6,861 research outputs found
Restoration of eucalypt grassy woodland: effects of experimental interventions on ground-layer vegetation
We report on the effects of broad-scale restoration treatments on the ground layer of eucalypt grassy woodland in south-eastern Australia. The experiment was conducted in two conservation reserves from which livestock grazing had previously been removed. Changes in biomass, species diversity, ground-cover attributes and life-form were analysed over a 4-year period in relation to the following experimental interventions: (1) reduced kangaroo density, (2) addition of coarse woody debris and (3) fire (a single burn). Reducing kangaroo density doubled total biomass in one reserve, but no effects on exotic biomass, species counts or ground cover attributes were observed. Coarse woody debris also promoted biomass, particularly exotic annual forbs, as well as plant diversity in one of the reserves. The single burn reduced biomass, but changed little else. Overall, we found the main driver of change to be the favourable growth seasons that had followed a period of drought. This resulted in biomass increasing by 67%, (mostly owing to the growth of perennial native grasses), whereas overall native species counts increased by 18%, and exotic species declined by 20% over the 4-year observation period. Strategic management of grazing pressure, use of fire where biomass has accumulated and placement of coarse woody debris in areas of persistent erosion will contribute to improvements in soil and vegetation condition, and gains in biodiversity, in the future.Funding and in-kind logistic support for this project was
provided by the ACT Government as part of an Australian Research
Council Linkage Grant (LP0561817; LP110100126). Drafts of the
manuscript were read by Saul Cunningham and Ben Macdonald
Visible and near infrared spectroscopy of Hayabusa re-entry using semi-autonomous tracking
A ground-based tracking camera and co-aligned slit-less spectrograph were used to measure the spectral signature of visible radiation emitted from the Hayabusa capsule as it entered into the Earth's atmosphere in June 2010. Good quality spectra were obtained that showed the presence of radiation from the heat shield of the vehicle and the shock-heated air in front of the vehicle. An analysis of the black body nature of the radiation concluded that the peak average temperature of the surface was about (3100±100) K
Radiometric temperature analysis of the Hayabusa spacecraft re-entry
Hayabusa, an unmanned Japanese spacecraft, was launched to study and collect samples from the surface of the asteroid 25143 Itokawa. In June 2010, the Hayabusa spacecraft completed it’s seven year voyage. The spacecraft and the sample return capsule (SRC) re-entered the Earth’s atmosphere over the central Australian desert at speeds on the order of 12 km/s. This provided a rare opportunity to experimentally investigate the radiative heat transfer from the shock-compressed gases in front of the sample return capsule at true-flight conditions. This paper reports on the results of observations from a tracking camera situated on the ground about 100 km from where the capsule experienced peak heating during re-entry
Health-seeking behaviour, views and preferences of adults with suspected increased intestinal permeability: A cross-sectional survey of Australian adults
Background: The public health consequence of increased intestinal permeability (IP) is currently limited by the lack of patient-centred research. This study aims to describe the health-seeking behaviour of Australian adults with suspected IP. Methods: A cross-sectional survey of 589 Australian adults who have been diagnosed with IP or have suspected (undiagnosed) IP. Results: The majority (56.2%) of participants with suspected IP reported self-diagnosing their condition, with the majority (56.7%) of these participants preferring to be assessed using an accurate method by a general practitioner or naturopath. On average, Australian adults with suspected IP spent 11.1 (95% CI: 9.5, 12.8) years between first suspecting IP and receiving a formal diagnosis. Over the previous 12 months, participants spent an average of 2176 on dietary supplements for the treatment of IP, and an average of 2963) on dietary supplements compared to participants who find it easy to live on their available household income ($1918) (p=0.015). Conclusion: The investigation of Australian adults with suspected IP found the majority of participants experienced a considerable length of time between first suspecting IP and receiving a diagnosis of IP. The out-of-pocket expenditure associated with the management of IP suggests a financial burden for people with suspected IP. The results of this study provide novel patient-centred considerations that can be used to inform a clinical practice guideline for the management of IP
The Subjective Well-being and Health-Related Quality of Life of Australian Adults with Increased Intestinal Permeability and Associations with Treatment Interventions.
Objective: The integrity and function of the gastrointestinal system is important in disease prevention and management. This study aims to describe the management methods used by Australian adults with suspected increased intestinal permeability (IP) and the association with subjective wellbeing (SWB) and health-related quality of life (HRQoL). Design and Setting: Cross-sectional survey of Australian adults diagnosed with IP or have suspected (undiagnosed) IP. Outcome Measures: Questionnaire items investigating demographic characteristics, self-reported outcome of IP and treatment methods used to manage IP. Participants' HRQoL and SWB according to the 20-Item Short Form Health Survey (SF-20) and Personal Wellbeing Index-Adult (PWI-A) scale, respectively. Results: Participants (n = 589) frequently used dietary products (87.9%), dietary supplements (72.9%) and lifestyle therapies (54.6%) for managing IP. Participants had lower (i.e., worse) mean SWB scores for all domains compared to the Australian population (p p p = 0.015), use dietary supplements (OR = 2.66, p = 0.003), participate in vigorous exercise (OR = 2.99, p p = 0.010). Conversely, they were less likely to consume gluten (OR = 0.35, p p = 0.022). Self-reported improvement of IP (β = 10.70, p p = 0.008) were predictors of a higher level of SWB. Conclusions: Altered IP may pose a greater health burden than previously thought, with poor SWB and HRQoL reported in Australian adults with self-reported IP. Our results highlight the potential clinical relevance and consequence of altered IP, providing the first indication of a possible relationship between altered IP and both SWB and HRQoL
Prerequisites for National Health Insurance in South Africa: Results of a national household survey
Background. National Health Insurance (NHI) is currently highon the health policy agenda. The intention of this financing system is to promote efficiency and the equitable distribution of financial and human resources, improving health outcomes for the majority. However, there are some key prerequisites that need to be in place before an NHI can achieve these goals.Objectives. To explore public perceptions on what changes inthe public health system are necessary to ensure acceptabilityand sustainability of an NHI, and whether South Africans areready for a change in the health system.Methods. A cross-sectional nationally representative surveyof 4 800 households was undertaken, using a structured questionnaire. Data were analysed in STATA IC10.Results and conclusions. There is dissatisfaction with bothpublic and private sectors, suggesting South Africans are ready for health system change. Concerns about the quality of public sector services relate primarily to patient-provider engagements (empathic staff attitudes, communication and confidentiality issues), cleanliness of facilities and drug availability. There are concerns about the affordability of medical schemes and how the profit motive affects private providers’ behaviour. South Africans do not appear to bewell acquainted or generally supportive of the notion of risk cross-subsidies. However, there is strong support for income cross-subsidies. Public engagement is essential to improve understanding of the core principles of universal pre-payment mechanisms and the rationale for the development of NHI. Importantly, public support for pre-payment is unlikely to be forthcoming unless there is confidence in the availability of quality health services
Late Miocene to early Pliocene stratigraphic record in northern Taranaki Basin: Condensed sedimentation ahead of Northern Graben extension and progradation of the modern continental margin
The middle Pliocene-Pleistocene progradation of the Giant Foresets Formation in Taranaki Basin built up the modern continental margin offshore from western North Island. The late Miocene to early Pliocene interval preceding this progradation was characterised in northern Taranaki Basin by the accumulation of hemipelagic mudstone (Manganui Formation), volcaniclastic sediments (Mohakatino Formation), and marl (Ariki Formation), all at bathyal depths. The Manganui Formation has generally featureless wireline log signatures and moderate to low amplitude seismic reflection characteristics. Mohakatino Formation is characterised by a sharp decrease in the GR log value at its base, a blocky GR log motif reflecting sandstone packets, and erratic resistivity logs. Seismic profiles show bold laterally continuous reflectors. The Ariki Formation has a distinctive barrel-shaped to blocky GR log motif. This signature is mirrored by the SP log and often by an increase in resistivity values through this interval. The Ariki Formation comprises (calcareous) marl made up of abundant planktic foraminifera, is 109 m thick in Ariki-1, and accumulated over parts of the Western Stable Platform and beneath the fill of the Northern Graben. It indicates condensed sedimentation reflecting the distance of the northern region from the contemporary continental margin to the south
The utilisation of public and private health care among Australian women with diabetes: Findings from the 45 and Up Study
Aim
To describe the prevalence of health care utilisation and out-of-pocket expenditure associated with the management of diabetes among Australian women aged 45 years and older.
Design
Cross-sectional survey design.
Methods
The questionnaire was administered to 392 women (a cohort of the 45 and Up Study) reporting a diagnosis of diabetes between August and November 2016. It asked about the use of conventional medicine, complementary medicine (CM) and self-prescribed treatments for diabetes and associated out-of-pocket spending.
Results
Most women (88.3%; n = 346) consulted at least one health care practitioner in the previous 12 months for their diabetes; 84.6% (n = 332) consulted a doctor, 44.4% (n = 174) consulted an allied health practitioner, and 20.4% (n = 80) consulted a CM practitioner. On average, the combined annual out-of-pocket health care expenditure was AU252 million per annum. Of this total figure, approximately AU$70 million was spent on CM per annum.
Conclusions
Women with diabetes use a diverse range of health services and incur significant out-of-pocket expense to manage their health. The degree to which the health care services women received were coordinated, or addressed their needs and preferences, warrants further exploration. Limitations of this study include the use of self-report and inability to generalise findings to other populations
Electron mobility in surface- and buried- channel flatband In<sub>0.53</sub>Ga<sub>0.47</sub>As MOSFETs with ALD Al<sub>2</sub>O<sub>3</sub> gate dielectric.
In this paper, we investigate the scaling potential of flatband III-V MOSFETs by comparing the mobility of surface and buried In<sub>0.53</sub>Ga<sub>0.47</sub>As channel devices employing an Atomic Layer Deposited (ALD) Al<sub>2</sub>O<sub>3</sub> gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure.
Peak electron mobilities of 4300 cm<sup>2</sup>/V·s and 6600 cm<sup>2</sup>/V·s at a carrier density of 3×1012 cm<sup>-2</sup> for the surface and buried channel structures respectively were determined. In contrast to similarly scaled inversion-channel devices, we find that mobility in surface channel flatband structures does not drop rapidly with electron density, but rather high mobility is maintained up to carrier concentrations around 4x10<sup>12</sup> cm<sup>-2</sup> before slowly dropping to around 2000 cm<sup>2</sup>/V·s at 1x10M<sup>13</sup> cm<sup>-2</sup>. We believe these to be world leading metrics for this material system and an important development in informing the III-V MOSFET device architecture selection process for future low power, highly scaled CM
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