Altered hippocampal function in major depression despite intact structure and resting perfusion.

BACKGROUND: Hippocampal volume reductions in major depression have been frequently reported. However, evidence for functional abnormalities in the same region in depression has been less clear. We investigated hippocampal function in depression using functional magnetic resonance imaging (fMRI) and neuropsychological tasks tapping spatial memory function, with complementing measures of hippocampal volume and resting blood flow to aid interpretation. METHOD: A total of 20 patients with major depressive disorder (MDD) and a matched group of 20 healthy individuals participated. Participants underwent multimodal magnetic resonance imaging (MRI): fMRI during a spatial memory task, and structural MRI and resting blood flow measurements of the hippocampal region using arterial spin labelling. An offline battery of neuropsychological tests, including several measures of spatial memory, was also completed. RESULTS: The fMRI analysis showed significant group differences in bilateral anterior regions of the hippocampus. While control participants showed task-dependent differences in blood oxygen level-dependent (BOLD) signal, depressed patients did not. No group differences were detected with regard to hippocampal volume or resting blood flow. Patients showed reduced performance in several offline neuropsychological measures. All group differences were independent of differences in hippocampal volume and hippocampal blood flow. CONCLUSIONS: Functional abnormalities of the hippocampus can be observed in patients with MDD even when the volume and resting perfusion in the same region appear normal. This suggests that changes in hippocampal function can be observed independently of structural abnormalities of the hippocampus in depression.

Role of regression analysis and variation of rheological data in calculation of pressure drop for sludge pipelines.

Sludge pumps in wastewater treatment plants are often oversized due to uncertainty in calculation of pressure drop. This issue costs millions of dollars for industry to purchase and operate the oversized pumps. Besides costs, higher electricity consumption is associated with extra CO2 emission which creates huge environmental impacts. Calculation of pressure drop via current pipe flow theory requires model estimation of flow curve data which depends on regression analysis and also varies with natural variation of rheological data. This study investigates impact of variation of rheological data and regression analysis on variation of pressure drop calculated via current pipe flow theories. Results compare the variation of calculated pressure drop between different models and regression methods and suggest on the suitability of each method.

Gender differences, physiological arousal and the role of winning in fruit machine gamblers.

AIMS: To examine gender differences in changes in physiological arousal as indexed by heart rate during fruit machine gambling while controlling for the confounding effect of movement and as a function of winning and losing, and to examine relationships between sensation-seeking, self-reported arousal during gambling, heart rate during gambling and loss of control of gambling behaviour. SAMPLE, DESIGN AND MEASUREMENTS: Heart rate and subjective arousal were recorded in a sample of 22 male and 20 female fruit machine players before, during and after the gambling process. At baseline measures were taken of sensation seeking, self-reported arousal during gambling and loss of control of gambling. A simulation of the behaviour used to operate fruit machines was used during baseline measurement. FINDINGS: Significant increases in heart-rate over movement controlled baselines were observed within participants during gambling. However, for the losing group these differences were slight compared to the increases found when participants won during play. Furthermore, winning/losing was the only variable among a range of variables which was a significant predictor of heart-rate increase during play over a baseline control. Additionally HR levels of males and females behaved the same way in relation to the manipulations. Significant correlations between HR during play and the measures of both subjective arousal and sensation seeking were also present. CONCLUSIONS: Winning during gambling is essential in order to maintain increased HR levels over baseline after play. Subjective arousal and sensation seeking may be predictors of levels of arousal experienced during play.

Physiological arousal and sensation-seeking in female fruit machine gamblers.

AIMS: To examine changes in physiological arousal, as indexed by heart rate, during fruit machine gambling while controlling for the confounding effect of movement and as a function of winning and losing, and to examine relationships between sensation-seeking, self-reported arousal during gambling, heart rate during gambling and frequency of gambling. SAMPLE, DESIGN AND MEASUREMENTS: Heart rate and subjective arousal were recorded in a sample of 32 female fruit machine players before, during and after the gambling process. At baseline measures were taken of sensation-seeking, self-reported arousal during gambling and frequency of gambling. A simulation of the behaviour used to operate fruit machines was used during baseline measurement. FINDINGS: Significant increases in heart-rate over movement controlled baselines were observed within participants during gambling, but only in those who won during play. No correlations between HR levels and subjective arousal were found. However, striking negative correlations between sensation-seeking and frequency of gambling, and between subjective arousal and frequency were present. CONCLUSIONS: Gambling alone is not enough to induce increases in HR levels for female fruit machine gamblers; the experience of winning or the anticipation of that experience is necessary to increase HR levels. In addition sensation-seeking appears to be negatively associated with this kind of gambling behaviour.

Sensation seeking, gambling and gambling addictions.

Male off-course bettors were assessed using: the Sensation-Seeking Scale (SSS) Form V, two measures of subjective arousal while betting, and questions concerning chasing, preferences for gambling activities and other aspects of betting behaviour. The SSS was also administered to a random sample of the male general population of Glasgow, together with questions concerning preferences for gambling activities to allow comparison between regular gamblers and the general population. In comparison with the general population and with non-gamblers, off-course bettors scored lower on SSS; gamblers preferring the casino and/or the race-track scored higher on SSS; gamblers betting on many different forms scored higher on SSS. A further analysis produced a cluster of variables among off-course bettors associated with impaired control of gambling, among which both SSS scores and chasing were prominent features.

Arousal, sensation seeking and frequency of gambling in off-course horse racing bettors.

Heart rate was recorded in a sample of 32 off-course horse racing bettors before, during and after the gambling process, together with sensation seeking and information regarding frequency and expenditure on gambling. Importantly, the present study controlled for the confounding effects of movement on heart rate present in previous studies. Significant differences within subjects were found for heart rate at different points in the gambling process, but no differences were found comparing high- and low-frequency gamblers or gamblers that chase with those that don't chase. These findings are discussed in relation to the theoretical role of arousal and sensation seeking in the explanation of gambling behaviour.

Visual speech aids: a British survey of use and evaluation by speech and language therapists.

One hundred and eighty speech and language therapists throughout the UK completed a postal questionnaire which asked for ratings of visual speech aids (VSAs) on a number of dimensions together with information regarding frequency of use of such aids, comments on the range of applicability of each type of aid and other demographic data relating to the diversity of client groups covered in case loads. The results (using analysis of variance) revealed a main effect of VSA type. There was also a main effect of question type; all VSAs scored poorly on some dimensions as compared with others. Furthermore there was a significant interaction between type of VSA and dimension type. This suggests that VSAs not only tend to be built for particular client groups, but that the makers tend to focus on some specific design criteria to the detriment of others. These results are discussed with respect to the future design of VSAs, and with respect to their testing and future evaluation.

Specialist speech and language therapists' use and evaluation of visual speech aids.

Sixty speech and language therapy service managers and 233 specialist speech and language therapists (SLTs) throughout the UK completed a postal questionnaire which asked for caseload data, patterns of use of visual speech aids (VSAs) and ratings of VSAs on a number of dimensions (in a follow-up to the survey carried out by Coventry, Clibbens, Cooper and Rood, 1997). Information was also elicited about frequency of use of VSAs together with comments relating to the range of applicability of each type of aid. The results revealed that no VSA scored better than average ratings and, in particular, 'Portability' and 'Affordability' scored lowest overall. In addition, no differences were found in ratings of particular VSAs between specialist types. The caseload data reported also confirmed the need to take baserate into account when purchasing and designing VSAs.