Rapid determination of the dry weight of single, living cyanobacterial cells using the Mach-Zehnder double-beam interference microscope

The transmitted double-beam interference microscope was used to determine the dry weight per unit biovolume of single living cells, trichomes and mucous sheaths of eight mainly terrestrial species of cyanobacteria from cultures and in situ samples. The minimum dry weight was 131.7 fg µm-3 whereas the maximum was 459.2 fg µm-3 from single cell measurements. The average (±SD) of all 72 measurements was 265 ± 46 fg µm-3. This value is lower than the average calculated from literature data by a factor of 1.8. Additional elemental measurements of the amount of carbon resulted in an average value (±SD) of 48 ± 3% of dry weight, which corresponds with literature data. Thus we recommend a new conversion factor of 0.127 for biovolume (mm3) of cells to mg carbon, which could be used for cyanobacteria in respect to overall biomass calculations. Dry weight measurements were also carried out on the mucous sheaths of both trichomes (Phormidium) and coenobia (Gloeocapsa). Dry weights per unit volume of the sheaths varied greatly, ranging from 28 fg µm-3 (Phormidium) to 70 fg µm-3 and even 210 fg µm-3 (Gloeocapsa). In Gloeocapsa the dry mass of sheath material of a single coenobium exceeded the cellular dry weight 6-fold. As the interference microscopical technique is unique in its ability to determine dry masses of single living untreated cells, even in complex environmental samples, we intended to develop this method to make it available to a broad range of applications

A Card Game Description Language

Abstract. We present initial research regarding a system capable of generating novel card games. We furthermore propose a method for computationally analysing existing games of the same genre. Ultimately, we present a formalisation of card game rules, and a context-free grammar Gcardgame capable of expressing the rules of a large variety of card games. Example derivations are given for the poker variant Texas hold ’em, Blackjack and UNO. Stochastic simulations are used both to verify the implementation of these well-known games, and to evaluate the results of new game rules derived from the grammar. In future work, this grammar will be used to evolve completely novel card games using a grammarguided genetic program

In vivo assessment by Mach-Zehnder double-beam interferometry of the invasive force exerted by the Asian soybean rust fungus ( Phakopsora pachyrhizi )

Asian soybean rust (Phakopsora pachyrhizi) causes a devastating disease in soybean (Glycine max). We tested the hypothesis that the fungus generates high turgor pressure in its hyaline appressoria to mechanically pierce epidermal cells. Turgor pressure was determined by a microscopic technique, called transmitted light double-beam interference Mach–Zehnder microscopy (MZM), which was developed in the 1960s as a forefront of live cell imaging. We revitalized some original microscopes and equipped them for modern image capturing. MZM data were corroborated by cytorrhysis experiments. Incipient cytorrhysis determined the turgor pressure in appressoria of P. pachyrhizi to be equivalent to 5.13 MPa. MZM data revealed that osmotically active sugar alcohols only accounted for 75% of this value. Despite having a lower turgor pressure, hyaline rust appressoria were able to penetrate non-biodegradable polytetrafluoroethylene (PTFE) membranes more efficiently than do melanized appressoria of the anthracnose fungus Colletotrichum graminicola or the rice blast fungus Magnaporthe oryzae. Our findings challenge the hypotheses that force-based penetration is a specific hallmark of fungi differentiating melanized appressoria and that this turgor-driven process is solely caused by metabolic degradation products. The appressorial turgor pressure may explain the capability of P. pachyrhizi to forcefully invade a wide range of different plants and may pave the way to novel plant protection approaches

3D characterization of microstructured poly(methacrylic acid) thin films via Mach-Zehnder interference microscopy

We demonstrate the adaption of a further developed Mach–Zehnder interference (MZI) microscope for the rapid 3D characterization of transparent microstructured polymer thin films. In order to quantify the accuracy of the Mach-Zehnder interferometer, comparative film thickness measurements of photolithographically patterned poly(methacrylic acid) polymer brushes are performed employing two alternative techniques: white light profilometry (WIM) and atomic force microscopy (AFM). When the refractive index of the polymer brushes is calculated from MZI data, we obtain a good agreement with results received from an independent method (ellipsometry). In contrast to surface probing techniques such as AFM or WIM, Mach-Zehnder interferometry is a transmitted light method that measures both surface height profiles and refractive index distributions. MZI thus enables the quantification of film homogeneity with respect to height and density variations at the lateral resolution of a refraction limited microscope. We conclude that MZI is an adequate tool for the rapid and non-destructive characterization of structured polymer thin films. This method should be particularly useful for production quality control of microstructured polymer thin films which possess great potential in electronic device fabrication and biotechnology

Parallel murine and human aortic wall genomics reveals metabolic reprogramming as key driver of abdominal aortic aneurysm progression

BACKGROUND: While numerous interventions effectively interfered with abdominal aortic aneurysm (AAA) formation/progres-sion in preclinical models, none of the successes translated into clinical success. Hence, a systematic exploration of parallel and divergent processes in clinical AAA disease and its 2 primary models (the porcine pancreatic elastase and angiotensin-II infusion [AngII] murine model) was performed to identify mechanisms relevant for aneurysm disease. METHODS AND RESULTS: This study combines Movat staining and pathway analysis for histological and genomic comparisons between clinical disease and its models. The impact of a notable genomic signal for metabolic reprogramming was tested in a rescue trial (AngII model) evaluating the impact of 1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PFK15)-mediated interference with main glycolytic switch PFKFB3. Histological evaluation characterized the AngII model as a dissection model that is accompanied by adventitial fibrosis. The porcine pancreatic elastase model showed a transient inflammatory response and aortic dilatation, followed by stabilization and fibrosis. Normalization of the genomic responses at day 14 confirmed the self-limiting nature of the porcine pancreatic elastase model. Clear parallel genomic responses with activated adaptive immune responses, and particularly strong signals for metabolic switching were observed in human AAA and the AngII model. Rescue intervention with the glycolysis inhibitor PFK15 in the AngII model showed that interference with the glycolytic switching quenches aneurysm formation. CONCLUSIONS: Despite clear morphological contrasts, remarkable genomic parallels exist for clinical AAA disease and the AngII model. The metabolic response appears causatively involved in AAA progression and provides a novel therapeutic target. The clear transient genomic response classifies the porcine pancreatic elastase model as a disease initiation model

Parallel Murine and Human Aortic Wall Genomics Reveals Metabolic Reprogramming as Key Driver of Abdominal Aortic Aneurysm Progression

Background: While numerous interventions effectively interfered with abdominal aortic aneurysm (AAA) formation/progression in preclinical models, none of the successes translated into clinical success. Hence, a systematic exploration of parallel and divergent processes in clinical AAA disease and its 2 primary models (the porcine pancreatic elastase and angiotensin-II infusion [AngII] murine model) was performed to identify mechanisms relevant for aneurysm disease. Methods and Results: This study combines Movat staining and pathway analysis for histological and genomic comparisons between clinical disease and its models. The impact of a notable genomic signal for metabolic reprogramming was tested in a rescue trial (AngII model) evaluating the impact of 1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PFK15)-mediated interference with main glycolytic switch PFKFB3. Histological evaluation characterized the AngII model as a dissection model that is accompanied by adventitial fibrosis. The porcine pancreatic elastase model showed a transient inflammatory response and aortic dilatation, followed by stabilization and fibrosis. Normalization of the genomic responses at day 14 confirmed the self-limiting nature of the porcine pancreatic elastase model. Clear parallel genomic responses with activated adaptive immune responses, and particularly strong signals for metabolic switching were observed in human AAA and the AngII model. Rescue intervention with the glycolysis inhibitor PFK15 in the AngII model showed that interference with the glycolytic switching quenches aneurysm formation. Conclusions: Despite clear morphological contrasts, remarkable genomic parallels exist for clinical AAA disease and the AngII model. The metabolic response appears causatively involved in AAA progression and provides a novel therapeutic target. The clear transient genomic response classifies the porcine pancreatic elastase model as a disease initiation model