Electrical motor current signal analysis using a modified bispectrum for fault diagnosis of downstream mechanical equipment

This paper presents the use of the induction motor current to identify and quantify common faults within a two-stage reciprocating compressor based on bispectrum analysis. The theoretical basis is developed to understand the nonlinear characteristics of current signals when the motor undertakes a varying load under different faulty conditions. Although conventional bispectrum representation of current signal allows the inclusion of phase information and the elimination of Gaussian noise, it produces unstable results due to random phase variation of the sideband components in the current signal. A modified bispectrum based on the amplitude modulation feature of the current signal is then adopted to combine both lower sidebands and higher sidebands simultaneously and hence characterise the current signal more accurately. Based on this new bispectrum analysis a more effective diagnostic feature, namely normalised bispectral peak, is developed for fault classification. In association with the kurtosis value of the raw current signal, the bispectrum feature gives rise to reliable fault classification results. In particular, the low feature values can differentiate the belt looseness from the other fault cases and different degrees of discharge valve leakage and inter-cooler leakage can be separated easily using two linear classifiers. This work provides a novel approach to the analysis of stator current for the diagnosis of motor drive faults from downstream driving equipment.     

Social Suppression of Song Is Associated With a Reduction in Volume of a Song-Control Nucleus in European Starlings (Sturnus vulgaris).

In seasonally breeding songbirds, variations in testosterone and song correlate with volume changes in brain nuclei associated with song, including the HVC. The authors tested whether singing can lead to activity-dependent increases in HVC volume by examining song output in starlings (Sturnus vulgaris). The authors manipulated males' environments so that only some were dominant with nestboxes, whereas others were not. Some of these males thus sang at higher rates and had larger HVC volume than others. The study was conducted over 2 years. In 1 year, males selectively occupied nestboxes but did not sing. HVC volume did not differ in these starlings, indicating that nestbox possession alone cannot increase HVC. The findings suggest that changes in song nuclei volume can be driven by changes in singing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heparin-induced thrombocytopenia: pathophysiology

We have used computer modeling of insulin 3-D structure and experimental data about action of site point mutation on insulin activity to design functionally important domain with signaling activity and synthesized peptide than might be sufficient for the binding to insulin receptor. The designed and synthesized peptide consist of ten residues and may be obtained in two forms: oxidized and reduced (with or without disulfide bond). The synthesized decapeptide peptide represents functionally important site for binding to the insulin receptor. Amino acid residues at position 1-8 correlate with B-chain of insulin at position (B19-B26). Residues at position 9.10 correlate with A-chain at position A-10-A21. This peptide was tested with cell culture L-929 (glucose uptake) in comparison with bioactive commercial peptide (R-G-FF) and insulin. It was shown that synthesized peptide exhibit biological activity at molar concentration 0.01-1 mkM. Our results successfully demonstrate the synthetic insulin fragment have insulin-like biological activity.     

Self-sustained pH oscillations in immobilized proteolytic enzyme systems

The efficacy of doramectin, a novel avermectin, was assessed against both naturally-acquired and experimentally-induced infections of gastrointestinal roundworms, lungworms, kidneyworms, lice and mites in studies conducted across North America and Europe. Twenty-two studies evaluated efficacy against fourth larval and adult stages of the following nematode species: Hyostrongylus rubidus, Ascaris suum, Strongyloides ransomi, Oesophagostomum dentatum, Oesophagostomum quadrispinulatum, Trichuris suis, Metastrongylus spp. and Stephanurus dentatus. Efficacy was evaluated against the louse Haematopinus suis in six studies and against the mite Sarcoptes scabiei in four studies. A common study design was employed for each study type. In all studies, animals were allotted at random to a doramectin-treated or a saline-treated group. The doramectin-treated group received the drug at 300 micrograms kg-1 by intramuscular injection while the saline-treated group received saline by the same route. In the nematode studies, worm burdens were determined for each animal at slaughter 14-16 days after treatment. Efficacy against each nematode species/stage was assessed on the basis of percentage reduction in geometric mean worm burden in doramectin-treated animals compared with saline-treated controls. In louse and mite studies, counts were made immediately before treatment and then at weekly intervals for four weeks. Efficacy was based on a comparison of the level of infestation on the day of treatment with that on the last day of test. Data from individual studies were combined to derive a single estimate of efficacy against each of the parasite species represented in the study program. Efficacy of doramectin was 98% or greater against all nematode species except T. suis for which the efficacy was 87% and 79% against adult and fourth larval stage, respectively. Efficacy was 100% against both Haematopinus suis and Sarcoptes scabiei.     

Factors affecting young children's mental development and their significance in intervention

Factors affecting their developmental quotients (DQ) in 48 normal young children, who were involved in regular development assessments at child health care outpatient visits and whose parents received child-rearing guidance at Chaoyangmen Subdistrict of Dongcheng District, Beijing, and 43 controls aged 36 months were analyzed. Factors, such as their parents' receiving child-rearing guidance, paternal education, maternal education, paternal occupation, type of nursery schools, home environment quality score (HEQS) at 24 and 36 months of age, and mothers' knowledge of child-rearing were associated with children's DQ at their age of 36 months, with statistical significance at a level of 0.05 in univariate analysis. With multiple regression analysis, HEQS at the age of 36 months, family size at the age of 24 months, paternal education, children's sex, and mothers' age had influences on DQ at age of 36 months with statistical significance, and the degree of correlation of HEQS with DQ at 36 months was much higher than that of other factors, and it suggested that HEQS was an important link in child developmental intervention.     

School-based health care for urban minority junior high school students

OBJECTIVE: To describe the use of school-based health clinics by urban minority junior high school students. DESIGN: Review of demographic and utilization data collected by service providers during clinic visits. SETTINGS AND PARTICIPANTS: Health clinics in four junior high schools that enrolled predominantly Hispanic students who were residing in an economically disadvantaged, medically underserved New York (NY) school district. RESULTS: Of 5757 students who were enrolled in the schools, 5296 (92%) obtained parental consent to use the clinics, and 3723 (65%) used the clinics during the 1991-1992 academic year. Clinic users were 11 to 15 years old, 50% male and 50% female, 81% Hispanic and 14% black, and 29% sixth graders, 33% seventh graders, and 38% eighth graders. Clinic users made 16,340 clinic visits during the 1991-1992 academic year. Presenting complaints were mental health problems (32%), illness (14%), injury (12%), physical examination (5%), immunization (3%), follow-up (21%), and other (13%). Referral sources were clinic outreach (48%), self (44%), and school personnel (8%). Disposition of visits was on-site treatment (92%), referral to an affiliated hospital (5%), and referral elsewhere (3%). Compared with a nationwide group of high school-based clinics that served predominantly black adolescents, these clinics provided more mental health care (31% vs 21%), similar illness/injury care (32% vs 30%), and less preventive (10% vs 24%) and reproductive/contraceptive (7% vs 12%) care. CONCLUSIONS: Junior high school-based clinics can provide a wide range of primary and preventive health care services for large numbers of medically underserved youths. The provision of mental health services may fill a critical need among inner-city adolescents. Clinic outreach may be necessary to maximize utilization, especially among high-risk students.     

Role-based access control with X.509 attribute certificates

We adapted the standard X.509 privilege management infrastructure to build an efficient role-based trust management system in which role assignments can be widely distributed among organizations, and an XML-based local policy determines which roles to trust and which privileges to grant. A simple Java API lets target applications easily incorporate the system. The Permis API has already proven its general utility in four very different applications throughout Europe.     

Suprachiasmatic nucleus organization

OBJECTIVE: To assess the effect of a combined exercise and motivation program on the compliance and level of disability of patients with chronic and recurrent low back pain. DESIGN: A double-blind prospective randomized controlled trial. SETTING: Physical therapy outpatient department, tertiary care. PATIENTS: Ninety-three low back pain patients were randomly assigned to either a standard exercise program (n = 49) or a combined exercise and motivation program (n = 44). INTERVENTIONS: Patients were prescribed 10 physical therapy sessions and were advised to continue exercising after treatment termination. The motivation program consisted of five compliance-enhancing interventions. Follow-up assessments were performed at 3 1/2 weeks, 4 months, and 12 months. MAIN OUTCOME MEASURES: Disability (low back outcome score), pain intensity, physical impairment (modified Waddell score, fingertip-to-floor distance, abdominal muscle strength), working ability, motivation, and compliance. RESULTS: The patients in the motivation group were significantly more likely to attend their exercise therapy appointments (p = .0005). Four and 12 months after study entry there was a significant difference in favor of the motivation group with regard to the disability score (p = .004) and pain intensity (p < or = .026). At 4 months, there was a significant advantage for the motivation group in the fingertip-to-floor distance (p = .01) and in abdominal muscle strength (p = .018). No significant differences were found in motivation scores, self-reported compliance with long-term exercise, and modified Waddell score. In terms of working ability, there was a trend favoring the combined exercise and motivation program. CONCLUSION: The combined exercise and motivation program increased the rate of attendance at scheduled physical therapy sessions, ie, short-term compliance, and reduced disability and pain levels by the 12-month follow-up. However, there was no difference between the motivation and control groups with regard to long-term exercise compliance.