97 research outputs found

    New iron-based Heusler compounds Fe2YZ: Comparison with theoretical predictions of the crystal structure and magnetic properties

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    The present work reports on the new soft ferromagnetic Heusler phases Fe2NiGe, Fe2CuGa, and Fe2CuAl, which in previous theoretical studies have been predicted to exist in a tetragonal regular Heusler structure. Together with the known phases Fe2CoGe and Fe2NiGa these materials have been synthesized and characterized by powder XRD, 57 Fe M\"ossbauer spectroscopy, SQUID and EDX measurements. In particular M\"ossbauer spectroscopy was used to monitor the degree of local atomic order/disorder and to estimate magnetic moments at the Fe sites from the hyperfine fields. It is shown that in contrast to the previous predictions all the materials except Fe2NiGa basically adopt the inverse cubic Heusler (X-) structure with differing degrees of disorder. The disorder is more enhanced in case of Fe2NiGa, which was predicted as an inverse Heusler phase. The experimental data are compared with results from ab-inito electronic structure calculations on LDA level incorporating the effects of atomic disorder by using the coherent potential approximation (CPA). A good agreement between calculated and experimental magnetic moments is found for the cubic inverse Heusler phases. Model calculations on various atomic configurations demonstrate that antisite disorder tends to enhance the stability of the X-structure. Given the fundamental scientific and technological importance of tetragonal Heusler phases the present results call for further investigations to unravel the factors stabilizing tetragonal Heusler materials

    Overview of ImageCLEF 2017: Information extraction from images

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    This paper presents an overview of the ImageCLEF 2017 evaluation campaign, an event that was organized as part of the CLEF (Conference and Labs of the Evaluation Forum) labs 2017. ImageCLEF is an ongoing initiative (started in 2003) that promotes the evaluation of technologies for annotation, indexing and retrieval for providing information access to collections of images in various usage scenarios and domains. In 2017, the 15th edition of ImageCLEF, three main tasks were proposed and one pilot task: (1) a LifeLog task about searching in LifeLog data, so videos, images and other sources; (2) a caption prediction task that aims at predicting the caption of a figure from the biomedical literature based on the figure alone; (3) a tuberculosis task that aims at detecting the tuberculosis type from CT (Computed Tomography) volumes of the lung and also the drug resistance of the tuberculosis; and (4) a remote sensing pilot task that aims at predicting population density based on satellite images. The strong participation of over 150 research groups registering for the four tasks and 27 groups submitting results shows the interest in this benchmarking campaign despite the fact that all four tasks were new and had to create their own community

    Treatment of displaced intra-articular calcaneal fractures by ligamentotaxis: current concepts’ review

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    Introduction: A large variety of therapeutic modalities for calcaneal fractures have been described in the literature. No single treatment modality for displaced intra-articular calcaneal fractures has proven superior over the other. This review describes and compares the different percutaneous distractional approaches for intra-articular calcaneal fractures. The history, technique, anatomical and fracture considerations, limitations and the results of different distractional approaches reported in the literature are reviewed. Method: Literature review on different percutaneous distractional approaches for displaced intra-articular calcaneal fractures. Results: Eight studies in which application of a distraction technique was used for the treatment of calcaneal fractures were identified. Because of the use of different classification, techniques, and outcome scoring systems, a meta-analysis was not possible. A literature review reveals overall fair to poor result in 10-29% of patients. Ten up to 26% of patients are unable to return to work after percutaneous treatment of their fracture. A secondary arthrodesis has to be performed in 2-15% of the cases. Infectious complications occur in 2-15%. Some loss of reduction is reported in 4-67%. Conclusion: Percutaneous distractional reduction and fixation appears to be a safe technique with overall good results and an acceptable complication rate, compared with other treatment modalities for displaced intra-articular calcaneal fractures. A meta-analysis, based on Cochrane Library criteria is not possible, because of a lack of level 1 and 2 trials on this subject

    TGF-β in progression of liver disease

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    Transforming growth factor-β (TGF-β) is a central regulator in chronic liver disease contributing to all stages of disease progression from initial liver injury through inflammation and fibrosis to cirrhosis and hepatocellular carcinoma. Liver-damage-induced levels of active TGF-β enhance hepatocyte destruction and mediate hepatic stellate cell and fibroblast activation resulting in a wound-healing response, including myofibroblast generation and extracellular matrix deposition. Being recognised as a major profibrogenic cytokine, the targeting of the TGF-β signalling pathway has been explored with respect to the inhibition of liver disease progression. Whereas interference with TGF-β signalling in various short-term animal models has provided promising results, liver disease progression in humans is a process of decades with different phases in which TGF-β or its targeting might have both beneficial and adverse outcomes. Based on recent literature, we summarise the cell-type-directed double-edged role of TGF-β in various liver disease stages. We emphasise that, in order to achieve therapeutic effects, we need to target TGF-β signalling in the right cell type at the right time

    Magic-factor 1, a partial agonist of Met, induces muscle hypertrophy by protecting myogenic progenitors from apoptosis.

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    Hepatocyte Growth Factor (HGF) is a pleiotropic cytokine of mesenchymal origin that mediates a characteristic array of biological activities including cell proliferation, survival, motility and morphogenesis. Its high affinity receptor, the tyrosine kinase Met, is expressed by a wide range of tissues and can be activated by either paracrine or autocrine stimulation. Adult myogenic precursor cells, the so called satellite cells, express both HGF and Met. Following muscle injury, autocrine HGF-Met stimulation plays a key role in promoting activation and early division of satellite cells, but is shut off in a second phase to allow myogenic differentiation. In culture, HGF stimulation promotes proliferation of muscle precursors thereby inhibiting their differentiation

    The origins and spread of domestic horses from the Western Eurasian steppes

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    Domestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 bc. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture

    The Origins and Spread of Domestic Horses from the Western Eurasian Steppes

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    Domestication of horses fundamentally transformed long-range mobility and warfare1. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling2–4 at Botai, Central Asia around 3500 bc3. Other longstanding candidate regions for horse domestication, such as Iberia5 and Anatolia6, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc8,9 driving the spread of Indo-European languages10. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture11,12. © 2021, The Author(s).We thank all members of the AGES group at CAGT. We are grateful for the Museum of the Institute of Plant and Animal Ecology (UB RAS, Ekaterinburg) for providing specimens. The work by G. Boeskorov is done on state assignment of DPMGI SB RAS. This project was supported by the University Paul Sabatier IDEX Chaire d’Excellence (OURASI); Villum Funden miGENEPI research programme; the CNRS ‘Programme de Recherche Conjoint’ (PRC); the CNRS International Research Project (IRP AMADEUS); the France Génomique Appel à Grand Projet (ANR-10-INBS-09-08, BUCEPHALE project); IB10131 and IB18060, both funded by Junta de Extremadura (Spain) and European Regional Development Fund; Czech Academy of Sciences (RVO:67985912); the Zoological Institute ZIN RAS (АААА-А19-119032590102-7); and King Saud University Researchers Supporting Project (NSRSP–2020/2). The research was carried out with the financial support of the Russian Foundation for Basic Research (19-59-15001 and 20-04-00213), the Russian Science Foundation (16-18-10265, 20-78-10151, and 21-18-00457), the Government of the Russian Federation (FENU-2020-0021), the Estonian Research Council (PRG29), the Estonian Ministry of Education and Research (PRG1209), the Hungarian Scientific Research Fund (Project NF 104792), the Hungarian Academy of Sciences (Momentum Mobility Research Project of the Institute of Archaeology, Research Centre for the Humanities); and the Polish National Science Centre (2013/11/B/HS3/03822). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie (grant agreement 797449). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreements 681605, 716732 and 834616)

    The origins and spread of domestic horses from the Western Eurasian steppes

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    Analysis of 273 ancient horse genomes reveals that modern domestic horses originated in the Western Eurasian steppes, especially the lower Volga-Don region.Domestication of horses fundamentally transformed long-range mobility and warfare(1). However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling(2-4) at Botai, Central Asia around 3500 bc(3). Other longstanding candidate regions for horse domestication, such as Iberia(5) and Anatolia(6), have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association(7) between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc(8,9) driving the spread of Indo-European languages(10). This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture(11,12).Descriptive and Comparative Linguistic
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