| 1. |
- Davies, Thomas G., et al.
(författare)
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Open data and digital morphology.
- 2017
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 284:1852, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility.
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| 2. |
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| 3. |
- Ng, Bobby G., et al.
(författare)
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DPAGT1 deficiency with encephalopathy (DPAGT1-CDG) : Clinical and genetic description of 11 new patients
- 2018
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Ingår i: JIMD Reports. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 2192-8312 .- 2192-8304. ; 44, s. 85-92
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Bokkapitel (refereegranskat)abstract
- Pathogenic mutations in DPAGT1 cause a rare type of a congenital disorder of glycosylation termed DPAGT1-CDG or, alternatively, a milder version with only myasthenia known as DPAGT1-CMS. Fourteen disease-causing mutations in 28 patients from 10 families have previously been reported to cause the systemic form, DPAGT1-CDG. We here report on another 11 patients from 8 families and add 10 new mutations. Most patients have a very severe disease course, where common findings are pronounced muscular hypotonia, intractable epilepsy, global developmental delay/intellectual disability, and early death. We also present data on three affected females that are young adults and have a somewhat milder, stable disease. Our findings expand both the molecular and clinical knowledge of previously published data but also widen the phenotypic spectrum of DPAGT1-CDG.
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| 4. |
- Bengtson, A, et al.
(författare)
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Fast synthesis of aryl triflates with controlled microwave heating
- 2002
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Ingår i: Organic Letters. - Uppsala Univ, Dept Organ Pharmaceut Chem, BMC, SE-75123 Uppsala, Sweden. : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 4:7, s. 1231-1233
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Tidskriftsartikel (refereegranskat)abstract
- [GRAPHICS] Synthesis of aryl triflates from phenols using N-phenyltriflimide requires only 6 min for completion when conducted with controlled microwave heating. The methodology was applied to both solution- and solid-phase conditions. Ten different aryl triflates were synthesized and isolated in good yields. Applications in high-throughput chemistry are suggested.
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| 5. |
- Bengtson, A, et al.
(författare)
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Protected indanones by a Heck-Aldol annulation reaction
- 2002
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Ingår i: Journal of Organic Chemistry. - Uppsala Univ, Dept Organ Pharmaceut Chem, SE-75123 Uppsala, Sweden. : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 67:16, s. 5854-5856
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Tidskriftsartikel (refereegranskat)abstract
- Monoprotected 3-hydroxyindan-1-ones have been prepared in moderate to good yields by a new tandem reaction involving salicylaldehyde triflates and commercially available 2-hydroxyethyl vinyl ether. This one-pot annulation reaction proceeds in the presence of a palladium bidentate catalyst and results in the formation of two new ring systems.
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| 6. |
- Bengtson, Annika, et al.
(författare)
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Three new species of metalasia (asteraceae gnaphalieae) from the western cape and an updated key to the genus
- 2013
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Ingår i: South African Journal of Botany. - : Elsevier BV. - 0254-6299 .- 1727-9321. ; 84, s. 72-82
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Tidskriftsartikel (refereegranskat)abstract
- Three new species of Metalasia from the Western Cape of South Africa are described; Metalasia tristis A.Bengtson & P.O.Karis, a small shrublet from the Groot Winterhoek Mountains, and Metalasia formosa A.Bengtson & P.O.Karis and Metalasia eburnea A.Bengtson & P.O.Karis both found in the Langeberg Mountains. The morphology and relationships of the three new species are discussed, and an updated key to the genus is provided.
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| 7. |
- Berggren, M., et al.
(författare)
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Terrestrial support of zooplankton biomass in northern rivers
- 2018
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Ingår i: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 63:6, s. 2479-2492
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of terrestrially derived carbon to micro-crustacean zooplankton biomass (i.e., allochthony) has been previously studied in lakes, reservoirs, and estuaries, but little is known about zooplankton allochthony in rivers. In lacustrine environments, allochthony is regulated by distinct selective feeding behavior of different taxa. However, we hypothesized that restricted possibility for selective grazing in turbulent environments such as rivers would decouple zooplankton from specific microbial and algal food resources, such that their allochthony would mirror the terrestrial contribution to the surrounding bulk particle pool. We tested this idea by analyzing allochthony in 13 widely distributed Swedish rivers, using a dual-isotope mixing model. Zooplankton biomasses were generally low, and allochthony in different micro-crustacean groups (Cladocera, Cyclopoida, Calanoida) varied from 2% to 77%. As predicted, there were no correlations between allochthony and variables indicating the supply of algal and microbial food resources, such as chlorophyll a and bacterial production. Instead, the allochthony was generally similar to the share allochthonous contribution in bulk particulate organic matter, with relationships close to the 1 : 1 line. The zooplankton community allochthony was strongly regulated by the ecosystem metabolic balance between production and respiration, which in turn was dependent upon the ratio between total autochthonous organic carbon concentrations and water color. Our study for the first time shows that micro-crustacean allochthony is regulated differently in rivers compared to in lacustrine systems, and points to inefficient support of zooplankton biomass by algal resources in turbulent waters.
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| 8. |
- Carreras, A., et al.
(författare)
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In vivo genome and base editing of a human PCSK9 knock-in hypercholesterolemic mouse model
- 2019
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Ingår i: Bmc Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background Plasma concentration of low-density lipoprotein (LDL) cholesterol is a well-established risk factor for cardiovascular disease. Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9), which regulates cholesterol homeostasis, has recently emerged as an approach to reduce cholesterol levels. The development of humanized animal models is an important step to validate and study human drug targets, and use of genome and base editing has been proposed as a mean to target disease alleles.ResultsTo address the lack of validated models to test the safety and efficacy of techniques to target human PCSK9, we generated a liver-specific human PCSK9 knock-in mouse model (hPCSK9-KI). We showed that plasma concentrations of total cholesterol were higher in hPCSK9-KI than in wildtype mice and increased with age. Treatment with evolocumab, a monoclonal antibody that targets human PCSK9, reduced cholesterol levels in hPCSK9-KI but not in wildtype mice, showing that the hypercholesterolemic phenotype was driven by overexpression of human PCSK9. CRISPR-Cas9-mediated genome editing of human PCSK9 reduced plasma levels of human and not mouse PCSK9, and in parallel reduced plasma concentrations of total cholesterol; genome editing of mouse Pcsk9 did not reduce cholesterol levels. Base editing using a guide RNA that targeted human and mouse PCSK9 reduced plasma levels of human and mouse PCSK9 and total cholesterol. In our mouse model, base editing was more precise than genome editing, and no off-target editing nor chromosomal translocations were identified.ConclusionsHere, we describe a humanized mouse model with liver-specific expression of human PCSK9 and a human-like hypercholesterolemia phenotype, and demonstrate that this mouse can be used to evaluate antibody and gene editing-based (genome and base editing) therapies to modulate the expression of human PCSK9 and reduce cholesterol levels. We predict that this mouse model will be used in the future to understand the efficacy and safety of novel therapeutic approaches for hypercholesterolemia.
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| 9. |
- Cunningham, J. A., et al.
(författare)
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Experimental taphonomy of giant sulphur bacteria: implications for the interpretation of the embryo-like Ediacaran Doushantuo fossils.
- 2012
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Ingår i: Proceedings of the Royal Society of London. B. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 279:1734, s. 1857-1864
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Tidskriftsartikel (refereegranskat)abstract
- The Ediacaran Doushantuo biota has yielded fossils interpreted as eukaryotic organisms, either animal embryos or eukaryotes basal or distantly related to Metazoa. However, the fossils have been interpreted alternatively as giant sulphur bacteria similar to the extant Thiomargarita. To test this hypothesis, living and decayed Thiomargarita were compared with Doushantuo fossils and experimental taphonomic pathways were compared with modern embryos. In the fossils, as in eukaryotic cells, subcellular structures are distributed throughout cell volume; in Thiomargarita, a central vacuole encompasses approximately 98 per cent cell volume. Key features of the fossils, including putative lipid vesicles and nuclei, complex envelope ornament, and ornate outer vesicles are incompatible with living and decay morphologies observed in Thiomargarita. Microbial taphonomy of Thiomargarita also differed from that of embryos. Embryo tissues can be consumed and replaced by bacteria, forming a replica composed of a threedimensional biofilm, a stable fabric for potential fossilization. Vacuolated Thiomargarita cells collapse easily and do not provide an internal substrate for bacteria. The findings do not support the hypothesis that giant sulphur bacteria are an appropriate interpretative model for the embryo-like Doushantuo fossils. However, sulphur bacteria may have mediated fossil mineralization and may provide a potential bacterial analogue for other macroscopic Precambrian remains.
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| 10. |
- Ebinghaus, Ralf, et al.
(författare)
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Berlin statement on legacy and emerging contaminants in polar regions
- 2023
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 327
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Tidskriftsartikel (refereegranskat)abstract
- Polar regions should be given greater consideration with respect to the monitoring, risk assessment, and management of potentially harmful chemicals, consistent with requirements of the precautionary principle. Protecting the vulnerable polar environments requires (i) raising political and public awareness and (ii) restricting and preventing global emissions of harmful chemicals at their sources. The Berlin Statement is the outcome of an international workshop with representatives of the European Commission, the Arctic Council, the Antarctic Treaty Consultative Meeting, the Stockholm Convention on Persistent Organic Pollutants (POPs), environmental specimen banks, and data centers, as well as scientists from various international research institutions. The statement addresses urgent chemical pollution issues in the polar regions and provides recommendations for improving screening, monitoring, risk assessment, research cooperation, and open data sharing to provide environmental policy makers and chemicals management decision-makers with relevant and reliable contaminant data to better protect the polar environments. The consensus reached at the workshop can be summarized in just two words: “Act now!”Specifically, “Act now!” to reduce the presence and impact of anthropogenic chemical pollution in polar regions by.•Establishing participatory co-development frameworks in a permanent multi-disciplinary platform for Arctic-Antarctic collaborations and establishing exchanges between the Arctic Monitoring and Assessment Program (AMAP) of the Arctic Council and the Antarctic Monitoring and Assessment Program (AnMAP) of the Scientific Committee on Antarctic Research (SCAR) to increase the visibility and exchange of contaminant data and to support the development of harmonized monitoring programs.•Integrating environmental specimen banking, innovative screening approaches and archiving systems, to provide opportunities for improved assessment of contaminants to protect polar regions.
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| 11. |
- Petkevicius, K., et al.
(författare)
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TLCD1 and TLCD2 regulate cellular phosphatidylethanolamine composition and promote the progression of non-alcoholic steatohepatitis
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The regulation of cellular phosphatidylethanolamine (PE) acyl chain composition is poorly understood. Here, the authors show that TLCD1 and TLCD2 proteins mediate the formation of monounsaturated fatty acid-containing PE species and promote the progression of non-alcoholic steatohepatitis. The fatty acid composition of phosphatidylethanolamine (PE) determines cellular metabolism, oxidative stress, and inflammation. However, our understanding of how cells regulate PE composition is limited. Here, we identify a genetic locus on mouse chromosome 11, containing two poorly characterized genes Tlcd1 and Tlcd2, that strongly influences PE composition. We generated Tlcd1/2 double-knockout (DKO) mice and found that they have reduced levels of hepatic monounsaturated fatty acid (MUFA)-containing PE species. Mechanistically, TLCD1/2 proteins act cell intrinsically to promote the incorporation of MUFAs into PEs. Furthermore, TLCD1/2 interact with the mitochondria in an evolutionarily conserved manner and regulate mitochondrial PE composition. Lastly, we demonstrate the biological relevance of our findings in dietary models of metabolic disease, where Tlcd1/2 DKO mice display attenuated development of non-alcoholic steatohepatitis compared to controls. Overall, we identify TLCD1/2 proteins as key regulators of cellular PE composition, with our findings having broad implications in understanding and treating disease.
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| 12. |
- Alberts, D., et al.
(författare)
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In-depth profile analysis of filled alumina and titania nanostructured templates by radiofrequency glow discharge coupled to optical emission spectrometry
- 2010
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 396:8, s. 2833-2840
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Tidskriftsartikel (refereegranskat)abstract
- The development of highly ordered and self-assembled magnetic nanostructures such as arrays of Fe or Ni nanowires and their alloys is arousing increasing interest due to the peculiar magnetic properties of such materials at the nanoscale. These nanostructures can be fabricated using nanoporous anodic alumina membranes or self-assembled nanotubular titanium dioxide as templates. The chemical characterization of the nanostructured layers is of great importance to assist the optimization of the filling procedure or to determine their manufacturing quality. Radiofrequency glow discharge (RF-GD) coupled to optical emission spectrometry (OES) is a powerful tool for the direct analysis of either conducting or insulating materials and to carry out depth profile analysis of thin layers by multi-matrix calibration procedures. Thus, the capability of RF-GD-OES is investigated here for the in-depth quantitative analysis of self-aligned titania nanotubes and self-ordered nanoporous alumina filled with arrays of metallic and magnetic nanowires obtained using the template-assisted filling method. The samples analysed in this work consisted of arrays of Ni nanowires with different lengths (from 1.2 up to 5 μm) and multilayer nanowires of alternating layers with different thicknesses (of 1-2 μm) of Ni and Au, or Au and FeNi alloy, deposited inside the alumina and titania membranes. Results, compared with other techniques such as scanning electron microscopy and energy-dispersive X-ray spectroscopy, show that the RF-GD-OES surface analysis technique proves to be adequate and promising for this challenging application. © 2009 Springer-Verlag.
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| 13. |
- Bengtson, A, et al.
(författare)
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Activation of the complement cascade by trypsin.
- 1991
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Ingår i: Biological chemistry Hoppe-Seyler. - : Walter de Gruyter GmbH. - 0177-3593. ; 372:4, s. 273-8
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Tidskriftsartikel (refereegranskat)abstract
- In twenty-three patients with acute pancreatitis, the plasma levels of immunoreactive trypsin were determined with a RIA method. The patients were divided into groups according to the severity of the disease. Ranson's criteria and the development of multisystem organ failure were used for the classification. Elevated plasma levels of immunoreactive trypsin were found in all groups after admittance. Incubation of fresh human serum and plasma with bovine trypsin in concentrations between 10(-6) and 10(-4) M at 20 degrees C activated the complement cascade. The anaphylatoxins C3a and C5a were determined with a RIA and the terminal complement complex (TCC) with an ELISA method. C3a and C5a were released and TCC was formed. The effect of trypsin on leukocyte activation was determined with a chemiluminescence technique. Trypsin dissolved in saline did not activate the leukocytes. However, serum digested by trypsin-activated leukocytes in a dose-dependent manner. The present study supports the theory that trypsin can activate complement components and results in formation of split products which have potent vascular, and leukocyte activating effects.
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| 14. |
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| 15. |
- Bengtson, A, et al.
(författare)
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Evidensbaserad omvårdnad, sjukvård och kunskap
- 2002
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Ingår i: Vård i Norden. - 0107-4083. ; 22:2, s. 48-51
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Tidskriftsartikel (refereegranskat)abstract
- Research within nursing and medicine is moving at an increasing pace. This makes it difficult for the staff - involved with medical care to find the right path through all the new research and development. Working according to evidencebased procedures within both medicine and nursing means using in one’s work the recommendations which have been based on literature studies that have compiled, reviewed, assessed and interpreted the published research. The aim of a systematic literature review is to find the best scientific base for nursing and community care. The literature review according to SBU originates from Goodman’s definitions, which results in an order of precedence for the reviewed studies. Implementation at the work place is made easier by literature studies and discussions at meetings with the nurses. A literature review requires a structured way of working where the question is clearly defined, the project plan prepared and the literature search published. The relevant material is clearly defined, while the quality of the studies, precision and generalization taken from the results produces a combination and conclusion. To make the most of evidencebased methods in the daily work education of existing staff, courses integrated in the education of all nursing staff and an awareness when planning nationally, regionally and locally is essential.
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| 16. |
- Bengtson, Annika, et al.
(författare)
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Evolution and diversification related to rainfall regimes : diversification patterns in the South African genus Metalasia (Asteraceae-Gnaphalieae)
- 2015
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 42:1, s. 121-131
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Tidskriftsartikel (refereegranskat)abstract
- AimThe Cape region is known for its exceptional species richness, although much remains unknown regarding the appearance of the modern Cape flora. One explanation is that floral diversification was influenced by the establishment of winter rainfall/summer arid conditions hypothesized to have occurred towards the end of the Miocene. We studied the evolution and diversification of the plant genus Metalasia (Asteraceae-Gnaphalieae), with the aim of testing whether radiation patterns may have been influenced by the climatic changes. LocationSouth Africa, with emphasis on the south-west. MethodsThe radiation of Metalasia was investigated using two approaches: a species diffusion approach, which estimated the ancestral areas by means of a relaxed random walk while sampling from extant distributions; and a discrete approach, in which distributions were defined according to the phytogeographical centres of the Cape region. Secondarily derived clock rates from an earlier Gnaphalieae study were used for calibration purposes. ResultsOur analyses date Metalasia to approximately 6.9Ma, after the Miocene-Pliocene boundary and the establishment of the winter rainfall/summer arid conditions. Metalasia consists of two sister clades: Clade A and Clade B. Clade B, which is endemic to the winter rainfall area, is estimated to have diversified c. 6.4Ma, whereas Clade A, with a main distribution in the all-year rainfall area, is considerably younger, with a crown group age estimated to 3.3Ma. Diversification rates suggest an early rapid speciation, with rates decreasing through time both for Metalasia and for clades A and B separately. Ancestral area estimations show a possible scenario for the radiation of Metalasia to its current diversity and distribution, with no conflict between results inferred from diffusion or discrete methods. Main conclusionsThe diversification of Metalasia is estimated to have begun after the establishment of the winter rainfall/summer arid conditions, consistent with its radiation having been influenced by changes in the climatic regime.
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| 17. |
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| 18. |
- Bengtson, Annika, et al.
(författare)
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Phylogeny and evolution of the South African genus Metalasia (Asteraceae-Gnaphalieae) inferred from molecular and morphological data
- 2014
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Ingår i: Botanical journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4074 .- 1095-8339. ; 174:2, s. 173-198
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Tidskriftsartikel (refereegranskat)abstract
- Metalasia is a genus in tribe Gnaphalieae (Asteraceae), endemic to South Africa and with its main distribution in the Cape Floristic Region. The genus comprises 57 species and, with a number of closely related genera, it constitutes the Metalasia clade'. A species-level phylogenetic analysis is presented, based on DNA sequences from two nuclear (internal and external transcribed spacer: ITS, ETS) and two plastid (psbA-trnH, trnL-trnF) regions together with morphological data. Analyses combining molecular and morphological data attempt not only to resolve species interrelationships, but also to detect patterns in character evolution. Phylogenetic analyses corroborate our earlier study and demonstrate that Metalasia is formed of two equally sized, well-supported sister groups, one of which is characterized by papillose cypselas. The results differ greatly from earlier hypotheses based on morphology alone, as few morphological characters support the phylogenetic patterns obtained. The two clades of Metalasia do, however, appear to differ in distribution, corresponding to the different rainfall regimes of South Africa. Analyses show a few taxa to be problematic; one example is the widely distributed M.densa which appears to be an intricate species complex.
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| 19. |
- Bengtson, Annika, et al.
(författare)
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PHYLOGENY AND GENERIC DELIMITATION OF THE METALASIA CLADE (ASTERACEAE-GNAPHALIEAE)
- 2011
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 172:8, s. 1067-1075
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Tidskriftsartikel (refereegranskat)abstract
- The Metalasia clade, which consists of the genus Metalasia and a number of much smaller satellite genera, is a South African group in the tribe Gnaphalieae (Asteraceae). This study scrutinizes the phylogenetic relationships of the Metalasia clade by means of chloroplast (trnL-trnF, psbA-trnH) and nuclear (external transcribed spacer, internal transcribed spacer) sequence data. The Metalasia clade is confirmed to be a monophyletic group, and the phylogenetic positions of the included genera are determined. The genus Metalasia may be monophyletic if the monotypic Planea is included, but the node has very poor support and further studies are needed. The Metalasia species fall into two well-supported groups, distinguishing the members of Karis's Metalasia densa group from the others. Lachnospermum is shown to be monophyletic and is placed as a possible sister group to Metalasia. Phaenocoma is placed as sister to the branch consisting of Metalasia and Lachnospermum. Calotesta, Hydroidea, and Atrichantha form a clade, with the monotypic Dolichothrix as their sister group.
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| 20. |
- Bengtson, Annika, et al.
(författare)
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Phylogeny of Anisopappus with species circumscriptions revisited (Asteraceae: Athroismeae)
- 2021
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Ingår i: Taxon. - : Wiley. - 0040-0262 .- 1996-8175. ; 70:2, s. 351-364
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Tidskriftsartikel (refereegranskat)abstract
- Anisopappus (Asteraceae: Athroismeae) is a genus with its main distribution in Africa (one species also in Asia), currently considered to include around 21 species. A molecular phylogenetic study of Anisopappus is presented for the first time, based on plastid (ndhF, trnL-trnF, trnQ-rps16) and nuclear (ETS, ITS) data. Anisopappus is confirmed to be monophyletic, and species interrelationships are resolved. The results differ from earlier treatments based on morphology, and the phylogenetic analyses reveal a need for changes in species circumscriptions as compared to those of the most recent treatment. Consequently, many taxa currently treated as synonyms are here shown to represent separate species indicating that the genus includes well over 40 species. Distribution patterns now emerge where several clades are found to consist of species restricted to a particular geographical region. The Anisopappus of Madagascar, many of which were earlier placed in synonymy with species found on the African continent, are here shown to be endemic, and the results reveal a need for further studies of that group.
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| 21. |
- Bengtson, Annika, et al.
(författare)
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Species diversification in the Mediterranean genus Chiliadenus (Inuleae-Asteraceae)
- 2018
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110 .- 2199-6881. ; 304:7, s. 853-860
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Tidskriftsartikel (refereegranskat)abstract
- Chiliadenus is a small genus in the Inuleae (Asteraceae), consisting of ten species with allopatric distributions along the southern edge of the Mediterranean Sea. The different species have restricted areas of distribution, with only one being more widely distributed. The first molecular phylogenetic study of the genus with complete sampling, as well as a biogeographic analysis of the origin and biogeographic patterns leading to the current diversity of Chiliadenus is presented. Results confirm Chiliadenus as monophyletic and placed as sister to Dittrichia. The ancestor of Chiliadenus is dated to have diverged from that of Dittrichia around 5.45 Ma ago, coinciding with the Messinian salinity crisis, whereas the Chiliadenus crown group is dated to 2.29 Ma, around 3 million years later. Ancestral area reconstructions show the crown group to likely have originated in the area around Morocco and northwestern Algeria, which is also the area where the early divergences have occurred. Chiliadenus has then later diverged and dispersed over the Mediterranean to its current distribution. The evolution of the Chiliadenus crown group coincides with the onset of the Mediterranean climate, and its evolution may be connected to the subsequent climatic changes.
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| 22. |
- Bengtson, Annika, et al.
(författare)
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The Malagasy enigmatic genus Apodocephala (Asteraceae), a new member of the tribe Athroismeae
- 2021
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Ingår i: Willdenowia. - : Botanic Garden and Botanical Museum Berlin, Freie Universitaet Berlin. - 0511-9618 .- 1868-6397. ; 51:2, s. 221-230
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Tidskriftsartikel (refereegranskat)abstract
- Apodocephala is a small genus of nine species of shrubs and trees endemic to Madagascar and currently classified in the tribe Astereae (Asteraceae). However, its present tribal position has been questioned, as it lacks some of the salient morphological features of that tribe. This study includes for the first time DNA sequences from Apodocephala (two species including the type of the generic name) to test its phylogenetic position. Phylogenetic analyses based on sequence data from nuclear ribosomal (ETS and ITS) and plastid (ndhF and trnL–trnF) DNA regions, using Bayesian inference and maximum parsimony methods, strongly reject the placement of Apodocephala in the Astereae. Our results, instead, support its position as sister to the Malagasy monospecific genus Lowryanthus within the tribe Athroismeae. Morphological comparison of these sister genera reveal similarities in cypsela morphology, and the inclusion of Apodocephala in the subtribe Lowryanthinae is proposed here. The tribe Athroismeae is now represented by ten genera (Anisochaeta, Anisopappus, Apodocephala, Artemisiopsis, Athroisma, Blepharispermum, Centipeda, Leucoblepharis, Lowryanthus and Symphyllocarpus), six of which occur in Madagascar. The Malagasy Athroismeae occur in all Malagasy terrestrial ecosystems (rainforests, deciduous dry forests, thicket spiny forests and savannas) and are likely the result of multiple independent colonization events mostly from mainland Africa.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Bengtson, Sven-Axel, et al.
(författare)
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Man-dependence of House Sparrows (Passer domesticus) in the Faroe Islands: habitat patch characteristics as determinants of presence and numbers
- 2010
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Ingår i: Dorete - her book, Annales Societatis Scientiarum Færoensis, Suppl. 52. ; , s. 227-243
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The House Sparrow (Passer domesticus) began to colonize the Faroe Islands in the mid-1940s and occurs in most built-up areas. Breeding is confined to the discrete human habitations (settlements) that form a pattern of patches (”habitat-islands”). In 2002 all settlements were surveyed and the number of pairs of sparrows (total number ca. 2,700 pairs) and amount of vegetation (”green space”) were estimated. The settlements ranged in size from 0.01 km2 (a single farmstead) to 8.72 km2 (the capital) and 68% of them (n=118) were occupied by sparrows. Patch occupancy was positively correlated with both area and amount of vegetation (p < 0.001) but not quite with the degree of isolation (p = 0.15). The latter was crudely scored as a function of distance to nearest settlement with > 10 pairs (a possible source area) and topography (mainly mountains and open sea). The patch variables area, human population, number of houses and houses were strongly intercorrelated. Abundance (number of pairs) of sparrows was positively correlated with the number of houses (r = 0.84, p < 0.001). In all but one of the settlements with < 10 houses sparrows were absent, and also in many of those with 10-60 houses where the scatter swas wide (no significant correlation p = 0.25). All but one of the settlements with > 60 houses supported sparrows and the correlation with abundance was highly significant (p < 0.001). The absence of sparrows in small settlements is discussed in terms of risks of associated with small populations such as stochastic extinctions, Allee effects, competition, and predation (incl. persecution by Man). Various anthropogenic effects on abundance of sparrows are discussed; e.g. age, type and conditions of buildings and the presence of gardens, cultivations, and plantations all contributing to shelter and food resources. The Faroese House Sparrow as a metapopulation is briefly discussed.
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| 27. |
- Bengtson, Stefan, 1947-, et al.
(författare)
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A merciful death for the “earliest bilaterian,” Vernanimalcula.
- 2012
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Ingår i: Evolution and Development. - 1520-541X. ; 14:5, s. 421-427
-
Tidskriftsartikel (refereegranskat)abstract
- Fossils described as Vernanimalcula guizhouena, from the nearly 600 million-year-old Doushantuo Formation in South China, have been interpreted as the remains of bilaterian animals. As such they would represent the oldest putative record of bilaterian animals in Earth history, and they have been invoked in debate over this formative episode of early animal evolution. However, this interpretation is fallacious. We review the evidential basis of the biological interpretation of Vernanimalcula, concluding that the structures key to animal identity are effects of mineralization that do not represent biological tissues, and, furthermore, that it is not possible to derive its anatomical reconstruction on the basis of the available evidence. There is no evidential basis for interpreting Vernanimalcula as an animal, let alone a bilaterian. The conclusions of evolutionary studies that have relied upon the bilaterian interpretation of Vernanimalcula must be called into question.
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| 28. |
- Callier, Myriam D., et al.
(författare)
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Attraction and repulsion of mobile wild organisms to finfish and shellfish aquaculture: A review
- 2018
-
Ingår i: Reviews in Aquaculture. - : Wiley. - 1753-5123 .- 1753-5131. ; 10:4, s. 924-949
-
Tidskriftsartikel (refereegranskat)abstract
- © 2017 Wiley Publishing Asia Pty Ltd. Knowledge of aquaculture-environment interactions is essential for the development of a sustainable aquaculture industry and efficient marine spatial planning. The effects of fish and shellfish farming on sessile wild populations, particularly infauna, have been studied intensively. Mobile fauna, including crustaceans, fish, birds and marine mammals, also interact with aquaculture operations, but the interactions are more complex and these animals may be attracted to (attraction) or show an aversion to (repulsion) farm operations with various degrees of effects. This review outlines the main mechanisms and effects of attraction and repulsion of wild animals to/from marine finfish cage and bivalve aquaculture, with a focus on effects on fisheries-related species. Effects considered in this review include those related to the provision of physical structure (farm infrastructure acting as fish aggregating devices (FADs) or artificial reefs (ARs), the provision of food (e.g. farmed animals, waste feed and faeces, fouling organisms associated with farm structures) and some farm activities (e.g. boating, cleaning). The reviews show that the distribution of mobile organisms associated with farming structures varies over various spatial (vertical and horizontal) and temporal scales (season, feeding time, day/night period). Attraction/repulsion mechanisms have a variety of direct and indirect effects on wild organisms at the level of individuals and populations and may have implication for the management of fisheries species and the ecosystem in the context of marine spatial planning. This review revealed considerable uncertainties regarding the long-term and ecosystem-wide consequences of these interactions. The use of modelling may help better understand consequences, but long-term studies are necessary to better elucidate effects.
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| 29. |
- Cunningham, J.A., et al.
(författare)
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Distinguishing geology from biology in the Ediacaran Doushantuo biota relaxes constraints on the timing of the origin of bilaterians.
- 2012
-
Ingår i: Proceedings of the Royal Society. B. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 279:1737, s. 2369-2376
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Tidskriftsartikel (refereegranskat)abstract
- The Ediacaran Doushantuo biota has yielded fossils that include the oldest widely accepted record of the animal evolutionary lineage, as well as specimens with alleged bilaterian affinity. However, these systematic interpretations are contingent on the presence of key biological structures that have been reinterpreted by some workers as artefacts of diagenetic mineralization. On the basis of chemistry and crystallographic fabric, we characterize and discriminate phases of mineralization that reflect: (i) replication of original biological structure, and (ii) void-filling diagenetic mineralization. The results indicate that all fossils from the Doushantuo assemblage preserve a complex me´lange of mineral phases, even where subcellular anatomy appears to be preserved. The findings allow these phases to be distinguished in more controversial fossils, facilitating a critical re-evaluation of the Doushantuo fossil assemblage and its implications as an archive of Ediacaran animal diversity. We find that putative subcellular structures exhibit fabrics consistent with preservation of original morphology. Cells in later developmental stages are not in original configuration and are therefore uninformative concerning gastrulation. Key structures used to identify Doushantuo bilaterians can be dismissed as late diagenetic artefacts. Therefore, when diagenetic mineralization is considered, there is no convincing evidence for bilaterians in the Doushantuo assemblage.
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| 30. |
- Cunningham, John A., et al.
(författare)
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The origin of animals: Can molecular clocks and the fossil record be reconciled?
- 2016
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Ingår i: Bioessays. - : Wiley. - 0265-9247 .- 1521-1878. ; 38, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- The evolutionary emergence of animals is one of the most significant episodes in the history of life, but its timing remains poorly constrained. Molecular clocks estimate that animals originated and began diversifying over 100 million years before the first definitive metazoan fossil evidence in the Cambrian. However, closer inspection reveals that clock estimates and the fossil record are less divergent than is often claimed. Modern clock analyses do not predict the presence of the crown-representatives of most animal phyla in the Neoproterozoic. Furthermore, despite challenges provided by incomplete preservation, a paucity of phylogenetically informative characters, and uncertain expectations of the anatomy of early animals, a number of Neoproterozoic fossils can reasonably be interpreted as metazoans. A considerable discrepancy remains, but much of this can be explained by the limited preservation potential of early metazoans and the difficulties associated with their identificationin the fossil record. Critical assessment of both recordsmay permitbetter resolutionof the tempo and mode of early animal evolution.
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| 31. |
- Cunningham, John A., et al.
(författare)
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The Weng’an Biota (Doushantuo Formation): an Ediacaran window on soft bodied and multicellular microorganisms.
- 2017
-
Ingår i: journal of the geological society. - London : Geological Society. - 2041-479X .- 0016-7649. ; 174:5, s. 793-802
-
Tidskriftsartikel (refereegranskat)abstract
- The Weng’an Biota is a fossil Konservat-Lagerstätte in South China that is approximately 570-600 million years old and provides an unparalleled snapshot of marine life during the interval in which molecular clocks estimate that animal clades were diversifying. It yields specimens that are three-dimensionally preserved in calcium phosphate with cellular and sometimes subcellular fidelity. The biota includes candidates for the oldest animals in the fossil record, including embryonic, larval and adult forms. We argue that, while the Weng’an Biota includes forms that could be animals, none can currently be assigned to this group with confidence. Nonetheless, the biota offers a rare and valuable window on the evolution of multicellular and soft-bodied organisms in the prelude to the Cambrian radiation.
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| 32. |
- Dong, Xi-ping, et al.
(författare)
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Embryos, polyps and medusae of the early Cambrian scyphozoan Olivooides.
- 2013
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Ingår i: Proceedings of the Royal Society Biological Sciences Series B. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 280:2130071, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The Early Cambrian organism Olivooides is known from both embryonic and post-embryonic stages and, consequently, it has the potential to yield vital insights into developmental evolution at the time that animal body plans were established. However, this potential can only be realized if the phylogenetic relationships of Olivooides can be constrained. The affinities of Olivooides have proved controversial because of the lack of knowledge of the internal anatomy and the limited range of developmental stages known. Here, we describe rare embryonic specimens in which internal anatomical features are preserved. We also present a fuller sequence of fossilized developmental stages of Olivooides, including associated specimens that we interpret as budding ephyrae ( juvenile medusae), all of which display a clear pentaradial symmetry. Within the framework of a cnidarian interpretation, the new data serve to pinpoint the phylogenetic position of Olivooides to the scyphozoan stem group. Hypotheses about scalidophoran or echinoderm affinities of Olivooides can be rejected.
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| 33. |
- Donoghue, Philip C. J., et al.
(författare)
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Synchrotron X-ray tomographic microscopy of fossil embryos
- 2006
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Ingår i: Nature. - 0028-0836. ; 442:7103, s. 601-718
-
Tidskriftsartikel (refereegranskat)abstract
- Fossilized embryos from the late Neoproterozoic and earliest Phanerozoic have caused much excitement because they preserve the earliest stages of embryology of animals that represent the initial diversification of metazoans1, 2, 3, 4. However, the potential of this material has not been fully realized because of reliance on traditional, non-destructive methods that allow analysis of exposed surfaces only1, 2,3, 4, and destructive methods that preserve only a single two-dimensional view of the interior of the specimen5, 6. Here, we have applied synchrotron-radiation X-ray tomographic microscopy (SRXTM)7, obtaining complete three-dimensional recordings at submicrometre resolution. The embryos are preserved by early diagenetic impregnation and encrustation with calcium phosphate, and differences in X-ray attenuation provide information about the distribution of these two diagenetic phases. Three-dimensional visualization of blastomere arrangement and diagenetic cement in cleavage embryos resolves outstanding questions about their nature, including the identity of the columnar blastomeres. The anterior and posterior anatomy of embryos of the bilaterian worm-like Markuelia confirms its position as a scalidophoran, providing new insights into body-plan assembly among constituent phyla. The structure of the developing germ band in another bilaterian, Pseudooides, indicates a unique mode of germ-band development. SRXTM provides a method of non-invasive analysis that rivals the resolution achieved even by destructive methods, probing the very limits of fossilization and providing insight into embryology during the emergence of metazoan phyla.
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| 34. |
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| 35. |
- Drevenhorn, E., et al.
(författare)
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Counselling on lifestyle factors in hypertension care after training on the stages of change model
- 2007
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Ingår i: European Journal of Cardiovascular Nursing. - : Sage Publications. - 1474-5151 .- 1873-1953. ; :6, s. 46-53
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:In assisting the nurse's counselling on lifestyle changes in hypertension care a behaviour model can be used.AIM:To analyse the effects of nurses' training on the use of the stages of change model when counselling hypertensive patients to perform lifestyle changes.METHODS:As part of a randomised, controlled trial, 19 nurses belonging to the intervention group took part in video-recorded consultation training with simulated patients. To evaluate the training, the nurses audio-recorded their consultations with two patients before and after the intervention. Analysis focused on the areas of non-pharmacological treatment and the nurses' attention to the patients' readiness for change.RESULTS:Patient participation in the consultations increased after the training. The importance of non-pharmacological treatment was mentioned more frequently for all areas of lifestyle behaviour, exercise, smoking, alcohol consumption, food and stress, and the nurses acquired a more distinct structure for their consultations. The mean length of the recorded consultations increased from 18 min to 20.5 min. All the criteria for fulfillment of attention to patient's readiness to change were met in nine consultations before the training and in seven after it. After the training, attention was paid to support more frequently than before in the action and maintenance stages and a great deal of information was provided.
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| 36. |
- El Albani, Abder, et al.
(författare)
-
Organism motility in an oxygenated shallow-marine environment 2.1 billion years ago
- 2019
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 116:9, s. 3431-3436
-
Tidskriftsartikel (refereegranskat)abstract
- The 2.1 billion-year-old sedimentary strata contain exquisitely preserved fossils that provide an ecologic snapshot of the biota inhabiting an oxygenated shallow-marine environment. Most striking are the pyritized string-shaped structures, which suggest that the producer have been a multicellular or syncytial organism able to migrate laterally and vertically to reach for food resources. A modern analogue is the aggregation of amoeboid cells into a migratory slug phase in modern cellular slime molds during time of food starvation. While it remains uncertain whether the amoeboidlike organisms represent a failed experiment or a prelude to subsequent evolutionary innovations, they add to the growing record of comparatively complex life forms that existed more than a billion years before animals emerged in the late Neoproterozoic.Evidence for macroscopic life in the Paleoproterozoic Era comes from 1.8 billion-year-old (Ga) compression fossils [Han TM, Runnegar B (1992) Science 257:232–235; Knoll et al. (2006) Philos Trans R Soc Lond B 361:1023–1038], Stirling biota [Bengtson S et al. (2007) Paleobiology 33:351–381], and large colonial organisms exhibiting signs of coordinated growth from the 2.1-Ga Francevillian series, Gabon. Here we report on pyritized string-shaped structures from the Francevillian Basin. Combined microscopic, microtomographic, geochemical, and sedimentologic analyses provide evidence for biogenicity, and syngenicity and suggest that the structures underwent fossilization during early diagenesis close to the sediment–water interface. The string-shaped structures are up to 6 mm across and extend up to 170 mm through the strata. Morphological and 3D tomographic reconstructions suggest that the producer may have been a multicellular or syncytial organism able to migrate laterally and vertically to reach food resources. A possible modern analog is the aggregation of amoeboid cells into a migratory slug phase in cellular slime molds at times of starvation. This unique ecologic window established in an oxygenated, shallow-marine environment represents an exceptional record of the biosphere following the crucial changes that occurred in the atmosphere and ocean in the aftermath of the great oxidation event (GOE).
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| 37. |
- Gurell, J., et al.
(författare)
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Laser induced breakdown spectroscopy for fast elemental analysis sorting of metallic scrap pieces using certified reference materials
- 2012
-
Ingår i: Spectrochimica Acta Part B: Atomic Spectroscopy. - : Elsevier BV. - 0584-8547. ; 74, s. 46-50
-
Tidskriftsartikel (refereegranskat)abstract
- A setup utilizing laser induced breakdown spectroscopy (LIBS) for performing elemental analysis in order to classify metallic samples is currently under construction. The setup uses short laser pulses to locally ablate the sample create luminous plasmas. The emitted light is analyzed spectroscopically for instantaneous determination of the elemental composition. A table-top system based on a compact CCD spectrometer has been constructed combined with fast software in order to test the concept of remote, single shot material classification with LIBS. Certified reference materials with known elemental compositions were used in the laboratory tests. We report on successful laboratory tests in which samples were classified using an analysis based on optical emission following a single laser pulse with an operating distance of approximately 1 m. Details regarding field tests of this versatile promising technique are discussed.
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| 38. |
- Hein Bengtson, Stefan, et al.
(författare)
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A Shared Pose Regression Network for Pose Estimation of Objects from RGB Images
- 2022
-
Ingår i: IEEE/RSJ International Conference on Signal Image Technology & Internet Based Systems (SITIS). - 9781665464956 - 9781665464963
-
Konferensbidrag (refereegranskat)abstract
- In this paper we propose a shared regression network to jointly estimate the pose of multiple objects, replacing multiple object-specific solutions. We demonstrate that this shared network can outperform other similar approaches that rely on multiple object-specific models by evaluating it on the TLESS dataset using the VSD (Visible Surface Discrepancy). Our approach offers a less complex solution, with fewer parameters, lower memory consumption and less training required. Furthermore, it inherently handles symmetric objects by using a depth-based loss during training and can predict in real-time. Finally, we show how our proposed pipeline can be used for fine-tuning a feature extractor jointly on all objects while training the shared pose regression network. This fine-tuning process improves the pose estimation performance.
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| 39. |
- Kouchinsky, A, et al.
(författare)
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Cnidarian-like embryos associated with the first shelly fossils in Siberia
- 1999
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Ingår i: GEOLOGY. - : ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER. - 0091-7613. ; 27:7, s. 609-612
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphatized spheroids, similar to 0.5 mm in diameter, in the Lower Cambrian Manykay Formation at the Bol'shaya Kuonamka River in northern Sakha (Yakutia) are interpreted as cnidarian embryos of late developmental stages, One of the poles has a double cro
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| 40. |
- Kouchinsky, Artem, et al.
(författare)
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Early-middle Cambrian stratigraphy and faunas from northern Siberia
- 2022
-
Ingår i: Acta Palaeontologica Polonica. - : Institute of Paleobiology, Polish Academy of Sciences. - 0567-7920 .- 1732-2421. ; 67:2, s. 341-464
-
Tidskriftsartikel (refereegranskat)abstract
- New assemblages of skeletal fossils chemically extracted from carbonates of the Cambrian Stage 2-Drumian Stage are reported from the lower reaches of the Lena River as well as from the Khorbusuonka, Malaya Kuonamka, and Bol'shaya Kuonamka rivers in northern part of the Siberian Platform. The fauna studied with scanning electron microscopy includes brachiopods, molluscs, hyoliths, halkieriids, chancelloriids, tommotiids, lobopodians, palaeoscolecidans, bradoriids, echinoderms, anabaritids, hyolithelminths, and sponges showing similarity to previously described fossil assemblages from Siberia, Laurentia, and Gondwana. The material includes emended descriptions of Halkieria proboscidea, Hadimopanella knappologica, Archaeopetasus typicus, and first descriptions of Hadimopanella foveata Kouchinsky sp. nov. and Archaeopetasus pachybasalis Kouchinsky sp. nov. Affinity of Archaeopetasus to chancelloriids is suggested. Finding of an in-place operculum in a planispiral shell of Michniakia minuta enables reinterpretation of this form as a hyolith, not a mollusc. The cambroclavids Cambroclavus sp. and Zhijinites clavus and the earliest echinoderms belonging to the Rhombifera and Ctenocystoidea are reported respectively from the lower Botoman stage and Botoman-Toyonian transitional beds, correlated with Cambrian Stage 4. Carbon isotopes are analysed from sections of the Chuskuna (upper Kessyusa Group), Erkeket, Kuonamka, Olenyok, Yunkyulyabit-Yuryakh, Tyuser and Sekten formations. A major part of the delta C-13 record is obtained from the Cambrian Stage 4-Drumian Stage strata which remain incompletely characterised by chemostratigraphy. The Lower Anomocarioides limbataeformis Carbon isotope Excursion (LACE) from the Drumian Stage of the Khorbusuonka River is introduced herein. New chemostratigraphic data are used for regional and global correlation and facilitate study of the evolutionary development of animals and faunas through the "Cambrian explosion".
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| 41. |
- Raff, Elizabeth C., et al.
(författare)
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Doushantuo fossils are not giant bacteria, but bacterial pseudomorphs of animal embryos
- 2008
-
Ingår i: The Palaeontological Association.
-
Konferensbidrag (refereegranskat)abstract
- Embryos from the Ediacaran Doushantuo Formation are among the most astonishing examples of exceptional fossilization. However, the mechanism of fossilization ispoorly understood, leading directly to debate over the interpretation of the fossils, someauthors even questioning their interpretation as embryos. It has been hypothesized thatmicrobial processes are responsible for preservation and mineralization of organic tissues.However, the actions of microbes in preservation of embryos have not been demonstratedexperimentally. We show that bacterial biofilms assemble rapidly in marine embryos,forming detailed pseudomorphs of cellular organization and structure. We define threeessential steps in embryo preservation: 1) blockage of autolysis by reducing or anaerobic conditions; 2) rapid formation of microbial biofilms that consume the embryo butform a replica that retains cell organization and morphology; 3) bacterially-catalyzedmineralization. We identified major bacterial taxa in embryo decay biofilms using16S rDNA sequencing. Decay processes were similar in different taphonomic conditions,but bacterial populations depended on specific conditions. Experimental taphonomyresembles preservation states of fossils. Our data show how fossilization of soft tissues insediments is mediated by bacterial replacement and mineralization, providing a foundationfor experimentally creating biofilms from defined microbial species to model fossilization asa biological process.
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| 42. |
- Schuurmans, C. C. L., et al.
(författare)
-
Complex coacervation-based loading and tunable release of a cationic protein from monodisperse glycosaminoglycan microgels
- 2018
-
Ingår i: Soft Matter. - : Royal Society of Chemistry. - 1744-683X .- 1744-6848. ; 14:30, s. 6327-6341
-
Tidskriftsartikel (refereegranskat)abstract
- Glycosaminoglycans (GAGs) are of interest for biomedical applications because of their ability to retain proteins (e.g. growth factors) involved in cell-to-cell signaling processes. In this study, the potential of GAG-based microgels for protein delivery and their protein release kinetics upon encapsulation in hydrogel scaffolds were investigated. Monodisperse hyaluronic acid methacrylate (HAMA) and chondroitin sulfate methacrylate (CSMA) micro-hydrogel spheres (diameters 500-700 μm), were used to study the absorption of a cationic model protein (lysozyme), microgel (de)swelling, intra-gel lysozyme distribution and its diffusion coefficient in the microgels dispersed in buffers (pH 7.4) of varying ionic strengths. Upon incubation in 20 mM buffer, lysozyme was absorbed up to 3 and 4 mg mg−1 dry microspheres for HAMA and CSMA microgels respectively, with loading efficiencies up to 100%. Binding stoichiometries of disaccharide : lysozyme (10.2 : 1 and 7.5 : 1 for HAMA and CSMA, respectively) were similar to those for GAG-lysozyme complex coacervates based on soluble GAGs found in literature. Complex coacervates inside GAG microgels were also formed in buffers of higher ionic strengths as opposed to GAG-lysozyme systems based on soluble GAGs, likely due to increased local anionic charge density in the GAG networks. Binding of cationic lysozyme to the negatively charged microgel networks resulted in deswelling up to a factor 2 in diameter. Lysozyme release from the microgels was dependent on the ionic strength of the buffer and on the number of anionic groups per disaccharide, (1 for HAMA versus 2 for CSMA). Lysozyme diffusion coefficients of 0.027 in HAMA and <0.006 μm2 s−1 in CSMA microgels were found in 170 mM buffer (duration of release 14 and 28 days respectively). Fluorescence Recovery After Photobleaching (FRAP) measurements yielded similar trends, although lysozyme diffusion was likely altered due to the negative charges introduced to the protein through the FITC-labeling resulting in weaker protein-matrix interactions. Finally, lysozyme-loaded CSMA microgels were embedded into a thermosensitive hydrogel scaffold. These composite systems showed complete lysozyme release in ∼58 days as opposed to only 3 days for GAG-free scaffolds. In conclusion, covalently crosslinked methacrylated GAG hydrogels have potential as controlled release depots for cationic proteins in tissue engineering applications.
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| 43. |
- Tham, Emma, et al.
(författare)
-
A novel phenotype in N-glycosylation disorders: Gillessen-Kaesbach-Nishimura skeletal dysplasia due to pathogenic variants in ALG9.
- 2015
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813.
-
Tidskriftsartikel (refereegranskat)abstract
- A rare lethal autosomal recessive syndrome with skeletal dysplasia, polycystic kidneys and multiple malformations was first described by Gillessen-Kaesbach et al and subsequently by Nishimura et al. The skeletal features uniformly comprise a round pelvis, mesomelic shortening of the upper limbs and defective ossification of the cervical spine. We studied two unrelated families including three affected fetuses with Gillessen-Kaesbach-Nishimura syndrome using whole-exome and Sanger sequencing, comparative genome hybridization and homozygosity mapping. All affected patients were shown to have a novel homozygous splice variant NM_024740.2: c.1173+2T>A in the ALG9 gene, encoding alpha-1,2-mannosyltransferase, involved in the formation of the lipid-linked oligosaccharide precursor of N-glycosylation. RNA analysis demonstrated skipping of exon 10, leading to shorter RNA. Mass spectrometric analysis showed an increase in monoglycosylated transferrin as compared with control tissues, confirming that this is a congenital disorder of glycosylation (CDG). Only three liveborn children with ALG9-CDG have been previously reported, all with missense variants. All three suffered from intellectual disability, muscular hypotonia, microcephaly and renal cysts, but none had skeletal dysplasia. Our study shows that some pathogenic variants in ALG9 can present as a lethal skeletal dysplasia with visceral malformations as the most severe phenotype. The skeletal features overlap with that previously reported for ALG3- and ALG12-CDG, suggesting that this subset of glycosylation disorders constitutes a new diagnostic group of skeletal dysplasias.European Journal of Human Genetics advance online publication, 13 May 2015; doi:10.1038/ejhg.2015.91.
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| 44. |
- Vajro, Pietro, et al.
(författare)
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Three unreported cases of TMEM199-CDG, a rare genetic liver disease with abnormal glycosylation
- 2018
-
Ingår i: Orphanet Journal of Rare Diseases. - : Springer Science and Business Media LLC. - 1750-1172. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: TMEM199 deficiency was recently shown in four patients to cause liver disease with steatosis, elevated serum transaminases, cholesterol and alkaline phosphatase and abnormal protein glycosylation. There is no information on the long-term outcome in this disorder. Results: We here present three novel patients with TMEM199-CDG. All three patients carried the same set of mutations (c.13-14delTT (p.Ser4Serfs∗30) and c.92G > C (p.Arg31Pro), despite only two were related (siblings). One mutation (c.92G > C) was described previously whereas the other was deemed pathogenic due to its early frameshift. Western Blot analysis confirmed a reduced level of TMEM199 protein in patient fibroblasts and all patients showed a similar glycosylation defect. The patients presented with a very similar clinical and biochemical phenotype to the initial publication, confirming that TMEM199-CDG is a non-encephalopathic liver disorder. Two of the patients were clinically assessed over two decades without deterioration. Conclusion: A rising number of disorders affecting Golgi homeostasis have been published over the last few years. A hallmark finding is deficiency in protein glycosylation, both in N- and O-linked types. Most of these disorders have signs of both liver and brain involvement. However, the present and the four previously reported patients do not show encephalopathy but a chronic, non-progressive (over decades) liver disease with hypertransaminasemia and steatosis. This information is crucial for the patient/families and clinician at diagnosis, as it distinguishes it from other Golgi homeostasis disorders, in having a much more favorable course.
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| 45. |
- Yin, Zongjun, et al.
(författare)
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Nuclei and nucleoli in embryo-like fossils from the Ediacaran Weng’an Biota.
- 2017
-
Ingår i: Precambrian Research. - Amsterdam : Elsevier. - 0301-9268 .- 1872-7433. ; 301, s. 145-151
-
Tidskriftsartikel (refereegranskat)abstract
- The embryo-like microfossils from the Ediacaran Weng’an Biota (ca. 609 million years old) are among the oldest plausible claims of animals in the fossil record. Fossilization frequently extends beyond the cellular, to preserve subcellular structures including contentious Large Intracellular Structures (LISs) that have been alternately interpreted as eukaryote nuclei or organelles, degraded remains, or abiological structures. Here we present new data on the structure, morphology, and development of the LISs in these embryo-like fossils, based on Synchrotron Radiation X-ray Tomographic Microscopy (SRXTM) and quantitative computed tomographic analysis. All the lines of evidence, including consistency in the number, shape, position, and relative size (LIS-to-cytoplasm ratio) of the LISs, as well as their occurrence within preserved cytoplasm, support their interpretation as cell nuclei. Our results allow us to reject the view that nuclei cannot be preserved in early eukaryote fossils, offering new potential for interpreting the fossil record of early eukaryote evolution.
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