Code extraction algorithms which unify slicing and concept assignment

One approach to reverse engineering is to partially automate subcomponent extraction, improvement and subsequent recombination. Two previously proposed automated techniques for supporting this activity are slicing and concept assignment. However, neither is directly applicable in isolation; slicing criteria (sets of program variables) are simply too low level in many cases, while concept assignment typically fails to produce executable subcomponents. This paper introduces a unification of slicing and concept assignment which exploits their combined advantages, while overcoming their individual weaknesses. Our 'concept slices' are extracted using high level criteria, while producing executable subprograms. The paper introduces three ways of combining slicing, and concept assignment and algorithms for each. The application of the concept slicing algorithms is illustrated with a case study from a large financial organisation

The effect of internal pressure on axial fracture characteristics of internally surface-flawed specimens

Internally precracked thick-walled cylinders were fractured under uniaxial stress conditions both without and with internal pressure to determine the difference in fracture characteristics. The complex loading and interaction with the pressuring media are possible factors to explain the subcritical crack growth

Evaluating Lexical Approximation of Program Dependence

Complex dependence analysis typically provides an underpinning approximation of true program dependence. We investigate the effectiveness of using lexical information to approximate such dependence, introducing two new deletion operators to Observation-Based Slicing (ORBS). ORBS provides direct observation of program dependence, computing a slice using iterative, speculative deletion of program parts. Deletions become permanent if they do not affect the slicing criterion. The original ORBS uses a bounded deletion window operator that attempts to delete consecutive lines together. Our new deletion operators attempt to delete multiple, non-contiguous lines that are lexically similar to each other. We evaluate the lexical dependence approximation by exploring the trade-off between the precision and the speed of dependence analysis performed with new deletion operators. The deletion operators are evaluated independently, as well as collectively via a novel generalization of ORBS that exploits multiple deletion operators: Multi-operator Observation-Based Slicing (MOBS). An empirical evaluation using three Java projects, six C projects, and one multi-lingual project written in Python and C finds that the lexical information provides a useful approximation to the underlying dependence. On average, MOBS can delete 69% of lines deleted by the original ORBS, while taking only 36% of the wall clock time required by ORBS

Distinguishing copies from originals in software clones

Cloning is widespread in today's systems where automated assistance is required to locate cloned code. Although the evolution of clones has been studied for many years, no attempt has been made so far to automatically distinguish the original source code leading to cloned copies. This paper presents an approach to classify the clones of a clone pair based on the version information available in version control systems. This automatic classification attempts to distinguish the original from the copy. It allows for the fact that the clones may be modified and thus consist of lines coming from different versions. An evaluation, based on two case studies, shows that when comments are ignored and a small tolerance is accepted, for the majority of clone pairs the proposed approach can automatically distinguish between the original and the copy. © 2010 ACM

Contributions of clinical and technical factors to longitudinal change in trabecular bone score and bone density: a registry‐based individual‐level analysis

Lumbar spine trabecular bone score (TBS), a grey-level texture measure derived from spine dual-energy x-ray absorptiometry (DXA) images, is a bone mineral density (BMD)-independent risk factor for fracture. An unresolved question is whether TBS is sufficiently responsive to change over time or in response to widely used osteoporosis therapy at the individual level to serve as a useful biomarker. Using the Manitoba DXA Registry we identified 11,643 individuals age 40 years and older with two fan-beam DXA scans performed on the same instrument within 5 years (mean interval 3.2 years), of whom 6,985 (60.0%) received antiresorptive osteoporosis medication (majority oral bisphosphonate) between the scans. We examined factors that were associated with a change in lumbar spine TBS, lumbar spine BMD and total hip BMD exceeding the 95% least significant change (LSC). Change exceeding the LSC was identified in 23.0% (9.3% increase, 13.8% decrease) of lumbar spine TBS, 38.2% (22.1% increase, 16.1% decrease) lumbar spine BMD, and 42.5% (17.6% increase, 24.9% decrease) total hip BMD measurement-pairs. From regression models, the variables most strongly associated with significant change in TBS (decreasing order) were tissue thickness change, acquisition mode change, weight change and spine percent fat change. Consistent with the insensitivity of TBS to oral antiresorptive therapies, use of these agents showed very little effect on TBS change. In contrast, for both spine BMD change and total hip BMD change, osteoporosis medication use was the most significant variable, while tissue thickness change, acquisition mode change and weight change had relatively weak effects. In summary, change in spine TBS using the present algorithm appears to be strongly affected by technical factors. This suggests a limited role, if any, for using TBS change in untreated individuals or for monitoring response to anti-resorptive treatment in routine clinical practice with the current version of the TBS algorithm

Trabecular bone score (TBS) as a new complementary approach for osteoporosis evaluation in clinical practice.

Trabecular bone score (TBS) is a recently-developed analytical tool that performs novel grey-level texture measurements on lumbar spine dual X-ray absorptiometry (DXA) images, and thereby captures information relating to trabecular microarchitecture. In order for TBS to usefully add to bone mineral density (BMD) and clinical risk factors in osteoporosis risk stratification, it must be independently associated with fracture risk, readily obtainable, and ideally, present a risk which is amenable to osteoporosis treatment. This paper summarizes a review of the scientific literature performed by a Working Group of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis. Low TBS is consistently associated with an increase in both prevalent and incident fractures that is partly independent of both clinical risk factors and areal BMD (aBMD) at the lumbar spine and proximal femur. More recently, TBS has been shown to have predictive value for fracture independent of fracture probabilities using the FRAX® algorithm. Although TBS changes with osteoporosis treatment, the magnitude is less than that of aBMD of the spine, and it is not clear how change in TBS relates to fracture risk reduction. TBS may also have a role in the assessment of fracture risk in some causes of secondary osteoporosis (e.g., diabetes, hyperparathyroidism and glucocorticoid-induced osteoporosis). In conclusion, there is a role for TBS in fracture risk assessment in combination with both aBMD and FRAX

Efficient Identification of Linchpin Vertices in Dependence Clusters

Several authors have found evidence of large dependence clusters in the source code of a diverse range of systems, domains, and programming languages. This raises the question of how we might efficiently locate the fragments of code that give rise to large dependence clusters. We introduce an algorithm for the identification of linchpin vertices, which hold together large dependence clusters, and prove correctness properties for the algorithm’s primary innovations. We also report the results of an empirical study concerning the reduction in analysis time that our algorithm yields over its predecessor using a collection of 38 programs containing almost half a million lines of code. Our empirical findings indicate improvements of almost two orders of magnitude, making it possible to process larger programs for which it would have previously been impractical

Effect of BMI-discordant abdominal tissue thickness on fracture probability: a registry-based study

FRAX, which is used to assess fracture probability, considers body mass index (BMI), but BMI may not reflect individual variation in body composition and distribution. We examined the effect of BMI-discordant abdominal thickness on FRAX-derived fracture probability for major osteoporotic fracture (MOF) and hip fracture. We studied 73,105 individuals, mean age 64.2 years. During mean 8.7 years, 7048 (9.6%) individuals sustained incident MOF, including 2155 (3.0%) hip fractures. We defined abdominal thickness index (ATI) as the difference between abdominal thickness measured by dual-energy X-ray absorptiometry (DXA) and thickness predicted by BMI using sex-stratified regression. ATI was categorized from lower (+2 cm) with referent around zero (−1 to +1 cm). Adjusted for FRAX probability, increasing ATI was associated with incident MOF and hip fracture (p < 0.001). For the highest ATI category, MOF risk was increased (hazard ratio [HR] = 1.23, 95% confidence interval [CI] 1.12–1.35) independent of FRAX probability. Similar findings were noted for hip fracture probability (HR = 1.28, 95% CI 1.09–1.51). There was significant age-interaction with much larger effects before age 65 years (HR = 1.44, 95% CI 1.23–1.69 for MOF; 2.29, 95% CI 1.65–3.18 for hip fracture). In contrast, for the subset of individuals with diabetes, there was also increased risk for those in the lowest ATI category (HR = 1.73, 95% CI 1.12–2.65 for MOF; 2.81, 95% CI 1.59–4.97 for hip fracture). Calibration plots across ATI categories demonstrated deviation from the line of identity in women (calibration slope 2.26 for MOF, 2.83 for hip fracture). An effect of ATI was not found in men, but this was inconclusive as the sex-interaction terms did not show significant effect modification. In conclusion, these data support the need to investigate increased abdominal thickness beyond that predicted by BMI and sex as a FRAX-independent risk factor for fracture. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)

The Calcitonin and Glucocorticoids Combination: Mechanistic Insights into Their Class-Effect Synergy in Experimental Arthritis

PMCID: PMC3564948This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited