Behavioral comparisons of liked and disliked hyperactive children in play contexts and the behavioral accommodations by their classmates.

This study examined the behavioral differences among liked and disliked hyperactive children and their normal peers during joint activities. 25 hyperactive children and 39 normal control subjects were selected and observed in high- and low-structured play settings (counterbalanced for order) in one of 3 dyadic groupings (10 liked hyperactive children, each with a control; 15 disliked hyperactive children, each with a control; and 7 control–control pairs). For the most part, the differences observed did not depend on setting or gender comparisons. Hyperactive children were more active, talkative, and physically off-task than their peers, but they made fewer positive social statements. Disliked hyperactive children made more negative statements with accompanying negative physical interactions. Specifically, in response to disliked hyperactive children, normal partners became more negative and active, were less talkative and cooperative, and engaged in more solitary play than when playing with other normal children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical implications of research on brief dynamic psychotherapy II. How the therapist helps or hinders therapeutic progress.

In this second of a two-part article, we describe how the therapist's interpretations promote therapeutic progress. Any therapist behavior that is in accord with the patient's plan will be helpful to the patient, but interventions that are at cross purposes with the patient's plan will not be helpful. The implications of the plan concept for brief dynamic therapy are described and contrasted with other key technical, concepts such as transference interpretations, therapeutic alliance, and interpretive activity. The importance of understanding the patient's plan and intervening in accord with it are illustrated in several case vignettes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure-resilient transaction management in multidatabase

Failure recovery in a multidatabase environment is addressed. It is shown that local autonomy considerations force the designer of a multidatabase system to trade off certain desirable properties to achieve reliability for transaction management. Representative techniques in the research literature are contrasted and compared. The author's approach to the problem is described     

Remarks on “some comments on concurrent readers and writers” by Reidar Conradi

Summary The Synchronization primitive P ^* was introduced by Conradi in order to present a more compact and efficient algorithm for synchronization of concurrent readers and writers. Unfortunately, Conradi's solutions fail when the conventional definitions of semaphores are used in conjunction with this primitive. This paper proposes a definition of the semaphore operations P, V and P ^* that make Conradi's readers-writers solutions correct. This definition is compatible with the definition given by Dijkstra.This work was partially supported by the National Science Foundation Grant Number MCS7702463     

Mathematical Modeling of Drying of Liquid/Solid Slurries in Steady State One-Dimensional Flow

A mathematical model of simultaneous mass, heat and momentum transfer for two-phase flow of a gas and a solid/liquid slurry was developed. The model was applied to calculation of the drying process of coal-water slurry droplets in a gas medium in a steady one-dimensional flow. The model was based on the well-known two-stage drying process for slurry droplets. After the first period of drying, in which the evaporation rate is controlled by the gas phase resistance, the evaporating liquid diffuses through the porous shell (crust) and then, by convection, into the gas medium. Inside the dry external crust of the drop, a wet central core forms, which shrinks as evaporation proceeds. The temperature of the slurry droplet rises. The process ends when the temperature of the dry outer crust reaches the coal ignition temperature in the case of combustion or when the moisture of the particle reaches the final required moisture. The developed model was based on one-dimensional balance equations of mass, energy and momentum for the liquid/solid and gas phases. The system of governing equations was represented by first-order differential equations and solved simultaneously. The numerical solution of the governing equations was obtained using Gear's method. The model permitted calculation     

Mariposa: a wide-area distributed database system

The requirements of wide-area distributed database systems differ dramatically from those of local-area network systems. In a wide-area network (WAN) configuration, individual sites usually report to different system administrators, have different access and charging algorithms, install site-specific data type extensions, and have different constraints on servicing remote requests. Typical of the last point are production transaction environments, which are fully engaged during normal business hours, and cannot take on additional load. Finally, there may be many sites participating in a WAN distributed DBMS. In this world, a single program performing global query optimization using a cost-based optimizer will not work well. Cost-based optimization does not respond well to site-specific type extension, access constraints, charging algorithms, and time-of-day constraints. Furthermore, traditional cost-based distributed optimizers do not scale well to a large number of possible processing sites. Since traditional distributed DBMSs have all used cost-based optimizers, they are not appropriate in a WAN environment, and a new architecture is required. We have proposed and implemented an economic paradigm as the solution to these issues in a new distributed DBMS called Mariposa. In this paper, we present the architecture and implementation of Mariposa and discuss early feedback on its operating characteristics. Edited by Henry F. Korth and Amith Sheth. Received November 1994 / Revised June 1995 / Accepted September 14, 1995     

Efficient Biocatalytic Synthesis of (R)‐Pantolactone

Screening for stereoselective cyanohydrin synthesis in 96‐well plates was employed in the development of an efficient, pH‐stable hydroxynitrile lyase for the conversion of sterically hindered aliphatic aldehydes. Site‐saturation mutagenesis (SSM) resulted in a powerful catalyst for the stereoselective conversion of hydroxypivalaldehyde and pivalaldehyde to their corresponding (R)‐cyanohydrins (ee >97%) which are used as chiral building blocks (e.g., for pantothenic acid production). Furthermore, redesigning the PaHNL5 gene and improving its expression by Pichia pastoris with the help of a new P_AOX1 promoter variant and the helper protein PDI (protein disulfide isomerase) led to elevated amounts of today’s most efficient biocatalyst for vitamin B₅ synthesis.