Using textile topography to analyze X‐ray CT data of composite microstructure

The 3‐dimensional yarn architecture in a 2‐dimensional woven fabric reinforced composite is nonuniform. Many structural features appear that are not obvious from consideration only of the yarn architecture in the single layer textile fabric. A complete set of 3‐dimensional image data was acquired for a representative volume of the composite using X‐ray micro‐computed tomography. Extensive image analysis was, however, necessary to reveal the yarn architecture due to relatively low signal‐to‐noise ratio and contrast levels relative to optical microscopy of polished cross sections.     

A novel video-tracking system to quantify the behaviour of nocturnal mosquitoes attacking human hosts in the field

Many vectors of malaria and other infections spend most of their adult life within human homes, the environment where they bloodfeed and rest, and where control has been most successful. Yet, knowledge of peri-domestic mosquito behaviour is limited, particularly how mosquitoes find and attack human hosts or how insecticides impact on behaviour. This is partly because technology for tracking mosquitoes in their natural habitats, traditional dwellings in disease-endemic countries, has never been available. We describe a sensing device that enables observation and recording of nocturnal mosquitoes attacking humans with or without a bed net, in the laboratory and in rural Africa. The device addresses requirements for sub-millimetre resolution over a 2.0 × 1.2 × 2.0 m volume while using minimum irradiance. Data processing strategies to extract individual mosquito trajectories and algorithms to describe behaviour during host/net interactions are introduced. Results from UK laboratory and Tanzanian field tests showed that Culex quinquefasciatus activity was higher and focused on the bed net roof when a human host was present, in colonized and wild populations. Both C. quinquefasciatus and Anopheles gambiae exhibited similar behavioural modes, with average flight velocities varying by less than 10%. The system offers considerable potential for investigations in vector biology and many other fields.     

Effect of Nonstoichiometry on Fracture Toughness and Hardness of Yttrium Oxide Ceramics

This work deals with the changes in mechanical properties of yttrium oxide ceramics induced by nonstoichiometry. The maximum fracture toughness, K_lc, is observed at the stoichiometric composition. For an oxygendeficient ceramic, a decrease of K_lc is observed from 3.5 to 2.3 MPa.m^1/2. On the other hand, the Vickers hardness seems to be less dependent on stoichiometry. These results are discussed in the frame of the evolution of the Y-O bond with the stoichiometry. They set in particular the problem of the role of electrostatic energy stored in a brittle material containing charged defects in the energy balance controlling crack propagation.     

First suckling: A crucial event for mother-young attachment? An experimental study in horses (Equus caballus).

This study investigates the consequences of interference during first suckling for subsequent mare-young attachment in horses (Equus caballus). Foals brought to their dams' teats appeared, at later ages (1-3 months), to remain closer to their dams and to play less than control foals that had been allowed to suckle spontaneously. Higher levels of play and distance initiatives from the mother are considered criteria for secure attachment in horses, humans, and other species. As this unique handling was the only event that distinguished experimental from control groups, the authors concluded that first suckling is a crucial event in the development of secure dam-young attachment. These results could have important implications for all mammal species, including humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Photocatalytic oxidation of substituted toluenes with irradiated TiO2 semiconductor. Effect of zeolite

Photocatalytic oxidation of substituted toluenes was investigated on irradiated TiO₂ and TiO₂ combined with HY₁₅ and HY₂₀ zeolites. In all cases the oxidation occurred in the first step exclusively on either one substituent or the other, but never on both simultaneously. In the presence of a zeolite, photooxidation conversion was higher than that obtained without zeolite.     

User acceptance studies to evaluate discomfort glare in daylit rooms

As for now, it seems to be infeasible to predict or measure the perceived degree of discomfort glare from windows. Within an international research project between Delft University of Technology and Berlin University of Technology, user acceptance studies are carried out in full-scale rooms under real sky conditions to study discomfort glare in daylit situations. The aim of the studies was to draw up a relation between glare assessments and measured quantities. For this purpose two test rooms are used: one room was occupied by the subject, in the other one the required measuring equipment was placed. An electronic questionnaire was developed for these studies and installed on the computer of the subject. Continuous measurements were necessary to link subjective assessments to measured quantities that are obtained concurrently. The obtained relation can be used to predict the average visual comfort evaluation under specific lighting conditions and to propose visual comfort criteria to maintain visual comfort. The study showed that the vertical illuminance measured near the facade and the average sky luminance measured from the back of the room are good measures to monitor visual comfort under intermediate and overcast sky conditions. The visual comfort criteria should nonetheless be used with care, since the diversity of individual preferences is large. The user preferably has an user interface to overrule the glare protection when it is controlled on these visual comfort criteria.     

Cyclic AMP increases incorporation of exogenous fatty acids into triacylglycerols in hamster fibroblasts

Incorporation of various exogenous saturated or unsaturated [¹⁴C]labeled fatty acids (palmitic, stearic, oleic, linoleic and arachidonic) into triacylglycerols by hamster fibroblasts was markedly enhanced (two-to fourfold) in the presence of theophylline or dibutyryl cyclic adenosinemonophosphate (dbcAMP). This effect was observed for short-term (1–6 hr) as well as long-term (15–24 hr) preincubation with dbcAMP. In the presence of sodium fluoride, a phosphoprotein phosphatase inhibitor, measurement of diacylglycerol acyltransferase (DGAT) activity in cells pretreated with dbcAMP pointed out a marked increase (3X) in specific activity. The results suggest that DGAT activity in fibroblasts could be activated by a cAMP-dependent phosphorylation process.