Model refactoring by example: A multi‐objective search based software engineering approach

Declarative rules are frequently used in model refactoring in order to detect refactoring opportunities and to apply the appropriate ones. However, a large number of rules is required to obtain a complete specification of refactoring opportunities. Companies usually have accumulated examples of refactorings from past maintenance experiences. Based on these observations, we consider the model refactoring problem as a multi objective problem by suggesting refactoring sequences that aim to maximize both structural and textual similarity between a given model (the model to be refactored) and a set of poorly designed models in the base of examples (models that have undergone some refactorings) and minimize the structural similarity between a given model and a set of well‐designed models in the base of examples (models that do not need any refactoring). To this end, we use the Non‐dominated Sorting Genetic Algorithm (NSGA‐II) to find a set of representative Pareto optimal solutions that present the best trade‐off between structural and textual similarities of models. The validation results, based on 8 real world models taken from open‐source projects, confirm the effectiveness of our approach, yielding refactoring recommendations with an average correctness of over 80%. In addition, our approach outperforms 5 of the state‐of‐the‐art refactoring approaches.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143783/1/smr1916.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143783/2/smr1916_am.pd

Example-based model refactoring using heuristic search

Software maintenance is considered the most expensive activity in software systems development: more than 80% of the resources are devoted to it. During the maintenance activities, software models are very rarely taken into account. The evolution of these models and the transformations that manipulate them are at the heart of model-driven engineering (MDE). However, as the source code, the model changes and tends to become increasingly complex. These changes generally have a negative impact on the quality of models and they cause damage to the software. In this context, refactoring is the most used technique to maintain an adequate quality of these models. The refactoring process is usually done in two steps: the detection of elements of the model to correct (design defects), then the correction of these elements. In this thesis, we propose two main contributions related to detection and correction of defects in class diagrams. The first contribution aims to automate the design defect detection. We propose to adapt genetic algorithms (e.g., genetic programming) to detect parts of the model that may correspond to design defects. The second contribution concerns the automation of the correction of these design defects. We propose to adapt three heuristic methods to suggest refactorings: 1. A single-objective optimization method based on structural similarities between a given model (i.e., the model to be refactored) and a set of examples of models (i.e., models that have undergone some refactorings); 2. An interactive single-objective optimization method based on structural similarity and the opinion of the designer; and 3. A multi-objective optimization method that maximizes both the structural and semantic similarities between the model under study and the models in the set of examples. All the proposed methods were implemented and evaluated on models generated from existing open-source projects and the obtained results confirm their efficiency

Africa’s neglected area of human resources for health research – the way forward

Building the skills for doing, managing and delivering healthresearch is essential for every country’s development. Yet humanresources for health research (HRHR) are seldom considered inAfrica and elsewhere. Africa’s health research capacity has grownconsiderably, with potential to increase this growth. However, asystemic way of defining, co-ordinating and growing the HRHRneeded to support health systems development is missing.Reviewing the status of HRHR in Africa, we assert that it consistsof unco-ordinated, small-scale activities, primarily driven fromoutside Africa. We present examples of ongoing HRHR capacitybuilding initiatives in Africa. There is no overarching framework, strategy or body for African countries to optimise research support and capacity in HRHR. A simple model is presented to help countries plan and strategisefor a comprehensive approach to research capacity strengthening.Everyone engaged with global, regional and national researchfor health enterprises must proactively address human resourceplanning for health research in Africa. Unless this is made explicitin global and national agendas, Africa will remain only an interestedspectator in the decisions, prioritisation, funding allocations,conduct and interpretation, and in the institutional, economic andsocial benefits of health research, rather than owning and drivingits own health research agendas

School-based intervention to promote healthy nutrition in Sousse, Tunisia

Introduction: Obesity among children is a major risk factor for chronic diseases. School interventions programs can represent a mean to implement healthy nutrition attitudes at early ages. Our objective was to evaluate the effects of a school intervention program to promote healthy nutrition among adolescents, in terms of knowledge, behaviors and intention. Methods: Quasi experimental study among urban students in Sousse, Tunisia with 2 groups, intervention and control. The intervention group had an interactive program integrated with school courses that promoted healthy nutrition habits. Both groups had a pre post evaluation. Results: 2200 students aged from 12 to 16 participated to the pre post evaluation. In the intervention group, there were significant changes form pre to post test in knowledge, intentions, and behaviors. In the control group, almost no significant changes were observed. Conclusion: School intervention programs can represent an interesting approach to promote healthy nutrition habits among adolescent

Physiological mechanisms and adaptation strategies of Lactuca sativa L. in response to Olea europaea L. and Ficus carica L. allelochemicals

Agro-industrial wastes of Ficus carica L. and Olea europaea L. represent great sources of bioactive phenolic compounds that would be actively involved in sustainable development. Most of these wastes possess a valuable source of phytotoxic compounds that would be used as potential bioherbicides, but their function and mechanisms of action in cultivated crops remain far to be understood. In this study, we investigate the biochemical and physiological mechanisms of action of fig and olive allelochemicals extracts in lettuce as a model plant for weed species studies. Results revealed that these allelochemicals triggered an oxidative stress through cell membrane damage in lettuce roots and leaves, which was mitigated by various adaptive responses. Therefore, an intricate defense system was implicated by the increase of enzymatic and non-enzymatic antioxidants in lettuce tissues. This adaptive physiological response was highly correlated with the regulation of the phenylpropanoid pathway through the distinguished activation of phenylalanine ammonia-lyase by 98% and phenolic accumulation by 85% under olive and fig leaves aqueous extracts. The outcomes of this study will help understanding the response of cultivated crop to fig and olive phenolic compounds that can be selective in their actions, or the plants can be selective in their responses

Effect of Heavy Metal Pollution on Invertebrates

Metal pollutants are widespread in air, soil and water causing a decline in invertebrates worldwide. The increase of environmental pollution by heavy metals has a negative impact to organisms and influence their diversity, distribution, physiology and behavior. Contrary to other pollutants, metals are non-degradable and can potentially bio-accumulate and be biomagnified in the trophic chain. Because soil invertebrates tend to be strongly affected by environmental disturbances, high concentrations of these metals can become hazardous to invertebrates. Noxious effects can affect all biological levels, and toxins affect all ecological interactions. In this brief chapter, we have tried to develop a comprehensive understanding of the influence of metal contamination on ecosystem disturbance. We give examples of studies on the effects of pollutants on invertebrates

Aquatic insects as bio-indicators of water quality – a study on Sungai Kawal, Johor National Park of Endau-Rompin, Peninsular Malaysia

Biological indicator species or bio-indicators are sensitive to specific environmental factors so that changes in their environment will be reflected by their incidence or abundance. In fact, aquatic insects of freshwater river and stream ecosystems have been widely used as bioindicators to examine the species-habitat relationship with regard to the water quality of the habitat. Therefore, this study attempted to determine species richness of aquatic insects in Sungai Kawal, Johor National Park of Endau-Rompin (TNJER), Mersing, Johor, Malaysia; to identify traditional knowledge (TK) used by Jakun tribe in Kampung Peta, TNJER for maintaining rivers and streams at good level; and then to correlate the relationship between the scientific perspective and TK perspective. Aquatic insects were collected and sampled by using kick sampling technique and D-framed net. Throughout the study, a total of 618 individuals consisting of 23 families belonging to seven orders of aquatic insects were reported. The documentation of TK was done by interviewing 10 total respondents of the Jakun tribe in Kampung Peta. Physical features of Sungai Kawal were also recorded during sampling. The correlation between the scientific perspective and TK perspective regarding how the ecosystem maintenance by the Jakun tribe has contributed to an excellent habitat for the aquatic insects to breed and multiply. The number of species recorded indicated the good status of water quality of Sungai Kawal based on science and then supported by TK of the Jakun tribe of Kampung Peta. Furthermore, the findings also suggested a good correlation between the scientific perspective and TK perspective, and the significant contribution of TK of the Jakun tribe to the management of natural resources

Long term effect of a school based intervention to prevent chronic diseases in Tunisia, 2009-2015

Background & Objectives: We aimed to evaluate the long term effect of school based intervention to prevent non- communicable disease risk factors.Methods: It was a quasi experimental study conducted during the period of 2009-2015. We involved school children aged from 11 to 16 years old. For the assessment of the program’s effectiveness, subjects in both groups were examined at baseline, at the end of the 3-year intervention period and at the follow-up, one year after program’s cessation.Results: In the intervention group, the prevalence of school children who reported to be eating 5 fruits and vegetable sdaily increased significantly from 30.0% at pre-assessment to 33.2% at post-assessment, one year after (p=0.02, p=0.41 respectively). For the control group, this prevalence had significantly decreased from 40.2% at baseline to 35.0% at post-intervention, at the follow up, this proportion increased to 44.5%(p=0.001, p<10-3 respectively). Concerning smoking habits, we observed a decreasing trend in the intervention group from 5.7% at pre-assessment, to 4.8% at post-assessment and to 3.4% at the follow-up (p=0.19 and p=0.25 respectively). There was also a significant decrease in school children who did recommended physical activity in the same group.Conclusion: The present work showed that interventions promoting healthy lifestyles should be maintained. Developing countries should be encouraged and supported to design, conduct, and evaluate robust preventive interventions.Keywords: Schools, lifestyle, intervention