Dietary intake of essential and long-chain polyunsaturated fatty acids in pregnancy

The dietary intake of EFA and long-chain PUFA (LCPUFA) by women with (n=14) and without (n=31) gestational diabetes mellitus (GDM) was determined by repeated 24-h recalls. Women with GDM consumed significantly more energy as fat compared with women who had uncomplicated pregnancies; absolute dietary fat did not differ. Dietary n−3 LCPUFA was substantially lower than the current recommendation for pregnancy, whereas intake of saturated FA (SFA) exceeded it. We conclude that replacing dietary sources of SFA with those of EFA and LCPUFA, especially n−3 LCPUFA, would benefit the dietary fat profiles of all pregnant women.     

Escherichia coli growth under modeled reduced gravity

Bacteria exhibit varying responses to modeled reduced gravity that can be simulated by clino-rotation. When Escherichia coli was subjected to different rotation speeds during clino-rotation, significant differences between modeled reduced gravity and normal gravity controls were observed only at higher speeds (30-50 rpm). There was no apparent affect of removing samples on the results obtained. When E. coli was grown in minimal medium (at 40 rpm), cell size was not affected by modeled reduced gravity and there were few differences in cell numbers. However, in higher nutrient conditions (i.e., dilute nutrient broth), total cell numbers were higher and cells were smaller under reduced gravity compared to normal gravity controls. Overall, the responses to modeled reduced gravity varied with nutrient conditions; larger surface to volume ratios may help compensate for the zone of nutrient depletion around the cells under modeled reduced gravity.     

Influence of air abrasion preparation on microleakage in glass ionomer cement restorations

The aim of this study was to assess microleakage in class V cavities prepared by air abrasion or high-speed dental bur and restored with different glass ionomer cements. Sixty bovine incisors were equally divided into 6 groups: I, II and III (preparation by high-speed) and IV, V and VI (preparation by air abrasion). Groups I and IV were restored with Fuji IX; groups II and V with Ketac Molar; and groups III and VI with Vitremer. After 24 h (37 °C), specimens were thermocycled, isolated with nail varnish, immersed in a 0.2% Rhodamine B solution for 24 hours, sectioned longitudinally and analyzed for microleakage using an optical microscope connected to a digital camera and a computer. The images were digitized and a software allowed the quantitative evaluation of microleakage in millimeters. Data were analyzed by Wilcoxon and Kruskal-Wallis tests. It was observed that there were significant differences (p ≤ 0.05) between incisal (enamel) and cervical (dentine/cementum) margins, mainly for Ketac Molar; there was no difference (p ≥ 0.05) between preparation methods, except for group II (high-speed/Ketac Molar) that showed higher infiltration; regarding the materials, Ketac Molar demonstrated the highest microleakage values (p ≤ 0.05), and only Vitremer sealed completely both margins of restorations. It was concluded that air abrasion preparation did not influence microleakage in class V restorations with the employed glass ionomer cements.     

Field screening of waterborne petroleum hydrocarbons by thickness shear-mode resonator measurements

An inexpensive, field-portable sensor for direct, aggregate determination of aqueous petroleum hydrocarbons (PH) down to sub-ppm levels was developed. The basis of this sensor was an unusual, highly nongravimetric frequency response of 10 MHz (series fundamental) AT-cut quartz crystals when coated with rubbery silicone films. The response depended linearly and reliably on the total concentration of dissolved hydrocarbons over a range of 0.01-100 mg x L(-1) or up to aqueous solubility limits. Calibration sensitivities were measured individually for laboratory-prepared solutions of BTEX (benzene, toluene, ethylbenzene, and xylene isomers) and C6-C8 aliphatic components. Each component demonstrated a method detection limit (MDL) in the low-to sub-ppm range (benzene 10 mg x L(-1), n-hexane 0.54 mg x L(-1)) for light coatings of a commercially available poly-(dimethylsiloxane) gum (OV-1, > 10(6) g x mol(-1)) and lower MDLs for heavier coatings. Pairwise responses for the aliphatic and benzenoid standards were additive, indicating that aggregate determinations of mixtures (especially light fuels) were possible. Natural matrix interferences caused by sample turbidity and ionic strength were overcome by simple preparative methods. Fuel-spiked natural waters were determined with respect to standards and verified by gas chromatography. A 0.19 mg x L(-1) MDL for gasoline was obtained for heavy OV-1 films. Field determinations of groundwater surrounding a leaking underground fuel tank demonstrated that the sensor and method were useful for on-site PH screening. Large differences between the equilibration times of aliphatic and benzenoid components also indicated one avenue for BTEX speciation with the device.     

Ozone formation potential of organic compounds in the Eastern United States: a comparison of episodes, inventories, and domains

Direct sensitivity analysis is applied for 3-D assessment of ozone reactivity (or ozone formation potential) in the Eastern United States. A detailed chemical mechanism (SAPRC-99) is implemented in a multiscale air quality model to calculate the reactivity of 32 explicit and 9 lumped compounds. Simulations are carried out for two different episodes and two different emission scenarios. While absolute reactivities of VOCs show a great deal of spatial variability, relative reactivities (normalized to the reactivity of a base mixture) produce a significantly more homogeneous field. Three types of domain-wide relative reactivity metrics are formed for 1-h and 8-h averaging intervals. In general, ozone reactivity metrics (with the exception of those based on daily peak ozone) are fairly robust and consistent between different episodes or emission scenarios. The 3-D metrics also show fairly similar rankings for VOC reactivity when compared to the box model scales. However, the 3-D metrics have a noticeably narrower range for species reactivities, as they result in lower reactivity for some of the more reactive, radical-producing VOCs (especially aldehydes). As expected, episodes and emission scenarios with less radical availability have higher absolute reactivities for all species and higher relative reactivities for the more radical-producing species. Finally, comparing the results with those from a different domain (central California) shows that relative reactivity metrics are comparable over these two significantly different domains.     

A simulation-based embedded probe technique for human-computer interaction evaluation

There is growing interest in developing video-based methods to evaluate the usefulness and usability of computerised tools in healthcare. In this paper, we propose a human-computer interaction evaluation method that protects the confidentiality of patient information and reduces litigation risks for participants by embedding and analysing performance on probes in complex scenarios with high face validity in a simulated setting. We describe the application of the method to a series of three studies of bar code medication administration (BCMA) software, used to reduce medication errors in the Veterans Administration.     

Effect of oestradiol treatment on mast cell populations and microflora in the vaginal cul-de-sac of seasonally anoestrous brushtail possums (Trichosurus vulpecula)

Mast cell populations in the vaginal cul-de-sac of female brushtail possums do not appear to be related to microbial invasion but changes in their density occur at oestrus, indicating a hormonal influence. The present study examined the effect of treatment with oestradiol on microflora and on mast cell numbers and their spatial location in cul-de-sac tissue of seasonally anoestrous brushtail possums. Tissue was collected from seasonally anoestrous brushtail possums (n = 6 per group) that were either untreated (anoestrous group) or were subjected to 6 days of treatment with oestradiol (oestradiol group) administered via subcutaneous implants or with the oil vehicle alone (control group). Tissue was collected aseptically for microbiological procedures and the fractionator and optical disector were used to quantify mast cell populations. Microflora populations were low (< 4.0 x 10(4) organisms g(-1)) and numbers of mast cells were similar in all groups. Mast cell density was greatest in epithelial and connective tissues from seasonally anoestrous and control animals and lowest in oestradiol-treated possums, in which there was a significant increase in cul-de-sac mass and volume. There is an inverse relationship between circulating oestrogen concentrations and mast cell density in possum cul-de-sac tissue, which is probably the result of an increase in tissue volume.