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Microbial Adaptations to Pulses of Organic Matter in the Deep-Sea
No full textDen biologiske kulstofpumpe i havet henviser til eksporten af partikulært organisk materiale (POM)fra overfladen til dybere vandlag, en proces der bidrager til langvarig kulstoflagring i havet. Mikrobiel omdannelse af både partikulært organisk materiale (POM) og opløst organisk materiale(DOM) modulerer effektiviteten af denne pumpe ved at regulere skæbnen for kulstof på tværs af dybder og oceanografiske forhold. I den del af havet der henligger i mørke, særligt i den bathypelagiske zone (1000-4000 m), styres denne omdannelse af organisk stof af et komplekst samspil af miljømæssige faktorer, herunder temperatur, højt hydrostatisk tryk (HHP) og kvaliteten af organiske materiale. På trods af den store betydning af disse processer, er de samlede påvirkninger af disse faktorer på mikrobielt stofskifte og sammensætningen af de mikrobielle samfund dårligt belyst, hvilket begrænser anvendeligheden af globale modeller for kulstofkredsløbet i dybhavet. Denne afhandling undersøger, hvordan disse faktorer påvirker prokaryote mikroorganismers respiration (PR), produktion (PP), væksteffektivitet (PGE) og samfundssammensætning (PCC) over et bredt interval havdybder og oceanografiske forhold. Manuskript I indeholder en systematisk vurdering af hvordan temperatur (0 - 25℃), organisk material sammensætning (primært C:N-forholdet), og substratkompleksitet påvirker det mikrobielle stofskifte fra overflade til den bathypelagiske zone. Alanin (C:N = 3:1) understøttede den højeste PGE, mens glukose (Ingen N) stimulerede den mikrobielle respirationen. Q10 værdier varierede fra1,9-2,9, hvor de mikrobielle samfund i de dybere zoner viste større temperaturfølsomhed. Sekventering af 16S rRNA afslørede at forskydninger PCC (ændringer sammensætningen af i de mikrobielle samfund) afspejlede de metaboliske ændringer med dybden, og dybe samfund viste den mest udtalte taksonomiske omstrukturering med stigende temperatur. Dette indikerer en tæt kobling mellem metabolisme og samfundssammensætning i dybhavet. Disse resultater antyder, at selv bathypelagiske mikrober responderer på temperaturændringer, og er reguleret af OM kvalitet. Manuskript II behandlede, hvordan HHP og OM kompleksitet modulerer PR, PP, PGE, og PCC i dybhav (2000 - 4000 m) i forhold til i lavvandede (20 m) mikrobielle samfund. Overfladesamfund viste stærk trykfølsomhed, med næsten fuldstændig hæmning af PP og endda celledød ved tryk≥32,5 MPa. Forsøg med at genoprette den mikrobielle aktivitet efter trykhæmning, der involverede tryksænkning for at måle genopretning i metaboliske hastigheder ved atmosfærisk tryk efter HHP eksponering, bekræftede at denne trykinducerede undertrykkelse i overflademikrober ved tryk≥32,5 var irreversibel. I modsætning til dette, opretholdt dybhavssamfund deres metabolisk aktivitet under in-situ trykforhold, især når de blev forsynet med det komplekse polymere substrat chitin. Disse resultater viser hvordan det komplekse samspil af miljøfaktorer, der er karakteristiske for dybhavet, såsom HHP og tilgængelighed og kvalitet af OM, påvirker de mikrobielle processer. Manuskript III udvidede denne ramme ved at sammenligne effekten af OM kvalitet og HHP på metabolisme og sammensætning af mikrobielle samfund på to lokaliteter i den vestlige Nordatlanten med meget forskellige produktionsforhold (oligotrof gyre vs næringsrige lokalitet) på tværs af en vertikal dybdegradient med 6 dybder fra 10 m til 4000 m. Påvirkningen af de mikrobielle reaktioner varierede med OM-type (tilsætning af koncentrerede partikler vs POC og DOC), og tilsætningen af chitin understøttede en højere PR og PP under in-situ tryk, hvilket er i overensstemmelse med resultaterne fra Manuskript II. Kulstofremineralisering integreret overdybdeintervallet 0-4000 m var cirka 25 % lavere under in situ-tryk sammenlignet med atmosfærisktryk, hvor den næringsrige station havde omkring 1,4 gange højere rater end den oligotrofe gyre. Disse observationer fremhæver den stærke indflydelse af regionale biogeokemiske forhold på mikrobielt stofskifte og afslører, at biomasseproduktion respondere mere end respiration på de lokale miljømæssige variationer. Tilsammen demonstrerer disse opdagelser, at mikrobielkulstofomsætning i oceanets indre er stærkt afhængig af den lokale fysisk-kemiske forhold. Effekterne af tryk og temperatur moduleres af OM-kvalitet, med implikationer for modellering af kulstoffluxe. Denne afhandling demonstrerer behovet for undersøgelser betydningen af tryk, stedsspecifikke forhold og substratsammensætning for at opnå en mere detaljeret forståelse af hvordan den mikrobielle metabolisme reguleres og hvilken rolle de spiller in det globale kulstofkredsløb.The biological carbon pump of the ocean refers to the export of particulate organic matter (POM)from surface to depth, a process that contributes to long-term carbon sequestration in the ocean. Microbial transformation of both particulate organic matter (POM) and dissolved organic matter(DOM) modulates the efficiency of this pump by regulating the fate of carbon across depths and oceanographic settings. In the dark ocean, particularly the bathypelagic zone (1000-4000 m), these transformations are governed by a complex interplay of environmental factors including temperature, high hydrostatic pressure (HHP), and organic matter (OM) quality. Yet, the combined effects of these variables on microbial metabolism and community composition remain poorly resolved, limiting predictive models of deep-ocean carbon cycling. This thesis investigates how these factors shape prokaryotic respiration (PR), production (PP), growth efficiency (PGE), and community composition (PCC) across a range of depths and oceanographic settings. Manuscript Isystematically assessed how temperature (0 - 25℃), OM stoichiometry (C:N), and substrate complexity influence microbial metabolism from surface to bathypelagic waters. Alanine (C:N =3:1) supported the highest PGE, while glucose (N-poor) preferentially stimulated respiration. Q10values ranged from 1.9-2.9, with deeper communities exhibiting greater temperature sensitivity. Crucially, 16S rRNA sequencing revealed that PCC shifts mirrored metabolic trends, and deep communities showed the most pronounced taxonomic restructuring with increasing temperature,indicating tighter coupling between metabolism and community turnover at depth. These resultssuggest that even bathypelagic microbes retain temperature-responsive traits, modulated by OMquality. Manuscript II addressed how HHP and OM complexity modulate PR, PP, PGE and PCC indeep-sea (2000 - 4000 m) vs shallow (20 m) microbial communities. Surface communities exhibited strong pressure sensitivity, with near-complete suppression of PP and even cell-death at pressures≥32.5 MPa. Recovery experiments which involved pressurizing surface microbes followed by depressurization to measure recovery in metabolic rates at atmospheric pressure confirmed their reversibility of this pressure-induced suppression in surface microbes at pressures ≥32.5. In contrast, deep-sea communities maintained metabolic activity under in-situ pressure conditions, particularly when supplied with the complex polymeric substrate chitin. These results show the complex interplay of environmental factors characteristic of the deep-sea such as HHP and OM availability and quality in shaping microbial responses. Manuscript III expanded this framework by comparing metabolic and community composition responses to OM quality and HHP at two contrasting sites in the Western North Atlantic (oligotrophic gyre vs nutrient-rich boundary current) across a vertical depth gradient with 6 depths from 10 m to 4000 m. Microbial responses varied with OM type (concentrated particles vs POC and DOC), and chitin addition supported higher PR and PP under in-situ pressures, consistent with the results from Manuscript II. Carbonremineralisation integrated over the 0-4000 m depth range was approximately 25% lower under insitu pressure compared to atmospheric conditions, with the nutrient-rich station showing rates about1.4 times higher than those in the oligotrophic gyre. These findings highlight the strong influence of regional biogeochemical conditions on microbial metabolism and reveal that biomass production responds far more dramatically than respiration to local environmental context. Together, these findings demonstrate that microbial carbon processing in the ocean interior is highly contingent upon local physicochemical context. The effects of pressure and temperature are modulated by OMquality, with implications for carbon flux modeling. This thesis demonstrates the need for pressureaware, site-specific and substrate-specific studies to refine our understanding of microbial dynamics and their role in the biological carbon pump
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
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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