Distributed Ledger Technology for the systematic Investigation and Reduction of Information Asymmetry in Collaborative Networks

Costs, risks and inefficiencies in Collaborative Networks (CNs) resulting from information asymmetries have been discussed in the scientific community for years. In this work, supply chain networks, as common representative of CNs, are used as object of investigation. Therein, problems and requirements of interorganizational information exchange are elaborated as well as the potential role Distributed Ledger Technology (DLT) could play to address them. As major challenge, convincing all relevant network partners to resolve asymmetric information by sharing sensitive data is identified. To face this issue, the value of shared information is prioritized as a motivational aspect. Finally, we propose a search process to systematically assess the benefits of information sharing in collaborative networks. To coordinate and implement this process regarding the derived requirements of CNs we propose system components based on DLT design patterns

Instructional guidelines based on conceptions of students and scientists about economic and population growth within planetary boundaries

The burden placed by human activities on Earth is ever-increasing. Global environmental changes have profoundly affected the Earth’s core systems and processes, thus, risking their stability. These core systems and processes are described in the planetary boundary framework. The drastic rate of environmental change over the last 200 years, which is also known as the Great Acceleration, has been depicted graphically by the International Geosphere-Biosphere Program. This study is aimed to (1) examine the conceptions of students and scientists regarding socioeconomic growth within planetary boundaries, and (2) develop instructional guidelines based on the comparison of their conceptions. Accordingly, relevant conceptions of 22 junior and 20 senior secondary school students were analyzed. Scientists’ conceptions were extracted by thoroughly analyzing nine publications, which were selected by systematic literature search. Student statements and scientific inferences were coded following established protocols. Our results indicated that junior and senior secondary school students considered global population growth to be the primary cause of global environmental changes. On the contrary, the scientists considered the quantity of natural resources consumed by rich countries in their economic pursuits as the most critical factor in environmental degradation. Based on our findings, we proposed instructional guidelines for planning lessons on changing current socioeconomic systems to enable humans to live within planetary boundaries

A Robustness Study for the Extraction of Watertight Volumetric Models from Boundary Representation Data

Geometrically induced topology plays a major role in applications such as simulations, navigation, spatial or spatio-temporal analysis and many more. This article computes geometrically induced topology useful for such applications and extends previous results by presenting the unpublished used algorithms to find inner disjoint (d+1)-dimensional simplicial complexes from a set of intersecting d-dimensional simplicial complexes which partly shape their B-Reps (Boundary Representations). CityGML has been chosen as the input data format for evaluation purposes. In this case, the input data consist of planar segment complexes whose triangulated polygons serve as the set of input triangle complexes for the computation of the tetrahedral model. The creation of the volumetric model and the computation of its geometrically induced topology is partly parallelized by decomposing the input data into smaller pices. A robustness analysis of the implementations is given by varying the angular precision and the positional precision of the epsilon heuristic inaccuracy model. The results are analysed spatially and topologically, summarised and presented. It turns out that one can extract most, but not all, volumes and that the numerical issues of computational geometry produce failures as well as a variety of outcomes

Data Sovereignty in Data Donation Cycles - Requirements and Enabling Technologies for the Data-driven Development of Health Applications

Personalized healthcare is expected to increase the efficiency and the effectiveness of health services using different kinds of algorithms on existing data. This approach is currently confronted with the lack of digital data and the desire for self-determined personal data handling. However, the issue of health data donation is on the political agenda of some governments. Within this work, a knowledge base will be created by reviewing existing approaches and technologies regarding this topic with the focus on chronic diseases. A list of requirements will be derived from which we conceptualize a data donation cycle to demonstrate the challenges and opportunities of health data sovereignty and its future possibilities concerning data-driven health application development. By linking the requirements to technological approaches, the baseline for future open ecosystems will be presented

Immunocytochemical Phenotyping of Disseminated Tumor Cells in Bone Marrow by uPA Receptor and CK18: Investigation of Sensitivity and Specificity of an Immunogold/Alkaline Phosphatase Double Staining Protocol

Phenotyping of cytokeratin (CK) 18-positive cells in bone marrow is gaining increasing importance for future prognostic screening of carcinoma patients. Urokinase-type plasminogen activator receptor (uPA-R) is one example of a potential aggressive marker for those cells. However, a valid and reliable double staining method is needed. Using monoclonal antibodies against uPA-R and CK18, we modified an immunogold/alkaline phosphatase double staining protocol. UPA-R/CK18-positive tumor cell controls exhibited black uPA-R staining in 15–80 of cases and red CK18 staining in almost 100 of tumor cells. Isotype- and cross-matched controls were completely negative. Bone marrow from healthy donors was always CK18-negative. Reproducibility of CK18-positive cell detection was estimated in a series of specimens from 61 gastric cancer patients comparatively stained with the single alkaline phosphatase-anti-alkaline phosphatase (APAAP) and our double staining method (106 bone marrow cells/patient). In four cases, double staining could not reproduce CK18-positive cells. In 34 cases it revealed fewer or equal numbers, and in 23 cases more CK18-positive cells than the APAAP method. Overall quantitative analysis of detected cell numbers (838 in APAAP, range 1–280 in 106; double staining 808, range 0–253) demonstrated relative reproducibility of APAAP results by double staining of 97. Correlation of results between both methods was significant (p<0.001, linear regression). Sensitivity of double staining tested in logarithmic tumor cell dilutions was one CK18-positive cell in 300,000. Specific uPA-R staining was seen on CK18-positive cells in bone marrow from 29 of 61 patients, and also on single surrounding bone marrow cells. To test the specificity of this staining, bone marrow cytospins from 10 patients without tumor disease were stained for uPA-R with the APAAP method. uPA-R expression was confirmed in all 10 cases, with a mean of 6.5 uPA-R-positive cells in 1000 bone marrow cells (SEM 1.2). These results suggest that our double staining protocol is a sensitive, reproducible, and specific method for routine uPA-R phenotyping of disseminated CK18-positive cells in bone marrow of carcinoma patients

Transport and magnetic properties of La_(1-x)Ca_xMnO_3-films (0.1<x<0.9)

By laser ablation we prepared thin films of the colossal magnetoresistive compound La_(1-x)Ca_xMnO_3 with doping levels 0.1<x<0.9 on MgO substrates. X-ray diffraction revealed epitaxial growth and a systematic decrease of the lattice constants with doping. The variation of the transport and magnetic properties in this doping series was investigated by SQUID magnetization and electrical transport measurements. For the nonmetallic samples resistances up to 10^13 Ohm have been measured with an electrometer setup. While the transport data indicate polaronic transport for the metallic samples above the Curie temperature the low doped ferromagnetic insulating samples show a variable range hopping like transport at low temperature.Comment: 2 pages, 3 EPS figures, LT22 Proceedings to appear in Physica

Kompetenzorientierten Unterricht konzipieren – am Beispiel der Naturwissenschaften

Kompetenzorientierter Unterricht lässt sich einfach konzipieren, wenn man in drei Schritten vorgeht: 1) Die zu erreichende Kompetenz analysieren, 2) den möglichen Lernweg der Schülerinnen und Schüler strukturieren, 3) die entsprechenden Unterrichtssequenzen entwickeln. Diesen Konzeptionsprozess unterstützen das sog. Kompetenzerwerbsschema und die kompetenzorientierte Didaktische Rekonstruktion. (DIPF/Orig.