Mutations that prevent associative learning in C. elegans.

The nematode Caenorhabditis elegans offers a promising system for the reductionist study of learning and memory. In this article, classical conditioning in C. elegans is demonstrated with a variety of associative learning assays. These assays allowed for the isolation and behavioral characterization of 2 mutant C. elegans lines impaired in associative learning. Both lines show no short-term or long-term associative conditioning; however, they appear relatively normal in tests of nonassociative learning and sensorimotor function. In combination with the well-described genetics and neuroanatomy of C. elegans, the isolation of mutants selectively, yet completely, blocked in associative learning provides the basis for an effective characterization of the cellular and molecular aspects of associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crystal structure,electron-to-atom ratio and hydrogen storage capacity of zirconium based intermetallic laves phases

Laves phases of the type AB₂, where A is zirconium, have potential for use as hydrogen storage materials. These Laves phases have one of two different crystal structures, namely the C15 (cubic MgCu₂-type) or the C14 (hexagonal MgZn₂-type) Strukterbericht types. Data are presented on the lattice parameters for the two phases and relationships are developed between the lattice parameters of the two phases both for the binary (ZrB₂) and the pseudobinary (Zr(B′_xB″_1?x)2) Laves phases. Electron-to-atom ratios are calculated for both the binary and pseudobinary Laves phases and these are related to hydrogen storage capacity (hydrogen-to-metal ratio, H/M). The hydrogen-to-metal ratio is shown to decrease with increasing electron-to-atom ratio.     

Impulse sampling sequences in time-convolution electromagnetic transient analysis in power systems

The paper refers specifically to the process by which numerical solutions for transmission line step responses and indicial-impedance functions, as formed from inverse Fourier transform evaluations, are used in time-convolution electromagnetic transient analysis in power systems. Previously, curve-fitting and linear-segment matching procedures have been adopted, whereas the present paper develops a form of representation based on sequences of impulse samples. By avoiding curve-fitting altogether, the proposals further advance time-convolution methods in power systems, and improve the procedures required in applying them in practice. Typical solutions in the paper confirm the solution accuracy to which the proposals can lead, together with their computing time requirements.     

Chlorophenols from wood preservatives in broiler house litter

A survey of fresh shavings from 32 commercial broiler houses for 2,3,4,6-tetra-and pentachlorophenols has shown levels of 4 to 307 parts/million (mean 53) and 1 to 83 parts/million (mean 12), respectively. Most of this was lost during the period of growth of the chickens, residual levels of 0 to 5.6 parts/million (mean 0.7) and 0 to 4.1 parts/million (mean 0.3), respectively, being present in the spent litter. Only traces of the corresponding anisoles were found in a few samples. Observations on the source of these chlorophenols, their implications in relation to musty taint in chickens and the route by which they are lost from the litter are discussed.     

Effect of Processing Conditions on Styrene-Butadiene-Styrene-Thermoplastic Rubber

The effects of shear rate, extrusion temperature and heat treatment on a lamellar triblock copolymer of styrene-butadiene-styrene were studied using extrudates from a capillary rheometer. The rheological behaviour is mainly non-Newtonian in the region studied and the flow curves can be time-temperature reduced. The quality of the domain structure PS phase was measured mechanically in terms of the stress at yield and optically by birefringence. Some of the factors considered during the analysis of the results are: rearrangement of the imperfect original domain structure taking place in the barrel, before extrusion, for temperatures higher than 145°C; partial destruction of this pre-developed structure during extrusion; orientation of the chains during extrusion and under some conditions, the development of sharkskin on the surface of the extrudate. The heat treatment induces the copolymer to undergo three processes: internal stress relaxation (～135°C); rearrangement of the imperfect domain structure (145°CT240°C); and crosslinking in the rubbery phase (T200°C).     

Semantics at a glance: Is the right hemisphere special?

32 undergraduate Ss made an odd/even judgment to a single lateralized logograph, an Arabic numeral. All Ss were right-handed and had normal or corrected-to-normal vision. Stimuli were computer generated; Ss were shown the 8 Arabic numerals used by D. Besner et al (1986). Each S was tested with 1 block for each response hand. Data suggest that the left and right hemispheres are equally efficient at extracting meaning from at least some simple, highly familiar logographs. Particularly notable are the consistent reaction time (RT) differences between the left visual field and right visual field conditions for each response hand condition. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shaping futures: A dialogue on chemical engineering education

Engineering as a discipline, profession, practice, and area of study continues to add substantial value in an increasingly complex world. With continually evolving complexity around the planet, such as the need for massive energy transition, global health technologies, or sustainable food systems, how might engineering education practices and theory be considered within these rapid and necessary changes? This paper presents an experiment of co-creation through experiential reflection about the state of chemical engineering education. Four chemical engineering professors engaged in a dialogue, facilitated by a researcher in education, through collaborative and actionable research. This dialogue uncovered innovative possibilities, educational themes, experiences, and opportunities for others in the profession to consider. The process of dialogue also encouraged the development of an imaginative future sense-making, known as futuring, through a collective experience. The findings reveal instructive perspectives on the shape of chemical engineering education that should be of value not only to engineers, but also other professionals, practitioners, or those in various science, technology, and math fields.     

Hazardous waste disposal in New Zealand

The quantities of hazardous wastes generated in New Zealand are relatively small, both in total volume and on a per capita basis: they consist principally of liquids and solids derived from primary industries such as horticulture and forestry, and from the Petroleum, chemical and manufacturing industries. There is no satisfactory inventory of hazardous waste quantities or relative toxicity at the national level, nor is there any central coordinating organisation responsible for the implementation of sound management strategies. Current legislation involves several Government departments in statutory or advisory roles connected with hazardous waste management, but administration of disposal practices devolves to regional and local authorities. The occasional uncontrolled discharge of chemical wastes, unsatisfactory past practices regarding landfill siting and leachate management, and the development of major petrochemical industries, together require better coordinated and enforced policies concerning hazardous waste disposal. The most widely advocated method of hazardous waste disposal for New Zealand is codisposal in appropriately sited and controlled landfills, with particular emphasis on protection of freshwater resources, both surface and subsurface. The secure landfill solution adopted for the Waireka chemical dump site near New Plymouth demonstrates that containment is a necessary management strategy in particular situations: alternative methods of disposal such as incineration of certain intractable wastes should also be promoted as technically feasible and environmentally acceptable. Greater use of replacement, recycling or reprocessing must be encouraged in order to minimise the quantities, and toxicity of hasardous wastes requiring disposal in New Zealand.