51 research outputs found

    Influencia de los métodos de conservación en las actividades enzimáticas de suelos forestales mediterráneos

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    Soil storage method may alter enzymatic activity being storage conditions of the soil samples prior to analysis decisive for the results. Studies made on freshly collected soils are generally preferred. However it is always not possible due to practical reasons since for example sampling is often restricted to short period of the year or because a great quantity of microbiological analyses must be made on time and by few people. On this context, soil storage methods are needed, being cold at 4°C the most widely used although sometimes alternative storage methods are also utilized. The aim of this study is to evaluate the effect of two alternative storage methods of soil samples (freezing at –20°C and air drying conservation methods) in comparison to cold at 4°C on the enzymatic activities (dehydrogenase, phosphatase, β-glucosidase and urease soil enzymes). Samples of two forest ecosystems (pine and holm oak forest stand) were taken in two different season of the year (winter and spring 2009). Results showed that enzymatic activities differed when freezing or air drying conservation methods were used in comparison with cold soil samples. Generally, alternative soil storage methods presented lower enzymatic activity than cold at 4°C. However, these changes depend on season and sampling location.El método de conservación del suelo utilizado puede alterar la actividad enzimática, siendo decisivas para los resultados, las condiciones de conservación previas a los análisis. Para los estudios es preferible realizar los análisis en muestras frescas y recién cogidas. Sin embargo, esto no es siempre posible por razones prácticas ya que las muestras se tienen que recoger en un corto periodo del año o porque los análisis los debe hacer poca gente y siempre en un determinado tiempo. En este contexto, se necesita un método de conservación, siendo el mantenimiento en el frigorífico a 4°C el método más usado, aunque existen otros métodos alternativos. El objetivo de este trabajo es el de evaluar el efecto de dos métodos alternativos de conservación (congelado a –20°C y secado a temperatura ambiente) sobre las actividades enzimáticas (deshidrogenasa, fosfatasa, β-glucosidasa y ureasa), en comparación con el mantenido en el frigorífico a 4°C. Las muestras se obtuvieron de dos zonas forestales diferentes (pinar y encinar) y en dos épocas distintas (primavera y verano de 2009). Los resultados mostraron diferencias en las actividades enzimáticas cuando se usó el congelado o secado al aire de las muestras de suelo en comparación con el mantenimiento en el frigorífico. De forma general, los métodos de conservación alternativos mostraron una menor actividad enzimática en las muestras de suelo analizadas. Sin embargo, estos cambios dependen de la época del año y la zona de muestreo

    Unexpected high toughness of Samia cynthia ricini silk gut

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    Silk gut fibers were produced from the silkworm Samia cynthia ricini silk glands by the usual procedure of immersion in a mildly acidic solution and subsequent stretching. The morphology of the silk guts was assessed by scanning electron microscopy, and their microstructure was assessed by infrared spectroscopy and X-ray diffraction. It was found that both naturally spun and Samia silk guts share a common semicrystalline microstructure. The mechanical characterization of the silk guts revealed that these fibers show an elastomeric behavior when tested in water, and exhibit a genuine ground state to which the fiber may revert independently of its previous loading history. In spite of its large cross-sectional area compared with naturally spun silk fibers, Samia silk guts show values of work to fracture up to 160 MJ m, much larger than those of most of their natural counterparts, and establish a new record value for this parameter in silk guts

    Salivary biomarkers as pioneering indicators for diagnosis and severity stratification of pediatric long COVID

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    Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), manifests as persistent and often debilitating symptoms enduring well beyond the initial COVID-19 infection. This disease is especially worrying in children since it can seriously alter their development. Presently, a specific diagnostic test or definitive biomarker set for confirming long COVID is lacking, relying instead on the protracted presence of symptoms post-acute infection. We measured the levels of 13 biomarkers in 105 saliva samples (49 from children with long COVID and 56 controls), and the Pearson correlation coefficient was used to analyse the correlations between the levels of the different salivary biomarkers. Multivariate logistic regression analyses were performed to determine which of the 13 analysed salivary biomarkers were useful to discriminate between children with long COVID and controls, as well as between children with mild and severe long COVID symptoms. Pediatric long COVID exhibited increased oxidant biomarkers and decreased antioxidant, immune response, and stress-related biomarkers. Correlation analyses unveiled distinct patterns between biomarkers in long COVID and controls. Notably, a multivariate logistic regression pinpointed TOS, ADA2, total proteins, and AOPP as pivotal variables, culminating in a remarkably accurate predictive model distinguishing long COVID from controls. Furthermore, total proteins and ADA1 were instrumental in discerning between mild and severe long COVID symptoms. This research sheds light on the potential clinical utility of salivary biomarkers in diagnosing and categorizing the severity of pediatric long COVID. It also lays the groundwork for future investigations aimed at unravelling the prognostic value of these biomarkers in predicting the trajectory of long COVID in affected individuals

    Salivary biomarkers as pioneering indicators for diagnosis and severity stratification of pediatric long COVID

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    IntroductionLong COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), manifests as persistent and often debilitating symptoms enduring well beyond the initial COVID-19 infection. This disease is especially worrying in children since it can seriously alter their development. Presently, a specific diagnostic test or definitive biomarker set for confirming long COVID is lacking, relying instead on the protracted presence of symptoms post-acute infection.MethodsWe measured the levels of 13 biomarkers in 105 saliva samples (49 from children with long COVID and 56 controls), and the Pearson correlation coefficient was used to analyse the correlations between the levels of the different salivary biomarkers. Multivariate logistic regression analyses were performed to determine which of the 13 analysed salivary biomarkers were useful to discriminate between children with long COVID and controls, as well as between children with mild and severe long COVID symptoms.ResultsPediatric long COVID exhibited increased oxidant biomarkers and decreased antioxidant, immune response, and stress-related biomarkers. Correlation analyses unveiled distinct patterns between biomarkers in long COVID and controls. Notably, a multivariate logistic regression pinpointed TOS, ADA2, total proteins, and AOPP as pivotal variables, culminating in a remarkably accurate predictive model distinguishing long COVID from controls. Furthermore, total proteins and ADA1 were instrumental in discerning between mild and severe long COVID symptoms.DiscussionThis research sheds light on the potential clinical utility of salivary biomarkers in diagnosing and categorizing the severity of pediatric long COVID. It also lays the groundwork for future investigations aimed at unravelling the prognostic value of these biomarkers in predicting the trajectory of long COVID in affected individuals

    Food and nutrition security discursive frames in the context of the Spanish economic crisis

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    [EN] The recent economic crisis in Spain has provoked a number of food and nutrition security (FNS) impacts that have fuelled a fragmented landscape of food-related debates, although these have not taken the form of a coherent and allembracing public discussion on national food security. This paper is an inductive analysis of such debates, mostly based on media coverage, in an attempt to disentangle the different discourse frames on FNS in Spain, and the role played by the economic crisis in the shaping and underpinning of such frames. For this purpose a frame matrix was constructed, paying particular attention to the stakeholders governance claims in order to confront frame-specific problems. Results show how stakeholders have used elements of the crisis to underpin or reinterpret their core arguments. In addition, governance claims have concentrated on the malfunctioning of the food chain, mostly due to unequal bargaining power, and the way this could be putting at risk crucial components of the food system and future FNS. Also, the short-termism of most stakeholders approaches obscures the long run threats to the Spanish food system.This research is part of the project "Assessment of the impact of global drivers of change on Europe's food security" (TRANSMANGO), granted by the EU under 7th Framework Programme, theme KBBE.2013.2.5-01, Grant agreement no: 613532. Authors gratefully appreciate the comments and suggestions made by the three anonymous reviewers and the editors of the Journal.OOrtiz Miranda, D.; Moreno Pérez, OM.; Arnalte Alegre, EV. (2016). Food and nutrition security discursive frames in the context of the Spanish economic crisis. Food Security. 8(3):665-677. https://doi.org/10.1007/s12571-016-0574-xS66567783Antentas, J. M., & Vivas, E. (2014). 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    Chapter Determinants and Tools to Evaluate the Ecological Sustainability of Using Forest Biomass as an Alternative Energy Source

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    Forest biomass, the most ancient of fuels, is again in the center of renewable energy production. This chapter provides an introductory view of the main factors that condition the ecological sustainability of this energy source. The basic concepts of ecological sustainability, ecological rotation, and ecological thresholds (among others) are presented. The state of the art on approaches to assess the sustainability of forest biomass production for heat and electricity is discussed, and tools available for decision-makers to evaluate the sustainability of forest biomass production and management are described. This chapter then describes the main advantages and drawbacks of forest certification, growth and yield tables, and ecological models in relationship to their use in sustainable forest management for biomass and energy production

    Chapter Determinants and Tools to Evaluate the Ecological Sustainability of Using Forest Biomass as an Alternative Energy Source

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    Forest biomass, the most ancient of fuels, is again in the center of renewable energy production. This chapter provides an introductory view of the main factors that condition the ecological sustainability of this energy source. The basic concepts of ecological sustainability, ecological rotation, and ecological thresholds (among others) are presented. The state of the art on approaches to assess the sustainability of forest biomass production for heat and electricity is discussed, and tools available for decision-makers to evaluate the sustainability of forest biomass production and management are described. This chapter then describes the main advantages and drawbacks of forest certification, growth and yield tables, and ecological models in relationship to their use in sustainable forest management for biomass and energy production
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