Phylogeny and phylogeography of chelonians from sub-Saharan Africa—A review of current knowledge in tribute to Margaretha D. Hofmeyr

Species-level phylogeny and especially phylogeography of African chelonians is a comparatively under-studied field of research. We review the current knowledge of phylogeny and phylogeography, highlight congruence of spatial phylogeographic patterns amongst chelonians and other taxa and suggest future research directions to address gaps in knowledge. Our review shows that phylogeographic and phylogenetic investigations have led to unexpected findings. For example, for Pelomedusa, a putatively wide-ranging monotypic terrapin genus, cryptic diversity was revealed, with more than ten species being uncovered. The formerly recognized tortoise genus Homopus sensu lato was found to be paraphyletic with respect to Chersina. To resolve this situation, Homopus was restricted to the four-toed species H. areolatus and H. femoralis and the genus Chersobius was resurrected for the five-toed species C. boulengeri, C. signatus, and C. solus. Three previously recognized taxa were shown to be invalid, viz. the putatively extinct terrapin species Pelusios seychellensis and the tortoise subspecies Chersobius signatus cafer and Stigmochelys pardalis babcocki. Together with taxonomy, the knowledge of phylogeographic structuring sets a solid foundation for conservation measures and allows the identification of Management and Conservation Units. However, the current legislation, in particular the enforcement of the Nagoya Protocol under the Convention of Biological Diversity (CBD), has largely halted research on widely distributed taxa and turned the well-intended concept of Access and Benefit Sharing into a major impediment for conservation and research. The current situation leads for many species to a continued usage of outdated and incorrect taxonomic classifications resulting in an error cascade of conservation decisions. This is counterproductive to the aims of the CBD, that is, the protection of biodiversity. Sequencing historical DNA from museum specimens using aDNA approaches could be a short-term approach to mitigate, but not solve, this impediment

DNA methylation classifier to diagnose pancreatic ductal adenocarcinoma metastases from different anatomical sites

Background - We have recently constructed a DNA methylation classifier that can discriminate between pancreatic ductal adenocarcinoma (PAAD) liver metastasis and intrahepatic cholangiocarcinoma (iCCA) with high accuracy (PAAD-iCCA-Classifier). PAAD is one of the leading causes of cancer of unknown primary and diagnosis is based on exclusion of other malignancies. Therefore, our focus was to investigate whether the PAAD-iCCA-Classifier can be used to diagnose PAAD metastases from other sites. Methods - For this scope, the anomaly detection filter of the initial classifier was expanded by 8 additional mimicker carcinomas, amounting to a total of 10 carcinomas in the negative class. We validated the updated version of the classifier on a validation set, which consisted of a biological cohort (n = 3579) and a technical one (n = 15). We then assessed the performance of the classifier on a test set, which included a positive control cohort of 16 PAAD metastases from various sites and a cohort of 124 negative control samples consisting of 96 breast cancer metastases from 18 anatomical sites and 28 carcinoma metastases to the brain. Results - The updated PAAD-iCCA-Classifier achieved 98.21% accuracy on the biological validation samples, and on the technical validation ones it reached 100%. The classifier also correctly identified 15/16 (93.75%) metastases of the positive control as PAAD, and on the negative control, it correctly classified 122/124 samples (98.39%) for a 97.85% overall accuracy on the test set. We used this DNA methylation dataset to explore the organotropism of PAAD metastases and observed that PAAD liver metastases are distinct from PAAD peritoneal carcinomatosis and primary PAAD, and are characterized by specific copy number alterations and hypomethylation of enhancers involved in epithelial-mesenchymal-transition. Conclusions - The updated PAAD-iCCA-Classifier (available at https://classifier.tgc-research.de/) can accurately classify PAAD samples from various metastatic sites and it can serve as a diagnostic aid

BIRA: A Spherical Bistatic Reflectivity Measurement System

The upcoming 6G mobile communication standard will offer a revolutionary new feature: Integrated sensing and communication (ISAC) reuses mobile communication signals to realize multi-static radar for various applications including localization. Consequently, applied ISAC propagation research necessitates to evolve from classical monostatic radar cross section (RCS) measurement of static targets on to bistatic radar reflectivity characterization of dynamic objects. Here, we introduce our "Bistatic Radar" (BIRA) and antenna measurement facility for bistatic spherical positioning with sub-millimeter accuracy on a diameter of up to 7 m and with almost continuous frequency coverage from 0.7 up to 260 GHz. Currently, BIRA is the only bistatic measurement facility capable of unrestricted ISAC research: In addition to vector network analysis, BIRA employs advanced wideband transceiver technology with an instantaneous bandwidth of up to 4 GHz. These transceivers grant BIRA the unique ability to characterize dynamic targets in both Doppler and range, while also significantly accelerating RCS measurements of static objects.Comment: 9 pages, 8 figure

Distinct tissue niches direct lung immunopathology via CCL18 and CCL21 in severe COVID-19

Prolonged lung pathology has been associated with COVID-19, yet the cellular and molecular mechanisms behind this chronic inflammatory disease are poorly understood. In this study, we combine advanced imaging and spatial transcriptomics to shed light on the local immune response in severe COVID-19. We show that activated adventitial niches are crucial microenvironments contributing to the orchestration of prolonged lung immunopathology. Up-regulation of the chemokines CCL21 and CCL18 associates to endothelial-to-mesenchymal transition and tissue fibrosis within these niches. CCL21 over-expression additionally links to the local accumulation of T cells expressing the cognate receptor CCR7. These T cells are imprinted with an exhausted phenotype and form lymphoid aggregates that can organize in ectopic lymphoid structures. Our work proposes immune-stromal interaction mechanisms promoting a self-sustained and non-resolving local immune response that extends beyond active viral infection and perpetuates tissue remodeling

Diagnosing recipient- vs. donor-derived posttransplant myelodysplastic neoplasm via targeted single-cell mutational profiling

BACKGROUND: Distinguishing donor- vs. recipient-derived myelodysplastic neoplasm (MDS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is challenging and has direct therapeutical implications. METHODS: Here, we took a translational approach that we used in addition to conventional diagnostic techniques to resolve the origin of MDS in a 38-year-old patient with acquired aplastic anemia and evolving MDS after first allo-HSCT. Specifically, we used single-cell transcriptional profiling to differentiate between donor- and recipient-derived bone marrow cells and established a strategy that additionally allows identification of cells carrying the MDS-associated U2AF1(S34Y) variant. RESULTS: The patient exhibited mixed donor chimerism combined with severely reduced erythropoiesis and dysplastic morphology within the granulocytic and megakaryocytic lineage along with the MDS-associated U2AF1(S34Y) mutation in the bone marrow. Single-cell transcriptional profiling together with targeted enrichment of the U2AF1(S34Y)-specific locus further revealed that, while the immune compartment was mainly populated by donor-derived cells, myelopoiesis was predominantly driven by the recipient. Additionally, concordant with recipient-derived MDS, we found that U2AF1(S34Y)-mutated cells were exclusively recipient derived with X but not Y chromosome-specific gene expression. CONCLUSION: Our study highlights the clinical potential of integrating high-resolution single-cell techniques to resolve complex cases for personalized treatment decisions

Distinct tissue niches direct lung immunopathology via CCL18 and CCL21 in severe COVID-19

Prolonged lung pathology has been associated with COVID-19, yet the cellular and molecular mechanisms behind this chronic inflammatory disease are poorly understood. In this study, we combine advanced imaging and spatial transcriptomics to shed light on the local immune response in severe COVID-19. We show that activated adventitial niches are crucial microenvironments contributing to the orchestration of prolonged lung immunopathology. Up-regulation of the chemokines CCL21 and CCL18 associates to endothelial-to-mesenchymal transition and tissue fibrosis within these niches. CCL21 over-expression additionally links to the local accumulation of T cells expressing the cognate receptor CCR7. These T cells are imprinted with an exhausted phenotype and form lymphoid aggregates that can organize in ectopic lymphoid structures. Our work proposes immune-stromal interaction mechanisms promoting a self-sustained and non-resolving local immune response that extends beyond active viral infection and perpetuates tissue remodeling

FLEXIBLE Cu In,Ga Se2 THIN FILM SOLAR CELLS FOR SPACE APPLICATIONS RECENT RESULTS FROM A GERMAN JOINT PROJECT PIPV2

Since 2007 a German consortium of academic and industrial partners develops an extremely light and flexible Cu(In,Ga)Se2 (CIGSe) thin film solar cell technology for space applications. The combination with a light support structure and an appropriate interconnection technology enables the construction of a solar generator with previously unmatched specific power (W/kg). This can be attractive as power supply for large platforms in space and is also compatible with alternative, flexible large area applications. The idea of the project is to utilize a solar cell technology, which - in comparison to the highly efficient, multi-junction III-V technology - is cheap and can be fabricated using manufacturing facilities for the terrestrial technology. Project activities encompass topics as fundamental as CIGSe thin film growth, individual aspects of single device components and also device interconnection, together with a corresponding support structure development. So far a maximum efficiency of 12.6% (57.8 cm²; AM1.5) could be demonstrated on an in-line roll-to-roll fabricated single device and a support structure prototype with a projected area density <1 kg/m² has been demonstrated. An earlier version of this constantly evolving technology was successfully tested on-orbit as part of the TET-1 mission

Estimation of fading parameter correlation for modeling the land mobile satellite channel

This paper addresses the correlation of fading signal parameters for dual-satellite land mobile satellite (LMS) channels. We use Loo's model to describe the slow and fast variations that occur due to varying shadowing conditions and multipath fading, respectively. Loo's parameters (mean power of direct signal component, standard deviaton of direct signal component, and average multipath power) are estimated segment-by-segment from fading signals of two simultaneously measured geostationary satellites using a curve-fitting approach. The parameter correlation between the signals of the two satellites is investigated. A significant correlation is found in the mean power of the direct signal components in some environments, when both satellites are shadowed or blocked by obstacles