A closer look at parameter identifiability, model selection and handling of censored data with Bayesian Inference in mathematical models of tumour growth

Mathematical models (MMs) are a powerful tool to help us understand and predict the dynamics of tumour growth under various conditions. In this work, we use 5 MMs with an increasing number of parameters to explore how certain (often overlooked) decisions in estimating parameters from data of experimental tumour growth affect the outcome of the analysis. In particular, we propose a framework for including tumour volume measurements that fall outside the upper and lower limits of detection, which are normally discarded. We demonstrate how excluding censored data results in an overestimation of the initial tumour volume and the MM-predicted tumour volumes prior to the first measurements, and an underestimation of the carrying capacity and the MM-predicted tumour volumes beyond the latest measurable time points. We show in which way the choice of prior for the MM parameters can impact the posterior distributions, and illustrate that reporting the highest-likelihood parameters and their 95% credible interval can lead to confusing or misleading interpretations. We hope this work will encourage others to carefully consider choices made in parameter estimation and to adopt the approaches we put forward herein.Comment: 15 pages, 7 figure

Cross-sectional validation of the Aging Perceptions Questionnaire: a multidimensional instrument for assessing self-perceptions of aging

<p>Abstract</p> <p>Background</p> <p>Self-perceptions of aging have been implicated as independent predictors of functional disability and mortality in older adults. In spite of this, research on self-perceptions of aging is limited. One reason for this is the absence of adequate measures. Specifically, there is a need to develop a measure that is theoretically-derived, has good psychometric properties, and is multidimensional in nature. The present research seeks to address this need by adopting the Self-Regulation Model as a framework and using it to develop a comprehensive, multi-dimensional instrument for assessing self-perceptions of aging. This study describes the validation of this newly-developed instrument, the Aging Perceptions Questionnaire (APQ).</p> <p>Methods</p> <p>Participants were 2,033 randomly selected community-dwelling older (+65 yrs) Irish adults who completed the APQ alongside measures of physical and psychological health. The APQ assesses self-perceptions of aging along eight distinct domains or subscales; seven of these examine views about own aging, these are: timeline chronic, timeline cyclical, consequences positive, consequences negative, control positive, control negative, and emotional representations; the eighth domain is the identity domain and this examines the experience of health-related changes.</p> <p>Results</p> <p>Mokken scale analysis showed that the majority of items within the views about aging subscales were strongly scalable. Confirmatory factor analysis also indicated that the model provided a good fit for the data. Overall, subscales had good internal reliabilities. Hierarchical linear regression was conducted to investigate the independent contribution of APQ subscales to physical and psychological health and in doing so determine the construct validity of the APQ. Results showed that self-perceptions of aging were independently related to physical and psychological health. Mediation testing also supported a role for self-perceptions of aging as partial mediators in the relationship between indices of physical functioning and physical and psychological health outcomes.</p> <p>Conclusion</p> <p>Findings support the complex and multifaceted nature of the aging experience. The good internal reliability and construct validity of the subscales suggests that the APQ is a promising instrument that can enable a theoretically informed, multidimensional assessment of self-perceptions of aging. The potential role of self-perceptions of aging in facilitating physical and psychological health in later life is also highlighted.</p

Inclusionary control? Theorizing the effects of penal voluntary organizations’ work

Recent penal policy developments in many jurisdictions suggest an increasing role for voluntary organizations. Voluntary organizations have long worked alongside penal institutions, but the multifaceted ways their programmes affect (ex-)offenders remain insufficiently understood. This article addresses the implications of voluntary organizations’ work with (ex-)offenders, using original empirical data. It adds nuance to netwidening theory, reframing the effects of voluntary organizations’ work as inclusionary and exclusionary. Exclusionary effects sometimes have inclusionary aspects, and inclusionary effects are constrained by a controlling carceral net. We propose the novel concept of inclusionary control. This is not an alibi for punishment but enables rich analysis of the effects of voluntary organizations’ work, and raises possibilities for change in penal practice

What’s a (Childless) Man Without a Woman? The Differential Importance of Couple Dynamics for the Wellbeing of Childless Men and Women in the Netherlands

Using rich couple data from the Netherlands Kinship Panel Study, we investigated to what extent there were gender differences in couple dynamics within childless couples (N = 163). Though the childless partners reported similar relationship satisfaction, we found gender differences in the link between relationship conflict and relationship satisfaction - the childless men were more strongly affected by the negative aspects of the partnership. This gender difference was not evident for the association between partner support and relationship satisfaction - the positive aspects of the partnership were equally important for the male and the female childless partners. Furthermore, the association between relationship satisfaction and health was stronger for the childless men than for the childless women and this difference was particularly evident when the levels of relationship satisfaction were low. These results indicate that when they are in unsatisfying romantic relationships, childless men are at a greater risk than childless women of physical and mental ill health

Basics of noise control

Peer reviewed: NoNRC publication: Ye

Program for hand-held computer estimating energy savings from reinsulating houses

The program presented in this note provides a fast and versatile way of performing energy audit calculations. It is written for the Sharp PC-1211 pocket computer and executes the energy audit calculations used in Building Practice Note No. 20, "Estimating energy savings from reinsulating houses". Step by step instructions are provided for loading, debugging, and running the program.Le programme pr\ue9snt\ue9 dans cette note permet d'effectuer rapidement et facilement les calculs de v\ue9rification de la consommation d'\ue9nergie. Il est \ue9crit pour la calculatrice de poche Sharp PC-1211 et effectue les calculs de v\ue9rification d\ue9crits dans Note sur la construction n\ub0 20, "Estimation des \ue9conomies d'\ue9nergie dues \ue0 1'am\ue9lioration de 1'isolation des maisons". On donne des instructions point par point pour le chargement, la mise au point et l'ex\ue9cution du programme.Peer reviewed: NoNRC publication: Ye

Estimating energy savings from reinsulating houses

This note presents a method for estimating energy savings from reinsulating houses. The method uses the previous year' s fuel bill and is aimed at existing houses; it is not intended for use in the design of new houses. As further information becomes available, some of the factors and tables may be revised. The Division of Building Research welcomes comments.Peer reviewed: NoNRC publication: Ye

Estimation des \ue9conomies d'\ue9nergie dues \ue0 l'am\ue9lioration de l'isolation des maisons

La pr\ue9sente publication d\ue9crit une m\ue9thode qui permet d'estimer les \ue9conomies d'\ue9nergie dues \ue0 l'am\ue9lioration de l'isolation des maisons. La m\ue9thode utilise le co\ufbt du chauffage de l'ann\ue9e pr\ue9c\ue9dente et vise les maisons existantes ; elle n'est pas destin\ue9e \ue0 \ueatre utilis\ue9e dans la conception des nouvelles maisons. Certains tableaux et certains facteurs pourront \ueatre r\ue9vis\ue9s lorsque plus de reseignements seront disponibles. Les commentaires sont les bienvenues.Peer reviewed: NoNRC publication: Ye