1,720,954 research outputs found
The impact of fishing on coral reefs
No full textU ovom radu opisan je utjecaj ribolova na koraljne grebene. Koraljni grebeni su staništa velikog broja vrsta riba, mekušaca i rakova koji su nezamjenjiv izvor proteina za lokalno stanovništvo, kao i značajan izvor prihoda zbog visokih tržišnih vrijednosti. Gospodarski najznačajnije su ribe iz porodica Serranidae i Lutjanidae, a veliku ulogu imaju i beskralježnjaci, posebice jastozi (Panulirus argus, Jasus edwardii), morski trpovi (koljeno Echinodermata), morski puž Trochus nilocticus i hobotnica (Octopus vulgaris). Izlov na grebenu najčešće se obavlja automatiziranim i ručnim povrazima, parangalima i vršama, dok je pridnena povlačna mreža koća zabranjena. Osim navedenog, iskorištavanje koraljnih grebena provodi se i nedozvoljenim, ali profitabilnim metodama, poput ribolova eksplozivom ili korištenjem otrova poput cijanida. Kontrola ribolova provodi se primjenom različitih, više ili manje uspješnih mjera, a za očuvanje i obnovu živog svijeta koraljnih grebena do sada su se pokazala najučinkovitijima proglašenja zaštićenih morskih područja. Budućnost koraljnih grebena je neizvjesna zbog niza negativnih, uglavnom antropogenih utjecaja te će stoga trebati uložiti znatne napore kako bi se osigurala dugoročna održivost ovih jedinstvenih i bogatih morskih zajednica.This thesis presents the impact of fishing on coral reefs. Coral reefs are habitats of a large number of species of fish, molluscs and crustaceans, which are an irreplaceable source of protein for the local population as well as a significant source of income due to high market values. Commercially most important are fish of the families Serranidae and Lutjanidae, and invertebrates, especially lobsters (Panulirus argus, Jasus edwardii), sea cucumbers (phylum Echinodermata), the sea snail Trochus nilocticus and the common octopus (Octopus vulgaris). Fishing on the reef is most often performed by automated or manual lines, longlines and traps, while use of bottom trawl nets is prohibited. In addition, the exploitation of coral reefs is carried out by illegal but profitable methods such as fishing with dynamite, or use of poisons such as cyanide. Fisheries controls are carried out by applying different, more or less successful measures, and proclamation of protected marine areas appears to be the most effective method for conservation and restoration of coral reefs so far. The future of coral reefs is uncertain due to a number of negative, mostly anthropogenic impacts and therefore considerable efforts will be required to ensure the long-term sustainability of these unique and rich marine communities
Morphology of jaws and gills of sparus aurata linnaeus, 1758 and dicentrarchus labrax (Linnaeus, 1758) from the aquaculture
No full textU ovom su diplomskom radu analizirana morfološka i morfometrijska obilježja čeljusti i škrga za dvije vrste iz uzgoja, i to za oradu, Sparus aurata i lubina, Dicentrarchus labrax. Ukupna dužina tijela svih analiziranih jedinki vrste S. aurata se nalazila u rasponu od 22,5 do 29,5 cm, s prosječnom dužinom od 26,20 ± 1,77 cm. Ukupna dužina tijela svih analiziranih jedinki vrste D. labrax je bila u rasponu od 22,5 do 34,5 cm, s prosječnom dužinom od 30,75 ± 2,70 cm. Zubi orade i lubina su smješteni na gornjoj i donjoj čeljusti. Zubi orade su u pravilu okrugli i tupi, a zubi lubina šiljasti. Njihova veličina (opseg i površina kod oradi i dužina kod lubina) je u linearnom odnosu s dužinom ribe. Škržni listići orade bili su resaste strukture, dok su škržni nastavci bili mali i vidljivi samo na prvom škržnom luku. Škrge lubina također imaju škržne listiće resaste strukture te se škržni nastavci također vide samo na prvom škržnom luku, ali su za razliku od onih kod orade puno veći. Prosječna dužina donjeg dijela škržnih lukova je bila veća od dužine gornjeg dijela škržnih lukova i za lubina i za komarču. Navedene dužine su bile u linearnom odnosu s dužinom ribe.In this thesis, we analysed the morphological and morphometric characteristics of jaws and gills for two species from the aquaculture, namely for the sea bream, Sparus aurata and the sea bass, Dicentrarchus labrax. The total body length of all analysed S. aurata individuals ranged from 22.5 to 29.5 cm, with an average length of 26.20 ± 1.77 cm. The total body length of all analysed D. labrax individuals ranged from 22.5 to 34.5 cm, with an average length of 30.75 ± 2.70 cm. The sea bream and the sea bass teeth are located on the upper and lower jaws. The sea bream teeth are usually round and blunt, while the sea bass teeth are pointed. Their size (area and perimeter in the sea bream and length in the sea bass) is in a linear relationship with the length of the fish. Gill filaments of the sea bream had fringed structures, while gill rakers were small and visible only on the first gill arch. The gills of the sea bass also have fringed structured gill filaments and the gill rakers are also visible only on the first gill arch, but unlike those of the sea bream they are much larger. The average length of the lower part of the gill arches was greater than the length of the upper part of the gill arches for both sea bass and sea bream. The mentioned lengths were in a linear relationship with the length of the fish
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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