119 research outputs found

    Placemaker : Autobahn Inhabited Bridges on the Berlin Stadtring A100

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    Zugleich gedruckt erschienen im Universitätsverlag der TU Berlin unter der ISBN 978-3-7983-2646-0.PLACEMAKER is the third in a series of four PLACE studios conducted at ADIP the Architecture Design Innovation Program at the TU Berlin. PLACEMAKER investigats non-places – places of transience that do not hold enough significance to be regarded as places. An architectural object that is placed into a non-place environment must have the ability to create a field of transition and subsequently become an actual destination. Its architectural design and its hybrid-public as well as internal program must become an attraction in order for the original non-place to become a new place. The non-place environment of investigation for this studio was Berlin’s intercity highway - the A100 Stadtautobahn. Four sites were selected based on the diversity of their context and the evident discontinuation of the city fabric inflicted by the highway

    Fully automated breast segmentation on spiral breast computed tomography images

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    INTRODUCTION The quantification of the amount of the glandular tissue and breast density is important to assess breast cancer risk. Novel photon-counting breast computed tomography (CT) technology has the potential to quantify them. For accurate analysis, a dedicated method to segment the breast components-the adipose and glandular tissue, skin, pectoralis muscle, skinfold section, rib, and implant-is required. We propose a fully automated breast segmentation method for breast CT images. METHODS The framework consists of four parts: (1) investigate, (2) segment the components excluding adipose and glandular tissue, (3) assess the breast density, and (4) iteratively segment the glandular tissue according to the estimated density. For the method, adapted seeded watershed and region growing algorithm were dedicatedly developed for the breast CT images and optimized on 68 breast images. The segmentation performance was qualitatively (five-point Likert scale) and quantitatively (Dice similarity coefficient [DSC] and difference coefficient [DC]) demonstrated according to human reading by experienced radiologists. RESULTS The performance evaluation on each component and overall segmentation for 17 breast CT images resulted in DSCs ranging 0.90-0.97 and in DCs 0.01-0.08. The readers rated 4.5-4.8 (5 highest score) with an excellent inter-reader agreement. The breast density varied by 3.7%-7.1% when including mis-segmented muscle or skin. CONCLUSION The automatic segmentation results coincided with the human expert's reading. The accurate segmentation is important to avoid the significant bias in breast density analysis. Our method enables accurate quantification of the breast density and amount of the glandular tissue that is directly related to breast cancer risk

    Digital twin for Advanced Service delivery systems: Opportunities and challenges

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    Implementing an Advanced Services strategy may bring economic, social and environmental sustainability, but requires orchestration of a complex system of interdependent actors. Customers, suppliers, contractors and other intermediaries must be co-ordinated effectively for mutual benefit. Doing so requires appropriate data not only related to products, but also service delivery and (customers’) use environment. This research proposes a Digital Twin approach to capturing and processing real-time data from each of these three levels, in order to orchestrate successful value creation

    Direct visualization of magnetic correlations in frustrated spinel ZnFe2_2O4_4

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    Magnetic materials with the spinel structure (A2+^{2+}B23+^{3+}_2O4^4) form the core of numerous magnetic devices, but ZnFe2_2O4_4 constitutes a peculiar example where the nature of the magnetism is still unresolved. Susceptibility measurements revealed a cusp around Tc=13  KT_c=13\;\mathrm{K} resembling an antiferromagnetic transition, despite the positive Curie-Weiss temperature determined to be ΘCW=102.8(1)  K\Theta_{CW}=102.8(1)\;\mathrm{K}. Bifurcation of field-cooled and zero-field-cooled data below TcT_c in conjunction with a frequency dependence of the peak position and a non-zero imaginary component below TcT_c shows it is in fact associated with a spin-glass transition. Highly structured magnetic diffuse neutron scattering from single crystals develops between 50  K50\;\mathrm{K} and 25  K25\;\mathrm{K} revealing the presence of magnetic disorder which is correlated in nature. Here, the 3D-mΔ\DeltaPDF method is used to visualize the local magnetic ordering preferences, and ferromagnetic nearest-neighbor and antiferromagnetic third nearest-neighbor correlations are shown to be dominant. Their temperature dependence is extraordinary with some flipping in sign, and a strongly varying correlation length. The correlations can be explained by orbital interaction mechanisms for the magnetic pathways, and a preferred spin cluster. Our study demonstrates the power of the 3D-mΔ\DeltaPDF method in visualizing complex quantum phenomena thereby providing a way to obtain an atomic scale understanding of magnetic frustration

    Cellular in vivo 3D imaging of the cornea by confocal laser scanning microscopy

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    We present an in vivo confocal laser scanning microscopy based method for large 3D reconstruction of the cornea on a cellular level with cropped volume sizes up to 266 x 286 x 396 µm3. The microscope objective used is equipped with a piezo actuator for automated, fast and precise closed-loop focal plane control. Furthermore, we present a novel concave surface contact cap, which significantly reduces eye movements by up to 87%, hence increasing the overlapping image area of the whole stack. This increases the cuboid volume of the generated 3D reconstruction significantly. The possibility to generate oblique sections using isotropic volume stacks opens the window to slit lamp microscopy on a cellular level

    Vi polysaccharide and conjugated vaccines afford similar early, IgM or IgG-independent control of infection but boosting with conjugated Vi vaccines sustains the efficacy of immune responses

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    IntroductionVaccination with Vi capsular polysaccharide (Vi-PS) or protein-Vi typhoid conjugate vaccine (TCV) can protect adults against Salmonella Typhi infections. TCVs offer better protection than Vi-PS in infants and may offer better protection in adults. Potential reasons for why TCV may be superior in adults are not fully understood.Methods and resultsHere, we immunized wild-type (WT) mice and mice deficient in IgG or IgM with Vi-PS or TCVs (Vi conjugated to tetanus toxoid or CRM197) for up to seven months, with and without subsequent challenge with Vi-expressing Salmonella Typhimurium. Unexpectedly, IgM or IgG alone were similarly able to reduce bacterial burdens in tissues, and this was observed in response to conjugated or unconjugated Vi vaccines and was independent of antibody being of high affinity. Only in the longer-term after immunization (>5 months) were differences observed in tissue bacterial burdens of mice immunized with Vi-PS or TCV. These differences related to the maintenance of antibody responses at higher levels in mice boosted with TCV, with the rate of fall in IgG titres induced to Vi-PS being greater than for TCV.DiscussionTherefore, Vi-specific IgM or IgG are independently capable of protecting from infection and any superior protection from vaccination with TCV in adults may relate to responses being able to persist better rather than from differences in the antibody isotypes induced. These findings suggest that enhancing our understanding of how responses to vaccines are maintained may inform on how to maximize protection afforded by conjugate vaccines against encapsulated pathogens such as S. Typhi.</p

    Induction and Exhaustion of Lymphocytic Choriomeningitis Virus–specific Cytotoxic T Lymphocytes Visualized Using Soluble Tetrameric Major Histocompatibility Complex Class I–Peptide Complexes

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    This study describes the construction of soluble major histocompatibility complexes consisting of the mouse class I molecule, H-2Db, chemically biotinylated β2 microglobulin and a peptide epitope derived from the glycoprotein (GP; amino acids 33–41) of lymphocytic choriomeningitis virus (LCMV). Tetrameric class I complexes, which were produced by mixing the class I complexes with phycoerythrin-labeled neutravidin, permitted direct analysis of virus-specific cytotoxic T lymphocytes (CTLs) by flow cytometry. This technique was validated by (a) staining CD8+ cells in the spleens of transgenic mice that express a T cell receptor (TCR) specific for H-2Db in association with peptide GP33–41, and (b) by staining virus-specific CTLs in the cerebrospinal fluid of C57BL/6 (B6) mice that had been infected intracranially with LCMV-DOCILE. Staining of spleen cells isolated from B6 mice revealed that up to 40% of CD8+ T cells were GP33 tetramer+ during the initial phase of LCMV infection. In contrast, GP33 tetramers did not stain CD8+ T cells isolated from the spleens of B6 mice that had been infected 2 mo previously with LCMV above the background levels found in naive mice. The fate of virus-specific CTLs was analyzed during the acute phase of infection in mice challenged both intracranially and intravenously with a high or low dose of LCMV-DOCILE. The results of the study show that the outcome of infection by LCMV is determined by antigen load alone. Furthermore, the data indicate that deletion of virus-specific CTLs in the presence of excessive antigen is preceded by TCR downregulation and is dependent upon perforin

    Small DNA Pieces in C. elegans Are Intermediates of DNA Fragmentation during Apoptosis

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    While studying small noncoding RNA in C. elegans, we discovered that protocols used for isolation of RNA are contaminated with small DNA pieces. After electrophoresis on a denaturing gel, the DNA fragments appear as a ladder of bands, ∼10 nucleotides apart, mimicking the pattern of nuclease digestion of DNA wrapped around a nucleosome. Here we show that the small DNA pieces are products of the DNA fragmentation that occurs during apoptosis, and correspondingly, are absent in mutant strains incapable of apoptosis. In contrast, the small DNA pieces are present in strains defective for the engulfment process of apoptosis, suggesting they are produced in the dying cell prior to engulfment. While the small DNA pieces are also present in a number of strains with mutations in predicted nucleases, they are undetectable in strains containing mutations in nuc-1, which encodes a DNase II endonuclease. We find that the small DNA pieces can be labeled with terminal deoxynucleotidyltransferase only after phosphatase treatment, as expected if they are products of DNase II cleavage, which generates a 3′ phosphate. Our studies reveal a previously unknown intermediate in the process of apoptotic DNA fragmentation and thus bring us closer to defining this important pathway
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