1,746 research outputs found
Phenomenological tests of the Two-Higgs-Doublet Model with MFV and flavour-blind phases
In the context of a Two-Higgs-Doublet Model in which Minimal Flavour
Violation (MFV) is imposed, one can allow the presence of flavour-blind
CP-violating phases without obtaining electric dipole moments that overcome the
experimental bounds. This choice permits to accommodate the hinted large phase
in the mixing and, at the same time, to soften the observed anomaly in
the relation between and .Comment: 8 pages, 2 figures, Proceedings of "DISCRETE 2010" - December 6-11,
2010 - Rome (Italy
High-Throughput Design of Refractory High-Entropy Alloys: Critical Assessment of Empirical Criteria and Proposal of Novel Guidelines for Prediction of Solid Solution Stability
Refractory high-entropy alloys (RHEAs) are a new class of metallic alloys which have been extensively studied in the past decade due to their excellent high-temperature performances. However, the design of new lightweight and ductile RHEAs is a challenging task, since an extensive exploration of the immense compositional space of multicomponent systems is practically impossible. Aiming to reduce the experimental effort, several research groups have proposed different predictive criteria to design new high-performing HEAs. Nevertheless, the criteria proposed so far are often based on a limited amount of data and, generally, do not differentiate between refractory and nonrefractory HEAs. To overcome these limitations, herein, a comprehensive database of properties of 265 RHEAs reported in the open literature from 2010 to 2022 is developed. Such a database is used to assess the validity of predictive empirical criteria and new guidelines for the prediction of solid solution stability in RHEAs are proposed
Digital business models in cultural tourism
Purpose Digitalization had a relevant impact on the cultural tourism sector, both demand and supply. If, on the one hand, advances in digital technologies provided tourists with new mobile services able to amplify the cultural experience, on the other hand, they catalyzed the development of new business models by digital enterprises. This paper has a twofold purpose: to detect business models and key characteristics of mobile apps for cultural tourism and to analyze the offering of app-based services in this sector. Design/methodology/approach The authors defined a methodology to identify, characterize and analyze a particular category of digital products for cultural tourism: app-based services. They are studied in terms of value creation, proposition and capture with the aim to identify the distinctive features of business models. As a result, the authors identified a classification framework on three main dimensions, namely "how to exploit mobile app features to create value for cultural tourists" (value creation), "which valuable services are delivered to cultural tourists" (value proposition) and "how companies are rewarded for the value they offered" (value capture). The authors apply the framework to perform a situation analysis of app-based services in the cultural tourism market. Findings The analysis highlights that digital enterprises offering app-based services do not fully exploit advances in technologies about users' value requirements. Hence, the results of our work suggest some directions that digital enterprises may follow to better exploit mobile app technology. Originality/value To date, little research has been devoted to investigating cultural tourism business models involving the exploitation of mobile app-based services. This research provides a useful framework to analyze fundamental aspects of business models in this sector. Such a framework represents a practical tool that provides fruitful insights for the design of a new generation of app-based services within the so-called "Internet of things" domain
Mixed Land Use as an Intrinsic Feature of Sprawl: A Short-Term Analysis of Settlement Growth and Population Distribution Using European Urban Atlas
This study investigates the land-use/population mix over time as the base to derive an indicator of urban sprawl. Land-use individual patches (provided by Urban Atlas, hereafter UA, with a detailed spatial geometry at 1:10,000 scale) were associated with the total (resident) population based on official statistics (census enumeration districts and other public data sources), providing a comprehensive mapping of the spatial distribution of population density by land-use class in a representative case study for the Mediterranean region (metropolitan Athens, Greece). Data analysis adopted a mix of statistical techniques, such as descriptive statistics, non-parametric curve interpolation (smoothing splines), and exploratory multivariate statistics, namely hierarchical clustering, non-metric multi-dimensional scaling and confirmative factor analysis. The results of this study indicate a non-linear gradient of density decline from downtown (dominated by compact settlements) to peripheral locations (dominated by natural land). Population density in agricultural land was locally high and increasing over time; this result suggests how mixed land use may be the base of intense sprawl in large metropolitan regions. The methodology implemented in this study can be generalized over the whole sample of European cities included in Urban Atlas, providing a semi-automatic assessment of exurban development and population re-distribution over larger metropolitan regions
Katian GSSP and Carbonates of the Simpson and Arbuckle Groups in Oklahoma
This guidebook was written for the 2015 International Symposium on the Ordovician System (ISOS) as a synopsis of the recent work (e.g., Goldman et al. 2007; Carlucci et al. 2014, forthcoming work for the ISOS meeting) on Ordovician-Silurian rocks of south-central and south-eastern Oklahoma. This new research and past studies (e.g., Harris 1957; Longman 1976; Longman 1982a, b; Fay et al. 1982a; Fay et al. 1982b) underscore the scientific importance of this region. The global stratotype section and point for the Katian Stage of the Upper Ordovician Series is examined on this trip. The first appearances of important graptolites, conodonts and chitinozoans in that section are crucial for worldwide chronostratigraphic correlation.
Vertical and lateral facies changes of the Simpson Group demonstrate the variety and intricacy of sedimentary cycles and the importance of updating depositional models with sequence stratigraphic data. Carbonate facies of the Arbuckle Group are of general interest to all geologists, as they demonstrate a wide variety of sedimentary structures and fabrics that were deposited in tropical epeiric seas. Arbuckle Group carbonates show a variety of peloidal, oolitic, fossiliferous, stromatolitic, and brecciated facies that provide important insights into the depositional history of the “Great American Carbonate Bank” (Taylor et al. 2012).
Simply put, these deposits are an exceptional natural laboratory for the sedimentary geologist. Siliciclastic deposits are also common in the Simpson and Arbuckle Groups, with shoreface sands and siltstones forming “bookends” to formation boundaries. The scientific importance of the Arbuckle region also extends into the realm of structural geology, where geologic cross sections (Fig. 1) of the Ardmore Basin, Arbuckle Anticline, and Washita Valley demonstrate overturned strata, extensive reverse faulting, and a series of major synclines and anticlines at a variety of scales. Pennsylvanian age tectonic features are just another example of why the Arbuckle Mountains is an excellent natural laboratory for field geologists
Managing multiple pressures for cetaceans’ conservation with an Ecosystem-Based Marine Spatial Planning approach
Despite the recognized important ecological role that cetaceans play in the marine environment, their protection is still scarcely enforced in the Mediterranean Sea even though this area is strongly threatened by local human pressures and climate change. The piecemeal of knowledge related to cetaceans' ecology and distribution in the basin undermines the capacity of addressing cetaceans' protection and identifying effective conservation strategies. In this study, an Ecosystem-Based Marine Spatial Planning (EB-MSP) approach is applied to assess human pressures on cetaceans and guide the designation of a conservation area in the Gulf of Taranto, Northern Ionian Sea (Central-eastern Mediterranean Sea). The Gulf of Taranto hosts different cetacean species that accomplish important phases of their life in the area. Despite this fact, the gulf does not fall within any area-based management tools (ABMTs) for cetacean conservation. We pin down the Gulf of Taranto being eligible for the designation of diverse ABMTs for conservation, both legally and non-legally binding. Through a risk-based approach, this study explores the cause-effect relationships that link any human activities and pressures exerted in the study area to potential effects on cetaceans, by identifying major drivers of potential impacts. These were found to be underwater noise, marine litter, ship collision, and competition and disturbance on preys. We draw some recommendations based on different sources of available knowledge produced so far in the area (i.e., empirical evidence, scientific and grey literature, and expert judgement) to boost cetaceans’ conservation. Finally, we stress the need of sectoral coordination for the management of human activities by applying an EB-MSP approach and valuing the establishment of an ABMT in the Gulf of Taranto
Estimations of length-weight relationships and consumption rates of odontocetes in the Mediterranean Sea from stranding data
Stranding data provide fundamental information on biometric traits of cetaceans useful to increase knowledge on ecological traits and their consumption patterns. In this study, the length weight (L-W) relationships through the power regression model (W = a ×Lb ) were calculated for three dolphin species (the striped dolphin, the common bottlenose dolphin and the Risso’s dolphin) in several Mediterranean subregions and at the scale of the entire basin. Length (L) and weight (W) data were collected from stranding records during the period from 1983 to 2021 acquired from several databases and the literature. Starting from L-W relationships, a bootstrap method was applied to estimate the mean body weights, the daily ingested biomass (IB) and annual food consumption (AFC) rates of different dolphin species. In particular, four different equations were used to estimate the IB rates. Prey consumption by dolphin species was calculated through AFC rates and the available diet information (expressed in weight fractions) of dolphin species for different Mediterranean subregions.
Considering the L-W relationships in the Mediterranean Sea, b coefficient values were equal to 2.578, 2.975 and 2.988 for the striped, the common bottlenose and the Risso’s dolphin, respectively. At the Mediterranean scale, the AFC values estimated were 3913 kg (CI 2469–5306) for the Risso’s dolphin, 2571 kg (1372–3963) for the common bottlenose dolphin and 1118 kg (531–1570) for the striped dolphin. Prey consumption pattern showed a clear partitioning among the investigated species, where the common bottlenose dolphin exploits neritic demersal and pelagic fishes (e.g. eel fishes, sparids), the striped dolphin exploits mesopelagic fishes and myctophids, and the Risso’s dolphin was specialized on bathyal cephalopods of Histioteuthidae family.
The results obtained in this study provide new information for the investigated species in several Mediterranean subregions providing a first consistent baseline to support the population dynamics modelling. At the same time, the wide uncertainty ranges of some parameters, as well as the lack of information for some species, stress the necessity of improving the data collection associated to stranding events, especially in the southern Mediterranean areas
The Industrial Pattern of Italian Regions: A Disaggregated Sectoral Analysis Based on Input–Output Tables
Italy joined the so-called ‘Industry 4.0’ European framework in 2016, which designed and approved a national plan to regulate this key issue for regional development. To better support such a framework, the present study attempts to quantify the contribution of the Italian regions to the output formation process. More specifically, a multi-sectoral Input–Output (IO) model that supports national policies was proposed to cumulatively consider 29 industries that partition the Italian economy into representative branches at the level of administrative regions. Elementary input data were derived from the inter-sectoral table of the economy released by the Italian National Institute of Statistics (ISTAT). The economic outcomes of the Italian regions were estimated using a non-survey procedure, based on Flegg Location Quotients, to determine the upstream and downstream positions of each industry at country and regional levels. Indices grounded on the Hypothetical Extraction Method (HEM) further delineated the role each industry plays in the regional economy. The empirical findings of this study demonstrate how non-survey IO regionalization and the resulting industry-based indices provide appropriate knowledge for regional development policies
Functional traits reveal coastal vegetation assembly patterns in a short edaphic gradient in southern Brazil
The relationship between plant functional traits and soil variables is useful for understanding plant community composition and circumscribing plant functional groups to highlight their adaptations to environmental conditions. The principal aim of this study was to explain assembly patterns of coastal vegetation using functional traits along a short edaphic gradient. The work was carried out on the pioneer zone in the coastal lowland vegetation (foredune) in southern Brazil. We selected 40 functional traits related to the morphology and anatomy of leaves, stems and roots for 60 species recorded in 25 vegetation plots positioned along three transects from the shoreline to slacks. In each plot, floristic and soil data were collected, and functional traits measured. We analysed the relationships between species functional traits and soil factors through RLQ and fourth-corner analyses. Salinity and organic matter content were the most significant edaphic factors in the differentiation of foredune vegetation, while the most significant traits to explain plant adaptations to coastal environments were plant height, sclerenchyma, spongy parenchyma and reserves of inulin in the root. Two functional groups of plants were circumscribed: a conservative group formed by trees and shrubs dominated the Woody Community, with low values of SLA (specific leaf area), thick cuticles, high frequencies of phenolic compounds and crystals, woody stems and great plant heights, which tended to invest in permanent aerial organs; and a more heterogeneous group of herbaceous plants (found in Beach Community, Non-floodable, and Wet Communities) with acquisitive characteristics (high SLA values) or conservative strategy (rhizome and xylopodium). Finally, our results suggested that root and stem functional traits, which are infrequently taken into consideration, were useful to differentiate subtropical coastal plants and, in general, to study plant adaptations to environmental conditions in depth
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