529 research outputs found

    Advice on testing the null hypothesis that a sample is drawn from a Normal distribution.

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    The Normal distribution remains the most widely-used statistical model, so it is only natural that researchers will frequently be required to consider whether a sample of data appears to have been drawn from a Normal distribution. Commonly-used statistical packages offer a range of alternative formal statistical tests of the null hypothesis of Normality, with inference being drawn on the basis of a calculated p-value. Here we aim to review the statistical literature on the performance of these tests, and briefly survey current usage of them in recently-published papers, with a view to offering advice on good practice. We find that authors in animal behaviour seem to be using such testing most commonly in situations where it is inadvisable (or at best unnecessary) involving pre-testing to select parametric or not-parametric analyses; and making little use of it in model-fitting situations where it might be of value. Of the many alternative tests, we recommend the routine use of either the Shapiro-Wilk or Chen-Shapiro tests; these are almost always superior to commonly-used alternatives like the Kolmogorov-Smirnov test, often by a substantial margin. We describe how both our recommend tests can be implemented. In contrast to current practice as indicated by our survey, we recommend that the results of these tests are reported in more detail (providing both the calculated sample statistic and the associated p-value). Finally, emphasize that even the higher-performing tests of Normality have low power (generally below 0.5 and often much lower) when sample sizes are less than 50, as is often the case in our field. Keywords: Gaussian distribution, parametric statistics, Schapiro-Wilk test, statistics, statistical powe

    Quality and Safety Aspects of Infant Nutrition

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    Quality and safety aspects of infant nutrition are of key importance for child health, but oftentimes they do not get much attention by health care professionals whose interest tends to focus on functional benefits of early nutrition. Unbalanced diets and harmful food components induce particularly high risks for untoward effects in infants because of their rapid growth, high nutrient needs, and their typical dependence on only one or few foods during the first months of life. The concepts, standards and practices that relate to infant food quality and safety were discussed at a scientific workshop organized by the Child Health Foundation and the Early Nutrition Academy jointly with the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, and a summary is provided here. The participants reviewed past and current issues on quality and safety, the role of different stakeholders, and recommendations to avert future issues. It was concluded that a high level of quality and safety is currently achieved, but this is no reason for complacency. The food industry carries the primary responsibility for the safety and suitability of their products, including the quality of composition, raw materials and production processes. Introduction of new or modified products should be preceded by a thorough science based review of suitability and safety by an independent authority. Food safety events should be managed on an international basis. Global collaboration of food producers, food-safety authorities, paediatricians and scientists is needed to efficiently exchange information and to best protect public health. Copyright (C) 2012 S. Karger AG, Base

    Arcanobacterium phocae infection in mink (Neovison vison), seals (Phoca vitulina, Halichoerus grypus) and otters (Lutra lutra)

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    Abstract Background Infectious skin disorders are not uncommon in mink. Such disorders are important as they have a negative impact on animal health and welfare as well as on the quality and value of the fur. This study presents the isolation of Arcanobacterium phocae from mink with severe skin lesions and other pathological conditions, and from wild seals and otters. Results In 2015, A. phocae was isolated for the first time in Denmark from outbreaks of dermatitis in mink farms. The outbreaks affected at least 12 farms. Originating from these 12 farms, 23 animals cultured positive for A. phocae. The main clinical findings were necrotizing pododermatitis or dermatitis located to other body sites, such as the lumbar and cervical regions. A. phocae could be isolated from skin lesions and in nine animals also from liver, spleen and lung, indicating a systemic spread. The bacterium was also, for the first time in Denmark, detected in dead seals (n = 9) (lungs, throat or wounds) and otters (n = 2) (throat and foot). Conclusions An infectious skin disorder in mink associated with A. phocae has started to occur in Danish farmed mink. The origin of the infection has not been identified and it is still not clear what the pathogenesis or the port of entry for A. phocae infections are

    Listeria monocytogenes in Milk Products

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    peer-reviewedMilk and milk products are frequently identified as vectors for transmission of Listeria monocytogenes. Milk can be contaminated at farm level either by indirect external contamination from the farm environment or less frequently by direct contamination of the milk from infection in the animal. Pasteurisation of milk will kill L. monocytogenes, but post-pasteurisation contamination, consumption of unpasteurised milk and manufacture of unpasteurised milk products can lead to milk being the cause of outbreaks of listeriosis. Therefore, there is a concern that L. monocytogenes in milk could lead to a public health risk. To protect against this risk, there is a need for awareness surrounding the issues, hygienic practices to reduce the risk and adequate sampling and analysis to verify that the risk is controlled. This review will highlight the issues surrounding L. monocytogenes in milk and milk products, including possible control measures. It will therefore create awareness about L. monocytogenes, contributing to protection of public health

    Competitive Benchmarking: An IS Research Approach to Address Wicked Problems with Big Data and Analytics

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    Wicked problems like sustainable energy and financial market stability are societal challenges that arise from complex socio-technical systems in which numerous social, economic, political, and technical factors interact. Understanding and mitigating them requires research methods that scale beyond the traditional areas of inquiry of Information Systems (IS) “individuals, organizations, and markets” and that deliver solutions in addition to insights. We describe an approach to address these challenges through Competitive Benchmarking (CB), a novel research method that helps interdisciplinary research communities to tackle complex challenges of societal scale by using different types of data from a variety of sources such as usage data from customers, production patterns from producers, public policy and regulatory constraints, etc. for a given instantiation. Further, the CB platform generates data that can be used to improve operational strategies and judge the effectiveness of regulatory regimes and policies. We describe our experience applying CB to the sustainable energy challenge in the Power Trading Agent Competition (Power TAC) in which more than a dozen research groups from around the world jointly devise, benchmark, and improve IS-based solutions

    Digital Work Design

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    Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)More and more academic studies and practitioner reports claim that human work is increasingly disrupted or even determined by information and communication technology (ICT) (Cascio and Montealegre 2016). This will make a considerable share of jobs currently performed by humans susceptible to automation (e.g., Frey and Osborne 2017; Manyika et al. 2017). These reports often sketch a picture of ‘machines taking over’ traditional domains like manufacturing, while ICT advances and capabilities seem to decide companies’ fate. Consequently, ICT is often put at the core of innovative efforts. While this applies to nearly all areas of workplace design, a recent popular example of increasing technology centricity is ‘Industry 4.0’, which is often delineated as ‘machines talking to computers’

    Evaluation of seven commercial African swine fever virus detection kits and three Taq polymerases on 300 well-characterized field samples

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    peer reviewedAfrican swine fever virus (ASFV) is a complex double stranded DNA virus, responsible for a highly infectious and fatal disease in pigs and boars and for important deterioration of animal welfare. Over the last decade, the disease spread to several European and Asian countries causing unprecedented dramatic economic losses in pig industry. In the absence of a vaccine, affected countries rely on trustful diagnostic tests and adapted testing policies to set up control programs to fight against the disease. In this study, we evaluated the sensitivity and specificity of seven commercially available ASFV real-time PCR detection kits and three Taq polymerases on 300 well-characterized wild boar samples collected in Belgium during the 2018–2019 outbreak. This study confirms that all commercial kits and two Taq polymerases are suitable for ASFV detection in diagnostic laboratories. Furthermore, the use of endogenous controls is emphasized when testing field samples harvested on carcasses in an advanced stage of decomposition, in order to avoid false negative results. © 2020 Elsevier B.V
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