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Biomedical subjects

B Wallace

Publications and source records attributed to B Wallace.

At least 19 recordsLinked to original sources
PubMed1998

Deja vu: nosocomial hepatitis B virus transmission and fingerstick monitoring.

PURPOSE: Three patients with acute hepatitis B virus infection were identified who had been hospitalized on the same medical ward during a 19-day period several months earlier. An investigation was undertaken to determine if nosocomial transmission had occurred. SUBJECTS AND METHODS: A cohort study of patients admitted to the medical ward during the 19-day period in 1995 was conducted. In addition, we reviewed medical charts and laboratory records of all patients with acute hepatitis B virus infection who had been admitted to the hospital from 1992 through October 1996 to identify other cases with possible nosocomial acquisition. RESULTS: The 3 patients who had developed acute hepatitis B infection 2 to 5 months after hospitalization on the same medical ward had diabetes mellitus but no identified risk factors for hepatitis B infection. A source patient with diabetes mellitus and hepatitis B "e" antigenemia also was present on the same medical ward at the same time; all 4 patients were infected with the same viral subtype (adw2). Diabetes mellitus and fingerstick monitoring were associated with illness (P <0.001). Through the review of medical charts and laboratory records, 11 additional cases of suspected nosocomial acquisition via fingersticks were identified in 1996, including two clusters involving an unusual subtype of hepatitis B virus (adw4). The fingerstick device employed had a reusable base onto which disposable lancet caps were inserted. There was ample opportunity for cross-contamination among patients because deficiencies in infection control practices, particularly failure to change gloves between patients, were reported by nurses and patients with diabetes mellitus. CONCLUSION: Transmission during fingerstick procedures was the most likely cause of these cases of nosocomial hepatitis B infection. Contamination probably occurred when healthcare workers failed to change gloves between patients undergoing fingerstick monitoring, although other means of contamination cannot be ruled out.

Aged↗
PubMed1998

Nutrition and obesity in the chronic mentally ill.

OBJECTIVE: The aim of this study was to determine the need for nutrition intervention in a group of people living in mental health residential houses in the Northern Sydney Area. METHOD: A nutrition assessment was conducted by the researcher using a face-to-face interview with mental health residents and a survey on medical background completed by case managers. RESULTS: The prevalence of overweight and obesity was significantly greater than that reported for the general population. Respondents also had a significantly higher prevalence of abdominal obesity than the general population. No respondent met the minimum core food group requirements as outlined in the 12345+ Food and Nutrition Plan. CONCLUSIONS: The needs assessment has shown that nutrition promotion is required in this group. The task ahead is to motivate the group to change their food and nutrition behaviours, where many barriers to a healthy lifestyle exist.

Adolescent↗
PubMed1996

Adaptive spatial alignment and strategic perceptual-motor control.

When starting limb and target locations were simultaneously visible in a visuomotor task, performance during prism exposure was nearly perfect, but aftereffects were absent. When starting limb location was not visible, accurate exposure performance was slow to develop, but aftereffects were substantial. Adaptive spatial alignment of sensorimotor spaces and strategic perceptual-motor control to coordinate sensorimotor systems are distinct processes. However, realignment is dependent on whether the exposure task evokes control strategies that enable detection of misalignment. If the task can be performed solely by coding the visible difference between limb and target locations, misalignment detection is disabled. If movement is initiated by target location and then the limb is controlled by the visible difference between target and limb, the discordance between initialized and terminal locations enables misalignment detection and realignment.

Adult↗
PubMed1996

Hypnotic susceptibility, imaging ability, and anagram-solving activity.

Anagram-solving activity was examined as a function of hypnotic susceptibility level and imaging ability. In Experiment 1, anagrams that were composed of sets of letters that formed actual words (word anagrams), but when unscrambled formed other words, were compared to sets of letters that formed nonwords (nonsense anagrams). Word anagrams required more time to solve than nonsense anagrams. Also, fewer word anagrams were correctly solved compared to nonsense anagrams. Those individuals judged both high in hypnotic susceptibility and vivid in imaging ability demonstrated the best performance. In Experiment 2, anagrams that when unscrambled formed high-imagery words were compared to those that formed low-imagery words. High-imagery-word anagrams were solved more quickly and correctly than low-imagery-word anagrams. Such activity was best demonstrated by individuals who were judged to be both high in hypnotic susceptibility and vivid in imaging ability. These results are discussed in terms of strategies for solving anagrams and the individual differences that appear to be associated with using such strategies.

Adolescent↗
PubMed1995

Severe acidosis alone does not predict mortality in the trauma patient.

BACKGROUND: Because severe acidosis is an indicator of poor prognosis in trauma patients, medical records of these patients were analyzed to determine whether aggressive resuscitation was appropriate. PATIENTS AND METHODS: Data from a level 1 trauma center registry were reviewed retrospectively to identify patients with a pH < or = 7.0. Thirty-seven patients were identified. Severely acidotic patients were compared to average trauma patients in terms of demographics, resuscitation, injury, and outcome. Surviving acidotic patients were also compared to nonsurviving acidotic patients. RESULTS: Half of the severely acidotic group survived initial resuscitation with approximately one third surviving to leave the hospital. There were no chronically disabled survivors. Nonsurviving acidotic patients were more unstable, more neurologically depressed, and more severely injured. Resuscitation efforts did not consume excessive hospital resources. CONCLUSION: Severe acidosis alone is not a sufficiently powerful predictor of outcome to justify withholding resuscitation; however, when combined with coma and shock, this condition had no survivors in this small series.

Acidosis↗
PubMed1995

Influence of case type, word frequency, and exposure duration on visual word recognition.

The authors report 4 lexical decision experiments in which case type, word frequency, and exposure duration were varied. These data indicated that there is a larger mixed-case disadvantage for nonwords than for words for longer duration presentations of targets. However, when targets were presented for 100 ms (followed by a postdisplay pattern mask), a larger mixed-case disadvantage occurred for words than for nonwords. For word frequency, the data from Experiments 1, 2, and 3 revealed a slightly larger mixed- case disadvantage for higher frequency words than for lower frequency words. (There was additivity between word frequency and case type for experiment 4.) These results are consistent with a holistically biased, hybrid model of visual word recognition but inconsistent with analytically biased, hybrid models of word recognition, such as the process model (Besner & Johnston, 1989) and the interactive-activation model (McClelland & Rumelhart, 1981).

Decision Making↗
PubMed1995

Fluctuations in hypnotic susceptibility and imaging ability over a 16-hour period.

Within-subject variability for hypnotic susceptibility as measured by the Harvard Group Scale of Hypnotic Susceptibility, Form A and for imaging ability as measured by the Vividness of Visual Imagery Questionnaire was determined over a 16-hour period. Half of the subjects were day persons, those most alert during daytime hours (as determined by the Alertness Questionnaire); the remaining subjects were night persons. For day persons, hypnotic susceptibility was greatest at 10:00 a.m. and 2:00 p.m.; for night persons, susceptibility was greatest at 1:00 p.m. and between 6:00 p.m. and 9:00 p.m. Imaging ability also varied as a function of time of administration. However, these peak periods occurred before and after hypnotic susceptibility peaks. Such a pattern was interpreted as indicating the possible existence of an ultradian cycle for imaging ability.

Activity Cycles↗
PubMed1994

Norms of reaction and diversifying selection.

The numbers of progeny produced by comparable numbers of female Drosophila melanogaster of 26 geographic strains on nine different culture media are examined in the context of norms of reaction. Having emphasized that diversifying selection is seldom discussed simultaneously with its seemingly related topic, norms of reaction, I present the following argument: diversifying selection has generally been viewed as involving sub-populations inhabiting separate localities and subject to different patterns of selection, norms of reaction as variation whose weighted average determines the relative fitnesses of different genotypes within individual sub-populations. Should environmental challenges frequently involve life or death (including sterility) outcomes, norms of reaction involving components of fitness engender diversifying selection within local populations (demes).

Animals↗
PubMed1994

Hypnotic susceptibility, imaging ability, and the detection of embedded words within letters.

Two experiments were conducted to determine the role of hypnotic susceptibility level (high or low) and imaging ability (vivid or poor) in the performance of a visual search for words embedded within matrices of letters. In Experiment 1, subjects searched for target words from a list; however, distractor words were also embedded in the matrices. Results indicated that subjects judged both high in hypnotic susceptibility and vivid in imaging ability demonstrated the fastest search speed with a greater percentage of target words found. These subjects also made fewer false alarm errors (locating distractor words not on the target list). The poorest performance was exhibited by subjects judged both low in hypnotic susceptibility and poor in imaging ability. The amount of variance accounted for by hypnotic susceptibility and imaging ability was approximately equal for each dependent measure. In Experiment 2, when subjects searched for target words from a list without distractor words embedded in matrices, similar results to those reported for Experiment 1 were produced, except that the percentage of words found was equivalent across groups. This was attributed to the elimination of potential false alarm errors. The results are explained in terms of the use of either a holistic or a detail strategy in the performance of a visual search.

Adult↗
PubMed1994

Influence of imaging ability on word transformation.

In the present study, we examined whether individual differences in imaging ability affect visual word recognition. Poor and vivid imagers performed a naming task that involved nonreversed (e.g., JUMP) and reversed (e.g., PMUJ) words (Experiment 1). Poor and vivid imagers were also tested on a naming task that was controlled for verbal ability; all the words were reversed and presentation time was varied (Experiment 2). In both experiments, imaging ability interacted with task difficulty, suggesting that individual differences in imaging ability affect visual word recognition. Specifically, the present data suggest that poor imagers may be less efficient than vivid imagers at processing words analytically. The data are interpreted within a limited-capacity, hybrid, word recognition model, in which words can be processed as either word-level or letter-level codes.

Adult↗
PubMed1993

Day persons, night persons, and variability in hypnotic susceptibility.

Day persons (those most alert during daytime hours) and night persons participated in 2 experiments to examine within-subject variability of scores over time on the Harvard Group Scale of Hypnotic Susceptibility, Form A, and the Stanford Hypnotic Susceptibility Scale, Form C. Regardless of scale used, day persons exhibited peak susceptibility at 10 a.m. and 2 p.m.; for night persons, peak susceptibility was found at 1 p.m. and between 6 p.m. and 9 p.m. Furthermore, 2 peaks of temperature increase (1 p.m. and 6 p.m.) appeared to be associated with peaks in hypnotic susceptibility. However, such was shown to be associated with periods of food intake rather than with increases in hypnotic susceptibility. Results are examined with respect to methodological concerns and the potential existence of ultradian rhythms for hypnotic responsiveness.

Adult↗
PubMed1993

Determinants of diagnostic hypothesis generation: effects of information, base rates, and experience.

Physicians generated diagnostic hypotheses for case histories for which 2 types of diagnoses were plausible, with one having a higher population base rate but less severe clinical consequences than the other. The number of clinical and background symptoms pointing towards the 2 diagnoses was factorially manipulated. The order and frequency with which physicians generated hypotheses varied with the amount of relevant clinical and background information and as a function of population incidence rates, with little evidence of base rate neglect. Availability of a hypothesis, made possible by diagnosis of a similar case before, also made doctors generate this diagnosis earlier and more frequently. Physicians' experience affected hypothesis generation solely by increasing the availability of similar cases. The results are consistent with the use of similarity-based hypothesis generation processes that operate on memory for prior cases.

Adult↗
PubMed1993

Working with shame in the group treatment of male batterers.

The authors argue that shame is a core issue for many men who assault their partners. Shame must therefore be addressed in treatment groups. This article outlines how one intervention, "the confession," elicits shame and how that shame is negotiated through the various stages of group development.

Anger↗
PubMed1992

Experience of peripheral temperature change during hypnotic analgesia.

Many Ss who experience hypnotic analgesia in a portion of their body often report that it is accompanied by sensations of coldness in the affected area. Experiments were conducted to determine if such reports are the result of a physical change in peripheral temperature or are due to psychological factors. When analgesia was induced in a limb or in the back of the neck, a concomitant physical change in temperature was not observed. Ss did report experiencing coldness, however, in the affected body part. Such experiences were attributed to associations that Ss developed between numbness or analgesia and a drop in peripheral temperature. As a result, coldness as an associate of hypnotic analgesia is suggested as a manipulation check for the presence of such sensation reduction.

Female↗
PubMed1992

Revised nucleotide sequence of the gltP gene, which encodes the proton-glutamate-aspartate transport protein of Escherichia coli K-12.

The gene encoding the proton-glutamate carrier (GltP) of Escherichia coli K-12 was sequenced, and the primary structure of the protein was analyzed. The nucleotide sequence was found to differ in several aspects from the previously published sequence (B. Wallace, Y. Yang, J. Hong, and D. Lum, J. Bacteriol. 172:3214-3220, 1990). The corrected open reading frame encodes a protein of 437 (instead of 395) amino acids. Hydropathy analysis predicts 12 membrane-spanning alpha-helical regions. The complementary strand does contain an open reading frame possibly encoding a highly hydrophilic polypeptide of 272 amino acids.

Amino Acid Sequence↗