1,720,956 research outputs found
Coastal acidification and deoxygenation enhance settlement but do not influence movement behaviour of creeping polyps of the Irukandji jellyfish, Alatina alata (Cubozoa)
No full textDeoxygenation and acidification co-occur in many coastal ecosystems because nutrient enrichment produces excess organic matter that intensifies aerobic respiration during decomposition, thereby depleting O2, increasing CO2 and lowering pH. Despite this link between coastal deoxygenation (CD) and acidification (CA), and evidence that both stressors pose a risk to marine fauna, few studies have examined the effects of these drivers in combination on marine animals including invertebrates. Here, we studied the individual and combined effects of CD (~1.5 mg L−1 O2) and CA (~7.7 pH) on the survival, number of tentacles, settlement and movement behaviours of creeping polyps of the Irukandji jellyfish, Alatina alata. Low DO increased the survival rate (17% more) of the creeping polyps. 12% more creeping polyps settled in low pH than ambient pH and 16.7% more settled in low DO than ambient DO treatment. Exposure to CA and CD did not influence the number of tentacles, mobility or movement velocity of the creeping polyps, but after 4 h exposure to the treatments, they moved approximately half as fast. Our results indicate that CD can enhance survival and settlement success, but CA does not intensify these outcomes on A. alata creeping polyps.No Full Tex
Ocean acidification impairs the physiology of symbiotic phyllosoma larvae of the lobster Thenus australiensis and their ability to detect cues from jellyfish
No full textOcean acidification (OA) can alter the behaviour and physiology of marine fauna and impair their ability to interact with other species, including those in symbiotic and predatory relationships. Phyllosoma larvae of lobsters are symbionts to many invertebrates and often ride and feed on jellyfish, however OA may threaten interactions between phyllosomas and jellyfish. Here, we tested whether OA predicted for surface mid-shelf waters of Great Barrier Reef, Australia, under ∆ pH = −0.1 (pH ~7.9) and ∆pH = −0.3 (pH ~7.7) relative to the present pH (~8.0) (P) impaired the survival, moulting, respiration, and metabolite profiles of phyllosoma larvae of the slipper lobster Thenus australiensis, and the ability of phyllosomas to detect chemical cues of fresh jellyfish tissue. We discovered that OA was detrimental to survival of phyllosomas with only 20% survival under ∆pH = −0.3 compared to 49.2% and 45.3% in the P and ∆pH = −0.1 treatments, respectively. The numbers of phyllosomas that moulted in the P and ∆pH = −0.1 treatments were 40% and 34% higher, respectively, than those in the ∆pH = −0.3 treatment. Respiration rates varied between pH treatments, but were not consistent through time. Respiration rates in the ∆pH = −0.3 and ∆pH = −0.1 treatments were initially 40% and 22% higher, respectively, than in the P treatment on Day 2 and then rates varied to become 26% lower (∆pH = −0.3) and 17% (∆pH = −0.1) higher towards the end of the experiment. Larvae were attracted to jellyfish tissue in treatments P and ∆pH = −0.1 but avoided jellyfish at ∆pH = −0.3. Moreover, OA conditions under ∆pH = −0.1 and ∆pH = −0.3 levels reduced the relative abundances of 22 of the 34 metabolites detected in phyllosomas via Nuclear Magnetic Resonance (NMR) spectroscopy. Our study demonstrates that the physiology and ability to detect jellyfish tissue by phyllosomas of the lobster T. australiensis may be impaired under ∆pH = −0.3 relative to the present conditions, with potential negative consequences for adult populations of this commercially important species.Full Tex
Size-frequency distributions of scleractinian coral (Porites spp.) colonies inside and outside a marine reserve in Leyte Gulf, central Philippines
No full textCoral colony size-frequency distributions (SFDs) can elucidate demographic differences among coral species and their responses to environmental drivers. However, studies on species-specific demography of coral colonies in the Coral Triangle are rare despite the knowledge about the regional variability of reef conditions. Coral reefs in the Southern Philippine Sea biogeographic zone (SPS) frequently experience natural (e.g. typhoons) and anthropogenic disturbances. Coral colony sizes in the SPS may vary with depth within a small-distance (< 1 km) scale and with the presence of marine protected areas (MPA) but studies rarely demonstrate this variability in Indo-Pacific coral reefs. Here, we examined the colony density, SFDs and the extent of partial mortality of scleractinian coral species Porites cylindrica and P. rus in Leyte Gulf, SPS. Field surveys were conducted within and outside (locations) the Bagonbanua Marine Reserve and Fish Sanctuary, SPS and between depths (3 m and 8 m) of each location. High densities of colonies of both species occur at shallow depths. We found that SFDs and colony sizes were similar between depths and between locations (inside and outside of the MPA). The percent partial mortality of only P. cylindrica colonies was significantly different between depths and between locations with low mortality at 3 m inside the MPA. Our study showed small-sized colonies that could be linked to high colony recruitment, fragmentation and potential recovery from disturbances.Full Tex
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
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
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