Calculating the Fickian diffusivity for a lattice-based random walk with agents and obstacles of different shapes and sizes

Random walk models are often used to interpret experimental observations of the motion of biological cells and molecules. A key aim in applying a random walk model to mimic an in vitro experiment is to estimate the Fickian diffusivity (or Fickian diffusion coefficient),D. However, many in vivo experiments are complicated by the fact that the motion of cells and molecules is hindered by the presence of obstacles. Crowded transport processes have been modeled using repeated stochastic simulations in which a motile agent undergoes a random walk on a lattice that is populated by immobile obstacles. Early studies considered the most straightforward case in which the motile agent and the obstacles are the same size. More recent studies considered stochastic random walk simulations describing the motion of an agent through an environment populated by obstacles of different shapes and sizes. Here, we build on previous simulation studies by analyzing a general class of lattice-based random walk models with agents and obstacles of various shapes and sizes. Our analysis provides exact calculations of the Fickian diffusivity, allowing us to draw conclusions about the role of the size, shape and density of the obstacles, as well as examining the role of the size and shape of the motile agent. Since our analysis is exact, we calculateDdirectly without the need for random walk simulations. In summary, we find that the shape, size and density of obstacles has a major influence on the exact Fickian diffusivity. Furthermore, our results indicate that the difference in diffusivity for symmetric and asymmetric obstacles is significant.

Exploring changing culture and building capacity in research with consumers, carers and consumer companions

Background Australian policy mandates consumer and carer participation in mental health services at all levels including research. Inspired by a UK model - Service Users Group Advising on Research [SUGAR] - we conducted a scoping project in 2013 with a view to create a consumer and carer led research process that moves beyond stigma and tokenism, that values the unique knowledge of lived experience and leads to people being treated better when accessing services. This poster presents the initial findings. Aims The project’s purpose was to explore with consumers, consumer companions and carers at the Metro North Mental Health-RBWH their interest in and views about research partnerships with academic and clinical colleagues. Methods This poster overviews the initial findings from three audio-recorded focus groups conducted with a total of 14 consumers, carers and consumer companions at the Brisbane site. Analysis Our work was guided by framework analysis (Gale et al. 2013). It defines 5 steps for analysing narrative data: familiarising; development of categories; indexing; charting and interpretation. Eight main ideas were initially developed and were divided between the authors to further index. This process identified 37 related analytic ideas. The authors integrated these by combining, removing and redefining them by consensus though a mapping process. The final step is the return of the analysis to the participants for feedback and input into the interpretation of the focus group discussions. Results 1. Value & Respect: Feeling Valued & Respected, Tokenism, Stigma, Governance, Valuing prior knowledge / background 2. Pathways to Knowledge and Involvement in Research: ‘Where to begin’, Support, Unity & partnership, Communication, Co-ordination, Flexibility due to fluctuating capacity 3. Personal Context: Barriers regarding Commitments & the nature of mental illness, Wellbeing needs, Prior experience of research, Motivators, Attributes 4. What is research? Developing Knowledge, What to do research on, how and why? Conclusion and Discussion Initial analysis suggests that participants saw potential for ‘amazing things’ in mental health research such as reflecting their priorities and moving beyond stigma and tokenism. The main needs identified were education, mentoring, funding support and research processes that fitted consumers’ and carers’limitations and fluctuating capacities. They identified maintaining motivation and interest as an issue since research processes are often extended by ethics and funding applications. Participants felt that consumer and carer led research would value the unique knowledge that the lived experience of consumers and carers brings and lead to people being treated better when accessing services.

The effectiveness of the teach-back method on adherence and self-management in health education for people with chronic disease: A systematic review

- BACKGROUND Chronic diseases are increasing worldwide and have become a significant burden to those affected by those diseases. Disease-specific education programs have demonstrated improved outcomes, although people do forget information quickly or memorize it incorrectly. The teach-back method was introduced in an attempt to reinforce education to patients. To date, the evidence regarding the effectiveness of health education employing the teach-back method in improved care has not yet been reviewed systematically. - OBJECTIVES This systematic review examined the evidence on using the teach-back method in health education programs for improving adherence and self-management of people with chronic disease. - INCLUSION CRITERIA Types of participants: Adults aged 18 years and over with one or more than one chronic disease. Types of intervention: All types of interventions which included the teach-back method in an education program for people with chronic diseases. The comparator was chronic disease education programs that did not involve the teach-back method. Types of studies: Randomized and non-randomized controlled trials, cohort studies, before-after studies and case-control studies. Types of outcomes: The outcomes of interest were adherence, self-management, disease-specific knowledge, readmission, knowledge retention, self-efficacy and quality of life. - SEARCH STRATEGY Searches were conducted in CINAHL, MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science, ProQuest Nursing and Allied Health Source, and Google Scholar databases. Search terms were combined by AND or OR in search strings. Reference lists of included articles were also searched for further potential references. - METHODOLOGICAL QUALITY Two reviewers conducted quality appraisal of papers using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. - DATA EXTRACTION Data were extracted using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument data extraction instruments. - DATA SYNTHESIS There was significant heterogeneity in selected studies, hence a meta-analysis was not possible and the results were presented in narrative form. - RESULTS Of the 21 articles retrieved in full, 12 on the use of the teach-back method met the inclusion criteria and were selected for analysis. Four studies confirmed improved disease-specific knowledge in intervention participants. One study showed a statistically significant improvement in adherence to medication and diet among type 2 diabetics patients in the intervention group compared to the control group (p < 0.001). Two studies found statistically significant improvements in self-efficacy (p = 0.0026 and p < 0.001) in the intervention groups. One study examined quality of life in heart failure patients but the results did not improve from the intervention (p = 0.59). Five studies found a reduction in readmission rates and hospitalization but these were not always statistically significant. Two studies showed improvement in daily weighing among heart failure participants, and in adherence to diet, exercise and foot care among those with type 2 diabetes. - CONCLUSION Overall, the teach-back method showed positive effects in a wide range of health care outcomes although these were not always statistically significant. Studies in this systematic review revealed improved outcomes in disease-specific knowledge, adherence, self-efficacy and the inhaler technique. There was a positive but inconsistent trend also seen in improved self-care and reduction of hospital readmission rates. There was limited evidence on improvement in quality of life or disease related knowledge retention.

Human and pathogen factors associated with chlamydia trachomatis-related infertility in women

Chlamydia trachomatis is the most common bacterial sexually transmitted pathogen worldwide. Infection can result in serious reproductive pathologies, including pelvic inflammatory disease, ectopic pregnancy, and infertility, in women. However, the processes that result in these reproductive pathologies have not been well defined. Here we review the evidence for the human disease burden of these chlamydial reproductive pathologies. We then review human-based evidence that links Chlamydia with reproductive pathologies in women. We present data supporting the idea that host, immunological, epidemiological, and pathogen factors may all contribute to the development of infertility. Specifically, we review the existing evidence that host and pathogen genotypes, host hormone status, age of sexual debut, sexual behavior, coinfections, and repeat infections are all likely to be contributory factors in development of infertility. Pathogen factors such as infectious burden, treatment failure, and tissue tropisms or ascension capacity are also potential contributory factors. We present four possible processes of pathology development and how these processes are supported by the published data. We highlight the limitations of the evidence and propose future studies that could improve our understanding of how chlamydial infertility in women occurs and possible future interventions to reduce this disease burden.

Diverse populations of T cells with NK cell receptors accumulate in the human intestine in health and in colorectal cancer

T cells expressing NK cell receptors (NKR) display rapid MHC-unrestricted cytotoxicity and potent cytokine secretion and are thought to play roles in immunity against tumors. We have quantified and characterized NKR+ T cells freshly isolated from epithelial and lamina propria layers of duodenum and colon from 16 individuals with no evidence of gastrointestinal disease and from tumor and uninvolved tissue from 19 patients with colorectal cancer. NKR+ T cell subpopulations were differentially distributed in different intestinal compartments, and CD161+ T cells accounted for over one half of T cells at all locations tested. Most intestinal CD161+ T cells expressed alpha beta TCR and either CD4 or CD8. Significant proportions expressed HLA-DR,CD69 and Fas ligand. Upon stimulation in vitro, CD161+ T cells produced IFN-gamma and TNF-alpha but not IL-4. NKT cells expressing the Valpha24Vbeta11 TCR, which recognizes CD1d,were virtually absent from the intestine, but colonic cells produced IFN-gamma in response to the NKT cell agonist ligand alpha-galactosylceramide. NKR+ T cells were not expanded in colonic tumors compared to adjacent uninvolved tissue. The predominance, heterogeneity and differential distribution of NKR+ T cells at different intestinal locations suggests that they are central to intestinal immunity.

Diabetic ketoacidosis and electroencephalographic changes in newly diagnosed pediatric patients

Objective: To document electroencephalogram (EEG) changes and their correlation with clinical parameters in a newly diagnosed pediatric cohort of type 1 diabetes mellitus (T1DM) patients with and without diabetic ketoacidosis (DKA) and to define their medium term utility and significance. Research design and methods: Prospective longitudinal study of children presenting with T1DM. EEGs were performed within 24 h of diagnosis, day 5, and at 6 months post-diagnosis and reviewed by a neurologist blinded to clinical status. Severity of encephalopathy was graded from 1 to 5 using the Aoki and Lombroso encephalopathy scale. Cognitive abilities were assessed using standardized tests of attention, memory, and intelligence. Results: Eighty eight children were recruited; 34 presented with DKA. Abnormal background slowing was more often observed in the first 24 h in children with DKA (p = 0.01). Encephalopathy scores on day 1 correlated with initial pH, CO2, HCO3, base excess, respiratory rate, heart rate, diastolic blood pressure, and IV fluid intake (all parameters p < 0.05). EEG scores at day 1 did not correlate with contemporaneous mental state or cognition in the medium term. Conclusions: DKA was associated with significant clinical and neurophysiologic signs of brain dysfunction at presentation. While EEG is sensitive to the detection of encephalopathy in newly diagnosed T1DM, it has limited use in identifying children at risk of later cognitive deficits.