Electrophysiological and Fos immunohistochemical evidence for the excitatory nature of the parafascicular projection to the globus pallidus

Extracellular recordings and immunohistological detection of c-Fos-like immunoreactive proteins were used to determine the synaptic effect of the parafascicular projection to the globus pallidus. Electrical stimulation of the parafascicular neurons induced a single-spike excitatory response with a stable latency of 2.3 ms, suggesting a monosynaptically driven effect. Pharmacological stimulation of the parafascicular nucleus with carbachol increased tonically the pallidal discharge rate by 142%. The discharge rate of the pallidal neurons was described by 37% in parafascicular-lesioned rats. These results demonstrate the excitatory nature and the tonic action of the parafasciculopallidal projection. Carbachol activation of parafascicular neurons also induced the synthesis of c-Fos-like immunoreactive proteins in the pallidal neurons. Control experiments in subthalamic-lesioned rats showed that the parafascicular excitation of the pallidal neurons remained, but both electrophysiological and expression of c-Fos-like immunoreactive proteins were attenuated. This suggests that the direct parafascicular excitation of the pallidal neurons is indirectly reinforced by the previously described parafascicular excitatory input to the subthalamic nucleus. Conversely, the effect of this last input to the subthalamic nucleus is dramatically enhanced in rats with pallidal lesion. Our results demonstrate the complex role of the parafascicular nucleus in activating both the globus pallidus and the subthalamic nucleus, two closely related structures. These results illustrate the integrative capacities of the globus pallidus, whose activity is modulated by multiple afferents.     

Large deformation analysis in the context of 3D compressible nonlinear elasticity using the VDQ method

In this article, a new solution approach is developed to numerically compute large deformations of 3D hyperelastic solids based on the compressible nonlinear elasticity. The governing equations are derived by the minimum total potential energy principle, and the Neo-Hookean model is used for the hyperelastic character of material. One of the key novelties of the work is its formulation in which the tensor form of equations is replaced by an efficient matrix–vector form that can be readily utilized in the coding process. Moreover, the variational differential quadrature technique is adopted to arrive at the discretized governing equations in a direct way. Simple implementation, fast convergence rate, and computational efficiency are the main advantages of present approach. Through some examples, the accuracy and effectiveness of the proposed numerical approach are revealed.

     

Design optimization of the quantization and a pipelined 2D-DCT for real-time applications

The Discrete Cosine Transform (DCT) is one of the most widely used techniques for image compression. Several algorithms are proposed to implement the DCT-2D. The scaled SDCT algorithm is an optimization of the DCT-1D, which consists in gathering all the multiplications at the end. In this paper, in addition to the hardware implementation on an FPGA, an extended optimization has been performed by merging the multiplications in the quantization block without having an impact on the image quality. A simplified quantization has been performed also to keep higher the performances of the all chain. Tests using MATLAB environment have shown that our proposed approach produces images with nearly the same quality of the ones obtained using the JPEG standard. FPGA-based implementations of this proposed approach is presented and compared to other state of the art techniques. The target is an an Altera Cyclone II FPGA using the Quartus synthesis tool. Results show that our approach outperforms the other ones in terms of processing-speed, used resources and power consumption. A comparison has been done between this architecture and a distributed arithmetic based architecture.     

Dual Band PIFA MIMO Antenna Design with High Isolation for Mobile and Wireless Applications by Using the Genetics Algorithms and Non-uniform Overlapping Method

Wireless Personal Communications - Due to the development and growth of Internet platforms and web services as communication resources, the competition for the network and its limited resources is...     

A dual‐broadband circularly polarized halved falcate‐shape printed monopole antenna

A halved falcate‐shape dual‐broadband circularly polarized printed monopole antenna is proposed. To generate the equal amplitude orthogonal modes, two halved falcate‐shaped antenna are used. Also, to provide the 90° phase difference between the two modes, three stubs are used in the ground plane of the antenna. The proposed antenna provides 22.6 (1.36–1.72 GHz) and 44.4% (5.25–8.25 GHz) 3 dB axial ratio bandwidth over the lower and upper bands, respectively. By adjusting the parameters of the antenna, the lower and upper band center frequencies can be tuned individually. The proposed antenna is fabricated, and results are compared with those of the simulation. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

Efficient biodegradation of naphthalene by a newly characterized indigenous Achromobacter sp. FBHYA2 isolated from Tehran Oil Refinery Complex

A bacterial strain, FBHYA2, capable of degrading naphthalene, was isolated from the American Petroleum Institute (API) separator of the Tehran Oil Refinery Complex (TORC). Strain FBHYA2 was identified as Achromobacter sp. based on physiological and biochemical characteristics and also phylogenetic similarity of 16S rRNA gene sequence. The optimal growth conditions for strain FBHYA2 were pH 6.0, 30 °C and 1.0% NaCl. Strain FBHYA2 can utilize naphthalene as the sole source of carbon and energy and was able to degrade naphthalene aerobically very fast, 48 h for 96% removal at 500 mg/L concentration. The physiological response of Achromobacter sp., FBHYA2 to several hydrophobic chemicals (aliphatic and aromatic hydrocarbons) was also investigated. No biosurfactant was detected during bacterial growth on any aliphatic/aromatic hydrocarbons. The results of hydrophobicity measurements showed no significant difference between naphthalene- and LB-grown cells. The capability of the strain FBHYA2 to degrade naphthalene completely and rapidly without the need to secrete biosurfactant may make it an ideal candidate to remediate polycyclic aromatic hydrocarbon (PAH)-contaminated sites.     

A Hybrid Virtual Cloud Learning Model during the COVID-19 Pandemic

The COVID-19 pandemic has affected the educational systems worldwide, leading to the near-total closures of schools, universities, and colleges. Universities need to adapt to changes to face this crisis without negatively affecting students’ performance. Accordingly, the purpose of this study is to identify and help solve to critical challenges and factors that influence the e-learning system for Computer Maintenance courses during the COVID-19 pandemic. The paper examines the effect of a hybrid modeling approach that uses Cloud Computing Services (CCS) and Virtual Reality (VR) in a Virtual Cloud Learning Environment (VCLE) system. The VCLE system provides students with various utilities and educational services such as presentation slides/text, data sharing, assignments, quizzes/tests, and chatrooms. In addition, learning through VR enables the students to simulate physical presence, and they respond well to VR environments that are closer to reality as they feel that they are an integral part of the environment. Also, the research presents a rubric assessment that the students can use to reflect on the skills they used during the course. The research findings offer useful suggestions for enabling students to become acquainted with the proposed system’s usage, especially during the COVID-19 pandemic, and for improving student achievement more than the traditional methods of learning.