Mid-UV Narrow-Band Indices of Evolved Simple Stellar Populations

We explore the properties of selected mid-ultraviolet (1900-3200 angstrom) spectroscopic indices of simple stellar populations. We incorporate the high-resolution UVBLUE stellar spectral library into an evolutionary population synthesis code, based on the most recent Padova isochrones. We analyze the trends of UV indices with respect to age and chemical composition. As a first test against observations, we compare our results with the empirical mid-UV spectral indices of Galactic globular clusters (GGCs), observed with the International Ultraviolet Explorer. We find that synthetic indices exhibit a variety of properties, the main one being the slight age sensitivity of most of them for ages >2 Gyr. However, for high metallicity, two indices, Fe II 2332 and Fe II 2402, display a remarkably different pattern, with a sharp increase within the first two Gyr and, thereafter, a rapid decline. These indices clearly mark the presence of young (similar to 1 Gyr) metal-rich (Z >= Z(circle dot)) stellar populations. We complement existing UV indices of GGCs with new measurements, and carefully identify a subsample of 10 indices suitable for comparison with theoretical models. The comparison shows a fair agreement and, in particular, the strong trend of the indices with metallicity is well reproduced. We also discuss the main improvements that should be considered in future modeling concerning, among others, the effects of alpha-enhancement in the spectral energy distributions

Ecology of the Mayan Cichlid, Cichlasoma urophthalmus Günther, in the Alvarado Lagoonal System, Veracruz, Mexico

The Mayan cichlid, Cichlasoma urophthalmus, has a wide distribution in southeastern Mexico where it inhabits rivers and coastal lagoons. In the Alvarado lagoonal system, Veracruz, it is distributed towards the north in Camaronera Lagoon. The Mayan cichlid shows an affinity for oligohaline to mesohaline sites with submerged vegetation, well-oxygenated, deep, and transparent water. The major abundance and biomass of this species was obtained during December to February. The diet of Mayan cichlids consists principally of plant detrital material and algae. Length-frequency distribution shows 2 size classes during both the dry and rainy seasons, corresponding to reproductive fish and young of the year; during the nortes season there is only one modal size class of fish between 60–100 mm SL. Individuals with developed gonads are found throughout the year, although most reproductive adults are found between April and December. The highest Gonadosomatic Index (GSI) values coincided with the peak in reproductive activity between May and July. The fecundity ranged from 1,556–3,348 eggs/female, and there was no relationship between female size and fecundity

Nanocrystalline silicon optomechanical cavities

"© 2018 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited"[EN] Silicon on insulator photonics has offered a versatile platform for the recent development of integrated optomechanical circuits. However, there are some constraints such as the high cost of the wafers and limitation to a single physical device level. In the present work we investigate nanocrystalline silicon as an alternative material for optomechanical devices. In particular we demonstrate that optomechanical crystal cavities fabricated of nanocrystalline silicon have optical and mechanical properties enabling non-linear dynamical behaviour and effects such as thermo-optic/free-carrier-dispersion self-pulsing, phonon lasing and chaos, all at low input laser power and with typical frequencies as high as 0.3 GHz. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing AgreementEuropean Commission project PHENOMEN (H2020-EU-713450), MINECO Severo Ochoa Excellence program (SEV-2013-0295), MINECO (FIS2015-70862-P, RYC-2014-15392) and CERCA Programme/Generalitat de Catalunya.Navarro-Urrios, D.; Capuj, N.; Maire, J.; Colombano, M.; Jaramillo-Fernandez, J.; Chavez-Angel, E.; Martín-Rodríguez, LL.... (2018). Nanocrystalline silicon optomechanical cavities. Optics Express. 26(8):9829-9839. https://doi.org/10.1364/OE.26.009829S98299839268Kippenberg, T. J., & Vahala, K. J. (2008). Cavity Optomechanics: Back-Action at the Mesoscale. Science, 321(5893), 1172-1176. doi:10.1126/science.1156032Aspelmeyer, M., Kippenberg, T. J., & Marquardt, F. (2014). Cavity optomechanics. Reviews of Modern Physics, 86(4), 1391-1452. doi:10.1103/revmodphys.86.1391Navarro-Urrios, D., Capuj, N. E., Gomis-Bresco, J., Alzina, F., Pitanti, A., Griol, A., … Sotomayor Torres, C. M. (2015). A self-stabilized coherent phonon source driven by optical forces. Scientific Reports, 5(1). doi:10.1038/srep15733Navarro-Urrios, D., Capuj, N. E., Colombano, M. F., García, P. D., Sledzinska, M., Alzina, F., … Sotomayor-Torres, C. M. (2017). Nonlinear dynamics and chaos in an optomechanical beam. Nature Communications, 8(1). doi:10.1038/ncomms14965Leijssen, R., La Gala, G. R., Freisem, L., Muhonen, J. T., & Verhagen, E. (2017). Nonlinear cavity optomechanics with nanomechanical thermal fluctuations. Nature Communications, 8(1). doi:10.1038/ncomms16024Gil-Santos, E., Labousse, M., Baker, C., Goetschy, A., Hease, W., Gomez, C., … Favero, I. (2017). Light-Mediated Cascaded Locking of Multiple Nano-Optomechanical Oscillators. Physical Review Letters, 118(6). doi:10.1103/physrevlett.118.063605Shah, S. Y., Zhang, M., Rand, R., & Lipson, M. (2015). Master-Slave Locking of Optomechanical Oscillators over a Long Distance. Physical Review Letters, 114(11). doi:10.1103/physrevlett.114.113602Weis, S., Rivière, R., Deléglise, S., Gavartin, E., Arcizet, O., Schliesser, A., & Kippenberg, T. J. (2010). Optomechanically Induced Transparency. Science, 330(6010), 1520-1523. doi:10.1126/science.1195596Verhagen, E., Deléglise, S., Weis, S., Schliesser, A., & Kippenberg, T. J. (2012). Quantum-coherent coupling of a mechanical oscillator to an optical cavity mode. Nature, 482(7383), 63-67. doi:10.1038/nature10787Tomes, M., & Carmon, T. (2009). Photonic Micro-Electromechanical Systems Vibrating atX-band (11-GHz) Rates. Physical Review Letters, 102(11). doi:10.1103/physrevlett.102.113601Thompson, J. D., Zwickl, B. M., Jayich, A. M., Marquardt, F., Girvin, S. M., & Harris, J. G. E. (2008). Strong dispersive coupling of a high-finesse cavity to a micromechanical membrane. Nature, 452(7183), 72-75. doi:10.1038/nature06715Eichenfield, M., Chan, J., Camacho, R. M., Vahala, K. J., & Painter, O. (2009). Optomechanical crystals. Nature, 462(7269), 78-82. doi:10.1038/nature08524Chan, J., Alegre, T. P. M., Safavi-Naeini, A. H., Hill, J. T., Krause, A., Gröblacher, S., … Painter, O. (2011). Laser cooling of a nanomechanical oscillator into its quantum ground state. Nature, 478(7367), 89-92. doi:10.1038/nature10461Safavi-Naeini, A. H., Alegre, T. P. M., Chan, J., Eichenfield, M., Winger, M., Lin, Q., … Painter, O. (2011). Electromagnetically induced transparency and slow light with optomechanics. Nature, 472(7341), 69-73. doi:10.1038/nature09933Pennec, Y., Laude, V., Papanikolaou, N., Djafari-Rouhani, B., Oudich, M., El Jallal, S., … Martínez, A. (2014). Modeling light-sound interaction in nanoscale cavities and waveguides. Nanophotonics, 3(6), 413-440. doi:10.1515/nanoph-2014-0004Davanço, M., Ates, S., Liu, Y., & Srinivasan, K. (2014). Si3N4 optomechanical crystals in the resolved-sideband regime. Applied Physics Letters, 104(4), 041101. doi:10.1063/1.4858975Balram, K. C., Davanço, M. I., Song, J. D., & Srinivasan, K. (2016). Coherent coupling between radiofrequency, optical and acoustic waves in piezo-optomechanical circuits. Nature Photonics, 10(5), 346-352. doi:10.1038/nphoton.2016.46Bochmann, J., Vainsencher, A., Awschalom, D. D., & Cleland, A. N. (2013). Nanomechanical coupling between microwave and optical photons. Nature Physics, 9(11), 712-716. doi:10.1038/nphys2748Xiong, C., Pernice, W. H. P., Sun, X., Schuck, C., Fong, K. Y., & Tang, H. X. (2012). Aluminum nitride as a new material for chip-scale optomechanics and nonlinear optics. New Journal of Physics, 14(9), 095014. doi:10.1088/1367-2630/14/9/095014Gomis-Bresco, J., Navarro-Urrios, D., Oudich, M., El-Jallal, S., Griol, A., Puerto, D., … Torres, C. M. S. (2014). A one-dimensional optomechanical crystal with a complete phononic band gap. Nature Communications, 5(1). doi:10.1038/ncomms5452Heck, M. J. R., Bauters, J. F., Davenport, M. L., Spencer, D. T., & Bowers, J. E. (2014). Ultra-low loss waveguide platform and its integration with silicon photonics. Laser & Photonics Reviews, 8(5), 667-686. doi:10.1002/lpor.201300183Solehmainen, K., Aalto, T., Dekker, J., Kapulainen, M., Harjanne, M., Kukli, K., … Leskela, M. (2005). Dry-etched silicon-on-insulator waveguides with low propagation and fiber-coupling losses. Journal of Lightwave Technology, 23(11), 3875-3880. doi:10.1109/jlt.2005.857750Sekoguchi, H., Takahashi, Y., Asano, T., & Noda, S. (2014). Photonic crystal nanocavity with a Q-factor of ~9 million. Optics Express, 22(1), 916. doi:10.1364/oe.22.000916Almeida, V. R., Barrios, C. A., Panepucci, R. R., & Lipson, M. (2004). All-optical control of light on a silicon chip. Nature, 431(7012), 1081-1084. doi:10.1038/nature02921Narayanan, K., & Preble, S. F. (2010). Optical nonlinearities in hydrogenated-amorphous silicon waveguides. Optics Express, 18(9), 8998. doi:10.1364/oe.18.008998Preston, K., Dong, P., Schmidt, B., & Lipson, M. (2008). High-speed all-optical modulation using polycrystalline silicon microring resonators. Applied Physics Letters, 92(15), 151104. doi:10.1063/1.2908869Wang, K.-Y., & Foster, A. C. (2012). Ultralow power continuous-wave frequency conversion in hydrogenated amorphous silicon waveguides. Optics Letters, 37(8), 1331. doi:10.1364/ol.37.001331Matres, J., Ballesteros, G. C., Gautier, P., Fédéli, J.-M., Martí, J., & Oton, C. J. (2013). High nonlinear figure-of-merit amorphous silicon waveguides. Optics Express, 21(4), 3932. doi:10.1364/oe.21.003932Waldow, M., Plötzing, T., Gottheil, M., Först, M., Bolten, J., Wahlbrink, T., & Kurz, H. (2008). 25ps all-optical switching in oxygen implanted silicon-on-insulator microring resonator. Optics Express, 16(11), 7693. doi:10.1364/oe.16.007693Wang, K.-Y., Petrillo, K. G., Foster, M. A., & Foster, A. C. (2012). Ultralow-power all-optical processing of high-speed data signals in deposited silicon waveguides. Optics Express, 20(22), 24600. doi:10.1364/oe.20.024600Ylönen, M., Torkkeli, A., & Kattelus, H. (2003). In situ boron-doped LPCVD polysilicon with low tensile stress for MEMS applications. Sensors and Actuators A: Physical, 109(1-2), 79-87. doi:10.1016/j.sna.2003.09.017Theodorakos, I., Zergioti, I., Vamvakas, V., Tsoukalas, D., & Raptis, Y. S. (2014). Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications. Journal of Applied Physics, 115(4), 043108. doi:10.1063/1.4863402Navarro-Urrios, D., Gomis-Bresco, J., El-Jallal, S., Oudich, M., Pitanti, A., Capuj, N., … Sotomayor Torres, C. M. (2014). Dynamical back-action at 5.5 GHz in a corrugated optomechanical beam. AIP Advances, 4(12), 124601. doi:10.1063/1.4902171Barclay, P. E., Srinivasan, K., & Painter, O. (2005). Nonlinear response of silicon photonic crystal micresonators excited via an integrated waveguide and fiber taper. Optics Express, 13(3), 801. doi:10.1364/opex.13.000801Cuffe, J., Ristow, O., Chávez, E., Shchepetov, A., Chapuis, P.-O., Alzina, F., … Sotomayor Torres, C. M. (2013). Lifetimes of Confined Acoustic Phonons in Ultrathin Silicon Membranes. Physical Review Letters, 110(9). doi:10.1103/physrevlett.110.095503Volklein, F., & Balles, H. (1992). A Microstructure For Measurement Of Thermal Conductivity Of Polysilicon Thin Films. Journal of Microelectromechanical Systems, 1(4), 193-196. doi:10.1109/jmems.1992.752511Pennec, Y., Rouhani, B. D., El Boudouti, E. H., Li, C., El Hassouani, Y., Vasseur, J. O., … Martinez, A. (2010). Simultaneous existence of phononic and photonic band gaps in periodic crystal slabs. Optics Express, 18(13), 14301. doi:10.1364/oe.18.014301Escalante, J. M., Martínez, A., & Laude, V. (2014). Design of single-mode waveguides for enhanced light-sound interaction in honeycomb-lattice silicon slabs. Journal of Applied Physics, 115(6), 064302. doi:10.1063/1.486466

Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival.</p> <p>Case presentation</p> <p>A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years.</p> <p>Conclusions</p> <p>Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be achieved in patients with this malignant tumor.</p

Evaluación del estado nutricional en población menor de 10 años de edad del municipio Pereira, Risaralda, Colombia, 2011. Primera parte: Desnutrición global

Introducción: La evaluación del estado nutricional en la población pediátrica es uno de los aspectos de mayor importancia en salud pública. Por estas razones se realizó un estudio para determinar la situación nutricional en menores de 10 años en el municipio Pereira, 2011. En este artículo se presenta la primera parte de sus resultados para desnutrición global. Materiales y Métodos: Estudio de corte transversal, con una muestra probabilística, estratificada, evaluando el indicador Peso para la Edad en niños y niñas menores de 10 años del municipio Pereira (2011). La muestra fue recogida en colegios y en hogares familiares del municipio. Los resultados son comparados con los indicadores de los estudios de 2001 y 2008, con metodologías similares. Resultados: Para 2011 se aprecia una mejoría considerable en los niveles de desnutrición global, comparado con los resultados de 2001, con una reducción de 9,8% (de 32,5% a 22,7%). Ya dicha tasa había disminuido en 2008, pero en 2,4% (de 32,5% en 2001 a 30,1% en 2008), sin embargo, la reducción entre 2008 y 2011 fue más marcada, 7,4% (de 30,1% en 2008 a 22,7% en 2011), adicionalmente considerando que entre los 2 estudios previos trascurrieron 7 años, en tanto que entre el último estudio y el actual tan solo 3 años. Discusión: Los presentes resultados deben orientar al diseño de políticas públicas que impulsen el avance del desarrollo social, el mejoramiento de las condiciones de vida, así como incidir en forma directa en la disponibilidad de alimentos y la educación nutricional en el Municipio a los fines de mejorar en forma integral las condiciones nutricionales que tiene la población infantil en Pereira

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the flavour composition of dijet events in pp collisions at root s=7 TeV with the ATLAS detector

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at &#8730;s=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y|&#60;2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions

The cis-regulatory map of Shewanella genomes

While hundreds of microbial genomes are sequenced, the challenge remains to define their cis-regulatory maps. Here, we present a comparative genomic analysis of the cis-regulatory map of Shewanella oneidensis, an important model organism for bioremediation because of its extraordinary abilities to use a wide variety of metals and organic molecules as electron acceptors in respiration. First, from the experimentally verified transcriptional regulatory networks of Escherichia coli, we inferred 24 DNA motifs that are conserved in S. oneidensis. We then applied a new comparative approach on five Shewanella genomes that allowed us to systematically identify 194 nonredundant palindromic DNA motifs and corresponding regulons in S. oneidensis. Sixty-four percent of the predicted motifs are conserved in at least three of the seven newly sequenced and distantly related Shewanella genomes. In total, we obtained 209 unique DNA motifs in S. oneidensis that cover 849 unique transcription units. Besides conservation in other genomes, 77 of these motifs are supported by at least one additional type of evidence, including matching to known transcription factor binding motifs and significant functional enrichment or expression coherence of the corresponding target genes. Using the same approach on a more focused gene set, 990 differentially expressed genes derived from published microarray data of S. oneidensis during exposure to metal ions, we identified 31 putative cis-regulatory motifs (16 with at least one type of additional supporting evidence) that are potentially involved in the process of metal reduction. The majority (18/31) of those motifs had been found in our whole-genome comparative approach, further demonstrating that such an approach is capable of uncovering a large fraction of the regulatory map of a genome even in the absence of experimental data. The integrated computational approach developed in this study provides a useful strategy to identify genome-wide cis-regulatory maps and a novel avenue to explore the regulatory pathways for particular biological processes in bacterial systems

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results