Ratios of sample percentiles or of quantiles based on a single sample are often published for skewed income data to illustrate aspects of income inequality, but distribution-free confidence intervals ...for such ratios are not available in the literature. Here we derive and compare two large-sample methods for obtaining such intervals. They both require good distribution-free estimates of the quantile density at the quantiles of interest, and such estimates have recently become available. Simulation studies for various sample sizes are carried out for Pareto, lognormal and exponential distributions, as well as fitted generalized lambda distributions, to determine the coverage probabilities and widths of the intervals. Robustness of the estimators to contamination or a positive proportion of zero incomes is examined via influence functions and simulations. The motivating example is Australian household income data where ratios of quantiles measure inequality, but of course these results apply equally to data from other countries.
Background and Purpose
To investigate whether physical activity levels are predictive of short‐term changes in physical function for people discharged to independent living in the community following ...withdrawal of rehabilitation services after hip fracture; and to describe short‐term recovery in physical activity, physical function, walking confidence, health‐related quality of life and walking participation.
Methods
This prospective cohort study comprised 57 older adults (39 females, mean age 80.4, SD 8.4 years) living independently in the community after hip fracture. Accelerometer‐based physical activity, physical function (Functional Independence Measure FIM, de Morton Mobility Index, Frenchay Activities Index and Participation in outdoor walking), walking confidence and health‐related quality of life were measured after discharge from rehabilitation services (baseline) and 12 weeks later. Multiple linear regression analyses determined the ability of physical activity (daily steps), walking self‐confidence, health‐related quality of life and demographic factors (age, sex and time since fracture) to predict Week 12 physical function using Week 0 physical function as a covariate.
Results
Participants at baseline averaged 4439 daily steps which did not change 12 weeks later. There were small increases in all measures of physical function and walking confidence, but not health‐related quality of life. Increased walking self‐confidence was associated with an increase in FIM total, FIM mobility and de Morton Index scores. Physical activity did not predict change in measures of physical function.
Conclusions
Walking confidence of adults discharged from rehabilitation services after hip fracture had a greater association with short‐term recovery of physical function than level of physical activity. Community‐dwelling adults continue to make small short‐term improvements in physical function and walking confidence after discharge home and withdrawal of rehabilitation services.
Central homeostatic regulation of fat stores is attenuated during pregnancy, to allow for adequate fat deposition to support fetal development and lactation. What factors particular to pregnancy ...facilitate fat accumulation, and why gestational weight gain (GWG) is so variable, are not clear. The aim of this cross-sectional study was to examine the associations between GWG and circulating hormones with known effects on appetite and growth.
Women without obesity (body mass index, BMI <30 kg/m
), with a healthy singleton pregnancy, were recruited at the time of delivery by elective Caesarean section at a tertiary obstetric hospital. Women with preterm (<37 weeks) delivery and smokers were excluded. Maternal blood was collected at the time of delivery for measurement of fasting oestradiol, progesterone, prolactin, insulin, leptin, insulin-like growth factor 1 and insulin-like growth factor binding protein 3. Comparisons were made between women who gained weight within the range recommended by Institute of Medicine guidelines for normal weight women (11.5-16 kg; n=34) and those who gained excessive weight (>16 kg; n=35) during pregnancy. Analysis of covariance was carried out using multiple linear regression to test the effect of GWG group on biochemical parameters, accounting for pre-pregnancy BMI.
The 69 participants had a mean age of 34.6 ± 4.3 years, and pre-pregnancy BMI of (23.3 ± 1.8 kg/m
), with no significant differences between groups in pre-pregnancy weight, BMI, age, birthweight or parity. Mean GWG was 14.0 ± 1.3 kg in the "recommended" group and 19.6 ± 3.2 kg in the "excessive" group. Leptin was significantly higher (43.4 ± 21.6 vs 33.4 ± 15.0 ng/mL, p=0.03) and prolactin tended to be lower (159.5 ± 66.1 vs 194.0 ± 85.6 ng/mL, p=0.07) at delivery in women with excessive (vs recommended) GWG. No other circulating factors were found to differ between groups. The between-group difference in leptin remained after adjustment for pre-pregnancy BMI in multiple linear regression and quantile regression analyses.
In women without obesity, leptin remains a marker of adiposity during pregnancy. GWG was not associated with other circulating hormones with effects on appetite and growth.
Highlights • The present studies examine the role of mGluR signaling in ethanol dependence. • Hippocampal explants are effective as a high-throughout screen of toxicity. • Group 1 metabotrophic ...receptor antagonism attenuates hippocampal cytotoxicity. • Blocking these receptors prior to withdrawal reduces development of dependence.
Background: There is variability in the language of children with autism, even those who are high functioning. However, little is known about how they process language structures in real time, ...including how they handle potential ambiguity, and whether they follow referential constraints. Previous research with older autism spectrum disorder (ASD) participants has shown that these individuals can use context to access rapidly the meaning of ambiguous words. The severity of autism has also been shown to influence the speed in which children with ASD access lexical information.
Aims: To understand more about how children with ASD process language in real time (i.e., as it unfolds). The focus was the integration of information and use of referential constraints to identify a referent named in a sentence.
Methods & Procedures: We used an eye‐tracking task to compare performance between young, high‐functioning children with autism (HFA) and children with typical development (TD). A large sample of 5–9‐year‐old children (mean age = 6;8 years), 48 with HFA and 56 with TD participated; all were attending mainstream schools. For each item participants were shown a display of four images that differed in two dimensions. Each sentence contained an adjective and noun that restricted the choice from four to two (the target and competitor), followed by a prepositional phrase (e.g., the blue square with dots); this added modifying information to provide a unique description of the target. We calculated looking time at the target, the competitor and the two distractors for each 200 ms time interval as children processed the sentence and looked at the display. Generalized estimating equations were used to carry out repeated‐measures analyses on the proportion of looking time to target and competitor and time to fixate to target.
Outcomes & Results: Children in both groups (HFA and TD) looked at the target and competitor more than at the distractors following the adjective and noun and following the modifying information in the prepositional phrase more at the target. However, the HFA group was significantly slower in both phases and looked proportionally less at the target. Across the sample, IQ and language did not affect the results; however, age and attention had an impact. The older children showed an advantage in processing the information as did the children with higher attention scores.
Conclusions & Implications: The HFA group took longer than the TD group to integrate the disambiguating information provided in the course of processing a sentence and integrate it with the visual information, indicating that for the ASD group incremental processing was not as advanced as for children with ASD, and they were less sensitive to referential conventions. Training for young children with ASD on the use of referential conventions and available contextual clues may be of benefit to them in understanding the language they hear.
The purpose of this study was to determine whether positive changes in self-reported attitudes toward disability were retained after students had participated in a 12-week voluntary community-based ...exercise programme for young people with disability.
Sixty-eight physiotherapy and exercise physiology students (45 women, 23 men; mean age 21 y) volunteered. Each student was matched with a young person with disability, and the pair exercised together twice a week for 12 weeks at their local gymnasium. The primary outcome measure was self-reported attitude toward disability. Secondary outcomes were self-reported professional skills competency, confidence, future work intentions, and motivations for volunteering. The outcomes were measured at Weeks 0, 13, and 24. The data were analyzed using generalized linear mixed-effects models, ordinal regression, and linear regression.
The students' attitudes toward disability were more positive at Weeks 13 and 24 than at baseline, but positive changes were not fully retained by Week 24. Small statistically significant reductions occurred after Week 13. Self-reported skills competencies, confidence, and future intentions of working in disability were higher at Weeks 13 and 24. Students' motivation for volunteering was wanting to support others, wanting to learn, and perceived positive career effects.
Positive changes in students' attitudes toward disability were generally retained 3 months after volunteering in a community-based exercise programme.
Background
Previous clinical studies have suggested that high polyphenol extra virgin olive oil (EVOO) provides a superior cardioprotective effect compared to low polyphenol olive oil. However, ...further studies are required to replicate these results in non‐Mediterranean populations.
Aim
To investigate the effect of high polyphenol EVOO versus low polyphenol olive oil with known polyphenol composition on markers of cardiovascular disease risk in a healthy non‐Mediterranean cohort.
Methods
In a double‐blind randomised cross‐over trial, the present study will examine the effect of high polyphenol EVOO versus low polyphenol olive oil in 50 healthy participants. Each intervention phase will be 3 weeks long with a 2‐week washout period between each phase. Outcomes to be assessed include HDL cholesterol efflux, oxidised LDL, blood lipids, C‐reactive protein, arterial stiffness, blood pressure and cognitive function. Dietary intake, physical activity levels and anthropometry will also be collected.
Discussion
Because of the rigorous trial design, novel and clinically relevant outcomes, the use of a well‐characterised EVOO, and, in contrast to the current literature, the non‐Mediterranean study population, the present study will provide a significant contribution to the understanding of the clinical importance of polyphenol intake in the Australian sociocultural context.
In this paper we show that estimated sufficient summary plots can be greatly improved when the dimension reduction estimates are adjusted according to minimization of an objective function. The ...dimension reduction methods primarily considered are ordinary least squares, sliced inverse regression, sliced average variance Estimates and principal Hessian directions. Some consideration to minimum average variance estimation is also given. Simulations support the usefulness of the approach and three data sets are considered with an emphasis on two- and three-dimensional estimated sufficient summary plots.
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