Firm Size Distribution: Testing the "Independent Submarkets Model" in the Italian Motor Insurance Industry

This paper tests the presence of multiple independent submarkets in the Italian motor insurance industry. Independence is motivated by administrative boundaries among provinces and by further locational reasons. We find that the independence effects are sufficient to induce a minimum degree of inequality in the size distribution of firms once submarkets are aggregated. These results are fully consistent with the predictions of Sutton (1998). We also show that the degree of skewness in the firms size distribution is related to characteristics such as the population living in an area, its density and the riskiness of a submarket.Size distribution of firms, independent submarkets, insurance companies

A Novel Approach for the Assessment of the Nocturnal Image of the Cultural Landscape

Policies aimed at urban and territorial development stressed the importance of landscape as a significant resource for sustainable and economic development. In this perspective, research on landscape visual values and people preferences can support the enhancement of the global values of territories. Currently, the theoretical framework and approaches are mainly limited to the day images of sites, while nighttime landscape is not usually considered. In this study, we defined a methodological approach to address the analysis of the nocturnal image of cultural landscape contexts, in order to define indications and support the inclusion of visual values in the process of public lighting design. The approach was conceived for territorial contexts characterized by the presence of small urban settlements located in prominent positions and involved a subjective survey, an in-field measurement campaign, and statistical analysis to identify significant correlations between subjective judgments and quantitative parameters. The effectiveness of the approach was assessed through the application to a case study. The study allowed identifying subjective factors (overall impact, architecture and historicity, correspondence, alteration) and objective parameters (ratios of regions’ area, luminance values, and luminance contrasts) which describe the nightscape of cultural landscape. Results demonstrated the presence of significant correlation between subjective factors and objective parameters. The application of the method could provide designers and planners indications useful for the design of outdoor lighting system, in order to include perceptual aspects in a holistic design approach, which promotes environmental, energy, economic, and cultural sustainability

[FeFe]-hydrogenases as biocatalysts in bio-hydrogen production

© 2016, Accademia Nazionale dei Lincei. [FeFe]-hydrogenases catalyse H2 production at exceptionally high turnover numbers (up to 104s−1). They are found in a variety of strict or facultative anaerobic microorganisms, such as bacteria of the genus Clostridium, Desulfovibrio, Thermotoga, and eukaryotes ranging from unicellular and coenobial green algae to anaerobic fungi, ciliates and trichomonads. Key to their activity is an organometallic centre, the H-cluster that cooperates tightly with the protein framework to reduce two protons into molecular hydrogen. The assembly of the catalytic site requires a specialised cellular mechanism based on the action of three other enzymes, called maturases: HydE, HydF and HydG. Recent advancements in the recombinant production of [FeFe]-hydrogenases have provided leaps forward in their exploitation in H2 production for clean energy storage. [FeFe]-hydrogenases have been used in several fermentative approaches where microorganisms are engineered to overexpress specific [FeFe]-hydrogenases to convert low-cost materials (e.g. wastes) into H2. [FeFe]-hydrogenases have also been proven to be excellent catalysts in different in vitro devices that can produce hydrogen directly from water, either via water electrolysis or via light-driven mechanisms, thus allowing the direct storage of solar energy into H2

Cultural landscape: Towards the design of a nocturnal lightscape

The current debate on the cultural landscape is focused on an inclusive definition. It proposes active enhancement practices and local planning tools that are also dedicated to the study of scenic-perceptive components and visual values. However, the current indications are limited to the definition of day images of sites, and are not based on investigations of the corresponding nocturnal images. The legislation and the recommendations in force in the field of lighting supply performance requirements, related to street and urban lighting, do not provide any indications regarding territorial contexts or widespread heritage sites. This paper presents a critical analysis of the lighting condition of different territorial contexts, places of widespread heritage, in particular with reference to the Italian context. The present situation has been investigated through a qualitative analysis, based on a comparison between day and night images, and a quantitative analysis, developed through a measurement campaign on representative case studies of the recurrent territorial context. In most cases, an absence of a specific lighting design strategy, aimed at defining a suitable nocturnal perception of the cultural landscape, has emerged from the collected data. The aim of the work has been to underline the importance of the study of nocturnal images and to show the possibility of developing an analysis and design methodology for these contexts. This approach should be based on a systemic vision, which should allow not only single monuments to be valorised, but also the places and landscapes that characterise a territory from a morphological and cultural point of view

Meiotic behavior of two polyploid species of genus Pleurodema (Anura: Leiuperidae) from central Argentina

Polyploidy is an important evolutionary force but rare in vertebrates. However, in anurans, the genus Pleurodema has polyploid species, two of them tetraploid and one octoploid. The manner in which the chromosomes join in diakinesis can vary among species and, crucially, if they differ in their ploidy levels. In this work, we describe the meiotic configurations in two cryptic species from central Argentina, with different ploidy levels, Pleurodema kriegi (tetraploid) and P. cordobae (octoploid). A total of 306 diakineses from 19 individuals were analyzed. In meiosis, P. kriegi form 22 bivalents, whereas P. cordobae exhibits variation in meiotic figures. We discuss the possible allo- and autopolyploid origin of these species, and we consider that the autopolyploid origin of P. cordobae from P. kriegi might be the most feasible.Fil: Salas, Nancy Edith. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Valetti, Julian Alonso. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grenat, Pablo Raúl. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otero, Manuel Alejandro. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martino, Adolfo Ludovico. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Renovation of Public Lighting Systems in Cultural Landscapes: Lighting and Energy Performance and Their Impact on Nightscapes

The technological innovation in the field of lighting and the need to reduce energy consumption connected to public lighting are leading many municipalities to undertake the renewal of public lighting systems, by replacing the existing luminaires with LED technologies. This renovation process is usually aimed at increasing energy efficiency and reducing maintenance costs, whist improving the lighting performance. To achieve these results, the new luminaires are often characterised by a luminous flux distribution much more downward oriented, which may remarkably influence and alter the perception of the night image of the sites. In this study the implications of the renovation of public lighting systems in terms of lighting and energy performance as well as the effects relating to the alteration of the night image, in historical contexts characterized by significant landscape value, are analysed. Results, along with demonstrating the positive effect that more sustainable and energy efficient lighting systems may have on the lighting performance and energy consumptions of public lighting systems, evidences the impact they may have on the alteration of the nocturnal image

Characterization of chymotrypsin-ι-carrageenan complex in aqueous solution: A solubility and thermodynamical stability study

The aim of this study is to report the results of research work on the molecular mechanism of complex formation between chymotrypsin and a negatively charged natural strong polyelectrolyte, ι-carrageenan, using spectroscopy techniques. The carrageenan-chymotrypsin complex showed a maximal non-solubility at pH around 4.50 with a stoichiometric ratio between 8 and 33. g of chymotrypsin per g of carrageenan. These values were depended on the enzyme concentration, pH and ionic strength medium. The insoluble complex was redissolved by modifying the pH and by a NaCl concentration around 0.2. M in agreement with a coulombic mechanism of complex formation. The non-soluble complex formation showed biphasic kinetics. A fast step was carried out around 10. s and a coulombic mechanism takes place, and a slower step of around 120. s, where participate only Van der Waals forces. The enzymatic activity of chymotrypsin was maintained even in the presence of carrageenan (0.005%, w/v).Fil: Woitovich Valetti, Nadia. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Boeris, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario; ArgentinaFil: Picó, Guillermo Alfredo. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin