1,721,057 research outputs found
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
Omsetning av næringsstoffer i en humøs innsjø (Lundebyvannet) dominert av algen Gonyostomum semen
No full textNåleflagellaten Gonyostomum semen (Ehrenberg) Diesing, har hatt en markant økning i både utbredelse, forekomst og hyppige oppblomstringer i innsjøer i den boreale og subboreale sonen de siste 50 årene. G. semen blir sett på som en «problemalge» grunnet dens evne til å produsere slimtråder. Det har blitt rapportert om allergiske utslett på badegjester og tette filter ved drikkevannsproduksjon. Dette har ført til nedstengning av badeplasser og medført økonomisk tap for lokalsamfunn. Nyere studier har funnet sammenheng mellom innhold av løst organisk materiale (DOM) og G. semen biomasse. Samtidig ser man en jevn økning av DOM i skogsinnsjøer grunnet klimaforandringer og redusert sur nedbør. Denne studien fokuserer på G. semen sin evne til å omsette og utnytte næringsstoffer fra DOM. Det vil gi en stor konkurransefordel og kan forklare G. semen sin utbredelse og biomassedominans.
Feltstudien ble utført i en eutrof innsjø, Lundebyvannet (59.54911 N, 11.47843 E), som ligger i Indre Østfold kommune, Viken fylke, Norge. Feltperioden varte fra 20. mai til 25. august, 2020. G. semen har vært den dominerende algen i Lundebyvannet siden 1977, og danner årlige oppblomstringer med klorofyllkonsentrasjoner som jevnlig overstiger 100 μg/l. Dette har ført til at Lundebyvannet har vippet mellom «svært dårlig» og «dårlig» økologisk tilstand.
G. semen etablerte seg den 03. juni og forekom ut feltperioden. Det ble registrert to perioder med høye konsentrasjoner av G. semen. Studien fant ingen signifikant sammenheng mellom G. semen biomasse og løst organisk karbon (DOC), og dermed avkrefter at G. semen klarer å omsette DOM. Biomasseveksten av G. semen blir dermed knyttet opp til resirkulering av nitrogen og fosfor fra innsjøinterne kilder. Anaerobe forhold i hypolimnion førte til interngjødsling av fosfat og akkumulering av ammonium. G. semen sin evne til å utføre «diel vertical migration» (DVM) blir sett på som algens største konkurransefordel, og fører til at algen får tilgang til næringsstoffene i hypolimnion.
Selv om studien avkrefter sammenheng mellom DOM og G. semen biomasse, vil en økning av DOM tilrettelegge gunstige forhold for G. semen, ved å påvirke vannets egenskaper. En videre økning i DOM innhold i innsjøer vil dermed kunne føre til videre utbredelse av G. semen og gi utfordringer for vannforvaltning. Overvåkningsprogrammene som benyttes av vannforvaltningen bør videre utvikles, ved å overvåke hypolimnion. Dette vil kunne tilrettelegge data, som vil gi mulighet for riktige tiltak, mot en videre utbredelse av G. semen
Mobilization of metals and circulation patterns in meromictic lakes adjacent to roads
Get PDFForurensning fra veg er vist i flere studier å påvirke innsjøer ved å tilføre tungmetaller og vegsalt. Tilførsel av metaller kan ha potensielle toksiske effekter på biota, og vegsalt kan føre til endrede sirkulasjonsforhold i veinære innsjøer. Flere veinære innsjøer i Norge og andre land har fått forhøyede konsentrasjoner av vegrelaterte metaller som kobber, kadmium og bly. Søndre Brutjern er en innsjø i Østfold som ligger tett på E18 og FV128 og har i en lang periode vært utsatt for veiavrenning. I denne oppgaven har det vært forsøkt å finne ut om det er tilførsel av metaller fra E18 og om metaller kan mobiliseres på grunn av de meromiktiske forholdene skapt som følge av saltbrukt. Ved å bruke loggere som målte kontinuerlig konduktivitet og temperatur fra februar til august ble det undersøkt om det var tilførsel av salt fra E18 og undersøkt hvordan konduktivitet og temperatur varierte. Det ble valgt ut et punkt i den sørlige delen av Søndre Brutjern for å undersøke eventuelle tilførsler og hvordan sirkulasjonsforholdene var. Feltarbeidet ble utført fra april til august hvor det ble tatt 7 vannprøver annenhver uke fra 0,5-11,5 meters dyp. Prøvene ble undersøkt for metaller, farge, DOC og anioner. Det ble målt oksygenkonsentrasjon, temperatur og konduktivitet in situ under feltarbeid ved alle dyp. PCA analyse ble gjort for å undersøke korrelasjonen og variasjonen mellom de ulike variablene og t-test ble utført for å undersøke ulikhetene. Resultatene fra feltarbeidet viste at innsjøen var meromiktisk med påfølgende oksygensvinn under hele perioden som følge av saltsjiktning. Konsentrasjonen av de ulike vegrelaterte metallene som kobber, kadmium og bly var relativt lave, men det var økte konsentrasjoner i monimolimnion. Det var tilførsel av kobber og kadmium tidlig på våren, noe som antyder korrelasjon med snøsmelting. Resultatene viste også at det var tilførsel av vegsalt tidlig på våren, selv om vegen var blitt flyttet for å unngå dette problemet. Enkelte metaller ble holdt i løsning og konsentrasjonen av disse metallene økte utover sommeren. Kobolt, mangan og bly var i høyere konsentrasjoner i øvre vannlag enn i bunn utover sesongen. Selv om innsjøen er meromiktisk er det noe kontakt mellom mixolimnion og monimolimnion som kan føre til delvis utveksling av metaller og salt. Det var relativt lave konsentrasjoner av metaller og ingen metaller hadde konsentrasjoner som oversteg tilstandsklasse 2. Toksisiteten av disse metallene er derfor ansett å være lave og ikke et stort problem for biota.Road runoff have been shown in several studies to affect lakes by being a source of heavy metals and road salt. Input of metals can have potential toxic effects on biota and road salt can lead to a change in the circulation pattern in lakes adjacent to roads. Several lakes in Norway and other countries close to roads have increased concentration of metals associated to roads like copper, cadmium and lead. Søndre Brutjern, a lake in Østfold, lies in close proximity to E18 and FV128 and have for a long time been exposed to runoff from roads. This thesis has tried to investigate if there is runoff of metals from E18 and if metals can be mobilized because of the meromictic conditions as a result of salt usage. Measurements by continuous logging that measured conductivity and temperature from February until August were used to investigate if there is a supply of salt from E18 and to see how temperature and conductivity varied. A point in the south end of Søndre Brutjern were selected to investigate the possibility of a supply of metals and how the circulation patterns were. The field work was conducted between April and August, were 7 water samples between 0,5- 11 m depth were taken every time. The samples were analyzed for metals, color, DOC and anions. Oxygen concentration, temperature and conductivity were also measured in situ at every depth. A PCA analysis was performed to estimate the correlation and variation in the dataset and a t-test was performed to find significant differences. The results from the field work showed that the lake was meromictic and had anoxic conditions during the whole period as a result of salt stratification. The concentration of road related metals like copper, cadmium and lead was relatively low, however there were higher concentrations in monimolimnion. There were a supply of copper and cadmium during spring, which indicates correlation with snow melting. The results also showed a supply of road salt to the lake during spring, even though the road previously was moved to prevent this problem. Some metals stayed dissolved and the concentrations of these increased during summer and were found in higher concentrations at low depths. Cobolt, manganese and lead were found in higher concentrations in the top part and middle part than the lower part late in the season. Even though the lake is meromictic there is some contact between mixolimnion and monimolimnion which can lead to an exchange of metals and salt between these two zones. The concentrations of metals were generally low and none of the metals were in concentrations that exceeded class 2 according to an Environmental index system. The toxicity of these metals is therefore considered low and not a problem for biota.Statens VegvesenM-MIN
Langtidsutvikling innsjøen Øyeren studert med limnologiske metoder
Get PDFLake Øyeren is a freshwater lake in SE-Norway that is located in the lower part of the river Glomma, having a large drainage area. In the northern part of the lake, river Glomma and two smaller rivers have built up the largest inland delta of Northern Europe.
This study has two major purposes: (1) to reconstruct the long-term development in primary production of Lake Øyeren; (2) to identify inorganic pollution from local and long-range sources based on paleolimnological methods. Additionally, the impact of flooding and water level regulations on sediment transport in the lake was discussed. The sediment cores obtained from the deeper Øyeren basin were analysed to determine pigments and elements (macro- and trace elements) in the lake’s sediment.
In the first part of the thesis, the general information about Lake Øyeren and anthropogenic impact on its ecosystem are represented. The data obtained from the sediment cores were systemized and presented. The unusual period with a sharp increase in sedimentation rate and pigment amount was detected. That phenomenon was attributed to an internal movement of surface sediment. The multivariate relations between the sediment parameters were analysed by principal component analysis, while the multivariate relations between the parameters and explanatory variables (weather conditions) were analysed by redundancy analysis. Finally, the obtained results were interpreted in the discussion part with respect to the historical records from the catchment area. Also, the direct comparison of the water quality monitoring data and sediment records was conducted.
The research covers the development study of Lake Øyeren from the 1960s until present. It was concluded that the primary production remains at the same level as at the beginning of the 1960s, despite the high nutrient loading. The major sources of inorganic pollution since the 1970s until present are most probably an anthropogenic atmospheric deposition and upstream mineral particles, while for the 1960s we have observed the effect of point source pollution. Flood events and water level regulations seem to have a minor impact on the sedimentation rate.submittedVersionM-MIN
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
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