Attempts to eradicate two Pelargonium viruses (PFBV and PLPV) by meristem culture and shoot-tip cryotherapy

Attempts to eradicate the Pelargonium flower break virus (PFBV) and Pelargonium line pattern virus (PLPV) by meristem culture and apex “droplet-vitrification” cryopreservation was carried out using 5 different cultivars. A simple meristem culture did not permit to eliminate PFBV and only 15% of Pelargonium x hortorum ‘Stellar Artic’ plants regenerated from meristems was PLPV-ELISA-negative. Plants regenerated from cryopreserved apices were tested by DAS-ELISA after a 3-month growing period. Viruses were not detected in 25 and 50% of the tested plants for PFBV and PLPV respectively. Immunolocalisations were carried out for virus localisation in apices from greenhouse plants (control) and vitroplants regenerated after meristem culture or cryopreservation. Immunolocalisations realised on control explants excised from DAS-ELISA positive plants showed that PFBV and PLPV were present in the apices, even in the meristematic dome. However, viral particles were more numerous in the cells of the basal zone than in the more meristematic ones. Immunolocalisations realised on apices from the DAS-ELISA negative cryoregenerated plants showed the viruses were still present. Our results firstly demonstrated that PFBV and PLPV are even present inside meristematic cells and secondly that cryopreservation could decrease their amount in Pelargonium plants but without eliminating them totally. More knowledge on virus behaviour during cryopreservation processes could optimize the management of genetic resources using this conservation method

Almanak mercantil o Guía de comerciantes : para el año de 1798

Según Aguilar Piñal, IV, 235 las iniciales D. M. G. corresponden a Diego María GallardMarca tip. en portSign.: []\p2\s, *\p4\s, A-Z\p8\s, 2A-2G\p8\s, 2H\p10\s, a-b\p8\s, c\p6\

Cryopreservation of Pelargonium species: a comparative study of encapsulation-dehydration and droplet-vitrification protocols

In order to guarantee safe, long-term conservation of the Agrocampus Ouest - INHP Pelargonium collection, apex cryopreservation studies have been undertaken. An encapsulation-dehydration procedure has been first developed. More recently, studies were undertaken in order to adapt the droplet-vitrification procedure to this genus. For both procedures, protocols were optimized using P. × peltatum ‘Balcon Lilas’ as model accession. Survival and plant regeneration were obtained with the two newly determined protocols. However, droplet-vitrification gave higher and more reproducible regeneration results. To confirm these results, we carried out experiments in order to compare both protocols applying them to four accessions. Droplet-vitrification gave always better results than encapsulation-dehydration, and permitted to obtain shoot regrowth for each accession. To compare the two protocols, a histo-cytological study was performed on P. × peltatum ‘Balcon Lilas’ apices. Samples were fixed after each step of both protocols in order to observe the modifications at the cellular level. Important differences were noted concerning starch accumulation and nucleus aspect. The droplet-vitrification was then tested on 28 genotypes representative of the diversity of the genus. Apex survival was obtained for each accession out of the 28 tested. An average of 65% survival rate was obtained ranging from 14.8% for P. × fragans to 90% for P. capitatum and P. × hortorum ‘Neurot’. Plants were regenerated for all genotypes, except P. × peltatum ‘Papa Crousse’

Limited Elimination of Two Viruses by Cryotherapy of Pelargonium Apices Related to Virus Distribution

The possibility of eradicating the pelargonium flower break virus (PFBV) and pelargonium line pattern virus (PLPV) by cryotherapy of axillary shoot apices was investigated using five Pelargonium cultivars. Viruses were detected by DAS-ELISA and their location was determined by immunolocalization. Apex culture did not permit elimination of PFBV and only 15% regenerated plants of \u27Stellar Artic\u27 cultivar were ELISA PLPVnegative. Plants regenerated from cryotherapy-treated apices were tested by DAS-ELISA after a 3-month in vitro culture period. Viruses were not detected in 25% and 50% of the plants tested for PFBV and PLPV, respectively. However, immunolocalization carried out on apices originating from cryopreserved shoot tips sampled from DAS-ELISA negative plants showed that they were still virus-infected. Using immunolocalization, PFBV and PLPV could be detected in Pelargonium apices, even in the meristematic dome. However, viral particles were more numerous in basal zone cells than in meristematic cells. Our results demonstrate that PFBV and PLPV are present within meristematic cells and that cryopreservation can partly reduce the quantity of these viruses in Pelargonium plants but not eliminate them totally. Additional knowledge on localization and behaviour of viruses during cryopreservation is essential to optimize cryotherapy and plant genetic resource management

Mind the Gap: Persistent and Mobile Organic Compounds—Water Contaminants That Slip Through

The discharge of persistent and mobile organic chemicals (PMOCs) into the aquatic environment is a threat to the quality of our water resources. PMOCs are highly polar (mobile in water) and can pass through wastewater treatment plants, subsurface environments and potentially also drinking water treatment processes. While a few such compounds are known, we infer that their number is actually much larger. This Feature highlights the issue of PMOCs from an environmental perspective and assesses the gaps that appear to exist in terms of analysis, monitoring, water treatment and regulation. On this basis we elaborate strategies on how to narrow these gaps with the intention to better protect our water resources

Técnicas de niching: estrategias evolutivas vs. algoritmos genéticos

Varias técnicas de especiación y niching han sido diseñadas y probadas en Algoritmos Genéticos (AGs) mostrando buenos resultados en la optimización de problemas donde el descubrir y mantener múltiples soluciones es importante. Las Estrategias Evolutivas (EEs) surgieron desde el área de la optimización numérica, manteniendo las mismas desventajas que los AGs simples al abordar problemas donde el objetivo es localizar múltiples soluciones. Por ejemplo para problemas de optimización multimodal (funciones con varios óptimos a localizar), optimización multiobjetivo (donde hay más de un criterio a optimizar) o en el caso de simulación de sistemas adaptativos complejos {6}. Este trabajo investiga la posibilidad de mejorar la performance de las EEs contemporáneas estándar para resolver problemas de soluciones múltiples mediante el uso de métodos de niching y especiación, analizando cuál es su ventaja con respecto a los resultados obtenidos con AGs.I Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Técnicas de niching: estrategias evolutivas vs. algoritmos genéticos

Varias técnicas de especiación y niching han sido diseñadas y probadas en Algoritmos Genéticos (AGs) mostrando buenos resultados en la optimización de problemas donde el descubrir y mantener múltiples soluciones es importante. Las Estrategias Evolutivas (EEs) surgieron desde el área de la optimización numérica, manteniendo las mismas desventajas que los AGs simples al abordar problemas donde el objetivo es localizar múltiples soluciones. Por ejemplo para problemas de optimización multimodal (funciones con varios óptimos a localizar), optimización multiobjetivo (donde hay más de un criterio a optimizar) o en el caso de simulación de sistemas adaptativos complejos {6}. Este trabajo investiga la posibilidad de mejorar la performance de las EEs contemporáneas estándar para resolver problemas de soluciones múltiples mediante el uso de métodos de niching y especiación, analizando cuál es su ventaja con respecto a los resultados obtenidos con AGs.I Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Técnicas de niching: estrategias evolutivas vs. algoritmos genéticos

Varias técnicas de especiación y niching han sido diseñadas y probadas en Algoritmos Genéticos (AGs) mostrando buenos resultados en la optimización de problemas donde el descubrir y mantener múltiples soluciones es importante. Las Estrategias Evolutivas (EEs) surgieron desde el área de la optimización numérica, manteniendo las mismas desventajas que los AGs simples al abordar problemas donde el objetivo es localizar múltiples soluciones. Por ejemplo para problemas de optimización multimodal (funciones con varios óptimos a localizar), optimización multiobjetivo (donde hay más de un criterio a optimizar) o en el caso de simulación de sistemas adaptativos complejos {6}. Este trabajo investiga la posibilidad de mejorar la performance de las EEs contemporáneas estándar para resolver problemas de soluciones múltiples mediante el uso de métodos de niching y especiación, analizando cuál es su ventaja con respecto a los resultados obtenidos con AGs.I Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Optimization of tardiness related objectives in single machine environments via multirecombined evolutionary algorithms

Tardiness related objectives are of utmost importance in production systems when client satisfaction is a main goal of a company. These objectives measure the system response to the client requirements and rate manager´s performance In scheduling problems with diverse single or multiple objectives and environments Evolutionary algorithms (EAs) were successfully applied. Latest improvements in EAs have been developed by means of multirecombination, a method, which allows multiple exchange of genetic material between individuals of the mating pool. These individuals can be provided by the current population or by an external source. The performance of the algorithm depends o the number of individuals in the mating pool and their mating frequency. MCMP-SRI and MCMP-SRSI are multirecombined evolutionary approaches using the concept of the stud (a breeding individual), random immigrants and/or seeds, to avoid premature convergence and adding problem-specific- knowledge. Here, both methods applied to tardiness related problems in single machine environmen are discussed and contrasted against conventional heuristics.Eje: Inteligencia artificialRed de Universidades con Carreras en Informática (RedUNCI