1,721,115 research outputs found
Effect of probiotic treatment on the host gut metabolic profiles via gas-chromatography-mass spectrometry-solid phase microextraction and 1H nuclear magnetic resonance spectroscopy
No full textThe capacity of human Lactobacilli and Bifidobacteria to produce metabolites under conditions that may prevail in the human intestine has been studied in vitro. However the effect of systematic probiotics consumption on human metabolic phenotype has not been investigated in feces.
This paper shows the potential for the use of 1H-Nuclear Magnetic Resonance (1H-NMR) spectroscopy for studying the changes of the metabolic profiles of human fecal slurries.
Feces of 16 subjects characterized by natural different level of Lactobacilli and Bifidobacteria before and after 1 month of supplementation with a symbiotic food based on Lactobacillus acidophilus, Bifidobacterium longum and fructooligosaccharides have been analyzed with 1H NMR. Multivariate statistical approach has been applied to the data obtained and particularly Canonical Discriminant Analysis of Principal Coordinates (CAP).
More than 150 molecules belonging to the short chain fatty acids, organic acids, esters, alcohols and amino acids were detected and quantified in the samples considered. The number and the extent of these molecules in fecal slurries were strongly affected by the symbiotic food consumption and gave rise to characteristic metabolic signature. In particular, the short chain fatty acids concentrations significantly increased while the amino acids contents decreased. The comparison of the data indicated that the intake of the symbiotic food taken into consideration alters the metabolism of hosts in a measure dependent on the natural initial level of Lactobacilli and Bifidobacteria in the host fecal slurries. 1H NMR profiles combined with CAP allowed a separation of fecal slurries of the subjects considered on the basis of the thirty days supplementation or not with symbiotic food. The analytical system and the multivariate statistical approach used demonstrate the potential of metabolic profiling of the gut microbial activity related to dietary supplementation of probiotics
Inactivation of foodborne pathogens on leek and alfalfa seeds with supercritical carbon dioxide
Full text linkThis study aimed to evaluate the effect of supercritical CO2 process for the inactivation of artificially contaminated seeds of leek and alfalfa. The seeds were inoculated with E. coli O157:H7, Listeria monocytogenes, and Salmonella Thompson and S. Typhimurium and treated at 80 and 120 bar and at 35 and 45 °C for 20 min. The process did not influence the germination rate of the seeds. The inactivation was dependent from the type of seed and pressure and temperature. At 120 bar and 45 °C E. coli O157:H7, L. monocytogenes, and Salmonella spp. were reduced by 2.92 ± 0.27, 1.14 ± 0.63, and 1.74 ± 0.55 log CFU/g, respectively, on alfalfa and by 4.96 ± 0.37, 2.93 ± 0.27, and 3.18 ± 0.27, respectively on leek. Overall, these results indicated that supercritical CO2 can be used to improve the microbial safety of sprouts, especially for leek
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
Rotating Dielectric Barrier Discharge Plasma Source for Effective Bacterial Decontamination of Bioaerosols
Full text linkThe airborne transmission of pathogens such as bacteria and viruses via aerosols is one of the most insidious ways of spreading diseases, such as COVID-19, hospital-acquired infections (HAIs), and, in the food industry, contamination of processed foods with food pathogens. Due to their small size, the nuclei of such aerosol droplets can remain suspended in the air for a long time and travel long distances. It is thus of high importance to identify increasingly effective solutions in terms of microbial decontamination of air to be used as a stand-alone application or in synergy with traditional techniques (e.g., filters and UV lamps). In this study, a DBD architecture, rotating dielectric barrier discharge, (RDBD) was devised. Its efficacy as a plasma source was tested inside a chamber containing bioaerosols contaminated with Staphylococcus epidermidis. The results showed that RDBD achieves bacterial inactivation levels greater than 3.6 Log 10 CFU, comparable to those achieved with a commercial device operating at comparable ozone concentrations. Moreover, an observable distinction lies in the reduced average discharge power exhibited by RDBD compared to the power output of the commercial device. Additionally, it is noteworthy that the air flow rate elaborated by RDBD surpasses that of the commercial device by a factor of 3.5. Furthermore, the empirical demonstration established a strong correlation between mean discharge power and resulting ozone concentration, underscoring their pivotal roles in bacterial inactivation. Conversely, the voltage range examined in this investigation does not manifest any discernible effect on the inactivation of microorganisms, given comparable power levels and ozone concentrations. Consequently, these last parameters are critical in scaling a plasma source for air decontamination
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
- …
