1,051 research outputs found

    Einstein-Smoluchowsky equation handled by complex fractional moments

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    In this paper the response of a non linear half oscillator driven by a-stable white noise in terms of probability density function (PDF) is investigated. The evolution of the PDF of such a system is ruled by the so called Einstein-Smoluchowsky equation involving, in the diffusive term, the Riesz fractional derivative. The solution is obtained by the use of complex fractional moments of the PDF, calculated with the aid of Mellin transform operator. It is shown that solution can be found for various values of stability index a and for any nonlinear function f (X; t)

    Probabilistic characterization of nonlinear systems under α-stable white noise via complex fractional moments

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    The probability density function of the response of a nonlinear system under external α-stable Lévy white noise is ruled by the so called Fractional Fokker-Planck equation. In such equation the diffusive term is the Riesz fractional derivative of the probability density function of the response. The paper deals with the solution of such equation by using the complex fractional moments. The analysis is performed in terms of probability density for a linear and a non-linear half oscillator forced by Lévy white noise with different stability indexes α. Numerical results are reported for a wide range of non-linearity of the mechanical system and stability index of the Lévy white noise

    Guidelines for the use and interpretation of diagnostic methods in adult food allergy

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    Food allergy has an increasing prevalence in the general population and in Italy concerns 8 % of people with allergies. The spectrum of its clinical manifestations ranges from mild symptoms up to potentially fatal anaphylactic shock. A number of patients can be diagnosed easily by the use of first- and second-level procedures (history, skin tests and allergen specific IgE). Patients with complex presentation, such as multiple sensitizations and pollen-food syndromes, frequently require a third-level approach including molecular diagnostics, which enables the design of a component-resolved sensitization profile for each patient. The use of such techniques involves specialists' and experts' skills on the issue to appropriately meet the diagnostic and therapeutic needs of patients. Particularly, educational programs for allergists on the use and interpretation of molecular diagnostics are needed

    The role of credence attributes in consumer choices of sustainable fish products: A review

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    This review aims to assess consumer choices of sustainable fish products, considering a number of attributes that have been considered in the academic literature on this topic. In order to examine the effectiveness of sustainable labels, the research question was focused on the relation between sustainable fish labels and consumers’ willingness to pay (WTP). The findings showed how, overall, consumers have positive perceptions regarding sustainable fish products and show a willingness to pay a premium price for the attribute of sustainability. According to the results, the country of origin attribute was found to be the most important attribute in relation to consumer choice. The results indicated a high WTP for local fish products, relative to imported alternatives. Consumers prefer wild-caught fish for its perceived quality, better safety and health aspects, and taste perception than the farm-raised option. As for animal welfare, the results show that consumers are willing to pay a moderate premium price for products that have an improved fish welfare or those that avoid by-catch, such as products with eco-labels like “turtle safe”. With regard to organic labels, the studies identified a positive organic price premium for fish products. However, organic labels do not play a major role in consumer choice, when compared with other attributes

    What's in organic wine consumer mind? A review on purchasing drivers of organic wines

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    Consumer interest in organic wine is growing, but the effects of organic label, consumer quality perception and the support for the benefits claim of organic wine are not yet fully understood and at times doubtful. The literature shows a very heterogeneous picture regarding consumer behaviour and preferences for organic wine. This study seeks to understand the link between organic wine and consumer' purchasing drivers. Using a systematic literature review, the paper explores the characteristics of consumer of organic wine, the motivation on consumer behaviour and preferences for organic wine, as well as the sensory quality and the presence of additives when evaluating wine quality and in shaping consumers' attitudes. The results show how socio-economic and psychological characteristics of consumer as well as quality perception affect their behaviour for organic wine. Little consensus on the benefits in terms of improved sensory quality of organic wine compared to conventional one. Among sensory qualities, taste has been found to be both a key driver and barrier to organic wine consumption. Based on literature studies, consumers have positive opinions toward organic wine, which is perceived as healthy and environmental friendly. However, despite the growing market interest in wine, scientific information about the organoleptic differences between conventional and organic remains scarce and the topic requires more in-depth analysis. Understanding the profile of consumer and the factors that influence consumer' behaviour provide information to the organic wine industry

    Metallobiochemistry of ultratrace levels of bismuth in the rat I. Metabolic patterns of 205+206Bi3+ in the blood

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    Background The number of the applications of bismuth (Bi) is rapidly and remarkably increasing, enhancing the chance to increase the levels to which humans are normally daily exposed. The interest to Bi comes also from the potential of Bi-based nanoparticles (BiNPs) for industrial and biomedical purposes. Like other metal-based NPs used in nanomedicine, BiNPs may release ultratrace amounts of Bi ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. At present, knowledge of Bi metabolism in laboratory animals refers almost solely to studies under unnatural “extreme” exposures, i.e. pharmacologically relevant high-doses (up to thousand mg kg−1) in relation to its medical use, or infinitesimal-doses (pg kg−1 as non-carrier-added Bi radioisotopes) for radiobiology protection, diagnostic and radiotherapeutic purposes. No specific study exists on the “metabolic patterns” in animal models exposed to levels of Bi, i.e. at “environmental dose exposure” that reflect the human daily exposure (μg kg−1). Methodology Rats were intraperitoneally injected with 0.8 μg Bi kg−1 bw as 205+206Bi(NO)3 alone or in combination with 59Fe for radiolabelling of iron proteins. The use of 205+206Bi radiotracers allowed the detection and measurement down to pg fg−1 of the element in the blood biochemical compartments and protein fractions as isolated by differential centrifugation, size exclusion- and ion exchange chromatography, electrophoresis, solvent extraction, precipitation and dialysis. Results 24 h after the administration, the blood concentration of Bi was 0.18 ng mL−1, with a repartition plasma/red blod cells (RBC) in a ratio of 2:1. Elution profiles of plasma from gel filtration on Sephadex G-150 showed four pools of Bi-binder proteins with different molecular sizes (> 300 kDa, 160 kDa, 70 kDa and < 6.5 kDa). In the 70 kDa fraction transferrin and albumin were identified as biomolecule carriers for Bi. In red blood cells, Bi was distributed between cytosol and membranes (ghosts) in a ratio of about 5:1. In the cytosol, low molecular components (LMWC) and the hemoglobin associated the Bi in a ratio of about 1.8:1. In the hemoglobin molecule, Bi was bound to the beta polypeptide chain of the globin. In the ghosts, Bi was detected at more than one site of the protein fraction, with no binding with lipids. Dialysis experiments and the consistently high recovery (80–90 %) of 206Bi from chromatography of 206Bi-containing biocomponents suggest that Bi was firmly complexed at physiological pH with a low degree of breaking during the applications of experimental protocols for the isolation of the 206Bi-biocomplexes. These latter were sensitive to acid buffer pH 5, and to the presence of complexing agents in the dialysis fluid. Conclusions On the basis of an environmental biochemical toxicology approach, we have undertaken a study on the metabolic patterns of Bi3+ ions in rats at tissue, subcellular and molecular level with the identification of cellular Bi-binding components. As a first part of the study the present work reports the results concerned with the metabolic fate of ultratrace levels of 205+206Bi(NO)3 in the blood

    Metallobiochemistry of ultratrace levels of bismuth in the rat II. Interaction of 205+206Bi3+ with tissue, intracellular and molecular components

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    Background Knowledge on Bi metabolism in laboratory animals refers to studies at “extreme” exposures, i.e. pharmacologically relevant high-doses (mg kg−1 b.w.) in relation to its medical use, or infinitesimal doses (pg kg−1b.w.) concerning radiobiology protection and radiotherapeutic purposes. There are no specific studies on metabolic patterns of environmental exposure doses (ultratrace level, μg kg−1 b.w.), becoming in this context Bi a “heavy metal fallen into oblivion”. We previously reported the results of the metabolic fate of ultratrace levels of Bi in the blood of rats [1]. In reference to the same study here we report the results of the retention and tissue binding of Bi with intracellular and molecular components. Methods Animals were intraperitoneally injected with 0.8 μg Bi kg−1 b.w. as 205+206Bi(NO)3, alone or in combination with 59Fe for the radiolabeling of iron proteins. The use of 205+206Bi radiotracer allowed the determination of Bi down to pg fg−1 in biological fluids, tissues, subcellular fractions, and biochemical components isolated by differential centrifugation, size exclusion chromatography, solvent extraction, precipitation, immunoprecipitation and dialysis. Main findings At 24 h post injection the kidney contained by far the highest Bi concentration (10 ng g−1 wt.w.) followed by the thymus, spleen, liver, thyroid, trachea, femur, lung, adrenal gland, stomach, duodenum and pancreas (0.1 to 1.3 ng g−1 wt.w.). Brain and testis showed smaller but consistently significant concentrations of the element (0.03 ng g−1 wt.w). Urine was the predominant route of excretion. Intracellularly, liver, kidney, spleen, testis, and brain cytosols displayed the highest percentages (35%–58%) of Bi of homogenates. Liver and testis nuclei were the organelles with the highest Bi content (24 % and 27 %). However, when the recovered Bi of the liver was recorded as percent of total recovered Bi divided by percent of total recovered protein the lysosomes showed the highest relative specific activity than in other fractions. In the brain subcellular fractions Bi was incorporated by neuro-structures with the protein and not lipidic fraction of the myelin retaining 18 % of Bi of the total homogenate. After the liver intra-subcellular fractionation: (i) 65 % of the nuclear Bi was associated with the protein fraction of the nuclear membranes and 35 % with the bulk chromatin bound to non-histone and DNA fractions; (ii) about 50 % of the mitochondrial Bi was associated with inner and outer membranes being the other half recovered in the intramitochondrial matrix; (iii) in microsomes Bi showed a high affinity (close to 90 %) for the membranous components (rough and smooth membranes); (iv) In the liver cytosol three pools of Bi-binding proteins (molecular size &gt; 300 kDa, 70 kDa and 10 kDa) were observed with ferritin and metallothionein–like protein identified as Bi-binding biomolecules. Three similar protein pools were also observed in the kidney cytosol. However, the amount of Bi, calculated in percent of the total cytosolic Bi, were significantly different compared to the corresponding pools of the liver cytosol. Conclusions At the best of our knowledge the present paper represents the first in vivo study, on the basis of an environmental toxicology approach, aiming at describing retention and binding of Bi in the rat at tissue, intracellular and molecular levels

    Sublingually administered bacterial lysates: rationale, mechanisms of action and clinical outcomes

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    This review discusses available evidence on the mechanisms of action of bacterial lysates, and the clinical effects of their sublingual administration. Bacterial lysates act through many immunological effects, including dendritic cell activation, modification of circulating lymphocyte subsets and antibody production. The production of salivary IgA was repeatedly shown to be induced by the sublingual administration of a prototype bacterial lysate containing soluble and corpuscular antigens. Bacterial lysates are a useful tool for the prevention of recurrent respiratory tract infections. Sublingual administration should be the preferred option

    Circular economy models in agro-food systems: A review

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    Around the world, interest is growing in the circular economy in response to the current unsustainable model of production and consumption based on increased use and depletion of resources. This paper provides a review of the academic literature on the circular economy in agri-food systems, with the aims of understanding its main characteristics and perspectives, and summarizing and discussing the literature in this field. This review provides a deeper understanding of the opportunities provided by the circular economy as a solution to the current need to reduce the environmental impacts of business-as-usual economic systems and the state of the art of the circular economy in the academic debate. The results are discussed based on the chosen topiccore investigated in this review: business model and organization management, food loss and waste along the supply chain, analytical tools for the circular economy, stakeholder acceptance of the circular economy, and mitigation strategies and political approach. The findings show the need for the implementation of cleaner production models and consequent increases in stakeholder responsibilities and awareness, from both producers and consumers, as well as the need for the implementation of suitable policies and tools
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