Georg Zehfuss: Sein Leben und seine Werke

Es ist viel über den historischen Ursprung der Definition des Tensorproduktes von Matrizen geschrieben worden, so haben ihn einige Autoren Kronecker und anderen Autoren Zehfuss zugeschrieben. Aber bis jetzt waren bibliographische Informationen von Georg Zehfuss (1832-1901) knapp und die Liste seiner Veröffentlichungen unvollständig, so dass schwer zu verstehen ist, dass ein so unbekannter Mathematiker hier mitbestimmend war. Wir beabsichtigen hier diese Lücke auszufüllen, indem wir Daten aus verschiedenen bekannten und neuen Quellen sammeln, gruppieren, kategorisieren und kommentieren. Dies umfasst biographische Daten, seine Lehrer und Tutoren, viele seiner Publikationen und die Auswirkungen einiger seiner Errungenschaften in Mathematik und Physik. Die Schlussfolgerung ist, dass der Beitrag von Zehfuss zur Mathematik sich nicht auf die Definition vom Tensorprodukt von Matrizen beschränkt ist, da es weitere Beiträge zur Mathematik und nicht nur zur Determinantenttheorie, auch zur Physik von ihm gibt, und abgesehen von seinen Beiträgen zur Bildung von späteren Ingenieuren an höheren Gewerbeschulen mit seiner Lehrtätigkeit und mit seinen Büchern

Aus den wissenschaftlichen anfängen hermann minkowskis

AbstractThe inspiration and core of this paper is a previously unknown letter from H. Weber to R. Dedekind, which sheds information on Hermann Minkowski's mathematical studies and investigations while he was still a student. The article begins with descriptions of the Gymnasium that Minkowski attended at Königsberg, and his teachers there. Minkowski's first introduction to higher mathematics is studied, along with his arithmetical investigations before he composed the memoir submitted for the Prize of the Academy of Paris in 1883. After observations on Minkowski's studies at the University of Königsberg, the polemics surrounding his prize from the Paris Academy are discussed, taking into consideration new documents which are quoted in the text

Loss of RAF kinase inhibitor protein is involved in myelomonocytic differentiation and aggravates RAS-driven myeloid leukemogenesis

RAS-signaling mutations induce the myelomonocytic differentiation and proliferation of hematopoietic stem and progenitor cells. Moreover, they are important players in the development of myeloid neoplasias. RAF kinase inhibitor protein (RKIP) is a negative regulator of RAS-signaling. As RKIP loss has recently been described in RAS-mutated myelomonocytic acute myeloid leukemia, we now aimed to analyze its role in myelomonocytic differentiation and RAS-driven leukemogenesis. Therefore, we initially analyzed RKIP expression during human and murine hematopoietic differentiation and observed that it is high in hematopoietic stem and progenitor cells and lymphoid cells but decreases in cells belonging to the myeloid lineage. By employing short hairpin RNA knockdown experiments in CD34+ umbilical cord blood cells and the undifferentiated acute myeloid leukemia cell line HL-60, we show that RKIP loss is indeed functionally involved in myelomonocytic lineage commitment and drives the myelomonocytic differentiation of hematopoietic stem and progenitor cells. These results could be confirmed in vivo, where Rkip deletion induced a myelomonocytic differentiation bias in mice by amplifying the effects of granulocyte macrophage-colony-stimulating factor. We further show that RKIP is of relevance for RAS-driven myelomonocytic leukemogenesis by demonstrating that Rkip deletion aggravates the development of a myeloproliferative disease in NrasG12D-mutated mice. Mechanistically, we demonstrate that RKIP loss increases the activity of the RAS-MAPK/ERK signaling module. Finally, we prove the clinical relevance of these findings by showing that RKIP loss is a frequent event in chronic myelomonocytic leukemia, and that it co-occurs with RAS-signaling mutations. Taken together, these data establish RKIP as novel player in RAS-driven myeloid leukemogenesis

Myeloid STAT3 promotes formation of colitis-associated colorectal cancer in mice

Myeloid cells lacking STAT3 promote antitumor responses of NK and T cells but it is unknown if this crosstalk affects development of autochthonous tumors. We deleted STAT3 in murine myeloid cells (STAT3(Δm)) and examined the effect on the development of autochthonous colorectal cancers (CRCs). Formation of Azoxymethane/Dextransulfate (AOM/DSS)-induced CRCs was strongly suppressed in STAT3(Δm) mice. Gene expression profiling showed strong activation of T cells in the stroma of STAT3(Δm) CRCs. Moreover, STAT3(Δm) host mice were better able to control the growth of transplanted MC38 colorectal tumor cells which are known to be killed in a T cell-dependent manner. These data suggest that myeloid cells lacking STAT3 control formation of CRCs mainly via cross activation of T cells. Interestingly, the few CRCs that formed in STAT3(Δm) mice displayed enhanced stromalization but appeared normal in size indicating that they have acquired ways to escape enhanced tumor surveillance. We found that CRCs in STAT3(Δm) mice consistently activate STAT3 signaling which is implicated in immune evasion and might be a target to prevent tumor relapse

APEX: Current Status of the Airborne Dispersive Pushbroom Imaging Spectrometer

ABSTRACT Over the past few years, a joint Swiss/Belgium ESA initiative resulted in a project to build a precursor mission of future spaceborne imaging spectrometers, namely APEX (Airborne Prism Experiment). APEX is designed to be an airborne dispersive pushbroom imaging spectrometer operating in the solar reflected wavelength range between 400 and 2500 nm. The system is optimized for land applications including limnology, snow, and soil, amongst others. The instrument is optimized with various steps taken to allow for absolute calibrated radiance measurements. This includes the use of a pre-and post-data acquisition internal calibration facility as well as a laboratory calibration and a performance model serving as a stable reference. The instrument is currently in its breadboarding phase, including some new results with respect to detector development and design optimization for imaging spectrometers. In the same APEX framework, a complete processing and archiving facility (PAF) is developed. The PAF not only includes imaging spectrometer data processing up to physical units, but also geometric and atmospheric correction for each scene, as well as calibration data input. The PAF software includes an Internet based web-server and provides interfaces to data users as well as instrument operators and programmers. The software design, the tools and its life cycle are discussed as well

Cognition in patients with neuromyelitis optica spectrum disorders: a prospective multicentre study of 217 patients (CogniNMO-Study)

BACKGROUND: There is limited and inconsistent information on the prevalence of cognitive impairment in neuromyelitis optica spectrum disorders (NMOSD). OBJECTIVE: To assess cognitive performance and changes over time in NMOSD. METHODS: This study included data from 217 aquaporin-4-IgG-seropositive (80%) and double-seronegative NMOSD patients. Cognitive functions measured by Symbol Digit Modalities Test (SDMT), Paced Auditory Serial-Addition Task (PASAT), and/or Multiple Sclerosis Inventory Cognition (MuSIC) were standardized against normative data (N = 157). Intraindividual cognitive performance at 1- and 2-year follow-up was analyzed. Cognitive test scores were correlated with demographic and clinical variables and assessed with a multiple linear regression model. RESULTS: NMOSD patients were impaired in SDMT (p = 0.007), MuSIC semantic fluency (p < 0.001), and MuSIC congruent speed (p < 0.001). No significant cognitive deterioration was found at follow-up. SDMT scores were related to motor and visual disability (p(Bon) < 0.05). No differences were found between aquaporin-4-IgG-seropositive and double-seronegative NMOSD. CONCLUSIONS: A subset of NMOSD patients shows impairment in visual processing speed and in semantic fluency regardless of serostatus, without noticeable changes during a 2-year observation period. Neuropsychological measurements should be adapted to physical and visual disabilities

APEX: Current Status of the Airborne Dispersive Pushbroom Imaging Spectrometer

ABSTRACT Over the past few years, a joint Swiss/Belgium ESA initiative resulted in a project to build a precursor mission of future spaceborne imaging spectrometers, namely APEX (Airborne Prism Experiment). APEX is designed to be an airborne dispersive pushbroom imaging spectrometer operating in the solar reflected wavelength range between 400 and 2500 nm. The system is optimized for land applications including limnology, snow, and soil, amongst others. The instrument is optimized with various steps taken to allow for absolute calibrated radiance measurements. This includes the use of a pre-and post-data acquisition internal calibration facility as well as a laboratory calibration and a performance model serving as a stable reference. The instrument is currently in its breadboarding phase, including some new results with respect to detector development and design optimization for imaging spectrometers. In the same APEX framework, a complete processing and archiving facility (PAF) is developed. The PAF not only includes imaging spectrometer data processing up to physical units, but also geometric and atmospheric correction for each scene, as well as calibration data input. The PAF software includes an Internet based web-server and provides interfaces to data users as well as instrument operators and programmers. The software design, the tools and its life cycle are discussed as well

Costs and health-related quality of life in patients with NMO spectrum disorders and MOG-antibody-associated disease: CHANCE(NMO) study

OBJECTIVE: To evaluate costs and health-related quality of life (HRQoL) of neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein-antibody associated disease (MOGAD).MethodsIn this multicenter cross-sectional study, data on consumption of medical and non-medical resources and work ability were assessed via patient questionnaires. Costs were analyzed in EUR for 2018 from the societal perspective. HRQoL was captured by the EuroQoL EQ-5D-5L questionnaire. Clinical data were retrieved from the Neuromyelitis Optica Study Group (NEMOS) database. RESULTS: Two hundred twelve patients (80% women; median age 50 [19-83] years; median disease duration 7 [0-43] years; median Expanded Disability Status Scale [EDSS] 3.5 [0-8.5]; 66% Aquaporin-4 IgG, 22% MOG IgG positive, 12% double seronegative) were analyzed. The mean total annual per capita cost of illness accounted for EUR (Euro) 59 574 (95% CI 51 225 to 68 293; USD [United States dollars] 70 297, 95% CI 60 445 to 80 586), and the mean index value of the EQ-5D-5L was 0.693 (95% CI 0.65 to 0.73). The most important cost drivers were informal care costs (28% of total costs), indirect costs (23%) and drugs (16%), especially immunotherapeutics. Costs showed a positive correlation with disease severity (ρ=0.56, 95% CI 0.45 to 0.65); in the EDSS 6.5-8.5 subgroup the mean annual costs were EUR 129 687 (95% CI 101 946 to 160 336; USD 153 031, 95% CI 120 296 to 189 196). The HRQoL revealed a negative correlation to disease severity (ρ=-0.69, 95% CI -0.76 to -0.61); in the EDSS 6.5-8.5 subgroup the EQ-5D-5L mean index value was 0.195 (95% CI 0.13 to 0.28). Neither antibody status nor disease duration influenced the total annual costs or HRQoL. CONCLUSION: These German data from the era without approved preventive immunotherapies show enormous effects of the diseases on costs and quality of life. An early and cost-effective therapy should be provided to prevent long-term disability and preserve quality of life