N=4 Multi-Particle Mechanics, WDVV Equation and Roots

We review the relation of N=4 superconformal multi-particle models on the real line to the WDVV equation and an associated linear equation for two prepotentials, F and U. The superspace treatment gives another variant of the integrability problem, which we also reformulate as a search for closed flat Yang-Mills connections. Three- and four-particle solutions are presented. The covector ansatz turns the WDVV equation into an algebraic condition, for which we give a formulation in terms of partial isometries. Three ideas for classifying WDVV solutions are developed: ortho-polytopes, hypergraphs, and matroids. Various examples and counterexamples are displayed

Reducing artifacts in surface meshes extracted from binary volumes

We present a mesh filtering method for surfaces extracted from binary volume data which guarantees a smooth and correct representation of the original binary sampled surface, even if the original volume data is inaccessible or unknown. This method reduces the typical block and staircase artifacts but adheres to the underlying binary volume data yielding an accurate and smooth representation. The proposed method is closest to the technique of Constrained Elastic Surface Nets (CESN). CESN is a specialized surface extraction method with a subsequent iterative smoothing process, which uses the binary input data as a set of constraints. In contrast to CESN, our method processes surface meshes extracted by means of Marching Cubes and does not require the binary volume. It acts directly and solely on the surface mesh and is thus feasible even for surface meshes of inaccessible or unknown volume data. This is possible by reconstructing information concerning the binary volume from artifacts in the extracted mesh and applying a relaxation method constrained to the reconstructed information

An die Arbeit!

Die Welt befindet sich in multiplen Krisen. Der Bund für Umwelt und Naturschutz Deutschland e.V. und der Deutsche Gewerkschaftsbund sind entschlossen, grundsätzliche Fragen unserer  gesellschaftlichen Ordnung neu auszuloten:  Dafür haben Olaf Bandt und Konrad Klingenburg  gemeinsame Statements für einen neuen sozial-ökologisch gerechten Gesellschaftsvertrag  formuliert

Efficient algorithms for electrostatic interactions including dielectric contrasts

Coarse grained models of soft matter are usually combined with implicit solvent models that take the electrostatic polarizability into account via a dielectric background. In biophysical or nanoscale simulations that include water, this constant can vary greatly within the system. Performing molecular dynamics or other simulations that need compute exact electrostatic interactions between charges in those systems is computationally demanding. We review here several algorithms developped by us that perform exactly this task. For planar dielectric surfaces in partial periodic boundary conditions, the arising image charges can be either treated with the MMM2D algorithm in a very efficient and accurate way, or with the ELC term that enables the user to use his favorite 3D periodic Coulomb solver . Arbitrarily shaped interfaces can be dealt with using induced surface charges with the ICC algorithm. Finally, the local electrostatics algorithm MEMD (Maxwell Equations Molecular Dynamics) allows even to employ a smoothly varying dielectric constant in the systems. We introduce the concepts of these three algorithms, and an extension for the inclusion of boundaries that are to be held fixed at constant potential (metal conditions). For each method, we present a showcase application to highlight the importance of dielectric interfaces

Recursive Definitions of Monadic Functions

Using standard domain-theoretic fixed-points, we present an approach for defining recursive functions that are formulated in monadic style. The method works both in the simple option monad and the state-exception monad of Isabelle/HOL's imperative programming extension, which results in a convenient definition principle for imperative programs, which were previously hard to define. For such monadic functions, the recursion equation can always be derived without preconditions, even if the function is partial. The construction is easy to automate, and convenient induction principles can be derived automatically.Comment: In Proceedings PAR 2010, arXiv:1012.455

Fever and hypothermia represent two populations of sepsis patients and are associated with outside temperature

Abstract Background Fever and hypothermia have been observed in septic patients. Their influence on prognosis is subject to ongoing debates. Methods We did a secondary analysis of a large clinical dataset from a quality improvement trial. A binary logistic regression model was calculated to assess the association of the thermal response with outcome and a multinomial regression model to assess factors associated with fever or hypothermia. Results With 6542 analyzable cases we observed a bimodal temperature response characterized by fever or hypothermia, normothermia was rare. Hypothermia and high fever were both associated with higher lactate values. Hypothermia was associated with higher mortality, but this association was reduced after adjustment for other risk factors. Age, community-acquired sepsis, lower BMI and lower outside temperatures were associated with hypothermia while bacteremia and higher procalcitonin values were associated with high fever. Conclusions Septic patients show either a hypothermic or a fever response. Whether hypothermia is a maladaptive response, as indicated by the higher mortality in hypothermic patients, or an adaptive response in patients with limited metabolic reserves under colder environmental conditions, remains an open question. Trial registration The original trial whose dataset was analyzed was registered at ClinicalTrials.gov (NCT01187134) on August 23, 2010, the first patient was included on July 1, 2011

Targeting class I histone deacetylase 2 in MYC amplified group 3 medulloblastoma

Introduction: Medulloblastoma (MB) is the most frequent malignant brain tumor in children. Four subgroups with distinct genetic, epigenetic and clinical characteristics have been identified. Survival remains particularly poor in patients with Group 3 tumors harbouring a MYC amplification. We herein explore the molecular mechanisms and translational implications of class I histone deacetylase (HDAC) inhibition in MYC driven MBs. Material and Methods: Expression of HDACs in primary MB subgroups was compared to normal brain tissue. A panel of MB cell lines, including Group 3 MYC amplified cell lines, were used as model systems. Cells were treated with HDAC inhibitors (HDACi) selectively targeting class I or IIa HDACs. Depletion of HDAC2 was performed. Intracellular HDAC activity, cellular viability, metabolic activity, caspase activity, cell cycle progression, RNA and protein expression were analyzed. Results: HDAC2 was found to be overexpressed in MB subgroups with poor prognosis (SHH, Group 3 and Group 4) compared to normal brain and the WNT subgroup. Inhibition of the enzymatic activity of the class I HDACs reduced metabolic activity, cell number, and viability in contrast to inhibition of class IIa HDACs. Increased sensitivity to HDACi was specifically observed in MYC amplified cells. Depletion of HDAC2 increased H4 acetylation and induced cell death. Simulation of clinical pharmacokinetics showed time-dependent on target activity that correlated with binding kinetics of HDACi compounds. Conclusions: We conclude that HDAC2 is a valid drug target in patients with MYC amplified MB. HDACi should cover HDAC2 in their inhibitory profile and timing and dosing regimen in clinical trials should take binding kinetics of compounds into consideration

Med Care

Abstract Background: As physicians are pressured to deliver an increasing number of preventive services, follow guidelines, engage in evidence-based practice, and deliver patient-centered care in managerially driven organizations, they struggle with how much control they have over their time

Durability of bioprosthetic aortic valve replacement in patients under the age of 60 years - 1-year follow-up from the prospective INDURE registry.

OBJECTIVES We report 1-year safety and clinical outcomes in patients <60 years undergoing bioprosthetic surgical aortic valve intervention. METHODS The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, multicentre registry to assess clinical outcomes of patients <60 years. Patients with planned SAVR with or without concomitant replacement of the ascending aorta and/or coronary bypass surgery were included. Time-related valve safety, haemodynamic performance, and quality of life (QoL) at 1 year were assessed. RESULTS 421 patients were documented with a mean age of 53.5 years, 76.5% being male, and 27.2% in NYHA class III/IV. Outcomes within 30 days included cardiovascular-related mortality (0.7%), time-related valve safety (VARC-2; 5.8%), thromboembolic events (1.7%), valve-related life-threatening bleeding (VARC-2; 4.3%), and permanent pacemaker implantation (3.8%). QoL was significantly increased at 6 months and sustained at 1 year. Freedom from all-cause mortality at 1 year was 98.3% (95%CI 97.1;99.6) and 81.8% were NYHA I vs. 21.9% at baseline. No patient developed structural valve deterioration Stage 3 (VARC-3). Mean aortic pressure gradient was 12.6 mmHg at 1 year and effective orifice area was 1.9 cm2. CONCLUSIONS The 1-year data from the INSPIRIS RESILIA valve demonstrate good safety and excellent haemodynamic performance as well as an early QoL improvement. CLINICALTRIALS NUMBER NCT03666741

Durability of bioprosthetic aortic valves in patients under the age of 60 years - Rationale and design of the international INDURE registry

Background: There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR. Methods: The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INS