753 research outputs found

    Modelling indoor air carbon dioxide concentration using grey-box models

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    Predictive control is the strategy that has the greatest reported benefits when it is implemented in a building energy management system. Predictive control requires low-order models to assess different scenarios and determine which strategy should be implemented to achieve a good compromise between comfort, energy consumption and energy cost. Usually, a deterministic approach is used to create low-order models to estimate the indoor CO2 concentration using the differential equation of the tracer-gas mass balance. However, the use of stochastic differential equations based on the tracer-gas mass balance is not common. The objective of this paper is to assess the potential of creating predictive models for a specific room using for the first time a stochastic grey-box modelling approach to estimate future CO2 concentrations. First of all, a set of stochastic differential equations are defined. Then, the model parameters are estimated using a maximum likelihood method. Different models are defined, and tested using a set of statistical methods. The approach used combines physical knowledge and information embedded in the monitored data to identify a suitable parametrization for a simple model that is more accurate than commonly used deterministic approaches. As a consequence, predictive control can be easily implemented in energy management systems.Peer ReviewedPostprint (author's final draft

    Reproduction in captivity of Meiacanthus grammistes

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    Rotifers and Artemia salina nauplii are the most widely used live prey for newly hatched larvae, but they do not always promote optimal survival and growth. Alternative food sources such as copepods, which bypass these inadequacies and promote adequate growth, are needed and they are viewed with considerable interest by the scienti¢c community. The aim of the present study was to test two diierent diets [rotifers and A. salina nauplii (group A) and a mixture (group B) of rotifers/Tisbe spp. copepods and A. salina nauplii/copepods] during the larval rearing of the striped blenny Meiacanthus grammistes. The analysis of the survival rate, size (total length and wet weight) and metamorphosis time during the larval phase of this species showed thatTisbe spp. administration can signi¢cantly improve larval survival and growth and also reduce the metamorphosis time. The results obtained are related to the fatty acid content of the live prey used and are essential in order to improve the captive production of M. grammistes through a closed system and, in turn, to preserve natural stocks

    Efficacy of an enterovaccine in recurrent episodes of diarrhea in the dog – a pilot study

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    Recurrent episodes of self-limiting diarrhea in the dog, due to sudden dietary changes and to stressful or exciting situations, are conditions sometimes difficult to treat. Colifagina®, a commercially available bacterial enterovaccine, showed, in previous studies performed on experimentally induced colitis in mice, to be able to improve both disease activity index and histological appearance, increase colonic secretion of IgA, and reduce inflammatory chemokine secretion. In the present study Colifagina® was administered to five dogs presenting recurrent episodes of self-limiting diarrhea and to one dog presenting chronic diarrhea. During the follow-up period, almost all patients decreased the number of episodes of abnormal defecation and the fecal score of such episodes improved in five out of six dogs. Even if further studies are needed to understand the exact potential of the compound, in dogs presenting recurrent episodes of self-limiting diarrhea due to sudden dietary changes and/or stressing or exciting situations, Colifagina® seems to be helpful in managing most of these patients

    Efficacy of an enterovaccine in recurrent episodes of diarrhea in the dog: a pilot study

    Get PDF
    Recurrent episodes of self-limiting diarrhea in the dog, due to sudden dietary changes and to stressful or exciting situations, are conditions sometimes difficult to treat. Colifagina ® , a commercially available bacterial enterovaccine, showed, in previous studies performed on experimentally induced colitis in mice, to be able to improve both disease activity index and histological appearance, increase colonic secretion of IgA, and reduce inflammatory chemokine secretion. In the present study Colifagina ® was administered to five dogs presenting recurrent episodes of self-limiting diarrhea and to one dog presenting chronic diarrhea. During the follow-up period, almost all patients decreased the number of episodes of abnormal defecation and the fecal score of such episodes improved in five out of six dogs. Even if further studies are needed to understand the exact potential of the compound, in dogs presenting recurrent episodes of self-limiting diarrhea due to sudden dietary changes and/or stressing or exciting situations, Colifagina ® seems to be helpful in managing most of these patients

    Operando atomic-scale study of graphene CVD growth at steps of polycrystalline nickel

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    An operando investigation of graphene growth on (100) grains of polycrystalline nickel (Ni) surfaces was performed by means of variable-temperature scanning tunneling microscopy complemented by density functional theory simulations. A clear description of the atomistic mechanisms ruling the graphene expansion process at the stepped regions of the substrate is provided, showing that different routes can be followed, depending on the height of the steps to be crossed. When a growing graphene flake reaches a monoatomic step, it extends jointly with the underlying Ni layer; for higher Ni edges, a different process, involving step retraction and graphene landing, becomes active. At step bunches, the latter mechanism leads to a peculiar \u2018staircase formation\u2019 behavior, where terraces of equal width form under the overgrowing graphene, driven by a balance in the energy cost between C\u2013Ni bond formation and stress accumulation in the carbon layer. Our results represent a step towards bridging the material gap in searching new strategies and methods for the optimization of chemical vapor deposition graphene production on polycrystalline metal surfaces

    DNA methylation changes in genes involved in inflammation and depression in fibromyalgia: a pilot study

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    Objectives: The present pilot study aims to investigate DNA methylation changes of genes related to fibromyalgia (FM) development and its main comorbid symptoms, including sleep impairment, inflammation, depression and other psychiatric disorders. Epigenetic modifications might trigger or perpetuate complex interplay between pain transduction/transmission, central pain processing and experienced stressors in vulnerable individuals. Methods: We conducted DNA methylation analysis by targeted bisulfite NGS sequencing testing differential methylation in 112 genomic regions from leukocytes of eight women with FM and their eight healthy sisters as controls. Results: Tests for differentially methylated regions and cytosines brought focus on the GRM2 gene, encoding the metabotropic glutamate receptor2. The slightly increased DNA methylation observed in the GRM2 region of FM patients may confirm the involvement of the glutamate pathway in this pathological condition. Logistic regression highlighted the simultaneous association of methylation levels of depression and inflammation-related genes with FM. Conclusions: Altogether, the results evidence the glutamate pathway involvement in FM and support the idea that a combination of methylated and unmethylated genes could represent a risk factor to FM or its consequence, more than single genes. Further studies on the identified biomarkers could contribute to unravel the causative underlying FM mechanisms, giving reliable directions to research, improving the diagnosis and effective therapiesThis study was supported by Spanish Government Funding (Ministerio de Economía y Competitividad: grant PSI2013-45818-R). The genotyping service was carried out at CEGEN-PRB3-ISCIII; it is supported by grant PT17/0019, of the PE I + D + i 2013–2016, funded by ISCIII and ERDF. MCG and LAN are part of the Center for Neuroplasticity and Pain (CNAP) which is supported by the Danish National Research Foundation (DNRF121)S

    Knock-Down of Cathepsin D Affects the Retinal Pigment Epithelium, Impairs Swim-Bladder Ontogenesis and Causes Premature Death in Zebrafish

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    The lysosomal aspartic protease Cathepsin D (CD) is ubiquitously expressed in eukaryotic organisms. CD activity is essential to accomplish the acid-dependent extensive or partial proteolysis of protein substrates within endosomal and lysosomal compartments therein delivered via endocytosis, phagocytosis or autophagocytosis. CD may also act at physiological pH on small-size substrates in the cytosol and in the extracellular milieu. Mouse and fruit fly CD knock-out models have highlighted the multi-pathophysiological roles of CD in tissue homeostasis and organ development. Here we report the first phenotypic description of the lack of CD expression during zebrafish (Danio rerio) development obtained by morpholino-mediated knock-down of CD mRNA. Since the un-fertilized eggs were shown to be supplied with maternal CD mRNA, only a morpholino targeting a sequence containing the starting ATG codon was effective. The main phenotypic alterations produced by CD knock-down in zebrafish were: 1. abnormal development of the eye and of retinal pigment epithelium; 2. absence of the swim-bladder; 3. skin hyper-pigmentation; 4. reduced growth and premature death. Rescue experiments confirmed the involvement of CD in the developmental processes leading to these phenotypic alterations. Our findings add to the list of CD functions in organ development and patho-physiology in vertebrates
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