Instabilities, motion and deformation of active fluid droplets

We consider two minimal models of active fluid droplets that exhibit complex dynamics including steady motion, deformation, rotation and oscillating motion. First we consider a droplet with a concentration of active contractile matter adsorbed to its boundary. We analytically predict activity driven instabilities in the concentration profile, and compare them to the dynamics we find from simulations. Secondly, we consider a droplet of active polar fluid of constant concentration. In this system we predict, motion and deformation of the droplets in certain activity ranges due to instabilities in the polarisation field. Both these systems show spontaneous transitions to motility and deformation which resemble dynamics of the cell cytoskeleton in animal cells

Spectral graph theory efficiently characterizes ventilation heterogeneity in lung airway networks

This paper introduces a linear operator for the purposes of quantifying the spectral properties of transport within resistive trees, such as airflow in lung airway networks. The operator, which we call the Maury matrix, acts only on the terminal nodes of the tree and is equivalent to the adjacency matrix of a complete graph summarizing the relationships between all pairs of terminal nodes. We show that the eigenmodes of the Maury operator have a direct physical interpretation as the relaxation, or resistive, modes of the network. We apply these findings to both idealized and image-based models of ventilation in lung airway trees and show that the spectral properties of the Maury matrix characterize the flow asymmetry in these networks more concisely than the Laplacian modes, and that eigenvector centrality in the Maury spectrum is closely related to the phenomenon of ventilation heterogeneity caused by airway narrowing or obstruction. This method has applications in dimensionality reduction in simulations of lung mechanics, as well as for characterization of models of the airway tree derived from medical images

Spectral graph theory efficiently characterises ventilation heterogeneity in lung airway networks

This paper introduces a linear operator for the purposes of quantifying the spectral properties of transport within resistive trees, such as airflow in lung airway networks. The operator, which we call the Maury matrix, acts only on the terminal nodes of the tree and is equivalent to the adjacency matrix of a complete graph summarising the relationships between all pairs of terminal nodes. We show that the eigenmodes of the Maury operator have a direct physical interpretation as the relaxation, or resistive, modes of the network. We apply these findings to both idealised and image-based models of ventilation in lung airway trees and show that the spectral properties of the Maury matrix characterise the flow asymmetry in these networks more concisely than the Laplacian modes, and that eigenvector centrality in the Maury spectrum is closely related to the phenomenon of ventilation heterogeneity caused by airway narrowing or obstruction. This method has applications in dimensionality reduction in simulations of lung mechanics, as well as for characterisation of models of the airway tree derived from medical images

Optimizing real time fMRI neurofeedback for therapeutic discovery and development

While reducing the burden of brain disorders remains a top priority of organizations like the World Health Organization and National Institutes of Health, the development of novel, safe and effective treatments for brain disorders has been slow. In this paper, we describe the state of the science for an emerging technology, real time functional magnetic resonance imaging (rtfMRI) neurofeedback, in clinical neurotherapeutics. We review the scientific potential of rtfMRI and outline research strategies to optimize the development and application of rtfMRI neurofeedback as a next generation therapeutic tool. We propose that rtfMRI can be used to address a broad range of clinical problems by improving our understanding of brain–behavior relationships in order to develop more specific and effective interventions for individuals with brain disorders. We focus on the use of rtfMRI neurofeedback as a clinical neurotherapeutic tool to drive plasticity in brain function, cognition, and behavior. Our overall goal is for rtfMRI to advance personalized assessment and intervention approaches to enhance resilience and reduce morbidity by correcting maladaptive patterns of brain function in those with brain disorders

Quality of care for Black and Latina women living with HIV in the U.S.: a qualitative study

Background: Ending the HIV epidemic requires that women living with HIV (WLWH) have access to structurally competent HIV-related and other health care. WLWH may not regularly engage in care due to inadequate quality; however, women's perspectives on the quality of care they receive are understudied. Methods: We conducted 12 focus groups and three in-depth interviews with Black (90%) and Latina (11%) WLWH enrolled in the Women's Interagency HIV Study in Atlanta, GA, Birmingham, AL, Brooklyn, NY, Chapel Hill, NC, Chicago, IL, and Jackson, MS from November 2017 to May 2018 (n = 92). We used a semi-structured format to facilitate discussions about satisfaction and dissatisfaction with health care engagement experiences, and suggestions for improvement, which were audio-recorded, transcribed, and coded using thematic analysis. Results: Themes emerged related to women's health care satisfaction or dissatisfaction at the provider, clinic, and systems levels and across Institute of Medicine-defined quality of care domains (effectiveness, efficiency, equity, patient-centeredness, safety and timeliness). Women's degree of care satisfaction was driven by: 1) knowledge-based care resulting in desired outcomes (effectiveness); 2) coordination, continuity and necessity of care (efficiency); 3) perceived disparities in care (equity); 4) care delivery characterized by compassion, nonjudgment, accommodation, and autonomous decision-making (patient-centeredness); 5) attention to avoiding side effects and over-medicalization (safety); and 6) limited wait time (timeliness). Conclusions: Quality of care represents a key changeable lever affecting engage in care among WLWH. The communities most proximally affected by HIV should be key stakeholders in HIV-related quality assurance. Findings highlight aspects of the health care experience valued by WLWH, and potential participatory, patient-driven avenues for improvement

Patient Health Literacy and Communication with Providers Among Women Living with HIV: A Mixed Methods Study

In this mixed-methods study, we examine the relationship between provider communication and patient health literacy on HIV continuum of care outcomes among women living with HIV in the United States. We thematically coded qualitative data from focus groups and interviews (N = 92) and conducted mediation analyses with quantitative survey data (N = 1455) collected from Women’s Interagency HIV Study participants. Four qualitative themes related to provider communication emerged: importance of respect and non-verbal cues; providers’ expressions of condescension and judgement; patient health literacy; and unclear, insufficient provider communication resulting in diminished trust. Quantitative mediation analyses suggest that higher health literacy is associated with higher perceived patient–provider interaction quality, which in turn is associated with higher levels of trust in HIV providers, improved antiretroviral medication adherence, and reduced missed clinical visits. Findings indicate that enhancing provider communication and bolstering patient health literacy could have a positive impact on the HIV continuum of care

Associations of autozygosity with a broad range of human phenotypes

In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (F-ROH) for >1.4 million individuals, we show that F-ROH is significantly associated (p <0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: F-ROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44-66%] in the odds of having children. Finally, the effects of F-ROH are confirmed within full-sibling pairs, where the variation in F-ROH is independent of all environmental confounding.Peer reviewe