892 resultados para young population


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The incidence of Squamous Cell Carcinoma (SCG) is growing in certain populations to the extent that it is now the most common skin lesion in young men and women in high ultraviolet exposure regions such as Queensland. In terms of incidence up to 40% of the Australian population over 40 years of age is thought to possess the precancerous Solar Keratosis (SK) lesion and with a small, but significant, chance of progression into SCC, understanding the genetic events that play a role in this process is essential. The major aims of this study were to analyse whole blood derived samples for DNA aberrations in genes associated with tumour development and cellular maintenance, with the ultimate aim of identifying genes associated with non-melanoma skin cancer development. More specifically the first aim of this project was to analyse the SDHD and MMP12 genes via Dual-Labelled Probe Real-Time PCR for copy number aberrations in an affected Solar Keratosis and control cohort. It was found that 12 samples had identifiable copy-number aberrations in either the SDHD or MMP12 gene (this means that a genetic section of either of these two genes is aberrantly amplified or deleted), with five of the samples exhibiting aberrations in both genes. The significance of this study is the contribution to the knowledge of the genetic pathways that are malformed in the progression and development of the pre-cancerous skin lesion Solar Keratosis. © 2008 Springer Science+Business Media, LLC.

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Purpose: Over 40% of the permanent population of Norfolk Island possesses a unique genetic admixture dating to Pitcairn Island in the late 18 th century, with descendents having varying degrees of combined Polynesian and European ancestry. We conducted a population-based study to determine the prevalence and causes of blindness and low vision on Norfolk Island. Methods: All permanent residents of Norfolk Island aged ≥ 15 years were invited to participate. Participants completed a structured questionnaire/interview and underwent a comprehensive ophthalmic examination including slit-lamp biomicroscopy. Results: We recruited 781 people aged ≥ 15, equal to 62% of the permanent population, 44% of whom could trace their ancestry to Pitcairn Island. No one was bilaterally blind. Prevalence of unilateral blindness (visual acuity [VA] < 6/60) in those aged ≥ 40 was 1.5%. Blindness was more common in females (P=0.049) and less common in people with Pitcairn Island ancestry (P<0.001). The most common causes of unilateral blindness were age-related macular degeneration (AMD), amblyopia, and glaucoma. Five people had low vision (Best-Corrected VA < 6/18 in better eye), with 4 (80%) due to AMD. People with Pitcairn Island ancestry had a lower prevalence of AMD (P<0.001) but a similar prevalence of glaucoma to those without Pitcairn Island ancestry. Conclusions: The prevalence of blindness and visual impairment in this isolated Australian territory is low, especially amongst those with Pitcairn Island ancestry. AMD was the most common cause of unilateral blindness and low vision. The distribution of chronic ocular diseases on Norfolk Island is similar to mainland Australian estimates.

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Objectives To investigate the factors associated with sudden infant death syndrome (SIDS) from birth to age 2 years, whether recent advice has been followed, whether any new risk factors have emerged, and the specific circumstances in which SIDS occurs while cosleeping (infant sharing the same bed or sofa with an adult or child). Design Four year population based case-control study. Parents were interviewed shortly after the death or after the reference sleep (within 24 hours) of the two control groups. Setting South west region of England (population 4.9 million, 184 800 births). Participants 80 SIDS infants and two control groups weighted for age and time of reference sleep: 87 randomly selected controls and 82 controls at high risk of SIDS (young, socially deprived, multiparous mothers who smoked). Results The median age at death (66 days) was more than three weeks less than in a study in the same region a decade earlier. Of the SIDS infants, 54% died while cosleeping compared with 20% among both control groups. Much of this excess may be explained by a significant multivariable interaction between cosleeping and recent parental use of alcohol or drugs (31% v 3% random controls) and the increased proportion of SIDS infants who had coslept on a sofa (17% v 1%). One fifth of SIDS infants used a pillow for the last sleep (21% v 3%) and one quarter were swaddled (24% v 6%). More mothers of SIDS infants than random control infants smoked during pregnancy (60% v 14%), whereas one quarter of the SIDS infants were preterm (26% v 5%) or were in fair or poor health for the last sleep (28% v 6%). All of these differences were significant in the multivariable analysis regardless of which control group was used for comparison. The significance of covering the infant’s head, postnatal exposure to tobacco smoke, dummy use, and sleeping in the side position has diminished although a significant proportion of SIDS infants were still found prone (29% v 10%). Conclusions Many of the SIDS infants had coslept in a hazardous environment. The major influences on risk, regardless of markers for socioeconomic deprivation, are amenable to change and specific advice needs to be given, particularly on use of alcohol or drugs before cosleeping and cosleeping on a sofa.

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Near work may play an important role in the development of myopia in the younger population. The prevalence of myopia has also been found to be higher in occupations that involve substantial near work tasks, for example in microscopists and textile workers. When nearwork is performed, it typically involves accommodation, convergence and downward gaze. A number of previous studies have examined the effects of accommodation and convergence on changes in the optics and biometrics of the eye in primary gaze. However, little is known about the influence of accommodation on the eye in downward gaze. This thesis is primarily concerned with investigating the changes in the eye during near work in downward gaze under natural viewing conditions. To measure wavefront aberrations in downward gaze under natural viewing conditions, we modified a commercial Shack-Hartmann wavefront sensor by adding a relay lens system to allow on-axis ocular aberration measurements in primary gaze and downward gaze, with binocular fixation. Measurements with the modified wavefront sensor in primary and downward gaze were validated against a conventional aberrometer using both a model eye and in 9 human subjects. We then conducted an experiment to investigate changes in ocular aberrations associated with accommodation in downward gaze over 10 mins in groups of both myopes (n = 14) and emmetropes (n =12) using the modified Shack-Hartmann wavefront sensor. During the distance accommodation task, small but significant changes in refractive power (myopic shift) and higher order aberrations were observed in downward gaze compared to primary gaze. Accommodation caused greater changes in higher order aberrations (in particular coma and spherical aberration) in downward gaze than primary gaze, and there was evidence that the changes in certain aberrations with accommodation over time were different in downward gaze compared to primary gaze. There were no obvious systematic differences in higher order aberrations between refractive error groups during accommodation or downward gaze for fixed pupils. However, myopes exhibited a significantly greater change in higher order aberrations (in particular spherical aberration) than emmetropes for natural pupils after 10 mins of a near task (5 D accommodation) in downward gaze. These findings indicated that ocular aberrations change from primary to downward gaze, particularly with accommodation. To understand the mechanism underlying these changes in greater detail, we then extended this work to examine the characteristics of the corneal optics, internal optics, anterior biometrics and axial length of the eye during a near task, in downward gaze, over 10 mins. Twenty young adult subjects (10 emmetropes and 10 myopes) participated in this study. To measure corneal topography and ocular biometrics in downward gaze, a rotating Scheimpflug camera and an optical biometer were inclined on a custom built, height and tilt adjustable table. We found that both corneal optics and internal optics change with downward gaze, resulting in a myopic shift (~0.10 D) in the spherical power of the eye. The changes in corneal optics appear to be due to eyelid pressure on the anterior surface of the cornea, whereas the changes in the internal optics (an increase in axial length and a decrease in anterior chamber depth) may be associated with movement of the crystalline lens, under the action of gravity, and the influence of altered biomechanical forces from the extraocular muscles on the globe with downward gaze. Changes in axial length with accommodation were significantly greater in downward gaze than primary gaze (p < 0.05), indicating an increased effect of the mechanical forces from the ciliary muscle and extraocular muscles. A subsequent study was conducted to investigate the changes in anterior biometrics, axial length and choroidal thickness in nine cardinal gaze directions under the actions of the extraocular muscles. Ocular biometry measurements were obtained from 30 young adults (10 emmetropes, 10 low myopes and 10 moderate myopes) through a rotating prism with 15° deviation, along the foveal axis, using a non-contact optical biometer in each of nine different cardinal directions of gaze, over 5 mins. There was a significant influence of gaze angle and time on axial length (both p < 0.001), with the greatest axial elongation (+18 ± 8 μm) occurring with infero-nasal gaze (p < 0.001) and a slight decrease in axial length in superior gaze (−12 ± 17 μm) compared with primary gaze (p < 0.001). There was a significant correlation between refractive error (spherical equivalent refraction) and the mean change in axial length in the infero-nasal gaze direction (Pearson's R2 = 0.71, p < 0.001). To further investigate the relative effect of gravity and extraocular muscle force on the axial length, we measured axial length in 15° and 25° downward gaze with the biometer inclined on a tilting table that allowed gaze shifts to occur with either full head turn but no eye turn (reflects the effect of gravity), or full eye turn with no head turn (reflects the effect of extraocular muscle forces). We observed a significant axial elongation in 15° and 25° downward gaze in the full eye turn condition. However, axial length did not change significantly in downward gaze over 5 mins (p > 0.05) in the full head turn condition. The elongation of the axial length in downward gaze appears to be due to the influence of the extraocular muscles, since the effect was not present when head turn was used instead of eye turn. The findings of these experiments collectively show the dynamic characteristics of the optics and biometrics of the eye in downward gaze during a near task, over time. These were small but significant differences between myopic and emmetropic eyes in both the optical and biomechanical changes associated with shifts of gaze direction. These differences between myopes and emmetropes could arise as a consequence of excessive eye growth associated with myopia. However the potentially additive effects of repeated or long lasting near work activities employing infero-nasal gaze could also act to promote elongation of the eye due to optical and/or biomechanical stimuli.

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While participatory processes have become an important part of planning, young people are a particularly vulnerable group in terms of potential marginalisation and exclusion from effective participation. Including the views of young people in participatory planning is not simply a matter of bringing them into existing processes. Instead, participatory processes must find ways to integrate and accommodate their needs and ways of expressing their views. Without these adjustments young people may simply move from being kept outside the planning process to a situation where, although they are formally included, their claims are not taken seriously and they are not treated with equal respect. In this paper we reflect on the success of a community advisory committee, formed to consider water planning issues, in integrating the views of young people into their deliberations. Using Iris Marion Young’s (1995) ideas of communicative democracy we highlight the challenges and opportunities presented by this participatory approach, as articulated by both the young people involved and the adult participants. We specifically consider how the elements of greeting, rhetoric and narrative were reflected in the committee process. We argue that both planners and adult participants need to ensure that participatory processes allow for the equal engagement of all participants and place equal value on their contributions. Our research shows that this involves both an institutional and attitudinal commitment to include the views of young people. The institutional commitment requires young people to be included in processes and for their involvement to be supported. However, the attitudinal commitment it is equally important and requires that adult participants be prepared not only to accept the views of younger participants but to actively encourage and support their full participation.

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Young men figure prominently in sleep-related road crashes. Non-driving studies show them to be particularly vulnerable to sleep loss, compared with older men. We assessed the effect of a normal night's sleep vs. prior sleep restricted to 5 h, in a counterbalanced design, on prolonged (2 h) afternoon simulated driving in 20 younger (av. 23 y) and 19 older (av. 67 y) healthy men. Driving was monitored for sleepiness related lane deviations, EEGs were recorded continuously and subjective ratings of sleepiness taken every 200 s. Following normal sleep there were no differences between groups for any measure. After sleep restriction younger drivers showed significantly more sleepiness-related deviations and greater 4–11 Hz EEG power, indicative of sleepiness. There was a near significant increase in subjective sleepiness. Correlations between the EEG and subjective measures were highly significant for both groups, indicating good self-insight into increasing sleepiness. We confirm the greater vulnerability of younger drivers to sleep loss under prolonged afternoon driving.

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This thesis explored the knowledge and reasoning of young children in solving novel statistical problems, and the influence of problem context and design on their solutions. It found that young children's statistical competencies are underestimated, and that problem design and context facilitated children's application of a wide range of knowledge and reasoning skills, none of which had been taught. A qualitative design-based research method, informed by the Models and Modeling perspective (Lesh & Doerr, 2003) underpinned the study. Data modelling activities incorporating picture story books were used to contextualise the problems. Children applied real-world understanding to problem solving, including attribute identification, categorisation and classification skills. Intuitive and metarepresentational knowledge together with inductive and probabilistic reasoning was used to make sense of data, and beginning awareness of statistical variation and informal inference was visible.

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A cross-sectional survey was conducted, and the construct validity and reliability of the Brisbane Practice Environment Measure in an Australian sample of registered nurses were examined. Nurses were randomly selected from the database of an Australian nursing organization. The original 33 items of the Brisbane Practice Environment Measure were utilized to inform the psychometric properties using confirmatory factor analysis. The Cronbach's alpha was 0.938 for the total scale and ranged 0.657–0.887 for the subscales. A five-factor structure of the measure was confirmed, χ2 = 944.622, (P < 0.01), χ2/d.f. ratio = 2.845, Tucker Lewis Index 0.929, Root Mean Square Error = 0.061 and Comparative Fit Index = 0.906. The selected 28 items of the measure proved reliable and valid in measuring effects of the practice environment upon Australian nurses. The implications are that regular measurement of the practice environment using these 28 items might assist in the development of strategies which might improve job satisfaction and retention of registered nurses in Australia.

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Taking an empirical, critical approach to the problem of drugs, this thesis explores the interaction of drug policies and young people's drug use in Brisbane. The research argues that criminalising drug users does not usually prevent harmful drug use, but it can exacerbate harm and change how young people use drugs. Contemporary understandings of drug use as either recreational or addictive can create a false binary, and influence how illicit drugs are used. These understandings interact with policy responses to the drug problem, with some very real implications for the lived experiences of drug users. This research opens up possibilities for new directions in drug research and allows for a redefinition of drug related harm.

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While initial research supports the effectiveness of protective strategies in mitigating young people’s alcohol-related harm, few studies have investigated these behaviours from a uniquely female perspective. Yet, young women consume alcohol within a social context that is distinctly different from that of young men and face risks that are specific to their gender. To explore a group of young Australian women’s experiences, perceptions of risks and use of protective strategies in relation to drinking in public places, we conducted either focus groups or one-on-one telephone interviews with a total of 40 women aged 18–24 years. While young women reported substantial risks associated with drinking, they also reported using a range of protective behaviours that moderated the adverse effects of alcohol, with most of these strategies being derived from the friendship group to which the women belonged. Our findings add to the limited body of knowledge on women’s insights into, and their use of protective strategies to minimise the negative consequences of alcohol.

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While participatory processes have become an important part of water planning, young people are a particularly vulnerable group in terms of potential marginalisation and exclusion from effective participation. Including the views of young people in water planning is not simply a matter of bringing them into existing processes. Instead, processes must be modified to accommodate their needs and ways of expressing their views. Without these adjustments young people may simply move from being kept outside the process to a situation where although they are formally included, their claims are not taken seriously and they are not treated with equal respect. In this paper we reflect on the success of the community advisory committee, formed to develop the Gold Coast Waterfuture Strategy, in integrating the views of young people into their deliberations. Using Young's communicative democracy we highlight the challenges and opportunities presented by this approach, as articulated by both the young people involved and the adult participants, and specifically consider the how the elements of greeting, rhetoric and narrative were reflected in the committee process.

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Background: Young motherhood is commonly associated with vulnerabilities, stereotyping of young women’s behaviour and poor outcomes for them and their children. The objective was to understand how maternity care is experienced for this group in the transition to parenthood. Methods: Data from a large-scale 2010 survey of women’s experience of maternity care were analysed using qualitative methods with open text responses. Results: 7,193 women responded to the survey: 237 were aged 20 years or less. Most (83%) of these young women provided open text responses. The main themes were: ‘being a consumer’, ‘the quality of care’, ‘needing support’ and ‘pride in parenthood’ while subthemes included ‘being young’ and ‘how staff made me feel’, ‘testimonials for staff’, ‘not being left’ and ‘it’s all worthwhile’. Conclusion: Many young women responding described a positive experience. For many first time mothers this marked a positive change in their identity. Nevertheless staff perceptions and attitudes affected how they saw themselves and what they took away from their experience of maternity care. A key message for other women supported and reinforced their role as active and involved consumers who, in engaging with services, have to stand up for themselves and make their needs and wishes known.

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Conservation of free-ranging cheetah (Acinonyx jubatus) populations is multi faceted and needs to be addressed from an ecological, biological and management perspective. There is a wealth of published research, each focusing on a particular aspect of cheetah conservation. Identifying the most important factors, making sense of various (and sometimes contrasting) findings, and taking decisions when little or no empirical data is available, are everyday challenges facing conservationists. Bayesian networks (BN) provide a statistical modeling framework that enables analysis and integration of information addressing different aspects of conservation. There has been an increased interest in the use of BNs to model conservation issues, however the development of more sophisticated BNs, utilizing object-oriented (OO) features, is still at the frontier of ecological research. We describe an integrated, parallel modeling process followed during a BN modeling workshop held in Namibia to combine expert knowledge and data about free-ranging cheetahs. The aim of the workshop was to obtain a more comprehensive view of the current viability of the free-ranging cheetah population in Namibia, and to predict the effect different scenarios may have on the future viability of this free-ranging cheetah population. Furthermore, a complementary aim was to identify influential parameters of the model to more effectively target those parameters having the greatest impact on population viability. The BN was developed by aggregating diverse perspectives from local and independent scientists, agents from the national ministry, conservation agency members and local fieldworkers. This integrated BN approach facilitates OO modeling in a multi-expert context which lends itself to a series of integrated, yet independent, subnetworks describing different scientific and management components. We created three subnetworks in parallel: a biological, ecological and human factors network, which were then combined to create a complete representation of free-ranging cheetah population viability. Such OOBNs have widespread relevance to the effective and targeted conservation management of vulnerable and endangered species.

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Objective To analyze the epidemiological trend of hepatitis B from 1990 to 2007 in Shandong province, and to find the high risk population so as to explore the further control strategy. Methods Based on the routine reporting incidence data of hepatitis B and demographic data of Shandong province, the incidence rates and sex - specific, age - specific incidence rates of hepatitis B were calculated and statistically analyzed in the simple linear regression model. Results The total number of hepatitis B was 437 094, the annual average morbidity was 27132 per 100 000 population during 1990 to 2007. The incidence of men (38142 per 100 000) was higher than that for women (15183 per 100 000) 1The annual incidence rate of hepatitis B indicated an increasing trend for the whole population, while a decreased trend for the 0~9 year - old children p resented in the past 18 years. It showed that the average age of onset moved to the older. Conclusion Young adult men are the high-risk groups for the onset of hepatitis B. For the prevention of hepatitis B, the immunization of hepatitis B vaccine should be enhanced for other groups, especially for the high - risk population on the basis of imp roving the immunization coverage rate for newborns.