1,721,010 research outputs found
Management of Non-Indigenous Species in the Mediterranean Sea with an Emphasis on Lionfish (Pterois miles)
Get PDFThe 21st century faces a global challenge; understanding the ecosystem changes and regulating fish resources is essential to provide food for humankind and to preserve the oceans. Marine ecosystems are being increasingly altered because of global, regional, and anthropogenic stressors such as climate change, Non-Indigenous Species (NIS), pollution, fisheries, eutrophication, and habitat loss. In an era of escalating transformations of marine ecosystems, the Mediterranean Sea is recognized as a hotspot of global biotic and abiotic changes. In recent decades, human-mediated introductions of NIS have notably reshaped the marine ecological structures and processes of the region. The Suez Canal (constructed in 1869 and subsequently expanded) has established a permanent sea-level waterway connecting Red Sea with the Mediterranean Sea. Lack of preventive measures and climate change allow more thermophilic NIS of Indo-Pacific origin to find their niche in the Mediterranean Sea. Over 750 multicellular NIS have established viable populations in the region and a complete halt of their spread is impossible. Non-indigenous species have become members of a complex system of interactions between economy, society, and environment, affecting the livelihoods of local communities. Managers are faced with a complex task of navigating the changing conditions. They must find ways to utilize the potential benefits that some NIS may provide, while simultaneously protecting ecosystems from the harmful impacts that some invasive species can induce. This PhD started in 2018 at a moment when the Mediterranean Sea was experiencing the lionfish (Pterois miles) expansion in one of the fastest population expansions ever recorded for marine invasive species. With a documented invasion history in the Western Atlantic, and proven possible management measures, the lionfish invasion in the Mediterranean Sea offered a critical opportunity for research and acquisition of fundamental knowledge about management possibilities during escalating invasion stages. With an emphasis on lionfish, this PhD employed social (surveys and questionnaires) and ecological research methods (visual census surveys) to provide novel knowledge on four management action priorities for NIS and guide a holistic management in the region. The priority management actions were (i) Education and public awareness (Chapters 1, 3, and 4), (ii) Rehabilitation of the environment (Chapter 2), (iii) Commercial and recreational utilization (Chapters 2 and 4), and (iv) Targeted removal of the species (Chapters 2 and 3). Considering the identified gaps in public awareness and knowledge about lionfish and NIS in the Mediterranean Sea (Action 1), questionnaire surveys conducted in Chapter 1 revealed high awareness of stakeholders about lionfish and its impacts but limited public awareness and support for new fisheries from lionfish. The Chapter analysed stakeholder motivations, the guided the implementation of communication initiatives aiming at involving the local communities in lionfish management. Chapter 4 revealed lack of knowledge and awareness of fishers regarding the origin of many common NIS, and divergent perceptions on the ecological impacts that were correlated with the price of the species in the market. There is potential here for collaborative and communicative management processes to harmonize divergent views amongst fishers. The goal would be to mutually agree management measures that can support livelihoods and restore the ecosystem. Rehabilitation of the environment (Action 2) and development of a healthy functioning ecosystem has the potential to control the distribution and abundances of introduced species. Two experiments that conducted visual census surveys in Chapter 2 demonstrated that recent fishery restrictions in a Marine Protected Area (MPA) of Cyprus likely benefited the spatial and temporal expansion of lionfish populations. Additional management measures, such as selective fishing and targeted removals, to offset invasive species spread would help MPAs recovery processes especially in the early years of MPAs’ designation and contribute to their conservation objective. The decreased lionfish densities in fished areas compared to strictly MPA zones (no fishing) found in Chapter 2 demonstrated the potential contribution of fisheries (commercial and recreational utilization – Action 3) to regulate NIS populations. Chapter 4 used fishery-dependent data and questionnaire surveys to demonstrate the emerging and important contribution of NIS catches in Cyprus fisheries, both in terms of volume and value. The Chapter has shown that recreational fishers avoided common NIS and even easy targets, such as lionfish. Recreational fishers are potentially driven by motivations beyond economic gain, such as traditional norms for larger and ‘trophy’ fish which are often keystone top-predators within marine ecosystems. Conversely, targeting of NIS by commercial fishers was largely driven by the price and their familiarity with the species. By reforming both recreational and commercial fisheries to adapt to NIS and launching market campaigns to address motivational factors, it could be possible to mitigate the negative impacts of NIS and generate greater profits and yields for local communities. Chapters 2 and 3 demonstrated the efficiency of targeted removals (Action 4) with volunteers in controlling lionfish populations from priority sites. Social and environmental benefits from the execution of such events outweigh the economic costs, as demonstrated by their potential to incentivize lionfish fisheries, collect biological and ecological data, enhance public knowledge, awareness, secure support, and promote cooperative efforts. Chapters 5-6 used the knowledge from Chapters 1-4 to guide reforms in the management and policy frameworks of NIS in the Mediterranean Sea and ameliorate the impacts of established NIS. Chapter 5 documented challenges encountered with a proposal to include lionfish in the European Union List of Invasive Alien Species (IAS) (EC/1143/2014) and provided recommendations on the basic IAS Regulation and the Delegated Regulation on risk assessments (EC/2018/968) that could be applied to improve relevance, coverage, effectiveness, and management of marine IAS at a European and regional level. To move beyond current problematic management approaches that do not adapt to the presence of non-indigenous species, Chapter 6 proposed major fishery reforms and an Ecosystem Based Fisheries Management framework that could direct a concerted and harmonized holistic approach against NIS to limit the socioeconomic and ecological impacts. Finally, results were summarized and a comprehensive tailored-made guide for the management of lionfish in the Mediterranean region was also developed and supplemented the major outputs of the PhD as Appendix. The guide provides information about key topics for the management of lionfish such as targeted lionfish removals, development of markets, outreach and communication activities, research and monitoring, and regional cooperation
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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