Characterizing correlations of flow oscillations at bottlenecks

"Oscillations" occur in quite different kinds of many-particle-systems when two groups of particles with different directions of motion meet or intersect at a certain spot. We present a model of pedestrian motion that is able to reproduce oscillations with different characteristics. The Wald-Wolfowitz test and Gillis' correlated random walk are shown to hold observables that can be used to characterize different kinds of oscillations

On the confluence of lambda-calculus with conditional rewriting

The confluence of untyped \lambda-calculus with unconditional rewriting is now well un- derstood. In this paper, we investigate the confluence of \lambda-calculus with conditional rewriting and provide general results in two directions. First, when conditional rules are algebraic. This extends results of M\"uller and Dougherty for unconditional rewriting. Two cases are considered, whether \beta-reduction is allowed or not in the evaluation of conditions. Moreover, Dougherty's result is improved from the assumption of strongly normalizing \beta-reduction to weakly normalizing \beta-reduction. We also provide examples showing that outside these conditions, modularity of confluence is difficult to achieve. Second, we go beyond the algebraic framework and get new confluence results using a restricted notion of orthogonality that takes advantage of the conditional part of rewrite rules

Spezielle Therapiesituationen beim metastasierten kolorektalen Karzinom

Specific Treatment Situations in Metastatic Colorectal Cancer As far as the management of primary resectable liver metastases is concerned, three approaches are currently competing with each other: surgery alone, surgery with pre- and postoperative chemotherapy, and surgery with postoperative chemotherapy alone. The core of the argument for pre- and postoperative chemotherapy in these patients is the European Organisation for Research and Treatment of Cancer (EORTC) 40983 study, which concluded that, in comparison with surgery alone, perioperative chemotherapy improved the 3-year progression-free survival (PFS) by 7 months. In contrast to this, there are two smaller studies - at a somewhat lower strength of evidence - indicating that adjuvant chemotherapy extends PFS by 9.1 months compared with surgery alone. In Germany, the adjuvant approach continues to be favored in many places; this can also be seen in the formulation of the S3 guideline. In patients with unresectable liver metastases - with the associated difficulty of classification due to the lack of clear and definitive criteria preoperative systemic therapy to induce `conversion' is indicated, in order to allow secondary resection. In KRAS wild-type tumors, high response rates ( in terms of a reduction in size of the metastases, such as according to RECIST ( Response Evaluation Criteria in Solid Tumors)) and a high conversion rate are achieved using a cetuximab/chemotherapy combination. Triple chemotherapy combinations with 5-fluorouracil (5-FU), oxaliplatin and irinotecan also produce high response rates. Bevacizumab/chemotherapy combinations have led to a high number of complete and partial pathohistological remissions in phase II studies; these seem to correlate with long survival times. In the absence of long-term survival data, it therefore seems to remain unclear as to what is the best parameter to use in order to assess the success of preoperative treatment. Lung metastases, too, or local peritoneal carcinomatosis can nowadays be operated on in selected patients with a good prospect of long-term remission or even cure. The surgery should, however, generally only be carried out in experienced centers, especially in the case of peritoneal carcinomatosis. For synchronous metastasization, the appropriate management depends on the size and extent of liver metastases and of the primary tumor. Small, peripherally lying and safely resectable liver metastases can be removed before or at the same time as the primary tumor, especially if a hemicolectomy is being carried out. If the metastases are unresectable and there is no bleeding or stenosis, the primary tumor can also be left in situ and systemic chemotherapy can be carried out first. However, it should be borne in mind that, according to current data, palliative resection of the primary tumor combined with systemic therapy leads to longer overall survival than does chemotherapy alone. Whether resection or chemotherapy should be done first therefore depends on the patient's clinical situation

Physics of Transport and Traffic Phenomena in Biology: from molecular motors and cells to organisms

Traffic-like collective movements are observed at almost all levels of biological systems. Molecular motor proteins like, for example, kinesin and dynein, which are the vehicles of almost all intra-cellular transport in eukayotic cells, sometimes encounter traffic jam that manifests as a disease of the organism. Similarly, traffic jam of collagenase MMP-1, which moves on the collagen fibrils of the extracellular matrix of vertebrates, has also been observed in recent experiments. Traffic-like movements of social insects like ants and termites on trails are, perhaps, more familiar in our everyday life. Experimental, theoretical and computational investigations in the last few years have led to a deeper understanding of the generic or common physical principles involved in these phenomena. In particular, some of the methods of non-equilibrium statistical mechanics, pioneered almost a hundred years ago by Einstein, Langevin and others, turned out to be powerful theoretical tools for quantitaive analysis of models of these traffic-like collective phenomena as these systems are intrinsically far from equilibrium. In this review we critically examine the current status of our understanding, expose the limitations of the existing methods, mention open challenging questions and speculate on the possible future directions of research in this interdisciplinary area where physics meets not only chemistry and biology but also (nano-)technology.Comment: 33 page Review article, REVTEX text, 29 EPS and PS figure

The Fundamental Diagram of Pedestrian Movement Revisited

The empirical relation between density and velocity of pedestrian movement is not completely analyzed, particularly with regard to the `microscopic' causes which determine the relation at medium and high densities. The simplest system for the investigation of this dependency is the normal movement of pedestrians along a line (single-file movement). This article presents experimental results for this system under laboratory conditions and discusses the following observations: The data show a linear relation between the velocity and the inverse of the density, which can be regarded as the required length of one pedestrian to move. Furthermore we compare the results for the single-file movement with literature data for the movement in a plane. This comparison shows an unexpected conformance between the fundamental diagrams, indicating that lateral interference has negligible influence on the velocity-density relation at the density domain $1 m^{-2}<\rho<5 m^{-2}$. In addition we test a procedure for automatic recording of pedestrian flow characteristics. We present preliminary results on measurement range and accuracy of this method.Comment: 13 pages, 9 figure

Platelets Boost Recruitment of CD133+ Bone Marrow Stem Cells to Endothelium and the Rodent Liver-The Role of P-Selectin/PSGL-1 Interactions

Lehwald N, Duhme C, Pinchuk I, et al. Platelets Boost Recruitment of CD133+ Bone Marrow Stem Cells to Endothelium and the Rodent Liver-The Role of P-Selectin/PSGL-1 Interactions. International journal of molecular sciences. 2020;21(17): 6431.We previously demonstrated that clinical administration of mobilized CD133+ bone marrow stem cells (BMSC) accelerates hepatic regeneration. Here, we investigated the potential of platelets to modulate CD133+BMSC homing to hepatic endothelial cells and sequestration to warm ischemic livers. Modulatory effects of platelets on the adhesion of CD133+BMSC to human and mouse liver-sinusoidal- and micro- endothelial cells (EC) respectively were evaluated in in vitro co-culture systems. CD133+BMSC adhesion to all types of EC were increased in the presence of platelets under shear stress. This platelet effect was mostly diminished by antagonization of P-selectin and its ligand P-Selectin-Glyco-Ligand-1 (PSGL-1). Inhibition of PECAM-1 as well as SDF-1 receptor CXCR4 had no such effect. In a model of the isolated reperfused rat liver subsequent to warm ischemia, the co-infusion of platelets augmented CD133+BMSC homing to the injured liver with heightened transmigration towards the extra sinusoidal space when compared to perfusion conditions without platelets. Extravascular co-localization of CD133+BMSC with hepatocytes was confirmed by confocal microscopy. We demonstrated an enhancing effect of platelets on CD133+BMSC homing to and transmigrating along hepatic EC putatively depending on PSGL-1 and P-selectin. Our insights suggest a new mechanism of platelets to augment stem cell dependent hepatic repair

Social Integrating Robots Suggest Mitigation Strategies for Ecosystem Decay

We develop here a novel hypothesis that may generate a general research framework of how autonomous robots may act as a future contingency to counteract the ongoing ecological mass extinction process. We showcase several research projects that have undertaken first steps to generate the required prerequisites for such a technology-based conservation biology approach. Our main idea is to stabilise and support broken ecosystems by introducing artificial members, robots, that are able to blend into the ecosystem's regulatory feedback loops and can modulate natural organisms' local densities through participation in those feedback loops. These robots are able to inject information that can be gathered using technology and to help the system in processing available information with technology. In order to understand the key principles of how these robots are capable of modulating the behaviour of large populations of living organisms based on interacting with just a few individuals, we develop novel mathematical models that focus on important behavioural feedback loops. These loops produce relevant group-level effects, allowing for robotic modulation of collective decision making in social organisms. A general understanding of such systems through mathematical models is necessary for designing future organism-interacting robots in an informed and structured way, which maximises the desired output from a minimum of intervention. Such models also help to unveil the commonalities and specificities of the individual implementations and allow predicting the outcomes of microscopic behavioural mechanisms on the ultimate macroscopic-level effects. We found that very similar models of interaction can be successfully used in multiple very different organism groups and behaviour types (honeybee aggregation, fish shoaling, and plant growth). Here we also report experimental data from biohybrid systems of robots and living organisms. Our mathematical models serve as building blocks for a deep understanding of these biohybrid systems. Only if the effects of autonomous robots onto the environment can be sufficiently well predicted can such robotic systems leave the safe space of the lab and can be applied in the wild to be able to unfold their ecosystem-stabilising potential

Pancreatic ductal adenocarcinoma concomitant with pancreatic metastases of clear-cell renal cell carcinoma: a case report

Background!#!Metastatic spread to the pancreas is a rare event. Renal cell carcinoma represents one possible site of origin of pancreatic metastases. Renal cell carcinoma often metastasizes late and exclusively to the pancreas, suggesting a special role of renal cell carcinoma among primaries metastasizing to the pancreas. Even rarer, renal cell carcinoma may occur simultaneously with pancreatic ductal adenocarcinoma.!##!Case presentation!#!We present the case of a 78-year-old male Caucasian patient with a history of clear-cell renal cell carcinoma treated with oncological left nephrectomy 20 years before. The patient was diagnosed with pancreatic ductal adenocarcinoma by fine-needle aspiration cytology. At our institution, he received neoadjuvant therapy with folic acid, fluorouracil, irinotecan, oxaliplatin for borderline-resectable pancreatic ductal adenocarcinoma, and subsequently underwent total pancreatectomy. Upon resection, pancreatic ductal adenocarcinoma as well as two metachronous metastases of clear-cell renal cell carcinoma occurring simultaneously and cospatially with pancreatic ductal adenocarcinoma were diagnosed in the pancreatic body.!##!Conclusions!#!Renal cell carcinoma metastases of the pancreas are rare and often occur decades after the initial diagnosis of renal cell carcinoma. The combination of renal cell carcinoma metastases and pancreatic ductal adenocarcinoma is even rarer. However, the possibility should be considered by clinicians, radiologists, and pathologists. The special role of renal cell carcinoma as a site of origin of pancreatic metastasis should be further elucidated