Learnersourcing Subgoal Labels for How-to Videos

Websites like YouTube host millions of how-to videos, but the interfaces are not optimized for learning. Previous research suggests that users learn more from how-to videos when the information from the video is presented in outline form, with individual steps and labels for groups of steps (subgoals) shown. We envision an alternative video player where the steps and subgoals are displayed alongside the video. To generate this information for existing videos, we propose a learnersourcing approach, where people actively learning from a video provide such information. To demonstrate this method, we created a workflow where learners contribute and refine subgoal labels for how-to videos. We deployed a live website with our workflow implemented on a set of introductory web programming videos. For the four videos with the highest participation, we found that a majority of learner-generated subgoals were comparable in quality to expert-generated ones. Learners commented that the system helped them grasp the material, suggesting that our workflow did not detract from the learning experience.Massachusetts Institute of Technology. Undergraduate Research Opportunities ProgramCisco Systems, Inc.Quanta Computer (Firm) (Qmulus Project)National Science Foundation (U.S.) (Award SOCS-1111124)Alfred P. Sloan Foundation (Sloan Research Fellowship)Samsung (Firm) (Fellowship

Crowdsourcing step-by-step information extraction to enhance existing how-to videos

Millions of learners today use how-to videos to master new skills in a variety of domains. But browsing such videos is often tedious and inefficient because video player interfaces are not optimized for the unique step-by-step structure of such videos. This research aims to improve the learning experience of existing how-to videos with step-by-step annotations. We first performed a formative study to verify that annotations are actually useful to learners. We created ToolScape, an interactive video player that displays step descriptions and intermediate result thumbnails in the video timeline. Learners in our study performed better and gained more self-efficacy using ToolScape versus a traditional video player. To add the needed step annotations to existing how-to videos at scale, we introduce a novel crowdsourcing workflow. It extracts step-by-step structure from an existing video, including step times, descriptions, and before and after images. We introduce the Find-Verify-Expand design pattern for temporal and visual annotation, which applies clustering, text processing, and visual analysis algorithms to merge crowd output. The workflow does not rely on domain-specific customization, works on top of existing videos, and recruits untrained crowd workers. We evaluated the workflow with Mechanical Turk, using 75 cooking, makeup, and Photoshop videos on YouTube. Results show that our workflow can extract steps with a quality comparable to that of trained annotators across all three domains with 77% precision and 81% recall

High pressure transport studies of the LiFeAs analogues CuFeTe2 and Fe2As

We have synthesized two iron-pnictide/chalcogenide materials, CuFeTe2 and Fe2As, which share crystallographic features with known iron-based superconductors, and carried out high-pressure electrical resistivity measurements on these materials to pressures in excess of 30 GPa. Both compounds crystallize in the Cu2Sb-type crystal structure that is characteristic of LiFeAs (with CuFeTe2 exhibiting a disordered variant). At ambient pressure, CuFeTe2 is a semiconductor and has been suggested to exhibit a spin-density-wave transition, while Fe2As is a metallic antiferromagnet. The electrical resistivity of CuFeTe2, measured at 4 K, decreases by almost two orders of magnitude between ambient pressure and 2.4 GPa. At 34 GPa, the electrical resistivity decreases upon cooling the sample below 150 K, suggesting the proximity of the compound to a metal-insulator transition. Neither CuFeTe2 nor Fe2As superconduct above 1.1 K throughout the measured pressure range.Comment: 6 pages, 7 figure

Rural men and mental health: their experiences and how they managed

There is a growing awareness that a primary source of information about mental health lies with the consumers. This article reports on a study that interviewed rural men with the aim of exploring their mental health experiences within a rural environment. The results of the interviews are a number of stories of resilience and survival that highlight not only the importance of exploring the individuals' perspective of their issues, but also of acknowledging and drawing on their inner strengths. Rural men face a number of challenges that not only increase the risk of mental illness but also decrease the likelihood of them seeking and/or finding professional support. These men's stories, while different from each other, have a common thread of coping. Despite some support from family and friends participants also acknowledged that seeking out professional support could have made the recovery phase easier. Mental health nurses need to be aware, not only of the barrier to professional support but also of the significant resilience that individuals have and how it can be utilised

How is it best to deliver care in acute medical units? A systematic review

The majority of medical patients presenting to hospital in the UK are cared for in acute medical units (AMUs). Such units are also increasingly present internationally. Care delivery varies across units: this review aims to examine the evidence for how best to deliver AMU care. Six electronic databases and grey literature were searched. Inclusion criteria comprised interventions applied to undifferentiated patients in AMU settings. All studies were quality assessed. A narrative approach was undertaken. Nine studies, all conducted in the UK or Ireland, evaluated 1.3 million episodes, 3617 patients and 49 staff. There was single study evidence for beneficial effects of: enhanced pharmacy care, a dedicated occupational therapy service, an all-inclusive consultant work pattern, a rapid-access medical clinic and formalized handovers. Two studies found increased consultant presence was associated with reduced mortality; one of these studies found an association with a reduction in 28-day readmissions; and the other found an association with an increased proportion of patients discharged on the day they were admitted. Three studies provide evidence of the beneficial effects of multiple interventions developed from local service reviews. Overall, the quality of the evidence was limited. This review has identified operationally relevant evidence that increased consultant presence is associated with improved outcomes of care; has highlighted the potential to improve outcomes locally through service reviews; and has demonstrated an important knowledge gap of how best to deliver AMU care. These findings have importance given the challenges acute services currently face

Estimating hidden population sizes with venue-based sampling: Extensions of the generalized network scale-up estimator

Background: Researchers use a variety of population size estimation methods to determine the sizes of key populations at elevated risk of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), an important step in quantifying epidemic impact, advocating for high-risk groups, and planning, implementing, and monitoring prevention, care, and treatment programs. Conventional procedures often use information about sample respondents' social network contacts to estimate the sizes of key populations of interest. A recent study proposes a generalized network scale-up method that combines two samples - a traditional sample of the general population and a link-tracing sample of the hidden population - and produces more accurate results with fewer assumptions than conventional approaches. Methods: We extended the generalized network scale-up method from link-tracing samples to samples collected with venue-based sampling designs popular in sampling key populations at risk of HIV. Our method obviates the need for a traditional sample of the general population, as long as the size of the venue-attending population is approximately known. We tested the venue-based generalized network scale-up method in a comprehensive simulation evaluation framework. Results: The venue-based generalized network scale-up method provided accurate and efficient estimates of key population sizes, even when few members of the key population were sampled, yielding average biases below ±6% except when false-positive reporting error is high. It relies on limited assumptions and, in our tests, was robust to numerous threats to inference. Conclusions: Key population size estimation is vital to the successful implementation of efforts to combat HIV/AIDS. Venue-based network scale-up approaches offer another tool that researchers and policymakers can apply to these problems

Programmed Iteration Controls the Assembly of the Nonanoic Acid Side Chain of the Antibiotic Mupirocin

\ua9 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH. Mupirocin is a clinically important antibiotic produced by Pseudomonas fluorescens NCIMB 10586 that is assembled by a complex trans-AT polyketide synthase. The polyketide fragment, monic acid, is esterified by a 9-hydroxynonanoic acid (9HN) side chain which is essential for biological activity. The ester side chain assembly is initialised from a 3-hydroxypropionate (3HP) starter unit attached to the acyl carrier protein (ACP) MacpD, but the fate of this species is unknown. Herein we report the application of NMR spectroscopy, mass spectrometry, chemical probes and in vitro assays to establish the remaining steps of 9HN biosynthesis. These investigations reveal a complex interplay between a novel iterative or “stuttering” KS-AT didomain (MmpF), the multidomain module MmpB and multiple ACPs. This work has important implications for understanding the late-stage biosynthetic steps of mupirocin and will be important for future engineering of related trans-AT biosynthetic pathways (e.g. thiomarinol)

Atmospheric Methane in GEOS-5: Development of the Methane Module in GEOS, Current Status and Planned Capabilities

No abstract availabl