1,720,978 research outputs found
A SCORING MODEL FOR RISK CHARACTERISATION AND SETTING PRIORITIES IN VETERINARY PUBLIC HEALTH
Full text linkA model for prioritization and risk characterization was developed for diseases of interest in veterinary public health. This model was called scorecard and focused on zoonosis and food safety at regional level. The scorecard was part of a shared initiative between Lombardy regional government and the Department of Veterinary Science and Public Health (University of Milan) aimed to improve veterinary regional services. A previous model (DISCONTOOLS) was used as starting point to develop the new one. Formalized Consensus Process approach involving academics and veterinary officers was used to develop the scorecard model. Furthermore, a guide and a form were settled in order lead the scoring process. Formalized Consensus Process is a five-step procedure which includes a systematic review of literature, an assessment of issues, initial proposals, a discussion and improvement of proposals and, finally, a validation of operational recommendations. The final scorecard model has a maximum theoretical score of 1,000; it includes several areas of interest, with different categories and coefficient of importance. The following areas were identified: relevance of the disease, socio-economic impact, impact on public health, impact on trade, impact on animal welfare, control tools. Scorecards were filled following available data, literature and expert opinions. From an initial list of 38 disease, 23 were scored. Among bovine diseases, mastitis (S. aureus) showed the highest score; among small ruminants Query fever was the highest, among swine diseases the highest was salmonellosis, while among other animal diseases toxoplasmosis had the highest score. This approach is conceived to aid professionals in risk prioritization, decision-making and to improve disease control systems at a regional level. It also allows to perform risk characterization in different backgrounds and to identify lacks of data in specific areas of interest for the diseases considered
Staphylococcus aureus virulence factors in evasion from innate immune defenses in human and animal diseases
No full textIn the last decades, Staphylococcus aureus acquired a dramatic relevance in human and veterinary
medicine for different reasons, one of them represented by the increasing prevalence of antibiotic resistant
strains. However, antibiotic resistance is not the only weapon in the arsenal of S. aureus. Indeed,
these bacteria have plenty of virulence factors, including a vast ability to evade host immune defenses.
The innate immune system represents the first line of defense against invading pathogens. This system
consists of three major effector mechanisms: antimicrobial peptides and enzymes, the complement
system and phagocytes. In this review, we focused on S. aureus virulence factors involved in the immune
evasion in the first phases of infection: TLR recognition avoidance, adhesins affecting immune response
and resistance to host defenses peptides and polypeptides.
Studies of innate immune defenses and their role against S. aureus are important in human and veterinary
medicine given the problems related to S. aureus antimicrobial resistance. Moreover, due to
the pathogen ability to manipulate the immune response, these data are needed to develop efficacious
vaccines or molecules against S. aureu
Pattern characterization of genes involved in non-specific immune response in Staphylococcus aureus isolates from intramammary infections
Full text linkStaphylococcus aureus isolated from mammary gland are characterized by different genetic patterns. Ninety four isolates from 33 dairy herds were analyzed by the means of amicroarray to investigate S. aureus virulence patterns and the distribution of genes believed to be involved in immune evasion. None of the 94 isolates considered were MRSA. However, 50% of the isolates belonged to complexes related to MRSA and to human diseases, while only about 25% of them can be considered as exclusively of bovine origin. The distribution of clonal complexes and the different gene patterns observed confirmed the presence of an influence of geographical localization.
The assessment of the influence of genes related to immune evasion on quarter milk cell count showed as four of them showed to be significantly associated to an increase quarter milk SCC. These genes could be potential target for developing new vaccines against S.aureus
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
Indagine sulla patogenicità di ceppi mobili di aeromonas spp. isolati da specie ittiche
No full textLo studio della patogenicità di Aeromonas spp. è caratterizzato da notevole complessità, sviluppandosi in genere su più livelli e comprendendo saggi biologici in vitro (linee cellulari) ed in vivo (modelli animali), esami molecolari ed analisi delle proprietà fenotipiche degli isolati.
Nell’ambito di una tesi di specialità (Allevamento, Igiene, Patologia delle Specie Acquatiche e Controllo dei Prodotti Derivati) sulla caratterizzazione in vitro della virulenza di questi microrganismi, sono stati esaminati 101 ceppi di Aeromonas mobili, provenienti da specie ittiche selvatiche (69), allevate (26), ed ornamentali (6). L’isolamento è avvenuto da pesci setticemici (27) e apparentemente sani (74). Per ciascuno degli isolati, identificati biochimicamente a livello di complex, sono state analizzate le proprietà citotossiche su tre diverse linee cellulari (EPC, BF2, Vero) ed una serie di caratteristiche colturali (crescita a 37°C, emolisi), biochimiche (test VP, decarbossilazione della lisina, fenomeno del suicidio) ed enzimatiche (lipasi, gelatinasi) indicate in letteratura come potenziali fattori di virulenza di Aeromonas spp. In particolare, si è indagato sulla correlazione fra questi fattori, la fenospecie dei ceppi (A. hydrophila, A. sobria, A. caviae), la provenienza (selvatica, allevata) ed il quadro clinico delle specie ittiche d’isolamento.
In generale, lo studio ha registrato alte prevalenze (54.5-99.0%) dei potenziali indicatori di patogenicità all’interno del campione testato. La produzione di lipasi (98.0%) e gelatinasi (99.0%) è stata il fattore più frequentemente riscontrato. Anche le caratteristiche colturali/biochimiche hanno mostrato un’ampia diffusione fra i ceppi esaminati, con prevalenze variabili dal 70.3% (crescita a 37°C) al 94.1% (fenomeno del suicidio: attività non suicida). L’attività citotossica ha rappresentato il fattore di virulenza meno prevalente (54.5%).
Dai risultati è emersa una correlazione della capacità di crescita a 37°C, attività emolitica e citotossica con la fenospecie dei ceppi, in particolare con i complex A. caviae (crescita a 37°C) ed A. hydrophila (attività emolitica e citotossica). Ad esclusione dell’azione decarbossilasica sulla lisina, prevalente negli isolati selvatici, nessuno dei markers di virulenza è risultato associato all’origine dei ceppi. Solamente la crescita a 37°C è stata correlata con presenza di patologia nei pesci, indicando una scarsa significatività dei fattori fenotipici analizzati nella caratterizzazione in vitro in tal senso della patogenicità di Aeromonas spp.
Dei sistemi cellulari testati, le cellule Vero si sono dimostrate le più sensibili alle citotossine prodotte da Aeromonas spp. Si ritiene comunque che l’importanza di utilizzare le cellule Vero sia legata, oltre ad una migliore visualizzazione dell’effetto citopatico, anche alla possibilità di individuare ceppi in grado di esprimere il loro potenziale patogeno nei mammiferi e nell’uomo, il quale andrebbe però confermato mediante l’impiego dei tradizionali modelli animali.
Ulteriori studi si rendono necessari per meglio definire il significato clinico dei fattori di virulenza di Aeromonas spp. nei pesci, da eseguirsi su un maggior numero di isolati ed associando l’esame dei caratteri fenotipici dei ceppi alle analisi molecolari e, soprattutto, alle prove biologiche in vivo
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