441 research outputs found
Preliminary investigations into measurements and par scores taken from plaster and two types of digital study model
Aim: To determine if digital study models are a satisfactory alternative to plaster study models. Method: 1. Pilot study to compare linear measurements from plaster models with two types of digital model. 2. Study to compare PAR scores from plaster models with digital models created from scans of dental impressions. 3. Pilot study to compare PAR scores of plaster models with 30 printed models created from scans of dental impressions. Results: A mean difference of <O.5mm (range 0.02-0.51 mm) for single linear measurements and <3.0mm (0.47-3.03mm) for multiple linear measurements was indicated. A mean difference of 0.03 PAR points (SD=3) was demonstrated between PAR scores for plaster models and digital models. A mean difference of 1 PAR point (SD=3) was demonstrated between PAR scores for plaster models and 30 printed models. Conclusions: Both types of digital study model may be comparable with plaster models when used for linear measurements. Digital models created from scans of dental impressions are indicated to be comparable with plaster models for PAR scoring. 30 printed models may be comparable to plaster models for PAR scoring. Further research using a larger sample size is required to confirm above conclusions with regard to validity and reliability
Changing Minds? Implications of Conceptual Change for Teaching and Learning about Biological Evolution
Correlates of level and loss of grip strength in later life:Findings from the English Longitudinal Study of Ageing and the Hertfordshire Cohort Study
Characterisation of grip strength (GS) using isometric dynamometry is central to the definition of sarcopenia. Determinants of low GS include: older age, shorter stature, low physical activity, poor nutrition, socioeconomic disadvantage and multimorbidity. Less is known about risk factors for accelerated loss of GS. We investigated determinants of level and 8-year loss of GS in 3703 men and women (aged 52â82 years) in the English Longitudinal Study of Ageing (ELSA). Four hundred and forty-one men and women (aged 59â71 years) who participated in a 10-year follow-up of the Hertfordshire Cohort Study (HCS) were used for replication. Variables were harmonised between cohorts. Change in GS was characterised using mixed-effects models in ELSA and a residual change approach in HCS and analysed for men and women combined. Men in ELSA and HCS had higher average levels of GS at baseline, and accelerated rates of loss, compared with women. In ELSA, older age, shorter stature and multimorbidity were correlated with lower level, and accelerated rate of loss, of GS in both sexes (accelerated loss of 0.04 (95% CI 0.00â0.08) standard deviation scores per additional morbidity after multivariable adjustment). Socioeconomic disadvantage, low level of physical activity and poorer self-reported health were also correlated with low GS level, but not loss rate, after multivariable adjustment. Analysis in HCS yielded similar results. Our results identify multimorbidity as a modifiable determinant of loss of muscle strength in later life, and raise the possibility that developmental influences may impact on rate of involutional decline in muscle strength
Attitudes to ageing, biomarkers of ageing and mortality:The Lothian Birth Cohort 1936
Objective: To investigate whether people with more positive attitudes to ageing are biologically younger as defined by leucocyte telomere length, accelerated DNA methylation GrimAge (AgeAccelGrim) and brain-predicted age difference, and whether these biomarkers explain relationships between attitudes to ageing and mortality.Methods: We used linear regression to examine cross-sectionally attitudes to ageing (measured using the Attitudes to Ageing Questionnaire) and the three biomarkers in 758 adults, mean age 72.5 years, from the Lothian Birth Cohort 1936. We used Cox proportional hazards models to examine longitudinally attitudes to ageing and mortality and the role of the biomarkers.Results: More positive attitude to physical change was associated with younger biological age, as measured by AgeAccelGrim and brain-predicted age difference in age-adjusted and sex-adjusted models: for an SD higher score, AgeAccelGrim was lower by -0.73 (95% CI -1.03 to -0.42) of a year, and brain-predicted age difference was lower by -0.87 (1.51 to 0.23) of a year. Both associations were attenuated by adjustment for covariates and not significant after simultaneous adjustment for all covariates and correction for multiple testing. More positive attitudes to physical change were associated with lower mortality: for an SD higher score the age-adjusted and sex-adjusted HR (95%âCI) was 0.66 (0.56 to 0.78). Adjustment for AgeAccelGrim or brain-predicted age difference attenuated this association slightly. It remained significant after adjustment for all covariates.Conclusion: We found partial evidence that attitudes to ageing are linked with ageing biomarkers but they accounted for only a little of the association between attitudes and mortality
Differential function and maturation of human stem cell-derived islets after transplantation
Insulin-producing stem cell-derived islets (SC-islets) provide a virtually unlimited cell source for diabetes cell replacement therapy. While SC-islets are less functional when first differentiated in vitro compared to isolated cadaveric islets, transplantation into mice has been shown to increase their maturation. To understand the effects of transplantation on maturation and function of SC-islets, we examined the effects of cell dose, transplantation strategy, and diabetic state in immunocompromised mice. Transplantation of 2 and 5, but not 0.75 million SC-islet cells underneath the kidney capsule successfully reversed diabetes in mice with pre-existing diabetes. SQ and intramuscular injections failed to reverse diabetes at all doses and had undetectable expression of maturation markers, such as MAFA and FAM159B. Furthermore, SC-islets had similar function and maturation marker expression regardless of diabetic state. Our results illustrate that transplantation parameters are linked to SC-islet function and maturation, providing ideal mouse models for preclinical diabetes SC therapy research
Monitoring the itinerary of lysosomal cholesterol in Niemann-Pick Type C1-deficient cells after cyclodextrin treatment
Diverse and Variable Community Structure of Picophytoplankton across the Laurentian Great Lakes
The Laurentian Great Lakes provide economic support to millions of people, drive biogeochemical cycling, and are an important natural laboratory for characterizing the fundamental components of aquatic ecosystems. Small phytoplankton are important contributors to the food web in much of the Laurentian Great Lakes. Here, for the first time, we reveal and quantify eight phenotypically distinct picophytoplankton populations across the Lakes using a multilaser flow cytometry approach, which distinguishes cells based on their pigment phenotype. The distributions and diversity of picophytoplankton flow populations varied across lakes and depths, with Lake Erie standing out with the highest diversity. By sequencing sorted cells, we identified several distinct lineages of Synechococcales spanning Subclusters 5.2 and 5.3. Distinct genotypic clusters mapped to phenotypically similar flow populations, suggesting that there may not be a clear one-to-one mapping between genotypes and phenotypes. This suggests genome-level differentiation between lakes but some degree of phenotypic convergence in pigment characteristics. Our results demonstrate that ecological selection for locally adapted populations may outpace homogenization by physical transport in this interconnected system. Given the reliance of the Lakes on in situ primary production as a source for organic carbon, this work sets the foundation to test how the community structure of small primary producers corresponds to biogeochemical and food web functions of the Great Lakes and other freshwater systems
Use of web conferencing technology for conducting online focus groups among young people with lived experience of suicidal thoughts : mixed methods research
Background: There is an increasing interest in engaging people with lived experience in suicide prevention research. However, young people with suicidal thoughts have been described as a âhard-to-includeâ population due to time, distance, stigma, and social barriers. Objective: This study aims to investigate whether conducting synchronous Web conferencing technologyâbased online focus groups (W-OFGs) is a feasible method to engage young people with lived experience of suicidal thoughts in suicide prevention research. Methods: Young people aged between 16 and 25 years and living in Sydney, Australia, were recruited through flyers, emails, and social media advertisements. The W-OFGs were established using a Web conferencing technology called GoToMeeting. Participantsâ response rate, attendance, and feedback of the W-OFGs were analyzed to determine whether the W-OFG system is feasible for suicide prevention research. Researchersâ reflections about how to effectively implement the W-OFGs were also reported as part of the results. Results: In the preâW-OFG survey, 39 (97.5%) young people (n=40) chose to attend the online focus group. Among the 22 participants who responded to the W-OFG invitations, 15 confirmed that they would attend the W-OFGs, of which 11 participants attended the W-OFGs. Feedback collected from the participants in the W-OFG and the postâW-OFG survey suggested that online focus groups are acceptable to young people in suicide prevention research. Considerations for selecting the Web conferencing platform, conducting the mock W-OFGs, implementing the risk management procedure, inviting participants to the W-OFGs, and hosting and moderating the W-OFGs as well as a few potential ethical and pragmatic challenges in using this method are discussed in this study. Conclusions: The Web conferencing technology provides a feasible replacement for conventional methods, particularly for qualitative research involving vulnerable populations and stigmatized topics including suicide prevention. Our results indicate that this modality is an optimal alternative to engage young people in the focus group discussion. Future studies should compare the data collected from the Web conferencing technology and conventional face-to-face methods in suicide prevention research to determine if these two methods are equivalent in data quality from a quantitative approach
Rare variants in the sodium-dependent phosphate transporter gene SLC34A3 explain missing heritability of urinary stone disease
Urinary stone disease (USD) is a major health burden affecting over 10% of the United Kingdom population. While stone disease is associated with lifestyle, genetic factors also strongly contribute. Common genetic variants at multiple loci from genome-wide association studies account for 5% of the estimated 45% heritability of the disorder. Here, we investigated the extent to which rare genetic variation contributes to the unexplained heritability of USD. Among participants of the United Kingdom 100,000-genome project, 374 unrelated individuals were identified and assigned diagnostic codes indicative of USD. Whole genome gene-based rare variant testing and polygenic risk scoring against a control population of 24,930 ancestry-matched controls was performed. We observed (and replicated in an independent dataset) exome-wide significant enrichment of monoallelic rare, predicted damaging variants in the SLC34A3 gene for a sodium-dependent phosphate transporter that were present in 5% cases compared with 1.6% of controls. This gene was previously associated with autosomal recessive disease. The effect on USD risk of having a qualifying SLC34A3 variant was greater than that of a standard deviation increase in polygenic risk derived from GWAS. Addition of the rare qualifying variants in SLC34A3 to a linear model including polygenic score increased the liability-adjusted heritability from 5.1% to 14.2% in the discovery cohort. We conclude that rare variants in SLC34A3 represent an important genetic risk factor for USD, with effect size intermediate between the fully penetrant rare variants linked with Mendelian disorders and common variants associated with USD. Thus, our findings explain some of the heritability unexplained by prior common variant genome-wide association studies
Helping you help yourself (HYHY) for people with mild breathlessness: a service evaluation in Wales
Pulmonary rehabilitation (PR) is an evidence-based intervention which improves exercise
capacity and quality of life (QoL) for patients with chronic obstructive pulmonary disease
(COPD). Commonly, outpatient rehabilitation is available for patients with significant
breathlessness (Medical Research Council (MRC) >3). This evaluation explored changes in
exercise capacity and knowledge of condition and their relationship with the impact of COPD
(CAT score) at baseline following a community exercise and education programme delivered
by the British Lung Foundation (BLF) in people with mild breathlessness (MRC â€2).
Methods: People with mild breathlessness, MRC â€2, were recruited from GP surgeries, the
BLF website and support groups. The 6-week Helping You Help Yourself (HYHY)
programme included weekly exercise, education and social engagement. Participants were
assessed at baseline using the COPD Assessment Tool (CAT), six-minute walk test (6MWT),
Bristol COPD Knowledge quiz (BKQ), and questions on self-management was assessed by
questionnaire. After 6 weeks 6MWT, BKQ and self-management were assessed and related
to CAT at baseline. The usefulness of the programme to participants was also assessed by
questionnaire.
Results: In the 210 patients who completed assessments before and after rehabilitation,
there was an increase in 6MWT distance, median (IQR) 60 (30-80)m and BKQ 3 (1-4) points
(P<0.05), and most elements of self-management improved. Almost all participants
considered HYHY useful (P<0.05). There was no relationship between baseline CAT score
and change in outcome measures (P>0.05).
Conclusion: The results support the provision of community rehabilitation as an alternative to
hospital-based interventions to support and promote self-management in people with mild
breathlessness across the severity of disease burden as measured by CAT
- âŠ