121 research outputs found
Energy systems, socio-spatial relations, and power: the contested adoption of district heating with combined heat and power in Sweden, 1945-2011
District heating (DH) and combined heat and power (CHP) are often considered complementary green technologies (DH-CHP) that can reduce greenhouse gas emissions. They are, however, complex given their operation at the intersection of shifting socio-spatial relations and political power struggles. We investigate the political processes behind the diffusion (and blocked diffusion) of DH and CHP in Sweden from 1945 until 2011, considered through the lens of Jessop, Brenner and Jones’ (2008) Territory, Place, Scale and Networks (TPSN) framework. Foregrounding the socio-spatial constitution of policy decisions, we examine Sweden’s changing patterns of DH and CHP adoption. First, we present the TPSN framework that considers space as simultaneously a structuring principle, enabling and constraining action, as well as a field of operation in which agency is exercised. Second, we examine the socio-spatial structuration of energy systems. Third, we analyse how the changing socio-spatial constitution of each socio-technical system affects key actors’ interests and actions, including the spatial strategies they develop to advance their interests. District heating rapidly diffused across Swedish municipalities in large part because it was considered to be urban infrastructure aligned with the mission of municipalities and was not in direct competition with other actors supplying heat. CHP electricity generation, on the other hand, was initially seen as a benefit to municipal utilities, but was later considered a threat to the interests of large-scale utilities and blocked, only to gain favour again when changing sociospatial conditions made CHP an asset to large-scale utilities. Our analysis suggests that technological diffusion and blockage is far from a straightforward matter. It requires examination of the dynamics of multi-level governance and overlapping socio-technical systems. Socio-technical regimes are in constant evolution and actors struggle to adapt to new circumstances. Socio-technical systems are not merely material systems, but an expression of dynamic power relations and adaptation strategies
ORAL ADMINISTRATION OF RAW WHITE KIDNEY BEANS (PHASEOLUS VULGARIS L. VAR. BELDIA) INDUCES OVERGROWTH OF FECAL COLIFORMS AND LACTOBACILLI IN WISTAR RATS
Objective: The comprehensive dynamics of fecal microbiota in response to the ingestion of toxic bean lectins or phytohemagglutinins has not been well studied. The study aimed at evaluating the gavage effects of a raw Beldia bean variety on food intake, growth performance, gastrointestinal organs, and fecal microflora in Wistar rats.Methods: Twenty young adult male rats were randomly allotted into two groups of 10 rats each: Control rats were gavaged with 300 mg of a rodent pellet flour suspension and experimental rats were orogastrically fed a dose of 300 mg Beldia bean flour suspension (BBFS). Individual food intake, body weight, and fecal score were taken daily. To assess the impact on the gut flora, fecal samples were collected every day for 10 days. All animals were sacrificed on day 10, to obtain blood and internal organs samples.Results: The results revealed that the gavage of a BBFS to rats had no marked influence on average daily of food intake and weight gain. No significant differences were found in the weights of the small intestine, spleen, liver, and thymus of rats given raw Beldia diet. The counts of coliforms and lactobacilli on pooled fecal specimens of BBFS-fed rats were increased significantly compared to controls.Conclusion: In summary, the exposure to raw Beldia beans altered the fecal microbiota, without adverse effects on animals
Effets chroniques de faibles doses de carbonate de lithium chez la souris. Relations entre statut oxydant et modifications fonctionnelles et structurales des reins et du cerveau
A coupled viscoelastic-viscoplastic-damage model for short fibre reinforced composites
A constitutive model of viscous behaviour of short-fibre reinforced composites (SFRC) where complex distributions of fibre orientations are taken into account is proposed in this work. The approach considered for the computation of composite macroscopic behaviour is based on an additive decomposition of the state potential. The SFRC is assimilated to an assembly of several fibre media embedded in a polymeric matrix medium. One of the main assets of this approach is the possibility to model reinforcement with complex distributions of fibre orientations. Moreover, this decomposition allows the implementation of complex behaviour laws coupled with damage models. The polymeric matrix behaviour is typically strain-rate sensitive, i.e. viscoelastic-viscoplastic. This property has to be taken into account when the modelling of the composite behaviour over a large range of strain rate is intended. Therefore, a viscoelastic constitutive model, based on a generalised Maxwell model, and a viscoplastic correction scheme, based on an overstress approach, are implemented for matrix material. The developed constitutive model is then coupled to two damage laws. The first one is introduced in the framework of Continuum Damage Mechanics in order to model the ductile damage behaviour of the matrix material. The second one deals with fibre/matrix interfacial degradation through an interfacial debonding law. In order to identify the parameters involved in the present model, experimental tests are performed (case of polypropylene reinforced with short glass fibres). Micro-computed tomography is used for the characterisation of the fibres distribution of orientation. The efficiency of the proposed model is demonstrated by comparisons between numerical and experimental responses in different loading conditions, including dynamic loadings
Remotely Sensed Agroclimatic Classification and Zoning in Water-Limited Mediterranean Areas towards Sustainable Agriculture
Agroclimatic classification identifies zones for efficient use of natural resources leading to optimal and non-optimal crop production. The aim of this paper is the development of a methodology to determine sustainable agricultural zones in three Mediterranean study areas, namely, “La Mancha Oriental” in Spain, “Sidi Bouzid” in Tunisia, and “Bekaa” valley in Lebanon. To achieve this, time series analysis with advanced geoinformatic techniques is applied. The agroclimatic classification methodology is based on three-stages: first, the microclimate features of the region are considered using aridity and vegetation health indices leading to water-limited growth environment (WLGE) zones based on water availability; second, landform features and soil types are associated with WLGE zones to identify non-crop-specific agroclimatic zones (NCSAZ); finally, specific restricted crop parameters are combined with NCSAZ to create the suitability zones. The results are promising as compared with the current crop production systems of the three areas under investigation. Due to climate change, the results indicate that these arid or semi-arid regions are also faced with insufficient amounts of precipitation for supporting rainfed annual crops. Finally, the proposed methodology reveals that the employment and use of remote sensing data and methods could be a significant tool for quickly creating detailed, and up to date agroclimatic zones
No Benefit from Chronic Lithium Dosing in a Sibling-Matched, Gender Balanced, Investigator-Blinded Trial Using a Standard Mouse Model of Familial ALS
Background: In any animal model of human disease a positive control therapy that demonstrates efficacy in both the animal model and the human disease can validate the application of that animal model to the discovery of new therapeutics. Such a therapy has recently been reported by Fornai et al. using chronic lithium carbonate treatment and showing therapeutic efficacy in both the high-copy SOD1G93A mouse model of familial amyotrophic lateral sclerosis (ALS), and in human ALS patients. Methodology/Principal Findings: Seeking to verify this positive control therapy, we tested chronic lithium dosing in a sibling-matched, gender balanced, investigator-blinded trial using the high-copy (average 23 copies) SOD1G93A mouse (n = 27–28/group). Lithium-treated mice received single daily 36.9 mg/kg i.p. injections from 50 days of age through death. This dose delivered 1 mEq/kg (6.94 mg/kg/day lithium ions). Neurological disease severity score and body weight were determined daily during the dosing period. Age at onset of definitive disease and survival duration were recorded. Summary measures from individual body weight changes and neurological score progression, age at disease onset, and age at death were compared using Kaplan-Meier and Cox proportional hazards analysis. Our study did not show lithium efficacy by any measure. Conclusions/Significance: Rigorous survival study design that includes sibling matching, gender balancing, investigato
Optical Drug Monitoring: Photoacoustic Imaging of Nanosensors to Monitor Therapeutic Lithium in Vivo
Personalized medicine could revolutionize how primary care physicians treat chronic disease and how researchers study fundamental biological questions. To realize this goal, we need to develop more robust, modular tools and imaging approaches for in vivo monitoring of analytes. In this report, we demonstrate that synthetic nanosensors can measure physiologic parameters with photoacoustic contrast, and we apply that platform to continuously track lithium levels in vivo. Photoacoustic imaging achieves imaging depths that are unattainable with fluorescence or multiphoton microscopy. We validated the photoacoustic results that illustrate the superior imaging depth and quality of photoacoustic imaging with optical measurements. This powerful combination of techniques will unlock the ability to measure analyte changes in deep tissue and will open up photoacoustic imaging as a diagnostic tool for continuous physiological tracking of a wide range of analytes
Rheological, physicochemical, and microstructural properties of asphalt binder modified by fumed silica nanoparticles
Warm mix asphalt (WMA) is gaining increased attention in the asphalt paving industry as an eco-friendly and sustainable technology. WMA technologies are favorable in producing asphalt mixtures at temperatures 20–60 °C lower in comparison to conventional hot mix asphalt. This saves non-renewable fossil fuels, reduces energy consumption, and minimizes vapors and greenhouse gas emissions in the production, placement and conservation processes of asphalt mixtures. At the same time, this temperature reduction must not reduce the performance of asphalt pavements in-field. Low aging resistance, high moisture susceptibility, and low durability are generally seen as substantial drawbacks of WMA, which can lead to inferior pavement performance, and increased maintenance costs. This is partly due to the fact that low production temperature may increase the amount of water molecules trapped in the asphalt mixture. As a potential remedy, here we use fumed silica nanoparticles (FSN) have shown excellent potential in enhancing moisture and aging susceptibility of asphalt binders. In this study, asphalt binder modification by means of FSN was investigated, considering the effects of short-term and long-term aging on the rheological, thermal, and microstructural binder properties. This research paves the way for optimizing WMA by nanoparticles to present enhanced green asphalt technology
Could Selenium Administration Alleviate the Disturbances of Blood Parameters Caused by Lithium Administration in Rats?
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