Search results for "Tier"
showing 10 items of 968 documents
Etude de quelques liants de maçonnerie et briques du site archéologique de la rue des Veaux (Strasbourg – Bas-Rhin)
2010
Parent–offspring conflict and the genetic trade-offs shaping parental investment
2015
The genetic conflict between parents and their offspring is a cornerstone of kin selection theory and the gene-centred view of evolution, but whether it actually occurs in natural systems remains an open question. Conflict operates only if parenting is driven by genetic trade-offs between offspring performance and the parent's ability to raise additional offspring, and its expression critically depends on the shape of these trade-offs. Here we investigate the occurrence and nature of genetic conflict in an insect with maternal care, the earwig Forficula auricularia. Specifically, we test for a direct response to experimental selection on female future reproduction and correlated responses i…
Il litorale di Manfria (Gela) -
2010
Questo studio illustra il notevole patrimonio ambientale del Sito d'Interesse Comunitario "Torre Manfria", area tutelata ai sensi della Direttiva 92/43 CEE. Poiché l'area si trova nel comune di Gela, caratterizzato da una densità abitativa tra le più alte della Sicilia, l'occasione è buona anche per riflettere sui temi centrali del rapporto uomo-ambiente, prendendo spunto dagli innumerevoli esempi offerti dalla realtà locale. Ciò è stato fatto con la speranza di suscitare interesse verso un vivere "altro", che riconosca il valore della cultura, della conoscenza, dell'interazione virtuosa, facendosi ispirare dalla bellezza sobria ed essenziale degli ecosistemi.
Assessing the marginal cost of reducing greenhouse gas emissions in the English and Welsh water and sewerage industry: A parametric approach
2021
Abstract Reducing greenhouse gas (GHG) emissions involves effort from different sectors of the economy, including the water and sewerage industry. This study estimates the marginal cost of curtailing GHG emissions in the water and sewerage industry using stochastic frontier analysis techniques for a sample of ten English and Welsh water and sewerage companies over the 2010–2019 period. Results illustrated that the average marginal cost of reducing GHG emissions was 0.181 £/Kg CO2 equivalent. The marginal cost estimated notably differs across companies and over time. Findings further illustrate the impact of water companies' operating characteristics on the marginal cost of reducing carbon e…
Politics, Economics and Tourism Development in Egypt: insights into the sectoral transformations of a neo-patrimonial rentier state
2008
This article challenges claims that liberalising state-regulated markets in developing countries may induce lasting economic development. An analysis of the rise of tourism in Egypt during the past three decades suggests that the effects of liberalisation and structural adjustment are constrained by the neo-patrimonial character of the Egyptian political system. Since the decline of oil-rent revenues during the 1980s tourism development has been the optimal strategy to compensate for the resulting fiscal losses. Increasing tourism revenues have helped in coping with macroeconomic imbalances and in avoiding more costly adjustment of traditional economic sectors. Additionally they provided th…
Minimising value-at-risk in a portfolio optimisation problem using a multi-objective genetic algorithm
2011
[EN] In this paper, we develop a general framework for market risk optimisation that focuses on VaR. The reason for this choice is the complexity and problems associated with risk return optimisation (non-convex and non-differential objective function). Our purpose is to obtain VaR efficient frontiers using a multi-objective genetic algorithm (GA) and to show the potential utility of the algorithm to obtain efficient portfolios when the risk measure does not allow calculating an optimal solution. Furthermore, we measure differences between VaR efficient frontiers and variance efficient frontiers in VaR-return space and we evaluate out-sample capacity of portfolios on both bullish and bearis…
Scatter tabu search for multiobjective clustering problems
2011
We propose a hybrid heuristic procedure based on scatter search and tabu search for the problem of clustering objects to optimize multiple criteria. Our goal is to search for good approximations of the efficient frontier for this class of problems and provide a means for improving decision making in multiple application areas. Our procedure can be viewed as an extension of SSPMO (a scatter search application to nonlinear multiobjective optimization) to which we add new elements and strategies specially suited for combinatorial optimization problems. Clustering problems have been the subject of numerous studies; however, most of the work has focused on single-objective problems. Clustering u…
The research frontier on internationalization of social enterprises
2020
Abstract Social enterprises (SEs) are hybrid organizations that simultaneously pursue financial and social goals, while addressing institutional voids. Despite the extensive cross-border activities of SEs, the state of research addressing such flows of funds, technology and personnel is undeveloped. In this introductory article, we discuss the unique aspects of SEs and explore how the international business literature can inform our understanding of their internationalization. We outline promising areas for future research related to the drivers of and the processes underlying SE internationalization as well as its consequences. With this as a background, we introduce the five articles in t…
"VIVI" Opere di Massimo Palumbo
2013
In occasione della Mostra, a cura di Cristina Costanzo, “VIVI” Opere di Massimo Palumbo - promossa dalla Presidenza del Consiglio Comunale di Palermo e dall'Assessorato alla Cultura di Palermo e ospitata presso i Cantieri Culturali alla Zisa di Palermo - viene presentato l’omonimo catalogo, pubblicato da Palladino Editore. Il catalogo “VIVI” Opere di Massimo Palumbo si offre come guida all’esposizione e utile strumento scientifico per la lettura del lavoro dell’artista. Il catalogo, a cura di Cristina Costanzo, si avvale dei contributi critici di Marcella Cossu, Cristina Costanzo e Massimo Palumbo. Massimo Palumbo presenta nella sede dei Cantieri Culturali alla Zisa, oggi al centro di un am…
Design of cost-efficient and photocatalytically active Zn-based MOFs decorated with Cu 2 O nanoparticles for CO 2 methanation
2019
<div>Here we show for the first time a MOF that is photocatalytically</div><div>active for the light-assisted CO<sub>2</sub> methanation at mild conditions</div><div>(215 °C) without the inclusion of metallic nanoparticles or any</div><div>sacrificial agent. The presence of Cu<sub>2</sub>O nanoparticles causes a 50 % increase in the photocatalytic activity. These results pave the way to developping efficient and cost-effective materials for CO<sub>2</sub> elimination.</div>