Expectation-Complete Graph Representations with Homomorphisms

We investigate novel random graph embeddings that can be computed in expected polynomial time and that are able to distinguish all non-isomorphic graphs in expectation. Previous graph embeddings have limited expressiveness and either cannot distinguish all graphs or cannot be computed efficiently for every graph. To be able to approximate arbitrary functions on graphs, we are interested in efficient alternatives that become arbitrarily expressive with increasing resources. Our approach is based on Lov\'asz' characterisation of graph isomorphism through an infinite dimensional vector of homomorphism counts. Our empirical evaluation shows competitive results on several benchmark graph learning tasks.Comment: accepted for publication at ICML 202

An exploratory study on the role of serum fatty acids in the short-term dietary therapy of gingivitis.

A previous randomised controlled trial showed that an anti-inflammatory diet (AID) significantly reduced gingival inflammation despite constant plaque values. This exploratory study investigated the role of serum fatty acids in relation to the observed clinical effects. Therefore, data of thirty participants with gingivitis, following either a pro-inflammatory dietary pattern (PID) rich in saturated fat, omega 6 fatty acids, and refined carbohydrates or an AID for 4 weeks, were correlated with corresponding serum samples for a variety of fatty acids. Changes in the fatty acid profile and effects on clinical periodontal parameters were analysed. Results showed that the polyunsatured:saturated fatty acids ratio (PUFA:SFA ratio) and nervonic acid level were significantly higher in the AID group than in the PID group at the end of the study. Significant intragroup differences were seen only in the AID group. Diverse fatty acids showed heterogeneous relations to clinical parameters. This study demonstrated that the serum fatty acid profile was not fundamentally associated with the clinical gingivitis-lowering effects of an AID in short-term, although some fatty acids showed individual relations to clinical parameters with respect to inflammation. Hence, short-term effects of dietary therapy on gingivitis may be rather based on carbohydrate-related effects and/or micronutrients

Naturschutzleistungen des Ökologischen Landbaus: Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen naturräumlicher Herkünfte auf Ökobetrieben

Die Intensivierung der Landwirtschaft hat zum Rückgang vieler Ackerwildpflanzen geführt. Der Ökologische Landbau bietet günstige Voraussetzungen für ihren Schutz. Wie entsprechende Populationen etabliert werden können, untersuchte ein Verbundprojekt der Bayerischen Landesanstalt für Landwirtschaft, der Technischen Universität München und der Universität Kassel. Die AG Freising untersuchte drei seltene winterannuelle Arten (Consolida regalis, Legousia speculumveneris, Lithospermum arvense) in mehrfaktoriellen Feldversuchen, in Praxisaus-saaten auf Bio-Betrieben sowie in Gewächshausexperimenten. Messgrößen waren Individuendichte, Samenproduktion und Bodensamenvorrat der Zielarten, zudem wurde der Ertrag der Feldfrüchte bestimmt. Frühe Herbstsaaten und geringe Konkurrenz durch Kulturen brachten beste Erfolge. Zur erfolgreichen Ansiedlung der Ackerwildkräuter wird eine Aussaat in Blanksaat oder in reduziert gesäten Winterungen, wie Dinkel oder Roggen, bis spätestens Mitte Oktober empfohlen. Klee-Gras und Sommerungen wie Erbsen ermöglichten kaum bzw. kein Auflaufen der Zielarten, die jedoch teils im Bodensamenvorrat überdauern. Die AG Witzenhausen untersuchte die Wiederansiedlung von Ackerwildkräutern auf Praxis-betrieben. Dazu wurden artenreiche Spenderflächen identifiziert und autochthones Saatgut gefährdeter Arten entnommen. Samenmischungen wurden in Blühfenster und den benachbarten Getreidebestand ausgebracht. Zudem wurde die Übertragung von Oberboden arten-reicher Flächen getestet. Im Anlagejahr konnte sich bei beiden Verfahren ein Teil der eingebrachten Arten reproduzieren. Dies gelang bei Konkurrenz mit Getreide tendenziell schlechter. In den Folgejahren konnten bei Anbau von Getreide wiederum einige Arten nachgewiesen werden; die meisten Samen gelangten bei Bodenbearbeitung in tiefere Bodenschichten und reicherten die Samenbank an. Praxisempfehlungen zur Wiederansiedlung von Ackerwildkräutern auf ökologisch bewirtschafteten Äckern wurden als Broschüre veröffentlicht

AZT-resistant foamy virus

AbstractAzidothymidine (AZT) is a reverse transcriptase (RT) inhibitor that efficiently blocks the replication of spumaretroviruses or foamy viruses (FVs). To more precisely elucidate the mechanism of action of the FV RT enzyme, we generated an AZT-resistant FV in cell culture. Biologically resistant virus was obtained for simian foamy virus from macaque (SFVmac), which was insensitive to AZT concentrations of 1 mM, but not for FVs derived from chimpanzees. Nucleotide sequencing revealed four non-silent mutations in the pol gene. Introduction of these mutations into an infectious molecular clone identified all changes to be required for the fully AZT-resistant phenotype of SFVmac. The alteration of individual sites showed that AZT resistance in SFVmac was likely acquired by consecutive acquisition of pol mutations in a defined order, because some alterations on their own did not result in an efficiently replicating virus, neither in the presence nor in the absence of AZT. The introduction of the mutations into the RT of the closely related prototypic FV (PFV) did not yield an AZT-resistant virus, instead they significantly impaired the viral fitness

Modulation of the Naked-Eye and Fluorescence Color of a Protonated Boron-Doped Thiazolothiazole by Anion-Dependent Hydrogen Bonding

The reaction of a cyclic alkyl(amino)carbene (CAAC)-stabilized thiazaborolo[5,4-d]thiazaborole (TzbTzb) with strong Brønsted acids, such as HCl, HOTf (Tf=O2SCF3) and [H(OEt2)2][BArF4] (ArF=3,5-(CF3)2C6H3), results in the protonation of both TzbTzb nitrogen atoms. In each case X-ray crystallographic data show coordination of the counteranions (Cl−, OTf−, BArF4−) or solvent molecules (OEt2) to the doubly protonated fused heterocycle via hydrogen-bonding interactions, the strength of which strongly influences the 1H NMR shift of the NH protons, enabling tuning of both the visible (yellow to red) and fluorescence (green to red) colors of these salts. DFT calculations reveal that the hydrogen bonding of the counteranion or solvent to the protonated nitrogen centers affects the intramolecular TzbTzb-to-CAAC charge transfer character involved in the S0→S1 transition, ultimately enabling fine-tuning of their absorption and emission spectral features

Molecularly defined diffuse leptomeningeal glioneuronal tumor (DLGNT) comprises two subgroups with distinct clinical and genetic features

Diffuse leptomeningeal glioneuronal tumors (DLGNT) represent rare CNS neoplasms which have been included in the 2016 update of the WHO classification. The wide spectrum of histopathological and radiological features can make this enigmatic tumor entity difficult to diagnose. In recent years, large-scale genomic and epigenomic analyses have afforded insight into key genetic alterations occurring in multiple types of brain tumors and provide unbiased, complementary tools to improve diagnostic accuracy. Through genome-wide DNA methylation screening of > 25,000 tumors, we discovered a molecularly distinct class comprising 30 tumors, mostly diagnosed histologically as DLGNTs. Copy-number profiles derived from the methylation arrays revealed unifying characteristics, including loss of chromosomal arm 1p in all cases. Furthermore, this molecular DLGNT class can be subdivided into two subgroups [DLGNT methylation class (MC)-1 and DLGNT methylation class (MC)-2], with all DLGNT-MC-2 additionally displaying a gain of chromosomal arm 1q. Co-deletion of 1p/19q, commonly seen in IDH-mutant oligodendroglioma, was frequently observed in DLGNT, especially in DLGNT-MC-1 cases. Both subgroups also had recurrent genetic alterations leading to an aberrant MAPK/ERK pathway, with KIAA1549:BRAF fusion being the most frequent event. Other alterations included fusions of NTRK1/2/3 and TRIM33:RAF1, adding up to an MAPK/ERK pathway activation identified in 80% of cases. In the DLGNT-MC-1 group, age at diagnosis was significantly lower (median 5 vs 14 years, p < 0.01) and clinical course less aggressive (5-year OS 100, vs 43% in DLGNT-MC-2). Our study proposes an additional molecular layer to the current histopathological classification of DLGNT, of particular use for cases without typical morphological or radiological characteristics, such as diffuse growth and radiologic leptomeningeal dissemination. Recurrent 1p deletion and MAPK/ERK pathway activation represent diagnostic biomarkers and therapeutic targets, respectively—laying the foundation for future clinical trials with, e.g., MEK inhibitors that may improve the clinical outcome of patients with DLGNT

Simple Questionnaires to Improve Pooling Strategies for SARS-CoV-2 Laboratory Testing

Background: Liberal PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is key to contain the coronavirus disease 2019 (COVID-19) pandemic. Combined multi-sample testing in pools instead of single tests might enhance laboratory capacity and reduce costs, especially in low- and middle-income countries. Objective: The purpose of our study was to assess the value of a simple questionnaire to guide and further improve pooling strategies for SARS-CoV-2 laboratory testing. Methods: Pharyngeal swabs for SARS-CoV-2 testing were obtained from healthcare and police staff, hospital inpatients, and nursing home residents in the southwestern part of Germany. We designed a simple questionnaire, which included questions pertaining to a suggestive clinical symptomatology, recent travel history, and contact with confirmed cases to stratify an individual’s pre-test probability of having contracted COVID-19. The questionnaire was adapted repeatedly in face of the unfolding pandemic in response to the evolving epidemiology and observed clinical symptomatology. Based on the response patterns, samples were either tested individually or in multi-sample pools. We compared the pool positivity rate and the number of total PCR tests required to obtain individual results between this questionnaire-based pooling strategy and randomly assembled pools. Findings: Between March 11 and July 5, 2020, we processed 25,978 samples using random pooling (n = 6,012; 23.1%) or questionnaire-based pooling (n = 19,966; 76.9%). The overall prevalence of SARS-CoV-2 was 0.9% (n = 238). Pool positivity (14.6% vs. 1.2%) and individual SARS-CoV-2 prevalence (3.4% vs. 0.1%) were higher in the random pooling group than in the questionnaire group. The average number of PCR tests needed to obtain the individual result for one participant was 0.27 tests in the random pooling group, as compared to 0.09 in the questionnaire-based pooling group, leading to a laboratory capacity increase of 73% and 91%, respectively, as compared to single PCR testing. Conclusions: Strategies that combine pool testing with a questionnaire-based risk stratification can increase laboratory testing capacities for COVID-19 and might be important tools, particularly in resource-constrained settings

Towards Our Common Digital Future. Flagship Report.

In the report “Towards Our Common Digital Future”, the WBGU makes it clear that sustainability strategies and concepts need to be fundamentally further developed in the age of digitalization. Only if digital change and the Transformation towards Sustainability are synchronized can we succeed in advancing climate and Earth-system protection and in making social progress in human development. Without formative political action, digital change will further accelerate resource and energy consumption, and exacerbate damage to the environment and the climate. It is therefore an urgent political task to create the conditions needed to place digitalization at the service of sustainable development

Eleven strategies for making reproducible research and open science training the norm at research institutions

Across disciplines, researchers increasingly recognize that open science and reproducible research practices may accelerate scientific progress by allowing others to reuse research outputs and by promoting rigorous research that is more likely to yield trustworthy results. While initiatives, training programs, and funder policies encourage researchers to adopt reproducible research and open science practices, these practices are uncommon inmanyfields. Researchers need training to integrate these practicesinto their daily work. We organized a virtual brainstorming event, in collaboration with the German Reproducibility Network, to discuss strategies for making reproducible research and open science training the norm at research institutions. Here, weoutline eleven strategies, concentrated in three areas:(1)offering training, (2)adapting research assessment criteria and program requirements, and (3) building communities. We provide a brief overview of each strategy, offer tips for implementation,and provide links to resources. Our goal is toencourage members of the research community to think creatively about the many ways they can contribute and collaborate to build communities,and make reproducible research and open sciencetraining the norm. Researchers may act in their roles as scientists, supervisors, mentors, instructors, and members of curriculum, hiring or evaluation committees. Institutionalleadership and research administration andsupport staff can accelerate progress by implementing change across their institution

Eleven strategies for making reproducible research and open science training the norm at research institutions

Across disciplines, researchers increasingly recognize that open science and reproducible research practices may accelerate scientific progress by allowing others to reuse research outputs and by promoting rigorous research that is more likely to yield trustworthy results. While initiatives, training programs, and funder policies encourage researchers to adopt reproducible research and open science practices, these practices are uncommon inmanyfields. Researchers need training to integrate these practicesinto their daily work. We organized a virtual brainstorming event, in collaboration with the German Reproducibility Network, to discuss strategies for making reproducible research and open science training the norm at research institutions. Here, weoutline eleven strategies, concentrated in three areas:(1)offering training, (2)adapting research assessment criteria and program requirements, and (3) building communities. We provide a brief overview of each strategy, offer tips for implementation,and provide links to resources. Our goal is toencourage members of the research community to think creatively about the many ways they can contribute and collaborate to build communities,and make reproducible research and open sciencetraining the norm. Researchers may act in their roles as scientists, supervisors, mentors, instructors, and members of curriculum, hiring or evaluation committees. Institutionalleadership and research administration andsupport staff can accelerate progress by implementing change across their institution