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Learning from human demonstration (LfD), among many speedup techniques for reinforcement learning (RL), has seen many successful applications. We consider one LfD technique called human–agent transfer (HAT), where a model of the human demonstrator’s decision function is induced via supervised learning and used as an initial bias for RL. Some recent work in LfD has investigated learning from observations only, that is, when only the demonstrator’s states (and not its actions) are available to the learner. Since the demonstrator’s actions are treated as labels for HAT, supervised learning becomes untenable in their absence. We adapt the idea of learning an inverse dynamics model from the data acquired by the learner’s interactions with the environment and deploy it to fill in the missing actions of the demonstrator. The resulting version of HAT—called state-only HAT (SoHAT)—is experimentally shown to preserve some advantages of HAT in benchmark domains with both discrete and continuous actions. This paper also establishes principled modifications of an existing baseline algorithm—called A3C—to create its HAT and SoHAT variants that are used in our experiments.
Through diversity of composition, sequence, and interfacial structure, hybrid materials greatly expand the palette of materials available to access novel functionality. The NSF Division of Materials Research recently supported a workshop (October 17–18, 2019) aiming to (1) identify fundamental questions and potential solutions common to multiple disciplines within the hybrid materials community; (2) initiate interfield collaborations between hybrid materials researchers; and (3) raise awareness in the wider community about experimental toolsets, simulation capabilities, and shared facilities that can accelerate this research. This article reports on the outcomes of the workshop as a basis for cross-community discussion. The interdisciplinary challenges and opportunities are presented, and followed with a discussion of current areas of progress in subdisciplines including hybrid synthesis, functional surfaces, and functional interfaces.
Military attachés and wartime observers have received surprisingly little attention in international relations. Why do states exchange attachés, permitting uniformed foreigners to gather intelligence on their territory and during their wars? To explain, we adopt a broadly practice-theoretic approach, focusing on the individuals who developed the role by living it, showing how they both innovated a distinct military practice and established institutional legitimacy for attachés. We address an early historical case in which the practice proliferated: the Russo-Japanese War, throughout which observers represented multiple European states, on both sides of the conflict. Sometimes termed the first modern war, the conflict saw Japan's entry into the Eurocentric great power system. In this context, embedded attachés had a dual effect. On the one hand, a professional attaché community established itself: we show how local innovation by embedded officers, in the context of this structurally destabilising event, permitted the creation of a new institutional role that might otherwise have been impossible. On the other, the Japanese made use of the attachés as witnesses for Western governments, observing their performance of great power-hood, as they defeated Russia. The argument has implications for understanding both the military attaché system and communities of practice as such.
To quantify the impact of clinical guidance and rapid respiratory and meningitis/encephalitis multiplex polymerase chain reaction (mPCR) testing on the management of infants.
Before-and-after intervention study.
Tertiary-care children’s hospital.
Infants ≤90 days old presenting with fever or hypothermia to the emergency department (ED).
The study spanned 3 periods: period 1, January 1, 2011, through December 31, 2014; period 2, January 1, 2015, through April 30, 2018; and period 3, May 1, 2018, through June 15, 2019. During period 1, no standardized clinical guideline had been established and no rapid pathogen testing was available. During period 2, a clinical guideline was implemented, but no rapid testing was available. During period 3, a guideline was in effect, plus mPCR testing using the BioFire FilmArray respiratory panel 2 (RP 2) and the meningitis encephalitis panel (MEP). Outcomes included antimicrobial and ancillary test utilization, length of stay (LOS), admission rate, 30-day mortality. Outcomes were compared across periods using Kruskal-Wallis and Pearson tests and interrupted time series analysis.
Overall 5,317 patients were included: 2,514 in period 1, 2,082 in period 2, and 721 in period 3. Over the entire study period, we detected reductions in the use of chest radiographs, lumbar punctures, LOS, and median antibiotic duration. After adjusting for temporal trends, we observed that the introduction of the guideline was associated with reductions in ancillary tests and lumbar punctures. Use of mPCR testing with the febrile infant clinical guideline was associated with additional reductions in ancillary testing for all patients and a higher proportion of infants 29–60 days old being managed without antibiotics.
Use of mPCR testing plus a guideline for young infant evaluation in the emergency department was associated with less antimicrobial and ancillary test utilization compared to the use of a guideline alone.
The role of medical students in the current coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving. The aim of this review is to explore the involvement of medical students in past global health emergencies, to help inform current and future scenarios.
A rapid systematic review was undertaken, including articles from online databases discussing the roles, willingness and appropriateness of medical student involvement in global health emergencies. Data were extracted, appraised and written up as a narrative synthesis. This study was registered with PROSPERO (CRD42020177231).
Twenty-eight articles were included. Medical students played a wide variety of clinical and nonclinical roles including education and logistics, although medical assistance was the most commonly reported role. Challenges included a lack of preparedness and negative mental health impacts. A total of 91.7% of included articles about willingness found medical students were more willing to be involved than not.
This review shows medical students are capable and willing to be involved in global health emergencies. However, there should be clear protocols for the roles that they play, taking into account the appropriateness. As a rapid review, there were study limitations and more research is required regarding the impact of these roles on medical students and the system.
A volume-area scaling relation is commonly used to estimate glacier volume or its future changes on a global scale. The presence of an insulating supraglacial debris cover alters the mass-balance profile of a glacier, potentially modifying the scaling relation. Here, the nature of scaling relations for extensively debris-covered glaciers is investigated. Theoretical arguments suggest that the volume-area scaling exponent for these glaciers is ~7% smaller than that for clean glaciers. This is consistent with the results from flowline-model simulations of idealised glaciers, and the available data from the Himalaya. The best-fit scale factor for debris-covered Himalayan glaciers is ~60% larger compared to that for the clean ones, implying a significantly larger stored ice volume in a debris-covered glacier compared to a clean one having the same area. These results may help improve scaling-based estimates of glacier volume and future glacier changes in regions where debris-covered glaciers are abundant.
Frailty is increasingly used in clinical settings to describe a physiological state resulting from a combination of age-related co-morbidities. Frailty also has a strong ‘lay’ meaning that conjures a particular way of being. Recent studies have reported how frail older people perceive the term frailty, showing that frailty is often an unwanted and resisted label. While there are many scores and measures that clinicians can use to determine frailty, little has been published regarding how health-care professionals use and make sense of the term. This paper reports the findings of a qualitative study that explored how health professionals perceive frailty. Forty situated interviews were conducted with health-care professionals working in an emergency department in the English Midlands. The interview talk was analysed using discourse analysis. The findings show that the health professionals negotiate an ‘ideological dilemma’ – a tension between contradictory sets of meanings and consequences for action – based on their ‘lay’ and clinical experience of the term frailty. It is concluded that this dilemma could have a negative impact on the assessment of frailty depending on the system of assessment used.
The coronavirus disease 2019 pandemic has resulted in various changes in knowledge, attitude and practice among doctors. A survey was conducted of otolaryngologists in India regarding these aspects in relation to the coronavirus disease 2019 pandemic.
Otolaryngologists from West Bengal (India) were invited to participate in an online self-administered survey. Data were collected and analysed using appropriate methods.
Responses from 133 participants, grouped into 4 groups by their career stage, were collected and analysed. Of the participants, 36.8 per cent were directly involved in treating a known or suspected coronavirus disease 2019 patient, although 66.2 per cent considered the personal protective equipment inadequate. Ninety-four per cent indicated that their willingness to perform procedures depended on personal protective equipment availability. Of the respondents, 83.5 per cent revealed additional mental stress due to the pandemic. Of the participants, 41.4 per cent took hydroxychloroquine as coronavirus disease 2019 prophylaxis.
This study provides an insight into which issues may need attention, to help ENT surgeons tackle the coronavirus disease 2019 pandemic more effectively based on analysis of responses in the survey.