Control over the hydrophobic behavior of polystyrene surface by annealing temperature based on capillary template wetting method

The wetting behavior of water droplets was studied on tunable nanostructured polystyrene (PS) surfaces fabricated by temperature-induced capillary template wetting. The surface morphology of PS varied with the annealing temperature. Contact angle (CA) measurements showed that the wettability of polystyrene surfaces could be tuned from hydrophobic (CA = 104°) to superhydrophobic (CA = 161°) by rendering different morphologies, which could be explained by two distinct wetting modes, i.e., the Wenzel and Cassie–Baxter wetting state. Meanwhile, the critical annealing temperature inducing wetting transition between the Wenzel state and Cassie–Baxter state was obtained. This approach could be easily extended to produce superhydrophobic surfaces on other thermoplastic polymers.

A facile synthesis of mesoporous silica nanoparticle and its morphology manipulation by varying pH value

 Mesoporous silica nanoparticles (MSNs) with particle size of20 nm have been synthesised through the template directed method at low temperature. The pH value of the reaction solution was found to have a great impact on the morphology of the final products. The morphology of resultant MSNs were investigated through transmission electron microscope. The mesoporous structure was examined by Brunauer-Emmett-Teller and Barrett-Joyner-Halenda methods. The results suggested that the high pH value had a great effect on the morphology of the final MSNs. Higher pH value intensified the interaction between particles. The pH value less than 10 is good for the formation of nanoparticles, while at pH 12, a silica framework with heterogeneous mesopore structure can be obtained.

Predicting spatio-temporal distribution for eastern Australian birds using birds Australia's atlas data : survey method, habitat and seasonal effects

Faunal atlases are landscape-level survey collections that can be used for describing spatial and temporal patterns of distribution and densities. They can also serve as a basis for quantitative analysis of factors that may influence the distributions of species. We used a subset of Birds Australia’s Atlas of Australian Birds data (January 1998 to December 2002) to examine the spatio-temporal distribution patterns of 280 selected species in eastern Australia (17–37°S and 136–152°E). Using geographical information systems, this dataset was converted into point coverage and overlaid with a vegetation polygon layer and a half-degree grid. The exploratory data analysis involved calculating species-specific reporting rates spatially, per grid and per vegetation unit, and also temporally, by month and year. We found high spatio-temporal variability in the sampling effort. Using generalised linear models on unaggregated point data, the influences of four factors – survey method and month, geographical location and habitat type – were analysed for each species. When counts of point data were attributed to grid-cells, the total number of species correlated with the total number of surveys, while the number of records per species was highly variable. Surveys had high interannual location fidelity. The predictive values of each of the four factors were species-dependent. Location and habitat were correlated and highly predictive for species with restricted distribution and strong habitat preference. Month was only of importance for migratory species. The proportion of incidental sightings was important for extremely common or extremely rare species. In conclusion, behaviour of species differed sufficiently to require building a customized model for each species to predict distribution. Simple models were effective for habitat specialists with restricted ranges, but for generalists with wide distributions even complex models gave poor predictions.

Predicting avian distributions to evaluate spatiotemporal overlap with locust control operations in eastern Australia.

Locusts and grasshoppers cause considerable economic damage to agriculture worldwide. The Australian Plague Locust Commission uses multiple pesticides to control locusts in eastern Australia. Avian exposure to agricultural pesticides is of conservation concern, especially in the case of rare and threatened species. The aim of this study was to evaluate the probability of pesticide exposure of native avian species during operational locust control based on knowledge of species occurrence in areas and times of application. Using presence-absence data provided by the Birds Australia Atlas for 1998 to 2002, we developed a series of generalized linear models to predict avian occurrences on a monthly basis in 0.5 degrees grid cells for 280 species over 2 million km2 in eastern Australia. We constructed species-specific models relating occupancy patterns to survey date and location, rainfall, and derived habitat preference. Model complexity depended on the number of observations available. Model output was the probability of occurrence for each species at times and locations of past locust control operations within the 5-year study period. Given the high spatiotemporal variability of locust control events, the variability in predicted bird species presence was high, with 108 of the total 280 species being included at least once in the top 20 predicted species for individual space-time events. The models were evaluated using field surveys collected between 2000 and 2005, at sites with and without locust outbreaks. Model strength varied among species. Some species were under- or over-predicted as times and locations of interest typically did not correspond to those in the prediction data set and certain species were likely attracted to locusts as a food source. Field surveys demonstrated the utility of the spatially explicit species lists derived from the models but also identified the presence of a number of previously unanticipated species. These results also emphasize the need for special consideration of rare and threatened species that are poorly predicted by presence-absence models. This modeling exercise was a useful a priori approach in species risk assessments to identify species present at times and locations of locust control applications, and to discover gaps in our knowledge and need for further focused data collection.

A learning method for Top-N recommendations with incomplete data

In this paper, we tackle the incompleteness of user rating history in the context of collaborative filtering for Top-N recommendations. Previous research ignore a fact that two rating patterns exist in the user × item rating matrix and influence each other. More importantly, their interactive influence characterizes the development of each other, which can consequently be exploited to improve the modelling of rating patterns, especially when the user × item rating matrix is highly incomplete due to the well-known data sparsity issue. This paper proposes a Rating Pattern Subspace to iteratively re-optimize the missing values in each user’s rating history by modelling both the global and the personal rating patterns simultaneously. The basic idea is to project the user × item rating matrix on a low-rank subspace to capture the global rating patterns. Then, the projection of each individual user on the subspace is further optimized according to his/her own rating history and the captured global rating patterns. Finally, the optimized user projections are used to improve the modelling of the global rating patterns. Based on this subspace, we propose a RapSVD-L algorithm for Top-N recommendations. In the experiments, the performance of the proposed method is compared with the state-of-the-art Top-N recommendation methods on two real datasets under various data sparsity levels. The experimental results show that RapSVD-L outperforms the compared algorithms not only on the all items recommendations but also on the long tail item recommendations in terms of accuracy.

Legal regulation and corporate governance in China`s top 100 listed companies

This article reports findings from an empirical study of corporate governance in China's top 100 listed companies. It examines the effectiveness of legal regulation, enforcement and remedies, finding that China's company and securities laws have not provided as string a legal framework for the protection of stakeholders im China's stock exchange listed companies as might be expected by investors.

A rapid cell counting method utilising acridine orange as a novel discriminating marker for both cultured astrocytes and microglia

Cell culture analyses of growth, morphology and apoptosis commonly require counting of different cell types stained with antibodies to discriminate between them. Previously, we reported the use of l-Leucine methyl ester (l-LME) to prepare purified cultures of type 1 astrocytes with minimal microglia, and staining by GFAP and CD antibodies, respectively. Here, we demonstrate a novel use of acridine orange (AO) for rapid discrimination between these cell types using fluorescence microscopy. AO accumulates in the lysosomes and also binds strongly to nuclear DNA and cytoplasmic/nucleolar RNA. Microglia may contain abundant lysosomes due to known roles in homeostasis and immune response. AO staining of lysosomes was tested at a range of concentrations, and 2.5 μg/mL was most suitable. In agreement with previous reports, microglia treated with AO showed very intense yellow, orange or red granular cytoplasmic staining of lysosomes. Microglia contain a substantially higher number of lysosomes than astrocytes, which have a variable amount. We measured the microglia population at 5.14 ± 0.50% in mixed cultures. Thus, these results show AO is a novel discriminatory marker, as microglia were easily observed and counted in clumps on top of the monolayer of astrocytes, providing a rapid alternative to time-consuming and costly antibody-based assays.

One-step synthesis of AlN branched nanostructures by an improved DC arc discharge plasma method

Aluminium nitride (AlN) branched nanostructures with tree shapes and sea urchin shapes are synthesized via a one-step improved DC arc discharge plasma method without any catalyst and template. The branched nanostructures with tree shapes and sea urchin shapes can be easily controlled by the location of collection. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies show that the branches of tree shaped nanostructures grow in a sequence of nanowires, nanomultipeds and nanocombs. The growth mechanisms of these branched nanostructures are discussed in detail. The optical properties of AlN branched nanostructures with tree shapes and sea urchin shapes are investigated.

Learning rating patterns for Top-N recommendations

Two rating patterns exist in the user × item rating matrix and influence each other: the personal rating patterns are hidden in each user's entire rating history, while the global rating patterns are hidden in the entire user × item rating matrix. In this paper, a Rating Pattern Subspace is proposed to model both of the rating patterns simultaneously by iteratively refining each other with an EM-like algorithm. Firstly, a low-rank subspace is built up to model the global rating patterns from the whole user × item rating matrix, then, the projection for each user on the subspace is refined individually based on his/her own entire rating history. After that, the refined user projections on the subspace are used to improve the modelling of the global rating patterns. Iteratively, we can obtain a well-trained low-rank Rating Pattern Subspace, which is capable of modelling both the personal and the global rating patterns. Based on this subspace, we propose a RapSVD algorithm to generate Top-N recommendations, and the experiment results show that the proposed method can significantly outperform the other state-of-the-art Top-N recommendation methods in terms of accuracy, especially on long tail item recommendations.

Differences in primary health care delivery to Australia's Indigenous population : a template for use in economic evaluations

Background Health economics is increasingly used to inform resource allocation decision-making, however, there is comparatively little evidence relevant to minority groups. In part, this is due to lack of cost and effectiveness data specific to these groups upon which economic evaluations can be based. Consequently, resource allocation decisions often rely on mainstream evidence which may not be representative, resulting in inequitable funding decisions. This paper describes a method to overcome this deficiency for Australia’s Indigenous population. A template has been developed which can adapt mainstream health intervention data to the Indigenous setting.

Methods The ‘Indigenous Health Service Delivery Template’ has been constructed using mixed methods, which include literature review, stakeholder discussions and key informant interviews. The template quantifies the differences in intervention delivery between best practice primary health care for the Indigenous population via Aboriginal Community Controlled Health Services (ACCHSs), and mainstream general practitioner (GP) practices. Differences in costs and outcomes have been identified, measured and valued. This template can then be used to adapt mainstream health intervention data to allow its economic evaluation as if delivered from an ACCHS.

Results The template indicates that more resources are required in the delivery of health interventions via ACCHSs, due to their comprehensive nature. As a result, the costs of such interventions are greater, however this is accompanied by greater benefits due to improved health service access. In the example case of the polypill intervention, 58% more costs were involved in delivery via ACCHSs, with 50% more benefits. Cost-effectiveness ratios were also altered accordingly.

Conclusions The Indigenous Health Service Delivery Template reveals significant differences in the way health interventions are delivered from ACCHSs compared to mainstream GP practices. It is important that these differences are included in the conduct of economic evaluations to ensure results are relevant to Indigenous Australians. Similar techniques would be generalisable to other disadvantaged minority populations. This will allow resource allocation decision-makers access to economic evidence that more accurately represents the needs and context of disadvantaged groups, which is particularly important if addressing health inequities is a stated goal.

Surface-sensitive method to determine calcium carbonate filler contents in cellulose matrices

This paper describes a method using attenuated total reflectance infra-red spectroscopy to determine the surface concentration of calcium carbonate in paper samples, by applying the linear relationship between the relative infra-red absorption integrals and the concentration. The method was able to detect micro-variations in the surface concentration and could also distinguish between different sheets as well as between the top and bottom side of one sheet. The samples were also split and the calcium carbonate concentration was determined within and compared to bulk calcium carbonate concentration determined from ash testing. The surface results were also compared with analysed scanning electron microscopy images generated from back-scattering electrons. The comparison shows that both sets of results are in excellent agreement. Depending on the sample, large errors (95% confidence) were observed. These, however, are caused by micro-variations of the surface concentration, rather than by inaccuracies of the technique, which is estimated to be less than 1%. Furthermore, measurements of various sample orientations suggest that anisotropic polarisation effects can be neglected. The method can be applied to paper and cellulose matrices having calcium carbonate filler contents of less than 50%. Due to spectral overlaps it is not suitable to determine kaolin filler contents.

A simple and effective method to ameliorate the interfacial properties of cellulosic fibre based bio-composites using poly (ethylene glycol) based amphiphiles

In order to overcome interfacial incompatibility issues in natural fibre reinforced polymer bio-composites, surface modifications of the natural fibres using complex and environmentally unfriendly chemical methods is necessary. In this paper, we demonstrate that the interfacial properties of cellulose-based bio-composites can be tailored through surface adsorption of polyethylene glycol (PEG) based amphiphilic block copolymers using a greener alternative methodology. Mixtures of water or water/acetone were used to form amphiphilic emulsions or micro-crystal suspensions of PEG based amphiphilic block copolymers, and their deposition from solution onto the cellulosic substrate was carried out by simple dip-coating. The findings of this study evidence that, by tuning the amphiphilicity and the type of building blocks attached to the PEG unit, the flexural and dynamic thermo-mechanical properties of cellulose-based bio-composites comprised of either polylactide (PLA) or high density polyethylene (HDPE) as a matrix, can be remarkably enhanced. The trends, largely driven by interfacial effects, can be ascribed to the combined action of the hydrophilic and hydrophobic components of these amphiphiles. The nature of the interactions formed across the fibre-matrix interface is discussed. The collective outcome from this study provides a technological template to significantly improve the performance of cellulose-based bio-composite materials.

Template-free synthesis of functional 3D BN architecture for removal of dyes from water.

Three-dimensional (3D) architectures are of interest in applications in electronics, catalysis devices, sensors and adsorption materials. However, it is still a challenge to fabricate 3D BN architectures by a simple method. Here, we report the direct synthesis of 3D BN architectures by a simple thermal treatment process. A 3D BN architecture consists of an interconnected flexible network of nanosheets. The typical nitrogen adsorption/desorption results demonstrate that the specific surface area for the as-prepared samples is up to 1156 m(2) g(-1), and the total pore volume is about 1.17 cm(3) g(-1). The 3D BN architecture displays very high adsorption rates and large capacities for organic dyes in water without any other additives due to its low densities, high resistance to oxidation, good chemical inertness and high surface area. Importantly, 88% of the starting adsorption capacity is maintained after 15 cycles. These results indicate that the 3D BN architecture is potential environmental materials for water purification and treatment.

A general method to eliminate laboratory induced recombinants during massive, parallel sequencing of cDNA library.

Massive, parallel sequencing is a potent tool for dissecting the regulation of biological processes by revealing the dynamics of the cellular RNA profile under different conditions. Similarly, massive, parallel sequencing can be used to reveal the complexity of viral quasispecies that are often found in the RNA virus infected host. However, the production of cDNA libraries for next-generation sequencing (NGS) necessitates the reverse transcription of RNA into cDNA and the amplification of the cDNA template using PCR, which may introduce artefact in the form of phantom nucleic acids species that can bias the composition and interpretation of original RNA profiles.

Less is more: development and evaluation of an interactive e-atlas to support anatomy learning

An Interactive electronic Atlas (IeA) was developed to assist first-year nursing students with interpretation of laboratory-based prosected cadaveric material. It was designed, using pedagogically sound principles, as a student-centered resource accessible to students from a wide range of learning backgrounds. It consisted of a highly simplified interactive interface limited to essential anatomical structures and was intended for use in a blended learning situation. The IeA's nine modules mirrored the body systems covered in a Nursing Biosciences course, with each module comprising a maximum of 10 pages using the same template: an image displaying a cadaveric specimen and, in most cases, a corresponding anatomical model with navigation panes (menus) on one side. Cursor movement over the image or clicking the menu highlighted the structure with a transparent overlay and revealed a succinct functional description. The atlas was complemented by a multiple-choice database of nearly 1,000 questions using IeA images. Students' perceptions of usability and utility were measured by survey (n = 115; 57% of the class) revealing mean access of 2.3 times per week during the 12-week semester and a median time of three hours of use. Ratings for usability and utility were high, with means ranging between 4.24 and 4.54 (five-point Likert scale; 5 = strongly agree). Written responses told a similar story for both usability and utility. The role of providing basic computer-assisted learning support for a large first-year class is discussed in the context of current research into student-centered resources and blended learning in human anatomy.