| 1. |
- Bosi, Ferdinando, et al.
(författare)
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Late magmatic controls on the origin of schorlitic and foititic tourmalines from late-Variscan peraluminous granites of the Arbus pluton (SW Sardinia, Italy) : Crystal-chemical study and petrological constraints
- 2018
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Ingår i: Lithos. - : Elsevier BV. - 0024-4937 .- 1872-6143. ; 308-309, s. 395-411
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Tidskriftsartikel (refereegranskat)abstract
- Tourmalines from the late-Variscan Arbus pluton (SW Sardinia) and its metamorphic aureole were structurally and chemically characterized by single-crystal X-ray diffraction, electron and nuclear microprobe analysis, Mössbauer, infrared and optical absorption spectroscopy, to elucidate their origin and relationships with the magmatic evolution during the pluton cooling stages. The Arbus pluton represents a peculiar shallow magmatic system, characterized by sekaninaite (Fe-cordierite)-bearing peraluminous granitoids, linked via AFC processes to gabbroic mantle-derived magmas. The Fe2+-Al-dominant tourmalines occur in: a) pegmatitic layers and pods, as prismatic crystals; b) greisenized rocks and spotted granophyric dikes, as clots or nests of fine-grained crystals in small miaroles locally forming orbicules; c) pegmatitic veins and pods close to the contacts within the metamorphic aureole. Structural formulae indicate that tourmaline in pegmatitic layers is schorl, whereas in greisenized rocks it ranges from schorl to fluor-schorl. Tourmalines in thermometamorphosed contact aureole are schorl, foitite and Mg-rich oxy-schorl. The main substitution is Na + Fe2+ ↔ □ + Al, which relates schorl to foitite. The homovalent substitution (OH) ↔ F at the O1 crystallographic site relates schorl to fluor-schorl, while the heterovalent substitution Fe2+ + (OH, F) ↔ Al + O relates schorl/fluor-schorl to oxy-schorl. Tourmaline crystallization in the Arbus pluton was promoted by volatile (B, F and H2O) enrichment, low oxygen fugacity and Fe2+ activity. The mineralogical evolutive trend is driven by decreasing temperature, as follows: sekaninaite + quartz → schorl + quartz → fluor-schorl + quartz → foitite + quartz. The schorl → foitite evolution represents a distinct trend towards (Al + □) increase and unit-cell volume decrease. These trends are typical of granitic magmas and consistent with Li-poor granitic melts, as supported by the absence of elbaite and other Li-minerals in the Arbus pluton. Tourmaline-bearing rocks reflect the petrogenetic significance of contribution from a metapelitic crustal component during the evolution of magmas in the middle-upper crust.
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| 2. |
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| 3. |
- Hoffman, Tove, et al.
(författare)
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Association between guilds of birds in the African-Western Palaearctic region and the tick species Hyalomma rufipes, one of the main vectors of Crimean-Congo hemorrhagic fever virus.
- 2022
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Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The migratory behavior of wild birds contributes to the geographical spread of ticks and their microorganisms. In this study, we aimed to investigate the dispersal and co-occurrence of Francisella and spotted fever group Rickettsia (SFGR) in ticks infesting birds migrating northward in the African-Western Palaearctic region (AWPR). Birds were trapped with mist nests across the Mediterranean basin during the 2014 and 2015 spring migration. In total, 575 ticks were collected from 244 birds. We screened the ticks for the species Francisella tularensis, the genus Francisella, and SFGR by microfluidic real-time PCR. Confirmatory analyses and metagenomic sequencing were performed on tick samples that putatively tested positive for F. tularensis during initial screenings. Hyalomma rufipes was the most common tick species and had a high prevalence of Francisella, including co-occurrence of Francisella and SFGR. Metagenomic analysis of total DNA extracted from two H. rufipes confirmed the presence of Francisella, Rickettsia, and Midichloria. Average nucleotide identity and phylogenetic inference indicated the highest identity of the metagenome-assembled genomes to a Francisella-like endosymbiont (FLE), Rickettsia aeschlimannii, and Midichloria mitochondrii. The results of this study suggest that (i) FLE- and SFGR-containing ticks are dispersed by northbound migratory birds in the AWPR, (ii) H. rufipes likely is not involved in transmission of F. tularensis in the AWPR, and (iii) a dual endosymbiosis of FLEs and Midichloria may support some of the nutritional requirements of H. rufipes.
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| 4. |
- Kristiansson, Per, et al.
(författare)
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The implementation of a DSSSD in the upgraded boron analysis at LIBAF for applications in geochemistry
- 2014
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 332, s. 207-211
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Tidskriftsartikel (refereegranskat)abstract
- Interest in high spatial resolution boron analyses from a geochemical perspective is related to the recognition of boron as an important tracer of chemical recycling in the Earth, due to the high solubility of boron in aqueous fluids and silicate melts. Although boron is not a nominal component in common silicates they may still contain significant B-concentrations and hence constitute important boron reservoirs in the deeper parts of the Earth. Boron analyses have been performed at the Lund Ion Beam Analytical Facility for almost 20 years. For the analysis the nuclear reaction p+B-11 is used with beam energy just below 700 keV where the reaction has a broad resonance. In this paper we describe an upgrade of the system with a double sided silicon strip detector, which allows for much higher count rates compared to the old annular surface detector based system. A gain close to 20 in the data rate allows for high resolution mapping of boron distributions in crystals. This is illustrated by a number of examples. In addition, the detection limits for boron in geological samples are improved, now around 5 ppmw. In this work we address issues with data quality, especially charge normalization, lifetime correction and subtraction of different background components. (C) 2014 The Authors. Published by Elsevier B.V.
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| 5. |
- Nilsson, Charlotta, et al.
(författare)
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A nuclear geochemical analysis system for boron quantification using a focused ion beam
- 2017
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 311:1, s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- Ion beam analysis has for decades been used as a tool for geochemical analysis of trace elements using both X-rays (particle induced X-ray emission) and nuclear reaction analysis. With the geoanalytical setup at the Lund Ion Beam Analysis Facility, the boron content in geological samples with a spatial resolution of 1 µm is determined through nuclear reaction analysis. In the newly upgraded setup, a single detector has been replaced by a double sided silicon strip detector with 2048 segments. After optimization, boron content in geological samples as low as 1 µg g−1 can be measured.
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| 6. |
- Wallmenius, Katarina, et al.
(författare)
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Spotted fever Rickettsia species in Hyalomma and Ixodes ticks infesting migratory birds in the European Mediterranean area
- 2014
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Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: A few billion birds migrate annually between their breeding grounds in Europe and their wintering grounds in Africa. Many bird species are tick-infested, and as a result of their innate migratory behavior, they contribute significantly to the geographic distribution of pathogens, including spotted fever rickettsiae. The aim of the present study was to characterize, in samples from two consecutive years, the potential role of migrant birds captured in Europe as disseminators of Rickettsia-infected ticks. Methods: Ticks were collected from a total of 14,789 birds during their seasonal migration northwards in spring 2009 and 2010 at bird observatories on two Mediterranean islands: Capri and Antikythira. All ticks were subjected to RNA extraction followed by cDNA synthesis and individually assayed with a real-time PCR targeting the citrate synthase (gltA) gene. For species identification of Rickettsia, multiple genes were sequenced. Results: Three hundred and ninety-eight (2.7%) of all captured birds were tick-infested; some birds carried more than one tick. A total number of 734 ticks were analysed of which 353 +/- 1 (48%) were Rickettsia-positive; 96% were infected with Rickettsia aeschlimannii and 4% with Rickettsia africae or unidentified Rickettsia species. The predominant tick taxon, Hyalomma marginatum sensu lato constituted 90% (n = 658) of the ticks collected. The remaining ticks were Ixodes frontalis, Amblyomma sp., Haemaphysalis sp., Rhipicephalus sp. and unidentified ixodids. Most ticks were nymphs (66%) followed by larvae (27%) and adult female ticks (0.5%). The majority (65%) of ticks was engorged and nearly all ticks contained visible blood. Conclusions: Migratory birds appear to have a great impact on the dissemination of Rickettsia-infected ticks, some of which may originate from distant locations. The potential ecological, medical and veterinary implications of such Rickettsia infections need further examination.
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| 7. |
- Wilhelmsson, Peter, 1981-, et al.
(författare)
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Candidatus Rickettsia Vini DNA in Ticks Collected from Nest Burrows of the European Sand Martin (Riparia riparia) in Sweden
- 2023
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 23:7, s. 378-383
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Tidskriftsartikel (refereegranskat)abstract
- Background: Birds can cross geographical and environmental barriers and thereby facilitate dispersal of tick-borne pathogens both as carriers of infected ticks and as reservoirs of pathogenic microorganisms. Ixodes lividus (Ixodida: Ixodidae) is an endophilic tick in the Palearctic region that is highly specialized on its host, the European sand martin Riparia riparia. The purpose of this study was to determine whether I. lividus ticks sampled from sand martin nests in Sweden carry vector-borne pathogens.Materials and Methods: Fed ticks were collected in the autumns of 2017 and 2019 from the nests of a European sand martin colony in southern Sweden. Ticks were identified morphologically to developmental stage and species and were tested for tick-borne pathogens using PCR-based methods.Results: None of the 41 ticks tested positive for five tick-borne pathogens including Borrelia spp., tick-borne encephalitis virus (TBEV), Neoehrlichia mikurensis, Anaplasma phagocytophilum, and Babesia spp. Thirty-seven (13 females, 23 nymphs and 1 larva) of the 41 ticks tested positive for the gltA gene of Rickettsia spp. The sequences of the 17 kDa and gltA genes were most closely related to Candidatus Rickettsia vini.Conclusion: Our study confirms other reports that I. lividus ticks associated with the European sand martin have high infection prevalence of Ca. R. vini.
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