1,720,984 research outputs found
Fish market integration and demand analysis: a Mediterranean case study
No full textThis study discusses the importance of delineating market boundaries prior to undertaking demand analysis. The Northern Adriatic Sea is considered a good case study by which to test this approach, given the richness of species landed there and their heterogeneous distribution across the space involved. Three groups of demersal species (whitefish, cephalopods, and crustaceans) are chosen for the study. First, geographical market boundaries are defined for each product (species) using price–price relations between market places. Second, demand is analyzed inside the defined market area through the linear approximation of the inverse almost ideal demand system. Geographical market integration bears several patterns of complete or partial integration, depending on the species. It could be said that integration is higher for species of high economic relevance among regions where large quantities are landed. For all product groups, our estimations suggest that moderate substitution effects do exist among species. The characteristics of the fleets and of the buyers, as well as the biophysical attributes of the sea basin (i.e., species richness and heterogeneous spatial distribution) are discussed as explanatory variables of market integration/segmentation
Between innovation, sustainability and convenience, which affect mostly the choices for seafood? A survey with participants from Croatia
No full text
The Role of Strategic Behaviour in Ecosystem Service Modelling: Integrating Bayesian Networks With Game Theory
No full textHumans fulfil an active role, through management and economic activities, in the production of ecosystem services and related benefits. Different human groups may pursue different objectives, and their actions may affect each other's well-being. Bayesian networks have gained importance in ecosystem service modelling and we show how, in recent literature, this approach has attempted to address strategic behaviour issues. Using simple simulations, we illustrate that the strategic behaviour of stakeholders could be better modelled with an integration of game theory concepts in Bayesian networks. This approach may help to understand the rationale behind stakeholders' behaviour and foresee their actions. Furthermore, the comparison of environmental results with cooperative and strategic behaviours raises questions about the role of humans in the production of ecosystem services, and on the correct way to value their benefits
The relationship among catch, fishing effort, and measures of fish stock abundance: implications in the Adriatic Sea
No full textRelationships among catch, fishing effort, and measures of fish stock abundance have several implications for fisheries research. In this context, spatial and seasonal aspects are of significant importance for management decisions, especially when effort regulation schemes are used. In this paper, the multispecies trawl fishery in the Northern and Central Adriatic Sea was investigated, taking into account the heterogeneous distribution of fish stocks. Two approaches are presented depending on the availability (or not) of fishery-independent indices of stock abundance. The empirical results indicate that (i) aggregation and targeting behaviours affect catches by modifying the relationship between abundance and catch per unit effort and (ii) these relationships are not homogenous across space. Data from the Adriatic Sea is still insufficient to guarantee reliable estimations. However, these preliminary results call into question management decisions being made on the basis of catch per unit effort. Furthermore, the high heterogeneity between the northern and central areas of the sea basin calls for the adoption of spatially explicit management systems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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