3,715 research outputs found
Volume modulus inflection point inflation and the gravitino mass problem
Several models of inflection point inflation with the volume modulus as the
inflaton are investigated. Non-perturbative superpotentials containing two
gaugino condensation terms or one such term with threshold corrections are
considered. It is shown that the gravitino mass may be much smaller than the
Hubble scale during inflation if at least one of the non-perturbative terms has
a positive exponent. Higher order corrections to the Kahler potential have to
be taken into account in such models. Those corrections are used to stabilize
the potential in the axion direction in the vicinity of the inflection point.
Models with only negative exponents require uplifting and in consequence have
the supersymmetry breaking scale higher than the inflation scale. Fine-tuning
of parameters and initial conditions is analyzed in some detail for both types
of models. It is found that fine-tuning of parameters in models with heavy
gravitino is much stronger than in models with light gravitino. It is shown
that recently proposed time dependent potentials can provide a solution to the
problem of the initial conditions only in models with heavy gravitino. Such
potentials can not be used to relax fine tuning of parameters in any model
because this would lead to values of the spectral index well outside the
experimental bounds.Comment: 27 pages, 9 figures, comments and references added, version to be
publishe
Theoretical and experimental study on electron interactions with chlorobenzene: Shape resonances and differential cross sections
9 págs.; 6 figs.; 1 tab.In this work, we report theoretical and experimental cross sections for elastic scattering of electrons by chlorobenzene (ClB). The theoretical integral and differential cross sections (DCSs) were obtained with the Schwinger multichannel method implemented with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR). The calculations with the SMCPP method were done in the static-exchange (SE) approximation, for energies above 12 eV, and in the static-exchange plus polarization approximation, for energies up to 12 eV. The calculations with the IAM-SCAR method covered energies up to 500 eV. The experimental differential cross sections were obtained in the high resolution electron energy loss spectrometer VG-SEELS 400, in Lisbon, for electron energies from 8.0 eV to 50 eV and angular range from 7 to 110. From the present theoretical integral cross section (ICS) we discuss the low-energy shape-resonances present in chlorobenzene and compare our computed resonance spectra with available electron transmission spectroscopy data present in the literature. Since there is no other work in the literature reporting differential cross sections for this molecule, we compare our theoretical and experimental DCSs with experimental data available for the parent molecule benzene. Published by AIP Publishing.A.S.B., M.T.N.V., S.d’A.S., and M.H.F.B. acknowledge
the Brazilian Agency Coordenação de Aperfeiçoamento de
Pessoal de Nível Superior (CAPES), under CAPES/FCT
Programme (Process No. 23038.002465/2014-87). M.T.N.V.,
S.d’A.S., and M.H.F.B. acknowledge support from the
Brazilian Agency Conselho Nacional de Desenvolvimento
Científico e Tecnológico. M.H.F.B. acknowledges support
from Finep (under project CT-Infra), and M.T.N.V. from São
Paulo Research Foundation (FAPESP). A.S.B., S.d’A.S., and
M.H.F.B. acknowledge computational support from Professor
Carlos M. de Carvalho at LFTC-DFis-UFPR and at LCPADUFPR
and from CENAPAD-SP. F.F.S. acknowledges the
Portuguese National Funding Agency FCT through researcher
Contract No. IF-FCT IF/00380/2014 and together with P.LV.
the research Grant No. UID/FIS/00068/2013. F.B. and
G.G. acknowledge partial financial support from the Spanish
Ministry MINECO (Project No. FIS2012-31230).Peer Reviewe
Inflation with racetrack superpotential and matter field
Several models of inflation with the racetrack superpotential for the volume
modulus coupled to a matter field are investigated. In particular, it is shown
that two classes of racetrack inflation models, saddle point and inflection
point ones, can be constructed in a fully supersymmetric framework with the
matter field F-term as a source of supersymmetry breaking and uplifting. Two
models of F-term supersymmetry breaking are considered: the Polonyi model and
the quantum corrected O'Raifeartaigh model. In the former case, both classes of
racetrack inflation models differ significantly from the corresponding models
with non-supersymmetric uplifting. The main difference is a quite strong
dominance of the inflaton by the matter field. In addition, fine-tuning of the
parameters is relaxed as compared to the original racetrack models. In the case
of the racetrack inflation models coupled to the O'Raifeartaigh model, the
matter field is approximately decoupled from the inflationary dynamics. In all
of the above models the gravitino mass is larger than the Hubble scale during
inflation. The possibility of having the gravitino much lighter than the Hubble
scale is also investigated. It is very hard to construct models with light
gravitino in which the volume modulus dominates inflation. On the other hand,
models in which the inflationary dynamics is dominated by the matter field are
relatively simple and seem to be more natural.Comment: 40 pages, 13 figures, references added, typos corrected, version to
be publishe
Anaphylaxis related to avocado ingestion: a case and review
Anaphylaxis to avocado, independent of latex sensitization, has been rarely reported in the literature. This case report describes a 15 year old male who experienced anaphylaxis within half an hour after eating avocado-containing food. Avocado consumption is common in both North America and South America. It is important to consider avocado as a cause of anaphylaxis, even in patients not sensitized to latex
Experimental and theoretical electron-scattering cross- section data for dichloromethane
We report on a combination of experimental and theoretical investigations into the elastic differential cross sections (DCSs) and integral cross sections for electron interactions with dichloromethane, CH₂Cl₂, in the incident electron energy over the 7.0-30 eV range. Elastic electron-scattering cross-section calculations have been performed within the framework of the Schwinger multichannel method implemented with pseudopotentials (SMCPP), and the independent-atom model with screening-corrected additivity rule including interference-effects correction (IAM-SCAR+I). The present elastic DCSs have been found to agree reasonably well with the results of IAM-SCAR+I calculations above 20 eV and also with the SMC calculations below 30 eV. Although some discrepancies were found for 7 eV, the agreement between the two theoretical methodologies is remarkable as the electron-impact energy increases. Calculated elastic DCSs are also reported up to 10000 eV for scattering angles from 0⁰ to 180⁰ together with total cross section within the IAM-SCAR+I framework
The safety and clinical effectiveness of rapid infusion with CT-P10 in patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia: A retrospective non-interventional post-authorization safety study in Europe
Rapid infusion (RI) of the rituximab biosimilar CT-P10 is currently only an approved treatment regimen for the treatment of rheumatoid arthritis. Although both CT-P10 and reference rituximab are known to be frequently administered using a RI regimen (≤90 min) in clinical practice, published data on the safety of RI of CT-P10 in patients with NHL and CLL are limited. Hence, this study collected real-world safety and effectiveness data on RI-CT-P10 from the medical records of 196 patients with NHL or CLL in 10 European centers, 6 months after the date of the first RI (index date); the infusion-related reaction (IRR) rate was compared to previously published data. Ten percent (95% confidence interval 6%–15%; n = 20/196) of patients experienced an infusion-related reaction (IRR) on day 1–2 post-index, which was not significantly different (p = 0.45) to the IRR rate for rituximab described in a previous meta-analysis (8.8%). During the observation period, 2% of patients experienced grade 3–5 IRRs and 85% (n = 166) experienced an adverse event (non-IRR). The most common reason for discontinuation of first-line CT-P10 was planned treatment completion (81%; n = 158). Complete response and partial response to CT-P10 was observed in 74% (n = 142/192) and 22% (n = 42/192) of patients, respectively. The results of this real-world study demonstrate that the safety and effectiveness profile of RI-CT-P10 is similar to RI of reference rituximab and therefore support the current use of RI-CT-P10 in patients with NHL and CLL
Protein tyrosine phosphatase PTPN22 regulates LFA-1 dependent Th1 responses
A missense C1858T single nucleotide polymorphism within PTPN22 is a strong genetic risk factor for the development of multiple autoimmune diseases. PTPN22 encodes a protein tyrosine phosphatase that negatively regulates immuno-receptor proximal Src and Syk family kinases. Notably, PTPN22 negatively regulates kinases downstream of T-cell receptor (TCR) and LFA-1, thereby setting thresholds for T-cell activation. Alterations to the quality of TCR and LFA-1 engagement at the immune synapse and the regulation of downstream signals can have profound effects on the type of effector T-cell response induced. Here we describe how IFNγ+ Th1 responses are potentiated in Ptpn22−/− T-cells and in T-cells from mice expressing Ptpn22R619W (the mouse orthologue of the human genetic variant) as they age, or following repeated immune challenge, and explore the mechanisms contributing to the expansion of Th1 cells. Specifically, we uncover two LFA-1-ICAM dependent mechanisms; one T-cell intrinsic, and one T-cell extrinsic. Firstly, we found that in vitro anti-CD3/LFA-1 induced Th1 responses were enhanced in Ptpn22−/− T-cells compared to WT, whereas anti-CD3/anti-CD28 induced IFNy responses were similar. These data were associated with an enhanced ability of Ptpn22−/− T-cells to engage ICAM-1 at the immune synapse when incubated on planar lipid bilayers, and to form conjugates with dendritic cells. Secondly, we observed a T-cell extrinsic mechanism whereby repeated stimulation of WT OT-II T-cells with LPS and OVA323-339 pulsed Ptpn22−/− bone marrow derived dendritic cells (BMDCs) was sufficient to enhance Th1 cell development compared to WT BMDCs. Furthermore, this response could be reversed by LFA-1 blockade. Our data point to two related but distinct mechanisms by which PTPN22 regulates LFA-1 dependent signals to enhance Th1 development, highlighting how perturbations to PTPN22 function over time to regulate the balance of the immune response
Green Production of Anionic Surfactant Obtained from Pea Protein
A pea protein isolate was hydrolyzed by a double enzyme treatment method in order to obtain short peptide sequences used as raw materials to produce lipopeptides-based surfactants. Pea protein hydrolysates were prepared using the combination of Alcalase and Flavourzyme. The influence of the process variables was studied to optimize the proteolytic degradation to high degrees of hydrolysis. The average peptide chain lengths were obtained at 3–5 amino acid units after a hydrolysis of 30 min with the mixture of enzymes. Then, N-acylation in water, in presence of acid chloride (C12 and C16), carried out with a conversion rate of amine functions of 90%, allowed to obtain anionic surfactant mixtures (lipopeptides and sodium fatty acids). These two steps were performed in water, in continuous and did not generate any waste. This process was therefore in line with green chemistry principles. The surface activities (CMC, foaming and emulsifying properties) of these mixtures were also studied. These formulations obtained from natural renewable resources and the reactions done under environmental respect, could replace petrochemical based surfactants for some applications
Towards an Explicit Model of D-brane Inflation
We present a detailed analysis of an explicit model of warped D-brane
inflation, incorporating the effects of moduli stabilization. We consider the
potential for D3-brane motion in a warped conifold background that includes
fluxes and holomorphically-embedded D7-branes involved in moduli stabilization.
Although the D7-branes significantly modify the inflaton potential, they do not
correct the quadratic term in the potential, and hence do not cause a uniform
change in the slow-roll parameter eta. Nevertheless, we present a simple
example based on the Kuperstein embedding of D7-branes, z_1=constant, in which
the potential can be fine-tuned to be sufficiently flat for inflation. To
derive this result, it is essential to incorporate the fact that the
compactification volume changes slightly as the D3-brane moves. We stress that
the compactification geometry dictates certain relationships among the
parameters in the inflaton Lagrangian, and these microscopic constraints impose
severe restrictions on the space of possible models. We note that the shape of
the final inflaton potential differs from projections given in earlier studies:
in configurations where inflation occurs, it does so near an inflection point.
Finally, we comment on the difficulty of making precise cosmological
predictions in this scenario. This is the companion paper to arXiv:0705.3837.Comment: 68 pages, 6 figures; v2: fixed typos, added refs and clarifications;
v3: expanded discussion of inflection point inflatio
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