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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
Impact of Traffic Demand on Air Traffic Complexity
No full textAnalizom prometnih podataka objavljenih od strane HKZP-a vidljivo je povećanje prometa i prometne potražnje zadnjih nekoliko godina. Prometne prognoze prometne potražnje koje je objavio EUROCONTROL predviđaju rast prometa bez obzira na zadnje dvije godine koje su zabilježile veliki pad prometa zbog pandemije uzrokovane virusom SARS Covid-19. Prometna potražnja povezana je s kompleksnosti koja ovisi o različitim indikatorima. Pomoću programa NEST mogu se izračunati ti indikatori i napraviti konačan rezultat kompleksnosti pomoću formula za izračun kompleksnosti. U programu NEST mogu se napraviti različite simulacije prometa. U ovom radu su napravljene simulacije povećanja prometne potražnje prometa 2018. godine za 5, 10 i 15 % te je uspoređen promet i kompleksnost u odnosu na 2018. i 2019. godinu. Konačni rezultati pokazuju kako je prometna potražnja utjecala na kompleksnost zračnog prometa.An analysis of traffic data published by HKZP shows an increase in traffic and traffic demand over the past few years. Traffic demand forecasts published by EUROCONTROL predict traffic growth regardless of the last two years, which have seen a large drop in traffic due to the pandemic caused by the SARS Covid-19 virus. Traffic demand is associated with complexity that depends on different indicators. Using the NEST program, these indicators can be calculated and a final complexity result can be made using formulas for calculating complexity. Various traffic simulations can be made in the NEST program. In this paper, simulations of the increase in traffic demand in 2018 by 5, 10 and 15% were made, and traffic and complexity were compared to 2018 and 2019. The final results show how traffic demand affected the complexity of air traffic
Structure of telomere and role of telomeric proteins
Get PDFTelomere su zaštitne strukture na krajevima linearnih kromosoma koje su nužne na staničnoj razini za stabilnost genoma, dok na razini organizma sudjeluju u procesu starenja koji ima funkciju tumorske supresije. Telomere mogu regulirati duljinu životnog vijeka stanica i štite prirodne krajeve kromosoma od neželjenih aktivnosti popravka DNA kao što su nehomologno spajanje krajeva DNA i homologna rekombinacija. Kromosomi imaju na svojim krajevima telomernu DNA s uzastopnim ponavljanjem heksanukleotidne sekvence koja oblikuje omčastu strukturu uz pomoć specifičnih proteina, tzv. T petlju. Šelterin, zaštitni proteinski kompleks, sastoji se od šest proteina: TRF1, TRF2, TIN2, Rap1, TPP1 i POT1 koji su međusobno povezani i vežu telomernu sekvencu. Inhibicija TRF2 rezultira poremećajem telomernih struktura, aktivacijom p53 i procesima apoptoze ili starenja, odnosno fuzijom krajeva kromosoma, ovisno o tipu stanica. Najnovijim je istraživanjima dokazano da se na telomerama nalazi i velika nekodirajuća RNA koja stvara cjelovitu komponentu telomernog heterokromatina, TERRA. Na temelju njene funkcije, zaključeno je da je takva RNA uključena u regulaciju enzima telomeraze i remodeliranje kromatina tijekom razvoja i diferencijacije stanice.Telomeres are protective structures at the ends of linear chromosomes. They are critical at the cellular level for maintenance of the genome stability. At the organismal level they may contribute to ageing, which is considered to be tumor supressing mechanism. They can regulate the lifespan of cells and protect natural chromosome ends from unwanted DNA repair activities, such as non-homologous end joining and homologous recombination. The chromosomes end in telomeric DNA containing tandem hexanucleotid repeats in specific loop structure. The complex of specific proteins, named Shelterin, takes part in the maintenance of the T loop and telomere function. Shelterin consists of six proteins: TRF1, TRF2, TIN2, Rap1, TPP1 and POT1. The complex has a high affinity toward telomeric sequence. TRF2 inhibition compromises the structure of the telomeres and can cause p53 activation, apoptosis or cell senescence as well as chromosome end fusion, depending on the cell type. The recent investigations had identified telomeric repeat containing RNA, TERRA, a large noncoding RNA forming an integral component of telomeric heterochromatin. TERRA functions suggest important roles in the regulation of telomerase and in orchestrating chromatin remodelling throughout development and cellular differentiation
CpG methylation of MGAT3 and MGAT5 glyco-genes and glycosylation of immunoglobulin G in inflammatory bowel diseases
Get PDFUpalne bolesti crijeva (engl. inflammatory bowel diseases, IBD) su kronične bolesti probavnog trakta koje nastaju zbog neodgovarajućeg upalnog odgovora imunološkog sustava na crijevnu mikrofloru u osoba s genetičkom predispozicijom. Cjelogenomske studije povezanosti su povezale gliko-gen MGAT3 s glikozilacijom imunoglobulina G (IgG) i IBD-em. Druga istraživanja su s razvojem IBD-a povezala i gliko-gen MGAT5. Bisulfitnim pirosekvenciranjem analizirala sam metilaciju gena MGAT3 i MGAT5 iz krvi pacijenata s IBD-em dviju velikih neovisnih kohorti te pokazala da je metilacija ovih gena značajno promijenjena u ulceroznom kolitisu i Crohnovoj bolesti. Korelacijske analize upućuju na smanjenu ekspresiju gena MGAT3 (kodira za enzim GnT-III) u IBD-u, ako je točna pretpostavka da su analizirana CpG mjesta unutar promotora tog gena uključena u regulaciju ekspresije. U trećoj manjoj kohorti analizirala sam metilaciju gena MGAT3 i MGAT5 u mononuklearnim stanicama krvi, T-limfocitima izoliranim iz krvi i iz tkiva crijeva, te pokazala značajnu promjenu metilacije oba gena u T-limfocitima iz crijeva, te promijenjenu metilaciju i ekspresiju gena MGAT5 u T-limfocitima iz tkiva crijeva pacijenata s aktivnim oblikom ulceroznog kolitisa.Inflammatory bowel diseases (IBD) are a group of intestinal disorders that occur due to inappropriate immune response to intestinal microbiome in genetically susceptible individuals. Genome wide association studies associated MGAT3 gene with IgG glycosylation and IBD. Previous studies associated another glyco-gene, MGAT5 with IBD, too. Methylation of MGAT3 and MGAT5 genes was analysed from whole blood of IBD patients from two large independent cohorts using bisulfite pyrosequencing. The results showed significant change in methylation level between patients with Crohn's disease and ulcerative colitis, and healthy controls. Correlation analysis between MGAT3 methylation and IgG glycans suggests that MGAT3 (coding for GnT-III enzyme) expression is reduced in IBD, if CpG sites encompassed with methylation assays are relevant for transcriptional regulation. In third cohort with smaller number of patients with ulcerative colitis, methylation of MGAT3 and MGAT5 genes was analysed in mononuclear cells from blood, T cells from blood, and T cells from inflamed bowel tissue. Change in methylation level of both genes was observed only in T cells from bowel tissue. The methylation and expression of MGAT5 gene was significantly changed in T cells from bowel tissue in active ulcerative colitis
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
Relation of DNA traces from different surfaces with donor age and gender
No full textOvim se istraživanjem nastojalo otkriti ovisnost količine DNA-traga o različitim čimbenicima. Analizirala se povezanost dobi i spola donora te količine DNA koju su ispitanici ostavili na predmetima različite teksture (papir, plastika, plastificirani metal) prilikom trljanja prstima i dlanom ili držanja predmeta u ruci te ovisnost količine DNA-traga o vremenu kontakta ispitanika s predmetima. Predmeti su prebrisani navlaženim vatiranim štapićem, DNA se izolirala metodom Chelex, a za kvantifikaciju DNA se koristila lančana reakcija polimerazom u stvarnom vremenu (engl. Real Time PCR). Rezultati su pokazali da je količina DNA-traga neovisna o vremenu u kojem je ispitanik bio u dodiru s predmetima. Nasuprot tome, ovisna je o teksturi predmeta pri čemu je najveća količina DNA-traga ostala na plastificiranom metalu, a najmanja na papiru. Osobe između 35 i 44 godine starosti te muškarci ostavili su najveću količinu DNA-traga. Konačno, u ovom smo radu pokazali da je svojstvo ostavljanja određene količine DNA na predmetima individualno.The aim of this research was to discover the dependence of trace DNA quantity on various factors. We analyzed the correlation between handling time, donor age and gender and quantity of DNA trace left by individuals on items of different textures (paper, plastic, plastic coated metal) during rubbing with fingers and palm or holding items in a hand. Items were swabbed with moistened cotton swab, DNA was isolated by Chelex method and quantified by Real Time PCR. The results showed the amount of DNA transferred to an item was independent of the handling time. In contrast, it was dependent of item texture where the greatest amount was left on plastic coated metal and the least on paper. The greatest amount of DNA trace was left by individuals ranging in age from 35 to 44 years and men. Finally, this study showed that the tendency to deposit DNA on an item was an independent characteristic of a person
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
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