Implications of Dopant-Fluctuation-Induced $V_{rm t}$ Variations on the Radiation Hardness of Deep Submicrometer CMOS SRAMs

Accurately analyzing the single-event (SE) vulnerability of static random-access memory (SRAM) cells leads to precisely calculated soft-error rates (SERs). Random dopant-fluctuation-induced V_t variations affect the SE vulnerability of these memory cells and increase the intercell spread in critical charge (Q_crit), which cause SE upsets. This might consequently lead to higher SERs than would be calculated, assuming a single critical charge. Monte Carlo simulations in the IBM 130- and 90-nm technologies quantify this spread in Q_crit and in SRAM soft-error cross sections with increasing variance. For a radiation-tolerant design, a statistical-design methodology must be used to validate existing hardening schemes and to obtain the expected tolerance levels.     

Evaluation of the original Ontario Child Health Study scales

This article presents evaluative information on the use of the original Ontario Child Health Study scales to serve as original-level measures of conduct disorder, hyperactivity and emotional disorder among children in the general (non clinic) population. Problem checklist assessments were obtained from parents and teachers of children aged six to 16 and youth aged 12 to 16 drawn from a general population (n = 1,751); and a mental health clinic sample (n = 1,027) in the same industrialized, urban setting. The results showed that the original OCHS scales possess adequate psychometric properties to be used as original-level measures of disorder. Correlations between individual items and their hypothesized scales were very strong, indicating convergent validity, while correlations between the same items and other (non hypothesized) scales were lower, indicating discriminant validity. Item analyses indicated that individual scale items possess both convergent and discriminant validity. Although the scales were skewed to the positive end of the continuum, they demonstrated good internal consistency (all estimates > or = 0.74) and test-retest (all estimates > or = 0.65) reliability. Finally, three different validity analyses confirmed hypotheses about how the original OCHS scales should perform if they provide useful measures of disorder.     

The far infra-red spectrum of crystalline polytetrafluoroethylene

The far infra-red spectrum of highly crystalline polytetrafluoroethylene has been shown to contain a new band near 33cm^?1, the band at 55cm^?1 has been shown to be a close doublet and two further bands at 291 and 308cm^?1 have been observed. These results strongly support the conclusions of Boerio and Koenig from Raman observations that the unit cell contains at least two molecular segments.     

The variation of plastic anisotropy during straining

The relationship between length and width strain during a tensile test has been studied in detail for a wide range of low carbon steels. The data have been analyzed in terms of the conventionalr-value,r _e, the instantaneous r-value, r_i, and a linear regressionr-value,r _r. r_r is derived from a linear regression between width strain and length strain, as first suggested by Liu, using data obtained between yield and uniform elongation.r _r was found to be the most suitable method of characterizing the average anisotropic behavior, because its value is unaffected by the presence or absence of inhomogeneous yielding. There are reproducible variations of width strain from linear behavior which are not due to experimental error. These causer _e to vary with strain. No systematic increase or decrease ofr _e with strain was observed, in contrast to previous reports in the literature.     

Long-term climate patterns in Alaskan surface temperature andprecipitation and their biological consequences

Mean monthly climate maps of Alaskan surface temperature and precipitation produced by the parameter-elevation regression on independent slopes model (PRISM) were analyzed. Alaska is divided into interior and coastal zones with consistent but different climatic variability separated by a transition region; it has maximum interannual variability but low long-term mean variability. Pacific decadal oscillation (PDO)- and El Nino Southern Oscillation (ENSO)-type events influence Alaska surface temperatures weakly (1-2°C) statewide. PDO has a stronger influence than ENSO on precipitation but its influence is largely localized to coastal central Alaska. The strongest influence of Arctic oscillation (AO) occurs in northern and interior Alaskan precipitation. Four major ecosystems are defined. A major eco-transition zone occurs between the interior boreal forest and the coastal rainforest. Variability in insolation, surface temperature, precipitation, continentality, and seasonal changes in storm track direction explain the mapped ecosystems. Lack of westward expansion of the interior boreal forest into the western shrub tundra is influenced by the coastal marine boundary layer (enhanced cloud cover, reduced insolation, cooler surface and soil temperatures)     

Serial pulmonary function tests in the diagnosis of P. carinii pneumonia

The predictive value of serial versus isolated measurements of transfer factor for carbon monoxide (TLCO) in the diagnosis of pneumocystis carinii pneumonia (PCP) in a cohort of 474 HIV-1 seropositive patients, with all stages of HIV disease, was evaluated. Two groups of patients were studied, one group with serial lung function measurements (Group 1) and another with only a single set of measurements (Group 2). During the study period 118 patients performing serial tests developed a respiratory illness of which 58 were performing monthly and 60 three monthly measurements of lung function (Group 1). In 36 patients from Group 1, where PCP was diagnosed, monthly lung function tests showed a decrease in TLCO from 68% (+/- 3.2) (SEM), (8 weeks prior to illness), to 44% (+/- 2.5) predicted normal at presentation, whereas in 22 patients who did not have PCP, TLCO fell from 71% (+/- 4.5) to 57% (+/- 3.1). TLCO was thus reduced to lower values in these with PCP than in those without PCP (p < 0.05). A fall of TLCO of 5% from initial values when used as predictive for presence of PCP had a sensitivity of 75% and a specificty of 28% (positive predictive value 56%; negative predictive value 48%). TLCO was < 70% predicted in 72/78 patients with PCP who performed only single lung function tests (Group 2), which gave a sensitivity of 92% and a specificity of 71% as a diagnostic test for PCP when compared with the cohort as a whole. The positive predictive value was 34%, negative predictive value was 98%.(ABSTRACT TRUNCATED AT 250 WORDS)     

First-trimester growth and the risk of low birth weight

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.     

Flexible sail wind-turbines: Review of pertinent theoretical analyses

Our theoretical understanding of the mode of operation of propeller type wind-turbines is now well established, whereas even preliminary theoretical analyses of the behaviours of flexible-sail type wind-turbines are virtually non-existent. This paper presents a preliminary stage in the process of rectifying this omission. Previous theoretical investigations about the pertinent aerodynamics of yacht sails are reviewed and their possible modifications to describe the behaviours of flexible-sail wind-turbines discussed.     

Age-dependent deficits in spatial memory are related to impaired hippocampal kindling.

21 3-mo-old and 25 26-mo-old Fischer 334 rats were tested in an 8-arm maze in a behavioral assessment of spatial memory (SM) before undergoing hippocampal kindling (HK) to examine alterations in neuronal plasticity as a function of aging. Results indicate a positive relation between maze performance and speed of HK and that SM was poorer and HK slower in 26-mo-olds than in 3-mo-olds. Age-related deficits in SM and HK may reflect decreased efficacy of synaptic transmission in a common neuroanatomical substrate. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)