107 research outputs found

    Towards a risk register for natural capital

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    1. Natural capital is essential for goods and services on which people depend. Yet pressures on the environment mean that natural capital assets are continuing to decline and degrade, putting such benefits at risk. Systematic monitoring of natural assets is a major challenge that could be both unaffordable and unmanageable without a way to focus efforts. Here we introduce a simple approach, based on the commonly used management tool of a risk register, to highlight natural assets whose condition places benefits at risk. 2. We undertake a preliminary assessment using a risk register for natural capital assets in the UK based solely on existing information. The status and trends of natural capital assets are assessed using assetā€“benefit relationships for ten kinds of benefits (food, fibre (timber), energy, aesthetics, freshwater (quality), recreation, clean air, wildlife, hazard protection and equable climate) across eight broad habitat types in the UK based on three dimensions of natural capital within each of the habitat types (quality, quantity and spatial configuration). We estimate the status and trends of benefits relative to societal targets using existing regulatory limits and policy commitments, and allocate scores of high, medium or low risk to assetā€“benefit relationships that are both subject to management and of concern. 3. The risk register approach reveals substantial gaps in knowledge about assetā€“benefit relationships which limit the scope and rigour of the assessment (especially for marine and urban habitats). Nevertheless, we find strong indications that certain assets (in freshwater, mountain, moors and heathland habitats) are at high risk in relation to their ability to sustain certain benefits (especially freshwater, wildlife and climate regulation). 4. Synthesis and applications. With directed data gathering, especially to monitor trends, improve metrics related to assetā€“benefit relationships, and improve understanding of nonlinearities and thresholds, the natural capital risk register could provide a useful tool. If updated regularly, it could direct monitoring efforts, focus research and protect and manage those natural assets where benefits are at highest risk

    Calibration of the channel that determines the omega-hydroxylation regiospecificity of cytochrome P4504A1 - Catalytic oxidation of 12-halododecanoic acids

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    The fatty acid omega-hydroxylation regiospecificity of CYP4 enzymes may result from presentation of the terminal carbon to the oxidizing species via a narrow channel that restricts access to the other carbon atoms. To test this hypothesis, the oxidation of 12-iodo-, 12-bromo-, and 12-chlorododecanoic acids by recombinant CYP4A1 has been examined. Although all three 12-halododecanoic acids bind to CYP4A1 with similar dissociation constants, the 12-chloro and 12-bromo fatty acids are oxidized to 12-hydroxydodecanoic acid and 12-oxododecanoic acid, whereas the 12-iodo analogue is very poorly oxidized. Incubations in (H2O)-O-18 show that the 12-hydroxydodecanoic acid oxygen derives from water, whereas that in the aldehyde derives from O-2. The alcohol thus arises from oxidation of the halide to an oxohalonium species that is hydrolyzed by water, whereas the aldehyde arises by a conventional carbon hydroxylation-elimination mechanism. No irreversible inactivation of CYP4A1 is observed during 12-halododecanoic acid oxidation. Control experiments show that CYP2E1, which has an omega-1 regiospecificity, primarily oxidizes 12-halododecanoic acids to the omega-aldehyde rather than alcohol product. Incubation of CYP4A1 with 12,12-[H-2](2)-12-chlorododecanoic acid causes a 2-3-fold increase in halogen versus carbon oxidation. The fact that the order of substrate oxidation (Br > Cl >> I) approximates the inverse of the intrinsic oxidizability of the halogen atoms is consistent with presentation of the halide terminus via a channel that accommodates the chloride and bromide but not iodide atoms, which implies an effective channel diameter greater than 3.90 angstrom but smaller than 4.30 angstrom

    Intercultural ethics: questions of methods in language and intercultural communication

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    This paper explores how questions of ethics and questions of method are intertwined and unavoidable in any serious study of language and intercultural communication. It argues that the focus on difference and solution orientations to intercultural conflict has been a fundamental driver for theory, data collection and methods in the field. These approaches, the paper argues, have created a considerable consciousness raising industry, with methods, trainings and ā€˜critical incidentsā€™, which ultimately focus intellectual energy in areas which may be productive in terms of courses and publications but which have a problematic basis in their ethical terrain. Dieser Artikel untersucht wie ethische und methodische Fragen nicht nur ineinander greifen, sondern in keiner ernstzunehmenden Studie ueber Sprache und interkulturelle Kommunikation ausgelassen werden duerfen. Es wird hier argumentiert, dass der Schwerpunkt auf Verschiedenheit und Problemorientierung im interkulturellen Konflikt einen wesentlichen Einfluss auf theoretische Entwicklungen, Datenerhebung und Methoden in diesem Bereich hatte. Dieser Artikel legt auch dar, wie diese Ansaetze eine betraechtliche ā€˜Bewusstseinsbildungs ā€“ Branche' erzeugt haben, mit Methoden, Trainings, und ā€˜kritischen Interaktionssituationenā€™, welche letztendlich allen intellektuellen Arbeitseifer auf Bereiche konzentriert hat, die zwar ertragreich sind in Bezug auf Kurse und Publikationen, jedoch eine problematische Grundlage im ethischen Bereich aufweisen

    Coulomb explosion imaging of small organic molecules at LCLS.

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    Fragmentation of small organic molecules by intense few-femtosecond X-ray free-electron laser pulses has been studied using Coulomb explosion imaging. By measuring kinetic energies and emission angles of the ionic fragments in coincidence, we disentangle different fragmentation pathways, for certain cases can reconstruct molecular geometry at the moment of explosion, and show how it depends on LCLS pulse duration

    Is the ferric hydroperoxy species responsible for sulfur oxidation in cytochrome p450s?

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    Not the ferryl oxidant? The oxidation of thiafatty acids by P450BM3 (CYP102A1) was shown to be consistent with oxidation by the ferric hydroperoxy species (Cpd 0) rather than the expected ferryl species (Cpd 1). This is the first indication that sulfur oxidation in a wildtype P450 occurs via the hydroperoxy species

    Is the ferric hydroperoxy species responsible for sulfur oxidation in cytochrome p450s?

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    Not the ferryl oxidant? The oxidation of thiafatty acids by P450BM3 (CYP102A1) was shown to be consistent with oxidation by the ferric hydroperoxy species (Cpd 0) rather than the expected ferryl species (Cpd 1). This is the first indication that sulfur oxidation in a wildtype P450 occurs via the hydroperoxy species

    Carbon-carbon bond cleavage by P450 systems

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    Structural characterization of CYP165D3, a cytochrome P450 involved in phenolic coupling in teicoplanin biosynthesis

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    eicoplanin is a glycopeptide antibiotic with activity against Gramāˆ’positive bacteria and remains one of the last lines of clinical defense against certain bacterial infections. We have cloned, expressed, and purified the cytochrome P450 OxyE (CYP165D3) from the teicoplanin biosynthetic gene cluster of Actinoplanes teichomyceticus, which is responsible for the phenolic coupling of the aromatic side chains of the first and third peptide residues in the teicoplanin peptide. The crystal structure of OxyE has been determined to 2.5 ƅ resolution, revealing the probable binding surface for the carrier protein substrate and an extension of the active site into a pocket located above the Ī²āˆ’1 sheet. The binding of potential substrates to OxyE shows that peptidyl carrier proteināˆ’bound linear peptides bind to OxyE, albeit with low affinity in the absence of a phenolic crossāˆ’link that should normally be installed by another Oxy protein in the teicoplanin biosynthetic pathway. This result indicates that the carrier protein alone is not sufficient for tight substrate binding to OxyE and that the Oxy proteins sense the structure of the bound peptide in addition to the presence of the carrier protein, a feature distinct from other carrier protein/P450 system

    Products of Cytochrome P450BioI (CYP107H1)-Catalyzed Oxidation of Fatty Acids

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    [GRAPHICS] Oxidation of tetradecanoic and hexadecanoic acids by cytochrome P450(Biol) (CYP107H1) produces mainly the 11-, 12-, and 13-hydroxy C-14 fatty acids and the 11- to 15-hydroxy C-16 fatty acids, respectively. In contrast to previous reports, terminal hydroxylation is not observed. The enantiospecificity of fatty acid hydroxylation by P450(Biol) was also determined, and the enzyme was shown to be moderately selective for production of the (R)-alcohols

    A carbon-carbon bond cleaving enzyme involved in biotin biosynthesis

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