Mistracking in successive PCM/ADPCM transcoders

An analysis is presented of the causes of the accumulation of quantizing noise found in the transient state for successive CCITT adaptive differential pulse-code-modulation (ADPCM) transcoders connected synchronously. By decoupling the predictor and quantizer effect it is proved that, owing to a self-stabilization phenomenon, narrowband inputs cause local instabilities in the predictor of the jointly adaptive autoregressive moving-average-prediction/quantization used in the ADPCM 32-kb/s algorithm. Despite the assured global stability, these local instabilities are not synchronized at the encoder and its preceding decoder, and a mistracking occurs which creates quantizing noise accumulation. The tracking is then shown to be very sensitive to predictor/quantizer interaction. The discontinuities introduced in the standardized adaptive quantizer extend the mistracking problem to wideband inputs. A smoothed quantizer with reduced inauspicious interaction is proposed to remedy the problem     

Overcoming the luddite factor: some behavioural aspects of the field supervisor's role in construction planning

The way data is presented can seriously affect the ease with which it can be understood. The objectives and results of a survey of different types of presentation are given. Some psychological aspects of the problem are analysed.     

Psychosocial factors among members of religious and secular kibbutzim

Mortality in 11 secular kibbutzim between 1970 and 1985 was nearly twice that of 11 matched religious kibbutzim. A cross-sectional study was undertaken in 1991 in 10 of these settlements, 5 religious and 5 secular, to determine whether differences in risk factors could explain the unequal survival. These comprised physical, physiologic and biochemical measurements, health-relevant behaviors and psychosocial variables. This report addresses the psychosocial aspect of the study, which included assessment of sense of coherence, hostility, satisfaction with self, work-related stress, social supports and social contacts using self-administered questionnaires. The response rate among the sample of men and women, aged 35-64 years, was 76% (437 respondents, 208 men and 229 women). Analysis of variance and logistic regression (the latter comparing the upper or lower fourths of the distribution vs. the rest) were used. Religious kibbutz members reported a higher sense of coherence (odds ratio = 1.58, 95% CI 1.02 to 2.46) and a lower level of hostility (odds ratio = 0.49, 95% CI 0.33 to 0.75) than their secular counterparts. Findings for satisfaction with self and work-related stress were inconsistent; there were significant interactions between religious affiliation, sex and age. Younger women reported less satisfaction with self and higher work-related stress than the other age-sex groups in both types of kibbutz. There was no difference in social support or frequency of social contact between religious and secular kibbutzim. Voluntary work was more frequent among the religious kibbutzim. The findings are consistent with an interpretation that Jewish religious observance may enhance the formation of certain protective personality characteristics. Membership in a cohesive religious kibbutz community may increase host resistance to stressors and thereby promote overall well-being and a positive health status. This could reflect an interplay of individual and collective attributes of religion.     

Serum lipids and incidence of coronary heart disease. Findings from the Systolic Hypertension in the Elderly Program (SHEP)

BACKGROUND: The association of serum lipids with coronary heart disease has been studied extensively in middle-aged men and, to a lesser extent, in similar women. Less well defined are lipid variables predictive of CHD in individuals of age > or = 60 years. METHODS AND RESULTS: The Systolic Hypertension in the Elderly Program recruited 4736 persons (mean age, 72 years; 14% were black; and 43% were men). Mean systolic and diastolic blood pressures were 170 and 77 mm Hg, respectively. Baseline mean total cholesterol was 6.11 mmol/L (236 mg/dL); HDL cholesterol, 1.39 mmol/L (54 mg/dL); and non-HDL cholesterol, 4.72 mmol/L (182 mg/dL). Triglyceride levels were 1.62 mmol/L (144 mg/dL) for fasting participants and 1.78 mmol/L for the total group. LDL cholesterol, estimated in fasting samples with triglycerides of < 4.52 mmol/L, averaged 3.98 mmol/L (154 mg/dL). Mean follow-up was 4.5 years. In multivariate Cox regression analyses, baseline total, non-HDL, and LDL cholesterol levels and the ratios of total, non-HDL, and LDL to HDL cholesterol were significantly related to CHD incidence. HDL cholesterol and triglycerides were not significant in these analyses. In fasting participants with triglyceride levels of < 4.52 mmol/L, a 1.03 mmol/L (40 mg/dL) higher baseline total, non-HDL, or LDL cholesterol was associated with a 30% to 35% higher CHD event rate. CONCLUSIONS: The results of this study support the concept that serum lipids are CHD risk factors in older Americans.     

Penetrating cardiac wounds: prospective study of factors influencing initial resuscitation

A prospective study of 66 consecutive patients with cardiac wounds seen over a 27-month period is reported. No patient was excluded. Patients were stratified by injury mechanism and by physiologic scoring at admission using the cardiovascular-respiratory elements of the Trauma Score (CVRS). Admission cardiac rhythm was obtained in patients with a CVRS of 0 and a Glasgow Coma Scale (GCS) score of 3. Information concerning the anatomic extent of the cardiac wound, the presence or absence of tamponade, and the degree of injury to other structures was also collected prospectively. Seventy percent of the cardiac wounds were caused by gunshots. The probability of successful resuscitation was significantly related to mechanism of injury and physiologic condition on arrival. Among patients arriving with a CVRS of 0 and a GCS score of 3, survival correlated with cardiac rhythm. Pericardial tamponade did not prove to be an independent predictor of early survival. The presence of tamponade was statistically linked to the mechanism of injury. Transport by non-official conveyance was associated with a higher CVRS on arrival. Intoxication with alcohol or cocaine had no evident effect on resuscitation probability.     

Assessing declarative memory in schizophrenia using Wisconsin Card Sorting Test stimuli: the Paired Associate Recognition Test

The Paired Associate Recognition Test (PART) was developed to measure declarative memory using Wisconsin Card Sorting Test (WCST) stimuli, so that both tasks could be administered during functional neuroimaging to differentiate memory and executive function, and associated frontal and temporal lobe activation in schizophrenia. The current study was designed to compare PART and WCST performance in schizophrenic patients and to examine effects of medication and symptomatology. The PART, WCST, and standard declarative memory tasks were administered to 30 chronic schizophrenic patients and 30 matched healthy control subjects. Supporting task validity was the finding that patients were equally impaired on the PART and the WCST. Neuroleptics did not appear to affect performance. The effect of anticholinergic medication correlated negatively with WCST performance in a small subsample. Severity of schizophrenia-specific symptoms measured at intake on the Brief Psychiatric Rating Scale correlated negatively with performance on the WCST. These results support the application of the PART and WCST in future functional neuroimaging studies.