258 research outputs found
Structural correlates of spoken language abilities : a surface-based region-of interest morphometry study
Brain structure can predict many aspects of human behavior, though the extent of this relationship in healthy adults, particularly for language-related skills, remains largely unknown. The objective of the present study was to explore this relation using magnetic resonance imaging (MRI) on a group of 21 healthy young adults who completed two language tasks: (1) semantic fluency and (2) sentence generation. For each region of interest, cortical thickness, surface area, and volume were calculated. The results show that verbal fluency scores correlated mainly with measures of brain morphology in the left inferior frontal cortex and bilateral insula. Sentence generation scores correlated with structure of the left inferior parietal and right inferior frontal regions. These results reveal that the anatomy of several structures in frontal and parietal lobes is associated with spoken language performance. The presence of both negative and positive correlations highlights the complex relation between brain and language
Development of Wireless Techniques in Data and Power Transmission - Application for Particle Physics Detectors
Wireless techniques have developed extremely fast over the last decade and
using them for data and power transmission in particle physics detectors is not
science- fiction any more. During the last years several research groups have
independently thought of making it a reality. Wireless techniques became a
mature field for research and new developments might have impact on future
particle physics experiments. The Instrumentation Frontier was set up as a part
of the SnowMass 2013 Community Summer Study [1] to examine the instrumentation
R&D for the particle physics research over the coming decades: {\guillemotleft}
To succeed we need to make technical and scientific innovation a priority in
the field {\guillemotright}. Wireless data transmission was identified as one
of the innovations that could revolutionize the transmission of data out of the
detector. Power delivery was another challenge mentioned in the same report. We
propose a collaboration to identify the specific needs of different projects
that might benefit from wireless techniques. The objective is to provide a
common platform for research and development in order to optimize effectiveness
and cost, with the aim of designing and testing wireless demonstrators for
large instrumentation systems
Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review
A critical review on signatures of Quark-Gluon-Plasma formation is given and
the current (1998) experimental status is discussed. After giving an
introduction to the properties of QCD matter in both, equilibrium- and
non-equilibrium theories, we focus on observables which may yield experimental
evidence for QGP formation. For each individual observable the discussion is
divided into three sections: first the connection between the respective
observable and QGP formation in terms of the underlying theoretical concepts is
given, then the relevant experimental results are reviewed and finally the
current status concerning the interpretation of both, theory and experiment, is
discussed. A comprehensive summary including an outlook towards RHIC is given
in the final section.Comment: Topical review, submitted to Journal of Physics G: 68 pages,
including 39 figures (revised version: only minor modifications, some
references added
NA61/SHINE facility at the CERN SPS: beams and detector system
NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a multi-purpose
experimental facility to study hadron production in hadron-proton,
hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton
Synchrotron. It recorded the first physics data with hadron beams in 2009 and
with ion beams (secondary 7Be beams) in 2011.
NA61/SHINE has greatly profited from the long development of the CERN proton
and ion sources and the accelerator chain as well as the H2 beamline of the
CERN North Area. The latter has recently been modified to also serve as a
fragment separator as needed to produce the Be beams for NA61/SHINE. Numerous
components of the NA61/SHINE set-up were inherited from its predecessors, in
particular, the last one, the NA49 experiment. Important new detectors and
upgrades of the legacy equipment were introduced by the NA61/SHINE
Collaboration.
This paper describes the state of the NA61/SHINE facility - the beams and the
detector system - before the CERN Long Shutdown I, which started in March 2013
The N-terminus of IpaB provides a potential anchor to the Shigella type III secretion system tip complex protein IpaD
The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri, providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. The type III secretion apparatus (T3SA) is comprised of a basal body, external needle, and regulatory tip complex. The nascent needle is a polymer of MxiH capped by a pentamer of invasion plasmid antigen D (IpaD). Exposure to bile salts (e.g. deoxycholate) causes a conformational change in IpaD and promotes recruitment of IpaB to the needle tip. It has been proposed that IpaB senses contact with host cell membranes, recruiting IpaC and inducing full secretion of T3SS effectors. While the steps of T3SA maturation and their external triggers have been identified, details of specific protein interactions and mechanisms have remained difficult to study due to the hydrophobic nature of the IpaB and IpaC translocator proteins. Here we explored the ability for a series of soluble N-terminal IpaB peptides to interact with IpaD. We found that DOC is required for the interaction and that a region of IpaB between residues 11–27 is required for maximum binding, which was confirmed in vivo. Furthermore, intramolecular FRET measurements indicated that movement of the IpaD distal domain away from the protein core accompanied the binding of IpaB11-226. Together these new findings provide important new insight into the interactions and potential mechanisms that define the maturation of the Shigella T3SA needle tip complex and provide a foundation for further studies probing T3SS activation
MadQCI: a heterogeneous and scalable SDN QKD network deployed in production facilities
Current quantum key distribution (QKD) networks focus almost exclusively on
transporting secret keys with the highest possible rate. Consequently, they are
built as mostly fixed, ad hoc, logically, and physically isolated
infrastructures designed to avoid any penalty to the quantum channel. This
architecture is neither scalable nor cost-effective and future, real-world
deployments will differ considerably. The structure of the MadQCI QKD network
presented here is based on disaggregated components and modern paradigms
especially designed for flexibility, upgradability, and facilitating the
integration of QKD in the security and telecommunications-networks ecosystem.
These underlying ideas have been tested by deploying many QKD systems from
several manufacturers in a real-world, multi-tenant telecommunications network,
installed in production facilities and sharing the infrastructure with
commercial traffic. Different technologies have been used in different links to
address the variety of situations and needs that arise in real networks,
exploring a wide range of possibilities. Finally, a set of realistic use cases
have been implemented to demonstrate the validity and performance of the
network. The testing took place during a period close to three years, where
most of the nodes were continuously active
Structural Characterization of a Novel Chlamydia pneumoniae Type III Secretion-Associated Protein, Cpn0803
Type III secretion (T3S) is an essential virulence factor used by Gram-negative pathogenic bacteria to deliver effector proteins into the host cell to establish and maintain an intracellular infection. Chlamydia is known to use T3S to facilitate invasion of host cells but many proteins in the system remain uncharacterized. The C. trachomatis protein CT584 has previously been implicated in T3S. Thus, we analyzed the CT584 ortholog in C. pneumoniae (Cpn0803) and found that it associates with known T3S proteins including the needle-filament protein (CdsF), the ATPase (CdsN), and the C-ring protein (CdsQ). Using membrane lipid strips, Cpn0803 interacted with phosphatidic acid and phosphatidylinositol, suggesting that Cpn0803 may associate with host cells. Crystallographic analysis revealed a unique structure of Cpn0803 with a hydrophobic pocket buried within the dimerization interface that may be important for binding small molecules. Also, the binding domains on Cpn0803 for CdsN, CdsQ, and CdsF were identified using Pepscan epitope mapping. Collectively, these data suggest that Cpn0803 plays a role in T3S
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Head-to-head intra-individual comparison of biodistribution and tumor uptake of 68Ga-FAPI and 18F-FDG PET/CT in cancer patients
PURPOSE : FAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of 68Ga- FAPI versus standard-of-care 18F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers. MARERILA AND METHODS : This international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both 68Ga-FAPI and 18F-FDG PET/CT within a median time interval of 10 days (range 1–89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ). RESULTS : A total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. 68Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for 68Ga-FAPI than 18F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, 68Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases. CONCLUSION : Quantitative tumor uptake is comparable between 68Ga-FAPI and 18F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for 68Ga-FAPI. Thus, 68Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological 18F-FDG uptake.Open Access funding by Projekt DEAL.http://link.springer.com/journal/259am2022Nuclear Medicin
Injection of Pseudomonas aeruginosa Exo Toxins into Host Cells Can Be Modulated by Host Factors at the Level of Translocon Assembly and/or Activity
Pseudomonas aeruginosa type III secretion apparatus exports and translocates four exotoxins into the cytoplasm of the host cell. The translocation requires two hydrophobic bacterial proteins, PopB and PopD, that are found associated with host cell membranes following infection. In this work we examined the influence of host cell elements on exotoxin translocation efficiency. We developed a quantitative flow cytometry based assay of translocation that used protein fusions between either ExoS or ExoY and the ß-lactamase reporter enzyme. In parallel, association of translocon proteins with host plasma membranes was evaluated by immunodetection of PopB/D following sucrose gradient fractionation of membranes. A pro-myelocytic cell line (HL-60) and a pro-monocytic cell line (U937) were found resistant to toxin injection even though PopB/D associated with host cell plasma membranes. Differentiation of these cells to either macrophage- or neutrophil-like cell lines resulted in injection-sensitive phenotype without significantly changing the level of membrane-inserted translocon proteins. As previous in vitro studies have indicated that the lysis of liposomes by PopB and PopD requires both cholesterol and phosphatidyl-serine, we first examined the role of cholesterol in translocation efficiency. Treatment of sensitive HL-60 cells with methyl-ß-cyclodextrine, a cholesterol-depleting agent, resulted in a diminished injection of ExoS-Bla. Moreover, the PopB translocator was found in the membrane fraction, obtained from sucrose-gradient purifications, containing the lipid-raft marker flotillin. Examination of components of signalling pathways influencing the toxin injection was further assayed through a pharmacological approach. A systematic detection of translocon proteins within host membranes showed that, in addition to membrane composition, some general signalling pathways involved in actin polymerization may be critical for the formation of a functional pore. In conclusion, we provide new insights in regulation of translocation process and suggest possible cross-talks between eukaryotic cell and the pathogen at the level of exotoxin translocation
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