1,720,956 research outputs found
The possibility of infection of the invasive marbled crayfish, Procambarus virginalis Lyko, 2017 with crayfish plague pathogen, Aphanomyces astaci Schikora, 1906
No full textProcambarus virginalis (Lyko, 2017) je invazivna strana vrsta nepoznatog podrijetla s uspostavljenim populacijama u prirodi zabilježenim u 15 europskih zemalja. Ova vrsta ima veći fekunditet od autohtonih te od ostalih invazivnih stranih vrsta rakova. Uz to ima specifičan način razmnožavanja za deseteronožne rakove, razmnožava se partenogenetski, što je jedan od bitnijih faktora u uspjehu njezine invazije. Uz to je i mogući prijenosnik patogena Aphanomyces astaci, uzročnika bolesti račje kuge. američke vrste koje su ko-evoluirale s ovim patogenom su relativno tolerantne na njega te od njega ne ugibaju, dok su europske vrste manje tolerantne na njega te kod njih infekcija većinom dovodi do visokih stopa mortaliteta. U ovom radu se razmatra mogućnost zaraze mramornog raka patogenom račje kuge. S obzirom da je podrijetlo mramornog raka nepoznato i da je on srodan s vrstom Procambarus fallax mogao bi biti relativno otporan na patogen i time prenositi bolest račje kuge. U ovom radu sam eksperimentalno određivala mogućnost zaraze mramornog raka koncentracije patogena doze i opetovano zaražavanje dovode do mortaliteta u 15-20% slučajeva. Ovi rezultati ukazuju kako je mramorni rak potencijalni vektor različitih virulentnih genotipova račje kuge, čime predstavlja dodatnu opasnost za autohtone vrste rakova.Procambarus virginalis (Lyko, 2017) is an emerging invasive alien species of an unknown origin, with established populations in the wild in 15 European countries. This species has high fecundity compared to other native and invasive crayfish species and also reproduces by parthenogenesis, which significantly contributes to its invasion success. Additionally, marbled crayfish is a potential carrier of the crayfish plague pathogen, the oomycete Aphanomyces astaci. American crayfish species have co-evolved with the pathogen and are relatively tolerant to the infection, while European species are less resistant, and the infection usually leads to high mortality. Here, the potential of infection of marbled crayfish with the crayfish plague pathogen has been assessed. Because marbled crayfish origin is unknown, but closely related to the American species Procambarus fallax, it could be prone to the A. astaci infection and could act as its carrier. Here, I assessed experimentally the possibility of its infection by the virulent genotype B isolated from another successful invader, the signal crayfish. The results of the experiment have shown that chronic infection with the pathogen occurred in 40-55% of cases (depending on applied pathogen load) and that high pathogen load in combination with repeated infection leads to a mortality rate of 15-20%. These results show marbled crayfish is a potential vector of different virulent crayfish plague genotypes, and through disease transmission may exert an additional negative impact on native crayfish species
Sadržaj metala u eluatima tla s područja bivše tvornice glinice kod Obrovca i njihov učinak na klijanje sjemenki salate (Lactuca sativa)
No full textAlumina factories are plants for refining aluminum oxide from bauxite ore. Seven soil samples were taken in the vicinity of the former Jadral alumina factory near Obrovac, and the multielement analyses revealed elevated concentrations of heavy metals, especially iron (Fe), but high levels of Mn, Cr, V and Zn were also detected. Two types of soil eluates were prepared from the soil samples using two methods - the EN 12457-2 (European Standard Batch Leaching Test) and the TCLP-2 (Toxicity Characteristic Leaching Procedure). The soil eluates differed mainly in the pH values, while the metal content was generally low. The seed germination test was carried out not only with soil eluates prepared according to the two methods mentioned, but also with eluates whose pH was adjusted to 6.5. In addition to the influence of multielement composition of the eluates, the pH value had a predominant effect on both the germination of the lettuce seeds and the radicle growth. Comparing the effects of the samples on radicle growth and the germination process, radicle growth was the more sensitive parameter. This study sheds light on the impact of the former alumina factory, by showing the presence of heavy metals in the soil and possible consequences for the environment.Tvornice glinice su postrojenja za rafiniranje aluminijevog oksida iz boksitne rude. U sklopu ovog istraživanja uzeto je sedam uzoraka tla u blizini bivše tvornice Jadral kod Obrovca. Multielementna analiza otkrila je povišene koncentracije teških metala u tim uzorcima, posebice željeza (Fe), kao i visoke razine Mn, Cr, V i Zn. Kako bi se detaljnije istražili ovi nalazi, dvije vrste eluata tla pripremljene su iz uzoraka tla korištenjem dviju različitih metoda - EN 12457-2 (European Standard Batch Leaching Test) i TCLP-2 (Toxicity Characteristic Leaching Procedure). Dobiveni eluati tla razlikovali su se prvenstveno u pH vrijednosti, dok je njihov sadržaj metala općenito bio nizak. Uz navedeno, istražen je utjecaj eluata na klijavost sjemenki salate, ne samo eluata tla pripremljenih prema gore navedenim metodama, već i eluata čija je pH vrijednost podešena na 6,5. Rezultati su pokazali da je uz multielementni sastav uzoraka eluata tla, značajan bio utjecaj pH vrijednosti, kako na klijavost sjemenki salate tako i na rast korijenka. Uspoređujući učinke uzoraka na rast korijenka i proces klijanja, rast korijenka bio je osjetljiviji parametar. Ovo istraživanje ukazuje na utjecaj bivše tvornice aluminija, ističući prisutnost teških metala u tlu i moguće posljedice za okoliš
Sadržaj metala u eluatima tla s područja bivše tvornice glinice kod Obrovca i njihov učinak na klijanje sjemenki salate (Lactuca sativa)
No full textAlumina factories are plants for refining aluminum oxide from bauxite ore. Seven soil samples were taken in the vicinity of the former Jadral alumina factory near Obrovac, and the multielement analyses revealed elevated concentrations of heavy metals, especially iron (Fe), but high levels of Mn, Cr, V and Zn were also detected. Two types of soil eluates were prepared from the soil samples using two methods - the EN 12457-2 (European Standard Batch Leaching Test) and the TCLP-2 (Toxicity Characteristic Leaching Procedure). The soil eluates differed mainly in the pH values, while the metal content was generally low. The seed germination test was carried out not only with soil eluates prepared according to the two methods mentioned, but also with eluates whose pH was adjusted to 6.5. In addition to the influence of multielement composition of the eluates, the pH value had a predominant effect on both the germination of the lettuce seeds and the radicle growth. Comparing the effects of the samples on radicle growth and the germination process, radicle growth was the more sensitive parameter. This study sheds light on the impact of the former alumina factory, by showing the presence of heavy metals in the soil and possible consequences for the environment.Tvornice glinice su postrojenja za rafiniranje aluminijevog oksida iz boksitne rude. U sklopu ovog istraživanja uzeto je sedam uzoraka tla u blizini bivše tvornice Jadral kod Obrovca. Multielementna analiza otkrila je povišene koncentracije teških metala u tim uzorcima, posebice željeza (Fe), kao i visoke razine Mn, Cr, V i Zn. Kako bi se detaljnije istražili ovi nalazi, dvije vrste eluata tla pripremljene su iz uzoraka tla korištenjem dviju različitih metoda - EN 12457-2 (European Standard Batch Leaching Test) i TCLP-2 (Toxicity Characteristic Leaching Procedure). Dobiveni eluati tla razlikovali su se prvenstveno u pH vrijednosti, dok je njihov sadržaj metala općenito bio nizak. Uz navedeno, istražen je utjecaj eluata na klijavost sjemenki salate, ne samo eluata tla pripremljenih prema gore navedenim metodama, već i eluata čija je pH vrijednost podešena na 6,5. Rezultati su pokazali da je uz multielementni sastav uzoraka eluata tla, značajan bio utjecaj pH vrijednosti, kako na klijavost sjemenki salate tako i na rast korijenka. Uspoređujući učinke uzoraka na rast korijenka i proces klijanja, rast korijenka bio je osjetljiviji parametar. Ovo istraživanje ukazuje na utjecaj bivše tvornice aluminija, ističući prisutnost teških metala u tlu i moguće posljedice za okoliš
Sadržaj metala u eluatima tla s područja bivše tvornice glinice kod Obrovca i njihov učinak na klijanje sjemenki salate (Lactuca sativa)
No full textAlumina factories are plants for refining aluminum oxide from bauxite ore. Seven soil samples were taken in the vicinity of the former Jadral alumina factory near Obrovac, and the multielement analyses revealed elevated concentrations of heavy metals, especially iron (Fe), but high levels of Mn, Cr, V and Zn were also detected. Two types of soil eluates were prepared from the soil samples using two methods - the EN 12457-2 (European Standard Batch Leaching Test) and the TCLP-2 (Toxicity Characteristic Leaching Procedure). The soil eluates differed mainly in the pH values, while the metal content was generally low. The seed germination test was carried out not only with soil eluates prepared according to the two methods mentioned, but also with eluates whose pH was adjusted to 6.5. In addition to the influence of multielement composition of the eluates, the pH value had a predominant effect on both the germination of the lettuce seeds and the radicle growth. Comparing the effects of the samples on radicle growth and the germination process, radicle growth was the more sensitive parameter. This study sheds light on the impact of the former alumina factory, by showing the presence of heavy metals in the soil and possible consequences for the environment.Tvornice glinice su postrojenja za rafiniranje aluminijevog oksida iz boksitne rude. U sklopu ovog istraživanja uzeto je sedam uzoraka tla u blizini bivše tvornice Jadral kod Obrovca. Multielementna analiza otkrila je povišene koncentracije teških metala u tim uzorcima, posebice željeza (Fe), kao i visoke razine Mn, Cr, V i Zn. Kako bi se detaljnije istražili ovi nalazi, dvije vrste eluata tla pripremljene su iz uzoraka tla korištenjem dviju različitih metoda - EN 12457-2 (European Standard Batch Leaching Test) i TCLP-2 (Toxicity Characteristic Leaching Procedure). Dobiveni eluati tla razlikovali su se prvenstveno u pH vrijednosti, dok je njihov sadržaj metala općenito bio nizak. Uz navedeno, istražen je utjecaj eluata na klijavost sjemenki salate, ne samo eluata tla pripremljenih prema gore navedenim metodama, već i eluata čija je pH vrijednost podešena na 6,5. Rezultati su pokazali da je uz multielementni sastav uzoraka eluata tla, značajan bio utjecaj pH vrijednosti, kako na klijavost sjemenki salate tako i na rast korijenka. Uspoređujući učinke uzoraka na rast korijenka i proces klijanja, rast korijenka bio je osjetljiviji parametar. Ovo istraživanje ukazuje na utjecaj bivše tvornice aluminija, ističući prisutnost teških metala u tlu i moguće posljedice za okoliš
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
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