First-year law students’ construction of professional identity through writing

While there is a considerable body of research on law student identity construction based on interviews and transcripts of classroom talk, there is very little work based on student written texts. In this article two letters of advice written by beginning law students are analysed, using Ivanic and Camps’s (2001) framework, as an example of identity formation. Legal identity is argued to be formed by students’ attempts to accommodate a dynamic, partial, practitioner role of provider of advice to the traditional analytic focus of the law student. The process of accommodation is evident in the language of the letters, which show disfluencies resulting from attempts to combine different roles into a coherent legal identity. Comparison with a professionally written letter suggests that, rather than seeking to shape a coherent position, lawyers are able simultaneously to hold incompatible perspectives, concealing the tensions by foregrounding some perspectives and backgrounding others.

A potential novel rapid screening NMR approach to boundary film formation at solid interfaces in contact with ionic liquids

The boundary films generated on a series of inorganic compounds, typical of native films on metal and ceramic surfaces, when exposed to various ionic liquids (ILs) based on the trihexyl(tetradecyl)phosphonium cation have been characterized using multinuclear solid-state NMR. The NMR results indicate that SiO₂ and Mg(OH)₂ interact strongly with the anion and cation of each IL through a mechanism of adsorption of the anion and subsequent close proximity of the cation in a surface double layer (as observed through ¹H−²⁹Si cross polarization experiments). In contrast, Al₂O₃, MgO, ZnO, and ZrO₂ appear less active, strongly suggesting the necessity of hydroxylated surface groups in order to enhance the generation of these interfacial films. Using solid-state NMR to characterize such interfaces not only has the potential to elucidate mechanisms of wear resistance and corrosion protection via ILs, but is also likely to allow their rapid screening for such durability applications.

On the characteristics of substructure development through dynamic recrystallization

Substructure development in an austenitic Ni-30%Fe model alloy was investigated within a dynamic recrystallization (DRX) regime. The substructure characteristics of the deformed matrix and DRX grains were markedly different regardless of the grain size and orientation. The former largely displayed 'organized', banded subgrain arrangements with alternating misorientations, resulting from a limited number of active slip systems. In contrast, the substructure of DRX grains was generally more 'random' and exhibited complex subgrain/cell arrangements characterized by local accumulation of misorientations, suggesting multiple slip. The proposed mechanism of the unique substructure development within DRX grains suggests that the DRX nuclei, forming along pre-existing grain boundaries and triple points, essentially represent grain boundary regions, which experience multiple slip to preserve the compatibility with neighbouring deformed grains. This results in the formation of a complex cell/subgrain structure, which progressively extends as the grain boundary regions expand outwards during DRX growth.

Microphase separation through competitive hydrogen bonding in double crystalline diblock copolymer/homopolymer blends

Microphase separation induced by competitive hydrogen bonding interactions in double crystalline diblock copolymer/homopolymer blends was studied for the first time. Poly(ethylene oxide)- block-poly(e-caprolactone) (PEO-b-PCL)/poly(4-vinylphenol) (PVPh) blends were prepared in tetrahydrofuran. The diblock copolymer PEO-b-PCL consists of two immiscible crystallizable blocks wherein bothPEO and PCL blocks can form hydrogen bonds with PVPh. In these A-b-B/C diblock copolymer homopolymer blends, microphase separation takes place due to the disparity in intermolecular interactions; specifically, PVPh and PEO block interact strongly whereas PVPh and PCL block interact weakly. The TEM and SAXS results show that the cubic PEO-b-PCL diblock copolymer changes into ordered hexagonal cylindrical morphology upon addition of 20 wt % PVPh followed by disordered bicontinuous phase in the blend with 40 wt % PVPh and then to homogeneous phase at 60 wt % PVPh and above blends. Up to 40 wt % PVPh there is only weak interaction between PVPh and PCL due to the selective hydrogen bonding between PVPh and PEO. However, with higher PVPh concentration, the blends become homogeneous since a sufficient amount of PVPh is available to form hydrogen bonds with both PEO and PCL. A structural model was proposed to explain the self-assembly and microphase morphology of these blends based on the experimental results obtained. The formation of nanostructures and changes in morphologies depend on the relative strength of hydrogen bonding interaction between each block of the block copolymer and the homopolymer.

A probabilistic movement model for shortest path formation in virtual ant-like agents

We propose a probabilistic movement model for controlling ant-like agents foraging between two points. Such agents are all identical, simple, autonomous and can only communicate indirectly through the environment. These agents secrete two types of pheromone, one to mark trails towards the goal and another to mark trails back to the starting point. Three pheromone perception strategies are proposed (Strategy A, B and C). Agents that use strategy A perceive the desirability of a neighbouring location as the difference between levels of attractive and repulsive pheromone in that location. With strategy B, agents perceive the desirability of a location as the quotient of levels of attractive and repulsive pheromone. Agents using strategy C determine the product of the levels of attractive pheromone with the complement of levels of repulsive pheromone. We conduct experiments to confirm directionality as emergent property of trails formed by agents that use each strategy. In addition, we compare path formation speed and the quality of the formed path under changes in the environment. We also investigate each strategy's robustness in environments that contain obstacles. Finally, we investigate how adaptive each strategy is when obstacles are eventually removed from the scene and find that the best strategy of these three is strategy A. Such a strategy provides useful guidelines to researchers in further applications of swarm intelligence metaphors for complex problem solving.

Cordycepin interferes with 3' end formation in yeast independently of its potential to terminate RNA chain elongation

Cordycepin (3′ deoxyadenosine) is a biologically active compound that, when incorporated during RNA synthesis in vitro, provokes chain termination due to the absence of a 3′ hydroxyl moiety. We were interested in the effects mediated by this drug in vivo and analyzed its impact on RNA metabolism of yeast. Our results support the view that cordycepin-triphosphate (CoTP) is the toxic component that is limiting cell growth through inhibition of RNA synthesis. Unexpectedly, cordycepin treatment modulated 3′ end heterogeneity of ACT1 and ASC1 mRNAs and rapidly induced extended transcripts derived from CYH2 and NEL025c loci. Moreover, cordycepin ameliorated the growth defects of poly(A) polymerase mutants and the pap1-1 mutation neutralized the effects of the drug on gene expression. Our observations are consistent with an epistatic relationship between poly(A) polymerase function and cordycepin action and suggest that a major mode of cordycepin activity reduces 3′ end formation efficiency independently of its potential to terminate RNA chain elongation. Finally, chemical-genetic profiling revealed genome-wide pathways linked to cordycepin activity and identified novel genes involved in poly(A) homeostasis.

Efficient management of drinking water distribution systems through the application of water quality modeling

The quality of drinking water generally degrades when it is delivered through a distribution system due to the decay of disinfectant, which subsequently allows the re-growth of microorganisms in the distribution system. A model that describes the changes that occur in the water quality in distribution system is needed to determine whether to enhance the treatment processes or to improve the distribution system so that microbiological criteria are met. This paper describes how chlorine decay kinetics are modeled and the model output is used in finding the elements that are contributing to the consumption of chlorine at the treatment plant other than the water itself; this allows better control of chlorine dosing at the treatment plant, which in tum will reduce the formation of disinfectant by-products. In addition, the model will accurately predict the decay due to the organic/inorganic and nitrogenous compounds that are remaining in the water at any point in the distribution system, which will indicate the status of the distribution system with respect to its chlorine consumption. Further, if re-chlorination is introduced in the distribution system downstream of the treatment plant, the model will predict the chlorine decay due to the slow reacting organic and nitrogenous compounds accurately.

Rapid water quality characterization for chlorine demand and THM formation in drinking waters

The quality of drinking water generally deteriorates when it is delivered through a distribution system due to the decay of disinfectant, which subsequently allows the re-growth of microorganisms in the distribution system in addition to the formation of trihalomethane (THM). Therefore, a model which describes the changes that occur in the water quality in the distribution system is needed to determine whether to enhance the treatment processes or to improve the distribution system so that microbiological criteria are met. In this paper the chlorine decay kinetics and THM formation in treated water is modeled considering the reaction of chlorine with fast and slow reacting organic and nitrogenous compounds which are present in that water. The treated water was also passed through three types of resins to fractionate very hydrophobic acids (VHA), slightly hydrophobic acids (SHA), hydrophilic charged (CHA) and hydrophilic neutral (NEU) compounds which are present in the water. Chlorine decay tests were conducted on the effluents emerging from the resins to evaluate the chlorine demand and THM formation potential of those organic fractions. The model shows that the CHA presented in the waters has a very high THM formation potential (around 62% of the THM produced). VHA, NEU and CHA contributed to chlorine demand in the water.

Evaluating the drinking water quality through an efficient chlorine decay model

The performance of a treatment plant in reducing chlorine consuming substances as well as total trihalomethane formation (TTHM) could be evaluated rapidly using an accurate chlorine decay model as used in this study. The model could estimate the concentrations of fast and slow reacting agents (FRA and SRA–including organic and inorganic substances) and fast and slow reacting nitrogenous compounds (FRN and SRN) that are present in test waters. By estimating those concentrations in source and treated waters one could evaluate the performance of the treatment plant as well as provide options such as better catchment management for source water protection or treatment upgrades (e.g. enhanced coagulation) to remove chlorine consuming compounds which also have the potential to form THMs.

Effect of composition and processing parameters on the formation of nano-bainite in advanced high strength steels

The nano-bainitic microstructures were compared in a 0.79C-1.5Si-1.98Mn-0.24Mo-1.06Al (wt%) steel after isothermal heat-treatment and a Fe-0.2C-1.5Mn-1.2Si-0.3M0-0.6Al-0.02Nb (wt%) steel after controlled thermo-mechanical processing. The microstructure for both steels consisted of bainite. The microstructural characteristics of bainite, such as the morphology of the nano-bainite and thicknesses of bainitic ferrite and retained austenite layers, as a function of steel composition and processing was studied using transmission electron microscopy (TEM). It was found that the nano-bainitic structure can be formed in the low alloy steel through thermomechanical processing. Atom probe tomography (APT) was employed as a powerful technique to determine local composition distributions in three dimensions with atomic resolution. The important conclusions from the APT research were that the carbon content of bainitic ferrite is higher than expected from paraequilibrium level of carbon in ferrite for both steels and that Fe-C clusters and fine particles are formed in the bainitic ferrite in both steels despite the high level of Si.

Effect of cellulose nanofiber dimensions on sheet forming through filtration

Four different cellulose nanofibers samples were prepared from northern bleached softwood kraft fibers. Fiber diameter distributions were measured from SEM images. Fiber aspect ratios ranging from 84 to 146 were estimated from fiber suspension sedimentation measurements. Three samples had heterogeneous distributions of fiber diameters, while one sample was more homogeneous. Sheet forming experiments using filters with pores ranging from 150 to 5 μm showed that the samples with a heterogeneous distribution of fiber dimensions could be easily formed into sheets at 0. 2% initial solids concentration with all filter openings. On the other hand, sheets could only be formed from the homogenous sample by using 0. 5% or more initial solids content and a lower applied vacuum and smaller filter openings. The forming data and estimated aspect ratios show reasonable agreement with the predictions of the crowding number and percolation theories for the connectivity and rigidity thresholds for fiber suspensions.

Charting Australia Felix : re-interpreting cultural landscape creation through a land health lens

The landscape of the Western District of Victoria has been extensively transformed in the imagery and aspirations of United Kingdom estates but markedly modified to address the climatic and agricultural prospects of the District landscape. By assembling land, the original squatters had a clean sheet to map, comprehend, and configure an economically viable pastoral estate. ‘Charting Australia Felix’ seeks to ascertain the spatial and geographical logic and rationale that informed this pastoral estate formation. These settlers mastered an economically viable estate that respected climate, soil quality and ensured water security which were the essential ingredients of a quality land holding; their successful grazing and specialisation were dependent upon these attributes. Thus, they successfully comprehended the essences of the landscape in line with contemporary land care and rural land management strategies. Charting Australia Felix involves the use of the historic landscape characterisation method to map, assess and model some 5 exemplar pastoral stations in the Western District to quantify their temporal landscape characteristics, their responses to landscape evolution, and change to test and quantify what the archetypes are that may have informed these patterns. Using Murndal and Glenormiston pastoral stations as the lens of investigation, a preliminary appraisal is offered in this paper.

Investigation of the plasmodium falciparum food vacuole through inducible expression of the chloroquine resistance transporter (PfCRT)

Haemoglobin degradation during the erythrocytic life stages is the major function of the food vacuole (FV) of Plasmodium falciparum and the target of several anti-malarial drugs that interfere with this metabolic pathway, killing the parasite. Two multi-spanning food vacuole membrane proteins are known, the multidrug resistance protein 1 (PfMDR1) and Chloroquine Resistance Transporter (PfCRT). Both modulate resistance to drugs that act in the food vacuole. To investigate the formation and behaviour of the food vacuole membrane we have generated inducible GFP fusions of chloroquine sensitive and resistant forms of the PfCRT protein. The inducible expression system allowed us to follow newly-induced fusion proteins, and corroborated a previous report of a direct trafficking route from the ER/Golgi to the food vacuole membrane. These parasites also allowed the definition of a food vacuole compartment in ring stage parasites well before haemozoin crystals were apparent, as well as the elucidation of secondary PfCRT-labelled compartments adjacent to the food vacuole in late stage parasites. We demonstrated that in addition to previously demonstrated Brefeldin A sensitivity, the trafficking of PfCRT is disrupted by Dynasore, a non competitive inhibitor of dynamin-mediated vesicle formation. Chloroquine sensitivity was not altered in parasites over-expressing chloroquine resistant or sensitive forms of the PfCRT fused to GFP, suggesting that the PfCRT does not mediate chloroquine transport as a GFP fusion protein.

Coupled RNA polymerase II transcription and 3′ end formation with yeast whole-cell extracts

 RNA polymerase II (RNAP II) transcription and pre-mRNA 3' end formation are linked through physical and functional interactions. We describe here a highly efficient yeast in vitro system that reproduces both transcription and 3' end formation in a single reaction. The system is based on simple whole-cell extracts that were supplemented with a hybrid Gal4-VP16 transcriptional activator and supercoiled plasmid DNA templates encoding G-less cassette reporters. We found that the coupling of transcription and processing in vitro enhanced pre-mRNA 3' end formation and reproduced requirements for poly(A) signals and polyadenylation factors. Unexpectedly, however, we show that in vitro transcripts lacked m⁷G-caps. Reconstitution experiments with CF IA factor assembled entirely from heterologous components suggested that the CTD interaction domain of the Pcf11 subunit was required for proper RNAP II termination but not 3' end formation. Moreover, we observed reduced termination activity associated with extracts prepared from cells carrying a mutation in the 5'-3' exonuclease Rat1 or following chemical inhibition of exonuclease activity. Thus, in vitro transcription coupled to pre-mRNA processing recapitulates hallmarks of poly(A)-dependent RNAP II termination. The in vitro transcription/processing system presented here should provide a useful tool to further define the role of factors involved in coupling.

A preliminary study on the effect of macro cavities formation on properties of carbon nanotube bucky-paper composites

In this study, we focus on processing and characterizing composite material structures made of carbon nanotubes (CNTs) and reproducibly engineering macro-pores inside their structure. Highly porous bucky-papers were fabricated from pure carbon nanotubes by dispersing and stabilizing large 1 μm polystyrene beads within a carbon nanotube suspension. The polystyrene beads, homogeneously dispersed across the thickness of the bucky-papers, were then either dissolved or carbonized to generate macro cavities of different shape and properties. The impact of adding these macro cavities on the porosity, specific surface area and Young’s modulus was investigated and some benefits of the macro cavities will be demonstrated.