214,745 research outputs found
Further evidence for a gamma/delta T cell receptor-mediated TCT.1/CD48 recognition
No full textWe have demonstrated recently that a molecule, termed TCT.1 (Blast-1/CD48), is recognized on the surface of target cells by a series of alloreactive gamma/delta T cell clones generated from PBL of one healthy individual (designated E). Southern blot analyses suggested that these clones express a TCR associating a V3-JP2-C2 gamma-chain and V1-D-J1-C delta-chain. In the present study, we have developed from PBL of a second normal donor (designated G) a novel series of gamma/delta cloned T cell lines with similar functional activity (i.e., specific recognition of TCT.1 protein). The TCR-gamma- and delta-chain nucleotide sequences of both the E and G clones were determined. Results show that 1) sequences from all the clones are identical in each individual donor, 2) the delta-chains expressed by the E and the G clones are encoded by distinct gene rearrangements including V1-D-J-delta-1 and V1-D-J-delta-2, respectively, 3) the gamma-chains expressed by the E and the G clones are encoded by the same genomic variable elements, namely V-gamma-3 and JP2, whereas the junctional regions are distinct. Because the latter rearrangement is very infrequent in human peripheral blood, these data support the view that TCT.1/CD48 recognition is likely to be TCR dependent
Introduzione
No full textQuesta capitolo introduce la chiave di lettura empirica e concettuale del libr
D. T. Max, 36th Annual ODU Literary Festival
No full textD. T. Max is a graduate of Harvard University and a staff writer at The New Yorker. His new book, Every Love Story Is A Ghost Story: A Life of David Foster Wallace, was released in August 2012 and was a New York Times best-seller. He is also the author of The Family That Couldn\u27t Sleep: A Medical Mystery
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Vitamin D and blood pressure control among hypertensive adults: Results from NHANES 2001-2014
No full textObjective: Observational evidence supports an inverse association between hypovitaminosis D and blood pressure (BP), but intervention data have failed to demonstrate beneficial effects of vitamin D supplementation on BP. Following the downwards redefinition of hypertension treatment targets and the need to better identify individuals at greater risk for uncontrolled BP, our aim was to test the association of serum vitamin D levels with the definition of uncontrolled BP according to European guidelines in treated hypertensive adults.Methods:We retrospectively analyzed cross-sectional, nationally representative data from treated hypertensive adults aged at least 18 years with available serum 25 (OH)D measurements. BP was examined as continuous (mmHg) and categorical (at or above treatment goal, as recommended by guidelines) variable; BP means and odds ratios for uncontrolled BP according to vitamin D levels were calculated using progressively adjusted models.Results:Treated hypertensive adults with vitamin D deficiency had higher mean BP (+2.4/3.5 mmHg; P < 0.01) and 25-29% higher risk of uncontrolled BP compared to those with vitamin levels at least 75 nmol/l. These results were confirmed across age, sex, and racial/ethnic strata. Vitamin D insufficiency was associated with higher BP by 0.5/2.4 mmHg, but not with an increased risk of uncontrolled hypertension.Conclusions:25 (OH)D levels might indicate host-specific features related to poor BP control. The attempt to use a biomarker of exposure as an indicator of need for treatment risks to be misleading
DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire
No full textThe majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
Measurement of the D+/- production asymmetry in 7 TeV pp collisions
No full textThe asymmetry in the production cross-section \sigma of D+/- mesons, A_P = (\sigma(D+) - \sigma(D-))/(\sigma(D+) + \sigma(D-)), is measured in bins of pseudorapidity \eta and transverse momentum p_T within the acceptance of the LHCb detector. The result is obtained with a sample of D+ -> K_S pi+ decays corresponding to an integrated luminosity of 1.0 fb^-1, collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0 K_S pi+ decay is negligible. No significant dependence on \eta or p_T is observed
Overview of T and D-T results in JET with ITER-like wall
No full textIn 2021 JET exploited its unique capabilities to operate with T and D–T fuel with an ITER-like Be/W wall (JET-ILW). This second major JET D–T campaign (DTE2), after DTE1 in 1997, represented the culmination of a series of JET enhancements—new fusion diagnostics, new T injection capabilities, refurbishment of the T plant, increased auxiliary heating, in-vessel calibration of 14 MeV neutron yield monitors—as well as significant advances in plasma theory and modelling in the fusion community. DTE2 was complemented by a sequence of isotope physics campaigns encompassing operation in pure tritium at high T-NBI power. Carefully conducted for safe operation with tritium, the new T and D–T experiments used 1 kg of T (vs 100 g in DTE1), yielding the most fusion reactor relevant D–T plasmas to date and expanding our understanding of isotopes and D–T mixture physics. Furthermore, since the JET T and DTE2 campaigns occurred almost 25 years after the last major D–T tokamak experiment, it was also a strategic goal of the European fusion programme to refresh operational experience of a nuclear tokamak to prepare staff for ITER operation. The key physics results of the JET T and DTE2 experiments, carried out within the EUROfusion JET1 work package, are reported in this paper. Progress in the technological exploitation of JET D–T operations, development and validation of nuclear codes, neutronic tools and techniques for ITER operations carried out by EUROfusion (started within the Horizon 2020 Framework Programme and continuing under the Horizon Europe FP) are reported in (Litaudon et al Nucl. Fusion accepted), while JET experience on T and D–T operations is presented in (King et al Nucl. Fusion submitted)
DVB-T-based passive radar for silent surveillance of drones
No full textNowadays, Unmanned Aerial Vehicles (UAVs) and drones are used as threat’s
vectors that create personal and public security issues. The unpredictable and
complex motion along with the small Radar Cross Section (RCS) and low velocity
makes the drone detection a challenging task for any radar system.
In the context outlined earlier, the security level enabled by conventional
active radar systems could be augmented by the cost-effective, non-intrusive and
eco-friendly Passive Radar (PR) technology. As a PR system does not have its own
transmitter, this allows reduced costs, intrinsic covert operation capability and the
lack of additional electromagnetic pollution. To guarantee complete and
continuous coverage, PR can effectively be integrated within conventional active
radars not only to extend the surveillance coverage, acting as ‘gap-filler’, but also
to reduce the probability of out of service of the surveillance system. Moreover,
aiming at the monitoring of airport terminal areas or harbours, where the installation
of additional sensors might be limited by regulations related to public safety
and risk of interference with pre-existing systems, a network of PRs could easily be
deployed to provide continuous and complete coverage.
The stationary nature and the isotropic characteristic of many of the employable
Illuminators of Opportunity (IoO) provide a persistent illumination of the
targets of interest to generate Coherent Processing Intervals (CPIs) of long integration
times (Tint) on receive to counteract the limited power density offered by
the emitter. This certainly applies to many ground-based transmitters for analogue
or digital radio/TV broadcasting. Among them, the emitters of the Digital Video
Broadcasting-Terrestrial (DVB-T) are particularly attractive for counter-drone
applications. Specifically, the high radiated power of these transmitters and the
excellent coverage make them suitable for the detection of these small RCS and
low altitude targets. In addition, the continuous emissions and the fine range
resolution of about 20 m (equivalent monostatic range resolution yielded by a
signal bandwidth of approximately 8 MHz) make them potentially able to continuously
detect and discriminate closely spaced targets. Aiming at the detection of
the low Signal-to-Noise Ratio (SNR) targets and at widening the DVB-T-based PR
coverage area, very long integration times (up to few seconds) can be exploited if
the migration effects are properly compensated. It is worth noticing that the use
of long integration time allows also to improve the Doppler resolution as well as to
discriminate between slowly moving targets and clutter contributions, which is of
particular interest in a scenario with a high density of targets. By employing an
Orthogonal Frequency-Division Multiplexing (OFDM) modulation, DVB-T signals
are noise-like waveforms; thus, they provide ambiguity function with attractive
properties that are nearly independent of the signal content and almost time-invariant. Eventually, since a DVB-T transmitter typically broadcasts multiple channels
at different carrier frequencies, this provides the desired diversity of information that
could be successfully exploited for both target detection and its localization.
Recently, different authors have investigated the use of such sensor for
counter-drone operations proving the capability of such technology to
detect and localize small and medium drones up to a few kilometres from the PR
receiver. Moreover, the capability of such sensor in simultaneous detection of
drones flying near the airport area along with the conventional civil air traffic at
farther ranges has been proved.
This chapter reports the latest results of DVB-T-based PR for counter-drone
operations obtained by the research groups of the University of Alcala ́ and
Sapienza University of Rome
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