638 research outputs found

    Exciton Mott transition revisited

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    The dissociation of excitons into a liquid of holes and electrons in photoexcited semiconductors, despite being one of the first recognized examples of a Mott transition, still defies a complete understanding, especially regarding the nature of the transition, which is found to be continuous in some cases and discontinuous in others. Here we consider an idealized model of photoexcited semiconductors that can be mapped onto a spin-polarized half-filled Hubbard model, whose phase diagram reproduces most of the phenomenology of those systems and uncovers the key role of the exciton binding energy in determining the nature of the exciton Mott transition. We find indeed that the transition changes from discontinuous to continuous as the binding energy increases. Moreover, we uncover a rather anomalous electron-hole liquid phase next to the transition, which still sustains excitonic excitations despite being a degenerate Fermi liquid of heavy mass quasiparticles

    LIFE CYCLE ASSESSMENT OF BOVINE MILK PRODUCTION IN NORTHERN ITALY

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    Agriculture and animal husbandry are important contributors to global emissions of greenhouse and acidifying gases. Moreover, they concur to water pollution and to consumption of non-renewable natural resources, such as land and energy. The Life Cycle Assessment (LCA) methodology allows to evaluate the environmental impact of a process from the production of inputs to the final product and to assess simultaneously several environmental impact categories: among others, GHG emissions, acidification, eutrophication, land use and energy use. The main purpose of this study was to evaluate, with LCA methodology, the environmental impact of milk production in a sample of 41 intensive Italian dairy farms and to identify, among different farming strategies, those associated with the best environmental performances. The functional unit was 1 kg Fat and Protein Corrected Milk (FPCM). Farms showed characteristics of high production intensity: FPCM, expressed as t per hectare, was 30.8\ub115.1. Total GHG emission per kg of FPCM at farm gate was 1.30\ub10.19 kg CO2 eq. The main contributors to climate change potential were: emissions from barns and manure storage (50.1%) and emissions for production and transportation of purchased feeds (21.2%). Average emission of gases causing acidification to produce 1 kg of FPCM was 19.7\ub13.6 g of SO2 eq. Eutrophication was 9.01\ub11.78 PO43-eq. per kg FPCM on average. Farms from this study needed on average 5.97\ub11.32 MJ per kg FPCM from non-renewable energy sources. Energy consumption was mainly due to off-farm activities (58%) associated to purchased factors. Land use was 1.51\ub10.25 m2 per kg FPCM. The farming strategy based on high conversion efficiency at animal level was identified as the most advantageous to mitigate environmental impact per kg milk at farm gate, especially in terms of GHG production and non-renewable energy use per kg of FPCM

    How can farming intensification affect the environmental impact of milk production? 

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    The intensification process of the livestock sector has been characterized in recent decades by increasing output of product per hectare, increasing stocking rate, including more concentrated feed in the diet, and improving the genetic merit of the breeds. In dairy farming, the effects of intensification on the environmental impact of milk production are not completely clarified. The aim of the current study was to assess the environmental impacts of dairy production by a life cycle approach and to identify relations between farming intensity and environmental performances expressed on milk and land units. A group of 28 dairy farms located in northern Italy was involved in the study; data collected during personal interviews of farmers were analyzed to estimate emissions (global warming potential, acidification, and eutrophication potentials) and nonrenewable source consumption (energy and land use). The environmental impacts of milk production obtained from the life cycle assessment were similar to those of other recent studies and showed high variability among the farms. From a cluster analysis, 3 groups of farms were identified, characterized by different levels of production intensity. Clusters of farms showed similar environmental performances on product basis, despite important differences in terms of intensification level, management, and structural characteristics. Our study pointed out that, from a product perspective, the most environmentally friendly way to produce milk is not clearly identifiable. However, the principal component analysis showed that some characteristics related to farming intensification, such as milk production per cow, dairy efficiency, and stocking density, were negatively related to the impacts per kilogram of product, suggesting a role of these factors in the mitigation strategy of environmental burden of milk production on a global scale. Considering the environmental burden on a local perspective, the impacts per hectare were positively associated with the intensification level

    Environmental impact of milk production in intensive farming systems: life cycle assessment approach

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    Life cycle assessment (LCA) has been shown to be a valuable method for the environmental evaluation of farming systems and has been applied to several agricultural products, particularly in Europe. In LCA the potential environmental impacts of a product are assessed by quantifying the resources consumed and the emissions, at all stages of its life cycle, from the extraction of resources, through the production and transport of materials, to the production process at the farm. The aim of the study was to evaluate the environmental impacts of milk production in intensive farming systems using LCA approach on a sample of 44 dairy farms in northern Italy. Impact categories were: Land use, Non-renewable energy use, Climate change, Acidification and Eutrophication. Functional units were: 1 kg of Fat and Protein Corrected Milk (FPCM); 1 ha of farm land. Data were collected by personal interview with the farmers. Farms involved in the study reared on average 145 (\ub191) cows, with a daily milk production of 28.0 (\ub13.32) kg FPCM/cow. Average farm land was 49.9 (\ub137) ha and stocking density 5.3 (\ub12.5) LU/ha. On average, 59% of the total dry matter of cow rations consisted of feed ingredients produced on the farm. The average results for the 5 LCA categories per kg of FPCM were: 2.84 (\ub11.02) m2 for Land use, 4.98 (\ub11.34) MJ for Energy use, 0.93 (\ub10.29) kg CO2-eq for Climate change, 18.2 (\ub14.2) g SO2-eq for Acidification and 12.0 (\ub13.1) g PO4-eq for Eutrophication. Impact indicators from this study are similar to those reported in recent European LC analyses on intensive dairy farms, although the comparison among LCA studies from different countries can be misleading because of local peculiarities and different methodologies. Within the study, LCA indicators allowed to compare environmental impacts of milk production among farms characterized by different levels of intensification (stocking density, milk production, feed self-supply)

    A simple method to assess the oxidative susceptibility of low density lipoproteins

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    BACKGROUND: Oxidative modification of low density lipoproteins (LDL) is recognized as one of the major processes involved in atherogenesis. The in vitro standardized measurement of LDL oxidative susceptibility could thus be of clinical significance. The aim of the present study was to establish a method which would allow the evaluation of oxidative susceptibility of LDL in the general clinical laboratory. RESULTS: LDL was isolated from human plasma by selective precipitation with amphipathic polymers. The ability of LDL to form peroxides was assessed by measuring thiobarbituric acid reactive substances (TBARS) after incubation with Cu(2+) and H(2)O(2). Reaction kinetics showed a three-phase pattern (latency, propagation and decomposition phases) which allowed us to select 150 min as the time point to stop the incubation by cooling and EDTA addition. The mixture Cu(2+)/H(2)O(2) yielded more lipoperoxides than each one on its own at the same time end-point. Induced peroxidation was measured in normal subjects and in type 2 diabetic patients. In the control group, results were 21.7 ± 1.5 nmol MDA/mg LDL protein, while in the diabetic group results were significantly increased (39.0 ± 3.0 nmol MDA/mg LDL protein; p < 0.001). CONCLUSION: a simple and useful method is presented for the routine determination of LDL susceptibility to peroxidation in a clinical laboratory

    Leading transformation in a family-owned business: Insights from an Italian company

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    The increasing volatility of the global economy, coupled with the pace of technological innovation, presents new challenges for family-owned businesses. The complex business dynamics and business inertia of family-owned business require a comprehensive perspective when developing the capability to manage transformations in the face of a business context such as this. This article draws on literature from the field of organisational change and development, organisational behaviour and family business, and proposes an integrative framework. The study is embedded in a collaborative research project with an Italian fashion design company, and portrays a five-year transformation process, starting with the family's decision to hire an external CEO for the first time in its hundred-year history. What has been learned from the case serves as the foundation for a further advancement of the proposed process-model for the management of a transformation in a family-owned business. The implications for research and practice are discussed. Copyrigh

    The Real-World Observational Prospective Study of Health Outcomes with Dulaglutide and Liraglutide in Type 2 Diabetes Patients (TROPHIES): Baseline Patient-Reported Outcomes

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    Introduction: Although patient-reported outcome (PRO) measures provide important information beyond clinical data, studies that assess the PROs of type 2 diabetes mellitus (T2DM) patients initiating injectable glucose-lowering medications in routine clinical practice are limited. We describe the perspectives of patients based on a diversified panel of generic and disease-specific PRO measures at the time of enrollment (baseline) in the TROPHIES study. Methods: TROPHIES is a 24-month prospective observational study performed in France, Germany, and Italy in patients with T2DM who initiated their first injectable glucose-lowering medication with once-weekly dulaglutide or once-daily liraglutide. To better understand the perspectives of these patients regarding their overall health, treatment satisfaction, and quality of life and work, the patients’ responses to the following questionnaires were collected at baseline before they initiated treatment with dulaglutide or liraglutide: EQ-5D-5L (scale: 0–1), EQ-VAS (visual analog scale: 0–100), Impact of Weight on Self-Perceptions Questionnaire (IW-SP; scale: 0–100), Diabetes Treatment Satisfaction Questionnaire Status (DTSQs; scale: 0–36), and Diabetes Productivity Measure (DPM; scale: 0–100). Analyses were descriptive in nature, with higher scores reflecting better outcomes. Results: Data from patients at the time of enrollment were analyzed. At baseline, patients initiating dulaglutide (N = 1130) or liraglutide (N = 1051) rated their quality of life in terms of mean EQ-5D-5L index as 0.84 and 0.83, and in terms of mean EQ-VAS as 67.5 and 67.5, respectively. The mean baseline scores in patients initiating dulaglutide or liraglutide were 59.8 and 61.3 for IW-SP, 24.6 and 25.8 for DTSQs, 78.6 and 79.5 for DPM Life Productivity, and 87.5 and 86.8 for DPM Work Productivity, respectively. Conclusion: The information from this varied panel of PRO instruments collected at baseline complements clinical outcomes data

    The Real-World Observational Prospective Study of Health Outcomes with Dulaglutide and Liraglutide in Type 2 Diabetes Patients (TROPHIES): Design and Baseline Characteristics

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    Introduction: The TROPHIES observational study enrolled patients with type&nbsp;2 diabetes mellitus (T2DM) initiating their first injectable treatment with the glucagon-like peptide&nbsp;1 receptor agonists (GLP-1&nbsp;RAs) dulaglutide or liraglutide. This manuscript focuses on the study design, baseline characteristics of the enrolled population, and factors associated with GLP-1&nbsp;RA choice. Methods: TROPHIES is a prospective, observational, 24-month study conducted in France, Germany, and Italy. Inclusion criteria include adult patients with T2DM, naĂŻve to injectable antihyperglycemic treatments, initiating dulaglutide or liraglutide per routine clinical practice. The primary outcome is the duration of treatment on dulaglutide or liraglutide without a significant treatment change. Results: The analysis included 2181 patients (dulaglutide, 1130; liraglutide, 1051) (cutoff date May&nbsp;15, 2019). The population was 56% male with mean [standard deviation (SD)] patient characteristics at baseline as follows: age, 59.2 (11.0) years; body mass index (BMI), 33.9 (6.6) kg/m2; T2DM duration, 8.5 (6.9) years; and glycated hemoglobin (HbA1c), 8.2 (1.3)%. Between-cohort demographic and clinical characteristics were balanced. The mean (SD) HbA1c and BMI values for French, German, and Italian patients were, respectively, 8.6 (1.4)%, 8.2 (1.4)%, 8.0 (0.8)%; 33.3 (6.1) kg/m2, 36.0 (7.2) kg/m2, and 32.6 (5.9) kg/m2. Conclusion: This study analysis at baseline provides an opportunity to evaluate between-country differences in baseline HbA1c, weight, macrovascular complications, and factors driving GLP-1&nbsp;RA selection for patients with T2DM in daily practice

    The endogenous cannabinoid system in the gut of patients with inflammatory bowel disease

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    Activation of cannabinoid receptors (CBs) by endocannabinoids impacts on a number of gastrointestinal functions. Recent data indicate that CB1 agonists improve 2,4-dinitrobenzene sulfonic acid-induced colitis in mice, thus suggesting a role for the endocannabinoid agonist anandamide (AEA) in protecting the gut against inflammation. We here examined the gut endocannabinoid system in inflammatory bowel disease (IBD) patients, and investigated the ex vivo and in vitro effects of the non-hydrolysable AEA analog methanandamide (MAEA) on the mucosal proinflammatory response. The content of AEA, but not of 2-arachidonoyl-glycerol and N-palmitoylethanolamine, was significantly lower in inflamed than uninflamed IBD mucosa, and this was paralleled by lower activity of the AEA-synthesizing enzyme N-acyl-phosphatidylethanolamine-specific phospholipase D and higher activity of the AEA-degrading enzyme fatty acid amide hydrolase. MAEA significantly downregulated interferon-γ and tumor necrosis factor-α secretion by both organ culture biopsies and lamina propria mononuclear cells. Although these results are promising, further studies are needed to determine the role of cannabinoid pathways in gut inflammation. © 2011 Society for Mucosal Immunology
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