Practitioners’ Perspectives towards Requirements Engineering: A Survey

In this paper, we discuss the results of our survey among 84 practitioners in order to understand practitioners’ perspectives towards requirements engineering. We asked 28 questions to learn the practitioners’ motivations, the techniques and technologies used for different activities, practitioners’ experiences with customer involvement, and any challenges encountered. Some important results are as follows: the practitioners’ top motivations are the precise communication of requirements and analyzing the requirements to detect issues. Most practitioners (i) insist on using natural languages, (ii) specify requirements as the use case and scenario descriptions, (iii) neglect using/transforming requirements for making high-level decisions and reasoning about requirements, (iv) neglect the specifications of quality requirements and their reasoning while considering quality requirements important, and (v) neglect any technologies for facilitating requirements engineering (e.g., meta-modeling technologies, formal verification tools, and advanced tools). Practitioners are challenged by the cost and effort spent in specifying requirements, the omissions of errors, misinterpretations of requirements and their incorrect (manual) transformations, and customers’ lack of technical knowledge. With the survey results, practitioners can gain an awareness on the general perspectives, academics can trigger new research addressing the observed issues, and tool vendors can improve their tools with regard to the weaknesses determined

The effect of N-acetyl-cysteine and N-omega-nitro-L-arginine methyl ester treatment on lipopolysaccharide-induced oxidative stress in lung of rats

In the present study we investigated the effects of N-omega-Nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS) and N-acetyl-cysteine (NAC) on the activities of myeloperoxidase (MPO), xanthine oxidase (XO) and lipid peroxide levels as well as glutathione (GSH) levels and superoxide dismutase (SOD) activities in the lung of lipopolysaccharide (LPS)-treated rats. LPS treatment (5 mg/kg) caused a decrease in the GSH level and SOD activity while it led to increases in lipid peroxide levels and MPO and XO activities in the lung. LPS + L-NAME + NAC administration prevented GSH reduction and MPO, XO and lipid peroxide augmentation. The factors causing oxidative stress after LPS-treatment was found to be ameliorated following L-NAME + NAC treatment. The data suggest that L-NAME and NAC treatment together may have some beneficial effect on LPS induced lung injury

Effect of hypertension therapy with the angiotensin-converting enzyme inhibitor lisinopril on hyperandrogenism in women with polycystic ovary syndrome

Objective: To investigate the effect of an angiotensin-converting enzyme inhibitor, lisinopril, on serum androgen and sex-hormone-binding globulin (SHBG) levels in hypertensive women with polycystic ovary syndrome (PCOS)

The effects of N-acetyl cysteine treatment and nitric oxide synthase inhibition on oxidative stress induced by E-coli endotoxin

In the present study, we have examined the effects of N-acetyl cysteine (NAG) on hepatic lipid peroxidation and glutathione levels in lipopolysaccharide (LPS) and N-nitro-L-arginine (L-NAME) treated rats. LPS treatment to rats resulted in increased lipid peroxide levels and decreased glutathione (GSH) content in the liver homogenate and mitochondria. NAC plus L-NAME administration attenuated all the abnormalities caused by LPS. In conclusion, it has been suggested that NAC may have some beneficial effects in LPS + L-NAME treated rats

Mitochondrial lipid peroxidation and antioxidant system in aged rats

Mitochondria are especially important in cellular senescence since reactive oxygen species (ROS) have been found to be generated constantly as an endogen threat. On the other hand, mitochondrial defence depends mainly on glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GP(x)). In this study, liver and brain mitochondria of 6- and 22-month-old rats were investigated. Liver mitochondrial malondialdehyde (MDA) levels were found increased, whereas mitochondrial GSH was decreased. SOD activity has been observed elevated, whereas GP(x) was unchanged. However, brain mitochondrial MDA, GSH and SOD and GP(x) activites were found unchanged in old rats. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved