关联理论的神经学基础

关联理论是认知语用学的主要理论,对交际有很强的解释力,但对于关联理论的适用性和合理性有很大的争议。通过运用神经学及生物学的一些观点,论证关联理论对交际的解释力,从而寻找其神经学基础。

学习、记忆的神经细胞学基础

学习记忆本身是一个非常复杂的过程,其细胞和分子机制仍然很不清楚,但有几点是肯定的,即海马是学习记忆的关键部位,LTP(突触后长时程增强)和LDT(突触后长时程压抑)是海马记忆形成过程中的可能机制,是神经细胞突触可塑性的两种主要特征：受体和通道是产生LTP和LTD的生物学基础；神经递质即早基因的转录因子CREB(cAMP反应成分结合蛋白)参与学习记忆过程。

语言具身认知原理及其理论基础

具身认知是认知科学研究领域的最新范式与前沿主题之一,引起多学科的研究兴趣。具身认知与语言认知结合的研究方法是一种新的认知研究范式,即语言具身认知,它从认识论、心理学和认知神经学层面研究其认识论基础、心脑机制以及认知神经学基础,为理解语言内化、语言体验、语言处理、语言生成等符号文化的创造性加工机制提供了新颖的思想启示,也为探讨语言认知的理论与实践研究的新路径、提升语言研究与教学的社会效能提供了参考。

Culture and purification of human fetal olfactory bulb ensheathing cells

Objective:To obtain high purity of human fetal olfactory bulb ensheathing cells (OB-hOECs) in vitro and to develop a simple and effective method for primary culture of OB-hOECs. Methods: OB-hOECs were cultured based on the differential rates of attachment of the various harvested cell types. Then the method was combined with arabinoside cytosine (Ara-C)inhibition, serum-free starvation or intermittent neurotrophin 3 (NT3) nutrition method to observe cell states in different cultural environments. The purity of OB-hOECs was assessed with immunocytochemical analysis. Results: OB-hOECs appeared bipolar and tripolar shape, with slender processes forming network. The purity of OECs reached 88% with the selective attachment method on day 6, and then fibroblast proliferated quickly and reduced the purity. When combined with the starvation method, the purity of OECs was 91% on day 6 and 86% on day 9, however, OECs were in a poor state. While combined with the NT3 method, the purity reached 95% on day 9 and 83% on day 12, respectively. The cells still remained in a good state. Conclusion: A combination of selective attachment and intermittent NT3 nutrition is an effective method to obtain OECs with higher purity and quality.

Transferring superior gluteal nerve to pudendal nerve in reconstructing functional impairment in simple conus medullaris or pudendal nerve injury

Objective: 1Department of Anatomy, College of Basic Medical Sciences, Second Military Medical University, Shanghai 200433, China 2Department of Orthopedic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China Abstract Objective: To study the anatomical basis of transferring the superior gluteal nerve to the pudendal nerve in reconstructing the functional impairment in simple conus medullaris or pudendal nerve injury. Methods: Superior gluteal nerve and pudendal nerve were observed and measured by the gross and microsurgical anatomical methods in 62 sides of 31 adult cadavers. Results: Superior gluteal nerve came out of the superior foreman of piriformis as 1 to 4 branches(29.03%,56.45%,12.90% and 1.61% respectively) and the pelvic-leaving points were mainly in the middle 1/3(85.48%) of the line from the posterior superior iliac spine to the ischial tuberosity. The length of the inferior branch of the superior gluteal nerve was more than 5 cm, and the distance between the pelvic-leaving points of the superior gluteal nerve and pudandal nerve was about 4 cm only. The pudendal nerve left the pelvis mainly in the middle 1/3(48.39%) of the line from the posterior superior iliac spine to the ischial tuberosity,or at the junction of its inferior-middle 1/3(46.77%). In clinic, we have successfully made the operation transferring the superior gluteal nerve to the pudendal nerve in 3 patients suffered from the injury of conus medullaris. Conclusion: Distance between the pelvic-leaving points of the superior gluteal nerve and the pudendal nerve is close, so the inferior branch of the gluteal nerve can be anastomosed with the pudendal nerve directly. Transferring the superior gluteal nerve with higher spinal segemental origin to the pudendal nerve of a lower spinal segemental origin is practical and easy.

EFFICIENT GRADIENT DESCENT METHOD OFRBF NEURAL ENTWORKS WITHADAPTIVE LEARNING RATE

A new algorithm to exploit the learning rates of gradient descent method is presented, based on the second-order Taylor expansion of the error energy function with respect to learning rate, at some values decided by "award-punish" strategy. Detailed deduction of the algorithm applied to RBF networks is given. Simulation studies show that this algorithm can increase the rate of convergence and improve the performance of the gradient descent method.

Times Series Prediction to Basis of a Neural Network Conceived by a Real Genetic Algorithm

Neural network and genetic algorithms are complementary technologies in the design of adaptive intelligent system. Neural network learns from scratch by adjusting the interconnections betweens layers. Genetic algorithms are a popular computing framework that uses principals from natural population genetics to evolve solutions to problems. Various forecasting methods have been developed on the basis of neural network, but accuracy has been matter of concern in these forecasts. In neural network methods forecasted values depend to the choose of neural predictor structure, the number of the input, the lag. To remedy to these problem, in this paper, the authors are investing the applicability of an automatic design of a neural predictor realized by real Genetic Algorithms to predict the future value of a time series. The prediction method is tested by using meteorology time series that are daily and weekly mean temperatures in Melbourne, Australia, 1980-1990.

Anatomic basis of vascularized ulnar nerve graft by the pedicle of the superior collateral ulnar artery

Objective: To investigate the anatomic basis of vascularized ulnar nerve graft by the pedicle of the superior collateral ulnar artery (SCUA). Methods: Twenty-two fresh cadaver upper extremities injected intra-arterially with latex were dissected to study the extrinsic blood supply of the ulnar nerve. Other 6 fresh upper extremities were used to analyze the blood supply range of SCUA inside the ulnar nerve by microangiographic and histological methods. Results: The ulnar nerve was supplied by a branch of the lateral thoracic artery or directly by the axillary artery in the axillary section, by branches of SCUA in the upper arm, and by branches from the anastomosis of the collateral arteries and the posterior branch of the recurrent ulnar artery in the elbow. SCUA could supply the whole ulnar nerve from the axilla to the wrist. Conclusions: The ulnar nerve can be used as a vascularized nerve graft by the pedicle of SCUA in treatment of brachial plexus roots avulsion by C7 transfer from healthy side.

The molecular basis for ethnic variation and histological subtype differences in prostate cancer

Prostate cancer is a common malignancy among men in Western countries. Recently the morbidity and mortality of prostate cancer increase dramatically in several oriental countries including China. Rapidly evolving technology in molecular biology such as high-throughput sequencing and integrative analysis of genomic and transcriptomic landscapes have enabled the identification of key oncogenic events for prostate cancer initiation, progression and resistance to hormonal therapy. These surging data of prostate cancer genome also provide insights on ethnic variation and the differences in histological subtype of this disease. In this review, differences in the incidence of prostate cancer and the prevalence of main genetic alterations between Asian and Western populations are discussed. We also review the recent findings on the mechanisms underlying neuroendocrine differentiation of prostate cancer and the development of small cell neuroendocrine carcinoma after androgen deprivation therapy.