Motor simulation without motor expertise: enhanced corticospinal excitability in visually experienced dance spectators

The human “mirror-system” is suggested to play a crucial role in action observation and execution, and is characterized by activity in the premotor and parietal cortices during the passive observation of movements. The previous motor experience of the observer has been shown to enhance the activity in this network. Yet visual experience could also have a determinant influence when watching more complex actions, as in dance performances. Here we tested the impact visual experience has on motor simulation when watching dance, by measuring changes in corticospinal excitability. We also tested the effects of empathic abilities. To fully match the participants' long-term visual experience with the present experimental setting, we used three live solo dance performances: ballet, Indian dance, and non-dance. Participants were either frequent dance spectators of ballet or Indian dance, or “novices” who never watched dance. None of the spectators had been physically trained in these dance styles. Transcranial magnetic stimulation was used to measure corticospinal excitability by means of motor-evoked potentials (MEPs) in both the hand and the arm, because the hand is specifically used in Indian dance and the arm is frequently engaged in ballet dance movements. We observed that frequent ballet spectators showed larger MEP amplitudes in the arm muscles when watching ballet compared to when they watched other performances. We also found that the higher Indian dance spectators scored on the fantasy subscale of the Interpersonal Reactivity Index, the larger their MEPs were in the arms when watching Indian dance. Our results show that even without physical training, corticospinal excitability can be enhanced as a function of either visual experience or the tendency to imaginatively transpose oneself into fictional characters. We suggest that spectators covertly simulate the movements for which they have acquired visual experience, and that empathic abilities heighten motor resonance during dance observation

The study of prevalence of metabolic syndrome among nurses of Shahid Mohammadi Hospital of Bandar Abbas city, Iran

زمینه و هدف: سندرم متابولیک مجموعه‌ای از عواملی نظیر چاقی شکمی، فشارخون بالا، قند خون بالا، تری گلیسیرید بالا و لیپوپروتئین پر چگال (HDL) پایین می‌باشد که ریسک دیابت، بیماری‌های قلبی و سکته‌های مغزی را افزایش می‌دهد. هدف از مطالعه حاضر بررسی شیوع سندرم متابولیک در بین پرستاران بیمارستان شهید محمدی بندرعباس است. روش بررسی: این مطالعه، یک مطالعه توصیفی- مقطعی است که بر روی 197 نفر از پرستاران بیمارستان شهید محمدی شهر بندرعباس طی سال 93-92 صورت گرفته است. فراوانی سندرم متابولیک با معیارهای انجمن ملی قلب/ موسسه قلب، ریه، و خون (AHA/ NHLB)، فدراسیون بین‌المللی دیابت (IDF)، برنامه ملی آموزش کلسترول- پانل 3 NCEP (ATP III) و معیار ایرانی سندرم متابولیک ارزیابی گردید. تجزیه و تحلیل داده‌ها با استفاده از روش‌های آماری توصیفی، کای- دو، تی تست، آزمون من- ویتنی و با نرم‌افزار SPSS انجام شد. یافته‌ها: شیوع سندرم متابولیک در پرستاران، بر اساس معیار NCEP (ATP III) 7/11، AHA/NHLBI 8/19، IDF 2/16 و معیار ایرانی 7/12 تشخیص داده شد. بر اساس معیار NCEP (ATP III) شیوع سندرم در بین مردان، شاغلین در اورژانس و شب‌کار بیشتر بود هرچند نتایج آن ازنظر آماری معنی‌دار نبود. نتایج آزمون من‌ویتنی نشان داد که تفاوت معنی‌داری ازنظر شاخص توده بدنی بین افراد دارای سندرم متابولیک و افراد سالم وجود دارد (001/0=P). نتیجه‌گیری: یافته‌های مطالعه نشان داد که شیوع سندرم متابولیک در بین پرستاران مشابه شیوع این سندرم در جهان است و این سندرم ارتباط معنی‌داری با سن، جنس، بخش کاری و شیفت کاری ندارد و تنها ارتباط معنی‌دار در این مطالعه با شاخص توده بدنی دیده ‌شده است و درنهایت این سندرم نیازمند توجه و تشخیص و درمان به‌موقع جهت افزایش سلامت پرستاران و کاهش ناتوانی و هزینه‌های ناشی از عوارض آن می‌باشد

Double Relaxation via AdS/CFT

We exploit the AdS/CFT correspondence to investigate thermalization in an N=2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under variation of an external electric field leading to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS_5 X S^5 background. In the dual gravity theory, due to a time-dependent electric field an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe that two apparent horizons form on the brane. On the gauge theory side, it means that the state of the gauge theory experiences two different temperatures during the time evolution.Comment: 28 pages, 13 figures, published versio

Magnetic fields around evolved stars: further observations of H2_2O maser polarization

We aim to detect the magnetic field and infer its properties around four AGB stars using H$_2$O maser observations. The sample we observed consists of the following sources: the semi-regular variable RT Vir and the Mira variables AP Lyn, IK Tau, and IRC+60370. We observed the 6$_{1,6}-5_{2,3}$ H$_2$O maser rotational transition, in full-polarization mode, to determine its linear and circular polarization. Based on the Zeeman effect, one can infer the properties of the magnetic field from the maser polarization analysis. We detected a total of 238 maser features, in three of the four observed sources. No masers were found toward AP Lyn. The observed masers are all located between 2.4 and 53.0 AU from the stars. Linear and circular polarization was found in 18 and 11 maser features, respectively. We more than doubled the number of AGB stars in which magnetic field has been detected from H$_2$O maser polarization, as our results confirm the presence of fields around IK Tau, RT Vir and IRC+60370. The strength of the field along the line of sight is found to be between 47 and 331 mG in the H$_2$O maser region. Extrapolating this result to the surface of the stars, assuming a toroidal field ($\propto$ r$^{-1}$), we find magnetic fields of 0.3-6.9 G on the stellar surfaces. If, instead of a toroidal field, we assume a poloidal field ($\propto$ r$^{-2}$), then the extrapolated magnetic field strength on the stellar surfaces are in the range between 2.2 and $\sim$115 G. Finally, if a dipole field ($\propto$ r$^{-3}$) is assumed, the field strength on the surface of the star is found to be between 15.8 and $\sim$1945 G. The magnetic energy of our sources is higher than the thermal and kinetic energy in the H$_2$O maser region of this class of objects. This leads us to conclude that, indeed, magnetic fields probably play an important role in shaping the outflows of evolved stars. (abridged)Comment: 15 pages, 5 figures, 7 tables. Accepted for publication in A&

"Massless'' Spin-32\frac{3}{2} Fields in the de Sitter Space

In this paper, the ``massless" spin-$\frac{3}{2}$ fields in the de Sitter space are considered. This work is in the continuation of a previous paper devoted to the quantization of the de Sitter ``massive" spin-$\frac{3}{2}$ fields. Due to the appearance of gauge invariance and indefinite metric, the covariant quantization of the ``massless" spin-$\frac{3}{2}$ fields requires an indecomposable representation of the de Sitter group. The gauge fixing corresponding to the simplest Gupta-Bleuler structure is used, and gauge invariant field is discussed. The field equation is obtained by using the Casimir operator of the de Sitter group. The solutions are written in terms of the coordinate-independent de Sitter plane waves. Finally, the generalized two-point function is calculated.Comment: 18 pages, no figure, submitted in E. Phys. J. C. arXiv admin note: text overlap with arXiv:gr-qc/0608004 by other author

Optimization of medium composition for apple rootstocks

Impact of medium composition (plant growth regulators, mineral nutrients) on multiplication rate, shoot elongation, callusing and rooting of apple rootstocks ('M9', 'M27', and 'MM106') cultured on gelled basal Murashige and Skoog (MS) medium were investigated. Multiplication rate was mainly dependent upon kind of plant growth regulators especially, 6-benzylaminopurine (BA), mineral concentration and genotypes. The best shoot production in terms of shoot number and shoot quality was obtained using 4.4 μM BA and 2.27 μM thidiazuron (TZD) during the shoot multiplication phase, but 8.8 μM BA + 1.14 μM TZD and 2.8 μM gebberllic acid (GA3) during the shoot elongation phase for all genotypes. Application of high (2.8 μM) concentration of GA3 increased the elongation of adventitious shoots than low concentrations. The highest multiplication rate (5.7 No.//shoot) and the highest amount of total fresh weight (2.25 g/jar), as growth rate, were produced by applying 4.4 μM BA + 2.27 μM TDZ for ‘M27’ genotype. Micropropagation potential of ‘M27’ genotype was higher than other genotypes. 'MM106' genotype had the lowest multiplication rate (0.7 No./month), when 0 μM BA+9.08 μM TDZ was applied. Multiplication of explants from the 1st subculture was more sensitive to BA than that from the 3th or 4th subculture. The rooting of explants was promoted by indole-3-butyric acid (IBA) significantly and the best result for rooting was achieved in the half-strength MS medium containing 5.4 μM IBA and 1.2 μM 2,4-dichlorophenoxyacetic acid (2, 4-D). The highest percentage (64%) rooting was produced for ‘MM106’ genotype and the lowest (11%) for ‘M9' after 3 months. Root formation was increased with decreasing concentrations in cytokinins, but increasing auxins (IBA). Rooting percentage of shoot cultures in the low 1/2X-MS medium was significantly more than shoot cultures in the high 2X-MS medium.Key words: Apple rootstocks, medium composition, multiplication rate, plant growth regulators (PGRs)