Effect of sugars on the association between cowpea vicilin (7S storage proteins) and fungal cells.

Vicilins (7S storage proteins) found in various legume seeds have been previously shown to interfere with the germination of spores or conidia of phytopathogenic fungi and inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. In the present work vicilins from cowpea (Vigna unguiculata) seeds were added to the growth medium of Saccharomyces cerevisiae cells and Fusarium oxysporum conidia. Helix pomatia lectin, wheat germ agglutinin and Ulex europaeus lectin were used to identify differences in the binding of the vicilins to the surface of cells of S. cerevisiae and F. oxysporum treated with this protein. After the growth period, the material in suspension (yeast cells) was centrifuged and the final pellet was also treated with different sugar (glucose, sucrose, glucosamine, N-acetyl-glucosamine) concentrations and 0.1 M HCl for extraction of vicilins associated to chitinous structures present in yeast cells. Our results showed that vicilin sub-units were present in the different sugar extracts of yeast cells pretreated with the vicilins and these proteins were eluted by 0.5 M solutions of sugars in the following order of efficiency of elution: N-acetyl-glucosamine, sucrose/glucose and glucosamine.

Effect of sugars on the association between cowpea vicilin (7S storage proteins) and fungal cells

Vicilins (7S storage proteins) found in various legume seeds have been previously shown to interfere with the germination of spores or conidia of phytopathogenic fungi and inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. In the present work vicilins from cowpea (Vigna unguiculata) seeds were added to the growth medium of Saccharomyces cerevisiae cells and Fusarium oxysporum conidia. Helix pomatia lectin, wheat germ agglutinin and Ulex europaeus lectin were used to identify differences in the binding of the vicilins to the surface of cells of S. cerevisiae and F. oxysporum treated with this protein. After the growth period, the material in suspension (yeast cells) was centrifuged and the final pellet was also treated with different sugar (glucose, sucrose, glucosamine, N-acetyl-glucosamine) concentrations and 0.1 M HCl for extraction of vicilins associated to chitinous structures present in yeast cells. Our results showed that vicilin sub-units were present in the different sugar extracts of yeast cells pretreated with the vicilins and these proteins were eluted by 0.5 M solutions of sugars in the following order of efficiency of elution: N-acetyl-glucosamine, sucrose/glucose and glucosamine.

Legume vicilins (7S storage globulins) inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells.

Vicilin (7S storage proteins) isolated from different legume seeds were shown to inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. The degree of growth inhibition varied with the origin of vicilins. It was more than 90% for vicilins from cowpea (Vigna unguiculata, cultivar pitiuba) and equal to 65% for vicilins from Vigna radiata, in the case of Saccharomyces cerevisae. Vicilins from cowpea seeds inhibited the glucose stimulated acidification of the medium by S. cerevisae up to 60%. We have also observed that vicilins bind to yeast cells. We suggest that vicilins bind to chitin-containing structures of yeast cells and that such association could result in inhibition of H+ pumping, cell growth and spore formation. A final consequence of the yeast growth inhibition by vicilins is (probably) the formation of spores.

Electrical stimulation with Pt electrodes. VIII. Electrochemically safe charge injection limits with 0.2 ms pulses.

The charge injection limits of a Pt electrode using 0.2 ms charge balanced, biphasic current pulses ranged from 50 to 150 microC/cm2 geometric if the potential excursions of the electrode are kept below those at which H2 or O2 is produced. These charge densities are three to ten times smaller than the currently accepted value based on earlier experiments in which the reversible surface reactions were fully utilized and the pulse widths were longer.

Aspects of consensus in clinical predictions of imminent violence.

This research studied individual differences among psychiatric patients in the extent to which clinical workers agree about the likelihood that the patients will act violently. Predictions of imminent violence proneness for 40 male inpatients made by 35 experienced clinical practitioners were analyzed. As hypothesized, subgroups of patients who elicited high interjudge agreement were found, and admission profiles of these patients were presented. Clinical workers' predictive accuracy was found to be greater when they rated patients who elicited high consensus than for unselected patients or for those who elicited low consensus.

Patient recording of medically relevant data.

Procedures for augmenting subjective, anecdotal self-reports by outpatients with reliable, objective symptomatic data are discussed. The collection of rate data by patients in nonclinical settings is advocated as a source of relevant information for physicians and other health-care professionals. Methodological and training concerns are discussed. A case study illustrates the procedure.

Priming effects and recognition memory in young and elderly adults.

The present study explores the effects of age on the priming of alternate homophone spellings and recognition memory. Sixteen young and sixteen elderly adults were given a general information test, a spelling test, and a test of recognition memory. By embedding the less frequently spelled member of different homophone units (e.g., write vs. right) in the general information questions, certain of the homophones were primed during this task. The effect of this priming was assessed through the subjects' choice of spelling for these words on the spelling test. Recognition memory was assessed by asking subjects to indicate which words from a longer list were presented during the spelling test. As found in prior research priming effects were observed in younger subjects; however, no significant priming effects occurred in the older age group. On the recognition test, homophones were more often correctly recognized than nonhomophones, and priming affected the scores of the young negatively, but had no effects, positive or negative, on the elderly. These results suggest possible differences in the underlying bases of memory loss in aged adults and amnesics.

Assessment of capacitor electrodes for intracortical neural stimulation.

Capacitor electrodes offer the potential for the safest method of stimulation of neural tissue because they operate without any faradaic process occurring at the electrode-electrolyte interface. Their use eliminates problems associated with metal dissolution or water electrolysis which may occur with electrodes of noble metals. This paper reviews recent work aimed at increasing the charge storage density of capacitor electrodes to allow their application with the small areas of 10(-4) mm2 required for intracortical stimulation of single neurons. Increased charge storage with electrodes using anodic films such as TiO2 and Ta2O5 has been obtained by increasing the real surface area of microelectrodes. Experiments have also been done with BaTiO3 films which have a much higher dielectric constant than the anodic film dielectrics. State-of-the-art electrodes made with these materials, however, have a charge storage density which at best is comparable to that obtained with Pt and is considerably lower than electrochemically safe charge densities that have been reported for activated Ir. It is concluded that for very small intracortical electrodes, capacitor electrodes will not be competitive with electrodes which operate using surface localized faradaic reactions.

The effects of contingent water mist on the stereotypic responding of a severely handicapped adolescent.

The reductive effects of the water misting procedure on the stereotypic responding of a severely handicapped adolescent were investigated by using a variation of the multiple baseline design across settings, with sequential interventions across settings and simultaneous interventions across teachers. The results indicated that the intervention was related to reduced rates of stereotypic responding in each setting. The effects of the intervention were also maintained across multiple administrators of the procedure and during follow-up. Instructional implications are discussed. Further research is suggested.

Psychiatrists' judgments of dangerousness in patients on an acute care unit.

Statistical analyses suggest that psychiatrists emphasize hostility, agitation, previous assaultiveness, and suspiciousness as factors predictive of violence in psychiatric inpatients. When the actual correlates of violence in these patients are evaluated, a different picture of the assaultive inpatient emerges. Examination of differences between the cues emphasized by clinicians to make their predictions and the empirical correlates of violence suggests ways of improving the accuracy of clinical judgments of inpatients' dangerousness.

The effects of a face-name mnemonic in young, middle-aged, and elderly adults.

A mnemonic for learning name-to-face associations was taught to young, middle-aged, and elderly adults. Recall of names was assessed initially, before participants were introduced to the mnemonic, and after it had been learned. The youngest group recalled the most names overall whereas the oldest group recalled the least; middle-aged participants performed at intermediate levels. Despite this decline in performance with age, all three groups showed significant gains in recall after learning the mnemonic, and the amount of improvement was comparable across groups.

Semantic elaboration and the method of loci: a new trip for older learners.

The present study examined the effectiveness of two variations of a list learning mnemonic, the method of loci, on the recall of elderly subjects. In the Loci Only group (n = 20) subjects were instructed in the standard mnemonic and taught how to produce visual images associating each item to be remembered with one of several familiar locations. A second group, the Loci + Judgment condition (n = 17), received identical instructions except that they were taught, in addition, to make a personal judgment of the pleasantness of each visual image association. As predicted, subjects in the Loci Plus Judgment group showed greater improvement in their recall following instruction in the mnemonic. These results point to the importance of nonredundant forms of stimulus elaboration as a means of enhancing the accessibility of visual images and the effectiveness of visual mnemonic techniques.