Distributed coordination in unstructured intelligent agent societies

Current research on multi-agent coordination and distributed problem solving is still not robust or scalable enough to build large real-world collaborative agent societies because it relies on either centralised components with full knowledge of the domain or pre-defined social structures. Our approach allows overcoming these limitations by using a generic coordination framework for distributed problem solving on totally unstructured environments that enables each agent to decompose problems into sub-problems, identify those which it can solve and search for other agents to delegate the sub-problems for which it does not have the necessary knowledge or resources. Regarding the problem decomposition process, we have developed two distributed versions of the Graphplan planning algorithm. To allow an agent to discover other agents with the necessary skills for dealing with unsolved sub-problems, we have created two peer-to-peer search algorithms that build and maintain a semantic overlay network that connects agents relying on dependency relationships, which improves future searches. Our approach was evaluated using two different scenarios, which allowed us to conclude that it is efficient, scalable and robust, allowing the coordinated distributed solving of complex problems in unstructured environments without the unacceptable assumptions of alternative approaches developed thus far.As abordagens actuais de coordenação multi-agente e resolução distribuída de problemas não são suficientemente robustas ou escaláveis para criar sociedades de agentes colaborativos uma vez que assentam ou em componentes centralizados com total conhecimento do domínio ou em estruturas sociais pré-definidas. A nossa abordagem permite superar estas limitações através da utilização de um algoritmo genérico de coordenação de resolução distribuída de problemas em ambientes totalmente não estruturados, o qual permite a cada agente decompor problemas em sub-problemas, identificar aqueles que consegue resolver e procurar outros agentes a quem delegar os subproblemas para os quais não tem conhecimento suficiente. Para a decomposição de problemas, criámos duas versões distribuídas do algoritmo de planeamento Graphplan. Para procurar os agentes com as capacidades necessárias à resolução das partes não resolvidas do problema, criámos dois algoritmos de procura que constroem e mantêm uma camada de rede semântica que relaciona agentes dependentes com o fim de facilitar as procuras. A nossa abordagem foi avaliada em dois cenários diferentes, o que nos permitiu concluir que ´e uma abordagem eficiente, escalável e robusta, possibilitando a resolução distribuída e coordenada de problemas complexos em ambientes não estruturados sem os pressupostos inaceitáveis em que assentava o trabalho feito até agora

The “Fashionable Knowledge” of Management Consulting

In the evolution of strategic disciplines much of the knowledge produced has been widely diffused by the management consulting industry. But can this sector be regarded as knowledge intensive activity based on true structure of expertise knowledge? One way to understand if we can consider that sector as a source of knowledge dissemination is realizing its relationship with the market in terms of knowledge, rather than identify only as a set of static techniques to be applied as in most of times they have been doing. This article presents itself as a reflection about the real reasons for the increasing use ofmanagement consulting services, indicating simultaneously that can really be a true field of opportunities for the academic class if the study will focused in the establishment and institutionalization of micropractices (strategy-as-practice) that there are used and its implications in terms of organizational results.info:eu-repo/semantics/publishedVersio

Impact of heat stress on bovine sperm quality and competence

Áreas de pesquisa: Agriculture ; Veterinary Sciences ; Zoology - REVIEWGlobal warming has negatively influenced animal production performance, in addition to animal well-being and welfare, consequently impairing the economic sustainability of the livestock industry. Heat stress impact on male fertility is complex and multifactorial, with the fertilizing ability of spermatozoa affected by several pathways. Among the most significative changes are the increase in and accumulation of reactive oxygen species (ROS) causing lipid peroxidation and motility impairment. The exposure of DNA during the cell division of spermatogenesis makes it vulnerable to both ROS and apoptotic enzymes, while the subsequent post-meiotic DNA condensation makes restoration impossible, harming later embryonic development. Mitochondria are also susceptible to the loss of membrane potential and electron leakage during oxidative phosphorylation, lowering their energy production capacity under heat stress. Although cells are equipped with defense mechanisms against heat stress, heat insults that are too intense lead to cell death. Heat shock proteins (HSP) belong to a thermostable and stress-induced protein family, which eliminate protein clusters and are essential to proteostasis under heat stress. This review focuses on effects of heat stress on sperm quality and on the mechanisms leading to defective sperm under heat stress.info:eu-repo/semantics/publishedVersio

A vida feliz: uma reflexão sobre a concepção de felicidade em Santo Agostinho

ResumoO ser humano busca a felicidade, está na sua essência essa procura; por isso a importância de investigar ainda hoje esse tema. O presente artigo é fruto da análise e reflexão sobre a obra de Santo Agostinho que trata a temática da felicidade, intitulada De Beata Vita. Fruto da investigação bibliográfica dessa obra e de outras que versam sobre essa questão, o objetivo principal é analisar a obra em tela, buscando compreender qual a base do conceito de felicidade nesse filósofo e qual a sua aplicabilidade nos dias de hoje. Para tanto, faz-se um apanhado dos principais fatos da vida de Agostinho de Hipona, seguido por um breve esboço dos pressupostos da filosofia agostiniana. Também se desenvolve, na sequência, uma análise do livro De Beata Vita, finalizando com a relação dos principais tópicos tratados, além de algumas aplicações dos conceitos apresentados.Palavras-chave: Felicidade. Eudaimonia. Deus. Agostinho.AbstractThe human being seeks happiness, this search is in our essence; thus, it is important the investigating this topic even today. This article is the result of analysis and reflection on the work of Saint Augustine that deals with the theme of happiness, entitled De Beata Vita. As a result of the bibliographic investigation of this work and others that deal with this issue, the main objective is to analyze the work on screen, seeking to understand the basis of the concept of happiness in this philosopher and its applicability today. To this end, an overview of the main facts of the life of Augustine of Hippo is made, followed by a brief outline of the assumptions of Augustinian philosophy. An analysis of the book De Beata Vita is also developed next, ending with a list of the main topics covered, in addition to some applications of the concepts presented.Keywords: Happiness. Eudaimonia. God.Augustine.ResumenEl ser humano busca la felicidad; está en su esencia esa procura; de allí la importancia de investigar, todavía en los días de hoy, sobre ese tema. El presente artículo es fruto del análisis y reflexión acerca la obra de san Agustín que trata sobre la felicidad, cuyo título es De Beata Vita. Fruto de la investigación bibliográfica de esa obra y de otras que tratan la cuestión, el objetivo central es analizar la obra mencionada, buscando comprender la base del concepto de felicidad en ese filósofo y su aplicabilidad en los días actuales. Para ello, se presenta una visión general de la vida de Agustín de Hipona, seguida de una breve reseña de los presupuestos de la filosofía agustiniana. También se presenta, a seguir, un análisis del libro De Beata Vita, y se finaliza con una relación de los principales tópicos tratados, además de algunas aplicaciones de los conceptos estudiados.Palabras-clave: Felicidad. Eudaimonia. Dios. Agustín

EL “OUTSOURCING” COMO UN RECURSO ESTRATÉGICO DE LA COMPETITIVIDAD INTERNACIONAL DEL MERCADO ESPAÑOL

La globalización del mercado empresarial actual requiere de una visión global, lógica y de carácter funcional, vinculada a la creación de valor desde un punto de vista del coste, el tiempo y la prestación del servicio. La enfatización de nuevas formas organizacionales y nuevos procesos de trabajo en términos contractuales ha dejado de ser vista como un recurso pasando a ser entendida como una necesidad básica y fundamental. Este artículo tiene como objetivo presentar un componente teórico relacionado con una estrategia de negocio muy particular, dada la importancia que pueda tener en el actual contexto empresarial de España. En esta medida, cabe preguntarse lo siguiente: ¿es el sector del "Outsourcing" la respuesta ideal y una herramienta influyente y poderosa de cambio organizacional?, ¿podrá este sector ser uno de los focos de proyección internacional de España y una verdadera fuente de ingresos en tiempos de crisis y cerca de la recesión? En realidad, este puede ser el camino para capitalizar las ventajas de España, mejorar sus desventajas, crear empleo, generar riqueza, promover la competitividad internacional y, aún más importante, ser la medicina alternativa para curar la enfermedad que supone ahora el déficit publico español y que el tratamiento “Outsourcing” podría eventualmente ayudar a regenerar.info:eu-repo/semantics/publishedVersio

Capacity of the chestnut flour for extruded production

O objectivo deste trabalho foi estudar as possibilidades tecnológicas de produção de extrudidos à base de farinha de castanha. Usou-se uma extrusora de parafuso único. Numa primeira etapa (teste A), testaram-se diferentes proporções de mistura de farinha de castanha e de milho, e, nas diferentes misturas foram ensaiados o teor de humidade e a temperatura de processamento. Avaliaram-se os produtos extrudidos quanto à taxa de expansão, quanto ao perfil de viscosidades obtido com o amilógrafo e quanto à textura estimada pelos parâmetros força e energia de ruptura recorrendo a um texturómetro. Numa segunda etapa (teste B), fixou-se a composição de 100% de farinha de castanha, e testou-se a velocidade do parafuso. Os extrudidos obtidos foram avaliados como foi referido anteriormente. O delineamento experimental considerou assim três fatores (X1- humidade inicial das misturas, X2- temperatura de processamento e X3- incorporação de farinha de castanha no teste A ou velocidade do parafuso no teste B), com cinco níveis por fator e seis repetições para o ponto central. A farinha de castanha crua apresentou uma temperatura de gelatinização relativamente baixa (59 °C) e originou pastas de viscosidade elevada. O seu amido apresentou uma concentração de amilose de 43%, caracterizando-se por uma relação amilose/amilopectina de 0,75, a qual é superior à da maioria dos amidos dos cereais. O comportamento amilográfico das misturas e as características de textura dos extrudidos mostraram que a farinha de castanha tem potencial para ser utilizada como ingrediente na formulação de alimentos cozidos extrudidos. A análise sensorial revelou significativa aceitabilidade pelos elementos do painel para produtos processados a baixa humidade e temperatura intermédia.The objective of this work was to study the technological possibilities of producing extrudates based on chestnut flour. A single screw extruder was used. In a first step (test A), different mix ratios of chestnut and corn flours were analysed. The moisture content and the processing temperature were tested in the different mixtures. The extruded products were evaluated for the expansion rate, the viscosity profile obtained with amilograph and the texture estimated by the parameters breaking strength and energy using a texturometer. In a second step (test B), the composition of 100% chestnut flour was fixed and the screw speed was tested. The obtained extrudates were evaluated as previously mentioned. The experimental design thus considered three factors (X1- moisture content of the mixtures, X2- processing temperature and X3 - incorporation of chestnut flour in test A or screw speed in test B), with five levels per factor and six repetitions for the central point. Raw chestnut flour had a relatively low gelatinization temperature (59 °C) and gave pastes with high viscosity. Its starch had an amylose content of 43%, characterized by an amylose / amylopectin ratio of 0.75, which is higher than most of the cereal starches. The amylographic behavior of the mixtures and the texture characteristics of the extrudates showed that chestnut flour has potential to be used as an ingredient in the formulation of extruded cooked foods. Sensory analysis revealed significant acceptability by the panel elements for products processed at low moisture content and intermediate temperature.info:eu-repo/semantics/publishedVersio

In vivo notch signaling blockade induces abnormal spermatogenesis in the mouse

Copyright: © 2014 Murta et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In a previous study we identified active Notch signaling in key cellular events occurring at adult spermatogenesis. In this study, we evaluated the function of Notch signaling in spermatogenesis through the effects of in vivo Notch blockade. Adult CD1 male mice were either submitted to a long term DAPT (?-secretase inhibitor) or vehicle treatment. Treatment duration was designed to attain one half the time (25 days) or the time (43 days) required to accomplish a complete cycle of spermatogenesis. Blockade of Notch signaling was depicted from decreased transcription of Notch effector genes. Notch signaling blockade disrupted the expression patterns of Notch components in the testis, induced male germ cell fate aberrations, and significantly increased germ cell apoptosis, mainly in the last stages of the spermatogenic cycle, and epididymis spermatozoa morphological defects. These effects were more pronounced following the 43 day than the 25 day DAPT treatment schedule. These results indicate a relevant regulatory role of Notch signaling in mammalian spermatogenesis.We thank the Portuguese Foundation for Science and Technology (FCT) for the financial support (Project PTDC/CVT/105022/2008) and (Project PEst-OE/AGR/U10276/2014). DM is a PhD student supported by grant SFRH/BD/64416/2009 from FCT. MB has a research contract under the grant PTDC/CVT/105022/2008. ES is a Postdoctoral Researcher under the Portuguese Government initiative for research jobs, Ciência 2008-FCT. AT is a Postdoctoral Researcher supported by grant SFRH/BPD/47079/2008 from FCT.info:eu-repo/semantics/publishedVersio

Estudos de efeito antagônico entre Lactobacillus sakei em Escherichia coli, Listeria monocytogenes e Staphylococcus aureus

The antimicrobial activity of a commercial probiotic culture, Lactobacillus sakei(ATCC 1521) at followingconcentrations (30, 42, 60, 78 and 90 μg/ml, 105 - 107UFC/mL), temperatures of interaction (4, 10, 20, 30, 37 °C) and initial pH (3.5, 4.0, 4.5, 5.0 and 5.5) were tested against three foodborne pathogens, Escherichia coli, Listeria monocytogenesand Staphylococcus aureus. The antagonistic effect of the probiotic culture in vitro was performed by liquid microdilution method. The results indicated that the inhibitory substance present on a 24 hours culture broth could be an advantage when keeping the culture dominant during longer fermentations. For the highest lactic acid production, the incubation period of lactic acid bacteria (1.04 % v/v) was on MRS Broth in aerobic conditions, at 37 ºC/24 hours, which gave a minimum pH value of the supernatant (3.5). The data suggest that supernatant can have significant bacteriostatic activity against E. coli, L. monocytogenesand S. aureus, and may provide curedmeats with a degree of protection against this microorganism, particularly if employed with a combination of acid pH, and adequate refrigeration.A atividade antimicrobiana de uma cultura comercial probiótica  deLactobacillus  sakei  (ATCC  1521)  foi avaliada em termos de concentração celular (30, 42, 60, 78 e 90 mcg / ml, 105 - 107UFC/mL), temperatura de incubação (4, 10, 20, 30, 37 ° C) e pH inicial do meio de cultura (3.5, 4.0, 4.5, 5.0 e 5.5) contra três patógenos alimentares, Escherichia coli, Listeria monocytogenes e Staphylococcus aureus. O efeito antagônico da cultura probiótica in vitro foi realizada através da aplicação de método quantitativo espectrofotométrico. Os resultados indicaram que uma substância inibitória presente em caldo de cultura de 24 horas poderia ser vantajoso quando mantendo a cultura dominante durante fermentações mais prolongadas. Para a maior produção de ácido láctico (1,04%v/v), o período de incubação da bactéria em caldo MRS foi de 24 horas em condições aeróbicas e a 37 ºC, com um valor de pH mínimo do sobrenadante (3,5). Os dados sugerem que o sobrenadante pode ter atividade bacteriostática significativa contra E. coli,L. monocytogenes e S. aureus, e pode fornecer carnes curadas com um grau de protecção contra este microorganismo, particularmente se empregada com uma combinação de pH ácido, e de refrigeração adequada

Genomic and phenotypic characterization of Campylobacter fetus subsp. venerealis strains

Research Areas: MicrobiologyThe pathogenesis mechanisms of Campylobacter fetus subsp. venerealis (Cfv), the etiologic agent of Bovine Genital Campylobacteriosis remain elusive. This study evaluated the virulence potential and biovar characteristics of Cfv isolates (n = 13) by PCR screening of putative virulencefactor (VF) genes, Multilocus Sequence Typing (MLST) analysis, antimicrobial susceptibility to tetracycline, penicillin, enrofloxacin and streptomycin testing and whole-genome sequencing (WGS; n = 5), also comparing the latter with 26 other whole-genome sequences of Cfv strains. The putative VF genes encoding type IV secretion system of Cfv (virB2-virB11/virD4) were absent in 92% of isolates, including isolates from aborted foetuses, evidencing that these VF genes are not essential for Cfv pathogenicity. The parA gene, used as a Cfv diagnostic molecular target, was detected in only 3 of 13 isolates, invalidating its use for diagnosis purposes. Three novel sequence types were identified by MLST. Although no in vitro antimicrobial resistance was detected, WGS identified antimicrobial resistance-related genes, including those encoding the multidrug efflux pumps CmeABC and YkkCD, indicating that their presence is not enough to provide antimicrobial resistance. The SNP and accessory protein families analysis segregated the Cfv and Cfv biovar intermedius (Cfvi) strains into different clusters. In conclusion, this study evidenced virulence potential and biovar characteristics of Cfv and Cfvi, which are of relevance for the control of Bovine Genital Campylobacteriosis.info:eu-repo/semantics/publishedVersio

Nas rotas da cidade

Apresentação das comunicações resultantes do encontro A Cidade, entre projectos e políticas