7,148 research outputs found
Radion Assisted Gauge Inflation
We propose an extension to the recently proposed extranatural or gauge
inflation scenario in which the radius modulus field around which the Wilson
loop is wrapped assists inflation as it shrinks. We discuss how this might lead
to more generic initial conditions for inflation.Comment: 10 pages, 2 figure
Double Layer Studies using Depolarizers as Probe - A Reassessment
The influence of the double layer on mercury electrodes has
been assessed by examining a large number of depolarizers and
supporting cations. Cross-analysis of the results shows that,
besides the Frumkin mechanism, ion-pairing can be also a significant
factor, either by increasing the local concentration of the
depolarizer, or by enhancing its intrinsic electroactivity. These
effects are correlated to various other types of behavior (electrolytes,
colloids, exchangers) in terms of a common charge interaction
model taking into account structural changes brought to
the solvent
Sucar Coating the Envelope : Glycoconjucates for Microbe-Host Crosstalk
Tremendous progress has been made on mapping the mainly bacterial members of the human intestinal microbiota. Knowledge on what is out there, or rather what is inside, needs to be complemented with insight on how these bacteria interact with their biotic environment. Bacterial glycoconjugates, that is, the collection of all glycan-modified molecules, are ideal modulators of such interactions. Their enormous versatility and diversity results in a species-specific glycan barcode, providing a range of ligands for host interaction. Recent reports on the functional importance of glycosylation of important bacterial ligands in beneficial and pathogenic species underpin this. Glycoconjugates, and glycoproteins in particular, are an underappreciated, potentially crucial, factor in understanding bacteria-host interactions of old friends and foes.Peer reviewe
Anomalous amplitudes in a thermal bath
I review the implications of the axial anomaly in a thermal bath. I assume
that the Adler-Bardeen theorem applies at nonzero temperature, so that the
divergence of the axial current remains is independent of temperature.
Nevertheless, I argue that while the anomaly doesn't change with temperature,
``anomalous'' mesonic couplings do. This is verified by explicit calculations
in a low temperature expansion, and near the chiral phase transition.Comment: 11 pages, PTPTeX, to appear in the Proceedings of YKIS '9
Hard thermal loops effective action for piO -> gamma gamma
I consider the low temperature correction to the anomalous coupling of a
neutral pion to two photons from an effective Lagrangian point of view.Comment: 4 pages, revtex. Talk given by M. Tytgat at the 5th International
Workshop on Thermal Field Theories and their Applications, Regensburg
(Germany), August 199
APETx4, a novel sea anemone toxin and a modulator of the cancer-relevant potassium channel K<sub>V</sub>10.1
The human ether-Ă -go-go channel (hEag1 or KV10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. Peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs. Here, we report the activity-guided purification and electrophysiological characterization of a novel KV10.1 inhibitor from the sea anemone Anthopleura elegantissima. Purified sea anemone fractions were screened for inhibitory activity on KV10.1 by measuring whole-cell currents as expressed in Xenopus laevis oocytes using the two-microelectrode voltage clamp technique. Fractions that showed activity on Kv10.1 were further purified by RP-HPLC. The amino acid sequence of the peptide was determined by a combination of MALDI- LIFT-TOF/TOF MS/MS and CID-ESI-FT-ICR MS/MS and showed a high similarity with APETx1 and APETx3 and was therefore named APETx4. Subsequently, the peptide was electrophysiologically characterized on KV10.1. The selectivity of the toxin was investigated on an array of voltage-gated ion channels, including the cardiac human ether-Ă -go-go-related gene potassium channel (hERG or Kv11.1). The toxin inhibits KV10.1 with an IC50 value of 1.1 ÎĽM. In the presence of a similar toxin concentration, a shift of the activation curve towards more positive potentials was observed. Similar to the effect of the gating modifier toxin APETx1 on hERG, the inhibition of Kv10.1 by the isolated toxin is reduced at more positive voltages and the peptide seems to keep the channel in a closed state. Although the peptide also induces inhibitory effects on other KV and NaV channels, it exhibits no significant effect on hERG. Moreover, APETx4 induces a concentration-dependent cytotoxic and proapoptotic effect in various cancerous and noncancerous cell lines. This newly identified KV10.1 inhibitor can be used as a tool to further characterize the oncogenic channel KV10.1 or as a scaffold for the design and synthesis of more potent and safer anticancer drugs
Background reionization history from omniscopes
The measurements of the 21-cm brightness temperature fluctuations from the
neutral hydrogen at the Epoch of Reionization (EoR) should inaugurate the next
generation of cosmological observables. In this respect, many works have
concentrated on the disambiguation of the cosmological signals from the
dominant reionization foregrounds. However, even after perfect foregrounds
removal, our ignorance on the background reionization history can significantly
affect the cosmological parameter estimation. In particular, the
interdependence between the hydrogen ionized fraction, the baryon density and
the optical depth to the redshift of observation induce nontrivial degeneracies
between the cosmological parameters that have not been considered so far. Using
a simple, but consistent reionization model, we revisit their expected
constraints for a futuristic giant 21-cm omniscope by using for the first time
Markov Chain Monte Carlo (MCMC) methods on multiredshift full sky simulated
data. Our results agree well with the usual Fisher matrix analysis on the
three-dimensional flat sky power spectrum but only when the above-mentioned
degeneracies are kept under control. In the opposite situation, Fisher results
can be inaccurate. We show that these conditions can be fulfilled by combining
cosmic microwave background measurements with multiple observation redshifts
probing the beginning of EoR. This allows a precise reconstruction of the total
optical depth, reionization duration and maximal spin temperature. Finally, we
discuss the robustness of these results in presence of unresolved ionizing
sources. Although most of the standard cosmological parameters remain weakly
affected, we find a significant degradation of the background reionization
parameter estimation in presence of nuisance ionizing sources.Comment: 22 pages, 18 figures, uses RevTex. References added, matches
published versio
Generation of the Baryon Asymmetry of the Universe within the Left--Right Symmetric Model
Fermions scattering off first-order phase transition bubbles, in the
framework of models, may generate the
Baryon Asymmetry of the Universe (BAU), either at the -symmetry-breaking
scale, or at the weak scale. In the latter case, the baryon asymmetry of the
Universe is related to CP violation in the -- system.Comment: 17 pages, CERN--TH 6747/92, ULB--TH--07/92, UAB-FT-298/9
Bioink properties before, during and after 3D bioprinting
Bioprinting is a process based on additive manufacturing from materials containing living cells. These materials, often referred to as bioink, are based on cytocompatible hydrogel precursor formulations, which gel in a manner compatible with different bioprinting approaches. The bioink properties before, during and after gelation are essential for its printability, comprising such features as achievable structural resolution, shape fidelity and cell survival. However, it is the final properties of the matured bioprinted tissue construct that are crucial for the end application. During tissue formation these properties are influenced by the amount of cells present in the construct, their proliferation, migration and interaction with the material. A calibrated computational framework is able to predict the tissue development and maturation and to optimize the bioprinting input parameters such as the starting material, the initial cell loading and the construct geometry. In this contribution relevant bioink properties are reviewed and discussed on the example of most popular bioprinting approaches. The effect of cells on hydrogel processing and vice versa is highlighted. Furthermore, numerical approaches were reviewed and implemented for depicting the cellular mechanics within the hydrogel as well as for prediction of mechanical properties to achieve the desired hydrogel construct considering cell density, distribution and material-cell interaction
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