Comment on ``Reduction of static field equation of Faddeev model to first order PDE'', arXiv:0707.2207

The authors of the article Phys. Lett. B 652 (2007) 384, (arXiv:0707.2207), propose an interesting method to solve the Faddeev model by reducing it to a set of first order PDEs. They first construct a vectorial quantity $\bm \alpha$, depending on the original field and its first derivatives, in terms of which the field equations reduce to a linear first order equation. Then they find vectors $\bm \alpha_1$ and $\bm \alpha_2$ which identically obey this linear first order equation. The last step consists in the identification of the $\bm \alpha_i$ with the original $\bm \alpha$ as a function of the original field. Unfortunately, the derivation of this last step in the paper cited above contains an error which invalidates most of its results

Recent developments for an active UF6 gas target for photon-induced fission experiments

Recent developments for an active uranium-hexafluoride-loaded gas target as well as results on the detector gas properties are presented. The gas of choice is a mixture of argon with small amounts of UF6. This contribution presents the experimental setup and focusses on the electron drift velocity with increasing UF6 content. A time-dependent decrease in electron drift velocity is observed in our setup.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Hc2 of anisotropy two-band superconductors by Ginzburg-Landau approach

The purpose of this research is to study the upper critical field (Hc2) of two-band superconductors by two-band Ginzburg - Landau approach. The analytical formula of Hc2 included anisotropy of order parameter and anisotropy of effective-mass are found . The parameters of the upper critical field in ab-plane and c-axis can be found by fitting to the experimental data . Finally, we can find the ratio of upper critical field that temperature dependent in the range of experimental result .Comment: 10 pages. accepted by Physica

The Angiogenic Potential Of PH-neutral Borophosphate Bioactive Glasses

Borate bioactive glasses have gained attention in recent years due to their therapeutic and regenerative effects in vivo. However, borate bioactive glasses release alkaline ions, increasing the local pH and creating a toxic environment for cell culture studies. A partial compositional substitution of phosphate for borate can create a pH-neutral glass that does not significantly affect the local pH while still releasing therapeutic ions. In the present study, a series of Na-Ca-borophosphate bioactive glasses with different borate-to-phosphate ratios was evaluated in vitro and in vivo for cytotoxicity and angiogenic effects. Compared to more basic borate glasses, the pH-neutral glasses supported endothelial cell migration and stimulated greater blood vessel formation in a chick chorioallantoic membrane model. The results from this study indicate that these pH-neutral glasses are promising angiogenic biomaterials for use in tissue engineering and regenerative medicine

Speaking to a metronome reduces kinematic variability in typical speakers and people who stutter.

Background: Several studies indicate that people who stutter show greater variability in speech movements than people who do not stutter, even when the speech produced is perceptibly fluent. Speaking to the beat of a metronome reliably increases fluency in people who stutter, regardless of the severity of stuttering.Objectives: Here, we aimed to test whether metronome-timed speech reduces articulatory variability.Method: We analysed vocal tract MRI data from 24 people who stutter and 16 controls. Participants repeated sentences with and without a metronome. Midsagittal images of the vocal tract from lips to larynx were reconstructed at 33.3 frames per second. Any utterances containing dysfluencies or non-speech movements (e.g. swallowing) were excluded. For each participant, we measured the variability of movements (coefficient of variation) from the alveolar, palatal and velar regions of the vocal tract.Results: People who stutter had more variability than control speakers when speaking without a metronome, which was then reduced to the same level as controls when speaking with the metronome. The velar region contained more variability than the alveolar and palatal regions, which were similar.Conclusions: These results demonstrate that kinematic variability during perceptibly fluent speech is increased in people who stutter compared with controls when repeating naturalistic sentences without any alteration or disruption to the speech. This extends our previous findings of greater variability in the movements of people who stutter when producing perceptibly fluent nonwords compared with controls. These results also show, that in addition to increasing fluency in people who stutter, metronome-timed speech also reduces articulatory variability to the same level as that seen in control speakers