3,585 research outputs found

    Evaluation of Enzyme Additives on the Nutritional Use of Feeds with a High Content of Plant Ingredients for Mugil cephalus

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    The Mugilidae are a group of fish with a great interest for aquaculture due to their omnivorous profile, rapid growth, and resistance to environmental variations. The selection of feed ingredients for these species is currently focused on an extensive use of plant by-products, with this being limited by their content in anti-nutritive factors (mainly phytate and non-starch polysaccharides; NSPs). Nevertheless, specific enzymes can be used to counteract some of those negative effects. In the present study, the effect of pretreating two high-plant feeds with a mixture of enzymes (glucanases + phytase) on the digestive use of protein and phosphorus by juvenile mullets (Mugil cephalus) was assessed using both in vitro and in vivo assays. The enzymatic treatment significantly modified the potential bioavailability of some nutrients, such as a reduction of sugars, pentoses, and phytic phosphorus. Also, it increased the digestibility of protein in one of the feeds but reduced that of phosphorus in both of them. The potential usefulness of enzyme treatment and the information provided by the two types of assays are discusse

    Femtosecond time-resolved phase-change microscopy and ablation threshold calculations to understand ultrafast laser ablation

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    El trabajo recoge experimentos realizados en una configuración sonda-prueba haciendo uso de un láser de femtosegundos, con el objetivo de comprender los fenómenos de ablación de materiales sólidos ras irradiación con láseres de pulso ultracorto.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    The Importance of the Participatory Dimension in Urban Resilience Improvement Processes

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    This article discusses the approach adopted by the researchers into citizen participation in urban regeneration actions and projects. It describes the concepts of sustainability and habitability in relation to the urban environment and architecture within the framework of improving the resilience of our cities through the circular economy and decarbonisation processes in architecture. The authors review the participatory dimension of different urban regeneration actions carried out in Spain and the impact of this dimension on the results obtained by environmental, economic and social urban improvements. They then define possible strategies and methodological tools for integrating this dimension into traditional urban regeneration processes. The article presents case studies and their specific characteristics, and draws conclusions about their effectiveness and relevance. It also compares citizen-led interventions with interventions led by public administrations. Lastly, the authors analyse the potential reasons for success in these processes and projects, identifying weaknesses and proposing possible strategies for future development by researchers

    A Cholinergic Synaptically Triggered Event Participates in the Generation of Persistent Activity Necessary for Eye Fixation

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    An exciting topic regarding integrative properties of the nervous system is how transient motor commands or brief sensory stimuli are able to evoke persistent neuronal changes, mainly as a sustained, tonic action potential firing. A persisting firing seems to be necessary for postural maintenance after a previous movement. We have studied in vitro and in vivo the generation of the persistent neuronal activity responsible for eye fixation after spontaneous eye movements. Rat sagittal brainstem slices were used for the intracellular recording of prepositus hypoglossi (PH) neurons and their synaptic activation from nearby paramedian pontine reticular formation (PPRF) neurons. Single electrical pulses applied to the PPRF showed a monosynaptic glutamatergic projection on PH neurons, acting on AMPA-kainate receptors. Train stimulation of the PPRF area evoked a sustained depolarization of PH neurons exceeding (by hundreds of milliseconds) stimulus duration. Both duration and amplitude of this sustained depolarization were linearly related to train frequency. The train-evoked sustained depolarization was the result of interaction between glutamatergic excitatory burst neurons and cholinergic mesopontine reticular fibers projecting onto PH neurons, because it was prevented by slice superfusion with cholinergic antagonists and mimicked by cholinergic agonists. As expected, microinjections of cholinergic antagonists in the PH nucleus of alert behaving cats evoked a gaze-holding deficit consisting of a re-centering drift of the eye after each saccade. These findings suggest that a slow, cholinergic, synaptically triggered event participates in the generation of persistent activity characteristic of PH neurons carrying eye position signals.Unión Europea Grants BI04-CT98-0546España, Ministerio de Ciencia PB98-0011, BFI2000-00936, BFI2000-1190, y BFI2002-0137

    Principal Component Analysis of Results Obtained from Finite-Difference Time-Domain Algorithms

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    Finite-Differences Time-Domain (FDTD) algorithms are well established tools of computational electromagnetism. Because of their practical implementation as computer codes, they are affected by many numerical artefact and noise. In order to obtain better results we propose using Principal Component Analysis (PCA) based on multivariate statistical techniques. The PCA has been successfully used for the analysis of noise and spatial temporal structure in a sequence of images. It allows a straightforward discrimination between the numerical noise and the actual electromagnetic variables, and the quantitative estimation of their respective contributions. Besides, The GDTD results can be filtered to clean the effect of the noise. In this contribution we will show how the method can be applied to several FDTD simulations: the propagation of a pulse in vacuum, the analysis of two-dimensional photonic crystals. In this last case, PCA has revealed hidden electromagnetic structures related to actual modes of the photonic crystal

    A didactic experience dedicated to the quality of life in Caceres

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    En muchas ocasiones se ha aludido en la Enseñanza a las experiencias didácticas llevadas a cabo en el entorno más inmediato al alumno, en este caso la ciudad. Es un proyecto que no sólo pretende trasladar las enseñanzas académicas del aula a la calle, sino también traspasar el estricto marco académico y acercar al alumno al reconocimiento, reflexión y evaluación de los problemas de la calidad de vida en las ciudades. Ese es el objetivo primordial de nuestro proyecto: estudiar la calidad de vida en la ciudad de Cáceres desde una óptica científica pero a la vez comprensible por un sector de población entre los quince y los dieciséis años: los alumnos de 2 de BUP de I.B. "Norba Caesarina".Many times we have discussed the specialised experiences carried out in teaching about the nearest surrowndings of the pupil, in this case, the city. It is a project which not only tries to transfer the academic lessons from the class room to the street, but also penetrate the strict academic atmosphere and bring the pupil closer to recognition, reflexion and evaluation of the problems of the quality of life in the cities. This is the main objective of our project: studying the quality of lije in the city of Caceres from a scientific point of view but at the same time adapting it to the level of the 15 to 16 year-old sector: the second year pupils of BUP of the I.B. "Norba Caesarina".peerReviewe

    Decisional balance and processes of change in community-recruited with moderate-high versus mild severity of cannabis dependence

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    Decisional Balance and Processes of Change are generally addressed in motivational interventions for the treatment of cannabis use disorders. However, specific aspects of these multifaceted constructs, with greater relevance for severe cannabis users, need to be ascertained to enable better interventions. This study aimed to compare the different facets of decisional balance and processes of change between mild and severe cannabis users in a community-based sample of young undergraduates. Thirty-one severe cannabis users and 31 mild cannabis users, indicated with the Severity of Dependence Scale, were assessed using the Decisional Balance Questionnaire (DBQ) and the Processes of Change Questionnaire (PCQ). We found that severe cannabis users had higher scores in the DBQ dimensions of Utilitarian Gains for the Self, Utilitarian Gains for Significant Others, and Self-approval, as well as in the total subscale of Gains but not Losses. The group of severe cannabis users also had higher scores in the PCQ dimensions of Self-revaluations and Counter-conditioning. Our results pinpoint specific dimensions of Decisional Balance and Processes of Change that are endorsed by severe cannabis users. This knowledge could be applied to inform motivational interventions targeting severe cannabis users

    Non-esterified fatty acids profiling in rheumatoid arthritis: Associations with clinical features and Th1 response

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    Since lipid compounds are known to modulate the function of CD4+ T-cells and macrophages, we hypothesize that altered levels of serum non-esterified fatty acids (NEFA) may underlie rheumatoid arthritis (RA) pathogenesis.Serum levels of NEFA (palmitic, stearic, palmitoleic, oleic, linoleic, γ-linoleic, arachidonic -AA-, linolenic, eicosapentaenoic -EPA- and docosahexaenoic -DHA-) were quantified by LC-MS/MS after methyl-tert-butylether (MTBE)-extraction in 124 RA patients and 56 healthy controls (HC). CD4+ phenotype was studied by flow cytometry. TNFα, IL-8, VEGF, GM-CSF, IFNγ, IL-17, CCL2, CXCL10, leptin and resistin serum levels were quantified by immunoassays. The effect of FA on IFNγ production by PBMC was evaluated in vitro.Lower levels of palmitic (p<0.0001), palmitoleic (p = 0.002), oleic (p = 0.010), arachidonic (p = 0.027), EPA (p<0.0001) and DHA (p<0.0001) were found in RA patients, some NEFA being altered at onset. Cluster analysis identified a NEFA profile (hallmarked by increased stearic and decreased EPA and DHA) overrepresented in RA patients compared to HC (p = 0.002), being associated with clinical features (RF, shared epitope and erosions), increased IFNγ expression in CD4+ T-cells (p = 0.002) and a Th1-enriched serum milieu (IFNγ, CCL2 and CXCL10, all p<0.005). In vitro assays demonstrated that imbalanced FA could underlie IFNγ production by CD4+ T-cells. Finally, changes on NEFA levels were associated with clinical response upon TNFα-blockade.An altered NEFA profile can be found in RA patients associated with clinical characteristics of aggressive disease and enhanced Th1 response. These results support the relevance of lipidomic studies in RA and provide a rationale for new therapeutic targets
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