361 research outputs found
Design, processing and testing of LSI arrays, hybrid microelectronics task
Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated
Replication of a Tutor-Training Method for Improving Interaction Between Writing Tutors and Stem Students
The improvement of tutor training programs can impact the important work of writing centers. Tutors often feel less comfortable tutoring in genres different from their own discipline. A previous study introduced an assignment-specific tutor training model to improve writing center tutoring sessions between engineering students and writing tutors. The results of the previous study indicated a valuable addition to the resources available for engineering students. This model has now been replicated at two universities to assess the potential for wider dissemination.
Preliminary data analysis suggests a relationship between initial
tutor rating of student work, student perceptions of tutoring, and
tutor perception of student engagement in the tutorial. Plans for
future research include continued replication and expansion to test
larger sample sizes, analysis of impact within and adaptations for
other STEM areas, and continued study of the impact on tutoring
team projects
Potential climatic transitions with profound impact on Europe
We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/
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Coincidence/Multiplicity Photofission Measurements
An series of experiments using the Idaho National Laboratory (INL) photonuclear inspection system and a Los Alamos National Laboratory (LANL)-supplied, list-mode data acquisition method have shown enhanced performance utilizing pulsed photofission-induced, neutron coincidence counting between pulses of an up-to-10-MeV electron accelerator for nuclear material detection and identification. The enhanced inspection methodology has applicability to homeland security, treaty-related support, and weapon dismantlement applications. For the latter, this technology can directly support of Department of Energy/NA241 programmatic mission objectives relative to future Rocky Ridge-type testing campaigns for active inspection systems
Molecular Determinants and Genetic Modifiers of Aggregation and Toxicity for the ALS Disease Protein FUS/TLS
A combination of yeast genetics and protein biochemistry define how the fused in
sarcoma (FUS) protein might contribute to Lou Gehrig's disease
Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area
BACKGROUND: Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne). There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. METHODS: Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26) and controls (n = 62) were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults) sexual practices. RESULTS: In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]). CONCLUSION: The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other
Development and application of bivariate 2D-EMD for the analysis of instantaneous flow structures and cycle-to-cycle variations of in-cylinder flow
International audienceThe bivariate two dimensional empirical mode decomposition (Bivariate 2D-EMD) is extended to estimate the turbulent fluctuations and to identify cycle-to-cycle variations (CCV) of in-cylinder flow. The Bivariate 2D-EMD is an adaptive approach that is not restricted by statistical convergence criterion, hence it can be used for analyzing the nonlinear and non-stationary phenomena. The methodology is applied to a high-speed PIV dataset that measures the velocity field within the tumble symmetry plane of an optically accessible engine. The instantaneous velocity field is decomposed into a finite number of 2D spatial modes. Based on energy considerations, the in-cylinder flow large-scale organized motion is separated from turbulent fluctuations. This study is focused on the second half of the compression stroke. For most of the cycles, the maximum of turbulent fluctuations is located between 50 and 30 crank angle degrees before top dead center (TDC). In regards to the phase-averaged velocity field, the contribution of CCV to the fluctuating kinetic energy is approximately 55% near TDC
Sleep duration, vital exhaustion and perceived stress among pregnant migraineurs and non-migraineurs
<p>Abstract</p> <p>Background</p> <p>Migraine has been associated with sleep disorders in men and non-pregnant women, but little is known about sleep complaints among pregnant migraineurs.</p> <p>Methods</p> <p>A cohort of 1,334 women was interviewed during early pregnancy. At the time of interview we ascertained participants' migraine diagnosis status and collected information about sleep duration before and during early pregnancy, daytime sleepiness, vital exhaustion and perceived stress during early pregnancy. Multivariable logistic regression procedures were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of short/long sleep duration, excessive daytime sleepiness, vital exhaustion and elevated perceived stress associated with a history of migraine.</p> <p>Results</p> <p>Approximately 19.4% of the cohort (n = 259) reported having a medical diagnosis of migraine prior to the study pregnancy. Compared with women without migraine, the multivariable-adjusted ORs (95% CI) among migraineurs for short sleep duration before and during early pregnancy were 1.51 (1.09-2.09), and 1.57 (1.11-2.23), respectively. The corresponding OR (95% CI) for long sleep duration before and during pregnancy were 1.33 (0.77-2.31) and 1.31 (0.94-1.83), respectively. A modest and statistically insignificant association between migraine history and excessive daytime sleepiness in early pregnancy was noted (OR = 1.46; 95% CI 0.94-2.26). Migraineurs had an increased risk of vital exhaustion (OR = 2.04; 95% CI 1.52-2.76) and elevated perceived stress (OR = 1.57; 95% CI 1.06-2.31). Observed associations were more pronounced among overweight migraineurs.</p> <p>Conclusions</p> <p>These data support earlier research documenting increased risks of sleep disorders among migraineurs; and extends the literature to include pregnant women. Prospective studies are needed to more thoroughly explore factors that mediate the apparent migraine-sleep comorbidity among pregnant women.</p
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