Purification and biochemical characterization of chymotrypsin from the viscera of Monterey sardine (Sardinops sagax caeruleus)

Chymotrypsin was isolated from the viscera of Monterey sardine by ammonium sulphate fractionation, gel filtration, and ionic exchange chromatography. The approximate molecular weight was 26,000 and its isoelectric point was about 5. Identity as chymotrypsin was established by its catalytic specificity for amide or ester bonds on the synthetic substrates succinyl-l-ala-ala-pro-l-pheilalanine-p-nitroanilide and benzoyl-l-tyrosine-ethyl-ester, showing esterase activity 3.2-fold higher than amidase. It was inhibited by phenylmethylsulfonyl-fluoride and soybean trypsin inhibitor, partly inhibited by the specific chymotrypsin inhibitor N-toluenesulfonyl-l-phenylalanine chloromethyl-ketone, but not inhibited by EDTA or Benzamidine. Chymotrypsin showed its maximum activity at pH 8.0 and 50 °C for the hydrolysis of SAAPNA. The Michaelis–Menten constant was 0.074 mM with a catalysis constant of 18.6 seg⁻¹, and catalytic efficiency of 252 seg⁻¹ mM⁻¹. Results indicated that Monterey sardine chymotrypsin is a good catalyst and could be used as a biotechnological tool in food processing and using sardine industry wastes as a material for production of fine reagents.     

Microstructure/Process Relations in Sol-Gel-Prepared KnbO3 Thin Films on (100) MgO

Epitaxial (110) orthorhombic KNbO₃ thin films were prepared using alkoxide solutions. Single-phase films were produced with stoichiometric sols while slight variations in stoichiometry (52/48 Nb/K or 48/52 Nb/K) created residual second phases. Nucleation and growth of KNbO₃, as a function of process conditions were monitored by observing the KNbO₃ rosettes produced from niobium-rich solutions. Methanolic solutions produced films with the highest rosette density and the highest amount of KNbO₃. Hydrolysis of the sol aided the crystallization of the KNbO₃ phase but also promoted the formation of second phases. Hydrolysis at 0°C reduced second-phase formation.     

Cognitive profiles of difficult-to-remediate and readily remediated poor readers: Early intervention as a vehicle for distinguishing between cognitive and experiential deficits as basic causes of specific reading disability.

Reading impaired first graders were given daily tutoring as a "first cut" diagnostic to aid in distinguishing between reading difficulties caused by basic cognitive deficits and those caused by experiential deficits. Reading achievement in most of these children was found to be within or above the average range after one semester of remediation. Children who were difficult to remediate performed below both children who were readily remediated and normal readers on kindergarten and first-grade tests evaluating phonological skills, but not on tests evaluating visual, semantic and syntactic skills. The results are consistent with convergent findings from previous research suggesting that reading problems in some poor readers may be caused primarily by phonological deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic and perceptual priming: How similar are the underlying mechanisms?

Both semantic priming and perceptual priming consist of facilitation of the identification of primed stimuli and inhibition of the identification of nonprimed stimuli. The similarities between the two phenomena suggest that a common attentional mechanism underlies both, and this has been explicitly proposed by several attention theorists. In this article it is argued that the phenomena of semantic and perceptual priming are qualitatively different, perceptual priming reflecting a sensitivity change in the recognition process brought about by attention, and semantic priming reflecting a bias change in the recognition process brought about by attention. Because different mechanisms are required to produce sensitivity and bias changes, this implies that the attentional mechanisms responsible for semantic and perceptual priming are distinct. In terms of recent discussions of the modularity versus the unity of cognitive architecture, the present conclusion supports a modular architecture for attentional processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of imagery on vernier acuity under conditions of induced depth.

Imagery interferes with visual acuity (the "Perky effect") when an image is close to a visual target and both the image and the acuity target are located in the same depth plane. Whether imagery-induced interference occurs when a mental image and a target are separated by induced depth was investigated. Participants projected an image in front of or behind a vernier acuity target on a frontal or back plane suggested by the panels of an outline cube. A drop in accuracy for the target was found when an image was projected in front of, but not behind, the target. Thus, induced depth can influence the Perky effect. By contrast, real lines interfered with the target regardless of perceived depth plane, which is inconsistent with the hypothesis that imagery and perception are equivalent. Results support the hypothesis that images interfere with perception only when the participant must see through an image to obtain information specifying the visual target. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linking symptom-specific physiological reactivity to pain severity in chronic low back pain patients: A test of mediation and moderation models.

Symptom-specific reactivity to stress (lower paraspinal muscle reactivity) among chronic low back pain (CLBP) patients may exacerbate chronic pain. It was hypothesized that among CLBP patients (N?=?107) only stress-induced lower paraspinal reactivity, and not reactivity in other indexes, would predict pain severity (PS), and that lower paraspinal reactivity would mediate or moderate links between depression and PS. Electromyogram readings from lower paraspinal and trapezius muscles, systolic and diastolic blood pressures, and heart rate were collected during mental arithmetic (MA) and an anger recall interview. The moderator hypothesis was supported: Only lower paraspinal reactivity during MA was related significantly to PS, but only among patients with high levels of depression. Thus, a profile of lower paraspinal hyperreactivity plus depressed affect may aggravate CLBP. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postejaculatory quiescence in female and male rats: Consequences for sperm transport during group mating.

Studied the pattern of postejaculatory mating in the social context of a multimale–multifemale group of Sprague-Dawley rats (N?=?21), analyzing its timing and sequence from the females' as well as the males' perspective. During mating, females had a quiescent period following each ejaculation, which was comparable with the males' (a postejaculatory interval, PEI). The PEIs of both sexes were characterized by 3 behaviorally distinguishable phases: a stationary, an interactive, and a sexual phase. There was no significant sex difference in the total length of the PEI. Nonetheless, females began active sexual behavior and entered the sexual phase more quickly than males. The time course of each phase of the PEI is compared with the time course of sperm transport in the female, and the similarities and differences between the two sexes' reproductive strategies following an ejaculation are emphasized. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Professional Preparation: A Course That Successfully Teaches Needed Skills Using Different Pedagogical Techniques

To bridge a gap we perceive to exist between the traditionally educated engineer, who is skilled primarily in high tech, and the broader trained engineer being called for by industry, we have developed a senior level course entitled Professional Preparation. This course is built around a group design project, but also includes exposure to a wide variety of needed skills such as problem solving, creative thinking, ethics, writing to learn, producing documentation and making oral and written reports. Student and employer reaction to the course is uniformly enthusiastic. Data collected from a survey of over 400 of our graduates shows a marked difference in their perception of the importance of and their educational preparation in specific skills with additional differences between those who took this course and those who did not.     

Sex of authority role models and achievement by men and women: Leadership performance and recognition.

Investigated whether performance, for both sexes, is conditioned by expectations for them, with expectations being at least partly defined by same-sex role models. 276 undergraduates were exposed to all-male, all-female, or mixed-authority role models and then participated in a 4-person mixed-sex discussion. Vicarious cultural experience of authority models was represented by videotaped reenactments of TV commercials. Ss viewed either 4 traditional commercials showing a man as authority and woman as subordinate, or 4 reversed-role versions in which the male and female actors switched roles in the same scenarios. Personally observed authority models were represented by the experimenter, who supervised the discussion. Sex of authority in the commercials and sex of experimenter were crossed in a factorial design. In the all-male authority condition, men and women performed equally (as measured by talking time and number of substantive content suggestions), but recognized only the men as leaders in postdiscussion evaluation questionnaires. In the all-female authority condition, men and women also performed equally, and, in addition, they also received equal leadership recognition. In the 2 mixed-authority conditions, men objectively outperformed women. The data show that recognition is not a direct function of performance for either sex but is influenced by the evaluators' expectations, which are partly defined by sex of authority role models in the social environment. (103 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A computational analysis of mental image generation: Evidence from functional dissociations in split-brain patients.

Recent efforts to build computer simulation models of mental imagery have suggested that imagery is not a unitary phenomenon. Rather, such efforts have led to a modular analysis of the image-generation process, with separate modules that can activate visual memories, inspect parts of imaged patterns, and arrange separate parts into a composite image. This idea was supported by the finding of functional dissociations between the kinds of imagery tasks that could be performed in the left and right cerebral hemispheres of 2 patients (a 19-yr-old male and a 32-yr-old female) who had previously undergone surgical transection of their corpus callosa. The left hemisphere in both Ss could inspect imaged patterns and could generate single and multipart images. In contrast, although the right hemisphere could inspect imaged patterns and could generate images of overall shape, it had difficulty in generating multipart images. Results suggest a deficit in the module that arranges parts into a composite. The observed pattern of deficits and abilities implied that this module is not used in language, visual perception, or drawing. Findings also suggest that the basis for this deficit is not a difficulty in simply remembering visual details or engaging in sequential processing. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)