Probabilistically Safe Policy Transfer

Although learning-based methods have great potential for robotics, one concern is that a robot that updates its parameters might cause large amounts of damage before it learns the optimal policy. We formalize the idea of safe learning in a probabilistic sense by defining an optimization problem: we desire to maximize the expected return while keeping the expected damage below a given safety limit. We study this optimization for the case of a robot manipulator with safety-based torque limits. We would like to ensure that the damage constraint is maintained at every step of the optimization and not just at convergence. To achieve this aim, we introduce a novel method which predicts how modifying the torque limit, as well as how updating the policy parameters, might affect the robot's safety. We show through a number of experiments that our approach allows the robot to improve its performance while ensuring that the expected damage constraint is not violated during the learning process

The experience of diagnostic radiography students during the early stages of the COVID‐19 pandemic – a cross‐sectional study

Abstract: Introduction: The rationale for this study was to ascertain the impact of the COVID‐19 pandemic on Undergraduate B.Sc (Hons) Diagnostic Radiography students at the University of Hertfordshire in the UK. This would provide an ideal opportunity for students to reflect on their experience and indicate if they required additional support from the University. Methods: An online anonymous cross‐sectional survey was deployed to all year groups (n = 283) during the first nationwide lockdown in May 2020, eliciting qualitative responses on questions about the effect of the pandemic; emotions experienced; support required and consideration of their choice of a career in the health sector. Results: Two hundred and one students responded to the survey, with many having experienced the illness or loss of a loved one. Trying to balance family commitments and study was a concern to some students, as well as struggling with the financial burden of job losses or furlough. Many students commented that educational support was a requirement with the move to online teaching and assessment. The main focus of student responses was the emotions that they had experienced, many of which were negative. Anxiety and fear were commonly expressed feelings, along with sadness and feelings of isolation. A small number of students reported feeling grateful, happy and relieved. An overwhelming majority of respondents commented that they were proud to be healthcare students and they were resolute in wanting to continue the course and join the frontline of the NHS workforce. Conclusion: Some students have been deeply affected by their experiences of the pandemic, and University support mechanisms should be refined to better assist with their ongoing challenges.Peer reviewe

Therapeutic hypothermia augments the restorative effects of PKC-β and Nox2 inhibition on an in vitro model of human blood–brain barrier

To investigate whether therapeutic hypothermia augments the restorative impact of protein kinase C-β (PKC-β) and Nox2 inhibition on an in vitro model of human blood–brain barrier (BBB). Cells cultured in normoglycaemic (5.5 mM) or hyperglycaemic (25 mM, 6 to 120 h) conditions were treated with therapeutic hypothermia (35 °C) in the absence or presence of a PKC-β inhibitor (LY333531, 0.05 μM) or a Nox2 inhibitor (gp91ds-tat, 50 μM). BBB was established by co-culture of human brain microvascular endothelial cells (HBMECs) with astrocytes (HAs) and pericytes. BBB integrity and function were assessed via transendothelial electrical resistance (TEER) and paracellular flux of sodium fluorescein (NaF, 376 Da). Nox activity (lucigenin assay), superoxide anion production (cytochrome-C reduction assay), cellular proliferative capacity (wound scratch assay) and actin cytoskeletal formation (rhodamine-phalloidin staining) were assessed both in HBMECs and HAs using the specific methodologies indicated in brackets. Therapeutic hypothermia augmented the protective effects of PKC-β or Nox2 inhibition on BBB integrity and function in experimental setting of hyperglycaemia, as evidenced by increases in TEER and concomitant decreases in paracellular flux of NaF. The combinatory approaches were more effective in repairing physical damage exerted on HBMEC and HA monolayers by wound scratch and in decreasing Nox activity and superoxide anion production compared to sole treatment regimen with either agent. Similarly, the combinatory approaches were more effective in suppressing actin stress fibre formation and maintaining normal cytoskeletal structure. Therapeutic hypothermia augments the cerebral barrier-restorative capacity of agents specifically targeting PKC-β or Nox2 pathways

Quality of life in survivors of adult haematological malignancy

Background: Survivors of haematological malignancies endure long-term effects of both treatment and disease. This paper examines factors that influence their quality of life through reporting on the results of a survey. Methods: survey using previously validated quality of life questionnaires for use in cancer management. Participants were adults aged 18 and ove who had completed treatment for a haematological malignancy and were between 1-5 years post treatment. Findings: 131 participants, median age of 66, completed questionnaires (66% response rate). Significant associations were found between age, global quality of life, physical and role functioning. Men reported better physical functioning and lower symptom scores then women. Employed participants reported better quality of life. Increasing age was associated with lowest quality of life. Best role functioning was also noted in participants who lived beyond 2.5 years following treatment completion. The survey suggested a gender difference with men reporting better physical functioning, fewer symptoms of pain and less loss of sleep compared to women. Conclusion: this study contributes to the underdeveloped area of care for and research into adult haematological cancer survivors. Knowledge and understanding of the factors that affect the quality of life of such adults may provide an insight into implementation measures

Head up ; an interdisciplinary, participatory and co-design process informing the development of a novel neck support for people living with progressive neck muscle weakness

This paper presents the Head-Up project that aims to provide innovative head support to help improve posture, relieve pain and aid communication for people living with progressive neck muscle weakness. The initial focus is motor neurone disease. The case study illustrates collaborative, interdisciplinary research and new product development underpinned by participatory design. The study was initiated by a two-day stakeholder workshop followed by early proof-of-concept modeling and patient need evidence building. The work subsequently led to a successful NIHR i4i application funding a 24-month iterative design process, patenting, CE marking and clinical evaluation. The evaluation has informed amendments to the proposed design we refer to here as the Sheffield Support Snood (SSS). The outcome positively demonstrates use and performance improvements over current neck orthoses and, the process of multidisciplinary and user engagement has created a sense of ownership by MND participants, who have since acted as advocates for the product.</p

Dissociation of sensitivity to spatial frequency in word and face preferential areas of the fusiform gyrus

Different cortical regions within the ventral occipitotemporal junction have been reported to show preferential responses to particular objects. Thus, it is argued that there is evidence for a left-lateralized visual word form area and a right-lateralized fusiform face area, but the unique specialization of these areas remains controversial. Words are characterized by greater power in the high spatial frequency (SF) range, whereas faces comprise a broader range of high and low frequencies. We investigated how these high-order visual association areas respond to simple sine-wave gratings that varied in SF. Using functional magnetic resonance imaging, we demonstrated lateralization of activity that was concordant with the low-level visual property of words and faces; left occipitotemporal cortex is more strongly activated by high than by low SF gratings, whereas the right occipitotemporal cortex responded more to low than high spatial frequencies. Therefore, the SF of a visual stimulus may bias the lateralization of processing irrespective of its higher order properties