1,721,010 research outputs found
Microbial Risk Assessment of Thermophilic Campylobacter SPP. in Raw Vegetables from Farm to Table
Full text linkThe first aim of this study was to determine the prevalence and number of
thermophilic Campylobacter spp. (Campylobacter jejuni, Campylobacter coli and
Campylobacter fetus) in raw vegetables (ulam) at pre-harvest and retail level,
soil and animal manure in an organic and a traditional vegetable farm. The
biosafety of Campylobacter jejuni was assessed by phenotypic (antibiotic
resistance) and genotypic (presence of virulent and toxin genes) as well as
RAPD-PCR characteristics of the strains isolated from vegetables. A kitchen
simulation study was conducted to provide decontamination and crosscontamination
data and information for estimation of the risk of acquiring
campylobacteriosis from consumption of ulam using a step-wise risk
assessment. The prevalence of thermophilic Campylobacter spp. in 309 (number of
samples) raw vegetables purchased from two supermarkets and a wet
market was relatively high, 29% to 68%. Campylobacter jejuni (25.5% to 67.7%)
and C. coli (21.6% to 65.7%) were predominant species isolated; while C.
fetus was only detected in two samples (1.9%) from one of the supermarkets.
Only 18.3% of Campylobacter-MPN-PCR positive samples were recovered by
enumeration-plating method indicating that routine enumeration-plating
methods has very low recovery rate for Campylobacter spp. from vegetables.
The study was extended to investigate the level of contamination with
Campylobacter spp. in vegetables farms. A total of 172 samples of animal
manure (n=18), soil (n=60), irrigation water (n=45) and vegetables (n=49)
samples were collected from both an organic and a conventional vegetable
farm. The organic vegetable farm (20.5%) was found to have a higher
prevalence of Campylobacter spp. compared to the vegetable farm practicing
conventional farming (2%). The low contamination level in the conventional
farm was most probably due to the bed-burning practice and the use of
composted manure in the farm. Campylobacter coli was not detected in all the
samples from both farms. Soil (30.4%) and animal manure (57.1%) sampled from the organic vegetable farm were found to harbor Campylobacter spp.
and C. jejuni. However, none of the irrigation water samples examined from
both farms were positive for Campylobacter spp.
RAPD-PCR fingerprinting and antibiotic resistance profiling indicated that
multi-resistant Campylobacter spp. might be wide-spread in the study area.
Clustering of C. jejuni isolates based on RAPD-PCR profiles suggested that
some isolates from different sources and locations were genotypically
closely related. Clusters A2, A3, A5 and A6 comprised C. jejuni strains
isolated from raw vegetables in the supermarkets and a wet market. All
clusters including B1 and B3, which comprised strains only from
supermarkets, were actually consisted of isolates from different sources. The
isolates showed multi-resistance to as many as 10 antibiotics tested. All the
isolates were detected to carry the virulent genes, cadF, ceuE and flaA.
However, toxin genes detection indicated only 16.1% and 10.7% of the
isolates carry cdtB and cdtC toxin genes, respectively; while none of the
isolates carry cdtA gene.
The potential of raw salad vegetables as a vehicle in C. jejuni transmission
was demonstrated by a step-wise risk assessment. Based on the assumptions used in the step-wise risk assessment, the annual number of
cases of campylobacteriosis acquired from the consumption of ulam is
estimated to be 4992/100,000 of Malaysian population, assuming that 10% of
Campylobacter spp. infection translates into illness. However, the risk
estimate was predicted to reduce to 175/100,000 if an extra blanching step
was incorporated into the model. In conclusion, there is an immediate need
for further investigation to look into the wide-spread problem of
Campylobacter spp. in ready-to-eat foods, such as salad and ulam, in Malaysia
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
Elucidating the survival and response of carbapenem resistant Klebsiella pneumoniae after exposure to imipenem at sub-lethal concentrations
No full textThe increasing prevalence of antibiotic resistant pathogens poses a serious threat to global health. However, less emphasis has been placed to co-relate the gene expression and metabolism of antibiotic resistant pathogens. This study aims to elucidate gene expression and variations in metabolism of multidrug resistant Klebsiella pneumoniae after exposure to antibiotics. Phenotypic responses of three genotypically distinct carbapenem resistant Klebsiella pneumoniae (CRKP) strains untreated and treated with sub-lethal concentrations of imipenem were investigated via phenotype microarrays (PM). The gene expression and metabolism of the strain harboring blaNDM-1 before and after exposure to sub-lethal concentration of imipenem were further investigated by RNA-sequencing (RNA-Seq) and 1H NMR spectroscopy respectively. Most genes related to cell division, central carbon metabolism and nucleotide metabolism were downregulated after imipenem treatment. Similarly, 1H NMR spectra obtained from treated CRKP showed decrease in levels of bacterial end products (acetate, pyruvate, succinate, formate) and metabolites involved in nucleotide metabolism (uracil, xanthine, hypoxanthine) but elevated levels of glycerophosphocholine. The presence of anserine was also observed for the treated CRKP while FAPγ-adenine and methyladenine were only present in untreated bacterial cells. As a conclusion, the studied CRKP strain exhibited decrease in central carbon metabolism, cell division and nucleotide metabolism after exposure to sub-lethal concentrations of imipenem. The understanding of the complex biological system of this multidrug resistant bacterium may help in the development of novel strategies and potential targets for the management of the infections.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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