Suppression by abscisic acid of lignin production and monolignol pathway gene expression in interactions of Arabidopsis with oomycete and bacterial pathogens

The phytohormone, abscisic acid (ABA) has been shown to influence the outcome of the interactions between various hosts with biotrophic and hemibiotrophic pathogens. Susceptibility to avirulent isolates can be induced in plants by addition of low physiological concentrations of ABA. In contrast, addition of ABA biosynthesis inhibitors induced resistance following challenge of plants by virulent isolates. ABA deficient mutants of Arabidopsis, such as aba1-1, were resistant to virulent isolates of Peronospora parasitica. In interactions of Arabidopsis with avirulent isolates of Pseudomonas syringae pv. tomato, susceptibility was induced following addition of ABA or imposition of drought stress. These results indicate a pivotal, albiet undefined, role for ABA in determining either susceptibility or resistance to pathogen attack. We have found that the production of the cell wall strengthening compound, lignin, is increased during resistant interactions of aba1-1 but suppressed in ABA-induced susceptible interactions. Using RT-PCR and microarray analysis we have found down-regulation by ABA of key genes of the phenylpropanoid pathway especially of those genes involved directly in lignin biosynthesis. ABA also down-regulates a number of genes in other functional classes including those involved in defence and cell signalling.

Regulation of STARS and its downstream target suggest a novel pathway involved in human skeletal hypertrophy and atrophy

Skeletal muscle atrophy is a severe consequence of ageing, neurological disorders and chronic disease. Identifying the intracellular signalling pathways controlling changes in skeletal muscle size and function is vital for the future development of potential therapeutic interventions. Striated activator of Rho signalling (STARS), an actin-binding protein, has been implicated in rodent cardiac hypertrophy; however its role in human skeletal muscle has not been determined. This study aimed to establish if STARS, as well as its downstream signalling targets, RhoA, myocardin-related transcription factors A and B (MRTF-A/B) and serum response factor (SRF), were increased and decreased respectively, in human quadriceps muscle biopsies taken after 8 weeks of both hypertrophy-stimulating resistance training and atrophy-stimulating de-training. The mRNA levels of the SRF target genes involved in muscle structure, function and growth, such as α-actin, myosin heavy chain IIa (MHCIIa) and insulin-like growth factor-1 (IGF-1), were also measured. Following resistance training, STARS, MRTF-A, MRTF-B, SRF, α-actin, MHCIIa and IGF-1 mRNA, as well as RhoA and nuclear SRF protein levels were all significantly increased by between 1.25- and 3.6-fold. Following the de-training period all measured targets, except for RhoA, which remained elevated, returned to base-line. Our results show that the STARS signalling pathway is responsive to changes in skeletal muscle loading and appears to play a role in both human skeletal muscle hypertrophy and atrophy.

The calcineurin signal transduction pathway is essential for successful muscle regeneration in mdx dystrophic mice

Although mdx mice share the same genetic defect and lack dystrophin expression as in Duchenne muscular dystrophy (DMD), their limb muscles have a high regenerative capacity that ensures a more benign phenotype and essentially normal function. The cellular pathways responsible for this enhanced regenerative capacity are unknown. We tested the hypothesis that the calcineurin signal transduction pathway is essential for the successful regeneration following severe degeneration observed in the limb muscles of young mdx mice (2–4 weeks old) and that inhibition of this pathway using cyclosporine A (CsA) would exacerbate the dystrophic pathology. Eighteen-day-old mdx and C57BL/10 mice were treated with CsA for 16 days. CsA administration severely disrupted muscle regeneration in mdx mice, but had minimal effect in C57BL/10 mice. Muscles from CsA-treated mdx mice had fewer centrally nucleated fibers and extensive collagen, connective tissue, and mononuclear cell infiltration than muscles from vehicle-treated littermates. The deleterious effects of CsA on muscle morphology were accompanied by a 30–35% decrease in maximal force producing capacity. Taken together, these observations indicate that the calcineurin signal transduction pathway is a significant determinant of successful skeletal muscle regeneration in young mdx mice. Up-regulating this pathway may have clinical significance for DMD.

Re-engaging learners in schooling through applied learning reform : exploring the Victorian Certificate of Applied Learning as an 'alternative' senior schooling pathway in Australia

The Victorian Certificate of Applied Learning (VCAL) emerged in Australia to provide more relevant curriculum programs that would cater for increasing retention rates of high school students. It is also an example of the ‘new’ learning arising from contemporary debates and reforms that highlight inadequacies of the more traditional modes of learning. This book focuses on the pedagogical and sociological issues emerging from the VCAL being introduced as an ‘alternative’ learning pathway for ‘at-risk’ students within a traditional high school culture. Through the eyes of an insider- researcher, the book argues for a deeper understanding of applied learning as a ‘re-engaging’ pedagogy by studying the schooling experience of VCAL students and teachers. The book concludes that traditional modes of school teaching contribute to the social construction of ‘at-risk’ students and argues that high school pedagogy needs to be redefined as a cultural phenomenon requiring teachers to be reflexively aware of their role in bridging the gap between students’ life experiences and the curriculum.

Acid drainage, limnology and bioremediation of western Victorian coal mine lakes

Rehabilitation of Alcoa's Anglesea open cut brown coal mine to a healthy lake has many environmental challenges. The study of regional acid drainage, limnology of Wenslydale Coal Mine Lake and passive bioremediation of acid mine water has shown that a healthy lake can be created.

Investigation of proton dynamics and the proton transport pathway in choline dihydrogen phosphate using solid-state NMR

Choline dihydrogen phosphate has previously been shown to be a good ionic conductor as well as an excellent host for acid doping, leading to high proton conductivities required for e.g., electrochemical devices including proton membrane fuel cells and sensors. A combination of variable-temperature ¹H solid-state NMR and 2D NMR pulse sequences, including ³¹P and ¹³C CODEX and ¹H BaBa, show that the proton conduction mechanism primarily involves assisted transport via a restricted three-site motion of the phosphate unit around the P–O bond that is hydrogen bonded to the choline and exchange of protons between these anions. In other words, proton transport at ambient temperatures appears to occur most favorably along the crystallographic b axis, from phosphate dimer to dimer. At elevated temperatures exchange between the protons of the hydroxyl group on the choline cation and the hydrogen-bonded dihydrogen phosphate groups also contributes to the structural diffusion of the protons in this solid state conductor.

An evaluation of a mental health screening and referral pathway for community nursing care : nurses' and general practitioners' perspectives

Aims and objectives. To evaluate a feasible, best practice mental health screening and referral clinical pathway for generalist community nursing care of war veterans and war widow(er)s in Australia.
Background. War veterans commonly experience mental health difficulties and do not always receive required treatment, as can also occur for war widow(er)s. Whenever opportunity arises, such as during community nursing care, it is vital to identify mental health problems in a health promotion framework.
Design. A clinical pathway was developed by literature review and consultation and then trialled and evaluated using mixed methods – quantitative and qualitative.
Methods. Community nurses who trialled the pathway completed an evaluation survey and attended focus groups. General practitioners responded to an evaluation survey.
Results. Most nurses found the pathway clear and easy to understand but not always easy to use. They emphasised the need to establish trust and rapport with clients prior to implementing the pathway. It was sometimes difficult to ensure effective referral to general practitioners for clients who screened positive for a mental health problem. When referral was accomplished, general practitioners reported adequate and useful information was provided. Some general practitioners also commented on the difficulty of achieving effective communication between general practitioners and nurses.
Conclusions. Nurses and some general practitioners found the pathway useful for their practice. They offered several suggestions for improvement by simplifying the trialled pathway and accompanying guidelines and strategies to improve communication between nurses and general practitioners. This study adds understanding of how community nurses might productively screen for mental health difficulties.
Relevance to clinical practice. The trialled pathway, which was modified and refined following the study, is an evidence-based
resource for community nurses in Australia and similar contexts to guide practise and maximise holistic care for war veterans and war widow(er)s and possibly other client groups.

A pathway to enhancing professionalism: building a bridge between TAFE and university early childhood qualifications

It has been argued that a key strategy to improve developmental and educational outcomes for young children is to increase the number of childcare staff with early childhood university degrees (Saracho & Spodek, 2007). In order to upgrade the qualifications of staff, a number of Australian universities provide pathways that enable graduates of early childhood diploma programs to complete a degree. Several impediments, including institutional structures and individual contextual and personal factors, may affect these pathways. Although a range of organisations offer diploma programs, TAFE (Tertiary and Further Education) is a major provider. The aim of the present study was to investigate student transition between early childhood programs in TAFE and university. The research drew on several data sources, including a survey of the perceptions of students at various points of undertaking the transition. The current credit arrangement for TAFE Diploma graduates was found to be satisfactory; however, gaps were identified between the TAFE and university teaching and learning arrangements with regard to curriculum structures, teaching styles and assessment. Graduates of both programs considered that the completion of both awards would have a positive effect on their careers.

A reverse pathway? Actual and perceived skill proficiency and physical activity

Purpose: Motor skills are considered a prerequisite to physical activity, yet the relationship may be reciprocal and perceived sports competence might mediate associations.
Methods: In 2006/2007, 215 adolescents completed motor skill proficiency (Get Skilled Get Active), perceived sport competence (Physical Self-Perception Profile) and physical activity assessments (Adolescent Physical Activity Recall Questionnaire) as part of the Physical Activity and Skills Study. Using AMOS (Version 7.0), reciprocal relationships were examined between motor skill (object control and locomotor) and moderate to vigorous physical activity (MVPA). Both models were then run in different versions to understand the role of perceived sports competence as a potential mediator.
Results: Mean age was 16.4 yr (SD = 0.6), 51.6% (111/215) were females. A reciprocal relationship between object control and MVPA and a one-way relationship from MVPA to locomotor skill was found. When perceived sports competence was examined as a mediator, the best-fitting model versions explained 16% (R² = 0.16)
MVPA variation, and 30% object control (R² = 0.30), and 12% locomotor skill variation (R² = 0.12) (reverse relationship). Perceived sports competence partially mediates the relationship between object control proficiency and physical activity for both directions and fully mediates the relationship between physical activity and locomotor skill; but only when locomotor skill is the outcome.
Conclusions: If the relationship between object control skill and physical activity is viewed as a ‘‘positive feedback loop,’’ skill development and increasing physical activity should simultaneously be targeted in physical activity interventions. Increasing perceived sport competence should also be an intervention focus.