Development and validation of minicourses in the telecommunication industry.

Beginning in the early 1970s, American Telephone and Telegraph (AT&T) and the associated Bell companies have used minicourses for selecting personnel in a variety of jobs involving new technologies. The minicourse approach uses material representative of training content to assess the candidate's ability to acquire knowledge relevant to full-scale training and the job. A major advantage of the minicourse approach is the ability to implement a selection procedure concurrent with the introduction of a new training program. Although minicourses are initially validated using a content-oriented strategy, the AT&T model has included criterion-related validation where possible. The experience of AT&T with seven minicourses is discussed, and validities for training criteria and job performance are reported. Minicourses are a specific example of the general class of predictors known as trainability tests. The results of a meta-analysis indicate that validities for trainability tests are comparable with validities found for ability tests and work sample tests by Hunter and Hunter (1984). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Derivatives of Di-O-octanoylglycerol and mono-O-octylglycerol as modulators of protein kinase C and diacylglycerol kinase activities

Twelve analogs of 1,2-di-O-octanoylglycerol modified at C-3 and three quaternaryN-alkyl-ammonium derivatives of glycerol were synthesized. The compounds were testedin vitro as potential modulators of the calcium activated, phospholipid dependent protein kinase C (PKC) and diacylglycerol (DAG) kinase activities in order to understand the molecular interactions of these enzymes with their natural activators, inhibitors, or substrates. PKC activity was assayed by measuring histone H₁ phosphorylation, and the compounds synthesized were tested either in the presence (inhibitors) or in the absence (activators) of 1,2-di-O-octanoyglycerol analogs with the phosphatidylserine/Ca²⁺ mixture. DAG kinase activity was measured by the incorporation of phosphate into 1,2-di-O-oleoyl-sn-glycerol in the presence of the various analogs synthesized. In regard to PKC activity, the assays revealed that 1,2-di-O-octanoylglycerol analogs are inactive when modified at C-3 with groups which do not permit hydrogen bonding. Under our conditions, di-O-octanoylthioglycerol, which has been reported as inactive, was able to activate PKC in the presence of phosphatidylserine. It has been shown to give a synergistic activation with diacylglycerol and had no affinity for the phorbol ester receptor binding site, suggesting thatO-octanoylthioglycerol interacts with the enzyme at a different site from the phorbol ester receptor binding site. PKC and DAG kinase activities are inhibited byN-alkyl-ammonium compounds (IC₅₀ 24 μM) only when either two 8-carbon alkyl or acyl chains are present at the 1- and 2-positions of the glycerol backbone. The fact that these compounds have a strong effect on the binding of [³H]phorbol 12,13-dibutyrate to protein kinase C, and also inhibit DAG kinase, may suggest binding to the DAG site of the regulatory domain of PKC.     

Silicon carbide UV photodiodes

SiC photodiodes were fabricated using 6 H single-crystal wafers. These devices have excellent UV responsivity characteristics and very low dark current even at elevated temperatures. The reproducibility is excellent and the characteristics agree with theoretical calculations for different device designs. The advantages of these diodes are that they will operate at high temperatures and are responsive between 200 and 400 nm and not responsive to longer wavelengths because of the wide 3-eV bandgap. The responsivity at 270 nm is between 70% and 85%. Dark-current levels have been measured as a function of temperature that are orders of magnitude below those previously reported. Thus, these diodes can be expected to have excellent performance characteristics for detection of low light level UV even at elevated temperatures     

Relation between power and endurance for treadmill running of short duration

An exercise test was devised to investigate the relationship between power and endurance for treadmill running. The subjects were 19 males aged 21-25 yr (11 distance runners and 4 sprinters of provincial grade, and 4 non-competitive runners). Each subject ran to exhaustion on a treadmill at 15 km hr-1 at five different inclinations (31%-9%), giving maximum performance times in the range 10 s to 3 min. An iterative least-squares procedure was used to fit the following exponential model to each subject's data: It = I infinity + (I0-I infinity) exp (-t/tau), where It, I0 and I infinity are inclinations at time t = t, t = 0 and t----infinity, and tau is a time constant. The fit was excellent (r2 = 0.96-1.00). I0 and I infinity are interpreted as measures of maximum anaerobic (instantaneous) and maximum aerobic (continuous) power respectively. Inclinations corresponding to performance times of 10-180 s (I10-I180) were calculated from these parameters. Test-retest reliability was highest for I0-I30 (intraclass r = 0.97-0.94), lower for I60-I infinity (r = 0.89-0.84), and lowest for tau (r = 0.78). Good correlations were observed between I0-I30 and peak power in a 30 s all-out test on a cycle ergometer (r = 0.73-0.81), and between I180, I infinity and maximum oxygen consumption (r = 0.87, 0.81). The test may be useful for ranking or monitoring running performance for events of up to 1 min duration.     

The Deposition of Spray-Dried p-Galactosidase from Dry Powder Inhaler Devices

The object of this study was to evaluate the in vitro deposition properties of a model spray-dried protein (β-galactosidase) from a dry powder inhaler device (ISF inhaler). The stabilized spray-dried protein was evaluated alone and when blended with equal weights of (a) Avicel and (b) mannitol. The deposition properties were studied after exposure to environments of varying humidity using a twin impinger and a cascade impactor. The spray-dried material was extremely sensitive to humidity, with large reductions in respirable fraction occurring after storage at 43% relative humidity. The presence of a nonhygroscopic carrier (mannitol) did not prevent this reduction. There was no significant difference between the estimates of respirable fraction obtained using the cascade impactor and twin impinger for the material which had been stored in a dessicator. However, for the powders which had been exposed to environments of 43% relative humidity, the twin impinger was more reliable, as the cascade impactor results were adversely affected by entrainment of aggregates in the air stream.     

Oxidic precursors of molybdena supported on nickel and magnesium aluminate hydrotreating catalysts

The oxidic precursors of molybdena-based hydrotreating catalysts have been prepared using nickel and magnesium aluminates and characterized by laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS). Three series of supports (80, 120 and 140 m².g⁻¹) have been investigated. Their aluminate spinel structure was confirmed both by X-ray diffraction (XRD) and LRS. Nickel oxide and magnesia have also been detected on the low surface area systems. In both series, a surface deficit of the foreign cation has been observed relative to the Al³⁺ of the aluminate phase. This deficit was more pronounced for Ni²⁺. Deposition of molybdate species does not modify the surface composition of these supports and a monolayer-like coverage up to 4.5 to 5 Mo at.nm⁻² was obtained. Nickel added by impregnation was shown to interact with the supported oxomolybdate species, whereas the nickel of the support does not. These investigated supports closely resemble γ --- Al₂O₃ in the preparation of hydrotreating catalysts.     

Deformation of graphite at high pressures

In high pressure experiments, it is shown that the compression stress-strain curve of a porous polycrystalline graphite depends markedly on the confining pressure in the range 1–8 kb and that considerable volume changes occur during the deformation as well as during application of the pressure. There is also an almost complete recovery of both length and volume during release of the pressure after strains of up to 20 per cent. After allowing for the interaction with the stress-strain behaviour of the work associated with volume changes, it is concluded that, in addition to basal slip, frictional sliding on internal surfaces is an important mechanism of deformation, especially at the lower pressures, and that the deformation is accompanied by some process such as flexure of platelets which introduces the internal stresses responsible for the recovery effects.     

Les phenomenes de transport de masse dans la stratosphereMass transport in the stratosphereDie phänomene des massentransports in der stratosphäreявлeния пepeнoca мaccы в cтpaтocфepe

This paper describes various new experiments fulfilled in order to reach a better understanding on the mechanisms by which the low stratosphere pollutants are transported up to a higher altitude.     

Assessing Facial Symmetry and Attractiveness using Augmented Reality

Pattern Analysis and Applications - Facial symmetry is a key component in quantifying the perception of beauty. In this paper, we propose a set of facial features computed from facial landmarks...