A 2d Honeycomb Photonic Crystal Under Applied Magnetic Fields

The band-structure properties of a photonic two-dimensional honeycomb lattice formed by cylindrical semiconductor shell rods with dielectric permitivities ε 1 and ε 2, and embedded in a background with permitivity ε 3, is studied by using an standard plane-wave expansion. The properties of bandgaps and density of states, considering dispersive dielectric responses, are investigated together with the possibility of fabricating systems with tunable photonic bandgaps, due to the Voigt magneto-optical effect, under the influence of an external magnetic field. © 2008 SPIE.7138J. D. Joannopoulos, R. D. Meade, J. N. Winn, Photonic Crystals: Molding the Flow of Light, Princeton University Press, Princeton, 1995E. Istrate and E. H. Sargent, Rev. Mod. Phys. 78, 455 (2006)Xu, C., Hu, X., Li, Y., Liu, X., Fu, R., Zi, J., (2003) Phys. Rev. B, 68, p. 193201Kee, C.-S., Kim, J.-E., Park, H.Y., Park, I., Lim, H., (2000) Phys. Rev. B, 61, p. 15523Anderson, C.M., Giapis, K.P., (1996) Phys. Rev. Lett, 77, p. 2949Rezaei, B., Kalafi, M., (2006) Optics Commun, 266, p. 159Busch, K., John, S., (1999) Phys. Rev. Lett, 83, p. 967S. B. Cavalcanti, M. de Dios-Leyva, E. Reyes-Gómez, and L. E. Oliveira, Phys. Rev. B 74, 153102 (2006)ibid., Phys. Rev. E 75, 026607 (2007)Ho, K.M., Chan, C.T., Soukoulis, C.M., (1990) Phys. Rev. Lett, 65, p. 315

Ordering in the dilute weakly-anisotropic antiferromagnet Mn(0.35)Zn(0.65)F2

The highly diluted antiferromagnet Mn(0.35)Zn(0.65)F2 has been investigated by neutron scattering in zero field. The Bragg peaks observed below the Neel temperature TN (approximately 10.9 K) indicate stable antiferromagnetic long-range ordering at low temperature. The critical behavior is governed by random-exchange Ising model critical exponents (nu approximately 0.69 and gamma approximately 1.31), as reported for Mn(x)Zn(1-x)F2 with higher x and for the isostructural compound Fe(x)Zn(1-x)F2. However, in addition to the Bragg peaks, unusual scattering behavior appears for |q|>0 below a glassy temperature Tg approximately 7.0 K. The glassy region T<Tg corresponds to that of noticeable frequency dependence in earlier zero-field ac susceptibility measurements on this sample. These results indicate that long-range order coexists with short-range nonequilibrium clusters in this highly diluted magnet.Comment: 7 pages, 5 figure

Clinical And Neuropsychological Correlation In Patients With Rolandic Epilepsy [correlação Entre Achados Clínicos E Neuropsicológicos Em Pacientes Com Epilepsia Rolândica]

Objectives: To evaluate the presence of neurological soft signs (NSS) and to correlate them with the Wechsler Intelligence Scale for Children (WISC III) in patients with rolandic epilepsy (RE). Methods: Forty children and adolescents aged between 9 and 15 years were studied. They were divided into two groups: G1 - patients with RE (n=20) - and G2 - healthy controls without epilepsy (n=20). They were assessed with the Quick Neurological Screening Test (QNST II) - clinical trial to search for NSS -, and the WISC III - neuropsychological test. Results: No statistical difference between groups was found in WISC III and QNST II. However, children with poorer motor skills had worse performance in the QNST II and also in the execution intelligence quotient - IQ (p=0.001) and in total IQ (p=0.004), thus showing a positive correlation between them. Conclusions: The QNST II is a good screening tool for the neurologist to detect abnormalities in fine motor skills.709691693Berg, A.T., Berkovic, S.F., Brodie, M.J., Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005-2009 (2010) Epilepsia, 51, pp. 676-685Lerman, P., Kivity, S., Benign focal epilepsy of childhood. A follow-up study of 100 recovered patients (1975) Arch Neurol, 32, pp. 261-264Bouma, P.A., Bovenkerk, A.C., Westendorp, R.G., Brouwer, O.F., The course of benign partial epilepsy of childhood with centrotemporal spikes: A meta-analysis (1997) Neurology, 48 (2), pp. 430-437Hommet, C., Billard, C., Motte, J., Cognitive function in adolescents and young adults in complete remission from benign childhood epilepsy with centro-temporal spikes (2001) Epileptic Disord, 3, pp. 207-216D'Alessandro, P., Piccirilli, M., Tiacci, C., Neuropsychological features of benign partial epilepsy in children (1990) Ital J Neurol Sci, 11, pp. 265-269Binnie, C.D., Marston, D., Cognitive correlates of interictal discharges (1992) Epilepsia, 33 (SUPPL. 6), pp. S11-S17Fonseca, L.C., Tedrus, G.M., Pacheco, E.M., Epileptiform EEG discharges in benign childhood epilepsy with centrotemporal spikes: Reactivity and transitory cognitive impairment (2007) Epilepsy Behav, 11, pp. 65-70Baglietto, M.G., Battaglia, F.M., Nobili, N., Neuropsychological disorders related to interictal epileptic discharges during sleep in benign epilepsy of childhood with centrotemporal or rolandic spikes (2001) Dev Med Child Neurol, 43, pp. 407-412Hermann, B.P., Jones, J., Sheth, R., Seidenberg, M., Cognitive and magnetic resonance volumetric abnormalities in new-onset pediatric epilepsy (2007) Semin Pediatri Neurol, 14, pp. 173-180Panayiotopoulos, C.P., Benign childhood partial epilepsies: Benign childhood seizures susceptibility syndromes (1993) J Neurol Neurosurg Psychiatry, 56, pp. 2-5Lindgren, A., Kihlgren, M., Melin, L., Croona, C., Development of cognitive functions in children with rolandic epilepsy (2004) Epilepsy Behav, 5, pp. 903-910Weglage, J., Demsky, A., Pietsh, M., Kurlemann, G., Neuropsychological, intellectual, and behavioral findings in patients with centrotemporal spikes with and without seizure (1997) Dev Med Child Neurol, 39, pp. 645-651Deonna, T., Rolandic epilepsy: Neuropsychology of the active epilepsy phase (2000) Epileptic Disord, 2 (SUPPL. 1), pp. S59-S61Deonna, T., Zesiger, P., Davidoff, V., Benign partial epilepsy of childhood: A longitudinal neuropsychological and EEG study of cognitive function (2000) Dev Med Child Neurol, 42, pp. 595-60

Stellar populations of classical and pseudo-bulges for a sample of isolated spiral galaxies

In this paper we present the stellar population synthesis results for a sample of 75 bulges in isolated spiral Sb-Sc galaxies, using the spectroscopic data from the Sloan Digital Sky Survey and the STARLIGHT code. We find that both pseudo-bulges and classical bulges in our sample are predominantly composed of old stellar populations, with mean mass-weighted stellar age around 10 Gyr. While the stellar population of pseudo-bulges is, in general, younger than that of classical bulges, the difference is not significant, which indicates that it is hard to distinguish pseudo-bulges from classical bulges, at least for these isolated galaxies, only based on their stellar populations. Pseudo-bulges have star formation activities with relatively longer timescale than classical bulges, indicating that secular evolution is more important in this kind of systems. Our results also show that pseudo-bulges have a lower stellar velocity dispersion than their classical counterparts, which suggests that classical bulges are more dispersion-supported than pseudo-bulges.Comment: 10 pages, 8 figures. Accepted for publication in Astrophysics & Space Scienc

Sixty-four new records for the flora of Peru from rapid biological inventories in the Peruvian Amazon

Durante el período 2000 – 2016, se llevaron a cabo 15 inventarios biológicos en áreas remotas en el pie de monte andino y el llano amazónico del Perú. En estos inventarios, 27 botánicos colectaron un total de 9397 especímenes de plantas vasculares fértiles. Hasta finales del 2017, más de la mitad de estos especímenes se han identificado a nivel de especie, de los cuales 64 especies y 2 géneros (Dicorynia y Monopteryx) representan nuevos registros para la flora del Perú. Si esta tasa de novedades se mantiene, el número de registros nuevos en el material de los inventarios podría aumentar, lo cual nos indica que aún queda mucho por descubrir en la flora andino-amazónica del Perú.Between 2000 and 2016 we carried out 15 rapid biological inventories in remote areas of the Andean foothills and Amazon basin in Peru. During these inventories, 27 botanists collected 9397 fertile vascular plant specimens. By the end of 2017, more than half of these specimens had been identified to species. Of the 2303 species identified to date, 64 species and 2 genera (Dicorynia and Monopteryx) are new records for the flora of Peru. If this rate of discovery proves typical, the number of new records for Peru in the rapid inventory material could increase, which indicates that there is still much to discover in the Peruvian flora