Synergistic Model of Cardiac Function with a Heart Assist Device

The breakdown of cardiac self-organization leads to heart diseases and failure, the number one cause of death worldwide. The left ventricular pressure–volume relation plays a key role in the diagnosis and treatment of heart diseases. Lumped-parameter models combined with pressure–volume loop analysis are very effective in simulating clinical scenarios with a view to treatment optimization and outcome prediction. Unfortunately, often invoked in this analysis is the traditional, time-varying elastance concept, in which the ratio of the ventricular pressure to its volume is prescribed by a periodic function of time, instead of being calculated consistently according to the change in feedback mechanisms (e.g., the lack or breakdown of self-organization) in heart diseases. Therefore, the application of the time-varying elastance for the analysis of left ventricular assist device (LVAD)–heart interactions has been questioned. We propose a paradigm shift from the time-varying elastance concept to a synergistic model of cardiac function by integrating the mechanical, electric, and chemical activity on microscale sarcomere and macroscale heart levels and investigating the effect of an axial rotary pump on a failing heart. We show that our synergistic model works better than the time-varying elastance model in reproducing LVAD–heart interactions with sufficient accuracy to describe the left ventricular pressure–volume relation

Olive growing in Palestine: an everyday form of resistance

Everyday occupations have mainly been studied in the fields of occupational therapy and occupational science within a Western context. Research has mostly focused on individual occupations of people with disabilities, and findings were mostly interpreted within Eurocentric and human-centred perspectives that misrepresented marginalised communities and their daily lives. Aiming to reduce some of this gap in knowledge, I set out to explore everyday activities of olive farmers in the occupied Palestinian territories (oPt). My ‘liminal’ positionality of being a Palestinian living and working in the UK enabled a bridging between Palestinians’ ways of life in the Global South and occupational science as a Global North perspective. I posed two research questions: How do the structures, policies and practices of Israeli settler colonialism and its military occupation influence the daily activities of olive growing communities in the oPt? What are the means that communities adopt to enable the daily occupations of olive farming to continue? I wished to study the motivations and principles for the activity of olive growing which were used as active responses – or resistance – to occupational injustices caused by settler colonialism. I designed a study that adopted de-colonial ethnographic methods. Field trips were carried out throughout the olive growing cycle, during which 11 in-depth interviews were conducted with – and observations made of – participant families and individual participants. An iterative (inductive and deductive) thematic analysis and an ‘intercultural translation’ (Santos, 2014) resulted in identification of themes, which were analysed in relation to Wilcock’s ‘occupational determinants of health’ (2006). Sutra expressed the Doing for Well-being principle of olive growing, A’wna was identified as the collaborative aspect of the activity, or the Doing for Belonging to land and people, and Sumud – as a third principle of action for olive growing – means that olive farmers do this activity for Belonging and Becoming, or as a resistive daily act. Sutra-A’wna-Sumud were collectively conceptualised as Everyday-Forms-of-Resistance (to occupational apartheid), were found to extend occupational sciences’ notions of Doing-Being-Becoming-Belonging, and illustrated communal Palestinian ways of knowing and resisting. Sutra-A’wna-Sumud demonstrated a set of means of action and interpretation that move beyond the individual as the main area of concern, and perceive human communities as a continuation, and in mutual relation to, their environment. This study provides insights, learned from a Global South group, on specific manifestations of occupational apartheid, a unique collective occupation (olive growing) and an occupational consciousness (Sutra-A’wna-Sumud/ Everyday-Forms-of-Resistance) that was employed to counter occupational apartheid. This is hoped to widen occupational science’s and occupational therapy’s understanding of people, their environments and occupations, which will be useful in other fields of study concerned with humans, their daily activities and their well-being

Olive growing in Palestine: a decolonial ethnographic study of collective daily-forms- of-resistance

This article describes a study of the daily lives of Palestinian olive growers living under military occupation. Framed in de-colonial theory and occupational justice concepts, and using critical ethnographic methods, the research explored how land colonisation influences the daily activities relating to olive growing, and how olive-growing families respond to the experience of occupational apartheid through their daily activities and their shared values. In-depth interviews were conducted with four participant-families, and observations were made, in the West Bank, Palestine, during key periods in the olive farming cycle. Family stories and thematic analysis pointed to three themes, which were analysed in relation to Wilcock’s ‘occupational determinants of health’. These themes, identified as Sutra, A’wna, and Sumud, challenge and extend Western-oriented notions of doing-being-becoming-belonging, and illustrate communal Palestinian ways of knowing and resisting. Decolonial ethnographic methods highlight Palestine as a conceptual space illuminating a set of values and means of action that move beyond the individual as the main area of concern, and perceive human communities as a continuation, and in mutual relation to, their environment. This article provides insights on collective occupations learnt from a global South group, potentially widening occupational science’s and occupational therapy’s understanding of people, their environments and occupations, which may also be useful in other fields of study. More research on collective occupations, using decolonial theory and methods, is needed in different groups within Palestine and other global South societies to substantiate the insights resulting from this research

Enhanced Welding Operator Quality Performance Measurement: Work Experience-Integrated Bayesian Prior Determination

Measurement of operator quality performance has been challenging in the construction fabrication industry. Among various causes, the learning effect is a significant factor, which needs to be incorporated in achieving a reliable operator quality performance analysis. This research aims to enhance a previously developed operator quality performance measurement approach by incorporating the learning effect (i.e., work experience). To achieve this goal, the Plateau learning model is selected to quantitatively represent the relationship between quality performance and work experience through a beta-binomial regression approach. Based on this relationship, an informative prior determination approach, which incorporates operator work experience information, is developed to enhance the previous Bayesian-based operator quality performance measurement. Academically, this research provides a systematic approach to derive Bayesian informative priors through integrating multi-source information. Practically, the proposed approach reliably measures operator quality performance in fabrication quality control processes.Comment: 8 pages, 5 figures, 2 tables, i3CE 201

Global South perspectives on social justice

This paper draws on two studies that utilised an occupational science lens in understanding daily-life issues for Global South communities. International communities are experiencing fragmentation due to oppressive and unjust policies at home, or forced migration to safer and more just contexts. Studying the communal daily experiences of groups struggling against social injustice has become a key theme within occupational science, which is attempting to become a more inclusive and relevant field of study, by moving beyond the individual as a unit of study to focus on communal everyday experiences, including groups in the Global South. Boaventura de Sousa Santos described an ‘Epistemology of the South’ – a movement of thought and praxis from communities in the Global South who were struggling against socio-political phenomena related to colonialism, patriarchy, and globalised neoliberal capitalism. This movement is based on the need to learn from how communities resist such oppression in their daily lives to create social justice and ‘cognitive justice’ that would enable scholarly work to move beyond what Edward Said termed the ‘Epistemology of Imperialism’ – resulting from ignoring, or ‘othering’/’essentialising’, the experiences of marginalised groups in the process of knowledge production. Two processes are needed: ‘inter-cultural translation’ – the comparing and contrasting of ideas and practices of different communities; and the ‘ecologies of knowledge’, which involves stepping back from Eurocentric traditions to allow other analytical spaces that can explain reality to be involved in producing appropriate knowledge and theories that will contribute to social justice (Santos, 2014). The first study is a de-colonial ethnography in which the researcher’s “ability to shuttle between contrasting worlds of experience” was pivotal in researching olive growing as a daily form of resistance in Palestine (Zureik, 2014: 20). What emerged was a group of daily practices that were founded on historical, socio-political, cultural and spiritual principles. Olive growers in Palestine were observed to experience ‘occupational injustice’, or more specifically ‘occupational apartheid’, that is a particular form of social injustice based on restrictions on their daily lives imposed because of who they were (their belonging to Palestinian communities). Yet, rather than passively accept this situation, and despite all odds, they have continued this ancient, highly meaningful, and communal activity. This resilience was enabled by their need to survive and be dignified (Sutra/doing-being), to express solidarity and collaboration (‘Awna/belonging) and to aspire for a better shared future (Sumud/belonging-becoming) – and by their insistence upon meeting these collective needs. The second study addresses what is considered an increasingly prevalent social issue - the burden of older immigrants on host societies (Angel, 2003). This grounded theory study explored how Indian, Chinese and Korean older migrants to New Zealand sought to engage in everyday occupations, such as gardening, singing and caring for grandchildren, and thereby make valued contributions to their new community. Using an occupational science lens to critically examine the data revealed that these older immigrants were conscious of what New Zealand had to offer them and were determined not to take these opportunities for granted. Rather, through a social process of ‘strengthening community’, these elders worked to actively give back to their new homeland. However, coming to this understanding required further developing grounded theory methodology to encompass ‘inter-cultural translations’, as well as advance ‘ecologies of knowledge’. A willingness to employ new methods and ways of researching what may be framed as social problems from Global South perspectives is critical if we are to advance global understandings of the contributions that marginalised groups within society have to offer

WFOT special issue

In May 2018, the World Federation of Occupational Therapists (WFOT) held its congress in Cape Town, South Africa. The discipline of occupational science has a longstanding relationship with occupational therapy and the congress was an exciting opportunity to come together to showcase diverse perspectives on a shared occupational lens framing our understanding of the world, and our collaboration with the communities with which we research and work. Increasingly there has been a call within occupational science to consider more diverse perspectives; therefore, the timing was right to hear prominent, contemporary and highly relevant voices from the Global South, specifically those from the African continent

A Rational Explanation For Home Country Bias

While modern portfolio theory predicts that investors should diversify across international markets, corporate equity is essentially held by domestic investors. French and Poterba (1991) suggest that in order for this bias to be justified, investors must hold optimistic expectations about their domestic markets and pessimistic expectations about their foreign markets. Tesar and Werner (1995) find existing explanations to the home equity bias unsatisfactory and conclude that the issue poses a challenge for portfolio theory. We develop a model that incorporates both the foregone gains from diversification and the informational constraints of international investing, and shows that home equity bias is consistent with rational mean-variance portfolio choice. Specifically, we prove that the nature of estimation risk in international markets can be responsible for this phenomenon. We show that when the cross-market variability in the estimation errors of international markets' means far exceeds the cross-market variability in the means themselves, domestic dedication dominates international diversification. An examination of eleven international markets' returns over the last twenty-five years, from the perspective of German, Japanese and U.S investors provides evidence consistent with this explanation