Using the Values-Practice Framework to adopt lifetime optimising behaviours: the case of maintenance

The influence that consumers have on the lifespan of products has attracted increased attention in recent years. Studies have provided an overall understanding of the factors that influence consumer attitudes and behaviours towards product longevity, categorised around the physical properties of a product, and individual and societal characteristics. However, such studies do not yet adequately explain how people could adopt product lifetime optimising behaviours. To fill this gap, the paper analyses a range of studies on what influences product lifetimes, focusing on maintenance activities. It proposes the use of the Values-Practice framework derived from two theoretical positions, social psychology and social practice theory, to consider how to facilitate the adoption of lifetime optimising behaviours. To build this framework, it analyses studies that classify factors influencing attitudes and behaviours towards product lifetimes and then links these to the ‘meaning’, ‘competence’ and ‘material’ elements of practice. The framework could be used as a tool to aid designers under stand the different elements and factors that engage people in maintenance activities. The paper concludes by considering the research requirements for the future application of the framework

Experience with posttransplant lymphoproliferative disorders in solid organ transplant recipients

Nearly 6000 solid organ transplants have been performed at the University of Pittsburgh since 1981. Posttransplant lymphoproliferative disorders (PTLD) have occurred in 131 patients, at a frequency of 2.2%. The majority of cases manifest within 6 months following allograft, but individual lesions may arise several years thereafter. From 1981 to 1989, cyclosporine-A (CsA) served as the primary immunosuppressant in this population. In March of 1989, FK506 was introduced for clinical trials. Since that time, 1421 patients have received FK506 either for primary immunosuppression or as rescue therapy. The frequency of PTLD in this subpopulation is 1.5%. PTLD arising under FK506-containing regimens have clinicopathologic features similar to those arising with CsA immunosuppression. The frequency of PTLD at this point in time is approximately 1%, in kidney allograft patients, 2.7% in liver, 3.3% in heart and 3.8%, in heart/lung or lung recipients. An understanding of the range of histologic appearance is important for the diagnosis of PTLD, especially when it involves the allograft itself. Immunoglobulin heavy chain gene analysis shows that lesions with no rearrangements or with a rearrangement in only a small proportion of cells are more likely to respond to reduced immunosuppression than are those with clonal rearrangement involving a high proportion of cells. However, this distinction is not absolute, and a trial of reduced immunosuppression appears to be indicated regardless of clonal status

Local majority dynamics on preferential attachment graphs

Suppose in a graph $G$ vertices can be either red or blue. Let $k$ be odd. At each time step, each vertex $v$ in $G$ polls $k$ random neighbours and takes the majority colour. If it doesn't have $k$ neighbours, it simply polls all of them, or all less one if the degree of $v$ is even. We study this protocol on the preferential attachment model of Albert and Barab\'asi, which gives rise to a degree distribution that has roughly power-law $P(x) \sim \frac{1}{x^{3}}$, as well as generalisations which give exponents larger than $3$. The setting is as follows: Initially each vertex of $G$ is red independently with probability $\alpha < \frac{1}{2}$, and is otherwise blue. We show that if $\alpha$ is sufficiently biased away from $\frac{1}{2}$, then with high probability, consensus is reached on the initial global majority within $O(\log_d \log_d t)$ steps. Here $t$ is the number of vertices and $d \geq 5$ is the minimum of $k$ and $m$ (or $m-1$ if $m$ is even), $m$ being the number of edges each new vertex adds in the preferential attachment generative process. Additionally, our analysis reduces the required bias of $\alpha$ for graphs of a given degree sequence studied by the first author (which includes, e.g., random regular graphs)

Moving beyond the circular economy

The production model, which currently underpins our material prosperity, remains highly resource-intensive, and the volume of minerals, ores and fossil fuels consumed annually is set to triple by 2050 unless economic growth is decoupled from resource consumption [1]. One response that has been attracting significant attention is the idea of a circular economy (or close loop economy), in which waste is transformed into value rather than disposed of to landfill [2]. While acknowledging potential benefits to businesses of a circular economy, this paper critically reviews the model and proposes an approach that addresses concerns that even recycling processes have energy impacts through transportation, reprocessing and subsequent manufacturing, and that in practice it is impossible to have a complete circular system in which there is no use of virgin materials and no final waste. It presents an overarching framework that responds to such concerns, built by studying different circular models in a macro-level perspective and then tailoring tactics for different sectors in a micro - level perspective [3 ,4,5,6 ]. The paper explains how the framework was built and how it is applied to the large household appliance (LHA) sector, through developing two emerging models based on product-service systems (PSS). The paper presents findings from a workshop in which the two models were presented to industry representatives, revealing their responses regarding the opportunities and challenges to implement the proposed models to go beyond the circular economy

Editorial to the Proceedings of the Improving Residential Energy Efficiency International Conference, IREE 2017

Editorial to proceedings of Improving Residential Energy Efficiency International Conference, IREE 2017, 16-17 February 2017, Wollongong, Australi

Ma-Xu quantization rule and exact WKB condition for translationally shape invariant potentials

For translationally shape invariant potentials, the exact quantization rule proposed by Ma and Xu is a direct consequence of exactness of the modified WKB quantization condition proved by Barclay. We propose here a very direct alternative way to calculate the appropriate correction for the whole class of translationally shape invariant potentials