11 research outputs found

    Structure of a Hydrophilic-Hydrophobic Block Copolymer and Its Interactions with Salt and an Anionic Surfactant

    Full text link
    The aggregation of a hydrophilic−hydrophobic diblock copolymer consisting of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(methyl methacrylate) (PMMA) in aqueous solution has been investigated by small-angle neutron scattering. This polybase is extensively protonated at low pH and forms micelles with a dense core of PMMA and a diffuse coronal layer of cationic PDMAEMA. Addition of salt induced micellar growth, brought about by charge screening and more efficient packing of the chains. As a result, the aggregation number increased from 8 up to 31. A similar effect was observed at low concentrations of an anionic surfactant, sodium dodecyl sulfate (SDS) since the net cationic charge in the hydrophilic coronal layer was reduced due to surfactant binding. However, at higher surfactant concentrations, a drastic structural reorganization occurred, as the PMMA became solubilized into the SDS micellar cores and the PDMAEMA chains interacted with the surfactant micelles, resulting in a “pearl-necklace” structure. The presence of the cationic polyelectrolyte significantly increased the population of SDS micelles by effectively lowering the critical micelle concentration of this anionic surfactant

    Arriving at the empirically based conceptualization of restricted and repetitive behaviors: a 1 systematic review and meta-analytic examination of factor analyses

    Full text link
    An empirically based understanding of the factor structure of the restricted and repetitive behaviors (RRB) domain is a prerequisite for interpreting studies attempting to understand the correlates and mechanisms underpinning RRB and for measurement development. Therefore, this study aimed to conduct a systematic review and meta-analysis of RRB factor analytic studies. Sets of meta-analyses were performed to examine (a) the factor structure of individual RRB instruments, (b) associations between RRB subdomains across instruments, and (c) the association between RRB factors and other variables. Searches for peer-reviewed articles evaluating the factor structure of the RRB domain were performed in PsycINFO (Ovid), Medline (Ovid), and Embase (Ovid). No age, measurement, or informant-type limits were imposed. Quality and risk of bias for individual studies were assessed using relevant COSMIN sections. Among the 53 studies retained for review, 41 examined RRB factor structures among individuals with autism spectrum disorder (ASD) and 12 among non-ASD samples. Meta-analysis of factor correlations provided evidence that the RRB domain encompasses the following eight specific factors: repetitive motor behaviors, insistence on sameness, restricted interests, unusual interests, sensory sensitivity, and repetitive, stereotyped language. Although interrelated, RRB factors were distinct, showing a unique pattern of associations with demographic, cognitive, and clinical correlates. Meta-analyses of the associations between RRB factors and specific correlates, specifically adaptive functioning and communication impairments, should be considered preliminary due to the limited number of studies. Despite limitations, this review provides important insights into the factor structure of the RRB domain and highlights critical conceptual, measurement, and methodological limitations of the current research that will need to be addressed in order to improve our understanding of RRB

    Would you like fries with that? Investigating fast-food outlet availability near schools in Perth, Western Australia

    Get PDF
    Issue addressed: Locating fast-food outlets near schools is a potential public health risk to schoolchildren, given the easy access and repeated exposure to energy-dense, nutrient-poor foods they provide. Fast-food outlet availability near schools has not been previously investigated in Perth, Western Australia. This study aimed to quantify fast-food outlet availability near Perth schools and determine whether differences in area-level disadvantage and school type exist. Methods: Fast-food outlet locations were sourced from Perth Local Governments in 2018/2019. All Perth Primary (n = 454), Secondary (n = 107) and K-12 (n = 94) schools were assigned an area-level disadvantage decile ranking based on the Australian Bureau of Statistics Socio-Economic Index for Areas (SEIFA). Regression models assessed whether fast-food outlet availability within 400 m, 800 m and 1 km of schools differed by school type (ie, Primary/Secondary/K-12) or SEIFA. Results: Secondary schools were significantly more likely than Primary and K-12 schools to have a higher presence and density of fast-food outlets and the “Top 4” fast-food outlet chains (McDonalds, Hungry Jacks, KFC and Red Rooster) nearby. Schools located in low socio-economic status (SES) areas had a significantly higher density of fast-food outlets within 400 m, and “Top 4” fast-food outlet chains within 400 m and 1 km, than schools located in high SES area. Conclusions: Perth schools are surrounded by fast-food outlets with densities significantly higher around secondary schools and schools located in lower SES areas. So what?: Policies and regulations aimed at reducing fast-food outlets near schools is an essential strategy to improve dietary intakes and reduce obesity in schoolchildren

    Would you like fries with that? Investigating fast-food outlet availability near schools in Perth, Western Australia

    Get PDF
    Issue addressed: Locating fast-food outlets near schools is a potential public health risk to schoolchildren, given the easy access and repeated exposure to energy-dense, nutrient-poor foods they provide. Fast-food outlet availability near schools has not been previously investigated in Perth, Western Australia. This study aimed to quantify fast-food outlet availability near Perth schools and determine whether differences in area-level disadvantage and school type exist. Methods: Fast-food outlet locations were sourced from Perth Local Governments in 2018/2019. All Perth Primary (n = 454), Secondary (n = 107) and K-12 (n = 94) schools were assigned an area-level disadvantage decile ranking based on the Australian Bureau of Statistics Socio-Economic Index for Areas (SEIFA). Regression models assessed whether fast-food outlet availability within 400 m, 800 m and 1 km of schools differed by school type (ie, Primary/Secondary/K-12) or SEIFA. Results: Secondary schools were significantly more likely than Primary and K-12 schools to have a higher presence and density of fast-food outlets and the “Top 4” fast-food outlet chains (McDonalds, Hungry Jacks, KFC and Red Rooster) nearby. Schools located in low socio-economic status (SES) areas had a significantly higher density of fast-food outlets within 400 m, and “Top 4” fast-food outlet chains within 400 m and 1 km, than schools located in high SES area. Conclusions: Perth schools are surrounded by fast-food outlets with densities significantly higher around secondary schools and schools located in lower SES areas. So what?: Policies and regulations aimed at reducing fast-food outlets near schools is an essential strategy to improve dietary intakes and reduce obesity in schoolchildren

    Estimated Therapy Costs and Downstream Cost Consequences of iBASIS-Video Interaction to Promote Positive Parenting Intervention vs Usual Care Among Children Displaying Early Behavioral Signs of Autism in Australia

    Full text link
    IMPORTANCE: The growing global prevalence of autism spectrum disorder (ASD) is associated with increasing costs for support services. Ascertaining the effects of a successful preemptive intervention for infants showing early behavioral signs of autism on human services budgets is highly policy relevant.OBJECTIVE: To estimate the net cost impact of the iBASIS-Video Interaction to Promote Positive Parenting (iBASIS-VIPP) intervention on the Australian government.DESIGN, SETTING, AND PARTICIPANTS: Infants (aged 12 months) showing early behavioral indicators of autism were recruited through community settings into the multicenter Australian iBASIS-VIPP randomized clinical trial (RCT), a 5- to 6-month preemptive parent-mediated intervention, between June 9, 2016, and March 30, 2018, and were followed up for 18 months to age 3 years. This economic evaluation, including cost analysis (intervention and cost consequences) and cost-effectiveness analyses of iBASIS-VIPP compared with usual care (treatment as usual [TAU]), modeled outcomes observed at age 3 through to 12 years (13th birthday) and was conducted from April 1, 2021, to January 30, 2023. Data analysis was conducted from July 1, 2021, to January 29, 2023.EXPOSURES: iBASIS-VIPP intervention.MAIN OUTCOMES AND MEASURES: To project the diagnostic trajectory and associated disability support costs drawing on the Australian National Disability Insurance Scheme (NDIS), the main outcome was the differential treatment cost of iBASIS-VIPP plus TAU vs TAU and disability-related government costs modeled to age 12 years, using a clinical diagnosis of ASD and developmental delay (with autism traits) at 3 years. Costs were calculated in Australian dollars and converted to US dollars. Economic performance was measured through the following: (1) differential net present value (NPV) cost (iBASIS-VIPP less TAU), (2) investment return (dollars saved for each dollar invested, taking a third-party payer perspective), (3) break-even age when treatment cost was offset by downstream cost savings, and (4) cost-effectiveness in terms of the differential treatment cost per differential ASD diagnosis at age 3 years. Alternate values of key parameters were modeled in 1-way and probabilistic sensitivity analysis, the latter identifying the likelihood of an NPV cost savings.RESULTS: Of the 103 infants enrolled in the iBASIS-VIPP RCT, 70 (68.0%) were boys. Follow-up data at age 3 years were available for 89 children who received TAU (44 [49.4%]) or iBASIS-VIPP (45 [50.6%]) and were included in this analysis. The estimated mean differential treatment cost was A 5131(US5131 (US 3607) per child  for iBASIS-VIPP less TAU. The best estimate of NPV cost savings was A 10 695(US10 695 (US 7519) per child (discounted at 3% per annum). For each dollar invested in treatment, a savings of A 3.08(US3.08 (US 3.08) was estimated; the break-even cost occurred at age 5.3 years (approximately 4 years after intervention delivery). The mean differential treatment cost per lower incident case of ASD was A 37 181(US37 181 (US 26 138). We estimated that there was an 88.9% chance that iBASIS-VIPP would deliver a cost savings for the NDIS, the dominant third-party payer.CONCLUSIONS AND RELEVANCE: The results of this study suggest that iBASIS-VIPP represents a likely good-value societal investment for supporting neurodivergent children. The estimated net cost savings were considered conservative, as they covered only third-party payer costs incurred by the NDIS and outcomes were modeled to just age 12 years. These findings further suggest that preemptive interventions may be a feasible, effective, and efficient new clinical pathway for ASD, reducing disability and the costs of support services. Long-term follow-up of children receiving preemptive intervention is needed to confirm the modeled results.</p

    Tonsils at Telethon: Developing a standardised collection of tonsil photographs for group A streptococcal (GAS) research

    Full text link
    Introduction: Group A streptococcus (GAS) infections, such as pharyngitis and impetigo, can lead to rheumatic fever and rheumatic heart disease (RHD). Australian Aboriginal and Torres Strait Islander populations experience high rates of RHD and GAS skin infection, yet rates of GAS pharyngitis are unclear. Anecdotally, clinical presentations of pharyngitis, including tonsillar hypertrophy and sore throat, are uncommon. This study aimed to develop a standardised set of tonsil photographs and determine tonsil size distribution from an urban paediatric population. Methods: A prospective cohort of children aged 3–15 years were recruited at the public events “Discover Day” and “Telethon Weekend” (October 2017) in Perth, Western Australia, Australia. Tonsil photographs, symptomatology, and GAS rapid antigen detection tests (RADT) were collected. Tonsil size was graded from the photographs using the Brodsky Grading Scale of tonsillar hypertrophy (Brodsky) by two independent clinicians, and inter-rater reliability calculated. Pharyngitis symptoms and GAS RADT were correlated, and immediate results provided. Results: Four hundred and twenty-six healthy children participated in the study over three days. The median age was seven years [interquartile range (IQR) 5.9–9.7 years]. Tonsil photographs were collected for 92% of participants, of which 62% were rated as good-quality photographs and 79% were deemed of adequate quality for assessment by both clinicians. When scored by two independent clinicians, 57% received the same grade. Average Brodsky grades (between clinicians) were 11%, 35%, 28%, 22% and 5% of grades 0,1,2,3 and 4, respectively. There was moderate agreement in grading using photographs, and minimal to weak agreement for signs of infection. Of 394 participants, 8% reported a sore throat. Of 334 GAS RADT performed, \u3c1% were positive. Discussion: We report the first standardised use of paediatric tonsil photographs to assess tonsil size in urban-living Australian children. This provides a proof of concept from an urban-living cohort that could be compared with children in other settings with high risk of GAS pharyngitis or rheumatic fever such as remote-living Australian Indigenous populations

    Datasheet1_Tonsils at Telethon: developing a standardised collection of tonsil photographs for group A streptococcal (GAS) research.pdf

    Full text link
    IntroductionGroup A streptococcus (GAS) infections, such as pharyngitis and impetigo, can lead to rheumatic fever and rheumatic heart disease (RHD). Australian Aboriginal and Torres Strait Islander populations experience high rates of RHD and GAS skin infection, yet rates of GAS pharyngitis are unclear. Anecdotally, clinical presentations of pharyngitis, including tonsillar hypertrophy and sore throat, are uncommon. This study aimed to develop a standardised set of tonsil photographs and determine tonsil size distribution from an urban paediatric population.MethodsA prospective cohort of children aged 3–15 years were recruited at the public events “Discover Day” and “Telethon Weekend” (October 2017) in Perth, Western Australia, Australia. Tonsil photographs, symptomatology, and GAS rapid antigen detection tests (RADT) were collected. Tonsil size was graded from the photographs using the Brodsky Grading Scale of tonsillar hypertrophy (Brodsky) by two independent clinicians, and inter-rater reliability calculated. Pharyngitis symptoms and GAS RADT were correlated, and immediate results provided.ResultsFour hundred and twenty-six healthy children participated in the study over three days. The median age was seven years [interquartile range (IQR) 5.9–9.7 years]. Tonsil photographs were collected for 92% of participants, of which 62% were rated as good-quality photographs and 79% were deemed of adequate quality for assessment by both clinicians. When scored by two independent clinicians, 57% received the same grade. Average Brodsky grades (between clinicians) were 11%, 35%, 28%, 22% and 5% of grades 0,1,2,3 and 4, respectively. There was moderate agreement in grading using photographs, and minimal to weak agreement for signs of infection. Of 394 participants, 8% reported a sore throat. Of 334 GAS RADT performed, DiscussionWe report the first standardised use of paediatric tonsil photographs to assess tonsil size in urban-living Australian children. This provides a proof of concept from an urban-living cohort that could be compared with children in other settings with high risk of GAS pharyngitis or rheumatic fever such as remote-living Australian Indigenous populations.</p
    corecore