175 resultados para SECONDARY ELECTRONS
Resumo:
This study was an examination of the strength of relations among covitality, and its underlying constructs of belief in self, emotional competence, belief in others, and engaged living, and two outcome variables; subjective well-being and depression. Participants included 361 Australian secondary school students (75 males and 286 females) who completed a series of online questionnaires related to positive psychological well-being in adolescents. The results from the first standard multiple regression analysis indicated that higher levels of belief in self, belief in others, and engaged living were significant predictors of increased subjective well-being. The results from the second standard multiple regression showed that higher levels of belief in self, belief in others, and engaged living were significant predictors of decreased feelings of depression. In both standard multiple regression models, the combined effect of the traits that comprise covitality was greater than the effect of each individual positive psychological trait.
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The emphasis on collegiality and collaboration in the literature on teachers' work and school reform has tended to underplay the significance of teacher autonomy. This thesis explores the dynamics of teachers' understandings and experiences of individual teacher autonomy (as contrasted with collective autonomy) in an independent school in Queensland which promoted itself as a 'teachers' school' with a strong commitment to individual teacher autonomy. The research was a case study which drew on methodological signposts from critical, feminist and traditional ethnography. Intensive fieldwork in the school over five months incorporated the ethnographic techniques of observation, interviews and document analysis. Teachers at Thornton College understood their experience of individual autonomy at three interrelated levels--in terms of their work in the classroom, their working life in the school, and their voice in the decision-making processes of the school. They felt that they experienced a great deal of individual autonomy at each of these three levels. These understandings and experiences of autonomy were encumbered or enabled by a range of internal and external stakeholder groups. There were also a number of structural influences (community perceptions, market forces, school size, time and bureaucracy) emerging from the economic, social and political structures in Australian society which influenced the experience of autonomy by teachers. The experience of individual teacher autonomy was constantly shifting, but there were some emergent patterns. Consensus on educational goals and vision, and strong expressions of trust and respect between teachers and stakeholders in the school, characterised the contexts in which teachers felt they experienced high levels of autonomy in their work. The demand for accountability and desire for relatedness motivated stakeholders and structural forces to influence teacher autonomy. Some significant gaps emerged between the rhetoric of a commitment to individual teacher autonomy and decision-making practices in the school, that gave ultimate power to the co-principals. Despite the rhetoric and promotion of non-hierarchical structures and collaborative decision-making processes, many teachers perceived that their experience of individual autonomy remained subject to the exercise of 'partial democracy' by school leaders.
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Serum butyrylcholinesterase (BCHE) activity is associated with obesity, blood pressure and biomarkers of cardiovascular and diabetes risk. We have conducted a genome-wide association scan to discover genetic variants affecting BCHE activity, and to clarify whether the associations between BCHE activity and cardiometabolic risk factors are caused by variation in BCHE or whether BCHE variation is secondary to the metabolic abnormalities. We measured serum BCHE in adolescents and adults from three cohorts of Australian twin and family studies. The genotypes from approximately 2.4 million single-nucleotide polymorphisms (SNPs) were available in 8791 participants with BCHE measurements. We detected significant associations with BCHE activity at three independent groups of SNPs at the BCHE locus (P = 5.8 x 10(-262), 7.8 x 10(-47), 2.9 x 10(-12)) and at four other loci: RNPEP (P = 9.4 x 10(-16)), RAPH1-ABI2 (P = 4.1 x 10(-18)), UGT1A1 (P = 4.0 x 10(-8)) and an intergenic region on chromosome 8 (P = 1.4 x 10(-8)). These loci affecting BCHE activity were not associated with metabolic risk factors. On the other hand, SNPs in genes previously associated with metabolic risk had effects on BCHE activity more often than can be explained by chance. In particular, SNPs within FTO and GCKR were associated with BCHE activity, but their effects were partly mediated by body mass index and triglycerides, respectively. We conclude that variation in BCHE activity is due to multiple variants across the spectrum from uncommon/large effect to common/small effect, and partly results from (rather than causes) metabolic abnormalities.
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Sonography is an important clinical tool in diagnosing appendicitis in children as it can obviate both exposure to potentially harmful ionising radiation from computed tomography scans and the need for unnecessary appendicectomies. This review examines the diagnostic accuracy of ultrasound in the identification of acute appendicitis, with a particular focus on the the utility of secondary sonographic signs as an adjunct or corollary to traditionally examined criteria. These secondary signs can be important in cases where the appendix cannot be identified with ultrasound and a more meaningful finding may be made by incorporating the presence or absence of secondary sonographic signs. There is evidence that integrating these secondary signs into the final ultrasound diagnosis can improve the utility of ultrasound in cases where appendicitis is expected, though there remains some conjecture about whether they play a more important role in negative or positive prediction in the absence of an identifiable appendix.
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It is often assumed that teachers in rural and remote schools are at a disadvantage when it comes to accessing professional development. But is there sufficient evidence to support this assumption? This paper reports findings from two national surveys comparing the professional development priorities of primary and secondary science teachers from metropolitan, provincial and remote schools. The research found that while teachers' unmet needs for some PD opportunities increased significantly with school remoteness, this was not the case for all opportunities. In teasing out the different PD priorities of primary and secondary science teachers, the paper provides evidence to help education authorities and professional organisations address the specific needs of teachers in different locations.
Resumo:
Sonographic diagnosis of appendicitis in children is an important clinical tool, often obviating the need for potentially harmful ionising radiation from computed tomography (CT) scans and unnecessary appendectomies. Established criteria do not commonly account for the sonographic secondary signs of acute appendicitis as an adjunct or corollary to an identifiably inflamed appendix. If one of, or combinations of these secondary signs are a reliable positive and/or negative indicator of the condition, diagnostic accuracy may be improved. This will be of particular importance in cases where the appendix cannot be easily identified, possibly providing referring clinicians with a less equivocal diagnosis. Acute appendicitis (AA) is the most common emergency presentation requiring surgical intervention among both adults and children. During 2010-11 in Australia 25000 appendicectomies were performed on adults and children, more than double the number of the next most common surgical procedure [1]. Ultrasound has been commonly used to diagnose AA since the 1980s, however the best imaging modality or combination of modalities to accurately and cost-effectively diagnose the condition is still debated. A study by Puylaert advocated ultrasound in all presentations [2], whereas others suggested it only as a first line modality [3–5]. Conversely, York et al state that it is not appropriate as it delays treatment [6]. CT has been shown to more accurately diagnose AA than ultrasound, however its inherent radiation risks warrant cautionary use in children [7]. Improved accuracy in the diagnosis of suspected AA using ultrasound would enable surgeons to make a decision without the need to expose children to the potentially harmful effects of CT. Secondary signs of appendicitis are well established [8], although research into their predictive values has only recently been undertaken [9,10] indicating their potential diagnostic benefit in the absence of an identifiable appendix. The purpose of this review is to examine the history of appendiceal sonography, established sonographic criteria, paediatric specific techniques and the predictive value of secondary signs.
Resumo:
Science education has been the subject of increasing public interest over the last few years. While a good part of this attention has been due to the fundamental reshaping of school curricula and teacher professional standards currently underway, there has been a heightened level of critical media commentary about the state of science education in schools and science teacher education in universities. In some cases, the commentary has been informed by sound evidence and balanced perspectives. More recently, however, a greater degree of ignorance and misrepresentation has crept into the discourse. This chapter provides background on the history and status of science teacher education in Australia, along with insights into recent developments and challenges.
Resumo:
Volatile organic compounds (VOCs) in the headspace of bubble chambers containing branches of live coral in filtered reef seawater were analysed using gas chromatography with mass spectrometry (GC-MS). When the coral released mucus it was a source of dimethyl sulfide (DMS) and isoprene; however, these VOCs were not emitted to the chamber headspace from mucus-free coral. This finding, which suggests that coral is an intermittent source of DMS and isoprene, was supported by the observation of occasional large pulses of atmospheric DMS (DMSa) over Heron Island reef on the southern Great Barrier Reef (GBR), Australia, in the austral winter. The highest DMSa pulse (320 ppt) was three orders of magnitude less than the DMS mixing ratio (460 ppb) measured in the headspace of a dynamically purged bubble chamber containing a mucus-coated branch of Acropora aspera indicating that coral reefs can be strong point sources of DMSa. Static headspace GC-MS analysis of coral fragments identified mainly DMS and seven other minor reduced sulfur compounds including dimethyl disulfide, methyl mercaptan, and carbon disulfide, while coral reef seawater was an indicated source of methylene chloride, acetone, and methyl ethyl ketone. The VOCs emitted by coral and reef seawater are capable of producing new atmospheric particles < 15 nm diameter as observed at Heron Island reef. DMS and isoprene are known to play a role in low-level cloud formation, so aerosol precursors such as these could influence regional climate through a sea surface temperature regulation mechanism hypothesized to operate over the GBR.
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Introduction and Aims This study examines the association of alcohol and polydrug use with risky sexual behaviour in adolescents under 16 years of age and if this association differs by gender. Design and Methods The sample consisted of 5412 secondary school students under 16 years of age from Victoria, Australia. Participants completed an anonymous and confidential survey during class time. The key measures were having had sex before legal age of consent (16 years), unprotected sex before 16 (no condom) and latent-class derived alcohol and polydrug use variables based on alcohol, tobacco, cannabis, inhalants and other illegal drug use in the past month. Results There were 7.52% and 2.55% of adolescents who reported having sex and having unprotected sex before 16 years of age, respectively. After adjusting for antisocial behaviours, peers' drug use and family and school risk factors, girls were less likely to have unprotected sex (odds ratio = 0.31, P = 0.003). However, the interaction of being female and polydrug use (odds ratio = 4.52, P = 0.004) was significant, indicating that girls who engaged in polydrug use were at higher risk of having unprotected sex. For boys, the effect of polydrug use was non-significant (odds ratio = 1.44, P = 0.310). Discussion and Conclusions For girls, polydrug use was significantly associated with unprotected sex after adjusting for a range of risk factors, and this relationship was non-significant for boys. Future prevention programs for adolescent risky sexual behaviour and polydrug use might benefit from a tailored approach to gender differences.