Conceptualising dementia crisis and preferences for resolution: A public perspective

Background: Crisis intervention services for people with dementia in the United Kingdom are poorly defined with no standardized model of working. This may be due to the lack of a clear conceptualization of dementia crisis, resulting in variation in national service delivery. Methods: This study employed a novel public engagement questionnaire data collection technique with 57 participants to gain an updated perspective on the concept of health-related crisis from the point of view of the public. Results: Analysis revealed crisis as a transformational moment that may arrive unexpectedly but could also be the culmination of a sequence of events. Crisis resolution requires external and expert help, and associated feelings of panic and despair can engender the task of resolution by oneself insurmountable. Conclusions: Participants had clear expectations of crisis intervention services, with initial practical and emotional support to reduce risks, and a person-centered approach with family involvement

Swapping in lattice-based cell migration models

Cell migration is frequently modelled using on-lattice agent-based models (ABMs) that employ the excluded volume interaction. However, cells are also capable of exhibiting more complex cell-cell interactions, such as adhesion, repulsion, pulling, pushing and swapping. Although the first four of these have already been incorporated into mathematical models for cell migration, swapping has not been well studied in this context. In this paper, we develop an ABM for cell movement in which an active agent can `swap' its position with another agent in its neighbourhood with a given swapping probability. We consider a two-species system for which we derive the corresponding macroscopic model and compare it with the average behaviour of the ABM. We see good agreement between the ABM and the macroscopic density. We also analyse the movement of agents at an individual level in the single-species as well as two-species scenarios to quantify the effects of swapping on an agent's motility.<br/

Zebrafish adult pigment stem cells are multipotent and form pigment cells by a progressive fate restriction process:Clonal analysis identifies shared origin of all pigment cell types

Skin pigment pattern formation is a paradigmatic example of pattern formation. In zebrafish, the adult body stripes are generated by coordinated rearrangement of three distinct pigment cell-types, black melanocytes, shiny iridophores and yellow xanthophores. A stem cell origin of melanocytes and iridophores has been proposed although the potency of those stem cells has remained unclear. Xanthophores, however, seemed to originate predominantly from proliferation of embryonic xanthophores. Now, data from Singh et al. shows that all three cell-types derive from shared stem cells, and that these cells generate peripheral neural cell-types too. Furthermore, clonal compositions are best explained by a progressive fate restriction model generating the individual cell-types. The numbers of adult pigment stem cells associated with the dorsal root ganglia remain low, but progenitor numbers increase significantly during larval development up to metamorphosis, likely via production of partially restricted progenitors on the spinal nerves.</p

Swapping in lattice-based cell migration models

Cell migration is frequently modelled using on-lattice agent-based models (ABMs) that employ the excluded volume interaction. However, cells are also capable of exhibiting more complex cell-cell interactions, such as adhesion, repulsion, pulling, pushing and swapping. Although the first four of these have already been incorporated into mathematical models for cell migration, swapping is an interaction that has not been well studied in this context. In this paper, we develop an ABM to describe cell movement where an active agent can `swap' its position with another agent in its neighbourhood with a given swapping probability. We consider single-species and two-species systems. In both cases, we derive the corresponding macroscopic model and compare it with the average behaviour of the ABM. We see good agreement between the ABM and the macroscopic density. We also derive an expression for the cell-level diffusion coefficient in terms of the swapping probability and cell density. We conclude by showing applications of swapping by using the ABM to represent cell movement with proliferation and cell-cell adhesion.Comment: 32 pages, 12 figures, articl

Oxygen-Driven Tumour Growth Model : A Pathology-Relevant Mathematical Approach

We acknowledge Lucas Dias Fernandes and Dr Nicolas Rubido from the University of Aberdeen and Dr Neil Evans from the University of Warwick for the broad discussions on the mathematics.Peer reviewedPublisher PD

Impacts of COVID-19 on the Coping Behaviours of Canadian Women Experiencing Intimate Partner Violence

Background: Strict public health measures central to slowing the spread of COVID-19 have, unintentionally, exacerbated risks for women experiencing intimate partner violence (IPV) while impeding their usual coping strategies. The goal of this study was to understand how coping was influenced by COVID-19 for women who have experienced IPV and identify changes in coping strategies and gaps that need to be addressed to support coping. Methods: A qualitatively driven, sequential, cross-sectional design, where quantitative data informed and was embedded within qualitative data collection, was used to explore the experiences of IPV (CAS-R-SF scale) and coping (Brief-COPE scale) specific to IPV of 95 Canadian women. A subset of 19 women was invited to complete an interview exploring coping strategies identified within the survey to contextualize and validate these findings. Results: Survey data subjected to quantitative content analysis identified ten themes, all of which were explored in semi-structured interviews. Thematic interview findings included (1) influence of COVID-19 on coping, (2) coping during COVID-19, and (3) needed coping strategies. Conclusion: COVID-19 had important impacts on the experiences and coping strategies of women who experience IPV. To better support this population in pandemic circumstances, in-person services should be prioritized with an emphasis on accessible and empathetic care. Public health measures in response to COVID-19, and the eventuality of future pandemics, should aim to be gender- and violence-informed

Investigation of Superconducting Gap Structure in TbFeAsO0.9_{0.9}F0.1_{0.1} using Point Contact Andreev Reflection

Bulk samples of TbFeAsO$_{0.9}$F$_{0.1}$ (T$_{c}$(on) = 50K) were measured by point contact Andreev reflection spectroscopy. The spectra show unambiguous evidence for multiple gap-like features plus the presence of high bias shoulders. By measuring the spectra as a function of temperature with both gold and superconducting niobium tips, we establish that the gap-like features are associated with superconducting order parameter in this material. We discuss whether the well defined zero bias conductance peak that we observe infrequently is associated with a nodal superconducting order parameter.Comment: 11 pages, 5 figures, published versio

Subjective memory complaints, mood and MCI: a follow-up study

Objectives: Subjective memory complaints (SMC) are common in older people and previous research has shown an association with mood problems, such as depression and anxiety. SMC form part of the criteria for many definitions of mild cognitive impairment (MCI), but there is controversy over whether they should be included as they may be related more strongly to mood than to objective cognitive impairment. This study aims to clarify the relationship between mood and SMC in people with MCI. Method: This paper reports an analysis of data from the Medical Research Council Cognitive Function and Ageing study. Structured interviews were conducted with community-dwelling older people to assess a range of aspects of cognitive functioning and mood. Data from two time points approximately 24 months apart were used in this analysis. At baseline, participants without dementia or severe cognitive impairment were categorised into three groups according to cognitive status. Mood was investigated by assessing symptoms of anxiety and depression which were defined using a diagnostic algorithm. Associations were tested using logistic regression and chi square analyses. Results: A clear association was shown between SMC and mood, both cross-sectionally and over time. The relationship between our two competing definitions of MCI suggested that mood problems were more strongly related to the presence of SMC than objective cognitive impairment. Conclusion: SMC may be a function of anxiety and depression rather than being related to objective cognitive function. This questions whether SMC should be included in definitions of MCI

A Uniform Analysis of the Ly-alpha Forest at z=0 - 5: V. The extragalactic ionizing background at low redshift

In Paper III of our series "A Uniform Analysis of the Ly-alpha forest at z=0 - 5", we presented a set of 270 quasar spectra from the archives of the Faint Object Spectrograph on the Hubble Space Telescope. A total of 151 of these spectra, yielding 906 lines, are suitable for using the proximity effect signature to measure J(\nu_0), the mean intensity of the hydrogen-ionizing background radiation field, at low redshift. Using a maximum likelihood technique and the best estimates possible for each QSO's Lyman limit flux and systemic redshift, we find J(\nu_0)= 7.6^+9.4_-3.0 x 10^-23 ergs s^-1 cm^-2 Hz^-1 sr^-1 at at 0.03 < z < 1.67. This is in good agreement with the mean intensity expected from models of the background which incorporate only the known quasar population. When the sample is divided into two subsamples, consisting of lines with z 1, the values of J(\nu_0) found are 6.5^+38._-1.6 x 10^-23 ergs s^-1 cm^-2 Hz^-1 sr^-1, and 1.0^+3.8_-0.2 x 10^-22 ergs s^-1 cm^-2 Hz^-1 sr^-1, respectively, indicating that the mean intensity of the background is evolving over the redshift range of this data set. Relaxing the assumption that the spectral shapes of the sample spectra and the background are identical, the best fit HI photoionization rates are found to be 6.7 x 10^-13 s^-1 for all redshifts, and 1.9 x 10^-13 s^-1 and 1.3 x 10^-12 s^-1 for z 1, respectively. This work confirms that the evolution of the number density of Ly-alpha lines is driven by a decrease in the ionizing background from z ~ 2 to z ~ 0 as well as by the formation of structure in the intergalactic medium. (Abridged)Comment: 71 LaTeX pages, 20 encapsulated Postscript figures, Accepted for publication in ApJ, Figure 4 available at http://lithops.as.arizona.edu/~jill/QuasarSpectra/ or http://hea-www.harvard.edu/QEDT/QuasarSpectra

Predictive validity of the UK clinical aptitude test in the final years of medical school:a prospective cohort study

Peer reviewedPublisher PD