518 research outputs found
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The application of molecular techniques for the rapid and sensitive detection of gastrointestinal pathogens directly in food
Conventional microbiological methods are slow, labour intensive and are unable to meet the demands for rapid food testing. Molecular methods, such as PCR, offer a rapid, sensitive and specific means of detecting pathogens, however loss of sensitivity and lack of robustness have been reported when PCR is applied to heterogeneous and complex food matrices. The aim of this study was to establish a rapid, reliable and sensitive molecular method to detect pathogens in food samples.
Real-time PCR assays for the detection of Campylobacter jejuni and coli, Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Staphylococcus aureus in food enrichment samples were developed. A novel organism was constructed using a gfp gene cloned into the chromosome of a non-pathogenic Escherichia coli. Viable cells of the modified strain were encapsulated in Lenticule discs and used as process control in the PCR assays. MagNA Pureâ„¢ automated extraction was shown to be robust and reliable for preparing bacterial DNA from food enrichment broths. The PCR assays and MagNA Pureâ„¢ was applied to enrichment broths inoculated with 558 naturally-contaminated food and environmental samples in a field trial. Concordance was found between PCR results and those obtained using standard culture methods. Loss of assay sensitivity or PCR inhibition was detected in 6 % (32) of the enrichment samples. To improve the sensitivity the L monocytogenes hlyA gene PCR was nested. The assay was applied for the sensitive non-cultural diagnosis of listeriosis, with L monocytogenes detected in 15 of 17 clinical samples from patients with suspected listeriosis.
In conclusion, these assays provided a high throughput, robust, reliable PCR detection methods that could be used in clinical and food testing laboratories. The methods will be essential in outbreak situations and could be further developed to detecting bacterial pathogens, viruses, parasites, new and emerging pathogens
Data mining: a tool for detecting cyclical disturbances in supply networks.
Disturbances in supply chains may be either exogenous or endogenous. The ability automatically to detect, diagnose, and distinguish between the causes of disturbances is of prime importance to decision makers in order to avoid uncertainty. The spectral principal component analysis (SPCA) technique has been utilized to distinguish between real and rogue disturbances in a steel supply network. The data set used was collected from four different business units in the network and consists of 43 variables; each is described by 72 data points. The present paper will utilize the same data set to test an alternative approach to SPCA in detecting the disturbances. The new approach employs statistical data pre-processing, clustering, and classification learning techniques to analyse the supply network data. In particular, the incremental k-means
clustering and the RULES-6 classification rule-learning algorithms, developed by the present authors’ team, have been applied to identify important patterns in the data set. Results show that the proposed approach has the capability automatically to detect and characterize network-wide cyclical disturbances and generate hypotheses about their root cause
Compensated Proton Beam Production In An Accelerating Ring At a Current above The Space Charge Limit
Towards Crowdsourced Online Dispute Resolution
Using crowdsourcing for solving disputes is a subject that has not been discussed in many scientific publications. However, since Crowdsourced Online Dispute Resolution (CODR) provides a cheap, fast, and democratic dispute resolution, it has a potential that needs to be explored scientifically. How should eBay solve otherwise 60 millions disputes per year? Building a CODR platform with the convenience and attractiveness of other collective intelligence systems, such as Wikipedia, YouTube, and Google, may cause many variants of traditional forms of dispute resolution fading away. In order to shed more light on CODR, the present contribution defines this new type of dispute resolution, describes the present state of play, and builds a theoretical framework by investigating CODR building blocks. Although the paper provides only the start of a profound discussion, it shows introductory explorations of the key theoretical issues involved in CODR
Relation between first lactation milk yield and functional traits in dairy cows
The aim of the study was to analyze the relationship between first lactation milk yield
(FLMY) and age at first calving (AFC), longevity and productive life in dairy cows. The study
covered 944 Holstein cows housed in 5 dairy cattle farms in Bulgaria. All cows from the five
farms culled in the period 2012–2018 with FLMY data were included. The average AFC for all
culled cows included in the study was relatively high for the Holstein-Friesian breed - 29.75
months. The average FLMY of the herds included in the study was 7,660.94 kg with significant
herd variation from 5,899.09 kg to 8,646.0 kg. Significant effect of the herd (P < 0.001), AFC
and the associated effect of the herd and AFC (P < 0.05) on the average FLMY were found. The
highest FLMY was reported in primiparous with AFC of 28–30 months – 7,860.8 kg, and the
lowest in those with AFC ≤ 24 months – 7322.8 kg. In the herd with the lowest average FLMY -
5,899.09 kg 27.5% of the heifers had calved at age over 34 months. A statistically significant
effect of AFC (P < 0.001) was found on longevity, whereas the productive life was significantly
influenced by FLMY (P < 0.05). A tendency for higher longevity for cows with higher AFC of
34–37 months and over 37 months – 5.9 and 5.8 years, respectively was observed. The lowest
were the longevity values for cows calved at age up to 24 months – 4.9 years. The cows with the
lowest average FLMY (up to 4,000 kg) had the shortest productive. Both very low and high AFC
were associated with lower first lactation cow productivity and shorter productive life. The losses
for farmers were greater when keeping a high AFC in heifers, which increases the cost for housing
them, and the lower productivity and longer productive life reduce the probability
BASICS OF THEORETICAL APPROACHES OF TECHNOLOGICAL PROCESSES WITH REGULAR TOSSING OF THE GRANULAR MEDIUM
Vibration interaction is used for development of modern technological processes in which required quality of product is provided due to interaction of the granular medium with the vibrating surface. The paper is devoted to development of mathematical models and estimation criteria form of movement, taking into account the effect of unilateral constraints, in dynamic interactions of elements of vibration technological processes as applied to increase the reliability and quality of vibrational machines. The study is focused on the formation of theoretical ideas about the dynamic interactions of a solid body with the vibrating surface based on the development of mathematical models by introducing of additional external forces and elastic ties with unilateral contact, including mathematical models of gapless movement of the compounded solids. In terms of practical applications the task is to develop and to approve experimentally the opportunities of the measuring devices fixing the modes of continuous tossing. According to the research the generalized approach to problems of dynamic synthesis of vibration technology implemented in continuous tossing the introduction of additional forces is developed. The basis of the approach is the introduction of the concept of the function of the gap, allowing to justify the construction of forms of motion of material particles in accordance with certain criteria, reflecting the properties of the trajectories of motion of material particles in the interaction with the vibrating surface. The mathematical models to determine the conditions for the formation of dynamic reactions in the vibrational structure consisting of several interconnected elements, including the possibilities of their pre-pressing by elastic ties and power factors is offered. The measuring device fixing the modes of continuous tossing is developed and experimentally approved
From Heun to Painlev\'e on Sasaki-Einstein Spaces and Their Confluent Limits
The aim of this paper is to study the effect of isomonodromic deformations of
the evolution of scalar fields in Sasaki-Einstein spaces in the context of
holography. Here we analyze the monodromy data of the general Heun equation,
resulting from a scalar on Y, thus obtaining the corresponding
Painlev\'e VI equation. Furthermore we have considered limits leading to a
coalescence of singularities, which in turn transform the original Painlev\'e
VI equation, to one of lower rank. The confluent limits we have considered are
Y, T and Y.Comment: 32 pages, three figure
Compact Measurement Station for Low Energy Proton Beams
A compact, remote controlled, cost efficient diagnostic station has been
developed to measure the charge, the profile and the emittance for low energy
proton beams. It has been installed and tested in the proton beam line of the
Project Prometheus at SANAEM of the Turkish Atomic Energy Authority.Comment: 7 pages 2 column
Effect of grape pomace powder addition on chemical, nutritional and technological properties of cakes
Aim of the research was to study the influence of grape (Vitis vinifera) pomace powder, a by-product of wine manufacturing, on chemical composition, nutritional properties and physical characteristics of cakes prepared replacing bread wheat flour with 4%, 6%, 8% and 10% grape pomace powder. The addition of growing quantities of grape pomace powder gradually increased ash, lipid, proteins, fibres, free phenolics, anthocyanins and total polyphenol content as well as antioxidant capacity (DPPH, FRAP), while decreased moisture and \u440\u41d. The main phenolics provided by grape pomace were catechin, gallic acid, quercitin, protocatechuic acid, kaempferol and apigenin. The phenolic acids and flavonoids content increased from 4.1\u202fmg/kg DM (control) to 26.4\u201360.9\u202fmg/kg DM (cake with 4%\u201310% grape pomace powder). The colour coordinates L* and a* diminished, while b* augmented. The cake containing 4% grape pomace powder showed the best sensory quality. The addition of grape pomace powder significantly improved the content in free phenolics, highly bioavailable, that are scarce in bread wheat, and thus the nutritional value of cakes without penalising their technological and sensorial attributes. Therefore, grape pomace powder utilisation will give foods with nutritionally enhanced properties; additionally, its utilisation will alleviate the ecological problems connected to its disposal
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