1,720,996 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
Discriminazione rapida fra ceppi vaccinali e di campo di Metapneumovirus aviare mediante tecnica RFLP
No full textIn Italia l’infezione da Metapneumovirus aviare (AMPV) si è diffusa a partire dal 1987. Successivamente si è endemizzata nelle Regioni a maggior vocazione avicola, con prevalenza del sottotipo B. Per il controllo delle infezioni da AMPV nell'allevamento del tacchino sono utilizzati vaccini vivi attenuati; fra quelli disponibili nel nostro Paese è diffuso l’utilizzo del sottotipo B, somministrato nei tacchini da carne, via spray, in incubatoio. E’ stato dimostrato che ceppi vaccinali possono essere evidenziati tramite RT-PCR fino alla quarta settimana di età, associati o meno a sintomatologia respiratoria. In presenza di forme cliniche risulta necessario poter discriminare tra ceppi di campo e di origine vaccinale.
L'analisi della sequenza del gene G di numerosi ceppi AMPV sottotipo B isolati in varie aree geografiche del mondo, ha rivelato la presenza, nella sola sequenza del vaccino B (ceppo VCO3) maggiormente utilizzato in Italia, di un sito di riconoscimento dall’enzima di restrizione Msel. Tale sito è localizzato nell'amplicone che si ottiene con il protocollo di RT nested-PCR messo a punto da Naylor et al., e comunemente impiegato in Europa per la diagnosi delle infezioni da AMPV e la distinzione fra sottotipi A e B.
Basandosi su queste evidenze, è stato messo a punto e testato su alcuni AMPV isolati in Italia un protocollo di PCR-Restriction Fragment Length Polymorphism (RFLP) in grado di discriminare fra ceppi sottotipo B di campo e vaccinali
Infectious Laryngotracheitis in Italy: clinical cases, diagnosis and characterization by PCR-RFLP
No full textNo abstract availabl
Identification and functional characterization of the bile acid transport proteins in non-mammalian ileum and mammalian liver
No full textIt has been proposed that intracellular carrier proteins mediate active transport of the bile acids within hepatocytes and ileocytes, during the enterohepatic circulation. In mammalian species only ileal bile acid binding proteins have been so far identified, while liver cytosolic carriers have never been found. On the contrary, in non-mammalian vertebrates, only liver, and not ileal, bile acid binding proteins were reported. The aim of the present work is to find the missing cytosolic transport proteins. A bioinformatic search allowed us to identify a non-mammalian putative bile acid binding protein in the chicken ileum (cI-BABP), which we recombinantly expressed and purified. The protein exhibits the capability, tested by in vitro NMR experiments, of binding bile acids. Furthermore, strong NMR evidence reported that the human liver fatty acid binding protein (hL-FABP) can also bind bile acids. Taken together, these data strongly suggest that both cI-BABP and hL-FABP have a bile acid binding function in the two organisms, and support a previous hypothesis on the role of hL-FABP in regulating bile acid metabolism and determining bile acid pool size
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
Characterization and antimicrobial resistance analysis of avian pathogenic Escherichia coli isolated from Italian turkey flocks
No full textThis study investigated the occurrence of avian pathogenic Escherichia coli (APEC) in a finishing turkey commercial farm, carrying out longitudinal surveys involving 3 consecutive flocks. The diversity and the distribution of the E. coli strains detected during colisepticemia outbreaks were examined. The strains were isolated, serogrouped, assessed for the presence of virulence-associated genes, typed by random amplification of polymorphic DNA (RAPD), and antimicrobial resistance analysis was then carried out. Escherichia coli O78 and O2 were predominantly found. Moreover, based on the somatic antigens used in the study, strains were recovered that were nontypeable. On one occasion, an E. coli O111 strain was found in turkeys. The E. coli isolates differed in terms of antibiotic resistance and RAPD profile. All strains possessed the virulence genes that enabled them to be considered APEC. Strains not only differed between flocks, but also within the same flock. These findings point out the importance of addressing colibacillosis therapy on the basis of a sensitivity test
Avian Metapneumovirus, Hemorrhagic Enteritis Virus and Avian Pathogenic Escherichia coli (APEC) interaction in a finishing turkey farm subjected to colibacillosis-associated mortality
No full textThe spectrum of pathogens responsible for colibacillosis-associated mortality is investigated by longitudinal surveys performed in three consecutive production cycles of a finishing toms farm. The surveys mainly focus on the interaction between Avian Metapneumovirus (AMPV), Haemorrhagic Enteritis Virus (HEV) and Avian Pathogenic Escherichia Coli (APEC). Rhino-pharyngeal swabs, cloacal swabs and blood samples were weekly collected for AMPV and HEV PCR detection, and antibody response evaluation, until birds were 14-weeks-old. Mortality was reported and dead birds were examined post mortem. When colibacillosis was suspected, microbiological tests were performed from selected organs. All detected E. coli strains were serotyped and assessed for the presence of virulence-associated genes. In the first cycle, colisepticaemia associated mortality was recorded at week 4, due to AMPV and APEC O78. Late high O78 or O2 APEC associated mortality was observed respectively in the second and third cycle; these outbreaks were correlated to both HEV and AMPV infections
Epidemiology of Avian pathogenic Escherichia coli (APEC) in a finisching male turkey farm: longitudinal survey of three consecutive production cycles.
No full textThe purpose of this study was to investigate the epidemiology of APEC (Avian Pathogenic Escherichia coli), in a finishing male turkey commercial farm, conducting longitudinal surveys of three consecutive production cycles. The diversity and the distribution of APEC strains during the production cycles were examined using microbiological and molecular techniques. APEC isolates were serotyped, assessed for the presence of virulence-associated genes (pathogenic potential – pathotype) and for resistance to antibiotics (resistotype). Random Amplified Polymorphic DNA (RAPD) was applied to analyse their genetic relationship. Strains of high genetic homology were grouped into the same RAPD cluster (RAPD type).
Sampling included, when colisepticemic or articular lesions were observed, viscera and joints from day one until 14 weeks.
In the first cycle, APEC O78 was the most prevalent serotype with all isolates sharing the same resistotype and pathotype. Seven of them were included in the same RAPD cluster indicating high genetic similarity. In this cycle, APEC O111 was detected and this represents, to our knowledge,
In the second cycle, APEC O2 isolates predominated at the beginning, while O78 strains appeared later until the end of the survey. APEC O2 were classified in two resistotypes, same pathotype and RAPD type. APEC 078 belonged to three resistotypes, same pathotype and three RAPD types. APEC O78 strains, differently from serotype O2, were detected from both colisepticemic viscera (such as brain, pericardium, lungs) and joints. The articular tropism of this serotype is unique as it was observed only in APEC O78 strains of this cycle and of the previous one. Moreover, RAPD molecular studies identified a specific articular O78 cluster, including two strains, which was different from other RAPD clusters including O78 and O2 colisepticemic strains
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