parkin en la población de Peque (noroccidente de Antioquia)
In a large family from Peque population (Antioquia), there have been found some individuals affected with juvenile Parkinson’s disease, due to the G736A mutation located in exon 6 of the PARK2 gene. As a result of the tri-ethnic composition of our mixed populations and that this mutation was reported in Spain, our goal was to find the origin of this mutation. We typified molecular markers on the Y chromosome in 132 unrelated individuals from the general population and 31 of the family; in addition the records of surnames in two periods were also analyzed. The mutation was exclusively found in families where only one haplotype was European (haplogroup P) named Valle, and one native haplotype (Q1a3a) named SalasG736A, the mutation carriers. The mutation G736A, joined by European founders (P) named Valle, increased its frequency due to a founder effect, internal growth and inbreeding in the family but not in the total population and it expanded in a Native American context (Q1a3a) named Salas.En una gran familia de la población de Peque (Antioquia) se hallaron individuos afectados por la enfermedad de Parkinson juvenil, debido a la mutación G736A localizada en el exón 6 del gen PARK2. Dada la composición triétnica de nuestraspoblaciones mestizas, y dado que esta mutación fue reportada en España, nuestro objetivo fue buscar su origen. Para ello, tipificamos con marcadores moleculares del cromosoma Y a 132 individuos no relacionados de la población general y a 31 de la familia, además con registros de apellidos en dos periodos diferentes. La mutación solo se encontró en la familia en la que se dio un solo haplotipo europeo (haplogrupo P) de apellido Valle, y un solo haplotipo nativo (Q1a3a) de apellido Salas, portadores de la mutación G736A. La mutación G736A ingresó con fundadores europeos (P) de apellido Valle, aumentó su frecuencia debido a un efecto fundador, al crecimiento interno y a cruces endogámicos en la familia y no en la población total, y se expandió en un contexto amerindio (Q1a3a) de apellido Salas
Assessment of continuous and impulsive whole body vibration exposures in heavy equipment mining vehicles
The purpose of the study was to collect, compare and contrast continuous [A(8)] and impulsive [VDV(8) and S ed (8)] WBV exposures in 190, 240 and 320 ton mining trucks in order to determine whether the WBV exposures were above ISO and European Union action limits whether there were any differences in injury risk prediction across the WBV exposure parameters. All exposure parameters showed that the z-axis appeared to be the predominant axis of exposure with no exposure differences across trucks, whereas the x-and y-axis exposures differed and increased with truck size. In all trucks, the predominant axis A(8) and VDV(8) WBV exposures were below ISO and European Union (EU) action limits; however, all vector sum exposures were above action limits. In contrast, the S ed (8) WBV exposures were below ISO action limits. In conclusion, it appears that there is differential prediction of health risks between S ed (8) and the A(8) and VDV(8) WBV exposure parameters. Practitioner Summary: In the three types of mining truck evaluated, the vehicle operation times to reach the daily action limits for the vector sum A(8) and VDV(8) WBV exposures were less than 7 and 5 hours per day, respectively; in contrast, there was no daily limit for vehicle operation based on S ed (8) WBV exposure parameter. It appears the S ed (8) WBV exposure parameter may underestimate health risks
Microplastics and anthropogenic debris in rainwater from Bahia Blanca, Argentina
Concern about atmospheric microplastic (MP) contamination has increased in recent years. This study assessed the abundance of airborne anthropogenic particles, including MPs, deposited in rainfall in Bahia Blanca, southwest Buenos Aires, Argentina. Rainwater samples were collected monthly from March to December 2021 using an active wet-only collector consisting of a glass funnel and a PVC pipe that is only open during rain events. Results obtained show that all rain samples contained anthropogenic debris. The term “anthropogenic debris” is used to refer to the total number of particles as not all the particles found could be determined as plastic. Among all the samples, an average deposition of 77 ± 29 items (anthropogenic debris) m⁻²d⁻¹ was found. The highest deposition was observed in November (148 items m⁻²d⁻¹) while the lowest was found in March (46 items m⁻²d⁻¹). Anthropogenic debris ranged in size from 0.1 mm to 3.87 mm with the most abundant particles being smaller than 1 mm (77.8%). The dominant form of particles found were fibers (95%), followed by fragments (3.1%). Blue color predominated (37.2%) in the total number of samples, followed by light blue (23.3%) and black (21.7%). Further, small particles (<2 mm), apparently composed of mineral material and plastic fibers, were recognized. The chemical composition of suspected MPs was examined by Raman microscopy. The analysis of μ-Raman spectra confirmed the presence of polystyrene, polyethylene terephthalate, and polyethylene vinyl acetate fibers and provided evidence of fibers containing industrial additives such as indigo dye. This is the first assessment of MP pollution in rain in Argentina.Centro de Química Inorgánic
Crimen organizado y violencia homicida en ciudades intermedias
El presente libro compila un conjunto de investigaciones sobre las diferentes expresiones de la violencia homicida y el crimen organizado en Colombia, en el contexto de los esfuerzos discontinuos de construcción de Paz de la nación. Con perspectiva plural, muestra las distintas problemáticas de la violencia homicida, el conflicto armado y las reacciones de los afectados, así como los distintos impactos en un conjunto de ciudades intermedias. Abarca un conjunto de espacios urbanos diversos dentro del vasto y profundo territorio colombiano. Además de las lógicas de violencia homicida y de las actividades de organizaciones criminales en cada ciudad seleccionada en el libro, los autores exploran, en diversas formas, cuáles son las respuestas de los actores públicos, de la sociedad y los actores ilícitos armados, así como la manera en que las distintas violencias afectan las posibilidades de construcción de paz
Influence of NiTi alloy on the root canal shaping capabilities of the ProTaper Universal and ProTaper Gold rotary instrument systems
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