A soil climate monitoring network, consisting of seven automated weather stations, was established between 1999 and 2003 in the McMurdo Sound region of Antarctica. Soil temperature, soil water content, air temperature, relative humidity, solar radiation, and wind speed and direction are recorded hourly and downloaded annually. Two 30 m deep permafrost temperature monitoring boreholes were established adjacent to the soil climate stations in the Wright Valley and at Marble Point in January 2007. Sixteen thermistors (accurate to ±0.1°C) were installed in each borehole measuring temperature once every hour and recording the mean every six hours. One year of permafrost temperatures were available (January 2007 to January 2008). The overall aim of this thesis was to make use of the soil climate monitoring database from 1999 to 2007 to investigate Antarctic soil climate. Active layer depth (depth of thawing) varied inter-annually, with no significant trend between 1999 and 2007. The active layer increased with decreasing latitude (R2 = 0.94), and decreased with increasing altitude (R2 = 0.95). A multiple regression model was produced whereby active layer depth was predicted as a function of mean summer air temperature, mean winter air temperature, total summer solar radiation and mean summer wind speed (R2 = 0.73). Annual temperature cycles were observed at all depths in the boreholes. At Marble Point, an annual temperature range of lt;1°C occurred at 15.2 m, lt;0.5°C at 18.4 m and lt;0.1°C at 26.4 m and at Wright Valley, an annual temperature range of lt;1°C occurred at 14.0 m, lt;0.5°C at 17.2 m and lt;0.1°C at 25.2 m. Given that the depth of Zero Annual Amplitude determined depends on the sensitivity of the measurement method, it is suggested that instead of referring to a depth of Zero Annual Amplitude , the depth at which the annual temperature range is less than a given value is a more useful concept. Mean annual and mean seasonal air and soil temperatures varied inter-annually and there was no significant trend of warming or cooling over the 1999 - 2007 period. Mean annual air temperatures were primarily influenced by winter air temperatures. Mean annual and mean summer soil temperatures were warmer than air temperatures due to heating by solar radiation. Mean summer air temperatures correlated well with the Southern Annular Mode Index (SAMI) at all sites (0.61 lt; R2 lt; 0.73) except Victoria Valley; however there was no correlation between mean annual or mean winter temperatures and the SAMI. Air temperature was linearly correlated with near-surface soil temperature (1.3 - 7.5 cm) (R2 gt; 0.79). Near-surface soil temperature was strongly correlated with incoming solar radiation at Victoria Valley (0.14 lt; R2 lt; 0.76) and Granite Harbour (0.49 lt; R2 lt; 0.82), but was not significantly correlated at other sites (0 lt; R2 lt; 0.57). There was no significant correlation between air temperature and wind speed, air temperature and solar radiation and near-surface soil temperature and wind speed, despite occasions of strong correlation on the diurnal time scale. Diurnal summer cycles in air and soil temperatures were driven by solar radiation. Multiple regressions combining the effects of air temperature, solar radiation and wind speed approximated near-surface soil temperatures well at every site during both summer and winter (0.88 lt; R2 lt; 0.98).

o,o???-Dityrosine (dityrosine), an oxidation product of tyrosine produced by reaction between tyrosyl radicals, is becoming established as a biomarker of free radical oxidative protein damage in vivo. Attempts to measure dityrosine concentrations in various physiological and pathological systems have produced varied and often contradictory results. Dityrosine concentrations in urine, plasma, cerebrospinal fluid (CSF) and brain tissue varying over three orders of magnitude have been reported, together with inconsistent claims of significant dityrosine elevation in several ageing-related pathologies. Some of these findings have contributed to the implication of free radical activity in the pathology of several neurodegenerative disorders, vascular and ocular abnormalities and in phagocyte response to infection. The aim of this study was to test the hypothesis that dityrosine levels are elevated in ageing and ageing-related disease. The study also aims to determine the utility of dityrosine measurement as an index of oxidative damage, and elucidate possible explanations for the inconsistent levels reported. An assay for the quantification of dityrosine was developed using capillary HPLC with electrospray tandem quadrupole mass spectrometry (HPLC-MS/MS). The assay was highly specific for dityrosine and has the highest absolute sensitivity for dityrosine of any method reported to date, with a detection limit of 3 femtomoles of dityrosine on-column. Urine samples from volunteers of different age and from hospital patients with various pathologies were analysed. Plasma protein hydrolysates from control, Alzheimer???s and stroke subjects were analysed, together with hydrolysates of post mortem brain tissue from Alzheimer???s and control subjects. Urinary dityrosine level is elevated in states of acute infection and inflammation, but does not correlate with age or chronic disease. Protein dityrosine in four sections of Alzheimer???s brain was not significantly different from control sections. Dityrosine was present in human plasma and tissue proteins at approximately 5-35 residues per million tyrosine residues, and in normal urine at 5-25 micromol/mol creatinine or 20-200 nM. Most of the discrepancies in the literature relate to inadequate specificity of the analytical method. Interpretation of published data with critical appraisal of measurement technology specificity is essential in developing an accurate understanding of the role of free radicals in ageing and disease.

Bibliography: leaves 162-174.

Studies involving solids-stabilised foams have been limited and few have focused on the benefits of complex systems such as those involving mixtures of more than one surfactant. Little is known about the effectiveness of using mixed surfactant systems as foam stabilisers at the bulk level. The purpose of this project was to gain further understanding and insight into foam stability, on a bulk scale, in the absence, and in the presence, of solid colloidal particles, and for systems involving single or mixed surfactants. Foams were produced using sodium dodecyl sulphate (SDS), dodecanoic acid (DA), or a mixture of both surfactants at varying molar ratios. The surface tension at a given concentration, the limiting surface tension (at high concentrations), the critical micelle concentration, foamability and foam stability were all significantly affected by the molar ratio of SDS to DA. The initial pH of mixed surfactant solutions played a role in the shift of surface tension and CMC. The higher pH values, the lower surface activity, therefore resulted in higher surface tension. At a given pH, however, the mixed surfactant solutions with higher molar ratio of SDS to DA appeared to have lower CMC. The foam stabilising ability of colloidal dispersions of four hydrous metal oxides, namely hydrous iron oxide (formed by hydrolysis of Fe(III) solutions and referred to as HFO), hydrous zinc oxide (formed by hydrolysis of Zn(II) solutions and referred to as HZO), hydrous chromium oxide (formed by hydrolysis of Cr(III) solutions and referred to as HCO), and hydrous nickel oxide (formed by hydrolysis of Ni(II) solutions and referred to as HNO) were studied at varying concentrations. Generally foam stability increased as the solid concentration increased. Foams stabilised by HNO were found to be the most stable. Foams stabilised by HFO were found to be unstable regardless of the solid concentration. It is believed that the instability of such foams is primarily due to the large aggregated size of HFO flocs. The aggregate size of hydrous metal oxides was influenced by the concentration of NaOH used to hydrolyse the metal ion solution, and by sonication treatment immediately following solid formation. However, the final pH of the colloidal dispersions did not significantly change the aggregate size. Solids stabilised foams are believed to be highly dependent on the state of hydrophobicity of the solids used, and this is in turn controlled by adjustment of the pH dependent surface charge and potential. Electrophoretic mobility is a commonly used tool to probe the potential near the surface and was used in this thesis to determine the affect of surfactant adsorption (particularly from solutions containing mixtures of SDS and DA) on surface properties of the solids. The electrophoretic mobility of all hydrous metal oxide aggregates decreased as the concentration of SDS/DA increased. Specific adsorption was evident in all cases and resulted in charge reversal for most cases. Electrophoretic mobility data for surfactant adsorption, as a function of total surfactant concentration, was consistent with a three-stage model of surfactant adsorption involving (1) electrostatic adsorption, (2) cooperative adsorption and (3) surface saturation. The influence of surfactant adsorption on electrophoretic mobility was found to be consistent with models requiring the stabilising solids to be in a controlled state of flocculation, where the zeta potential (as probed by electrophoretic mobility) must be sufficiently high to prevent total flocculation of the solid and thus collapse of the foam, but sufficiently low that the solids have some degree of hydrophobicity such that they prefer to be only partially wetted (and thus reside at the air/water interface). The total percentage adsorption of SDS/DA surfactant mixtures on both hydrous iron oxide and hydrous nickel oxide was found to be independent of time. However, the proportion of adsorption due to SDS and DA was dependent on time. Moreover, the initial and final ratio of SDS to DA adsorption did not reflect their ratio in solution. SDS adsorbed, initially, to a greater extent that would be predicted from its solution concentration, but this trend was reversed after a period of time.

In a country such as Australia which claims adherence to democratic values, it would appear important that policies and laws on such a controversial and value laden issue as active voluntary euthanasia (AVE), need to have at least some basis in public opinion and in that of relevant professional groups. It has been argued that public opinion may be of limited value due to the public's lack of experience and exposure to this issue. The opinions of people with more exposure to and reflection on the ethical issues surrounding euthanasia need to be ascertained. Nurses are one group who have prolonged involvement with the care of dying or suffering people and their families. Nurses in the Australian Capital Territory (ACT) could be a particularly well informed group because of the ongoing open debate resulting from four proposed laws on AVE in this Territory since 1993. The overall purpose of this thesis was to identify the attitudes of nurses in the ACT towards AVE. This thesis was supported by a study which provided information on four aspects of nurses' attitudes towards AVE. Firstly, the attitudes of registered nurses in the ACT were compared to those of other nurses, medical practitioners and members of the general public in Australia. Secondly, the associations between characteristics of the nurses and their attitudes were investigated. Thirdly, the legal conditions which nurses believe should be in a law allowing active voluntary euthanasia were identified. Finally, the arguments nurses put forward to support their attitudes towards AVE were analysed This thesis does not attempt to evaluate the ethical arguments proposed, merely to reflect the views put forward. A postal survey was carried out in late 1996 of 2000 randomly selected registered nurses from the Australian Capital Territory. Responses were received from 1218 nurses (61%). Attitudes of Nurses: A majority of nurses who responded, supported AVE as "sometimes right", be it homicide by request (72%) or physician assisted suicide (71%). A slightly smaller majority of nurses believed the law should be changed to allow homicide by request (69%) and physician assisted suicide (67%) under certain conditions. If AVE were legal, 66% of the nurses indicated they were willing to be involved in the procedure. Only 30% were willing to assist patients to give themselves the lethal dose, while 14% were willing to administer the lethal dose to the patient. Comparing these results with previous surveys, it appears that nurses are less in favour of AVE than the general public but more in favour than medical practitioners. Associations between Characteristics of Nurses and Attitudes: Those nurses who were more likely to agree that the law should allow AVE, were under the age of 40 years, agnostic, atheist or of the Anglican religion, to have less contact with terminally ill patients, to work in the area of critical care or mental health, and to take less interest in the issue of AVE. Palliative care nurses were the only subgroup without a majority in favour (33%). There is other evidence in the euthanasia literature indicating that nurses and doctors are less in favour of AVE than the general public. Taken together with the present findings, it may be concluded that attitudes towards AVE are more favourable in people who have less contact with the terminally ill. Legal Conditions in an AVE Law: The conditions most strongly supported in any future AVE law were "second doctor's opinion" (85%), "cooling off period" (81%), "patient must have unbearable protracted suffering" (80%), "doctor must inform patient about illness and treatment" (78%) and "patient must be terminally ill" (63%). There was only minority support for "patient not suffering from treatable depression" (42%), "patient administers or assists to administer, the fatal dose themselves" (32%) and "patient over a certain age" (7%). Support for a change in the law to allow AVE was 38% for a young man with AIDS, 39% for an elderly man with early stage Alzheimer's disease, 44% for a young woman who had become quadriplegic and 71 % for a middle aged woman with metastases from breast cancer. Arguments Supporting AVE Attitudes: The most common argument in support of AVE was that people should have the right to control their own lives and thus be able to decide for themselves when and how they wanted to die. The most common argument against AVE was that of the slippery slope in which it is feared that the boundaries which society puts on killing will be extended. Conclusions: This inquiry pinpoints the discordance between attitudes towards AVE and the legal status of AVE. Parliamentary representatives need to consider the current attitudes of their constituents, and especially those of relevant health care professionals towards AVE. It is important that a nursing perspective is represented in any law legalising AVE and that the role of the nurse is clearly described in relevant legal acts. Future research would also be beneficial to investigate further the association between the experience of nurses working in a palliative care setting and AVE attitudes. There needs to be further debate about the legal conditions required in any future AVE bills. given the lack of support from nurses for some conditions which have been included in proposed AVE laws. Furthermore, it would be valuable to carry out surveys of the opinions of other health practitioners in order to inform legislators. These results form a baseline to examine the changes in attitudes towards AVE over time and change in the legal status of AVE.

Aerodynamic devices, such as wings, are used in higher levels of motorsport (Formula-1 etc.) to increase the contact force between the road and tyres (i.e. to generate downforce). This in turn increases the performance envelope of the race car. However the extra downforce increases aerodynamic drag which (apart from when braking) is generally detrimental to lap-times. The drag acts to slow the vehicle, and hinders the effect of available drive power and reduces fuel economy. Wings, in automotive use, are not constrained by the same parameters as aircraft, and thus higher angles of attack can be safely reached, although at a higher cost in drag. Variable geometry aerodynamic devices have been used in many forms of motorsport in the past offering the ability to change the relative values of downforce and drag. These have invariably been banned, generally due to safety reasons. The use of active aerodynamics is currently legal in both Formula SAE (engineering compet ition for university students to design, build and race an open-wheel race car) and production vehicles. A number of passenger car companies are beginning to incorporate active aerodynamic devices in their designs. In this research the effect of ground proximity on the lift, drag and moment coefficients of inverted, two-dimensional aerofoils was investigated. The purpose of the study was to examine the effect ground proximity on aerofoils post stall, in an effort to evaluate the use of active aerodynamics to increase the performance of a race car. The aerofoils were tested at angles of attack ranging from 0° - 135°. The tests were performed at a Reynolds number of 2.16 x 105 based on chord length. Forces were calculated via the use of pressure taps along the centreline of the aerofoils. The RMIT Industrial Wind Tunnel (IWT) was used for the testing. Normally 3m wide and 2m high, an extra contraction was installed and the section was reduced to form a width of 295mm. The wing was mounted between walls to simulate 2-D flow. The IWT was chosen as it would allow enough height to reduce blockage effect caused by the aerofoils when at high angles of incidence. The walls of the tunnel were pressure tapped to allow monitoring of the pressure gradient along the tunnel. The results show a delay in the stall of the aerofoils tested with reduced ground clearance. Two of the aerofoils tested showed a decrease in Cl with decreasing ground clearance; the third showed an increase. The Cd of the aerofoils post-stall decreased with reduced ground clearance. Decreasing ground clearance was found to reduce pitch moment variation of the aerofoils with varied angle of attack. The results were used in a simulation of a typical Formula SAE race car.

The harmful effects of aircraft noise, with respect to both comfort and occupational health, have long since been recognised, with many examples of sound control now implemented in commercial aircraft. However, the single engine light aircraft cabin is still an extremely noisy environment, which apparently has been side-lined by both cost and weight constraints, especially with respect to low frequency sound reduction. Consequently, pilots and passengers of these aircraft are still exposed to potentially damaging noise levels and hearing damage can only be avoided by the proper use of ear defenders. Minimisation of the noise around the occupants of the aircraft reduces the dependency of personal ear defenders and is conducive to a more comfortable, hygienic and less stressful environment. This thesis describes the basis of a theoretical and experimental project, directed at the design and evaluation of a practical active noise control (ANC) system suitable for a single engine light aircraft. Results from initial experiments conducted in a single engine aircraft demonstrated the viability of ANC for this application. However, the extreme noise, the highly damped cabin, the multiple tone excitation, the severe weight limitations and the requirement of air worthiness certification severely complicated the problem of achieving noise reduction throughout the entire aircraft cabin. Compromising the objective to only achieving local control around the occupants still presented difficulties because the region of attenuated noise around the error sensors was so small that a nearby observer experienced no sound level reduction whatsoever. The objective was therefore to move the control zone away from the error sensor and place a broad envelope of noise reduction immediately around the occupant's head, through the use of virtual sensors , thus creating the perception of global noise control. While virtual sensors are not new (Garcia-Bonito et al. (1996)), they are currently limited to acoustic pressure estimation (virtual microphones) via the initial measurement of an observer / sensor transfer function. In this research, new virtual sensor algorithms have been developed to: 1. minimise the sound level at the observer location, 2. broaden the control region, 3. adapt to any physical system changes and 4. produce a control zone that may ultimately follow an observer's head The performance of the virtual sensors were evaluated both analytically and experimentally in progressively more complex environments to identify their capabilities and limitations. It was found that the use of virtual sensors would, in general, attenuate the noise at the observer location more effectively than when using conventional remotely placed error sensors. Such a control strategy was considered to be ideal for a light single engine aircraft, because it would only require small light speakers (possibly fitted into a head-rest) to achieve a broad control zone that envelopes the region around the occupants heads. / Thesis (Ph.D.) -- University of Adelaide, Dept. of Mechanical Engineering), 2000.

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: Michael J. O'Donnell. Includes bibliographical references (leaves 279-310).

En France, en 2005, le taux de pauvreté s'élevait à 9,6 % de la population active selon la définition de la pauvreté relative de l'Insee, soit 2,6 millions d'actifs pauvres. Le taux de pauvreté renseigne bien sur une proportion d'actifs pauvres à un moment donné, mais n'informe pas sur les mouvements d'entrées dans la pauvreté et de sorties de la pauvreté de la population active. Les outils de l'analyse démographique permettent une analyse longitudinale de ces phénomènes. Dans le cadre de ce travail, nous répondrons aux deux questions suivantes : - parmi les actifs ayant vécu, au cours d'une même période, l'entrée dans la pauvreté, quelle est la proportion de ceux qui sortent de la pauvreté ? - parmi les actifs ayant vécu, au cours d'une même période, la sortie de la pauvreté, quelle est la proportion de ceux qui retournent dans la pauvreté ? La définition de la pauvreté relative mesure en réalité un changement de position du ménage sur l'échelle des revenus et non une modification effective du niveau de vie. Dans ce cas, la définition de la pauvreté absolue que nous proposons paraît donc plus adaptée pour une étude longitudinale de la pauvreté. Parmi les actifs pauvres, 7 sur 10 travaillent. Bien que l'emploi protège de la pauvreté, il n'est pas une protection suffisante. La situation familiale est aussi un facteur à prendre en compte. Finalement, les risques de sortie de la pauvreté et les risques d'entrée dans la pauvreté dépendent des caractéristiques individuelles de la personne active mais se modifient également lorsque la personne active connaît un changement favorable ou défavorable de sa situation sur le marché du travail ou de sa situation familiale.

La sonde couramment utilisée en microscopie NSOM consiste en une ouverture sub-longueur d'onde au bout d'une pointe diélectrique métallisée, ce qui permet d'atteindre une résolution optique de l'ordre de la taille de l'ouverture (soit 50 nm). Un concept prometteur consiste à remplacer l'ouverture par un matériau actif de taille sub-longueur d'ondes aussi petit qu'une seule molécule ou une nanoparticule semiconductrice. Dans ce schéma, la sonde active offre la possibilité d'obtenir une très haute résolution définie par la taille du nano-objet actif. Nous avons développé une méthode pour réaliser des pointes optiques actives pour l'optique en champ proche avec l'objectif de faire une nanosource de lumière stable utilisable à température ambiante et potentiellement capable d'offrir une résolution optique d'une dizaine de nanomètres. Une pointe optique métallisée est recouverte d'une fine couche de PMMA dans laquelle sont inclus des nanocristaux ou des nanorods de CdSe en faible densité. Pour ce faire, des pointes optiques spécifiques ont été préparées par attaque chimique suivie d'une métallisation. Elles ont en bout de pointe, une ouverture optique de l'ordre de 200 nm. L'évolution temporelle de la signature spectrale de ces sondes actives, couplée à l'analyse temporelle de leur émission dans un mode comptage de photons démontrent clairement qu'un très petit nombre de nanoparticules -voire une seule- sont actives en bout de pointe pour des taux de dilution de CdSe convenables. L'imagerie de surfaces test utilisant ces sondes actives sont actuellement en cours de réalisation.