Melanin is a critical component of biological systems, but the exact chemistry of melanin is stil... more Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin's complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palet...
Melanin is a critical component of biological systems, but the exact chemistry of melanin is stil... more Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin's complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palet...
I can strongly recommend this book to anyone interested in the environmental chemistry of mercury... more I can strongly recommend this book to anyone interested in the environmental chemistry of mercury. The editors have done an excellent job of bringing together a number of well-written, up-to-date, and informative chapters from various experts to produce a thorough treatise on this environmentally important and unique element. My knowledge, understanding, and interest in Hg were all greatly enhanced by this book. Because the book covers an assortment of topics written by quite different specialists, I include a list of chapters with brief remarks on each section. 1. A brief history of Hg and its environmental impact , by M.B. Parsons and J.B. Percival. An interesting and well-written background chapter which is accessible, wide-ranging, well-referenced, and intriguing. A good introduction to Hg for undergraduates. 2. Geogenic and mining sources of Hg to the environment , by J. Rytuba. Clear, fairly basic but informative look at Hg sources. 3. Anthropogenic sources and global inventor...
Around the world large quantities of sludge wastes derived from nuclear energy production are cur... more Around the world large quantities of sludge wastes derived from nuclear energy production are currently kept in storage facilities. In the UK, the British government has marked sludge removal as a top priority as these facilities are nearing the end of their operational lifetimes. Therefore chemical understanding of uranium uptake in Mg-rich sludge is critical for successful remediation strategies. Previous studies have explored uranium uptake by the calcium carbonate minerals, calcite and aragonite, under conditions applicable to both natural and anthropogenically perturbed systems. However, studies of the uptake by Mg-rich minerals such as brucite [Mg(OH)2], nesquehonite [MgCO3·3H2O] and hydromagnesite [Mg5(CO3)4(OH)2·4H2O], have not been previously conducted. Such experiments will improve our understanding of the mobility of uranium and other actinides in natural lithologies as well as provide key information applicable to nuclear waste repository strategies involving Mg-rich pha...
The detailed chemical analysis of fossils has the potential to reveal great insight to the compos... more The detailed chemical analysis of fossils has the potential to reveal great insight to the composition, preserva-tion and biochemistry of ancient life. Such analyses would ideally identify, quantify, and spatially resolve the chemical composition of preserved bone and soft tissue structures, but also the embedding matrix. Mapping the chemistry of a fos-sil in situ can place constraints on mass transfer between the enclosing matrix and the preserved organism(s), and there-fore aid in distinguishing taphonomic processes from origi-nal chemical zonation remnant within the fossils themselves. Conventional analytical methods, such as scanning electron microscopy (SEM) and pyrolysis–gas chromatography/mass
This copy is for your personal, non-commercial use only. clicking here.colleagues, clients, or cu... more This copy is for your personal, non-commercial use only. clicking here.colleagues, clients, or customers by, you can order high-quality copies for yourIf you wish to distribute this article to others here.following the guidelines can be obtained byPermission to republish or repurpose articles or portions of articles): December 25, 2012 www.sciencemag.org (this information is current as of The following resources related to this article are available online at
1411. Figure 1 – FTIR spectra of a) olivine and b) enstatite from Manchester Museum and ISAR. c) ... more 1411. Figure 1 – FTIR spectra of a) olivine and b) enstatite from Manchester Museum and ISAR. c) Miyake Jima anorthite showing the spectral variations due to orientation. d) an FTIR image following PCA analysis to visualize the orientation variations of anorthite in a Shawmere anorthosite. 2138.pdf 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083)
Mass transport by aqueous fluids is a dynamic process in shallow crustal systems, redistributing ... more Mass transport by aqueous fluids is a dynamic process in shallow crustal systems, redistributing nutrients as well as contaminants. Rock matrix diffusion into fractures (void space) within crystalline rock has been postulated to play an important role in the transient storage of solutes. The reacted volume of host rock involved, however, will be controlled by fluid-rock reactions. Here we present the results of a study which focusses on defining the length scale over which rock matrix diffusion operates within crystalline rock over timescales that are relevant to safety assessment of radioactive and other long-lived wastes. Through detailed chemical and structural analysis of natural specimens sampled at depth from an active system (Toki Granite, Japan), we show that, contrary to commonly proposed models, the length scale of rock matrix diffusion may be extremely small, on the order of centimetres, even over timescales of millions of years. This implies that in many cases the import...
Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ide... more Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatog...
This work is part of a project to build an infrared database in order to link IR data of planetar... more This work is part of a project to build an infrared database in order to link IR data of planetary materials (and therefore possible Mercury material) with remote sensing observations of Mercury, which will probably be obtained by the MERTIS instrument on the forthcoming BepiColombo mission.The unique achondrite Northwest Africa (NWA) 7325, which has previously been suggested to represent the first sample from Mercury, was investigated by optical and electron microscopy, and infrared and Raman spectroscopy. In addition, the oxygen, strontium, xenon, and argon isotopes were measured and the abundance of selected trace elements determined. The meteorite is a cumulate rock with subchondritic abundances of HFSE and REE and elevated Sr contents, which underwent a second heating and partial remelting process. Oxygen isotope measurements show that NWA 7325 plots in the ureilite field, close to the ALM-A trachyandesitic fragment found in the unique Almahata Sitta meteorite breccia. On the other hand, mineralogical investigations of the pyroxenes in NWA 7325 provide evidence for similarities to the lodranites and acapulcoites. Furthermore, the rock is weakly shocked and argon isotope data record ancient (~4.5 Ga) plateau ages that have not been reset. The sample records a cosmogenic exposure age of~19 Ma. Systematics of Rb-Sr indicate an extreme early volatile depletion of the precursor material, similar to many other achondrite groups. However, despite its compositional similarities to other meteorite groups, our results suggest that this meteorite is unique and unrelated to any other known achondrite group. An origin for NWA 7325 as a sample from the planet Mercury is not supported by the results of our investigation. In particular, the evidence from infrared spectroscopy indicates that a direct relationship between NWA 7325 and the planet Mercury can be ruled out: no acceptable spectral match between laboratory analyses and remote sensing observations from Mercury has been obtained. However, we demonstrate that infrared spectroscopy is a rapid and nondestructive method to characterize mineral phases and thus an excellent tool for planetary surface characterization in space missions.
Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ide... more Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multimodal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pinkred) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since
Industrialization rates in many developing countries typically outpace investment in water supply... more Industrialization rates in many developing countries typically outpace investment in water supply, sewage treatment and other waste water facilities. This is futher compounded by the absence of stringent land-use and waste disposal policies. The consequence of this has been contamination of land, surface water, and groundwater in such areas. Efforts to control and remediate these types of systems will rely
... 2 , FR Livens 2 , RAD Pattrick 1 and RA Wogelius 1 1 Department of Earth Sciences, University... more ... 2 , FR Livens 2 , RAD Pattrick 1 and RA Wogelius 1 1 Department of Earth Sciences, University of Manchester, Manchester M13 9PL, England. ([email protected]) 2 Department of Chemistry, University of Manchester, Manchester M13 9PL, England. Two parts of the ...
Iron oxides resulting from the corrosion of large quantities of steel that are planned to be inst... more Iron oxides resulting from the corrosion of large quantities of steel that are planned to be installed throughout a deep geological disposal facility (GDF) are expected to be one of the key surfaces of interest for controlling radionuclide behaviour under disposal conditions. Over the lengthy timescales associated with a GDF, the system is expected to become anoxic so that reduced Fe(II) phases will dominate. Batch experiments have therefore been completed in order to investigate how a model reduced Fe-oxide surface (wüstite, Fe1–xO) alters as a function of exposure to aqueous solutions with compositions representative of conditions expected within a GDF. Additional experiments were performed to constrain the effect that highly alkaline solutions (up to pH 13) have on the adsorption behaviour of the uranyl (UO22+) ion onto the surfaces of both wüstite and portlandite [Ca(OH)2; representative of the expected cementitious phases]. Surface co-ordination chemistry and speciation were de...
Melanin is a critical component of biological systems, but the exact chemistry of melanin is stil... more Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin's complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palet...
Melanin is a critical component of biological systems, but the exact chemistry of melanin is stil... more Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin's complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palet...
I can strongly recommend this book to anyone interested in the environmental chemistry of mercury... more I can strongly recommend this book to anyone interested in the environmental chemistry of mercury. The editors have done an excellent job of bringing together a number of well-written, up-to-date, and informative chapters from various experts to produce a thorough treatise on this environmentally important and unique element. My knowledge, understanding, and interest in Hg were all greatly enhanced by this book. Because the book covers an assortment of topics written by quite different specialists, I include a list of chapters with brief remarks on each section. 1. A brief history of Hg and its environmental impact , by M.B. Parsons and J.B. Percival. An interesting and well-written background chapter which is accessible, wide-ranging, well-referenced, and intriguing. A good introduction to Hg for undergraduates. 2. Geogenic and mining sources of Hg to the environment , by J. Rytuba. Clear, fairly basic but informative look at Hg sources. 3. Anthropogenic sources and global inventor...
Around the world large quantities of sludge wastes derived from nuclear energy production are cur... more Around the world large quantities of sludge wastes derived from nuclear energy production are currently kept in storage facilities. In the UK, the British government has marked sludge removal as a top priority as these facilities are nearing the end of their operational lifetimes. Therefore chemical understanding of uranium uptake in Mg-rich sludge is critical for successful remediation strategies. Previous studies have explored uranium uptake by the calcium carbonate minerals, calcite and aragonite, under conditions applicable to both natural and anthropogenically perturbed systems. However, studies of the uptake by Mg-rich minerals such as brucite [Mg(OH)2], nesquehonite [MgCO3·3H2O] and hydromagnesite [Mg5(CO3)4(OH)2·4H2O], have not been previously conducted. Such experiments will improve our understanding of the mobility of uranium and other actinides in natural lithologies as well as provide key information applicable to nuclear waste repository strategies involving Mg-rich pha...
The detailed chemical analysis of fossils has the potential to reveal great insight to the compos... more The detailed chemical analysis of fossils has the potential to reveal great insight to the composition, preserva-tion and biochemistry of ancient life. Such analyses would ideally identify, quantify, and spatially resolve the chemical composition of preserved bone and soft tissue structures, but also the embedding matrix. Mapping the chemistry of a fos-sil in situ can place constraints on mass transfer between the enclosing matrix and the preserved organism(s), and there-fore aid in distinguishing taphonomic processes from origi-nal chemical zonation remnant within the fossils themselves. Conventional analytical methods, such as scanning electron microscopy (SEM) and pyrolysis–gas chromatography/mass
This copy is for your personal, non-commercial use only. clicking here.colleagues, clients, or cu... more This copy is for your personal, non-commercial use only. clicking here.colleagues, clients, or customers by, you can order high-quality copies for yourIf you wish to distribute this article to others here.following the guidelines can be obtained byPermission to republish or repurpose articles or portions of articles): December 25, 2012 www.sciencemag.org (this information is current as of The following resources related to this article are available online at
1411. Figure 1 – FTIR spectra of a) olivine and b) enstatite from Manchester Museum and ISAR. c) ... more 1411. Figure 1 – FTIR spectra of a) olivine and b) enstatite from Manchester Museum and ISAR. c) Miyake Jima anorthite showing the spectral variations due to orientation. d) an FTIR image following PCA analysis to visualize the orientation variations of anorthite in a Shawmere anorthosite. 2138.pdf 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083)
Mass transport by aqueous fluids is a dynamic process in shallow crustal systems, redistributing ... more Mass transport by aqueous fluids is a dynamic process in shallow crustal systems, redistributing nutrients as well as contaminants. Rock matrix diffusion into fractures (void space) within crystalline rock has been postulated to play an important role in the transient storage of solutes. The reacted volume of host rock involved, however, will be controlled by fluid-rock reactions. Here we present the results of a study which focusses on defining the length scale over which rock matrix diffusion operates within crystalline rock over timescales that are relevant to safety assessment of radioactive and other long-lived wastes. Through detailed chemical and structural analysis of natural specimens sampled at depth from an active system (Toki Granite, Japan), we show that, contrary to commonly proposed models, the length scale of rock matrix diffusion may be extremely small, on the order of centimetres, even over timescales of millions of years. This implies that in many cases the import...
Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ide... more Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatog...
This work is part of a project to build an infrared database in order to link IR data of planetar... more This work is part of a project to build an infrared database in order to link IR data of planetary materials (and therefore possible Mercury material) with remote sensing observations of Mercury, which will probably be obtained by the MERTIS instrument on the forthcoming BepiColombo mission.The unique achondrite Northwest Africa (NWA) 7325, which has previously been suggested to represent the first sample from Mercury, was investigated by optical and electron microscopy, and infrared and Raman spectroscopy. In addition, the oxygen, strontium, xenon, and argon isotopes were measured and the abundance of selected trace elements determined. The meteorite is a cumulate rock with subchondritic abundances of HFSE and REE and elevated Sr contents, which underwent a second heating and partial remelting process. Oxygen isotope measurements show that NWA 7325 plots in the ureilite field, close to the ALM-A trachyandesitic fragment found in the unique Almahata Sitta meteorite breccia. On the other hand, mineralogical investigations of the pyroxenes in NWA 7325 provide evidence for similarities to the lodranites and acapulcoites. Furthermore, the rock is weakly shocked and argon isotope data record ancient (~4.5 Ga) plateau ages that have not been reset. The sample records a cosmogenic exposure age of~19 Ma. Systematics of Rb-Sr indicate an extreme early volatile depletion of the precursor material, similar to many other achondrite groups. However, despite its compositional similarities to other meteorite groups, our results suggest that this meteorite is unique and unrelated to any other known achondrite group. An origin for NWA 7325 as a sample from the planet Mercury is not supported by the results of our investigation. In particular, the evidence from infrared spectroscopy indicates that a direct relationship between NWA 7325 and the planet Mercury can be ruled out: no acceptable spectral match between laboratory analyses and remote sensing observations from Mercury has been obtained. However, we demonstrate that infrared spectroscopy is a rapid and nondestructive method to characterize mineral phases and thus an excellent tool for planetary surface characterization in space missions.
Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ide... more Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multimodal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pinkred) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since
Industrialization rates in many developing countries typically outpace investment in water supply... more Industrialization rates in many developing countries typically outpace investment in water supply, sewage treatment and other waste water facilities. This is futher compounded by the absence of stringent land-use and waste disposal policies. The consequence of this has been contamination of land, surface water, and groundwater in such areas. Efforts to control and remediate these types of systems will rely
... 2 , FR Livens 2 , RAD Pattrick 1 and RA Wogelius 1 1 Department of Earth Sciences, University... more ... 2 , FR Livens 2 , RAD Pattrick 1 and RA Wogelius 1 1 Department of Earth Sciences, University of Manchester, Manchester M13 9PL, England. ([email protected]) 2 Department of Chemistry, University of Manchester, Manchester M13 9PL, England. Two parts of the ...
Iron oxides resulting from the corrosion of large quantities of steel that are planned to be inst... more Iron oxides resulting from the corrosion of large quantities of steel that are planned to be installed throughout a deep geological disposal facility (GDF) are expected to be one of the key surfaces of interest for controlling radionuclide behaviour under disposal conditions. Over the lengthy timescales associated with a GDF, the system is expected to become anoxic so that reduced Fe(II) phases will dominate. Batch experiments have therefore been completed in order to investigate how a model reduced Fe-oxide surface (wüstite, Fe1–xO) alters as a function of exposure to aqueous solutions with compositions representative of conditions expected within a GDF. Additional experiments were performed to constrain the effect that highly alkaline solutions (up to pH 13) have on the adsorption behaviour of the uranyl (UO22+) ion onto the surfaces of both wüstite and portlandite [Ca(OH)2; representative of the expected cementitious phases]. Surface co-ordination chemistry and speciation were de...
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