11 research outputs found
Landholder Typologies Used in the Development of Natural Resource Management Programs in Australia - A Review
This article reviews the literature on the identification of landholder typologies that can be used to assist the design and delivery of natural resource management (NRM) programs. Australian researchers have developed typologies of landholders based on a variety of criteria. The rationale for developing landholder typologies is first discussed before reviewing the various approaches that have been used by Australian researchers and comparing their findings. The methods employed have differed according to the theories used to guide the research and the 'clients' or 'sponsors' of the research. The landholder types they describe, however, have a number of similarities. These similarities suggest that the studies have identified the same fundamental divisions in the rural community, and that it may be possible to integrate landholder typologies for a variety of NRM and non-NRM applications. It is concluded that further research could usefully investigate whether concepts of social class or sub-cultures may be appropriate to define and describe the variations in landholder types
Prion protein-specific antibodies that detect multiple TSE agents with high sensitivity
This paper describes the generation, characterisation and potential applications of a panel of novel anti-prion protein monoclonal antibodies (mAbs). The mAbs were generated by immunising PRNP null mice, using a variety of regimes, with a truncated form of recombinant ovine prion protein spanning residues 94â233. Epitopes of specific antibodies were mapped using solid-phase Pepscan analysis and clustered to four distinct regions within the PrP molecule. We have demonstrated the utility of these antibodies by use of Western blotting and immunohistochemistry in tissues from a range of different species affected by transmissible spongiform encephalopathy (TSE). In comparative tests against extensively-used and widely-published, commercially available antibodies, similar or improved results can be obtained using these new mAbs, specifically in terms of sensitivity of detection. Since many of these antibodies recognise native PrPC, they could also be applied to a broad range of immunoassays such as flow cytometry, DELFIA analysis or immunoprecipitation. We are using these reagents to increase our understanding of TSE pathogenesis and for use in potential diagnostic screening assays
Cycloaddition Reactions of Cobalt-Complexed Macrocyclic Alkynes: The Transannular PausonâKhand Reaction
The PausonâKhand reaction
is a powerful tool for the synthesis
of cyclopentenones through the efficient [2 + 2 + 1] cycloaddition
of dicobalt alkyne complexes with alkenes. While intermolecular and
intramolecular variants are widely known, transannular versions of
this reaction are unknown and the basis of this study. Macrocyclic
enyne and dienyne complexes were readily synthesized by palladiumÂ(II)-catalyzed
oxidative macrocyclizations of bisÂ(vinyl boronate esters) or ring-closing
metathesis reactions followed by complexation with dicobalt octacarbonyl.
Several reaction modalities of these macrocyclic complexes were uncovered.
In addition to the first successful transannular PausonâKhand
reactions, other intermolecular and transannular cycloaddition reactions
included intermolecular PausonâKhand reactions, transannular
[4 + 2] cycloaddition reactions, intermolecular [2 + 2 + 2] cycloaddition
reactions, and intermolecular [2 + 2 + 1 + 1] cycloaddition reactions.
The structural and reaction requirements for each process are presented
Using Ring Strain to Control 4Ï-Electrocyclization Reactions: Torquoselectivity in Ring Closing of Medium-Ring Dienes and Ring Opening of Bicyclic Cyclobutenes
Syntheses of strained
cyclic dienes were accomplished via palladiumÂ(II)-catalyzed
oxidative cyclizations of terminal bisÂ(vinylboronate esters). The
reactions generate strained (<i>E</i>,<i>E</i>)-1,3-dienes that undergo spontaneous 4Ï-electrocyclizations
to form bicyclic cyclobutenes. Formation of the cyclobutenes is driven
by the strain in the medium-ring (<i>E,E</i>)-1,3-diene
intermediate. Thermal ring openings of the cyclobutenes give (<i>Z</i>,<i>Z</i>)-1,3-diene products, again for thermodynamic
reasons. DFT calculations verified the thermodynamic versus kinetic
control of the reactions, and kinetic studies are in excellent agreement
with the calculated energy changes. An extension of the tandem coupling/4Ï-electrocyclization
pathway was demonstrated by a palladiumÂ(II)-catalyzed oxidative homocoupling/8Ï-electrocyclization
cascade
Cyclization Strategies to Polyenes Using Pd(II)-Catalyzed Couplings of Pinacol Vinylboronates
As a complement to Pd(0)-catalyzed cyclizations, seven Pd(II)-catalyzed cyclization strategies are reported. α,Ï-Diynes are selectively hydroborated to bis(boronate esters), which cyclize under Pd(II)-catalysis producing a diverse array of small, medium, and macrocyclic polyenes with controlled <i>E,E</i>, <i>Z,Z</i>, or <i>E,Z</i> stereochemistry. Various functional groups are tolerated including aryl bromides, and applications are illustrated
Cyclization Strategies to Polyenes Using Pd(II)-Catalyzed Couplings of Pinacol Vinylboronates
As a complement to Pd(0)-catalyzed cyclizations, seven Pd(II)-catalyzed cyclization strategies are reported. α,Ï-Diynes are selectively hydroborated to bis(boronate esters), which cyclize under Pd(II)-catalysis producing a diverse array of small, medium, and macrocyclic polyenes with controlled <i>E,E</i>, <i>Z,Z</i>, or <i>E,Z</i> stereochemistry. Various functional groups are tolerated including aryl bromides, and applications are illustrated