Scratch and match: Pigeons learn matching and oddity with gravel stimuli.

Two groups of 4 pigeons learned either matching-to-sample or oddity-from-sample by digging in white and black gravel for buried grain. Learning occurred as early as Trial 11, and acquisition was accelerated by as much as 100-fold compared with learning in traditional key-peck environments. Control experiments showed that performance was not controlled by cues other than the gravel stimuli and was not due to distributed practice effects of 8 trials per day and longer intertrial intervals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Torsion of intraperitoneal renal transplants: imaging appearances

OBJECTIVE: Torsion of a renal transplant is a rare complication with nonspecific clinical manifestations. Prompt detection is necessary to allow surgical treatment and to preserve renal function. We describe the radiologic appearances of torsion of intraperitoneal renal transplants in patients who have undergone simultaneous renal and pancreatic transplantation or dual renal transplantation. CONCLUSION: Renal transplant torsion should be suspected when a change in renal axis associated with abnormal perfusion occurs in an intraperitoneal kidney.     

Phospholipid metabolism inNeisseria gonorrhoeae: Phospholipid hydrolysis in nongrowing cells

Hydrolysis of cell envelope phospholipids was demonstrated in cells of both autolytic and nonautolytic strains ofNeisseria gonorrhoeae that were labeled during growth in the presence of [³H] acetate. The label incorporated into the cellular phospholipids was located exclusively in the fatty acid acyl side chains. Labeled cells were incubated for 2 hr in N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid buffer, pH 8.5, containing various additions, and then examined for distribution of³H in lipids. Ca⁺⁺ selectively stimulated the deacylation of phosphatidylethanolamine (PE), whereas Mn⁺⁺ stimulated the deacylation of phosphatidylglycerol (PG). Hydrolysis of phosphatidylethanolamine by phospholipase A was accompanied by the accumulation of lysophosphatidylethanolamine (LPE) and free fatty acids in the cells. Free fatty acids accumulated to a greater extent than lysophosphatidylethanolamine, suggesting that the latter was further hydrolyzed to glycerophosphorylethanolamine (GPE) and free fatty acids by a lysophospholipase. Methanol, ethanol, propanol, and isopropanol, added at concentrations which inhibited growth by 50%, stimulated phospholipase A, but not lysophospholipase activity. Differences in heat inactivation, metal ion requirements, and pH optima suggested that phospholipase A activities with phosphatidylethanolamine or phosphatidylglycerol as substrate and lysophospholipase may be separate enzymes.     

An instrumental variable method for model order identification

The paper describes a simple instrumental variable method for identifying the structure of a wide class of time-series models. The method is aimed at providing a parametrically efficient (parsimonious) model structure which will lead to a combination of low residual error variance, i.e. a good explanation of the data, and low parametric estimation error variance (as measured by some norm associated with the covariance matrix of the estimation errors). It can be applied to single input-single output and multivariable systems using either discrete or continuous-time series models. It can also function as a recursive (on-line) test for reduction in model order.     

Energy resources—are we planning for the future?—a review

Many governments are at present attempting to formulate energy strategies for ensuring future supplies. the debate over nuclear power is continuing and ‘pollution-free’ alternative energy sources are also being considered. Points for and against each of the possible energy sources are discussed here and the possible hazards of nuclear power (e.g. radioactivity) are compared with the possible dangers of ‘free-energy’ sources (e.g. an increased ‘greenhouse’ effect). the importance of an integrated energy policy is stressed. Such a policy does not rely on a single energy source but utilizes the full spectrum of possibilities and can incorporate the more immediate concepts of energy savings.     

New technologies for solar energy silicon—Cost analysis of dichlorosilane process

New technologies for producing polysilicon are being developed to provide lower cost material for solar cells which convert sunlight into electricity. This article presents results for a process to produce dichlorosilane (DCS) as a silicon source material for solar energy silicon. Major benefits of dichlorosilane include faster chemical vapor deposition of silicon and higher chemical equilibrium yield for silicon production. Hemlock Semiconductor Corporation has recently demonstrated that under comparable conditions and for rods up tp 42 mm dia., deposition rates and conversions for dichlorosilane are approximately twice those for trichlorosilane. Cost, sensitivity and profitability analysis results are presented based on a preliminary process design of a plant to produce dichlorosilane by the DCS process. Profitability analysis indicates a sales price of $1.29–$1.47/kg of dichlorosilane (1980 dollars) at a 0–15 per cent discounted cash flow rate of return after taxes. These results indicate good potential for dichlorosilane as a silicon source material to provide lower cost material for solar cells.     

Enhancing protein and sugar release from defatted soy flakes using ultrasound technology

This research focused on the use of high-power ultrasound prior to soy protein extraction to simultaneously enhance protein and sugar release in the extract. Defatted soy flakes dispersed in water were sonicated for 15, 30, 60 and 120 s using a bench-scale ultrasound unit. The ultrasonic amplitudes used were: 0, 21, 42, 63 and 84 μm_pp (peak-to-peak). The respective power densities were 0.30, 0.87, 1.53 and 2.56 W/ml. Scanning electron micrographs of sonicated samples showed the structural disruption of soy flakes. The particle size decreased nearly 10-fold following ultrasonic treatment at high amplitudes. Sonication at high amplitude for 120 s gave the highest increase in total sugar released (50%) and protein yield (46%) when compared with non-sonicated samples (control). Ultrasonic pretreatment was also carried out with and without cooling for temperature moderation. The heat generated during sonication had no significant effect on protein and sugar release from defatted soy flakes. The use of ultrasound can significantly improve protein yield and reduce the overall cost of producing soy protein from flakes.     

An Analytical Model for the Transfer Characteristics of a Polycrystalline Silicon Thin-Film Transistor With a Double Exponential Grain-Boundary Trap-State Energy Dispersion

For a thin-film transistor (TFT) built on excimer-laser crystallized polycrystalline silicon, the dependence of the effective ldquograin-boundary mobilityrdquo on the gate-to-source voltage can be divided into two subregimes exhibiting different power-law characteristics. An expression for the effective mobility is developed using a procedure previously proposed for a TFT built on polycrystalline silicon exhibiting only single power-law dependence. The additional power-law component is reflected in the model by a pair of measurable and physically meaningful parameters. The procedure for determining these parameters is described and demonstrated. Both the measured and calculated transfer characteristics are reported and compared. The double power-law dependence implies a grain-boundary trap-state energy dispersion characterized by two exponential functions. This is presently verified.