15,058 research outputs found
Growth of thin films of molybdenum and tungsten oxides by combustion CVD using aqueous precursor solutions
Using combustion chemical vapour deposition, layers of molybdenum and tungsten oxides have been deposited on glass and silicon at low temperatures. Inexpensive ammonium salts of molybdate and metatungstate ions were used as precursors and were delivered to the coating flame as an aqueous solution using a nebuliser. The resulting films were analysed by scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), Rutherford backscattering (RBS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). These indicate that the films are continuous, moderately smooth and consist of amorphous, disordered molybdenum and tungsten trioxides
"It's the Same Old Song": Draconian Counter-Terrorism Laws and the Deja Vu of Indigenous Australians
Over the course of the past four years, the Australian government's legislative response to the terrorist attacks in New York 11 September 2001 has been controversial. Central to the legislative response package has been the Security Legislation Amendment (Terrorism) Act 2002 (Cth) and the Australian Security Intelligence Organisation Legislation Amendment (Terrorism) Act 2003 (Cth) which has been scrutinised by many sectors of the Australian community for the way in which it impinges upon the fundamental human rights of all Australians such as freedom of speech, freedom of movement and freedom of association
Consequences of temperature and temperature variability on swimming activity, group structure, and predation of endangered delta smelt
The effects of water temperature on individual and group movement behaviour in prey fish can affect ecological interactions such as competition and predation, but how variability in temperature influence fish behaviour is less understood. Of particular concern is how increased warming in tidally fluctuating estuaries may impact the native and endangered delta smelt (Hypomesus transpacificus, Osmeridae). To help address this issue, we tested the effects of increased water temperature (fluctuating [17–21°C] and warm [21°C] acclimated treatments) on juvenile delta smelt individual and group behaviour, response to chemical alarm and predator cues, as well as capacity to evade predation. In addition, predation of delta smelt was tested in the presence of a dominant invasive competitor, Mississippi silversides (Menidia beryllina, Atherinopsidae), as well as comparative predation mortality on Mississippi silversides when isolated. After 7 days of increased temperature treatments, delta smelt in the warm treatment increased swimming velocity, decreased turning angle, and altered group structure with larger inter-individual distances compared to fish in the control (17°C) and fluctuating temperature treatments. Following conspecific and predator chemical alarm cues, delta smelt showed anti-predator responses. Control and fluctuating treatment fish responded to conspecific cues with increased swimming speeds, decreased inter-individual distances and near-neighbour distances, and, after 15 min, fish recovered back to baseline behaviours. In contrast, fish in the warm treatment had not recovered after 15 min, and swimming speeds were maintained at roughly 25 cm/s, close to maximum capabilities. Fish in control and fluctuating treatments showed minimal responses to predator cues, whereas delta smelt exposed to warm conditions significantly increased swimming speeds and decreased turning angle. Predation of delta smelt by largemouth bass (Micropterus salmoides, Centrarchidae) was greatest under the warm treatment, correlating with altered behaviours of delta smelt; however, predation of Mississippi silversides was greater than delta smelt, independent of temperature. This study provides novel insight into the group behaviour of delta smelt, their response to predation, and how prolonged exposure to elevated temperature may induce negative individual and group behaviours causing alterations in predator–prey dynamics. This work highlights the importance of testing ecologically realistic temperature fluctuations in experiments as delta smelt had significantly altered responses to elevated temperature, dependent on variability of warming
Episodic-Like Memory for What-Where-Which Occasion is Selectively Impaired in the 3xTgAD Mouse Model of Alzheimer’s Disease
Episodic memory loss is a defining feature of early-stage Alzheimer’s disease (AD). A test of episodic-like memory for the rat, the What-Where-Which occasion task (WWWhich), requires the association of object, location, and contextual information to form an integrated memory for an event. The WWWhich task cannot be solved by use of non-episodic information such as object familiarity and is dependent on hippocampal integrity. Thus, it provides an ideal tool with which to test capacity for episodic-like memory in the 3xTg murine model for AD. As this model captures much of the human AD phenotype, we hypothesized that these mice would show a deficit in the WWWhich episodic-like memory task. To test the specificity of any episodic-like deficit, we also examined whether mice could perform components of the WWWhich task that do not require episodic-like memory. These included object (Novel Object Recognition), location (Object Location Task, What-Where task), and contextual (What-Which) memory, as well as another three-component task that can be solved without reliance on episodic recall (What-Where-When; WWWhen). The results demonstrate for the first time that control 129sv/c57bl6 mice could form WWWhich episodic-like memories, wherea, 3xTgAD mice at 6 months of age were impaired. Importantly, while 3xTgAD mice showed some deficit on spatial component tasks, they were unimpaired in the more complex WWWhen combination task (which includes a spatial component and is open to non-episodic solutions). These results strongly suggest that AD pathology centered on the hippocampal formation mediates a specific deficit for WWWhich episodic-like memory in the 3xTgAD model
Further variability of the compact radio nebula of P Cygni
Skinner et al. presented two high-resolution 6-cm (5 GHz) images of the B-supergiant star P Cygni. These show the observed morphology and flux densities to have changed over the intervening month. Following on from this, we present a series of seven high-resolution 6-cm images (including re-reductions of the two from Skinner et al.). These confirm that radio emission from the inner 400 mas of the wind is inhomogeneous, consisting usually of several separated bright spots, and that the total and peak flux densities and the observed morphology vary over all time-scales sampled. We suggest that recombination in cooling clumps of gas which will decrease the radio emission, followed by the appearance of other ionized clumps, could explain such rapid changes, but detailed models must await further observations
Edward Thompson, MI5 and the Reasoner controversy: negotiating “Communist principle” in the crisis of 1956
The sixtieth anniversary of the 1956 crisis in international communism provoked a fresh wave of comment on its British dimensions and coincided with the declassification of MI5 files on party historians Edward Thompson and Rodney Hilton. This article approaches the question of communist commitment through a reinterpretation of the Reasoner controversy in which Thompson and Hilton were to different degrees involved. First, it uses the MI5 material alongside existing sources to illuminate tactical and political aspects of the engagement between the Reasoner editors and the party leadership, placing emphasis on the Reasoner’s role as bridgehead of an attempt to reform the party from within rather than as simply a precursor to the New Left.. Next, interrogating Thompson’s claim to ‘communist principle’, it compares his developing interpretation of what this meant and required with the views of a selection of other intellectuals. Far from representing a straightforward assertion of moral conscience against monolithic party bureaucracy, the Reasoner controversy reveals an extremely complex picture of the tensions and constraints involved in communist commitment
Testing the birth unit design spatial evaluation tool (BUDSET) in Australia: A pilot study
Objective: To pilot test the Birth Unit Design Spatial Evaluation Tool (BUDSET) in an Australian maternity care setting to determine whether such an instrument can measure the optimality of different birth settings. Background: Optimally designed spaces to give birth are likely to influence a woman's ability to experience physiologically normal labor and birth. This is important in the current industrialized environment, where increased caesarean section rates are causing concerns. The measurement of an optimal birth space is currently impossible, because there are limited tools available. Methods: A quantitative study was undertaken to pilot test the discriminant ability of the BUDSET in eight maternity units in New South Wales, Australia. Five auditors trained in the use of the BUDSET assessed the birth units using the BUDSET, which is based on 18 design principles and is divided into four domains (Fear Cascade, Facility, Aesthetics, and Support) with three to eight assessable items in each. Data were independently collected in eight birth units. Values for each of the domains were aggregated to provide an overall Optimality Score for each birth unit. Results: A range of Optimality Scores was derived for each of the birth units (from 51 to 77 out of a possible 100 points). The BUDSET identified units with low-scoring domains. Essentially these were older units and conventional labor ward settings. Conclusion: The BUDSET provides a way to assess the optimality of birth units and determine which domain areas may need improvement. There is potential for improvements to existing birth spaces, and considerable improvement can be made with simple low-cost modifications. Further research is needed to validate the tool. © 2011, Vendome Group, LLC. All rights reserved
A compact, variable radio nebula around P Cygni
We present high spatial resolution images, at a wavelength of 6 cm, of the luminous blue variable star P Cygni. The images fully resolve the core of the stellar wind, and show that it is very clumpy. Two images were taken, separated in time by approximately a month, during which the structure in the wind has changed radically. The total flux observed has also changed significantly. We show that the clump sizes and electron densities are consistent with the radio variability being due to recombination of the ionized gas within the clumps, after key cooling lines become optically thin, causing the free-free emission to disappear. This is the first time that resolved radio images of a hot star wind have been obtained. It also represents important confirmation of a previous observation that thermal free-free wind emission can vary rapidly in a hot stellar wind
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