267 research outputs found
Magnetic Field Dependence of Myocardial R2* Values and R2* Myocardial Segmental Inhomogeneity at 1.5 T, 3 T and 7 T.
No full textDetailing magnetic field strength dependence and segmental artifact distribution of myocardial effective transverse relaxation rate at 1.5, 3.0, and 7.0 T
No full textPURPOSE: Realizing the challenges and opportunities of effective transverse relaxation rate (R2 *) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 * at 1.5, 3.0, and 7.0 T. METHODS: Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. RESULTS: The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. CONCLUSION: At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium
Overcoming Fragmentation of Geochemical Data Resources: Collaboration between EarthChem, Astromat, GEOROC, and MetBase
No full textGlobal geochemical datasets are increasingly valuable for solving research questions in geochemistry, volcanology and beyond. To support new research, open sharing and access of geochemical data needs to be easy for researchers so they can take full advantage of the rapidly growing volume of data generated in laboratories across the globe, and to comply with the principles of Open Science. Instead, the fragmented landscape of geochemical data systems makes it difficult for researchers to find, access, and contribute their data: Geochemical data are curated and published in a range of thematic, institutional, and programmatic data systems that differ in architecture, metadata schemas, terminology, and data output formats. Researchers have to figure out where to obtain the data they need; learn to use different search applications; retrieve data from multiple databases and painstakingly reformat the datasets they obtained from different systems to integrate them. They need to select an appropriate repository for their data, and potentially work with different submission systems and templates. Collaboration among geochemical data systems is a critical step to overcome this fragmentation and facilitate geochemical data management and access for the research community by coordinating, aligning, and integrating their systems. Through collaboration, data repositories and databases can also leverage each other’s expertise and resources to operate their services more effectively and efficiently.
We here report about new collaborative efforts among four geochemical data systems that aim to harmonize and integrate their data holdings and software ecosystem for the benefit of the research community and to improve their sustainability: EarthChem (https://earthchem.org/), GEOROC (https://georoc.eu/), MetBase (https://metbase.org/), and the Astromaterials Data System (https://www.astromat.org/). Building on the long-term collaboration between EarthChem and GEOROC, this collaboration leverages the new development of the Astromaterials Data System with modern technology and two new projects funded to overhaul the infrastructure of the GEOROC and MetBase databases as an opportunity to jointly develop a more resilient, sustainable platform for data exchange. Results of the collaboration so far include: a) alignment of the Astronaut and MetBase data models b) migration of the MetBase data holdings into the Astromat synthesis database; c) alignment of the EarthChem and GEOROC data models; d) new automated synchronization process of GEOROC data to the ECP; e) harmonized vocabularies for chemical variables, analytical methods (Others are in development in alignment with emerging efforts of the OneGeochemstry initiative); f) design of the future shared architecture of EarthChem and GEOROC that includes plans for a joint data entry tool for curators and a single data submission platform for researchers to contribute their data to the affiliated domain repositories.
The ultimate goal of this harmonization between EarthChem, Astromat, GEOROC and MetBase is to make it easier for researchers to access and contribute data. We hope to integrate further systems in the future, building on ongoing collaborations with the Australian Geochemistry Network, the US Geological Survey, SAMIS (Sample Analysis Microinformation System), the GFZ Data Services, and the Sparrow software
Challenging the Status Quo: What Databases/Data Compilations are You Using for Your Data-Driven Geochemical Research? Will they still be accessible in 2030? Are your data compilations ethical?
No full textThe status quo of data-driven geochemical research is dominated by multiple, highly specialised and unsustainable data compilations to feed specific research questions: the future requires persistent FAIR geochemical data repositories that make data both human and machine-readable.
New, improved and automated instrumentation in the field of geochemistry mean that geochemical and isotopic data are being generated at faster rates and in greater volumes than have hitherto been possible. Data-driven analysis of existing geochemical datasets is growing as a research endeavour as new tools and new capabilities such as artificial intelligence (AI) and Machine Learning (ML) increase in popularity. Availability of cloud resources enable researchers to work with ever larger datasets.
Combined, these factors mean that large datasets suitable for these analyses are growing in availability. As it is near impossible for a single researcher to collect, analyse and then create a single dataset, researchers increasingly rely on open-access curated global databases (eg, EarthChem, GEOROC). Additional national databases are emerging to capture all analytical data produced in laboratories (eg, EPOS MSL, AusGeochem).
Today it is commonplace for project-based databases to be created by combining multiple datasets from the literature or downloading data from online databases. These compilation datasets rarely cite the individual researcher who created the dataset. Further, these compilations rarely have sustainable funding and are only maintained for as long as the creator has the capability. This leads to duplication of datasets with multiple conflicting versions that are rarely curated and kept up-to-date.
As well as threatening research validity, this also raises issues of ethics: in a research paper, the ideas of others are always referenced and credited. In these data compilations, even if permissive licensing allow data to be copied, the best scientific research method would require citation of and credit be given to all sources of any analysis. Increasingly funders are asking for evidence of return of investment on where they have funded sample collection, analytical equipment, laboratories, etc. But if a researcher has no idea of where their analysis is used in data compilations how can they report to their funders
Challenging the Status Quo: What Databases/Data Compilations are You Using for Your Data-Driven Geochemical Research? Will they still be accessible in 2030? Are your data compilations ethical?
No full textThe status quo of data-driven geochemical research is dominated by multiple, highly specialised and unsustainable data compilations to feed specific research questions: the future requires persistent FAIR geochemical data repositories that make data both human and machine-readable.
New, improved and automated instrumentation in the field of geochemistry mean that geochemical and isotopic data are being generated at faster rates and in greater volumes than have hitherto been possible. Data-driven analysis of existing geochemical datasets is growing as a research endeavour as new tools and new capabilities such as artificial intelligence (AI) and Machine Learning (ML) increase in popularity. Availability of cloud resources enable researchers to work with ever larger datasets.
Combined, these factors mean that large datasets suitable for these analyses are growing in availability. As it is near impossible for a single researcher to collect, analyse and then create a single dataset, researchers increasingly rely on open-access curated global databases (eg, EarthChem, GEOROC). Additional national databases are emerging to capture all analytical data produced in laboratories (eg, EPOS MSL, AusGeochem).
Today it is commonplace for project-based databases to be created by combining multiple datasets from the literature or downloading data from online databases. These compilation datasets rarely cite the individual researcher who created the dataset. Further, these compilations rarely have sustainable funding and are only maintained for as long as the creator has the capability. This leads to duplication of datasets with multiple conflicting versions that are rarely curated and kept up-to-date.
As well as threatening research validity, this also raises issues of ethics: in a research paper, the ideas of others are always referenced and credited. In these data compilations, even if permissive licensing allow data to be copied, the best scientific research method would require citation of and credit be given to all sources of any analysis. Increasingly funders are asking for evidence of return of investment on where they have funded sample collection, analytical equipment, laboratories, etc. But if a researcher has no idea of where their analysis is used in data compilations how can they report to their funders
Zuruf an Russlands Völker, zur Einführung nicht nur schönerer und wärmerer, sondern auch dauernhafterer, feuersicherer und doch sehr wohlfeiler Häuser, nebst Bekanntmachung eines sichern Mittels, Gebäude von Leimensteinen gegen die nachtheiligen Wirkungen der Nässe zu schützen. Dorpat, 1805, bei Johann Ludwig Friedrich Gauger, Universitäts-Buchhändler
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Freizeit in der Stadt Die zunehmende Freizeit in ihrer Auswirkung auf Standortfaktoren u. Flächenbedarf v. Freizeiteinrichtungen in neuen Wohngebieten. Entwicklung e. Planmodells als Entscheidungshilfe f. d. Bauleitplanung
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