Noise and Bias in Eliciting Preferences

In the context of eliciting preferences for decision making under risk, we ask the question: "which might be the 'best' method for eliciting such preferences?". It is well known that different methods differ in terms of the bias in the elicitation; it is rather less well-known that different methods differ in terms of their noisiness. The optimal trade-off depends upon the relative magnitutdes of these two effects. We examine four different elicitation mechanisms (pairwise choice, willingness-to-pay, willingness-to-accept, and certainty equivalents) and estimate both effect. Our results suggest that economists might be better advised to use what appears to be a relatively inefficient elicitation technique (i.e. pairwise choice) in order to avoid trhe bias in better-known and more widely-used techniques.Pairwise choice, willingness-to-pay, willingness-to-accept, errors, noise, biases

Noise and bias in eliciting preferences

In the context of eliciting preferences for decision making under risk, we ask the question: "which might be the 'best' method for eliciting such preferences?". It is well known that different methods differ in terms of the bias in the elicitation; it is rather less well-known that different methods differ in terms of their noisiness. The optimal trade-off depends upon the relative magnitutdes of these two effects. We examine four different elicitation mechanisms (pairwise choice, willingness-to-pay, willingness-to-accept, and certainty equivalents) and estimate both effect. Our results suggest that economists might be better advised to use what appears to be a relatively inefficient elicitation technique (i.e. pairwise choice) in order to avoid trhe bias in better-known and more widely-used techniques.In the context of eliciting preferences for decision making under risk, we ask the question: "which might be the 'best' method for eliciting such preferences?". It is well known that different methods differ in terms of the bias in the elicitation; it is rather less well-known that different methods differ in terms of their noisiness. The optimal trade-off depends upon the relative magnitutdes of these two effects. We examine four different elicitation mechanisms (pairwise choice, willingness-to-pay, willingness-to-accept, and certainty equivalents) and estimate both effect. Our results suggest that economists might be better advised to use what appears to be a relatively inefficient elicitation technique (i.e. pairwise choice) in order to avoid trhe bias in better-known and more widely-used techniques.Refereed Working Papers / of international relevanc

Hybridised sustainability metrics for use in life cycle assessment of bio-based products: resource efficiency and circularity

The development, implementation and social acceptance of resource efficient, circular, bio-based economies require critical understanding of the whole supply chain from feedstock to end-use. Trust, transparency and traceability will be paramount. Though life cycle assessment (LCA) is a universally chosen approach to fulfil this purpose, the nature of data required and the depth of analysis lead to complex interpretations of the findings. Herein, a new set of hybridised, first-line sustainability indicators, drawn from the principles of green chemistry and resource (material and energy) circularity, are reported. These flexible, potentially stand-alone metrics are demonstrated via application to an exemplary comparative LCA, incorporating the hybridised indicators including hazardous chemical use, waste generated, resource circularity and energy efficiency, from the “gate-to-gate” stages for the bio-based case studies and their petro-derived commercial counterparts. These metrics were observed to quantify critical new information relevant to our transition to a circular economy, bridging significant gaps in contemporary environmental impact assessment methodologies. Appropriate additional evaluations that examine the performance of metrics, when the embedded resource efficiency and circularity strategies are omitted, have also been undertaken and reported. The data drawn from employing these methods are crucial to inform and encourage operational optimisation, transparency in sustainability reporting and practices to a significant number of value-chain actors including manufacturers, policy makers and consumers

Post-stroke depression increases disability more than 15% in ischemic stroke survivors: a case-control study

We performed a retrospective, case-control study in consecutive ischemic stroke patients admitted to our stroke rehabilitation unit. Patients were matched for severity of neurological impairment (evaluated with the Canadian Neurological Scale, CNS), age (difference within 1 year), and onset admission interval (difference within 3 days). Participants were divided into two subgroups according to the presence or absence of PSD. Aim was to assess the specific influence of post-stroke depression (PSD) and antidepressant treatment on both basal functional status and rehabilitation outcomes. All PSD patients were treated primarily with serotoninergic antidepressants (AD). The final sample included 280 patients with depression (out of 320 found in a whole case series of 993 ischemic patients, i.e., 32.25%) and 280 without depression. Forty patients with depression were excluded because they had a history of severe psychiatric illness or aphasia, with a severe comprehension deficit. On one hand, PSD patients obtained lower Barthel Index (BI) and Rivermead Mobility Index (RMI) scores at both admission and discharge, with minor effectiveness of rehabilitative treatment and longer length of stay; on the other hand, this group had a lower percentage of dropouts. Lastly, PSD patients showed a different functional outcome, based on their response to antidepressant therapy, that was significantly better in responders than in non-responders (13.13%). Our results confirm the unfavorable influence of PSD on functional outcome, despite pharmacological treatment

Seeds Buffering for Information Spreading Processes

Seeding strategies for influence maximization in social networks have been studied for more than a decade. They have mainly relied on the activation of all resources (seeds) simultaneously in the beginning; yet, it has been shown that sequential seeding strategies are commonly better. This research focuses on studying sequential seeding with buffering, which is an extension to basic sequential seeding concept. The proposed method avoids choosing nodes that will be activated through the natural diffusion process, which is leading to better use of the budget for activating seed nodes in the social influence process. This approach was compared with sequential seeding without buffering and single stage seeding. The results on both real and artificial social networks confirm that the buffer-based consecutive seeding is a good trade-off between the final coverage and the time to reach it. It performs significantly better than its rivals for a fixed budget. The gain is obtained by dynamic rankings and the ability to detect network areas with nodes that are not yet activated and have high potential of activating their neighbours.Comment: Jankowski, J., Br\'odka, P., Michalski, R., & Kazienko, P. (2017, September). Seeds Buffering for Information Spreading Processes. In International Conference on Social Informatics (pp. 628-641). Springe

Proof-of-Principle of a Brain-Computer Interface approach to support post-stroke arm rehabilitation in hospitalized patients: design, acceptability and usability

Objective To evaluate the feasibility of brain-computer interface (BCI)-assisted motor imagery training to support hand/arm motor rehabilitation after stroke during hospitalization. Design Proof-of-principle study. Setting Neurorehabilitation hospital. Participants Convenience sample of patients (N=8) with new-onset arm plegia or paresis caused by unilateral stroke. Interventions The BCI-based intervention was administered as an "add-on" to usual care and lasted 4 weeks. Under the supervision of a therapist, patients were asked to practice motor imagery of their affected hand and received as a discrete feedback the movements of a "virtual" hand superimposed on their own. Such a BCI-based device was installed in a rehabilitation hospital ward. Main Outcome Measures Following a user-centered design, we assessed system usability in terms of motivation, satisfaction (by means of visual analog scales), and workload (National Aeronautics and Space Administration-Task Load Index). The usability of the BCI-based system was also evaluated by 15 therapists who participated in a focus group. Results All patients successfully accomplished the BCI training. Significant positive correlations were found between satisfaction and motivation (P=.001, r=.393). BCI performance correlated with interest (P=.027, r=.257) and motivation (P=.012, r=.289). During the focus group, professionals positively acknowledged the opportunity offered by BCI-assisted training to measure patients' adherence to rehabilitation. Conclusions An ecological BCI-based device to assist motor imagery practice was found to be feasible as an add-on intervention and tolerable by patients who were exposed to the system in the rehabilitation environment. © 2015 American Congress of Rehabilitation Medicine

Community psychology as a process of citizen participation in health policy: Comment on “the rise of post-truth populism in pluralist liberal democracies: Challenges for health policy”

This brief commentary discusses a recent paper by Speed and Mannion that explores “The Rise of post truth populism in liberal democracies: challenges for health policy.” It considers their assertion that through meaningful democratic engagement in health policy, some of the risks brought about by an exclusionary populist politics can be mediated. With an overview of what participation means in modern healthcare policy and implementation, the field of community psychology is presented as one way to engage marginalized groups at risk of exploitation or exclusion by nativist populist policy

Theories for influencer identification in complex networks

In social and biological systems, the structural heterogeneity of interaction networks gives rise to the emergence of a small set of influential nodes, or influencers, in a series of dynamical processes. Although much smaller than the entire network, these influencers were observed to be able to shape the collective dynamics of large populations in different contexts. As such, the successful identification of influencers should have profound implications in various real-world spreading dynamics such as viral marketing, epidemic outbreaks and cascading failure. In this chapter, we first summarize the centrality-based approach in finding single influencers in complex networks, and then discuss the more complicated problem of locating multiple influencers from a collective point of view. Progress rooted in collective influence theory, belief-propagation and computer science will be presented. Finally, we present some applications of influencer identification in diverse real-world systems, including online social platforms, scientific publication, brain networks and socioeconomic systems.Comment: 24 pages, 6 figure

Upper limb motor improvement in chronic stroke after combining botulinum toxin A injection and multi-joints robot-assisted therapy: A case report

Spasticity is one of the major complications after stroke. Botulinum toxin type A (BoNT-A) injection is commonly used to manage focal spasticity. However, it is uncertain whether BoNT-A can improve activities of daily living function of paretic arm. The recovery of functions of the affected arm is also the aim of robotic upper limb (UL) therapy. The motorized exoskeleton assists the patient in a large 3D work environment by promoting movement for the UL (shoulder, elbow, wrist, hand). The combination of the BoNT-A injection and the robotic therapy might enhance functional recovery after stroke.We reported the case of a chronic stroke patient in which the injection of BoNT-A was combined with multi-joint exoskeleton training. The patient showed improvement in the motor control of the UL, supporting the feasibility of this approach

Effects of Walking Endurance Reduction on Gait Stability in Patients with Stroke

Control of gait is usually altered following stroke, and it may be further compromised by overexertion and fatigue. This study aims to quantitatively assess patients' gait stability during six-minute walking, measuring upper body accelerations of twenty patients with stroke (64 ± 13 years old) and ten age-matched healthy subjects (63 ± 10 years old). Healthy subjects showed a steady gait in terms of speed and accelerations over the six minutes. Conversely, the patients unable to complete the test (n = 8) progressively reduced their walking speed (−22 ± 11%, confidence interval CI95%: −13, −29%, P = 0.046). Patients able to complete the test (n = 12) did not vary their walking speed over time (P = 0.493). However, this ability was not supported by an adequate capacity to maintain their gait stability, as shown by a progressive increase of their upper body accelerations (+5 ± 11%, CI95%: −1; +12%, P = 0.010). Walking endurance and gait stability should be both quantitatively assessed and carefully improved during the rehabilitation of patients with stroke