Crowdsourced assessment of surgical skill proficiency in cataract surgery

OBJECTIVE: To test whether crowdsourced lay raters can accurately assess cataract surgical skills. DESIGN: Two-armed study: independent cross-sectional and longitudinal cohorts. SETTING: Washington University Department of Ophthalmology. PARTICIPANTS AND METHODS: Sixteen cataract surgeons with varying experience levels submitted cataract surgery videos to be graded by 5 experts and 300+ crowdworkers masked to surgeon experience. Cross-sectional study: 50 videos from surgeons ranging from first-year resident to attending physician, pooled by years of training. Longitudinal study: 28 videos obtained at regular intervals as residents progressed through 180 cases. Surgical skill was graded using the modified Objective Structured Assessment of Technical Skill (mOSATS). Main outcome measures were overall technical performance, reliability indices, and correlation between expert and crowd mean scores. RESULTS: Experts demonstrated high interrater reliability and accurately predicted training level, establishing construct validity for the modified OSATS. Crowd scores were correlated with (r = 0.865, p \u3c 0.0001) but consistently higher than expert scores for first, second, and third-year residents (p \u3c 0.0001, paired t-test). Longer surgery duration negatively correlated with training level (r = -0.855, p \u3c 0.0001) and expert score (r = -0.927, p \u3c 0.0001). The longitudinal dataset reproduced cross-sectional study findings for crowd and expert comparisons. A regression equation transforming crowd score plus video length into expert score was derived from the cross-sectional dataset (r CONCLUSIONS: Crowdsourced rankings correlated with expert scores, but were not equivalent; crowd scores overestimated technical competency, especially for novice surgeons. A novel approach of adjusting crowd scores with surgery duration generated a more accurate predictive model for surgical skill. More studies are needed before crowdsourcing can be reliably used for assessing surgical proficiency

Perceived intensity of somatosensory cortical electrical stimulation

Artificial sensations can be produced by direct brain stimulation of sensory areas through implanted microelectrodes, but the perceptual psychophysics of such artificial sensations are not well understood. Based on prior work in cortical stimulation, we hypothesized that perceived intensity of electrical stimulation may be explained by the population response of the neurons affected by the stimulus train. To explore this hypothesis, we modeled perceived intensity of a stimulation pulse train with a leaky neural integrator. We then conducted a series of two-alternative forced choice behavioral experiments in which we systematically tested the ability of rats to discriminate frequency, amplitude, and duration of electrical pulse trains delivered to the whisker barrel somatosensory cortex. We found that the model was able to predict the performance of the animals, supporting the notion that perceived intensity can be largely accounted for by spatiotemporal integration of the action potentials evoked by the stimulus train

Developing the Next Generation of Entrepreneurs: Giving Students the Opportunity to Gain Experience and Thrive

Higher Education Institutions (HEIs) have increasingly utilized experiential approaches in business education; however, some researchers have suggested that further research is required to investigate the effectiveness and student reaction to such approaches. The aim of this study is to determine the impact of an experiential learning approach on the perceived development of entrepreneurial traits and to measure the level of both student engagement and satisfaction. The approach was designed and tested during a Higher National Diploma (HND) entrepreneurship module in a British HEI. Traditional taught sessions were blended with applied activities that required students to utilize the skills they learned to complete steps of the activities, which increased in length and complexity. Results found both a high level of student satisfaction and engagement and the belief that the module’s experiential approach had, in many instances, helped to develop entrepreneurial traits. Successful practice and modifications are discussed

Beringia as a High-Latitude Engine of Avian Speciation

Beringia is a biogeographically dynamic region that extends from northeastern Asia into northwestern North America. This region has affected avian divergence and speciation in three important ways: (i) by serving as a route for intercontinental colonisation between Asia and the Americas; (ii) by cyclically splitting (and often reuniting) populations, subspecies, and species between these continents; and (iii) by providing isolated refugia through glacial cycles. The effects of these processes can be seen in taxonomic splits of shallow to increasing depths and in the presence of regional endemics. We review the taxa involved in the latter two processes (splitting–reuniting and isolation), with a focus on three research topics: avian diversity, time estimates of the generation of that diversity, and the regions within Beringia that might have been especially important. We find that these processes have generated substantial amounts of avian diversity, including 49 pairs of avian subspecies or species whose breeding distributions largely replace one another across the divide between the Old World and the New World in Beringia, and 103 avian species and subspecies endemic to this region. Among endemics, about one in three is recognised as a full biological species. Endemic taxa in the orders Charadriiformes (shorebirds, alcids, gulls, and terns) and Passeriformes (perching birds) are particularly well represented, although they show very different levels of diversity through evolutionary time. Endemic Beringian Charadriiformes have a 1.31:1 ratio of species to subspecies. In Passeriformes, endemic taxa have a 0.09:1 species-to-subspecies ratio, suggesting that passerine (and thus terrestrial) endemism might be more prone to long-term extinction in this region, although such ‘losses’ could occur through their being reconnected with wider continental populations during favourable climatic cycles (e.g. subspecies reintegration with other populations). Genetic evidence suggests that most Beringian avian taxa originated over the past 3 million years, confirming the importance of Quaternary processes. There seems to be no obvious clustering in their formation through time, although there might be temporal gaps with lower rates of diversity generation. For at least 62 species, taxonomically undifferentiated populations occupy this region, providing ample potential for future evolutionary diversification

High-frequency genome editing using ssDNA oligonucleotides with zinc-finger nucleases

Zinc-finger nucleases (ZFNs) have enabled highly efficient gene targeting in multiple cell types and organisms. Here we describe methods for using simple ssDNA oligonucleotides in tandem with ZFNs to efficiently produce human cell lines with three distinct genetic outcomes: (i) targeted point mutation, (ii) targeted genomic deletion of up to 100 kb and (iii) targeted insertion of small genetic elements concomitant with large genomic deletions

Ethanol Inhibits Antigen Presentation by Dendritic Cells▿

Previous studies suggest that altered virus-specific T-cell responses observed during chronic ethanol exposure may be due to abnormal functioning of dendritic cells (DCs). Here we explored the effects of ethanol on exogenous antigen presentation by DCs. BALB/c, C57BL/6, and CBA/caj mice were fed ethanol or an isocaloric control diet for 8 weeks. The splenic DC population was expanded using an Flt3L expression plasmid via tail vein injection. DCs were purified and assessed for antigen presentation and processing and for peptide-major histocompatibility complex class I and II (MHCI and MHCII) formation on the cell surface. Interleukin-2 (IL-2) was measured as an indicator of antigen-specific T-cell activation by DCs in coculture. Antigen processing and peptide-MHCII complexes were evaluated by flow cytometry. We observed that ethanol not only suppressed allogeneic peptide presentation to T cells by DCs but also altered presentation of exogenous ovalbumin (OVA) peptide 323-339 to an OVA-specific DO11 T-cell line as well as to OVA-sensitized primary T cells. Smaller amounts of peptide-MHCII complexes were found on the DCs isolated from the spleens of ethanol-fed mice. In contrast to MHCII presentation, cross-presentation of exogenous OVA peptide via MHCI by DCs remained intact. More importantly, ethanol-exposed DCs had reduced B7-DC and enhanced ICOS-L (inhibitory) costimulatory molecule expression. Ethanol inhibits exogenous and allogeneic antigen presentation and affects the formation of peptide-MHCII complexes, as well as altering costimulatory molecule expression on the cell surface. Therefore, DC presentation of peptides in a favorable costimulatory protein environment is required to subsequently activate T cells and appears to be a critical target for the immunosuppressive effects of ethanol