Technical impossibility to solve exactly NP-hard combinatorial optimization problems for large instances requires the use of heuristics. Nevertheless, the exact methods can be useful, when ...sub-problems can be extracted from the whole problem. Indeed, their resolution contributes in the global solution search, by combining exact resolution of sub-problems and heuristic resolution of the global problem. This approach is generally efficient, because it combines the advantages of two different methods. In this paper we propose to hybridize the metaheuristic MA|PM (memetic algorithm with population management) and B&B to solve combinatorial optimization problems. Our idea is to add in the metaheuristic, an exact method, which has an absolute research power, in order to improve the intensification around the best current solution found by the metaheuristic. We have realized experiments on well-known benchmarks in the literature of the knapsack problem. The results obtained show the effectiveness of Meta/Exact hybridization.
C-Fos-like immunoreactivity (FLI) in the central nervous system, has been associated with the processing of nociceptive information in acute and chronic pain animal models. The aim of this study was ...to investigate whether intraplantar (i.pl.) injections of endotoxin (ET, 1.25 μg) can induce FLI in the lumbar spinal cord of rats and to assess the effects of morphine injection on c-fos expression. FLI was studied in various groups of rats at 2, 3, 4, 6, 9 and 24 h following ET injections. Labeled neurons were mainly detected in the lumbar segments ipsilateral to the ET-injected leg, with a major peak (71.01±4.79 positive neurons) at 4 h and a second peak (29.87±5.97 positive neurons) at 9 h followed by a recovery to the baseline at 24 h after ET injections. Within the laminae, the majority of positive neurons was observed at 2–3 h in laminae I and II and in deep laminae (V and VI mainly) starting at 4 h after ET injections. Rostrocaudally, labeled neurons were observed initially in L
4–L
5 segments (2–3 h post-ET) after which they extended to L
2–L
6 segments at 4 h after ET. Morphine injections either i.p. (1 or 2 mg/kg) or i.pl. (50 μg) significantly reduced ET-induced hyperalgesia and simultaneously the FLI. The maximum effect was observed on labeled neurons in the deep laminae (V and VI mainly). We conclude that local injections of ET can induce FLI in the lumbar spinal cord with a temporal and spatial patterns comparable to the described hyperalgesia, and that both FLI and hyperalgesia are reduced by morphine in a dose-dependent manner with a maximal effect shown by the local i.pl. morphine injections.
In this work we evaluate a recently proposed multiple-input multiple-output (MIMO) system called the Layered Steered Space-Time Codes (LSSTC) that combines the benefits of vertical Bell Labs ...space-time (VBLAST) scheme, space-time block codes (STBC) and beamforming. This evaluation is done by comparing the capacity and the error rate of LSSTC to the well-known MIMO system, known as VBLAST. For that, we derive a formula for the instantaneous capacity of single-user LSSTC. In addition, an adaptive scheme that is based on LSSTC and VBLAST systems is proposed. This scheme selects the configuration and the modulation scheme in order to improve the performance.
In this work we study a recently proposed multiple-input multiple-output (MIMO) system called the Layered Steered Space-Time Codes (LSSTC) that combines the benefits of vertical Bell Labs space-time ...(VBLAST) scheme, space-time block codes (STBC) and beamforming. The aim of this research is to investigate the analytical error performance of single user LSSTC. In addition, the tradeoff between several parameters of LSSTC is analyzed.
In purple membrane added with general anesthetics, there exists an acid-base equilibrium between two spectral forms of the pigment: bR570 and bR480 (apparent pKa = 7.3). As the purple 570 nm ...bacteriorhodopsin is reversibly transformed into its red 480 nm form, the proton pumping capability of the pigment reversibly decreases, as indicated by transient proton release measurements and proton translocation action spectra of mixture of both spectral forms. It happens in spite of a complete photochemical activity in bR480 that is mostly characterized by fast deprotonation and slow reprotonation steps and which, under continuous illumination, bleaches with a yield comparable to that of bR570. This modified photochemical activity has a correlated specific photoelectrical counterpart: a faster proton extrusion current and a slower reprotonation current. The relative areas of all photocurrent phases are reduced in bR480, most likely because its photochemistry is accompanied by charge movements for shorter distances than in the native pigment, reflecting a reversible inhibition of the pumping activity.
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