Application of Cognitive Engineering Principles to the Redesign of a Dichotomous Identification Key for Parasitology

Dichotomous identification keys are used throughout biology for identification of plants, insects, and parasites. However, correct use of identification keys can be difficult as they are not usually intended for novice users who may not be familiar with the terminology used or with the morphology of the organism being identified. Therefore, we applied cognitive engineering principles to redesign a parasitology identification key for the Internet. We addressed issues of visual clutter and spatial distance by displaying a single question couplet at a time and by switching to the appropriate next couplet after the user made a choice. Our analysis of the original paper-based key versus the Web-based approach found that of 26 applicable cognitive engineering principles, the paper key did not meet 4 (15%) and partially met 11 (42%). In contrast, the redesigned key met 100% of 32 applicable cognitive engineering principles.

Lipid-protein interactions drive membrane protein topogenesis in accordance with the positive inside rule.

Transmembrane domain orientation within some membrane proteins is dependent on membrane lipid composition. Initial orientation occurs within the translocon, but final orientation is determined after membrane insertion by interactions within the protein and between lipid headgroups and protein extramembrane domains. Positively and negatively charged amino acids in extramembrane domains represent cytoplasmic retention and membrane translocation forces, respectively, which are determinants of protein orientation. Lipids with no net charge dampen the translocation potential of negative residues working in opposition to cytoplasmic retention of positive residues, thus allowing the functional presence of negative residues in cytoplasmic domains without affecting protein topology.

New Name, New Format, New Publisher, Same Principles and Values

This issue of the Journal of Family Strengths is an opportunity for a fresh start, as the Family Preservation Journal is renewed and revived under a new name and a new format. Still keen on being a definitive record on developments in family strengths and parenting, the Journal is devoted to presenting theory, practice and evaluation articles on the strengths perspective in family preservation practice, all to assure and improve services and programs that promote and sustain family systems.

External validation study of a clinical prediction rule for ambulation outcomes after traumatic spinal cord injury

The main objective of this study was to determine the external validity of a clinical prediction rule developed by the European Multicenter Study on Human Spinal Cord Injury (EM-SCI) to predict the ambulation outcomes 12 months after traumatic spinal cord injury. Data from the North American Clinical Trials Network (NACTN) data registry with approximately 500 SCI cases were used for this validity study. The predictive accuracy of the EM-SCI prognostic model was evaluated using calibration and discrimination based on 231 NACTN cases. The area under the receiver-operating-characteristics curve (ROC) curve was 0.927 (95% CI 0.894 – 0.959) for the EM-SCI model when applied to NACTN population. This is lower than the AUC of 0.956 (95% CI 0.936 – 0.976) reported for the EM-SCI population, but suggests that the EM-SCI clinical prediction rule distinguished well between those patients in the NACTN population who were able to achieve independent ambulation and those who did not achieve independent ambulation. The calibration curve suggests that higher the prediction score is, the better the probability of walking with the best prediction for AIS D patients. In conclusion, the EM-SCI clinical prediction rule was determined to be generalizable to the adult NACTN SCI population.^