pinecone/core-2020-05-10-deduplication huggingface dataset:
In vivo fate mapping identifies mesenchymal progenitor cells

Adult mesenchymal progenitor cells have enormous potential for use in regenerative medicine. However, the true identity of the progenitors in vivo and their progeny has not been precisely defined. We hypothesize that cells expressing a smooth muscle α-actin promoter (αSMA)-directed Cre transgene represent mesenchymal progenitors of adult bone tissue. By combining complementary colors in combination with transgenes activating at mature stages of the lineage, we characterized the phenotype and confirmed the ability of isolated αSMA(+) cells to progress from a progenitor to fully mature state. In vivo lineage tracing experiments using a new bone formation model confirmed the osteogenic phenotype of αSMA(+) cells. In vitro analysis of the in vivo-labeled SMA9(+) cells supported their differentiation potential into mesenchymal lineages. Using a fracture-healing model, αSMA9(+) cells served as a pool of fibrocartilage and skeletal progenitors. Confirmation of the transition of αSMA9(+) progenitor cells to mature osteoblasts during fracture healing was assessed by activation of bone-specific Col2.3emd transgene. Our findings provide a novel in vivo identification of defined population of mesenchymal progenitor cells with active role in bone remodeling and regeneration
Optimizing compilation with preservation of structural code coverage metrics to support software testing

Code-coverage-based testing is a widely-used testing strategy with the aim of providing a meaningful decision criterion for the adequacy of a test suite. Code-coverage-based testing is also mandated for the development of safety-critical applications; for example, the DO178b document requires the application of the modified condition/decision coverage. One critical issue of code-coverage testing is that structural code coverage criteria are typically applied to source code whereas the generated machine code may result in a different code structure because of code optimizations performed by a compiler. In this work, we present the automatic calculation of coverage profiles describing which structural code-coverage criteria are preserved by which code optimization, independently of the concrete test suite. These coverage profiles allow to easily extend compilers with the feature of preserving any given code-coverage criteria by enabling only those code optimizations that preserve it. Furthermore, we describe the integration of these coverage profile into the compiler GCC. With these coverage profiles, we answer the question of how much code optimization is possible without compromising the error-detection likelihood of a given test suite. Experimental results conclude that the performance cost to achieve preservation of structural code coverage in GCC is rather low
Model refactoring using examples: a search‐based approach

One of the important challenges in model‐driven engineering is how to improve the quality of the models' design in order to help designers understand them. Refactoring represents an efficient technique to improve the quality of a design while preserving its behavior. Most of existing work on model refactoring relies on declarative rules to detect refactoring opportunities and to apply the appropriate refactorings. However, a complete specification of refactoring opportunities requires a huge number of rules. In this paper, we consider the refactoring mechanism as a combinatorial optimization problem where the goal is to find good refactoring suggestions starting from a small set of refactoring examples applied to similar contexts. Our approach, named model refactoring by example, takes as input an initial model to refactor, a set of structural metrics calculated on both initial model and models in the base of examples, and a base of refactoring examples extracted from different software systems and generates as output a sequence of refactorings. A solution is defined as a combination of refactoring operations that should maximize as much as possible the structural similarity based on metrics between the initial model and the models in the base of examples. A heuristic method is used to explore the space of possible refactoring solutions. To this end, we used and adapted a genetic algorithm as a global heuristic search. The validation results on different systems of real‐world models taken from open‐source projects confirm the effectiveness of our approach. Copyright © 2014 John Wiley & Sons, Ltd
Test Generation from Recursive Tile Systems

International audienceThis paper explores the generation of conformance test cases for Recursive Tile Systems (RTSs) in the framework of the classical ioco testing theory. The RTS model allows the description of reactive systems with recursion, and is very similar to other models like Pushdown Automata, Hyperedge Replacement Grammars or Recursive State Machines. Test generation for this kind of infinite state labelled transition systems is seldom explored in the literature. The first part presents an off-line test generation algorithm for Weighted RTSs, a determinizable sub-class of RTSs, and the second one, an on-line test generation algorithm for the full RTS model. Both algorithms use test purposes to guide test selection through targeted behaviours. Additionally, essential properties relating verdicts produced by generated test cases with both the soundness with respect to the specification, and the precision with respect to a test purpose, are proved
A random testing approach using pushdown automata

International audienceSince finite automata are in general strong abstractions of systems, many test cases which are automata traces generated uniformly at ran-dom, may be un-concretizable. This paper proposes a method extending the abovementioned testing approach to pushdown systems providing finer abstractions. Using combinatorial techniques guarantees the uniformity of generated traces. In addition, to improve the quality of the test suites, the combination of coverage criteria with random testing is investigated. The method is illustrated within both structural and model-based testing contexts
Empirical evaluation of a new composite approach to the coverage criteria and reachability testing of concurrent programs

Testing is a key activity to assure the quality of concurrent applications. In recent years, a variety of different\ud
mechanisms have been proposed to test concurrent software. However, a persistent problem is the high\ud
testing cost because of the large number of different synchronization sequences that must be tested. When\ud
structural testing criteria are adopted, a large number of infeasible synchronization sequences is generated,\ud
increasing the testing cost. Although the use of reachability testing reduces the number of infeasible combination\ud
(because only feasible synchronization sequences are generated), many synchronization combinations\ud
are also generated, and this again results in a testing cost with exponential behavior. This paper presents a\ud
new composite approach that uses reachability testing to guide the selection of the synchronization sequences\ud
tests according to a specific structural testing criterion. This new composite approach is empirically evaluated\ud
in the context of message-passing concurrent programs developed with MPI. The experimental study\ud
evaluates both the cost and effectiveness of proposed composite approach in comparison with traditional\ud
reachability testing and structural testing. The results confirm that the use of the new composite approach\ud
has advantages for testing of concurrent applications.FAPESPCAPES 2008/04614-5, 2009/04517-2, 2010/02839-0, 2013/01818-7, 1191/10-
Assessing and generating test sets in terms of behavioural adequacy

Identifying a finite test set that adequately captures the essential behaviour of a program such that all faults are identified is a well-established problem. This is traditionally addressed with syntactic adequacy metrics (e.g. branch coverage), but these can be impractical and may be misleading even if they are satisfied. One intuitive notion of adequacy, which has been discussed in theoretical terms over the past three decades, is the idea of behavioural coverage: If it is possible to infer an accurate model of a system from its test executions, then the test set can be deemed to be adequate. Despite its intuitive basis, it has remained almost entirely in the theoretical domain because inferred models have been expected to be exact (generally an infeasible task) and have not allowed for any pragmatic interim measures of adequacy to guide test set generation. This paper presents a practical approach to incorporate behavioural coverage. Our bestest approach (1) enables the use of machine learning algorithms to augment standard syntactic testing approaches and (2) shows how search-based testing techniques can be applied to generate test sets with respect to this criterion. An empirical study on a selection of Java units demonstrates that test sets with higher behavioural coverage significantly outperform current baseline test criteria in terms of detected faults.This work is funded by a Google Focused Research Award on ‘Test Amplification’, the DSTL-funded BATSproject DSTLX1000062430 and the DSTL-funded HASTE project. This project has been funded b y theEPSRC project ’EXOGEN’ (EP/K030353/1).Peer-reviewedPublisher Versio
Prioritizing MCDC test cases by spectral analysis of Boolean functions

Test case prioritization aims at scheduling test cases in an order that improves some performance goal. One performance goal is a measure of how quickly faults are detected. Such prioritization can be performed by exploiting the Fault Exposing Potential (FEP) parameters associated to the test cases. FEP is usually approximated by mutation analysis under certain fault assumptions. Although this technique is effective, it could be relatively expensive compared to the other prioritization techniques. This study proposes a cost-effective FEP approximation for prioritizing Modified Condition Decision Coverage (MCDC) test cases. A strict negative correlation between the FEP of a MCDC test case and the influence value of the associated input condition allows to order the test cases easily without the need of an extensive mutation analysis. The
method is entirely based on mathematics and it provides useful insight into how spectral analysis of Boolean functions can benefit software testing
Full predicate coverage for testing SQL database queries

In the field of database applications a considerable part of the business logic is implemented using a semi-declarative language: the Structured Query Language (SQL). Because of the different semantics of SQL compared to other procedural languages, the conventional coverage criteria for testing are not directly applicable. This paper presents a criterion specifically tailored for SQL queries (SQLFpc). It is based on Masking Modified Condition Decision Coverage (MCDC) or Full Predicate Coverage and takes into account a wide range of the syntax and semantics of SQL, including selection, joining, grouping, aggregations, subqueries, case expressions and null values. The criterion assesses the coverage of the test data in relation to the query that is executed and it is expressed as a set of rules that are automatically generated and efficiently evaluated against a test database. The use of the criterion is illustrated in a case study which includes complex querie
A taxonomy of model-based testing approaches

Model-based testing (MBT) relies on models of a system under test and/or its environment to derive test cases for the system. This paper discusses the process of MBT and defines a taxonomy that covers the key aspects of MBT approaches. It is intended to help with understanding the characteristics, similarities and differences of those approaches, and with classifying the approach used in a particular MBT tool. To illustrate the taxonomy, a description of how three different examples of MBT tools fit into the taxonomy is provided
Design and implementation of a monitoring system applied to a long-span prestressed concrete bridge

Currently, long-term monitoring systems are mandatory for major civil engineering structures such as bridges, tunnels and dams. Generally, they monitor a set of physical, chemical and mechanical parameters in critical sections of the structure by incorporating appropriate sensors. The set of data collected demonstrates great potential in the prevention of damage and contributes to more efficient maintenance of the structures monitored. This work presents the long-term monitoring system installed on the new Lezíria Bridge over the River Tagus in Portugal. The system was developed to control some aspects of the construction process and to survey the service life of the structure. A set of structural, durability and environmental parameters defining the bridge condition are remotely assessed in real-time via a fibreoptic network. Aspects such as architecture, installation and functionality of the monitoring system are discussed and the innovative aspects of the implementation are highlighted. In this context, the main goal of this work is to present the long-term monitoring system of Lezíria Bridge, sharing the experiences, the solutions and the procedures adopted, given their potential usefulness in the implementation of similar projects. Copyright © 2011 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin
ANALYSIS OF REINFORCED CONCRETE BEAMS BY THE EQUIVALENT SECTION METHOD

International audienceThis research investigates the analysis of reinforced concrete beams subjected to combined axial load, bending moment and shear force. Cross-sections of general shape are divided, along the height, into plane elements. The biaxial behavior is represented according to the smeared rotating crack approach. Using traditionally accepted hypotheses for beams, the shear flow is determined by applying the Jouravski formula to an "equivalent section", which takes into account the nonlinear material behavior. The "Equivalent Section Method", originally proposed by Diaz (1980) and Diaz and Schulz (1981), is improved and simplified. The formulation is implemented applying the bidimensional constitutive model A, proposed by Vecchio and Collins (1993). The tension-stiffening effect is considered as adopted by Polak and Vecchio (1993). Shear slip at crack surfaces, Poisson's ratio and other secondary effects are not considered. Validation is undertaken by comparison with experimental results obtained by other researchers. The examples include reinforced and prestressed concrete beams, for normal and high strength concrete. The formulation satisfactorily predicts the ultimate capacity under different load combinations. The whole set of equilibrium, compatibility and constitutive equations are satisfied, the stiffness derivatives are explicitly calculated and the algorithms show good convergence
Extension of tabulated design parameters for rectangular columns exposed to fire taking into account second order effects and various fire models

Fire, as one of the most severe load conditions, has an important impact on concrete structures. It does not only affect the material strength, but also the structural stiffness and stability. A concrete column, compared to other structural members, has most often to cope both with vertical forces and bending moments transmitted by slabs and beams. Consequently, it is essential to find a reliable and practical way to establish interaction curves for the overall structural behaviour of concrete columns subjected to fire. In this paper, a cross-section calculation method based on the material models of Eurocode 2 is explained and adopted to calculate interaction curves for a typical rectangular column exposed to the ISO834 standard fire. Subsequently, an iterative approach is introduced to develop interaction curves taking into account second order effects in case of four-side heated fire exposure. The maximum permitted slenderness ratios of columns under different fire durations are obtained and compared with Eurocode 2 provisions. Finally, this method is applied to calculate the maximum permitted slenderness ratios for columns exposed to hydrocarbon fires and natural fires
Estimating fixed-end rotations of reinforced concrete members at yielding and ultimate

Strain-penetration of the longitudinal reinforcement of reinforced concrete (RC) members in the joints and/or footings results in fixed-end rotations at the member ends. Several experimental studies have shown that fixed-end rotations caused by strain-penetration contribute significantly (up to 50%) to the total displacement capacity of RC members. Hence, accurate determination of these fixed-end rotations at yielding and ultimate limit states becomes of primary importance when defining the structural response of RC members. The purpose of this study is to present the theoretical background and the assumptions behind the most common relationships found in the literature for determining strain-penetration induced fixed-end rotations at yielding and ultimate. Furthermore, new simple relationships are proposed on the basis of realistic and mechanically-based assumptions. Comparisons between the existing and proposed relationships demonstrate the limitations of the former. Finally, the proposed relationships are calibrated against experimental measurements of RC column specimens subjected to cyclic loading with recorded fixed-end rotations due to strain-penetration in the adjacent joints and/or footings
New structural joint by rebar looping applied to staged box girder bridge construction: static tests

This paper shows the design, development and experimental checking of a modified type of structural joint with limited length between concrete segments cast “in-situ”. The design concept is based on the development length of an anchorage hook stiffened by transverse reinforcement bars and is particularly suited for the case of in-situ construction of staged box girder bridges, seeking to the possibility of using lighter scaffolding. The studies focusing on the strength, stiffness and serviceability of the proposed joint are presented. The research work comprises the bending behaviour of reinforced concrete slabs with loop joints with regard to the diameter of loop bar, loop joint width and ultimate and fatigue load. The results are compared to the behaviour of reinforced concrete slabs without joints. A total of 16 slabs were tested by static and fatigue loading tests. The present paper evaluates the flexural behaviour under static loading test. The results of fatigue tests have also shown an excellent performance. In the static tests, crack width and crack pattern were observed at service load levels, and the ultimate behaviour was evaluated by means of up to failure tests. From the test results, the service performance of the loop joints was confirmed similar to slabs without joints. The static loading tests confirm the good performance and effectiveness of this loop joint type under static loads. Details of loop joints design criteria are also suggested.Peer ReviewedPostprint (author's final draft
Limitations of the use of concrete resistivity as an indicator for the rate of chloride-induced macro-cell corrosion

An experimental setup was designed to study the impact of concrete resistivity on the rate of chloride-induced reinforcement corrosion. Small pieces of mild steel were used to simulate pits (anodes) that form when chlorides come into contact with the reinforcement. The galvanic current was measured between the simulated anodes and a cathode network. Comparisons were made between the galvanic current and the concrete bulk resistivity. The bulk resistivity was varied using two mortar mixes (made of plain Portland cement and a blended Fly ash cement) which were exposed in different temperature and moisture conditions. Despite a high scatter in the results, it was clear that the relationship between bulk resistivity and corrosion rate depended on the mortars tested. The findings presented in this paper and the accompanying work strongly indicate that concrete bulk resistivity alone does not provide sufficient information for assessment of the corrosion rate for chloride-induced macro-cell corrosio
Flexible formwork technologies: a state of the art review

Concrete is our most widely used construction material. Worldwide consumption of cement, the strength-giving component of concrete, is estimated at 4.10 Gt per year, rising from 2.22 Gt just ten years ago [1]. This rate of consumption means that cement manufacture alone is estimated to account for 5.2 % of global carbon dioxide emissions [2]. Concrete offers the opportunity to economically create structures of almost any geometry. Yet its unique fluidity is seldom capitalised upon, with concrete instead being cast into rigid, flat moulds to create unoptimised geometries that result in high material use structures with large carbon footprints. This paper will explore flexible formwork construction technologies which embrace the fluidity of concrete to facilitate the practical construction of concrete structures with complex and efficient geometries. This paper presents the current state of the art in flexible formwork technology, highlighting practical uses, research challenges and new opportunities
Contribution to sustainable seismic design of reinforced concrete members through embodied CO2 emissions optimization

The embodied CO2 emissions of reinforced concrete (RC) structures can be significantly reduced by structural optimization that maximizes structural efficiency. Previous studies dealing with design of RC structures for minimum CO2 emissions do not address seismic design provisions. This is the case despite the fact that in many countries around the world, including most of the top-10 countries in CO2 emissions from cement production, RC structures have to be designed against earthquake hazard. To fill a part of this gap, this study, using exhaustive search, examines optimum designs of RC beam and column members for minimum embodied CO2 emissions according to Eurocode-8 for all ductility classes and compares them with optimum designs based on material cost. It is shown that seismic designs for minimum CO2 footprint lead to less CO2 emissions but are more expensive than minimum cost designs. Their differences strongly depend on the assumed values of the environmental impact of reinforcing steel and concrete materials. Furthermore, it is concluded that seismic design for high ductility classes can drive to significant reductions in embodied CO2 emissions