1366 research outputs found
Sort by
Effects of land use and soil properties on taxon richness and abundance of soil assemblages
No full textAbstract: Land‐use change and habitat degradation are among the biggest drivers of aboveground biodiversity worldwide but their effects on soil biodiversity are less well known, despite the importance of soil organisms in developing soil structure, nutrient cycling and water drainage. Combining a global compilation of biodiversity data from soil assemblages collated as part of the PREDICTS project with global data on soil characteristics, we modelled how taxon richness and total abundance of soil organisms have responded to land use. We also estimated the global Biodiversity Intactness Index (BII)—the average abundance and compositional similarity of taxa that remain in an area, compared to a minimally impacted baseline, for soil biodiversity. This is the first time the BII has been calculated for soil biodiversity. Relative to undisturbed vegetation, soil organism total abundance and taxon richness were reduced in all land uses except pasture. Soil properties mediated the response of soil biota, but not in a consistent way across land uses. The global soil BII in cropland is, on average, a third of that originally present. However, in grazed sites the decline is less severe. The BII of secondary vegetation depends on age, with sites with younger growth showing a lower BII than mature vegetation. We conclude that land‐use change has reduced local soil biodiversity worldwide, and this further supports the proposition that soil biota should be considered explicitly when using global models to estimate the state of biodiversity.Copyright © 2023 The Authors. European Journal of Soil Science published by John Wiley & Sons Ltd on behalf of British Society of Soil Science. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The linked file is the published version of the article.NHM Repositor
Origin of the Jadar Volcano-Sedimentary Li-B Deposit, Serbia
No full textAbstract: The Jadar deposit (Serbia) is a unique end member of the volcano-sedimentary Li deposit class, where the main ore mineral is jadarite (LiNaSiB3O7(OH)), to date only recorded at the Jadar locality. We provide the first account of the features of the Jadar deposit based on the study of drill hole material, complemented by petrographic analysis, whole-rock, and isotopic geochemistry. The Li-B mineralization is hosted by sediments interlayered with tuffs that were deposited in a fault-bounded lacustrine basin. Mineralization processes initially involved alteration of volcanic glass through near-neutral and heated meteoric fluids, which resulted in the formation of hectorite. Lithium clays were later overprinted by higher-pH brines, which underwent significant evaporation, combined with conditions of Na+ and SiO2(aq) saturation, resulting in formation of siliceous gels that were the precursors to jadarite formation and extensive zeolitization of the intrabasinal sediments. Formation of jadarite occurred in two stages: (1) early diagenesis accompanied by zeolitization and precipitation of primary dolomite, which resulted in the sediment-hosted Li mineralization, (2) late remobilization of Li(B-Na)–saturated fluids, leading to formation of epigenetic jadarite-albite infills of fractured rocks. Isotopic geochemistry combined with mineral chemistry proxies indicate that early mineralizing processes were largely dominated by diagenetic fluids that experienced a thermal influence from the coeval cooling of the Miocene S-type granite member of the nearby Cer Mountain Complex. Late thermal maturation of organic matter then resulted in acidic fluids that dissolved the early ore assemblage and led to formation of late diagenetic lithiophosphate and low-Na borates.Copyright © 2025 Society of Economic Geologists. Gold Open Access: This paper is published under the terms of the CC-BY license. The linked file is the published version of the article.NHM Repositor
Helminth fauna of the black goby Gobius niger L. (Gobiiformes: Gobiidae) from the Finnish Archipelago, Baltic Sea: Molecular and morphological data
Get PDFBlack gobies (Gobius niger) from the Finnish Archipelago, Baltic Sea, were screened for helminth infections in summer 2020. Helminths were identified morphologically and/or molecularly. Altogether 26 novel sequences were generated and analysed using maximum likelihood estimation. Morphological and phylogenetic analyses based on mitochondrial genes revealed the presence of 8 species belonging to the Digenea (Diplostomum mergi Lineage 3), Cestoda (Bothriocephalus scorpii), Nematoda (Contracaecum rudolphii A, Cucullanus sp. and Hysterothylacium aduncum), and Acanthocephala (a putative new species of Corynosoma, Corynosoma semerme and Neoechinorhynchus sp.). Phylogenetic and comparative sequence analyses revealed that the putative new acanthocephalan species is closely related to C. neostrumosum described from the Caspian seal, Pusa caspica, in the Caspian Sea. The black goby represents a new host record for four parasite species (Diplostomum mergi Lineage 3, Contracaecum rudolphii A, Corynosoma semerme and Corynosoma sp.). The Finnish Archipelago is a novel locality record for three species (Corynosoma sp., Diplostomum mergi Lineage 3 and Bothriocephalus scorpii).Copyright © 2023 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). The attached file is the published version of the article.NHM Repositor
Use of standard analytical tools to detect small amounts of smalt in the presence of ultramarine as observed in 15th-century Venetian illuminated manuscripts
No full textA previous preliminary study of 15th-century Venetian manuscript fragments by the Master of the Murano Gradual identified the presence of cobalt in many ultramarine blue areas, suggesting the presence of smalt. This would represent an early use of this glassy pigment in Venetian illuminated manuscripts. Whereas sampling has been used to identify smalt in 15th century paintings, only non-invasive methods can be used on manuscripts due to their small size and fragile nature. Here we investigated four non-invasive analysis techniques to identify small amounts of smalt in the presence of ultramarine, including single-point and scanning XRF spectroscopy, UV–vis-NIR-SWIR reflectance spectroscopy (FORS), Raman spectroscopy, and external reflection FT-IR spectroscopy. This was done by studying paint mock-ups of ultramarine and smalt mixtures with and without the presence of a white pigment on parchment. The results showed molecular spectroscopy techniques (reflectance, Raman, and FTIR) require at least ~ 30–40% smalt by percent mass when in the presence of ultramarine in order to detect its presence, whereas elemental XRF spectroscopy can detect cobalt (and thus infer the presence of smalt) at the ~ 1% level. To further explore the inference of smalt by XRF, additional XRF analysis was conducted to specifically look for elements associated with cobalt minerals (i.e. nickel, arsenic, bismuth, etc.). High spatial resolution XRF scanning (60–100 μm X-ray spot size) was used to look for cobalt in smalt particles which are typically larger than those of ultramarine. These two XRF analysis approaches worked well with the mock-up paint samples, and were subsequently applied to the manuscripts for which molecular spectroscopy methods yielded no unambiguous evidence for smalt. The data underscore the challenges of conclusively identifying smalt in complex paint systems when samples are not available, but do suggest that the Master of the Murano illuminated manuscript fragments contain smalt, but perhaps not in a form or amount researchers are used to seeing in paintings.Copyright © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. The linked file is the published version of the article.NHM Repositor
Non-Invasive Technical Investigation of English Portrait Miniatures Attributed to Nicholas Hilliard and Isaac Oliver
No full textThis study presents the results of the technical investigation carried out on several English portrait miniatures painted in the 16th and 17th century by Nicholas Hilliard and Isaac Oliver, two of the most famous limners working at the Tudor and Stuart courts. The 23 objects chosen for the analysis, spanning almost the entire career of the two artists, belong to the collections of the Victoria and Albert Museum (London) and the Fitzwilliam Museum (Cambridge). A non-invasive scientific methodology, comprising of stereo and optical microscopies, Raman microscopy, and X-ray fluorescence spectroscopy, was required for the investigation of these small-scale and fragile objects. The palettes and working techniques of the two artists were characterised, focusing in particular on the examination of flesh tones, mouths, and eyes. These findings were also compared to the information written in the treatises on miniature painting circulating during the artists’ lifetime. By identifying the materials and techniques most widely employed by the two artists, this study provides information about similarities and differences in their working methods, which can help to understand their artistic practice as well as contribute to matters of attribution.Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). The linked file is the published version of the article.NHM Repositor
A high-resolution in situ X-ray diffraction study of mineral transitions due to post-hydration heating in CM chondrite meteorites
Get PDFAbstract - The effects of post-hydration heating over a broad range of temperatures are evident in many Mighei-like carbonaceous (CM) chondrites as a variety of mineral transitions. To better understand these processes and how a CM chondrite’s starting composition may have affected them, we experimentally heated two meteorites with different degrees of aqueous alteration, Allan Hills 83100 and Murchison, at 25 °C temperature steps from 200 °C to 950 °C and 300 °C to 750 °C, respectively. During heating, synchrotron in situ X-ray diffraction patterns were collected. With the exception of calcite decomposition and its products, most mineral transitions were unaffected by starting composition. Key observations include: (1) partial decomposition of tochilinite at 200 °C, which indicates that tochilinite breakdown might be a two-stage process due to its intergrown layers of brucite/amakinite and mackinawite; (2) the breakdown of serpentine occurring at 300 °C with transitional phases appearing at 525 °C and 575–600 °C, while secondary olivine formed at 600 °C; (3) cronstedtite decomposing faster than lizardite, (4) the formation of secondary enstatite at 750 °C, and (5) calcite decomposition temperature differing significantly between meteorites, occurring at 725 °C and 575 °C in ALH 83100 and Murchison, respectively. The results for calcite are likely controlled by differences in its microstructure and chemical composition, related to the meteorite’s impact history and degree of aqueous alteration. The difference in calcite decomposition temperature also explains the contrasts in the observed breakdown products, with clinopyroxene occurring in both meteorites, and oldhamite only in ALH 83100. Mineral transitions due to post-hydration heating have been characterized with a high resolution XRD method, enabling a better understanding of processes occurring on the parent asteroids of CM chondrites.© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ The attached file is the published version of the article.NHM Repositor
Contemporary intergeneric hybridization and backcrossing among birds-of-paradise
Get PDFDespite large differences in morphology, behavior and lek-mating strategies the birds-of-paradise are known to hybridize occasionally, even across different genera. Many of these bird-of-paradise hybrids were originally described as distinct species based on large morphological differences when compared to recognized species. Nowadays, these specimens are generally recognized as hybrids based on morphological assessments. Having fascinated naturalists for centuries, hybrid specimens of birds-of-paradise have been collected and the specimens kept in Natural History Collections. In the present study, we utilize this remarkable resource in a museomics framework and evaluate the genomic composition of most described intergeneric hybrids and some intrageneric hybrids. We show that the majority of investigated specimens are first-generation hybrids and that the parental species, in most cases, are in line with prior morphological assessments. We also identify two specimens that are the result of introgressive hybridization between different genera. Additionally, two specimens exhibit hybrid morphologies but have no identifiable signals of hybridization, which may indicate that minor levels of introgression can have large morphological effects. Our findings provide direct evidence of contemporary introgressive hybridization taking place between genera of birds-of-paradise in nature, despite markedly different morphologies and lek-mating behaviors.Copyright © The Author(s) 2024. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEN). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article.NHM Repositor
Lithium systematics in the Krafla volcanic system: comparison between surface rhyolites and felsic cuttings from the Iceland deep drilling project -1 (IDDP-1)
No full textAbstract - The unexpected discovery of felsic magma by the Iceland Deep Drilling Project-1 (IDDP-1) in the Krafla volcanic system (KVS) presents a unique opportunity to investigate pre-eruptive lithium (Li) dynamics and establish a more direct connection between magma reservoirs and volcanic deposits. Our study provides new insights into Li abundances and isotope compositions in bulk-rock, minerals, and groundmass glass from rhyolitic lavas at KVS, encompassing various stages of groundmass crystallisation. Additionally, we examined felsic cuttings retrieved from the IDDP-1 well, comprising crystal-poor obsidian and crystal-bearing to -rich ‘felsite’ particles. Groundmass glasses from surface lavas show limited variability in K/Na, indicating limited secondary hydration of the glasses and that their Li contents seem to not be affected by this post-eruptive process. Lithium inventories in groundmass glasses and minerals within lavas exhibit variations consistent with the cooling history of the deposit, resembling patterns seen in Snake River Plain ignimbrites. Lithium contents of glassy rhyolitic lavas, whether bulk-rock (avg. 27.2 ± 3.1 μg/g) or groundmass glass (average 28.4 ± 4.7 μg/g), and their bulk isotopic compositions (avg. δ7Li =+ 4.4 ± 0.2‰) overlap with those observed in IDDP-1 obsidian cuts (avg. 24.9 μg/g Li in bulk, 28.6 ± 1.5 μg/g in groundmass glass, and δ7Li = 4.5 ± 0.2‰). Glassy lavas lacking spherulites may potentially preserve pristine magmatic Li element and isotope compositions, while areas with extensive groundmass crystallisation reveal Li enrichments in phenocrysts. Plagioclases in slowly cooled parts of the deposit record a two-fold increase in Li contents compared to plagioclase found in glassy counterparts, along with evidence of open-system degassing marked by heavier bulk Li isotope compositions and lower bulk Li contents of the crystallised lava portions (avg. δ7Li = +7.2 ± 0.1‰ and 7 ± 0.8 μg/g Li) relative to bulk glassy lithologies (avg. δ7Li = +4.1 ± 0.1‰ and 28 ± 2 μg/g Li). Partition coefficients derived from IDDP-1 cuts successfully predict Li inventories in vitrophyres of rhyolites on the surface of the KVS. Lithium isotope compositions of the crystal-rich IDDP-1 cuts are significantly heavier (avg. δ7Li = +7.2 ± 0.2‰) than lavas and IDDP-1 obsidian cuts, casting doubt on the notion that the IDDP-1 rhyolitic magma could result from the melting of felsite lenses in the KVS. Lithium contents in groundmass glasses within IDDP-1 crystal-rich cuts show higher Li contents (avg. 55.1–60.7 μg/g), correlating with the higher crystal content and an increase in other incompatible elements (avg. 250 μg/g Rb) relative to obsidian cuttings (avg. 75 μg/g Rb).Copyright © The Author(s) 2024. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes
were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The linked file is the published version of the article.NHM Repositor
The genome sequence of the Rivulet moth, Perizoma affinitatum (Stephens, 1831)
Get PDFWe present a genome assembly from an individual male Perizoma affinitatum (the Rivulet moth; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 357.7 megabases in span. Most of the assembly is scaffolded into 25 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.9 kilobases in length.Copyright: © 2024 Broad GR et al. This is an open access article distributed under the terms of the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article.NHM Repositor
The genome sequence of the moss carder bee, Bombus muscorum (Linnaeus, 1758)
Get PDFWe present a genome assembly from an individual female Bombus muscorum (the moss carder bee; Arthropoda; Insecta; Hymenoptera; Apidae). The genome sequence spans 317.70 megabases. Most of the assembly is scaffolded into 17 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 21.15 kilobases in length. Gene annotation of this assembly on Ensembl identified 11,668 protein-coding genes. The attached file is the published version of the article.Copyright: © 2024 Broad GR et al. This is an open access article distributed under the terms of the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.NHM Repositor