Wearable device to assist independent living.

Older people increasingly want to remain living independently in their own homes. The aim of the ENABLE project is to develop a wearable device that can be used both within and outside of the home to support older people in their daily lives and which can monitor their health status, detect potential problems, provide activity reminders and offer communication and alarm services. In order to determine the specifications and functionality required for development of the device user surveys and focus groups were undertaken and use case analysis and scenario modeling carried out. The project has resulted in the development of a wrist worn device and mobile phone combination that can support and assist older and vulnerable wearers with a range of activities and services both inside and outside of their homes. The device is currently undergoing pilot trials in five European countries. The aim of this paper is to describe the ENABLE device, its features and services, and the infrastructure within which it operates

Spectral properties of zero temperature dynamics in a model of a compacting granular column

The compacting of a column of grains has been studied using a one-dimensional Ising model with long range directed interactions in which down and up spins represent orientations of the grain having or not having an associated void. When the column is not shaken (zero 'temperature') the motion becomes highly constrained and under most circumstances we find that the generator of the stochastic dynamics assumes an unusual form: many eigenvalues become degenerate, but the associated multi-dimensional invariant spaces have but a single eigenvector. There is no spectral expansion and a Jordan form must be used. Many properties of the dynamics are established here analytically; some are not. General issues associated with the Jordan form are also taken up.Comment: 34 pages, 4 figures, 3 table

Self-Averaging, Distribution of Pseudo-Critical Temperatures and Finite Size Scaling in Critical Disordered Systems

The distributions $P(X)$ of singular thermodynamic quantities in an ensemble of quenched random samples of linear size $l$ at the critical point $T_c$ are studied by Monte Carlo in two models. Our results confirm predictions of Aharony and Harris based on Renormalization group considerations. For an Ashkin-Teller model with strong but irrelevant bond randomness we find that the relative squared width, $R_X$, of $P(X)$ is weakly self averaging. $R_X\sim l^{\alpha/\nu}$, where $\alpha$ is the specific heat exponent and $\nu$ is the correlation length exponent of the pure model fixed point governing the transition. For the site dilute Ising model on a cubic lattice, known to be governed by a random fixed point, we find that $R_X$ tends to a universal constant independent of the amount of dilution (no self averaging). However this constant is different for canonical and grand canonical disorder. We study the distribution of the pseudo-critical temperatures $T_c(i,l)$ of the ensemble defined as the temperatures of the maximum susceptibility of each sample. We find that its variance scales as $(\delta T_c(l))^2 \sim l^{-2/\nu}$ and NOT as $\sim l^{-d}. We find that$R_\chi$is reduced by a factor of$\sim 70$with respect to$R_\chi (T_c)$by measuring$\chi$of each sample at$T_c(i,l)$. We analyze correlations between the magnetization at criticality$m_i(T_c,l)$and the pseudo-critical temperature$T_c(i,l)$in terms of a sample independent finite size scaling function of a sample dependent reduced temperature$(T-T_c(i,l))/T_c$. This function is found to be universal and to behave similarly to pure systems.Comment: 31 pages, 17 figures, submitted to Phys. Rev.

Dog ownership and physical activity: A review of the evidence

Background: Dog walking is a strategy for increasing population levels of physical activity (PA). Numerous cross-sectional studies of the relationship between dog ownership and PA have been conducted. The purpose was to review studies comparing PA of dog owners (DO) to nondog owners (NDO), summarize the prevalence of dog walking, and provide recommendations for research. Methods: A review of published studies (1990-2010) examining DO and NDO PA and the prevalence of dog walking was conducted (N = 29). Studies estimating the relationship between dog ownership and PA were grouped to create a pointestimate using meta-analysis. Results: Most studies were conducted in the last 5 years, were cross-sectional, and sampled adults from Australia or the United States. Approximately 60% of DO walked their dog, with a median duration and frequency of 160 minutes/week and 4 walks/week, respectively. Meta-analysis showed DO engage in more walking and PA than NDO and the effect sizes are small to moderate (d = 0.26 and d = 0.16, respectively). Three studies provided evidence of a directional relationship between dog ownership and walking. Conclusions: Longitudinal and interventional studies would provide stronger causal evidence for the relationship between dog ownership and PA. Improved knowledge of factors associated with dog walking will guide intervention research

Fluctuation-dissipation relations in the non-equilibrium critical dynamics of Ising models

We investigate the relation between two-time, multi-spin, correlation and response functions in the non-equilibrium critical dynamics of Ising models in d=1 and d=2 spatial dimensions. In these non-equilibrium situations, the fluctuation-dissipation theorem (FDT) is not satisfied. We find FDT `violations' qualitatively similar to those reported in various glassy materials, but quantitatively dependent on the chosen observable, in contrast to the results obtained in infinite-range glass models. Nevertheless, all FDT violations can be understood by considering separately the contributions from large wavevectors, which are at quasi-equilibrium and obey FDT, and from small wavevectors where a generalized FDT holds with a non-trivial limit fluctuation-dissipation ratio X. In d=1, we get X = 1/2 for spin observables, which measure the orientation of domains, while X = 0 for observables that are sensitive to the domain-wall motion. Numerical simulations in d=2 reveal a unique X = 0.34 for all observables. Measurement protocols for X are discussed in detail. Our results suggest that the definition of an effective temperature Teff = T / X for large length scales is generically possible in non-equilibrium critical dynamics.Comment: 26 pages, 10 figure

Possible origins of macroscopic left-right asymmetry in organisms

I consider the microscopic mechanisms by which a particular left-right (L/R) asymmetry is generated at the organism level from the microscopic handedness of cytoskeletal molecules. In light of a fundamental symmetry principle, the typical pattern-formation mechanisms of diffusion plus regulation cannot implement the "right-hand rule"; at the microscopic level, the cell's cytoskeleton of chiral filaments seems always to be involved, usually in collective states driven by polymerization forces or molecular motors. It seems particularly easy for handedness to emerge in a shear or rotation in the background of an effectively two-dimensional system, such as the cell membrane or a layer of cells, as this requires no pre-existing axis apart from the layer normal. I detail a scenario involving actin/myosin layers in snails and in C. elegans, and also one about the microtubule layer in plant cells. I also survey the other examples that I am aware of, such as the emergence of handedness such as the emergence of handedness in neurons, in eukaryote cell motility, and in non-flagellated bacteria.Comment: 42 pages, 6 figures, resubmitted to J. Stat. Phys. special issue. Major rewrite, rearranged sections/subsections, new Fig 3 + 6, new physics in Sec 2.4 and 3.4.1, added Sec 5 and subsections of Sec

Quantum Tomography under Prior Information

We provide a detailed analysis of the question: how many measurement settings or outcomes are needed in order to identify a quantum system which is constrained by prior information? We show that if the prior information restricts the system to a set of lower dimensionality, then topological obstructions can increase the required number of outcomes by a factor of two over the number of real parameters needed to characterize the system. Conversely, we show that almost every measurement becomes informationally complete with respect to the constrained set if the number of outcomes exceeds twice the Minkowski dimension of the set. We apply the obtained results to determine the minimal number of outcomes of measurements which are informationally complete with respect to states with rank constraints. In particular, we show that 4d-4 measurement outcomes (POVM elements) is enough in order to identify all pure states in a d-dimensional Hilbert space, and that the minimal number is at most 2 log_2(d) smaller than this upper bound.Comment: v3: There was a mistake in the derived finer upper bound in Theorem 3. The corrected upper bound is +1 to the earlier versio

Internalized HIV stigma predicts subsequent viremia in US HIV patients through depressive symptoms and antiretroviral therapy adherence

Objective:We sought to examine the prospective association between internalized HIV stigma and unsuppressed viral load and to investigate whether this relationship was sequentially mediated by depressive symptoms and antiretroviral therapy (ART) adherence.Design:Longitudinal study in a multisite observational clinical cohort.Methods:The Center for AIDS Research Network of Integrated Clinical Systems patient-reported outcomes survey measures internalized HIV stigma yearly using a four-item assessment (response scale 1 = strongly disagree to 5 = strongly agree). We obtained patient-reported outcome, lab, and appointment data from six center for AIDS research network of integrated clinical systems sites. We used multivariable logistic regression to examine the association between mean stigma and subsequent viremia. We then used Bayesian sequential mediation to fit a longitudinal sequential path model spanning four time points to test if depressive symptoms at T1and ART adherence at T2mediated the effect of stigma at T0on viral load at T3, adjusting for baseline covariates.Results:Between February 2016 and November 2018, 6859 patients underwent stigma assessment and were 81% cis-men, 38% Black, 16% Latinx, 32% heterosexual-identified, and 49% at least 50 years of age. Mean stigma level was 2.00 (SD 1.08). Stigma was significantly associated with subsequent viremia (adjusted odds ratio = 1.16, 95% confidence interval: 1.05-1.28, P = 0.004), as were younger age and Black race. The chained indirect effect from stigma to unsuppressed viral load through depressive symptoms and then adherence was significant (standardized β = 0.002; SD = 0.001).Conclusion:Internalized HIV stigma positively predicts subsequent viremia through depressive symptoms and ART adherence. Addressing the link between stigma and depressive symptoms could help improve viral suppression

Internalized HIV Stigma Predicts Suboptimal Retention in Care among People Living with HIV in the United States

HIV-related stigma is a known barrier to retention in care. However, no large-scale, multi-site studies have prospectively evaluated the effect of internalized stigma on retention in care. The Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort study integrates medical record and survey data from people living with HIV (PLWH) seen in HIV primary care clinics across the United States, and assesses internalized stigma yearly using a validated 4-item Likert scale. We used multivariable logistic regression models to evaluate associations between mean internalized stigma and two prospective retention in care outcomes: keeping the next primary care appointment and keeping all scheduled primary care appointments in the 12 months following stigma assessment. From February 2016 to November 2017, 5968 PLWH completed the stigma assessment and had adequate follow-up time. Mean stigma was 1.9 (standard deviation 1.08). Increased mean stigma scores were associated with decreased odds of attending the next primary care appointment [adjusted odds ratio (aOR) = 0.93, 95% confidence interval (CI) 0.88-0.99, p = 0.02], and all primary care appointments in the subsequent 12 months (aOR = 0.94, 95% CI 0.89-0.99, p = 0.02). In both models, younger age and Black race were also independently associated with suboptimal appointment attendance. There was no support for interactions between internalized stigma and covariates. Internalized HIV stigma had an independent negative effect on the odds of subsequent appointment attendance. This study highlights the importance of identifying even low levels of internalized stigma. Interventions to address internalized HIV stigma are critical to supporting retention in care and improving clinical outcomes

The Human Immunodeficiency Virus (HIV) Index: Using a Patient-Reported Outcome on Engagement in HIV Care to Explain Suboptimal Retention in Care and Virologic Control

Background: We investigated the prospective association between a brief self-report measure of engagement in human immunodeficiency virus (HIV) care (the Index of Engagement in HIV Care; hereafter "Index") and suboptimal retention and viral suppression outcomes. Methods: The Centers for AIDS Research Network of Integrated Clinical Systems cohort study combines medical record data with patient-reported outcomes from 8 HIV clinics in the United States, which from April 2016 to March 2017 included the 10-item Index. Multivariable logistic regression was used to estimate the risk and odds ratios of mean Index scores on 2 outcomes in the subsequent year: (1) not keeping ≥75% of scheduled HIV care appointments; and (2) for those with viral suppression at Index assessment, having viral load >200 copies/mL on ≥1 measurement. We also used generalized linear mixed models (GLMMs) to estimate the risk and odds ratios of appointment nonattendance or unsuppressed viral load at any given observation. We generated receiver operating characteristic curves for the full models overlaid with the Index as a sole predictor. Results: The mean Index score was 4.5 (standard deviation, 0.6). Higher Index scores were associated with lower relative risk of suboptimal retention (n = 2576; logistic regression adjusted risk ratio [aRR], 0.88 [95% confidence interval,. 87-.88]; GLMM aRR, 0.85 [.83-.87]) and lack of sustained viral suppression (n = 2499; logistic regression aRR, 0.75 [.68-.83]; GLMM aRR, 0.74 [.68-.80]). The areas under the receiver operating characteristic curve for the full models were 0.69 (95% confidence interval,. 67-.71) for suboptimal retention and 0.76 (.72-.79) for lack of sustained viral suppression. Conclusions: Index scores are significantly associated with suboptimal retention and viral suppression outcomes