Duration and persistence in multidimensional deprivation : methodology and Australian application

This article extends the recent literature on static multidimensional deprivation to propose dynamic deprivation measures that incorporate both the persistence and duration of deprivation across multiple dimensions. The article then illustrates the usefulness of the extension by applying it to Australian panel data for the recent period, 2001–2008. The empirical application exploits the subgroup decomposability of the deprivation measures to identify the subgroups that are more deprived than others. The proposed measure is also decomposable by dimensions and is used to identify the dimensions where deprivation is more persistent. The comparison between the subgroups shows that the divide between homeowners and non-homeowners is one of the sharpest, with the latter suffering much more deprivation than the former. The results are robust to alternative schemes for weighting and aggregating the dimensions as well as to the choice of model parameters.

Increased positive thought disorder with illness duration in patients with schizophrenia

It is unclear whether the severity of positive formal thought disorder, a core clinical feature of schizophrenia, is stable or worsening through the chronic course of the illness. The neurocognitive basis for positive thought disorder also remains unclear. The aim of the present paper was to examine the relationship between thought disorder as measured by the Thought Disorder Index (TDI) and duration of illness and neuropsychological indices in 79 patients with schizophrenia. TDI scores increased in proportion to illness duration. TDI scores were not associated with verbal memory or executive functioning. These results indicate an ongoing worsening of positive thought disorder through the course of illness in schizophrenia.

Biochemical responses of earthworm Eisenia fetida exposed to cadmium-contaminated soil with long duration

The biochemical responses of the earthworms, Eisenia fetida, exposed to a series of Cd concentrations (0.00, 1.25, 2.50, 5.00 and 10.00 mg Cd2+ kg−1 soil) for up to 8 weeks were investigated, aiming to evaluate the sublethal effects of Cd with long exposure and to explore the potential for applying these responses as biomarkers to indicate the Cd-contaminated soil. The following biochemical parameters were determined: cytochrome P450 (CYP) contents and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-s-transferase (GST). Cadmium concentrations in all earthworms were apparently accumulated in 4 weeks, and showed minor changes in weeks 6–8 compared to the first 4 weeks. CYP presented a significant elevation in 2–4 weeks and a decline in 6–8 weeks in each treated group. The activities of SOD and CAT showed an obvious increase with exposure of 6–8 weeks while their levels were not affected in 4 weeks in each treated group. GST activity revealed significant activation starting from week 4. This study confirmed the significance of applying a suite of biomarkers rather than a selective choice to assess the impact of pollutants on organisms. It also indicated that the observed effects were more dependent upon exposure duration than dose.

Sexual practices and the duration of last heterosexual encounter : findings from the Australian longitudinal study of health and relationships

This study investigated the association between sexual practices and duration of a sexual encounter. Using data from a population-based computer-assisted telephone survey of 8,656 Australians aged 16 to 64 years, four distinct patterns of sexual practices among respondents were found: “basic sexual encounter” (involving mainly kissing, cuddling, stroking one's partner and being stroked, and vaginal intercourse), “basic sexual encounter plus oral sex,” “all assessed sexual practices” (all sexual behaviors included in the survey), and “mainly vaginal intercourse” (characterized by lower levels of kissing, cuddling, and stroking). For both men and women, respondents classified in the basic sexual encounter plus oral sex, and all assessed sexual practices clusters reported significantly longer durations than those in the basic sexual encounter group, whereas respondents in the mainly vaginal intercourse cluster reported shorter durations. These differences were found even after allowing for demographic differences in sexual duration—specifically, age and partner type of the most recent opposite-sex partner. These findings add to the understanding of what typically happens in a sexual encounter. Overall, longer sexual encounters appear to be associated with the inclusion of the least common sexual practices—namely, oral sex and self-stimulation.

The implications of lung-regulated buoyancy control for dive depth and duration

Among air-breathing divers, control of buoyancy through lung volume regulation may be most highly developed in marine turtles. In short, the turtle lung may serve a dual role as both an oxygen store and in buoyancy control. A simple model is developed to show that, for turtles diving up to the maximum depth at which they can still use their lungs to attain neutral buoyancy, the total oxygen store will increase greatly with dive depth, and hence a corresponding increase in dive duration is predicted. Time–depth recorders attached to free-living green turtles (Chelonia mydas) at Ascension Island confirmed a marked increase in dive duration with depth, with the gradient of this relationship being >10 times that seen in diving birds and mammals. Consistent with the prediction that the lungs serve a dual role, we found that, when lead weights were added to some turtles to increase their specific gravity, the mean depth of dives decreased, but for dives to the same depth, weighted animals dived for longer. The depth distribution of green turtles seems to be generally constrained by the maximum depth at which they can still attain close to neutral buoyancy.

Is there variation in the response to contact call playbacks across the hybrid zone of the parrot Platycercus elegans?

Learned vocal signals could be important in the formation of prezygotic isolation between two hybridising taxa. This study examined whether vocal variation in the parrot Platycercus elegans facilitates the separation of individuals from two subspecies, P. e. elegans (CR) and P. e. flaveolus (YR). CR and YR have very different plumage coloration, respectively deep crimson and pale yellow, but hybridise where they meet creating an intermediate population (WS). In a factorial design playback experiment, we conducted 108 playback trials on three focal populations (YR, WS, CR), in and around this area of hybridisation, to test if they respond differently to contact calls from their own or another population. We also analysed whether differences in acoustic variables of the stimulus calls predicted the response to the call. We did not find any indication that individuals from the three focal populations responded differently to calls sampled from their own or another subspecies. We did find an effect of two of the five acoustic variables that we used to describe and classify contact calls from the three source populations. Specifically, duration of the stimulus call positively affected the response from individuals from WS and negatively the response from CR, and CR responded more to stimulus calls with a lower peak frequency. Overall, we found no indication that acoustic variation in contact calls on a subspecies level is involved in maintaining plumage colour differences between P. e. elegans and P. e. flaveolus subspecies.

Duration of unemployment and suicide in Australia over the period 1985–2006: an ecological investigation by sex and age during rising versus declining national unemployment rates

Background The relationship between unemployment and suicide may be sensitive to demographic factors, national unemployment rates, and length of time without employment. This study investigated these factors in relation to suicide in Australia for the period 1985–2006, in an ecological study. Methods The outcome variable was annual suicide rate by age group, sex and the eight states and territories over 22 years of observation (total observations=1760). The main predictor variable was the average duration of unemployment in the population, categorised into three time periods (<2 weeks, 2–4 weeks, >4 weeks). Poisson regression models were used to investigate the relationship between duration of unemployment and suicide over the years 1985–2006 in a series of cross-sectional analyses. Interaction analyses indicated significant differences during periods of declining or increasing labour market opportunity and by age group. Results During periods of declining unemployment rates in the country, longer durations of unemployment were associated with higher male suicide rates. During periods of increasing unemployment in the country, longer unemployment duration was associated with lower male suicide rates. Effect modification was also apparent by age-group, with stronger associations between unemployment duration and male suicide evident in those aged 25–34 and 55–64, and weaker associations in those aged 15–24 and 44–54 years. Longer length of unemployment was not associated with an increase in female suicide rates. Conclusions The labour market opportunities in Australia modified the effect of duration of unemployment on suicide, and the effect was more prominent in men and older age groups. This may reflect social norms and acceptability about unemployment, as well as life-stage influences associated with transitions into and out of the labour market.

Women’s sexual response to erotica: the effect of stimulus factors

This research investigated the effect of erotic stimulus content on women’s subjective sexual arousal. It was concluded that subtle changes in specific stimulus content did not affect women’s arousal. The research also found that women’s expectations predicted how aroused they would become. Absorption was also associated with women’s subjective arousal.

The long term effects of sports concussion on retired Australian football players: a study using Transranial Magnetic Stimulation

This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male AF players who played at the elite level (n=20; mean age 49.7±5.7 years) or amateur level (n=20; mean age 48.4±6.9 years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched male controls (mean age 47.56±6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125% of active motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity (p=0.003), reaction (p=0.003), and movement time (p=0.037) than did both AF groups. Differences between AF groups were found in AL (p=0.027) and SWM (p=0.024). TMS measures revealed that both AF groups showed reduced cSP duration at 125% aMT (p>0.001) and differences in SR curves (p>0.001) than did healthy controls. Similarly, SICI (p=0.012) and LICI (p=0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of inhibition differed, however, in terms of which performance measure they had a significant and unique predictive relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two decades previously.

A longitudinal study of the effect of psychosocial factors on exclusive breastfeeding duration

Objective
to examine the effect of psychosocial factors on exclusive breastfeeding duration to six months postpartum

Design
longitudinal, prospective questionnaire based study.

Setting
participants were recruited from a publically funded antenatal clinic located in the western metropolitan region of Melbourne, Victoria, Australia and asked to complete questionnaires at three time points; 32 weeks pregnancy, two months postpartum and six months postpartum.

Participants
the participants were 125 pregnant women aged 22–44 years.

Measurements and findings
psychosocial variables such as breastfeeding self-efficacy, body attitude, psychological adjustment, attitude towards pregnancy, intention, confidence and motivation to exclusively breastfeed and importance of exclusive breastfeeding were assessed using a range of psychometrically validated tools. Exclusive breastfeeding behaviour up to six months postpartum was also measured. At 32 weeks gestation a woman׳s confidence to achieve exclusive breastfeeding was a direct predictor of exclusive breastfeeding duration to six months postpartum. At two months postpartum, psychological adjustment and breastfeeding self-efficacy were predictive of exclusive breastfeeding duration. Finally, at six months postpartum, psychological adjustment, breastfeeding self-efficacy, confidence to maintain and feeling fat were directly predictive of exclusive breastfeeding duration.