1,925 research outputs found
Stability of singular, asymmetric stationary states of the Vlasov equation
We present Vlasov equilibria characterized by discontinuous distribution functions of electrons and of finite mass ions and by asymmetric electric potential profiles. These profiles well reproduce double layers, phase space holes,
solitary waves, sheaths near electrodes and near surfaces of airless bodies in Space. By means of the energy method, we show that the stability of the proposed equilibria is better than that of the steady-state solutions of the Vlasov equation based on continuous distribution functions and symmetric potential profiles
Restoring Lost Anti-HER-2 Th1 Immunity in Breast Cancer: A Crucial Role for Th1 Cytokines in Therapy and Prevention
The ErbB/B2 (HER-2/neu) oncogene family plays a critical role in the development and metastatic spread of several tumor types including breast, ovarian and gastric cancer. In breast cancer, HER-2/neu is expressed in early disease development in a large percentage of DCIS lesions and its expression is associated with an increased risk of invasion and recurrence. Targeting HER-2 with antibodies such as trastuzumab or pertuzumab has improved survival, but patients with more extensive disease may develop resistance to therapy. Interestingly, response to HER-2 targeted therapies correlates with presence of immune response genes in the breast. Th1 cell production of the cytokines interferon gamma (IFNγ) and TNFα can enhance MHC class I expression, PD-L1 expression, augment apoptosis and tumor senescence, and enhances growth inhibition of many anti-breast cancer agents, including anti-estrogens and HER-2 targeted therapies. Recently, we have identified that a loss of anti-HER-2 CD4 Th1 in peripheral blood occurs during breast tumorigenesis and is dramatically diminished, even in Stage I breast cancers. The loss of anti-HER-2 Th1 response is specific and not readily reversed by standard therapies. In fact, this loss of anti-HER-2 Th1 response in peripheral blood correlates with lack of complete response to neoadjuvant therapy and diminished disease-free survival. This defect can be restored with HER-2 vaccinations in both DCIS and IBC. Correcting the anti-HER-2 Th1 response may have significant impact in improving response to HER-2 targeted therapies. Development of immune monitoring systems for anti-HER-2 Th1 to identify patients at risk for recurrence could be critical to improving outcomes, since the anti-HER-2 Th1 response can be restored by vaccination. Correction of the cellular immune response against HER-2 may prevent recurrence in high-risk patients with DCIS and IBC at risk of developing new or recurrent breast cancer.Fil: Nocera, Nadia F.. University of Pennsylvania; Estados UnidosFil: Lee, M. Catherine. H. Lee Moffitt Cancer Center; Estados UnidosFil: De La Cruz, Lucy M.. University of Pennsylvania; Estados UnidosFil: Rosemblit, Cinthia. University of Pennsylvania; Estados UnidosFil: Czerniecki, Brian J.. H. Lee Moffitt Cancer Center; Estados Unido
Parton Distributions in Nucleons and Nuclei
We review the current status of Parton Distribution Function (PDF)
determinations for unpolarized and longitudinally polarized protons and for
unpolarized nuclei, which are probed by high-energy hadronic scattering in
perturbative Quantum Chromodynamics (QCD). We present the established
theoretical framework, the experimental information, and the methodological
aspects inherent to any modern PDF extraction. Furthermore, we summarize the
present knowledge of PDFs and discuss their limitations in both accuracy and
precision relevant to advance our understanding of QCD proton substructure and
pursue our quest for precision in the Standard Model and beyond. In this
respect, we highlight various achievements, discuss contemporary issues in PDF
analyses, and outline future directions of progress.Comment: 34 pages, 5 figures, 2 tables; invited review submitted to Annual
Review of Nuclear and Particle Science, Vol.70 (2020); version accepted for
publication; various references updated; improved discussion on implications
for astroparticle physic
TMDlib and TMDplotter: library and plotting tools for transverse-momentum-dependent parton distributions
Transverse-momentum-dependent distributions (TMDs) are central in high-energy
physics from both theoretical and phenomenological points of view. In this
manual we introduce the library, TMDlib, of fits and parameterisations for
transverse-momentum-dependent parton distribution functions (TMD PDFs) and
fragmentation functions (TMD FFs) together with an online plotting tool,
TMDplotter. We provide a description of the program components and of the
different physical frameworks the user can access via the available
parameterisations.Comment: version 2, referring to TMDlib 1.0.2 - comments and references adde
Dynamic Scaling in the Susceptibility of the Spin-1\2 Kagome Lattice Antiferromagnet Herbertsmithite
The spin-1/2 kagome lattice antiferromagnet herbertsmithite,
ZnCu(OH)Cl, is a candidate material for a quantum spin liquid
ground state. We show that the magnetic response of this material displays an
unusual scaling relation in both the bulk ac susceptibility and the low energy
dynamic susceptibility as measured by inelastic neutron scattering. The
quantity with can be expressed as a
universal function of or . This scaling is discussed in
relation to similar behavior seen in systems influenced by disorder or by the
proximity to a quantum critical point.Comment: 5 pages, 3 figures v2: updated to match published version
The strangest proton?
We present an improved determination of the strange quark and antiquark parton distribution functions of the proton by means of a global QCD analysis that takes into account a comprehensive set of strangeness-sensitive measurements: charm-tagged cross sections for fixed-target neutrino–nucleus deep-inelastic scattering, and cross sections for inclusive gauge-boson production and W-boson production in association with light jets or charm quarks at hadron colliders. Our analysis is accurate to next-to-next-to-leading order in perturbative QCD where available, and specifically includes charm-quark mass corrections to neutrino–nucleus structure functions. We find that a good overall description of the input dataset can be achieved and that a strangeness moderately suppressed in comparison to the rest of the light sea quarks is strongly favored by the global analysis
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