Hardware-accelerated parallel genetic algorithm for fitness functions with variable execution times

Genetic Algorithms (GAs) following a parallel master-slave architecture can be effectively used to reduce searching time when fitness functions have fixed execution time. This paper presents a parallel GA architecture along with two accelerated GA operators to enhance the performance of master-slave GAs, specially when considering fitness functions with variable execution times. We explore the performance of the proposed approach, and analyse its effectiveness against the state-of-the-art. The results show a significant improvement in search times and fitness function utilisation, thus potentially enabling the use of this approach as a faster searching tool for timing-sensitive optimisation processes such as those found in dynamic real-time systems

Hardware-accelerated Evolutionary Hard Real-Time Task Mapping for Wormhole Network-on-Chip with Priority-Preemptive Arbitration

Network-on-Chip (NoC) is an alternative on-chip interconnection paradigm to replace existing ones such as Point-to-Point and shared bus. NoCs designed for hard real-time systems need to guarantee the system timing performance, even in the worst-case scenario. A carefully planned task mapping which indicates how tasks are distributed on a NoC platform can improve or guarantee their timing performance. While existing offline mapping optimisations can satisfy timing requirements, this is obtained by sacrificing the flexibility of the system. In addition, the design exploration process will be prolonged with the continuous enlargement of the design space. Online mapping optimisations, by contrast, are affected by low success rates for remapping or a lack of guarantee of systems timing performance after remapping, especially in hard real-time systems. The existing limitations therefore motivate this research to concentrate on the mapping optimisation of real-time NoCs, and specifically dynamic task allocation in hard real-time systems. Four techniques and implementations are proposed to address this issue. The first enhances the evaluation efficiency of a hard real-time evaluation method from a theoretical point of view. The second technique addresses the evaluation efficiency from a practical point of view to enable online hard real-time timing analysis. The third technique advocates a dynamic mapper to enhance the remapping success rate with the accelerated model and architecture. The final technique yields a dynamic mapping algorithm that can search schedulable task allocation for hard real-time NoCs at run time, while simultaneously reducing the task migration cost after remapping

Diffractive lensing of nano-Hertz gravitational waves emitted from supermassive binary black holes by intervening galaxies

Pulsar timing array (PTA) experiments are expected to detect nano-Hertz gravitational waves (GWs) emitted from individual inspiralling supermassive binary black holes (SMBBHs). The GW signals from a small fraction of these SMBBHs may be diffractively lensed by intervening galaxies. In this paper, we investigate the diffractive lensing effects on the continuous GW signals from the lensed SMBBHs and estimate the detectable number of such signals by PTAs, such as the Chinese PTA (CPTA) and the Square Kilometer Array (SKA) PTA. We find that the amplitude of the lensed GW signals may be only amplified by a factor of $\sim 1.01-1.14$ ($16\%-84\%$ range) and the phase of the signals may shift somewhat due to the lensing, significantly different from those strongly lensed high frequency GW signals from compact binary mergers in the geometric optics. We estimate that $\sim 0.01\%$ of all detected nano-Hertz GW signals from individual SMBBHs by future PTA experiments are lensed by foreground galaxies (i.e., up to $\sim 106$ for CPTA and up to $\sim 289$ for SKA-PTA). However, the lensed nano-Hertz GW signals are difficult to be distinguished from those without lensing by the PTA observations only. We further discuss the possibility about the identification of the lensed nano-Hertz GW signals from SMBBHs via the electromagnetic detection of their host galaxies or active galactic nuclei.Comment: 12 pages, 8 figures, Accepted for publication in MNRA

Bexarotene enhances heart structure and function in diabetic rats by inhibiting ventricular remodeling and cardiomyocyte apoptosis

Purpose: To investigate the influence of bexarotene (Bex) on cardiac structure and function in streptozotocin (STZ)-induced diabetes mellitus (DM) rats, and the mechanism of action involved. Methods: Four groups of Sprague Dawley rats (n = 40) were used: normal control, DM, DM+ Bex (10 mg/kg/day), and DM+ Bex (20 mg/kg/day) (n = 10). The DM rat model was established by intraperitoneal injection of STZ. Cardiac structure and function of rats were determined and compared. Whole heart and left ventricle were weighed. The protein expressions of Bcl2 and Bax in rat myocardial tissue were determined using Western blotting. Results: Compared to control group, there was significant reduction in the levels of IVSd (inlet ventricular septal defect) and LVPWd (left ventricle posterior wall in diastole) in DM group, but significant increase in these parameters in DM +Bex (20 mg/kg/day) group, relative to DM-treated rats (p < 0.05). Moreover, there were higher expression levels of Bcl2 and Bax in DM group, when compared with normal control, but Bcl2/Bax ratio was significantly lower (p < 0.05). Furthermore, Bcl2 and Bax levels in DM + Bex (20 mg/kg/day) group were significantly lower than those in DM group, while Bcl2/Bax ratio increased significantly (p < 0.05). Conclusion: Bexarotene improves the cardiac structure of DM rats by lowering blood glucose, and by inhibiting ventricular remodeling and cardiomyocyte apoptosis. These findings may be beneficial in the development of new anti-DM drugs

Hardware-accelerated analysis of real-time Networks-on-Chip

A real-time Network-on-Chip (NoC) must guarantee that it is able to execute a set of tasks and deliver the communication packets that they generate, all within the respective deadlines even under a worst-case scenario. End-to-End Response Time Analysis (E2ERTA) is a mathematical formulation that can be used to test whether a particular NoC configuration is able to guarantee the timely execution of tasks and delivery packets. The complexity of E2ERTA calculation increases with the increase of the number of tasks and packet flows, and with the core count of the NoC. This paper presents an approach to accelerate E2ERTA calculations through the use of custom hardware and efficient implementation of its mathematical operations. We explore the performance of the proposed approach, and analyse its effectiveness against the state-of-the-art in the field. The results show a significant improvement in testing NoC guarantees, thus potentially enabling the use of E2ERTA as a fast and guaranteed deterministic admission controller for open and dynamic real-time systems. As a case-study, we integrate the proposed approach to a NoC optimisation framework aiming to accelerate the search for NoC configurations that meet all the NoC's hard real-time requirements

catena-Poly[[[bis­(thio­cyanato-κN)zinc(II)]-μ-1,2-bis­{[2-(2-pyrid­yl)-1H-imidazol-1-yl]meth­yl}benzene] 0.28-hydrate]

The title one-dimensional coordination polymer, {[Zn(NCS)2(C24H20N6)2]·0.28H2O}n, was obtained by the reaction of Zn(OAc)2·2H2O, KSCN and 1,2-bis­{[2-(2-pyrid­yl)-1H-imid­azol-1-yl]meth­yl}benzene (hereafter L). The ZnII ion shows a distorted octa­hedral coordination geometry and is coordin­ated by two N atoms from two SCN− anions and four N atoms from two organic ligands. The L ligands act as bridging bis-chelating ligands with cis coordination modes at the ZnII ion. One-dimensional coordination polymers are arranged into layers by π–π stacking inter­actions between the imidazole rings of adjacent chains, with an inter­planar distance of 3.46 (1) Å and centroid–centroid distances of 3.8775 (16) Å. One of the thio­cyanate ligands is disordered over two positions with an occupancy factor of 0.564 (3) for the major component. The partially occupied water mol­ecule forms an O—H⋯S hydrogen bond with the disordered thio­cyanate group

Toxicology and efficacy of tumor-targeting Salmonella typhimurium A1-R compared to VNP 20009 in a syngeneic mouse tumor model in immunocompetent mice.

Salmonella typhimurium A1-R (S. typhimurium A1-R) attenuated by leu and arg auxotrophy has been shown to target multiple types of cancer in mouse models. In the present study, toxicologic and biodistribution studies of tumor-targeting S. typhimurium A1-R and S. typhimurium VNP20009 (VNP 20009) were performed in a syngeneic tumor model growing in immunocompetent BALB/c mice. Single or multiple doses of S. typhimurium A1-R of 2.5 × 105 and 5 × 105 were tolerated. A single dose of 1 × 106 resulted in mouse death. S. typhimurium A1-R (5 × 105 CFU) was eliminated from the circulation, liver and spleen approximately 3-5 days after bacterial administration via the tail vein, but remained in the tumor in high amounts. S. typhimurium A1-R was cleared from other organs much more rapidly. S. typhimurium A1-R and VNP 20009 toxicity to the spleen and liver was minimal. S. typhimurium A1-R showed higher selective targeting to the necrotic areas of the tumors than VNP20009. S. typhimurium A1-R inhibited the growth of CT26 colon carcinoma to a greater extent at the same dose of VNP20009. In conclusion, we have determined a safe dose and schedule of S. typhimurium A1-R administration in BALB/c mice, which is also efficacious against tumor growth. The results of the present report indicate similar toxicity of S. typhimurium A1-R and VNP20009, but greater antitumor efficacy of S. typhimurium A1-R in an immunocompetent animal. Since VNP2009 has already proven safe in a Phase I clinical trial, the present results indicate the high clinical potential of S. typhimurium A1-R

Scintillation of tantalate compounds

A screening of 63 metal-tantalate-oxides was conducted in search of heavy scintillator materials operating at ambient temperature. While tantalates are known to have slow scintillation decay times, the high atomic number of tantalum (73) provides good stopping power for gamma rays. Screened samples were synthesized by solid state reactions. Scintillation properties of these materials were evaluated by X-ray diffraction, X-ray excited luminescence and pulsed X-ray luminescence. Of the 63 synthesized tantalates examined only 12 had luminosity values greater than 1000 ph/MeV at room temperature. From these, ScTaO4, YTa3O9, and Zn3Ta2O8 have greater than 40% of their emission in the first μs. The brightest and fastest compound of those tested was Zn3Ta2O8 with an estimated luminosity of 26,000 ph/MeV and a main decay time of 600 ns from its crystalline powder. Further attention is given to Zn3Ta2O8 and Mg4Ta2O9 scintillation properties, demonstrating their potential for scintillation applications