Construct Validity of a Simple Laparoscopic Ovarian Cystectomy Model Using a Validated Objective Structured Assessment of Technical Skills.

STUDY OBJECTIVE: To determine the construct validity and interrater reliability of a laparoscopic ovarian cystectomy simulator using a global rating scale. DESIGN: Prospective blinded observational study (Canadian Task Force classification II.3). SETTING: Academic teaching hospital. PARTICIPANTS: A total of 26 postgraduate year (PGY) 1 to 4 gynecology and obstetrics residents were recruited (15 junior residents, postgraduate year PGY 1-2 and 11 senior residents, PGY 3-4). INTERVENTION: We developed a simple, low-cost laparoscopic ovarian cystectomy simulator and incorporated it into our simulation curriculum. The simulation was directed at junior residents with instruction and immediate feedback in a scheduled simulation session once during the academic year. At the end of the year resident skills assessment, all levels were recorded with video using this model to assess the construct validity between junior and senior residents. Resident performance was later evaluated and scored by 2 blinded, experienced laparoscopists using a validated Objective Structured Assessment of Technical Skills (OSATS). MEASUREMENT AND MAIN RESULTS: Each resident received a unique identification number and the simulated laparoscopic ovarian cystectomy procedure was filmed during the end of the year assessment. Two blinded raters evaluated the video of each resident with the modified Global Rating Scale (OSATS), using 5 of the 7 domains (respect for tissue, time and motion, instrument handling, flow of operation and knowledge of specific procedure). An average of the 2 ratings was computed for each domain, and comparisons were made using the Mann-Whitney U test. Interrater reliability was calculated using the Kendall tau ß correlation coefficient. Construct validity was determined by comparing the rank scores of the junior to senior residents in each domain. Construct validity and interrater reliability was demonstrated in all of the measured domains except for respect for tissue. CONCLUSION: This simple, low-cost model can be used to teach important laparoscopic ovarian cystectomy skills. Construct validity discriminating between junior and senior residents was demonstrated using this model.

Repeated loss of function at HD mating-type genes and of recombination suppression without mating-type locus linkage in anther-smut fungi.

A wide diversity of mating systems occur in nature, with frequent evolutionary transitions in mating-compatibility mechanisms. Basidiomycete fungi typically have two mating-type loci controlling mating compatibility, HD and PR, usually residing on different chromosomes. In Microbotryum anther-smut fungi, there have been repeated events of linkage between the two mating-type loci through chromosome fusions, leading to large non-recombining regions. By generating high-quality genome assemblies, we found that two sister Microbotryum species parasitizing Dianthus plants, M. superbum and M. shykoffianum, as well as the distantly related M. scorzonarae, have their HD and PR mating-type loci on different chromosomes, but with the PR mating-type chromosome fused with part of the ancestral HD chromosome. Furthermore, progressive extensions of recombination suppression have generated evolutionary strata. In all three species, rearrangements suggest the existence of a transient stage of HD-PR linkage by whole chromosome fusion, and, unexpectedly, the HD genes lost their function. In M. superbum, multiple natural diploid strains were homozygous, and the disrupted HD2 gene was hardly expressed. Mating tests confirmed that a single genetic factor controlled mating compatibility (i.e. PR) and that haploid strains with identical HD alleles could mate and produce infectious hyphae. The HD genes have therefore lost their function in the control of mating compatibility in these Microbotryum species. While the loss of function of PR genes in mating compatibility has been reported in a few basidiomycete fungi, these are the first documented cases for the loss of mating-type determination by HD genes in heterothallic fungi. The control of mating compatibility by a single genetic factor is beneficial under selfing and can thus be achieved repeatedly, through evolutionary convergence in distant lineages, involving different genomic or similar pathways.