Effect of ozonated water treatment on microbial control and on browning of iceberg lettuce (Lactuca sativa L.)

We examined the effect of ozonated water treatment on microbial control and quality of cut iceberg lettuce (Lactuca sativa L.). Fresh-cut lettuce was washed in ozonated water (3, 5, and 10 ppm) for 5 min at ambient temperature. The native bacterial population on the lettuce declined in response to a rise in ozone concentration. However, there was no further bacterial reduction (1.4 log CFU/g) above 5 ppm ozone. Although ozonated water treatment increased the phenylalanine ammonia lyase (PAL) activity of the lettuce stored at 10 degrees C compared with the water wash treatment after 1 day of storage, the concentration of ozone did not affect PAL activity. The a* value of the residue of the lettuce methanol extracts, which reflects the extent of browning, increased dramatically in lettuce treated with 10 ppm ozonated water compared with other treatments. Treatment with 3 or 5 ppm ozonated water resulted in more rapid changes in the a* value than after the water treatment. The combined treatment of hot water (50 degrees C, 2.5 min) followed by ozonated water (5 ppm, 2.5 min) had the same bactericidal effect as treatment with ozonated water (5 ppm, 5 min) or sodium hypochlorite (NaOCl, 200 ppm, 5 min), giving a reduction in bacteria numbers of 1.2 to 1.4 log CFU/g. The ascorbic acid content of the lettuce was not affected by these treatments. The combined treatment of hot water followed by ozonated water greatly inhibited PAL activity for up to 3 days of storage at 10 degrees C. Treatment with this combination greatly suppressed increases in the a* value, thus retarding the progress of browning compared with other treatments throughout the 6-day storage. NaOCl treatment also inhibited browning for up to 3 days of storage. Bacterial populations on the lettuce treated with sanitizers were initially reduced but then showed rapid growth compared with that of the water wash treatment, which did not reduce bacterial counts initially.     

Defensive secretion of chrysomelid larvaeLinaeidea aenea linné andPlagiodera versicolora distincta Baly

The larval defensive secretions ofLinaeidea aenea Linné andPlagiodera versicolora distincta Baly were identified as plagiolactone and epiplagiolactone. In addition to these compounds, chrysomelidial and the acetates of hexadecanol, octadecanol and (Z)-I 1-eicosenol from the former insect, and plagiodial and epichrysomelidial from latter insect were identified.This is report No. 3 of the Defensive Secretion of Chrysomelid Beetles. Report No. 2 is Sugawara et al., 1979.     

Combustion characteristics of crude oils

Small‐scale free‐burning pool fire tests were conducted in a cone calorimeter to obtain the combustion characteristics of 14 different crude oils. Measurements included the heat release rate based on oxygen consumption calorimetry, mass loss rate, radiative heat flux from the flame to a nearby target, liquid fuel temperature, extinction coefficient and CO₂ and CO concentrations in the exhaust duct. The effective heat of combustion, radiative heat loss fraction and smoke yield were calculated on the basis of the measured data. It was found that the heat release rate, mass loss rate, flame radiation and smoke yield were a function of the type of crude oil. The effective heat of combustion, extinction coefficient and radiative heat loss fraction were nearly constant for the range of crude oils evaluated in this programme. The heat release rate, mass loss rate, flame radiation and smoke yield appeared to correlate well with the crude oil density. Copyright © 2001 John Wiley & Sons, Ltd.     

Multilayer Mg–Stainless Steel Sheets,Twinning and Texture Evolution

In the present study, different combinations of multilayer sheets were prepared from 1 and 2 mm Mg AZ31 along with 0.25, 0.5, and 1 mm 304 L stainless steel. The texture and microstructure of the elongated samples (20 and 30 pct strain) were studied. It was found that the transversal stress plays an important role in both texture evolution and twinning in these composites. The obtained pole figures revealed an axial texture tilt with increasing steel layer volume fraction (V _f). It was found that this is a direct effect of transverse stress, which becomes more significant upon reducing Mg V _f. This extra stress component tilts the basal planes away from the original normal direction in monolithic samples. Moreover, our results indicate that with decreasing Mg V _f, twinning activity was increased in the 20 pct deformed samples but reduced in the samples with 30 pct elongation. It is known that at high strains where sufficient transverse stress is generated, the activity of prismatic slip is significantly enhanced, which promotes the motion of dislocations and reduces the necessity of twinning. With decreasing Mg V _f, stronger transversal stress is generated and Mg reaches the critical threshold of prismatic activity at lower strains.

     

Diva, a Bcl-2 homologue that binds directly to Apaf-1 and induces BH3-independent cell death

We have identified and characterized Diva, which is a novel regulator of apoptosis. Sequence analysis revealed that Diva is a member of the Bcl-2 family of proteins containing Bcl-2 homology domain 1, 2, 3, and 4 (BH1, BH2, BH3, and BH4) regions and a carboxyl-terminal hydrophobic domain. The expression of Diva mRNA was detected in multiple embryonic tissues but was restricted to the ovary and testis in adult mice. The expression of Diva promoted the death of 293T, Ramsey, and T47D cells as well as that of primary sensory neurons, indicating that Diva is a proapoptotic protein. Significantly, Diva lacks critical residues in the conserved BH3 region that mediate the interaction between BH3-containing proapoptotic Bcl-2 homologues and their prosurvival binding partners. Consistent with this, Diva did not bind to cellular Bcl-2 family members including Bcl-2, Bcl-XL, Bcl-w, Mcl-1, and A1/Bfl-1. Furthermore, mutants of Diva lacking the BH3 region fully retained their proapoptotic activity, confirming that Diva promotes apoptosis in a BH3-independent manner. Significantly, Diva interacted with a viral Bcl-2 homologue (vBcl-2) encoded by the Kaposi's sarcoma-associated herpesvirus. Consistent with these associations, apoptosis induced by Diva was inhibited by vBcl-2 but not by Bcl-XL. Importantly, Diva interacted with Apaf-1, an adapter molecule that activates caspase-9, a central death protease of the apoptotic pathway. The expression of Diva inhibited the binding of Bcl-XL to Apaf-1, as determined by immunoprecipitation assays. Thus, Diva represents a novel type of proapoptotic Bcl-2 homologue that promotes apoptosis independently of the BH3 region through direct binding to Apaf-1, thus preventing Bcl-XL from binding to the caspase-9 regulator Apaf-1.     

A comparative study of visual field damage in low-tension and primary open-angle glaucoma

Methods to encapsulate biological materials are now widely used. Sometimes bioencapsulation is considered as a universal technique conducting to identical results independently on the biological material used. For instance, a similar behavior is frequently waited for different strains of immobilized microorganisms without taking into account substantial differences in its physiological and morphological characteristics. Often interactions with the matrix support are also neglected. Thus, some concepts developed throughout all these years working in bioencapsulation merits to be revisited.     

A 500 MHz, 32 bit, 0.4 μm CMOS RISC processor

A 500 MHz, 32 bit RISC microprocessor has been experimentally developed using an 8-stage pipelined architecture and high-speed circuits, including a 500 MHz 1 kilobyte double-stage pipelined cache, a 1.8 ns register file, a double-stage binary look-ahead carry (BLC) adder circuit, and a 500 MHz phase locked loop (PLL) frequency multiplier. Newly developed circuit-integrating techniques include a stacked power-line structure, which serves as a noise shield and also provides low bounce, a low voltage-swing interface circuit with on-chip adjustable termination resistors, a small-skew clock distribution method, and a clock synchronization circuit which provides small-skew clock among LSI chips. About 200000 transistors are integrated into a 7.90 mm×8.84 mm die area with 0.4 μm CMOS fabrication technology. Power dissipation is 6 W at a 500 MHz operation and 3.3 V supply voltage