Handling High-Level Model Changes Using Search Based Software Engineering

Model-Driven Engineering (MDE) considers models as first-class artifacts during the software lifecycle. The number of available tools, techniques, and approaches for MDE is increasing as its use gains traction in driving quality, and controlling cost in evolution of large software systems. Software models, defined as code abstractions, are iteratively refined, restructured, and evolved. This is due to many reasons such as fixing defects in design, reflecting changes in requirements, and modifying a design to enhance existing features. In this work, we focus on four main problems related to the evolution of software models: 1) the detection of applied model changes, 2) merging parallel evolved models, 3) detection of design defects in merged model, and 4) the recommendation of new changes to fix defects in software models. Regarding the first contribution, a-posteriori multi-objective change detection approach has been proposed for evolved models. The changes are expressed in terms of atomic and composite refactoring operations. The majority of existing approaches detects atomic changes but do not adequately address composite changes which mask atomic operations in intermediate models. For the second contribution, several approaches exist to construct a merged model by incorporating all non-conflicting operations of evolved models. Conflicts arise when the application of one operation disables the applicability of another one. The essence of the problem is to identify and prioritize conflicting operations based on importance and context – a gap in existing approaches. This work proposes a multi-objective formulation of model merging that aims to maximize the number of successfully applied merged operations. For the third and fourth contributions, the majority of existing works focuses on refactoring at source code level, and does not exploit the benefits of software design optimization at model level. However, refactoring at model level is inherently more challenging due to difficulty in assessing the potential impact on structural and behavioral features of the software system. This requires analysis of class and activity diagrams to appraise the overall system quality, feasibility, and inter-diagram consistency. This work focuses on designing, implementing, and evaluating a multi-objective refactoring framework for detection and fixing of design defects in software models.Ph.D.Information Systems Engineering, College of Engineering and Computer ScienceUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/136077/1/Usman Mansoor Final.pdfDescription of Usman Mansoor Final.pdf : Dissertatio

Nocardia Brain Abscess In A Patient With Advanced HIV-AIDS: Case Report

Nocardia is a gram-positive bacterium that causes localised and disseminated infections. A rare case of Nocardia infection in an immunocompromised individual is presented. Nocardiosis should be kept in mind as a diagnosis in immunocompromised patients with a solitary space occupying lesion in the brain

Association of CYP2C19*2 and *17 genetic variants with hypertension in Pakistani population

Purpose: To investigate the association of *2 and *17 single nucleotide polymorphisms (SNPs) of CYP2C19 gene with hypertension in Pakistani population. Methods: The study was conducted on 527 hypertensive patients and 530 unrelated healthy controls from selected regions of Pakistan. DNA was extracted from leukocytes and all patients and controls were genotyped for two SNPs (rs4244285 and rs12248560) of CYP2C19 gene by allele specific polymerase chain reaction (AS-PCR). Results: Multi-allelic polymorphism in CYP2C19 identified four distinct phenotypes known as ultra-rapid metabolizer (UM), extensive metabolizer (EM), intermediate metabolizer (IM) and poor metabolizer (PM) in hypertensive patients and controls. For CYP2C19*2 polymorphisms, overall wild type and mutant allele frequency were 75 and 25 % in hypertensive patients, and 64.2 and 35.8 % in controls. For CYP2C19*17 polymorphisms, the overall wild type and mutant allele frequency were 66.6 and 33.4 % in hypertensive patients and 75.6 % and 24.4 % in controls. Significant difference in allele frequencies for CYP2C19*2 and *17 was demonstrated between hypertensive and non-hypertensive subjects. Conclusion: To the best of our knowledge, this is the first report on CYP2C19 frequencies in hypertensive Pakistani patients. The finds should help clinicians to determine a suitable optimal dosage of some drugs in order to reduce side effects

Cytotoxicity, Morphology and Chemical Composition of Two Luting Cements: An in Vitro Study

Objective: To assess the cytotoxicity, surface morphology, elemental compositions and chemical characterization of two commonly used luting cement. Material and Methods: The two luting types of cement used were Elite Cement® and Hy-Bond Resiglass®. Freshly mixed (n=6) and set form (n=6) of each cement was placed in medium to obtain extracts. The extract from each sample was exposed to L929 mouse fibroblasts (1x104cells/well). Alamar Blue Assay assessed cell viability. Surface morphology and elemental composition were evaluated using scanning electron microscopy and energy dispersive spectroscopy. The chemical characterization was performed by Fourier Transform Infrared Spectroscopy. One-way ANOVA and post-hoc Tukey analysis were conducted to assess results. Results: Hy-Bond Resiglass® was the more cytotoxic of the two types of cement in both freshly mixed (68.10 +5.16; p<0.05) and set state (87.58 +4.86; p<0.05), compared to Elite Cement® both freshly mixed (77.01 +5.45; p<0.05) and set state (89.39 +5.66; p<0.05). Scanning electron microscopy revealed a more irregular and porous structure in Hy-Bond Resiglass® compared to Elite Cement®. Similarly, intense peaks of aluminium, tungsten and fluorine were observed in energy dispersive spectroscopy in Hy-Bond Resiglass. Conclusion: All these three elements (aluminium, tungsten and fluorine) have cytotoxic potential. The Fourier transform infrared spectroscopy revealed the presence of hydroxyethyl methacrylate in Hy-Bond Resiglass®, which has a cytotoxic potential

Screening of marigold (Tagetes erecta L.) cultivars for drought stress based on vegetative and physiological characteristics

Drought tolerance is an important genotypic character to be exploited for the plant cultivar selection under water deficit conditions. In the recent study, we examined the response of two marigold cultivars (Inca and Bonanza) under different regimes of drought stress. The aim was to determine the best performing cultivar under water/drought stress. Three irrigation treatments include; 4 days (T1), 6 days (T2) and 8 days (T3) in comparison to control 1 day (T0) interval were imposed. Response characters under study were morphological, physiological and anatomical. Complete Randomized Design (CRD) with four replications in two factorial arrangements was followed for experiment layout. The results revealed that increasing water stress adversely affect plant height, in both cultivars. Both cultivars showed a decreasing trend to the number of flowers under water stress. Total chlorophyll contents including a, b were also showed reduction under prolonged drought treatment in both cultivars from (2.7 mg g-1 FW) to (1 mg g-1 FW). Overall, the performance of cultivar (cv.) Inca was satisfactory under water stress regimes. These results are helpful for selecting drought tolerant marigold cultivars in water scarce areas.  Â

Biochar as a Fertilizer Replacement for Sustainable Agriculture

Biochar is a promising solution for pesticide pollution and soil degradation in agriculture. It improves fertilizer efficiency by increasing nutrient availability, and acts as a slow-release fertilizer. Biochar enhances soil fertility by retaining nutrients, and increasing organic matter, water retention, and microbial activity. It also shows potential in pesticide degradation through chemical, and microbial processes. However, the sorption of pesticides on biochar can hinder degradation. Factors like feedstock, pyrolysis temperature, and application rate influence biochar\u27s nutrient retention capabilities. Understanding these factors is crucial for optimizing biochar\u27s effectiveness in agricultural systems

Singly-fed rectangular dielectric resonator antenna with a wide circular polarization bandwidth and beamwidth for WiMAX/satellite applications

A rectangular dielectric resonator antenna (DRA) has been excited using a unique conformal H-shaped metal strip. Using this excitation, the degenerate mode pair of first higher orderTE d13 x and TE 1d3 y has been excited for bandwidth improvement and high gain. A broadband circular polarization (CP) over a bandwidth of -20% (3.67-4.4 GHz) in conjunction with a wide impedance-matching bandwidth of -27.7% (3.67-4.73 GHz) has been achieved. A CP beamwidth of 89° has been offered by the antenna in F = 0° plane and -32° in F = 90° plane. A high gain of -6.8 dBic has been provided by the antenna, which is a significant improvement to those circularly polarized rectangular DRAs reported in the literature for similar applications. This broad CP bandwidth and beamwidth can be considerably beneficial for the worldwide interoperability for microwave access (WiMAX) and satellite applications. Furthermore, the proposed antenna has been fabricated to validate the simulated results. The measured results have been observed to agree well with the simulated results