Mobility, well-being, and community participation among people with depression: an observation study using geographically-explicit ecological momentary assessment (GEMA) (Preprint)

BACKGROUND Globally, more than 300 million people suffer from depressive disorders. Despite a wide range of conducted research, information on the mobility and daily routines of persons with depression remains lacking. OBJECTIVE To describe a preliminary explication of the association between mobility, well-being, and community participation of people with depression as they occur in real-time settings. METHODS We used a multivariate, time-series, single-subject, repeated measures (MRSRM) design. People with depression (N=33) were invited to use a GPS device for over two weeks for continuous mobility tracking, while information on their well-being was collected with paper surveys before and after two-weeks periods. The tracking records from 32 participants were imported into Geographical Information Systems (GIS) to extract the specific mobility information. Socio-demographic and environmental information (building density, greenness index and PM2.5) was derived for statistical analysis to explore the relationship between mobility, community participation and mental health using correlation coefficients and logistic regression analysis. RESULTS The more hours participants stayed at home, the more often they had depressive symptoms (r=0.47, P<.01) but their satisfaction with life was higher (r=0.38, P<.05). On the contrary, participants with longer total distance reported more stress (r=0.47, P<.01) and the more destinations participants travelled to, the more depressive symptoms they had (r=-0.36, P<.05). Wide travelling area was positively associated with stress and negatively associated with satisfaction with life, while more time spent at home was positively associated with depressive symptoms and low self-esteem. Time spent outside the home was also negatively associated with satisfaction with life and self-esteem. The great majority (91%) perceived the tracking device as comfortable and convenient and 31% had positive feelings about mobility tracking. Still, three participants (9%) expressed that the device caused inconvenience, stress or fair as the battery needed to be charged frequently. CONCLUSIONS Our study showed that having signs of depression is associated with mobility area and time spent at home among persons with depression, which may mean that their activity level in society is limited. Staying home may be a solution for avoiding extra stress, problems with self-esteem and maintaining satisfaction with life. Low-threshold access to health services should be tailored for each person based on their needs. More information based on studies using robust design, bigger sample size, and more accurate measurement methods, however, is required before individualized services can be fully achieved. Although using GPS may be a feasible data collection method, more effort should be put into collecting the data with easy-to-use technology to avoid extra stress in the participants.

A Theoretical Analysis of Mobility Detection in Connectivity-Based Localization for Short-Range Networks

This paper presents a theoretical analysis of mobility detection in connectivity-based localization, which exploits connectivity information as range measurements to anchors at a known location, to investigate how well and how precise mobility can be detected with connectivity in short-range networks. We derive mobility detection, miss detection, and false alarm probabilities in terms of a mobility detection threshold, defined as the minimum distance to detect the mobility, under the shadow fading channel and arbitrary mobility models to take into account practical and general scenarios. Based on the derivations, we address the threshold determination with the criteria in the sense of the minimum average error from miss detection and false alarm. Numerical and simulation evaluations are performed to verify our theoretical derivations, to show that increasing anchor numbers can improve the mobility detection probability with a smaller detection threshold, and that the probabilities are bounded by the weights of miss detection and false alarm. This work is the first attempt at addressing the performance of mobility detection using connectivity, and it can be utilized as a baseline for connectivity-based mobility tracking.

Fission yeast condensin contributes to interphase chromatin organization and prevents transcription-coupled DNA damage

Background Structural maintenance of chromosomes (SMC) complexes are central organizers of chromatin architecture throughout the cell cycle. The SMC family member condensin is best known for establishing long-range chromatin interactions in mitosis. These compact chromatin and create mechanically stable chromosomes. How condensin contributes to chromatin organization in interphase is less well understood. Results Here, we use efficient conditional depletion of fission yeast condensin to determine its contribution to interphase chromatin organization. We deplete condensin in G2-arrested cells to preempt confounding effects from cell cycle progression without condensin. Genome-wide chromatin interaction mapping, using Hi-C, reveals condensin-mediated chromatin interactions in interphase that are qualitatively similar to those observed in mitosis, but quantitatively far less prevalent. Despite their low abundance, chromatin mobility tracking shows that condensin markedly confines interphase chromatin movements. Without condensin, chromatin behaves as an unconstrained Rouse polymer with excluded volume, while condensin constrains its mobility. Unexpectedly, we find that condensin is required during interphase to prevent ongoing transcription from eliciting a DNA damage response. Conclusions In addition to establishing mitotic chromosome architecture, condensin-mediated long-range chromatin interactions contribute to shaping chromatin organization in interphase. The resulting structure confines chromatin mobility and protects the genome from transcription-induced DNA damage. This adds to the important roles of condensin in maintaining chromosome stability.