Optical pattern recognition by use of a segmented semiconductor optical amplifier.

A technique for high-speed, all-optical pattern recognition based on cross correlation in a segmented semiconductor optical amplifier (SSOA) is presented. A counterpropagating pump-probe setup is used to perform cross correlation of the spatial gain-loss pattern in the SSOA with the optical data pattern (pump), and the result is read out with a counterpropagating probe. Cross correlation of 4-bit patterns at 85 Gbits/s is experimentally demonstrated. Simulations show reasonable agreement with experimental measurements and are used to address scalability to higher bit rates and longer data patterns.

Cognitive function and glycosylated hemoglobin in older patients with type II diabetes.

The purpose of this study was to assess whether there is a relationship between diabetes control and cognitive function in older persons with type II diabetes. Seventy-seven patients with type II diabetes mellitus-none of whom were taking insulin-were given two cognitive function tests (the Modified Mini-Mental State and the Delayed Word Recall Test) and a HbA1C assay. All patients were living independently at home in rural communities, and under the care of their family doctor. The mean age of the subjects was 67.6 years; the sample consisted of 23 males and 54 females. The mean glycosylated hemoglobin (HbA1C) level was 8.4 (range from 3.1 to 20.0). There was a nonsignificant trend for persons with extreme lower or higher HbA1C levels to have poorer cognitive function as assessed by the Modified Mini-Mental State but not the Delayed Word Recall Test. The effect of glycemic control on cognitive function may not be as clinically relevant as other factors in elderly persons with type II diabetes.

Cognitive function among the elderly. Comparison of home care clients and independent seniors.

A cross-sectional survey from the Centre for Rural Health Studies of 210 elderly clients in a rural home care program found that 18.1% had severe or moderate cognitive impairment, yet only 6.6% of 167 elderly community residents living independently in a rural community had similar impairment. While the difference was significant, our methodology could not determine whether a causal association existed.

Attention deficits in children and adolescents with hearing loss. A survey.

OBJECTIVES: To determine the prevalence of reported attention deficits in a sample of children who are deaf or hard of hearing and to examine associated variables. DESIGN: Cross-sectional survey. SETTING: Residential school for the deaf. PARTICIPANTS: All students attending the school (n = 238; median age, 16.0 years; range, 4 to 21 years). Subjects were subgrouped by cause of deafness for further analyses. INTERVENTION: None. MEASUREMENTS/MAIN RESULTS: School personnel completed questionnaires that are commonly used in the assessment of attention problems. Teachers completed the Attention Deficit Disorder With Hyperactivity (ADD-H) Comprehensive Teacher Rating Scale (ACTeRS) and an abbreviated version of the Attention-Activity section of the ANSER (Aggregate Neurobehavioral Student Health and Education Review) System Questionnaires. Dormitory supervisors rated students on the Conners' Parent Rating Scale and the ANSER System Questionnaires. The mean factor scores for the total sample of deaf and hard-of-hearing students on the Attention and Hyperactivity scales of the ACTeRS and Conners' questionnaires did not differ from the normative data. The 64 students with hereditary deafness received significantly better ratings than the 75 with an acquired cause of deafness such as bacterial meningitis or congenital rubella. Raw scores on the ACTeRS were converted to percentile equivalents based on the normative sample. On the Attention Scale, 38.7% of those with acquired deafness were rated below the 20th percentile (indicative of problems); only 14.1% of the students with hereditary deafness were in this range (P = .002). CONCLUSIONS: Ratings of attention for students with hearing loss, attending a residential school, did not differ from the normative data. However, the subgroup of children with acquired sensorineural deafness appear to be at increased risk for attention problems.

Effect of type II diabetes mellitus on cognitive function.

BACKGROUND: As people with diabetes mellitus suffer from peripheral and autonomic neuropathy, we thought it possible that deficits in cognitive function might also be found. Our objective was to compare the cognitive function of elderly persons with non-insulin-dependent diabetes mellitus (NIDDM) with a matched sample of persons without NIDDM: METHODS: Ninety outpatients over 50 years of age with NIDDM and 90 matched nondiabetic patients were recruited for the study. The Modified Mini-Mental State (3MS) and the Delayed Word Recall (DWR) test were used to assess cognitive function. RESULTS: On the 3MS test, the mean score of persons with NIDDM was 75.6, and that of nondiabetic persons was 79.5 (two-tailed t = 3.04, P = .013). On the DWR, the mean score of persons with NIDDM was 3.9, and that of persons without NIDDM was 4.7 (two-tailed t = 3.52, P = .012). CONCLUSIONS: Persons with NIDDM had significantly poorer scores on two tests of cognitive function. Physicians should be aware of this association between type II diabetes and a small but definite impairment of cognitive function.

Cognitive function. Survey of elderly persons living at home in rural Newfoundland.

We tested the cognitive function of elderly, community-dwelling residents in rural Newfoundland using the Canadian Mental Status Questionnaire. The prevalence of moderate and severe cognitive impairment was 9.3%. Physicians in the community had recognized those with severe impairment, but had not recognized any of those with moderate impairment. Cognitive function testing should be part of the periodic health examination of older patients.

The ratio of diagnosed to undiagnosed diabetes in patients 40 years and older.

A cross-sectional survey of a one in five random sample of apparently healthy adults aged 40 years and older was done in 17 family practice clinics in Newfoundland, in order to pick up previously undiagnosed diabetics, by fasting blood sugar (FBS) measurements. From a sample of 2,087 people, 1,767 were tested. Forty-eight persons had an elevated FBS on the first test, but only 19 had a sustained high FBS when a second test was done. There were 16 previously-known diabetics for each new diabetic found; in this population it was not worth screening healthy persons for diabetes. Testing should be restricted to high-risk people only. As a result of this study, the diabetes prevalence in the 40+ population rose from 12.4% to 13.1%.

Synchrotron X-ray Diffraction from a Microscopic Single Crystal Under Pressure.

Metallic filaments with submicrometer diametere have been fabricated. Standard diffraction techniques with conventional x-ray sources were unsuccessful in identifying the structure of these materials. However, with the use of synchrotron radiation produced on a wiggler beam line, diffraction data were obtained in measurement periods as short as 10 milliseconds. Two cylindrical single crystals of bismuth were studied, each with a diameter of 0.22 +/- 0.02 micrometer. The volume of sample illuminated for these measurements was 0.38 cubic micrometer, less than 0.5 femtoliter. The crystals are grown in glass capillaries, and, because bismuth expands on solidification, they are under a residual hoop stress. The crystallographic data indicate the presence of a linear compressive strain of about 2 percent, which is assumed to be the result of a residual stress of about 2 gigapascals.