75 research outputs found
Hybrid Algorithms Based on Integer Programming for the Search of Prioritized Test Data in Software Product Lines
In Software Product Lines (SPLs) it is not possible, in general, to test all products of the family. The number of products denoted by a SPL is very high due to the combinatorial explosion of features. For this reason, some coverage criteria have been proposed which try to test at least all feature interactions without the necessity to test all products, e.g., all pairs of features (pairwise coverage). In addition, it is desirable to first test products composed by a set of priority features. This problem is known as the Prioritized Pairwise Test Data Generation Problem. In this work we propose two hybrid algorithms using Integer Programming (IP) to generate a prioritized test suite. The first one is based on an integer linear formulation and the second one is based on a integer quadratic (nonlinear) formulation. We compare these techniques with two state-of-the-art algorithms, the Parallel Prioritized Genetic Solver (PPGS) and a greedy algorithm called prioritized-ICPL. Our study reveals that our hybrid nonlinear approach is clearly the best in both, solution quality and computation time. Moreover, the nonlinear variant (the fastest one) is 27 and 42 times faster than PPGS in the two groups of instances analyzed in this work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Partially funded by the Spanish Ministry of Economy and Competitiveness and FEDER under contract TIN2014-57341-R, the University of Málaga, Andalucía Tech and the Spanish Network TIN2015-71841-REDT (SEBASENet)
Dependencies between modularity metrics towards improved modules
Recent years have seen many advances in ontology modularisation. This has made it difficult to determine whether a module is actually a good module; it is unclear which metrics should be considered. The few existing works on evaluation metrics focus on only some metrics that suit the modularisation technique, and there is not always a quantitative approach to calculate them. Overall, the metrics are not comprehensive enough to apply to a variety of modules and it is unclear which metrics fare well with particular types of ontology modules. To address this, we create a comprehensive list of module evaluation metrics with quantitative measures. These measures were implemented in the new Tool for Ontology Module Metrics (TOMM) which was then used in a testbed to test these metrics with existing modules. The results obtained, in turn, uncovered which metrics fare well with which module types, i.e., which metrics need to be measured to determine whether a module of some type is a ‘good’ module
Self-renewing resident arterial macrophages arise from embryonic CX3CR1+ precursors and circulating monocytes immediately after birth
Resident macrophages densely populate the normal arterial wall, yet their origins and the mechanisms that sustain them are poorly understood. Here we use gene-expression profiling to show that arterial macrophages constitute a distinct population among macrophages. Using multiple fate-mapping approaches, we show that arterial macrophages arise embryonically from CX3CR1+ precursors and postnatally from bone marrow–derived monocytes that colonize the tissue immediately after birth. In adulthood, proliferation (rather than monocyte recruitment) sustains arterial macrophages in the steady state and after severe depletion following sepsis. After infection, arterial macrophages return rapidly to functional homeostasis. Finally, survival of resident arterial macrophages depends on a CX3CR1-CX3CL1 axis within the vascular niche
Abstract 478: Single-Cell Isolation and Analysis of Viable Proliferating Macrophages From Atherosclerotic Plaques
INTRODUCTION:
We have recently shown that the proliferation of macrophages within the atherosclerotic plaque, rather than the recruitment of new monocytes from the blood is the key driver of plaque growth in established atherosclerosis. The study of proliferating macrophages has been hampered by the lack of a technique for identifying proliferating macrophages and isolating them from the atherosclerotic plaque in a viable state.
OBJECTIVE:
Develop and validate a process for identifying proliferating macrophages in atherosclerotic lesions, and isolating them as single, viable cells, then perform a molecular characterization of these cells.
METHODS:
ApoE-/- and LDLR-/- mice were fed a diet high in fat and cholesterol. Atherosclerotic aortas were collected, and cells were isolated by mechanical and enzymatic dissociation. Cells were stained using fluorescent markers and DNA-binding dyes, then analyzed and isolated by fluorescence-activated cell sorting.
RESULTS:
Mincing and enzymatic digestion in collagenase I, collagenase XI, DNAse, and hyaluronidase optimally isolates macrophages from aortic explants. Cell-surface staining with fluorescent antibodies against B220, F4/80, Ly6c, MHC II, and CD11b allows identification of lesional macrophages. DNA staining with Vybrant DyeCycle Violet allows identification of proliferating cells. Combined, these processes allow for the FACS-based sorting of viable proliferating macrophages from atherosclerotic plaque, and subsequent RNA or protein analysis, or culture.
CONCLUSIONS:
The process described here allows the first-ever viable isolation of proliferating macrophages from atherosclerotic plaques. This will permit the investigation of molecular targets to interfere with the pathogenesis of atherosclerosis.
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Self-renewing resident arterial macrophages arise from embryonic CX3CR1+ precursors and circulating monocytes immediately after birth
Investigation of Impact of Airport Approach Lighting Towers
Peer reviewed: YesNRC publication: Ye
FEA Impact Simulation of Airport Approach Lighting Towers using LS-DYNA3D
Peer reviewed: YesNRC publication: Ye
Simulation of the Dynamic Response of Airport Approach Lighting Towers to Impact Loading
Peer reviewed: YesNRC publication: Ye
IMPACT SIMULATION OF AIRPORT APPROACH LIGHTING TOWERS USING LS-DYNA3D
Peer reviewed: YesNRC publication: Ye
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