Histology as a Valid and Reliable Tool To Differentiate Fresh from Frozen-Thawed Fish

2012 ◽  
Vol 75 (8) ◽  
pp. 1536-1541 ◽  
Author(s):  
E. BOZZETTA ◽  
M. PEZZOLATO ◽  
E. CENCETTI ◽  
K. VARELLO ◽  
F. ABRAMO ◽  
...  
Keyword(s):  
Fish Species ◽  
Interrater Agreement ◽  
Cohen’S Kappa ◽  
Method Performance ◽  
Tissue Samples ◽  
Fish Products ◽  
Cohen's Kappa ◽  
Accuracy And Precision ◽  
Fish Samples ◽  
Method Accuracy

Selling fish products as fresh when they have actually been frozen and thawed is a common fraudulent practice in seafood retailing. Unlike fish products frozen to protect them against degenerative changes during transportation and to extend the product's storage life, fish intended for raw consumption in European countries must be previously frozen at −20°C for at least 24 h to kill parasites. The aim of this study was to use histological analysis to distinguish between fresh and frozen-thawed fish and to evaluate this method for use as a routine screening technique in compliance with the requirements of European Commission Regulation No. 882/2004 on official food and feed controls. Method performance (i.e., accuracy and precision) was evaluated on tissue samples from three common Mediterranean fish species; the evaluation was subsequently extended to include samples from 35 fish species in a second experiment to test for method robustness. Method accuracy was tested by comparing histological results against a “gold standard” obtained from the analysis of frozen and unfrozen fish samples prepared for the study. Method precision was evaluated according to interrater agreement (i.e., three laboratories with expertise in histopathology in the first experiment and three expert analysts in the second experiment) by estimating Cohen's kappa (and corresponding 95% confidence intervals) for each pair of laboratories and experts and the combined Cohen's kappa for all three experts and laboratories. The observed interrater agreement among the three laboratories and the three experts indicated high levels of method accuracy and precision (high sensitivity and specificity) and method reproducibility. Our results suggest that histology is a rapid, simple, and highly accurate method for distinguishing between fresh and frozen-thawed fish, regardless of the fish species analyzed.

scholarly journals New Interpretations of Cohen’s Kappa

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Matthijs J. Warrens
Keyword(s):  
Weighted Kappa ◽  
Interrater Agreement ◽  
Cohen’S Kappa ◽  
Association Coefficient ◽  
Nominal Scale ◽  
Weighted Averages ◽  
Cohen's Kappa ◽  
Single Number ◽  
Research Studies

Cohen’s kappa is a widely used association coefficient for summarizing interrater agreement on a nominal scale. Kappa reduces the ratings of the two observers to a single number. With three or more categories it is more informative to summarize the ratings by category coefficients that describe the information for each category separately. Examples of category coefficients are the sensitivity or specificity of a category or the Bloch-Kraemer weighted kappa. However, in many research studies one is often only interested in a single overall number that roughly summarizes the agreement. It is shown that both the overall observed agreement and Cohen’s kappa are weighted averages of various category coefficients and thus can be used to summarize these category coefficients.

scholarly journals Levenshtein Distance as a Measure of Accuracy and Precision in Forensic PCR-MPS Methods

2021 ◽  
Author(s):  
Brian Young ◽  
Tom Faris ◽  
Luigi Armogida
Keyword(s):  
Standard Approach ◽  
Levenshtein Distance ◽  
Summary Statistics ◽  
Distance Metric ◽  
Method Performance ◽  
Equal Footing ◽  
Accuracy And Precision ◽  
Reference Sequences ◽  
Method Accuracy ◽  
Standard Components

ABSTRACTAccuracy and precision determinations are standard components of method validations where they help to describe the performance of the method. Despite their importance, a standard approach to calculating these parameters is not available for forensic PCR-MPS methods that detect sequence-based alleles. In this paper, we describe a method based on the Levenshtein distance metric which aptly summarizes method accuracy in terms of the closeness of read sequences to reference sequences, and method precision in terms of the agreement among read sequences. Inaccuracy or imprecision in forensic methods can lead to wrong allele calls. By expressing method performance in terms of a distance metric, this method places PCR-MPS on equal footing with distance-based measures in PCR-CE methods where inaccuracy or imprecision can result in wrong microvariant allele calls. Summary statistics based on the Levenshtein distance can be used to compare performance of different kits, markers, sequencers, or methods.

scholarly journals An Intelligent Gesture Classification Model for Domestic Wheelchair Navigation with Gesture Variance Compensation

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
H. M. Ravindu T. Bandara ◽  
K. S. Priyanayana ◽  
A. G. Buddhika P. Jayasekara ◽  
D. P. Chandima ◽  
R. A. R. C. Gopura
Keyword(s):  
Intelligent System ◽  
Confusion Matrix ◽  
Living Standards ◽  
Classification Model ◽  
Misclassification Rate ◽  
Navigation Systems ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Accuracy And Precision ◽  
Gesture Classification

Elderly and disabled population is rapidly increasing. It is important to uplift their living standards by improving the confidence towards daily activities. Navigation is an important task, most elderly and disabled people need assistance with. Replacing human assistance with an intelligent system which is capable of assisting human navigation via wheelchair systems is an effective solution. Hand gestures are often used in navigation systems. However, those systems do not possess the capability to accurately identify gesture variances. Therefore, this paper proposes a method to create an intelligent gesture classification system with a gesture model which was built based on human studies for every essential motion in domestic navigation with hand gesture variance compensation capability. Experiments have been carried out to evaluate user remembering and recalling capability and adaptability towards the gesture model. Dynamic Gesture Identification Module (DGIM), Static Gesture Identification Module (SGIM), and Gesture Clarifier (GC) have been introduced in order to identify gesture commands. The proposed system was analyzed for system accuracy and precision using results of the experiments conducted with human users. Accuracy of the intelligent system was determined with the use of confusion matrix. Further, those results were analyzed using Cohen’s kappa analysis in which overall accuracy, misclassification rate, precision, and Cohen’s kappa values were calculated.

Abstract WP276: Simplification of a Prehospital Short NIHSS Scale Does not Increase Interrater Agreement Between Emergency Medical Services and Stroke Specialists

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Jelle Demeestere ◽  
Carlos Garcia-Esperon ◽  
Longting Lin ◽  
Allan Loudfoot ◽  
Andrew Bivard ◽  
...  
Keyword(s):  
Emergency Medical Services ◽  
Weighted Kappa ◽  
Interrater Agreement ◽  
Medical Services ◽  
Kappa Statistics ◽  
Single Centre ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Emergency Medical ◽  
Patient Arrival

Objective: To assess if simplifying a prehospital 8-item NIHSS scale (NIHSS-8, fig 1) to a 0 (symptom absent) – 1 (symptom present) scoring system increases interrater agreement between emergency medical services (EMS) and stroke specialists. Methods: We analysed interrater agreement between EMS and stroke specialists of a single centre on a prospectively collected cohort of 64 suspected acute ischemic stroke patients. EMS performed NIHSS-8 score upon patient arrival at the emergency department. The stroke specialist scored the full 15-item NIHSS blind to the EMS scores and within 5 minutes of patient arrival. Linear-weighted Cohen’s kappa statistics was used to assess agreement between EMS and stroke specialist on the total NIHSS-8 score and each NIHSS-8 scale item. We then simplified each item to a 0-1 score and reassessed interrater agreement for the overall NIHSS-8 scale using linear-weighted Cohen’s kappa statistics and for each NIHSS-8 item using Cohen’s kappa statistics. We used Cohen’s kappa statistics to assess agreement for original and simplified NIHSS-8 cut-off scores. Results: EMS and stroke specialist reached substantial agreement on overall NIHSS-8 scoring (linear-weighted kappa 0.69). Optimum agreement was reached for right arm weakness (linear-weighted kappa 0.79; Table 1) and a cut-off score of 2 and 5 (Cohen’s kappa 0.78; Table 2). When the score was simplified to a 0-1, overall agreement between EMS and stroke specialists was substantial (linear-weighted kappa 0.65). Optimum agreement was seen for LOC questions (Cohen’s kappa 0.78; Table 1) and a cut-off score of 2 (Cohen’s kappa 0.77; Table 2). Conclusion: Simplifying an 8-item prehospital NIHSS stroke scale does not increase interrater agreement between emergency medical services and stroke specialists.

Effects of Drying Methods on the Biochemical Composition and Organoleptic Properties of Two Freshwater Fish Species (Mormyrus rume and Labeo coubie) of Cross River Obubra, Nigeria

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Moisture Content ◽  
Fish Species ◽  
Nutrition Status ◽  
Drying Methods ◽  
Organoleptic Properties ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Fish Samples ◽  
Fish And Fishery Products ◽  
Mormyrus Rume

Consumers all over the world are increasingly becoming aware of the health and nutrition status of fish and fishery products. There have develop some preference for fish species and even their processing methods. This study aims to investigate the effects of two drying methods (smoking and oven drying) on the biochemical components and organoleptic properties of two less preferred food fishes abundant in the study area. The fish samples Mormyrus rume and Labeo coubie were purchased from fresh landings of fishermen at Ahaha beach. The biochemical assay of the moisture, protein, fat, carbohydrate, ash, calcium (Ca), magnesium (Mg), phosphorus (P), iron (Fe), sodium (Na) and potassium (K) were conducted in the labouratory using standard methods. The proximate composition of raw M. rume was determined as moisture 70.38%, protein 17.43%, carbohydrate 1.13%, fat 5.93% and ash 2.77% while oven dried were 18.78, 63.85, 3.37, 8.73 and 7.58% respectively. All the proximate parameters and gross energy level investigated were higher (p < 0.05) in M. rume except the moisture content of dried samples of L. coubie. The mineral content were in the order Ca < Mg < Fe < Na < P and < K in both species and were higher in M. rume except Na. The drying methods showed increase in the proximate and mineral compositions in the order raw < smoking and < oven drying except moisture content that decreased respectively is both species. Organoleptic properties revealed that dried samples (smoked and oven) were not significantly different (p < 0.05) in taste, flavour, texture and overall acceptance, however while oven dried had better colour (4.33), smoked dried taste (4.63) better. The drying methods shows concentration of the required nutrients in human diets and were also found to be most palatable by the panellist. To improve fish nutrient quality smoke and oven drying should be encourage.

scholarly journals LC–MS/MS Analysis of Ciguatoxins Revealing the Regional and Species Distinction of Fish in the Tropical Western Pacific

2021 ◽  
Vol 9 (3) ◽  
pp. 299 ◽  
Author(s):  
Naomasa Oshiro ◽  
Takumi Tomikawa ◽  
Kyoko Kuniyoshi ◽  
Akira Ishikawa ◽  
Hajime Toyofuku ◽  
...  
Keyword(s):  
Fish Species ◽  
The Philippines ◽  
Western Pacific ◽  
Tropical Region ◽  
Northern Coast ◽  
Coastal Regions ◽  
Main Island ◽  
Tropical Western Pacific ◽  
The Pacific ◽  
Fish Samples

Ciguatera fish poisoning (CFP) is one of the most frequently reported seafood poisoning diseases. It is endemic to the tropical region and occurs most commonly in the regions around the Pacific Ocean, Indian Ocean, and Caribbean Sea. The principal toxins causing CFP are ciguatoxins (CTXs). In the Pacific region, more than 20 analogs of CTXs have been identified to date. Based on their skeletal structures, they are classified into CTX1B-type and CTX3C-type toxins. We have previously reported species-specific and regional-specific toxin profiles. In this study, the levels and profiles of CTXs in fish present in the tropical western Pacific regions were analyzed using the liquid chromatography–tandem mass spectrometry (LC–MS/MS) technique. Forty-two fish specimens, belonging to the categories of snappers, groupers, Spanish mackerel, and moray eel, were purchased from various places such as Fiji, the Philippines, Thailand, and Taiwan. Only the fish captured from Fijian coastal waters contained detectable amounts of CTXs. The toxin levels in the fish species found along the coastal regions of the Viti Levu Island, the main island in Fiji, and the toxin profiles were significantly different from those of the fish species present in other coastal regions. The toxin levels and profiles varied among the different fish samples collected from different coastal areas. Based on the toxin levels and toxin profiles, the coast was demarcated into three zones. In Zone-1, which covers the northern coast of the main island and the regions of the Malake Island and Korovau, CTXs in fish were below the detection level. In Zone-2, CTX3C-type toxins were present in low levels in the fish. CTX1B-type and CTX3C-type toxins co-occurred in the fish present in Zone-3. The toxin profiles may have reflected the variation in Gambierdiscus spp.

scholarly journals An update on image forming methods: structure analysis and Gestalt evaluation of images from rocket lettuce with shading, N supply, organic or mineral fertilization, and biodynamic preparations

2021 ◽  
Author(s):  
Miriam Athmann ◽  
Roya Bornhütter ◽  
Nicolaas Busscher ◽  
Paul Doesburg ◽  
Uwe Geier ◽  
...  
Keyword(s):  
Copper Chloride ◽  
Organic Fertilizer ◽  
Structural Features ◽  
Fertilizer Treatment ◽  
Friedman Test ◽  
Mineral Fertilization ◽  
Cohen’S Kappa ◽  
N Supply ◽  
Cohen's Kappa ◽  
Forming Methods

AbstractIn the image forming methods, copper chloride crystallization (CCCryst), capillary dynamolysis (CapDyn), and circular chromatography (CChrom), characteristic patterns emerge in response to different food extracts. These patterns reflect the resistance to decomposition as an aspect of resilience and are therefore used in product quality assessment complementary to chemical analyses. In the presented study, rocket lettuce from a field trial with different radiation intensities, nitrogen supply, biodynamic, organic and mineral fertilization, and with or without horn silica application was investigated with all three image forming methods. The main objective was to compare two different evaluation approaches, differing in the type of image forming method leading the evaluation, the amount of factors analyzed, and the deployed perceptual strategy: Firstly, image evaluation of samples from all four experimental factors simultaneously by two individual evaluators was based mainly on analyzing structural features in CapDyn (analytical perception). Secondly, a panel of eight evaluators applied a Gestalt evaluation imbued with a kinesthetic engagement of CCCryst patterns from either fertilization treatments or horn silica treatments, followed by a confirmatory analysis of individual structural features. With the analytical approach, samples from different radiation intensities and N supply levels were identified correctly in two out of two sample sets with groups of five samples per treatment each (Cohen’s kappa, p = 0.0079), and the two organic fertilizer treatments were differentiated from the mineral fertilizer treatment in eight out of eight sample sets with groups of three manure and two minerally fertilized samples each (Cohen’s kappa, p = 0.0048). With the panel approach based on Gestalt evaluation, biodynamic fertilization was differentiated from organic and mineral fertilization in two out of two exams with 16 comparisons each (Friedman test, p < 0.001), and samples with horn silica application were successfully identified in two out of two exams with 32 comparisons each (Friedman test, p < 0.001). Further research will show which properties of the food decisive for resistance to decomposition are reflected by analytical and Gestalt criteria, respectively, in CCCryst and CapDyn images.

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