3,543 research outputs found

    Analysis and Observations from the First Amazon Picking Challenge

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    This paper presents a overview of the inaugural Amazon Picking Challenge along with a summary of a survey conducted among the 26 participating teams. The challenge goal was to design an autonomous robot to pick items from a warehouse shelf. This task is currently performed by human workers, and there is hope that robots can someday help increase efficiency and throughput while lowering cost. We report on a 28-question survey posed to the teams to learn about each team's background, mechanism design, perception apparatus, planning and control approach. We identify trends in this data, correlate it with each team's success in the competition, and discuss observations and lessons learned based on survey results and the authors' personal experiences during the challenge

    Decreased reactive oxygen species concentration in the elongation zone contributes to the reduction in maize leaf growth under salinity

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    Reactive oxygen species (ROS) in the apoplast of cells in the growing zone of grass leaves are required for elongation growth. This work evaluates whether salinity‐induced reductions in leaf elongation are related to altered ROS production. Studies were performed in actively growing segments (SEZ) obtained from leaf three of 14‐d‐old maize (Zea mays L.) seedlings gradually salinized to 150 mM NaCl. Salinity reduced elongation rates and the length of the leaf growth zone. When SEZ obtained from the elongation zone of salinized plants (SEZs) were incubated in 100 mM NaCl, the concentration where growth inhibition was approximately 50%, O2•– production, measured as NBT formazan staining, was lower in these than in similar segments obtained from control plants. The NaCl effect was salt‐specific, and not osmotic, as incubation in 200 mM sorbitol did not reduce formazan staining intensity. SEZs elongation rates were higher in 200 mM sorbitol than in 100 mM NaCl, but the difference could be cancelled by scavenging or inhibiting O2•– production with 10 mM MgCl2 or 200 µM diphenylene iodonium, respectively. The actual ROS believed to stimulate growth is •OH, a product of O2•– metabolism in the apoplast. SEZs elongation in 100 mM NaCl was stimulated by a •OH‐generating medium. Fusicoccin, an ATPase stimulant, and acetate buffer pH 4, could also enhance elongation in these segments, although both failed to increase ROS activity. These results show that decreased ROS production contributes to the salinity‐associated reduction in grass leaf elongation, acting through a mechanism not associated with pH changes.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Rodriguez, Andrés Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); ArgentinaFil: Córdoba, Alicia R. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); ArgentinaFil: Ortega, Leandro Ismael. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); ArgentinaFil: Taleisnik, Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); Argentin

    Progresses in the development of a Step-NC compliant additive manufacturing system

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    The new standard of numerical control, known as STEP-NC, is categorized as the future of the advanced manufacturing systems. Greater flexibility and interoperability are some potential benefits offered by STEP-NC to meet the challenges of the new industrial landscape that is envisaged with the advent of Industry 4.0. Meanwhile, STEP-NC object-oriented programming has been partially applied and developed for machining processes (milling, turning...). But with the processes of additive manufacturing has not happened the same and the development is still incipient. This work presents the advances in the development of a new STEP-NC compliant additive manufacturing system, focusing particularly on the development of the information model. The application model activities in the IDEF0 nomenclature and application reference model in EXPRESS are presented. The AM-layer-feature concept has been introduced to define the manufacturing feature of additive processes based on material deposition layer-by-layer. Finally, a STEP-NC program generated from the EXPRESS model is presented, which can be implemented on an additive manufacturing system to validate the proposed model.El nuevo estándar de control numérico, conocido como STEP-NC, es categorizado como el futuro de los sistemas avanzados de manufactura. Mayor flexibilidad e interoperabilidad son algunos de los potenciales beneficios que ofrece STEP-NC para enfrentar los desafíos del nuevo panorama industrial que se vislumbra con el advenimiento de la Industria 4.0. Mientras tanto, la programación orientada a objeto de STEP-NC ha sido parcialmente aplicada y desarrollada hasta el momento para los procesos de mecanizado (fresado, torneado…). Pero con los procesos de manufactura aditiva no ha sucedido lo mismo y el desarrollo es aún incipiente. Este trabajo presenta los avances en el desarrollo de un nuevo sistema de manufactura aditiva basado en STEP-NC, enfocándose particularmente sobre el desarrollo del modelo de información. EL modelo de actividades de aplicación en la nomenclatura del IDEF0 y el modelo de referencia de aplicación en EXPRESS son presentados. El concepto AM-layer-feature ha sido introducido para definir la feature de manufactura de los procesos aditivos basados en deposición de material capa por capa. Finalmente, se presenta un programa en STEP-NC generado desde el modelo EXPRESS, el cual puede ser implementado sobre un sistema de manufactura aditiva para validar el modelo propuesto

    A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development

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    Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host’s nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host’s nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.Fil: Vargas, Walter Alberto. Universidad de Salamanca; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanz Martín, José M.. Universidad de Salamanca; EspañaFil: Rech, Gabriel E.. Universidad de Salamanca; EspañaFil: Armijos Jaramillo, Vinicio D.. Universidad de Salamanca; EspañaFil: Rivera Rodriguez, Lina Patricia. Universidad de Salamanca; EspañaFil: Echeverria, María de Las Mercedes. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Díaz Mínguez, José M.. Universidad de Salamanca; EspañaFil: Thon, Michael R.. Universidad de Salamanca; EspañaFil: Sukno, Serenella A.. Universidad de Salamanca; Españ
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