83 research outputs found
Visualising accessibility: an interactive tool and two applications to empirical case studies of urban development and public engagement
While a substantial body of literature exists on the theoretical definitions and measures of accessibility, the extent to which such measures are applied into practice to assess project alternatives is less frequent (Geurs and Van Wee, 2004). Recent studies affirm that one of the main barriers to the usability of accessibility measure is the lack of visualisation quality and mapping tool for accessibility representation (te Brömmelstroet et al, 2014), while visualisation tools are commonly recognised as the most effective methodology to facilitate knowledge sharing, particularly in those processes involving public stakeholders and non-experts with different expertise. Starting form this consideration, this paper presents an application of the Interactive Visualisation Tool, named InViTo (Pensa and Masala, 2014a; 2014b; Pensa, et al., 2014; Pensa, Masala and Lami, 2013; Pensa, Masala and Marina, 2013) able to generate maps of the level of perceived accessibility (i.e. “desirability”) of different urban areas. Desirability is here computed as the perceived level of access to different urban items as transport supply (metro and rail stations, public transport stops, parking) and urban activities such as hospitals, schools, museums. In this respect, the concept of desirability encompasses a measure of accessibility to several urban facilities, and the perception that residents of the study area have of such facilities. The InViTo tool allows to build up maps of desirability interactively, by making selection of the chosen items and by giving differential weights to each items. This makes the tools powerful and very useful particularly when discussing and showing analysis results to stakeholders, who could have the opportunity to see in real time the results of different scenario alternatives and assumptions.
In the paper two applications are presented. The first one to the empirical case study of Rome, presents the steps to undertake in order to apply the tool: from data gathering, maps coding, and results representation. The second application aims at exploring the potential usability of the tool in engaging public stakeholders into the assessment of different urban development options. Furthermore, the results of a workshop held in Turin, in which public and private stakeholders were interactively involved, are discussed.
The paper is organised as follows. In section 2, an overview of the InViTo tool is given with a focus on its applicability formeasuring accessibility. In section 3 the results of the two InViTo applications are discussed. Conclusions are drawn in section 4, with an outlook to undergoing research issues
Cross-linked cyclodextrins bimetallic nanocatalysts: Applications in microwave-assisted reductive aminations
The optimization of sustainable protocols for reductive amination has been a lingering challenge in green synthesis. In this context, a comparative study of different metal-loaded cross-linked cyclodextrins (CDs) were examined for the microwave (MW)-assisted reductive amination of aldehydes and ketones using either H2 or formic acid as a hydrogen source. The Pd/Cu heterogeneous nanocatalyst based on Pd (II) and Cu (I) salts embedded in a β-CD network was the most efficient in terms of yield and selectivity attained. In addition, the polymeric cross-linking avoided metal leaching, thus enhancing the process sustainability; good yields were realized using benzylamine under H2. These interesting findings were then applied to the MW-assisted one-pot synthesis of secondary amines via a tandem reductive amination of benzaldehyde with nitroaromatics under H2 pressure. The formation of a CuxPdy alloy under reaction conditions was discerned, and a synergic effect due to the cooperation between Cu and Pd has been hypothesized. During the reaction, the system worked as a bifunctional nanocatalyst wherein the Pd sites facilitate the reduction of nitro compounds, while the Cu species promote the subsequent imine hydrogenation affording structurally diverse secondary amines with high yields
Methodological advancements in organ-specific ectopic lipid quantitative characterization: Effects of high fat diet on muscle and liver intracellular lipids.
Ectopic lipid accumulation is a hallmark of metabolic diseases, linking obesity to non-alcoholic fatty liver disease, insulin resistance and diabetes. The use of zebrafish as a model of obesity and diabetes is raising due to the conserved properties of fat metabolism between humans and zebrafish, the homologous genes regulating lipid uptake and transport, the implementation of the '3R's principle and their cost-effectiveness. To date, a method allowing the conservation of lipid droplets (LDs) and organs in zebrafish larvae to image ectopic lipids is not available. Our objectives were to develop a novel methodology to quantitatively evaluate organ-specific LDs, in skeletal muscle and liver, in response to a nutritional perturbation.
We developed a novel embedding and cryosectioning protocol allowing the conservation of LDs and organs in zebrafish larvae. To establish the quantitative measures, we used a three-arm parallel nutritional intervention design. Zebrafish larvae were fed a control diet containing 14% of nutritional fat or two high fat diets (HFDs) containing 25 and 36% of dietary fats. In muscle and liver, LDs were characterized using immunofluorescence confocal microscopy. In liver, intrahepatocellular lipids were discriminated from intrasinusoid lipids. To complete liver characteristics, fibrosis was identified with Masson's Trichrome staining. Finally, to confirm the conservation and effect of HFD, molecular players of fat metabolism were evaluated by RT-qPCR.
The cryosections obtained after setting up the embedding and cryopreservation method were of high quality, preserving tissue morphology and allowing the visualization of ectopic lipids. Both HFDs were obesogenic, without modifying larvae survival or development. Neutral lipid content increased with time and augmented dietary fat. Intramuscular LD volume density increased and was explained by an increase in LDs size but not in numbers. Intrahepatocellular LD volume density increased and was explained by an increased number of LDs, not by their increased size. Sinusoid area and lipid content were both increased. Hepatic fibrosis appeared with both HFDs. We observed alterations in the expression of genes associated with LD coating proteins, LD dynamics, lipogenesis, lipolysis and fatty acid oxidation.
In this study, we propose a reproducible and fast method to image zebrafish larvae without losing LD quality and organ morphology. We demonstrate the impact of HFD on LD characteristics in liver and skeletal muscle accompanied by alterations of key players of fat metabolism. Our observations confirm the evolutionarily conserved mechanisms in lipid metabolism and reveal organ specific adaptations. The methodological advancements proposed in this work open the doors to study organelle adaptations in obesity and diabetes related research such as lipotoxicity, organelle contacts and specific lipid depositions
Microwave-Assisted Protocol for Green Functionalization of Thiophenes With a Pd/β-Cyclodextrin Cross-Linked Nanocatalyst
Microwaves (MW) are often the most efficient, in terms of heat exchange and conversion rate, of all the energy sources used to promote chemical reactions thanks to fast volumetric dielectric heating, and metal-catalyzed synthetic reactions under heterogeneous conditions are an eloquent example. We herein report a MW-assisted green protocol for the C-H arylation of thiophenes with substituted aryl halides. This sustainable protocol carried out in γ-valerolactone (GVL) is catalyzed by Pd nanoparticles embedded in cross-linked β-cyclodextrin. In view of the excellent results achieved with activated substrates, the one-pot synthesis of a 4(3H)-quinazolinone derivative has been accomplished. A pressure-resistant MW reactor, equipped with multiple gas inlets, was used for sequential (i) C-H arylation, (ii) reduction, and (iii) carbonylation in the presence of the same catalyst, but under different gas atmospheres. The robust heterogeneous Pd catalyst showed limited metal leaching in GVL, making this an efficient MW-assisted process with high atom economy
Cross-Linked Cyclodextrins Bimetallic Nanocatalysts: Applications in Microwave-Assisted Reductive Aminations
The optimization of sustainable protocols for reductive amination has been a lingering challenge in green synthesis. In this context, a comparative study of different metal-loaded cross-linked cyclodextrins (CDs) were examined for the microwave (MW)-assisted reductive amination of aldehydes and ketones using either H2 or formic acid as a hydrogen source. The Pd/Cu heterogeneous nanocatalyst based on Pd (II) and Cu (I) salts embedded in a β-CD network was the most efficient in terms of yield and selectivity attained. In addition, the polymeric cross-linking avoided metal leaching, thus enhancing the process sustainability; good yields were realized using benzylamine under H2. These interesting findings were then applied to the MW-assisted one-pot synthesis of secondary amines via a tandem reductive amination of benzaldehyde with nitroaromatics under H2 pressure. The formation of a CuxPdy alloy under reaction conditions was discerned, and a synergic effect due to the cooperation between Cu and Pd has been hypothesized. During the reaction, the system worked as a bifunctional nanocatalyst wherein the Pd sites facilitate the reduction of nitro compounds, while the Cu species promote the subsequent imine hydrogenation affording structurally diverse secondary amines with high yields
Sustainable isosorbide production by a neat one-pot MW-assisted catalytic glucose conversion
In the context of exploitation of new biomass-derived platform chemicals, isosorbide (1,4:3,6-dianhydro-D-sorbitol), obtained by the two-fold dehydration of sorbitol, is gaining increasing interest in several potential industrial applications. Seeking for more sustainable, efficient, and economically competitive green processes, the use of heterogeneous catalysts under microwave (MW) irradiation has been adopted for the development of a neat one-pot process from glucose. MW-assisted catalytic processes have shown the potential to reduce the reaction time and improve the selectivity, due to the interaction of MW with the reaction medium through the production of hot spots on the catalyst surface. Ru/C, Ru/Al2O3 and Ru/TiO2 were tested for glucose hydrogenation to sorbitol, while the dehydration step was favored by the addition of beta Zeolites (360:1 SiO2:Al2O3) allowing high isosorbide selectivity (>85 %). An extended structural and morphological characterization before and after the catalytic tests allowed to establish structure-activity relationships. Yields up to 47.1 % have been obtained directly from glucose in 1.5 h, achieving a considerable reduction of reaction time without the use of a solvent. thus paving the way for further investigations on biomass conversion into value-added products. With this aim, direct isosorbide production from milled cellulose was investigated. While the isosorbide yields still need to be improved, the dual role of formic acid both as acid catalyst for cellulose hydrolysis and H-donor for the reduction step was promisingly clarified
From seaweeds to cosmeceutics: A multidisciplinar approach
Macroalgae are widespread on the coasts of all the globe and lead to a negative ecological impact, requiring expensive remediations. Therefore, the valorization of invasive seaweed as a renewable source of bioactive products could represent a valid solution. In this context, three algal biomasses, belonging to brown, green, and red families (Sargassum muticum, Ulva lactuca, Solieria filiformis), collected in the venetian Laguna, were investigated as a source of active compounds for the formulation of cosmeceutics. Microwave (MW) and ultrasound (US) were applied to enhance the algae extraction by means of a hydroalcoholic solution. According to total phenolic content (TPC) evaluation, MW demonstrated the best performing outcomes, resulting in 19.77, 22.02, and 16.94 mgGAE/gExtr (30 min at 90◦C) for brown, green, and red algae, respectively. Antioxidant activity was tested as well, showing comparable trends (49.19, 26.24, and 3.02 mmolTrolox eq./gExtr for brown, green, and red algae, respectively). Due to natural algae predisposition to absorb contaminants, the metal content analysis helped to screen the applicability of these extracts, identifying Ulva lactuca as the most suitable source of antioxidants for cosmetic formulations. This MW extract was then adopted to formulate two different preparations, namely a gel and an emulsion. Thermal and mechanical tests confirmed the stability of each formulation, together with neutral organoleptic characteristics. Finally, the actives release was investigated by means of a tape stripping essay, showing an efficient controlled release for gel formulation, even after 7 h of test. The produced cosmeceutics merged non-conventional extraction technologies with formulation expertise, offering a valuable alternative to solve the macroalgae disposal issue
Where Are the Returns to Lifelong Learning?
We investigate the labour market determinants and outcomes of adult participation in formal education (lifelong learning) in Australia, a country with high levels of adult education. Employing longitudinal data and fixed effects methods allows identification of effects on outcomes free of ability bias. Different trends in outcomes across groups are also allowed for. The impacts of adult education differ by gender and level of study, with small or zero labour market returns in many cases. Wage rates only increase for males undertaking university studies. For men, vocational education and training (VET) lead to higher job satisfaction and fewer weekly hours. For women, VET is linked to higher levels of satisfaction with employment opportunities and higher employment probabilities
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