653 research outputs found
One-loop renormalisation of general N=1/2 supersymmetric gauge theory
We investigate the one-loop renormalisability of a general N=1/2
supersymmetric gauge theory coupled to chiral matter, and show the existence of
an N=1/2 supersymmetric SU(N)xU(1) theory which is renormalisable at one loop.Comment: 30 pages, including 8 figures. Plain TeX. Uses Harvmac and eps
One-loop renormalisation of N=1/2 supersymmetric gauge theory with a superpotential
We construct a superpotential for the general N=1/2 supersymmetric gauge
theory coupled to chiral matter in the fundamental and adjoint representations,
and investigate the one-loop renormalisability of the theories.Comment: 67 pages, including 17 figures. Plain TeX. Uses Harvmac and epsf.
Combined and condensed version of hep-th/0607194 and hep-th/0607195 with some
added material including in particular a generalisation of the Lunin-Rey
classification of potentially divergent operator
A bittern (Aves: Ardeidae) from the Early Miocene of New Zealand
Author version made available in accordance with Publisher copyright policy
Inhibitor regulation of tissue kallikrein activity in the synovial fluid of patients with rheumatoid athritis
Tissue kallikrein (TK) and 1-antitrypsin (AT)/TK complexes can be detected in SF from patients with RA if components of the fluids which interfere with the detection of TK are removed. 2-Macroglobulin (2-M) in SF was demonstrated to contain trapped proteases which were still active in amidase assays. Removal of 2-M from RA SF reduced their amidase activity. However, at least some of the remaining activity was due to TK because it was soya bean trypsin inhibitor resistant and trasylol sensitive and was partly removed by affinity chromatography on anti-TK sepharose. Removal of RF from the fluids reduced the values obtained for TK levels by ELISA. Addition of SF to human urinary kallikrein (HUK) considerably reduced the levels of TK detected suggesting the presence of a TK ELISA inhibitor in the fluids. Removal of components of >300 kDa from SF markedly reduced the TK ELISA inhibitory activity and increased the values for both the TK and l-AT/TK levels in fluids as measured by ELISA. It is considered this novel inhibitor does not bind to the active site of TK but rather binds to the site reactive with anti-TK antibodies
The Use of Reversible Covalent Bonding and Induced Intramolecularity to Achieve Selectivity and Rate Acceleration in Organic Reactions
Thesis advisor: Kian L. TanChapter 1. Catalytic directing group, I, which was designed with the ability to form a reversible covalent bond with a substrate and bind a metal, was shown to direct the hydroformylation of allylic amines. The efficient regioselective hydroformylation of a variety of 1,2-disubstituted allylic sulfonamides to form β-amino-aldehydes under mild conditions has been shown. Chapter 2. Building off of the successful application of I, enantioenriched catalytic directing group, II, was designed and synthesized. It retained the essential features to direct hydroformylation to obtain good regioselectivity while also providing a chiral environment to induce absolute stereocontrol. Under mild conditions, a variety of disubstituted olefins react to give good yields and excellent enantioselectivites. Thus, the first enantioselective reaction performed with a catalytic directing group was demonstrated. Chapter 3. A new set of organocatalysts was developed that benefits from reversible covalent bonding and induced intramolecularity. The desymmetrization of meso-1,2-diols was accomplished using organocatalyst III, which was synthesized easily and cheaply. Experimental results indicate that the selectivity and increased reactivity are a result of the ability of III to pre-organize the substrate through a reversible, covalent bond. A variety of cyclic and acylic substrates were shown to react efficiently with good enantioselectivities under mild conditions. The catalyst's ability to functionalize cis-1,2-diols selectively indicated it might be successfully applied to site selective catalysis. Thus, the selective functionalization of a secondary alcohol in the presence of a primary alcohol was developed using a combination of binding selectivity and stereoselectivity. The (S)-enantiomer forms the secondary functionalized product while the (R)-enantiomer forms the primary functionalized product with high selectivity. As the enantiomers preferentially form different functionalized products, a regiodivergent reaction on a racemic mixture resulted giving two valuable enriched products.Thesis (PhD) — Boston College, 2013.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Chemistry
Early Miocene fossil frogs (Anura: Leiopelmatidae) from New Zealand.
Author version made available in accordance with publisher copyright policy.The first pre-Quaternary anurans from New Zealand are reported from the Early Miocene (19–16 Ma) St Bathans Fauna based on 10 fossil bones. Four bones representing two new species differing in size are described in Leiopelma: Leiopelmatidae, and are the first Tertiary records for the family. Six indeterminate frog fossils are morphologically similar to leiopelmatids and represent two species consistent in size with those known from diagnostic material. These records are highly significant, as minimally, they reduce the duration of the leiopelmatid ‘ghost lineage’ by c.20 million years and demonstrate that a diversity of leiopelmatids has long been present on New Zealand, supporting the ancient dichotomy of the extant species based on molecular data
Molecular basis for functional switching of GFP by two disparate non-native post-translational modifications of a phenyl azide reaction handle
Through the genetic incorporation of a single phenyl azide group into superfolder GFP (sfGFP) at residue 148 we provide a molecular description of how this highly versatile chemical handle can be used to positively switch protein function in vitro and in vivo via either photochemistry or bioconjugation. Replacement of H148 with p-azido-L-phenylalanine (azF) blue shifts the major excitation peak ∼90 nm by disrupting the H-bond and proton transfer network that defines the chromophore charged state. Bioorthogonal click modification with a simple dibenzylcyclooctyne or UV irradiation shifts the neutral-anionic chromophore equilibrium, switching fluorescence to the optimal ∼490 nm excitation. Click modification also improved quantum yield over both the unmodified and original protein. Crystal structures of both the click modified and photochemically converted forms show that functional switching is due to local conformational changes that optimise the interaction networks surrounding the chromophore. Crystal structure and mass spectrometry studies of the irradiated protein suggest that the phenyl azide converts to a dehydroazepine and/or an azepinone. Thus, protein embedded phenyl azides can be used beyond simple photocrosslinkers and passive conjugation handles, and mimic many natural post-translational modifications: modulation though changes in interaction networks
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