From the editor.

Introduces this special issue of the International Journal of Play Therapy, which is divided into three sections. The first presents a view of the future of play therapy; that is, what the profession of play therapy will become in the next century. The second section is intended to provide a context for the research award article. The third section is the 1998 Student Research Award. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advanced Mutasynthesis Studies on the Natural α‐Pyrone Antibiotic Myxopyronin from Myxococcus fulvus

Myxopyronin is a natural α‐pyrone antibiotic from the soil bacterium Myxococcus fulvus Mx f50. Myxopyronin inhibits bacterial RNA polymerase (RNAP) by binding to a part of the enzyme not targeted by the clinically used rifamycins. This mode of action makes myxopyronins promising molecules for the development of novel broad‐spectrum antibacterials. We describe the derivatization of myxopyronins by an advanced mutasynthesis approach as a first step towards this goal. Site‐directed mutagenesis of the biosynthetic machinery was used to block myxopyronin biosynthesis at different stages. The resulting mutants were fed with diverse precursors that mimic the biosynthetic intermediates to restore production. Mutasynthon incorporation and production of novel myxopyronin derivatives were analyzed by HPLC‐MS/MS. This work sets the stage for accessing numerous myxopyronin derivatives, thus significantly expanding the chemical space of f α‐pyrone antibiotics.     

Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females

Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Surface impedance of clean type II superconductors

The surface impedance of clean type II superconductors in calculated in fields nearH _c2 . A marked dependence of the surface impedance on mean free path1, is predicted which is consistent with experiment. The dependence of the surface impedance on the direction of propagation of the microwave is also discussed.     

Infraadditive diuretic efficacy of concurrent aminophylline and frusemide

Male albino rats weighing between 150-225 gm fasted over night but freed having water ad libitum were used to assess the diuretic efficacy of intramuscular aminophylline and frusemide separately and concurrently after intraperitoneal 10 ml of distilled water loading. The normal rate of diuretic weight loss was less augmented by aminophylline and more augmented by frusemide. The diuretic response was more by the concurrent intramuscular administration of aminophylline and frusemide in comparison with that due to either drug alone. However, the observed diuretic response of the two drugs administered concurrently was lesser (infraadditive) than the sum of the individual diuretic response (additive).     

Design issues for a single core transformer thyristor controlledphase-angle regulator

Power electronics have become increasingly reliable and cost effective at the transmission voltage level. New applications of FACTS devices are just emerging, the thyristor controlled phase-angle regulator (TCPAR) being one of them. This paper identifies and discusses several gate control and system issues for application of a single core transformer thyristor controlled phase-angle regulator. Alternative TCPAR designs are proposed     

Early language behavior in Negro children and the testing of intelligence.

"Forty Negro children examined by a white examiner were found to have lowered language scores on third examination at two years of age. This was apparently due to lack of verbal responsiveness, rather than poor comprehension of language. This apparent early awareness of racial differences and loss of rapport has serious implications in the field of ethnic group psychology, particularly in the use of verbal items on intelligence testing." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negotiating Boundaries. Configuration Management in Software Development Teams

Using case-study material from threesmall software development teams, this paper analysesthe regionalisation of design spaces. Its mainpurpose is to understand problems and practices ofcooperative work in such spaces. Configurationmanagement is used to denote both a practice andsupporting software tools and their relationship. Amajor concern is how to develop practices and toolsthat support cooperation across multipleorganisational and social boundaries whilesimultaneously being respectful of regionalisations.