Adenosine-5′-phosphosulfate - a multifaceted modulator of bifunctional 3′-phospho-adenosine-5′-phosphosulfate synthases and related enzymes

All sulfation reactions rely on active sulfate in the form of 3′-phosphoadenosine-5′-phosphosulfate (PAPS). In fungi, bacteria, and plants, the enzymes responsible for PAPS synthesis, ATP sulfurylase and adenosine-5′-phosphosulfate (APS) kinase, reside on separate polypeptide chains. In metazoans, however, bifunctional PAPS synthases catalyze the consecutive steps of sulfate activation by converting sulfate to PAPS via the intermediate APS. This intricate molecule and the related nucleotides PAPS and 3′-phospho-adenosine-5′-phosphate modulate the function of various enzymes from sulfation pathways, and these effects are summarized in this review. On the ATP sulfurylase domain that initially produces APS from sulfate and ATP, APS acts as a potent product inhibitor, being competitive with both ATP and sulfate. For the APS kinase domain that phosphorylates APS to PAPS, APS is an uncompetitive substrate inhibitor that can bind both at the ATP/ADP binding site and the PAPS/APS-binding site. For human PAPS synthase 1, the steady-state concentration of APS has been modelled to be 1.6 lM, but this may increase up to 60 lM under conditions of sulfate excess. It is noteworthy that the APS concentration for maximal APS kinase activity is 15 lM. Finally, we recognized APS as a highly specific stabilizer of bifunctional PAPS synthases. APS most likely stabilizes the APS kinase part of these proteins by forming a dead-end enzyme–ADP–APS complex at APS concentrations between 0.5 and 5 lM; at higher concentrations, APS may bind to the catalytic centers of ATP sulfurylase. Based on the assumption that cellular concentrations of APS fluctuate within this range, APS can therefore be regarded as a key modulator of PAPS synthase functions

Photography, Knowledge and the South Kensington Museum

This thesis argues that the South Kensington Museum, through its governing body the Department of Science and Art and its neighbouring institutions in Albertopolis, formed a sophisticated photographic infrastructure. The photographic infrastructure extended beyond the official remit of the Museum and embedded it within wider structures of state power and imperialism. The pivotal roles in this infrastructure of the Royal Engineers barracked at the Museum created what I term a military-cultural complex. Comprehending the photographic infrastructure necessitates understanding Albertopolis as a totalizing entity formed of smaller institutions and societies across the arts and sciences. Albertopolis’s inhabitants interacted in personal, practical and political ways. I show the involvement of the Royal School of Science (now Imperial College London) and the National Art Training School (now the Royal College of Art) in the photographic infrastructure. I discuss how, through the Royal School of Science, key figures such as Thomas Henry Huxley, Francis Galton, William de Wiveleslie Abney, Norman Lockyer and H.G.Wells were present within the Museum complex and involved in the photographic infrastructure. Through this photographic infrastructure, the South Kensington Museum was involved in both cultural diplomacy and knowledge synthesis, and new hybrid technologies were developed. I argue that photographs were extended’ through methods such as hand-painting, photomechanical reproduction and projection. The National Art Training School students were the audience for the Museum’s photography collection, and their later careers in press illustration indicate how the ‘South Kensington System’ was disseminated. I examine how the products of the photographic infrastructure were used as political objects by the Museum’s first director Henry Cole, using a case study of photography of the Raphael Cartoons. I show how the photographic training of the Royal Engineers was deployed globally to gather state information, and how photographs made and/or collated at the Museum were used to bolster the position of the British Empire. In this regard I discuss the presence of the Palestine Exploration Fund and the Solar Physics Observatory at the Museum. Through a case study analysing photographs of two men from the Torres Strait, Garicha and Boyguda, I show how the Museum shaped public opinion on race and science as well as art and taste. Since the 1850s, photographs at the Museum have been relegated, ‘submerged’ and rediscovered. This thesis analyses the Victoria and Albert Museum (V&A) Photography Collection as an entity and the wide-reaching effects of the Museum’s photographic infrastructure.Arts and Humanities Research Counci

Luminescence tuning of MOFs via ligand to metal and metal to metal energy transfer by co-doping of 2∞[Gd2Cl6(bipy)3]*2bipy with europium and terbium

The series of anhydrous lanthanide chlorides LnCl3, Ln=Pr–Tb, and 4,4'-bipyridine (bipy) constitute isotypic MOFs of the formula 2∞[Ln2Cl6(bipy)3]*2bipy. The europium and terbium containing compounds both exhibit luminescence of the referring trivalent lanthanide ions, giving a red luminescence for Eu3+ and a green luminescence for Tb3+ triggered by an efficient antenna effect of the 4,4'-bipyridine linkers. Mixing of different lanthanides in one MOF structure was undertaken to investigate the potential of this MOF system for colour tuning of the luminescence. Based on the gadolinium containing compound, co-doping with different amounts of europium and terbium proves successful and yields solid solutions of the formula 2∞[Gd2-x-yEuxTbyCl6(bipy)3]*2bipy (1–8), 0≤x, y≤0.5. The series of MOFs exhibits the opportunity of tuning the emission colour in-between green and red. Depending on the atomic ratio Gd:Eu:Tb, the yellow region was covered for the first time for an oxygen/carboxylate-free MOF system. In addition to a ligand to metal energy transfer (LMET) from the lowest ligand-centered triplet state of 4,4'-bipyridine, a metal to metal energy transfer (MMET) between 4f-levels from Tb3+ to Eu3+ is as well vital for the emission colour. However, no involvement of Gd3+ in energy transfers is observed rendering it a suitable host lattice ion and connectivity centre for diluting the other two rare earth ions in the solid state. The materials retain their luminescence during activation of the MOFs for microporosity

Application of metal − organic frameworks

The burgeoning field of metal-organic frameworks or porous coordination polymers has received increasing interest in recent years. In the last decade these microporous materials have found several applications including storage and separation of gases, sensors, catalysis and functional materials. In order to better design new metal-organic frameworks and porous coordination polymers with specific functionalities a fundamental issue is to achieve a basic understanding of the relationship between molecular parameters and structures, preferred adsorption sites and properties by using using modern theoretical methods. The focus of this mini-review is a description of the potential and emerging applications of metal-organic framework

Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action

International audienceIntegrated high-resolution maps of carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits. A new integrated approach to biodiversity is therefore needed. Here, we (a) present a new high-resolution map of global above- and below-ground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and (c) examine patterns of carbon–biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. The western Amazon Basin, Central Africa and Southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been greatly reduced are mostly found in the tropical Andes and central Sundaland. There is 38 and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12 and 21% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactnes

Global Metrics for Terrestrial Biodiversity

Biodiversity metrics are increasingly in demand for informing government, business, and civil society decisions. However, it is not always clear to end users how these metrics differ or for what purpose they are best suited. We seek to answer these questions using a database of 573 biodiversity-related metrics, indicators, indices, and layers, which address aspects of genetic diversity, species, and ecosystems. We provide examples of indicators and their uses within the state–pressure–response–benefits framework that is widely used in conservation science. Considering complementarity across this framework, we recommend a small number of metrics considered most pertinent for use in decision-making by governments and businesses. We conclude by highlighting five future directions: increasing the importance of national metrics, ensuring wider uptake of business metrics, agreeing on a minimum set of metrics for government and business use, automating metric calculation through use of technology, and generating sustainable funding for metric production

A political ecology of REDD+: property rights, militarised protectionism, and carbonised exclusion in Cross River

This paper offers a critical assessment of REDD+ in Nigeria through a political ecology perspective. Focusing on questions of property rights and resource access, it maps the discursive articulations and contestations through which carbon rights are being determined. It also shows how these articulations and contestations are linked to land and forest rights, and how they shape everyday access to the forest. Evidence from the Nigerian case suggests that factors that complicate rights and undermine access to resources for forest communities under REDD+ are immanent to the contested terrain constituted in part by REDD+ proposals, proponents’ discourses and practices geared towards securing the forest for REDD+. Efforts to secure property rights and guarantee the permanence of REDD+ forests align with economic, ecological and ideological aspirations of state and non-state actors to produce a regime of militarised protectionism. I demonstrate how, in addition to its material and symbolic facilitation of the emergent carbon forestry economy, militarised protectionism as a regime of exclusion also constitutes collateral political economies of ‘more-than-carbon’ forest resources (such as timber and non-timber forest products) which perpetuate capital accumulation by the elites. It is this kind of exclusion–accumulation dialectic legitimised by carbon forestry claims that this paper describes as carbonised exclusion. The paper thus furthers debates on the political ecology of REDD+ and other carbon forestry projects, while productively engaging technocentric literature on REDD+ and property rights