Information-processing demands of transitive inference.

Investigated the information-processing demands of transitive inference problems with a probe reaction-time (RT) secondary task. Two versions of a primary task were used: the standard 3-term inference problem and a matched verification task that did not require premise integration. In the 1st 2 experiments, with a total of 40 undergraduates, the premise and target-matching components of the primary task were presented sequentially. Results indicate that for the transitive inference task, probe RT was especially slow when the probe occurred during the 2nd premise phase, but no such effect was found with the matched verification task. This implies that premise integration imposed an increased load on processing resources. A 3rd experiment with 10 undergraduates showed that the processing demand associated with premise integration also occurred with simultaneous presentation. Other variations in problem form (e.g., premise markedness, negation, and pivot search) did not influence probe RT, although they are known to affect solution time. It is concluded that solution time and measures of processing load may be independent. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cost-efficiency of psychology internship programs: Another look at the monetary and nonmonetary considerations.

Suggests modifications in a formula proposed by R. Weiskopf and J. P. Newman (see record 1983-04314-001) to calculate the revenue produced by an intern and the cost of an intern and describes the application of the revised formulas in a mental health center. A graph that can be used to plan service requirements and other parameters of a program is presented. In addition to a monetary evaluation, some nonmonetary benefits and costs of hosting an internship program are discussed. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors influencing the reduction of barium sulphate

The reduction of pure barium sulphate and of barytes to barium sulphide and soluble barium compounds has been carried out in an indirectly heated tube furnace using carbon as the reducing agent. Increasing the reduction temperature increases the yield of barium compounds. The best yield is obtained with a reduction period of 1–2 h at 850–1100°C, while excluding air during the reduction and subsequent cooling process. The influence of ferric oxide and silica impurities on the yield of soluble barium products has been studied at a reduction temperature of 1000°C. Both reduce the yield of soluble barium products, ferric oxide having a much greater effect. The effect of these two impurities is not additive, silica minimizing the effect of ferric oxide.     

Developments in rock-breaking techniques

A problem with secondary breaking at an Australian mine led to a study of new rock-breaking technologies. Many of the techniques being developed had emerged from the thrust in the U.S.A. for continuous drill-break excavation. Such approaches to rock breaking highlighted the applicability of what normally would be classified as tunnelling techniques, to the secondary breaking sector—and possibly the reverse. The investigations for suitable technologies led directly to the development of two improved rock-breaking methods specifically targeting secondary breaking, one of which could be applied to continuous excavation.     

Detection of cytotoxic activity on Vero cells in clinical isolates of Serratia marcescens

Cytotoxin production was studied in 60 Serratia marcescens strains isolated from hospitalized patients. Association of cytotoxic activity with serotype, source of isolation and presence of plasmids was also evaluated. Thirteen of the 60 S. marcescens strains produced a cytotoxic effect on Vero cells. These strains were isolated from distinct clinical sources and classified into seven different serotypes (O1:H7; O4:NM; O10:NT; O19:NM; O6,14:H4; O6,14:NM and O6,14:H1). No relationship was observed between cytotoxic activity and clinical source or serotypes of the strains. Plasmids from five cytotoxin-producing S. marcescens strains were transferred to E. coli K12/711. The transconjugants did not exhibit cytotoxicity, indicating that the cytotoxic effect is not plasmid-mediated among these strains. Although a cytotoxic activity was demonstrated in filtrates of some S. marcescens strains, further studies should be performed to assess the role of this toxin in pathogenesis.     

High-resolution HLA typing for the DRB3/4/5 genes by sequence-based typing

The mechanisms underlying the circadian rhythm of methotrexate (MTX)-induced toxicity (body weight loss and leukopenia) were investigated from the viewpoints of the sensitivity of living organisms to the drug and the pharmacokinetics of the drug. ICR male mice were housed in a standardized light-dark cycle (lights on at 0700, off at 1900) with food and water ad libitum. The body weight loss after an intraperitoneal injection of MTX (400 mg/kg) was more serious in the late dark period and the early light period and milder in the late light period and the early dark period. The MTX-induced leukopenia was more serious in the late dark period and the light period and milder in the early dark period. Lower toxicity was observed when DNA synthesis, dihydrofolate reductase (DHFR) activity in bone marrow cells and folate level in plasma decreased, and higher toxicity was observed when they increased. There was a significant circadian rhythm in plasma MTX concentration, with a higher level in the light period and a lower level in the dark period. The circadian rhythm of plasma MTX concentration was associated with that of MTX-induced toxicity. The present study suggests that the circadian rhythm of MTX-induced toxicity is caused by that of the sensitivity of living organisms to the drug and the pharmacokinetics of the drug.