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Purpose: Total hip arthroplasty (THA) using the direct anterior approach (DAA) is known to have a learning curve. The purpose of this study was to review cases where surgery was performed by an arthroplasty surgeon transitioning from the posterior approach (PA) to the DAA. We hypothesized similar complication rates and improvements in surgical duration over time., Materials and Methods: A review of 2,452 consecutive primary THAs was conducted. Surgical duration, length of stay (LOS), surgical complications, decrease in postoperative day (POD) 1 hemoglobin, transfusion rates, POD 0 and POD 1 pain scores, incision length, leg length discrepancy (LLD), and radiographic cup position were recorded., Results: No differences in surgical duration were observed after the first 50 DAA cases. A shorter LOS was observed for the DAA, and statistical difference was appreciated after the first 100 DAA cases. There were no differences in periprosthetic fractures. A higher rate of infections and hip dislocations were observed with the PA. The PA showed an association with higher transfusion rates without significant difference in POD 1 decrease in hemoglobin over the first 100 DAA cases. Similar POD 0 and POD 1 pain scores with a smaller incision were observed for the first 100 DAA cases. The DAA cohort showed less variation in cup inclination, version, and LLD., Conclusion: DAA is safe and non-inferior in terms of reduced LOS, smaller incision, and less variation in cup position. Fifty DAA cases was noted to be the learning curve required before no differences in duration between approaches were observed., Competing Interests: CONFLICT OF INTEREST: The authors declare that there is no potential conflict of interest relevant to this article., (Copyright © 2022 by Korean Hip Society.)

Parent-Child Interaction Therapy (PCIT) is one of the strongest evidence-based treatments available for young children and their families. Research has supported the use of PCIT for children with a history of trauma; however, the treatment does not directly address trauma in the child. PCIT is a dyadic treatment; yet, the impact of the carer's trauma on the carer-child relationship is not assessed or incorporated into treatment. For these reasons, therapists, families, agencies, and funders tend to view PCIT as a trauma treatment with skepticism. PCIT therapists who currently address trauma within the intervention do so without a standardized approach. Trauma-Directed Interaction (TDI) is an adaptation developed to directly address these concerns. TDI maintains the key elements and theoretical underpinnings of PCIT while adding sessions to cover psychoeducation about trauma, carer response to a child's trauma reactions (SAFE skills), and coping skills to aid both the child and the carer to manage trauma activators (COPE skills). The TDI module creates a consistent strategy for PCIT therapists to address trauma, thus allowing research and replication which will advance the dual fields of PCIT and family trauma. The theoretical conceptualization of TDI is presented along with next steps in its evaluation.

A popular theory explaining the maintenance of genetic recombination (sex) is the Red Queen Theory. This theory revolves around the idea that time-lagged negative frequency-dependent selection by parasites favors rare host genotypes generated through recombination. Although the Red Queen has been studied for decades, one of its key assumptions has remained unsupported. The signature host-parasite specificity underlying the Red Queen, where infection depends on a match between host and parasite genotypes, relies on epistasis between linked resistance loci for which no empirical evidence exists. We performed 13 genetic crosses and tested over 7000 Daphnia magna genotypes for resistance to two strains of the bacterial pathogen Pasteuria ramosa. Results reveal the presence of strong epistasis between three closely linked resistance loci. One locus masks the expression of the other two, while these two interact to produce a single resistance phenotype. Changing a single allele on one of these interacting loci can reverse resistance against the tested parasites. Such a genetic mechanism is consistent with host and parasite specificity assumed by the Red Queen Theory. These results thus provide evidence for a fundamental assumption of this theory and provide a genetic basis for understanding the Red Queen dynamics in the Daphnia-Pasteuria system., (© 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.)