Teaching Design to Freshmen: Style and Content

This paper describe a freshman course in engineering design that stresses the open-ended and ill-structured nature of design in a project-based context. The projects are chosen in part for their social context and utility. The projects are supplemented by lectures on design methodology and other topics related to engineering practice. Among the deliverables required of the students are proposals, progress reports, and written and oral presentations—the latter to an external design jury as part of a design competition.     

Location errors in tachistoscopic recognition: Guesses, probe errors, or spatial confusions?

Examined whether location errors in tachistoscopic visual probe tasks reflect (1) uncertainty about the actual position of items, (2) inappropriate guesses, encouraged by a requirement to respond, or (3) confusion about the position being tested. 46 undergraduates completed probe tasks in which they provided confidence ratings on each trial and tasks that substituted a color cue for a visual pointer or used a double bar probe. Results suggest that location errors on visual probe tasks reflect confusion about the spatial position of target items. Findings are consistent with data questioning the concept of iconic memory and imply that the bar-probe task cannot be used to study precategorical visual memory. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The social consequences of expressive suppression.

At times, people keep their emotions from showing during social interactions. The authors' analysis suggests that such expressive suppression should disrupt communication and increase stress levels. To test this hypothesis, the authors conducted 2 studies in which unacquainted pairs of women discussed an upsetting topic. In Study 1, one member of each pair was randomly assigned to (a) suppress her emotional behavior, (b) respond naturally, or (c) cognitively reappraise in a way that reduced emotional responding. Suppression alone disrupted communication and magnified blood pressure responses in the suppressors' partners. In Study 2, suppression had a negative impact on the regulators' emotional experience and increased blood pressure in both regulators and their partners. Suppression also reduced rapport and inhibited relationship formation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The L5178Y/tk+/- mouse lymphoma specific gene and chromosomal mutation assay a phase III report of the U.S. Environmental Protection Agency Gene-Tox Program

The L5178Y/tk+/- (-)3.7.2C mouse lymphoma assay (MLA) which detects mutations affecting the heterozygous thymidine kinase (tk) locus is capable of responding to chemicals acting as clastogens as well as point mutagens. Improvements in the assay to enhance detection of this spectrum of genetic events are summarized, and criteria for evaluating the data are defined. Using these criteria, the Phase III Work Group reviewed and evaluated literature containing MLA results published from 1976 through 1993. The data base included 602 chemicals of which 343 were evaluated as positive, 44 negative, 18 equivocal, 54 apparently inappropriate for evaluation in this test system with the published protocols, and 142 that were inadequately tested, and thus a definitive call could not be made. The overall performance of the assay is summarized by chemical class, and the outcome of testing 260 chemicals in the MLA is compared with Gene-Tox and National Toxicology Program evaluations of rodent carcinogenesis bioassay results for the same chemicals. Based on the Work Group's evaluation of published MLA data for chemicals that were considered adequately tested, it is concluded that for most chemicals the L5178Y/tk+/- mouse lymphoma assay is eminently well suited for genotoxicity testing and for predicting the potential for carcinogenicity.     

A Device-Level Vacuum-Packaging Scheme for Microbolometers on Rigid and Flexible Substrates

This paper reports on the design, fabrication, and characterization of device-level vacuum-packaged microbolometers on rigid Si wafers and flexible polyimide substrates. Semiconducting yttrium barium copper oxide (commonly referred to as YBCO) serves as the bolometric material. Operating micromachined bolometers in vacuum reduces the thermal conductance G_th from the detector to the substrate. If flexibility of the substrate is not to be sacrificed, then the vacuum packaging needs to be done at the device level. Here, the microbolometers are fabricated on a silicon nitride support membrane, isolated from the substrate using surface micromachining. Suitable materials as well as various dimensions in the vacuum cavity are determined using finite-element method (FEM)-based CoventorWARE. A vacuum cavity made of Al₂O₃ has been designed. The thermal conductance G_th of bolometers with the geometry implemented in this work is the same for devices on rigid and flexible substrates. The theoretical value of G_th was calculated to be 4.0 x 10^-6 W/K for devices operating in vacuum and 1.4 x 10^-4 W/K for devices operating at atmospheric pressure. Device-level vacuum-packaged microbolometers on both rigid Si and flexible polyimide substrates have been fabricated and characterized for optical and electrical properties. A low thermal conductance of 1.1 X 10^-6 W/K has been measured six months after fabrication, which implies an intact vacuum cavity.     

Fibre Bragg grating compression-tuned over 110 nm

A fibre Bragg grating with a tuning range covering beyond the C- and L-bands has been realised, which represents the broadest tuning range reported of any Bragg grating. The device exhibits constant spectral response and polarisation mode dispersion within these bands.     

Alterations of pH in response to increased dietary protein in cattle are unique to the uterus

This study was undertaken with two objectives: 1) to determine whether the effect of excess dietary protein on intrauterine pH in cattle is specific to the uterus or manifested in other bodily fluids and 2) to determine whether the effect of excess ruminally degradable protein on uterine pH can be ameliorated by substitution with a less-degradable protein source. Thirty-six Holstein cows in early lactation were fed isoenergetic total mixed rations that either 1) met undegradable intake protein (UIP) and degradable intake protein (DIP) requirements (Balanced), 2) met DIP requirements and exceeded UIP requirements by 25% (High UIP), or 3) met UIP requirements and exceeded DIP requirements by 25% (High DIP). After diets had been fed > or = 2 wk, uterine, blood, salivary, and urinary pH and plasma urea nitrogen were determined at estrus (d 0) and d 7. Plasma urea nitrogen (mg/dL) was not different between estrus and d 7 but was significantly affected by diet (Balanced, 16.1 +/- 2.3; High UIP, 19.2 +/- 1.6; High DIP, 22.3 +/- 2.6; P < .05). There was no effect of treatment on the pH of any fluid measured at estrus: intrauterine, blood, salivary, and urinary pH averaged 6.84 +/- .05, 7.39 +/- .01, 8.30 +/- .05, and 8.15 +/- .05, respectively. In contrast, on d 7, uterine pH was significantly lower in both high-protein groups, regardless of protein degradability (Balanced, 7.13 +/- .05; UIP, 6.95 +/- .04; DIP, 6.85 +/- .05; P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)