Mammary transfer and metabolism in the rat of halogenated fatty acids of halogenated olive oil

To assess possible incorporation of halogenated fatty acids into the neonate via the milk, a 4-day study was carried out in which lactating Wistar rats were orally dosed with either brominated olive oil (BOO) (0.6 g/kg body wt/day) or chlorinated olive oil (COO) (0.4 g/kg body wt/day) for the first 4 days. On days 1–5 inclusive 2 pups per litter were sacrificed and the stomach curd and livers analyzed for halogenated fatty acids by gas liquid chromatography (GLC). On day 5 all dams also were sacrificed and their livers and adipose tissue similarly analyzed. With BOO, brominated fatty acids (bfa) accumulated in both the milk lipids and neonate liver lipids, and appeared to plateau on day 4 at levels of 2% and 5% respectively. In contrast to the BOO in which approximately 100% of the bfa was dibromostearis (DBS), the milk bfa comprised 79% (DBS), 9% dibromopalmitic (DBP) and 12% dibromomyristic (DBM) acids, suggesting maternal metabolism to the shorter chain brominated acids. In the neonate liver lipids the bfa composition was 47% (DBS), 12% (DBP) and 41% (DBM), suggesting either further metabolism in the neonate and/or preferential accumulation of the shorter chain brominated acids. The analysis of maternal tissue indicated very low bfa residues, contrary to previous studies in non-lactating rats. Similar results were obtained with COO.     

Ventilation in the patient with unilateral lung disease

Severe ULD presents a challenge in ventilator management because of the marked asymmetry in the mechanics of the two lungs. The asymmetry may result from significant decreases or increases in the compliance of the involved lung. Traditional ventilator support may fail to produce adequate gas exchange in these situations and has the potential to cause further deterioration. Fortunately, conventional techniques can be safely and effectively applied in the majority of cases without having to resort to less familiar and potentially hazardous forms of support. In those circumstances when conventional ventilation is unsuccessful in restoring adequate gas exchange, lateral positioning and ILV have proved effective at improving and maintaining gas exchange. Controlled trials to guide clinical decision making are lacking. In patients who have processes associated with decreased compliance in the involved lung, lateral positioning may be a simple method of improving gas exchange but is associated with many practical limitations. ILV in these patients is frequently successful when differential PEEP is applied with the higher pressure to the involved lung. In patients in whom the pathology results in distribution of ventilation favoring the involved lung, particularly BPF, ILV can be used to supply adequate support while minimizing flow through the fistula and allowing it to close. The application of these techniques should be undertaken with an understanding of the pathophysiology of the underlying process; the reported experience with these techniques, including indications and successfully applied methods; and the potential problems encountered with their use. Fortunately, these modalities are infrequently required, but they provide a critical means of support when conventional techniques fail.     

Measurement of the elastic properties of polymer melts

A method and apparatus for measuring the elastic and other properties of polymers in the melt state is presented. The recoverable strain magnitude and the rate of strain recovery have been measured as a function of: applied shear rate, applied shear magnitude, temperature and molecular weight. The elastic properties indicate that there is an abrupt change or “transition” in the response of polystyrene melts at temperatures well above the glass transition. This abrupt change is found to be molecular weight dependent. The results are interpreted qualitatively in terms of molecular structure and practical processing operations. The possible relationship of this “transition” to T_u, is briefly discussed.     

Scaling J2EE™ application servers with the Multi‐tasking Virtual Machine

The Java? 2 Platform, Enterprise Edition (J2EE?), is established as the standard platform for hosting enterprise applications written in the Java programming language. Similar to an operating system, a J2EE server can host multiple applications, but this is problematic due to limitations on scalability, weak inter‐application isolation and inadequate resource management facilities in the underlying Java platform. These limitations lead to a proliferation of server instances with a consequent dramatic increase in the total memory footprint and more complex system administration. The Multi‐tasking Virtual Machine (MVM) solves this problem by providing an efficient and scalable implementation of the isolate API for multiple, isolated tasks, enabling the co‐location of multiple server instances in a single MVM process. Isolates also enable the restructuring of a J2EE server implementation as a collection of isolated components, offering increased flexibility and reliability. The resulting system is a step towards a complete and scalable operating environment for enterprise applications. Copyright © 2006 John Wiley & Sons, Ltd.     

Seeded growth of highly luminescent CdSe/CdS nanoheterostructures with rod and tetrapod morphologies

We have demonstrated that seeded growth of nanocrystals offers a convenient way to design nanoheterostructures with complex shapes and morphologies by changing the crystalline structure of the seed. By using CdSe nanocrystals with wurtzite and zinc blende structure as seeds for growth of CdS nanorods, we synthesized CdSe/CdS heterostructure nanorods and nanotetrapods, respectively. Both of these structures showed excellent luminescent properties, combining high photoluminescence efficiency (approximately 80 and approximately 50% for nanorods and nanotetrapods, correspondingly), giant extinction coefficients (approximately 2 x 10(7) and approximately 1.5 x 10(8) M(-1) cm(-1) at 350 nm for nanorods and nanotetrapods, correspondingly), and efficient energy transfer from the CdS arms into the emitting CdSe core.     

Photovoltaic-powered desalination system for remote Australian communities

This paper reports on the design and successful field testing of a photovoltaic (PV)-powered desalination system. The system described here is intended for use in remote areas of the Australian outback, where fresh water is extremely limited and it is often necessary to drink high salinity bore water. A hybrid membrane configuration is implemented, whereby an ultrafiltration (UF) module is used for removing particulates, bacteria and viruses, while a reverse osmosis (RO) or nanofiltration (NF) membrane retains the salts. The concepts of water and energy recovery are implemented in the design. Field trials, performed in White Cliffs (New South Wales), demonstrated that clean drinking water was able to be produced from a variety of feed waters, including high salinity (3500 mg/l) bore water and high turbidity (200 NTU) dam water. The specific energy consumption ranged from 2 to 8 kW h/m³ of disinfected and desalinated drinking water, depending on the salinity of the feed water and the system operating conditions. The optimum operating pressure when filtering bore water was determined to be in the range 6–7 bar.     

Water: a responsive small molecule

Unique among small molecules, water forms a nearly tetrahedral yet flexible hydrogen-bond network. In addition to its flexibility, this network is dynamic: bonds are formed or broken on a picosecond time scale. These unique features make probing the local structure of water challenging. Despite the challenges, there is intense interest in developing a picture of the local water structure due to water's fundamental importance in many fields of chemistry. Understanding changes in the local network structure of water near solutes likely holds the key to unlock problems from analyzing parameters that determine the three dimensional structure of proteins to modeling the fate of volatile materials released into the atmosphere. Pictures of the local structure of water are heavily influenced by what is known about the structure of ice. In hexagonal I(h) ice, the most stable form of solid water under ordinary conditions, water has an equal number of donor and acceptor bonds; a kind of symmetry. This symmetric tetrahedral coordination is only approximately preserved in the liquid. The most obvious manifestation of this altered tetrahedral bonding is the greater density in the liquid compared with the solid. Formation of an interface or addition of solutes further modifies the local bonding in water. Because the O-H stretching frequency is sensitive to the environment, vibrational spectroscopy provides an excellent probe for the hydrogen-bond structure in water. In this Account, we examine both local interactions between water and small solutes and longer range interactions at the aqueous surface. Locally, the results suggest that water is not a symmetric donor or acceptor, but rather has a propensity to act as an acceptor. In interactions with hydrocarbons, action is centered at the water oxygen. For soluble inorganic salts, interaction is greater with the cation than the anion. The vibrational spectrum of the surface of salt solutions is altered compared with that of neat water. Studies of local salt-water interactions suggest that the picture of the local water structure and the ion distribution at the surface deduced from the surface vibrational spectrum should encompass both ions of the salt.     

Do Farmers' Markets Increase Access to Healthy Foods for All Communities? Comparing Markets in 24 Neighborhoods in Los Angeles

Problem, research strategy, and findings: Farmers' markets provide one option for remedying the startling decline in fresh vegetable and fruit consumption in the United States, particularly in low-income, non-White neighborhoods where opportunities to access these components of a healthy diet are often limited. We lack empirical research on whether farmer's markets provide fresh vegetables and fruits consistently across locations. We audited product offerings at 24 farmers' markets in Los Angeles at two points in time and interviewed a sample of market managers to compare market offerings across neighborhoods to determine whether farmers' markets alleviate disparities experienced by low-income and non-White communities. Farmers' markets in low-income and non-White communities are smaller and provide fewer fresh fruits and vegetables than markets situated in more affluent communities. Managers suggest that their first priority is to stock fresh produce, but other factors such as competition and farmer recruitment and retention often influence market offerings.

Takeaway for practice: Planners cannot count on farmers' markets to fully remedy disparities in the availability of fresh vegetables and fruits. We need additional research to understand the range of social, ecological, and health benefits created by farmers' markets in a neighborhood. Planners should begin working with other agencies to conduct community food assessments to better evaluate strategies for addressing inequalities seen in neighborhood access to healthy food.     

Design issues for adaptive control charts

Adaptive control charts allow the components of the quality‐monitoring scheme to vary in order to obtain improved performance over non‐adaptive control charts. Research has centered on components such as the sample size, time between samples, warning limits, and control limits and has recommended a variety of schemes, many of which are optimal in some sense. In practice, there are many other adaptive schemes that are near optimal, which will still yield considerable improvement over non‐adaptive control charts. In addition, the impact of parameter estimation on adaptive control chart performance must be taken into consideration. Based on the simulation results shown here, adaptive control charts should only be used for mature processes, where a sufficient amount of Phase I data have been obtained to ensure that the estimated control limits are accurate. When evaluating control chart performance, we consider initial state performance measures for simplicity and note that the conclusions obtained here apply to steady‐state performance measures. The evaluation of performance measures is easily handled by the Markov chain approach detailed in the Appendix. Copyright © 2008 John Wiley & Sons, Ltd.     

Dynamic measurement of altered chemical messenger secretion after cellular uptake of nanoparticles using carbon-fiber microelectrode amperometry

In this work, carbon-fiber microelectrode amperometry is used to characterize serotonin exocytosis from murine peritoneal mast cells cocultured with fibroblasts in the presence of Au nanoparticles. In the case of mast cell exposure to 1 nM 28 nm diameter spherical Au nanoparticles, there is a decrease of greater than 30% in the number of successful granule transport and fusion events, greater than 30% increase in the rate of intragranular matrix expansion, and greater than 20% increase in the number of secreted serotonin molecules per granule. These results suggest that nanoparticles interrupt the dense-core biopolymer intragranular matrix and present the potential for systematic studies showing how exocytotic function is influenced by nanoparticle size, shape, and composition.