Application Portfolio Diversity and Software Maintenance Productivity:An Empirical Analysis

The research addresses the issue of productivity in application software maintenance. Specifically, it examines the effect of diversity in tools, techniques, hardware and software associated with the portfolio being maintained. In manufacturing environments, there is some evidence to suggest that production of products where there is little sharing of inputs and production processes reduces focus and results in lower manufacturing performance (Skinner, 1974). In economics, it is argued that there are cost complementarities or economies of scope in sharing common inputs and processes among various products with commonalities in production, and diseconomies of scope when inputs and processes differ (Panzar and Willig, 1977, 1981). In the software maintenance context, the issue of diversity and its effect on productivity is particularly salient. Software maintenance is work done to enhance software functionality, correct errors and improve the performance of software (Schneidewind, 1987). It is a costly activity for organizations, requiring from 50 to 80% of the Information Systems (IS) budget and representing more than threefourths of software costs on a life cycle basis (Arthur, 1988). Application portfolio diversity, i.e.,differences in technical platforms, software languages, and development tools and techniques in the set of the organization\u27s software systems, arises as a consequence of the organization\u27s information technology infrastructure decisions. To meet a particular customer need, an IS group acquires or develops software using a certain tool, methodology, and hardware platform. However, it may be that the software does not fit well into the organization\u27s existing technical platform. Furthermore, the software may have been developed using a different methodology or tools than other software systems in the organization\u27s portfolio. This diversity may have the result of increased difficulty in software maintenance because software enhancement can require modification of multiple software systems that have been created using a variety of languages, tools and techniques. The results of our analysis suggest that software portfolio diversity reduces productivity in software maintenance. Potential inefficiencies from diversity in software maintenance can arise from several causes. Switching costs are incurred due to multiple, varied process flows and frequent change over in processes required when modifying software created using different methodologies and tools. Diversity may also increase the difficulty of software quality control, testing and verification; for example, inefficiencies may occur due to the complexities of conducting system and integration testing across multiple technical platforms. Finally, there may be costs due to the difficulties in selecting project team members with the multiple and varied skills required to modify diverse sets of software

Estimating Effectiveness of the Control of Violence and Socioeconomic Development in Colombia: An Application of Dynamic Data Envelopment Analysis and Data Panel Approach

This paper develops an index to evaluate the level of effectiveness of the control of violence based on the data envelopment analysis approach. The index is used to examine the grade of effectiveness of the control of violence at the level of Colombian departments between 1993 and 2007. Comparing the results across Colombian departments, we find that the majority of departments show improvement in their scores of effectiveness. A second stage of the regression model reveals that departments with a higher gross domestic product and higher education and employment are more effective in the control of violence, whereas departments with higher political violence, unemployment rates, unsatisfied basic needs, a displaced population, and hectares cultivated with coca show lower effectiveness in the control of violence. All these findings are of particular interest in the formulation and development of policies against violence, taking into account that organised forms of violence, such as drug trafficking, impede the adequate effectiveness of its control. Moreover, violence decreases social investments, generating alterations in social services that produce long-run deterioration in faith in the government’s ability to govern, which should become an incentive to further violence

3D Multicolor Super-Resolution Imaging Offers Improved Accuracy in Neuron Tracing

The connectivity among neurons holds the key to understanding brain function. Mapping neural connectivity in brain circuits requires imaging techniques with high spatial resolution to facilitate neuron tracing and high molecular specificity to mark different cellular and molecular populations. Here, we tested a three-dimensional (3D), multicolor super-resolution imaging method, stochastic optical reconstruction microscopy (STORM), for tracing neural connectivity using cultured hippocampal neurons obtained from wild-type neonatal rat embryos as a model system. Using a membrane specific labeling approach that improves labeling density compared to cytoplasmic labeling, we imaged neural processes at 44 nm 2D and 116 nm 3D resolution as determined by considering both the localization precision of the fluorescent probes and the Nyquist criterion based on label density. Comparison with confocal images showed that, with the currently achieved resolution, we could distinguish and trace substantially more neuronal processes in the super-resolution images. The accuracy of tracing was further improved by using multicolor super-resolution imaging. The resolution obtained here was largely limited by the label density and not by the localization precision of the fluorescent probes. Therefore, higher image resolution, and thus higher tracing accuracy, can in principle be achieved by further improving the label density

Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved