3,406 research outputs found

    Supraspinal reorganization after pediatric-onset spinal cord injury.

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    Pediatric spinal cord injury (SCI) disrupts the efferent and afferent flow of the developing brain, leading to devastating functional impairments below the injury site, yet our understanding of its impact on the brain remains limited. This study examines supraspinal reorganization in children with SCI using electrophysiology and neuroimaging techniques to understand the relationship between residual spinal transmission and supraspinal reorganization. Chapter 2 discusses the development of a child-centric approach using ‘learn, play, and practice’ to foster a trusting relationship with each child and increase compliance with experimental protocols. Chapter 3 evaluates the residual neural transmission of three spinal pathways in children with SCI, revealing that supraspinal inputs onto spinal motor circuitry persist despite a clinical diagnosis of complete SCI. This finding supports the concept of discomplete injuries and suggests that clinical assessments may not fully capture the extent of residual sensorimotor function in this population. The neural conduction of the corticospinal tract (CST), the primary mediator of volitional motor function, was assessed via functional neurophysiological assessment (FNPA). Reticulospinal tract (RST) activity, crucial for movement coordination, was evaluated using acoustic startle response (ASR). Finally, the functional transmission of the dorsal column-medial lemniscus (DCML) pathway, which conveys touch information from the periphery to the brain, was evaluated by analyzing somatosensory evoked potentials (SSEP). In Chapter 4, the impact of SCI on the pediatric brain was investigated using neuroimaging techniques. Analysis of 8 children with SCI and 18 age- and gender-matched typically developing controls showed reduced gray matter morphometry and functional connectivity in cortical and subcortical sensorimotor structures and lower CST microstructural integrity in the brains of children with SCI. Additional analysis reveals that higher cortical and subcortical neuroimaging measures were associated with a higher probability of volitional muscle activation, and higher RST activity levels were correlated with better measurements of subcortical morphometry and functional connectivity. These findings provide valuable insights into the effects of pediatric SCI on the brain and their underlying relationships to motor pathways activity, suggesting the potential of supraspinal neuroimaging to serve as biomarkers to assess recovery and track the efficacy of interventions targeting spinal translesional connectivity

    Evaluating The Field Efficacy Of UV-C On Two California Strawberry Arthropod Pests

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    The efficacy of two different autonomous Ultraviolet-C (UV-C) units on two spotted spidermite, Tetranychus urticae Koch (Acari: Tetranychidae), and greenhouse whitefly, Trialeurodes vaporariorum. (Hemiptera: Aleyrodidae). was tested in four commercial strawberry fields in California. In 2020, California strawberry growers used 12 million pounds of active ingredients (AIs) to keep pests under economic thresholds. While pesticides are an important part of an integrated pest management program, their use poses threats to the environment and human health. To protect agricultural workers, the public and the environment, regulators in California have consistently limited or removed the use of certain pesticide AIs. For strawberry growers in the state, this trend signifies that reliance on pesticides may not be a sustainable approach. Resistant pest populations further intensify the need for more sustainable pest control measures. Tetranychus urticae populations in California strawberry production have documented resistance to at least three AIs; abamectin, bifenazate, and hexythiazox. Trialeurodes vaporariorum populations in California strawberry production have documented resistance to five AIs; imidacloprid, thiamethoxam, dinotefuran, acetamiprid, and chlorpyrifos. To address this issue, stakeholders must invest in research and development of new non-chemical control methods. One of these methods is the use of autonomous UV-C for pest control. These systems emit UV-C radiation, which affects the cellular and genetic structure of organisms, leading to detrimental effects. One unit, by Tric Robotics, emits an avg of 250 J m−2 of UV-C irradiation and was tested in three different strawberry fields. Another unit by Saga Robotics emits an avg of 200 J m−2 was tested on a single field different from the first three. In each field, a plot was treated with UV-C twice weekly at night. Untreated controls were not possible with this study, so UV-C has been tested against each grower’s standard (GS) treatment. Twenty leaflets from the middle and 20 bottom tier of the strawberry plant canopy were collected weekly to assess the presence of T. urticae and T. vaporariorum. Samples were compared using Kruskal-Wallis rank sum tests with Bonferroni adjusted Dunn tests in the R statistical environment. The data showed that UV-C may be an effective tool for the control of certain T. vaporariorum stages in strawberry. Follow-up studies with untreated controls are needed to validate the efficacy of UV-C on T. urticae and further validate the positive results observed on T. vaporariorum

    Insights into the Molecular Mechanisms of the N6-Methyladenosine (m6A) Methylation Machinery in the Regulation of the Infection Cycle of RNA Plant Viruses

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    [ES] La N6-metiladenosina (m6A) es una modificación generalizada en los ARN celulares de diferentes organismos que puede afectar muchos procesos y vías celulares. En las plantas, ocurre mediante un complejo de metilación que contiene varias proteínas: MTA, MTB, FIP37, VIR y HAKAI. Esta modificación es eliminada por desmetilasas de la familia AlkB, mientras que los miembros de la familia ETC son las proteínas mejor descritas que reconocen y procesan los ARN m6A-modificados. Estudios de epitransciptómica viral han revelado un papel igualmente importante de m6A durante la infección por virus; sin embargo, no existe una función pro- o antiviral de m6A generalizada. El laboratorio donde se ha llevado a cabo este trabajo ha sido pionero en el estudio del efecto de m6A en la interacción planta-virus, utilizando como virus modelo el AMV. El AMV pertenece a la familia Bromoviridae, y su genoma está formado por tres (+)ssARN. Los ARN1/2 codifican las subunidades de replicasa (P1 y P2), mientras que el ARN3 codifica la proteína de movimiento (MP) y sirve como molde para la síntesis del sgARN4, que codifica la proteína de cubierta (CP). Al comienzo de esta tesis, nuestro laboratorio ya había informado sobre: la presencia de supuestos motivos m6A en el 3'UTR/RNA3, una región crítica para la replicación de AMV, la primera m6A-desmetilasa de Arabidopsis (ALKBH9B), la relevancia funcional de ALKBH9B para mantener niveles adecuados de m6A/A para la correcta replicación de AMV, la capacidad de la CP de AMV para interactuar con ALKBH9B, posiblemente para usurpar la actividad de ALKBH9B, y la capacidad de las proteínas de Arabidopsis ECT2/3/5 para interactuar con el ARNv de AMV que contienen m6A. Dada la relevancia funcional de m6A en la biología de AMV, en esta tesis se decidió profundizar en el conocimiento de las implicaciones del mecanismo de regulación de m6A en el ciclo infeccioso viral de AMV. Para ello, se decidió: profundizar en la comprensión funcional de la m6A-desmetilasa ALKBH9B, evaluar la función in vivo de los supuestos dos sitios m6A presentes en el 3'UTR/ARN3, y explorar una posible implicación de algunas m6A metiltransferasas en la infección causada por AMV. El mapeo de los subdominios funcionales de atALKBH9B determinó la presencia de IDRs en la región N-terminal, dentro del dominio interno similar a AlkB y en la región C-terminal. Alrededor del 78% del RBD identificado en ALKBH9B está contenido en el IDR C-terminal. Debido a que las IDRs se localizan con frecuencia en proteínas que se someten a LLPS, un proceso que probablemente contribuye a la formación y estabilidad de los gránulos de ARN, es posible que las IDR y la RBD de ALKBH9B puedan actuar de manera cooperativa para promover la formación de gránulos de ARN. El análisis de los putativos motivos DRACH localizados en el bucle de hpB y en el tallo inferior de hpE del 3'UTR/ARN3 de AMV demostró que son sitios críticos involucrados en la replicación in vivo de AMV. La identidad de los residuos 2012A, 2013A y 2014A en el bucle hpB parece ser un requisito estructural clave para la replicación y/o acumulación de AMV. Con respecto a hpE, nuestros resultados determinaron que el supuesto residuo de m6A (1902A), así como el apareamiento de bases del tallo inferior de hpE, también son requisitos esenciales para la síntesis in vivo de ARNs de cadena positiva en AMV. Hasta donde sabemos, esta es la primera evidencia en AMV que muestra que el bucle de hpB y el tallo inferior de hpE están involucrados en la replicación/acumulación viral y la síntesis de ARNs de cadena positiva, respectivamente. Finalmente, en cuanto al estudio de la influencia de las m6A-metiltransferasas en el ciclo de infección viral de AMV, no se determinó un efecto proviral y/o antiviral en el complejo m6A-ARNm metiltransferasa conformado por atMTA:atMTB, ni en el putativo complejo m6A- ARNr metiltransferasa conformado por atMETTL5-like:atTRMT112-like sobre la biología de AMV.[CA] La N6-metiladenosina (m6A) és una modificació generalitzada en els ARN cellulars de diferents organismes que pot afectar molts processos i vies cellulars. En les plantes, ocorre mitjançant un complex de metilació que conté diverses proteïnes: MTA, MTB, FIP37, VIR i HAKAI. Aquesta modificació és eliminada per desmetilasas de la família AlkB, mentre que els membres de la família ETC són les proteïnes més ben descrites que reconeixen i processen els ARN m6A-modificats. Estudis de epitransciptómica viral han revelat un paper igualment important de m6A durant la infecció per virus; no obstant això, no existeix una funció pro- o antiviral de m6A generalitzada. El laboratori on s'ha dut a terme aquest treball ha sigut pioner en l'estudi de l'efecte de m6A en la interacció planta-virus, utilitzant com a virus model el AMV. El AMV pertany a la família Bromoviridae, i el seu genoma està format per tres (+) ssARN. Els ARN1/2 codifiquen les subunitats de replicasa (P1 i P2), mentre que l'ARN3 codifica la MP i serveix com a motle per a la síntesi del sgARN4, que codifica la CP. Al començament d'aquesta tesi, el nostre laboratori ja havia informat sobre: la presència de suposats motius m6A en el 3'UTR/RNA3, una regió crítica per a la replicació de AMV, la primera m6A-desmetilasa de Arabidopsis (ALKBH9B), la rellevància funcional d'ALKBH9B per a mantindre nivells adequats de m6A/A per a la correcta replicació de AMV, la capacitat de la CP de AMV per a interactuar amb ALKBH9B, possiblement per a usurpar l'activitat d'ALKBH9B, i la capacitat de les proteïnes de Arabidopsis ECT2/3/5 per a interactuar amb el ARNv de AMV que contenen m6A. Donada la rellevància funcional de m6A en la biologia de AMV, en aquesta tesi es va decidir aprofundir en el coneixement de les implicacions del mecanisme de regulació de m6A en el cicle infecciós viral de AMV. Per a això, es va decidir: aprofundir en la comprensió funcional de la m6A-desmetilasa ALKBH9B, avaluar la funció in vivo dels supòsits dos llocs m6A presents en el 3'UTR/ARN3, i explorar una possible implicació d'algunes m6A metiltransferasas en la infecció causada per AMV. El mapatge dels subdominis funcionals de atALKBH9B va determinar la presència de IDRs a la regió N-terminal, dins del domini intern similar a AlkB i a la regió C-terminal. Al voltant del 78% del RBD identificat en ALKBH9B està contingut en el IDR C-terminal. Pel fet que les IDRs es localitzen amb freqüència en proteïnes que se sotmeten a LLPS, un procés que probablement contribueix a la formació i estabilitat dels grànuls d'ARN, és possible que les IDR i la RBD d'ALKBH9B puguen actuar de manera cooperativa per a promoure la formació de grànuls d'ARN. L'anàlisi dels putatius motius DRACH localitzats en el bucle de hpB i en la tija inferior de hpE del 3'UTR/ARN3 de AMV va demostrar que són llocs crítics involucrats en la replicació in vivo de AMV. La identitat dels residus 2012A, 2013A i 2014A en el bucle hpB sembla ser un requisit estructural clau per a la replicació i/o acumulació de AMV. Respecte a hpE, els nostres resultats van determinar que el suposat residu de m6A (1902A), així com l'aparellament de bases de la tija inferior de hpE, també són requisits essencials per a la síntesi in vivo de ARNs de cadena positiva en AMV. Fins on sabem, aquesta és la primera evidència en AMV que mostra que el bucle de hpB i la tija inferior de hpE estan involucrats en la replicació/acumulació viral i la síntesi de ARNs de cadena positiva, respectivament. Finalment, quant a l'estudi de la influència de les m6A-metiltransferasas en el cicle d'infecció viral de AMV, no es va determinar un efecte proviral i/o antiviral en el complex m6A-ARNm metiltransferasa conformat per atMTA:atMTB, ni en el putatiu complex m6A-ARNr metiltransferasa conformat per atMETTL5-like:atTRMT112-like sobre la biologia de AMV.[EN] N6-methyladenosine (m6A) is a widespread modification on cellular RNAs of different organisms that can impact many cellular processes and pathways. In plants, m6A-methylation is mainly installed by a methylation complex containing several proteins: MTA, MTB, FIP37, VIR, and HAKAI. This modification is removed by demethylases of the AlkB family, and members of the ECT family are the best described proteins that recognize and process m6A-modified RNAs. Studies of viral epitransciptomics have revealed an equally important role of m6A during virus infection; however, there is no global pro- or antiviral role of m6A that can be generalized. The laboratory where this work was carried out has been a pioneer in the study of the effect of m6A on plant-viruses, using AMV as a model-virus. AMV belongs to the Bromoviridae family and, as the rest of the members of this family, its genome consists of three (+)ssRNAs. RNA1 and RNA2 encode the replicase subunits (P1 and P2), whereas RNA 3 encodes the MP and serves as a template for the synthesis of sgRNA 4, which encodes CP. At the beginning of this thesis, our laboratory had already reported on: the presence of putative m6A-motifs in the 3'UTR RNA3, a critical region for AMV replication, the first Arabidopsis m6A-demethylase (ALKBH9B), the functional relevance of ALKBH9B to maintain adequate m6A/A levels for correct AMV replication, the ability of AMV-CP to interact with ALKBH9B, possibly to usurp ALKBH9B activity, and the capability of Arabidopsis ECT2/3/5 to interact with m6A-containing AMV vRNAs. Given the functional relevance of m6A on the biology of AMV, in this thesis it was decided to deepen the knowledge of the implications of the m6A regulation mechanism on the viral infectious cycle of AMV. For this, it was decided: deepen the functional understanding of the m6A-demethylase ALKBH9B, evaluate the in vivo function of the putative two m6A-sites present in the 3'UTR-RNA 3, and explore a possible involvement of some m6A-methyltransferases in infection caused by AMV. We mapped functional subdomains in the atALKBH9B m6A-demethylase required for its binding to the vRNA and to the CP of AMV. Remarkably, it was observed the presence of IDRs in the N-terminal region, within the internal domain like AlkB and in the C-terminal region. About 78% of the RBD identified in ALKBH9B is contained in the C-terminal IDR. In this context, it has been proposed that the capability to specifically target different RNAs in RBPs containing IDRs is due to conformational flexibility as well as the establishment of extended conserved electrostatic interfaces with RNAs. Additionally, due that IDRs are frequently localized in proteins that undergo LLPS, a process that likely contributes to the formation and stability of RNA granules, it's possible that the IDRs and the RBD of ALKBH9B could act cooperatively to promote RNA granule formation. The analysis of the putative DRACH-motifs located in the hpB loop and the lower-stem of hpE in the 3'UTR RNA 3 present hot sites involved in AMV replication in vivo. The identity of residues 2012A, 2013A and 2014A in the hpB loop appears to be a key structural requirement for AMV replication and/or accumulation. Regarding hpE, our results determined that the putative m6A-residue 1902A, as well as the base pairing of the lower-stem of hpE, are also essential requirements for the in vivo plus-strand synthesis in AMV. To our knowledge, this is the first evidence in AMV to show that the hpB loop and the lower-stem of hpE are involved in viral replication/accumulation and plus-strand synthesis, respectively. Finally, regarding the study of the influence of m6A-methyltransferases on the viral infection cycle of AMV, a non-proviral and/or antiviral effect was determined in the m6A-mRNA methyltransferase complex made up of atMTA:atMTB, nor of the putative m6A-rRNA methyltransferase complex made up of atMETTL5-like:atTRMT112-like on the biology of AMV.Alvarado Marchena, LF. (2022). Insights into the Molecular Mechanisms of the N6-Methyladenosine (m6A) Methylation Machinery in the Regulation of the Infection Cycle of RNA Plant Viruses [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185122TESI

    New working conditions and well-being of elementary teachers in Ecuador

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    The objective of this study was to analyze the stressors and working conditions which affect elementary teachers according to the TP-M theory. For this purpose, a research study was performed with nine focus groups composed of 75 teachers, each working in a different elementary school in Guayaquil (Ecuador). The results showed that occupational risks could be classified in two categories: (1) risks stemming from the social environment in which the teachers carry out their work; (2) risks derived from the new organizational demands that affect the physical and psychological health of teachers as well as their social and family relationships.Este estudio tiene como objetivo analizar los estresores y las condiciones de trabajo que afectan a los docentes de educación primaria de acuerdo con la teoría TP-M. Para ello, se realizó un estudio cualitativo con 75 profesores de primaria de distintas escuelas de la ciudad de Guayaquil (Ecuador) agrupados en 9 grupos de discusión. Los resultados encontrados evidenciaron dos grandes grupos de riesgos: de una parte,riesgos provenientes del entorno social donde los profesores trabajan. Un segundo grupo, de la propia institución y sus nuevas demandas organizativas, afectando todos ellos a la salud física y psicológica de estos profesores así como a sus relaciones sociales y familiares

    Molecular identification of Trichoderma spp. in garlic and onion fields and In Vitro antagonism trials on Sclerotium cepivorum

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    Artículo científicoTrichoderma species are non-pathogenic microorganisms that protect against fungal diseases and contribute to increased crop yields. However, not all Trichoderma species have the same effects on crop or a pathogen, whereby the characterization and identification of strains at the species level is the first step in the use of a microorganism. The aim of this study was the identification – at species level – of five strains of Trichoderma isolated from soil samples obtained from garlic and onion fields located in Costa Rica, through the analysis of the ITS1, 5.8S, and ITS2 ribosomal RNA regions; as well as the determination of their individual antagonistic ability over S. cepivorum Berkeley. In order to distinguish the strains, the amplified products were analyzed using MEGA v6.0 software, calculating the genetic distances through the Tamura-Nei model and building the phylogenetic tree using the Maximum Likelihood method. We established that the evaluated strains belonged to the species T. harzianum and T. asperellum; however it was not possible to identify one of the analyzed strains based on the species criterion. To evaluate their antagonistic ability, the dual culture technique, Bell’s scale, and the percentage inhibition of radial growth (PIRG) were used, evidencing that one of the T. asperellum isolates presented the best yields under standard, solid fermentation conditions

    Daily profitability volatility forecast for the sugar market and its application for the coverage ratio

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    Este trabajo predice la volatilidad de la rentabilidad diaria del precio del azúcar, en el período compren­dido entre 1 de junio de 2011 y el 24 de octubre de 2013. Los datos diarios utilizados fueron los precios del azúcar, del etanol y la tasa de cambio de la moneda de Brasil (Real) en dólares. Se usaron modelos multivariados de volatilidad autoregresiva condicional generalizada. A partir de la predicción de los precios del azúcar se calcula la razón de cobertura de mínima varianza. Los resultados muestran, que la razón de cobertura es 0.37, esto significa que, si un productor adverso al riesgo, que tiene la intención de eliminar un porcentaje de la volatilidad de la rentabilidad diaria del mercado mundial del azúcar, y espera vender 25 contratos de azúcar, cada uno de ellos de 50,84 toneladas (1.271 toneladas), el número de contratos optimo tomando cobertura a futuro será 9 y el número de contratos sin tomar cobertura (de contado) será 16.This work predicts the volatility of the daily profitability of sugar prices for the period between 1 of June 2001 and 24th of October 2013. The daily data collected covered sugar, ethanol and the Brazilian Real and USD exchange rate information. The models used were multivariate generalized conditional autoregressive volatility. Parting from the sugar price prediction, the coverage ratio for the minimum variance is calculated. Results show that the coverage ratio is 0.37. This means that in the case of a risk adverse producer that wants to eliminate a percentage of volatility of the world's sugar market daily profitability, and expects to sell 25 sugar contracts, 50,84 tons each, (1,271 tons), the optimal number of contracts with future cover­age will be 9 and the number of contracts without coverage (spot price) will be 16Este trabalho prevê a volatilidade da rentabilidade diária do preço do açúcar, no período compreendido entre o dia 1º de junho de 2011 e 24 de outubro de 2013. Os dados diários utilizados foram os preços do açúcar, do etanol e a taxa de câmbio da moeda do Brasil (Real) em dólares. Se usaram modelos multivariados de volatilidade autorregressiva condicional generalizada. A partir da predição dos preços do açúcar se calcula a razão de cobertura de mínima variância. Os resultados mostram, que a razão de cobertura é 0.37, isto significa que, se um produtor adverso ao risco, que tem a intenção de eliminar uma porcentagem da volatilidade da rentabilidade diária do mercado mundial do açúcar, e espera vender 25 contratos de açúcar, cada um deles de 50,84 toneladas (1.271 toneladas), o número de contratos ótimo tomando cobertura a futuro será 9 e o número de contratos sem tomar cobertura (de contado) será 16

    Web para la transparencia del uso de los recursos del sistema escolar chileno

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    [ES] Este proyecto tuvo como propósito evaluar la factibilidad de diseñar un sitio web con información integrada, que aportara la transparencia en el uso de los recursos del sistema de educación chileno. El análisis consideró la revisión de casos internacionales, revisión de información de distintas bases de datos y fuentes de información. Lo anterior permitió diseñar un sitio web con reportes estadísticos y gráficos de uso de recursos financieros, los cuales fueron preparados con la información obtenida desde las páginas web de las instituciones relacionadas con educación, o a través del proceso de solicitud de acceso de información del Estado. Las principales dificultades detectadas para la implementación de un proyecto de integración de datos públicos estuvieron asociadas a problemas en el acceso a la información relevante, datos con distinto nivel de desagregación y con unidades de medidas distintas, cambios de estructura de los datos de una serie a otra, series incompletas para realizar análisis históricos, datos no automatizados e información de mala calidad o sin descripción del dignificado cada variable. A pesar de las dificultades, el desarrollo del sitio se considera un avance en pro de la transparencia de datos ya que pone a disposición información que actualmente no está disponible en ningún sitio del Estado. Uno de los reportes más relevantes es el buscador de colegios que entrega información de cuántos recursos ha recibido cada uno de los centros escolares en el año 2015 y 2016.[EN] The purpose of this project was to evaluate the feasibility of designing a website able to integrate information from different sources This website intends to contribute to transparency in the use of resources given to the educational system. The project analyzed international and national websites and datasets, and built economic reports and graphics using that information. The main difficulties detected in the implementation of the website were as follows: problems in accessing the datasets, data with different levels of aggregation and measure units; changes in the data set structure in following years; different datasets variables over the years; not automatized and low quality information; no specifications for the data variables. Despite the problems encountered, the website is considered an advance in for transparency, as it contains information that is actually not available in nay public website. For example, it reports how much money has received each of the education centers in 2015 and 2016.Alvarado Alvarado, JL. (2016). Web para la transparencia del uso de los recursos del sistema escolar chileno. http://hdl.handle.net/10251/71909.TFG
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