Temporal-Difference Learning to Assist Human Decision Making during the Control of an Artificial Limb

In this work we explore the use of reinforcement learning (RL) to help with human decision making, combining state-of-the-art RL algorithms with an application to prosthetics. Managing human-machine interaction is a problem of considerable scope, and the simplification of human-robot interfaces is especially important in the domains of biomedical technology and rehabilitation medicine. For example, amputees who control artificial limbs are often required to quickly switch between a number of control actions or modes of operation in order to operate their devices. We suggest that by learning to anticipate (predict) a user's behaviour, artificial limbs could take on an active role in a human's control decisions so as to reduce the burden on their users. Recently, we showed that RL in the form of general value functions (GVFs) could be used to accurately detect a user's control intent prior to their explicit control choices. In the present work, we explore the use of temporal-difference learning and GVFs to predict when users will switch their control influence between the different motor functions of a robot arm. Experiments were performed using a multi-function robot arm that was controlled by muscle signals from a user's body (similar to conventional artificial limb control). Our approach was able to acquire and maintain forecasts about a user's switching decisions in real time. It also provides an intuitive and reward-free way for users to correct or reinforce the decisions made by the machine learning system. We expect that when a system is certain enough about its predictions, it can begin to take over switching decisions from the user to streamline control and potentially decrease the time and effort needed to complete tasks. This preliminary study therefore suggests a way to naturally integrate human- and machine-based decision making systems.Comment: 5 pages, 4 figures, This version to appear at The 1st Multidisciplinary Conference on Reinforcement Learning and Decision Making, Princeton, NJ, USA, Oct. 25-27, 201

Marked expansion of exocrine and endocrine pancreas with incretin therapy in humans with increased exocrine pancreas dysplasia and the potential for glucagon-producing neuroendocrine tumors.

Controversy exists regarding the potential regenerative influences of incretin therapy on pancreatic β-cells versus possible adverse pancreatic proliferative effects. Examination of pancreata from age-matched organ donors with type 2 diabetes mellitus (DM) treated by incretin therapy (n = 8) or other therapy (n = 12) and nondiabetic control subjects (n = 14) reveals an ∼40% increased pancreatic mass in DM treated with incretin therapy, with both increased exocrine cell proliferation (P < 0.0001) and dysplasia (increased pancreatic intraepithelial neoplasia, P < 0.01). Pancreata in DM treated with incretin therapy were notable for α-cell hyperplasia and glucagon-expressing microadenomas (3 of 8) and a neuroendocrine tumor. β-Cell mass was reduced by ∼60% in those with DM, yet a sixfold increase was observed in incretin-treated subjects, although DM persisted. Endocrine cells costaining for insulin and glucagon were increased in DM compared with non-DM control subjects (P < 0.05) and markedly further increased by incretin therapy (P < 0.05). In conclusion, incretin therapy in humans resulted in a marked expansion of the exocrine and endocrine pancreatic compartments, the former being accompanied by increased proliferation and dysplasia and the latter by α-cell hyperplasia with the potential for evolution into neuroendocrine tumors

Human capital in family businesses: Focusing on the individual level

This article focuses on the construct of human capital in family businesses. It makes three key contributions. First, it furthers our understanding of human capital in family businesses by identifying the underlying dimensions of human capital, involving not only knowledge, skills and abilities but also individual attitudes and motivation. Second, the article puts forward the conditions under which family businesses can achieve and sustain over time an alignment of interests between individual human capital and organizational goals. These conditions will vary depending on whether the external environment is static or dynamic. Third, the article heeds the call, shared by strategic management scholars, to focus on the individual level as well as on the (predominant) group- and organizational-level constructs

Euripides\u27 \u27Andromache\u27 and Athenian Hegemonic Ideology

Scholarship on the political character of Athenian tragedy has increasingly turned its attention to the relationship between tragedy and empire. In Athenian panegyric, Athens’ rule is frequently portrayed as hegemonic, although historiographical sources reveal inconsistencies between the idealized image of the city and the historical realities of empire. Several recent approaches have concentrated especially on tragedies that feature an Athenian setting or character in the dramatic action as a means to explore the ways in which the plays engage with Athenian ideas on power and domination. In response, the primary aim of this analysis is an understanding of the way Athenian hegemonic ideology operates in tragedy when ‘Athens’ is conspicuously absent. To this effect, I argue that Euripides’ Andromache offers insight into how the Athenians conceptualized their roles as leaders of an empire. I suggest that the political overtones of the play are conveyed by the marriage alliance between the Spartan and Thessalian characters, which had implications for the historical relations between Athens, Sparta, and Thessaly. My approach, therefore, can be classified broadly speaking as belonging to the methodology of ‘audience studies’, as it considers what the play signified for the members of its original audience. In this regard, I draw on comparative analysis of the historical context of the drama as evidenced in Thucydides, the rest of Athenian tragedy, and other contemporary texts. The theoretical foundation of my analysis is informed by Antonio Gramsci’s theory of hegemony and the study of colonial discourse, first popularized by Edward Said, both of which conceive of predominance as achieved through the consent or inclusion of dominated parties. In keeping with these concepts, I suggest that the ideological message of Andromache speaks on two levels: the first is in part directed outward at subordinate groups and works to disseminate and promote an ideology, which actively contested the competing voice advanced by Sparta and implicitly justified Athens’ position of leadership over Greek city-states. The second is targeted inward at the Athenian audience members themselves and encourages self-reflection and criticism, a necessary precondition of a dominant group’s attainment and preservation of hegemonic status

End-of-life priorities of older adults with terminal illness and caregivers: A qualitative consultation

Abstract Background As older adults approach the end‐of‐life (EOL), many are faced with complex decisions including whether to use medical advances to prolong life. Limited information exists on the priorities of older adults at the EOL. Objective This study aimed to explore patient and family experiences and identify factors deemed important to quality EOL care. Method A descriptive qualitative study involving three focus group discussions (n = 18) and six in‐depth interviews with older adults suffering from either a terminal condition and/or caregivers were conducted in NSW, Australia. Data were analysed thematically. Results Seven major themes were identified as follows: quality as a priority, sense of control, life on hold, need for health system support, being at home, talking about death and competent and caring health professionals. An underpinning priority throughout the seven themes was knowing and adhering to patient's wishes. Conclusion Our study highlights that to better adhere to EOL patient's wishes a reorganization of care needs is required. The readiness of the health system to cater for this expectation is questionable as real choices may not be available in acute hospital settings. With an ageing population, a reorganization of care which influences the way we manage terminal patients is required