Coverage-based quality metric of mutation operators for test suite improvement

The choice of mutation operators is a fundamental aspect in mutation testing to guide the tester to an effective test suite. Designing a set of mutation operators is subject to a trade-off between effectiveness and computational cost: a larger mutation population might uncover more faults, but will take longer to analyse. With the aim of resolving this trade-off, several authors have defined an assortment of metrics to determine the most valuable operators. In this work, we extend an existing quality metric by incorporating an additional source of data and coverage information and therefore investigate the extent to which mutants that are often covered but rarely killed can improve the evaluation of mutation operators for the refinement of the test suite. As a case study, we analyse C++ class-level operators based on the new coverage-based quality metric to assess whether the original metric is enhanced. The results when selecting the best-valued operators show that this metric has great potential to help the tester in finding effective mutation operators. In comparison with the metric from which it is derived, the use of coverage data allows to reduce the number of mutants but often loses fewer test cases and, in addition, retains those that seem hard to design

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Anxiety, depression and behavioral problems among adolescents with recurrent headache: the Young-HUNT study

Background It is well documented that both anxiety and depression are associated with headache, but there is limited knowledge regarding the relation between recurrent primary headaches and symptoms of anxiety and depression as well as behavioral problems among adolescents. Assessment of co-morbid disorders is important in order to improve the management of adolescents with recurrent headaches. Thus the main purpose of the present study was to assess the relationship of recurrent headache with anxiety and depressive symptoms and behavioral problems in a large population based cross-sectional survey among adolescents in Norway. Methods A cross-sectional, population-based study was conducted in Norway from 1995 to 1997 (Young-HUNT1). In Young-HUNT1, 4872 adolescents aged 12 to 17 years were interviewed about their headache complaints and completed a comprehensive questionnaire that included assessment of symptoms of anxiety and depression and behavioral problems, i.e. conduct and attention difficulties. Results In adjusted multivariate analyses among adolescents aged 12–14 years, recurrent headache was associated with symptoms of anxiety and depression (OR: 2.05, 95% CI: 1.61-2.61, p < 0.001), but not with behavioral problems. A significant association with anxiety and depressive symptoms was evident for all headache categories; i.e. migraine, tension-type headache and non-classifiable headache. Among adolescents aged 15–17 years there was a significant association between recurrent headache and symptoms of anxiety and depression (OR: 1.64, 95% CI: 1.39-1.93, p < 0,001) and attention difficulties (OR: 1.25, 95% CI: 1.09-1.44, p =0.001). For migraine there was a significant association with both anxiety and depressive symptoms and attention difficulties, while tension-type headache was significantly associated only with symptoms of anxiety and depression. Non-classifiable headache was associated with attention difficulties and conduct difficulties, but not with anxiety and depressive symptoms. Headache frequency was significantly associated with increasing symptoms scores for anxiety and depressive symptoms as well as attention difficulties, evident for both age groups. Conclusions The results from the present study indicate that both anxiety and depressive symptoms and behavioral problems are associated with recurrent headache, and should accordingly be considered a part of the clinical assessment of children and adolescents with headache. Identification of these associated factors and addressing them in interventions may improve headache management

The role of agricultural cooperatives in sustaining the wheat diversity and productivity: the case of southern Italy

We hypothesize that institutions such as agricultural cooperatives influence regional levels of variety diversity through input supply, processing or marketing functions. This diversity can also affect yield, a partial measure of crop productivity. We test these hypotheses with data from southern Italy, a mega-diversity spot and centre of diversity for durum wheat. Cooperatives in the southern regions of Italy process farmers’ harvests of durum wheat into bread, label it, and sell it locally. In this relatively marginalized region of the country, cooperatives enable farmers to capture more of the value of the final product and reduce marketing costs. To test the hypothesis, we apply a two-stage estimation approach with a Cobb-Douglas production function and panel data analysis. Findings suggest that the density of cooperatives in a region is associated with greater spatial diversity in wheat varieties grown, and that, over a 14-year period, this diversity positively affected crop yields