A Canadian Critical Care Trials Group project in collaboration with the international forum for acute care trialists - Collaborative H1N1 Adjuvant Treatment pilot trial (CHAT): study protocol and design of a randomized controlled trial

Background

The Vaccine Assessment using Linked Data (VALiD) trial compared opt-in and opt-out parental consent for a population-based childhood vaccine safety surveillance program using data linkage. A subsequent telephone interview of all households enrolled in the trial elicited parental intent regarding the return or non-return of reply forms for opt-in and opt-out consent. This paper describes the rationale for the trial and provides an overview of the design and methods.

Methods/Design

Single-centre, single-blind, randomised controlled trial (RCT) stratified by firstborn status. Mothers who gave birth at one tertiary South Australian hospital were randomised at six weeks post-partum to receive an opt-in or opt-out reply form, along with information explaining data linkage. The primary outcome at 10 weeks post-partum was parental participation in each arm, as indicated by the respective return or non-return of a reply form (or via telephone or email response). A subsequent telephone interview at 10 weeks post-partum elicited parental intent regarding the return or non-return of the reply form, and attitudes and knowledge about data linkage, vaccine safety, consent preferences and vaccination practices. Enrolment began in July 2009 and 1,129 households were recruited in a three-month period. Analysis has not yet been undertaken. The participation rate and selection bias for each method of consent will be compared when the data are analysed.

Discussion

The VALiD RCT represents the first trial of opt-in versus opt-out consent for a data linkage study that assesses consent preferences and intent compared with actual opting in or opting out behaviour, and socioeconomic factors. The limitations to generalisability are discussed.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12610000332022     

Dependence of stability of the visual cognitive set on motivation

In order to reveal the character of motivation influence on the stability of the unconscious visual set, young adult healthy subjects were promised to be rewarded for correct solution of the cognitive task. A substantial increase in set stability was observed under conditions of augmented motivation of a subject to the result of his performance. Positive and negative aspects of the impact of the increased motivation of a subject on his cognitive activity at the stages of set formation and actualization are discussed.     

Importing statistical measures into Artemis enhances gene identification in the <Emphasis Type="Italic">Leishmania</Emphasis> genome project

Background

Seattle Biomedical Research Institute (SBRI) as part of the Leishmania Genome Network (LGN) is sequencing chromosomes of the trypanosomatid protozoan species Leishmania major. At SBRI, chromosomal sequence is annotated using a combination of trained and untrained non-consensus gene-prediction algorithms with ARTEMIS, an annotation platform with rich and user-friendly interfaces.

Results

Here we describe a methodology used to import results from three different protein-coding gene-prediction algorithms (GLIMMER, TESTCODE and GENESCAN) into the ARTEMIS sequence viewer and annotation tool. Comparison of these methods, along with the CODON USAGE algorithm built into ARTEMIS, shows the importance of combining methods to more accurately annotate the L. major genomic sequence.

Conclusion

An improvised and powerful tool for gene prediction has been developed by importing data from widely-used algorithms into an existing annotation platform. This approach is especially fruitful in the Leishmania genome project where there is large proportion of novel genes requiring manual annotation.

     

Dependence of the verbal set on the cognitive activity context

It was shown in adult healthy subjects (n = 60) that the set depends on the context of cognitive activity. Under conditions of its complication, when a subject had to solve successively several tasks, the stability of the verbal set markedly increased. This was expressed in a longer effect of "blindness" characteristic for the set to pseudo-word reading and increase in the time of reaction to a probe stimulus.     

Spatial synchronization of cortical electrical activity at different stages of visual set in preschool children

Changes in the alpha-rhythm synchronization were revealed at different stages of cognitive visual set in 5- to 7-year-old children. We found a clear-cut correlation of these changes with set plasticity. In children with a plastic set, the EEG synchronization between the frontal and other brain regions substantially increased in the period of set-shifting (the actualization stage). At the set extinction stage, after set-shifting has already taken place, the EEG-synchronization becomes minimal. On the contrary, in children who formed a rigid set, EEG coherence considerably increases at the set extinction stage. This finding suggests that the rigid set still affects the cognitive activity even after (judging from oral reports) the set shift has been completed. The age-related differences in cognitive set formation clearly correlate with the time course of the EEG synchronization between the frontal and other brain regions. We think that the ability to form a plastic visual set depends on the frontal cortex maturation, which occurs at the age of 6-7 years, and its age-related effect on the brain cognitive functions.     

Quantifying the complexity of bat wing kinematics

Body motions (kinematics) of animals can be dimensionally complex, especially when flexible parts of the body interact with a surrounding fluid. In these systems, tracking motion completely can be difficult, and result in a large number of correlated measurements, with unclear contributions of each parameter to performance. Workers typically get around this by deciding a priori which variables are important (wing camber, stroke amplitude, etc.), and focusing only on those variables, but this constrains the ability of a study to uncover variables of influence. Here, we describe an application of proper orthogonal decomposition (POD) for assigning importances to kinematic variables, using dimensional complexity as a metric. We apply this method to bat flight kinematics, addressing three questions: (1) Does dimensional complexity of motion change with speed? (2) What body markers are optimal for capturing dimensional complexity? (3) What variables should a simplified reconstruction of bat flight include in order to maximally reconstruct actual dimensional complexity? We measured the motions of 17 kinematic markers (20 joint angles) on a bat (Cynopterus brachyotis) flying in a wind tunnel at nine speeds. Dimensional complexity did not change with flight speed, despite changes in the kinematics themselves, suggesting that the relative efficacy of a given number of dimensions for reconstructing kinematics is conserved across speeds. By looking at subsets of the full 17-marker set, we found that using more markers improved resolution of kinematic dimensional complexity, but that the benefit of adding markers diminished as the total number of markers increased. Dimensional complexity was highest when the hindlimb and several points along digits III and IV were tracked. Also, we uncovered three groups of joints that move together during flight by using POD to quantify correlations of motion. These groups describe 14/20 joint angles, and provide a framework for models of bat flight for experimental and modeling purposes.     

Induced synchronization/desynchronization of the theta and alpha cortical electrical activity to a face stimuli with increasing visual working memory load

Using a cognitive set to emotional facial expression as a model, induced synchronization/desynchronization of the cortical theta- and alpha-activities were studied in adult healthy people under conditions of increased load on the working memory (additional task of the verbal stimuli recognition). A correlation was found between behavioral (increase in the set rigidity) and electrophysiological (decrease of the induced theta-rhythm synchronization) data. A hypothesis is suggested that the earlier revealed increase in the tonic prestimulus theta-activity and suppression of the poststimulus phasic activation of the cortico-hippocampal system are one of the mechanisms of the decrease in plasticity of the cognitive function of the emotional facial expression recognition under conditions of the increased load on the working memory. Reciprocal relations between two functional systems of the brain activity integration (cortico-hippocampal and fronto-thalamic) in the process of recognition of emotional facial expression are discussed.     

Cognitive control in recognition of emotionally negative face in 5-10-year-old children

We used the experimental model of cognitive visual set, designed by D.N. Uznadze, to study the influence of previous experience on emotional face expression recognition in pre-school (6.1 +/- 0.3 years) and elementary school (10.5 +/- 0.1 years) children. Our results suggest that the ability to form a cognitive set to an angry face expression develops in ontogenesis in strong concordance with functional maturation of prefrontal cortex that takes place at the age of approximately 10 years. At this age children display almost the same level of set plasticity and a similar kind of erroneous perceptions during set actualization as grown-ups. Children of younger age (6.1 +/- 0.3 years) display more perceverative erroneous perceptions, or assimilative illusions (probably of a priming origin), than the above mentioned groups. We consider this to be a result of a more strong influence of previous experience in their case.