Bayesian methods in meta-analysis and evidence synthesis

This paper reviews the use of Bayesian methods in meta-analysis. Whilst there has been an explosion in the use of meta-analysis over the last few years, driven mainly by the move towards evidence-based healthcare, so too Bayesian methods are being used increasingly within medical statistics. Whilst in many meta-analysis settings the Bayesian models used mirror those previously adopted in a frequentist formulation, there are a number of specific advantages conferred by the Bayesian approach. These include: full allowance for all parameter uncertainty in the model, the ability to include other pertinent information that would otherwise be excluded, and the ability to extend the models to accommodate more complex, but frequently occurring, scenarios. The Bayesian methods discussed are illustrated by means of a meta-analysis examining the evidence relating to electronic fetal heart rate monitoring and perinatal mortality in which evidence is available from a variety of sources.     

Child psychiatric patients'' interactions with their mothers

The different therapeutic options that may be employed in the treatment of elderly patients with acute leukemias and myelodysplastic states are considered following an analysis of certain biological features, that have been investigated by cytochemical, cytogenetic and cytokinetic techniques, immunophenotyping, and studies on G-6-PD isoenzymes. These studies imply that in the elderly the pattern of hematological malignancies and the lack of response to conventional treatment derive from intrinsic biological differences between these pathological states in older and younger patients. Treatment in elderly patients has ranged from palliative treatment to intensive chemotherapy, often with disappointing results in both cases. Palliative treatment does not induce remissions, and median survival is short. On the other hand, elderly patients do not tolerate well both induction and post-remission therapy due to the degree of toxicity and the effects of drug-induced pancytopenia. In this scenario, in vitro drug-sensitivity testing and karyotyping assume increasing importance, because they may predict which patients are likely to benefit from intensive therapy. In both acute leukemias and myelodysplasias, treatment ideally should be designed case by case, according to the hematological, clinical and biological features.     

Effect of ethyl alcohol on maternal and fetal acid-base balance and cardiovascular status in chronic sheep preparations

Thirteen chronically catheterized pregnant sheep were given intravenous infusions of 10 per cent ethyl alcohol in 5 per cent dextrose solution (15 mg/kg over two hours). Samples of blood from maternal femoral artery, uterine vein, and fetal brachiocephalic artery were drawn at hourly intervals before, during and after the infusions. Plasma was analyzed for alcohol concentration, protein concentration, haematocrit, PCO2 and pH. Maternal and fetal arterial blood pressures were monitored continuously. There were no significant differences between maternal and fetal arterial blood alcohol levels at any sampling interval nor was there any difference in elimination constants. Alcohol infusion did not produce any significant change in plasma protein concentration, haematocrit, PCO2 and pH, and mean arterial blood pressure in either mother or fetus. However, both maternal and fetal heart rate increased significantly following alcohol infusion.     

An evaluation of self-pacing in an auditory identification learning task.

Investigated a method of pacing in auditory identification learning in an experiment with 127 naval service school students. Traditionally, an instructor paces the learner by controlling the stimulus presentation during learning. The W. N. Dember and R. W. Earl theory and other research suggest that a learner might effectively pace himself, provided he has access to stimuli of appropriate complexity levels. An attempt was made to contrast these 2 positions and a condition in which there was no pacing and all training was on the criterion task. Major results were: (a) self-pacing was less efficient, but not less effective, than proficiency-pacing (traditional); (b) both pacing techniques were more effective than unpaced training on the criterion task; and (c) despite attempts to meet the restrictions of the Dember and Earl theory in designing the self-paced condition, the stimulus selection behavior of Ss in that condition was not mediated by stimulus complexity alone. The applicability of the Dember and Earl theory to complex learning situations is questioned. (French summary) (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-frequency heterodyne detection of 10.6-µm laser signals

A three-frequency 10.6-μm heterodyne receiver was demonstrated experimentally. Narrow-band reception of a 40-MHz IF was realized without tracking of the carrier frequency by the local oscillator laser. A signal-to-noise ratio within 1 dB of the theoretical value was measured for large SNR.     

Programming saccadic eye movements.

This article addresses questions about the preparatory processes that immediately precede saccadic eye movements. Saccade latencies were measured in a task in which subjects were provided partial advance information about the spatial location of a target fixation. In one experiment, subjects were faster in initiating saccades when they knew either the direction or amplitude of the required movement in advance compared to a condition with equal uncertainty about the number of potential saccade targets but without knowledge of the parameters required to execute the movement. These results suggest that the direction and amplitude for an upcoming saccade were calculated separately, and not in a fixed serial order. In another experiment, subjects appear to have programmed the saccades more holistically—with computations of direction and amplitude parameters occurring simultaneously. The implications of these results for models of eye movement preparation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a behavior analytically derived alcohol-specific role-play assessment instrument

Social learning theory postulates that chronic alcohol abusers may have deficits in ability to cope with stressful situations, and these deficits may be associated with relapse after treatment. Attempts to study the hypothesized deficits have been hampered by methodological problems. Therefore, a behavior analytic procedure was used to develop 10 categories of situations based on over 600 drinking situations elicited from alcoholics. Role plays were developed for each of these categories, and samples of alcoholics in treatment were asked to respond as if they were trying not to drink. Videotaped responses were behaviorally rated by trained judges for skill and anxiety, and subjects completed self-report ratings of urge to drink, anxiety, difficulty and skill after each role play. Good interrater reliabilities and internal consistency were found across three samples of alcoholics, with virtually no gender differences. Previous and current investigations show the validity and utility of this instrument. The Alcohol Specific Role Play Test therefore shows promise as a means of assessing alcoholics' reactions to high-risk situations.     

Changes in energy intakes during pregnancy and lactation in a national sample of US women

Increases in energy intakes during pregnancy and lactation were evaluated by examining dietary data for 458 pregnant women who participated in the Continuing Surveys of Food Intakes by Individuals conducted in 1985 and 1986. Energy intakes were well below recommendations during all reproductive states; however, increases during pregnancy approximated recommendations, while increases during lactation were low. Postpartum non-lactating intakes did not return to prepregnancy levels for Black women or women with lower incomes.     

Effects of alcohol on social anxiety in women: Cognitive versus physiological processes.

Randomly assigned 32 female social drinkers (18–25 yr old undergraduates) to 4 conditions in a 2?×?2 factorial design that controlled for drink content and expectations. Ss were administered either an alcoholic or a nonalcoholic beverage and were led to believe that their drinks contained or did not contain alcohol. After finishing their drinks Ss participated in a study of social anxiety in which they were requested to interact with a male confederate of the experimenter. Multiple measures, including heart rate, skin conductance, and overt behavioral and self-report responses, were recorded. Ss who expected alcohol showed significant elevations in physiological arousal and were rated as more anxious on observational measures of social behavior. Self-report measures failed to yield any differences among groups. Implications for the tension reduction theory of alcohol use and the importance of multiple response measures are discussed. (1? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)