1,204 research outputs found

    A Classification Framework for Beacon Applications

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    Beacons have received considerable attention in recent years, which is partially due to the fact that they serve as a flexible and versatile replacement for RFIDs in many applications. However, beacons are mostly considered from a purely technical perspective. This paper provides a conceptual view on application scenarios for beacons and introduces a novel framework for characterizing these. The framework consists of four dimensions: device movement, action trigger, purpose type, and connectivity requirements. Based on these, three archetypical scenarios are described. Finally, event-condition-action rules and online algorithms are used to formalize the backend of a beacon architecture

    Identifizierung und Analyse deutsch-türkischer Innovationsnetzwerke : erste Ergebnisse des TGIN-Projektes

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    Dieses Paper fasst die ersten Ergebnisse des Forschungsprojektes ?Wissenstransfer in Deutsch-Türkischen Innovationsnetzwerke (TGIN) im Kontext der Europäischen Union? zusammen. TGIN eröffnet eine neue Perspektive auf die deutsch-türkische Beziehungen, indem es die ökonomischen Win-Win Situationen aufzeigt, welche durch Deutsch-Türkische Wissensmigration, transnationale Unternehmer und Innovationsnetzwerke entstehen. Im Zentrum der europäischen Wachstumsstrategie steht die Schaffung von Arbeitsplätzen und Wettbewerbsfähigkeit durch Mobilität, Kooperation und Innovation. Internationale Unternehmer, Wissensmigration und kulturelle Vielfalt können ein wesentlicher Antreiber von Lernprozessen und Innovation sein. Aus innovations ökonomischer Sicht können die historisch gewachsenen Beziehungen zwischen Türkei, Deutschland und Europa viel besser genutzt werden. Die ersten Analysen zeigen, dass Deutsch-Türkische Innovationsnetzwerke zwar kein weit verbreitetes, aber dennoch existierendes und schnell wachsendes Phänomen mit großem Potential sind. Die Methoden der sozialen Netzwerkanalyse helfen, Strukturen, Stärken und Schwächen, Chancen und Herausforderungen aufzudecken. Angesichts des Fachkräfte- und Ingenieursmangels in Deutschland, des einseitigen Wachstums der Türkei sowie des zunehmenden globalen Wettbewerbes können Deutschland und die Türkei von der zunehmenden Vernetzung des Innovationsprozesses profitieren

    Spitzer View of Young Massive Stars in the LMC HII Complex N44

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    The HII complex N44 in the Large Magellanic Cloud (LMC) provides an excellent site to perform a detailed study of star formation in a mild starburst, as it hosts three regions of star formation at different evolutionary stages and it is not as complicated and confusing as the 30 Doradus giant HII region. We have obtained Spitzer Space Telescope observations and complementary ground-based 4m uBVIJK observations of N44 to identify candidate massive young stellar objects (YSOs). We further classify the YSOs into Types I, II, and III, according to their spectral energy distributions (SEDs). In our sample of 60 YSO candidates, ~65% of them are resolved into multiple components or extended sources in high-resolution ground-based images. We have modeled the SEDs of 36 YSOs that appear single or dominant within a group. We find good fits for Types I and I/II YSOs,but Types II and II/III YSOs show deviations between their observed SEDs and models that do not include PAH emission. We have also found that some Type III YSOs have central holes in their disk components. YSO counterparts are found in four ultracompact HII regions and their stellar masses determined from SED model fits agree well with those estimated from the ionization requirements of the HII regions. The distribution of YSOs is compared with those of the underlying stellar population and interstellar gas conditions to illustrate a correlation between the current formation of O-type stars and previous formation of massive stars. Evidence of triggered star formation is also presented.Comment: 63 pages, 15 figures, accepted for publication for ApJ; some figures in jpeg format to meet the size limit; preprint with high resolution images can be found at http://www.astro.virginia.edu/~cc5ye/n44yso.pd

    The circumstellar material around SN IIn 1997eg: Another detection of Very Narrow P Cygni profile

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    We report the detection of a very narrow P Cygni profile on top of the broad emission Ha and Hb lines of the Type IIn Supernova 1997eg. A similar feature has been detected in SN 1997ab (Salamanca et al. 1998), SN 1998S (Meikle & Geballe 1998, Fassia et al. 2001) and SN 1995G (Filippenko & Schlegel 1995). The detection of the narrow P Cygni profile indicates the existence of a dense circumstellar material (CSM) into which the ejecta of the supernova is expanding. From the analysis of the spectra of SN 1997eg we deduce (a) that such CSM is very dense (n ~ 5x10^7 cm^-3), (b) that has a low expanding velocity of about 160 \kms. The origin of such dense CSM can be either a very dense progenitor wind (dotM ~ 10^-2 solar masses per year) or a circumstellar shell product of the progenitor wind expanding into a high pressure environment.Comment: Accepted for publication in MNRA

    Phase locking the spin precession in a storage ring

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    This letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV/cc bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (121\approx 121 kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a one standard deviation range of σ=0.21\sigma = 0.21 rad. The minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753 kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of storage rings to look for an intrinsic electric dipole moment of charged particles

    Monitoring plant functional diversity from space

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    The world’s ecosystems are losing biodiversity fast. A satellite mission designed to track changes in plant functional diversity around the globe could deepen our understanding of the pace and consequences of this change and how to manage it

    Impact of porcine cytomegalovirus on long-term orthotopic cardiac xenotransplant survival

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    Xenotransplantation using pig organs has achieved survival times up to 195 days in pig orthotopic heart transplantation into baboons. Here we demonstrate that in addition to an improved immunosuppressive regimen, non-ischaemic preservation with continuous perfusion and control of post-transplantation growth of the transplant, prevention of transmission of the porcine cytomegalovirus (PCMV) plays an important role in achieving long survival times. For the first time we demonstrate that PCMV transmission in orthotopic pig heart xenotransplantation was associated with a reduced survival time of the transplant and increased levels of IL-6 and TNF alpha were found in the transplanted baboon. Furthermore, high levels of tPA-PAI-1 complexes were found, suggesting a complete loss of the pro-fibrinolytic properties of the endothelial cells. These data show that PCMV has an important impact on transplant survival and call for elimination of PCMV from donor pigs

    Next-generation insights into regulatory T cells: expression profiling and FoxP3 occupancy in Human

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    Regulatory T-cells (Treg) play an essential role in the negative regulation of immune answers by developing an attenuated cytokine response that allows suppressing proliferation and effector function of T-cells (CD4+ Th). The transcription factor FoxP3 is responsible for the regulation of many genes involved in the Treg gene signature. Its ablation leads to severe immune deficiencies in human and mice. Recent developments in sequencing technologies have revolutionized the possibilities to gain insights into transcription factor binding by ChiP-seq and into transcriptome analysis by mRNA-seq. We combine FoxP3 ChiP-seq and mRNA-seq in order to understand the transcriptional differences between primary human CD4+ T helper and regulatory T-cells, as well as to study the role of FoxP3 in generating those differences. We show, that mRNA-seq allows analyzing the transcriptomal landscape of T-cells including the expression of specific splice variants at much greater depth than previous approaches, whereas 50% of transcriptional regulation events have not been described before by using diverse array technologies. We discovered splicing patterns like the expression of a kinase-dead isoform of IRAK1 upon T-cell activation. The immunoproteasome is up-regulated in both Treg and CD4+ Th cells upon activation, whereas the ‘standard’ proteasome is up-regulated in Tregs only upon activation

    Next-generation insights into regulatory T cells: expression profiling and FoxP3 occupancy in Human

    Get PDF
    Regulatory T-cells (Treg) play an essential role in the negative regulation of immune answers by developing an attenuated cytokine response that allows suppressing proliferation and effector function of T-cells (CD4+ Th). The transcription factor FoxP3 is responsible for the regulation of many genes involved in the Treg gene signature. Its ablation leads to severe immune deficiencies in human and mice. Recent developments in sequencing technologies have revolutionized the possibilities to gain insights into transcription factor binding by ChiP-seq and into transcriptome analysis by mRNA-seq. We combine FoxP3 ChiP-seq and mRNA-seq in order to understand the transcriptional differences between primary human CD4+ T helper and regulatory T-cells, as well as to study the role of FoxP3 in generating those differences. We show, that mRNA-seq allows analyzing the transcriptomal landscape of T-cells including the expression of specific splice variants at much greater depth than previous approaches, whereas 50% of transcriptional regulation events have not been described before by using diverse array technologies. We discovered splicing patterns like the expression of a kinase-dead isoform of IRAK1 upon T-cell activation. The immunoproteasome is up-regulated in both Treg and CD4+ Th cells upon activation, whereas the ‘standard’ proteasome is up-regulated in Tregs only upon activation

    Immunophenotyping of Circulating and Intratumoral Myeloid and T Cells in Glioblastoma Patients

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    Glioblastoma is the most common and lethal primary brain malignancy that almost inevitably recurs as therapy-refractory cancer. While the success of immune checkpoint blockade (ICB) revealed the immense potential of immune-targeted therapies in several types of cancers outside the central nervous system, it failed to show objective responses in glioblastoma patients as of now. The ability of glioblastoma cells to drive multiple modes of T cell dysfunction while exhibiting low-quality neoepitopes, low-mutational load, and poor antigen priming limits anti-tumor immunity and efficacy of antigen-unspecific immunotherapies such as ICB. An in-depth understanding of the GBM immune landscape is essential to delineate and reprogram such immunosuppressive circuits during disease progression. In this view, the present study aimed to characterize the peripheral and intratumoral immune compartments of 35 glioblastoma patients compared to age- and sex-matched healthy control probands, particularly focusing on exhaustion signatures on myeloid and T cell subsets. Compared to healthy control participants, different immune signatures were already found in the peripheral circulation, partially related to the steroid medication the patients received. Intratumoral CD4+ and CD8+ TEM cells (CD62Llow/CD45ROhigh) revealed a high expression of PD1, which was also increased on intratumoral, pro-tumorigenic macrophages/microglia. Histopathological analysis further identified high PSGL-1 expression levels of the latter, which has recently been linked to increased metastasis in melanoma and colon cancer via P-selectin-mediated platelet activation. Overall, the present study comprises immunophenotyping of a patient cohort to give implications for eligible immunotherapeutic targets in neurooncology in the future
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