223,663 research outputs found

    Comparison of five different methods to assess the concentration of boar semen

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    Both for research and practical purposes, accurate and repeatable methods are required to assess the concentration of boar semen samples. Since the method which is used may influence the results considerably, the aim of the present study was to compare 5 frequently used techniques to determine boar semen concentration. Fifty ejaculates were collected from 37 different boars at an artificial insemination centre. Subsequently, each ejaculate was analyzed for sperm concentration by means of 2 different types of colorimeters (Colorimeter 1: Model 252, Sherwood Scientific Ltd, Cambridge, UK; Colorimeter 2: Ciba-Corning, Schippers, Bladel, The Netherlands), the Burker counting chamber (golden standard), and the Hamilton Thorne Analyzer (Ceros 42.1) using 2 types of Leja chambers (the 'former' and the 'recently developed'). Each ejaculate was assessed 5 times with each of the 5 methods, and the repeatability, expressed by coefficient of variation (CV), was determined for each method. The different methods were compared using Pearson's correlations and limits of agreement. The colorimeters yielded the lowest CV's (both 3.7%), while the former Leja chamber resulted in the highest CV (12.4%). Moreover, significant (P0.71) were found between the results obtained by the different methods. The limits of agreement plots showed that none of the methods consistently over- or underestimated the sperm concentrations when compared to the Burker chamber, although there was a tendency toward higher over- or underestimation in highly concentrated sperm samples. Based on our results, there were no major differences in the assessment of sperm concentration between the evaluated methods. The choice of method used in a laboratory could therefore be based on factors such as cost, number of samples to be assessed and practical use, without thereby negatively affecting the validity of the results thus obtained

    Phenotype-based and Self-learning Inter-individual Sleep Apnea Screening with a Level IV Monitoring System

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    Purpose: We propose a phenotype-based artificial intelligence system that can self-learn and is accurate for screening purposes, and test it on a Level IV monitoring system. Methods: Based on the physiological knowledge, we hypothesize that the phenotype information will allow us to find subjects from a well-annotated database that share similar sleep apnea patterns. Therefore, for a new-arriving subject, we can establish a prediction model from the existing database that is adaptive to the subject. We test the proposed algorithm on a database consisting of 62 subjects with the signals recorded from a Level IV wearable device measuring the thoracic and abdominal movements and the SpO2. Results: With the leave-one cross validation, the accuracy of the proposed algorithm to screen subjects with an apnea-hypopnea index greater or equal to 15 is 93.6%, the positive likelihood ratio is 6.8, and the negative likelihood ratio is 0.03. Conclusion: The results confirm the hypothesis and show that the proposed algorithm has great potential to screen patients with SAS

    Objective Assessment of Surgical Operative Performance by Observational Clinical Human Reliability Analysis (OC-HRA):A Systematic Review

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    Background: Both morbidity and mortality data (MMD) and learning curves (LCs) do not provide information on the nature of intraoperative errors and their mechanisms when these adversely impact on patient outcome. OCHRA was developed specifically to address the unmet surgical need for an objective assessment technique of the quality of technical execution of operations at individual operator level. The aim of this systematic review was to review of OCHRA as a method of objective assessment of surgical operative performance.Methods: Systematic review based on searching 4 databases for articles published from January 1998 to January 2019. The review complies with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and includes original publications on surgical task performance based on technical errors during operations across several surgical specialties.Results: Only 26 published studies met the search criteria, indicating that the uptake of OCHRA during the study period has been low. In 31% of reported studies, the operations were performed by fully qualified consultant/attending surgeons and by surgical trainees in 69% in approved training programs. OCHRA identified 7869 consequential errors (CE) during the conduct of 719 clinical operations (mean = 11 CEs). It also identified ‘hazard zones’ of operations and proficiency–gain curves (P-GCs) that confirm attainment of persistent competent execution of specific operations by individual trainee surgeons. P-GCs are both surgeon and operation specific.Conclusions: Increased OCHRA use has the potential to improve patient outcome after surgery, but this is a contingent progress towards automatic assessment of unedited videos of operations. The low uptake of OCHRA is attributed to its labor-intensive nature involving human factors (cognitive engineering) expertise. Aside from faster and more objective peer-based assessment, this development should accelerate increased clinical uptake and use of the technique in both routine surgical practice and surgical training.</p

    On the Distribution and Fishery Potential of the Japanese Red Crab Chaceon granulatus in the Palauan Archipelago, Western Caroline Islands

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    A deep-water trapping survey in the Palauan archipelago, Western Caroline Islands, has revealed an abundance of the Japanese red crab, Chaceon granulatus. The recorded depth range (250-900 m) is similar to that of other geryonids, but the large numbers of females caught below 700 m is atypical. Mean yields in excess of 5 kg crabs plus 1 kg shrimp, Heterocarpus laevigatus, by-catch per trap-night were attainable at optimum depths. Chaceon granulatus is apparently a very large geryonid, with maximum weights of 2.02 kg and 1.51 kg recorded for male and female specimens, respectively. A range of body colors was observed: Orange-red shades appear to dominate the deeper waters (below 500 m) while yellow-tan colors are more abundant in the upper reaches. Preliminary evidence suggests that Chaceon granulatus is highly marketable, and the infrastructure in Palau is such that crabs could either be marketed fresh locally or airfreighted to Japan as a quick-frozen product. The high post-trapping survival rates observed indicate that maintaining crabs in live-holding tanks may be a feasible option. The large catches and quality of deep-water crabs taken suggests that the Palauan population of Chaceon granulatus may be able to support a small-scale fishery. It is not yet known whether this population is unusually large or whether these findings typify the deep forereef fauna of the region
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