Carbon Nanotubes Anchored to Silicon for Device Fabrication

This report highlights recent progress in the fabrication of vertically aligned carbon nanotubes (VA‐CNTs) on silicon‐based materials. Research into these nanostructured composite materials is spurred by the importance of silicon as a basis for most current devices and the disruptive properties of CNTs. Various CNT attachments methods of covalent and adsorptive nature are critically compared. Selected examples of device applications where the VA‐CNT on silicon assemblies are showing particular promise are discussed. These applications include field emitters, filtration membranes, dry adhesives, sensors and scaffolds for biointerfaces.

     

Brain Metabolic Profile after Intranasal vs. Intraperitoneal Clomipramine Treatment in Rats with Ultrasound Model of Depression

Background: Molecular mechanisms of depression remain unclear. The brain metabolome after antidepressant therapy is poorly understood and had not been performed for different routes of drug administration before the present study. Rats were exposed to chronic ultrasound stress and treated with intranasal and intraperitoneal clomipramine. We then analyzed 28 metabolites in the frontal cortex and hippocampus. Methods: Rats’ behavior was identified in such tests: social interaction, sucrose preference, forced swim, and Morris water maze. Metabolic analysis was performed with liquid chromatography. Results: After ultrasound stress pronounced depressive-like behavior, clomipramine had an equally antidepressant effect after intranasal and intraperitoneal administration on behavior. Ultrasound stress contributed to changes of the metabolomic pathways associated with pathophysiology of depression. Clomipramine affected global metabolome in frontal cortex and hippocampus in a different way that depended on the route of administration. Intranasal route was associated with more significant changes of metabolites composition in the frontal cortex compared to the control and ultrasound groups while the intraperitoneal route corresponded with more profound changes in hippocampal metabolome compared to other groups. Since far metabolic processes in the brain can change in many ways depending on different routes of administration, the antidepressant therapy should also be evaluated from this point of view.     

Lipid class distribution of fatty acids including conjugated linoleic acids in healthy and cancerous parts of human kidneys

In this study the FA compositions of healthy and cancerous human renal tissues from the same patients are compared with special reference to the CLA and PUFA content. CLA was preferentially incorporated into neutral lipid compared with phospholipid classes. Its distribution profile was similar to that of monounsaturated FA, but unlike that found with 18∶2n−6. Different incorporation patterns were found for individual CLA isomers. Comparing renal cell carcinoma (RCC) and healthy kidney, the total CLA content was significantly lower in the cholesterylester fraction and significantly higher in the PE and PS fractions from RCC. The most significant differences between healthy and cancerous renal tissue were in the content of t10,c12-CLA. Furthermore, the lipid class distributions of n−6 PUFA were determined, and several significant differences between RCC and healthy renal tissue were found. This is of interest, as it has been proposed that the anticarcinogenic properties of dietary CLA are associated with their interference in the metabolism of 20∶4n−6. The involvement of CLA in preventing renal cancer cannot be definitively demonstrated from the design of this study, nor was it intended, but the complete determination of the FA composition of adjacent healthy and cancerous tissues may provide an insight if lipids are involved in this disease.     

Mathematical Model of Foraging in a Group of Robots: Effect of Interference

In multi-robot applications, such as foraging or collection tasks, interference, which results from competition for space between spatially extended robots, can significantly affect the performance of the group. We present a mathematical model of foraging in a homogeneous multi-robot system, with the goal of understanding quantitatively the effects of interference. We examine two foraging scenarios: a simplified collection task where the robots only collect objects, and a foraging task, where they find objects and deliver them to some pre-specified home location. In the first case we find that the overall group performance improves as the system size grows; however, interference causes this improvement to be sublinear, and as a result, each robot's individual performance decreases as the group size increases. We also examine the full foraging task where robots collect objects and deliver them home. We find an optimal group size that maximizes group performance. For larger group sizes, the group performance declines. However, again due to the effects of interference, the individual robot's performance is a monotonically decreasing function of the group size. We validate both models by comparing their predictions to results of sensor-based simulations in a multi-robot system and find good agreement between theory and simulations data.     

Transport properties of ion-exchange membrane systems in LysHCl solutions

This paper focuses on how characterising and understanding the dissonance between stakeholder perceptions of risk could be of value when carrying out participatory planning of water reuse projects. Knowledge of the variation in stakeholders' concerns regarding risk from the onset of a participatory process, could breed insight and help guide the knowledge requirements of the stakeholder groups involved. The research input for this paper was generated from a questionnaire survey investigating stakeholders' views regarding wider participation in water resources management with particular regard to the following points: (1) What they considered to be the most important risks of a wastewater reuse project or scheme; (2) Individual expectations with regard to the coincidence level of risk perception between the stakeholder groups. Responses from four stakeholder groups (regulators, researchers, managers and domestic customers) are presented. Perspectives on the risks and uncertainties inherent in a project will probably vary from one stakeholder to another. The research findings suggest that levels of expected agreement regarding risk vary between different stakeholder groups. There is also a marked variability in expectations by risk type. Identification and characterisation of individual stakeholders' expectations and knowledge requirements with regard to risk could therefore help to form a sound basis for equitable deliberation, understanding and decision making within a social learning environment.     

Occupational exposure to commercial decabromodiphenyl ether in workers manufacturing or handling flame-retarded rubber

Commercial decabromodiphenyl ether (DecaBDE) is commonly used as a flame retardant in different electrical and textile applications. It is also used in the production of flame-retarded rubber compound. DecaBDE is the major technical polybrominated diphenyl ether (PBDE) in use today and consists mainly of decabromodiphenyl ether (BDE-209). PBDEs, including BDE-209, are well-known environmental pollutants, ubiquitous both in aquatic and terrestrial environments. The aim of the present study was to assess the exposure to PBDEs in workers manufacturing or handling rubber which was flame retarded with DecaBDE. A referent group, abattoir workers (slaughterhouse workers), with no occupational exposure to PBDEs, was also investigated. Moreover, the methodology for analysis of PBDEs in serum was refined, with special emphasis on congeners with a high number of bromine substituents, i.e., octa- to decaBDEs. The highest BDE-209 concentration observed among the rubber workers was 280 pmol/g lipid weight (I.w.) (270 ng/g I.w.). The median concentration of BDE-209 among rubber workers was 37 pmol/g I.w. (35 ng/g I.w.). Among referents, the median was 2.5 (range 0.92-9.7) pmol/g I.w. (median 2.4 ng/g I.w.). In rubber workers the BDE-209 concentrations were up to 32% (median 4%) of the 2,2',4,4',5,5'-chlorobiphenyl (CB-153) concentrations, on a molar basis, whereas the referents had BDE-209 concentrations which were similar to that of 2,2',4,4'-bromodiphenyl ether (BDE-47), below 1.4% (median 0.3%) of the CB-153 concentration. Concentrations of all nonabromodiphenyl ethers (nonaBDEs) and several octabrmodiphenyl ethers (octaBDEs) congeners, including BDE-203, were also elevated among the rubber workers, with 2.5- to 11-fold higher median concentrations, compared to the referents. The results confirm a significant uptake of BDE-209 in the workers exposed to DecaBDE and indicate a potential for in vivo formation of lower BDEs in these persons.     

Social connectedness and mothering: Effects of maternal employment and maternal absence.

We conducted two separate studies to test N. Chodorow's (1978) theory concerning the relationship between mothering and social connectedness, that is, a sense of self in relation to others. In two correlational studies, we examined the effects of maternal employment and maternal absence (because of death or divorce) on young adults' social connectedness, as measured by the Interpersonal Orientation (IO) Scale (W. C. Swap and J. Z. Rubin; see record 1983-22471-001). Although differences in maternal employment were not related to IO, maternal absence was related to IO. Daughters whose mothers had been absent since the daughters' early childhood rated themselves lowest on IO; this was especially true of daughters who did not report having a mother substitute. This finding provides support for Chodorow's theory because it documents a predicted sex difference, a predicted effect of "mothering" versus "fathering," and a predicted difference between early (i.e., preoedipal) and later absence. Future empirical work on moderators of child-rearing experience is warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)