On the Consequences of the "No Free Lunch" Theorem for Optimization on the Choice of an Appropriate MDO Architecture

Multidisciplinary design optimization (MDO) based on high- delity models is challenging due to the high computational cost of evaluating the objective and constraints. To choose the best MDO architecture, a trial-and-error approach is not possible due to the high cost of the overall optimization and complexity of the implementation. We propose to address this issue by developing a generic methodology that applies to any (potentially expensive) physical problem and generates a scalable approximation that can be quickly computed, for which the input and output dimensions may be set independently. This facilitates evaluation of MDO architectures for the original MDO problem by capturing its structure and behavior. The methodology is applied to two academic MDO test cases: the Supersonic Business Jet problem and the propane combustion problem. Well-known architectures (MDF, IDF and BLISS) are benchmarked on various instances to demonstrate the dependency between the performance of the architecture and the problem dimensions

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

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

Una técnica para estabilizar la cantidad de individuos en algoritmos genéticos de población variable

La elección del tamaño de población condiciona el desempeño de los algoritmos genéticos. Una población pequeña puede aumentar la presión selectiva, conduciendo a una convergencia prematura, mientras que para un número de individuos muy grande el alcance de la solución se torna lenta. Una alternativa es usar un algoritmo genético de población variable, el cual ajusta la cantidad de individuos dinámicamente mediante el concepto de edad. Esta técnica, aunque más flexible, presenta una gran sensibilidad en relación con sus parámetros: pequeñas variaciones en el máximo tiempo de vida de un individuo pueden llevar de la extinción a la superpoblación para un mismo problema. En este trabajo se presenta la noción de inundación, la cual permite mantener estable la población. La idea es eliminar, con cierta probabilidad, a individuos por debajo del fitness medio. Asimismo, también se incluye un control para evitar la extinción. Los resultados revelan que, aunque el mejor individuo promedio no supera al obtenido por el método original, el nuevo algoritmo logra mejores tiempos de ejecución pues opera sobre poblaciones más chicas. Además, la media poblacional se incrementa debido a las inundaciones. De este modo, nuestra propuesta resulta apropiada cuando se requieren buenas poblaciones con bajos tiempos de ejecución.Eje: Computación evolutivaRed de Universidades con Carreras en Informática (RedUNCI

Efectos del tiempo de espera prefaena y la zona térmica en camión sobre la inmovilidad tónica en pollos parrilleros

La cadena de producción industrial de carne aviar incluye procedimientos que afectan el bienestar animal y consecuentemente la calidad del producto obtenido. Para evaluar el efecto del transporte y la manipulación pre-faena sobre el nivel de miedo en pollos, se han empleado pruebas de diferente tipo entre las cuales la inmovilidad tónica (IT) se destaca por su fácil determinación. El objetivo de este trabajo fue evaluar el efecto del tiempo de espera en playa de faena y la ubicación de la jaula en los camiones, sobre la duración de la IT en pollos parrilleros. El análisis comparativo se realizó mediante ANOVA en un arreglo factorial, tomándose como efectos principales el tiempo en playa de espera y la localización de la jaula en el camión. Se observaron diferencias estadísticamente significativas (p=0,0001) para IT, con valores de 248,88±12,86 s para el grupo espera larga y 167,88±13,4 s para espera corta. La zona térmica del camión también registró diferencias significativas (p=0,03) con valores de 189,06±14,74 s (zona ventilada) y 227,69±17,23 s (zona no ventilada). No se observaron diferencias significativas para el número de intentos de inducción a la inmovilidad en función del tiempo de espera y zona térmica del camión (p=0,08). No existieron correlaciones significativas entre las variables dependientes en ambos grupos experimentales. Los resultados de este trabajo permiten inferir que tiempos de espera en la playa pre-faena superiores a 3½ horas y altas temperaturas, provocan aumento en la duración de la IT, lo que la transforma en una herramienta útil para medir el estado de miedo de los pollos como consecuencia de ambas situacione

Efecto de la densidad de alojamiento y la zona del galpón sobre indicadores de bienestar en pollos parrilleros

The aim of this work was to evaluate the effect of decreasing stocking density and shed area on footpad dermatitis, hock burn, and ventral feathers cleanliness of broilers reared in winter. The work was carried out on a commercial farm in the northeast of the Santa Fe province, Argentina. 54,000 broilers were housed in sex-mixed batches, in two darkened sheds, divided into three zones: Panels, Intermediate and Extractors. Two stocking densities were evaluated: 14 and 12 chickens/m2, standard and reduced, respectively. At 41 days feet and hock lesions and cleanliness of ventral feathers was assessed in 120 chickens per area. Significant differences were registered for footpad lesions in Extractors (p = 0.0006), Intermediate (p = 0.0002) and Panels (p <0.0001) zones, with predominance of lesions 1 and 2 in Intermediate and Panels zones with standard density. Non-significant differences were observed for hock lesions in Extractors (p = 0.111) a response not seen in Intermediate (p = 0.024) and Panels (p <0.0001) zones, with more type 2 lesions in both zones under standard density. Feather cleanliness showed significant differences in Extractors (p = 0.014) Intermediate (p = 0.01) and Panels (p <0.0001), with a higher proportion of type 3 plumage dirt with standard density. Welfare indicators behaviour showed the favourable change achieved by reducing stocking density in broilers production.El objetivo de este trabajo fue evaluar el efecto de la disminución de la densidad de alojamiento y de la zona del galpón sobre lesiones en almohadilla plantar, tarso y suciedad de plumas ventrales de pollos de engorde criados en invierno. El trabajo se realizó en una granja comercial en el noreste de la provincia de Santa Fe, Argentina. Se alojaron 54.000 pollos de engorde en lotes mixtos, en dos galpones oscurecidos, divididos en tres zonas: Paneles, Intermedia y Extractores. Se evaluaron dos densidades de alojamiento: 14 y 12 pollos/m2, estándar y reducida, respectivamente. A los 41 días se valoró la presencia de lesiones y suciedad del plumaje ventral en 120 pollos por zona. Las lesiones de almohadilla plantar registraron diferencias significativas en Extractores (p= 0,0006), Intermedia (p= 0,0002) y Paneles (p< 0,0001), con mayoría de lesiones 1 y 2 en Intermedia y Paneles con densidad estándar. Las lesiones de tarso no fueron significativas en Extractores (p= 0,1107), sí en Intermedia (p= 0,0235) y Paneles (p< 0,0001), ambas, con más lesiones tipo 2 en la densidad estándar. En suciedad de plumas hubo diferencias significativas en Extractores (p= 0,014), Intermedia (p= 0,01) y Paneles (p< 0,0001), con mayor proporción de plumaje tipo 3 en la densidad estándar. Las variables evaluadas dan cuenta del cambio favorable en la situación de bienestar alcanzada mediante la reducción de la densidad de alojamiento en pollos de engorde

Biodereplication of antiplasmodial extracts: application of the amazonian medicinal plant piper coruscans kunth

Improved methodological tools to hasten antimalarial drug discovery remain of interest, especially when considering natural products as a source of drug candidates. We propose a biodereplication method combining the classical dereplication approach with the early detection of potential antiplasmodial compounds in crude extracts. Heme binding is used as a surrogate of the antiplasmodial activity and is monitored by mass spectrometry in a biomimetic assay. Molecular networking and automated annotation of targeted mass through data mining were followed by mass-guided compound isolation by taking advantage of the versatility and finely tunable selectivity offered by centrifugal partition chromatography. This biodereplication workflow was applied to an ethanolic extract of the Amazonian medicinal plant Piper coruscans Kunth (Piperaceae) showing an IC50 of 1.36 ug/mL on the 3D7 Plasmodium falciparum strain. It resulted in the isolation of twelve compounds designated as potential antiplasmodial compounds by the biodereplication workflow. Two chalcones, aurentiacin (1) and cardamonin (3), with IC50 values of 2.25 and 5.5 uM, respectively, can be considered to bear the antiplasmodial activity of the extract, with the latter not relying on a heme-binding mechanism. This biodereplication method constitutes a rapid, efficient, and robust technique to identify potential antimalarial compounds in complex extracts such as plant extracts

Heterogeneity assessment of functional T cell avidity.

The potency of cellular immune responses strongly depends on T cell avidity to antigen. Yet, functional avidity measurements are rarely performed in patients, mainly due to the technical challenges of characterizing heterogeneous T cells. The mean functional T cell avidity can be determined by the IFN-γ Elispot assay, with titrated amounts of peptide. Using this assay, we developed a method revealing the heterogeneity of functional avidity, represented by the steepness/hillslope of the peptide titration curve, documented by proof of principle experiments and mathematical modeling. Our data show that not only natural polyclonal CD8 T cell populations from cancer patients, but also monoclonal T cells differ strongly in their heterogeneity of functional avidity. Interestingly, clones and polyclonal cells displayed comparable ranges of heterogeneity. We conclude that besides the mean functional avidity, it is feasible and useful to determine its heterogeneity (hillslope) for characterizing T cell responses in basic research and patient investigation