Amino Acids 785, 787 of the Na+/H+ Exchanger Cytoplasmic Tail Modulate Protein Activity and Tail Conformation

The mammalian Na⁺/H⁺ exchanger isoform 1 (NHE1) is a plasma membrane protein ubiquitously present in humans. It regulates intracellular pH by removing an intracellular proton in exchange for an extracellular sodium. It consists of a 500 amino acid membrane domain plus a 315 amino acid, regulatory cytosolic tail. Here, we investigated the effect of mutation of two amino acids of the regulatory tail, Ser⁷⁸⁵ and Ser⁷⁸⁷, that were similar in location and context to two amino acids of the Arabidopsis Na⁺/H⁺ exchanger SOS1. Mutation of these two amino acids to either Ala or phosphomimetic Glu did not affect surface targeting but led to a slight reduction in the level of protein expressed. The activity of the NHE1 protein was reduced in the phosphomimetic mutations and the effect was due to a decrease in Vmax activity. The Ser to Glu mutations also caused a change in the apparent molecular weight of both the full-length protein and of the cytosolic tail of NHE1. A conformational change in this region was indicated by differential trypsin sensitivity. We also found that a peptide containing amino acids 783–790 bound to several more proximal regions of the NHE1 tail in in vitro protein interaction experiments. The results are the first characterization of these two amino acids and show that they have significant effects on enzyme kinetics and the structure of the NHE1 protein.     

National Conference on Postdoctoral Training in Professional Psychology.

The Ann Arbor Conference on postdoctoral training (held in October 1992) was the 1st national conference to focus on the articulation of standards for postdoctoral education and training in professional psychology. Experts in education, practice, and credentialing drafted a policy document addressing the purposes of postdoctural training; entrance requirements; program content, structure, and organization; supervision; faculty–staff; evaluation mechanisms; and recommendations for the promotion of excellence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning the Value of a New Currency From Prices.

In European countries, field studies investigate how citizens acquire knowledge of the new currency, the euro. In 3 laboratory experiments, the authors recruited 168 undergraduates to examine whether such accurate knowledge is acquired from learning prices in the new currency. The results show fast learning of prices of duration of cellular phone calls (quantity) when the prices were proportional to quantity. Inferences of call duration from given prices were likewise found to be accurate. Lower accuracy was however observed for one-to-many mappings of quantity on price and the inverse one-to-many mappings of price on quantity. Price variation may be an important reason for the difficulty in learning the value of the new currency observed in field studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure-activity relationships between stimulus molecule and response of a pheromone receptor cell in turnip moth,Agrotis segetum

The response of an antennal receptor cell of the turnip moth,Agrotis segetum, was recorded during stimulation with a series of (Z)-7-dodecenyl acetate analogs with structural variations of the acetate group. The investigated receptor cell is known to be highly selective to (Z)-7-dodecenyl acetate. All parts of the acetate group were found to be of great importance for full biological activity. The results indicate very strict requirements on the shape of the polar functional group, as well as on its electron distribution for a successful interaction with the antennal receptor cell.     

A least third-order cumulants objective function

A novel Least Cumulants Method is proposed to tackle the problem of fitting to underlying function in small data sets with high noise level because higher-order statistics provide an unique feature of suppressing Gaussian noise processes of unknown spectral characteristics. The current backpropagation algorithm is actually the Least Square Method based algorithm which does not perform very well in noisy data set. Instead, the proposed method is more robust to the noise because a complete new objective function based on higher-order statistics is introduced. The proposed objective function was validated by applying to predict benchmark sunspot data and excellent results are obtained. The proposed objective function enables the network to provide a very low training error and excellent generalization property. Our results indicate that the network trained by the proposed objective function can, at most, provide 73% reduction of normalized test error in the benchmark test.     

Shape From Shading by Using Neural Based Colour Reflectance Model

In this Letter, a new methodology for Colour Shape From Shading problem is proposed. The problem of colour SFS refers to the well-known fact that most real objects usually contain mixtures of diffuse and specular colour reflections. In this paper, these limitations are addressed and a new colour neural based model is proposed. The proposed approach focuses on developing a generalized neural based colour reflectance model. Experimental results on synthetic coloured objects and a real coloured object were performed to demonstrate the performance of the proposed methodology.     

Predicting wet weather accidents

The development of a wet weather safety index, WWSI_e, is presented. WWSI_e is an empirical formulation based on prediction equations for wet accident rates. These equations were derived by multiple regression techniques from a survey of 68 highway segments in Texas. These segments covered a range of wet accident rates from zero to 40 accidents per year per mile. In general, much higher values of wet accident rates are observed in urban areas than in rural areas. Also, the sensitivity to pavement skid resistance is much higher in urban than in rural areas. The findings and developments reported warrant a restructuring of many state programs to reduce wet weather accidents. The Wet Weather Safety Index and associated equations represent a practical method of predicting wet accident rates as a function of traffic, road geometric, and pavements surface characteristics. These predictive equations may be cautiously used to determine accident reduction due to specific remedial measures. These new developments can be integrated into a comprehensive plan to reduce wet weather accidents, a plan which should greatly increase the effectiveness of those resources devoted to this objective.     

A model for selection of attributes for automatic pattern recognition. Stepwise data compression monitored by visual classification

Based on a pattern recognition study of human chromosomes a model is proposed for selection of attributes for automatic pattern recognition. The basic concept is a stepwise data compression, each step being monitored for loss of significant information by visual classification of the compressed pattern. The attributes resulting from a number of data compression steps will retain the information allowing the patterns to be classified automatically.