Disability Standards for Education

This chapter of Higher Education and the Law considers the scope of the obligation of Australian Universities to make reasonable adjustments to facilities, procedures and curriculum, for students with disability. It reflects upon relevant case law to inform analysis of problematic aspects of that scope including, for example, the accommodation of students with problem behaviour flowing from disability and adjustment to assessment for students with disability.

A subculture of mental toughness in an Australian Football League club

Objective The current study aimed to provide a subcultural analysis of mental toughness in a high-performance context in sport. Design Using Schein's (1990) framework of organisational culture, an exploratory qualitative analysis, employing focus group and individual interviews, was used to investigate mental toughness in an Australian Football League club. Method Nine senior coaches and players participated in focus group and individual interviews. Photo elicitation was used as a method to capture mental toughness through the identification of prominent club artefacts. Participants were considered to have significant subcultural knowledge of their football club and were willing to describe personal experiences and perceptions of mental toughness through this cultural lens. Deductive and inductive analyses were conducted to capture the core themes of mental toughness across the disparate levels of Schein's organisational framework. Results Mental toughness was found to be a socially derived term marked by unrelenting standards and sacrificial displays. These acts were underpinned by subcultural values emphasising a desire for constant improvement, a team first ethos, relentless effort, and the maintenance of an infallible image. At its core, mental toughness was assumed to be an internal concept, epitomised an idealised form of masculinity, elitist values, and was rhetorically depicted through metaphors of war. Conclusions It may be difficult to understand mental toughness without giving attention to the contextual norms related to the term. Appreciating how people promote, instil, and internalise prized ideals coveted as mental toughness could be intriguing for future research in sport psychology.

Heterologous signals allow efficient targeting of a nuclear-encoded fusion protein to plastids and endoplasmic reticulum in diverse plant species

Approximately 30% of plant nuclear genes appear to encode proteins targeted to the plastids or endoplasmic reticulum (ER). The signals that direct proteins into these compartments are diverse in sequence, but, on the basis of a limited number of tests in heterologous systems, they appear to be functionally conserved across species. To further test the generality of this conclusion, we tested the ability of two plastid transit peptides and an ER signal peptide to target green fluorescent protein (GFP) in 12 crops, including three monocots (barley, sugarcane, wheat) and nine dicots (Arabidopsis, broccoli, cabbage, carrot, cauliflower, lettuce, radish, tobacco, turnip). In all species, transient assays following microprojectile bombardment or vacuum infiltration using Agrobacterium showed that the plastid transit peptides from tomato DCL (defective chloroplast and leaves) and tobacco RbcS [ribulose bisphosphate carboxylase (Rubisco) small subunit] genes were effective in targeting GFP to the leaf plastids. GFP engineered as a fusion to the N-terminal ER signal peptide from Arabidopsis basic chitinase and a C-terminal HDEL signal for protein retention in the ER was accumulated in the ER of all species. The results in tobacco were confirmed in stably transformed cells. These signal sequences should be useful to direct proteins to the plastid stroma or ER lumen in diverse plant species of biotechnological interest for the accumulation of particular recombinant proteins or for the modification of particular metabolic streams.

Abaca bunchy top virus, a new member of the genus Babuvirus (family Nanoviridae)

Two isolates of a novel babuvirus causing "bunchy top" symptoms were characterised, one from abaca (Musa textilis) from the Philippines and one from banana (Musa sp.) from Sarawak (Malaysia). The name abacá bunchy top virus (ABTV) is proposed. Both isolates have a genome of six circular DNA components, each ca. 1.0-1.1 kb, analogous to those of isolates of Banana bunchy top virus (BBTV). However, unlike BBTV, both ABTV isolates lack an internal ORF in DNA-R, and the ORF in DNA-U3 found in some BBTV isolates is also absent. In all phylogenetic analyses of nanovirid isolates, ABTV and BBTV fall in the same clade, but on separate branches. However, ABTV and BBTV isolates shared only 79-81% amino acid sequence identity for the putative coat protein and 54-76% overall nucleotide sequence identity across all components. Stem-loop and major common regions were present in ABTV, but there was less than 60% identity with the major common region of BBTV. ABTV and BBTV were also shown to be serologically distinct, with only two out of ten BBTV-specific monoclonal antibodies reacting with ABTV. The two ABTV isolates may represent distinct strains of the species as they are less closely related to each other than are isolates of the two geographic subgroups (Asian and South Pacific) of BBTV.

An asparaginyl endopeptidase mediates in vivo protein backbone cyclization

Proteases can catalyze both peptide bond cleavage and formation, yet the hydrolysis reaction dominates in nature. This presents an interesting challenge for the biosynthesis of backbone cyclized (circular) proteins, which are encoded as part of precursor proteins and require post-translational peptide bond formation to reach their mature form. The largest family of circular proteins are the plant-produced cyclotides; extremely stable proteins with applications as bioengineering scaffolds. Little is known about the mechanism by which they are cyclized in vivo but a highly conserved Asn (occasionally Asp) residue at the C terminus of the cyclotide domain suggests that an enzyme with specificity for Asn (asparaginyl endopeptidase; AEP) is involved in the process. Nicotiana benthamiana does not endogenously produce circular proteins but when cDNA encoding the precursor of the cyclotide kalata B1 was transiently expressed in the plants they produced the cyclotide, together with linear forms not commonly observed in cyclotide-containing plants. Observation of these species over time showed that in vivo asparaginyl bond hydrolysis is necessary for cyclization. When AEP activity was suppressed, either by decreasing AEP gene expression or using a specific inhibitor, the amount of cyclic cyclotide in the plants was reduced compared with controls and was accompanied by the accumulation of extended linear species. These results suggest that an AEP is responsible for catalyzing both peptide bond cleavage and ligation of cyclotides in a single processing event.

Allostery in tRNA Synthetases Elucidated from MD Simulations and Protein Structure Networks

tRNA synthetases (aaRS) are enzymes crucial in the translation of genetic code. The enzyme accylates the acceptor stem of tRNA by the congnate amino acid bound at the active site, when the anti-codon is recognized by the anti-codon site of aaRS. In a typical aaRS, the distance between the anti-codon region and the amino accylation site is approximately 70 Å. We have investigated this allosteric phenomenon at molecular level by MD simulations followed by the analysis of protein structure networks (PSN) of non-covalent interactions. Specifically, we have generated conformational ensembles by performing MD simulations on different liganded states of methionyl tRNA synthetase (MetRS) from Escherichia coli and tryptophenyl tRNA synthetase (TrpRS) from Human. The correlated residues during the MD simulations are identified by cross correlation maps. We have identified the amino acids connecting the correlated residues by the shortest path between the two selected members of the PSN. The frequencies of paths have been evaluated from the MD snapshots[1]. The conformational populations in different liganded states of the protein have been beautifully captured in terms of network parameters such as hubs, cliques and communities[2]. These parameters have been associated with the rigidity and plasticity of the protein conformations and can be associated with free energy landscape. A comparison of allosteric communication in MetRS and TrpRS [3] elucidated in this study highlights diverse means adopted by different enzymes to perform a similar function. The computational method described for these two enzymes can be applied to the investigation of allostery in other systems.

Structural Polymorphism of the Nucleosomal DNA and Implications for Protein Binding

A nucleosome forms a basic unit of the chromosome structure. A biologically relevant question is how much of the nucleosomal conformational space is accessible to protein-free DNA, and what proportion of the nucleosomal conformations are induced by bound histones. To investigate this, we have analysed high resolution xray crystal structure datasets of DNA in protein-free as well as protein-bound forms, and compared the dinucleotide step parameters for the two datasets with those for high resolution nucleosome structures. Our analysis shows that most of the dinucleotide step parameter values for the nucleosome structures lie within the range accessible to protein-free DNA, indirectly indicating that the histone core plays more of a stabilizing role. The nucleosome structures are observed to assume smooth and nearly planar curvature, implying that ‘normal’ B-DNA like parameters can give rise to a curved geometry at the gross structural level. Different nucleosome

Infection control standards and credentialing

Infection control professionals (ICPs) play an integral part of developing, implementing, and evaluating infection control programs. In Australia, there is no minimum or standardized education to practice as an ICP. The Australasian College of Infection Prevention and Control, the professional body for ICPs in Australasia, sought to address the issue by developing a credentialing process.1, 2 and 3 This decision was made in recognition that self-regulation is one of the hallmarks of professionalism.4 The process of becoming credentialed as an ICP in Australia involves the submission of evidence against a range of criteria with a subsequent peer-review process...

Diet quality and liveweight gain of steers grazing Leucaena-grass pasture estimated with faecal near infrared reflectance spectroscopy (F.NIRS)

Three drafts of Bos indicus cross steers (initially 178-216 kg) grazed Leucaena-grass pasture [Leucaena leucocephala subspecies glabrata cv. Cunningham with green panic (Panicum maximum cv. trichoglume)] from late winter through to autumn during three consecutive years in the Burnett region of south-east Queensland. Measured daily weight gain (DWGActual) of the steers was generally 0.7-1.1 kg/day during the summer months. Estimated intakes of metabolisable energy and dry matter (DM) were calculated from feeding standards as the intakes required by the steers to grow at the DWGActual. Diet attributes were predicted from near infrared reflectance spectroscopy spectra of faeces (F.NIRS) using established calibration equations appropriate for northern Australian forages. Inclusion of some additional reference samples from cattle consuming Leucaena diets into F.NIRS calibrations based on grass and herbaceous legume-grass pastures improved prediction of the proportion of Leucaena in the diet. Mahalanobis distance values supported the hypothesis that the F.NIRS predictions of diet crude protein concentration and DM digestibility (DMD) were acceptable. F.NIRS indicated that the percentage of Leucaena in the diet varied widely (10-99%). Diet crude protein concentration and DMD were usually high, averaging 12.4 and 62%, respectively, and were related asymptotically to the percentage of Leucaena in the diet (R2 = 0.48 and 0.33, respectively). F.NIRS calibrations for DWG were not satisfactory to predict this variable from an individual faecal sample since the s.e. of prediction were 0.33-0.40 kg/day. Cumulative steer liveweight (LW) predicted from F.NIRS DWG calibrations, which had been previously developed with tropical grass and grass-herbaceous legume pastures, greatly overestimated the measured steer LW; therefore, these calibrations were not useful. Cumulative steer LW predicted from a modified F.NIRS DWG calibration, which included data from the present study, was strongly correlated (R2 = 0.95) with steer LW but overestimated LW by 19-31 kg after 8 months. Additional reference data are needed to develop robust F.NIRS calibrations to encompass the diversity of Leucaena pastures of northern Australia. In conclusion, the experiment demonstrated that F.NIRS could improve understanding of diet quality and nutrient intake of cattle grazing Leucaena-grass pasture, and the relationships between nutrient supply and cattle growth.

Epithiospecifier protein activity in broccoli: The link between terminal alkenyl glucosinolates and sulphoraphane nitrile

The chemical nature of the hydrolysis products from the glucosinolate-myrosinase system depends on the presence or absence of supplementary proteins, such as epithiospecifier proteins (ESPs). ESPs (non-catalytic cofactors of myrosinase) promote the formation of epithionitriles from terminal alkenyl glucosinolates and as recent evidence suggests, simple nitriles at the expense of isothiocyanates. The ratio of ESP activity to myrosinase activity is crucial in determining the proportion of these nitriles produced on hydrolysis. Sulphoraphane, a major isothiocyanate produced in broccoli seedlings, has been found to be a potent inducer of phase 2 detoxification enzymes. However, ESP may also support the formation of the non-inductive sulphoraphane nitrile. Our objective was to monitor changes in ESP activity during the development of broccoli seedlings and link these activity changes with myrosinase activity, the level of terminal alkenyl glucosinolates and sulphoraphane nitrile formed. Here, for the first time, we show ESP activity increases up to day 2 after germination before decreasing again to seed activity levels at day 5. These activity changes paralleled changes in myrosinase activity and terminal alkenyl glucosinolate content. There is a significant relationship between ESP activity and the formation of sulforaphane nitrile in broccoli seedlings. The significance of these findings for the health benefits conferred by eating broccoli seedlings is briefly discussed.

Photo-induced double-strand DNA and site-specific protein cleavage activity of L-histidine (mu-oxo)diiron(III) complexes of heterocyclic bases

Three oxo-bridged diiron(III) complexes of L-histidine and heterocyclic bases [Fe-2(mu-O)(L-his)(2)(B)(2)](ClO4)(2) (1-3), where B is 2,2'-bipyridine (bpy),1,10-phenanthroline (phen), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq), were prepared and characterized. The bpy complex 1 was structurally characterized by X-ray crystallography. The molecular structure showed a {Fe-2(mu-O)} core in which iron(III) in a FeN4O2 coordination is bound to tridentate monoanionic L-histidine and bidentate bpy ligands. The Fe center dot center dot center dot Fe distance is similar to 3.5 angstrom. The Fe-O-Fe unit is essentially linear, giving a bond angle of similar to 172 degrees. The complexes showed irreversible cyclic voltammetric cathodic response near -0.1 V vs. SCE in H2O-0.1 M KCl. The binuclear units displayed antiferromagnetic interaction between two high-spin (S = 5/2) iron(III) centers giving a -J value of -110 cm(-1). The complexes showed good DNA binding propensity giving a binding constant value of similar to 10(5) M-1. Isothermal titration calorimetric data indicated single binding mode to the DNA. The binding was found to be driven by negative free energy change and enthalpy. The dpq complex 3 showed oxidative double-strand DNA cleavage on exposure to UV-A and visible light. The phen complex 2 displayed single-strand photocleavage of DNA. The DNA double-strand breaks were rationalized from theoretical molecular docking calculations. Mechanistic investigations showed formation of hydroxyl radicals as the reactive species through photodecarboxylation of the L-histidine ligand. The complexes exhibited good binding propensity to bovine serum albumin (BSA) protein in Tris-HCl/NaCl buffer medium. The dpq complex 3 showed UV-A light-induced site-specific oxidative BSA cleavage forming fragments of similar to 45 kDa and similar to 20 kDa molecular weights via SOH pathway.

Small local variations in B-form DNA lead to a large variety of global geometries which can accommodate most DNA-binding protein motifs

An important question of biological relevance is the polymorphism of the double-helical DNA structure in its free form, and the changes that it undergoes upon protein-binding. We have analysed a database of free DNA crystal structures to assess the inherent variability of the free DNA structure and have compared it with a database of protein-bound DNA crystal structures to ascertain the protein-induced variations.

A digital imaging technique to quantify the incidence of internal browning in potato (Solanum tuberosum) tubers

Internal browning disorders, including brown fleck (BF), in potato (Solanum tuberosum) tubers greatly reduce tuber quality, but the causes are not well understood. This is due, in part, to the highly variable data provided by visual value-based rating systems. A digital imaging technique was developed to quantify accurately the incidence of internal browning in potato tubers. Images of tuber sections were scanned using a flatbed scanner and digitally enhanced to highlight tuber BF lesions, and the area of affected tissue calculated using pixel quantification software. Digital imaging allowed for the determination of previously unused indices of the incidence and severity of internal browning in potato tubers. Statistical analysis of the comparison between digitally derived and visual-rating BF data from a glasshouse experiment showed that digital data greatly improved the delineation of treatment effects. The F-test probability was further improved through square root or logarithmic data transformations of the digital data, but not of the visual-rating data. Data from a field experiment showed that the area of tuber affected by BF and the number of small BF lesions increased with time and with increase in tuber size. The results from this study indicate that digital imaging of internal browning disorders of potato tubers holds much promise in determining their causes that heretofore have proved elusive.

Estrogen modulation of retinol-binding protein in immature chicks: Comparison with riboflavin carrier protein

The kinetics of estrogen (E) modulation of retinol-binding protein (RBP) production in the liver of immature chicks were compared with those governing de novo induction of riboflavin carrier protein (RCP) in the same tissue. A single dose of E markedly enhanced the plasma levels of RBP without any detectable lag period to reach peak value by 24 h and this was followed by a decline to attain the baseline by 4 days. There was no amplification of the response during secondary stimulation unlike the case with RCP induction. With multiple E administration, the 4-fold increased plasma RBP concentrations were sustained at a steady state during both primary and secondary stimulations, whereas concomitant RCP concentration progressively increased with each hormone administration and this response was further amplified during secondary stimulation. Unlike RCP induction, enhanced RBP accumulation was not strictly E dose dependent although a minimal threshold level of the steroid was required to elicit measurable response. Progesterone (P) could neither modulate nor substitute for E in enhancing plasma levels of either of the 2 proteins while the anti-estrogens, en- and zuclomifene citrate severely suppressed the production of both the proteins. RCP induction was completely inhibited by both α-amanitin and cycloheximide for prolonged periods while E-stimulated RBP production was affected only partially by α-amanitin. Likewise, cycloheximide inhibition of RBP accumulation followed a pattern similar to that of hepatic general protein synthesis.

Effects Of 5' Flanking Sequences And Changes In The 5' Internal Control Region On The Transcription Of Rice Transfer-Rna Gcc Cly Gene

A stretch of 71 nucleotides in a 1.2 kilobase pair Pst I fragment of rice DNA was identified as tRNA~ gene by hybridization and nucleotide sequence analyses. The hybridization of genomic DNA with the tRNA gene showed that there are about 10 glycine tRNA genes per diploid rice genome. The 3' and 5' internal control regions, where RNA polymerase III and transcription factors bind, were found to be present in the coding sequence. The gene was transcribed into a 4S product in an yeast cell-free extract. The substitution of 5' internal control region with analogous sequences from either M13mpl9 or M13mpl8 DNA did not affect the transcription of the gene in vitro. The changes in three highly conserved nucleotides in the consensus 5' internal control region (RGYNNARYGG; R = purine, Y = pyrimidine, N = any nucleotide) did not affect transcription showing that these nucleotides are not essential for promotion of transcription. There were two 16 base pair repeats, 'TGTTTGTTTCAGCTTA' at - 130 and - 375 positions upstream from the start of the gene. Deletion of 5' flanking sequences including the 16 base pair repeat at - 375 showed increased transcription indicating that these sequences negatively modulate the expression of the gene.