Mine waste beach profile and flow resistance equations

Four mine waste beach longitudinal profile equations are compared theoretically and in statistical analyses of profile data from 64 field and laboratory beaches formed by mine tailings, co-disposed coal mine wastes, and sand. All four equations fit the profile data well. The best performing equation both accounts for particle sorting and satisfies hydraulic constraints, and the combination of assumptions underlying it is considered to best represent the processes occurring on mine waste beaches. Combining these assumptions with the Lacey normal equation leads to a variant of the Manning resistance equation. Features that it is desirable to incorporate in theoretical and numerical models of mine waste beaches are listed.

Gymnoascolides A-C: Aromatic butenolides from an Australian isolate of the soil ascomycete Gymnoascus reessii

Three new aromatic butenolides, gymnoascolides A-C (1-3), have been isolated from the Australian soil ascomycete Gymnoascus reessii and assigned structures on the basis of detailed spectroscopic analysis. The absolute configurations of gymnoascolides B (2) and C (3) at C-5 were solved using a combination of chemical derivatization and quantum chemical simulations.

Calbistrin E and two other new metabolites from an Australian isolate of Penicillium striatisporum

An Australian isolate of Penicillium striatisporum collected near Shalvey, New South Wales, exhibited selective antifungal activity against Candida albicans versus Saccharomyces cerevisiae. Bioassay-directed fractionation yielded members of the rare class of fungal metabolites known as the calbistrins. These included a new example of this structure class, calbistrin E (1), as well as the known polyenes calbistrin C (2) and deformylcalbistrin A (3). Also recovered from P. striatisporum were new triene and butenolide acids, striatisporin A (4) and striatisporolide A (5), together with the known fungal metabolites versiol (6) and (+)-hexylitaconic acid (7). Structures for all metabolites were determined by detailed spectroscopic analysis.

(-)-echinobetaine A: Isolation, structure elucidation, synthesis, and SAR studies on a new nematocide from a southern Australian marine sponge, Echinodictyum sp.

A nematocidal agent present in a southern Australian marine sponge of the genus Echinodictyum has been isolated and identified by detailed spectroscopic analysis and total synthesis as the novel betaine (-)-echinobetaine A (6). Preliminary SAR investigations have been undertaken.

(+)-Echinobetaine B: isolation, structure elucidation, synthesis and preliminary SAR studies on a new nematocidal betaine from a southern Australian marine sponge, Echinodictyum sp.

The principle nematocidal agent present in a southern Australian marine sponge of the genus Echinodictyum has been isolated and identfied as the novel betaine (+)-echinobetaine B (6), and the structure assigned by spectroscopic analysis has been confirmed by total synthesis. Preliminary SAR conclusions are drawn from analysis of synthetic intermediates and the known marine metabolites zooanemonin (12) and norzooanemonin (13), and the new sponge metabolite norzooanemonin methyl ester (14). The latter compound is reported for the first time from a selection of Australian sponges, including an Axinyssa sp., a Niphates sp., an Axinella sp. and a Ptilocaulis sp.

Aspergillazines A-E: novel heterocyclic dipeptides from an Australian strain of Aspergillus unilateralis

Biological and chemical pro ling of an Australian strain of the fungus Aspergillus unilateralis (MST-F8675), isolated from a soil sample collected near Mount Isa, Queensland, revealed a complex array of metabolites displaying broad chemotherapeutic properties. Noteworthy among these metabolites were a unique series of highly modified dipeptides aspergillazines A-E, incorporating a selection of unprecedented and yet biosynthetically related heterocyclic systems. Co-occurring with the aspergillazines was the recently described marine-derived fungal metabolite trichodermamide A (cf. penicillazine), whereas re-fermentation of A. unilateralis in NaCl (1%) enriched media resulted in co-production of the only other known example of this structure class, the marine-derived fungal metabolite trichodermamide B. Further investigation of A. unilateralis returned the known terrestrial fungal metabolite viridicatumtoxin as the cytotoxic and antibacterial principle, together with E-2-decenedioic acid, ferulic acid, (7E,7'E)-5,5'-diferulic acid and (7E,7'E)-8,5'-diferulic acid. The aromatic diacids have previously been reported from the chemical and enzymatic (esterase) treatment of plant cell wall material, with their isolation from A. unilateralis being their first apparent reported occurrence as natural products. Structures for all metabolites were determined by detailed spectroscopic analysis and, where appropriate, comparison to literature data and/or authentic samples.

Roquefortine E, a diketopiperazine from an Australian isolate of Gymnoascus reessii

The new isoprenylated diketopiperazine roquefortine E (6) has been isolated from an Australian soil isolate of the ascomycete Gymnoascus reessii. The known fungal metabolite roquefortine C (1) was also recovered as the major antibacterial principle, and all structures were assigned by detailed spectroscopic analysis.

Citrinin revisited: from monomers to dimers and beyond

Detailed chemical analysis of the solid phase fermentation of an Australian Penicillium citrinum isolate has returned the known compounds citrinin (1), phenol A acid (6), dihydrocitrinone (7) and dihydrocitrinin (8), together with a novel cytotoxic dimer, dicitrinin A (5). Dicitrinin A (5) was determined to be a dimerised artefact of the major co-metabolite citrinin, and its structure solved by spectroscopic analysis and chemical modi. cation. Analysis of the products encountered during the controlled decomposition of citrinin led to the discovery of additional citrinin dimers and delineated a plausible mechanistic pathway linking all monomeric and dimeric citrinin degradation products.

Isokibdelones: Novel heterocyclic polyketides from a Kibdelosporangium sp.

The isokibdelones are an unprecedented family of polyketides produced by an Australian isolate of a rare actinomycete, Kibdelosporangium sp. The structures of the isokibdelones were assigned by spectroscopic analysis and chemical interconversion. A proposed biosynthesis requires a novel molecular twist that generates an unprecedented heterocyclic system and differentiates the isokibdelones from their kibdelone co-metabolites. SAR analysis on the isokibdelones further defines the anticancer pharmacophore of these novel polyketides.

Polyenylpyrroles and polyenylfurans from an Australian isolate of the soil ascomycete Gymnoascus reessii

An Australian isolate of the soil ascomycete Gymnoascus reessii yielded a series of cytotoxic metabolites, including the known polyenylpyrroles rumbrin (1) and auxarconjugatin A (2), and the new rumbrin stereoisomer 12E-isorumbrin (3), as well as an unprecedented class of polyenylfurans exemplified by gymnoconjugatins A (4) and B (5). Structures were assigned with detailed spectroscopic analysis.

Quinolactacins revisited: from lactams to imide and beyond

Chemical analysis of a solid phase fermentation of an Australian Penicillium citrinum strain has returned all known examples of a rare class of N-methyl quinolone lactams, quinolactacins A2 (1), B2 (2), C2 (3) and Al (4), together with the new quinolactacins B1 (5), C1 (6), D1 (7) and D2 (8), and the novel derivatives quinolonimide (9) and quinolonic acid (10). Complete stereostructures were assigned to all these compounds by detailed spectroscopic analysis and chemical interconversion. Carefully controlled and monitored decomposition studies have confirmed that quinolactacins readily undergo C-3 epimerization and oxidation, and under appropriate conditions convert to quinolonimide and quinolonic acid. Mechanisms for key transformations are proposed. The decomposition studies suggested that only quinolactacins A2 (1) and B2 (2) are genuine natural products, with all other isolated compounds being decomposition artefacts. Quinolactacins C1 (6), C2 (3), and the racemic mixture of quinolactacins D1/D2 (8/7) all displayed notable cytotoxic activity.

Doom and gloom or a time for optimism: Potential aspirants' views about school leadership - now and for the future

Principal recruitment has attracted national and international attention in recent years (eg. Barty et al, 2005 in Australia; Earley et al, 2002 in the UK; Brooking et al, 2003 in New Zealand; Williams, 2003 in Canada). Importantly, Australian research in both state and non-state schools suggests that potential principal aspirants are less enthusiastic than might be expected in their desire to become principals (D’Arbon et al, 2002; Cranston et al, 2004; Lacey, 2002). Given the importance of ensuring we have quality leaders for our schools in the future, the research reported here (which is on-going) examined the views of potential aspirants (primary and secondary deputy principals) from one large government education system in Australia about the principalship and their intentions in seeking promotion (or otherwise) to such positions and the reasons driving these intentions. Data were collected via the Aspiring Principals Questionnaire (APQ) – especially developed for the study – comprising 38 closed items mainly of a Likert-type format, 5 open-ended items linked to particular closed items allowing participants to add their own suggestions/ideas, expand/elaborate on responses; and 4 further more general open-ended items. A number of system-level policy and practice recommendations have been developed from the findings.