Supervised and Semi-Supervised Self-Organizing Maps for Regression and Classification Focusing on Hyperspectral Data

Machine learning approaches are valuable methods in hyperspectral remote sensing, especially for the classification of land cover or for the regression of physical parameters. While the recording of hyperspectral data has become affordable with innovative technologies, the acquisition of reference data (ground truth) has remained expensive and time-consuming. There is a need for methodological approaches that can handle datasets with significantly more hyperspectral input data than reference data. We introduce the Supervised Self-organizing Maps (SuSi) framework, which can perform unsupervised, supervised and semi-supervised classification as well as regression on high-dimensional data. The methodology of the SuSi framework is presented and compared to other frameworks. Its different parts are evaluated on two hyperspectral datasets. The results of the evaluations can be summarized in four major findings: (1) The supervised and semi-Supervised Self-organizing Maps (SOM) outperform random forest in the regression of soil moisture. (2) In the classification of land cover, the supervised and semi-supervised SOM reveal great potential. (3) The unsupervised SOM is a valuable tool to understand the data. (4) The SuSi framework is versatile, flexible, and easy to use. The SuSi framework is provided as an open-source Python package on GitHub

Accessing Cationic α-Silylated and α-Germylated Phosphorus Ylides

The synthesis and full characterization of α-silylated (α-SiCPs; 1–7) and α-germylated (α-GeCPs; 11–13) phosphorus ylides bearing one chloride substituent R$_{3}$PC(R$^{1}$)E(Cl)R$^{2}$$_{2}$ (R=Ph; R$^{1}$=Me, Et, Ph; R$^{2}$=Me, Et, iPr, Mes; E=Si, Ge) is presented. The molecular structures were determined by X-ray diffraction studies. The title compounds were applied in halide abstraction studies in order to access cationic species. The reaction of Ph$^{3}$PC(Me)Si(Cl)Me$^{2}$ (1) with Na[B(C$^{6}$F$^{5}$)$^{4}$] furnished the dimeric phosphonium-like dication [Ph$^{3}$PC(Me)SiMe$^{2}$]$^{2}$[B(C$^{6}$F$^{5}$)$^{4}$]$^{2}$ (8). The highly reactive, mesityl- or iPr-substituted cationic species [Ph$^{3}$PC(Me)SiMes$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (9) and [Ph$^{3}$PC(Et)SiiPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (10) could be characterized by NMR spectroscopy. Carrying out the halide abstraction reaction in the sterically demanding ether iPr$^{2}$O afforded the protonated α-SiCP [Ph$^{3}$PCH(Et)Si(Cl)iPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (6 dec) by sodium-mediated basic ether decomposition, whereas successfully synthesized [Ph$^{3}$PC(Et)SiiPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (10) readily cleaves the F−C bond in fluorobenzene. Thus, the ambiphilic character of α-SiCPs is clearly demonstrated. The less reactive germanium analogue [Ph$^{3}$PC(Me)GeMes$^{2}$][B{3,5-(CF$^{3}$)$^{2}$C$^{6}$H$^{3}$}$^{4}$] (14) was obtained by treating 11 with Na[B{3,5-(CF$^{3}$)$^{2}$C$^{6}$H$^{3}$}$^{4}$] and fully characterized including by X-ray diffraction analysis. Structural parameters indicate a strong C$^{Ylide}$−Ge interaction with high double bond character, and consequently the C−E (E=Si, Ge) bonds in 9, 10 and 14 were analyzed with NBO and AIM methods

Luther und die Reformation in internationalen Geschichtskulturen

What do texbook write to the topic reformation? How do they interprete the legacy of Martin Luther? How do they depict the role of the catholic church? This book proviedes answers to these questions in the ligth of discourses within history education research.Was schreiben Schulbücher zum Thema Reformation? Wie deuten sie das Wirken Martin Luthers? Wie stellen sie die Rolle der katholischen Kirche? Das Buch reflektiert die Antworten auf diese Fragen im Licht geschichtsdidaktischer Diskurse

Luther und die Reformation in internationalen Geschichtskulturen

What do texbook write to the topic reformation? How do they interprete the legacy of Martin Luther? How do they depict the role of the catholic church? This book proviedes answers to these questions in the ligth of discourses within history education research

Mythen in deutschsprachigen Geschichtsschulbüchern

Even in the 21st century, history textbooks are full of historical myths. This volume draws on cultural studies and history didactics to illuminate some of the myths contained in German Speking History Textbooks. The volume also reflects in depth upon the concept of ‘myth’ and proposes a definition that ties in to academic discourse on historical learning without denying the concept’s roots in cultural studies.Geschichtsschulbücher sind auch im 21. Jahrhundert immer noch reichlich mit historischen Mythen durchsetzt. In diesem Sammelband werden solche Mythen in Schulbüchern aus Deutschland, Österreich und der Schweiz aus kulturwissenschaftlicher und geschichtsdidaktischer Perspektive beleuchtet. Auch wird hier der Mythenbegriff geschichtsdidaktisch innovativ reflektiert und einleitend ein Vorschlag zu einer Definition unterbreitet, die einerseits anschlussfähig an die akademische Diskussion über historisches Lernen ist ,andererseits jedoch auch ihre kulturwissenschaftlichen Grundlagen nicht verleugnet

Health-Related Quality of Life and Mental Health after Surgical Treatment of Hepatocellular Carcinoma in the Era of Minimal-Invasive Surgery: Resection versus Transplantation

Laparoscopic liver resection (LLR) is an increasingly relevant treatment option for patients with resectable hepatocellular carcinoma (HCC). Orthotopic liver transplantation (OLT) has been considered optimal treatment for HCC in cirrhosis, but is challenged by rising organ scarcity. While health-related quality of life (HRQoL) and mental health are well-documented after OLT, little is known about HRQoL in HCC patients after LLR. We identified all HCC patients who underwent LLR at our hospital between 2014 and 2018. HRQoL and mental health were assessed using the Short Form 36 and the Hospital Anxiety and Depression Scale, respectively. Outcomes were compared to a historic cohort of HCC patients after OLT. Ninety-eight patients received LLR for HCC. Postoperative morbidity was 25% with 17% minor complications. LLR patients showed similar overall HRQoL and mental health to OLT recipients, except for lower General Health (p = 0.029) and higher anxiety scores (p = 0.010). We conclude that LLR can be safely performed in patients with HCC, with or without liver cirrhosis. The postoperative HRQoL and mental health are comparable to that of OLT recipients in most aspects. LLR should thus always be considered an alternative to OLT, especially in times of organ shortage

Adult cerebellar glioblastoma categorized into a pediatric methylation class with a unique radiological and histological appearance: illustrative case

BACKGROUND Recent studies report that cerebellar glioblastoma (GBM) is categorized into the RTK1 methylation class. GBM pediatric RTK (pedRTK) subtypes are distinct from those of adult GBM. We present a unique adult case of cerebellar GBM classified into the pedRTK subtype.OBSERVATIONS Magnetic resonance imaging revealed a homogeneous enhancing lesion in the right cerebellum in a 56-year-old woman presenting with ataxia and dizziness. Arterial spin labeling and angiographic findings and the intraoperative orange-colored tumor appearance were reminiscent of hemangioblastoma. She showed an atypical presentation in terms of high glucose metabolism. The histological diagnosis was high-grade glioma with differentiation similar to central nervous system neuroblastoma. The methylation class was GBM pedRTK1. Consistent with this classification, immunoexpression was positive for SOX10 and negative for ANKRD55. She underwent craniospinal radiotherapy (23.4 Gy) with a boost to the tumor bed (total 55.8 Gy). Twelve courses of temozolomide therapy were administered. There was no recurrence 18 months after surgery.LESSONS Radiological and intraoperative findings, such as hemangioblastoma and high glucose metabolism, were notable characteristics in the present case. Both glial and neuronal differentiation and SOX10 immunoexpression were presenting pathological features. Similar cerebellar GBMs might form a previously unestablished subtype. Establishing effective molecular diagnoses is important

Glioblastomas with primitive neuronal component harbor a distinct methylation and copy‑number profle with inactivation of TP53, PTEN, and RB1

Glioblastoma IDH-wildtype presents with a wide histological spectrum. Some features are so distinctive that they are considered as separate histological variants or patterns for the purpose of classification. However, these usually lack defined (epi-)genetic alterations or profiles correlating with this histology. Here, we describe a molecular subtype with overlap to the unique histological pattern of glioblastoma with primitive neuronal component. Our cohort consists of 63 IDH-wildtype glioblastomas that harbor a characteristic DNA methylation profile. Median age at diagnosis was 59.5 years. Copy-number variations and genetic sequencing revealed frequent alterations in TP53, RB1 and PTEN, with fewer gains of chromosome 7 and homozygous CDKN2A/B deletions than usually described for IDH-wildtype glioblastoma. Gains of chromosome 1 were detected in more than half of the cases. A poorly differentiated phenotype with frequent absence of GFAP expression, high proliferation index and strong staining for p53 and TTF1 often caused misleading histological classification as carcinoma metastasis or primitive neuroectodermal tumor. Clinically, many patients presented with leptomeningeal dissemination and spinal metastasis. Outcome was poor with a median overall survival of only 12 months. Overall, we describe a new molecular subtype of IDH-wildtype glioblastoma with a distinct histological appearance and genetic signature.publishedVersio

Glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA): a molecularly distinct brain tumor type with recurrent NTRK gene fusions

Glioneuronal tumors are a heterogenous group of CNS neoplasms that can be challenging to accurately diagnose. Molecular methods are highly useful in classifying these tumors-distinguishing precise classes from their histological mimics and identifying previously unrecognized types of tumors. Using an unsupervised visualization approach of DNA methylation data, we identified a novel group of tumors (n = 20) that formed a cluster separate from all established CNS tumor types. Molecular analyses revealed ATRX alterations (in 16/16 cases by DNA sequencing and/or immunohistochemistry) as well as potentially targetable gene fusions involving receptor tyrosine-kinases (RTK; mostly NTRK1-3) in all of these tumors (16/16; 100%). In addition, copy number profiling showed homozygous deletions of CDKN2A/B in 55% of cases. Histological and immunohistochemical investigations revealed glioneuronal tumors with isomorphic, round and often condensed nuclei, perinuclear clearing, high mitotic activity and microvascular proliferation. Tumors were mainly located supratentorially (84%) and occurred in patients with a median age of 19 years. Survival data were limited (n = 18) but point towards a more aggressive biology as compared to other glioneuronal tumors (median progression-free survival 12.5 months). Given their molecular characteristics in addition to anaplastic features, we suggest the term glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA) to describe these tumors. In summary, our findings highlight a novel type of glioneuronal tumor driven by different RTK fusions accompanied by recurrent alterations in ATRX and homozygous deletions of CDKN2A/B. Targeted approaches such as NTRK inhibition might represent a therapeutic option for patients suffering from these tumors