341 research outputs found

    From Component-Based Architectures to Microservices: A 25-years-long Journey in Designing and Realizing Service-Based Systems

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    Distributed information systems and applications are generally described in terms of components and interfaces among them. How these component-based architectures have been designed and implemented evolved over the years, giving rise to the so-called paradigm of Service-Oriented Computing (SOC). In this chapter, we will follow a 25-years-long journey on how design methodologies and supporting technologies influenced one each other, and we discuss how already back in the late 90s the ancestors of the SOC paradigm were there, already paving the way for the technological evolution recently leading to microservice architectures and serverless computing

    On the Deployment of IoT Systems: An Industrial Survey

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    Internet of Things (IoT) systems are complex and multifaceted, and the design of their architectures needs to consider many aspects at a time. Design decisions concern, for instance, the modeling of software components and their interconnections, as well as where to deploy the components within the available hardware infrastructure in the Edge-Cloud continuum. A relevant and challenging task, in this context, is to identify optimal deployment models due to all the different aspects involved, such as extra-functional requirements of the system, heterogeneity of the hardware resources concerning their processing and storage capabilities, and constraints like legal issues and operational cost limits. To gain insights about the deployment decisions concerning IoT systems in practice, and the factors that influence those decisions, we report about an industrial survey we conducted with 66 IoT architects from 18 countries across the world. Each participant filled in a questionnaire that comprises 15 questions. By analyzing the collected data, we have two main findings: (i) architects rely on the Cloud more than the Edge for deploying the software components of IoT systems, in the majority of the IoT application domains; and (ii) the main factors driving deployment decisions are four: reliability, performance, security, and cost

    Resistin, visfatin, leptin and omentin are differently related to hormonal and metabolic parameters in growth hormone-deficient children

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    PURPOSE: The effect of growth hormone (GH) on adipose tissue and the role of adipokines in modulating metabolism are documented, but with discordant data. Our aim was to evaluate the impact of GH treatment on a series of selected adipokines known to have a metabolic role and poorly investigated in this setting. METHODS: This is a prospective study. Thirty-one prepubertal children (25 M, 6 F; aged 8.5 ± 1.6 years) with isolated GH deficiency treated with GH for at least 12 months and 30 matched controls were evaluated. Auxological and metabolic parameters, insulin sensitivity indexes, leptin, soluble leptin receptor, adiponectin, visfatin, resistin, omentin, adipocyte fatty acid-binding protein and retinol-binding protein-4 were evaluated before and after 12 months of treatment. RESULTS: At baseline, no significant difference in metabolic parameters was found between GHD children and controls, except for higher LDL cholesterol (p = 0.004) in the first group. At multivariate analysis, LDL cholesterol was independently associated with resistin (B 0.531; p = 0.002), while IGF-I was the only variable independently associated with visfatin (B 0.688; p < 0.001). After 12 months, a significant increase in fasting insulin (p = 0.008), Homa-IR (p = 0.007) and visfatin (p < 0.001) was found, with a concomitant decrease in LDL cholesterol (p = 0.015), QUICKI (p = 0.001), ISI Matsuda (p = 0.006), leptin (p = 0.015) and omentin (p = 0.003)]. At multivariate analysis, BMI was the only variable independently associated with leptin (B 0.485; p = 0.040). CONCLUSIONS: GH treatment modifies adipokine secretion and the perturbation of some adipokine levels could contribute to the clinical and metabolic changes observed during the follow-up

    Interspecific variations in the gastrointestinal microbiota in penguins

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    Despite the enormous amount of data available on the importance of the gastrointestinal (GI) microbiota in vertebrate (especially mammals), information on the GI microbiota of seabirds remains incomplete. As with many seabirds, penguins have a unique digestive physiology that enables them to store large reserves of adipose tissue, protein, and lipids. This study used quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene pyrosequencing to characterize the interspecific variations of the GI microbiota of four penguin species: the king, gentoo, macaroni, and little penguin. The qPCR results indicated that there were significant differences in the abundance of the major phyla Firmicutes, Bacteroides, Actinobacteria, and Proteobacteria. A total of 132,340, 18,336, 6324, and 4826 near full-length 16S rRNA gene sequences were amplified from fecal samples collected from king, gentoo, macaroni, and little penguins, respectively. A total of 13 phyla were identified with Firmicutes, Bacteroidetes, Proteobacteria, and Fusobacteria dominating the composition; however, there were major differences in the relative abundance of the phyla. In addition, this study documented the presence of known human pathogens, such as Campylobacter, Helicobacter, Prevotella, Veillonella, Erysipelotrichaceae, Neisseria, and Mycoplasma. However, their role in disease in penguins remains unknown. To our knowledge, this is the first study to provide an in-depth investigation of the GI microbiota of penguins.<br /

    Frequencies of Salmonella enterica in growing pigs in Paraguay

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    The objective of this study was to (1) estimate frequencies of Salmonella enterica in growing pigs and (2) investigate farmers' perception and practices towards pig farming in Central Department, Paraguay. Twelve out of 19 districts in the department were selected and 33 farms with growers in the selected districts were recruited. Questionnaire interviews for each study farm, in combination with faecal sample collections (n = 30 per farm), which were microbiologic ally examined and visual inspection of pig production facilities were performed between March and November 2009. A questionnaire was designed to obtain basic information of a farm such as the number of pigs owned and some selected farming management practices. Faecal samples were used for Salmonella isolation, using buffered peptone water to have salmonellae pre-enriched, followed by xylose lysine tergitol 4 agar and brilliant green sulfapyridine agar. Suspect colonies were bio chemically tested by triple sugar iron agar in combination with lysine iron agar to confirm the identity. The true frequency probability and associated 95% Bayesian credible intervals (95% BCI) were computed via the Gibbs sampler, a Markov chain Monte Carlo technique. Overall, 18% (95% BCI: 8-31%) of the tested 1000 faecal samples were classified as positive for Salmonella enterica. All the study farms had at least one positive sample for Salmonella enterica (frequency range: 3-60%). Apparent prevalence at farm-level was therefore 100% (one-sided 97.5% confidence limit: 89%). Twenty-eight different serovars for Salmonella enterica were found. Based on increase the number of study districts, farms as well as animals in combination with improvement of sampling methods, possible spatial differences and risk factors/indicators should be clarified by further investigations.Facultad de Ciencias Veterinaria

    Frequencies of Salmonella enterica in growing pigs in Paraguay

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    The objective of this study was to (1) estimate frequencies of Salmonella enterica in growing pigs and (2) investigate farmers' perception and practices towards pig farming in Central Department, Paraguay. Twelve out of 19 districts in the department were selected and 33 farms with growers in the selected districts were recruited. Questionnaire interviews for each study farm, in combination with faecal sample collections (n = 30 per farm), which were microbiologic ally examined and visual inspection of pig production facilities were performed between March and November 2009. A questionnaire was designed to obtain basic information of a farm such as the number of pigs owned and some selected farming management practices. Faecal samples were used for Salmonella isolation, using buffered peptone water to have salmonellae pre-enriched, followed by xylose lysine tergitol 4 agar and brilliant green sulfapyridine agar. Suspect colonies were bio chemically tested by triple sugar iron agar in combination with lysine iron agar to confirm the identity. The true frequency probability and associated 95% Bayesian credible intervals (95% BCI) were computed via the Gibbs sampler, a Markov chain Monte Carlo technique. Overall, 18% (95% BCI: 8-31%) of the tested 1000 faecal samples were classified as positive for Salmonella enterica. All the study farms had at least one positive sample for Salmonella enterica (frequency range: 3-60%). Apparent prevalence at farm-level was therefore 100% (one-sided 97.5% confidence limit: 89%). Twenty-eight different serovars for Salmonella enterica were found. Based on increase the number of study districts, farms as well as animals in combination with improvement of sampling methods, possible spatial differences and risk factors/indicators should be clarified by further investigations.Facultad de Ciencias Veterinaria
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