393 resultados para SECONDARY ORGANIC AEROSOL
Resumo:
This paper reports and discusses a contentious result from an Australia-wide study of the influences on students' decisions about taking senior science subjects. As part of the Choosing Science study (Lyons and Quinn 2010) 3759 Year 10 students were asked to indicate which stage of their schooling (lower primary, upper primary, lower secondary, middle secondary) they had most enjoyed learning science. Crosstabulations of responses revealed that around 78% of students indicated that they had enjoyed learning science more in secondary than in primary school, and 55% enjoyed it the most during Years 9 and 10. The perception that school science was more enjoyable in high school was also found among students who did not intend taking science in Year 11, though to a lesser extent. These findings are unexpected and significant, challenging the prevailing view that enjoyment of school science steadily declines after primary school. The paper elaborates on the findings and suggests that the different conclusions arrived at by studies in this field may be due to the different methodologies employed.
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“Supermax” prisons, conceived by the United States in the early 1980s, are typically reserved for convicted political criminals such as terrorists and spies and for other inmates who are considered to pose a serious ongoing threat to the wider community, to the security of correctional institutions, or to the safety of other inmates. Prisoners are usually restricted to their cells for up to twenty-three hours a day and typically have minimal contact with other inmates and correctional staff. Not only does the Federal Bureau of Prisons operate one of these facilities, but almost every state has either a supermax wing or stand-alone supermax prison. The Globalization of Supermax Prisons examines why nine advanced industrialized countries have adopted the supermax prototype, paying particular attention to the economic, social, and political processes that have affected each state. Featuring essays that look at the U.S.-run prisons of Abu Ghraib and Guantanemo, this collection seeks to determine if the American model is the basis for the establishment of these facilities and considers such issues as the support or opposition to the building of a supermax and why opposition efforts failed; the allegation of human rights abuses within these prisons; and the extent to which the decision to build a supermax was influenced by developments in the United States. Additionally, contributors address such domestic matters as the role of crime rates, media sensationalism, and terrorism in each country’s decision to build a supermax prison.
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This report provides the Queensland Department of Education and Training (DET) with independent evidence based data to enable the identification of barriers and enablers to effective attraction and retention of suitably qualified people to specialist teaching and non‐teaching roles in Queensland secondary schools. The scope of this report is to consider the strategic imperatives, trends, and drivers as they apply to the recruitment and retention of specialised teachers and non‐teaching professionals. The research was specifically designed to inform DET on innovative and novel strategies to recruit and retain staff within Education Queensland in areas specifically identified as at risk of experiencing shortages in the near future. Those areas considered to be at risk of experiencing shortages included: • Teaching principals • Specialist teachers in mathematics, science, industrial technology and design, and special education • Non‐teaching professional roles, such as speech pathologists, occupational therapists, physiotherapists and registered nurses providing services in schools to students with special needs.
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AIM The aim of this paper was to review the current discourse in relation to intensive care unit (ICU) delirium. In particular, it will discuss the predisposing and contributory factors associated with delirium's development as well as effects of delirium on patients, staff and family members. BACKGROUND Critically ill patients are at greater risk of developing delirium and, with an ageing population and increased patient acuity permitted by medical advances, delirium is a growing problem in the ICU. However, there is a universal consensus that the definition of ICU delirium needs improvement to aid its recognition and to ensure both hypoalert-hypoactive and hyperalert-hyperactive variants are easily and readily identified. RELEVANCE TO CLINICAL PRACTICE The effects of ICU delirium have cost implications to the National Health Service in terms of prolonged ventilation and length of hospital stay. The causes of delirium can be readily classified as either predisposing or precipitating factors, which are organic in nature and commonly reversible. However, contributory factors also exist to exacerbate delirium and having an awareness of all these factors promises to aid prevention and expedite treatment. This will avoid or limit the host of adverse physiological and psychological consequences that delirium can provoke and directly enhance both patient and staff safety. CONCLUSIONS Routine screening of all patients in the ICU for the presence of delirium is crucial to its successful management. Nurses are on the front line to detect, manage and even prevent delirium.
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Dynamic light scattering (DLS) has become a primary nanoparticle characterization technique with applications from materials characterization to biological and environmental detection. With the expansion in DLS use from homogeneous spheres to more complicated nanostructures, comes a decrease in accuracy. Much research has been performed to develop different diffusion models that account for the vastly different structures but little attention has been given to the effect on the light scattering properties in relation to DLS. In this work, small (core size < 5 nm) core-shell nanoparticles were used as a case study to measure the capping thickness of a layer of dodecanethiol (DDT) on Au and ZnO nanoparticles by DLS. We find that the DDT shell has very little effect on the scattering properties of the inorganic core and hence can be ignored to a first approximation. However, this results in conventional DLS analysis overestimating the hydrodynamic size in the volume and number weighted distributions. By introducing a simple correction formula that more accurately yields hydrodynamic size distributions a more precise determination of the molecular shell thickness is obtained. With this correction, the measured thickness of the DDT shell was found to be 7.3 ± 0.3 Å, much less than the extended chain length of 16 Å. This organic layer thickness suggests that on small nanoparticles, the DDT monolayer adopts a compact disordered structure rather than an open ordered structure on both ZnO and Au nanoparticle surfaces. These observations are in agreement with published molecular dynamics results.
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In this paper, we seek to operationalize Amartya Sen's concept of human capability to guide a scholarly investigation of student career choice capability. We begin by outlining factors affecting youth labour markets in Australia; a prosperous country that is affected by a ‘two-speed’ national economy. We then examine recent government initiatives that have been designed to combat youth unemployment and cyclical disadvantage by enhancing the aspirations and career knowledge of secondary school students. We argue that these policy measures are based on four assumptions: first, that career choice capability is a problem of individual agency; second, that the dissemination of career information can empower students to act as ‘consumers’ in an unequal job market; third, that agency is simply a question of will; and finally, that school education and career advice – as a means to freedom in the space of career development – is of equal quality, distribution and value to an increasingly diverse range of upper secondary school students. The paper concludes by outlining a conceptual framework capable of informing an empirical research project that aims to test these assumptions by measuring and comparing differences between groups in the range of freedom to achieve and, therefore, to choose.
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The purpose of this research is to examine School Based Youth Health Nurses experience of partnerships for health education and team teaching. The School Based Youth Health Nurse Program is a contemporary model of school nursing in Queensland, Australia. The role of the School Based Youth Health Nurse consists of individual health consultations and health promotion. This research analyses a subset of qualitative data collected for a larger project about the experience of school based youth health nursing. The Health Promoting Schools model is used as a deductive framework. The findings reveal five subthemes across the three areas of the Health Promoting Schools approach. There are two subthemes within the curriculum, teaching and learning area; We were on the same page so to speak and I can go and do my reports or whatever. There are two sub-themes within the partnerships and services area; I had a beautiful science teacher who was just delightful and really just wanted to do things in partnerships and It’s all airy fairy arty farty stuff that’s not important. There is one theme in the school organisation, ethos and environment area; I just don’t know how well the top of these organisations communicate with the bottom of those organisations. Successful partnerships for health education and team teaching between school nurses and teachers are based on personal relationships based on rapport which lead to trust and reciprocity. Partnerships are limited by teachers understanding of the role of the school nurse and engagement with school nurses in the classroom. Administrative support from the top down is fundamental.
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Many fungi, lichens, and bacteria produce xanthones (derivatives of 9H-xanthen-9-one, “xanthone” from the Greek “xanthos”, for “yellow”) as secondary metabolites. Xanthones are typically polysubstituted and occur as either fully aromatized, dihydro-, tetrahydro-, or, more rarely, hexahydro-derivatives. This family of compounds appeals to medicinal chemists because of their pronounced biological activity within a notably broad spectrum of disease states, a result of their interaction with a correspondingly diverse range of target biomolecules. This has led to the description of xanthones as “privileged structures”.(1) Historically, the total synthesis of the natural products has mostly been limited to fully aromatized targets. Syntheses of the more challenging partially saturated xanthones have less frequently been reported, although the development in recent times of novel and reliable methods for the construction of the (polysubstituted) unsaturated xanthone core holds promise for future endeavors. In particular, the fascinating structural and biological properties of xanthone dimers and heterodimers may excite the synthetic or natural product chemist.
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o-Bromo(propa-1,2-dien-1-yl)arenes exhibit novel and orthogonal reactivity under Pd catalysis in the presence of secondary amines to form enamines (concerted Pd insertion, intramolecular carbopalladation, and terminative Buchwald–Hartwig coupling) and of amides to form indoles (addition, Buchwald–Hartwig cyclization, and loss of the acetyl group). The substrates for these reactions can be accessed in a reliable and highly selective two-step process from 2-bromoaryl bromides.
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The Surface Ocean Aerosol Production (SOAP) study was undertaken in February/March 2012 in the biologically active waters of the Chatham Rise, NZ. Aerosol hygroscopicity and volatility were examined with a volatility hygroscopicity tandem differential mobility analyser. These observations confirm results from other hygroscopicity-based studies that the dominant fraction of the observed remote marine particles were non-sea salt sulfates. Further observations are required to clarify the influences of seawater composition, meteorology and analysis techniques seasonally across different ocean basins.
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Mycotoxins – from the Greek μύκης (mykes, mukos) “fungus” and the Latin (toxicum) “poison” – are a large and growing family of secondary metabolites and hence natural products produced by fungi, in particular by molds (1). It is estimated that well over 1,000 mycotoxins have been isolated and characterized so far, but this number will increase over the next few decades due the availability of more specialized analytical tools and the increasing number of fungi being isolated. However, the most important classes of fungi responsible for these compounds are Alternaria, Aspergillus (multiple forms), Penicillium, and Stachybotrys. The biological activity of mycotoxins ranges from weak and/or sometimes positive effects such as antibacterial activity (e.g. penicillin derivatives derived from Penicillium strains) to strong mutagenic (e.g. aflatoxins, patulin), carcinogenic (e.g. aflatoxins), teratogenic, neurotoxic (e.g. ochratoxins), nephrotoxic (e.g. fumonisins, citrinin), hepatotoxic, and immunotoxic (e.g. ochratoxins, diketopiperazines) activities (1, 2), which are discussed in detail in this volume.
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There has been tremendous interest in watermarking multimedia content during the past two decades, mainly for proving ownership and detecting tamper. Digital fingerprinting, that deals with identifying malicious user(s), has also received significant attention. While extensive work has been carried out in watermarking of images, other multimedia objects still have enormous research potential. Watermarking database relations is one of the several areas which demand research focus owing to the commercial implications of database theft. Recently, there has been little progress in database watermarking, with most of the watermarking schemes modeled after the irreversible database watermarking scheme proposed by Agrawal and Kiernan. Reversibility is the ability to re-generate the original (unmarked) relation from the watermarked relation using a secret key. As explained in our paper, reversible watermarking schemes provide greater security against secondary watermarking attacks, where an attacker watermarks an already marked relation in an attempt to erase the original watermark. This paper proposes an improvement over the reversible and blind watermarking scheme presented in [5], identifying and eliminating a critical problem with the previous model. Experiments showing that the average watermark detection rate is around 91% even with attacker distorting half of the attributes. The current scheme provides security against secondary watermarking attacks.
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In this Account we have compiled a list of reliable bond energies that are based on a set of critically evaluated experiments. A brief description of the three most important experimental techniques for measuring bond energies is provided. We demonstrate how these experimental data can be applied to yield the heats of formation of organic radicals and the bond enthalpies of more than 100 representative organic molecules.