1,720,968 research outputs found
Cnidocyst morphology and distribution in Corallium rubrum (Cnidaria, Anthozoa)
No full textCnidocytes are the most specialized cells of cnidarians and the structural morphology of their capsules, the cnidocysts, has been recognized as an important taxonomic character within the phylum Cnidaria. Nevertheless, this character has been almost completely neglected by specialists of alcyonarians (Octocorallia), due mainly to the difficulties inherent in the examination of soft tissues lacking calcareous sclerites and the supposed homogeneity of the Octocorallia cnidome. Two different types of cnidocysts, holotrichous isorhizas and atrichous isorhizas, are described here for the first time from the Mediterranean red coral Corallium rubrum (L.) (Octocorallia). Proposed evolutionary trends of anthozoan cnidocysts are also discussed
Reporting Marine Microplastics Data: the Need for a Standardized Protocol
No full textMarine microplastics have become an issue of great concern at the global level. The attention towards the issue of marine microplastics, highly recognized by international policy and scientific research, has increased considerably over the last decades. At the European level, several initiatives have been promoted addressing the reduction of plastic pollution as a high priority target, among which the Marine Strategy Framework Objective (D10) and the European Strategy for Plastics in a Circular Economy. In addition, researchers have explored many strategies to optimize the detection and monitoring of microplastics in sediments, seawater, and organisms and to effectively demonstrate their potential ecological harm. However, since pollution dynamics, the functioning of natural ecosystems, and their relationships are very complex, there still lacks a comprehensive understanding of the impacts of microplastics on marine ecosystems. This lack of knowledge may impact the effectiveness of decision-making processes in terms of plastic reduction and waste management. In this study, we present the results of a literature review which focuses on particularly impactful marine microplastic methodological and analytical articles from 2004 to 2017 to identify possible gaps or inconsistencies in the reported data. Based on this review, a framework for a general reporting protocol (GRP) is outlined to encourage increased collaborative research efforts to harmonize the reporting of microplastics data in scientific studies. The proposed GRP outline could be useful in addressing data needs for effective ecological risk assessment. (C) 2022 L&H Scientific Publishing, LLC. All rights reserved
Assessing the effects of habitat patches ensuring propagule supply and different costs inclusion in marine spatial planning through multivariate analyses
No full textMarine Protected Areas are considered key tools for conservation of coastal ecosystems. However, many
reserves are characterized by several problems mainly related to inadequate zonings that often do not
protect high biodiversity and propagule supply areas precluding, at the same time, economic important
zones for local interests. The Gulf of Naples is here employed as a study area to assess the effects of
inclusion of different conservation features and costs in reserve design process. In particular eight scenarios
are developed using graph theory to identify propagule source patches and fishing and exploitation
activities as costs-in-use for local population. Scenarios elaborated by MARXAN, software
commonly used for marine conservation planning, are compared using multivariate analyses (MDS,
PERMANOVA and PERMDISP) in order to assess input data having greatest effects on protected areas
selection.
MARXAN is heuristic software able to give a number of different correct results, all of them near to the
best solution. Its outputs show that the most important areas to be protected, in order to ensure longterm
habitat life and adequate propagule supply, are mainly located around the Gulf islands. In addition
through statistical analyses it allowed us to prove that different choices on conservation features
lead to statistically different scenarios. The presence of propagule supply patches forces MARXAN to
select almost the same areas to protect decreasingly different MARXAN results and, thus, choices for
reserves area selection.
The multivariate analyses applied here to marine spatial planning proved to be very helpful allowing to
identify i) how different scenario input data affect MARXAN and ii) what features have to be taken into
account in study areas characterized by peculiar biological and economic interests
The scientific research on rhodolith beds: A review through bibliometric network analysis
No full textRhodolith beds are benthic biogenic calcareous habitats formed by the aggregation of unattached, non-geniculate coralline algae. They have a worldwide distribution and, due to their 3D structural complexity and functioning, they provide several ecosystem services (i.e., provisioning and regulating). Recently, their importance and vulnerability have been internationally recognized by international policy and scientific research, and more attention has been drawn to their investigation and conservation. In this study, we conducted a systematic review integrated with a bibliometric analysis of the academic literature related to rhodolith beds. The analysis was based on published literature data over the period 1965-2022, and allowed the generation of maps based on network data displaying the relationships among countries, researchers, keywords, and scientific journals. A total of 853 publications were identified, revealing that scientific research on rhodolith beds is still relatively limited if compared to other coastal vegetated habitats (e.g., seagrass beds, kelp forests), although it has increased over time. Results showed that the scientific documents were published by 77 countries, 2255 researchers, and 279 journals. USA led the research production in this field with 159 documents and 4802 citations, and Amado-Filho was the most productive author with 36 documents and 1126 citations. The co-occurrence network map of keywords showed that the main research fields linked to rhodolith beds are geology, paleontology, algal tax-onomy, community ecology, conservation, and physiology. The results also highlighted that most focus on the subject is recently shifting from geological and paleontological aspects to molecular taxonomic, conservation, and ecophysiological ones, while studies on the current topics of ecosystem services and carbon sequestration are still very limited
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
Uso del territorio marino nei SIC marino-costieri della costa lucana tirrenica: metodologia e applicazione
No full textAppropriate 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
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