A Novel Method for Hand Movement Recognition Based on Wavelet Packet Transform and Principal Component Analysis with Surface Electromyogram.

As an input method of signal language, the hand movement classification technology has developed into one of the ways of natural human-computer interaction. The surface electromyogram (sEMG) signal contains abundant human movement information and has significant advantages as the input signal of human-computer interaction. However, how to effectively extract components from sEMG signals to improve the accuracy of hand motion classification is a difficult problem. Therefore, this work proposes a novel method based on wavelet packet transform (WPT) and principal component analysis (PCA) to classify six kinds of hand motions. The method applies WPT to decompose the sEMG signal into multiple sub-band signals. To efficiently extract the intrinsic components of the sEMG signal, the classification performance of different wavelet packet basis functions is evaluated. The PCA algorithm is used to reduce the dimension of the feature space composed of the features reflecting hand motions extracted from each sub-band signal. Besides, to ensure higher classification performance while reducing the dimension of the feature space by the PCA algorithm, the classification performance of different dimensions of the feature space is compared. In addition, the effects of the variability of the sEMG signal and the size of the window on the proposed method are further analyzed. The proposed method was tested on the sEMG for Basic Hand Movements Data Set and achieved an average accuracy of 96.03%. Compared with the existing research, the proposed method has better classification performance, which indicates that the research results can be applied to the fields of exoskeleton robot, rehabilitation training, and intelligent prosthesis.

Parent-Child Discrepancies in Reports of Exposure to Violence/Pornography on Mobile Devices and the Impact on Children's Psychosocial Adjustment.

This study assessed the discrepancies between reports from parents and children concerning children's exposure to violence/pornography on mobile devices and the impact on the psychosocial adjustment of children. Data were obtained from a sample of 2,230 parent-child dyads recruited from 16 elementary schools (1,140 dyads) in Taiwan and 9 schools (1,090 dyads) in China. A self-administered questionnaire was used. The results showed that about 30 percent of children reported being exposed to violence on mobile devices. Approximately 70 percent of their parents were unaware of their child's exposure to violence on mobile devices. About 16 percent of children reported exposure to pornography on mobile devices, and 80 percent of their parents were unaware of this exposure. Multinomial logistic regression results showed that after controlling for parent and child sociodemographic variables, factors related to parental unawareness of child exposure to violence on mobile devices included a child's ownership of mobile devices, smartphone/tablet use time, a lower level of parental understanding, and a residence in China or in a rural area, whereas the parent-child relationship and a child's smartphone/tablet use time were associated with parents who were unaware of their child's exposure to pornography. Multiple regression results showed that children who were living with household poverty, had a poor parent-child relationship, spent much time using a smartphone/tablet, and with parents who were unaware of their exposure to violence/pornography on mobile devices were more likely to have emotional and behavioral problems.

Effect of active immunization against GnRH-I on the reproductive function in cat.

This study was designed to explore the effect of active immunization against maltose binding protein-gonadotropin releasing hormone I hexamer (MBP-GnRH-I6) on the reproductive function in cats. Each immunized cat was administered twice intramuscularly in the neck at 16 and 20 weeks old. The concentrations of the testosterone and estradiol and the level of anti-GnRH-I antibody in the serum were measured by radioimmunoassay and ELISA, respectively. The results showed that the weight and size of testicles and ovaries, and the concentrations of serum testosterone and estradiol in the immunized animals were lower than those of the control cats (P < 0.05), but that the levels of anti-GnRH-I antibody were significant higher compared to control animals (P < 0.05). Testicular tissues from the immunized male cats showed that seminiferous tubules were depauperate with the lumen relatively empty and that the differentiation of spermatogonia was not obvious. Tissues from the immunized female cats showed that the ovaries had many primordial follicles and primary follicles, but no secondary follicle was observed. These results showed active immunization against MBP-GnRH-I6 could make the gonads atrophy and reduce the concentrations of gonadal hormones, which suggested that MBP-GnRH-I6 was a very effective immunogen in the cat.

Immunization of dogs with recombinant GnRH-1 suppresses the development of reproductive function.

This study was designed to evaluate the effect of active immunization using recombinant GnRH-I protein on reproductive function in dogs. Six male and six female dogs were randomly assigned to either a control group or an immunization group (n = 3 males or 3 females/group). Dogs (aged 16 weeks) were immunized against GnRH-I with a maltose-binding protein-gonadotropin-releasing hormone I hexamer generated by recombinant DNA technology. Blood samples were taken at 4-week intervals after immunization. The serum concentrations of testosterone and estradiol and anti-GnRH-I antibodies were determined by RIA and ELISA, respectively. The results showed that active immunization with recombinant GnRH-I increased the serum levels of anti-GnRH antibodies (P < 0.05) and reduced the serum concentrations of testosterone (P < 0.05) and estradiol (P < 0.05) as compared with the controls. At 28 weeks of age, testes and ovaries were taken surgically for morphologic evaluation. Histologic studies performed on testicular and ovarian tissues revealed clear signs of atrophy in the recombinant GnRH-I-immunized dogs and a significant reduction (P < 0.05) in the weights and sizes of paired testes and ovaries in the treated dogs. Microscopically, spermatogonia were visible, but no spermatids and spermatozoa were detected in the seminiferous tubules. Neither early antral nor antral follicles were found in the immunized group. These results demonstrate that recombinant GnRH-I is an effective immunogen in dogs.

Analysis of the serum concentrations of kisspeptin and neurokinin B in the geese during reproductive cycle and their localisation in the ovary.

Kisspeptin and neurokinin B (NKB) have various functions. Their expression has been demonstrated in rat and human ovary, and estrogen affects their activity, suggesting a role for these molecules in the control of ovary function. However, whether these signaling systems are present in geese ovary, and the associated with serum estrogen remains largely unexplored. In this study we investigated the expression of kisspeptin and NKB in the ovary, and analysed their changes in the serum during the reproductive cycle and their association with serum estradiol in the geese. The results showed both kisspeptin and NKB immunoreactivity was found in the ovary, with marked expression in the granular layer and theca of the follicle, where intense coexpression of kisspeptin and NKB was also detected. The serum concentrations of kisspeptin and NKB in geese were significantly higher (P<0.05) in broody period than in laying period and laying cessation stage. However, the level of estradiol was markedly higher (P<0.05) in laying period than in broody and laying cessation stage. Serum kisspeptin was positively correlated with NKB (r=0.866, P<0.001), serum estradiol was negatively correlated with kisspeptin (r=-0.977, P<0.05) and NKB (r=-0.887, P<0.05). Overall, the existence of kisspeptin and NKB in geese ovary, and the difference of their serum concentrations during reproductive cycle and the inverse correlation with serum estradiol are highly suggestive of a role for kisspeptin and NKB in the regulation of geese reproductive function.

[Treatment of elbow joint ankylosis by repair of articular surface with periosteal autograft].

OBJECTIVE: To evaluate the clinical effect of periosteal autograft in repair of ankylosis of elbow joint. METHODS: From May 1985 to November 1999, 18 cases of elbow joints ankylosis (6 cases of osteo-ankylosis, 12 cases of fibroankylosis) were treated by repairing articular surface with periosteal autografting. Out of 18 cases, 13 were caused by old dislocation and fracture of elbow joints, 3 by late rheumatoid arthritis, and 2 by old total joint tuberculosis. In this surgical approach, periosteum from upper end of tibia was transplanted into articular surface after correction of the elbow joint from ankylosis deformity, and continuous passive or active movement of the operated joint was adopted with skeletal traction through olecranon of ulna for 4 weeks after operation. All of the cases were followed up for 1-9 years, 5.2 years on average, before clinical evaluation. RESULTS: The elbow joints in 11 cases were restored to normal, the joints in 4 cases obtained active movement in the range of 100 degrees-0 degree, and the joints in the other 3 cases could only have limited movement because of severe muscular atrophy. CONCLUSION: The articular surface in arthroplasty of elbow joint ankylosis could be effectively repaired by periosteal autograft, and the function of the joints could be obviously improved by continuous movement of the joints after operation with skeletal traction.