Do Stack Traces Help Developers Fix Bugs?

A widely shared belief in the software engineering community is that stack traces are much sought after by developers to support them in debugging. But limited empirical evidence is available to confirm the value of stack traces to developers. In this paper, we seek to provide such evidence by conducting an empirical study on the usage of stack traces by developers from the ECLIPSE project. Our results provide strong evidence to this effect and also throws light on some of the patterns in bug fixing using stack traces. We expect the findings of our study to further emphasize the importance of adding stack traces to bug reports and that in the future, software vendors will provide more support in their products to help general users make such information available when filing bug reports

REMOTE TRACKING OF ANDROID SMARTPHONES

The Purpose of the paper is to trace out the status and progress of the employee mobile and the relevant information is transferred to the mobile of the project manager and updated in the web server. The employee’s problem related to the company can be monitored by the project manager and he can also track the employee’s current location through the GPS. In existing system, the CBI alone can trace the mobile phone of any person with the help of unique IMEI number in telephone exchange. So there is no possibility to trace any information regarding the employee’s mobile details by the project manager. So to overcome, this system was implemented

Virological remission after antiretroviral therapy interruption in female African HIV seroconverters.

INTRODUCTION: There are few data on the frequency of virological remission in African individuals after treatment with antiretroviral therapy (ART) in primary HIV infection (PHI). METHODS: We studied participants (n = 82) from South Africa and Uganda in Short Pulse Antiretroviral Treatment at HIV-1 Seroconversion, the first trial of treatment interruption in African individuals with PHI randomized to deferred ART or 48 weeks of immediate ART. All were female and infected with non-B HIV subtypes, mainly C. We measured HIV DNA in CD4 T cells, CD4 cell count, plasma viral load (pVL), cell-associated HIV RNA and T-cell activation and exhaustion. We explored associations with clinical progression and time to pVL rebound after treatment interruption (n = 22). Data were compared with non-African Short Pulse Antiretroviral Treatment at HIV-1 Seroconversion participants. RESULTS: Pretherapy pVL and integrated HIV DNA were lower in Africans compared with non-Africans (median 4.16 vs. 4.72 log10 copies/ml and 3.07 vs. 3.61 log10 copies/million CD4 T cells, respectively; P < 0.001). Pre-ART HIV DNA in Africans was associated with clinical progression (P = 0.001, HR per log10 copies/million CD4 T cells increase (95% CI) 5.38 (1.95-14.79)) and time to pVL rebound (P = 0.034, HR per log10 copies/ml increase 4.33 (1.12-16.84)). After treatment interruption, Africans experienced longer duration of viral remission than non-Africans (P < 0.001; HR 3.90 (1.75-8.71). Five of 22 African participants (22.7%) maintained VL less than 400 copies/ml over a median of 188 weeks following treatment interruption. CONCLUSION: We find evidence of greater probability of virological remission following treatment interruption among African participants, although we are unable to differentiate between sex, ethnicity and viral subtype. The finding warrants further investigation

Carbohydrate scaffolds as glycosyltransferase inhibitors with in vivo antibacterial activity

The rapid rise of multi-drug-resistant bacteria is a global healthcare crisis, and new antibiotics are urgently required, especially those with modes of action that have low-resistance potential. One promising lead is the liposaccharide antibiotic moenomycin that inhibits bacterial glycosyltransferases, which are essential for peptidoglycan polymerization, while displaying a low rate of resistance. Unfortunately, the lipophilicity of moenomycin leads to unfavourable pharmacokinetic properties that render it unsuitable for systemic administration. In this study, we show that using moenomycin and other glycosyltransferase inhibitors as templates, we were able to synthesize compound libraries based on novel pyranose scaffold chemistry, with moenomycin-like activity, but with improved drug-like properties. The novel compounds exhibit in vitro inhibition comparable to moenomycin, with low toxicity and good efficacy in several in vivo models of infection. This approach based on non-planar carbohydrate scaffolds provides a new opportunity to develop new antibiotics with low propensity for resistance induction

The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR.

The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca2+]i) in ASM cells, some of which were (paradoxically) associated with ASM relaxation. Subsequent studies showed a terpenoid molecule (nerol)-stimulated OR2W3 caused increases in [Ca2+]i and relaxation of ASM cells. Of note, OR2W3-evoked [Ca2+]i mobilization and ASM relaxation required Ca2+ flux through the store-operated calcium entry (SOCE) pathway and accompanied plasma membrane depolarization. This chemosensory odorant receptor response was not mediated by adenylyl cyclase (AC)/cyclic nucleotide-gated (CNG) channels or by protein kinase A (PKA) activity. Instead, ASM olfactory responses to the monoterpene nerol were predominated by the activity of Ca2+-activated chloride channels (TMEM16A), including the cystic fibrosis transmembrane conductance regulator (CFTR) expressed on endo(sarco)plasmic reticulum. These findings demonstrate compartmentalization of Ca2+ signals dictates the odorant receptor OR2W3-induced ASM relaxation and identify a previously unrecognized E-C coupling mechanism that could be exploited in the development of therapeutics to treat obstructive lung diseases

Interactive Exploration of Co-evolving Software Entities

Frequent changes to groups of software entities belonging to different parts of the system may indicate structural issues in the system’s decomposition. An in-depth analysis of such groups of entities is needed to understand the underly- ing reasons for co-changes, and also determine how to resolve the issues. To date, static visualizations have been proposed to identify possible structural issues in software systems, but they help only to a certain extent. In this paper we discuss how interactive visualizations can further support the process of analyzing the identified structural issues. We implemented a tool that interactively visualizes software evolution and applied it to a large embedded software system having a development history of more than a decade. Our experience in using the tool along with the architects and developers suggests that interactivity adds much value when analyzing groups of co-changed software entities

Resolving Unwanted Couplings Through Interactive Exploration of Co-Evolving Software Entities: An Experience Report

Context: Frequent changes to groups of software entities belonging to different parts of the system may indicate unwanted couplings between those parts. Visualizations of co-changing software entities have been proposed to help developers identify unwanted couplings. Identifying unwanted couplings, however, is only the first step towards an important goal of a software architect: to improve the decomposition of the software system. An in-depth analysis of co-changing entities is needed to understand the underlying reasons for co-changes, and also determine how to resolve the issues. Objective: In this paper we discuss how interactive visualizations can support the process of analyzing the identified unwanted couplings. Method: We applied a tool that interactively visualizes software evolution in 10 working sessions with architects and developers of a large embedded software system having a development history of more than a decade. Results: The participants of the working sessions were overall very positive about their experiences with the interactive visualizations. In 70% of the cases investigated, a decision could be taken on how to resolve the unwanted couplings. Conclusion: Our experience suggests that interactive visualization not only helps to identify unwanted couplings but it also helps experts to reason about and resolve them. © 2011 Elsevier B.V. All rights reserved

Approximating Change Sets at Philips Healthcare: A Case Study

Abstract—A single development task such as solving a bug or implementing a new feature often involves changing a number of entities, also known together as a change set. Change sets can be approximated from the version control system. They are then used by the architects and developers to take important decisions. So change sets need to be approximated carefully. It is common to assume that two entities checked-in less than a small time interval from each other, and having the same meta-data associated with them, belong to the same transaction. Transactions may be good approximations of change sets if developers commit change sets in one go and if the required meta-data is available. This is however not the case in the industrial environment (Philips Healthcare) we study. Our paper presents a case study in which we investigated how change sets can be approximated in an environment with a complex workflow and limited meta-data in the version repositories. We found that, dependent on the commit practices used, a suitable time intervals between check-in timestamps of files has to be determined and leveraged to reliably approximate change sets. Keywords-mining software archives; change set approxi-mation; case study; empirical software engineering; I

Local and Network Dynamics of a Non-Integer Order Resistor–Capacitor Shunted Josephson Junction Oscillators

Spiral waves are an intriguing phenomenon that can be found in a variety of chemical and biological systems. We consider the fractional-order resistor–capacitor shunted Josephson junction chaotic oscillator to investigate the spiral wave pattern. For a preliminary understanding, we look at the dynamics of isolated FJJs and show that infinitely coexisting periodic and chaotic attractors depend on the fractional order. In addition, we perform bifurcation analysis to show the dynamical transition of the attractors as a function of fractional order and basin stability analysis to show the infinitely coexisting attractors. This is followed by the existence of spiral waves which is observed under various intrinsic and extrinsic system parameters. Finally, the impact of noise on SW is also analyzed by dispersing it to the entire stimulation period or defined time-period