130 research outputs found
Dynamics in Stationary, Non-Globally Hyperbolic Spacetimes
Classically, the dynamics in a non-globally hyperbolic spacetime is ill
posed. Previously, a prescription was given for defining dynamics in static
spacetimes in terms of a second order operator acting on a Hilbert space
defined on static slices. The present work extends this result by giving a
similar prescription for defining dynamics in stationary spacetimes obeying
certain mild assumptions. The prescription is defined in terms of a first order
operator acting on a different Hilbert space from the one used in the static
prescription. It preserves the important properties of the earlier one: the
formal solution agrees with the Cauchy evolution within the domain of
dependence, and smooth data of compact support always give rise to smooth
solutions. In the static case, the first order formalism agrees with second
order formalism (using specifically the Friedrichs extension). Applications to
field quantization are also discussed.Comment: 18 pages, 1 figure, AMSLaTeX; v2: expanded discussion of field
quantization, new Proposition 3.1, revised Theorem 4.2, corrected typos, and
updated reference
Linguistic analysis of the journal Naš glas
U radu se analizira jezik Našega glasa (list „Riviere“ – radne organizacije za ugostiteljstvo, turizam, trgovinu i proizvodnju) koji je izlazio u Poreču od 1969. do 1982. godine. Nakon kratkoga osvrta na strukturu, sadržaj i ulogu toga lista te njegov značaj za stanovništvo lokalne zajednice, slijedi prikaz jezičnih zbivanja u vrijeme njegova izlaženja. U žarištu su istraživanja pravopisne, morfološke, sintaktičke, tvorbene, leksičke i stilske karakteristike lista. Rezultati istraživanja pokazuju da su dugogodišnja nastojanja na unifikaciji hrvatskoga i srpskoga jezika ostavila traga u pisanim izvorima na istarskome tlu i u desetljećima nakon objave Deklaracije o nazivu i položaju hrvatskoga književnog jezika.The language development of the second half of the 20th century was influenced considerably by the extralinguistic (social and political) situation. Although the state had guaranteed legal equality to all its languages after 1945, in reality the idea of a Croatian and Serbian linguistic and orthographic unity was growing stronger and stronger. The opposition to the Yugoslav unitarist policy would gain strength at the end of the 1960\u27s, which would result in the publication of the Deklaracija o nazivu i položaju hrvatskoga književnog jezika (Declaration on the name and status of the Croatian literary language) as well as in an increasing promotion of the Croatian linguistic and orthographic peculiarities. This paper demonstrates the manner and extent of the influence of the political situation on the language of public media in Istria in the second half of the 20th century. The research is focused on the orthographical, morphological, syntactical and lexical characteristics in the journal Naš glas, published by the hotel and tourist company "Riviera" in Poreč from 1969 to 1982, and attempts to compare them to the contemporary normatively acceptable and orthographical solutions
Applications of a New Proposal for Solving the "Problem of Time" to Some Simple Quantum Cosmological Models
We apply a recent proposal for defining states and observables in quantum
gravity to simple models. First, we consider a Klein-Gordon particle in an ex-
ternal potential in Minkowski space and compare our proposal to the theory ob-
tained by deparametrizing with respect to a time slicing prior to quantiza-
tion. We show explicitly that the dynamics of the deparametrization approach
depends on the time slicing. Our proposal yields a dynamics independent of the
choice of time slicing at intermediate times but after the potential is turned
off, the dynamics does not return to the free particle dynamics. Next we apply
our proposal to the closed Robertson-Walker quantum cosmology with a massless
scalar field with the size of the universe as our time variable, so the only
dynamical variable is the scalar field. We show that the resulting theory has
the semi-classical behavior up to the classical turning point from expansion to
contraction, i.e., given a classical solution which expands for much longer
than the Planck time, there is a quantum state whose dynamical evolution
closely approximates this classical solution during the expansion. However,
when the "time" gets larger than the classical maximum, the scalar field be-
comes "frozen" at its value at the maximum expansion. We also obtain similar
results in the Taub model. In an Appendix we derive the form of the Wheeler-
DeWitt equation for the Bianchi models by performing a proper quantum reduc-
tion of the momentum constraints; this equation differs from the usual one ob-
tained by solving the momentum constraints classically, prior to quantization.Comment: 30 pages, LaTeX 3 figures (postscript file or hard copy) available
upon request, BUTP-94/1
Particle detectors, geodesic motion, and the equivalence principle
It is shown that quantum particle detectors are not reliable probes of
spacetime structure. In particular, they fail to distinguish between inertial
and non-inertial motion in a general spacetime. To prove this, we consider
detectors undergoing circular motion in an arbitrary static spherically
symmetric spacetime, and give a necessary and sufficient condition for the
response function to vanish when the field is in the static vacuum state. By
examining two particular cases, we show that there is no relation, in general,
between the vanishing of the response function and the fact that the detector
motion is, or is not, geodesic. In static asymptotically flat spacetimes,
however, all rotating detectors are excited in the static vacuum. Thus, in this
particular case the static vacuum appears to be associated with a non-rotating
frame. The implications of these results for the equivalence principle are
considered. In particular, we discuss how to properly formulate the principle
for particle detectors, and show that it is satisfied.Comment: 14 pages. Revised version, with corrections; added two references.
Accepted for publication in Class. Quantum Gra
Volterra Distortions, Spinning Strings, and Cosmic Defects
Cosmic strings, as topological spacetime defects, show striking resemblance
to defects in solid continua: distortions, which can be classified into
disclinations and dislocations, are line-like defects characterized by a delta
function-valued curvature and torsion distribution giving rise to rotational
and translational holonomy. We exploit this analogy and investigate how
distortions can be adapted in a systematic manner from solid state systems to
Einstein-Cartan gravity. As distortions are efficiently described within the
framework of a SO(3) {\rlap{\supset}\times}} T(3) gauge theory of solid
continua with line defects, we are led in a straightforward way to a Poincar\'e
gauge approach to gravity which is a natural framework for introducing the
notion of distorted spacetimes. Constructing all ten possible distorted
spacetimes, we recover, inter alia, the well-known exterior spacetime of a
spin-polarized cosmic string as a special case of such a geometry. In a second
step, we search for matter distributions which, in Einstein-Cartan gravity, act
as sources of distorted spacetimes. The resulting solutions, appropriately
matched to the distorted vacua, are cylindrically symmetric and are interpreted
as spin-polarized cosmic strings and cosmic dislocations.Comment: 24 pages, LaTeX, 9 eps figures; remarks on energy conditions added,
discussion extended, version to be published in Class. Quantum Gra
Multifunctional T-cell Analyses to Study Response and Progression in Adoptive Cell Transfer Immunotherapy
Adoptive cell transfer (ACT) of genetically engineered T cells expressing cancer-specific T-cell receptors (TCR) is a promising cancer treatment. Here, we investigate the in vivo functional activity and dynamics of the transferred cells by analyzing samples from 3 representative patients with melanoma enrolled in a clinical trial of ACT with TCR transgenic T cells targeted against the melanosomal antigen MART-1. The analyses included evaluating 19 secreted proteins from individual cells from phenotypically defined T-cell subpopulations, as well as the enumeration of T cells with TCR antigen specificity for 36 melanoma antigens. These analyses revealed the coordinated functional dynamics of the adoptively transferred, as well as endogenous, T cells, and the importance of highly functional T cells in dominating the antitumor immune response. This study highlights the need to develop approaches to maintaining antitumor T-cell functionality with the aim of increasing the long-term efficacy of TCR-engineered ACT immunotherapy.
Significance: A longitudinal functional study of adoptively transferred TCR–engineered lymphocytes yielded revealing snapshots for understanding the changes of antitumor responses over time in ACT immunotherapy of patients with advanced melanoma
Health-related quality of life and pain with selinexor in patients with advanced dedifferentiated liposarcoma
[Objective] Compare health-related quality of life (HRQoL) of selinexor versus placebo in patients with dedifferentiated liposarcoma.[Materials & methods] HRQoL was assessed at baseline and day 1 of each cycle using the European Organization for Research and Treatment of Cancer 30-item core quality of life questionnaire. Results were reported from baseline to day 169 (where exposure to treatment was maximized while maintaining adequate sample size).[Results] Pain scores worsened for placebo versus selinexor across all postbaseline visits, although differences in HRQoL at some visits were not significant. Other domains did not exhibit significant differences between arms; however, scores in both arms deteriorated over time.[Conclusion] Patients treated with selinexor reported lower rates and slower worsening of pain compared with patients who received placebo.This study was funded by Karyopharm Therapeutics, Inc. M Gounder: reports an institutional research grant from Karyopharm, personal fees from Karyopharm, Epizyme, Springworks, Daiichi, Bayer, Amgen, Tracon, Flatiron, Medscape, Physicians Education Resource, Guidepoint, GLG and UpToDate; and grants from the National Cancer Institute, National Institutes of Health (P30CA008748) – core grant (CCSG shared resources and core facility). ARA Razak: consulting/Ad board: Merck & Adaptimmune Research support: Karyopharm Therapeutics, Deciphera, Blueprint Medicines, Pfizer, Adaptimmune, Merck, Roche/Genentech, Bristol-Myers Squibb, Medimmune, Amgen, GSK, AbbVie, Iterion Therapeutics. AM Gilligan: employee of Karyopharm Therapeutics, Inc. H Leong: employee of Karyopharm Therapeutics, Inc. X Ma: employee of Karyopharm Therapeutics, Inc. N Somaiah: consultant for Deciphera, Blueprint, Bayer Research Support from Ascentage, Astra-Zeneca, Daiichi-Sankyo, Deciphera, Eli Lilly, Karyopharm and GSK. SP Chawla: consultant for Amgen, Roche, GlaxoSmithKline, Threshold Pharmaceuticals, CytRx Corporation, Ignyta, Immune Design, TRACON Pharma, Karyopharm Therapeutics, SARC: Sarcoma Alliance for Research though Collaboration, Janssen, Advenchen Laboratories, Bayer, NKMax, InhibRx. Grants or contracts from Amgen, Roche, GlaxoSmithKline, Threshold Pharmaceuticals, CytRx Corporation, Ignyta, Immune Design, TRACON Pharma, Karyopharm Therapeutics, SARC: Sarcoma Alliance for Research though Collaboration, Janssen, Advenchen Laboratories, Bayer, InhibRx, NKMax. G Grignani: consultant for Eli Lilly, Novartis, Glaxo, Pharmamar, EISAI, Bayer, Merck. SM Schuetze: consultant – NanoCarrier, UpToDate. Research funding to institution – Adaptimmune, Amgen, Blueprint, Glaxo-SmithKline, Karyopharm. B Vincenzi: Consultant for Pharmamar Eisai, Lilly, Abbott, Novartis, Accord AJ Wagner: consultant for Daiichi-Sankyo, Deciphera, Eli Lilly, Epizyme, NovoCarrier, Mundipharma, and Research Support to My Institution from Aadi Bioscience, Daiichi-Sankyo, Deciphera, Eli Lilly, Karyopharm and Plexxikon. RL Jones: consultant for Adaptimmune, Athenex, Bayer, Boehringer Ingelheim, Blueprint, Clinigen, Eisai, Epizyme, Daichii, Deciphera, Immunedesign, Lilly, Merck, Pharmamar, Springworks, Tracon, Upto Date. J Shah: employee of Karyopharm Therapeutics, Inc. S Shacham: employee of Karyopharm Therapeutics, Inc. M Kauffman: employee of Karyopharm Therapeutics, Inc. RF Riedel: ownership - Limbguard, LLC (Spouse); Institutional Clinical Research Support - AADi, AROG, Blueprint, Daiichi-Sankyo, Deciphera, Glaxo-SmithKline, Karyopharm, Ignyta, Immune Design, NanoCarrier, Oncternal, Philogen, Plexxikon, Roche, Springworks, Tracon; Consultant/Advisor - Bayer, Blueprint, Daiichi-Sankyo, Deciphera, Ignyta, NanoCarrier. S Attia: reports research funding from Desmoid Tumor Research Foundation and research funding to their institution from: AB Science, TRACON Pharma, Bayer, Novartis, Lilly, Immune Design, Karyopharm Therapeutics, Epizyme, Blueprint Medicines, Genmab, CBA Pharma, Merck, Philogen, Gradalis, Deciphera, Takeda, Incyte, Springworks, Adaptimmune, Advenchen Laboratories, Bavarian Nordic, BTG, PTC Therapeutics, GlaxoSmithKline, FORMA Therapeutics. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.Peer reviewe
Reversing Melanoma Cross-Resistance to BRAF and MEK Inhibitors by Co-Targeting the AKT/mTOR Pathway
The sustained clinical activity of the BRAF inhibitor vemurafenib (PLX4032/RG7204) in patients with BRAF(V600) mutant melanoma is limited primarily by the development of acquired resistance leading to tumor progression. Clinical trials are in progress using MEK inhibitors following disease progression in patients receiving BRAF inhibitors. However, the PI3K/AKT pathway can also induce resistance to the inhibitors of MAPK pathway.The sensitivity to vemurafenib or the MEK inhibitor AZD6244 was tested in sensitive and resistant human melanoma cell lines exploring differences in activation-associated phosphorylation levels of major signaling molecules, leading to the testing of co-inhibition of the AKT/mTOR pathway genetically and pharmacologically. There was a high degree of cross-resistance to vemurafenib and AZD6244, except in two vemurafenib-resistant cell lines that acquired a secondary mutation in NRAS. In other cell lines, acquired resistance to both drugs was associated with persistence or increase in activity of AKT pathway. siRNA-mediated gene silencing and combination therapy with an AKT inhibitor or rapamycin partially or completely reversed the resistance.Primary and acquired resistance to vemurafenib in these in vitro models results in frequent cross resistance to MEK inhibitors, except when the resistance is the result of a secondary NRAS mutation. Resistance to BRAF or MEK inhibitors is associated with the induction or persistence of activity within the AKT pathway in the presence of these drugs. This resistance can be potentially reversed by the combination of a RAF or MEK inhibitor with an AKT or mTOR inhibitor. These combinations should be available for clinical testing in patients progressing on BRAF inhibitors
611 Biodistribution and shedding analysis following treatment with RP1 oncolytic immunotherapy in the skin cancer patients from the IGNYTE clinical trial
610 Immune biomarker analysis of RP1 in combination with nivolumab in patients with advanced solid tumors
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