Quantum Confinement Effects On The Phonons Of Pbte Quantum Dots In Tellurite Glasses

We present Raman-scattering results for PbTe quantum dots (QDs) in doped telluride glasses which clearly show the confinement effects on the phonon spectra as a function of the quantum-dot size..6892Kraus and F. Wise;Phys. Rev. Lett. 79 (25), 5102-05 (1997)Thoen, E.R., (1998) Appl, Phys. Lett, 73 (15), p. 2149Wise, F., (2000) Ace. Chem. Res, 33, pp. 773-780Tsuda, S., Cruz, C.H.B., (1991) Opt. Lett, 16, p. 1596Nakamura, A., Tokizaki, T., Akiyama, H., Kataoka, T., (1992) J. Lumin, 53, p. 105Ohtsuka, S., Koyama, T., Tsunetomo, K., Nagata, H., Tanaka, S., (1992) Appl. Phys. Lett, 61, p. 2953Tsunetomo, K., Ohtsuka, S., Koyama, T., Tanaka, S., Sasaki, F., Kobayashi, S., (1995) Nonlin. Opt, 13, p. 109Colvin, V.L., Schlamp, M.C., Alivisatos, A.P., (1995) Nature ∼London, 370, p. 354Dabbousi, M., Bawendi, G., Onitsuka, O., Rubner, M.F., (1995) Appl. Phys. Lett, 66, p. 1316Guerreiro, T., Ten, S., Borrelli, N.F., Butty, J., Jabbour, G.E., Peyghambarian, N., (1997) Appl. Phys. Lett, 71, p. 1595Murray, C.B., Kagan, C.R., Bawendi, M.G., (1995) Science, 270, p. 1335Kang, I., Wise, F.W., (1997) J. Opt. Soc. Am. B, 14, p. 1632Reynoso, V.C.S., de Paula, A.M., Cuevas, R.F., Medeiros Neto, J.A., Alves, O.L., Cesar, C.L., Barbosa, L.C., (1995) Electron. Lett, 31, p. 1013G.J.Jacob, C.L.Cesar,L.C.Barbosa, Chem.Phys.Glass 43C (2002)250-252Esch, V., Fluegel, B., Khitrova, G., Gibbs, H.M., Jiajin, X., Kang, K., Koch, S.W., Peyghambarian, N., (1990) Phys. Rev, B42, p. 7450Sercel, P.C., Valhala, K.J., (1990) Phys. Rev, B42, p. 3690Schoenlein, R.W., Mittleman, D.M., Shiang, J.J., Alivisatos, A.P., Shank, C.V., (1993) Phys. Rev. Lett, 70, p. 1014Ekimov, A.I., Hache, F., Schanne-Klein, M.C., Ricard, D., Flytzanis, C., Kudryavtsev, I.A., Yazeva, T.V., Efros, A.L., (1993) J. Opt. Soc. Am, B10, p. 100Norris, D.J., Sacra, A., Bawendi, C.B.M.M.G., (1994) Phys. Rev. Lett, 72, p. 2612de Oliveira, C.R.M., de Paula, A.M., Filho, F.O.P., Neto, J.A.M., Barbosa, L.C., Alves, O.L., Menezes, E.A., Cesar, C.L., (1995) Appl. Phys. Lett, 66, p. 439R. Ruppin and R. Englman, Rep. Prog. Phys. 33, 149 (1970)R. Ruppin, J. Phys. C: 8, 1969 (1975)Thoen, E.R., Steinmeyer, G., Langlois, P., Ippen, E.P., Tudury, G.E., Brito Cruz, C.H., Barbosa, L.C., Cesar, C.L., (1998) Appl. Phys. Lett, 73Krauss, T.D., Wise, F.W., Coherent and Acoustical Phonon in a Semiconductor Quantum DotsPhis (1997) Rev. Lett, 79, pp. 5102-510

Genetic evaluation of age at first calving for Guzerá beef cattle using linear, threshold, and survival Bayesian models

Age at first calving (AFC) is characterized as a censored trait due to missing values provided by recording mistakes and nonoccur-rence or delay in calving communication. In this context, we aimed to compare several statistical methods for genetic evaluation of AFC in Guzerá beef cattle under a Bayesian approach. Seven different methods were used for this purpose. The traditional linear mixed model (LM), which considers only uncensored records; the LM with simulated records (SM), which is based on data augmentation framework; the penalty method, in which a constant of 21 d was added to censored records; the bivariate threshold-linear method considering (TLcens) or not (TLmiss) censored information; and the piecewise Weibull proportional hazards model considering (PWPHcens) or not (PWPH) censored records. Heritability estimates ranged from 0.19 (TLcens) to 0.28 (SM) in non-survival approaches; and 0.40 and 0.46 to PWPH and PWPHcens methods, respectively. In general, breeding values correlations between different methods and the percentage of selected bulls in common indicated reranking, with these correlation ranging from -0.28 (between SM and PWPH) to 0.99 (between TLmiss and LM). The traditional LM, which considers only uncensored records, should be preferred due to its robustness and simplicity. Based on cross-validation analyses, we conclude that the TLmiss could be also a suitable alternative for breeding value prediction, and censored methods did not improve the analysis

Pbte Quantum Dots In Tellurite Glass Microstructured Optical Fiber

PbTe doped tellurite glass photonic optical fiber for non linear application were developed using rod in tube method in a draw tower. We follow the growth kinetics of the quantum dots in the optical fiber by High Resolution Transmission Electron Microscopy giving some results related with the growth kinetic of the same in function of time so much for optical fiber as for the glass bulk. Absorption peak near 1500 nm as observed and it was attributed the optical resonance due PbTe quantum dots in the core fiber.6902Tsunetomo, K., (1995) Nonlinear Opt, 13, p. 109Borrelli, N.F., Smith, D.W., (1994) J. Non-Cryst. Soi, 180, p. 25Lipovskii, A., Kolobkova, E.A., Petrikov, V., Kang, I., Olkhovets, A., Krauus, T., Thomas, M., Kycia, S., (1997) Appl. Phys. Lett, 71, p. 3406Reynoso, V.C.S., de Paula, A.M., Cuevas, R.F., Medeiros Neto, J.A., Alves, O.L., Cesar, C.L., Barbosa, L.C., (1995) Elect. Lett, 31 (12), pp. 1013-1014Rodrigues, E., Jimenez, E., Jacob, G.J., Neves, A.A.A., Cesar, C.L., Barbosa, L.C., (2005) Phisica E, 26, pp. 321-325Jacob, G.J., Cesar, C.L., Barbosa, L.C., Tellurite Glass Doped with PbTe Quantum Dots (2002) Physics and Chemistry of Glass, 43 C, pp. 250-253Jacob, G.J., Rodriguez, E., Barbosa, L.C., Cesar, C.L., Tellurite Glass Optical fiber doped with PbTe Quantum DotsPhotonics West 2005, The International Society for Optical Engineering SPIEEnomoto, Y., Tokuyama, M., Kawasaki, K., (1986) Act. Metall, 34, p. 2139Marqusee, J.A., Ross, J., (1984) J. Chem. Phys, 80, p. 536Lifshitz, E.M., Slyozov, V.V., (1961) J. Phys. Chem. Sol, 19, p. 3

Byrsonima Crassa Niedenzu (ik): Antimicrobial Activity And Chemical Study

The methanolic extract of leaves from Byrsonima crassa, a Brazilian medicinal plant, was analyzed by CC and HPLC. Four constituents were isolated and identified as quercetin, methyl gallate, (-)-epigallocatechin gallate and quercetin-3-O-(2″-galloyl)-α-L-arabinopyranoside. The methanolic and hydromethanolic extract, as well as fractions, were evaluated regarding their possible antimicrobial activity using in vitro methods. Results showed that both extracts and fractions exhibited significant antimicrobial activity against all tested strains.2617175Agrawal, P.K., (1989) Carbon 13NMR of Flavonoids, , Amsterdam:ElsevierAlzoreky, N.S., Nakahara, K., Antibacterial activity of extracts from some edible plants commonly consumed in Asia (2003) Int J Food Microbiol, 80, pp. 223-230Amarqiuise, A., Che, C.T., Bejar, E., Malone, M.H., Fong, H.H.S., A New Glycolipid from Byrsonima crassifolia (1994) Planta Med, 60, pp. 85-86Basile, A., Sorbo, S., Giordano, S., Ricciardi, L., Ferrara, S., Montesano, D., Cobianchi, R.C., Ferrara, L., Antibacterial and allelopathic activity of extract from Castanea sativa leaves (2000) Fitoterapia, 71, pp. S110-S116Bauer, A.W., Kirby, M.D.K., Sherries, J.C., Truck, M., Antibiotic susceptibilities testing by standard single disc diffusion method (1966) Am J Clin Pathol, 45, pp. 493-496Bejar, E., Amarquaye, A., Che, C.T., Malone, M.H., Fong, H.H.S., Constituents of Byrsonima crassifolia and their spasmogenic activity (1995) Int J Pharmacog, 33, pp. 25-32Binutu, O.A., Cordell, G.A., Gallic acid derivatives from Mezoneuron benthamianum leaves (2000) Pharm Biol, 38, pp. 284-286Djipa, C.D., Delmee, M., Quetin-Leclercq, J., Antimicrobial activity of bark extracts of Syzygium jambos (L.) Alston (Myrtaceae) (2000) J Ethnopharmacol, 71, pp. 307-313Geiss, F., Heinrich, M., Hunkler, D., Rimpler, H., Heinrich, M., Proanthocyanidins with (+)-epicatechin units from Byrsonima crassifolia bark (1995) Phytochemistry, 39, pp. 635-643Gottlieb, O.R., Henriques Mendes, P., Taveira Magalhães, M., Triterpenoids from Byrsonima verbascifolia (1975) Phytochemistry, 14, pp. 1456-1456Harborne, J.B., (1996) The Flavonoids: Advances in Research since 1986, , New York:Chapman & HallLopez, A., Hudson, J.B., Towers, G.H.N., Antiviral and antimicrobial activities of Colombian medicinal plants (2001) J Ethnopharmacol, 77, pp. 189-196Martínez-Vasquéz, M., González-Esquinca, A.R., Cazares Luna, L., Moreno Gutiérrez, M.N., García-Argáez, A.N., Antimicrobial activity of Byrsonima crassifolia (L.) H.B.K (1999) J Ethnopharmacol, 66, pp. 79-82Mendes, C.C., Cruz, F.G., David, J.M., Nascimento, I.P., David, J.P., Triterpenes esterified with fatty acid and triterpene acids isolated from Byrsonima microphylla (1999) Quím Nova, 22, pp. 185-188Nascimento, G.G.F., Locatelli, J., Freitas, P.C., Silva, G.L., Antibacterial activity of plants extracts and phytochemicals on antibiotic-resistant bacteria (2000) Braz J Microbiol, 31, pp. 247-256(2003) Performance Standards for Antimicrobial Disc Susceptibility Tests, , Approved Standard M2-A7, Pennsylvania:WaynePenna, C., Marino, S., Vivot, E., Cruanes, M.C., Munoz, J.D., Cruanes, J., Ferraro, G., Martino, V., Antimicrobial activity of Argentine plants used in the treatment of infectious diseases. Isolation of active compounds from Sebastiania brasiliensis (2001) J Ethnopharmacol, 77, pp. 37-40Pretorius, J.C., Magama, S., Zietsman, P.C., Purification and identification of antibacterial compounds from Euclea crispa subsp crispa (Ebenaceae) leaves (2003) S Afr J Bot, 69, pp. 579-586Rastrelli, L., De Tommasi, N., Berger, I., Caceres, A., Saravia, A., De Simone, F., Glycolipids from Byrsonima crassifolia (1997) Phytochemistry, 45, pp. 647-650Sannomiya, M., Rodrigues, C.M., Coelho, R.G., Santos, L.C., Hiruma-Lima, C.A., Souza Brito, A.R.M., Vilegas, W., Application of preparative high-speed counter-current chromatography for the separation of flavonoids from the leaves of Byrsonima crassa Niedenzu (IK) (2004) J Chromatogr A, 1035, pp. 47-51Sannomiya, M., Fonseca, V.B., Da Silva, M.A., Rocha, L.R.M., Dos Santos, L.C., Souza, H.C.A., Brito, A.R.M., Vilegas, W., Flavonoids and antiulcerogenic activity from Byrsonima crassa leaves extracts (2005) J Ethnopharmacol, 97, pp. 1-6Silva, S.R., Silva, A.P., Munhoz, C.B., Silva Jr., M.C., Medeiros, M.B., (2001) Guia de Plantas Do Cerrado Utilizadas Na Chapada Dos Veadeiros, , Brasília:WWF58pSrinivasan, D., Nathan, S., Suresh, T., Perumalsamy, P.L., Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine (2001) J Ethnopharmacol, 74, pp. 217-220Wagner, H., Bladt, H., Zgainski, E.M., (1984) Plant Drug Analysis, , Berlin:Springer320

Censored Bayesian models for genetic evaluation of age at first calving in Brazilian Brahman cattle

We compared different Bayesian models to handle censored data for genetic parameters estimation of age at first calving (AFC) in Brazilian Brahman cattle. Data from females with AFC above 1825 days of age were assumed to have failed to calve and were considered as censored records. Data including information of 53, 703 cows were analyzed through the following methods: conventional linear model method (LM), which consider only uncensored records; simulation method (SM), in which the data were augmented by drawing random samples from positive truncated normal distributions; penalty method (PM), in which a constant of 21 days was added to censored records; and the bivariate threshold-linear method (TLcens). The LM was the most suited for genetic evaluation of AFC in Brazilian Brahman cattle based on the predictive ability evaluation through cross-validation analysis. The similar results for LM and PM regarding Spearman correlations, and the higher percentages of selected animals in common, indicated that there was not relevant reranking of animals when censored records were used. In summary, the heritability estimates for AFC ranged from 0.09 (TLcens) to 0.20 (LM). Given its poor predictive performance, the SM is not recommended for handling censored records for genetic evaluation of AFC

Tellurite Photonic Crystal Fiber With Er3+-tm3+ For Broadband Optical Amplifier In 1550nm

Er3+-Tm3+ co-doped tellurite photonic crystal fiber was fabricated via a stack-and-draw procedure and without using extrusion in any stage. The final fiber presents a 187 nm bandwidth of amplified spontaneous emission (ASE) intensity around 1550nm when pumped with 790nm. In this manuscript a soft-glass tube fabrication technique, using the centrifugation method, is also shown.6116Knight, J.C., Birks, T.A., Russel, P.St.J., Atkin, D.M., All-silica single-mode optical fiber with photonic crystal cladding (1996) Opt. Lett, 21, pp. 1547-1549Jeong, H., Oh, K., Han, S.R., Morse, T.F., Characterization of broadband amplified spontaneous emission from an Er3+-Tm3+ -codoped silica fiber (2003) Opt. Lett, 367, pp. 507-511Chillcce, E.F., Rodriguez, E., Neves, A.A.R., Moreira, W.C., César, C.L., Barbosa, L.C., Er3+-Tm3+ co-doped tellurite fibers for broadband optical fiber amplifier around 1550 nm band (2005) Opt. Fiber Technol., , article in pressRussell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Kumar, V.V.R.K., George, A.K., Knight, J.C., Russell, P.St.J., Tellurite photonic crystal fiber (2003) Opt. Exp, 20, pp. 2641-2645Kumar, V.V.R.K., George, A.K., Reeves, W.H., Knight, J.C., Russell, P.St.J., Omenetto, F.G., Taylor, A.J., Extruded soft glass photonic crystal fiber for ultrabroad supercontinuum generation (2002) Opt. Exp, 10 (25), pp. 1520-1525Kiang, K.M., Frampton, K., Monro, T.M., Moore, R., Tucknott, J., Hewak, D.W., Richardson, D.J., Rutt, H.N., Extruded singlemode non-silica glass holey optical fiber (2002) Electron. Lett, 38 (12), pp. 546-54

Development Of Soft-glasses Photonic Crystal Fiber Made By Stacking-and-draw Technique

We have been able to produce soft glass conventional core-clad and micro-structured fibers using rod-and-tube and stack-and-draw method respectively. The stack-and-draw technique shows several difficulties when used with soft glasses, that we managed to avoid using two different lead and alkaline glasses. Non commercial glasses and fibers were thermo-mechanically and optically characterized.6469White, T.P., McPhedran, R.C., de Sterke, C.M., Botten, L.C., Steel, M.J., Confinement losses in micro structure optical fibers (2001) Opt. Lett, 26 (21), p. 1660Russell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Chillcce, E.F., Cordeiro, C.M., Rodriguez, E., Brito Cruz, C.H., Cesar, C.L., Barbosa, L.C., Tellurite photonic crystal with Er 3+-Tm3+ for broadband optical amplifier in 1550nm (2006) Proc. of SPIE, 6116, p. 611604A. Hruby, Czech J. Phys. B, Evaluation of glass-forming tendency by means of DTA 1972, 22, 118