Comment on "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons"

In a recent paper "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons" [Astrophys. Space Sci. 338, 271-278 (2012)] Eslami, Mottaghizadeh and Pakzad deal with the problem of the head-on collisions between two weakly nonlinear electron-acoustic solitary waves. Unfortunately, their treatment is deficient and leads to erroneous conclusions.Comment: Accepted for publication in "Astrophysics and Space Science

Suppression of Harmaline Tremor by Activation of an Extrasynaptic GABAA Receptor: Implications for Essential Tremor

Background: Metabolic imaging has revealed excessive cerebellar activity in essential tremor patients. Golgi cells control cerebellar activity by releasing gamma-aminobutyric acid (GABA) onto synaptic and extrasynaptic receptors on cerebellar granule cells. We postulated that the extrasynaptic GABAA receptor-specific agonist THIP (gaboxadol; 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) would suppress tremor in the harmaline model of essential tremor and, since cerebellar extrasynaptic receptors contain α6 and δsubunits, would fail to do so in mice lacking either subunit. Methods: Digitally measured motion power, expressed as 10–16 Hz power (the tremor bandwidth) divided by background 8–32 Hz motion power, was accessed during pre-harmaline baseline, pre-THIP harmaline exposure, and after THIP administration (0, 2, or 3 mg/kg). These low doses were chosen as they did not impair performance on the straight wire test, a sensitive test for psychomotor impairment. Littermate δ wild-type and knockout (Gabrd+/+, Gabrd–/–) and littermate α6 wild-type and knockout (Gabra6+/+, Gabra6–/–) mice were tested. Results: Gabrd+/+ mice displayed tremor reduction at 3 mg/kg THIP but not 2 mg/kg, and Gabra6+/+ mice showed tremor reduction at 2 and 3 mg/kg. Their respective subunit knockout littermates displayed no tremor reduction compared with vehicle controls at either dose. Discussion: The loss of anti-tremor efficacy with deletion of either δ or α6 GABAA receptor subunits indicates that extrasynaptic receptors containing both subunits, most likely located on cerebellar granule cells where they are highly expressed, mediate tremor suppression by THIP. A medication designed to activate only these receptors may display a favorable profile for treating essential tremor

Evaluation of Benzimidazole Resistance in Haemonchus contortus Using Comparative PCR-RFLP Methods

Background: In order to deworm the ruminants especially of sheep in Iran, consumption of benzimi­dazoles has more than 2 decades history and today farmers are using imidazothiazoles, macrocyclic lactones and mostly benzimidazole compounds (BZs) to treat infected farm animals. It has been demonstrated that the most common molecular mechanism leading to BZsresistance in Haemonchus contortus is a single mutation at amino acid 200 (phenylalanine to tyrosine) of the isotype 1 of beta tubulin gene. According to the report of such mutations in Iranian Telador­sagia circumcincta isolates with Restriction Site Created PCR-RFLP, we decided to evaluate the frequency of such mutations in H. contortus in three different geographical areas of Iran.Methodes: A total of 102 collected adult male H. contortus were evaluated with PCR-RFLP (us­ing PSP1406I as restriction enzyme). By means of a second step to compare function of different methods and to increase sensitivity of detection mechanism, a third of samples were examined by another PCR-RFLP method (using TaaI as restriction enzyme) and finally beta tubulin gene of two samples was sequenced.Results: All of samples were detected as BZss homozygote. Finally, beta tubulin gene sequenc­ing of two samples showed no point mutation at codon 200.Conclusion: It seems that BZresistance of H. contortus in Iran is not a serious problem as antici­pated before

Baby Skyrme models for a class of potentials

We consider a class of (2+1) dimensional baby Skyrme models with potentials that have more than one vacum. These potentials are generalisation of old and new baby Skyrme models;they involve more complicated dependence on phi_3.We find that when the potential is invariant under phi_3 -> -phi_3 the configuration corresponding to the baby skyrmions lying "on top of each other" are the minima of the energy. However when the potential breaks this symmetry the lowest field configurations correspond to separated baby skyrmions. We compute the energy distributions for skyrmions of degrees between one and eight and discuss their geometrical shapes and binding energies. We also compare the 2-skyrmion states for these potentials. Most of our work has been performed numerically with the model being formulated in terms of three real scalar fields (satisfying one constraint).Comment: LaTeX, 14 pages, 10 figure

Effect of pot size, planting date and genotype on minituber production of Marfona potato cultivar

This study was carried out to evaluate the effects of pot size, planting date and type of genotype on mini-tuber production of Marfona potato cultivar (Solanum tuberosum L.) in greenhouse conditions.Four genotypes (M-129, M-128P, M-127P and M-124P) originated from virus free sprouts and a genotype of the same cultivar (Marfona) originated from apical meristem, in 3 sizes of pot and 3 planting datewere investigated. The results showed that using larger pots of 3-liter has no advantage and pots smaller than 2-liter is not suitable for mini-tuber production. Also, time of Nov 18 was the best of datefor planting of potato in studied conditions and delay in date of planting reduced the mini-tuber production. The reduction in number of mini-tubers and growing period was greater for the genotype M-129 compared with the other potato genotypes. Furthermore, higher numbers of mini-tubers were produced by the M-127P and M-124P genotypes and M-127P had the highest total weight of mini-tubers.However the number of mini-tubers per plant was higher for genotypes originated from meristem culture than genotypes obtained from sprouts. It seems that genotypes originated from potato sprouts are not as efficient as the apical meristem ones. On the other hand, later genotype showed more homogenous in growth rate and phenotype

Baby Skyrmion chains

Previous results on multi-charged Baby Skyrmion solutions have pointed to a modular structure, comprised of charge two rings and single charge one Skyrmions, which combine to form higher charged structures. In this paper we present numerical evidence which shows an alternative finite chain, multi-charged global energy minimum Baby Skymion solution. We then proceed from the infinite plane, to Baby Skyrmions on a cylinder and then a torus, to obtain the solutions of periodic Baby Skyrmions, of which periodic segments will correspond to sections of large charge Baby Skyrmions in the plane

Dynamics of the topological structures in inhomogeneous media

We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics

Dynamics of the topological structures in inhomogeneous media

We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics

Dynamics of the topological structures in inhomogeneous media

We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics