998 resultados para Sub-microscopic
Resumo:
Cellular lipids frequently co-purify with lipid binding proteins isolated from tissue extracts or heterologous host systems and as such hinder in vitro ligand binding approaches for which the apo-protein is a prerequisite. Here we present a technique for the complete removal of unesterified fatty acids, phospholipids, steroids and other lipophilic ligands bound to soluble proteins, without protein denaturation. Peroxisome proliferator activated receptor gamma ligand binding domain and intracellular fatty acid binding proteins were expressed in an Escherichia coli host and completely delipidated by hydrophobic interaction chromatography using phenyl sepharose. The delipidation procedure operates at room temperature with complete removal of bound lipids in a single step, as ascertained by mass spectrometry analysis of organic solvent extracts from purified protein samples. The speed and capacity of this method makes it amenable to scale-up and high-throughput applications. The method can also easily be adapted for other lipid binding proteins that require delipidation under native conditions.
Resumo:
There has been increased focus on establishing landscape and sub-continental scale linkages and corridors in Australia in recent years. These include the WildCountry, Alps to Atherton, Naturelinks and Gondwana Link initiatives. However, there has been little discussion as to what the underlying tenure, land use and protection mechanisms might look like on the ground. The development of Biosphere Reserves and Conservation Management Networks (collectively ‘multi-tenure reserve networks’) which incorporate public and private conservation lands under a variety of tenures and protection mechanisms provides example of how this might be achieved.
Whilst the rhetoric has been strong the amount of actual research on what multi-tenure reserve networks mean in practice has been limited. This paper reflects on the lessons acquired from research into these networks and discusses with this practical insight the difference between rhetoric and performance in this vital area. In particular we discuss some of the ecological, social, governance and legal aspects of these networks. We will also proceed to hypothesise on what the future challenges are for multi-tenure reserve networks and what will be needed to overcome these challenges.
Resumo:
The production of alumina involves the use of a process known as the Bayer process. This method involves the digestion of raw bauxite in sodium hydroxide at temperatures around 250°C. The resultant pregnant liquor then goes through a number of filtering and precipitation processes to obtain the aluminium oxide crystals which are then calcined to obtain the final product. The plant is situated in a sub tropical climate in Northern Australia and this combined with the hot nature of the process results in a potential for heat related illnesses to develop. When assessing a work environment for heat stress a heat stress index is often employed as a guideline and to date the Wet Bulb Globe Temperature (WBGT) has been the recommended index. There have been concerns over the past that the WBGT is not suited to the Northern Australian climate and in fact studies in other countries have suggested this is the case. This study was undertaken in the alumina plant situated in Gladstone Queensland to assess if WBGT was in fact the most suitable index for use or if another was more applicable. To this end three indices, Wet Bulb Globe Temperature (WBGT), Heat Stress Index (HSI) and Required Sweat Rate (SWreq) were compared and assessed using physiological monitoring of heart rate and surrogate core temperature. A number of different jobs and locations around the plant were investigated utilising personal and environmental monitoring equipment. These results were then collated and analysed using a computer program written as part of the study for the manipulation of the environmental data . Physiological assessment was carried out using methods approved by international bodies such as National Institute for Occupational Safety & Health (NIOSH) and International Standards Organisation (ISO) and incorporated the use of a ‘Physiological Factor’ developed to enable the comparison of predicted allowable exposure times and strain on the individual. Results indicated that of the three indices tested, Required Sweat Rate was found to be the most suitable for the climate and in the environment of interest. The WBGT system was suitable in areas in the moderate temperature range (ie 28 to 32°C) but had some deficiencies above this temperature or where the relative humidity exceeded approximately 80%. It was however suitable as a first estimate or first line indicator. HSI over-estimated the physiological strain in situations of high temperatures, low air flows and exaggerated the benefit of artificial air flows on the worker in certain environments ie. fans.
Resumo:
This paper examines the relationship between democracy and economic growth in 30 Sub-Saharan African countries. As our proxy for democracy we first use the democracy index constructed by Freedom House and then check the sensitivity of our findings using, as an alternative proxy for democracy, the Legislative Index of Electoral Competitiveness (LIEC). We find support for the Lipset hypothesis - in the long run, real GDP Granger causes democracy and an increase in GDP results in an improvement in democracy ??? in Botswana and Niger with both datasets, for Chad with the Freedom House data only and for Cote d???Ivoire and Gabon with the LIEC data only. Support for the compatibility hypothesis - in the long run democracy Granger causes real income and an increase in democracy has a positive effect on real income - is found for Botswana with the Freedom House data and for Madagascar, Rwanda, South Africa and Swaziland with the LIEC data. Support for the conflict hypothesis - in the long run democracy Granger causes real income and an increase in democracy has a negative effect on real income - is found for Gabon with the Freedom House data and Sierra Leone with the LIEC data.
Resumo:
The self-assembling behavior of a single-chain quaternary ammonium amphiphile bearing azobenzene (C12AzoC6N+) on freshly cleaved mica sheet has been investigated by atomic force microscopy (AFM) method. Confocal microscopic Raman spectra confirm the adsorption of the self-assembled monolayer structure. Ex-situ AFM reveals that C12AzoC6N+ forms branch-like stripes indicating the fusion and reorganization of the micelles during drying in air as the in-situ AFM has revealed that surfactant forms spherical micelles on the mica surface. The nano-sized surface structure is strongly dependent on the change of molecular structure, which resulted from photo-induced isomerization. The nano-sized stripe is quite stable even being annealed at 90 °C for 4 h.
Resumo:
The subsurface geology of the Kerang District was examined. The stratigraphic relationships between the Cenozoic western marine and eastern non-marine provinces of the Riverine Plain of the Murray Basin are now far better understood. A new three-fold subdivision of the Renmark Group, including the new Mystic Park Formation, is proposed.
Resumo:
The ovarian follicles and oviducal glands have structural organisations similar to other chondrichthyans. Sperm are stored in the oviducal gland of all maturing and mature animals throughout the year and throughout pregnancy. Microscopic features of the uterine epithelium suggest nutrients are supplied to developing embryos without placenta formation.
Resumo:
This paper uses 1974 to 2001 panel data for 31 sub-Saharan African and 10 Arab countries and Arellano–Bond estimations to empirically assess the impact on growth of an important indicator associated with MDG 3; namely the ratio of 15–24-year-old literate females to males. Our findings indicate that gender inequalities in literacy have a statistically significant negative effect that is robust to changes in the specification. In addition, it seems that gender inequality has a stronger effect on growth in Arab countries. Interestingly, we find that the interaction between openness to trade and gender inequality has a positive impact. This result suggests that trade-induced growth may be accompanied by greater gender inequalities.
Resumo:
A small but growing literature has been concerned about the economic (and
environmental) vulnerability on the level of countries. Less attention is paid to the economic vulnerability of different regions within countries. By focusing on the vulnerability of subnational regions, this paper contributes to the small literature on the “vulnerability of place”. They authors see the vulnerability of place as being due to vulnerability in various domains, such as economic vulnerability, vulnerability of environment, and governance, demographic and health fragilities. They use a subnational data set on 354 magisterial districts from South Africa, recognize the potential relevance of measuring vulnerability on a subnational level, and construct a Local Vulnerability Index for the various districts. They condition this index on district per capita income and term this a Vulnerability Intervention Index, interpreting this as an indicator of where higher income per capita, often seen in the literature as a measure of resilience, will in itself be unlikely to reduce vulnerability.
Resumo:
Nanocomposite electrolytes of a fully amorphous trifunctional polyether (3PEG) and poly- (methylene ethylene oxide) (PMEO) have been complexed with two lithium salts and nanoparticulate (~20 nm) fillers of TiO2 and Al2O3. Addition of the fillers to the polymer salt complexes shows a significant change in the conformational modes of both polymers, especially the D-LAM region between 200 and 400 cm-1, indicating a reduced segmental flexibility of the chain. These changes are more pronounced with the use of TiO2 than Al2O3. Incorporation of the nanoparticulate fillers to the electrolytes fails to influence the degree of ion association, suggesting that the number of charge carriers available for conduction in both polymers using both LiClO4 and LiCF3SO3 is not the source of any conductivity increase. Addition of the fillers, which was seen to increase the conductivity in PEO-based systems, generally lowers the conductivity in the present PMEO systems, while the addition of TiO2 has little or no effect except in the cases of 3PEG 1.5 and 1.25 mol/kg LiClO4. In this case, 10 wt % TiO2 provides a conductivity increase of half an order of magnitude at approximately 60 °C. We also report for the first time a Raman spectroscopy investigation into the PEO-based nanocomposite electrolytes. The present results are discussed in terms of the electrostatic interactions involving dielectric properties of the fillers, of special interest being the interactions between the polymer and the fillers and between the ionic species and the fillers, when the effect of crystallization can be ignored.
Resumo:
Studies on market convergence are well considered in the literature. However, the majority of the previous research focused on housing markets and few studies have concentrated on construction markets. Owing to a simultaneously dramatic increase in the construction prices of the sub-markets in the building construction sector in Australia, this paper aims to identify the convergence among these markets, involving house construction market, other-residential building construction market, and non-residential building construction market. To achieve it the Granger causality test and generalized response function depending on the vector error correction model with the quarterly data of Australia’s eight states from 1998 to 2010 will be applied. Based upon the econometric tests, the price diffusion patterns among these construction markets have been identified. Research on the convergences of construction markets not only helps construction firms perform well in business operations and arbitrage activities, but also provides policy makers with useful information for enacting effective construction policies for national perspectives and approaches to infrastructure planning.
Resumo:
Modeling network traffic has been a critical task in the development of Internet. Attacks and defense are prevalent in the current Internet. Traditional network models such as Poisson-related models do not consider the competition behaviors between the attack and defense parties. In this paper, we present a microscopic competition model to analyze the dynamics among the nodes, benign or malicious, connected to a router, which compete for the bandwidth. The dynamics analysis demonstrates that the model can well describe the competition behavior among normal users and attackers. Based on this model, an anomaly attack detection method is presented. The method is based on the adaptive resonance theory, which is used to learn the model by normal traffic data. The evaluation shows that it can effectively detect the network attacks.
Resumo:
Detection of lane boundaries of a road based on the images or video taken by a video capturing device in a suburban environment is a challenging task. In this paper, a novel lane detection algorithm is proposed without considering camera parameters; which robustly detects lane boundaries in real-time especially for sub-urban roads. Initially, the proposed method fits the CIE L*a*b* transformed road chromaticity values (that is a* and b* values) to a bi-variate Gaussian model followed by the classification of road area based on Mahalanobis distance. Secondly, the classified road area acts as an arbitrary shaped region of interest (AROI) in order to extract blobs resulting from the filtered image by a two dimensional Gabor filter. This is considered as the first cue of images. Thirdly, another cue of images was employed in order to obtain an entropy image. Moreover, results from the color based image cue and entropy image cue were integrated following an outlier removing process. Finally, the correct road lane points are fitted with Bezier splines which act as control points that can form arbitrary shapes. The algorithm was implemented and experiments were carried out on sub-urban roads. The results show the effectiveness of the algorithm in producing more accurate lane boundaries on curvatures and other objects on the road.