Interventions to Reduce Spasticity and Improve Function in People With Chronic Incomplete Spinal Cord Injury: Distinctions Revealed by Different Analytical Methods.

Background. Spinal cord injury (SCI) results in impaired function, and ankle joint spasticity is a common secondary complication. Different interventions have been trialed with variable results. Objective. We investigated the effects of pharmacological and physical (locomotor training) interventions on function in people living with incomplete motor function loss caused by SCI and used different analytical techniques to understand whether functional levels affect recovery with different interventions. Methods. Participants with an incomplete SCI were assigned to 3 groups: no intervention, Lokomat, or tizanidine. Outcome measures were the 10-m walk test, 6-minute walk test, and the Timed Up and Go. Participants were classified in 2 ways: (1) based on achieving an improvement above the minimally important difference (MID) and (2) using growth mixture modeling (GMM). Functional levels of participants who achieved the MID were compared and random coefficient regression (RCR) was used to assess recovery in GMM classes. Results. Overall, walking speed and endurance improved, with no difference between interventions. Only a small number of participants achieved the MID. Both MID and GMM-RCR analyses revealed that tizanidine improved endurance in high-functioning participants. GMM-RCR classification also showed that speed and mobility improved after locomotor training. Conclusions. Improvements in function were achieved in a limited number of people with SCI. Using the MID and GMM techniques, differences in responses to interventions between high-and low-functioning participants could be identified. These techniques may, therefore, have potential to be used for characterizing therapeutic effects resulting from different interventions

A Knowledge Management View of Teaching English as a Foreign Language (TEFL) in General Educational System (GES) of Iran

AbstractEnglish is the main foreign language in Iran. It is used and taught more than other foreign languages. Teaching this language in General Education System (GES) of Iran, occurs during two high school levels. The process of teaching English during these six years was probed from the viewpoint of knowledge management (KM), using the Delphi method of obtaining information to grasp GES weaknesses. Conducting two rounds of Delphi and exerting Kendall's coefficient of concordance on the acquired informatin from 18 English teachers -who have taught English for thirty years-about the process of teaching English as a foreign language (TEFL) in GES, we could acquire 41 viewpoints that can be counted on as the tacit knowledge of the teachers and may be used in future studies

INVESTIGATION OF WEAR CHARACTERISTICS OF CONICAL DELRIN THRUST BEARINGS

This study focuses on the wear rate in conical thrust bearings, which is responsible for field failures of stepper motors in optical disk drives (ODD). These bearings support the stepper motor worm shaft and consist of a steel ball supported in a polymer conical bearing cup. The tribological behaviors of polymers used in bearing application has been addressed by using Archard's wear model, a well known classical model for fretting wear in the literature. However, these studies were for planar bearing surfaces and other geometries, not for the conical geometry addressed in this study. Tests were designed and implemented to study the wear rate of the conical bearing cups at with different load levels. The tribological behavior of Delrin in conical thrust bearing applications has been characterized, by quantifying the wear factors used in the modified Archard's model. Distinct reduction of wear rate is observed due to formation of a polymer transfer film on the steel ball. The variability of the wear properties is explored through replication of the test conditions. Destructive physical analysis is conducted to gain insight into the fundamental wear mechanisms as a part of this study. The results of the wear tests are used to develop a life model of the stepper motor as a case study, to demonstrate an application of this approach. The life model is used to study the effect of variability in the initial axial bearing preload (due to manufacturing tolerances), on the wear rate and life of the stepper motor

A Projected Upper Bound for Mining High Utility Patterns from Interval-Based Event Sequences

High utility pattern mining is an interesting yet challenging problem. The intrinsic computational cost of the problem will impose further challenges if efficiency in addition to the efficacy of a solution is sought. Recently, this problem was studied on interval-based event sequences with a constraint on the length and size of the patterns. However, the proposed solution lacks adequate efficiency. To address this issue, we propose a projected upper bound on the utility of the patterns discovered from sequences of interval-based events. To show its effectiveness, the upper bound is utilized by a pruning strategy employed by the HUIPMiner algorithm. Experimental results show that the new upper bound improves HUIPMiner performance in terms of both execution time and memory usage

Design, modeling, fabrication and testing of a membrane piezoelectric tactile sensor with four sensing elements

The fundamental requirement of a competent tactile sensor for manipulating an object is to determine the magnitude and the position of an applied force on it. In addition, it is important to determine orientation of the object in relation to the tactile sensor. In order to achieve these goals, most investigators have attempted to design a tactile sensor using an array of sensing elements arranged in matrix form. There are several problems associated with this type of tactile sensors. These problems include cross-talk between sensing elements, fragility, and complexity. This thesis reports on the design, modeling, fabrication and testing of a membrane tactile sensing system with only four sensing elements. By using membrane stress combined with triangulation approach, it is shown that it is possible to overcome the above problems. The prototype sensor consists of a single film of 25 micron thick Polyvinylidene Fluoride (PVDF) film, which is held between two 12 mm-thick flat Plexiglass plates, each with a 90 mm-diameter center hole. Four square sensing elements, each 3 min side, were fabricated around the center of the membrane. The fabrication of the sensing elements is performed using photolithographic and etching techniques. By applying force with a probe of various shapes and sizes at various points away from the sensing elements, and using a geometric mapping process, the sensor is calibrated. As the result of calibration various isocharge contours were drawn. Using both finite element and experimental analysis, it is shown that it is possible to determine the position, orientation and the magnitude of the applied load though various flat shaped probes, by using only four sensing elements. The experimental and the finite element results are compared. It is shown that there is a good correlation between the finite element predictions and experimental data

Isolation and Identification of Alicyclobacillus with High Dipicolinic Acid and Heat Resistant Proteins from Mango Juice

Background and Objectives: Microbial spoilage of juices and industries related with Alicyclobacillus are considerable international issues. This spore-forming bacterium causes changes in juices odor and taste. The isolation and identification of Alicyclobacillus contamination in juice producing and packaging industries has an essential role in the prevention and control of this type of spoilage bacterium in HACCP (Hazard analysis and critical control points ) manner.Materials and Methods: A thermo-acidophilic, non-pathogenic and sporeforming bacterium was isolated from mango juice. Preliminary identification of the isolates was based on morphological, biochemical and physiological properties. Identification at species level was made by PCR amplification. The influence of temperature in the range of 25-65°C in the growth of bacterium and in the range of 80-120°C in spore-resistant and heat resistant proteins was investigated and compared with other spore producing bacteria.Results and Conclusion: Phylogenetic analysis of the 16S rRNA gene sequencing indicated that the isolated strain constituted a distinct lineage in the Alicyclobacillus cluster and submitted to NCBI with access number Alicyclobacillus HRM-5 KM983424.1. The spores resisted 110°C for 3 h, and produced 28% dipicolinic acid more comparable to Bacillus licheniformis. Also they could produce 0.69 mg heat resistance protein after 1.5 h treatment in 100°C. The results showed that this strain could have biotechnological applications.Conflict of interests: The authors declare no conflict of interest

Linear MMSE Receivers for Interference Suppression & Multipath Diversity Combining in Long-Code DS-CDMA Systems

This thesis studies the design and implementation of a linear minimum mean-square error (LMMSE) receiver in asynchronous bandlimited direct-sequence code-division multiple-access (DS-CDMA) systems that employ long-code pseudo-noise (PN) sequences and operate in multipath environments. The receiver is shown to be capable of multiple-access interference (MAI) suppression and multipath diversity combining without the knowledge of other users' signature sequences. It outperforms any other linear receiver by maximizing output signal-to-noise ratio (SNR) with the aid of a new chip filter which exploits the cyclostationarity of the received signal and combines all paths of the desired user that fall within its supported time span. This work is motivated by the shortcomings of existing LMMSE receivers which are either incompatible with long-code CDMA or constrained by limitations in the system model. The design methodology is based on the concept of linear/conjugate linear (LCL) filtering and satisfying the orthogonality conditions to achieve the LMMSE filter response. Moreover, the proposed LMMSE receiver addresses two drawbacks of the coherent Rake receiver, the industry's current solution for multipath reception. First, unlike the Rake receiver which uses the chip-matched filter (CMF) and treats interference as additive white Gaussian noise (AWGN), the LMMSE receiver suppresses interference by replacing the CMF with a new chip pulse filter. Second, in contrast to the Rake receiver which only processes a subset of strongest paths of the desired user, the LMMSE receiver harnesses the energy of all paths of the desired user that fall within its time support, at no additional complexity. The performance of the proposed LMMSE receiver is analyzed and compared with that of the coherent Rake receiver with probability of bit error, Pe, as the figure of merit. The analysis is based on the accurate improved Gaussian approximation (IGA) technique. Closed form conditional Pe expressions for both the LMMSE and Rake receivers are derived. Furthermore, it is shown that if quadriphase random spreading, moderate to large spreading factors, and pulses with small excess bandwidth are used, the widely-used standard Gaussian Approximation (SGA) technique becomes accurate even for low regions of Pe. Under the examined scenarios tailored towards current narrowband system settings, the LMMSE receiver achieves 60% gain in capacity (1. 8 dB in output SNR) over the selective Rake receiver. A third of the gain is due to interference suppression capability of the receiver while the rest is credited to its ability to collect the energy of the desired user diversified to many paths. Future wideband systems will yield an ever larger gain. Adaptive implementations of the LMMSE receiver are proposed to rid the receiver from dependence on the knowledge of multipath parameters. The adaptive receiver is based on a fractionally-spaced equalizer (FSE) whose taps are updated by an adaptive algorithm. Training-based, pilot-channel-aided (PCA), and blind algorithms are developed to make the receiver applicable to both forward and reverse links, with or without the presence of pilot signals. The blind algorithms are modified versions of the constant modulus algorithm (CMA) which has not been previously studied for long-code CDMA systems. Extensive simulation results are presented to illustrate the convergence behavior of the proposed algorithms and quantify their performance loss under various levels of MAI. Computational complexities of the algorithms are also discussed. These three criteria (performance loss, convergence rate, and computational complexity) determine the proper choice of an adaptive algorithm with respect to the requirements of the specific application in mind