Detecting the nerve function of fibril in patients with cervicalspondylotic radiculopathy using quantitative sensory testing

BACKGROUND: Pain and sensory disability are greatly affected by subjective factors, there are no quantitative indexes to evaluate cervical spondylotic radiculopathy(CSR). The judgment on clinical body examination and chief complaint always causes nonobjective results with great individual differences. Quantitative sensory testing (QST) can be used to judge the nerve function of fibril. The application of QST for the quantitative evaluation of peripheral nervous system disease needs to be further studied. OBJECTIVE: The cold-thermal sensation and pain of patients with CSR are quantitatively analyzed by using QST technology in order to evaluate the nerve function of fibril in patients with CSR. DESIGN: Case-control observation. SETTING: Pain Center of Beijing Hospital of Ministry of Health. PARTICIPANTS: Twenty patients with CSR, including 8 males and 12 females, aged from 33 to 70 years, who received treatment between January and April 2005 in Pain Center of Beijing Hospital of Ministry of Health were involved in CSR group. All the involved patients presented symptoms in unilateral upper extremity (left side 10 patients, right side 10 patients). They did not undergo physical therapy or nerve block therapy in 1 week before examination. Eight non-CSR patients who received treatment in Pain Center concurrently were involved in the control group (2 patients with trigeminal neuralgia, 4 with osteoarthrosis of knee joint and 2 with lumbar intervertebral disc protrusion), and another 12 healthy volunteers were involved. Four non-CSR patients and 12 healthy volunteers, 8 male and 12 female, were aged from 23 to 75 years. The informed consents were obtained from all the involved subjects. METHODS: The volar thresholds of cold sensation, thermal sensation, cryalgesia of thenar eminence of both upper extremities of all the subjects were examined separately by limit method with type TSA-Ⅱ temperature sensation analysator made by Medco Company (Israel). The subjects were pre-examined to be familiar with the method for sensory discrimination and affirmation. Thenar eminence vola of bilateral upper extremities were detected. The infrared detector of a semiconductor was contacted with skin. The infrared detector could be used to heat and cool skin. A group of cold-heat water circulation device was given electric current to produce temperature gradient, which was higher or lower than skin temperature. The initial temperature of infrared detector was 32 ℃, stimulation temperature was increased or decreased progressively at 1 ℃/s, and temperature change range was 0 to 50 ℃. In the first step, subjects pressed down the button to stop the stimulation when the temperature of infrared detector was decreased progressively until the subjects felt, and the threshold of cold sensation was obtained; In the second step, the threshold of thermal sensation was obtained when the temperature of infrared detector was increased progressively until the subjects felt; In the third step, the threshold of cryalgesia was obtained when the temperature of infrared detector was decreased progressively until subjects felt; and in the fourth step, the threshold of thermalgesia was obtained when the temperature of infrared detector was increased progressively until subjects felt. Each step was conducted 4 times and the mean threshold was obtained. Before each measurement, the temperature was made to rebound to the initial temperature and kept for 10 s. MAIN OUTCOME MEASURES: The thresholds of cold sensation, thermal sensation and cryalgesia, thermalgesia of thenar eminence vola of bilateral upper extremities of all the subjects. RESULTS: Twenty patients with CSR and 20 healthy subjects participated in the final results. ① In the CSR group, the threshold of cold sensation of affected side was lower than that of intact side [(29.00±1.26) ℃ vs.(30.00±1.06) ℃, P < 0.05], and the threshold of thermal sensation of affected side was higher than that of intact side [(35.04±0.87) ℃ vs. (34.14±0.99) ℃, P < 0.05]. There were no significant differences in the thresholds of cold and thermal sensation between affected side and intact side (P > 0.05). ②In the CSR group, the difference of threshold of cold sensation, thermal sensation, cryalgesia and thermalgesia between affected side and intact side was (-1.01±0.57), (0.89±0.39), (2.49±1.10) and (-1.62±0.86) ℃, respectively , the absolute value of which was higher than that of control group, respectively [(0.04±0.28),(0.05±0.26),(0.28±1.79),(0.17±1.10) ℃,P < 0.01]. In the CSR group, the threshold of cold sensation and thermalgesia of affected side was lower than that of intact side, respectively; and the threshold of thermal sensation and cryalgesia of affected side was higher than that of intact side, respectively. CONCLUSION: The superficial sensation of affected extremity of patients with CSR is lessened as compared with that of intact extremity. There are dysfunctions of small myelinated fiber (Aδ fiber) and demyelinated fiber (C fiber) in the affected-side extremity. QST, as a mean for quantitatively evaluating the function of Aδ fiber and C fiber, plays an objective evaluative role in the diagnosis and therapeutic effect observation of CSR.

Edge detection algorithm based on ICA-domain shrinkage in noisy images

We propose a robust edge detection method based on ICA-domain shrinkage （in- dependent component analysis）. It is known that most basis functions extracted from natural images by ICA are sparse and similar to localized and oriented receptive fields, and in the proposed edge detection method, a target image is first transformed by ICA basis functions and then the edges are detected or recon- structed with sparse components. Furthermore, by applying a shrinkage algorithm to filter out the components of noise in ICA-domain, we can readily obtain the sparse components of the original image, resulting in a kind of robust edge detec- tion even for a noisy image with a very low SN ratio. The efficiency of the proposed method is demonstrated by experiments with some natural images.

Improved Flight Conflict Detection Algorithm Based on Gauss-Hermite Particle Filter

In order to improve the accuracy of free flight conflict detection and reduce the false alarm rate, an improved flight conflict detection algorithm is proposed based on Gauss-Hermite particle filter（GHPF）. The algorithm improves the traditional flight conflict detection method in two aspects：（i） New observation data are integrated into system state transition probability, and Gauss-Hermite Filter（GHF） is used for generating the importance density function.（ii） GHPF is used for flight trajectory prediction and flight conflict probability calculation. The experimental results show that the accuracy of conflict detection and tracing with GHPF is better than that with standard particle filter. The detected conflict probability is more precise with GHPF, and GHPF is suitable for early free flight conflict detection.

Exploring the tidal effect of urban business district with large-scale human mobility data

Business districts are urban areas that have various functions for gathering people,such as work,consumption,leisure and entertainment.Due to the dynamic nature of business activities,there exists significant tidal effect on the boundary and functionality of business districts.Indeed,effectively analyzing the tidal patterns of business districts can benefit the economic and social development of a city.However,with the implicit and complex nature of business district evolution,it is non-trivial for existing works to support the fine-grained and timely analysis on the tidal effect of business districts.To this end,we propose a data-driven and multi-dimensional framework for dynamic business district analysis.Specifically,we use the large-scale human trajectory data in urban areas to dynamically detect and forecast the boundary changes of business districts in different time periods.Then,we detect and forecast the functional changes in business districts.Experimental results on real-world trajectory data clearly demonstrate the effectiveness of our framework on detecting and predicting the boundary and functionality change of business districts.Moreover,the analysis on practical business districts shows that our method can discover meaningful patterns and provide interesting insights into the dynamics of business districts.For example,the major functions of business districts will significantly change in different time periods in a day and the rate and magnitude of boundaries varies with the functional distribution of business districts.

Robust fault diagnosis for non-Gaussian stochastic systems based on the rational square-root approximation model

The task of robust fault detection and diagnosis of stochastic distribution control （SDC） systems with uncertainties is to use the measured input and the system output PDFs to still obtain possible faults information of the system. Using the rational square-root B-spline model to represent the dynamics between the output PDF and the input, in this paper, a robust nonlinear adaptive observer-based fault diagnosis algorithm is presented to diagnose the fault in the dynamic part of such systems with model uncertainties. When certain conditions are satisfied, the weight vector of the rational square-root B-spline model proves to be bounded. Conver- gency analysis is performed for the error dynamic system raised from robust fault detection and fault diagnosis phase. Computer simulations are given to demon- strate the effectiveness of the proposed algorithm.

ANALYSIS OF LIMIT CYCLES TO A PERTURBED INTEGRABLE NON-HAMILTONIAN SYSTEM

Bifurcation of limit cycles to a perturbed integrable non-Hamiltonian system is investigated using both qualitative analysis and numerical exploration.The investigation is based on detection functions which are particularly effective for the perturbed integrable non-Hamiltonian system.The study reveals that the system has 3 limit cycles.By the method of numerical simulation,the distributed orderliness of the 3 limitcycles is observed,and their nicety places are determined.The study also indicates that each of the 3 limit cycles passes the corresponding nicety point.