Multiphoton imaging with a direct‐diode pumped femtosecond Ti:sapphire laser

A direct‐diode pumped Ti:sapphire femtosecond oscillator is used to perform multiphoton imaging for the first time.     

Protein Quality of Cheddar Cheese Compared with Casein and Fabricated Cheese in the Rat

The protein quality of freeze-dried cheddar cheese, spray-dried cheddar cheese, freeze-dried fabricated cheddar cheese (with casein as the main protein source), and sodium caseinate was evaluated in rats using the protein efficiency ratio (PER) assay (AOAC procedures) in two feeding experiments with casein as the control. Biological evaluation of the products showed that PER values for freeze-dried cheddar cheese were significantly higher than casein (3.7 vs 2.5). Freeze-dried cheddar also had a PER value significantly higher than spray-dried cheddar cheese (3.7 vs 3.0). Freeze-dried fabricated cheddar cheese and sodium caseinate had PER values not significantly different from the casein control.     

OPTIMIZATION OF CONDITIONS FOR THE PRODUCTION OF EICOSAPENTAENOIC ACID BY MORTIERELLA

This research characterized the optimum growth conditions of Mortierella for accumulation of eicosapentaenoic acid (EPA). Eight strains of Mortierella, NRRL 5513, 2761, 1757, 6337, 2493 and ATCC 24786, 16271, 16266, were evaluated for their ability to produce EPA. Temperature, temperature shifting, media, and media supplementation (carbon/nitrogen sources, growth factors and antibiotic supplementation) were studied to determine their effect on mycelial mass and EPA accumulation. M. elongata ATCC 16271 was the most effective strain for EPA production when grown at 18C, in yeast malt broth, pH 5. 1, and harvested after 7 days, yielding 66 mg EPA/g dry mycelial cells. In another experiment, temperature shifting (2 days at 24C, to 5 days at 12C) increased the yield of EPA about eight times to 32 mg EPA/g dry mycelial celis from 4 mg EPA/g dry mycelial cells for nontemperature shifted cultures. This research describes methodologies that resulted in EPA content higher than any previously reported.     

Using the FIB to characterize nanoparticle materials

In the 1–100‐nm size regime, the properties of materials can differ significantly from those of their bulk counterparts. The present study applies the focused ion beam (FIB) tool to the characterization of nanoscale structures for scanning and transmission electron microscopy. The strength of this method is its ability to manufacture samples that cannot be produced using traditional means. The films of nanoparticles examined here are examples of such systems; the films are found to be not fully dense, composed of chemically heterogeneous areas and mechanically different from the substrate. Distinct advantages of the application of the FIB for characterization of nanoscale structures are highlighted for several nanoparticle structures. This successful application of FIB techniques provides a pathway to integrate the study of nanoscale production techniques and their resulting structure–property relationships.     

Discovering Patterns: An Industry Report

Design patterns are a relatively new topic of study in software engineering. As such, the ideas have yet to make a widespread transfer to industry. What may help are some early success stories that will complement the intuitively appealing idea of patterns, and provide more incentive for the skeptical, time-pressed, practising software engineer to explore them. This paper describes one such successful introduction of patterns into a real development project, and the ways in which they are affecting the ongoing course of the work. Some background material on the company and the project is given to provide context, followed by a discussion of how patterns were introduced to the project and which patterns were found to be especially useful. Along the way, observations about the nature and use of patterns are offered for further consideration.     

TOUGHENING IN BLANCHED ASPARAGUS: IDENTIFICATION OF PHENOLIC COMPOUNDS AND EVIDENCE FOR A FREE RADICAL MECHANISM

Prior research in this laboratory established apparent nonenzymatic toughening occurs in heat treated asparagus tissue. The present work attempted to identify the phenol compounds involved and to discern the mechanism(s) of this reaction. Toughness (Warner-Bratzler shear) of blanched (no detectable per-oxidase or polyphenol oxidase activity) spears stored at 22°C increased significantly over a 4 day period. Reverse phase-high pressure liquid chromatography (RP-HPLC) of methanolic tissue extracts indicated 7 major phenolic peaks. HPLC retention times and Fourier transform-infrared spectroscopy tentatively identified the extracted phenols as: (1) 4-hydroxybenzoic acid; (2) caffeic acid; (3) vanillic acid; (4) syringic acid; (5) p-coumaric acid; (6) syringaldehyde; and (7) ferulic acid. A significant decrease in the concentration (HPLC peak area) of 1, 2, 5, 6 and 7 occurred after 4 days storage. In vitro studies with homogenized (blanched and unblanched) asparagus tissue indicated a significant decrease in the concentration of added phenols. Unblanched tissue produced greater changes. The site of added phenol incorporation (a significant increase in fluorescence intensity) was determined to be the vascular bundle region. Metal ion chelation (EDTA), addition of iron (Fe²⁺) and reduction of metal ions using L-ascorbic acid affected added phenol utilization variably. Only the addition of a mixed antioxidant (BHA, PG, citric acid) served to significantly decrease utilization of the added phenols by blanched tissue blends, therefore implicating a free radical mediated phenol coupling mechanism. ESR spectroscopy detected the ascorbate radical anion in the blanched homogenate.