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Cutting Planes from Wide Split Disjunctions [chapter]

Pierre Bonami, Andrea Lodi, Andrea Tramontani, Sven Wiese
2017 Lecture Notes in Computer Science  
In this paper, we discuss an extension of split cuts that is based on widening the underlying disjunctions. That the formula for deriving intersection cuts based on splits can be adapted to this case has been known for a decade now. For the first time though, we present applications and computational results. We further discuss extensions of the existing theory with respect to cut strengthening procedures, and present some ideas on how to use the wider disjunctions also in branching. D(y 5,5 )
more » ... {1, 2, 5, 6, 8}. In MILP instead, we would write 1 ≤ y 5,5 ≤ 8, y 5,5 ∈ Z,
doi:10.1007/978-3-319-59250-3_9 fatcat:idyidjuhyzdgvl4o2coyennluy

Mathematical programming techniques in water network optimization

Claudia D'Ambrosio, Andrea Lodi, Sven Wiese, Cristiana Bragalli
2015 European Journal of Operational Research  
In this article we survey mathematical programming approaches to problems in the field of water network optimization. Predominant in the literature are two different, but related problem classes. One can be described by the notion of network design, while the other is more aptly termed by network operation. The basic underlying model in both cases is a nonlinear network flow model, and we give an overview on the more specific modeling aspects in each case. The overall mathematical model is a
more » ... ed Integer Nonlinear Program having a common structure with respect to how water dynamics in pipes is described. Finally, we survey the algorithmic approaches to solve the proposed problems and we discuss computation on various types of water networks.
doi:10.1016/j.ejor.2014.12.039 fatcat:bnz2xndmdrayjfyvomcp2dg7hi

Antitumor Anthraquinones from an Easter Island Sea Anemone: Animal or Bacterial Origin?

Ignacio Sottorff, Sven Künzel, Jutta Wiese, Matthias Lipfert, Nils Preußke, Frank Sönnichsen, Johannes Imhoff
2019 Marine Drugs  
The presence of two known anthraquinones, Lupinacidin A and Galvaquinone B, which have antitumor activity, has been identified in the sea anemone (Gyractis sesere) from Easter Island. So far, these anthraquinones have been characterized from terrestrial and marine Actinobacteria only. In order to identify the anthraquinones producer, we isolated Actinobacteria associated with the sea anemone and obtained representatives of seven actinobacterial genera. Studies of cultures of these bacteria by
more » ... LC, NMR, and HRLCMS analyses showed that the producer of Lupinacidin A and Galvaquinone B indeed was one of the isolated Actinobacteria. The producer strain, SN26_14.1, was identified as a representative of the genus Verrucosispora. Genome analysis supported the biosynthetic potential to the production of these compounds by this strain. This study adds Verrucosispora as a new genus to the anthraquinone producers, in addition to well-known species of Streptomyces and Micromonospora. By a cultivation-based approach, the responsibility of symbionts of a marine invertebrate for the production of complex natural products found within the animal's extracts could be demonstrated. This finding re-opens the debate about the producers of secondary metabolites in sea animals. Finally, it provides valuable information about the chemistry of bacteria harbored in the geographically-isolated and almost unstudied, Easter Island.
doi:10.3390/md17030154 fatcat:2jlcxkjtgvdy5jwi5grymtraze

Bringing Policy Decisions to the People—Education for Sustainable Development through a Digital Simulation Game

Sven Ivens, Gerlinde Wiese, Klaus Dittert, Oliver Mußhoff, Monika Oberle
2020 Sustainability  
After repeated warnings by the European Commission regarding high nitrate concentrations in German waters, in 2017, Germany implemented a new fertilizer application ordinance (FO) with stricter nitrate value limits. The new regulations have severely affected agricultural regions in Germany and could lead to a high number of job losses if farmers must conform to the new regulations and do not implement new production methods. Therefore, a simulation game was developed to educate farmers and
more » ... ents about the new FO and to facilitate adaptation to the new environmentally friendly legislation. The aims of the newly developed simulation game are to educate residents and farmers in affected regions about the new FO and to develop new ideas on how to comply with the new regulations. The aims of the present study are, first, to research participants' evaluation of the simulation game and, second, to assess the effect of the simulation game on subjective knowledge, internal efficacy, and attitude towards the new FO. This pre- and post-comparison design study was based on pre-test and post-test with participants in two games (N = 90). The results were analyzed using descriptive statistics, multiple regression analyses, qualitative content analysis, and mean value comparisons. The simulation game had a positive effect on participants' subjective knowledge (Cohen's d 0.65) and internal efficacy (Cohen's d 0.36), but it did not have an effect on their attitudes toward the new FO, and it was shown to slightly lower their interest in agriculture politics (Cohen's d −0.33). The participants reported that the game made them more aware of both the difficulty and necessity of finding compromises in the field of agriculture politics. Overall, the simulation was rated very positively and was perceived as interesting and informative by the participants.
doi:10.3390/su12208743 fatcat:s4zt6ear7vfkzgakkslbs4zzmq

Interaction of CAP18-Derived Peptides with Membranes Made from Endotoxins or Phospholipids

Thomas Gutsmann, Sven O. Hagge, James W. Larrick, Ulrich Seydel, Andre Wiese
2001 Biophysical Journal  
, peptides, and other chemicals For the formation of planar membranes, monolayers, and liposomes, deep rough mutant LPS from Escherichia coli strain F515 (F515 LPS) (chemical structures according to Wiese  ...  chemical structure of LPSs of different bacterial strains is responsible for their sensitivity or resistance against rCAP18 106 -137 (Gutsmann et al., 1999 (Gutsmann et al., , 2000 and polymyxin B (Wiese  ... 
doi:10.1016/s0006-3495(01)76259-5 pmid:11371466 pmcid:PMC1301477 fatcat:bgeo32pewnathlyelsewfjzewa

Noninvasive Mechanical Ventilation Improves Endurance Performance in Patients With Chronic Respiratory Failure Due to Thoracic Restriction

Bernd Schonhofer, Sven Wallstein, Conny Wiese, Dieter Kohler
2001 Chest  
Objective: Treatment with noninvasive mechanical ventilation (NMV) alleviates hypoventilation and improves gas exchange in patients with chronic respiratory failure (CRF) due to thoracic restriction. However, little is known about the effects of NMV on respiratory and peripheral muscle endurance. Design: Prospective case-control study. Subjects: Ten patients in clinically stable condition (age, 53.5 ؎ 8.2 years [mean ؎ SD]) with mild-to-moderate CRF due to thoracic restriction (PCO 2 between 45
more » ... mm Hg and 55 mm Hg) were treated with NMV during the night for 3 months. Ten matched patients (age, 52.2 ؎ 9.5 years) receiving 3 months of normal care without NMV served as a control group. Intervention and measurements: After a 3-day period of familiarization with the endurance tests, all patients performed a baseline preintervention inspiratory threshold loading test, cycle ergometer test, and shuttle walking test on the same day. The endurance tests were then repeated following the 3-month intervention period. Results: NMV was used on average for 7.1 ؎ 0.9 h/d during the 3-month period. There was a significant improvement in endurance time (p < 0.0001) in all three endurance tests in the NMV group compared with the control group. In the NMV group, endurance time increased by 278 ؎ 269% during the inspiratory threshold loading test, by 176 ؎ 159% during the cycle ergometer test, and by 32 ؎ 22% during the shuttle walking test. Significant improvements (p < 0.01) in both PO 2 and PCO 2 were also observed in the NMV group but not in the control group. Conclusions: Three months of treatment with NMV increases both respiratory and peripheral muscle endurance in patients with CRF due to thoracic restriction. (CHEST 2001; 119:1371-1378) Abbreviations: CRF ϭ chronic respiratory failure; fresp ϭ breathing frequency; NMV ϭ noninvasive mechanical ventilation; PCV ϭ pressure-controlled ventilation; Pimax ϭ peak static inspiratory mouth pressure; V co 2 ϭ carbon dioxide elimination; VC ϭ vital capacity; VCV ϭ volume-controlled ventilation; V o 2 ϭ oxygen consumption; Vt ϭ tidal volume *From the Krankenhaus Kloster Grafschaft, Zentrum fü r Pneumologie, Beatmungs-und Schlafmedizin,
doi:10.1378/chest.119.5.1371 pmid:11348941 fatcat:qvvsvsl2xje3ziecxhmn6b6gyy

Inhibition of Heat Shock Protein 90 with AUY922 Represses Tumor Growth in a Transgenic Mouse Model of Islet Cell Neoplasms

Volker Fendrich, Sven Wichmann, Dominik Wiese, Jens Waldmann, Matthias Lauth, Peter Rexin, Carolin L.-Lopez, Hans J. Schlitt, Detlef K. Bartsch, Sven A. Lang
2014 Neuroendocrinology  
compared to untreated controls (p = 0.000), and median survival in the used transgenic mouse model was prolonged (110 vs. 119 days; p = 0.75). Quantitative real-time PCR for downstream target genes of HSP90 demonstrated significant downregulation in the islet cell tumors of RIP1-Tag2 mice treated with AUY922, confirming our ability to achieve effective pharmacologic levels of AUY922 within the desired tissue site in vivo. Conclusion: This is the first study to show that the HSP90 antagonist
more » ... 22 may provide a new option for therapy of islet cell neoplasms. Introduction Pancreatic neuroendocrine neoplasia (pNEN) represents a rare, but important subset of pancreatic neoplasms. These tumors account for 2-4% of all clinically detected pancreatic tumors. Their overall incidence is approximately 1 in 100,000 people per year [1] . pNENs present as either functional tumors, causing specific hormonal syndromes like Zollinger-Ellison syndrome or or- Key Words Heat shock protein 90 · AUY922 · Transgenic RIP1-Tag2 mice · Islet cell tumors Abstract Background: This study was designed to evaluate the role of heat shock protein 90 (HSP90) in tumor progression of murine islet cell tumors. Blockade of HSP90 has recently been proposed as a therapeutic target, but effects in models of islet cell tumors with AUY922, a newly developed HSP90 inhibitor, have not been examined. Material and Methods: The carcinoid cell line BON-1 and the HSP90 inhibitor AUY922 were used to determine effects on signaling and growth in vitro. In vivo transgenic RIP1-Tag2 mice, which develop islet cell neoplasms, were treated with vehicle or AUY922 (25 mg/ kg/twice per week) from week 5 until death. The resected pancreata were evaluated macroscopically and microscopically by immunohistochemistry. Quantitative real-time PCR was performed for HSP90 targets with RNA from islets isolated from treated and untreated RIP1-Tag2 mice. Results: HSP90 blockade impaired constitutive and growth factorinduced signaling in vitro. Moreover, HSP90 inhibition attenuated in vitro cell growth in a dose-dependent manner. In vivo, AUY922 significantly reduced tumor volume by 92%
doi:10.1159/000368610 pmid:25301256 fatcat:sgn36m2ebjegtn2g3hkkc2w2je

Inner Field Compensation as a Tool for the Characterization of Asymmetric Membranes and Peptide-Membrane Interactions

Sven O. Hagge, Andre Wiese, Ulrich Seydel, Thomas Gutsmann
2004 Biophysical Journal  
Minnesota strain R595 (LPS R595), and P. mirabilis strain R45 (LPS R45) (Zähringer et al., 1985; Rietschel et al., 1992 Rietschel et al., , 1994 Vinogradov et al., 1994; Wiese et al., 1998; Holst, 1999  ...  Fig. 2 ) induce a negative surface potential at the outer leaflet of the OM, which leads to an up-concentration of polycationic antimicrobial peptides, such as polymyxin B (Schindler and Teuber, 1975; Wiese  ... 
doi:10.1016/s0006-3495(04)74167-3 pmid:14747327 pmcid:PMC1303939 fatcat:bk3wnxrmlvh2xj5bpqdq476ccy

Calcium adsorption and displacement: characterization of lipid monolayers and their interaction with membrane-active peptides/proteins

Sven O Hagge, Malte U Hammer, Andre Wiese, Ulrich Seydel, Thomas Gutsmann
2006 BMC Biochemistry  
The first target of antimicrobial peptides (AMPs) is the bacterial membrane. In the case of Gram-negative bacteria this is the outer membrane (OM), the lipid composition of which is extremely asymmetric: Whereas the inner leaflet is composed of a phospholipid mixture, the outer leaflet is made up solely from lipopolysaccharides (LPSs). LPS, therefore, represents the first target of AMPs. The binding and intercalation of polycationic AMPs is driven by the number and position of negatively
more » ... groups of the LPS. Also, proteins other than cationic AMPs can interact with LPS, e.g. leading eventually to a neutralization of the endotoxic effects of LPS. We compared different biophysical techniques to gain insight into the properties of the electrical surface potentials of lipid monolayers and aggregates composed of LPSs and various phospholipids and their interaction with peptides and proteins. The net negative charge calculated from the chemical structure of the phospholipid and LPS molecules is linearly correlated with the adsorption of calcium to two-dimensional lipid monolayers composed of the respective lipids. However, the zeta-potentials determined by the electrophoretic mobility of LPS aggregates can only be interpreted by assuming a dependence of the plane of shear on the number of saccharides and charged groups. Various peptides and proteins were able to displace calcium adsorbed to monolayers. To characterize the electrical properties of negatively charged phospholipids and LPSs and their electrostatic interaction with various polycationic peptides/proteins, the adsorption of calcium to and displacement from lipid monolayers is a suitable parameter. Using the calcium displacement method, the binding of peptides to monolayers can be determined even if they do not intercalate. The interpretation of zeta-potential data is difficulty for LPS aggregates, because of the complex three-dimensional structure of the LPS molecules. However, the influence of peptides/proteins on the zeta-potential can be used to characterize the underlying interaction mechanisms.
doi:10.1186/1471-2091-7-15 pmid:16672047 pmcid:PMC1488853 fatcat:i5esisvcobbuxk6lsmyvrp6exm

Isolation, Structure, Synthesis and Cytotoxicity of an Unprecedented Flupirtine Dimer

René Csuk, Sven Sommerwerk, Jana Wiese, Christoph Wagner, Bianka Siewert, Ralph Kluge, Dieter Ströhl
2012 Zeitschrift für Naturforschung. B, A journal of chemical sciences  
A previously unknown dimer of the well-established analgesic flupirtine has been found, and its structure was revealed by ESI-MS, NMR spectroscopy and an independent synthesis. Thus, starting from 2-amino-6-chloro-3-nitro-pyridine the target compound was obtained in a four-step synthesis. Key-step of this synthesis is a nickel-mediated aryl-aryl coupling. The dimer 4 did not show any cytotoxicity, and its IC50 values were > 30 μm for all six human cancer cell lines and mouse fibroblasts used in this study
doi:10.5560/znb.2012-0258 fatcat:25jxnqjxhjf2tealx35hflbr2u

MITRAC Links Mitochondrial Protein Translocation to Respiratory-Chain Assembly and Translational Regulation

David U. Mick, Sven Dennerlein, Heike Wiese, Robert Reinhold, David Pacheu-Grau, Isotta Lorenzi, Florin Sasarman, Woranontee Weraarpachai, Eric A. Shoubridge, Bettina Warscheid, Peter Rehling
2012 Cell  
Mitochondrial respiratory-chain complexes assemble from subunits of dual genetic origin assisted by specialized assembly factors. Whereas core subunits are translated on mitochondrial ribosomes, others are imported after cytosolic translation. How imported subunits are ushered to assembly intermediates containing mitochondria-encoded subunits is unresolved. Here, we report a comprehensive dissection of early cytochrome c oxidase assembly intermediates containing proteins required for normal
more » ... chondrial translation and reveal assembly factors promoting biogenesis of human respiratory-chain complexes. We find that TIM21, a subunit of the inner-membrane presequence translocase, is also present in the major assembly intermediates containing newly mitochondria-synthesized and imported respiratory-chain subunits, which we term MITRAC complexes. Human TIM21 is dispensable for protein import but required for integration of early-assembling, presequence-containing subunits into respiratory-chain intermediates. We establish an unexpected molecular link between the TIM23 transport machinery and assembly of respiratory-chain complexes that regulate mitochondrial protein synthesis in response to their assembly state.
doi:10.1016/j.cell.2012.11.053 pmid:23260140 fatcat:7ypig7pnpnggdhf345mwnck4hm

The effect of copper trace routing on the drop test reliability of BGA modules

Frank Kraemer, Sven Rzepka, Steffen Wiese, Jens Lienig
2010 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC)  
The JEDEC drop test has become a popular method for the assessment of the dynamic mechanical reliability of 2 nd level assemblies. It delivers repeatable results and is thus well suited for the development of a virtual lifetime model based on FEM simulations. Detailed experimental studies showed PCB copper trace fractures as the dominating failure mode. The virtual risk assessment applied a two steps approach (sub-modeling technique). The overall PCB motion was computed by a global model of the
more » ... entire JEDEC board. In the second step, the copper trace load was investigated with a single component. The resultant plastic strain showed a clear dependency on the relation between copper trace routing and dominating PCB deformation. A strain map was derived which indicates the strain level as a pre-factor to each trace routing condition. The validity of the strain map concept was proven by comparison with experimental results. The strain map was able to precisely identify the failing interconnections at each component position. The combination of interconnection strain energy from the global model and the strain map was able to match the experimental sequence of failures across the JEDEC board exactly. A lifetime model was derived which is able to predict the cycles-to-failure of three different package types with less than 25% deviation to the tests. Hence, this lifetime model sets the ground for virtual prototyping that also includes the BGA drop test endurance.
doi:10.1109/ectc.2010.5490855 fatcat:mfh3gsobl5flneqe7copn4wdgu

RES-Q-Trace: A Mobile CEAS-Based Demonstrator for Multi-Component Trace Gas Detection in the MIR

Norbert Lang, Uwe Macherius, Henrik Zimmermann, Sven Glitsch, Mathias Wiese, Jürgen Röpcke, Jean-Pierre H. van Helden
2018 Sensors  
Sensitive trace gas detection plays an important role in current challenges occurring in areas such as industrial process control and environmental monitoring. In particular, for medical breath analysis and for the detection of illegal substances, e.g., drugs and explosives, a selective and sensitive detection of trace gases in real-time is required. We report on a compact and transportable multi-component system (RES-Q-Trace) for molecular trace gas detection based on cavity-enhanced
more » ... in the mid-infrared (MIR). The RES-Q-Trace system can operate four independent continuous wave quantum or interband cascade lasers each combined with an optical cavity. Twice the method of off-axis cavity-enhanced absorption spectroscopy (OA-CEAS) was used, twice the method of optical feedback cavity-enhanced absorption spectroscopy (OF-CEAS), respectively. Multi-functional software has been implemented (i) for the general system control; (ii) to drive the four different laser sources and (iii) to analyze the detector signals for concentration determination of several molecular species. For the validation of the versatility and the performance of the RES-Q-Trace instrument the species NO, N 2 O, CH 4 , C 2 H 4 and C 3 H 6 O, with relevance in the fields of breath gas analysis and the detection of explosives have been monitored in the MIR with detection limits at atmospheric pressure in the ppb and ppt range.
doi:10.3390/s18072058 pmid:29954146 pmcid:PMC6069445 fatcat:wu5hmh5ianc6dafgobqnrqe65i

Pore Formation and Function of Phosphoporin PhoE ofEscherichia coliAre Determined by the Core Sugar Moiety of Lipopolysaccharide

Sven O. Hagge, Hans de Cock, Thomas Gutsmann, Frank Beckers, Ulrich Seydel, Andre Wiese
2002 Journal of Biological Chemistry  
The lipid matrix of the outer membrane of Gram-negative bacteria is an asymmetric bilayer composed of a phospholipid inner leaflet and a lipopolysaccharide outer leaflet. Incorporated into this lipid matrix are, among other macromolecules, the porins, which have a sieve-like function for the transport or exclusion of hydrophilic substances. It is known that a reduced amount of porins is found in the outer membrane of rough mutants as compared with wild-type bacteria. This observation was
more » ... ed to be caused by a reduced number of insertion sites in the former. We performed electrical measurements on reconstituted planar bilayers composed of lipopolysaccharide on one side and a phospholipid mixture on the other side using lipopolysaccharide from various rough mutant strains of Salmonella enterica serovar Minnesota. We found that pore formation by PhoE trimers that were added to the phospholipid side of the bilayers increased with the increasing length of the lipopolysaccharide core sugar moiety. These results allow us to conclude that the length of the sugar moiety of lipopolysaccharide is the parameter governing pore formation and that no particular insertion sites are required. Furthermore, we found that the voltage gating of the porin channels is strongly dependent on the composition of the lipid matrix.
doi:10.1074/jbc.m201950200 pmid:12091383 fatcat:4o3lp35f6zb6bhqyfdttbf6ijm

Scaffold fragmentation and substructure hopping reveal potential, robustness, and limits of computer-aided pattern analysis (C@PA)

Vigneshwaran Namasivayam, Katja Silbermann, Jens Pahnke, Michael Wiese, Sven Marcel Stefan
2021 Computational and Structural Biotechnology Journal  
Wiese, Small-molecule inhibitors of multidrug resistanceassociated protein 1 and related processes: A historic approach and recent advances, Med Res Rev, 39 (2019) 176-264. [24] S.F. Zhou, L.L.  ... 
doi:10.1016/j.csbj.2021.05.018 pmid:34141145 pmcid:PMC8193046 fatcat:bv4latgnmrc2xj7jb4p5h4waai
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