1,720,959 research outputs found
The effects of COX-Inhibitors (Diclofenac and Ibuprofen) on growth rate, mortality and sexreversal in Nile Tilapia (Oreochromis niloticus)
Full text linkSeveral studies have been conducted to detect the direct effect of inhibiting the aromatase
activity, the rate limiting enzyme that converts androgens to estrogens needed for ovarian differentiation
in fish to overcome the immediate need for a more environmentally friendly substitute of methyl
testosterone. Cyclooxygenase (COX)-inhibitors are potent and irreversible inhibitors of the COX pathway
and since studies on human breast cancer cells shows that they decrease aromatase messenger
ribonucleic acid (mRNA) expression at the transcriptional level we tested the hypothesis of possible
aromatase inhibition by the non-selective COX-inhibitors in fry fish tilapia. The effects of supplementation
of COX-inhibitors (diclofenac and ibuprofen) in the diets of tilapia on growth rate, mortality and sexual
differentiation have been studied. 20 Genetically females (XX) (O. niloticus) larvae were stocked in
triplicates in a closed system and each were given control diet (C group) and control diet supplemented
with (10 mgKg-1) diclofenac (1% diclofenac group), (5 mgKg-1) ibuprofen (0.5% ibuprofen group), and (5
mgKg-1) (0.5% diclofenac group) respectively for 4 weeks. After the 4th week all diets were changed to
control diet. At the end of 12-weeks, no significant differences were found in growth rate (GR) between
diets (p>0.05). Mortality ranged from 1.67% +- 2.89 (SD, n=3) in control group to 58.3% +- 14.4 (SD,
n=3) in the 1% diclofenac group during the experimental feeding and from 6.67+-2.89 (SD, n=3) to
63.3%+-10.4 (SD, n=3) at the end of 12-weeks period. 7% In the control group, 36% in the 1%
diclofenac group, 17% in the 0.5% ibuprofen group, and 22.2% in the 0.5% diclofenac group
respectively never produced egg during the entire experimental period. Macroscopically all the nonspawning
fish in the experimental groups were females with apparently larger ovaries and full of eggs
compared to control. Microscopically they were full of apparently normal eggs with morphology similar to
those of control. Postulated mechanisms of action of the supplemented COX-inhibitors are discussed.
Based on the above it can be concluded that the use of COX-Inhibitors during the crucial period could
modulate aromatase activity and affect reproduction in Nile tilapia.This study was funded by the Deutsche Forschungsgemeinschaft
(DFG; German Research Foundation). Project’s number BE1133/13
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
Determination of different heavy metals concentrations in cosmetics purchased from the Palestinian markets by ICP/MS
Full text linkCosmetic products are a possible source of heavy metal exposure to human beings. This
research investigated the content of heavy metals in various types of cosmetics: lipsticks, Kohl
(eyeliner), henna (hair dye or temporary tattoo), eye shadows, cream; freckles, moisturizing and
foundation, and face powders. Eighteen products of different brands or misbrands cosmetics (expensive
and inexpensive) that are found in the Palestinian markets were analyzed to determine the
concentrations of thirteen metals (Ba, Pb, Bi, Al, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag and Cd) in these
products using Inductive Couple Plasma Mass Spectrometry (ICP-MS). Results showed that two brands of
cosmetics have lead content higher than 10 ppm. 50% of the samples contained nickel by more than 5
ppm while one compact powder contained 214.54 ppm. Furthermore, results showed that the
concentrations of Cr, Cd and Co are found to be higher than the allowed regulation limits in 69%, 81%
and 12.5% of the analyzed samples, respectively. In general, eleven of examined metals were found in
100% of samples. Two heavy metals (Ba and Cd) were found in 94, and 81% of analyzed samples,
respectively. Among the different cosmetics products studied, the highest heavy metal contaminations
was found in a very cheap brand of lipstick and in a cheap brand of kohl which is used inside the eyes
and also in a brand of compact face powder. Additionally, results revealed that 75% of the cosmetics
contained more than five parts per million of at least one of lead, cobalt, nickel, and chromium, and that
100% of the products contained more than one part per million of at least one of those metals. Our
findings call for an instant mandatory regular testing program to check lead, cadmium, cobalt and other
toxic heavy metals in cosmetic products imported to Palestine in order to limit their overabundance and
protect consumer health.The authors are gratefully for the Al-Quds Bard Master of Arts
(MAT) for their financial support
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
Utilization of desalinated brackish water residues for cultivation of the marine fish species,Dicentrarchus labrax, Sparus aurata, and Sciaenops ocellatus
Full text linkThe utilization of brackish water residues from desalination units for fish mariculture in
Palestine could represent an environmental friendly alternative of disposing brine water which could have
an adverse effect on wild life. In this study, three juvenile marine fish species (Gilt-head bream S.
aurata, European sea bass D. labrax, and red drum S. ocellatus) with average weights of 0.7-4.9 g, were
acclimated and reared in brine brackish water residues collected from Jericho desalination units with
salinities of 6.5 ‰ and 11 ‰ diluted sea water as control for 3-7 months. Fish were fed 56 % rich
protein diet. Brine brackish water contained high levels of Cl-1 (3369 mgL-1), Na+1(3735 mgL-1), K+1(300
mgL-1), SO4
-2 (716 mgL-1) with the divalent ions Mg+2 (57.3 mgL-1) and Ca+2 (276 mgL-1).The
experimental well showed more than the maximum allowable concentration of Cr (14.49 μgL-1), Ag (5.3
μgL-1) and Mn (27.88 μgL-1) for water quality of fisheries use. The sea bass with an average weight of
0.76 g (at a salinity of 6.5 ‰) showed an acceptable growth performance parameters and reached a
percentage weight gain (% WG) of 6345.23 % and a survival rate of 77.5 % compared to control groups
at 11 ‰ that reached at the same time a % WG of 6543.78 % and a survival rate of 82 % after 30
weeks. The red drum juveniles reached a % WG of 2661.6 % and 2673.92 % after 15 weeks at 6.5 ‰
and 11 ‰ respectively while sea bream reached a % WG of 241.63 % and 772.44 % after 15 weeks at
6.5 ‰ and 11 ‰ respectively. Survival rate was only 5 % at both salinities for the two species. In a
further study sea bass fingerlings with an average weight of 20.5 g were reared in brackish water of 6.5
‰ salinity for 7 weeks and were fed superior fish meal with fish oil. They received diets of 2.1 %, 3.0
%, and 4.0 % of body weight. Sea bass fingerlings which received diets of 2.1 %, had the highest FCE
(0.82) and PER (1.46) with the lowest FCR (1.22). These results confirm that the most suitable fish for
cultivation utilizing brackish water from Jericho desalination units with salinity of 6.5 ‰ is sea bass D.
labrax, while the other two species need some modification to acclimatize to this water. Furthermore, the
best food % for optimum growth of sea bass at this salinity is 2.1 % after 7 weeks. Brackish water from
Jericho desalination units are suitable for cultivation of these species, but may need some modification
as adding salts to fish diet or water and reducing toxicity of some high trace metals present by a
suitable method
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