A Quantitative Study of Java Software Buildability

Researchers, students and practitioners often encounter a situation when the build process of a third-party software system fails. In this paper, we aim to confirm this observation present mainly as anecdotal evidence so far. Using a virtual environment simulating a programmer's one, we try to fully automatically build target archives from the source code of over 7,200 open source Java projects. We found that more than 38% of builds ended in failure. Build log analysis reveals the largest portion of errors are dependency-related. We also conduct an association study of factors affecting build success

Prescribable mHealth apps identified from an overview of systematic reviews

AbstractMobile health apps aimed towards patients are an emerging field of mHealth. Their potential for improving self-management of chronic conditions is significant. Here, we propose a concept of “prescribable” mHealth apps, defined as apps that are currently available, proven effective, and preferably stand-alone, i.e., that do not require dedicated central servers and continuous monitoring by medical professionals. Our objectives were to conduct an overview of systematic reviews to identify such apps, assess the evidence of their effectiveness, and to determine the gaps and limitations in mHealth app research. We searched four databases from 2008 onwards and the Journal of Medical Internet Research for systematic reviews of randomized controlled trials (RCTs) of stand-alone health apps. We identified 6 systematic reviews including 23 RCTs evaluating 22 available apps that mostly addressed diabetes, mental health and obesity. Most trials were pilots with small sample size and of short duration. Risk of bias of the included reviews and trials was high. Eleven of the 23 trials showed a meaningful effect on health or surrogate outcomes attributable to apps. In conclusion, we identified only a small number of currently available stand-alone apps that have been evaluated in RCTs. The overall low quality of the evidence of effectiveness greatly limits the prescribability of health apps. mHealth apps need to be evaluated by more robust RCTs that report between-group differences before becoming prescribable. Systematic reviews should incorporate sensitivity analysis of trials with high risk of bias to better summarize the evidence, and should adhere to the relevant reporting guideline.</jats:p

Are systematic reviews up-to-date at the time of publication?

BACKGROUND: Systematic reviews provide a synthesis of evidence for practitioners, for clinical practice guideline developers, and for those designing and justifying primary research. Having an up-to-date and comprehensive review is therefore important. Our main objective was to determine the recency of systematic reviews at the time of their publication, as measured by the time from last search date to publication. We also wanted to study the time from search date to acceptance, and from acceptance to publication, and measure the proportion of systematic reviews with recorded information on search dates and information sources in the abstract and full text of the review. METHODS: A descriptive analysis of published systematic reviews indexed in Medline in 2009, 2010 and 2011 by three reviewers, independently extracting data. RESULTS: Of the 300 systematic reviews included, 271 (90%) provided the date of search in the full-text article, but only 141 (47%) stated this in the abstract. The median (standard error; minimum to maximum) survival time from last search to acceptance was 5.1 (0.58; 0 to 43.8) months (95% confidence interval = 3.9 to 6.2) and from last search to first publication time was 8.0 (0.35; 0 to 46.7) months (95% confidence interval = 7.3 to 8.7), respectively. Of the 300 reviews, 295 (98%) stated which databases had been searched, but only 181 (60%) stated the databases in the abstract. Most researchers searched three (35%) or four (21%) databases. The top-three most used databases were MEDLINE (79%), Cochrane library (76%), and EMBASE (64%). CONCLUSIONS: Being able to identify comprehensive, up-to-date reviews is important to clinicians, guideline groups, and those designing clinical trials. This study demonstrates that some reviews have a considerable delay between search and publication, but only 47% of systematic review abstracts stated the last search date and 60% stated the databases that had been searched. Improvements in the quality of abstracts of systematic reviews and ways to shorten the review and revision processes to make review publication more rapid are needed

Linking partial and quasi dynamical symmetries in rotational nuclei

Background: Quasi dynamical symmetries (QDS) and partial dynamical symmetries (PDS) play an important role in the understanding of complex systems. Up to now these symmetry concepts have been considered to be unrelated. Purpose: Establish a link between PDS and QDS and find an emperical manifestation. Methods: Quantum number fluctuations and the intrinsic state formalism are used within the framework of the interacting boson model of nuclei. Results: A previously unrecognized region of the parameter space of the interacting boson model that has both O(6) PDS (purity) and SU(3) QDS (coherence) in the ground band is established. Many rare-earth nuclei approximately satisfying both symmetry requirements are identified. Conclusions: PDS are more abundant than previously recognized and can lead to a QDS of an incompatible symmetry.Comment: 5 pages, 4 figures, 1 tabl

The Geometry of the Cholesteric Phase

We propose a construction of a cholesteric pitch axis for an arbitrary nematic director field as an eigenvalue problem. Our definition leads to a Frenet-Serret description of an orthonormal triad determined by this axis, the director, and the mutually perpendicular direction. With this tool we are able to compare defect structures in cholesterics, biaxial nematics, and smectics. Though they all have similar ground state manifolds, the defect structures are different and cannot be, in general, translated from one phase to the other.Comment: 5 pages, the full catastroph

Lipid droplets: A dynamic organelle moves into focus.

Lipid droplets (LDs) were perceived as static storage deposits, which passively participate in the energy homeostasis of both cells and entire organisms. However, this view has changed recently after the realization of a complex and highly dynamic LD proteome. The proteome contains key components of the fat mobilization system and proteins that suggest LD interactions with a variety of cell organelles, including the endoplasmic reticulum, mitochondria and peroxisomes. The study of LD cell biology, including cross-talk with other organelles, the trafficking of LDs in the cell and regulatory events involving the LD coat proteins is now on the verge of leaving its infancy and unfolds that LDs are highly dynamic cellular organelles

Geometry of the cholesteric phase

We propose a construction of a cholesteric pitch axis for an arbitrary nematic director field as an eigenvalue problem. Our definition leads to a Frenet-Serret description of an orthonormal triad determined by this axis, the director, and the mutually perpendicular direction. With this tool, we are able to compare defect structures in cholesterics, biaxial nematics, and smectics. Though they all have similar ground state manifolds, the defect structures are different and cannot, in general, be translated from one phase to the other

Space Transportation System Meteorological Expert

Computers are being used today to build the expert systems of tomorrow. Expert systems are computer programs that are smart about a domain in the way that people are smart. Expert systems technology is being applied to weather forecasting to support Shuttle operations for launch and for ground processing at Kennedy Space Center (KSC), Florida. The Space Transportation System Meterological ExperT (STSMET) is a long term project, now-in its third year, to capture general Shuttle operational weather forecasting expertise specific to our locale, to apply it to Shuttle operational weather forecasting tasks at the Cape Canaveral Forecast Facility (CCFF) at the Cape Canaveral Air Force Station (CCAFS), and to ultimately provide an on-line, real-time operational aid to the duty forecasters in performing their tasks. The first domain addressed by the project has been summer thunderstorms. The effort to represent this knowledge and a control structure to reason about it has resulted in an approach that we call scenario-based reasoning. Other meteorological domains on our agenda are frontal weather phenomena, visibility including fog, and wind shear. We believe that scenario-based reasoning is also applicable to these other meteorological domains. The specific operational tasks to which to apply the general knowledge about summer thunderstorms are being identified during this phase of the contract. The project is being developed using state-of-the-art hardware and software: a Symbolics Lisp Machine, Zetalisp and Automated Reasoning Tool (ART), an expert system shell. Scenario-based reasoning appears to have applications outside of weather forecasting. The abilities of a scenario-based system to reason qualitatively, to reason over time, and to reason across scale are all applicable to planning in autonomous systems. With further research, we expect to add analogical reasoning to the abilities of scenario-based reasoning

Which health-related quality of life score? A comparison of alternative utility measures in patients with Type 2 diabetes in the ADVANCE trial.

BACKGROUND: Diabetes has a high burden of illness both in life years lost and in disability through related co-morbidities. Accurate assessment of the non-mortality burden requires appropriate health-related quality of life and summary utility measures of which there are several contenders. The study aimed to measure the impact of diabetes on various health-related quality of life domains, and compare several summary utility measures. METHODS: In the ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation) study, 978 Australian patients with Type 2 diabetes completed two health-related quality of life questionnaires at baseline: the EQ-5D and the SF-36v2, from which nine summary utility measures were calculated, and compared. The algorithms were grouped into four classes: (i) based on the EQ-5D; (ii) using fewer items than those in the SF-12 (iii) using the items in the SF-12; and (iv) using all items of the SF-36. RESULTS: Overall health-related quality of life of the subjects was good (mean utility ranged from 0.68 (+/-0.08) to 0.85(+/-0.14) over the nine utility measures) and comparable to patients without diabetes. Summary indices were well correlated with each other (r = 0.76 to 0.99), and showed lower health-related quality of life in patients with major diabetes-related events such as stroke or myocardial infarction. Despite the smaller number of items used in the scoring of the EQ-5D, it generally performed at least as well as SF-36 based methods. However, all utility measures had some limitation such as limited range or ceiling effects. CONCLUSION: The summary utility measures showed good agreement, and showed good discrimination between major and minor health state changes. However, EQ-5D based measures performed as well and are generally simpler to use