346 research outputs found

    SCIP-Jack—a solver for STP and variants with parallelization extensions

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    This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record The Steiner tree problem in graphs is a classical problem that commonly arises in practical applications as one of many variants. While often a strong relationship between different Steiner tree problem variants can be observed, solution approaches employed so far have been prevalently problemspecific. In contrast, this paper introduces a general-purpose solver that can be used to solve both the classical Steiner tree problem and many of its variants without modification. This versatility is achieved by transforming various problem variants into a general form and solving them by using a state-ofthe-art MIP-framework. The result is a high-performance solver that can be employed in massively parallel environments and is capable of solving previously unsolved instances.German Federal Ministry of Education and Researc

    Through-membrane electron-beam lithography for ultrathin membrane applications

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    We present a technique to fabricate ultrathin (down to 20 nm) uniform electron transparent windows at dedicated locations in a SiN membrane for in situ transmission electron microscopy experiments. An electron-beam (e-beam) resist is spray-coated on the backside of the membrane in a KOH- etched cavity in silicon which is patterned using through-membrane electron-beam lithography. This is a controlled way to make transparent windows in membranes, whilst the topside of the membrane remains undamaged and retains its flatness. Our approach was optimized for MEMS-based heating chips but can be applied to any chip design. We show two different applications of this technique for (1) fabrication of a nanogap electrode by means of electromigration in thin free-standing metal films and (2) making low-noise graphene nanopore devices

    AnsĂ€tze fĂŒr die Verbesserung von PPS-Systemen durch Fuzzy-Logik

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    Ziel dieses Arbeitsberichts ist es, die Teilbereiche von Produktionsplanungs- und -steuerungssystemen (PPS-Systemen) zu identifizieren, die unter Beachtung der Interdependenzen zu anderen Teilbereichen mit einem Fuzzy-Ansatz modelliert und dadurch in ihrer Effizienz gesteigert werden können. Nach einer kurzen EinfĂŒhrung in die Fuzzy-Logik werden zunĂ€chst AnsĂ€tze fĂŒr den Einsatz der Fuzzy-Logik innerhalb der Datenstrukturen der Produktionsplanung und -steuerung dargestellt. Danach werden die Funktionen von PPS-Systemen systematisch auf diesbezĂŒgliche Potentiale untersucht, wobei zwischen originĂ€rer und derivativer Verwendung der Fuzzy-Logik unterschieden wird, und Nutzeffekte sinnvoller 'VerunschĂ€rfungen' aufgezeigt werden. Der Arbeitsbericht schließt mit einem Ausblick

    A Gestational High Protein Diet Affects the Abundance of Muscle Transcripts Related to Cell Cycle Regulation throughout Development in Porcine Progeny

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    BACKGROUND: In various animal models pregnancy diets have been shown to affect offspring phenotype. Indeed, the underlying programming of development is associated with modulations in birth weight, body composition, and continual diet-dependent modifications of offspring metabolism until adulthood, producing the hypothesis that the offspring's transcriptome is permanently altered depending on maternal diet. METHODOLOGY/PRINCIPAL FINDINGS: To assess alterations of the offspring's transcriptome due to gestational protein supply, German Landrace sows were fed isoenergetic diets containing protein levels of either 30% (high protein--HP) or 12% (adequate protein--AP) throughout their pregnancy. Offspring muscle tissue (M. longissimus dorsi) was collected at 94 days post conception (dpc), and 1, 28, and 188 days post natum (dpn) for use with Affymetrix GeneChip Porcine Genome Arrays and subsequent statistical and Ingenuity pathway analyses. Numerous transcripts were found to have altered abundance at 94 dpc and 1 dpn; at 28 dpn no transcripts were altered, and at 188 dpn only a few transcripts showed a different abundance between diet groups. However, when assessing transcriptional changes across developmental time points, marked differences were obvious among the dietary groups. Depending on the gestational dietary exposure, short- and long-term effects were observed for mRNA expression of genes related to cell cycle regulation, energy metabolism, growth factor signaling pathways, and nucleic acid metabolism. In particular, the abundance of transcripts related to cell cycle remained divergent among the groups during development. CONCLUSION: Expression analysis indicates that maternal protein supply induced programming of the offspring's genome; early postnatal compensation of the slight growth retardation obvious at birth in HP piglets resulted, as did a permanently different developmental alteration and responsiveness to the common environment of the transcriptome. The transcriptome modulations are interpreted as the molecular equivalent of developmental plasticity of the offspring that necessitates adaptation and maintenance of the organismal phenotype

    The 2019 surface acoustic waves roadmap

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    Today, surface acoustic waves (SAWs) and bulk acoustic waves are already two of the very few phononic technologies of industrial relevance and can been found in a myriad of devices employing these nanoscale earthquakes on a chip. Acoustic radio frequency filters, for instance, are integral parts of wireless devices. SAWs in particular find applications in life sciences and microfluidics for sensing and mixing of tiny amounts of liquids. In addition to this continuously growing number of applications, SAWs are ideally suited to probe and control elementary excitations in condensed matter at the limit of single quantum excitations. Even collective excitations, classical or quantum are nowadays coherently interfaced by SAWs. This wide, highly diverse, interdisciplinary and continuously expanding spectrum literally unites advanced sensing and manipulation applications. Remarkably, SAW technology is inherently multiscale and spans from single atomic or nanoscopic units up even to the millimeter scale. The aim of this Roadmap is to present a snapshot of the present state of surface acoustic wave science and technology in 2019 and provide an opinion on the challenges and opportunities that the future holds from a group of renown experts, covering the interdisciplinary key areas, ranging from fundamental quantum effects to practical applications of acoustic devices in life science

    The distinct roles of the nucleus and nucleus-cytoskeleton connections in three-dimensional cell migration

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    Cells often migrate in vivo in an extracellular matrix that is intrinsically three-dimensional (3D) and the role of actin filament architecture in 3D cell migration is less well understood. Here we show that, while recently identified linkers of nucleoskeleton to cytoskeleton (LINC) complexes play a minimal role in conventional 2D migration, they play a critical role in regulating the organization of a subset of actin filament bundles – the perinuclear actin cap - connected to the nucleus through Nesprin2giant and Nesprin3 in cells in 3D collagen I matrix. Actin cap fibers prolong the nucleus and mediate the formation of pseudopodial protrusions, which drive matrix traction and 3D cell migration. Disruption of LINC complexes disorganizes the actin cap, which impairs 3D cell migration. A simple mechanical model explains why LINC complexes and the perinuclear actin cap are essential in 3D migration by providing mechanical support to the formation of pseudopodial protrusions

    Seedling emergence and establishment of Pinus sylvestris in the Mongolian forest-steppe ecotone

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    Syftet med studien Ă€r att undersöka och beskriva pedagogers uppfattningar av hur de skapar delaktighet och inflytande, i en kommuns förskoleverksamhet och organisation.Mina frĂ„gestĂ€llningar Ă€r hur pedagogerna beskriver sina möjligheter och hinder för att fĂ„ och skapa delaktighet och inflytande, samt vilka inre och yttre faktorer som finns som pĂ„verkar möjligheten för delaktighet och inflytande.För att undersöka detta har jag valt en kvalitativ forskningsansats. Jag har genomfört semistrukturerade intervjuer med sju pedagoger. Det empiriska materialet har bearbetats kvalitativt i en empirinĂ€ra ansats.I resultatet sĂ„g jag att ett större fokus pĂ„ processkvaliteten behöver lĂ€ggas och medvetenheten behöver ökas, kring den pedagogiska dokumentationens betydelse.Sammanfattningsvis behöver den undersökta kommunens förskolor en gemensam samsyn i hela systemet i ett förstĂ„elsebaserat och tolkande perspektiv som gynnar en lĂ„ngsiktig och hĂ„llbar utveckling.Participation and influence in the preschool, a study with teachers in one municipality.The purpose of this study is to explore and describe teacher’s perceptions of how they create participation and influence, in a municipalityÂŽs preschool and organization.My questions are how teachers describe their opportunities and barriers to get and create participation and influence, and what internal and external factors that affecting the ability of participation and influence.To examine this, I have chosen a qualitative research approach. I have conducted semi structured interviews, with seven teachers. The empirical data have been processed in a qualitative empirical closely approach.In the result, I found that a greater focus on process quality needs to be added and awareness needs to be increased, on the pedagogic documentations significances.In conclusion, needs the municipal preschools, which have been examined, get a common consensus of the entire system in a understanding based and interpretive perspective, that support a long term and sustainable development

    Smooth Muscle Cell Phenotype Modulation and Contraction on Native and Cross-Linked Polyelectrolyte Multilayers

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    Smooth muscle cells convert between a motile, proliferative “synthetic ” phenotype and a sessile, “contractile ” phenotype. The ability to manipulate the phenotype of aortic smooth muscle cells with thin biocompatible polyelectrolyte multilayers (PEMUs) with common surface chemical characteristics but varying stiffness was investigated. The stiffness of (PAH/ PAA) PEMUs was varied by heating to form covalent amide bond cross-links between the layers. Atomic force microscopy (AFM) showed that cross-linked PEMUs were thinner than those that were not cross-linked. AFM nanoindentation demonstrated that the Young’s modulus ranged from 6 MPa for hydrated native PEMUs to more than 8 GPa for maximally cross-linked PEMUs. Rat aortic A7r5 smooth muscle cells cultured on native PEMUs exhibited morphology and motility of synthetic cells and expression of the synthetic phenotype markers vimentin, tropomyosin 4, and nonmuscle myosin heavy chain IIB (nmMHCIIB). In comparison, cells cultured on maximally cross-linked PEMUs exhibited the phenotype markers calponin, smooth muscle myosin heavy chain (smMHC), myocardin, transgelin, and smooth muscle R-actin (smActin) that are characteristic of the smooth muscle “contractile ” phenotype. Consistent with those cells being “contractile”, A7r5 cells grown on cross-linked PEMUs produced contractile force when stimulated with a Ca2+ ionophore
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