1,265 research outputs found
System and process development for selection of high stress tolerance personnel
Process development of system for digital computer processing of psychophysiological data to obtain high stress tolerance personne
Comparing theories: the dynamics of changing vocabulary. A case-study in relativity theory
There are several first-order logic (FOL) axiomatizations of special
relativity theory in the literature, all looking essentially different but
claiming to axiomatize the same physical theory. In this paper, we elaborate a
comparison, in the framework of mathematical logic, between these FOL theories
for special relativity. For this comparison, we use a version of mathematical
definability theory in which new entities can also be defined besides new
relations over already available entities. In particular, we build an
interpretation of the reference-frame oriented theory SpecRel into the
observationally oriented Signalling theory of James Ax. This interpretation
provides SpecRel with an operational/experimental semantics. Then we make
precise, "quantitative" comparisons between these two theories via using the
notion of definitional equivalence. This is an application of logic to the
philosophy of science and physics in the spirit of Johan van Benthem's work.Comment: 27 pages, 8 figures. To appear in Springer Book series Trends in
Logi
Predictions from Lattice QCD
In the past year, we calculated with lattice QCD three quantities that were
unknown or poorly known. They are the dependence of the form factor in
semileptonic decay, the decay constant of the meson, and the
mass of the meson. In this talk, we summarize these calculations, with
emphasis on their (subsequent) confirmation by experiments.Comment: v1: talk given at the International Conference on QCD and Hadronic
Physics, Beijing, June 16-20, 2005; v2: poster presented at the XXIIIrd
International Symposium on Lattice Field Theory, Dublin, July 25-3
Activity and safety of NGR-hTNF, a selective vascular-targeting agent, in previously treated patients with advanced hepatocellular carcinoma
Background:Hepatocellular carcinoma (HCC) is a highly vascularised and poor-prognosis tumour. NGR-hTNF is a vascular-targeting agent consisting of human tumour necrosis factor-alpha fused to the tumour-homing peptide NGR, which is able to selectively bind an aminopeptidase N overexpressed on tumour blood vessels.Methods:Twenty-seven patients with advanced-stage disease resistant to either locoregional (59%; range, 1-3), systemic treatments (52%; range, 1-3) or both (33%) received NGR-hTNF 0.8 gm-2 once every 3 weeks. The primary aim of the study was progression-free survival (PFS).Results:No grade 3-4 treatment-related toxicities were noted. Common toxicity included mild-to-moderate, short-lived chills (63%). Median PFS was 2.3 months (95% CI: 1.7-2.9). A complete response ongoing after 20 months was observed in a sorafenib-refractory patient and a partial response in a Child-Pugh class-B patient, yielding a response rate of 7%. Six patients (22%) experienced stable disease. The disease control rate (DCR) was 30% and was maintained for a median PFS time of 4.3 months. Median survival was 8.9 months (95% CI: 7.5-10.2). In a subset of 12 sorafenib-resistant patients, the response rate was 8% and the median survival was 9.5 months.Conclusion:NGR-hTNF was well tolerated and showed single-agent activity in HCC. Further investigation in HCC is of interest
Experimental observation of the optical spin-orbit torque
Spin polarized carriers electrically injected into a magnet from an external
polarizer can exert a spin transfer torque (STT) on the magnetization. The phe-
nomenon belongs to the area of spintronics research focusing on manipulating
magnetic moments by electric fields and is the basis of the emerging
technologies for scalable magnetoresistive random access memories. In our
previous work we have reported experimental observation of the optical
counterpart of STT in which a circularly polarized pump laser pulse acts as the
external polarizer, allowing to study and utilize the phenomenon on several
orders of magnitude shorter timescales than in the electric current induced
STT. Recently it has been theoretically proposed and experimentally
demonstrated that in the absence of an external polarizer, carriers in a magnet
under applied electric field can develop a non-equilibrium spin polarization
due to the relativistic spin-orbit coupling, resulting in a current induced
spin-orbit torque (SOT) acting on the magnetization. In this paper we report
the observation of the optical counterpart of SOT. At picosecond time-scales,
we detect excitations of magnetization of a ferromagnetic semiconductor
(Ga,Mn)As which are independent of the polarization of the pump laser pulses
and are induced by non-equilibrium spin-orbit coupled photo-holes.Comment: 4 figure, supplementary information. arXiv admin note: text overlap
with arXiv:1101.104
Molecular therapy for the treatment of hepatocellular carcinoma
Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Conventional cytotoxic chemotherapy has failed to show a substantial benefit for patients with HCC. Recently, a number of new drugs targeting molecular mechanisms involved in liver cell transformation have entered into clinical trials and led to encouraging results. In this review we summarise this data and point to a number of new compounds, which are currently being tested and can potentially broaden our therapeutic arsenal even further
A novel PKC activating molecule promotes neuroblast differentiation and delivery of newborn neurons in brain injuries
Neural stem cells are activated within neurogenic niches in response to brain injuries. This results in the production of neuroblasts, which unsuccessfully attempt to migrate toward the damaged tissue. Injuries constitute a gliogenic/non-neurogenic niche generated by the presence of anti-neurogenic signals, which impair neuronal differentiation and migration. Kinases of the protein kinase C (PKC) family mediate the release of growth factors that participate in different steps of the neurogenic process, particularly, novel PKC isozymes facilitate the release of the neurogenic growth factor neuregulin. We have demonstrated herein that a plant derived diterpene, (EOF2; CAS number 2230806-06-9), with the capacity to activate PKC facilitates the release of neuregulin 1, and promotes neuroblasts differentiation and survival in cultures of subventricular zone (SVZ) isolated cells in a novel PKC dependent manner. Local infusion of this compound in mechanical cortical injuries induces neuroblast enrichment within the perilesional area, and noninvasive intranasal administration of EOF2 promotes migration of neuroblasts from the SVZ towards the injury, allowing their survival and differentiation into mature neurons, being some of them cholinergic and GABAergic. Our results elucidate the mechanism of EOF2 promoting neurogenesis in injuries and highlight the role of novel PKC isozymes as targets in brain injury regeneration
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
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