| 1. |
- Álvaro, J. Javier, et al.
(författare)
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Global Cambrian trilobite palaeobiogeography assessed using parsimony analysis of endemicity
- 2013
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Ingår i: Early Palaeozoic Biogeography and Palaeogeography. - 0435-4052. - 9781862393738 ; Memoir 38:38, s. 273-296
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Bokkapitel (refereegranskat)abstract
- Palaeobiogeographical data on Cambrian trilobites obtained during the twentieth century are combined in this paper to evaluate palaeoceanographic links through c. 30 myr, once these arthropods biomineralized. Worldwide major tectonostratigraphic units are characterized at series intervals of Cambrian time and datasets of trilobite genera (629 for Cambrian Series 2, 965 for Cambrian Series 3, and 866 for the Furongian Series) are analysed using parsimony analysis of endemicity. Special attention is given to the biogeographical observations made in microcontinents and exotic terranes. The same is done for platform-basinal transects of well-known continental margins. The parsimony analysis of endemicity analysis resulted in distinct palaeogeographical area groupings among the tectonostratigraphic units. With these groupings, several palaeobiogeographical units are distinguished, which do not necessarily fit the previously proposed biogeographical realms and provinces. Their development and spatial distributions are broadly controlled by Cambrian palaeoclimates, palaeogeographical conditions (e.g. carbonate productivity and anoxic conditions) and ocean current circulation.
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| 2. |
- Ekhtiari, Hamed, et al.
(författare)
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A methodological checklist for fMRI drug cue reactivity studies : development and expert consensus
- 2022
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Ingår i: Nature Protocols. - : Nature Portfolio. - 1754-2189 .- 1750-2799. ; 17:3, s. 567-595
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Tidskriftsartikel (refereegranskat)abstract
- Cue reactivity measured by functional magnetic resonance imaging is used in studies of substance-use disorders. This Consensus Statement is the result of a Delphi process to arrive at parameters that should be reported in describing these studies. Cue reactivity is one of the most frequently used paradigms in functional magnetic resonance imaging (fMRI) studies of substance use disorders (SUDs). Although there have been promising results elucidating the neurocognitive mechanisms of SUDs and SUD treatments, the interpretability and reproducibility of these studies is limited by incomplete reporting of participants characteristics, task design, craving assessment, scanning preparation and analysis decisions in fMRI drug cue reactivity (FDCR) experiments. This hampers clinical translation, not least because systematic review and meta-analysis of published work are difficult. This consensus paper and Delphi study aims to outline the important methodological aspects of FDCR research, present structured recommendations for more comprehensive methods reporting and review the FDCR literature to assess the reporting of items that are deemed important. Forty-five FDCR scientists from around the world participated in this study. First, an initial checklist of items deemed important in FDCR studies was developed by several members of the Enhanced NeuroImaging Genetics through Meta-Analyses (ENIGMA) Addiction working group on the basis of a systematic review. Using a modified Delphi consensus method, all experts were asked to comment on, revise or add items to the initial checklist, and then to rate the importance of each item in subsequent rounds. The reporting status of the items in the final checklist was investigated in 108 recently published FDCR studies identified through a systematic review. By the final round, 38 items reached the consensus threshold and were classified under seven major categories: Participants Characteristics, General fMRI Information, General Task Information, Cue Information, Craving Assessment Inside Scanner, Craving Assessment Outside Scanner and Pre- and Post-Scanning Considerations. The review of the 108 FDCR papers revealed significant gaps in the reporting of the items considered important by the experts. For instance, whereas items in the General fMRI Information category were reported in 90.5% of the reviewed papers, items in the Pre- and Post-Scanning Considerations category were reported by only 44.7% of reviewed FDCR studies. Considering the notable and sometimes unexpected gaps in the reporting of items deemed to be important by experts in any FDCR study, the protocols could benefit from the adoption of reporting standards. This checklist, a living document to be updated as the field and its methods advance, can help improve experimental design, reporting and the widespread understanding of the FDCR protocols. This checklist can also provide a sample for developing consensus statements for protocols in other areas of task-based fMRI.
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| 3. |
- Habibi, M., et al.
(författare)
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Microstructure, fractal geometry and corrosion properties of CrN thin films : The effect of shot number and angular position
- 2022
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Ingår i: Materials Today Communications. - : Elsevier Ltd. - 2352-4928. ; 32
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Tidskriftsartikel (refereegranskat)abstract
- The effect of different plasma focus shots and angular positions (0° and 30°) on the properties of chromium nitride (CrN) coatings, deposited by a plasma focus (PF) device on stainless steel substrates, have been systematically investigated in this paper. The structural and morphological properties of CrN thin films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). Moreover, the corrosion behavior of the CrN thin films was investigated using the ‘c’ method. The XRD patterns demonstrated the growth of the polycrystalline structure composed of CrN/Cr2N nanograins and the enhanced crystallinity of the CrN coatings upon increasing the shot numbers. In addition, AFM results showed enhanced multifractal properties of the sample prepared at 0° angular position and a reducing trend in these properties for the layers prepared at 30° angular position. Moreover, they exhibited sharp hillock-like features on the surface, corresponding to the columnar growth of the CrN coatings, which further protruded as the number of shots increased. The results of the corrosion test showed that the resistance of stainless-steel substrate was improved by depositing the CrN coatings due to the formation of a passive and protective layer on its surface. Notably, ceramic CrN film, prepared through 10 shots at 30° angular position, showed the best corrosion resistance. Our strategy is advantageous for designing and manufacturing novel devices and instruments based on CrN corrosion resistant coating.
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| 4. |
- Ghobadi Pour, M., et al.
(författare)
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Early Ordovician (Tremadocian) faunas and biostratigraphy of the Gerd-Kuh section, eastern Alborz, Iran
- 2015
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Ingår i: Stratigraphy. - 1547-139X .- 2331-656X. ; 12:2, s. 55-61
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Tidskriftsartikel (refereegranskat)abstract
- The Tremadocian of the East Alborz Region is dominated by condensed fine clasticsediments. These beds have yielded low to medium diversity trilobite associations, which belong to theolenid, nileid and raphiophorid biofacies, characteristic of an outer shelf environment. Five successivetrilobite biozones can be recognised in the Tremadocian succession of Alborz. The lower TremadocianAsaphellus inflatus–Dactylocephalus and Psilocephalina lubrica zones are characterised by mediumdiversity trilobite associations with strong links to contemporaneous faunas of South China. Three upperzones are documented in the section at Gerd-Kuh, the successive Vachikaspis insueta and Kayseraspiszones represent a low diversity interval during a time of rapid changes in the sea level changes; themedium diversity fauna of the Asaphellus fecundus–Taihungshania miqueli zone shows strong links tothe faunas of Mediterranean segment of Gondwana. Brachiopods in Gerd-Kuh are represented by themonotaxic Tarfaya Association and the low diversity Paralenorthis–Xinanorthis Association. Therecurrent oligotaxic Protambonites Association invaded the area in the late Tremadocian during shortterm regressive episodes.
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| 5. |
- Holmer, Lars E., 1960-, et al.
(författare)
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Evolutionary significance of a middle Cambrian (Series 3) in situ occurrence of the pedunculate rhynchonelliform brachiopod Nisusia sulcata
- 2018
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Ingår i: Lethaia. - : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931. ; 51:3, s. 424-432
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Tidskriftsartikel (refereegranskat)abstract
- Exceptionally preserved, silicified and articulated complete shells of the rhynchonelliform kutorginate brachiopod Nisusia sulcata are redescribed from the middle Cambrian (Series 3) Marjum Limestone, Utah. Cylindroid sausage-like protrusions, emerging posteriorly between the valves, were originally interpreted as faecal in origin, but restudy under the SEM shows that these features represent silicified pedicles as they are attached in situ to other Nisusia. The Nisusia host most likely was alive at the time of attachment. Restudy of the pedicles of Nisusia provides new phylogenetic information on the anatomy of the earliest rhynchonelliforms. The silicified pedicles differ considerably from the pedicles of living crown group rhynchonelliforms in being strongly annulated, distally tapering, and were likely to have been rather more flexible. The Nisusia pedicles are more similar to the exceptionally preserved pedicles from other Cambrian rhynchonelliform brachiopods, including Kutorgina, Longtancunella and Alisina, but these emerge from the ventral apical foramen rather than from between the valves as in Nisusia. Although generally similar, these two types of pedicles are unlikely to represent homologous structures as Nisusia is provided with both an apical foramen (possibly larval attachment) and a posterior adult pedicle. The similarities may be explained by similar type of accretionary growth from two different types of epithelia. The Nisusia-like pedicle appeared early within the kutorginates and rhynchonellates. The discovery of hollow spines in Nisusia sulcata further supports the generic assignation of the species.
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| 6. |
- Holmer, Lars E., 1960-, et al.
(författare)
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Linguliform brachiopods from the Cambrian (Guzhangian) Karpinsk Formation of Novaya Zemlya
- 2020
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Ingår i: Papers in Palaeontology. - : John Wiley & Sons. - 2056-2799 .- 2056-2802. ; 6:4, s. 571-592
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Tidskriftsartikel (refereegranskat)abstract
- Abstract A moderately diverse assemblage of micromorphic linguliform brachiopods, including Tapuritreta gribovensis sp. nov., Wahwahlingula? pankovensis sp. nov., Acrothele sp., Anabolotreta? sp., Orbithele? sp. and Stilpnotreta sp., is for the first time described from the Cambrian Karpinsk Formation (Miaolingian, Guzhangian) of the South Island of Novaya Zemlya. The morphology of the metamorphic shell in Acrothele and Wahwahlingula? suggest that both taxa had a single pair of larval setal sacs, similar to the recent discinids, but their metamorphosis was completed only at the end of the pelagic stage and shows that they did have direct development, which is characteristic of all recent lingulides. The biogeographical signature of the new Cambrian brachiopod fauna from Novaya Zemlya is discussed, and the new fauna gives new information on the poorly known Cambrian margins of the Baltica palaeocontinent.
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| 7. |
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| 8. |
- Zhang, Zhiliang, et al.
(författare)
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The oldest Cambrian trilobite - brachiopod association in South China
- 2021
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Ingår i: Gondwana Research. - : Elsevier. - 1342-937X .- 1878-0571. ; 89, s. 147-167
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Tidskriftsartikel (refereegranskat)abstract
- Limestones of the Xihaoping Member of the Dengying Formation in the Xiaoyangba section, South China, yield the oldest known Cambrian brachiopod-trilobite association. In this member, the trilobite Parabadiella cf. huoi co-occurs with the new brachiopod species Eoobolus incipiens sp. nov. The association provides potential for correlation of lower Cambrian successions and gives novel insights into the origin, palaeobiogeographic distribution and early evolution of linguliform brachiopods. Parabadiella occurs in shallow marine clastic and carbonate rocks in South China, demonstrating a broad distribution for this taxon. The new discovery indicates an early Chiungchussuan age (Parabadiella trilobite Zone, Cambrian Age 3) for the longstanding problematic Xihaoping Member. Furthermore, this earliest Parabadiella-Eoobolus association helps to establish close links with the oldest knowntrilobite-brachiopod assemblage from the upper Micrina etheridgei Zone (Parabadiella huoi trilobite Zone) in Australia. Eoobolus incipiens represents one of the earliest known linguliform brachiopods, with a distinctive mixture of characters shared with both problematic tommotiids, as well as paterinide, lingulide and acrotretide brachiopods, indicating that these features may be plesiomorphic for the Linguliformea. An age-constrained dispersal mode for early lingulate brachiopods is proposed, indicating that the Subphylum Linguliformea may have originated in East Gondwana and South China during Cambrian Age 3, and only subsequently dispersed to other major Cambrian palaeocontinents (e.g. Siberia, Laurentia, Antarctica, Baltica, Avalonia, West Gondwana, North China) during the late stage of the Cambrian evolutionary radiation of animals. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of International Association for Gondwana Research.
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