Accumulation of eicosapentaenoic acid in plasma phospholipids of subjects fed canola oil

The metabolism of α-linolenic acid from canola oil was studied in eight normolipidemic men. The 42-day study was divided into three periods: a 6-day pre-experimental and two 18-day experimental. Approximately 75% of the dietary fat (28% of total energy) was provided by a mixture of fats during the pre-experimental period and either canola oil (CO) or sunflower oil (SO) during the experimental periods. The CO and SO diets were fed in a cross-over design. The ratios of linoleic to linolenic acid were 2.6∶1 and 73.9∶1 in the CO and SO diets, respectively. Dietary fat source had an effect on plasma phospholipid fatty acids: 18∶1n−9, 18∶3n−3 and 20∶5n−3 were higher (p<0.05), and 18∶2n−6 was lower in the phosphatidylcholine fraction; 18∶1n−9 was higher and 20∶4n−6 lower in the phosphatidyl-ethanolamine fraction; and 18∶1n−9 and 20∶5n−3 were higher and 20∶4n−6 and 22∶6n−3 were lower in the alkenylacyl-ethanolamine phospholipid fraction on the CO diet as compared to the SO diet. Consumption of the canola oil diet resulted in higher n−3 fatty acid levels and lower n−6 fatty acid levels in plasma phospholipids than consumption of the sunflower oil diet.     

Facile regeneration vitreous microfibrous entrapped supported ZnO sorbent with high contacting efficiency for bulk H2S removal from reformate streams in fuel cell applications

In this study, a microfibrous carrier consisting of 3 vol.% of 8 μm (diameter) glass fibers is used to entrap 45 vol.% of 150 to 250 μm (diameter) SiO₂ support particulates. ZnO is then nanodispersed onto the support by impregnation at the loading of 17 wt.%. At equivalent bed volumes, ZnO/SiO₂-entrapped materials provide twofold longer breakthrough times for H₂S (with a 67% reduction in sorbent loading) compared with packed beds of 1 to 2 mm commercial extrudates. Five-log reductions in H₂S concentration with up to 75% ZnO utilization at breakthrough are achieved. H₂S concentrations from 60 to 2000 parts per million in volume (ppmv) can be reduced to as little as 0.6 ppmv at 400°C in 30% H₂O at a face velocity of 1.7 cm/s for layers as thin as 1.0 mm. At 500 to 600°C, ZnO/SiO₂-entrapped materials provide much higher regenerability in air than do 1 to 2 mm commercial extrudates. The use of glass fibers permits greater than 50 regeneration cycles. This paper was presented at the ASM Materials Solutions Conference & Show held October 18–21, 2004 in Columbus, OH.     

Note: Heated sample platform for in situ temperature-programmed XPS

We present the design, fabrication, and performance of the multi-specimen heated platform for linear in situ heating during the Temperature-Programmed XPS (TPXPS). The platform is versatile, compatible with high vacuum (HV) and bakeout. The heater platform is tested under in situ linear heating of typical high surface area sorbent∕catalyst support--nanoporous TiO(2). The platform allows the TPXPS of multiple samples located on specimen disk that can be transferred in and out of the TPXPS chamber. Electric characteristics, temperature and pressure curves are provided. Heating power supply, PID temperature controller, data-logging hardware and software are described.     

Measuring ranked list robustness for query performance prediction

We introduce the notion of ranking robustness, which refers to a property of a ranked list of documents that indicates how stable the ranking is in the presence of uncertainty in the ranked documents. We propose a statistical measure called the robustness score to quantify this notion. Our initial motivation for measuring ranking robustness is to predict topic difficulty for content-based queries in the ad-hoc retrieval task. Our results demonstrate that the robustness score is positively and consistently correlation with average precision of content-based queries across a variety of TREC test collections. Though our focus is on prediction under the ad-hoc retrieval task, we observe an interesting negative correlation with query performance when our technique is applied to named-page finding queries, which are a fundamentally different kind of queries. A side effect of this different behavior of the robustness score between the two types of queries is that the robustness score is also found to be a good feature for query classification.      

Guest Editors' Introduction: The Evolution of RFIC Design and Test

There are several challenges facing RFIC design and test. The demand in the wireless market will drive RFIC products. For RFIC chipsets, improvements are needed for the elimination of passive components, better integrated passives, power reduction, modeling of devices and interconnects, packaging, and cost-effective testing. However, this innovation cannot come at the cost of time to market for new products. Also, development costs must be driven to a minimum, as average selling prices for RFICs remain flat or decline. Moreover, one of the biggest challenges in moving from low GHz to higher frequencies is the lack of integration between the production testing infrastructure, EDA tools, and device designs. Advancements in device and test equipment modeling and simulation technology are beginning to bridge this gap. Finally, RF measurement requires specialized capital equipment investments and highly skilled engineers with many years of experience. This special issue on design and test of RFIC chips describes some of these challenges and proposes some interesting solutions.     

Applications, techniques, and microfluidic interfacing for nanoscale biosensing

Biosensors based on nanotechnology are rapidly developing and are becoming widespread in the biomedical field and analytical chemistry. For these nanobiosensors to reach their potential, they must be integrated with appropriate packaging techniques, which are usually based on nano/microfluidics. In this review we provide a summary of the latest developments in nanobiosensors with a focus on label-based (fluorescence and nanoparticle) and label-free methods (surface plasmon resonance, micro/nanocantilever, nanowires, and nanopores). An overview on how these sensors interface with nano/microfluidics is then presented and the latest papers in the area summarized.     

Collaborative writing in multiple discourse contexts

Research in computer-supported writing has traditionally compared electronic communication with oral, face-to-face communication to identify the benefits and weaknesses of each, as if they entailed dichotomous choices. In this article, we challenge that view and argue instead that any form of communication and its educational usefulness is shaped by the situation in which it is used, the backgrounds and goals of the participants, the institutional and technological setup, and the intended purpose of the medium. Three modes of communication in one graduate course are examined — oral discussion, synchronous written discussion on a local area network, and asynchronous written postings on an email list set up for the class. It was found that patterns of participation, topic introduction, and topic development differed across the three communication modes, but that the three were interwoven with each other and embedded within the larger classroom context and forms of knowledge creation in the class. Thus, rather than examining different communication media separately, researchers interested in understanding computer-supported collaborative writing need to look at how different media are used to create a meta-medium, which is established by the discourse community involved.     

Kirchhoff calculations of the coherent scatter from a series of very rough surfaces

Calculations are presented for the scattering of polarized light from a series of very rough one-dimensional gold-coated surfaces, as determined by the use of the Kirchhoff approximation with geometric shadowing. These surfaces have Gaussian autocorrelation functions with a 1/e width of 3.3 μm and Gaussian probability distributions of height with standard deviation varying between 0.25 and 1.73 μm. Calculations are performed for the scattering of light of wavelength 3.392 μm, so that the validity of the geometric-shadowing approximation and the Kirchhoff approximation itself are open questions. The values of the coherent (or specular) component of the scattered light for the four nonzero elements of the Mueller matrix (which fully describe the polarization properties of the scattered light) are calculated. Comparisons between the calculated results and experimental measurements on surfaces of the same parameters [Knotts and O'Donnell, J. Opt. Soc. Am. A 11, 697 (1994)] show good agreement up to approximately 70° incidence angle.