1,720,956 research outputs found
NON-INVASIVE MONITORING OF HORMONAL PROFILE IN TWO PUBERTAL CAPTIVE POLAR BEARS (URSUS MARITIMUS): THYROID HORMONES
No full textLittle research have been published concerning endocrine profiles in bears, the existing literature mainly focusing on sun (Ursus malayanus) and Formosan bear (Ursus thibetanus formosanus). Almost no information is available on the endocrine profile of polar bears (Ursus maritimus). Our present research aims at evaluating thyroid hormones profile in captive pubertal polar bears through the non-invasive measurement of thyroid hormones in feces.
Samples were collected from two juvenile polar bear, one male and one female, and stored frozen until analysis. Hormone extraction was performed on 0.3 g homogenized feces with a double ethanol extraction and analyzed with commercial ELISA kits for thyroxine (T4) and triiodothyronine (T3). In all samples T4 presented higher concentrations than T3. The female bear showed higher level of fecal T3 than the male (40.67 ± 55.49 ng/g vs 25.87 ± 4.78 ng/g
respectively). Similarly, a higher variation in T3 and T4 excretion was observed in the female bear with respect to male. Finally, a decrease in T4 excretion was observed in both bears in summer months.
Our preliminary results strongly suggest that feces can be used as tool for monitoring thyroid function in bears. This is also the first study presenting data concerning thyroid hormones from non-invasive, fecal samples in bears
PRELIMINARY RESULTS OF METAL CONTAMINATION IN CAPTIVE KILLER WHALES (ORCINUS ORCA)
No full textMost studies conducted on toxicology of killer whales (Orcinus orca) focus on the accumulation of organochlorine compounds. Few heavy metals studies have been published on stranded individuals. The aim of this work is to monitor the accumulation of inorganic compounds in live captive orcas, using non-invasive methods and the periodical veterinary blood sampling in animals kept in a controlled environment. Metal and metalloid contamination has been
evaluated in four captive killer whales: one adult and one sub-adult male, and two adult females. Low levels of contaminants were found in all of the animals, with the exception of lead, showing higher levels than observed in wild bottlenose dolphins. One female gave birth during the period of study and showed a decrease in Pb and Fe concentrations and an increase in Zn levels after parturition (0.7 μg/ml vs 0.4 μg/ml; 303.6 μg/ml vs 273.90 μg/ml; 2.92 μg/ml
vs 3.121 μg/ml respectively) These changes can be partially ascribed to lactation, as already found in humans and domestic animals.
This study is the first step for the definition of reference baseline values for hematic metals in killer whales, to be applied in the future in the study of wild animals
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
Basal levels of inorganic elements healthy nesting loggerhead sea turtles (Caretta caretta): results from a large study on the nesting colony of Boa Vista Island (Cape Verde)
No full textHeavy metals and other inorganic elements (mainly from anthropogenic sources) have an increased impact on marine wildlife. Sea turtles are considered sentinels of ecological health in marine ecosystems. Loggerhead sea turtle (Caretta caretta) population from Cape Verde is the second largest population of this species in the Atlantic and the third in the world. In this picture to know baseline levels of the most physiologically or toxicologically relevant inorganic elements is mandatory. For this purpose concentrations of 11 inorganic elements (Cu, Mn, Pb, Zn, Cd, Ni, Cr, As, Al, Hg, and Se) were assessed in a large sample of loggerhead sea turtles from a nesting colony of BoaVista Island, Cape Verde, (Eastern Atlantic). 201 female turtles were sampled and levels of inorganic elements were measured with Inductively Coupled Plasma-Optic Emission Spectrometry technique (ICP-OES) using a Perkin Elmer Optima 2100 DV instrument, coupled with a CETAC U5000AT+ ultrasound nebulizer for mercury. It has to be highlighted that all the samples (100%) showed detectable levels of the 11 elements quantified, and only one sample showed levels of mercury below the limit of detection. The most prevalent elements in blood were the essential elements Zn and Se reaching median values in blood as high as 6.05 and 2.28 μg/g, respectively. Other essentials elements, such as Cu, Cr, and Mn were also present, but at lower levels (0.50, 0.08, and 0.02 μg/g, respectively). The median concentration of the most toxic metals Cd, Pb, and Hg, were 0.24, 0.06, and 0.03 μg/g, respectively. In addition, the metalloid As was present at levels of 0.38 μg/g. Having into account the large number of animals involved in this study we can assure that these figures represent the basal levels of these inorganic elements in healthy nesting loggerhead sea turtles, and, as a consequence, these values may be used as reference in future studies involving such population. Additionally, our study reinforce the utility of blood as an excellent sample to monitoring, in a relatively non-invasive way, levels of contamination by toxic inorganic elements in sea turtles
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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