1,720,957 research outputs found
Genetic modifications, characteristics and ethical dilemmas in transgenic salmon
Get PDFAquAdvantage Salmon je linija transgenih atlantskih lososov, ki je prva pridobila dovoljenje za uporabo v človeški prehrani. Namen diplomskega dela je pregled objavljenih raziskav s področja genetske modifikacije te linije, primerjava lastnosti transgenega lososa z nemodificiranim in predstavitev etičnih dilem, ki se pojavljajo. Linijo so ustvarili z vstavljanjem rekombinantne DNK, sestavljene iz »antifriz« promotorja ribe oceanski molič ter iz gena za sintezo rastnega hormona kraljevega lososa, v atlantskega lososa,. Takšen transgeni losos raste več kot 2-krat hitreje kakor nemodificiran losos, ima za 10% izboljšano izkoriščanje krme, zmožen je hitrejšega razvoja skozi sladkovodno fazo, ima za 2,2-krat povečano površino tankega črevesa ter je počasnejši plavalec v primerjavi z divjim tipom atlantskega lososa. Po sestavi telesa se transgeni losos ne razlikuje od nemodificiranega lososa, tudi vsebnost hormona IGF se ne nahaja v škodljivih količinah v tkivih transgenega lososa. Tveganja proizvodnje transgenega lososa so okoljska in prehranska. Dokler obstaja tveganje pobega transgenega lososa, obstaja tudi tveganje za okolje. Mnenja glede tega so deljena. Javnost precej nasprotuje proizvodnji transgenega lososa, prav tako zahteva obvezno označevanje živil in večjo transparentnost pri postopkih sprejemanja nadaljnjih dovoljenj za gojenje transgenih živali v prehranske namene.AquAdvantage Salmon is a line of transgenic Atlantic salmon that was the first to obtain a permit for use in human diet. The aim of the B. Sc. Thesis was to review the published research on topic of genetic modification, comparison of characteristics of transgenic salmon and unmodified salmon, and ethical dilemmas. This transgenic line was created by inserting rDNA, made of an anti-freeze promoter from the ocean pout and of a growth hormone gene from the Chinook salmon. The transgenic salmon has its growth enhanced by more than two fold comparing to unmodified salmon and feed conversion is better by 10%. Transgenic salmon is capable of faster development through the freshwater phase, it has 2,2 times more of intestinal surface area than unmodified salmon, and is a slower swimmer in comparison with wild Atlantic salmon. Body composition of transgenic salmon does not vary from that of unmodified salmon. Tissues of transgenic salmon do not contain dangerous levels of IGF hormone. Risks of producing transgenic salmon are environmental and nutritional. As long as there exists a risk of escaped transgenic salmon, there is a risk for the environment. Opinions about that vary. The public is very opposed to transgenic salmon production, as well as they demand obligatory labelling of food, and more transparent processes of permit review for transgenic animal production to be used in human diet
Effects of olive leaves and cake on parameters of oxidative stress in growing pigs
Get PDFProizvodnja oljčnega olja iz leta v leto narašča, zaradi česar nastane vedno več stranskih proizvodov, kot so oljčni listi in tropine. Oljčni listi in tropine niso dober vir hranil in energije, a so bogat vir polifenolov. Polifenoli imajo tudi antioksidativno delovanje in tako prispevajo k zaščiti živali pred oksidativnim stresom. Cilj raziskave je bil ugotoviti vpliv dodajanja oljčnih listov in tropin v krmne mešanice na kazalnike oksidativnega stresa pri rastočih prašičih. V sklopu poskusa smo v bilančne kletke individualno uhlevili 24 rastočih prašičev, težkih 10–12 kg, starosti 40–55 dni. Razdeljeni so bili v tri skupine po osem živali. Živali v skupini Kontrola smo krmili z osnovno krmno mešanico, živali v skupini Listi z osnovno krmno mešanico z dodatkom 7,5 % oljčnih listov, živali v skupini Tropine pa z osnovno krmno mešanico z dodatkom 7,5 % oljčnih tropin. Živali smo krmili restriktivno. Med poskusom smo zbirali blato in seč, na koncu smo jim odvzeli vzorce krvi. Rezultati so pokazali ugoden vpliv dodajanja oljčnih listov na maščobnokislinsko sestavo krvne plazme, povečanje aktivnosti encimov desaturaz v krvni plazmi, a poslabšanje absorpcije maščobnih kislin. Dodajanje oljčnih listov in tropin ni imelo vpliva na koncentracije vitamina E, antioksidativna kapaciteta v maščobah topnih antioksidantov (ACL) in antioksidativna kapaciteta v vodi topnih antioksidantov (ACW) v krvni plazmi. Prav tako dodatka nista imela vpliva na preučevane kazalnike oksidativnega stresa: malondialdehid (MDA), F2-izoprostanov, oksidirani lipoproteini majhne gostote (oxLDL) in 8-hidroksi-2\u27-deoksigvanozin (8-OHdG).Olive oil production is increasing year by year, resulting in increased quantities of by-products, such as olive leaves and cake. Olive leaves and cake are not a good source of nutrients and energy, but are an abundant source of polyphenols. Polyphenols act as antioxidants and thus help to protect the animals from oxidative stress. The goal of this study was to evaluate the effect of adding olive leaves and cake to feed mixtures on parameters of oxidative stress in growing pigs. As a part of the experiment, 24 growing pigs, weighing 10–12 kg and aged 40–55 days, were individually housed in metabolic cages. They were divided in three groups of eight animals. Control group (Kontrola) was fed with basic feeding mixture, leaves group (Listi) was fed with basic feeding mixture with added olive leaves in concentration of 7.5 %, and the cake group (Tropine) was fed with basic feeding mixture with added olive cake in concentration of 7.5 %. During the experiment, faeces and urine were collected, and at the end of the experiment blood samples were collected. The results showed a beneficial effect of adding olive leaves on fatty acid composition in plasma and on increase in the activity of the desaturase enzymes in plasma but also showed an impairment of the absorption of fatty acids. Supplementation of olive leaves and cake had no effect on the concentrations of vitamin E, lipid-soluble antioxidant capacity (ACL), and water-soluble antioxidant capacity (ACW) in blood plasma. The supplements also had no effect on the markers of oxidative stress: malondialdehyde (MDA), F2-isoprostanes, oxidised low-density lipoprotein (oxLDL), and 8-hydroxy-2’ –deoxyguanosine (8-OHdG)
Effect of tannins and drying methods on in vitro dry matter and crude protein degradability and digestibility of soybean meal for ruminants
No full textSoybean meal is a widely used protein source for ruminants, but its high ruminal degradability can limit its nutritional value. Tannins reduce ruminal crude protein degradability by forming tannin-protein complexes, which are facilitated by water addition and heat during drying. The study evaluated the effects of drying methods (freeze-dried, 50 °C, 80 °C) combined with two tannin types (chestnut and quebracho) at two concentrations (50 and 100 g/kg) on the in vitro degradability and digestibility
of soybean meal dry matter and crude protein. Tannins combined with drying methods effectively reduced ruminal degradation of soybean meal protein. The drying at 80 °C combined with chestnut or quebracho tannins at both concentrations (except 100 g/kg chestnut tannins) showed the largest reduction in ruminal crude protein degradability without negatively affecting post-ruminal digestibility.
The most effective combination for reducing crude protein (-42.3%) degradability compared to the control was 50 g/kg chestnut tannins with drying at 80 °C without affecting in vitro dry matter and crude protein digestibility. This combination also increased by-pass protein content (431 g/kg DM) and improved its digestibility by 21%
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
