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

Improving evolutionary algorithms performance by extending incest prevention

Provision of population diversity is one of the main goals to avoid premature convergence in Evolutionary Algorithms (EAs). In this way the risk of being trapped in local optima is minimised. Eshelman and Shaffer [4] attempted to maintain population diversity by using diverse strategies focusing on mating, recombination and replacement. One of their approaches, called incest prevention, avoided mating of pairs showing similarities based on the parent’s hamming distance. Conventional selection mechanisms does not consider if the members of the new population have common ancestors and consequently due to a finite fixed population size, a loss of genetic diversity can frequently arise. This paper shows an extended approach of incest prevention by maintaining information about ancestors within the chromosome and modifying the selection for reproduction in order to impede mating of individuals belonging to the same “family”, for a predefined number of generations. This novel approach was tested on a set of multimodal functions. Description of experiments and analyses of improved results are also shown.Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Contrasting main selection methods in genetic algorithms

In genetic algorithms selection mechanisms aim to favour reproduction of better individuals imposing a direction on the search process. It does not create new individuals; instead it selects comparatively good individuals from a population and typically does it according to their fitness. The idea is that interacting with other individuals (competition), those with higher fitness have a higher probability to be selected for mating. In that manner, because the fitness of an individual gives a measure of its "goodness", selection introduces the influence of the fitness function to the evolutionary process. Moreover, selection is the only operator of genetic algorithm where the fitness of an individual affects the evolution process. In such a process two important, strongly related, issues exist: selective pressure and population diversity. They are the sides of the same coin: exploitation of information gathered so far versus exploration of the searching space. Selection plays an important role here because strong selective pressure can lead to premature convergence and weak selective pressure can make the search ineffective [14]. Focussing on this equilibrium problem significant research has been done. In this work we introduce the main properties of selection, the usual selection mechanisms and finally show the effect of applying proportional, ranking and tournament selection to a set of well known multimodal testing functions on simple genetic algorithms. These are the most widely used selection mechanisms and each of them has their own features. A description of each method, experiment and statistical analyses of results under different parameter settings are reported.Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

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

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

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 situacionesTo evaluate the effect of transport and pre-slaughter manipulation on the level of fear in chickens, different tests have been used, among them tonic immobility (TI) stands out for its easy determination. The objective of this work was to evaluate the effect of pre-slaughter lairage time and the location of the cage in transport trucks on the duration of TI in broilers. The comparative analysis was done using ANOVA in a factorial arrangement, taking as main effects the time on pre-slaughter lairage periods and the location of the cage in the truck. There were statistically significant differences (p=0.0001) for TI, with values of 248.88±12.86 s and 167.88±13.4 s for the long and short waiting periods, respectively. The thermal area of the truck also showed significant differences (p=0.03) with values of 189.06±14.74 s (ventilated area) and 227.69±17.23 s (nonventilated area). There were no significant differences in the number of attempts to induce immobility as a function of the waiting time and the thermal area of the truck (p=0.08). There were no significant correlations between the dependent variables in both experimental groups. The waiting time on holding area greater than 3½ h and a higher temperature causes a longer duration of TI, making it a useful tool to measure the grade of fear of chickens as consequence of these situationsEEA ReconquistaFil: Gallard, Eliana Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Menichelli, Marcela Liliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Revidatti, Fernando. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; ArgentinaFil: Fernandez, R.. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; ArgentinaFil: Sanz, P. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; Argentin

Contrasting main selection methods in genetic algorithms

In genetic algorithms selection mechanisms aim to favour reproduction of better individuals imposing a direction on the search process. It does not create new individuals; instead it selects comparatively good individuals from a population and typically does it according to their fitness. The idea is that interacting with other individuals (competition), those with higher fitness have a higher probability to be selected for mating. In that manner, because the fitness of an individual gives a measure of its "goodness", selection introduces the influence of the fitness function to the evolutionary process. Moreover, selection is the only operator of genetic algorithm where the fitness of an individual affects the evolution process. In such a process two important, strongly related, issues exist: selective pressure and population diversity. They are the sides of the same coin: exploitation of information gathered so far versus exploration of the searching space. Selection plays an important role here because strong selective pressure can lead to premature convergence and weak selective pressure can make the search ineffective [14]. Focussing on this equilibrium problem significant research has been done. In this work we introduce the main properties of selection, the usual selection mechanisms and finally show the effect of applying proportional, ranking and tournament selection to a set of well known multimodal testing functions on simple genetic algorithms. These are the most widely used selection mechanisms and each of them has their own features. A description of each method, experiment and statistical analyses of results under different parameter settings are reported.Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Improving evolutionary algorithms performance by extending incest prevention

Provision of population diversity is one of the main goals to avoid premature convergence in Evolutionary Algorithms (EAs). In this way the risk of being trapped in local optima is minimised. Eshelman and Shaffer [4] attempted to maintain population diversity by using diverse strategies focusing on mating, recombination and replacement. One of their approaches, called incest prevention, avoided mating of pairs showing similarities based on the parent’s hamming distance. Conventional selection mechanisms does not consider if the members of the new population have common ancestors and consequently due to a finite fixed population size, a loss of genetic diversity can frequently arise. This paper shows an extended approach of incest prevention by maintaining information about ancestors within the chromosome and modifying the selection for reproduction in order to impede mating of individuals belonging to the same “family”, for a predefined number of generations. This novel approach was tested on a set of multimodal functions. Description of experiments and analyses of improved results are also shown.Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700