Application of power functions to chromatographic data for the enhancement of signal to noise ratios and separation resolution

Chromatographic detection responses are recorded digitally. A peak is represented ideally by a Guassian distribution. Raising a Guassian distribution to the power ‘n’ increases the height of the peak to that power, but decreases the standard deviation by √n. Hence there is an increasing disparity in detection responses as the signal moves from low level noise, with a corresponding decrease in peak width. This increases the S/N ratio and increases peak to peak resolution. The ramifications of these factors are that poor resolution in complex chromatographic data can be improved, and low signal responses embedded at near noise levels can be enhanced. The application of this data treatment process is potentially very useful in 2D-HPLC where sample dilution occurs between dimension, reducing signal response, and in the application of post-reaction detection methods, where band broadening is increased by virtue of reaction coils. In this work power functions applied to chromatographic data are discussed in the context of (a) complex separation problems, (b) 2D-HPLC separations, and (c) post-column reaction detectors.

A-REIT rights issues

Purpose – This is the first REIT paper to seek to empirically examine potential influencing factors on the discounts and underwriting fees of Australian REIT rights issues.

Design/methodology/approach – Using a methodology similar to Owen and Suchard, and Armitage, a sample of 62 A-REIT rights issues during 2001-2009 is analyzed. A variety of potential factors influencing discounts and underwriting fees are explored.

Findings – Over A$20 billion was raised by A-REIT rights issues during 2001-2009 (this around three times that raised through A-REIT initial public offerings during the same period). The mean offer price was discounted around 9.5 percent from the current market price and underwriting fees averaged 2.9 percent of gross proceeds raised – both substantially less than for industrial rights issues. The standard deviation of daily returns for the past year appears to influence the percentage discount offered to subscribers. This volatility was particularly noticeable in 2008 and 2009, during the global financial crisis, where new issues were discounted substantially so as to raise equity to repay debt. This historical risk variable appears paramount in determining the discounts to subscribers and fees to underwriters.

Practical implications – A-REITs seeking to minimize the discounts offered to subscribers and to minimize their underwriting costs with rights issue equity capital raisings must first minimize their share price volatility.

Originality/value – This paper adds to the international costs of capital raising literature of REITs by examining such costs with A-REIT rights issues and is the first paper to examine factors influencing these costs.

The relationship between body dysmorphic disorder symptoms and self-construals

Background:  Cognitive models of body dysmorphic disorder (BDD) suggest that beliefs and evaluations related to self-concept are central to the maintenance of the disorder, but such beliefs have received little empirical attention. This study examined the relative importance of contingent self-worth and self-ambivalence to BDD symptoms in comparison to their importance to obsessive–compulsive disorder and social phobia symptoms.

Method:  The sample comprised 194 non-clinical participants (female, N = 148; males, N = 46) with a mean age of 24.70 years (standard deviation = 9.34). Participants were asked to complete a battery of self-report questionnaires. Results:  While significant relationships were found between the self-beliefs and symptoms of all three disorders, some specificity was found in the relationships.

Conclusions:  Self-worth based upon appearance was most important in BDD, while contingent self-worth based on the approval of others was important in social phobia. Self-ambivalence was associated with each disorder. Implications and limitations are discussed.

Trauma-related symptoms in Sri Lankan adult survivors after the tsunami: pretraumatic and peritraumatic factors

Limited research has addressed factors associated with psychological distress following disasters among non-Western populations. The 2004 tsunami affected 1.7 million people across South Asia and Africa, with considerable variations in trauma-related outcomes. Pretraumatic and peritraumatic conditions associated with trauma-related symptoms in 305 Sri Lankan adult survivors (28% male, aged 18-83 years; mean = 39.9 years; standard deviation = 15.3), clinically assessed 1 month posttsunami, were evaluated retrospectively. Outcome measures were total scores on 11 trauma-related symptoms. Multivariate linear regression analyses tested for associations between pretraumatic and peritraumatic conditions and symptom scores, with peritraumatic conditions adjusted for pretraumatic variables. Pretraumatic conditions of female gender, employment, prior health and social issues, and substance use and peritraumatic conditions of loss of family, witnessing the tsunami, or suffering an injury were associated with trauma-related symptoms. The findings facilitate understanding cultural contexts that define risk factors associated with trauma-related symptoms in Sri Lankans, which are critical for developing culturally appropriate interventions.

Altered cardiac autonomic nervous function in depression

Background:
Depression is an independent risk factor for coronary artery disease. Autonomic instability may play a mediating or moderating role in this relationship; however this is not well understood. The objective of this study was to explore cardiac autonomic function and cardiac arrhythmia in depression, the correlation between depression severity and Heart Rate Variability (HRV) related indices, and the prevalence of arrhythmia.

Methods:
Individuals (n = 53) with major depression as assessed by the Diagnostic and Statistical Manual of Mental Disorders, who had a Hamilton Rating Scale for Depression (HAMD) score ≥20 and a Zung Self-Rating Depression Scale score > 53 were compared to 53 healthy individuals, matched for age and gender. Multichannel Electrocardiograph ECG-92C data were collected over 24 hours. Long-term changes in HRV were used to assess the following vagally mediated changes in autonomic tone, expressed as time domain indices: Standard deviation of the NN intervals (SDNN), standard deviation of 5 min averaged NN intervals (SDANN), Root Mean Square of the Successive Differences (RMSSD) and percentage of NN intervals > 50 ms different from preceding interval (pNN50). Pearson’s correlations were conducted to explore the strength of the association between depression severity (using the SDS and HRV related indices, specifically SDNN and low frequency domain / high frequency domain (LF/HF)).

Results:
The values of SDNN, SDANN, RMSSD, PNN50 and HF were lower in the depression group compared to the control group (P<.05). The mean value of the LF in the depression group was higher than the in control group (P<.05). Furthermore the ratio of LF/HF was higher among the depression group than the control group (P<.05). A linear relationship was shown to exist between the severity of the depression and HRV indices. In the depression group, the prevalence of arrhythmia was significantly higher than in the control group (P<.05), particularly supraventricular arrhythmias.

Conclusions:
Our findings suggest that depression is accompanied by dysfunction of the cardiac autonomic nervous system, and further, that depression severity is linked to severity of this dysfunction. Individuals with depression appear to be susceptible to premature atrial and/or ventricular disease.

Physical activity in three regional communities in Queensland

Objective
To describe physical activity participation in three Queensland regional communities.

Design
Cross-sectional mail survey of randomly selected residents, stratified by age and sex.

Setting
Esk, Mareeba and Mount Isa.

Participants
1219 (58% women) adults, with a mean age 46.7 (standard deviation 14.7) years.

Main outcome measures
Proportion of people inactive, meeting Australian activity guidelines (a minimum of 150 min week−1 and five sessions week−1) and walking a dog daily; time spent walking and cycling for transport; location and type of recreational physical activities.

Results
Overall, 18% of respondents were inactive, with the highest proportions among women (22.3%) and older adults in Mount Isa (24.3%). The proportion meeting activity guidelines was 47%, with the lowest proportion among women in Mount Isa (40.4%). Although 63% reported owning a dog, only 22% reported walking a dog daily. Few people reported walking or cycling for transport. The most common types of activities were walking, home-based exercise, running/jogging and swimming, and the most common location was at or near home.

Conclusions
Physical activity levels were lower in these regional communities than the state average. The findings indicate a need for physical activity policy and intervention strategies targeting regional and rural areas. This could focus on women and older adults, dog walking and physical activity opportunities in or near the home.

A cluster-randomised, controlled trial to assess the impact of a workplace osteoporosis prevention intervention on the dietary and physical activity behaviours of working women: study protocol

Background Osteoporosis is a debilitating disease and its risk can be reduced through adequate calcium consumption and physical activity. This protocol paper describes a workplace-based intervention targeting behaviour change in premenopausal women working in sedentary occupations. Method/Design A cluster-randomised design was used, comparing the efficacy of a tailored intervention to standard care. Workplaces were the clusters and units of randomisation and intervention. Sample size calculations incorporated the cluster design. Final number of clusters was determined to be 16, based on a cluster size of 20 and calcium intake parameters (effect size 250 mg, ICC 0.5 and standard deviation 290 mg) as it required the highest number of clusters. Sixteen workplaces were recruited from a pool of 97 workplaces and randomly assigned to intervention and control arms (eight in each). Women meeting specified inclusion criteria were then recruited to participate. Workplaces in the intervention arm received three participatory workshops and organisation wide educational activities. Workplaces in the control/standard care arm received print resources. Intervention workshops were guided by self-efficacy theory and included participatory activities such as goal setting, problem solving, local food sampling, exercise trials, group discussion and behaviour feedback. Outcomes measures were calcium intake (milligrams/day) and physical activity level (duration: minutes/week), measured at baseline, four weeks and six months post intervention. Discussion This study addresses the current lack of evidence for behaviour change interventions focussing on osteoporosis prevention. It addresses missed opportunities of using workplaces as a platform to target high-risk individuals with sedentary occupations. The intervention was designed to modify behaviour levels to bring about risk reduction. It is the first to address dietary and physical activity components each with unique intervention strategies in the context of osteoporosis prevention. The intervention used locally relevant behavioural strategies previously shown to support good outcomes in other countries. The combination of these elements have not been incorporated in similar studies in the past, supporting the study hypothesis that the intervention will be more efficacious than standard practice in osteoporosis prevention through improvements in calcium intake and physical activity.

Height, aging and cognitive abilities across Europe

Previous research has found that as a marker of childhood circumstances, height is correlated with cognitive functioning at older ages. Using data from the Survey of Health, Ageing, and Retirement in Europe (SHARE) and about 17,000 respondents from 11 countries, we find that height is positively and significantly associated with cognitive functioning in later life despite controlling for a myriad of possible confounding factors. A 10 cm increase in height is associated with a 0.04 standard deviation increase in a summary cognitive score (mean 0.02, std. dev. 0.77). We find that being born in a country where the infant mortality rate at the time of birth is high has a negative and significant influence on cognitive functioning in later life. A 10% increase in the infant mortality rate is associated with a 0.1 standard deviation decrease in the summary cognitive score. We also find some evidence that height serves as a protective factor against age related deterioration in cognitive functioning. For persons of average stature, age related decreases in cognition scores are 3–5 percentage points smaller if they move up a quartile in the height distribution. Our results also suggest that there is a significant positive association between height and cognitive abilities across countries for this pre-1950 birth cohort of respondents, with correlations ranging from 0.4 to 0.8.

Nurses' understanding of patient-centred care in Bhutan

Aim The purpose of the study was to explore nurses' perceptions and understanding of patient-centred care (PCC) in Bhutan. Background Nurses' perceptions and understanding of PCC in Bhutan are unknown. Methods A non-probability convenience sample was taken and a mixed method (quantitative and qualitative descriptive) used. Survey questionnaires were administered to 87 Bhutanese nurses in three types of hospitals -- the National Referral Hospital, the regional referral hospital and the district hospital. Descriptive statistics including frequency distribution, mean and standard deviation (SD) were used for analysis. Spearman's correlation coefficients were used to investigate relationships between demographic variables. Results The nursing labour force in Bhutan knows which behaviours are considered necessary for practising PCC. The mean (SD) rating of behaviours considered critical for practising PCC was 4.29 (0.22), five being the highest score. Bhutanese nurses described PCC, according to qualitative descriptive analysis, as being based on individual patient assessment (22/87 or 25% of respondents), using a holistic model of care (38/87 or 44%) that was based on evidence (38/87 or 44%). A higher level of education (79/87 or 91%) was found to be the main factor that would facilitate the development of PCC, while inadequate staffing, in terms of insufficient numbers of staff and lack of advanced practitioners (56/87 or 64%), was revealed as the main factor that hinders development of PCC. Conclusion Bhutanese nurses believed certain behaviours were critical to PCC. Reform of higher nursing education, putting an emphasis on PCC, would improve nursing practice and increase its scope.

Recombinant human growth hormone for the treatment of growth disorders in children: a systematic review and economic evaluation

Recombinant human growth hormone (rhGH) is licensed for short stature associated with growth hormone deficiency (GHD), Turner syndrome (TS), Prader-Willi syndrome (PWS), chronic renal insufficiency (CRI), short stature homeobox-containing gene deficiency (SHOX-D) and being born small for gestational age (SGA). To assess the clinical effectiveness and cost-effectiveness of rhGH compared with treatment strategies without rhGH for children with GHD, TS, PWS, CRI, SHOX-D and those born SGA. The systematic review used a priori methods. Key databases were searched (e.g. MEDLINE, EMBASE, NHS Economic Evaluation Database and eight others) for relevant studies from their inception to June 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK. Two reviewers assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers, and screened them against inclusion criteria. Data from included studies were extracted by one reviewer and checked by a second. Quality of included studies was assessed using standard criteria, applied by one reviewer and checked by a second. Clinical effectiveness studies were synthesised through a narrative review. Twenty-eight randomised controlled trials (RCTs) in 34 publications were included in the systematic review. GHD: Children in the rhGH group grew 2.7 cm/year faster than untreated children and had a statistically significantly higher height standard deviation score (HtSDS) after 1 year: -2.3 ± 0.45 versus -2.8 ± 0.45. TS: In one study, treated girls grew 9.3 cm more than untreated girls. In a study of younger children, the difference was 7.6 cm after 2 years. HtSDS values were statistically significantly higher in treated girls. PWS: Infants receiving rhGH for 1 year grew significantly taller (6.2 cm more) than those untreated. Two studies reported a statistically significant difference in HtSDS in favour of rhGH. CRI: rhGH-treated children in a 1-year study grew an average of 3.6 cm more than untreated children. HtSDS was statistically significantly higher in treated children in two studies. SGA: Criteria were amended to include children of 3+ years with no catch-up growth, with no reference to mid-parental height. Only one of the RCTs used the licensed dose; the others used higher doses. Adult height (AH) was approximately 4 cm higher in rhGH-treated patients in the one study to report this outcome, and AH-gain SDS was also statistically significantly higher in this group. Mean HtSDS was higher in treated than untreated patients in four other studies (significant in two). SHOX-D: After 2 years' treatment, children were approximately 6 cm taller than the control group and HtSDS was statistically significantly higher in treated children. The incremental cost per quality adjusted life-year (QALY) estimates of rhGH compared with no treatment were: 23,196 pounds for GHD, 39,460 pounds for TS, 135,311 pounds for PWS, 39,273 pounds for CRI, 33,079 pounds for SGA and 40,531 pounds for SHOX-D. The probability of treatment of each of the conditions being cost-effective at 30,000 pounds was: 95% for GHD, 19% for TS, 1% for PWS, 16% for CRI, 38% for SGA and 15% for SHOX-D.

Employment arrangements and mental health in a cohort of working Australians : are transitions from permanent to temporary employment associated with changes in mental health?

We investigated whether being in temporary employment, as compared with permanent employment, was associated with a difference in Short Form 36 mental health and whether transitions from permanent employment to temporary employment were associated with mental health changes. We used fixed-effects regression in a nationally representative Australian sample with 10 waves of data collection (2001–2010). Interactions by age and sex were tested. Two forms of temporary employment were studied: “casual” (no paid leave entitlements or fixed hours) and “fixed-term contract” (a defined employment period plus paid leave). There were no significant mental health differences between temporary employment and permanent employment in standard fixed-effects analyses and no significant interactions by sex or age. For all age groups combined, there were no significant changes in mental health following transitions from stable permanent employment to temporary employment, but there was a significant interaction with age (P = 0.03) for the stable-permanent-to-casual employment transition, because of a small transition-associated improvement in mental health for workers aged 55–64 years (β = 1.61, 95% confidence interval: 0.34, 2.87; 16% of the standard deviation of mental health scores). Our analyses suggest that temporary employment is not harmful to mental health in the Australian context and that it may be beneficial for 55- to 64-year-olds transitioning from stable permanent employment to casual employment.

A study of the impact of environmental surroundings on personal well-being in urban China using a multi-item well-being indicator

We examine the relationship between atmospheric and water pollution, traffic congestion, access to parkland and personal well-being using a survey administered across six Chinese cities in 2007. In contrast to existing studies of well-being determinants by economists which typically employ single-item indicators, we use the Personal Well-being Index (PWI). We also employ the Job Satisfaction Survey (JSS) to measure job satisfaction, which is one of the variables for which we control when examining the relationship between environmental surroundings and personal well-being. Previous research by psychologists has shown the PWI and JSS to have good psychometric properties in western and Chinese samples. A robust finding is that in cities with higher levels of atmospheric pollution and traffic congestion, respondents report lower levels of personal well-being ceteris paribus. Specifically, we find that a one standard deviation increase in suspended particles or sulphur dioxide emissions is roughly equivalent to a 12-13% reduction in average monthly income in the six cities. © 2010 Springer Science+Business Media, LLC.

The platelet intracellular calcium response to serotonin and thrombin in patients with panic disorder.

Serotonin is implicated in both the biology of depression and anxiety. The aim of this study was to examine the platelet intracellular calcium response to serotonin and thrombin using spectrofluorometry in 14 patients with DSM-4 panic disorder compared to 14 matched controls. Patients did not show significantly higher baseline platelet intracellular calcium levels and serotonin stimulated levels of intracellular calcium than control subjects. There was a much smaller standard deviation in the control subjects than in the panic patients. The intracellular calcium response to thrombin activation was however greater in panic patients than in control subjects (P<0.001). The failure of this study to find enhanced sensitivity of 5-HT2 receptors in panic disorder is compatible with the findings of previous challenge studies that found no consistent dysregulation of serotonin in panic disorder. The enhanced thrombin sensitivity, nevertheless suggests some receptor mediated second messenger changes independent of serotonin in the disorder.

Physical and psychosocial wellbeing of nurses in a regional Queensland hospital

Occupational stress is common among nurses. Two factors that may influence stress levels are diet and physical activity. The purpose of this study was to investigate the diets and physical activity levels of nurses and to quantify the relationships between these behaviours and anxiety, depressed mood, stress, and burnout. Nurses (N = 52) from one regional hospital completed a survey assessing physical activity, nutrition, and psychological functioning. Almost two-thirds (65%) of participants had met recommended levels of both moderate and vigorous physical activity in the week prior. Participants met recommended levels for fruit, but not vegetable, consumption. Burnout and stress levels were close to norms for physicians and nurses. Scores for depressed mood, anxiety, and stress symptoms were within one standard deviation of norms for the Australian adult population. Several moderately sized correlations were found between the psychological constructs measured and both physical activity and nutrition. Although most of the participants were physically active and seemed to be consuming nutritious diets, some nurses may need encouragement to adopt similarly healthy behaviours.

A parent-based intervention to promote healthy eating and active behaviours in pre-school children: evaluation of the MEND 2-4 randomized controlled trial.

BACKGROUND: There is a paucity of studies evaluating targeted obesity prevention interventions in pre-school children. OBJECTIVES: We conducted a randomized controlled trial to evaluate the efficacy of a parent-based obesity prevention intervention for pre-schoolers - MEND (Mind, Exercise, Nutrition … Do It!) 2-4 on child diet, eating habits, physical activity/sedentary behaviours, and body mass index (BMI). METHODS: Parent-child dyads attended 10 weekly 90-min workshops relating to nutrition, physical activity and behaviours, including guided active play and healthy snack time. Assessments were conducted at baseline, immediately post-intervention, and 6 and 12 months post-intervention; child intake of vegetables, fruit, beverages, processed snack foods, fussiness, satiety responsiveness, physical activity, sedentary behaviour and neophobia were assessed via parent proxy report. Parent and child height and weight were measured. RESULTS: Two hundred one parent-child dyads were randomized to intervention (n = 104) and control (n = 97). Baseline mean child age was 2.7 (standard deviation [SD] 0.6) years, and child BMI-for-age z-score (World Health Organization) was 0.66 (SD 0.88). We found significant positive group effects for vegetable (P = 0.01) and snack food (P = 0.03) intake, and satiety responsiveness (P = 0.047) immediately post-intervention. At 12 months follow-up, intervention children exhibited less neophobia (P = 0.03) than controls. CONCLUSION: Future research should focus on additional strategies to support parents to continue positive behaviour change. ACTRN12610000200088.