Phase separation in optically opaque emulsions

Creaming of the dispersed oil phase in opaque oil-in-water emulsions was followed as a function of time and position using proton magnetic resonance. Measurements of T₁ along a vertical slice were used to quantify the oil-phase concentration. Emulsions were also described by laser-diffraction particle-size analysis to compare particle-size analysis with creaming behavior as determined by T₁ measurements in model triolein-in-water emulsions and more complex milk fat-in-water emulsions. Particle-size distributions failed to accurately predict the measured creaming behavior in the emulsions studied. Measurements of component nuclear relaxation were shown to be useful for characterizing oil-phase migration as a function of surfactant level, dispersed phase volume, and crystallization behavior of the lipid phase in emulsions.     

Evaluation of child safety seat checkpoint events

Objective

To determine the effectiveness of child safety seat checkpoints in generating change in child restraint practice to reduce the prevalence and extent of misuse.

Methods

Child safety seats underwent an initial checkpoint evaluation and participants received a training session. Participants were asked to return within 6–12 months to a checkpoint for follow-up evaluation. During each visit, a data collection sheet was used to assess the participants’ use of their child safety seat, and to subsequently calculate a restraint misuse score to characterize the child safety seat's usage before and after the intervention.

Results

During the period of study, 42 participants underwent both the initial and follow-up child safety seat check. Before the intervention, at least one misuse was identified in 100% of installed child safety seats. After the intervention, there was a significant reduction in the proportion of rear-facing child safety seats (18.8%) and forward-facing child safety seats (64.0%) that had at least one misuse (p < 0.001). Almost all (93.4%) of those using rear-facing child safety seats and the majority (64.0%) of those using forward-facing child safety seats improved their safety score as measured after the intervention.

Conclusions

Although misuse was universally observed, child safety seat checkpoint events were successful in improving usage practices.     

Scanning tunneling microscopy images of alkane derivatives on graphite: role of electronic effects

Scanning tunneling microscopy (STM) images of self-assembled monolayers of close-packed alkane chains on highly oriented pyrolitic graphite often display an alternating bright and dark spot pattern. Classical simulations suggest that a tilt of the alkane backbone is unstable and, therefore, unlikely to account for the contrast variation. First principles calculations based on density functional theory show that an electronic effect can explain the observed alternation. Furthermore, the asymmetric spot pattern associated with the minimum energy alignment is modulated depending on the registry of the alkane adsorbate relative to the graphite surface, explaining the characteristic moiré pattern that is often observed in STM images with close packed alkyl assemblies.     

Low‐Dose Irradiation Can be Used as a Phytosanitary Treatment for Fresh Table Grapes

Grapes (Vitis vinifera var. Sugraone and Vitis labrusca var. Crimson Seedless) were treated with 400, 600, and 800 Gy and the effects on physicochemical factors were measured alongside sensory testing during 3 wk of storage. Significant changes in texture and color with irradiation and age were measured but little visual difference was seen between control and irradiated grapes. However, age had a greater effect on firmness than irradiation for Sugraone grapes. Irradiation did not significantly (P ≤ 0.05) affect the SSC/TA ratio, which increased during storage. The trained panel detected significant changes in the berry texture and rachis color but rated sweetness and flavor significantly higher (P ≤ 0.05) for irradiated Sugraone as compared to the control. Consumers liked both the untreated and 800 Gy treated Sugraone grapes, but liked the untreated grapes more for texture (P ≤ 0.05). However, there was no difference in liking between irradiated (600 Gy or 800 Gy) and control samples of Crimson Seedless for any attribute. The results show that there are varietal differences in response to irradiation but the overall maintenance in quality of irradiated grapes during 3 wk of storage indicates that irradiation can serve as a viable phytosanitary treatment.     

The impact of driver education on self-reported collisions among young drivers with a graduated license

In this study, we assess the impact of driver education on the risk of collisions in a Graduated Licensing System (GLS). Ontario's GLS requires all new drivers to successfully pass through two stages of graduated license (referred to as G1 and G2, respectively) before full licensure is granted. Surveys of driving behaviour and related factors were administered to Grades 11 and 12 students with a graduated license in seven Ontario schools in 1996 and 1998. A total of 1533 students completed the survey in 2 years. Multivariate logistic regression analysis revealed a significantly lower odds of self-reported collision involvement among G1 license holders with driver education (OR: 0.31, 95% CI: 0.12-0.83). No significant effects were observed for G2 license holders. Other significant predictors of collisions include sex of driver, months of licensure and kilometers driven for G2 license holders. These results suggest that the impact of driver education may be dependent on the stage of driver learning in which it occurs.     

Lethality of commercial whole-muscle beef jerky manufacturing processes against Salmonella serovars and Escherichia coli O157:H7

Thermal processes used in making whole-muscle beef jerky include a drying step, which may result in enhanced pathogen thermotolerance and evaporative cooling that reduce process lethality. Several salmonellosis outbreaks have been associated with beef jerky. In this study, a standardized process was used to inoculate beef strips with five-strain cocktails of either Salmonella serovars or Escherichia coli O157:H7, to marinate the strips at pH 5.3 for 22 to 24 h at 5 degrees C, and to convert the strips to jerky using various heating and drying regimes. Numbers of surviving organisms were determined during and after heating and drying. Salmonella reductions of > or = 6.4 log CFU and similar reductions in E. coli O157:H7 were best achieved by ensuring that high wet-bulb temperatures were reached and maintained early in the process (51.7 or 54.4 degrees C for 60 min, 57.2 degrees C for 30 min, or 60 degrees C for 10 min) followed by drying at 76.7 degrees C (dry-bulb temperature). Processes with less lethality that reduced counts of both pathogens by > or = 5.0 log CFU were (i) heating and drying at 76.7 degrees C (dry bulb) within 90 min of beginning the process, (ii) heating for successive hourly intervals at 48.9, 54.4, 60, and 76.7 degrees C (dry bulb), and (iii) heating at 51.7 degrees C (dry bulb) and then drying at 76.7 degrees C (dry bulb), starting before the product water activity dropped below 0.86. In several trials, separate beef strips were inoculated with a commercial Pediococcus acidilactici starter culture as a potential surrogate for evaluating pathogen thermotolerance. The results of these trials suggested that this experimental approach may be useful for in-plant validation of process lethality.     

Individual Development Accounts for Housing Policy: Analysis of Individual and Program Characteristics

Homeownership is a desirable goal for most Americans and is considered an integral part of the American Dream. Empirical studies indicate homeownership has many positive outcomes. However, homeownership is not prevalent among low-income populations. Individual Development Accounts (IDAs) are matched savings accounts designed to help the working poor save for a home or other assets. This paper examines the savings outcomes of IDA participants saving for a home in the American Dream Policy Demonstration, which was the first large-scale test of IDAs. Data were collected from 1997 to 2001 on 1176 participants saving to purchase a home. Results indicate that low-income IDA participants can successfully save when provided structured opportunities. This paper examines individual and program characteristics that are important to explaining saving behaviors. Implications for policy makers, program administrators, and future research are given.     

Berry juices, teas, antioxidants and the prevention of atherosclerosis in hamsters

The effects of raspberry, strawberry and bilberry juices and green and black tea on early atherosclerosis in hamsters were investigated. They received an atherogenic diet and at the same time either a juice or a tea at a daily dose corresponding to the consumption of 275 ml by a 70 kg human. After 12 weeks berry juices and teas inhibited aortic lipid deposition by 79–96% and triggered reduced activity of hepatic antioxidant enzymes, not accompanied by lowered plasma cholesterol. These findings suggest that moderate consumption of berry juices and teas can help prevent the development of early atherosclerosis. There were substantial differences between the five beverages in terms of composition and concentration of individual phenolic compounds that were present. This indicates that anti-atherosclerotic effects can be induced by a diversity of phenolic compounds rather than a few specific components. The possible mechanisms by which this is brought about are discussed.     

Reproducibility of BOLD localization of interictal activity in patients with focal epilepsy: intrasession and intersession comparisons

Object  

Simultaneous EEG-fMRI recordings allow the identification of haemodynamic changes induced by neuronal activity during ictal or interictal epileptiform events (IEDs). We evaluated the reproducibility of continuous EEG-fMRI (cEEG-fMRI) in patients with focal epilepsy.     

Modelling Photonic Band-Gap Structures having Multiple Defects

A powerful and efficient method based on the Bloch theorem, widely used in solid state physics to model electrons running into a periodic lattice, and recently applied by the authors to model defect-free optical periodic structures, is used to characterize photonic bandgap (PBG) structures incorporating multiple defects, having arbitrary shape and dimensions. The importance of the defect-mode characterization in PBG materials is due to the intensive use of defects for light localization to design optical and microwave devices giving high performances.