scholarly journals Elastic Light Scatter Pattern Analysis for the Expedited Detection of Yersinia Species in Pork Mince: Proof of Concept

2021 ◽  
Vol 12 ◽  
Author(s):  
Stephen L. W. On ◽  
Yuwei Zhang ◽  
Andrew Gehring ◽  
Valery Patsekin ◽  
Venkata Chelikani ◽  
...  

Isolation of the pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis from foods typically rely on slow (10–21 day) “cold enrichment” protocols before confirmed results are obtained. We describe an approach that yields results in 39 h that combines an alternative enrichment method with culture on a non-selective medium, and subsequent identification of suspect colonies using elastic light scatter (ELS) analysis. A prototype database of ELS profiles from five Yersinia species and six other bacterial genera found in pork mince was established, and used to compare similar profiles of colonies obtained from enrichment cultures from pork mince samples seeded with representative strains of Y. enterocolitica and Y. pseudotuberculosis. The presumptive identification by ELS using computerised or visual analyses of 83/90 colonies in these experiments as the target species was confirmed by partial 16S rDNA sequencing. In addition to seeded cultures, our method recovered two naturally occurring Yersinia strains. Our results indicate that modified enrichment combined with ELS is a promising new approach for expedited detection of foodborne pathogenic yersiniae.

2018 ◽  
Vol 4 (1) ◽  
pp. 331-335
Author(s):  
David Schote ◽  
Tim Pfeiffer ◽  
Georg Rose

AbstractComputed tomography (CT) scans are frequently used intraoperatively, for example to control the positioning of implants during intervention. Often, to provide the required information, a full field of view is unnecessary. I nstead, the region-of-interest (ROI) imaging can be performed, allowing for substantial reduction in the applied X-ray dose. However, ROI imaging leads to data inconsistencies, caused by the truncation of the projections. This lack of information severely impairs the quality of the reconstructed images. This study presents a proof-of-concept for a new approach that combines the incomplete CT data with ultrasound data and time of flight measurements in order to restore some of the lacking information. The routine is evaluated in a simulation study using the original Shepp-Logan phantom in ROI cases with different degrees of truncation. Image quality is assessed by means of normalized root mean square error. The proposed method significantly reduces truncation artifacts in the reconstructions and achieves considerable radiation exposure reductions.


1998 ◽  
Vol 66 (2) ◽  
pp. 480-485 ◽  
Author(s):  
S. Schubert ◽  
A. Rakin ◽  
H. Karch ◽  
E. Carniel ◽  
J. Heesemann

ABSTRACT The fyuA-irp gene cluster contributes to the virulence of highly pathogenic Yersinia (Yersinia pestis,Yersinia pseudotuberculosis, and Yersinia enterocolitica 1B). The cluster encodes an iron uptake system mediated by the siderophore yersiniabactin and reveals features of a pathogenicity island. Two evolutionary lineages of this “high pathogenicity island” (HPI) can be distinguished on the basis of DNA sequence comparison: a Y. pestis group and a Y. enterocolitica group. In this study we demonstrate that the HPI of the Y. pestis evolutionary group is disseminated among species of the family Enterobacteriaceae which are pathogenic to humans. It prevails in enteroaggregativeEscherichia coli and in E. coli blood culture isolates (93 and 80%, respectively), but is rarely found in enteropathogenic E. coli, enteroinvasive E. coli, and enterotoxigenic E. coli isolates. In contrast, the HPI was absent from enterohemorrhagic E. coli, Shigella, and Salmonella entericastrains investigated. Polypeptides encoded by the fyuA,irp1, and irp2 genes located on the HPI could be detected in E. coli strains pathogenic to humans. However, these E. coli strains showed a reduced sensitivity to the bacteriocin pesticin, whose uptake is mediated by the FyuA receptor. Escherichia strains do not possess thehms gene locus thought to be a part of the HPI of Y. pestis. Deletions of the fyuA-irp gene cluster affecting solely the fyuA part of the HPI were identified in 3% of the E. coli strains tested. These results suggest horizontal transfer of the HPI between Y. pestis and some pathogenic E. coli strains.


2021 ◽  
Author(s):  
Vasileios Kourakos ◽  
Andreas Efstratiadis ◽  
Ioannis Tsoukalas

<p>Hydrological calibrations with historical data are often deemed insufficient for deducing safe estimations about a model structure that imitates, as closely as possible, the anticipated catchment behaviour. Ιn order to address this issue, we investigate a promising strategy, using as drivers synthetic time series, which preserve the probabilistic properties and dependence structure of the observed data. The key idea is calibrating a model on the basis of synthetic rainfall-runoff data, and validating against the full observed data sample. To this aim, we employed a proof of concept on few representative catchments, by testing several lumped conceptual hydrological models with alternative parameterizations and across two time-scales, monthly and daily. Next, we attempted to reinforce the validity of the recommended methodology by employing monthly stochastic calibrations in 100 MOPEX catchments. As before, a number of different hydrological models were used, for the purpose of proving that calibration with stochastic inputs is independent of the chosen model. The results highlight that in most cases the new approach leads to stronger parameter identifiability and stable predictive capacity across different temporal windows, since the model is trained over much extended hydroclimatic conditions.</p>


2019 ◽  
Vol 123 (7) ◽  
pp. 756-767 ◽  
Author(s):  
Maguy Daures ◽  
Kevin Phelan ◽  
Mariama Issoufou ◽  
Séni Kouanda ◽  
Ousmane Sawadogo ◽  
...  

AbstractThe Optimising treatment for acute MAlnutrition (OptiMA) strategy trains mothers to use mid upper arm circumference (MUAC) bracelets for screening and targets treatment to children with MUAC < 125 mm or oedema with one therapeutic food at a gradually reduced dose. This study seeks to determine whether OptiMA conforms to SPHERE standards (recovery rate > 75 %). A single-arm proof-of-concept trial was conducted in 2017 in Yako district, Burkina Faso including children aged 6–59 months in outpatient health centres with MUAC < 125 mm or oedema. Outcomes were stratified by MUAC category at admission. Multivariate survival analysis was carried out to identify variables predictive of recovery. Among 4958 children included, 824 (16·6 %) were admitted with MUAC < 115 mm or oedema, 1070 (21·6 %) with MUAC 115–119 mm and 3064 (61·8 %) with MUAC 120–124 mm. The new dosage was correctly implemented at all visits for 75·9 % of children. Global recovery was 86·3 (95 % CI 85·4, 87·2) % and 70·5 (95 % CI 67·5, 73·5) % for children admitted with MUAC < 115 mm or oedema. Average therapeutic food consumption was 60·8 sachets per child treated. Recovery was positively associated with mothers trained to use MUAC prior to child’s admission (adjusted hazard ratio 1·09; 95 % CI 1·01, 1·19). OptiMA was successfully implemented at the scale of an entire district under ‘real-life’ conditions. Programme outcomes exceeded SPHERE standards, but further study is needed to determine if increasing therapeutic food dosages for the most severely malnourished will improve recovery.


2019 ◽  
Vol 10 ◽  
pp. 1523-1536 ◽  
Author(s):  
Loïc Crouzier ◽  
Alexandra Delvallée ◽  
Sébastien Ducourtieux ◽  
Laurent Devoille ◽  
Guillaume Noircler ◽  
...  

At this time, there is no instrument capable of measuring a nano-object along the three spatial dimensions with a controlled uncertainty. The combination of several instruments is thus necessary to metrologically characterize the dimensional properties of a nano-object. This paper proposes a new approach of hybrid metrology taking advantage of the complementary nature of atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques for measuring the main characteristic parameters of nanoparticle (NP) dimensions in 3D. The NP area equivalent, the minimal and the maximal Feret diameters are determined by SEM and the NP height is measured by AFM. In this context, a kind of new NP repositioning system consisting of a lithographed silicon substrate has been specifically developed. This device makes it possible to combine AFM and SEM size measurements performed exactly on the same set of NPs. In order to establish the proof-of-concept of this approach and assess the performance of both instruments, measurements were carried out on several samples of spherical silica NP populations ranging from 5 to 110 nm. The spherical nature of silica NPs imposes naturally the equality between their height and their lateral diameters. However, discrepancies between AFM and SEM measurements have been observed, showing significant deviation from sphericity as a function of the nanoparticle size.


2017 ◽  
Vol 48 (5) ◽  
pp. 705-713 ◽  
Author(s):  
G. Perna ◽  
M. Grassi ◽  
D. Caldirola ◽  
C. B. Nemeroff

Personalized medicine (PM) aims to establish a new approach in clinical decision-making, based upon a patient's individual profile in order to tailor treatment to each patient's characteristics. Although this has become a focus of the discussion also in the psychiatric field, with evidence of its high potential coming from several proof-of-concept studies, nearly no tools have been developed by now that are ready to be applied in clinical practice. In this paper, we discuss recent technological advances that can make a shift toward a clinical application of the PM paradigm. We focus specifically on those technologies that allow both the collection of massive as much as real-time data, i.e., electronic medical records and smart wearable devices, and to achieve relevant predictions using these data, i.e. the application of machine learning techniques.


Author(s):  
Nicholas Nathaniel Pilau ◽  
Shehu Zaid ◽  
Abubakar Sadiq Yakubu ◽  
Bashir Saidu ◽  
Umar , Yakubu Dabai ,

Background: Zoonotic Yersinia infection has been previously reported in humans and animal hosts in Nigeria, occasionally with fulminant disease. Despite earlier evidence of Yersinia pathogen circulating in human and animal populations in Nigeria, studies and suspicion index to Yersinia is below an acceptable average amongst clinicians, diagnosticians, academics and health policy officers. Methods: The deoxycholate Citrate Agar (DCA) was used as a selective media to culture Yersinia, preceded by inoculation in MacConkay agar. Plates with evident growth in the differential media consistent with reported accounts for Yersinia were picked and inoculated in selective medium and left for 48 hours until growth was seen, other samples were left until five days before being discarded as negative. Pure cultures were subjected to a comprehensive biochemical test standard and previously applied for diagnosis and discrimination of Yersinia species. Result: This research recorded an overall microbial prevalence of 30%. Prevalence of Yersinia enterocolitica was 18.3% and Y. pseudotuberculosis 11.7%. Male dogs presented a relative prevalence of Y. enterocolitica 40.9% compared with 59.1% recorded for female dogs. Symptomatic dogs presented a relative prevalence of Y. enterocolitica of 86.4% and Y. pseudotuberculosis of 71.4%


2018 ◽  
Vol 64 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Wojciech Węgrzyński

AbstractSmoke control solutions are used to maintain tenable conditions in buildings, enabling evacuation process, rescue operations and reducing the thermal stress on the building structure. For last 50-years the design process of such solutions did not significantly change – a required volumetric capacity is calculated with theoretical and empirical models, and further, mechanical design is prepared to deliver this capacity. In this paper, a new approach – “smart smoke control” is introduced, as a system that adapts the performance parameters based on the momentary measurements of temperature in the building. The system follows the growth and decay of fire in the building, which allows optimization of its mechanical parameters, and provides substantial increase in the performance. This paper provides a discussion on traditional and new concepts in smoke control, and defines areas, in which a paradigm shift must occur, to enable widespread adoption new and more efficient solutions. The paper does also refer to previous proof of concept studies, presenting the preliminary assessment of the performance of a smart smoke control system.


2020 ◽  
Author(s):  
Jonathan Demaeyer ◽  
Stéphane Vannitsem

&lt;p&gt;For most statistical post-processing schemes used to correct weather forecasts, changes to the forecast model induce a considerable reforcasting effort. We present a new approach based on response theory to cope with slight model change. In this framework, the model change is seen as a perturbation of the original forecast model. The response theory allows then to evaluate the variation induced on the averages involved in the statistical post-processing, provided that the magnitude of this perturbation is not too large.&lt;/p&gt;&lt;p&gt;This approach is studied in the context of a simple quasi-geostrophic model. It provides a proof-of-concept of the potential performances of response theory in a chaotic system. The parameters of the statistical post-processing used - an &lt;em&gt;Error-in-Variables&lt;/em&gt; Model Output Statistics (EVMOS) - are appropriately corrected when facing a model change. The potential application in a more operational environment is also discussed.&lt;/p&gt;


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