Can Listening to a Verbal Trauma Report Induce Intrusions? - Replication of a Randomized Trial.

Recent evidence suggests that indirect verbal exposure to traumatic events can be sufficient to cause intrusions and other posttraumatic stress symptoms. In this study, we used a verbal trauma report to experimentally induce intrusions and a tactile task to manipulate the putative processes underlying intrusion development. Our findings indicate that the verbal report indeed induced intrusive recall. Moreover, the verbal report induced negative mood, state anxiety, and state dissociation, with mood and state dissociation predicting intrusion development. Additionally, the tactile task interfered with intrusion formation as indicated by the primary diary measure, but not the retrospective self-report. However, these results await further replication as this and previous trials suffered from limited statistical power. The findings support the reports by trauma therapists who experience secondary traumatization. They also challenge the assumption that all intrusions develop bottom-up from low-level sensory input via sensory representations. Future studies should explore differential processes for intrusion development based on their modality.

Assessing Consistency in Single-Case Data Features Using Modified Brinley Plots.

The current text deals with the assessment of consistency of data features from experimentally similar phases and consistency of effects in single-case experimental designs. Although consistency is frequently mentioned as a critical feature, few quantifications have been proposed so far: namely, under the acronyms CONDAP (consistency of data patterns in similar phases) and CONEFF (consistency of effects). Whereas CONDAP allows assessing the consistency of data patterns, the proposals made here focus on the consistency of data features such as level, trend, and variability, as represented by summary measures (mean, ordinary least squares slope, and standard deviation, respectively). The assessment of consistency of effect is also made in terms of these three data features, while also including the study of the consistency of an immediate effect (if expected). The summary measures are represented as points on a modified Brinley plot and their similarity is assessed via quantifications of distance. Both absolute and relative measures of consistency are proposed: the former expressed in the same measurement units as the outcome variable and the latter as a percentage. Illustrations with real data sets (multiple baseline, ABAB, and alternating treatments designs) show the wide applicability of the proposals. We developed a user-friendly website to offer both the graphical representations and the quantifications.

Experimental replications in animal trials.

The recent discussion on the reproducibility of scientific results is particularly relevant for preclinical research with animal models. Within certain areas of preclinical research, there exists the tradition of repeating an experiment at least twice to demonstrate replicability. If the results of the first two experiments do not agree, then the experiment might be repeated a third time. Sometimes data of one representative experiment are shown; sometimes data from different experiments are pooled. However, there are hardly any guidelines about how to plan for such an experimental design or how to report the results obtained. This article provides a thorough statistical analysis of pre-planned experimental replications as they are currently often applied in practice and gives some recommendations about how to improve on study design and statistical analysis.

Invited review: Reproducible research from noisy data: Revisiting key statistical principles for the animal sciences.

Reproducible results define the very core of scientific integrity in modern research. Yet, legitimate concerns have been raised about the reproducibility of research findings, with important implications for the advancement of science and for public support. With statistical practice increasingly becoming an essential component of research efforts across the sciences, this review article highlights the compelling role of statistics in ensuring that research findings in the animal sciences are reproducible-in other words, able to withstand close interrogation and independent validation. Statistics set a formal framework and a practical toolbox that, when properly implemented, can recover signal from noisy data. Yet, misconceptions and misuse of statistics are recognized as top contributing factors to the reproducibility crisis. In this article, we revisit foundational statistical concepts relevant to reproducible research in the context of the animal sciences, raise awareness on common statistical misuse undermining it, and outline recommendations for statistical practice. Specifically, we emphasize a keen understanding of the data generation process throughout the research endeavor, from thoughtful experimental design and randomization, through rigorous data analysis and inference, to careful wording in communicating research results to peer scientists and society in general. We provide a detailed discussion of core concepts in experimental design, including data architecture, experimental replication, and subsampling, and elaborate on practical implications for proper elicitation of the scope of reach of research findings. For data analysis, we emphasize proper implementation of mixed models, in terms of both distributional assumptions and specification of fixed and random effects to explicitly recognize multilevel data architecture. This is critical to ensure that experimental error for treatments of interest is properly recognized and inference is correctly calibrated. Inferential misinterpretations associated with use of P-values, both significant and not, are clarified, and problems associated with error inflation due to multiple comparisons and selective reporting are illustrated. Overall, we advocate for a responsible practice of statistics in the animal sciences, with an emphasis on continuing quantitative education and interdisciplinary collaboration between animal scientists and statisticians to maximize reproducibility of research findings.

eRP arrangement: a strategy for assembled genomic contig rearrangement based on replication profiling in bacteria.

BACKGROUND: The reduced cost of sequencing has made de novo sequencing and the assembly of draft microbial genomes feasible in any ordinary biology lab. However, the process of finishing and completing the genome remains labor-intensive and computationally challenging in some cases, such as in the study of complete genome sequences, genomic rearrangements, long-range syntenic relationships, and structural variations. METHODS: Here, we show a contig reordering strategy based on experimental replication profiling (eRP) to recapitulate the bacterial genome structure within draft genomes. During the exponential growth phase, the majority of bacteria show a global genomic copy number gradient that is enriched near the replication origin and gradually declines toward the terminus. Therefore, if genome sequencing is performed with appropriate timing, the short-read coverage reflects this copy number gradient, providing information about the contig positions relative to the replication origin and terminus. RESULTS: We therefore investigated the appropriate timing for genomic DNA sampling and developed an algorithm for the reordering of the contigs based on eRP. As a result, this strategy successfully recapitulates the genomic structure of various structural mutants with draft genome sequencing. CONCLUSIONS: Our strategy was successful for contig rearrangement with intracellular DNA replication behavior mechanisms and can be applied to almost all bacteria because the DNA replication system is highly conserved. Therefore, eRP makes it possible to understand genomic structural information and long-range syntenic relationships using a draft genome that is based on short reads.

Web-Based Positive Psychology Interventions: A Reexamination of Effectiveness.

OBJECTIVE: Seligman, Steen, Park, and Peterson (2005) suggested that positive psychology interventions (PPIs) contain specific, powerful, therapeutic ingredients that effect greater increases in happiness and reductions in depression than a placebo control. This study reexamined the three PPIs that Seligman et al. found to be most effective when delivered over the internet. METHOD: Three PPIs and a placebo control, identical with the interventions used by Seligman et al., were examined in a web-based, randomized assignment design. RESULTS: Mixed-design analysis of variance and multilevel modeling showed that all interventions, including the placebo, led to significant increases in happiness and reductions in depression. The effects of PPIs were indistinguishable from those of the placebo control. CONCLUSION: Using web-based delivery, both PPIs and theoretically neutral placebos can increase happiness and reduce depression in self-selected populations. Possible explanations include that non-specific factors common to most therapeutic treatments are responsible for the observed changes, or that cultural or other context-related variables operate to account for the divergent findings.

Site fidelity and homing behaviour of intertidal sculpins revisited.

To assess the repeatability of an ecological study, this study both partially replicates and extends a previous study on the site fidelity and homing ability of two abundant and ecologically important species of rocky intertidal sculpin fishes, Oligocottus maculosus and Oligocottus snyderi. A traditional mark and recapture approach was utilized and found that both of these species display high site fidelity to a home range of tidepools and homing ability to these pools, confirming the findings of previous work. Unlike the previous study, however, there was no effect of body size on homing ability and a modelling approach that incorporates encounter probability provided evidence for a sex effect on homing ability. In addition, this study extends the maximum homing ability of O. snyderi to 179 m and O. maculosus to 218 m, which were the maximum displacement distances for each species in this study, suggesting they may be capable of even greater homing distances. This work, however, finds that homing success was negatively related to displacement distance. These findings suggest adult sculpin populations are likely to be highly sub-structured geographically, possibly contributing to the exceptionally high species richness of the group.

Evidence of toothpick groove formation in Neandertal anterior and posterior teeth.

OBJECTIVES: During the microscopic examination of the Neandertal dentitions from El Sidrón (Spain) and Hortus (France), we found unusual fine parallel microstriations on the mesial and distal sides of all tooth types, near the cervix. As its appearance was similar to toothpick grooves described in other Homo species, it could correspond to early stages on its formation. To test this hypothesis we developed an experimental replication of a groove using grass stalks. MATERIALS AND METHODS: Comparisons between 204 isolated Neandertal teeth and the two experimental dental specimens corroborate that the marks correspond to initial stages of toothpick groove formation, and we propose a five-grade recording scale that summarized the groove formation process. RESULTS: Using this new recording procedure, we found that Hortus individuals have higher incidence of this trait (eight individuals out of nine) than the El Sidrón individuals (nine out of 11). Toothpick grooves from El Sidrón show the earliest stages of development, whereas the grooves found on Hortus Neandertals were well-developed. Toothpick grooves were also found in 21 incisors and canines. CONCLUSIONS: These differences could be due to the more advanced occlusal dental wear in Hortus individuals, maybe age-related and with a more meat-based diet maybe favoring the inclusion of food debris and thus probing as the cleaning methodology. Our results allow the identification and characterization of incipient toothpick grooves on the human fossil record and contribute to increase our knowledge on Neandertals behavioral and oral care habits.

Harnessing the Undiscovered Resource of Student Research Projects.

This article suggests that undergraduate research can help advance the science of psychology. We introduce a hypothetical "question-list paradigm" as a mechanism to do this. Each year, thousands of undergraduate projects are completed as part of the educational experience. Although many of these studies may not contain sufficient contributions for publication, they provide a good test of the replicability of established findings across populations at different institutions and geographic locations. Thus, these projects could meet the needs of recent calls for increased replications of psychological studies while simultaneously benefiting the student researchers, their instructors, and the field in general.