The effect of tethers on artificial cell membranes: A coarse-grained molecular dynamics study

© 2016 Hoiles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Tethered bilayer lipid membranes (tBLMs) provide a stable platform for modeling the dynamics and order of biological membranes where the tethers mimic the cytoskeletal supports present in biological cell membranes. In this paper coarse-grained molecular dynamics (CGMD) is applied to study the effects of tethers on lipid membrane properties. Using results from the CGMD model and the overdamped Fokker-Planck equation, we show that the diffusion tensor and particle density of water in the tBLM is spatially dependent. Further, it is shown that the membrane thickness, lipid diffusion, defect density, free energy of lipid flip-flop, and membrane dielectric permittivity are all dependent on the tether density. The numerically computed results from the CGMD model are in agreement with the experimentally measured results from tBLMs containing different tether densities and lipids derived from Archaebacteria. Additionally, using experimental measurements from Escherichia coli bacteria and Saccharomyces Cerevisiae yeast tethered membranes, we illustrate how previous molecular dynamics results can be combined with the proposed model to estimate the dielectric permittivity and defect density of these membranes as a function of tether density

Did It Change How We Teach? A Qualitative Exploration Into Teacher Perceptions of How Technology Changed in the Classroom as a Result of the Pandemic

The purpose of this case study was to understand the perceived change in educator attitudes from the pandemic concerning technology at Cornerstone School. The problem addressed in this study was the lack of motivation of educators to try new ways to use technology in their classrooms. The theory guiding this study was J. Bruner’s constructivist theory which focuses on obtaining knowledge through discovery. The connection between Bruner’s theory and the perceived change in teachers’ attitudes was that teachers learned technology through their use and discovery. A qualitative case study design was used to carry out this investigation. Ten educators were recruited using a typical purposeful sampling strategy; all were from a small private school. These included educators from the kindergarten through 11th-grade levels. The data were collected through a questionnaire followed by semi-structured individual interviews, an analysis of reflective journal prompts, and an analysis of artifacts. Findings revealed themes pertaining to the study’s purpose, including pre-pandemic attitudes toward technology, successful practices using technology during the pandemic, and post-pandemic attitudes toward technology. Confidence developed by the participants through the discovery of technology used confirmed Bruner’s theory that learning through discovery gave the participants a more positive attitude towards technology and influenced how the participants taught

A Randomised Controlled Trial of Guided Self-Help Cognitive Behaviour Therapy for Clinical Perfectionism

Perfectionism has been found to be elevated across disorders, with evidence that it can interfere with treatment outcome. Study 1, provides evidence of convergent validity of the CPQ in a mixed clinical sample (N = 32). In Study 2, guided self-help CBT for clinical perfectionism decreased perfectionism and psychopathology in an elevated perfectionism sample (N = 40) with self-criticism mediating treatment outcome. The intervention also reduced primary DSM-IV diagnosis and comorbid presentations

Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses

Correlates of psychiatric inpatient admission in a paediatric eating disorder cohort

Objective: The prevalence and correlates of impending psychiatric inpatient admissions in children and adolescents with eating disorders were examined. Method: The sample comprised patients aged 8 to 17 years (91% female), with DSM-5 eating disorder diagnosis, categorised as with (n = 38) or without (n = 247) impending psychiatric admission, assessed between 2006 and 2013. The data source was the Helping to Outline Paediatric Eating Disorders (HOPE) Project registry (N ~ 1000), a prospective, ongoing registry study comprising consecutive paediatric tertiary eating disorder referrals. Results: Multivariate analysis of variance and discriminant function analysis were conducted to examine correlates. The prevalence of impending psychiatric admission was 13.3%. Significant group differences were found on psychological, behavioural, and situational correlates. Specifically, suicidal ideation, depressive symptoms, eating pathology, multiple methods of weight control, anxiety, purging behaviours, family functioning, and exercise for shape and weight control. Conclusions: Almost 1 in 7 young people with an eating disorder who attended assessment had a presentation needing inpatient psychiatric care, and these individuals could be differentiated from individuals not hospitalised or treated in inpatient medical settings. Implications of these findings include better identification of patients at critical psychiatric risk, earlier recognition and intervention for these patients and more focused assessment of comorbid psychiatric symptoms in specialised eating disorder triage and assessment. Adaptions at the study site to clinical and training protocols will be discussed

Know and grow: A qualitative evaluation of a parent skills training intervention

Objective: This qualitative study examined the experience of parents of children and adolescents with eating disorders after having participated in a skills-based training intervention. Method: Participants were interviewed and transcripts were analysed using inductive thematic analysis. Results: Parent responses were organised around key themes of (1) effectiveness and acceptability of the intervention; (2) interpersonal experience of the group process; and (3) feedback on intervention content. Overall, the program was seen by parents to be highly relevant with direct application to supporting their child in home and hospital environments. Discussion: This study reports on preliminary evidence that skillsbased training is acceptable to parents and improves parent functioning including parent self-efficacy, and reduces psychological distress, anxiety, and burden. The study also demonstrated that the intervention can be delivered in a tertiary paediatric treatment setting and it may become cost-effective method for supporting parents and other carers. Future research is required on treatment efficacy and patient outcomes

Rural-metropolitan health differential for young persons with eating disorders referred for specialist treatment

Objective: The aim was to explore associations between residing in a rural area and clinical characteristics of children and adolescents with eating disorders presenting to a specialist eating disorders program. Method: The data source was the Helping to Outline Paediatric Eating Disorders (HOPE) Project registry (N ~ 1000), a prospective ongoing registry study comprising consecutive paediatric tertiary eating disorder referrals. The sample (N = 399) comprised children and adolescents presenting with a DSM-5 eating disorder, with ages ranging from 8 to 16 years (M = 14.49, 92% female). Results Consistent with the hypotheses, living in a rural area was associated with a lower body mass index z-score, and a higher likelihood of medical complications at intake assessment. Contrary to our hypothesis, eating pathology and living in a rural area were negatively associated. No relationship was observed between living in a rural area and duration of illness or greater percentage of bodyweight lost. Conclusions: The results suggest that living in a rural area and being a greater distance from specialist services is associated with more severe malnutrition and medical complications by the time the young person and their family obtain specialist care. These findings have implications for service planning and provision for rural communities. The modifications to service delivery in the study setting will be described