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The Effects of Ocean Acidification on the Development, Behavior and Survival of Marine Fish Eggs and Larvae Inferred from Laboratory and Natural Experiments
Full text linkThe physiology, development, behavior and survival of the early life history stagesof marine fish are challenged by increasing carbon dioxide concentrations in the ocean,known as ocean acidification. A widespread effect of elevated pCO2 on fish larvae isincreased otolith size. To understand the functional consequences of larger otoliths on thevestibular system of fish larvae, Chapter 2 investigated the vestibulo-ocular reflex (VOR)of white seabass (Atractoscion nobilis) larvae reared at 2500 μatm pCO2. The VOR isan otolith-dependent response in fish that stabilizes vision during body movement. Larvaereared at high pCO2 possessed saccular and utricular otoliths that were 17% and 38% larger in size. Despite the increased otolith size, the gain of the VOR, which describes theratio of eye to head amplitude, was not statistically different between treatment (0.39 +- 0.05, n = 28) and control (0.30 +- 0.03, n = 20) larvae.Fish spawning habitat and survival of offspring are greatly influenced by environmentalconditions. In Chapter 3, the effects of pCO2 on the spawning habitat of Anchoveta(Engraulis ringens) and mortality of eggs and early stage larvae were investigated. Eggs,larvae, and oceanographic data, were collected across an onshore-offshore gradient in pCO2 that ranged from 167-1392 μatm. pCO2 was statistically significant in explaining egg presence. The abundance of eggs and relative absence of larvae at high pCO2 suggests that Anchoveta preferentially spawned at high pCO2 (>800 μatm) and that these eggs had lower survival.Fish living in a high-pCO2 world may have to spend more energy on acid-basebalance. Chapter 4 explores the effects of elevated pCO2 on the oxygen consumption rate(OCR) and abundance of Na+-K+-ATPase (NKA) proteins in white seabass larvae reared at 2000 μatm pCO2. OCR, a proxy for aerobic metabolic rate, did not differ significantlybetween larvae reared at present-day (0.18 +- 0.03 μL O2 individual-1 h-1, n = 80) and future (0.19 +- 0.03 μL O2 individual-1 h-1, n = 80) pCO2. Consistent with this finding, the relative abundance of NKA proteins that fuel important ion exchangers for acid-base balance did not differ between control and treatment larvae in Western blot and immunohistochemistry analyses. Mass and length were also unchanged at high pCO2, suggesting larvae were physiologically robust in these variables to ocean acidification conditions
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The Santa Barbara Basin Fish Assemblage in the Last Two Millennia Inferred from Otoliths in Sediment Cores
Full text linkThe Santa Barbara Basin (SBB) fish assemblage over the last two millennia was examined using fish otoliths recovered from sediment cores. In Chapter 2, the hypothesis that otolith shape and elemental composition can be used to accurately discriminate between common southern California Current System fish taxa was tested. Digital images of 905 sagittal otoliths, representing 6 major taxonomic-based groups, were used to develop geometric (GEO) and elliptic Fourier (EF) shape measurements and a subset of 143 otoliths also analyzed for trace elements (ELM). Results indicate that random forest analysis was superior to discriminant function analysis and GEO features outperformed EF and ELM features for classification. Highest classification accuracy (96.3%) resulted from using the 10 strongest discriminatory features, which included a mixture of GEO, EF, and ELM features.In Chapter 3, fossil otoliths (n = 1188) recovered from 3 Kasten and one box core sampled in the SBB were classified to taxonomic group by expert opinion (EO) and, after measuring shape and elemental features, by using the classification models developed in Chapter 2. Results of the EO and feature-based classification methods agreed strongly for the most abundant taxa and indicated that Myctophidae (52.7%) and Bathylagidae (31.5%) have dominated the forage fish assemblage in the SBB over the last two millennia. Less abundant taxa include Merlucciidae (6.9%), Sebastidae (4.8%), and Engraulidae (3.9%). Taxa displayed similar periods of variability on the decadal (50-90 years) and century scale (200 +/-50 years).In Chapter 4, the relation of climate and SBB fish assemblage was investigated by comparing the otolith deposition rate (ODR) record with proxies of climate over the same period. Results indicate coherence between the ODR of Myctophidae, Bathylagidae, Engraulidae, and Sebastidae, which display significant correlation with temperature-based climate indices. The coherent pattern in several fish populations and basin-wide climate variability observed over off the coast of Southern California demonstrate the role of climatic forcing in regulating forage fish populations over the past two millennia. Our results provide baseline composition data and an increase understanding of natural variability of SBB fish populations
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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