Synthesis and photochemical stability of 1-phenylazo-2-naphthol dyes containing insulated singlet oxygen quenching groups

Although 1-arylazo-2-naphthols undergo direct and sensitised photochemical fading in solution by a singlet oxygen mechanism, the introduction of singlet oxygen-quenching substituents (N,N-dialkylaminomethyl-) affords no protection against fading, and in many cases accelerates photodegradation. This has been attributed to the high reactivity of the dialkylaminomethyl-groups towards hydrogen abstraction, thus rendering free radical modes of decomposition more favourable. In the presence of peroxide-radical scavengers the latter reactions are suppressed, and the dialkylaminomethyl-groups then show a protecting effect against fading by singlet oxygen.     

Relationship between job satisfaction and job performance between western and tribal Black employees.

Examined the effect of westernization on the job performance/job satisfaction relationship in 132 Black male 1st-level supervisors in 15 different South African factories. When the sample was split into western and tribal subgroups, the relationship between performance and satisfaction was significantly higher among western Ss. The 2 subgroups were also compared on measures of intrinsic motivation, instrumentality, and valence of job rewards. Because the western subgroup only obtained a significantly higher score on the measure of intrinsic motivation, it is suggested that it may be because they are more concerned about performing well than that the performance–satisfaction relationship is higher among western employees. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploring the dimensions of egocentricity in aircraft navigation displays.

Researchers explain a model of navigation that proposes that local guidance and global awareness are better supported by more, and less, egocentric displays, respectively. Greater egocentrism is created by perspective viewing, map rotation, and viewpoint positions that correspond to the axis of control. The model was tested in an experiment in which 40 pilots flew simulated landings with displays that varied the degree of egocentrism between a fully egocentric viewpoint, 3 distances of exocentric 3-dimensional viewpoints, and a 2-dimensional planar display. The results generally supported model predictions: The egocentric viewpoint supported best guidance, whereas the mid-distance exocentric viewpoint supported best global awareness. Implications of the model for the design of flight displays in particular, and navigational displays in general, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some responses of Chrysanthemum morifolium (cv.“hurricane”), grown as a year-round crop in a peat-sand substrate,to micronutrients and liming

The effects of a fritted micronutrient mixture on the growth and flowering of spray chrysanthemums (cv.“Hurricane”) were studied in relation to pH in a peatsand substrate (3:1 by volume). The treatments consisted of three rates of application of a fritted micronutrient mixture (0, 200, 500 g/m³) in factorial combination with four rates of liming (average pH values 4.2, 5.0, 6.3 and 7.1). Five successive crops were grown under conditions, including controlled day-length, used commercially for year-round chrysanthemum production. Bud initiation and development were greatly delayed in the absence of micro-nutrients, particularly at high pH, and some plants failed to flower. The proportion of marketable sprays was decreased by omission of micronutrients (P<0.001) and by liming (P<0.001), and those that were saleable were reduced in size. Omission of micronutrients decreased the numbers of flowers per spray (P<0.001). Plants grown without added micronutrients developed more leaves and bracts on their lateral shoots (P<0.001), particularly at high pH (6.3–7.1); the interaction between lime and micronutrients was significant at P<0.01. Leaf samples were analysed for micronutrient content (B, Fe, Mn, Cu and Zn). Symptoms of boron deficiency (“quilling” of the petals) were recorded and shown to be significantly correlated with the boron content of the leaves (P<0.001). The copper content of plants grown without added micronutrients was well below the published critical level, and this deficiency is considered responsible for many of the effects observed.     

Interfaces and programs for classroom experiments in biology

The advantages of the microcomputer as an instrument for the classroom laboratory — adaptability, price and its pedagogical role — are considered. Simple interfaces, including a tension transducer, are described for several physiological experiments. Programs can either be simple presentations of the data collected or be comprehensive with teaching modules, apparatus checks and data filing systems.     

Conditioning and extinction of tolerance to the hypothermic effect of ethanol in rats.

Examined the contribution of classical conditioning to tolerance to the hypothermic effect of ethanol in 56 male albino rats. During the tolerance acquisition phase, Ss were exposed at 4-day intervals to a distinctive set of environmental cues paired with injections of ethanol (1.4 g/kg, ip). Interspersed between these drug trials were exposures to an alternate set of cues paired with injections of saline. In addition, 3 groups experienced different amounts of stimulation and activity during drug exposure in order to determine whether "behavioral augmentation" of tolerance would occur. In subsequent tests, Ss were tolerant only in the presence of cues previously paired with ethanol. Moreover, this environmentally specific tolerance was associated with a conditioned hyporthermic response to placebo (saline) injections in the drug environment. An extinction procedure designed to weaken tolerance mediated by classical conditioning was also found to be effective. Evidence for conditioned tolerance was weakest in Ss experiencing low levels of activity during the initial drug exposure periods. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive correlates of third-grade skill in arithmetic, algorithmic computation, and arithmetic word problems.

The purpose of this study was to examine the cognitive correlates of 3rd-grade skill in arithmetic, algorithmic computation, and arithmetic word problems. Third graders (N = 312) were measured on language, nonverbal problem solving, concept formation, processing speed, long-term memory, working memory, phonological decoding, and sight word efficiency as well as on arithmetic, algorithmic computation, and arithmetic word problems. Teacher ratings of inattentive behavior also were collected. Path analysis indicated that arithmetic was linked to algorithmic computation and to arithmetic word problems and that inattentive behavior independently predicted all 3 aspects of mathematics performance. Other independent predictors of arithmetic were phonological decoding and processing speed. Other independent predictors of arithmetic word problems were nonverbal problem solving, concept formation, sight word efficiency, and language. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single- Versus Dual-Drug Target: Effects in a Brief Abstinence Incentive Procedure.

The number of drugs targeted may have an important influence on the ability of drug abusers to abstain during motivational incentive procedures. The authors investigated outcomes in methadone maintenance patients (n = 58), who had evidence of both opiate and cocaine use, when continuous abstinence from cocaine only (single target) or from both cocaine and heroin (dual target) was required to earn $200 in voucher incentives over a 4-day period. Study patients were equally likely to initiate and sustain abstinence from cocaine under the single- versus the dual-drug target. They were more likely to initiate opiate abstinence under the dual-target condition, demonstrating sensitivity to reinforcer effects. Results suggest that adding a second drug target does not impede short-term cocaine abstinence initiation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of water content on thermal and dynamic mechanical properties of xanthan powder: A comparison between standard and novel techniques

In this work, the sorption isotherms of xanthan powder obtained under static and dynamic conditions and their fitting with mathematical models were discussed. The transitions within xanthan-water systems have been investigated using a standard material characterization technique - Differential Scanning Calorimetry (DSC) - and two novel techniques - Dynamic Mechanical Thermal Analysis (DMTA) material pocket and Phase Transition Analysis (PTA). It was found that within water-xanthan systems, the onset temperature for the melting of freezable water obtained from DSC method was in agreement with freezable water melting peaks obtained via DMTA material pocket at levels of hydration when the freezable water was present. Also, low-temperature transitions, related to polysaccharide-water interactions, were observed by both techniques within xanthan systems which contained no freezable water. However, the use of the PTA technique was limited to xanthan systems with low water content.