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Dai Qing, une femme libre
No full textde Goldfiem Jacques. Dai Qing, une femme libre. In: Perspectives chinoises, n°1, 1992. pp. 16-17
Binding of plasma proteins by Staphylococcus epidermidis: characterisation of protein-protein interactions
No full textCoagulase-negative staphylococci (CoNS), in particular, Staphylococcus epidermidis, have emerged as major nosocomial pathogens associated with infections of implanted medical devices. These organisms, which are among the most prevalent bacteria of the human skin and mucous membrane microflora, gain access to the surface of the implant at the insertion. However, the subsequent infection may erupt up to a year later or more. It is currently believed that two steps are involved in the infections: 1) primary bacterial adhesion to the biomaterial surface, which has been covered by host factors; 2) bacterial cell accumulation and biofilm formation. Specific interaction between bacteria and host factors, e.g. adsorbed plasma proteins on a biomaterial surface, has long been regarded as a key step in the pathogenesis of S. epidermidis infections. Our studies deal with the binding of vitronectin (Vn), clusterin (Clu), recombinant von Willebrand factor (rvWF) and thrombospondin (TSP) by S. epidermidis. S. epidermidis binds soluble forms of Clu, rvWF and TSP specifically. Bacterial binding to immobilised Vn, rvWF and TSP was higher than the positive control Staphylococcus aureus strains. Although S. epidermidis might not utilise immobilised Clu as an attachment site on biomaterial, Clu binding by S. epidermidis can abate the inhibitory effects of Clu on membrane attack complex (MAC) formation. Therefore, the binding may contribute to endothelial cell injury and inflammation developing around colonised implants. In addition, two Vn-binding proteins (21 and 52 kDa) of S. epidermidis strain BD5703, isolated from cerebrospinal fluid (CSF) shunt infection, were purified and identified. Glucosaminidase (the 52 kDa protein) is the major Vn-binding protein of BD5703. Extracellular cysteine protease (the 21 kDa protein) may also be important in the pathogenesis of CSF shunt infections. With increased bacterial resistance to traditional antibiotics, vaccination is likely to become more important to combat staphylococcal infections. In a mouse sepsis model, immunisation with cell surface extract of S. aureus strain Phillips stimulated the host to produce protective antibodies. This is promising for further investigations
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
Binding of plasma proteins by Staphylococcus epidermidis: characterisation of protein-protein interactions
No full textPopular Abstract in Swedish Sammanfattning på svenska Stafylokocker ingår i vår normala bakterieflora på hud och slemhinnor, men kan också ge upphov till infektioner. Staphylococcus aureus, den gula stafylokocken, är den vanligaste orsaken till sårinfektioner och "sjukhussjuka", och orsakar allvarliga djupa infektioner i ben, hjärta och andra inre organ, samt blodförgiftning. S. epidermidis, den vita stafylokocken, har mycket lägre sjukdomsframkallande förmåga och orsakade tidigare främst infektioner hos patienter med nedsatt infektionsförsvar. Nu är S. epidermidis och närbesläktade, s.k. koagulasnegativa stafylokocker, KNS, den viktigaste orsaken till infektioner i anslutning till främmande kroppar, biomaterial, som satts in för temporärt eller permanent bruk. Användningsområden för biomaterial är t.ex. katetrar i kärl för tillförsel av näring och medicin, bukkatetrar för dialys hos patienter med njursvikt, shunt och kateter i hjärnan för att avleda ryggmärgsvätska ("vattenskalle"), ögonlinser, ledproteser, hjärtklaffar och ersättning av kärldelar vid grav åderförkalkning. Infektioner med KNS har ett smygande förlopp och kan ge kliniska symptom upp till år efter insättandet. De är i princip omöjliga att behandla med antibiotika, utan leder till att materialet måste bytas ut. I anslutning till penicillinets upptäckt på 1940-talet trodde vi, att alla bakteriella infektioner kunde behandlas framgångsrikt med antibiotika. S. aureus utvecklade emellertid relativt snabbt motståndskraft (resistens) mot penicillin genom produktion av ett inaktiverande enzym. Numera sprids stammar, som är resistenta även mot enzymstabilt penicillin, s.k. methicillinresistenta S. aureus, MRSA, över stora delar av världen. Sverige är hitintills relativt förskonat, eftersom vi undersöker alla patienter och all personal, som har varit i kontakt med sjukvård utomlands för bärarskåp av MRSA, innan de läggs in på en allmän avdelning. Det senaste decenniet har även methicillinresistenta S. epidermidis , MRSE, spridits inom sjukvården. Detta har aktiverat forskning för att framställa ett stafylokockvaccin. För att göra detta måste de sjukdomsframkallande egenskaperna kartläggas. Hos S. aureus känner vi till ett 30-tal toxiner, t.ex. tampongsjuketoxin, enzymer och proteinbindande strukturer, som kan vara vidhäftningsfaktorer. Dessa binder kroppsproteiner i serum och vävnad under hud och slemhinnor, vilka exponeras vid skador på de senare, t.ex. brännskada. Tre proteiner, som binder fibrinogen, två, som binder fibronektin, och andra, som binder kollagen, vitronektin, trombospondin m.fl. har beskrivits. S. epidermidis producerar långt färre toxiner, enzymer och proteinbindande strukturer. Ett vitronektinbindande och ett fibrinogenbindande protein, samt en kolhydratstruktur har karakteriserats. Den allmänna uppfattningen är, att bindande strukturer, som uttrycks på bakteriens yta, kan vara viktiga som vaccinkandidater. I denna avhandling beskrivs vitronektinbindning närmare. Det viktigaste proteinet för vitronektinbindning är ett enzym, glucosaminidase (52 kDa), men även ett cysteine proteas, som utsöndras från bakterien (21 kDa), kan vara av klinisk betydelse. Vitronektinbindning hos KNS skiljer sig helt från den tidigare beskrivna hos S. aureus. Ett tidigare inte känt trombospondinbindande protein karakteriseras, och visas binda till en annan del av molekylen än den, som S. aureus binder till (en heparinbindande domän). Flera icke tidigare kända proteiner, som binder von Willebrand faktor, ett serumprotein, beskrivs. En del av dessa kunde också binda trombospondin. Bindning av clusterin, ett serumprotein med egenskaper liknande vitronektin, har karakteriserats. Proteiner kan exponera olika potentiellt bindande domäner, om de befinner sig i löslig form, t.ex. i serum, eller är immobiliserade på en fast yta, t.ex. ett biomaterial. S. epidermidis kunde binda clusterin endast i löslig form. Clusterinbindning av stafylokocker visades ge ökad komplementaktivering, så även om clusterinbindning inte är sannolik som vidhäftnings-mekanism, så kan den bidra till den inflammatoriska reaktionen och slemhinneskada, just genom att öka komplementaktiveringen. I en musmodell för blodförgiftning vaccinerades mössen med extrakt av ytskalet av S. aureus respektive S. epidermidis. Djuren bildade antikroppar mot identifierade strukturer hos båda bakterierna. När djuren sedan fick injektion av levande bakterier, var djuren som vaccinerats med ytextrakt av S. aureus skyddade mot allvarlig form av infektionen, medan de, som vaccinerats med S. epidermidis uppvisade visst skydd, men denna nådde ej statistisk signifikans. Slutsatsen är, att för S. aureus infektioner är identifiering av ytstrukturer, som ger skydd mot infektion en framkomlig väg för ett framtida stafylokockvaccin. För S. epidermidis och andra KNS är bilden inte lika klar. Här kan tillförsel av färdigframställda antikroppar, s.k. passiv immunisering, vara en framkomlig väg.Coagulase-negative staphylococci (CoNS), in particular, Staphylococcus epidermidis, have emerged as major nosocomial pathogens associated with infections of implanted medical devices. These organisms, which are among the most prevalent bacteria of the human skin and mucous membrane microflora, gain access to the surface of the implant at the insertion. However, the subsequent infection may erupt up to a year later or more. It is currently believed that two steps are involved in the infections: 1) primary bacterial adhesion to the biomaterial surface, which has been covered by host factors; 2) bacterial cell accumulation and biofilm formation. Specific interaction between bacteria and host factors, e.g. adsorbed plasma proteins on a biomaterial surface, has long been regarded as a key step in the pathogenesis of S. epidermidis infections. Our studies deal with the binding of vitronectin (Vn), clusterin (Clu), recombinant von Willebrand factor (rvWF) and thrombospondin (TSP) by S. epidermidis. S. epidermidis binds soluble forms of Clu, rvWF and TSP specifically. Bacterial binding to immobilised Vn, rvWF and TSP was higher than the positive control Staphylococcus aureus strains. Although S. epidermidis might not utilise immobilised Clu as an attachment site on biomaterial, Clu binding by S. epidermidis can abate the inhibitory effects of Clu on membrane attack complex (MAC) formation. Therefore, the binding may contribute to endothelial cell injury and inflammation developing around colonised implants. In addition, two Vn-binding proteins (21 and 52 kDa) of S. epidermidis strain BD5703, isolated from cerebrospinal fluid (CSF) shunt infection, were purified and identified. Glucosaminidase (the 52 kDa protein) is the major Vn-binding protein of BD5703. Extracellular cysteine protease (the 21 kDa protein) may also be important in the pathogenesis of CSF shunt infections. With increased bacterial resistance to traditional antibiotics, vaccination is likely to become more important to combat staphylococcal infections. Ina mouse sepsis model, immunisation with cell surface extract of S. aureus strain Phillips stimulated the host to produce protective antibodies. This is promising for further investigations
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
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