Effect of communication media on developmental relationships: Self-reported and observed behaviors

This study examined the effect of four communication modes (computer-based video teleconferencing, computer-based electronic chat, telephone, and face-to-face) on developmental interactions between dyads; specifically on the transmission of psychosocial versus instrumental information. The dyads consisted of undergraduates at a southeastern university. One member of the dyad was an incoming first year student; the second member was an upper division student who served as a developmental coach. The study was experimental in design, which controlled the amount of interaction, the frequency of interaction, and prior acquaintanceship of the dyadic pair. The small amount of variance attributable to communication mode suggests that people matter more than the machines. Specifically, in terms of implementing non-face-to-face developmental programs, it might be more useful to focus on reducing the variability in the coaches’ behaviors through selection or training, than to focus on communication mode. Additionally, independent observers watched and rated the dyadic interactions to provide a third point of view. There was very little overlap between coach and trainee perceptions, although there was considerable agreement between the raters’ and coaches’ ratings.     

Sorption-desorption of ionogenic compounds at the mineral-water interface: study of metal oxide-rich soils and pure-phase minerals

Sorption of the ionic compounds 2,4-D and quinmerac onto iron oxide-rich, variable charged soils was strongly influenced by mineralogy, particularly soil iron and aluminum oxides, whereas sorption of the neutral norflurazon was only related to total soil C. An appreciable fraction of the mass sorbed in stirred-flow studies was easily desorbed by deionized water, and desorption of ionic compounds was initially more rapid than sorption. This sorption-desorption behavior, although contrary to desorption hysteresis commonly observed in batch studies, suggests that the reversibly sorbed fraction is weakly bound to the soil surface. 2,4-D sorption to iron oxide-rich soils and pure-phase metal oxides appears to be driven by nonspecific electrostatic attraction, with specific electrostatic attraction and van der Waals interactions being secondary. Both the carboxylate and the heterocyclic N groups may participate in sorption of quinmerac, facilitated by specific and nonspecific electrostatic attraction and surface complexation. The heterocyclic N, amine, and carbonyl groups of norflurazon do not appear to interact with soil minerals.     

Development and validation of dry reagent time-resolved fluoroimmunoassays for zeranol and alpha-zearalenol to assist in distinguishing zeranol abuse from Fusarium spp. toxin contamination in bovine urine

Zeranol, an oestrogenic growth promoter in food animals, is banned within the European Union (EU). However, commercially available immunoassay kits for zeranol cross-react with toxins formed by naturally occurring Fusarium spp. fungi, leading to false-positive screening results. This paper describes the validation of a specificity enhanced, rapid dry reagent time-resolved fluoroimmunoassay (TR-FIA) for zeranol (recovery 99%, limit of detection 1.3 ng ml(-1)) demonstrating that up to 150 ng ml(-1) of Fusarium spp. toxins in urine do not lead to false-positive results. This assay will assist EU Member States to implement Council Directive 96/23/EC, which requires states to monitor for potential abuses of zeranol. A similar TR-FIA for the Fusarium spp. toxin alpha-zearalenol, using the same sample extract, is also described (recovery 68%, limit of detection 5.6 ng ml(-1)). Only the addition of diluted sample extract is required to perform these dry-reagent TRFIAs, the results being available within 1h of extract application. The EU-funded project 'Natural Zeranol' (FAIR5-CT97-3443) will use these fluoroimmunoassays to screen bovine urine in four Member States to gather data on the seasonality of Fusarium spp. toxin contamination of urine and the incidence of zeranol screening test positives.     

Critical Behavior in the Low-Energy Spin Fluctuations in High-Tc Superconductors

We study the spin fluctuations of pure and Zn-substituted La_{2 – x} Sr _x CuO₄ using the muon spin relaxation technique. Superconductivity is found to coexist with low-frequency spin fluctuations over a large region of the superconducting phase diagram. The characteristic temperature of spin fluctuations detected by SR decreases with increasing x and vanishes above a critical doping x _c 0.19. This value of x _c coincides with the doping at which the normal state pseudogap extrapolates to zero. These results are discussed in terms of a quantum transition that separates the superconducting phase diagram of high-temperature superconductors into two distinct ground states.     

Gel protein capillary extraction apparatus. electronic protein transfer

A gel protein capillary extraction apparatus is developed and demonstrated for its rapid and effective transfer of SDS-protein complexes from polyacrylamide gel to a fused-silica capillary. The small dimensions of capillary columns permit the application of high voltages for achieving rapid and effective transfer of gel proteins. Furthermore, the fused-silica capillaries are internally coated with polyacrylamide for the elimination of electroosmotic pumping and protein adsorption onto the capillary wall. The extracted proteins are present in a highly concentrated solution plug as the result of field amplification and sample stacking during the extraction process. Three model proteins, including cytochrome c (14 kDa), ovalbumin (45 kDa), and beta-galactosidase (116 kDa), are visualized using coomassie blue staining and electrophoretically extracted from the gels with protein loading as low as 50 ng. The SDS-cytochrome c complexes extracted from a 50-ng protein loading are concentrated in a 30-nL solution plug inside the capillary with an estimated concentration of 0. 1 mg/mL or 10(-5) M. The capillary format allows the straightforward integration of a miniaturized trypsin-membrane reactor for on-line proteolytic digestion and ESI-MS analysis for protein/peptide identification.     

Last clock

The Last clock displays a space's history and rhythm. Trails behind its hands paint the clock face with a video feed, creating a mandala of archived time. The Last clock began as an investigation into representations of time. The goal was to use the mutable properties of digital technology, hoping to create something aesthetically pleasing, interesting, and ever changing without having to succumb to randomness. The clock reveals the rhythm of events and spaces. It provides a record of and a means of reflection for what is happening and what has happened. With the Internet-connected streaming version, the clock can connect two or more remote spaces so that people feel a sense of each other's presence. The clock does not show precisely the activity in the space, just a filtered version of it. Beyond being an aesthetic object, Last serves a real purpose as a display that shows an overview of a given space's dynamics and history. By borrowing the form of a traditional analog clock, Last becomes an easy-to-read visualization of complex information, which includes the type of activity captured, the pace and volume of motion, and the point in time that this activity happened. it shows all this information in a continuously updated, live, single image. This article is available with a short video documentary on CD-ROM.     

Bringing forth worlds

Kress encourages us to understand writing as “transformative engagement in the world,” and his emphasis on the materiality of modes draws our attention to the multiple possibilities offered by different materials and sensory channels. Writing involves the transformation of all aspects of the resources for meaning; thus writing is always an ethical act, and the worlds that different cultures and communities bring forth through their semiotic work offer different possibilities of being.     

Development and Application of a Phosphorus Model for a Shallow Oxbow Lake

A three-dimensional numerical model was developed for simulating the phosphorus concentration in shallow lakes. In this model, the computational domain was divided into two parts: the water column and the bed sediment layer. The processes of mineralization, settling, adsorption, desorption, bed release (diffusion), growth, and death of phytoplankton were taken into account, and the concentration of organic phosphorus, phosphate, and related water quality constituents was simulated. The concentrations of adsorbed (particulate) and dissolved phosphate due to adsorption-desorption were calculated using two formulas derived based on the Langmuir equation. The release rate of phosphorus from the bed sediment layer was calculated by considering the effects of the concentration gradient across the water-sediment interface, pH, temperature, dissolved oxygen concentration, and flow conditions. The adsorption and desorption of phosphate from sediment particles, as well as its release from bed sediment, were verified using laboratory experimental data. The model was calibrated and applied to Deep Hollow Lake in the Mississippi alluvial plain. The simulated trends and magnitudes of phosphorus concentration were compared with field observations. The simulation results show that there are strong interactions between sediment-related processes and phosphorus concentration.