The variability of urinary cotinine levels in young children: implications for measuring ETS exposure.

This study examined the within-subject variability of urinary cotinine levels in young children (aged = 0.6-7.2 years) of smoking parents to determine the number of urine samples needed to provide accurate estimates of exposure to environmental tobacco smoke (ETS) for different time intervals. Secondary analyses were conducted of five independent studies (N = 376), in which multiple urinary cotinine measures had been collected over time periods up to 13 months. Over measurement periods of 4-15 days, the within-subject cotinine levels varied 3-5 times more than would be expected based on measurement error alone. Over 7-13 months, the within-subject variability was 10-20 times higher than would be expected based on the measurement error. Findings indicated that cotinine measures from single urine samples provided highly accurate estimates of only recent exposure (i.e., 2-3 days; rho = 0.99). To achieve similarly precise estimates of the mean cotinine level of an individual child over 4-15 days, up to nine urine samples may be necessary. Up to 12 urine samples may be required to achieve similarly precise estimates of ETS exposure over a 4- to 13-month period. Epidemiologic and clinical research on ETS exposure in children can benefit from multiple urine samples (a) to accurately measure average exposure at the level of the individual child, (b) to describe temporal patterns, (c) to detect incidences of peak exposure that would remain underrecognized if monitoring is limited to a single time point, and (d) to establish stable baseline levels and endpoints based on urine samples collected over clinically relevant time periods.     

In-situ measurement of ethanol tolerance in an operating fuel cell

Ethanol is seen as an attractive option as a fuel for direct ethanol fuel cells and as a source for on-demand production of hydrogen in portable applications. While the effect of ethanol on in-situ electrode behavior has been studied previously, these efforts have mostly been limited to qualitative analysis. In alkaline fuel cells, several cathode catalysts, including Pt, Cu triazole, and Ag can be used. Here, we apply a methodology using a microfluidic fuel cell to analyze in-situ the performance of these cathodes as well as Pt anodes in the presence of ethanol and acetic acid, a common side product from ethanol oxidation. For a given concentration of ethanol (or acetic acid), the best cathode catalyst can be determined and the kinetic losses due to the presence of ethanol (or acetic acid) can be quantified. These experiments also yield information about power density losses from the presence of contaminants such as ethanol or acetic acid in an alkaline fuel cell. The methodology demonstrated in these experiments will enable in-situ screening of new cathodes with respect to contaminant tolerance and determining optimal operational conditions for alkaline ethanol fuel cells.     

Hydroxyl Group Separation Distances in Anti-Freeze Compounds and Their Effects on Ice Nucleation

Since the discovery of biological antifreeze glycoproteins (AFGPs), which can inhibit ice nucleation, there has been considerable interest in understanding their mechanisms and mimicking them in synthetic polymers. In this study, we used molecular dynamics simulations of modified polyvinyl alcohol (PVA) compounds to show that the hydroxyl (OH) group distance is a key factor in whether certain compounds promote or inhibit ice nucleation. A hydroxyl distance smaller than ~2.8 Å but greater than ~7.1 Å in modified PVA (MPVA) compounds was associated with the promotion of ice nucleation, while a hydroxyl group separation distance of approximately ~5.0 Å was correlated with a delay in ice nucleation, owing to changes in the energy of the system. Thus, these results may help explain some of the mechanisms of current known anti-freeze compounds and may have implications for designing new anti-freeze compounds in the future.     

Selective Deflection and Localization of Flowing Aerosols onto a Substrate

Pulsed airflow cued by the fluorescence spectrum of a particular aerosol can be used to distinguish and deflect particles of biological origin out of an aerosol stream, permitting concentration of these particles for subsequent analysis (Pan et al. 2004 Pan, Y. L., Boutou, V., Bottiger, J. R., Zhang, S. S., Wolf, J. P. and Chang, R. K. 2004. A Puff of Air Sorts Bioaerosols for Pathogen Identification. Aerosol Sci. Technol., 38: 598–602. [CROSSREF][CSA][Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). However, these high velocity pulses of air have an inherent tendency to scatter particles, confounding efforts to concentrate these deflected particles for analysis. The ability to concentrate large numbers of biological particles into a small area on a collection substrate is particularly important for more species-specific techniques such as Raman and FTIR (Fourier Transform Infra-Red) spectroscopy, which require long integration times due to their weak signal strength. In the present work, a simple method is developed for deflecting and localizing particles after classification by a pulsed airflow. The concept is both modeled and experimentally tested. A specially designed funnel is used to localize the scattered particles onto an area of substrate as small as 1 mm in diameter. Computational fluid dynamics simulations were performed to investigate the interaction of the pulsed airflow with the deflected particles and the localizing funnel, in order to gain insight into design parameters and operating conditions that affect the efficiency of this technique. The results show that the combination of pulsed airflow with a localizing funnel effectively deflects and localizes the concentrated bioaerosol onto a small area of substrate or an opening of a microfluidic cell.     

Catalytic steam gasification of Miscanthus X giganteus in fluidised bed reactor on olivine based catalysts

The Miscanthus X giganteus (MXG) presents many advantages (high yield, perennial crop, easy harvesting…) so it can be considered as a good candidate in terms of renewable energy sources. Several works have been carried out and were devoted to the MXG, especially in the agricultural field, but this study is the first which deals with gasification in order to produce syngas. The catalytic steam gasification of MXG in a fluidised bed reactor into presence of olivine based catalysts was investigated. Three parameters were studied, the temperature (800 °C and 900 °C), the pellets size (6 mm and 8 mm) and the nature of catalyst (olivine and Ni/olivine). Noteworthy is the efficiency shown by the Ni/olivine at 800 °C, which leads to the production of 1.7 m³ kg^− 1 daf of gas, containing 50% of H₂. Ni/olivine catalyst was characterised by XRD, TPR and SEM-EDX in order to monitor its structural changes during the process. Moreover, a solvent system of tar recovery was tested, which allows to obtain a more representative set of the whole tars. Then, the tars composition was determined by GC/MS. The identification of different compounds shows the presence of different PAHs, in majority naphthalene.     

Effects of diet type and supplementation of glucosamine, chondroitin, and MSM on body composition, functional status, and markers of health in women with knee osteoarthritis initiating a resistance-based exercise and weight loss program

Background

The purpose of this study was to determine whether sedentary obese women with knee OA initiating an exercise and weight loss program may experience more beneficial changes in body composition, functional capacity, and/or markers of health following a higher protein diet compared to a higher carbohydrate diet with or without GCM supplementation.

Methods

Thirty sedentary women (54 ± 9 yrs, 163 ± 6 cm, 88.6 ± 13 kg, 46.1 ± 3% fat, 33.3 ± 5 kg/m²) with clinically diagnosed knee OA participated in a 14-week exercise and weight loss program. Participants followed an isoenergenic low fat higher carbohydrate (HC) or higher protein (HP) diet while participating in a supervised 30-minute circuit resistance-training program three times per week for 14-weeks. In a randomized and double blind manner, participants ingested supplements containing 1,500 mg/d of glucosamine (as d-glucosamine HCL), 1,200 mg/d of chondroitin sulfate (from chondroitin sulfate sodium), and 900 mg/d of methylsulfonylmethane or a placebo. At 0, 10, and 14-weeks, participants completed a battery of assessments. Data were analyzed by MANOVA with repeated measures.

Results

Participants in both groups experienced significant reductions in body mass (-2.4 ± 3%), fat mass (-6.0 ± 6%), and body fat (-3.5 ± 4%) with no significant changes in fat free mass or resting energy expenditure. Perception of knee pain (-49 ± 39%) and knee stiffness (-42 ± 37%) was decreased while maximal strength (12%), muscular endurance (20%), balance indices (7% to 20%), lipid levels (-8% to -12%), homeostasis model assessment for estimating insulin resistance (-17%), leptin (-30%), and measures of physical functioning (59%), vitality (120%), and social function (66%) were improved in both groups with no differences among groups. Functional aerobic capacity was increased to a greater degree for those in the HP and GCM groups while there were some trends suggesting that supplementation affected perceptions of knee pain (p < 0.08).

Conclusions

Circuit style resistance-training and weight loss improved functional capacity in women with knee OA. The type of diet and dietary supplementation of GCM provided marginal additive benefits.

Trial Registration

ClinicalTrials.gov: NCT01271218     

A Survey of Birds Odorous or Unpalatable to Humans: Possible Indications of Chemical Defense

We solicited information from field and museum ornithologists on the birds that they consider odorous and/or unpalatable in order to identify species that may use chemicals to deter predators. Ninety-two ornithologists from the Americas and Eastern Europe responded to our survey. Eighty genera and 10 families representing 17 orders, primarily Procellariiformes, Falconiformes, Psittaciformes, Cuculiformes, Piciformes, and Passeriformes, were cited as containing malodorous or uniquely odorous birds. Two orders (Opisthocomiformes and Trogoniformes), five families (Procellariidae, Cuculidae, Bucconidae, Picidae, and Furnriidae), and one subfamily (Drepanidinae) were reported to us as either containing many odorous species or consisting primarily of them. Thirty genera and three families representing 13 orders, primarily Passeriformes, were reported to us as unpalatable. The birds cited in our survey and those previously reported as odorous and/or unpalatable are tabulated. Our survey and review point to a number of taxa that may use chemicals to deter predators, although we acknowledge that compounds imparting aversive or unique odors or flavors may arise for a variety of reasons, e.g., as dietary by-products.     

Synchrony of net nitrogen mineralization and maize nitrogen uptake following applications of composted and fresh swine manure in the Midwest U.S.

Understanding how the quality of organic soil amendments affects the synchrony of nitrogen (N) mineralization and plant N uptake is critical for optimal agronomic N management and environmental protection. Composting solid livestock manures prior to soil application has been promoted to increase N synchrony; however, few field tests of this concept have been documented. Two years of replicated field trials were conducted near Boone, Iowa to determine the effect of composted versus fresh solid swine manure (a mixture of crop residue and swine urine and feces produced in hoop structures) on Zea mays (maize) N uptake, in situ soil net N mineralization, and soil inorganic N dynamics. Soil applications of composted manure increased maize N accumulation by 25?% in 2000 and 21?% in 2001 compared with fresh manure applications (application rate of 340?kg?N?ha^?1). Despite significant differences in net N mineralization between years, within year seasonal total in situ net N mineralization was similar for composted and fresh manure applications. Partial N budgets indicated that changes in soil N pools (net N mineralization and soil inorganic N) in the surface 20?cm accounted for 67?% of the total plant N accumulation in 2000 but only 16?% in 2001. Inter-annual variation in maize N accumulation could not be attributed to soil N availability. Overall, our results suggest that composting manures prior to soil application has no clear benefit for N synchrony in maize crops. Further work is required to determine the biotic and abiotic factors underlying this result.     

An implementation of drive key cellular manufacturing

The drive key is one of the most important high-precision components of aircraft braking systems. In this paper, a cost effective drive keys manufacturing process is developed. This proposed manufacturing process makes use of near-net-shape manufacturing, computer numerical control (CNC) machining, and cellular manufacturing methods. To make the proposed process a reality, proper engineering with the proposed parts along with group technology are applied to the product design in conjunction with the proposed manufacturing methods. In addition, a general spreadsheet program is developed for each style of fixture modules to assist in part program coding. Moreover, statistical process control (SPC) is implemented to verify product quality and accept the product at the point of manufacture. It is observed that the implementation of the proposed drive key cellular manufacturing process results in a tremendous improvement in quality, throughput and productivity as well as a drastic reduction in manufacturing operations, workholding fixtures, cutting tools, and inspection media.