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Sample records for hoplias malabaricus bloch

  1. Morphometric evaluation of the spermatogenesis in trahira Hoplias malabaricus (Bloch (Characiformes, Erythrinidae Avaliação morfométrica da espermatogênese da traíra Hoplias malabaricus (Bloch (Characiformes, Erythrinidae

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    Paula M. Bizzott

    2007-01-01

    Full Text Available The Erythrinidae trahira, Hoplias malabaricus (Bloch, 1794, is widespread throughout South America river basins. We determined Sertoli cell supporting capacity (ratio of primary spermatocytes: Sertoli cells and spermatids: Sertoli cells, meiotic index (ratio of spermatids: primary spermatocytes and the number of spermatogonial mitotic generations of this fish. The fish were captured in the Igarapava reservoir, Grande River, Alto Paraná River basin, Brazil. Testis fragments of three sexually mature trahiras were fixed in 5% buffered glutaraldehyde solution and embedded in glycol methacrylate. Serial sections of 2 and 3 µm in thickness were stained with 0.5% toluidine blue. Histological counts from cysts of primary spermatocytes and spermatids revealed, respectively, 326 ± 99 and 468 ± 73 nuclei of these cells. Sertoli cell supporting capacity was considerably higher for spermatids (113.3 ± 16:1 when compared to primary spermatocytes (71 ± 5:1. Between eight and ten spermatogonial generations were formed to give rise to primary spermatocytes. These values were within the generation range of those already found in freshwater teleosts of external fertilization. Correlation between the number of Sertoli cells and primary spermatocytes per cyst, and Sertoli cells and spermatids per cyst were statistically significant (p A traíra, Hoplias malabaricus (Bloch, 1794, da família Erythrinidae, encontra-se espalhada pelas bacias fluviais da América do Sul. Determinou-se a capacidade de suporte das células de Sertoli (espermatócitos primários: células de Sertoli e espermátides: células de Sertoli, índice meiótico (espermátides: espermatócitos primário e o número de gerações mitóticas de espermatogônias desse peixe. Os indivíduos foram capturados no reservatório de Igarapava, rio Grande, bacia do Alto Paraná, Brasil. Fragmentos dos testículos de três traíras sexualmente maduras foram fixados em glutaraldeído a 5%, e inclu

  2. Feeding of Hoplias aff. malabaricus (Bloch, 1794 and Oligosarcus robustus Menezes, 1969 in a lagoon under estuarine influence, Pelotas, RS

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    Fabiano Corrêa

    2009-09-01

    Full Text Available The objective of the present paper was to study the diets of Hoplias aff. malabaricus and Oligosarcus robust in “Pequena Lagoon” and evaluate the importance of estuarine organisms in the feeding of freshwater fish. A total of twelve food categories were identified and it was established that the fish resource was the most frequent in the diet of both species. Euryhaline fish such as Mugil platanus mullets and Odontesthes argentinensis silversides were common items in the diets of these two species, which included not only freshwater fish but also euryhaline fish from the adjacent estuarine zone, integrating both resources in the food chain.

  3. Efeito dos conservantes sobre a densidade calórica em músculos de Hoplias aff. malabaricus (Bloch, 1794 (Osteichthyes, Erythrinidae Effect of preservatives on caloric density in the muscles of Hoplias aff. malabaricus (Bloch, 1794 (Osteichthyes, Erythrinidae

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    Milena Morimoto

    2002-05-01

    Full Text Available A conservação de amostras para a determinação dos valores calóricos em estudos de bioenergética de peixes tem se apresentado, na literatura, com uma variedade de métodos. Com o intuito de identificar o efeito de conservantes sobre os resultados obtidos com as diferentes técnicas de conservação, foram coletados exemplares adultos de Hoplias aff. malabaricus (Osteichthyes, Erythrinidae na planície de inundação do rio Paraná. De cada exemplar, foram retiradas 5 amostras da musculatura, as quais foram submetidas aos seguintes tratamentos: formol (4%, álcool (70%, congelamento (-10oC, nitrogênio líquido (-180oC e estufa à 60oC (amostra controle. Depois de 30 dias, todas as amostras foram secas em estufa à 60oC e posteriormente procedeu-se à determinação calórica de cada uma das amostras em bomba calorimétrica. Detectaram-se diferenças significativas entre os tratamentos (ANOVA: N=206; F=50,28; pThe preservation of samples for caloric values determination in bioenergetic studies of fish has been presented literature with a variety of methods. To identify the effect of preservatives over the results obtained with different preservation techniques, adult individuals of Hoplias aff. malabaricus (Osteichthyes, Erythrinidae were collected in Paraná river floodplain. From each fish, five samples were extracted from its dorsal muscle and submitted each sample for a different treatment: ice (-10ºC, formaldehyde (4%, alcohol (70%, liquid nitrogen (-180oC and a control sample immediately oven dried (60oC. After 30 days, the treatments were oven dried (60oC and caloric values of each sample were determined in a caloric bomb. Significant differences among the treatments were found (ANOVA: n = 206; F = 50.28; p < 0.001. Some evaluations of the effects of each treatment were presented for further comparisons with the results published in literature.

  4. Cytogenetic characterization of Hoplias malabaricus (Bloch, 1794 from the Ctalamochita River (Córdoba, Argentina: first evidence for southernmost populations of this species complex and comments on its biogeography

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    Diego Javier Grassi

    2017-01-01

    Full Text Available Hoplias malabaricus (Bloch, 1794, a predatory freshwater fish with a wide distribution throughout South America, represents a species complex with seven well characterized karyomorphs at the cytogenetic level. Although this species has been extensively studied in several Brazilian basins, data are still scarce for hydrographic systems from other South American countries. This study aims to characterize cytogenetically the Hoplias malabaricus populations from the Argentinean Central Region, close to the southernmost distribution of this species complex. A total of 32 specimens from the Ctalamochita River, a tributary of Lower Paraná Basin located in the province of Córdoba, were analyzed using cytogenetic techniques (Giemsa staining, C- and Ag-NOR banding and fluorescent in situ hybridization with 18S rDNA. All the specimens showed diploid number 2n=42, chromosomic formula 22m + 20sm and absence of sexual chromosomes. Thus, the analyzed populations belong to the karyomorph named A. These populations showed a remarkable degree of divergence in their cytogenetic traits such as karyotypic formula, C-banding, NORs and 18S rDNA patterns for Hoplias malabaricus from other populations bearing the same karyomorph in the Middle and Upper Paraná Basin. These findings are consistent with molecular data from a recent study (where specimens collected in the present work were included, which indicate a closer phylogenetic relationship of Hoplias malabaricus populations from the Ctalamochita River with those from the Uruguay basin and the coastal regions of South Brazil than with populations from the Middle and Upper Paraná Basin. Overall, these pieces of evidence highlight the distinctive features of Hoplias malabaricus from the Ctalamochita River, and also reveal a complex history of dispersion of these populations. The present work is the first to provide cytogenetic information and include some phylogeographic aspects of Hoplias malabaricus populations

  5. Mudança na dieta da traíra Hoplias malabaricus (Bloch (Erythrinidae, Characiformes em lagoas da bacia do rio Doce devido à introdução de peixes piscívoros Diet changes of the trahira Hoplias malabaricus (Bloch (Erythrinidae, Characiformes due to piscivorous introductions in Rio Doce valley lakes

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    Paulo dos Santos Pompeu

    2001-12-01

    Full Text Available Two piscivorous fishes, peacock bass (Cichla monoculus Spix & Agassiz, 1831 (Perciformes and piranha (Pygocentrus nattereri Kner, 1860 (Characiformes, were introduced in some Rio Doce valley lakes (19º50'S, 42º40'W for sport fisheries enhancement. As a consequence, small individuals and species were practically vanished in the host lakes. In this study, the effects of peacock bass and piranha introductions on the diet of a native piscivorous fish, the trahira - Hoplias malabaricus (Bloch, 1794 are presented. Trahira's diet from three lakes were was compared with the stomach contentsdiet of trahira's living in another between three lakes with and three withoutstocked with the piscivorous species peacock bass and piranha. In the lakes with introduced fishes species, the consumption of fish was significantly smaller and this food item have been this item partly replaced by aquatic invertebrates. This shift on of trahira's diet to the low abundance of its original prey, is attributed to the small fishes. This diet plasticity adaptative capacity he diet plasticity detected for trahira might be allowing its maintenance in the lakes with peacock bass and piranha.

  6. Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

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    M. R. Aquino-Silva

    Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

  7. Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

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    Aquino-Silva M. R.

    2003-01-01

    Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

  8. CRECIMIENTO Y MORTALIDAD DEL MONCHOLO (Hoplias malabaricus EN LA CIÉNAGA GRANDE DE LORICA, COLOMBIA

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    Glenys Tordecilla-Petro,

    2005-12-01

    Full Text Available Para estimar los parámetros de crecimiento y mortalidad del moncholo (Hoplias malabaricus Bloch 1794en la Ciénaga Grande de Lorica (CGL se aplicó el análisis de frecuencia de tallas (ELEFAN a la informacióncolectada entre enero y diciembre 2000. Los valores estimados para L¥, K y t0 fueron 48.1 (± 0.09 cm.,0.29 (+ 0.01 año-1 y -0.50 años, respectivamente, con temperatura media anual de 28 °C y límites deconfianza del 95%. Las estimaciones para L¥ y K indican que es un pez de longevidad y tasa de crecimientomedios. La mortalidad total (Z fue estimada en 2.31 (± 0.23 año-1, la mortalidad natural (M en 0.70año–1, la mortalidad por captura (F se calculó en 1.61 año –1, y la tasa de explotación (E=F/Z 0.70. Latalla de su primera captura (Lc es de 29.4 cm., LT, y su talla media de captura (TMC es de 30.0 cm., LT.Como la especie no presenta migración reproductiva, permanece en la CGL, siendo capturada en laausencia de las especies reofílicas tradicionalmente capturadas, la presión pesquera aumenta sobre ella,alcanzando niveles de sobrepesca. La construcción y operación de la hidroeléctrica Urrá (HU y lacontaminación orgánica e inorgánica durante el año 2000 afectaron la dinámica poblacional de los pecesde la Cuenca del río Sinú, por lo que es necesario que se agilice el ordenamiento de su pesquería en elmediano plazo considerando que el moncholo es la tercera especie en la composición de la captura en lacuenca.

  9. Different foods in larvicultura of traíra (Hoplias malabaricus

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    Samuel Louzada Pereira

    2015-10-01

    Full Text Available ABSTRACT. Pereira S.L., Mendonça P.P., Pellanda A.S., Matielo M.D. & Gon- çalves Junior L.P. [Different foods in larvicultura of traíra (Hoplias malabaricus.] Utilização de diferentes alimentos na larvicultura de traíra (Hoplias malabaricus. Revista Brasileira de Medicina Veterinária, 37(3:233-238, 2015. Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ 28013-602, Brasil. E-mail: samuell_lp@hotmail.com The feeding in the larviculture of species carnivorous view point for closing of the technological packages of rearing culture. Developed in the sector of Aquicultura of the IFES - Campus of Alegre, this work it aimed at to compare the performance with four diet feed as first exogenous feeding for traíra (Hoplias malabaricus, parameters evaluated: Survival, length final (CF, final weight (PF, tax of specific growth (TCE, development tax specifies (TDE, being put in container with fifteen liters of water, with constant aeration, have five larva of traíra/container. The delineation entire was aleatory with four treatments and five repetitions. Being the diet feeds represented for T1: Nauplios de Artemia sp.; T2: microworm of oats (Pannagrelos redivivus; T3: Wild Zooplâncton; e the inert food represented by T4: Commercial ration in dust with 55% of crude protein and 4,200 Kcal de ED/kg of ration. The water exchange was of 80% daily, the average temperature was of 27.5±1°C. The indices of survival in the T1, T2, T3 and T4, had been 84%, 72%, 100% and 92%, respectively. The date had been submitted analyze it statistics ANOVA and test of Tukey (P<0.01. Wild Zooplâncton was biggest CTF, PF, GP, TCE and TDE. Did not have difference statistics between the Artemia sp. the ration for TCE and TDE. The microworm of oats was minor CF, PF, TCE and TDE. The treatment Wild zooplankton (T3 showed optimum diet food among the other diet feeds tested for the development and

  10. Species of the Hoplias aff malabaricus complex (Characiformes: Erythrinidae: An investigation of coexistence in a Neotropical floodplain

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    Marília Hauser

    2012-02-01

    Full Text Available This study assessed the coexistence of three species of thraira present in the Upper Paraná River floodplain, using population structure as an investigation tool. The species were designated as: Hoplias sp. 1, introduced after the construction of the Itaipu reservoir, and Hoplias sp. 2 and Hoplias sp. 3, native species that have been identified as Hoplias aff. malabaricus. We tested the hypothesis that those species in fact differ from each other in respect of population abundance, sex ratio, relative frequency of adults and juveniles, length structure and weight-length relationship. Additionally, possible effects of the flood pulse on the first four of these parameters were investigated. Samples were collected quarterly from March 2006 to December 2007 from nine collection sites on the floodplain. Hoplias sp. 1 presented a greater balance of sex ratio and length structures over the seasons, as well as a higher allometric coefficient. The population attributes of Hoplias sp. 2 and Hoplias sp. 3 showed a high responsiveness to hydrological seasonality, indicating that these species exploit available resources in a conspicuous flood period with greater efficiency. These differences, beyond reflecting possible mechanisms that allow closely related species to coexist, indicate the importance of understanding the life strategies adopted by each species which, as part of a complex system, are considered key elements of the aquatic community structure in the region, providing important information for habitat management and biodiversity conservation.

  11. Cytogenetic and DNA barcoding reveals high divergence within the trahira, Hoplias malabaricus (Characiformes: Erythrinidae from the lower Amazon River

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    Diego Ferreira Marques

    Full Text Available Molecular and cytogenetic data have provided evidence of cryptic speciation in the widespread South American trahira, Hoplias malabaricus. In the present study, karyotypes and DNA barcode sequences of specimens from seven populations inhabiting the lower Amazon River were analyzed in order to characterize the levels of genetic divergence within a single karyomorph. All the specimens presented karyotypes with 2n = 40 chromosomes (20m+20sm that were consistent with the species' C karyomorph. The DNA barcodes revealed six haplogroups, with clear divergence between populations from Brazil and Argentina. The results support the species complex hypothesis and indicate that a single karyomorph of H. malabaricus may harbor more than one species

  12. Amino acids and carbohydrates absorption by Na+-dependent transporters in the pyloric ceca of Hoplias malabaricus (Erythrinidae

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    Vieira Vania Lucia Pimentel

    2001-01-01

    Full Text Available Information about amino acids and carbohydrate absorption in fish is important to formulate an adequate diet to obtain optimal growth. Therefore, the objective of this study was to investigate if Na+-dependent transporters are involved on the absorption of glycine, L-glutamine, L-leucine, L-lysine, L-proline, L-alanine, and the carbohydrates fructose and glucose in the pyloric ceca of Hoplias malabaricus. The pyloric ceca were mounted in a system of continuous perfusion "in vitro". Amino acids and carbohydrates were placed on the mucosal side at concentrations of 10, 20, and 40mM. The serosal side of the pyloric ceca was positive in relation to the mucosal side. The addition of glycine, L-glutamine, L-leucine, L-lysine, L-proline (all tested concentrations, and glucose (at concentrations of 20 and 40mM increased the positivity of the serosal side, indicating the presence of Na+-dependent transporters in the absorption of these substances. L-alanine and fructose did not change the positivity of the serosal side. The pyloric ceca seem to be the main site of nutrient absorption in the digestive tract of H. malabaricus.

  13. Hematological findings in neotropical fish Hoplias malabaricus exposed to subchronic and dietary doses of methylmercury, inorganic lead, and tributyltin chloride

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    Oliveira Ribeiro, C.A.; Filipak Neto, F.; Mela, M.; Silva, P.H.; Randi, M.A.F.; Rabitto, I.S.; Alves Costa, J.R.M.; Pelletier, E.

    2006-01-01

    Hematological indices are gaining general acceptance as valuable tools in monitoring various aspects the health of fish exposed to contaminants. In this work some effects of methyl mercury (MeHg), inorganic lead (Pb 2+ ), and tributyltin (TBT) in a tropical fish species were evaluated by hematological methods after a trophic exposition at a subchronic level. Forty-two mature individuals of the freshwater top predator fish Hoplias malabaricus were exposed to trophic doses (each 5 days) of MeHg (0.075 μg g -1 ), Pb 2+ (21 μg g -1 ), and TBT (0.3 μg g -1 ) using young fish Astyanax sp. as prey vehicle. After 14 successive doses over 70 days, blood was sampled from exposed and control groups to evaluate hematological effects of metals on erythrocytes, total leukocytes and differential leukocytes counts, hematocrit, hemoglobin concentration, and red blood cell indices mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). Transmission electron microscopy and image analysis of erythrocytes were also used to investigate some morphometric parameters. Results show no significant effects in MCH and MCHC for all tested metals, but differences were found in erythrocytes, hemoglobin, hematocrit, MCV, and white blood cells counts. The number of leukocytes was increased in the presence of MeHg, suggesting effects on the immune system. Also the MCV increased in individuals exposed to MeHg. No ultrastructural damages were observed in red blood cells but the image analysis using light microscopy revealed differences in area, elongation, and roundness of erythrocytes from individuals exposed to Pb 2+ and TBT but not in the group exposed to MeHg. The present work shows that changes in hematological and blood indices could highlight some barely detectable metal effects in fish after laboratory exposure to contaminated food, but their application in field biomonitoring using H. malabaricus will need more detailed

  14. Response of mucous cells of the gills of traíra (Hoplias malabaricus and jeju (Hoplerythrinus unitaeniatus (Teleostei: Erythrinidae to hypo- and hyper-osmotic ion stress

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    Sandro Estevan Moron

    Full Text Available The mucous cells (MC of traíra, Hoplias malabaricus, and jeju, Hoplerythrinus unitaeniatus, two ecologically distinct erythrinid species, were analyzed in fish exposed to deionized (DW and high ion concentration (NaCl and Ca2+ water (HIW during 15 days to evaluate the MC responses to ion challenge. MCs are localized in the leading and trailing edge and, interlamellar region of the gill filament epithelium but, in H. unitaeniatus, they are also found in the breathing or lamellar epithelium. MC density is lower in H. malabaricus, the exclusively water-breathing fish, than in H. unitaeniatus, a facultative air-breathing fish. The transference to DW or HIW did not change the MC density and surface area, excepting in H. malabaricus, in the first day of exposure to DW. A single MC containing three types of glycoproteins (neutral, acidic and sulphated was identified in the gill epithelium of both, H. malabaricus and H. unitaeniatus. The amount (based on the intensity of histochemistry reaction of these glycoproteins differed between the species and were altered after exposure to DW and HIW showing little adjustments in the amount of mucosubstances in the MC of H. malabaricus and reduction of acidic and sulphated glycoproteins in H. unitaeniatus. The decreasing of these glycoproteins in H. unitaeniatus reduced the mucus protection against desiccation of gill tissue when change the ion concentration in water.

  15. Contracaecum sp (ANISAKIDAE EN EL PEZ Hoplias malabaricus, CAPTURADO EN LA CIÉNAGA GRANDE DE LORICA, CÓRDOBA

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    Sandra Pardo C

    2008-08-01

    Full Text Available Objective. To determine the presence of Contracaecum nematodes in the fish Hoplias malabaricus (moncholo. Materials and methods. A total of 45 fish, captured between July. 2006 and May, 2007 were sampled. In the laboratory, biometric analysis was done on each fish; the fish was gutted and examined for nematodes. Skeletal musculature was extracted, dissected in thin layers and observed with ultraviolet light to evaluate the presence of nematodes. Nematodes were counted, isolated and fixed in formaldehyde. Nematodes tissues were cleared in order to visualize their internal structures, and morphometric keys were used to confirm their identification. Results. Nematodes were found only in viscera and identified as Contracaecum spp in the third larval state (L3. Prevalence was 100% with light (88.9% and moderate (11.1% infestation. The condition factor value was 0.036±0.04, the hepatosomatic, branchiasomatic and somatic spleen indices were 1.65±0.37, 3.40±0.43, 0.09±0.04, respectively. There was no significant relationship between these indices and the parasite index (r0.05. Conclusions. Moncholo sampled from Ciénaga Grande de Lorica were infected with Contracaecum spp. The condition factor index and the somatic organ indices were not significant predictors of infection.

  16. Blood parameter analysis and morphological alterations as biomarkers on the health of Hoplias malabaricus and Geophagus brasiliensis

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    Silvia Romão

    2006-05-01

    Full Text Available This study aimed to assess the influence of the environment on fish health. Samples of Hoplias malabaricus and Geophagus brasiliensis, were collected from three different environments: area I was urban and areas II and III were rural. Analyses of red blood cell count, microhematocrit, hemoglobin concentration, white blood cell count and differential white cell count in blood smear were carried out. Mean corpuscular volume and mean corpuscular hemoglobin concentration were calculated. To analyze morphological alterations, gills, liver, kidney and gonads were submitted to routine histological processing. Individuals collected from area III had slightly lower blood indices than collected from area I . Severe kidney changes, degeneration of and crystallization within kidney tubules were observed. In area I, crystallization was observed in 92% of the specimens of G. brasiliensis. These results suggested that such alterations were related with poor water circulation in the place.Este trabalho teve como objetivo avaliar a influência do ambiente sobre a higidez dos peixes. Animais, das espécies Hoplias malabaricus e Geophagus brasiliensis foram coletados em três ambientes distintos, sendo ambiente I região urbana e ambientes II e III em região rural. Foram realizadas análises do número total de eritrócitos por microlitro de sangue, microhematócrito, taxa de hemoglobina, porcentagem de leucócito e contagem diferencial de leucócitos em extensão sanguínea. Calcularam-se os índices hematimétricos absolutos: volume corpuscular médio e concentração de hemoglobina corpuscular média. Para análises das alterações morfológicas, brânquias, fígado, gônadas e rim seguiram processamento histológico de rotina. Foram observados índices hematológicos ligeiramente menores em indivíduos coletados no ambiente III em relação aos animais coletados no ambiente I. As análises histológicas de brânquias, fígado e gônadas das espécies G

  17. Dactylogyrids (Platyhelminthes, Monogenoidea) from the gills of Hoplias malabaricus (Characiformes: Erythrinidae) from coastal rivers of the Oriental Amazon Basin: species of Urocleidoides and Constrictoanchoratus n. gen.

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    Ferreira, K D C; Rodrigues, A R O; Cunha, J-M; Domingues, M V

    2018-05-01

    Five species of Urocleidoides (one new) and two new species of Constrictoanchoratus n. gen. are described in this study. All were collected from the gills of Hoplias malabaricus (Characiformes: Erythrinidae) captured in six localities of coastal rivers of the north-eastern sector the State of Pará (Oriental Amazon): Urocleidoides brasiliensis Rosim, Mendoza-Franco & Luque, 2011; Urocleidoides bulbophallus n. sp.; Urocleidoides cuiabai Rosim, Mendoza-Franco & Luque, 2011; Urocleidoides eremitus Kritsky, Thatcher & Boeger, 1986; Urocleidoides malabaricusi Rosim, Mendoza-Franco & Luque, 2011; Constrictoanchoratus lemmyi n. gen. n. sp.; and Constrictoanchoratus ptilonophallus n. gen. n. sp. This is the first reported occurrence of the four previously described species of Urocleidoides parasitizing H. malabaricus from streams in the Oriental Amazon Basin. The analysis of voucher specimens of U. eremitus parasitizing the gills of H. malabaricus from the Upper Paraná River floodplain in the limits of States of Paraná and Mato Grosso do Sul, Brazil, indicates that these specimens are members of a new species of Urocleidoides, described here as Urocleidoides paranae n. sp. Constrictoanchoratus n. gen. is proposed for the species with a male copulatory organ sclerotized, coiled, clockwise; ventral anchor with elongate superficial root, inconspicuous deep root; dorsal anchor with inconspicuous roots, and a constriction at the intersection between the shaft and the point. The host-parasite diversity scenario and host specificity of the species of Constrictoanchoratus n. gen. and Urocleidoides from the gills of H. malabaricus are also discussed in this study.

  18. Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus

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    C.L. Tanan

    2006-07-01

    Full Text Available Methyl mercury (MeHg is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group or by trophic exposure (T group. Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas, 0.05 (N = 2 retinas and 0.1 mg/kg (N = 1 retina, whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina, 0.075 (N = 8 retinas or 0.0075 (N = 4 retinas mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

  19. Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus

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    D.M.O. Bonci

    2006-03-01

    Full Text Available To quantify the effects of methylmercury (MeHg on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus at two dose levels (2 and 6 µg/g, ip. The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase C (alphaPKC immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR and alphaPKC (alphaPKC-IR in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and alphaPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g showed significant reduction of the ON-bipolar alphaPKC-IR cell density (mean density = 1306 ± 393 cells/mm² compared to control (1886 ± 892 cells/mm²; P < 0.001. The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm² (2 µg/g and 845 ± 82 cells/mm² (6 µg/g, also lower than control (1312 ± 31 cells/mm²; P < 0.05, differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of alphaKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.

  20. Alternagin-C (ALT-C), a Disintegrin-Like Cys-Rich Protein Isolated from the Venom of the Snake Rhinocerophis alternatus, Stimulates Angiogenesis and Antioxidant Defenses in the Liver of Freshwater Fish, Hoplias malabaricus.

    Science.gov (United States)

    Monteiro, Diana Amaral; Selistre-de-Araújo, Heloisa Sobreiro; Tavares, Driele; Fernandes, Marisa Narciso; Kalinin, Ana Lúcia; Rantin, Francisco Tadeu

    2017-09-28

    Alternagin-C (ALT-C) is a disintegrin-like protein isolated from Rhinocerophis alternatus snake venom, which induces endothelial cell proliferation and angiogenesis. The aim of this study was to evaluate the systemic effects of a single dose of alternagin-C (0.5 mg·kg -1 , via intra-arterial) on oxidative stress biomarkers, histological alterations, vascular endothelial growth factor (VEGF) production, and the degree of vascularization in the liver of the freshwater fish traíra, Hoplias malabaricus , seven days after the initiation of therapy. ALT-C treatment increased VEGF levels and hepatic angiogenesis. ALT-C also enhanced hepatic antioxidant enzymes activities such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, decreasing the basal oxidative damage to lipids and proteins in the fish liver. These results indicate that ALT-C improved hepatic tissue and may play a crucial role in tissue regeneration mechanisms.

  1. Feeding and morphological analysis of the digestive tract of four species of fish (Astyanax altiparanae, Parauchenipterus galeatus, Serrasalmus marginatus and Hoplias aff. malabaricus from the upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    D. Peretti

    Full Text Available The present study is inspired by the great wealth of species exhibited by the ichthiofauna. Not only concepts and techniques of ecology deserve attention, but also knowledge in other biological areas, such as zoology and anatomy, are necessary. The intention of the present work is to discover the morphology of fish through the study of the digestive tract morphology, associating it to diet data, in order to better understand the biology of four fish species of the upper Paraná River floodplain. The samples were collected quarterly in the year 2000 with gillnets of different meshes. The stomach content was analyzed under a stereoscopic microscope and the frequencies of occurrence (FO and volumetric (FV and the alimentary index (IAi were calculated. Various morphologic characteristics were analyzed and schematized using a light chamber. The species were grouped into two trophic guilds - insectivores (Astyanax altiparanae and Parauchenipterus galeatus and piscivores (Serrasalmus marginatus and Hoplias aff. malabaricus. The first two, although consumers of insects, preyed on different alimentary groups, notably Hymenoptera in the case of A. altiparanae and Coleoptera in the case of P. galeatus. Serrasalmus marginatus and H. aff. malabaricus consumed mainly fishes. However, only pieces of prey were usually found in the stomach content of the first species, whereas whole fishes were found in the stomach content of the second. Astyanax altiparanae exhibited characteristics that allowed it to obtain food in several compartments of the water column. Similarly P. galeatus consumed food resources that were available in all aquatic compartments, although the abilities to capture, to manipulate and to absorb food differed, as shown by the importance of teeth plates and pharyngeal teeth. Serrasalmus marginatus and H. aff. malabaricus, although resembling each other in many aspects of the digestive tract morphology, differed in the strategies used to capture

  2. LEVANTAMENTO PARASITOLÓGICO EM Hoplias Malabaricus, Bloch, (1794 (TRAIRA DE ÁGUAS DA REGIÃO DE SANTA MARIA - RS

    Directory of Open Access Journals (Sweden)

    Ana Maria Weiblen

    1992-08-01

    Full Text Available No presente trabalho estudou-se os parasitos encontrados em 139 traíras coletadas nas diferentes estações do ano em lagoas e açudes do município de Santa Maria, RS. Os objetivos deste levantamento foram: determinar a localização preferencial dos parasites no hospedeiro, relacionar a prevalência dos parasites com as estações do ano e identificar os mesmos a nível de gênero e se possível espécie. Dos 139 peixes necropsiados, 2812 parasites foram coletados ficando assim distribuídos: 469 na primavera, 921 no verão, 482 no outono e 940 no inverno. Destes 2812 parasitos, 1637 foram nematódeos pertencentes as seguintes espécies: Contracaecum sp, Parasseuratum soaresi, Paracappilaria piscicola, Guyanema baudi, Spirocamallanus hilarii, Procamallanus peraccuratus e nematódeos não identificados; 931 trematódeos pertencentes a Ithyoclinostomulum dimorphum, Tylodelphylus sp. 1, Dendrorchis sp, Clinostomum sp e Halipegus overstreeti; 106 acantocéfalos pertencentes a Quadrigyrus machadoi; 138 microcrustáceos do gênero Ergasilus e 20 argulídeos do gênero Dolops.

  3. The effects of temperature on gastric emptying time of malabar blood snapper (Lutjanus malabaricus, Bloch & Schneider 1801) using X-radiography technique

    International Nuclear Information System (INIS)

    Mazumder, Sabuj Kanti; Ghaffar, Mazlan Abd.; Das, Simon Kumar

    2015-01-01

    Water temperature can influence the metabolic rate of ectothermal animal such as, fish. This study aims to investigate the gastric emptying time (GET) of malabar blood snapper (L. malabaricus) at different temperature (22, 26, 30, 34°C) fed with commercial diet pellet. The gastric emptying times at different temperatures were determined X-radiographically, using barium sulfate (BaSO 4 ) as a contrast medium food marker. The food marker and X-radiography showed that initial voidance of fecal matter began 4-8 h after feeding at all temperature. The fastest GET (18 h) was obsereved at 30°C, whereas the longest (28 h) GET was seen at 22°C. GET was increased with increasing temperature up to 30°C whereas decreased at extreme (34°C) and stress temperature (22°C). The findings of this study suggest to culture L. malabaricus at 26-30°C with commercial diet pellet as this temperature ranges escalate the faster digestion process which may contribute faster growth rate of this commercially important fish species. Overall, the data obtained from this study may have important consequences for optimization of commercial production of malabar blood snapper

  4. The effects of temperature on gastric emptying time of malabar blood snapper (Lutjanus malabaricus, Bloch & Schneider 1801) using X-radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, Sabuj Kanti, E-mail: sabujsau@gmail.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Ghaffar, Mazlan Abd., E-mail: magfish05@yahoo.com [Marine Ecosystem Research Centre (EKOMAR), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Institute of Tropical Aquaculture, University of Malaysia Terengganu, 21030 Kuala Terengganu (Malaysia); Das, Simon Kumar, E-mail: skdas-maa@yahoo.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Marine Ecosystem Research Centre (EKOMAR), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Water temperature can influence the metabolic rate of ectothermal animal such as, fish. This study aims to investigate the gastric emptying time (GET) of malabar blood snapper (L. malabaricus) at different temperature (22, 26, 30, 34°C) fed with commercial diet pellet. The gastric emptying times at different temperatures were determined X-radiographically, using barium sulfate (BaSO{sub 4}) as a contrast medium food marker. The food marker and X-radiography showed that initial voidance of fecal matter began 4-8 h after feeding at all temperature. The fastest GET (18 h) was obsereved at 30°C, whereas the longest (28 h) GET was seen at 22°C. GET was increased with increasing temperature up to 30°C whereas decreased at extreme (34°C) and stress temperature (22°C). The findings of this study suggest to culture L. malabaricus at 26-30°C with commercial diet pellet as this temperature ranges escalate the faster digestion process which may contribute faster growth rate of this commercially important fish species. Overall, the data obtained from this study may have important consequences for optimization of commercial production of malabar blood snapper.

  5. Temperature and diet effect on the pepsin enzyme activities, digestive somatic index and relative gut length of Malabar blood snapper (Lutjanus malabaricus Bloch & Schneider, 1801

    Directory of Open Access Journals (Sweden)

    Sabuj Kanti Mazumder

    2018-02-01

    Full Text Available An integrated experiment was performed on juvenile Malabar blood snapper (Lutjanus malabaricus to investigate the effect of temperature and diet in their pepsin activities in relation with digestive somatic index (IDS and relative gut length (RGL. One hundred twenty L. malabaricus juvenile (13–15 cm were equally distributed among four exposed temperature treatments (22, 26, 30 and 34 °C representing their seasonal range and to account for end of century predicted temperatures, and two diets as commercial pellet and natural shrimp. After 7 days of acclimation period fish were reared for 30 days in twenty four 400 l glass aquaria at a stocking density of 5 fish tank−1. All treatments were three replications. The result showed that, IDS and RGL gradually decreased with increasing temperature up to 30 °C and again increase at 34 °C. And the values were also higher in pellet feeding fish than shrimp feeding fish at all the temperatures. Alternatively, in pepsin activity, an increased activity was seen between 26 °C to 30 °C and this activity was significantly higher than the 22 °C and 34 °C (P < 0.05. In general, highest pepsin activity was observed among fish which fed on a natural shrimp diet reared at temperature 30 °C (5.47 ± 1.60 U mg protein−1, followed by those at 26, 34 and 22 °C (P < 0.05 at both diet however, no mortalities were observed. These results could be used as a basis for selecting a suitable diet for maximizing the growth and sustainable aquaculture coping with global warming.

  6. Taxonomic study of Hoplias microlepis (Günther, 1864, a trans-Andean species of trahiras (Ostariophysi: Characiformes: Erythrinidae

    Directory of Open Access Journals (Sweden)

    George M. T. Mattox

    Full Text Available The Hoplias malabaricus species group represents one of the most complexes taxonomical problems in the systematics of Neotropical fishes, including specimens widely distributed in most drainages of South America and part of Central America with great variation or overlap of putative diagnostic characters. The large number of nominal species, many of which without known type material, renders the problem more complicated. Currently, at least three nominal species can be included in the Hopliasmalabaricusspecies group based on the form of the medial margins of dentaries and presence of tooth plates on the tongue: Hoplias malabaricus, H. teres, and H. microlepis, the latter representing the only exclusively trans-Andean known species of the genus. We present herein a taxonomic study of Hoplias microlepis based on examination of syntypes and recently collected specimens, including a redescription of the species. Hoplias microlepisoccurs in the Pacific drainages of Panama and Southwestern Costa Rica, in addition to the río Guayas basin in Ecuador and the region near its mouth (río Tumbes, Northwestern Peru. Records of the species on the Atlantic coast of Panama are restricted to the Canal Zone, suggesting dispersal through the Panama Canal. We also designate lectotype and paralectotypes.

  7. Sex Chromosome Evolution and Genomic Divergence in the Fish Hoplias malabaricus (Characiformes, Erythrinidae)

    Czech Academy of Sciences Publication Activity Database

    Sember, Alexandr; Bertollo, L.A.C.; Ráb, Petr; Yano, C. F.; Hatanaka, T.; de Oliveira, E. A.; de Bello Cioffi, M.

    2018-01-01

    Roč. 9, č. 1 (2018), č. článku 71. ISSN 1664-8021 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : fish cytogenetics * multiple sex chromosomes * sex-determining region Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.789, year: 2016

  8. Mutagenic effects of tributyltin and inorganic lead (Pb II on the fish H. malabaricus as evaluated using the comet assay and the piscine micronucleus and chromosome aberration tests

    Directory of Open Access Journals (Sweden)

    Ferraro Marcos Vinícius M.

    2004-01-01

    Full Text Available Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT and inorganic lead (PbII using samples of the fish Hoplias malabaricus (commonly called traíra using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 mg/g of body weight (bw of TBT, six to 21 mg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus which had been injected with solutions of TBT, PbII or with water (the control group. After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01, the micronucleus assay showing morphological alterations of the nucleus.

  9. Biochemical and pharmacological characterization of Trimersurus malabaricus snake venom.

    Science.gov (United States)

    Gowda, Raghavendra; Rajaiah, Rajesh; Angaswamy, Nataraj; Krishna, Sharath; Bannikuppe Sannanayak, Vishwanath

    2018-03-12

    Trimeresurus malabaricus is a venomous pit viper species endemic to southwestern part of India. In earlier reports, we have shown that envenomation by T. malabaricus venom leading to strong local tissue damage but the mechanism of action is not clearly revealed. Local tissue damage affected by T. malabaricus venom is of great importance since the poison has serious systemic effects including death in the case of multiple attacks. The present study details the major manifestations of T. malabaricus venom and the induction of local tissue damage, which suggests that most toxins are present in the form of hydrolytic enzymes. Hydrolytic activity of the enzymes was measured and the data indicated that protease and phospholipase A 2 activity was high which is responsible for local tissue damage. Furthermore, the role of hydrolytic enzymes in the induction of pathological events such as hemorrhage, edema, myotoxicity, and blood coagulation examination were assessed through animal models. © 2018 Wiley Periodicals, Inc.

  10. The chromosomal distribution of microsatellite repeats in the genome of the wolf fish Hoplias malabaricus, focusing on the sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Cioffi, M.B.; Kejnovský, Eduard; Bertollo, L.A.C.

    2011-01-01

    Roč. 132, č. 4 (2011), s. 289-296 ISSN 1424-8581 R&D Projects: GA ČR(CZ) GAP305/10/0930 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : fish sex chromosomes * fluorescence in situ hybridization * microsatellites Subject RIV: BO - Biophysics Impact factor: 1.533, year: 2011

  11. Tracking the evolutionary pathway of sex chromosomes among fishes: characterizing the unique XX/XY1Y2 system in Hoplias malabaricus (Teleostei, Characiformes)

    Czech Academy of Sciences Publication Activity Database

    de Oliveira, E. A.; Sember, Alexandr; Bertollo, L.A.C.; Yano, C. F.; Ezaz, T.; Moreira-Filho, O.; Hatanaka, T.; Trifonov, V.; Liehr, T.; Al-Rikabi, A. B. H.; Ráb, Petr; Pains, H.; de Bello Cioffi, M.

    2018-01-01

    Roč. 127, č. 1 (2018), s. 115-128 ISSN 0009-5915 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : fish cytogenetics * male-specific region * whole chromosome painting Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 4.414, year: 2016

  12. A theory of generalized Bloch oscillations

    International Nuclear Information System (INIS)

    Duggen, Lars; Lassen, Benny; Lew Yan Voon, L C; Willatzen, Morten

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact calculation is given to confirm this phenomenon. Our results allow for a greater freedom of design for experimentally observing Bloch oscillations. For strongly coupled oscillator systems displaying Bloch oscillations, it is further demonstrated that reordering of oscillators leads to destruction of Bloch oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics. (paper)

  13. Felix Bloch (1905–1983)

    Indian Academy of Sciences (India)

    IAS Admin

    1905, to Jewish parents, Gustav and Agnes Bloch. The year he ... Both the student and the supervisor were in their 20's, separated by 5– ... up on the West Coast, in the University of Stanford, where he stayed for the rest of his academic life.

  14. A theory of generalized Bloch oscillations

    DEFF Research Database (Denmark)

    Duggen, Lars; Lew Yan Voon, L. C.; Lassen, Benny

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact...... oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics....

  15. Electric dipoles on the Bloch sphere

    OpenAIRE

    Vutha, Amar C.

    2014-01-01

    The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic & molecular physics.

  16. Electric dipoles on the Bloch sphere

    International Nuclear Information System (INIS)

    Vutha, Amar C

    2015-01-01

    The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic and molecular physics. (paper)

  17. First data on the parasites of Hoplias aimara (Characiformes): description of two new species of gill monogeneans (Dactylogyridae)

    Czech Academy of Sciences Publication Activity Database

    Moreira, J.; Scholz, Tomáš; Luque, J.L.

    2015-01-01

    Roč. 60, č. 2 (2015), s. 254-260 ISSN 1230-2821 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Monogenea * Dactylogyridae * Urocleidoides * Erythrinidae * Hoplias aimara * Xingu River * Brazil Subject RIV: EG - Zoology Impact factor: 1.293, year: 2015

  18. Bloch walls in a nickel single crystal

    International Nuclear Information System (INIS)

    Peters, J.; Treimer, W.

    2001-01-01

    We present a consistent theory for the dependence of the magnetic structure in bulk samples on external static magnetic fields and corresponding experimental results. We applied the theory of micromagnetism to this crystal and calculated the Bloch wall thickness as a function of external magnetic fields. The theoretical results agree well with the experimental data, so that the Bloch wall thickness of a 71 deg. nickel single crystal was definitely determined with some hundred of nanometer

  19. Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae and delayed initial feeding effects

    Directory of Open Access Journals (Sweden)

    Rodolfo N. Sirol

    1998-06-01

    Full Text Available Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days. Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15, were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding, was not apparent in this species.

  20. The basic properties of Bloch functions

    Directory of Open Access Journals (Sweden)

    Joseph A. Cima

    1979-01-01

    Full Text Available A Bloch function f(z is an analytic function on the unit disc whose derivative grows no faster than a constant times the reciprocal of the distance from z to ∂. We reprove here the basic analytic facts concerning Bloch functions. We establish the Banach space structure and collect facts concerning the geometry of the space. We indicate duality relationships, and known isomorphic correspondences are given. We give a rather complete list of references for further study in the case of several variables.

  1. On history and salvation in Emmanuel Levinas and Ernst Bloch

    African Journals Online (AJOL)

    p1243322

    “Chronos” who devours his own children.13 In addition to this, one would invert ... death” against Bloch, one could argue that Bloch, in effect, is glorifying death .... fantasy or wishful thinking) to Bloch's belief that in a humanised world the.

  2. Chaos synchronization of nonlinear Bloch equations

    International Nuclear Information System (INIS)

    Park, Ju H.

    2006-01-01

    In this paper, the problem of chaos synchronization of Bloch equations is considered. A novel nonlinear controller is designed based on the Lyapunov stability theory. The proposed controller ensures that the states of the controlled chaotic slave system asymptotically synchronizes the states of the master system. A numerical example is given to illuminate the design procedure and advantage of the result derived

  3. Reve et action: Bloch, Heidegger et Levinas

    Czech Academy of Sciences Publication Activity Database

    Bierhanzl, Jan

    2016-01-01

    Roč. 12, č. 3 (2016), s. 1-6 ISSN 1336-6556 R&D Projects: GA ČR(CZ) GA16-23046S Institutional support: RVO:67985955 Keywords : possibility * wishing * decision * action * dream * utopia Subject RIV: AA - Philosophy ; Religion http://www.ostium.sk/sk/r%C8%87ve-er-action-bloch-heidegger-et-levinas/

  4. Squeezing corrections to the Bloch equations

    International Nuclear Information System (INIS)

    Abundo, M.; Accardi, L.

    1991-01-01

    The general analysis of quantum noise shows that a squeezing noise can produce quadratic nonlinearities in the Langevin equations leading to the Bloch equations. These quadratic nonlinearities are governed by the imaginary part of the off-diagonal terms of the covariance of the noise (the squeezing terms) and imply a correction to the usual form of the Bloch equations. Here the case of spin-one nuclei subjected to squeezing noises of particular type is studied numerically. It is shown that the corrections to the Bloch equations, suggested by the theory, to the behaviour of the macroscopic nuclear polarization in a scale of times of the order of the relaxation time can be quite substantial. In the equilibrium regime, even if the qualitative behaviour of the system is the same (exponential decay), the numerical equilibrium values predicted by the theory are consistently different from those predicted by the usual Bloch equation. It is suggested that this difference might be used to test experimentally the observable effects of squeezing noises

  5. The Bloch Approximation in Periodically Perforated Media

    International Nuclear Information System (INIS)

    Conca, C.; Gomez, D.; Lobo, M.; Perez, E.

    2005-01-01

    We consider a periodically heterogeneous and perforated medium filling an open domain Ω of R N . Assuming that the size of the periodicity of the structure and of the holes is O(ε),we study the asymptotic behavior, as ε → 0, of the solution of an elliptic boundary value problem with strongly oscillating coefficients posed in Ω ε (Ω ε being Ω minus the holes) with a Neumann condition on the boundary of the holes. We use Bloch wave decomposition to introduce an approximation of the solution in the energy norm which can be computed from the homogenized solution and the first Bloch eigenfunction. We first consider the case where Ωis R N and then localize the problem for abounded domain Ω, considering a homogeneous Dirichlet condition on the boundary of Ω

  6. Taking a peek at Bloch oscillations

    Science.gov (United States)

    Morsch, Oliver

    2016-11-01

    Bloch oscillations arise when matter waves inside a periodic potential, such as a crystal lattice, are accelerated by a constant force. Keßler et al (2016 New J. Phys. 18 102001) have now experimentally tested a method that allows one to observe those oscillations continuously, without a destructive measurement on the matter wave. Their approach could help to make cold atom-based accelerometers and gravimeters more precise.

  7. Modeling Bloch oscillations in nanoscale Josephson junctions

    Science.gov (United States)

    Vora, Heli; Kautz, R. L.; Nam, S. W.; Aumentado, J.

    2018-01-01

    Bloch oscillations in nanoscale Josephson junctions with a Coulomb charging energy comparable to the Josephson coupling energy are explored within the context of a model previously considered by Geigenmüller and Schön that includes Zener tunneling and treats quasiparticle tunneling as an explicit shot-noise process. The dynamics of the junction quasicharge are investigated numerically using both Monte Carlo and ensemble approaches to calculate voltage-current characteristics in the presence of microwaves. We examine in detail the origin of harmonic and subharmonic Bloch steps at dc biases I = (n/m)2ef induced by microwaves of frequency f and consider the optimum parameters for the observation of harmonic (m = 1) steps. We also demonstrate that the GS model allows a detailed semiquantitative fit to experimental voltage-current characteristics previously obtained at the Chalmers University of Technology, confirming and strengthening the interpretation of the observed microwave-induced steps in terms of Bloch oscillations. PMID:29577106

  8. Chaotic dynamics in the Maxwell-Bloch equations

    International Nuclear Information System (INIS)

    Holm, D.D.; Kovacic, G.

    1992-01-01

    In the slowly varying envelope approximation and the rotating wave approximation for the Maxwell-Bloch equations, we describe how the presence of a small-amplitude probe laser in an excited, two-level, resonant medium leads to homoclinic chaos in the laser-matter dynamics. We also describe a derivation of the Maxwell-Bloch equations from an action principle

  9. Composition operators between Bloch type spaces and Zygmund ...

    Indian Academy of Sciences (India)

    MS received 1 September 2009; revised 31 March 2011. Abstract. The boundedness and compactness of composition operators between. Bloch type spaces and Zygmund spaces of holomorphic functions in the unit ball are characterized in the paper. Keywords. Composition operator; Bloch type space; Zygmund space. 1.

  10. Bloch-mode analysis for retrieving effective parameters of metamaterials

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Ha, Sangwoo; Sukhorukov, Andrey A.

    2012-01-01

    by our method with a high accuracy. We employ both surface and volume averaging of the electromagnetic fields of the dominating (fundamental) Bloch modes to determine the Bloch and wave impedances, respectively. We discuss how this method works for several characteristic examples, and demonstrate...

  11. Optical Bloch equations with multiply connected states

    International Nuclear Information System (INIS)

    Stacey, D N; Lucas, D M; Allcock, D T C; Szwer, D J; Webster, S C

    2008-01-01

    The optical Bloch equations, which give the time evolution of the elements of the density matrix of an atomic system subject to radiation, are generalized so that they can be applied when transitions between pairs of states can proceed by more than one stimulated route. The case considered is that for which the time scale of interest in the problem is long compared with that set by the differences in detuning of the radiation fields stimulating via the different routes. It is shown that the Bloch equations then reduce to the standard form of linear differential equations with constant coefficients. The theory is applied to a two-state system driven by two lasers with different intensities and frequencies and to a three-state Λ-system with one laser driving one transition and two driving the second. It is also shown that the theory reproduces well the observed response of a cold 40 Ca + ion when subject to a single laser frequency driving the 4S 1/2 -4P 1/2 transition and a laser with two strong sidebands driving 3D 3/2 -4P 1/2

  12. Spin wave vortex from the scattering on Bloch point solitons

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho-Santos, V.L., E-mail: vagson.carvalho@usach.cl [Instituto Federal de Educação, Ciência e Tecnologia Baiano - Campus Senhor do Bonfim, Km 04 Estrada da Igara, 48970-000 Senhor do Bonfim, Bahia (Brazil); Departamento de Física, Universidad de Santiago de Chile and CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Elías, R.G., E-mail: gabriel.elias@usach.cl [Departamento de Física, Universidad de Santiago de Chile and CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Nunez, A.S., E-mail: alnunez@dfi.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago (Chile)

    2015-12-15

    The interaction of a spin wave with a stationary Bloch point is studied. The topological non-trivial structure of the Bloch point manifests in the propagation of spin waves endowing them with a gauge potential that resembles the one associated with the interaction of a magnetic monopole and an electron. By pursuing this analogy, we are led to the conclusion that the scattering of spin waves and Bloch points is accompanied by the creation of a magnon vortex. Interference between such a vortex and a plane wave leads to dislocations in the interference pattern that can be measurable by means of magnon holography.

  13. Larval morphology of Hoplias lacerdae Miranda Ribeiro, 1908 (Characiformes, Erythrinidae, from hatching to metamorphosis, related to exogenous food capture ability

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Reis Raposo Maciel

    2009-09-01

    Full Text Available For the accomplishment of this work, 510 specimens of Hoplias lacerdae were used from one to 30 days after hatching, with the objective of studying the mesoscopic morphological characteristics that enable this species, in the initial phases of its development, to present adaptations for movement and the capture of exogenous food. The yolk sac larvae at 11 days after hatching have the potentiality to capture exogenous food, i.e. prey, even before the total yolk absorption which happens at 12 days, presenting in this phase: an open mouth at one day after hatching, displaying the terminal position at four days; notochord flexion, that takes place at seven days and provides greater efficiency of movement; pectoral fins, also developed at seven days, which facilitate its balance and direction in the water column; formation of the dorsal and anal fins at eight days and the pelvic ones, at 11 days.

  14. Skyrmion clusters from Bloch lines in ferromagnetic films

    KAUST Repository

    Garanin, Dmitry A.; Chudnovsky, Eugene M.; Zhang, Xixiang

    2017-01-01

    anisotropy, and dipole-dipole interaction. Evolution of labyrinth domains into compact topological structures on application of the magnetic field is found to be governed by the configuration of Bloch lines inside domain walls. Depending on the combination

  15. Quantum anomalous Bloch-Siegert shift in Weyl semimetal

    Science.gov (United States)

    Kumar, Upendra; Kumar, Vipin; Enamullah, Setlur, Girish S.

    2018-05-01

    A periodic exchange of energy between the light field and two level system is known as Rabi oscillations. The Bloch-Siegert shift (BSS) is a shift in Rabi oscillation resonance condition, when the driving field is sufficiently strong. There are new type of oscillations exhibit in Weyl semimetal at far from resonance, known as anomalous Rabi oscillation. In this work, we study the phenomenon of the Bloch-Siegert shift in Weyl semimetal at far from resonance called anomalous Bloch-Siegert shift (ABSS) by purely quantum mechanical treatment and describe it's anisotropic nature. A fully numerical solution of the Floquet-Bloch equations unequivocally establishes the presence of not only anomalous Rabi oscillations in these systems but also their massless character.

  16. Bloch spaces of holomorphic functions in the polydisk

    Directory of Open Access Journals (Sweden)

    Anahit Harutyunyan

    2007-01-01

    Full Text Available This work is an introduction to anisotropic spaces of holomorphic functions, which have ω-weight and are generalizations of Bloch spaces to a polydisc. We prove that these classes form an algebra and are invariant with respect to monomial multiplication. Some theorems on projection and diagonal mapping are proved. We establish a description of (Ap(ω* (or (Hp(ω* via the Bloch classes for all 0

  17. Modeling Bloch oscillations in ultra-small Josephson junctions

    Science.gov (United States)

    Vora, Heli; Kautz, Richard; Nam, Sae Woo; Aumentado, Jose

    In a seminal paper, Likharev et al. developed a theory for ultra-small Josephson junctions with Josephson coupling energy (Ej) less than the charging energy (Ec) and showed that such junctions demonstrate Bloch oscillations which could be used to make a fundamental current standard that is a dual of the Josephson volt standard. Here, based on the model of Geigenmüller and Schön, we numerically calculate the current-voltage relationship of such an ultra-small junction which includes various error processes present in a nanoscale Josephson junction such as random quasiparticle tunneling events and Zener tunneling between bands. This model allows us to explore the parameter space to see the effect of each process on the width and height of the Bloch step and serves as a guide to determine whether it is possible to build a quantum current standard of a metrological precision using Bloch oscillations.

  18. Weighted Composition Operators from Hardy Spaces into Logarithmic Bloch Spaces

    Directory of Open Access Journals (Sweden)

    Flavia Colonna

    2012-01-01

    Full Text Available The logarithmic Bloch space Blog⁡ is the Banach space of analytic functions on the open unit disk 𝔻 whose elements f satisfy the condition ∥f∥=sup⁡z∈𝔻(1-|z|2log⁡  (2/(1-|z|2|f'(z|<∞. In this work we characterize the bounded and the compact weighted composition operators from the Hardy space Hp (with 1≤p≤∞ into the logarithmic Bloch space. We also provide boundedness and compactness criteria for the weighted composition operator mapping Hp into the little logarithmic Bloch space defined as the subspace of Blog⁡ consisting of the functions f such that lim⁡|z|→1(1-|z|2log⁡  (2/(1-|z|2|f'(z|=0.

  19. Skyrmion clusters from Bloch lines in ferromagnetic films

    KAUST Repository

    Garanin, Dmitry A.

    2017-12-29

    Conditions under which various skyrmion objects emerge in experiments on thin magnetic films remain largely unexplained. We investigate numerically centrosymmetric spin lattices in films of finite thickness with ferromagnetic exchange, magnetic anisotropy, and dipole-dipole interaction. Evolution of labyrinth domains into compact topological structures on application of the magnetic field is found to be governed by the configuration of Bloch lines inside domain walls. Depending on the combination of Bloch lines, the magnetic domains evolve into individual skyrmions, biskyrmions, or more complex topological objects. While the geometry of such objects is sensitive to the parameters, their topological charge is uniquely determined by the topological charge of Bloch lines inside the magnetic domain from which the object emerges.

  20. Variational principle for the Bloch unified reaction theory

    International Nuclear Information System (INIS)

    MacDonald, W.; Rapheal, R.

    1975-01-01

    The unified reaction theory formulated by Claude Bloch uses a boundary value operator to write the Schroedinger equation for a scattering state as an inhomogeneous equation over the interaction region. As suggested by Lane and Robson, this equation can be solved by using a matrix representation on any set which is complete over the interaction volume. Lane and Robson have proposed, however, that a variational form of the Bloch equation can be used to obtain a ''best'' value for the S-matrix when a finite subset of this basis is used. The variational principle suggested by Lane and Robson, which gives a many-channel S-matrix different from the matrix solution on a finite basis, is considered first, and it is shown that the difference results from the fact that their variational principle is not, in fact, equivalent to the Bloch equation. Then a variational principle is presented which is fully equivalent to the Bloch form of the Schroedinger equation, and it is shown that the resulting S-matrix is the same as that obtained from the matrix solution of this equation. (U.S.)

  1. Bloch-Siegert shift in Dirac-Weyl fermionic systems

    Science.gov (United States)

    Kumar, Upendra; Kumar, Vipin; Enamullah, Setlur, Girish S.

    2018-04-01

    The Bloch-Siegert shift is a phenomenon in quantum optics, typically seen in two-level systems, when the driving field is sufficiently strong. The inclusion of frequency doubling effect (counter rotating term) in the conventional rotating wave approximation (RWA) changes the resonance condition thereby producing a rather small shift in the resonance condition, which is known as the Bloch-Siegert shift (BSS). Rabi oscillations in Dirac-Weyl fermionic systems exhibit anomalous behavior far from resonance, called anomalous Rabi oscillations. Therefore, in the present work, we study the phenomenon of the Bloch-Siegert shift in Weyl semimetal and topological insulator (TI) far from resonance, called anomalous Bloch-Siegert shift (ABSS). It is seen that the change in the resonance condition of anomalous Rabi oscillations is drastic in Weyl semimetal and TI. The ABSS in Weyl semimetals is highly anisotropic, whereas it is isotropic in TI. In case of TI, it is the Chern number which plays a crucial role to produce substantial change in the ABSS.

  2. News Focus: NSF Director Erich Bloch Discusses Foundation's Problems, Outlook.

    Science.gov (United States)

    Chemical and Engineering News, 1987

    1987-01-01

    Relates the comments offered in an interview with Erich Bloch, the National Science Foundation (NSF) Director. Discusses issues related to NSF and its funding, engineering research centers, involvement with industry, concern for science education, computer centers, and its affiliation with the social sciences. (ML)

  3. Improved Reading Gate For Vertical-Bloch-Line Memory

    Science.gov (United States)

    Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

    1994-01-01

    Improved design for reading gate of vertical-Bloch-line magnetic-bubble memory increases reliability of discrimination between binary ones and zeros. Magnetic bubbles that signify binary "1" and "0" produced by applying sufficiently large chopping currents to memory stripes. Bubbles then propagated differentially in bubble sorter. Method of discriminating between ones and zeros more reliable.

  4. Influence of relaxation times on the Bloch-Siegert shift

    International Nuclear Information System (INIS)

    Cao Long Van

    1981-01-01

    A new method for calculations of Bloch-Siegert shifts in resonances between excited states with the inclusion of relaxation times is given. It will be shown that in this case the definition of the resonance given by I. Bialynicka-Birula is in agreement with the criterion defining the resonance used by D.A. Andrews and G. Newton. (author)

  5. Behaviour of neutrons passing through the Bloch wall

    International Nuclear Information System (INIS)

    Schaerpf, O.

    1976-01-01

    In part I of the present paper the pertinent knowledge about Bloch walls is presented and developed insofar as it appears necessary for the experiments with neutrons, that is to say the direction of magnetization within the domains, the calculation of the variation of magnetization in the wall, the wall thickness, and the zigzag structure of the Bloch wall. In part II it is first clarified why the Bloch wall can be treated as a continuum problem. It shows that this is possible far away from Laue reflexes. For angles far away from Laure-reflex angles the interaction of the periodic structure of the magnetization can be described with the aid of an averaged magnetic flux density. The consequence of it is the possibility of treating the problem by means of a Schroedinger equation with continous interaction. This leads to a law of refraction. The question of the possibilities for explaining the intensity behavior is treated in part III. This part, from different aspects, describes the fact, which already was pointed out in Schaerpf, O., Vehoff, H., Schwink, Ch. 1973, that the spin of the neutrons in passing through the wall is partly taken along by the magnetization gradually rotating in the wall. (orig./WBU) [de

  6. Orbital magnetism of Bloch electrons I. General formula

    International Nuclear Information System (INIS)

    Ogata, Masao; Fukuyama, Hidetoshi

    2015-01-01

    We derive an exact formula of orbital susceptibility expressed in terms of Bloch wave functions, starting from the exact one-line formula by Fukuyama in terms of Green's functions. The obtained formula contains four contributions: (1) Landau-Peierls susceptibility, (2) interband contribution, (3) Fermi surface contribution, and (4) contribution from occupied states. Except for the Landau-Peierls susceptibility, the other three contributions involve the crystal-momentum derivatives of Bloch wave functions. Physical meaning of each term is clarified. The present formula is simplified compared with those obtained previously by Hebborn et al. Based on the formula, it is seen first of all that diamagnetism from core electrons and Van Vleck susceptibility are the only contributions in the atomic limit. The band effects are then studied in terms of linear combination of atomic orbital treating overlap integrals between atomic orbitals as a perturbation and the itinerant feature of Bloch electrons in solids are clarified systematically for the first time. (author)

  7. Properties of Floquet-Bloch space harmonics in 1D periodic magneto-dielectric structures

    DEFF Research Database (Denmark)

    Breinbjerg, O.

    2012-01-01

    Recent years have witnessed a significant research interest in Floquet-Bloch analysis for determining the homogenized permittivity and permeability of metamaterials consisting of periodic structures. This work investigates fundamental properties of the Floquet-Bloch space harmonics in a 1......-dimensional magneto-dielectric lossless structure supporting a transverse-electric-magnetic Floquet-Bloch wave; in particular, the space harmonic permittivity and permeability, as well as the space harmonic Poynting vector....

  8. Traffic restrictions on Routes Bloch, Maxwell and Bohr

    CERN Multimedia

    IT Department

    2008-01-01

    Excavation and pipework is being carried out in the framework of the transfer of the waste water treatment plant for the effluents from the surface treatment workshops from Building 254 to Building 676, currently under construction. This work may encroach onto Routes Bloch, Maxwell and Bohr and disrupt the flow of traffic. Users are requested to comply with the road signs that will be erected. The work is expected to last until the beginning of December 2008. Thank you for your understanding. TS/CE and TS/FM Groups Tel.7 4188 or 16 4314

  9. Bipolaron assisted Bloch-like oscillations in organic lattices

    International Nuclear Information System (INIS)

    Ribeiro, Luiz Antonio; Ferreira da Cunha, Wiliam; Magela e Silva, Geraldo

    2017-01-01

    The transport of a dissociated bipolaron in organic one-dimensional lattices is theoretically investigated in the scope of a tight-binding model that includes electron-lattice interactions and an external electric field. Remarkably, the results point to a physical picture in which the dissociated bipolaron propagates as a combined state of two free-like electrons that coherently perform spatial Bloch oscillations (BO) above a critical field strength. It was also obtained that the BO's trajectory presents a net forward motion in the direction of the applied electric field. The impact of dynamical disorder in the formation of electronic BOs is determined.

  10. Bipolaron assisted Bloch-like oscillations in organic lattices

    Science.gov (United States)

    Ribeiro, Luiz Antonio; Ferreira da Cunha, Wiliam; Magela e Silva, Geraldo

    2017-06-01

    The transport of a dissociated bipolaron in organic one-dimensional lattices is theoretically investigated in the scope of a tight-binding model that includes electron-lattice interactions and an external electric field. Remarkably, the results point to a physical picture in which the dissociated bipolaron propagates as a combined state of two free-like electrons that coherently perform spatial Bloch oscillations (BO) above a critical field strength. It was also obtained that the BO's trajectory presents a net forward motion in the direction of the applied electric field. The impact of dynamical disorder in the formation of electronic BOs is determined.

  11. Bipolaron assisted Bloch-like oscillations in organic lattices

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Luiz Antonio, E-mail: ribeirojr@unb.br [International Center for Condensed Matter Physics, University of Brasília, P.O. Box 04531, 70.919-970, Brasília, DF (Brazil); University of Brasília, UnB Faculty of Planaltina, 73.345-010, Planaltina, DF (Brazil); Ferreira da Cunha, Wiliam; Magela e Silva, Geraldo [Institute of Physics, University of Brasília, 70.919-970, Brasília (Brazil)

    2017-06-15

    The transport of a dissociated bipolaron in organic one-dimensional lattices is theoretically investigated in the scope of a tight-binding model that includes electron-lattice interactions and an external electric field. Remarkably, the results point to a physical picture in which the dissociated bipolaron propagates as a combined state of two free-like electrons that coherently perform spatial Bloch oscillations (BO) above a critical field strength. It was also obtained that the BO's trajectory presents a net forward motion in the direction of the applied electric field. The impact of dynamical disorder in the formation of electronic BOs is determined.

  12. A formula for the Bloch vector of some Lindblad quantum systems

    International Nuclear Information System (INIS)

    Salgado, D.; Sanchez-Gomez, J.L.

    2004-01-01

    Using the Bloch representation of an N-dimensional quantum system and immediate results from quantum stochastic calculus, we establish a closed formula for the Bloch vector, hence also for the density operator, of a quantum system following a Lindblad evolution with selfadjoint Lindblad operators

  13. Bloch electrons in 2D periodic electric and magnetic fields; Bloch-Elektronen in 2D periodischen elektrischen und magnetischen Feldern

    Energy Technology Data Exchange (ETDEWEB)

    Naundorf, B.

    2001-06-01

    The following topics were dealt with: electrons in periodic potentials, Bloch states, Landau states, wave packets, Harper equation, uncoupled Landau band states, matrix elements and matrix equations, periodic electric and magnetic fields (WL)

  14. Nonlinear Bloch waves in metallic photonic band-gap filaments

    International Nuclear Information System (INIS)

    Kaso, Artan; John, Sajeev

    2007-01-01

    We demonstrate the occurrence of nonlinear Bloch waves in metallic photonic crystals (PCs). These periodically structured filaments are characterized by an isolated optical pass band below an effective plasma gap. The pass band occurs in a frequency range where the metallic filament exhibits a negative, frequency-dependent dielectric function and absorption loss. The metallic losses are counterbalanced by gain in two models of inhomogeneously broadened nonlinear oscillators. In the first model, we consider close-packed quantum dots that fill the void regions of a two-dimensional (2D) metallic PC, and whose inhomogeneously broadened emission spectrum spans the original optical pass band of the bare filament. In the second model, we consider thin (10-50 nm) layers of inhomogeneously broadened two-level resonators, with large dipole oscillator strength, that cover the interior surfaces of 2D metallic (silver and tungsten) PCs. These may arise from localized surface plasmon resonances due to small metal particles or an otherwise rough metal surface. For simplicity, we treat electromagnetic modes with electric field perpendicular to the plane of metal periodicity. In both models, a pumping threshold of the resonators is found, above which periodic nonlinear solutions of Maxwell's equations with purely real frequency within the optical pass band emerge. These nonlinear Bloch waves exhibit a laserlike input pumping to output amplitude characteristic. For strong surface resonances, these nonlinear waves may play a role in light emission from a hot tungsten (suitably microstructured) filament

  15. Nonlinear Bloch waves in metallic photonic band-gap filaments

    Science.gov (United States)

    Kaso, Artan; John, Sajeev

    2007-11-01

    We demonstrate the occurrence of nonlinear Bloch waves in metallic photonic crystals (PCs). These periodically structured filaments are characterized by an isolated optical pass band below an effective plasma gap. The pass band occurs in a frequency range where the metallic filament exhibits a negative, frequency-dependent dielectric function and absorption loss. The metallic losses are counterbalanced by gain in two models of inhomogeneously broadened nonlinear oscillators. In the first model, we consider close-packed quantum dots that fill the void regions of a two-dimensional (2D) metallic PC, and whose inhomogeneously broadened emission spectrum spans the original optical pass band of the bare filament. In the second model, we consider thin (10 50 nm) layers of inhomogeneously broadened two-level resonators, with large dipole oscillator strength, that cover the interior surfaces of 2D metallic (silver and tungsten) PCs. These may arise from localized surface plasmon resonances due to small metal particles or an otherwise rough metal surface. For simplicity, we treat electromagnetic modes with electric field perpendicular to the plane of metal periodicity. In both models, a pumping threshold of the resonators is found, above which periodic nonlinear solutions of Maxwell’s equations with purely real frequency within the optical pass band emerge. These nonlinear Bloch waves exhibit a laserlike input pumping to output amplitude characteristic. For strong surface resonances, these nonlinear waves may play a role in light emission from a hot tungsten (suitably microstructured) filament.

  16. Entanglement and the three-dimensionality of the Bloch ball

    Energy Technology Data Exchange (ETDEWEB)

    Masanes, Ll., E-mail: ll.masanes@gmail.com [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Müller, M. P. [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany); Pérez-García, D. [Departamento de Analisis Matematico and IMI, Universidad Complutense de Madrid, 28040 Madrid (Spain); Augusiak, R. [ICFO-Institut de Ciencies Fotoniques, 08860 Castelldefels, Barcelona (Spain)

    2014-12-15

    We consider a very natural generalization of quantum theory by letting the dimension of the Bloch ball be not necessarily three. We analyze bipartite state spaces where each of the components has a d-dimensional Euclidean ball as state space. In addition to this, we impose two very natural assumptions: the continuity and reversibility of dynamics and the possibility of characterizing bipartite states by local measurements. We classify all these bipartite state spaces and prove that, except for the quantum two-qubit state space, none of them contains entangled states. Equivalently, in any of these non-quantum theories, interacting dynamics is impossible. This result reveals that “existence of entanglement” is the requirement with minimal logical content which singles out quantum theory from our family of theories.

  17. Terahertz emission of Bloch oscillators excited by electromagnetic field in lateral semiconductor superlattices

    International Nuclear Information System (INIS)

    Dodin, E.P.; Zharov, A.A.

    2003-01-01

    The effect of the strong high-frequency electromagnetic field on the lateral semiconductor superlattice is considered on the basis of the quasi-classical theory on the electron transport in the self-consistent wave arrangement. It is theoretically identified, that the lateral superlattice in the strong feed-up wave field may emit the terahertz radiation wave trains, which are associated with the periodical excitation of the Bloch oscillations in the superlattice. The conditions, required for the Bloch oscillators radiation observation, are determined. The spectral composition of the radiation, passing through the superlattice, and energy efficiency of multiplying the frequency, related to the Bloch oscillator excitation, are calculated [ru

  18. From Bloch to random lasing in ZnO self-assembled nanostructures

    DEFF Research Database (Denmark)

    Garcia-Fernandez, Pedro David; Cefe, López

    2013-01-01

    In this paper, we present measurements on UV lasing in ZnO ordered and disordered nanostructures. Bloch lasing is achieved in the ordered structures by exploiting very low group-velocity Bloch modes in ZnO photonic crystals. In the second case, random lasing is observed in ZnO photonic glasses. We...... study the lasing threshold in both cases and its dependence on the structural parameters. Finally, we present the transition from Bloch to random lasing by deliberately doping a ZnO inverse photonic crystal with a controlled amount of lattice vacancies effectively converting it into a translationally...

  19. Quantum Transport in Solids: Bloch Dynamics and Role of Oscillating Fields

    National Research Council Canada - National Science Library

    Kim, Ki

    1997-01-01

    .... The specific areas of research are those of Bloch electron dynamics, quantum transport in oscillating electric fields or in periodic potentials, and the capacitive nature of atomic size structures...

  20. Surface Acoustic Analog of Bloch Oscillations, Wannier-Stark Ladders and Landau-Zener Tunneling

    Science.gov (United States)

    de Lima, M. M.; Kosevich, Yu. A.; Santos, P. V.; Cantarero, A.

    2011-12-01

    In this contribution, we discuss the recent experimental demonstration of Wannier-Stark ladders, Bloch Oscillations and Landau Zener tunneling in a solid by means of surface acoustic waves propagating through perturbed grating structures.

  1. Non-Bloch decay of Rabi oscillations in liquid state NMR

    Science.gov (United States)

    Chakrabarti, Arnab; Bhattacharyya, Rangeet

    2018-03-01

    Rabi oscillations are known to exhibit non-Bloch behaviour in anisotropic media. In this letter, we report an experimental observation of non-Bloch decay of Rabi oscillations in isotropic liquid state NMR. To avoid the dephasing due to the radio-frequency inhomogeneities, we develop a modified version of the rotary echo protocol and use it to determine the decay rates of Rabi oscillations. We find that the measured decay rates are proportional to the square of the Rabi frequencies and the proportionality constant is of the order of tens of picoseconds. Further, we show that this non-Bloch nature of the decay rates becomes less prominent with increasing temperature. The implications of the presence of non-Bloch decay rates in liquid state NMR in the context of ensemble quantum computing are also discussed.

  2. On the equilibrium configuration of the Kittel type domain structure with Bloch walls, l80deg

    International Nuclear Information System (INIS)

    Gavrila, H.

    1975-01-01

    Using a phenomenologic method for appreciating different components of the free energy, the equilibrium configuration of the Kittel-type domain structure with Bloch walls is obtained. By improving the known methods, more accurate magnetostatic energy calculations are reported. In order to determine the equilibrium structure, the total free energy is minimized with respect to two system parameters: the Bloch wall width and the structure half-period. (author)

  3. Optical Effects Induced by Bloch Surface Waves in One-Dimensional Photonic Crystals

    Directory of Open Access Journals (Sweden)

    Irina V. Soboleva

    2018-01-01

    Full Text Available The review considers the influence of Bloch surface waves on the optical and magneto-optical effects observed in photonic crystals; for example, the Goos–Hänchen effect, the Faraday effect, optical trapping and so on. Prospects for using Bloch surface waves for spatial light modulation, for controlling the polarization of light, for optical trapping and control of micro-objects are discussed.

  4. Optimization of process parameters for the production of collagen peptides from fish skin (Epinephelus malabaricus) using response surface methodology and its characterization.

    Science.gov (United States)

    Hema, G S; Joshy, C G; Shyni, K; Chatterjee, Niladri S; Ninan, George; Mathew, Suseela

    2017-02-01

    The study optimized the hydrolysis conditions for the production of fish collagen peptides from skin of Malabar grouper ( Epinephelus malabaricus ) using response surface methodology. The hydrolysis was done with enzymes pepsin, papain and protease from bovine pancreas. Effects of process parameters viz: pH, temperature, enzyme substrate ratio and hydrolysis time of the three different enzymes on degree of hydrolysis were investigated. The optimum response of degree of hydrolysis was estimated to be 10, 20 and 28% respectively for pepsin, papain and protease. The functional properties of the product developed were analysed which showed changes in the properties from proteins to peptides. SDS-PAGE combined with MALDI TOF method was successfully applied to determine the molecular weight distribution of the hydrolysate. The electrophoretic pattern indicated that the molecular weights of peptides formed due to hydrolysis were nearly 2 kDa. MALDI TOF spectral analysis showed the developed hydrolysate contains peptides having molecular weight in the range below 2 kDa.

  5. Philippe Bloch: Reducing distance between experiments and CERN

    CERN Multimedia

    2009-01-01

    With its unique combination of several hundred staff members and thousands of users from around the world sharing offices and physics data and profiting from mutually beneficial exchanges of know-how and expertise, the PH Department is a good example of a successful worldwide collaboration, set up as it was to construct and run the Laboratory’s physics experiments. The PH Depart-ment has always played host to thousands of users that contribute to CERN experiments and work on them, and whose numbers are set to grow in the years to come. With his long-standing experience as a user and then as the head of the CERN group within the CMS collaboration, Philippe Bloch, the new PH Department Head, is in favour of closer links between the Department and the experiments. "I think that the PH management should have a direct link to the experiments, and to do so we are holding regular management team meetings comprising members of the Department’s management and the e...

  6. Bloch-Nordsieck estimates of high-temperature QED

    International Nuclear Information System (INIS)

    Fried, H. M.; Sheu, Y.-M.; Grandou, T.

    2008-01-01

    In anticipation of a subsequent application to QCD, we consider the case of QED at high temperature. We introduce a Fradkin representation into the exact, Schwingerian, functional expression of a fermion propagator, as well as a new and relevant version of the Bloch-Nordsieck model, which extracts the soft contributions of every perturbative graph, in contradistinction to the assumed separation of energy scales of previous semiperturbative treatments. Our results are applicable to the absorption of a fast particle which enters a heat bath, as well as to the propagation of a symmetric pulse within the thermal medium due to the appearance of an instantaneous, shockwave-like source acting in the medium. An exponentially decreasing time dependence of the incident particle's initial momentum combines with a stronger decrease in the particle's energy, estimated by a sum over all Matsubara frequencies, to model an initial 'fireball', which subsequently decays in a Gaussian fashion. When extended to QCD, qualitative applications could be made to RHIC scattering, in which a fireball appears, expands, and is damped away

  7. Metazoários parasitos de seis espécies de peixes do Reservatório de Lajes, Estado do Rio de Janeiro, Brasil Metazoan parasites of six fishes species from Lajes Reservoir in the State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Aline R. Paraguassú

    2007-09-01

    Full Text Available Entre abril de 2002 e julho de 2003, foram necropsiados 231 espécimes de peixes: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus (Cuvier, 1819, 23 Hypostomus affinis (Steindachner, 1877, 26 Hoplias malabaricus (Bloch, 1794, 30 Loricariichthys castaneus (Castelnau, 1855 e 34 Trachelyopterus striatulus (Steindachner, 1876 provenientes do Reservatório de Lajes (22º42' - 22º50'S, 43º53' 44º05'O, Estado do Rio de Janeiro, Brasil, para estudo das suas comunidades parasitárias. A maioria dos espécimes de H. affinis (95,6% e H. malabaricus (84,6% estavam parasitados por pelo menos uma espécie de metazoário. Em A. bimaculatus, A. fasciatus, L. castaneus e T. striatulus 41%, 39,2%, 56,7% e 14,7% dos espécimes estavam parasitados, respectivamente. Foram coletadas oito diferentes espécies de metazoários parasitos: 2 em A. bimaculatus, 3 em A. fasciatus, 3 em H. affinis, 4 em H. malabaricus, 4 em L. castaneus e 1 em T. striatulus. As comunidades de metazoários parasitos das seis espécies de peixes estudadas apresentaram típico padrão de distribuição agregada. Foram observados dois casos de correlação negativa entre a abundância e a prevalência parasitárias e o comprimento total dos hospedeiros. A comunidade parasitária de L. castaneus apresentou os maiores valores de intensidade média, índice de dispersão e diversidade. As comunidades parasitárias dos peixes estudados apresentaram escassez de correlação entre a abundância, riqueza parasitária e diversidade com o comprimento total dos hospedeiros. Os baixos valores de riqueza e diversidade das comuni-dades parasitárias podem ser atribuídos as características oligotróficas do Reservatório de Lajes.From April 2002 to July 2003, 231 freshwater fishes from Lajes Reservoir in the State of Rio de Janeiro, Brazil (22º42' - 22º50'S, 43º53' - 44º05'W were necropsied to study their community metazoan parasites: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus

  8. Bloch-Surface-Polariton-Based Hybrid Nanowire Structure for Subwavelength, Low-Loss Waveguiding

    Directory of Open Access Journals (Sweden)

    Weijing Kong

    2018-03-01

    Full Text Available Surface plasmon polaritons (SPPs have been thoroughly studied in the past decades for not only sensing but also waveguiding applications. Various plasmonic device structures have been explored due to their ability to confine their optical mode to the subwavelength level. However, with the existence of metal, the large ohmic loss limits the propagation distance of the SPP and thus the scalability of such devices. Therefore, different hybrid waveguides have been proposed to overcome this shortcoming. Through fine tuning of the coupling between the SPP and a conventional waveguide mode, a hybrid mode could be excited with decent mode confinement and extended propagation distance. As an effective alternative of SPP, Bloch surface waves have been re-investigated more recently for their unique advantages. As is supported in all-dielectric structures, the optical loss for the Bloch surface wave is much lower, which stands for a much longer propagating distance. Yet, the confinement of the Bloch surface wave due to the reflections and refractions in the multilayer structure is not as tight as that of the SPP. In this work, by integrating a periodic multilayer structure that supports the Bloch surface wave with a metallic nanowire structure, a hybrid Bloch surface wave polariton could be excited. With the proposed hybrid nanowire structure, a hybrid mode is demonstrated with the deep subwavelength mode confinement and a propagation distance of tens of microns.

  9. Quasiperiodicity in time evolution of the Bloch vector under the thermal Jaynes-Cummings model

    Science.gov (United States)

    Azuma, Hiroo; Ban, Masashi

    2014-07-01

    We study a quasiperiodic structure in the time evolution of the Bloch vector, whose dynamics is governed by the thermal Jaynes-Cummings model (JCM). Putting the two-level atom into a certain pure state and the cavity field into a mixed state in thermal equilibrium at initial time, we let the whole system evolve according to the JCM Hamiltonian. During this time evolution, motion of the Bloch vector seems to be in disorder. Because of the thermal photon distribution, both a norm and a direction of the Bloch vector change hard at random. In this paper, taking a different viewpoint compared with ones that we have been used to, we investigate quasiperiodicity of the Bloch vector’s trajectories. Introducing the concept of the quasiperiodic motion, we can explain the confused behaviour of the system as an intermediate state between periodic and chaotic motions. More specifically, we discuss the following two facts: (1) If we adjust the time interval Δt properly, figures consisting of plotted dots at the constant time interval acquire scale invariance under replacement of Δt by sΔt, where s(>1) is an arbitrary real but not transcendental number. (2) We can compute values of the time variable t, which let |Sz(t)| (the absolute value of the z-component of the Bloch vector) be very small, with the Diophantine approximation (a rational approximation of an irrational number).

  10. Integral type operators from normal weighted Bloch spaces to QT,S spaces

    Directory of Open Access Journals (Sweden)

    Yongyi GU

    2016-08-01

    Full Text Available Operator theory is an important research content of the analytic function space theory. The discussion of simultaneous operator and function space is an effective way to study operator and function space. Assuming that  is an analytic self map on the unit disk Δ, and the normal weighted bloch space μ-B is a Banach space on the unit disk Δ, defining a composition operator C∶C(f=f on μ-B for all f∈μ-B, integral type operator JhC and CJh are generalized by integral operator and composition operator. The boundeness and compactness of the integral type operator JhC acting from normal weighted Bloch spaces to QT,S spaces are discussed, as well as the boundeness of the integral type operators CJh acting from normal weighted Bloch spaces to QT,S spaces. The related sufficient and necessary conditions are given.

  11. Mechanical Properties of Laminate Materials: From Surface Waves to Bloch Oscillations

    DEFF Research Database (Denmark)

    Liang, Z.; Willatzen, Morten; Christensen, Johan

    2015-01-01

    for designing Bloch oscillations in classical plate structures and show how mechanical Bloch oscillations can be generated in arrays of solid plates when the modal wavelength is gradually reduced. The design recipe describes how Bloch oscillations in classical structures of arbitrary dimensions can be generated......We propose hitherto unexplored and fully analytical insights into laminate elastic materials in a true condensed-matter-physics spirit. Pure mechanical surface waves that decay as evanescent waves from the interface are discussed, and we demonstrate how these designer Scholte waves are controlled......, and we demonstrate this numerically for structures with millimeter and centimeter dimensions in the kilohertz to megahertz range. Analytical predictions agree entirely with full wave simulations showing how elastodynamics can mimic quantum-mechanical condensed-matter phenomena....

  12. Incorporating excitation-induced dephasing into the Maxwell-Bloch numerical modeling of photon echoes

    International Nuclear Information System (INIS)

    Burr, G.W.; Harris, Todd L.; Babbitt, Wm. Randall; Jefferson, C. Michael

    2004-01-01

    We describe the incorporation of excitation-induced dephasing (EID) into the Maxwell-Bloch numerical simulation of photon echoes. At each time step of the usual numerical integration, stochastic frequency jumps of ions--caused by excitation of neighboring ions--is modeled by convolving each Bloch vector with the Bloch vectors of nearby frequency detunings. The width of this convolution kernel follows the instantaneous change in overall population, integrated over the simulated bandwidth. This approach is validated by extensive comparison against published and original experimental results. The enhanced numerical model is then used to investigate the accuracy of experiments designed to extrapolate to the intrinsic dephasing time T 2 from data taken in the presence of EID. Such a modeling capability offers improved understanding of experimental results, and should allow quantitative analysis of engineering tradeoffs in realistic optical coherent transient applications

  13. Bloch wave deafness and modal conversion at a phononic crystal boundary

    Directory of Open Access Journals (Sweden)

    Vincent Laude

    2011-12-01

    Full Text Available We investigate modal conversion at the boundary between a homogeneous incident medium and a phononic crystal, with consideration of the impact of symmetry on the excitation of Bloch waves. We give a quantitative criterion for the appearance of deaf Bloch waves, which are antisymmetric with respect to a symmetry axis of the phononic crystal, in the frame of generalized Fresnel formulas for reflection and transmission at the phononic crystal boundary. This criterion is used to index Bloch waves in the complex band structure of the phononic crystal, for directions of incidence along a symmetry axis. We argue that within deaf frequency ranges transmission is multi-exponential, as it is within frequency band gaps.

  14. On averaging the Kubo-Hall conductivity of magnetic Bloch bands leading to Chern numbers

    International Nuclear Information System (INIS)

    Riess, J.

    1997-01-01

    The authors re-examine the topological approach to the integer quantum Hall effect in its original form where an average of the Kubo-Hall conductivity of a magnetic Bloch band has been considered. For the precise definition of this average it is crucial to make a sharp distinction between the discrete Bloch wave numbers k 1 , k 2 and the two continuous integration parameters α 1 , α 2 . The average over the parameter domain 0 ≤ α j 1 , k 2 . They show how this can be transformed into a single integral over the continuous magnetic Brillouin zone 0 ≤ α j j , j = 1, 2, n j = number of unit cells in j-direction, keeping k 1 , k 2 fixed. This average prescription for the Hall conductivity of a magnetic Bloch band is exactly the same as the one used for a many-body system in the presence of disorder

  15. Bloch-wave engineered submicron-diameter quantum-dot micropillars for cavity QED experiments

    DEFF Research Database (Denmark)

    Gregersen, Niels; Lermer, Matthias; Reitzenstein, Stephan

    2013-01-01

    The semiconductor micropillar is attractive for cavity QED experiments. For strong coupling, the figure of merit is proportional to Q/√V, and a design combining a high Q and a low mode volume V is thus desired. However, for the standard submicron diameter design, poor mode matching between the ca...... the cavity and the DBR Bloch mode limits the Q. We present a novel adiabatic design where Bloch-wave engineering is employed to improve the mode matching, allowing the demonstration of a record-high vacuum Rabi splitting of 85 μeV and a Q of 13600 for a 850 nm diameter micropillar....

  16. Simulation of NMR signals through the Bloch equations; Simulação de sinais de RMN através das equações de Bloch

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Tiago Bueno, E-mail: tiagobuemoraes@gmail.com [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Física; Colnago, Luiz Alberto, E-mail: tiagobuemoraes@gmail.com [Embrapa Instrumentação, São Carlos, SP (Brazil)

    2014-07-01

    The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonance signals using the Bloch equations. These phenomenological equations describe the classical behavior of macroscopic magnetization and are easily simulated using rotation matrices. Many NMR pulse sequences can be simulated with this formalism, allowing a quantitative description of the influence of many experimental parameters. Finally, the paper presents simulations of conventional sequences such as Single Pulse, Inversion Recovery, Spin Echo and CPMG. (author)

  17. Computational Modeling of Bloch Surface Waves in One-Dimensional Periodic and Aperiodic Multilayer Structures

    Science.gov (United States)

    Koju, Vijay

    Photonic crystals and their use in exciting Bloch surface waves have received immense attention over the past few decades. This interest is mainly due to their applications in bio-sensing, wave-guiding, and other optical phenomena such as surface field enhanced Raman spectroscopy. Improvement in numerical modeling techniques, state of the art computing resources, and advances in fabrication techniques have also assisted in growing interest in this field. The ability to model photonic crystals computationally has benefited both the theoretical as well as experimental communities. It helps the theoretical physicists in solving complex problems which cannot be solved analytically and helps to acquire useful insights that cannot be obtained otherwise. Experimentalists, on the other hand, can test different variants of their devices by changing device parameters to optimize performance before fabrication. In this dissertation, we develop two commonly used numerical techniques, namely transfer matrix method, and rigorous coupled wave analysis, in C++ and MATLAB, and use two additional software packages, one open-source and another commercial, to model one-dimensional photonic crystals. Different variants of one-dimensional multilayered structures such as perfectly periodic dielectric multilayers, quasicrystals, aperiodic multilayer are modeled, along with one-dimensional photonic crystals with gratings on the top layer. Applications of Bloch surface waves, along with new and novel aperiodic dielectric multilayer structures that support Bloch surface waves are explored in this dissertation. We demonstrate a slow light configuration that makes use of Bloch Surface Waves as an intermediate excitation in a double-prism tunneling configuration. This method is simple compared to the more usual techniques for slowing light using the phenomenon of electromagnetically induced transparency in atomic gases or doped ionic crystals operated at temperatures below 4K. Using a semi

  18. Properties of solutions of Bloch-type equations for the paraelectric phase of KDP

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, M; Paszkiewicz, T [Wroclaw Univ. (Poland). Inst. Fyziki Teoretycznej

    1979-10-01

    Exact solutions for two sets of Bloch-like equations describing the paraelectric phase of the model of KDP were studied. The general properties of both solutions are the same. However, in numerical calculations they differ significantly. A modification of the decay law connected with the soft mode frequency fluctuations is considered.

  19. Integral-Type Operators from Bloch-Type Spaces to QK Spaces

    Directory of Open Access Journals (Sweden)

    Stevo Stević

    2011-01-01

    Full Text Available The boundedness and compactness of the integral-type operator Iφ,g(nf(z=∫0zf(n(φ(ζg(ζdζ, where n∈N0, φ is a holomorphic self-map of the unit disk D, and g is a holomorphic function on D, from α-Bloch spaces to QK spaces are characterized.

  20. Bloch oscillations and accelerated Bose–Einstein condensates in an optical lattice

    Energy Technology Data Exchange (ETDEWEB)

    Sacchetti, Andrea, E-mail: andrea.sacchetti@unimore.it

    2017-01-30

    Highlights: • Discrete nonlinear Schrödinger model for accelerated BECs in optical lattices. • Numerical computation of wavefunction BECs dynamics. • Correlation between nonlinearity and the oscillating period of the BEC's center of mass. • Discussion of the validity of the Bloch Theorem for accelerated BECs in an optical lattice. - Abstract: We discuss the method for the measurement of the gravity acceleration g by means of Bloch oscillations of an accelerated BEC in an optical lattice. This method has a theoretical critical point due to the fact that the period of the Bloch oscillations depends, in principle, on the initial shape of the BEC wavepacket. Here, by making use of the nearest-neighbor model for the numerical analysis of the BEC wavefunction, we show that in real experiments the period of the Bloch oscillations does not really depend on the shape of the initial wavepacket and that the relative uncertainty, due to the fact that the initial shape of the wavepacket may be asymmetrical, is smaller than the one due to experimental errors. Furthermore, we also show that the relation between the oscillation period and the scattering length of the BEC's atoms is linear; this fact suggests us a new experimental procedure for the measurement of the scattering length of atoms.

  1. Diagrammatical display of the counter-example to non-Abelian Bloch-Nordsieck conjecture

    International Nuclear Information System (INIS)

    Yoshida, Nobuo

    1981-01-01

    The reason why the Bloch-Nordsieck theorem breaks down in the Drell-Yan process is shown through a simple diagrammatical calculation. The uncancelled contribution is from the retarded soft gluons, and the colour weight different for each ''double cut diagram'' interrupts the cancellation analogous to QED. (author)

  2. Direct Observation of Bloch Harmonics and Negative Phase Velocity in Photonic Crystal Waveguides

    NARCIS (Netherlands)

    Gersen, H.; Karle, T.J.; Engelen, R.J.P.; Engelen, R.J.P.; Bogaerts, W.; Korterik, Jeroen P.; van Hulst, N.F.; Krauss, T.F.; Kuipers, L.

    2005-01-01

    The eigenfield distribution and the band structure of a photonic crystal waveguide have been measured with a phase-sensitive near-field scanning optical microscope. Bloch modes, which consist of more than one spatial frequency, are visualized in the waveguide. In the band structure, multiple

  3. New algorithm for efficient Bloch-waves calculations of orientation-sensitive ELNES

    Czech Academy of Sciences Publication Activity Database

    Rusz, Ján; Muto, S.; Tatsumi, K.

    2013-01-01

    Roč. 125, Feb (2013), s. 81-88 ISSN 0304-3991 Institutional support: RVO:68378271 Keywords : transmission electron microscopy * density functional theory * dynamical diffraction theory * Bloch waves * electron magnetic circular dichroism Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.745, year: 2013

  4. A new characterization of Bloch function in the unit ball of Cn

    International Nuclear Information System (INIS)

    Shi Jihuai.

    1989-07-01

    Bloch function in the unit disc v has many different but equivalent characterizations. Recently, a new characterization has been obtained by the study of Hankel operators. The purpose of this note is to generalize this characterization to the unit ball of C n . 7 refs

  5. Self-consistent Maxwell-Bloch theory of quantum-dot-population switching in photonic crystals

    International Nuclear Information System (INIS)

    Takeda, Hiroyuki; John, Sajeev

    2011-01-01

    We theoretically demonstrate the population switching of quantum dots (QD's), modeled as two-level atoms in idealized one-dimensional (1D) and two-dimensional (2D) photonic crystals (PC's) by self-consistent solution of the Maxwell-Bloch equations. In our semiclassical theory, energy states of the electron are quantized, and electron dynamics is described by the atomic Bloch equation, while electromagnetic waves satisfy the classical Maxwell equations. Near a waveguide cutoff in a photonic band gap, the local electromagnetic density of states (LDOS) and spontaneous emission rates exhibit abrupt changes with frequency, enabling large QD population inversion driven by both continuous and pulsed optical fields. We recapture and generalize this ultrafast population switching using the Maxwell-Bloch equations. Radiative emission from the QD is obtained directly from the surrounding PC geometry using finite-difference time-domain simulation of the electromagnetic field. The atomic Bloch equations provide a source term for the electromagnetic field. The total electromagnetic field, consisting of the external input and radiated field, drives the polarization components of the atomic Bloch vector. We also include a microscopic model for phonon dephasing of the atomic polarization and nonradiative decay caused by damped phonons. Our self-consistent theory captures stimulated emission and coherent feedback effects of the atomic Mollow sidebands, neglected in earlier treatments. This leads to remarkable high-contrast QD-population switching with relatively modest (factor of 10) jump discontinuities in the electromagnetic LDOS. Switching is demonstrated in three separate models of QD's placed (i) in the vicinity of a band edge of a 1D PC, (ii) near a cutoff frequency in a bimodal waveguide channel of a 2D PC, and (iii) in the vicinity of a localized defect mode side coupled to a single-mode waveguide channel in a 2D PC.

  6. Comprehensive solutions to the Bloch equations and dynamical models for open two-level systems

    Science.gov (United States)

    Skinner, Thomas E.

    2018-01-01

    The Bloch equation and its variants constitute the fundamental dynamical model for arbitrary two-level systems. Many important processes, including those in more complicated systems, can be modeled and understood through the two-level approximation. It is therefore of widespread relevance, especially as it relates to understanding dissipative processes in current cutting-edge applications of quantum mechanics. Although the Bloch equation has been the subject of considerable analysis in the 70 years since its inception, there is still, perhaps surprisingly, significant work that can be done. This paper extends the scope of previous analyses. It provides a framework for more fully understanding the dynamics of dissipative two-level systems. A solution is derived that is compact, tractable, and completely general, in contrast to previous results. Any solution of the Bloch equation depends on three roots of a cubic polynomial that are crucial to the time dependence of the system. The roots are typically only sketched out qualitatively, with no indication of their dependence on the physical parameters of the problem. Degenerate roots, which modify the solutions, have been ignored altogether. Here the roots are obtained explicitly in terms of a single real-valued root that is expressed as a simple function of the system parameters. For the conventional Bloch equation, a simple graphical representation of this root is presented that makes evident the explicit time dependence of the system for each point in the parameter space. Several intuitive, visual models of system dynamics are developed. A Euclidean coordinate system is identified in which any generalized Bloch equation is separable, i.e., the sum of commuting rotation and relaxation operators. The time evolution in this frame is simply a rotation followed by relaxation at modified rates that play a role similar to the standard longitudinal and transverse rates. These rates are functions of the applied field, which

  7. A new distributional record of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) along Goa, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sanaye, S.V.; Rivonker, C.U.; Ansari, Z.A; Sreepada, R.A

    Present study is based on a single male specimen of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) collected from the bay-estuarine system of, Goa (central west coast of India) which is the new distributional record for this species. A...

  8. Quantum Theory of Conducting Matter Newtonian Equations of Motion for a Bloch Electron

    CERN Document Server

    Fujita, Shigeji

    2007-01-01

    Quantum Theory of Conducting Matter: Newtonian Equations of Motion for a Bloch Electron targets scientists, researchers and graduate-level students focused on experimentation in the fields of physics, chemistry, electrical engineering, and material sciences. It is important that the reader have an understanding of dynamics, quantum mechanics, thermodynamics, statistical mechanics, electromagnetism and solid-state physics. Many worked-out problems are included in the book to aid the reader's comprehension of the subject. The Bloch electron (wave packet) moves by following the Newtonian equation of motion. Under an applied magnetic field B the electron circulates around the field B counterclockwise or clockwise depending on the curvature of the Fermi surface. The signs of the Hall coefficient and the Seebeck coefficient are known to give the sign of the major carrier charge. For alkali metals, both are negative, indicating that the carriers are "electrons." These features arise from the Fermi surface difference...

  9. On an Integral-Type Operator Acting between Bloch-Type Spaces on the Unit Ball

    Directory of Open Access Journals (Sweden)

    Stevo Stević

    2010-01-01

    Full Text Available Let 𝔹 denote the open unit ball of ℂn. For a holomorphic self-map φ of 𝔹 and a holomorphic function g in 𝔹 with g(0=0, we define the following integral-type operator: Iφgf(z=∫01ℜf(φ(tzg(tz(dt/t, z∈𝔹. Here ℜf denotes the radial derivative of a holomorphic function f in 𝔹. We study the boundedness and compactness of the operator between Bloch-type spaces ℬω and ℬμ, where ω is a normal weight function and μ is a weight function. Also we consider the operator between the little Bloch-type spaces ℬω,0 and ℬμ,0.

  10. Modeling Dzyaloshinskii-Moriya Interaction at Transition Metal Interfaces: Constrained Moment versus Generalized Bloch Theorem

    KAUST Repository

    Dong, Yao-Jun; Belabbes, Abderrezak; Manchon, Aurelien

    2017-01-01

    Dzyaloshinskii-Moriya interaction (DMI) at Pt/Co interfaces is investigated theoretically using two different first principles methods. The first one uses the constrained moment method to build a spin spiral in real space, while the second method uses the generalized Bloch theorem approach to construct a spin spiral in reciprocal space. We show that although the two methods produce an overall similar total DMI energy, the dependence of DMI as a function of the spin spiral wavelength is dramatically different. We suggest that long-range magnetic interactions, that determine itinerant magnetism in transition metals, are responsible for this discrepancy. We conclude that the generalized Bloch theorem approach is more adapted to model DMI in transition metal systems, where magnetism is delocalized, while the constrained moment approach is mostly applicable to weak or insulating magnets, where magnetism is localized.

  11. Modeling Dzyaloshinskii-Moriya Interaction at Transition Metal Interfaces: Constrained Moment versus Generalized Bloch Theorem

    KAUST Repository

    Dong, Yao-Jun

    2017-10-29

    Dzyaloshinskii-Moriya interaction (DMI) at Pt/Co interfaces is investigated theoretically using two different first principles methods. The first one uses the constrained moment method to build a spin spiral in real space, while the second method uses the generalized Bloch theorem approach to construct a spin spiral in reciprocal space. We show that although the two methods produce an overall similar total DMI energy, the dependence of DMI as a function of the spin spiral wavelength is dramatically different. We suggest that long-range magnetic interactions, that determine itinerant magnetism in transition metals, are responsible for this discrepancy. We conclude that the generalized Bloch theorem approach is more adapted to model DMI in transition metal systems, where magnetism is delocalized, while the constrained moment approach is mostly applicable to weak or insulating magnets, where magnetism is localized.

  12. Bloch Surface Waves Using Graphene Layers: An Approach toward In-Plane Photodetectors

    Directory of Open Access Journals (Sweden)

    Richa Dubey

    2018-03-01

    Full Text Available A dielectric multilayer platform was investigated as a foundation for two-dimensional optics. In this paper, we present, to the best of our knowledge, the first experimental demonstration of absorption of Bloch surface waves in the presence of graphene layers. Graphene is initially grown on a Cu foil via Chemical Vapor Deposition and transferred layer by layer by a wet-transfer method using poly(methyl methacrylate, (PMMA. We exploit total internal reflection configuration and multi-heterodyne scanning near-field optical microscopy as a far-field coupling method and near-field characterization tool, respectively. The absorption is quantified in terms of propagation lengths of Bloch surface waves. A significant drop in the propagation length of the BSWs is observed in the presence of graphene layers. The propagation length of BSWs in bare multilayer is reduced to 17 times shorter in presence of graphene monolayer, and 23 times shorter for graphene bilayer.

  13. General PFG signal attenuation expressions for anisotropic anomalous diffusion by modified-Bloch equations

    Science.gov (United States)

    Lin, Guoxing

    2018-05-01

    Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) anomalous diffusion is complicated, especially in the anisotropic case where limited research has been reported. A general PFG signal attenuation expression, including the finite gradient pulse (FGPW) effect for free general anisotropic fractional diffusion { 0 integral modified-Bloch equation, were extended to obtain general PFG signal attenuation expressions for anisotropic anomalous diffusion. Various cases of PFG anisotropic anomalous diffusion were investigated, including coupled and uncoupled anisotropic anomalous diffusion. The continuous-time random walk (CTRW) simulation was also carried out to support the theoretical results. The theory and the CTRW simulation agree with each other. The obtained signal attenuation expressions and the three-dimensional fractional modified-Bloch equations are important for analyzing PFG anisotropic anomalous diffusion in NMR and MRI.

  14. Optimal cloning of qubits given by an arbitrary axisymmetric distribution on the Bloch sphere

    International Nuclear Information System (INIS)

    Bartkiewicz, Karol; Miranowicz, Adam

    2010-01-01

    We find an optimal quantum cloning machine, which clones qubits of arbitrary symmetrical distribution around the Bloch vector with the highest fidelity. The process is referred to as phase-independent cloning in contrast to the standard phase-covariant cloning for which an input qubit state is a priori better known. We assume that the information about the input state is encoded in an arbitrary axisymmetric distribution (phase function) on the Bloch sphere of the cloned qubits. We find analytical expressions describing the optimal cloning transformation and fidelity of the clones. As an illustration, we analyze cloning of qubit state described by the von Mises-Fisher and Brosseau distributions. Moreover, we show that the optimal phase-independent cloning machine can be implemented by modifying the mirror phase-covariant cloning machine for which quantum circuits are known.

  15. The Bloch wave operator: generalizations and applications: Part I. The time-independent case

    CERN Document Server

    Killingbeck, J P

    2003-01-01

    This is part 1 of a two-part review on wave operator theory and methods. The basic theory of the time-independent wave operator is presented in terms of partitioned matrix theory for the benefit of general readers, with a discussion of the links between the matrix and projection operator approaches. The matrix approach is shown to lead to simple derivations of the wave operators and effective Hamiltonians of Loewdin, Bloch, Des Cloizeaux and Kato as well as to some associated variational forms. The principal approach used throughout stresses the solution of the nonlinear equation for the reduced wave operator, leading to the construction of the effective Hamiltonians of Bloch and of Des Cloizeaux. Several mathematical techniques which are useful in implementing this approach are explained, some of them being relatively little known in the area of wave operator calculations. The theoretical discussion is accompanied by several specimen numerical calculations which apply the described techniques to a selection ...

  16. Chaos synchronization in bi-axial magnets modeled by Bloch equation

    International Nuclear Information System (INIS)

    Moukam Kakmeni, F.M.; Nguenang, J.P.; Kofane, T.C.

    2005-10-01

    In this paper, we show that the bi-axial magnetic material modelled by Bloch equation admits chaotic solutions for a certain set of numerical values assigned to the system of parameters and initial conditions. Using the unidirectional linear and nonlinear feedback schemes, we demonstrate that two such systems can be synchronized together. The chaotic synchronization is discussed in the context of complete synchronization which means that the difference of the states of two relevant systems converge to zero. (author)

  17. Weighted Differentiation Composition Operator from Logarithmic Bloch Spaces to Zygmund-Type Spaces

    Directory of Open Access Journals (Sweden)

    Huiying Qu

    2014-01-01

    Full Text Available Let H( denote the space of all holomorphic functions on the unit disk of ℂ, u∈H( and let  n be a positive integer, φ a holomorphic self-map of , and μ a weight. In this paper, we investigate the boundedness and compactness of a weighted differentiation composition operator φ,unf(z=u(zf(n(φ(z,f∈H(, from the logarithmic Bloch spaces to the Zygmund-type spaces.

  18. Effective Hamiltonians, two level systems, and generalized Maxwell-Bloch equations

    International Nuclear Information System (INIS)

    Sczaniecki, L.

    1981-02-01

    A new method is proposed involving a canonical transformation leading to the non-secular part of time-independent perturbation calculus. The method is used to derive expressions for effective Shen-Walls Hamiltonians which, taken in the two-level approximation and on the inclusion of non-Hamiltonian terms into the dynamics of the system, lead to generalized Maxwell-Bloch equations. The rotating wave approximation is written anew within the framework of our formalism. (author)

  19. Bloch-Kohn and Wannier-Kohn functions in one dimension

    International Nuclear Information System (INIS)

    Bruno-Alfonso, Alexys; Guo-Qiang, Hai

    2003-01-01

    Bloch and Wannier functions of the Kohn type for a quite general one-dimensional Hamiltonian with inversion symmetry are studied. Important clarifications on null minigaps and the symmetry of those functions are given, with emphasis on the Kronig-Penney model. The lack of a general selection rule on the miniband index for optical transitions between edge states in semiconductor superlattices is discussed. A direct method for the calculation of Wannier-Kohn functions is presented

  20. Designing non-Hermitian dynamics for conservative state evolution on the Bloch sphere

    Science.gov (United States)

    Yu, Sunkyu; Piao, Xianji; Park, Namkyoo

    2018-03-01

    An evolution on the Bloch sphere is the fundamental state transition, including optical polarization controls and qubit operations. Conventional evolution of a polarization state or qubit is implemented within a closed system that automatically satisfies energy conservation from the Hermitian formalism. Although particular forms of static non-Hermitian Hamiltonians, such as parity-time-symmetric Hamiltonians, allow conservative states in an open system, the criteria for the energy conservation in a dynamical open system have not been fully explored. Here, we derive the condition of conservative state evolution in open-system dynamics and its inverse design method, by developing the non-Hermitian modification of the Larmor precession equation. We show that the geometrically designed locus on the Bloch sphere can be realized by different forms of dynamics, leading to the isolocus family of non-Hermitian dynamics. This increased degree of freedom allows the complementary phenomena of error-robust and highly sensitive evolutions on the Bloch sphere, which could be applicable to stable polarizers, quantum gates, and optimized sensors in dynamical open systems.

  1. Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity

    Science.gov (United States)

    Li, Xinwei; Bamba, Motoaki; Zhang, Qi; Fallahi, Saeed; Gardner, Geoff C.; Gao, Weilu; Lou, Minhan; Yoshioka, Katsumasa; Manfra, Michael J.; Kono, Junichiro

    2018-06-01

    A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger's equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch-Siegert shift. Here, we report the vacuum Bloch-Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch-Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.

  2. Observation of Bloch oscillations in complex PT-symmetric photonic lattices

    Science.gov (United States)

    Wimmer, Martin; Miri, Mohammed-Ali; Christodoulides, Demetrios; Peschel, Ulf

    2015-01-01

    Light propagation in periodic environments is often associated with a number of interesting and potentially useful processes. If a crystalline optical potential is also linearly ramped, light can undergo periodic Bloch oscillations, a direct outcome of localized Wannier-Stark states and their equidistant eigenvalue spectrum. Even though these effects have been extensively explored in conservative settings, this is by no means the case in non-Hermitian photonic lattices encompassing both amplification and attenuation. Quite recently, Bloch oscillations have been predicted in parity-time-symmetric structures involving gain and loss in a balanced fashion. While in a complex bulk medium, one intuitively expects that light will typically follow the path of highest amplification, in a periodic system this behavior can be substantially altered by the underlying band structure. Here, we report the first experimental observation of Bloch oscillations in parity-time-symmetric mesh lattices. We show that these revivals exhibit unusual properties like secondary emissions and resonant restoration of PT symmetry. In addition, we present a versatile method for reconstructing the real and imaginary components of the band structure by directly monitoring the light evolution during a cycle of these oscillations. PMID:26639941

  3. Bloch oscillations of ultracold atoms and measurement of the fine structure constant; Oscillations de Bloch d'atomes ultrafroids et mesure de la constante de structure fine

    Energy Technology Data Exchange (ETDEWEB)

    Clade, P

    2005-10-15

    From a measurement of the recoil velocity of an atom absorbing a photon, it is possible to deduce a determination of the ratio h/m between the Planck constant and the mass of the atoms and then to deduce a value of the fine structure constant alpha. To do this measurement, we use the technique of Bloch oscillations, which allows us to transfer a large number of recoils to atoms. A velocity sensor, based on velocity selective Raman transition, enables us to measure the momentum transferred to the atoms. A measurement with a statistical uncertainty of 4.4 10{sup -9}, in conjunction with a careful study of systematic effects (5 10{sup -9}), has led us to a determination of alpha with an uncertainty of 6.7 10{sup -9}: {alpha}{sup -1}(Rb) = 137.03599878 (91). This uncertainty is similar to the uncertainty of the best determinations of alpha based on atom interferometry. (author)

  4. Magnon localization and Bloch oscillations in finite Heisenberg spin chains in an inhomogeneous magnetic field.

    Science.gov (United States)

    Kosevich, Yuriy A; Gann, Vladimir V

    2013-06-19

    We study the localization of magnon states in finite defect-free Heisenberg spin-1/2 ferromagnetic chains placed in an inhomogeneous magnetic field with a constant spatial gradient. Continuous transformation from the extended magnon states to the localized Wannier-Zeeman states in a finite spin chain placed in an inhomogeneous field is described both analytically and numerically. We describe for the first time the non-monotonic dependence of the energy levels of magnons, both long and short wavelength, on the magnetic field gradient, which is a consequence of magnon localization in a finite spin chain. We show that, in contrast to the destruction of the magnon band and the establishment of the Wannier-Stark ladder in a vanishingly small field gradient in an infinite chain, the localization of magnon states at the chain ends preserves the memory of the magnon band. Essentially, the localization at the lower- or higher-field chain end resembles the localization of the positive- or negative-effective-mass band quasiparticles. We also show how the beat dynamics of coherent superposition of extended spin waves in a finite chain in a homogeneous or weakly inhomogeneous field transforms into magnon Bloch oscillations of the superposition of localized Wannier-Zeeman states in a strongly inhomogeneous field. We provide a semiclassical description of the magnon Bloch oscillations and show that the correspondence between the quantum and semiclassical descriptions is most accurate for Bloch oscillations of the magnon coherent states, which are built from a coherent superposition of a large number of the nearest-neighbour Wannier-Zeeman states.

  5. Magnon localization and Bloch oscillations in finite Heisenberg spin chains in an inhomogeneous magnetic field

    International Nuclear Information System (INIS)

    Kosevich, Yuriy A; Gann, Vladimir V

    2013-01-01

    We study the localization of magnon states in finite defect-free Heisenberg spin-1/2 ferromagnetic chains placed in an inhomogeneous magnetic field with a constant spatial gradient. Continuous transformation from the extended magnon states to the localized Wannier–Zeeman states in a finite spin chain placed in an inhomogeneous field is described both analytically and numerically. We describe for the first time the non-monotonic dependence of the energy levels of magnons, both long and short wavelength, on the magnetic field gradient, which is a consequence of magnon localization in a finite spin chain. We show that, in contrast to the destruction of the magnon band and the establishment of the Wannier–Stark ladder in a vanishingly small field gradient in an infinite chain, the localization of magnon states at the chain ends preserves the memory of the magnon band. Essentially, the localization at the lower- or higher-field chain end resembles the localization of the positive- or negative-effective-mass band quasiparticles. We also show how the beat dynamics of coherent superposition of extended spin waves in a finite chain in a homogeneous or weakly inhomogeneous field transforms into magnon Bloch oscillations of the superposition of localized Wannier–Zeeman states in a strongly inhomogeneous field. We provide a semiclassical description of the magnon Bloch oscillations and show that the correspondence between the quantum and semiclassical descriptions is most accurate for Bloch oscillations of the magnon coherent states, which are built from a coherent superposition of a large number of the nearest-neighbour Wannier–Zeeman states. (paper)

  6. Bloch Oscillations in the Chains of Artificial Atoms Dressed with Photons

    Directory of Open Access Journals (Sweden)

    Ilay Levie

    2018-06-01

    Full Text Available We present a model of one-dimensional chain of two-level artificial atoms driven with DC field and quantum light simultaneously in a strong coupling regime. The interaction of atoms with light leads to electron-photon entanglement (dressing of the atoms with light. The driving via dc field leads to the Bloch oscillations (BO in the chain of dressed atoms. We consider the mutual influence of dressing and BO and show that scenario of oscillations dramatically differs from predicted by the Jaynes-Cummings and Bloch-Zener models. We study the evolution of the population inversion, tunneling current, photon probability distribution, mean number of photons, and photon number variance, and show the influence of BO on the quantum-statistical characteristics of light. For example, the collapse-revivals picture and vacuum Rabi-oscillations are strongly modulated with Bloch frequency. As a result, quantum properties of light and degree of electron-photon entanglement become controllable via adiabatic dc field turning. On the other hand, the low-frequency tunneling current depends on the quantum light statistics (in particular, for coherent initial state it is modulated accordingly the collapse-revivals picture. The developed model is universal with respect to the physical origin of artificial atom and frequency range of atom-light interaction. The model is adapted to the 2D-heterostructures (THz frequencies, semiconductor quantum dots (optical range, and Josephson junctions (microwaves. The data for numerical simulations are taken from recently published experiments. The obtained results open a new way in quantum state engineering and nano-photonic spectroscopy.

  7. Motives and algebraic cycles a celebration in honour of Spencer J. Bloch

    CERN Document Server

    Jeu, Rob de; Lewis, James D

    2009-01-01

    Spencer J. Bloch has, and continues to have, a profound influence on the subject of Algebraic K-Theory, Cycles and Motives. This book, which is comprised of a number of independent research articles written by leading experts in the field, is dedicated in his honour, and gives a snapshot of the current and evolving nature of the subject. Some of the articles are written in an expository style, providing a perspective on the current state of the subject to those wishing to learn more about it. Others are more technical, representing new developments and making them especially interesting to res

  8. Third harmonic generation by Bloch-oscillating electrons in a quasioptical array

    International Nuclear Information System (INIS)

    Ghosh, A.W.; Wanke, M.C.; Allen, S.J.; Wilkins, J.W.

    1999-01-01

    We compute the third harmonic field generated by Bloch-oscillating electrons in a quasioptical array of superlattices under THz irradiation. The third harmonic power transmitted oscillates with the internal electric field, with nodes associated with Bessel functions in eEd/ℎω. The nonlinear response of the array causes the output power to be a multivalued function of the incident laser power. The output can be optimized by adjusting the frequency of the incident pulse to match one of the Fabry-Pacute erot resonances in the substrate. Within the transmission-line model of the array, the maximum conversion efficiency is 0.1%. copyright 1999 American Institute of Physics

  9. Manipulation of Bloch surface waves: from subwavelength focusing to nondiffracting beam

    Science.gov (United States)

    Kim, Myun-Sik; Herzig, Hans Peter

    2018-01-01

    We present a different type of electromagnetic surface wave than a surface plasmon polariton (SPP), called Bloch surface wave (BSW). BSWs are sustained by dielectric multilayers, and therefore they do not suffer from dissipation. Their propagation length is unbeatably long, e.g., over several millimeters. Thanks to this feature, larger integrations of 2D photonic chips are realizable. To do this, 2D optical components and corresponding techniques are necessary to manipulate in-plane propagation of surface waves. We overview recent progresses of the BSW research on manipulation techniques and developed components. Our study will provide a good guideline of the BSW components for users.

  10. Identification of Bloch-modes in hollow-core Photonic Crystal Fiber cladding

    DEFF Research Database (Denmark)

    Couny, F.; Benabid, F.; Roberts, John

    2007-01-01

    We report on the experimental visualization of the cladding Bloch-modes of a hollow-core photonic crystal fiber. Both spectral and spatial field information is extracted using the approach, which is based on measurement of the near-field and Fresnel-zone that results after propagation over a short...... length of fiber. A detailed study of the modes near the edges of the band gap shows that it is formed by the influence of three types of resonator: the glass interstitial apex, the silica strut which joins the neighboring apexes, and the air hole. The cladding electromagnetic field which survives...

  11. Self-consistent Maxwell-Bloch model of quantum-dot photonic-crystal-cavity lasers

    DEFF Research Database (Denmark)

    Cartar, William; Mørk, Jesper; Hughes, Stephen

    2017-01-01

    -level emitters are solved numerically. Phenomenological pure dephasing and incoherent pumping is added to the optical Bloch equations to allow for a dynamical lasing regime, but the cavity-mediated radiative dynamics and gain coupling of each QD dipole (artificial atom) is contained self-consistently within......-mode to multimode lasing is also observed, depending on the spectral peak frequency of the QD ensemble. Using a statistical modal analysis of the average decay rates, we also show how the average radiative decay rate decreases as a function of cavity size. In addition, we investigate the role of structural disorder...

  12. Near-field imaging of light propagation in photonic crystal waveguides: Explicit role of Bloch harmonics

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Volkov, V.S.; Søndergaard, Thomas

    2002-01-01

    We employ a collection scanning near-field optical microscope (SNOM) to image the propagation of light at telecommunication wavelengths along straight and bent regions of silicon-on-insulator photonic crystal waveguides (PCWs) formed by removing a single row of holes in the triangular 410-nm...... the interference between a quasihomogeneous background field and Bloch harmonics of the PCW mode, we account for spatial frequency spectra of the intensity variations and determine the propagation constant of the PCW mode at 1520 nm. The possibilities and limitations of SNOM imaging for the characterization...

  13. Surface Acoustic Bloch Oscillations, the Wannier-Stark Ladder, and Landau-Zener Tunneling in a Solid

    Science.gov (United States)

    de Lima, M. M., Jr.; Kosevich, Yu. A.; Santos, P. V.; Cantarero, A.

    2010-04-01

    We present the experimental observation of Bloch oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling of surface acoustic waves in perturbed grating structures on a solid substrate. A model providing a quantitative description of our experimental observations, including multiple Landau-Zener transitions of the anticrossed surface acoustic Wannier-Stark states, is developed. The use of a planar geometry for the realization of the Bloch oscillations and Landau-Zener tunneling allows a direct access to the elastic field distribution. The vertical surface displacement has been measured by interferometry.

  14. Desenvolvimento morfológico das larvas de Hoplias lacerdae Miranda Ribeiro, 1908 (Characiformes, Erythrinidae, da eclosão até a metamorfose, relacionado com a capacidade de capturar alimento exógeno

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Reis Raposo Maciel

    2009-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2009v22n3p103 Para a realização deste trabalho foram utilizados 510 exemplares de Hoplias lacerdae, com um a 30 dias após a eclosão, com o objetivo de estudar as características morfológicas, mesoscópicas, que capacitam essa espécie, nas fases iniciais do seu desenvolvimento, a apresentarem estruturas adaptadas para se locomoverem e capturarem alimento exógeno. As larvas vitelínicas com 11 dias após a eclosão têm potencialidade para capturar alimento exógeno, ou seja, presas, mesmo antes da absorção total do vitelo, o que acontece com 12 dias. Nesta fase apresentam: boca aberta com um dia após a eclosão e posição terminal aos quatro dias; aos sete dias demonstram flexão da notocorda, proporcionando maior eficiência locomotora, bem como apresenta neste período nadadeiras peitorais desenvolvidas, as quais facilitam o equilíbrio e direcionamento na coluna d’água; e aos oito dias visualizou-se a formação das nadadeiras dorsal e anal, porém as nadadeiras pélvicas foram visualizadas aos 11 dias.

  15. Bloch Modes and Evanescent Modes of Photonic Crystals: Weak Form Solutions Based on Accurate Interface Triangulation

    Directory of Open Access Journals (Sweden)

    Matthias Saba

    2015-01-01

    Full Text Available We propose a new approach to calculate the complex photonic band structure, both purely dispersive and evanescent Bloch modes of a finite range, of arbitrary three-dimensional photonic crystals. Our method, based on a well-established plane wave expansion and the weak form solution of Maxwell’s equations, computes the Fourier components of periodic structures composed of distinct homogeneous material domains from a triangulated mesh representation of the inter-material interfaces; this allows substantially more accurate representations of the geometry of complex photonic crystals than the conventional representation by a cubic voxel grid. Our method works for general two-phase composite materials, consisting of bi-anisotropic materials with tensor-valued dielectric and magnetic permittivities ε and μ and coupling matrices ς. We demonstrate for the Bragg mirror and a simple cubic crystal closely related to the Kelvin foam that relatively small numbers of Fourier components are sufficient to yield good convergence of the eigenvalues, making this method viable, despite its computational complexity. As an application, we use the single gyroid crystal to demonstrate that the consideration of both conventional and evanescent Bloch modes is necessary to predict the key features of the reflectance spectrum by analysis of the band structure, in particular for light incident along the cubic [111] direction.

  16. Notes on the genus Amphiprion Bloch & Schneider, 1801 (Teleostei: Pomacentridae) and its host sea anemones in the Seychelles

    NARCIS (Netherlands)

    Hartog, den J.C.

    1997-01-01

    The genus Amphiprion Bloch & Schneider, 1801, is represented in the Seychelles by two species, A. akallopisos Bleeker, 1853, and the endemic A. fuscocaudatus Allen, 1972. Throughout its distributional range Amphiprion akallopisos has exclusively been recorded to associate with the clownfish anemones

  17. A 2D multi-term time and space fractional Bloch-Torrey model based on bilinear rectangular finite elements

    Science.gov (United States)

    Qin, Shanlin; Liu, Fawang; Turner, Ian W.

    2018-03-01

    The consideration of diffusion processes in magnetic resonance imaging (MRI) signal attenuation is classically described by the Bloch-Torrey equation. However, many recent works highlight the distinct deviation in MRI signal decay due to anomalous diffusion, which motivates the fractional order generalization of the Bloch-Torrey equation. In this work, we study the two-dimensional multi-term time and space fractional diffusion equation generalized from the time and space fractional Bloch-Torrey equation. By using the Galerkin finite element method with a structured mesh consisting of rectangular elements to discretize in space and the L1 approximation of the Caputo fractional derivative in time, a fully discrete numerical scheme is derived. A rigorous analysis of stability and error estimation is provided. Numerical experiments in the square and L-shaped domains are performed to give an insight into the efficiency and reliability of our method. Then the scheme is applied to solve the multi-term time and space fractional Bloch-Torrey equation, which shows that the extra time derivative terms impact the relaxation process.

  18. Boundedness and compactness of a new product-type operator from a general space to Bloch-type spaces

    Directory of Open Access Journals (Sweden)

    Stevo Stević

    2016-09-01

    Full Text Available Abstract We characterize the boundedness and compactness of a product-type operator, which, among others, includes all the products of the single composition, multiplication, and differentiation operators, from a general space to Bloch-type spaces. We also give some upper and lower bounds for the norm of the operator.

  19. Permittivity and Permeability for Floquet-Bloch Space Harmonics in Infinite 1D Magneto-Dielectric Periodic Structures

    DEFF Research Database (Denmark)

    Breinbjerg, Olav; Yaghjian, Arthur D.

    2014-01-01

    -Bloch space harmonics. We discuss how space harmonic permittivity and permeability can be expressed in seemingly different though equivalent forms, and we investigate these parameters of the zeroeth order space harmonic for a particular 1D periodic structure that is based on a previously reported 3D periodic...

  20. Design of Slow and Fast Light Photonic Crystal Waveguides for Single-photon Emission Using a Bloch Mode Expansion Technique

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Rigal, B.; Kapon, E.

    We design slow and fast light photonic crystal waveguides for single-photon emission using a Bloch mode expansion and scattering matrix technique. We propose slow light designs that increase the group index-waveguide mode volume ratio for larger Purcell enhancement, and address efficient slow-to-...

  1. Self-consistent Maxwell-Bloch model of quantum-dot photonic-crystal-cavity lasers

    Science.gov (United States)

    Cartar, William; Mørk, Jesper; Hughes, Stephen

    2017-08-01

    We present a powerful computational approach to simulate the threshold behavior of photonic-crystal quantum-dot (QD) lasers. Using a finite-difference time-domain (FDTD) technique, Maxwell-Bloch equations representing a system of thousands of statistically independent and randomly positioned two-level emitters are solved numerically. Phenomenological pure dephasing and incoherent pumping is added to the optical Bloch equations to allow for a dynamical lasing regime, but the cavity-mediated radiative dynamics and gain coupling of each QD dipole (artificial atom) is contained self-consistently within the model. These Maxwell-Bloch equations are implemented by using Lumerical's flexible material plug-in tool, which allows a user to define additional equations of motion for the nonlinear polarization. We implement the gain ensemble within triangular-lattice photonic-crystal cavities of various length N (where N refers to the number of missing holes), and investigate the cavity mode characteristics and the threshold regime as a function of cavity length. We develop effective two-dimensional model simulations which are derived after studying the full three-dimensional passive material structures by matching the cavity quality factors and resonance properties. We also demonstrate how to obtain the correct point-dipole radiative decay rate from Fermi's golden rule, which is captured naturally by the FDTD method. Our numerical simulations predict that the pump threshold plateaus around cavity lengths greater than N =9 , which we identify as a consequence of the complex spatial dynamics and gain coupling from the inhomogeneous QD ensemble. This behavior is not expected from simple rate-equation analysis commonly adopted in the literature, but is in qualitative agreement with recent experiments. Single-mode to multimode lasing is also observed, depending on the spectral peak frequency of the QD ensemble. Using a statistical modal analysis of the average decay rates, we also

  2. Bloch oscillations of ultracold atoms and measurement of the fine structure constant

    International Nuclear Information System (INIS)

    Clade, P.

    2005-10-01

    From a measurement of the recoil velocity of an atom absorbing a photon, it is possible to deduce a determination of the ratio h/m between the Planck constant and the mass of the atoms and then to deduce a value of the fine structure constant alpha. To do this measurement, we use the technique of Bloch oscillations, which allows us to transfer a large number of recoils to atoms. A velocity sensor, based on velocity selective Raman transition, enables us to measure the momentum transferred to the atoms. A measurement with a statistical uncertainty of 4.4 10 -9 , in conjunction with a careful study of systematic effects (5 10 -9 ), has led us to a determination of alpha with an uncertainty of 6.7 10 -9 : α -1 (Rb) = 137.03599878 (91). This uncertainty is similar to the uncertainty of the best determinations of alpha based on atom interferometry. (author)

  3. A note on the Königs domain of compact composition operators on the Bloch space

    Directory of Open Access Journals (Sweden)

    Jones Matthew

    2011-01-01

    Full Text Available Abstract Let be the unit disk in the complex plane. We define to be the little Bloch space of functions f analytic in which satisfy lim|z|→1 (1 - |z|2|f'(z| = 0. If is analytic then the composition operator Cφ : f ↦ f ∘ φ is a continuous operator that maps into itself. In this paper, we show that the compactness of Cφ , as an operator on , can be modelled geometrically by its principal eigenfunction. In particular, under certain necessary conditions, we relate the compactness of Cφ to the geometry of , where σ satisfies Schöder's functional equation σ ∘ φ = φ'(0σ. 2000 Mathematics Subject Classification: Primary 30D05; 47B33 Secondary 30D45.

  4. Effects of gamma radiations on certain tissues of heteropneustes fossils bloch

    International Nuclear Information System (INIS)

    Purohit, R.K.; Rathore, N.; Ahluwalia, P.; Srivastava, M.; Gupta, M.L.

    1992-01-01

    In the present investigation effect of gamma radiation on certain tissues (kidney, stomach and gills) of Heteropneustes fossilis Bloch, an Indian Cat fish, were studied. The fish were irradiated with 10 Gy of gamma radiations at the dose rate of 1.60 Gy/minute from a 60 Co source. Five fish were autopsied at each post-irradiation time of 1,2,3,7,15 and 30 days. Radiation induced histopathology was observed in all the tissues studied. The radio lesions appeared on day-1 after exposure which became exaggerated on day-2 and 3. Signs of recovery were noticed on day-7 which progressed on day-15 and normal histology was observed on day-30. (author). 18 refs

  5. The Bergman spaces, the Bloch space and the pluriharmonic conjugates in the unit ball of Cn

    International Nuclear Information System (INIS)

    Shi Jihuai.

    1989-06-01

    It has been proved that if f is holomorphic in the unit ball B of C m , then f is an element of L p (B,dν) if all the functions (1 - |z| 2 ) m (D n f)(z) with |α| = m are in L p (B,dν). This method can only deal with the case of p ≥ 1. In this paper, we give a new approach to prove that the above result holds for all p is an element of (0, ∞). A simple proof about the characterization of the Bloch space will be given. As a by-product of our approach, we generalize a theorem to the unit ball of C m , and use this result to generalize some theorems about the pluriharmonic conjugates to the case 0 < p < 1. 9 refs

  6. Generalized Bloch Theorem for Complex Periodic Potentials - A Powerful Application to Quantum Transport Calculations

    International Nuclear Information System (INIS)

    Zhang, Xiaoguang; Varga, Kalman; Pantelides, Sokrates T

    2007-01-01

    Band-theoretic methods with periodically repeated supercells have been a powerful approach for ground-state electronic structure calculations, but have not so far been adapted for quantum transport problems with open boundary conditions. Here we introduce a generalized Bloch theorem for complex periodic potentials and use a transfer-matrix formulation to cast the transmission probability in a scattering problem with open boundary conditions in terms of the complex wave vectors of a periodic system with absorbing layers, allowing a band technique for quantum transport calculations. The accuracy and utility of the method is demonstrated by the model problems of the transmission of an electron over a square barrier and the scattering of a phonon in an inhomogeneous nanowire. Application to the resistance of a twin boundary in nanocrystalline copper yields excellent agreement with recent experimental data

  7. Bloch surface wave structures for high sensitivity detection and compact waveguiding

    Science.gov (United States)

    Khan, Muhammad Umar; Corbett, Brian

    2016-01-01

    Resonant propagating waves created on the surface of a dielectric multilayer stack, called Bloch surface waves (BSW), can be designed for high sensitivity monitoring of the adjacent refractive index as an alternative platform to the metal-based surface plasmon resonance (SPR) sensing. The resonant wavelength and polarization can be designed by engineering of the dielectric layers unlike the fixed resonance of SPR, while the wide bandwidth low loss of dielectrics permits sharper resonances, longer propagation lengths and thus their use in waveguiding devices. The transparency of the dielectrics allows the excitation and monitoring of surface-bound fluorescent molecules. We review the recent developments in this technology. We show the advantages that can be obtained by using high index contrast layered structures. Operating at 1550 nm wavelengths will allow the BSW sensors to be implemented in the silicon photonics platform where active waveguiding can be used in the realization of compact planar integrated circuits for multi-parameter sensing.

  8. Illuminating "spin-polarized" Bloch wave-function projection from degenerate bands in decomposable centrosymmetric lattices

    Science.gov (United States)

    Li, Pengke; Appelbaum, Ian

    2018-03-01

    The combination of space inversion and time-reversal symmetries results in doubly degenerate Bloch states with opposite spin. Many lattices with these symmetries can be constructed by combining a noncentrosymmetric potential (lacking this degeneracy) with its inverted copy. Using simple models, we unravel the evolution of local spin splitting during this process of inversion symmetry restoration, in the presence of spin-orbit interaction and sublattice coupling. Importantly, through an analysis of quantum mechanical commutativity, we examine the difficulty of identifying states that are simultaneously spatially segregated and spin polarized. We also explain how surface-sensitive experimental probes (such as angle-resolved photoemission spectroscopy, or ARPES) of "hidden spin polarization" in layered materials are susceptible to unrelated spin splitting intrinsically induced by broken inversion symmetry at the surface.

  9. Bloch oscillations of quasispin polaritons in a magneto-optically controlled atomic ensemble

    International Nuclear Information System (INIS)

    Jiang, Chang; Lu, Jing; Zhou, Lan

    2012-01-01

    We consider the propagation of quantized polarized light in a magneto-optically-manipulated atomic ensemble with a tripod configuration. A polariton formalism is applied when the medium is subjected to a washboard magnetic field under electromagnetically-induced transparency. The dark-state polariton with multiple components is achieved. We analyze the quantum dynamics of the dark-state polariton using experimental data from the rubidium D1-line. It is found that one component propagates freely, however the wave packet trajectory of the other component performs Bloch oscillations. -- Highlights: ► We study the wave–particle dualism of quasiparticles in a magneto-optical medium. ► We generate a “spin”-component dark-state polariton. ► Magnetic fields lead to oscillation and free propagation of a dark-state polariton. ► Our approach shows the role of entanglement of degrees of freedom of photons.

  10. Bloch oscillations of quasispin polaritons in a magneto-optically controlled atomic ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chang [Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Department of Physics, Hunan Normal University, Changsha 410081 (China); Lu, Jing, E-mail: lujing@hunnu.edu.cn [Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Department of Physics, Hunan Normal University, Changsha 410081 (China); Zhou, Lan [Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Department of Physics, Hunan Normal University, Changsha 410081 (China)

    2012-10-01

    We consider the propagation of quantized polarized light in a magneto-optically-manipulated atomic ensemble with a tripod configuration. A polariton formalism is applied when the medium is subjected to a washboard magnetic field under electromagnetically-induced transparency. The dark-state polariton with multiple components is achieved. We analyze the quantum dynamics of the dark-state polariton using experimental data from the rubidium D1-line. It is found that one component propagates freely, however the wave packet trajectory of the other component performs Bloch oscillations. -- Highlights: ► We study the wave–particle dualism of quasiparticles in a magneto-optical medium. ► We generate a “spin”-component dark-state polariton. ► Magnetic fields lead to oscillation and free propagation of a dark-state polariton. ► Our approach shows the role of entanglement of degrees of freedom of photons.

  11. Dynamics of Peregrine combs and Peregrine walls in an inhomogeneous Hirota and Maxwell-Bloch system

    Science.gov (United States)

    Wang, Lei; Wang, Zi-Qi; Sun, Wen-Rong; Shi, Yu-Ying; Li, Min; Xu, Min

    2017-06-01

    Under investigation in this paper is an inhomogeneous Hirota-Maxwell-Bloch (IHMB) system which can describe the propagation of optical solitons in an erbium-doped optical fiber. The breather multiple births (BMBs) are derived with periodically varying group velocity dispersion (GVD) coefficients. Under large periodic modulations in the GVD coefficient of IHMB system, the Peregrine comb (PC) solution is produced, which can be viewed as the limiting case of the BMBs. When the amplitude of the modulation satisfies a special condition, the Peregrine wall (PW) that can be regarded as an intermediate state between rogue wave and PC is obtained. The effects of the third-order dispersion on the spatiotemporal characteristics of PCs and PWs are studied. Our results may be useful for the experimental control and manipulation of the formation of generalized Peregrine rogue waves in inhomogeneous erbium-doped optical fiber.

  12. Exact solutions for fermionic Green's functions in the Bloch-Nordsieck approximation of QED

    International Nuclear Information System (INIS)

    Kernemann, A.; Stefanis, N.G.

    1989-01-01

    A set of new closed-form solutions for fermionic Green's functions in the Bloch-Nordsieck approximation of QED is presented. A manifestly covariant phase-space path-integral method is applied for calculating the n-fermion Green's function in a classical external field. In the case of one and two fermions, explicit expressions for the full Green's functions are analytically obtained, with renormalization carried out in the modified minimal subtraction scheme. The renormalization constants and the corresponding anomalous dimensions are determined. The mass-shell behavior of the two-fermion Green's function is investigated in detail. No assumptions are made concerning the structure of asymptotic states and no IR cutoff is used in the calculations

  13. Violation of Bloch's Law That Specifies Reciprocity of Intensity and Duration with Brief Light Flashes

    Directory of Open Access Journals (Sweden)

    Ernest Greene

    2013-12-01

    Full Text Available For more than a century researchers have been reporting that the visual impact of a very brief flash is determined by the quantity of photons that the flash delivers. This has been variously described as the Bunsen-Roscoe Law or Bloch's Law, often specified as reciprocity of intensity × duration. Prior research found no evidence for such reciprocity when microsecond-duration flashes from a light-emitting diode array were used to display the major contours of nameable shapes. The present work tested with flash durations ranging up to 100 ms and also found no reciprocity. This departure from classic principles might be due to the specific range of wavelengths of the light-emitting diodes and to a mesopic level of ambient light, which together would preclude activation of rods. The reciprocity of intensity and duration may only be valid with full dark adaptation and very dim flashes that activate rods.

  14. Bloch surface waves confined in one dimension with a single polymeric nanofibre

    Science.gov (United States)

    Wang, Ruxue; Xia, Hongyan; Zhang, Douguo; Chen, Junxue; Zhu, Liangfu; Wang, Yong; Yang, Erchan; Zang, Tianyang; Wen, Xiaolei; Zou, Gang; Wang, Pei; Ming, Hai; Badugu, Ramachandram; Lakowicz, Joseph R.

    2017-02-01

    Polymeric fibres with small radii (such as ≤125 nm) are delicate to handle and should be laid down on a solid substrate to obtain practical devices. However, placing these nanofibres on commonly used glass substrates prevents them from guiding light. In this study, we numerically and experimentally demonstrate that when the nanofibre is placed on a suitable dielectric multilayer, it supports a guided mode, a Bloch surface wave (BSW) confined in one dimension. The physical origin of this new mode is discussed in comparison with the typical two-dimensional BSW mode. Polymeric nanofibres are easily fabricated to contain fluorophores, which make the dielectric nanofibre and multilayer configuration suitable for developing a large range of new nanometric scale devices, such as processor-memory interconnections, devices with sensitivity to target analytes, incident polarization and multi-colour BSW modes.

  15. A Bloch-Torrey Equation for Diffusion in a Deforming Media

    International Nuclear Information System (INIS)

    Rohmer, Damien; Gullberg, Grant T.

    2006-01-01

    Diffusion Tensor Magnetic Resonance Imaging (DTMRI)technique enables the measurement of diffusion parameters and therefore, informs on the structure of the biological tissue. This technique is applied with success to the static organs such as brain. However, the diffusion measurement on the dynamically deformable organs such as the in-vivo heart is a complex problem that has however a great potential in the measurement of cardiac health. In order to understand the behavior of the Magnetic Resonance (MR)signal in a deforming media, the Bloch-Torrey equation that leads the MR behavior is expressed in general curvilinear coordinates. These coordinates enable to follow the heart geometry and deformations through time. The equation is finally discredited and presented in a numerical formulation using implicit methods, in order to get a stable scheme that can be applied to any smooth deformations. Diffusion process enables the link between the macroscopic behavior of molecules and the microscopic structure in which they evolve. The measurement of diffusion in biological tissues is therefore of major importance in understanding the complex underlying structure that cannot be studied directly. The Diffusion Tensor Magnetic Resonance Imaging(DTMRI) technique enables the measurement of diffusion parameters and therefore provides information on the structure of the biological tissue. This technique has been applied with success to static organs such as the brain. However, diffusion measurement of dynamically deformable organs such as the in-vivo heart remains a complex problem, which holds great potential in determining cardiac health. In order to understand the behavior of the magnetic resonance (MR) signal in a deforming media, the Bloch-Torrey equation that defines the MR behavior is expressed in general curvilinear coordinates. These coordinates enable us to follow the heart geometry and deformations through time. The equation is finally discredited and presented in a

  16. A Bloch-Torrey Equation for Diffusion in a Deforming Media

    Energy Technology Data Exchange (ETDEWEB)

    Rohmer, Damien; Gullberg, Grant T.

    2006-12-29

    Diffusion Tensor Magnetic Resonance Imaging (DTMRI)technique enables the measurement of diffusion parameters and therefore,informs on the structure of the biological tissue. This technique isapplied with success to the static organs such as brain. However, thediffusion measurement on the dynamically deformable organs such as thein-vivo heart is a complex problem that has however a great potential inthe measurement of cardiac health. In order to understand the behavior ofthe Magnetic Resonance (MR)signal in a deforming media, the Bloch-Torreyequation that leads the MR behavior is expressed in general curvilinearcoordinates. These coordinates enable to follow the heart geometry anddeformations through time. The equation is finally discretized andpresented in a numerical formulation using implicit methods, in order toget a stable scheme that can be applied to any smooth deformations.Diffusion process enables the link between the macroscopic behavior ofmolecules and themicroscopic structure in which they evolve. Themeasurement of diffusion in biological tissues is therefore of majorimportance in understanding the complex underlying structure that cannotbe studied directly. The Diffusion Tensor Magnetic ResonanceImaging(DTMRI) technique enables the measurement of diffusion parametersand therefore provides information on the structure of the biologicaltissue. This technique has been applied with success to static organssuch as the brain. However, diffusion measurement of dynamicallydeformable organs such as the in-vivo heart remains a complex problem,which holds great potential in determining cardiac health. In order tounderstand the behavior of the magnetic resonance (MR) signal in adeforming media, the Bloch-Torrey equation that defines the MR behavioris expressed in general curvilinear coordinates. These coordinates enableus to follow the heart geometry and deformations through time. Theequation is finally discretized and presented in a numerical formulationusing

  17. THE ACTION OF CORAGEN INSECTICIDE ON CERTAIN PHYSIOLOGICAL BIOMARKERS ON CARASSIUS AURATUS GIBELIO BLOCH L. 1758

    Directory of Open Access Journals (Sweden)

    Claudiu Alexandru Baciu

    2015-12-01

    Full Text Available In our researches we have determined the variation of certain physiological indexes, such as the oxygen consume, the breathing rhythm, the glycaemia and the number of red blood cells under the action of Coragen insecticide on Carassius auratus gibelio Bloch. Under the action of Coragen, we have registered significant changes in the oxygen consume, the breathing rhythm, the number of red blood cells and glycemia at the Carassius auratus gibelio Bloch items, considered as answers to the stress provoked by emissions. The highest variations of the physiological indexes, from the perspective of the percentage, were noticed at the glycemia, which at the mark was 28 mg/dl, and in the treated sample, with 0.1 ml/l Coragen is 42 mg/dl, representing a 50% growth and at the breathing rhythm in 24 hours, where values significantly decreased with 41.18% at the concentration of 0.07 ml/l and with 39.33% at the concentrations of 0.05 and 0.1 ml/l Coragen. The slightest variations of the physiological indexes, from the perspective of percentage, were noticed at the oxygen consumption, which, at the mark is of 55.302 ml oxygen/kg/hour, and for the treated sample, with 0.1 ml/l Coragen is 34.81 ml oxygen/kg/hour, representing a decrease of 37.06% in 24 hours and the number of red blood cells, where the values have significantly decrease with 9.58%, 13.48%, respectively 18.44% for the concentrations of 0.05, 0.07 and 0.1 ml/l Coragen.

  18. An Optomechanical Elevator: Transport of a Bloch Oscillating Bose–Einstein Condensate up and down an Optical Lattice by Cavity Sideband Amplification and Cooling

    Directory of Open Access Journals (Sweden)

    B. Prasanna Venkatesh

    2015-12-01

    Full Text Available In this paper we give a new description, in terms of optomechanics, of previous work on the problem of an atomic Bose–Einstein condensate interacting with the optical lattice inside a laser-pumped optical cavity and subject to a bias force, such as gravity. An atomic wave packet in a tilted lattice undergoes Bloch oscillations; in a high-finesse optical cavity the backaction of the atoms on the light leads to a time-dependent modulation of the intracavity lattice depth at the Bloch frequency which can in turn transport the atoms up or down the lattice. In the optomechanical picture, the transport dynamics can be interpreted as a manifestation of dynamical backaction-induced sideband damping/amplification of the Bloch oscillator. Depending on the sign of the pump-cavity detuning, atoms are transported either with or against the bias force accompanied by an up- or down-conversion of the frequency of the pump laser light. We also evaluate the prospects for using the optomechanical Bloch oscillator to make continuous measurements of forces by reading out the Bloch frequency. In this context, we establish the significant result that the optical spring effect is absent and the Bloch frequency is not modified by the backaction.

  19. Matter-wave solitons and finite-amplitude Bloch waves in optical lattices with spatially modulated nonlinearity

    Science.gov (United States)

    Zhang, Jie-Fang; Li, Yi-Shen; Meng, Jianping; Wu, Lei; Malomed, Boris A.

    2010-09-01

    We investigate solitons and nonlinear Bloch waves in Bose-Einstein condensates trapped in optical lattices (OLs). By introducing specially designed localized profiles of the spatial modulation of the attractive nonlinearity, we construct an infinite set of exact soliton solutions in terms of Mathieu and elliptic functions, with the chemical potential belonging to the semi-infinite gap of the OL-induced spectrum. Starting from the particular exact solutions, we employ the relaxation method to construct generic families of soliton solutions in a numerical form. The stability of the solitons is investigated through the computation of the eigenvalues for small perturbations, and also by direct simulations. Finally, we demonstrate a virtually exact (in the numerical sense) composition relation between nonlinear Bloch waves and solitons.

  20. Matter-wave solitons and finite-amplitude Bloch waves in optical lattices with spatially modulated nonlinearity

    International Nuclear Information System (INIS)

    Zhang Jiefang; Meng Jianping; Wu Lei; Li Yishen; Malomed, Boris A.

    2010-01-01

    We investigate solitons and nonlinear Bloch waves in Bose-Einstein condensates trapped in optical lattices (OLs). By introducing specially designed localized profiles of the spatial modulation of the attractive nonlinearity, we construct an infinite set of exact soliton solutions in terms of Mathieu and elliptic functions, with the chemical potential belonging to the semi-infinite gap of the OL-induced spectrum. Starting from the particular exact solutions, we employ the relaxation method to construct generic families of soliton solutions in a numerical form. The stability of the solitons is investigated through the computation of the eigenvalues for small perturbations, and also by direct simulations. Finally, we demonstrate a virtually exact (in the numerical sense) composition relation between nonlinear Bloch waves and solitons.

  1. Matter-wave solitons and finite-amplitude Bloch waves in optical lattices with a spatially modulated nonlinearity

    OpenAIRE

    Zhang, Jie-Fang; Li, Yi-Shen; Meng, Jianping; Wu, Lei; Malomed, Boris A.

    2010-01-01

    We investigate solitons and nonlinear Bloch waves in Bose-Einstein condensates trapped in optical lattices. By introducing specially designed localized profiles of the spatial modulation of the attractive nonlinearity, we construct an infinite number of exact soliton solutions in terms of the Mathieu and elliptic functions, with the chemical potential belonging to the semi-infinite bandgap of the optical-lattice-induced spectrum. Starting from the exact solutions, we employ the relaxation met...

  2. Nonlinear tunneling of bright and dark rogue waves in combined nonlinear Schrödinger and Maxwell-Bloch systems

    Science.gov (United States)

    Raju, Thokala Soloman; Pal, Ritu

    2018-05-01

    We derive the analytical rogue wave solutions for the generalized inhomogeneous nonlinear Schrödinger-Maxwell-Bloch (GINLS-MB) equation describing the pulse propagation in erbium-doped fibre system. Then by suitably choosing the inhomogeneous parameters, we delineate the tunneling properties of rogue waves through dispersion and nonlinearity barriers or wells. Finally, we demonstrate the propagating characteristics of optical solitons by considering their tunneling through periodic barriers by the proper choice of external potential.

  3. Perturbation theory for the bloch electrons on strongly coupled chains in both uniform electric and magnetic fields

    International Nuclear Information System (INIS)

    Zhao, X.G.; Chen, S.G.

    1992-01-01

    In this paper, the energy spectrum and the wave functions for a tight-binding Bloch electron on coupled chains under the action of both uniform electric and magnetic fields are studied in detail. Exact results are obtained for the case when the coupling between chains is large by using the perturbation theory, from which it is found that the spectrum is that of two interspaced Stark ladders. The magnetic field dependence of the energy spectrum is also discussed

  4. Quasi-periodic Schroedinger operators in one dimension, absolutely continuous spectra, Bloch waves, and integrable Hamiltonian systems

    International Nuclear Information System (INIS)

    Chierchia, L.

    1986-01-01

    In the first chapter, the eigenvalue problem for a periodic Schroedinger operator, Lf = (-d 2 /dx 2 + v)f = Ef, is viewed as a two-dimensional Hamiltonian system which is integrable in the sense of Arnold and Liouville. With the aid of the Floquet-BLoch theory, it is shown that such a system is conjugate to two harmonic oscillators with frequencies α and omega, being the rotation number for L and 2π/omega the period of the potential v. This picture is generalized in the second chapter, to quasi periodic Schroedinger operators, L/sub epsilon/, with highly irrational frequencies (omega 1 , ..., omega/sub d/), which are a small perturbation of periodic operators. In the last chapter, the absolutely continuous spectrum σ/sub ac/ of a general quasi-periodic Schroedinger operators is considered. The Radon-Nikodym derivatives (with respect to Lebesgue measure) of the spectral measures are computed in terms of special independent eigensolutions existing for almost ever E in σ/sub ac/. Finally, it is shown that weak Bloch waves always exist for almost ever E in σ/sub ac/ and the question of the existence of genuine Bloch waves is turned into a regularity problem for a certain nonlinear partial differential equation on a d-dimensional torus

  5. Differential geometric invariants for time-reversal symmetric Bloch-bundles: The “Real” case

    International Nuclear Information System (INIS)

    De Nittis, Giuseppe; Gomi, Kiyonori

    2016-01-01

    Topological quantum systems subjected to an even (resp. odd) time-reversal symmetry can be classified by looking at the related “Real” (resp. “Quaternionic”) Bloch-bundles. If from one side the topological classification of these time-reversal vector bundle theories has been completely described in De Nittis and Gomi [J. Geom. Phys. 86, 303–338 (2014)] for the “Real” case and in De Nittis and Gomi [Commun. Math. Phys. 339, 1–55 (2015)] for the “Quaternionic” case, from the other side it seems that a classification in terms of differential geometric invariants is still missing in the literature. With this article and its companion [G. De Nittis and K. Gomi (unpublished)] we want to cover this gap. More precisely, we extend in an equivariant way the theory of connections on principal bundles and vector bundles endowed with a time-reversal symmetry. In the “Real” case we generalize the Chern-Weil theory and we show that the assignment of a “Real” connection, along with the related differential Chern class and its holonomy, suffices for the classification of “Real” vector bundles in low dimensions.

  6. Corrections to Newton’s law of gravitation - application to hybrid Bloch brane

    Science.gov (United States)

    Almeida, C. A. S.; Veras, D. F. S.; Dantas, D. M.

    2018-02-01

    We present in this work, the calculations of corrections in the Newton’s law of gravitation due to Kaluza-Klein gravitons in five-dimensional warped thick braneworld scenarios. We consider here a recently proposed model, namely, the hybrid Bloch brane. This model couples two scalar fields to gravity and is engendered from a domain wall-like defect. Also, two other models the so-called asymmetric hybrid brane and compact brane are considered. Such models are deformations of the ϕ 4 and sine-Gordon topological defects, respectively. Therefore we consider the branes engendered by such defects and we also compute the corrections in their cases. In order to attain the mass spectrum and its corresponding eigenfunctions which are the essential quantities for computing the correction to the Newtonian potential, we develop a suitable numerical technique. The calculation of slight deviations in the gravitational potential may be used as a selection tool for braneworld scenarios matching with future experimental measurements in high energy collisions

  7. Cytotoxic and genotoxic affects of acid mine drainage on fish Channa punctata (Bloch).

    Science.gov (United States)

    Talukdar, B; Kalita, H K; Basumatary, S; Saikia, D J; Sarma, D

    2017-10-01

    The investigation deals with the effects of Acid Mine Drainage (AMD) of coal mine on fish Channa punctata (Bloch) by examining the incidence of haematological, morphological, histological changes and DNA fragmentation in tissues of C. punctata in laboratory condition. For this study fishes were exposed to 10% of AMD for a period of 30 days. The fusion of the primary and secondary gill lamellae, distortion, loss of alignment, deposition of worn out tissues and mucous on the surface of the lamella in the gills; degeneration of morphological architecture, loss of alignment of tubules, mucous deposition in the kidney; cellular damage, cellular necrosis, extraneous deposition on the surface, pore formation in the liver are some important changes detected by scanning electron microscopy. Fishes of AMD treated group showed gradual significant decrease in TEC, Hb and, increase in TLC and DLC as compared to that of the control. DNA fragmentation observed in kidney of fishes from treated group indicates an intricate pollutant present in the AMD. The high incidence of morphological and histological alterations, haematological changes along with DNA breakage in C. punctata is an evidence of the cytotoxic and genotoxic potential of AMD of coal mines. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Microbiological and biochemical changes in pearl spot (Etroplus suratensis Bloch) stored under modified atmospheres.

    Science.gov (United States)

    Lalitha, K V; Sonaji, E R; Manju, S; Jose, L; Gopal, T K S; Ravisankar, C N

    2005-01-01

    This study aimed to determine the effect of packaging [air, modified atmosphere (MA)] on microbial growth, sensory and chemical parameters and also on shelf life of fresh pearl spot (Etroplus suratensis Bloch) and on the selection of microbial association. Fresh pearl spot (whole, gutted) were packaged under both 100% air and MAs (40%CO(2)/60% O(2), 50%CO(2)/50%O(2), 60% CO(2)/40%O(2), 70% CO(2)/30% O(2) and 40% CO(2)/30% O(2)/30% N(2)) and stored at 0 degrees C. Microbial growth (counts of total aerobic bacteria, H(2)S-producing bacteria, Lactic acid bacteria, Brochothrix thermosphacta, yeast and mould), chemical spoilage indicators (pH, total volatile basic nitrogen) and sensory characteristics were monitored. Microbial changes in Pearl spot packed under 100% air and 40% CO(2)/30%O(2)/30% N(2) were similar. The total volatile basic nitrogen values increased, but the values never exceeded the acceptability limit of 25 mg 100 g(-1). MA 60% CO(2) : 40%O(2) was found to be better with a shelf life of 21 days whereas air stored samples had a shelf-life of 12-14 days only. Storage of pearl spot under MAs 60% CO(2) : 40%O(2) is a promising method to extend shelf-life. Longer shelf life expands the market potential of pearl spot and reduces waste during distribution and retail display.

  9. Emergence of quasiparticle Bloch states in artificial crystals crafted atom-by-atom

    Directory of Open Access Journals (Sweden)

    Jan Girovsky, Jose L. Lado, Floris E. Kalff, Eleonora Fahrenfort, Lucas J. J. M. Peters, Joaquín Fernández-Rossier, Alexander F. Otte

    2017-06-01

    Full Text Available The interaction of electrons with a periodic potential of atoms in crystalline solids gives rise to band structure. The band structure of existing materials can be measured by photoemission spectroscopy and accurately understood in terms of the tight-binding model, however not many experimental approaches exist that allow to tailor artificial crystal lattices using a bottom-up approach. The ability to engineer and study atomically crafted designer materials by scanning tunnelling microscopy and spectroscopy (STM/STS helps to understand the emergence of material properties. Here, we use atom manipulation of individual vacancies in a chlorine monolayer on Cu(100 to construct one- and two-dimensional structures of various densities and sizes. Local STS measurements reveal the emergence of quasiparticle bands, evidenced by standing Bloch waves, with tuneable dispersion. The experimental data are understood in terms of a tight-binding model combined with an additional broadening term that allows an estimation of the coupling to the underlying substrate.

  10. Energies and bounds from perturbative approximations to the Bloch-Horowitz effective Hamiltonian

    International Nuclear Information System (INIS)

    Darema-Rogers, F.; Vincent, C.M.

    1978-01-01

    Bloch-Horowitz perturbation theory is applied to the calculation of approximate energies and model-space eigenvectors, for the solvable large-matrix Hamiltonian H used by Pittel, Vincent, and Vergados. Two types of upper and lower bounds to the energies are discussed: moment-theory bounds, obtained by applying moment theory to the terms of perturbation theory, and norm bounds, derived from the expectation E-bar and variance sigma 2 of H with respect to an eigenvector approximated by nth order perturbation theory (n < or = 6). It is shown that lower bounds cannot be constructed unless some fourth-order quantity is known. The upper bounds are generally stricter than the lower bounds. All of the bounds apply even when back-door intruder states cause perturbation theory to diverge; but they lose their rigor and become ''quasibounds'' when there are physical intruders. The moment-theory and norm lower quasibounds always require estimation of a parameter. For the solvable Hamiltonians, it is shown that this can be done quite reliably, and that the resulting quasibounds are tight enough to have some practical utility. The energy-independent effective interaction V is constructed and its errors are displayed and discussed. Finally, a certain [1/2] pseudo-Pade approximant is empirically shown to give energies with a mean absolute error of less than 0.3 MeV in all cases

  11. Establishment of a cell line from kidney of seabass, Lates calcarifer (Bloch

    Directory of Open Access Journals (Sweden)

    Phromkunthong, W.

    2003-01-01

    Full Text Available Primary cell culture from caudal fin and kidney of seabass (Lates calcarifer Bloch using tissue explant method were cultured in three different medias with various salt concentrations. Only seabass kidney (SK cells grew well in Leibovitze's-15 medium containing 8 g/l of NaCl supplemented with 10 % fetal bovine serum at an optimum temperature of 25 oC. Over a period of 24 months, SK cells were subcultured over than 75 passages and exhibited epithelial-like cells. The chromosome number of SK cells was 42. The cells were found to be free from bacterial, fungal and mycoplasma contamination. Seabass cells can be kept at -80 oC and/or in liquid nitrogen (-196 oC for at least 24 months with a survival rate of 83.20 and 74.50 %, respectively. Nine fish viruses were tested for their infectivity and this SK cells were susceptible to sand goby virus (SGV, chub reovirus (CRV, snake-head rhabdovirus (SHRV, red seabream iridovirus (RSIV, seabass iridovirus (SIV and grouper iridovirus-2 (GIV-2.

  12. Development of immune functionality in larval and juvenile crimson snapper Lutjanus erythropterus (Bloch 1790

    Directory of Open Access Journals (Sweden)

    Ke Cui

    2018-05-01

    Full Text Available Ontogenetic development of the immune system in crimson snapper (Lutjanus erythropterus Bloch 1790 larvae was histologically and enzymatically studied from hatch to 36 days post-hatch (DPH. Primitive hepatopancreas appeared on 2 DPH and renal tubules started hematopoiesis on 4 DPH. The spleen anlage appeared on 6 DPH and the thymus formed on 14 DPH. Total activities of superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPX and sodium-potassium adenosine triphosphatase (Na+ K+-ATPase gradually increased after hatch, and showed a sharp increase after 29 DPH during the transitional feeding period from Artemia to inert feed. The specific activities of SOD, CAT, and GPX showed a trend of sharp increase and reached the maximum level on 4 DPH when exogenous feeding started, except for Na+ K+-ATPase where the peak occurred on10 DPH. The specific activities of these five enzymes reached the peak during the food transition from rotifers to Artemia, but the total activity of enzymes showed an increasing trend as fish grew. The present study provides new knowledge of the development of functional enzymes relevant to fish larvae immunity, sheds light on the understanding of the change of larval health, and improves hatchery management of crimson snapper. Keywords: Immune system, Enzyme activity, Ontogenetic development, Crimson snapper Lutjanus erythropterus

  13. A size selective porous silicon grating-coupled Bloch surface and sub-surface wave biosensor.

    Science.gov (United States)

    Rodriguez, Gilberto A; Ryckman, Judson D; Jiao, Yang; Weiss, Sharon M

    2014-03-15

    A porous silicon (PSi) grating-coupled Bloch surface and sub-surface wave (BSW/BSSW) biosensor is demonstrated to size selectively detect the presence of both large and small molecules. The BSW is used to sense large immobilized analytes at the surface of the structure while the BSSW that is confined inside but near the top of the structure is used to sensitively detect small molecules. Functionality of the BSW and BSSW modes is theoretically described by dispersion relations, field confinements, and simulated refractive index shifts within the structure. The theoretical results are experimentally verified by detecting two different small chemical molecules and one large 40 base DNA oligonucleotide. The PSi-BSW/BSSW structure is benchmarked against current porous silicon technology and is shown to have a 6-fold higher sensitivity in detecting large molecules and a 33% improvement in detecting small molecules. This is the first report of a grating-coupled BSW biosensor and the first report of a BSSW propagating mode. © 2013 Published by Elsevier B.V.

  14. The peripheral olfactory organ in the Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801

    Directory of Open Access Journals (Sweden)

    Laura Ghigliotti

    2015-11-01

    Full Text Available The Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801 is the largest predatory fish in Arctic waters. The socio-economic significance of Greenland shark is demonstrated by its impact on the fishing cultures in Greenland, Scandinavia and Iceland for centuries. The fundamental biology and ecological role of Greenland shark, on the other hand, is virtually unknown. Although knowledge of its life history is limited, increasing evidence indicates that the Greenland shark may undertake long-distance migrations and perform vertical movements from the surface to the deep sea. It is an omnivorous species feeding on carrion and a wide variety of pelagic and bottom-dwelling organisms ranging from invertebrates to mammals, and including active species such as fishes and seals. Accordingly, Greenland shark should be recognized as a top predator, with a strong potential to influence the trophic dynamics of the Arctic marine ecosystem. The sensory biology of Greenland shark is scarcely studied, and considering the importance of olfaction in chemoreception, feeding and other behavioral traits, we examined the architecture of the peripheral olfactory organ where olfactory cues are received from the environment – the olfactory rosette. The structural organization of the olfactory rosette, in terms of histological features of the sensory epithelium, number of primary lamellae and total sensory surface area, provides a first proxy of the olfactory capability of Greenland shark. Based on own results and published studies, the overall morphology of the olfactory rosette is viewed in context of the functional and trophic ecology among other elasmobranch species.

  15. An Update on the Invasion of Weakfish Cynoscion regalis (Bloch & Schneider, 1801 (Actinopterygii: Sciaenidae into Europe

    Directory of Open Access Journals (Sweden)

    Pedro Morais

    2017-10-01

    Full Text Available New information on weakfish introduction vectors, its invasive status, distribution, and use as a fishing resource arose after the publication of “The transatlantic introduction of weakfish Cynoscion regalis (Bloch & Schneider, 1801 (Sciaenidae, Pisces into Europe” by Morais and Teodósio (2016. Currently, the first known report of weakfish in Europe dates back to September 2009, with a specimen captured in the Schelde estuary (Belgium/The Netherlands. This fact suggests that weakfish could have been introduced into Europe via multiple and independent ballast water introduction events, and not through a point-source introduction event with subsequent dispersion as previously hypothesized. It is also unlikely that Schelde weakfish migrated southwards to colonize Iberian aquatic ecosystems. Weakfish have established a population in the Gulf of Cádiz region and have already reached an invasive status in the Sado estuary (Portugal. Weakfish were also captured in several other locations along the Portuguese coast, including the Tagus and Mira estuaries at least since 2013 or 2014, and the Ria Formosa lagoon in 2017. Tagus anglers caught weakfish specimens of ~1 kg and ~40 cm in November 2016, which corresponds to fish of 3+ years of age in the native range. The presence of weakfish in the Tagus estuary is still fairly unknown to local anglers. Sado weakfish has already been sold in local fish markets in southern Portugal for 3 to 10 € kg−1. However, we consider that the weakfish sale price is underrated in comparison with other wild species (e.g., meagre, seabass, gilthead seabream. Increasing sale price will convince fishers to use weakfish as a new fishing resource; however, it is necessary to promote the species among consumers and evaluate consumers’ preference in respect to other species. A putative biological threat might turn into a new valuable fishing resource by implementing adequate management solutions.

  16. Several Growth Characteristics of an Invasive Cyprinid Fish (Carassius gibelio Bloch, 1782

    Directory of Open Access Journals (Sweden)

    Sait BULUT

    2013-05-01

    Full Text Available Age composition, length-weight relationships, growth, and condition factors of the gibel carp (Carassius gibelio Bloch, 1782 were determined using specimens collected from Seyitler Reservoir between July 2005 to June 2006. A total of 149 gibel carp were observed and examined. The age composition of the samples ranged between I and VII years of age. It has been determined than 82.55% of the obtained samples are comprised of females, 16.11% is comprised of males and 1.34% is comprised of immature. The population is dominated by females able to reproduce gynogenetically. The mean fork lengths and mean weights of the population were 14.8-32.5 cm and 43.1-807.3 g respectively. The length-weight relation were calculated as W = 0.0696 L2.132, r=0.838 for females, for males W = 0.2942 L2.6417 r=0.784 and W = 0.0274 L2.9382, r=0.813 for all samples. The mean Fulton Condition Factor was calculated as 2.342 for females, 2.064 for males and 2.276 for all samples. Age-length and age-weight relations were determined according to von Bertalanffy growth equation formula. Growth parameters of the population were Lt = 48.09 [1-e-0.093(t+0.29], and Wt=2323.62 [1-e-0.093(t+0.29]2.9382. The growth performance index value (Ø´ was computed as 5.37 for all specimens.

  17. Asymmetric rogue waves, breather-to-soliton conversion, and nonlinear wave interactions in the Hirota–Maxwell–Bloch system

    International Nuclear Information System (INIS)

    Wang Lei; Zhu Yujie; Wang Ziqi; Xu Tao; Qi Fenghua; Xue Yushan

    2016-01-01

    We study the nonlinear localized waves on constant backgrounds of the Hirota–Maxwell–Bloch (HMB) system arising from the erbium doped fibers. We derive the asymmetric breather, rogue wave (RW) and semirational solutions of the HMB system. We show that the breather and RW solutions can be converted into various soliton solutions. Under different conditions of parameters, we calculate the locus of the eigenvalues on the complex plane which converts the breathers or RWs into solitons. Based on the second-order solutions, we investigate the interactions among different types of nonlinear waves including the breathers, RWs and solitons. (author)

  18. Asymmetric Rogue Waves, Breather-to-Soliton Conversion, and Nonlinear Wave Interactions in the Hirota-Maxwell-Bloch System

    Science.gov (United States)

    Wang, Lei; Zhu, Yu-Jie; Wang, Zi-Qi; Xu, Tao; Qi, Feng-Hua; Xue, Yu-Shan

    2016-02-01

    We study the nonlinear localized waves on constant backgrounds of the Hirota-Maxwell-Bloch (HMB) system arising from the erbium doped fibers. We derive the asymmetric breather, rogue wave (RW) and semirational solutions of the HMB system. We show that the breather and RW solutions can be converted into various soliton solutions. Under different conditions of parameters, we calculate the locus of the eigenvalues on the complex plane which converts the breathers or RWs into solitons. Based on the second-order solutions, we investigate the interactions among different types of nonlinear waves including the breathers, RWs and solitons.

  19. Fast-forward scaling theory for phase imprinting on a BEC: creation of a wave packet with uniform momentum density and loading to Bloch states without disturbance

    Science.gov (United States)

    Masuda, Shumpei; Nakamura, Katsuhiro; Nakahara, Mikio

    2018-02-01

    We study phase imprinting on Bose-Einstein condensates (BECs) with the fast-forward scaling theory revealing a nontrivial scaling property in quantum dynamics. We introduce a wave packet with uniform momentum density (WPUM) which has peculiar properties but is short-lived. The fast-forward scaling theory is applied to derive the driving potential for creation of the WPUMs in a predetermined time. Fast manipulation is essential for the creation of WPUMs because of the instability of the state. We also study loading of a BEC into a predetermined Bloch state in the lowest band from the ground state of a periodic potential. Controlled linear potential is not sufficient for creation of the Bloch state with large wavenumber because the change in the amplitude of the order parameter is not negligible. We derive the exact driving potential for creation of predetermined Bloch states using the obtained theory.

  20. KONSERVASI GENETIK IKAN BETOK (Anabas testudineus Bloch 1792 DI PERAIRAN RAWA, KALIMANTAN SELATAN

    Directory of Open Access Journals (Sweden)

    Slamat Slamat

    2016-05-01

    Full Text Available Penelitian ini dilakukan dengan menggunakan sample ikan betok (Anabas testudineus Bloch 1972 yang berasal dari perairan rawa Kalimantan Selatan, dengan tujuan untuk mendeskripsikan keragaman  genetik dan aspek konservasinya dengan metode amplifikasi mtDNA. Proses amplifikasi mtDNA ikan betok terjadi di daerah D Loop.  Hasil analisis mt-DNA D Loop ikan betok menunjukkan bahwa, analisis keseimbangan populasi Hardy-Weinberg  berkisar antara 0,02 - 0,09, sedangkan haplotipe tertinggi terdapat pada rawa monoton (0,9384, kemudian tadah hujan (0,7111 dan pasang surut (0,6.  Heterozigositas ditemukan unik pada populasi rawa monoton (BAAAA dan rawa pasang surut (BAACA dan umum di temukan di ketiga ekosistem rawa (AAABA.  Ikan betok di bagi menjadi dua stok populasi yaitu populasi rawa monoton dan pasang surut serta stok tadah hujan.  Konsep utama dalam konservasi genetik adalah fitness population dimana populasi dipertahankan minimal 500 ekor/kawasan. Untuk meningkatkan keragaman genetik ikan betok, dilakukan dengan cara introduksi individu-individu baru yang memiliki keragaman genetik yang lebih tinggi kedalam populasi lokal, restocking dan membuat kawasan suaka yang dilindungi oleh Dinas Perikanan setempat bersama-sama dengan masyarakat di sekitar perairan rawa tersebut.   The research was conducted using climbing perch samples originated from the swampy waters of the southern Borneo, and the objektive of this study to investigate the genetic diversity and the conservation aspect using mtDNA amplification method.  mtDNA amplification process occurs in the D Loop region.  The results of the analysis of D-Loop mtDNA of climbing perch showed that, the analysis of Hardy-Weinberg equilibrium population ranged from 0.02 to 0.09, while the highest haplotypes found in swamp bogs (monotonic (0.9384 then rainfed (0.7111 and tides (0.6. Heterozygosity was found uniquely in the swamp monotonic population (BAAAA and marsh tides (BAACA and common in all

  1. Web-based description of the space radiation environment using the Bethe-Bloch model

    Science.gov (United States)

    Cazzola, Emanuele; Calders, Stijn; Lapenta, Giovanni

    2016-01-01

    Space weather is a rapidly growing area of research not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary, bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We give a new approach to presenting the topic by developing a web-based application that combines some of the fundamental concepts from these two fields into a single tool that can be used in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to rapidly assess the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions (ACE, GOES-13, GOES-15) to produce a first order approximation of the radiation dose an astronaut would receive during a mission of exploration in deep space (i.e. far from the Earth’s shielding magnetic field and from the radiation belts). DREADCode is based on an easy-to-use GUI interface available online from the European Space Weather Portal (www.spaceweather.eu/dreadcode). The core of the radiation transport computation to produce the radiation dose from the observed fluence of radiation observed by the spacecraft fleet considered is based on a relatively simple approximation: the Bethe-Bloch equation. DREADCode also assumes a simplified geometry and material configuration for the shields used to compute the dose. The approach is approximate and sacrifices some important physics on the altar of rapid execution time, which allows a real-time operation scenario. There is no intention here to produce an operational tool for use in space science and engineering. Rather, we present an educational tool at undergraduate level that uses modern web-based and programming methods to learn some of the most important

  2. ESTIMASI KELIMPAHAN IKAN GABUS (Channa striata Bloch, 1793 DENGAN METODE HIDROAKUSTIK DI SUNGAI LEMPUING, SUMATERA SELATAN

    Directory of Open Access Journals (Sweden)

    Zulkarnaen Fahmi

    2016-03-01

    Full Text Available Kegiatan pengkajian stok sumberdaya ikan yang dilakukan secara berkala bertujuan untuk optimasi pemanfaatan sumberdaya perikanan bagi kegiatan perikanan tangkap. Kegiatan pengkajian stok ikandengan survey akustik di perairan Lubuk Lampam telah dilakukan pada tahun 2011 sebanyak 2 (dua kali dengan interval waktu 3 (tiga bulan untuk melihat perubahan kelimpahan ikan gabus (Channa striatadi perairan tersebut. Ekstraksi data akustik meliputi data sebaran kelimpahan dan distribusi ukuran ikan dilakukan untuk melihat keragaman (variance nilai yang diperoleh. Hasil penelitian menunjukkan bahwa estimasi rata-rata kelimpahan ikan pada bulan Maret sebesar 7.53 ± 1.33 ekor/m2  lebih rendah dibandingkan pada bulan Mei sebesar 53.11 ± 9.43  ekor/m2  . Biomass ikan pada bulan Maret sebesar 75.59 ± 30.22 kg/ha lebih rendah dibandingkan pada bulan Mei sebesar 521 ± 65.01 kg/ha. Nilai rataan target strength ikan tunggal yang terdeteksi pada bulan Maret sebesar -54.81 ± 0.9 dB lebih rendah dibandingkan pada bulan Mei sebesar -50.03 ± 0.35 dB. Estimasi kelimpahan dan distribusi ikan di sungai Lempuing menunjukkan nilai keragaman (variance yang lebih rendah pada bulan Maret dibandingkan dengan bulan Mei 2011 untuk parameter kelimpahan dan biomass ikan, sedangkan untuk nilai rataan target strength ikan menunjukkan sebaliknya. Fish assessment using hydroacoustic in inland water was conducted to optimize fish exploitation activity. Successive hydroacoustic survey was conducted twice with interval three months in 2011 to estimated distribution fish abundance and size distribution of snakehead fish (Channa striata Bloch, 1793 in Lempuing River, South Sumatera. Reability test was conducted on hydroacoustic data including data distribution and abundance of fish size distribution to obtain edvariance value. The results showed that the average estimate abundance of fish on March about 7.53 ± 1.33 fish/m2 lower than in the month of May at 53.11 ± 9.43 fish/m2

  3. Web-based description of the space radiation environment using the Bethe–Bloch model

    International Nuclear Information System (INIS)

    Cazzola, Emanuele; Lapenta, Giovanni; Calders, Stijn

    2016-01-01

    Space weather is a rapidly growing area of research not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary, bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We give a new approach to presenting the topic by developing a web-based application that combines some of the fundamental concepts from these two fields into a single tool that can be used in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to rapidly assess the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions (ACE, GOES-13, GOES-15) to produce a first order approximation of the radiation dose an astronaut would receive during a mission of exploration in deep space (i.e. far from the Earth’s shielding magnetic field and from the radiation belts). DREADCode is based on an easy-to-use GUI interface available online from the European Space Weather Portal (www.spaceweather.eu/dreadcode). The core of the radiation transport computation to produce the radiation dose from the observed fluence of radiation observed by the spacecraft fleet considered is based on a relatively simple approximation: the Bethe–Bloch equation. DREADCode also assumes a simplified geometry and material configuration for the shields used to compute the dose. The approach is approximate and sacrifices some important physics on the altar of rapid execution time, which allows a real-time operation scenario. There is no intention here to produce an operational tool for use in space science and engineering. Rather, we present an educational tool at undergraduate level that uses modern web-based and programming methods to learn some of the most

  4. Full-angle Negative Reflection with An Ultrathin Acoustic Gradient Metasurface: Floquet-Bloch Modes Perspective and Experimental Verification

    KAUST Repository

    Liu, Bingyi

    2017-07-01

    Metasurface with gradient phase response offers new alternative for steering the propagation of waves. Conventional Snell\\'s law has been revised by taking the contribution of local phase gradient into account. However, the requirement of momentum matching along the metasurface sets its nontrivial beam manipulation functionality within a limited-angle incidence. In this work, we theoretically and experimentally demonstrate that the acoustic gradient metasurface supports the negative reflection for full-angle incidence. The mode expansion theory is developed to help understand how the gradient metasurface tailors the incident beams, and the full-angle negative reflection occurs when the first negative order Floquet-Bloch mode dominates. The coiling-up space structures are utilized to build desired acoustic gradient metasurface and the full-angle negative reflections have been perfectly verified by experimental measurements. Our work offers the Floquet-Bloch modes perspective for qualitatively understanding the reflection behaviors of the acoustic gradient metasurface and enables a new degree of the acoustic wave manipulating.

  5. Influence of rotating in-plane field on vertical Bloch lines in the walls of second kind of dumbbell domains

    International Nuclear Information System (INIS)

    Sun, H.Y.; Hu, H.N.; Sun, Y.P.; Nie, X.F.

    2004-01-01

    Influence of rotating in-plane field on vertical Bloch lines in the walls of second kind of dumbbell domains (IIDs) was investigated, and a critical in-plane field range [H ip 1 ,H ip 2 ] of which vertical-Bloch lines (VBLs) annihilated in IIDs is found under rotating in-plane field (H ip 1 is the maximal critical in-plane-field of which hard domains remain stable, H ip 2 is the minimal critical in-plane-field of which all of the hard domains convert to soft bubbles (SBs, without VBLs)). It shows that the in-plane field range [H ip 1 , H ip 2 ] changes with the change of the rotating angle Δφ H ip 1 maintains stable, while H ip 2 decreases with the decreasing of rotating angle Δφ. Comparing it with the spontaneous shrinking experiment of IIDs under both bias field and in-plane field, we presume that under the application of in-plane field there exists a direction along which the VBLs in the domain walls annihilate most easily, and it is in the direction that domain walls are perpendicular to the in-plane field

  6. Plasmonic Photonic-Crystal Slabs: Visualization of the Bloch Surface Wave Resonance for an Ultrasensitive, Robust and Reusable Optical Biosensor

    Directory of Open Access Journals (Sweden)

    Alexander V. Baryshev

    2014-12-01

    Full Text Available A one-dimensional photonic crystal (PhC with termination by a metal film—a plasmonic photonic-crystal slab—has been theoretically analyzed for its optical response at a variation of the dielectric permittivity of an analyte and at a condition simulating the molecular binding event. Visualization of the Bloch surface wave resonance (SWR was done with the aid of plasmon absorption in a dielectric/metal/dielectric sandwich terminating a PhC. An SWR peak in spectra of such a plasmonic photonic crystal (PPhC slab comprising a noble or base metal layer was shown to be sensitive to a negligible variation of refractive index of a medium adjoining to the slab. As a consequence, the considered PPhC-based optical sensors exhibited an enhanced sensitivity and a good robustness in comparison with the conventional surface-plasmon and Bloch surface wave sensors. The PPhC biosensors can be of practical importance because the metal layer is protected by a capping dielectric layer from contact with analytes and, consequently, from deterioration.

  7. The annihilation of vertical-Bloch lines in the walls of hard domains to which bias fields and in-plane fields are alternately applied

    International Nuclear Information System (INIS)

    Sun, H.Y.; Hu, H.N.; Nie, X.F.

    2001-01-01

    The annihilation of vertical-Bloch lines in magnetic domain walls of the ordinary hard bubbles, to which both bias fields and in-plane fields are alternately applied, is investigated experimentally. The influence of an in-plane magnetic field on ordinary hard bubbles (OHB), dumbbell domains of the first kind (ID), and dumbbell domains of the second kind (IID) was analyzed, and a critical in-plane field range [H ip 0 ,H ip 2 ] for vertical Bloch line (VBL) annihilation was found. For the three types of hard domains (H ip 0 is the minimum critical in-plane field of VBLs which begin to be unstable, H ip 2 is the minimum critical in-plane field which only needs to be applied one time for collapse of all OHBs), the critical field range is the same with H ip 0 ≅8πM s . We hypothesize that there exists a direction along which the vertical-Bloch lines in the domain walls are annihilated most easily. It is also observed that the stability of vertical-Bloch lines in the domain walls does not depend on the initial state. This provides a more detailed description of the minimum critical in-plane field than previously known

  8. Computational Diffusion Magnetic Resonance Imaging Based on Time-Dependent Bloch NMR Flow Equation and Bessel Functions.

    Science.gov (United States)

    Awojoyogbe, Bamidele O; Dada, Michael O; Onwu, Samuel O; Ige, Taofeeq A; Akinwande, Ninuola I

    2016-04-01

    Magnetic resonance imaging (MRI) uses a powerful magnetic field along with radio waves and a computer to produce highly detailed "slice-by-slice" pictures of virtually all internal structures of matter. The results enable physicians to examine parts of the body in minute detail and identify diseases in ways that are not possible with other techniques. For example, MRI is one of the few imaging tools that can see through bones, making it an excellent tool for examining the brain and other soft tissues. Pulsed-field gradient experiments provide a straightforward means of obtaining information on the translational motion of nuclear spins. However, the interpretation of the data is complicated by the effects of restricting geometries as in the case of most cancerous tissues and the mathematical concept required to account for this becomes very difficult. Most diffusion magnetic resonance techniques are based on the Stejskal-Tanner formulation usually derived from the Bloch-Torrey partial differential equation by including additional terms to accommodate the diffusion effect. Despite the early success of this technique, it has been shown that it has important limitations, the most of which occurs when there is orientation heterogeneity of the fibers in the voxel of interest (VOI). Overcoming this difficulty requires the specification of diffusion coefficients as function of spatial coordinate(s) and such a phenomenon is an indication of non-uniform compartmental conditions which can be analyzed accurately by solving the time-dependent Bloch NMR flow equation analytically. In this study, a mathematical formulation of magnetic resonance flow sequence in restricted geometry is developed based on a general second order partial differential equation derived directly from the fundamental Bloch NMR flow equations. The NMR signal is obtained completely in terms of NMR experimental parameters. The process is described based on Bessel functions and properties that can make it

  9. Resonant absorption in semiconductor nanowires and nanowire arrays: Relating leaky waveguide modes to Bloch photonic crystal modes

    Energy Technology Data Exchange (ETDEWEB)

    Fountaine, Katherine T., E-mail: kfountai@caltech.edu [Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Whitney, William S. [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Department of Physics, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Atwater, Harry A. [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Department of Applied Physics and Materials Science, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States)

    2014-10-21

    We present a unified framework for resonant absorption in periodic arrays of high index semiconductor nanowires that combines a leaky waveguide theory perspective and that of photonic crystals supporting Bloch modes, as array density transitions from sparse to dense. Full dispersion relations are calculated for each mode at varying illumination angles using the eigenvalue equation for leaky waveguide modes of an infinite dielectric cylinder. The dispersion relations along with symmetry arguments explain the selectivity of mode excitation and spectral red-shifting of absorption for illumination parallel to the nanowire axis in comparison to perpendicular illumination. Analysis of photonic crystal band dispersion for varying array density illustrates that the modes responsible for resonant nanowire absorption emerge from the leaky waveguide modes.

  10. Narrow Bloch walls and intrinsic characteristics of the pseudoternary Nd14Fe78-xMnxC8 systems

    International Nuclear Information System (INIS)

    Xing, F.; Ho, W.W.

    1990-01-01

    The lattice constants of Nd 14 Fe 78-x Mn x C 8 compounds decrease with the increase of Mn context x and have a minimum at about x=14. The Curie temperature T c decreases linearly and falls off below room temperature beyond x=14. The strong reduction of the saturation magnetization and T c are attributed to the antiparallel alignment of the Mn and Fe atoms moments. The behavior of magnetization and magnetization reversal in the high-Mn-containing samples at low temperature can be interpreted by the narrow domain wall effect. The relationship of the intrinsic coercive force i H c on temperature agrees well with the exponential formula of the narrow Bloch wall

  11. High-Q contacted ring microcavities with scatterer-avoiding “wiggler” Bloch wave supermode fields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yangyang, E-mail: yangyang.liu@colorado.edu; Popović, Miloš A., E-mail: milos.popovic@colorado.edu [Nanophotonic Systems Laboratory, Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309 (United States)

    2014-05-19

    High-Q ring resonators with contacts to the waveguide core provide a versatile platform for various applications in chip-scale optomechanics, thermo-, and electro-optics. We propose and demonstrate azimuthally periodic contacted ring resonators based on multi-mode Bloch matching that support contacts on both the inner and outer radius edges with small degradation to the optical quality factor (Q). Radiative coupling between degenerate modes of adjacent radial spatial order leads to imaginary frequency (Q) splitting and a scatterer avoiding high-Q “wiggler” supermode field. We experimentally measure Qs up to 258 000 in devices fabricated in a silicon device layer on buried oxide undercladding and up to 139 000 in devices fully suspended in air using an undercut step. Wiggler supermodes are true modes of the microphotonic system that offer additional degrees of freedom in electrical, thermal, and mechanical design.

  12. Caracterização da piscicultura na região do Vale do Ribeira - SP Characterization of fish farming in the Ribeira Valley region - SP

    Directory of Open Access Journals (Sweden)

    Daniela Castellani

    2005-02-01

    Full Text Available Este trabalho buscou caracterizar a piscicultura na Região do Vale do Ribeira quanto aos sistemas de manejo. Estudaram-se quarenta e duas pisciculturas sendo que, destas, 36 praticam o sistema semi-intensivo e seis o sistema intensivo, com os seguintes objetivos: engorda de peixes, produção de alevinos e pesque-pagues. Foram listadas 41 espécies de peixes cultivadas. Apenas 6 espécies são nativas da Bacia do Rio Ribeira de Iguape: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier e Valenciennes, 1928, jundiá (Rhamdia quelen Quoy e Gaimard, 1824, cascudo (Hypostomus sp Marschall, 1873 e cará (Geophagus brasiliensis Quoy e Gaimard, 1824. Em 95% das pisciculturas foram verificadas fugas de peixes exóticos e alóctones dos cultivos. A tilápia nilótica (Oreochromis niloticus Linneaus, 1758 foi a espécie mais freqüente em escapes, e também é a segunda mais cultivada pelos piscicultores, perdendo somente para o pacu (Piaractus mesopotamicus Halmberg, 1887. Foi possível verificar mediante o cálculo da conversão alimentar, que há um desperdício anual de cerca de 32% da ração utilizada nos cultivos pesquisados. A piscicultura encontra-se em plena expansão nesta região, e já representa a atividade agropecuária mais importante após a bananicultura.The aim of this work was to characterize the fish farming in the Ribeira de Iguape Basin, southern São Paulo State (Brazil, in relation to the management systems. Forty two farms were studied. A semi-intensive system is used by 36 farmers, while an intensive system is used only by 6 studied farmers. Their objectives were raising fish, juvenile fish production and sportive fishery. Forty one fish species were found to be cultivated, but only six were native species from Ribeira Valley: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier and Valenciennes, 1928, jundi

  13. The impact of a biomanipulation experiment on the ichthyofauna diet from a neotropical reservoir in Brazilian semiarid

    Directory of Open Access Journals (Sweden)

    Cristiane de Carvalho Ferreira Lima Moura

    2018-04-01

    Full Text Available Abstract Aim To evaluate the impact of a biomanipulation experiment on the feeding of fish species from a neotropical semiarid reservoir, before and after the removal of the exotic species Oreochromis niloticus. Methods The values of Food Index were analyzed for six species: Oreochromis niloticus , Prochilodus brevis Steindachner,1875, Hypostomus cf. paparie Fowler,1941, Hoplias gr. malabaricus Bloch,1794, Astyanax bimaculatus Linnaeus,1758 and Leporinus piau Fowler,194. All data were obtained in two periods, before of the removal O. niloticus (May 2012 to January 2013 and after its removal (April 2013 to November 2013. The Morisita-Horn index was used to evaluate the feeding similarity among the six species and determine trophic categories (insectivorous, omnivorous, iliophaga and piscivora. To establish the probable variations due the presence of O. niloticus species, the Food Index of the six species was used in a Bray-Curtis similarity matrix. Through the Non-metric Multidimensional Scaling (NMDS we could not observe any differences among items consumed by different species. The Canonical Correspondence Analysis (CCA was used to assay the influence of environmental variables on the dietary, from the Food Index data. Results All species were classified in four trophic categories that do not shown any variation among the formed groups during studied periods. After the removal of Nile tilapia some species showed changes in food items, according to NMDS. The CCA indicated low association among the monthly Food Index of species and the environmental changes. Conclusion The process of biomanipulation on the Ecological Station from Serra Negra reservoir, which compares the dietaries from five local species before and after removal of exotic species Oreochromis niloticus, resulted in modification of dietary composition from three of five studied species.

  14. High-order-harmonic generation from solids: The contributions of the Bloch wave packets moving at the group and phase velocities

    Science.gov (United States)

    Du, Tao-Yuan; Huang, Xiao-Huan; Bian, Xue-Bin

    2018-01-01

    We study numerically the Bloch electron wave-packet dynamics in periodic potentials to simulate laser-solid interactions. We introduce an alternative perspective in the coordinate space combined with the motion of the Bloch electron wave packets moving at group and phase velocities under the laser fields. This model interprets the origins of the two contributions (intra- and interband transitions) in the high-order harmonic generation (HHG) processes by investigating the local and global behaviours of the wave packets. It also elucidates the underlying physical picture of the HHG intensity enhancement by means of carrier-envelope phase, chirp, and inhomogeneous fields. It provides a deep insight into the emission of high-order harmonics from solids. This model is instructive for experimental measurements and provides an alternative avenue to distinguish mechanisms of the HHG from solids in different laser fields.

  15. Magnetic susceptibility of Dirac fermions, Bi-Sb alloys, interacting Bloch fermions, dilute nonmagnetic alloys, and Kondo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Buot, Felix A., E-mail: fbuot@gmu.edu [Computational Materials Science Center, George Mason University, Fairfax, VA 22030 (United States); TCSE Center, Spintronics Group, Physics Department, University of San Carlos, Talamban, Cebu 6000 (Philippines); C& LB Research Institute, Carmen, Cebu 6005 (Philippines); Otadoy, Roland E.S.; Rivero, Karla B. [TCSE Center, Spintronics Group, Physics Department, University of San Carlos, Talamban, Cebu 6000 (Philippines)

    2017-03-01

    Wide ranging interest in Dirac Hamiltonian is due to the emergence of novel materials, namely, graphene, topological insulators and superconductors, the newly-discovered Weyl semimetals, and still actively-sought after Majorana fermions in real materials. We give a brief review of the relativistic Dirac quantum mechanics and its impact in the developments of modern physics. The quantum band dynamics of Dirac Hamiltonian is crucial in resolving the giant diamagnetism of bismuth and Bi-Sb alloys. Quantitative agreement of the theory with the experiments on Bi-Sb alloys has been achieved, and physically meaningful contributions to the diamagnetism has been identified. We also treat relativistic Dirac fermion as an interband dynamics in uniform magnetic fields. For the interacting Bloch electrons, the role of translation symmetry for calculating the magnetic susceptibility avoids any approximation to second order in the field. The expressions for magnetic susceptibility of dilute nonmagnetic alloys give a firm theoretical foundation of the empirical formulas used in fitting experimental results. The unified treatment of all the above calculations is based on the lattice Weyl-Wigner formulation of discrete phase-space quantum mechanics. For completeness, the magnetic susceptibility of Kondo alloys is also given since Dirac fermions in conduction band and magnetic impurities exhibit Kondo effect.

  16. Time-dependent Bloch-Maxwell modelling of 1 mJ, 200 fs seeded soft x-ray laser

    International Nuclear Information System (INIS)

    Zeitoun, Ph.; Oliva, E.; Fajardo, M.; Velarde, P.; Ros, D.; Sebban, S.

    2010-01-01

    Complete text of publication follows. Seeding of high harmonic generation in a soft x-ray plasma amplifier has been first proposed and tested by T. Ditmire and collaborators. The experiment demonstrated low amplification (*2), with a very strong background coming from the soft x-ray laser ASE. Later seeding experiments reached very high amplification factors (up to 600) in both gas (Ph. Zeitoun et al.) and solid amplifiers (Wang et at.). Surprisingly, solid amplifiers extracted less energy (90 nJ) than gas amplifier (∼ 1 μJ) with equivalent pump energy. We recently demonstrated that 50-100 μJ is achievable with adequate plasma tailoring. However, this energy is still low as compared to the 10 mJ per pulse demonstrated on the ASE soft x-ray laser running at PALS facility (Czech Republic). In order to model the seeding process of PALS soft x-ray laser, we developed a time-dependent Bloch-Maxwell model that solves coherently the pumping, amplification and saturation processes. We demonstrated that direct seeding, with femtosecond pulse, a soft x-ray plasma amplifier having gain duration of several 100s of picosecond cannot extract the stored energy keeping the output beam energy in the 100 μJ range. We proposed and fully modelled a new seeding scheme that allows to achieve 10 mJ, 200 fs soft x-ray laser.

  17. Bloch Surface Waves Biosensors for High Sensitivity Detection of Soluble ERBB2 in a Complex Biological Environment.

    Science.gov (United States)

    Sinibaldi, Alberto; Sampaoli, Camilla; Danz, Norbert; Munzert, Peter; Sonntag, Frank; Centola, Fabio; Occhicone, Agostino; Tremante, Elisa; Giacomini, Patrizio; Michelotti, Francesco

    2017-08-17

    We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of the cancer biomarker ERBB2 in cell lysates. Overexpression of the ERBB2 protein is associated with aggressive breast cancer subtypes. To detect soluble ERBB2, we developed an optical set-up which operates in both label-free and fluorescence modes. The detection approach makes use of a sandwich assay, in which the one-dimensional photonic crystals sustaining Bloch surface waves are modified with monoclonal antibodies, in order to guarantee high specificity during the biological recognition. We present the results of exemplary protein G based label-free assays in complex biological matrices, reaching an estimated limit of detection of 0.5 ng/mL. On-chip and chip-to-chip variability of the results is addressed too, providing repeatability rates. Moreover, results on fluorescence operation demonstrate the capability to perform high sensitive cancer biomarker assays reaching a resolution of 0.6 ng/mL, without protein G assistance. The resolution obtained in both modes meets international guidelines and recommendations (15 ng/mL) for ERBB2 quantification assays, providing an alternative tool to phenotype and diagnose molecular cancer subtypes.

  18. Fish condensate as effective replacer of fish meal protein in diet for striped snakehead, Channa striata (Bloch).

    Science.gov (United States)

    Wattanakul, Wattana; Wattanakul, Uraiwan; Thongprajukaew, Karun; Muenpo, Chutchawan

    2017-02-01

    The optimal protein replacement of fish meal (FM) by fish condensate (FC) was investigated in striped snakehead, Channa striata (Bloch) (1.78 ± 0.02 g initial weight). The FM-based diet (0FC) was replaced by substituting protein from FC for 100 (100FC), 200 (200FC), 300 (300FC), 400 (400FC), 500 (500FC) or 600 (600FC) g kg -1 of the FM, and a commercial diet (CD) for carnivorous fish was included for comparison. The experiment was conducted indoors under completely randomized design (8 treatments × 3 replications × 60 fish per pond) over a 6-month trial. There were no significant differences in water quality during the experiment. The fish fed with 500FC had superior growth performance and feed utilization. This dietary treatment gave similar levels to all observed specific activities of digestive enzymes as did baseline 0FC. Survival, carcass composition, hematological parameters and liver histopathology were not negatively impacted by this protein replacement level. Economic analysis also supports the use of this by-product as a potent protein replacer in striped snakehead diet. Findings from the current study indicate that a 500 g kg -1 protein replacement of FM by FC is near optimal for striped snakehead, and similar use of it in the aquafeed of other species appears worth further studies.

  19. Morphological, histological and molecular characterization of Myxobolus kingchowensis and Thelohanellus cf. sinensis infecting gibel carp Carassius auratus gibelio (Bloch, 1782).

    Science.gov (United States)

    Zhang, Bo; Zhai, Yanhua; Gu, Zemao; Liu, Yang

    2018-06-26

    A Myxobolus species and a Thelohanellus species infecting Carassius auratus gibelio (Bloch, 1782) were redescribed by their morphological, histological and molecular characterization. In the present study, the Myxobolus species infecting the muscle was identified as Myxobolus kingchowensis Chen et Ma, 1998 by the morphological and molecular data. Histologically, mature spores of M. kingchowensis were observed in the intercellular and connective tissue of muscle, though the plasmodia were not found. In addition, scattered spores also occurred in the intercellular of haematopoietic cells, intraepithelial of the renal tubules and interior of the melano-macrophage centres. Phylogenetic analysis showed that M. kingchowensis clustered in the clade of muscle-infecting Myxobolus species, further supporting muscle as the infection site of M. kingchowensis. The present Thelohanellus species infecting the gills was identified conspecific as Thelohanellus sinensis reported in Sun (2006) (mark it as T. sinensis-Sun)based on spore morphology, biological traits (host specificity and organ specificity), and molecular data. However, compared with the original description of T. sinensis Chen et Hsieh, 1960, the present Thelohanellus species and T. sinensis-Sun both infecting the gills of gibel carp are distinguishable from the original description in the host and infection site, which made the validity of T. sinensis-Sun dubious. Due to the absence of molecular data in the original description of T. sinensis, we suggest marking the present species and T. sinensis-Sun as T. cf. sinensis to avoid the confusion until T. sinensis is obtained from the type host and type infection site.

  20. Azimuthal spin-wave excitations in magnetic nanodots over the soliton background: Vortex, Bloch, and Néel-like skyrmions

    Science.gov (United States)

    Mruczkiewicz, M.; Gruszecki, P.; Krawczyk, M.; Guslienko, K. Y.

    2018-02-01

    We study azimuthal spin-wave (SW) excitations in a circular ferromagnetic nanodot in different inhomogeneous, topologically nontrivial magnetization states, specifically, vortex, Bloch-type skyrmion, and Néel-type skyrmion states. A continuous transition between these states is realized by gradually changing the out-of-plane magnetic anisotropy and the Dzyaloshinskii-Moriya exchange interaction (DMI), and the corresponding SW spectra are calculated for each state. We observe the lifting of degeneracy of SW mode frequencies and a change in the systematics of frequency levels. The latter effect is induced by the geometric Berry phase, which occurs in SWs localized at the edge of the dot in the vortex state, and vanishes in the skyrmion states. Furthermore, channeling of edge-localized azimuthal SWs and a related large frequency splitting are observed in the skyrmion states. This is attributed to DMI-induced nonreciprocity, while the coupling of the breathing and gyrotropic modes is related to the skyrmion motion. Finally, we demonstrate efficient coupling of the dynamic magnetization to a uniform magnetic field in nanodots of noncircular symmetry in the skyrmion states.

  1. Optimal cloning of arbitrary mirror-symmetric distributions on the Bloch sphere: a proposal for practical photonic realization

    International Nuclear Information System (INIS)

    Bartkiewicz, Karol; Miranowicz, Adam

    2012-01-01

    We study state-dependent quantum cloning that can outperform universal cloning (UC). This is possible by using some a priori information on a given quantum state to be cloned. Specifically, we propose a generalization and optical implementation of quantum optimal mirror phase-covariant cloning, which refers to optimal cloning of sets of qubits of known modulus of the expectation value of Pauli's Z operator. Our results can be applied to cloning of an arbitrary mirror-symmetric distribution of qubits on the Bloch sphere including in special cases UC and phase-covariant cloning. We show that the cloning is optimal by adapting our former optimality proof for axisymmetric cloning (Bartkiewicz and Miranowicz 2010 Phys. Rev. A 82 042330). Moreover, we propose an optical realization of the optimal mirror phase-covariant 1→2 cloning of a qubit, for which the mean probability of successful cloning varies from 1/6 to 1/3 depending on prior information on the set of qubits to be cloned. The qubits are represented by polarization states of photons generated by the type-I spontaneous parametric down-conversion. The scheme is based on the interference of two photons on an unbalanced polarization-dependent beam splitter with different splitting ratios for vertical and horizontal polarization components and the additional application of feedforward by means of Pockels cells. The experimental feasibility of the proposed setup is carefully studied including various kinds of imperfections and losses. Moreover, we briefly describe two possible cryptographic applications of the optimal mirror phase-covariant cloning corresponding to state discrimination (or estimation) and secure quantum teleportation.

  2. The transmission factor of a bloch wall for spin waves whose wave vector is perpendicular to the wall (1961); Facteur de transmission d'une paroi de bloch pour des ondes de spin de vecteur d'onde normal a la paroi (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Boutron, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    When, for a ferromagnetic, the anisotropic energy takes the form E= K sin{sup 2} {alpha}, the study of the propagation of spin waves of low energy across a Bloch wall leads to a one-dimensional Schrodinger equation in which is found a potential well which has the remarkable property of being completely transparent for all values of the incident wave energy. (author) [French] Dans un ferromagnetique, lorsque la densite d'energie d'anisotropie est de la forme E= K sin{sup 2} {alpha}, l'etude de la propagation des ondes de spin de faible energie a travers une paroi de Bloch, conduit a une equation de Schrodinger a une dimension, dans laquelle figure un puits de potentiel qui a la propriete remarquable d'etre completement transparent quelle que soit l'energie de l'onde incidente. (auteur)

  3. Dark and bright solitons for the two-dimensional complex modified Korteweg-de Vries and Maxwell-Bloch system with time-dependent coefficient

    Science.gov (United States)

    Shaikhova, G.; Ozat, N.; Yesmakhanova, K.; Bekova, G.

    2018-02-01

    In this work, we present Lax pair for two-dimensional complex modified Korteweg-de Vries and Maxwell-Bloch (cmKdV-MB) system with the time-dependent coefficient. Dark and bright soliton solutions for the cmKdV-MB system with variable coefficient are received by Darboux transformation. Moreover, the determinant representation of the one-fold and two-fold Darboux transformation for the cmKdV-MB system with time-dependent coefficient is presented.

  4. The Bloch self-consistently renormalized spin wave approximation and behaviour of some thermodynamic quantities of a Heisenberg ferromagnet in the critical region

    International Nuclear Information System (INIS)

    Jezewski, W.

    1979-01-01

    Properties of the Bloch self-consistently renormalized spin wave approximation are analyzed near the zero-field transition temperature Tsub(m). The analysis is carried out on the basis of the application of this approximation to the Heisenberg ferromagnet involving nearest neighbour interaction. Series expansions for the resulting Helmholtz free energy, magnetization, and specific heat in the reduced temperature t=(Tsub(m)-T)/Tsub(m) are derived and the critical exponents β and α' are obtained. The limiting case of infinite spin (the classical limit) is also investigated. (author)

  5. Projectile-z3 and -z4 corrections to basic Bethe-Bloch stopping power theory and mean excitation energies of Al, Si, Ni, Ge, Se, Y, Ag and Au

    International Nuclear Information System (INIS)

    Porter, L.E.; Bryan, S.R.

    1980-01-01

    Three independent sets of measurements of the stopping power of solid elemental targets for alpha particles were previously analyzed in terms of basic Bethe-Bloch theory with the low velocity projectile-z 3 correction term included. These data for Al, Si, Ni, Ge, Se, Y, Ag and Au have now been analyzed with the Bloch projectile-z 4 term and a revised projectile-z 3 term incorporated in the Bethe-Bloch formula, the projectile-z 3 revision having been effected by variation of the single free parameter of the projectile-z 3 effect formalism. The value of this parameter, fixed at 1.8 in previous studies, which counteracts inclusion of the projectile-z 4 term is 1.3 +- 0.1 for all target elements except Si. (orig.)

  6. Influence of in-plane field on vertical Bloch line in the walls of the second kind of dumbbell domains at various temperatures

    International Nuclear Information System (INIS)

    Xu, J.P.; Liu, S.P.; Guo, G.X.; Zhen, C.M.; Tang, G.D.; Sun, H.Y.; Nie, X.F.

    2004-01-01

    The stability of vertical Bloch lines (VBLs) in the second kind of dumbbell domain (IIDs) walls in liquid phase epitaxy garnet bubble films subjected to an in-plane field at various temperatures is studied experimentally. It is found that there exists a critical in-plane field range depending on temperature, in which vertical Bloch lines (VBLs) in the second kind of IIDs walls are unstable, i.e., [Hip(1)(T),Hip(2)(T)]. Here, Hip(1)(T) is the initial critical in-plane field at which VBLs in the walls of IIDs annihilate; while Hip(2)(T) is the lowest in-plane field at which all VBLs in the walls of IIDs have annihilated completely. Also, the critical in-plane field range [Hip(1)(T),Hip(2)(T)],Hip(1)(T) and Hip(2)(T) all decrease with the temperature increasing. Hip(1)(T) and Hip(2)(T) reach zero at T0' and T0, respectively

  7. Hybrid Bloch brane

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Lima, Elisama E.M.; Losano, L. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil)

    2017-02-15

    This work reports on models described by two real scalar fields coupled with gravity in the five-dimensional spacetime, with a warped geometry involving one infinite extra dimension. Through a mechanism that smoothly changes a thick brane into a hybrid brane, one investigates the appearance of hybrid branes hosting internal structure, characterized by the splitting on the energy density and the volcano potential, induced by the parameter which controls interactions between the two scalar fields. In particular, we investigate distinct symmetric and asymmetric hybrid brane scenarios. (orig.)

  8. BIOLOGICAL CHARACTERISTICS OF PRUSSIAN CARP (CARASSIUS AURATUS GIBELIO (BLOCH, 1782 COMMERCIAL STOCK OF THE DNIEPER-BUG ESTUARY

    Directory of Open Access Journals (Sweden)

    К. Heina

    2017-09-01

    Full Text Available Purpose. To provide the biological assessment of the silver Prussian carp (Carassius auratus gibelio (Bloch, 1782 commercial stock of the Dnieper-Bug estuary in the conditions of the transformed Dnieper river flow. Methodology. During the analysis of the biological state of the Prussian carp commercial stock, the main attention was given to the dynamics of age and sexual structure, length-weight growth rate, absolute fecundity and condition factor. The basic data were collected during the work of control-observation stations of the Institute of Fisheries in the Dnieper-Bug estuary during the current century. The collection and processing of ichthyological materials were performed in accordance with the generally accepted methodologies. Findings. The analysis showed that during the current century, the age structure of the Prussian carp of the Dnieper-Bug estuary was the most labile among other commercial cyprinids. It was found that as a result of an increase in the right wing of the age series, there was a gradual increase of the mean weighted age of its commercial stock. At the beginning of studies (2001-2002, the core of the stock was formed by age-3-6 fish (up ; however in subsequent years, a displacement of dominant groups toward the dominance of age-4-7 fish (more than 80% of the total stock was observed. At the same time, the relative number of age-3 fish (recruits was at a relatively high level – up to 10.6%. The linear growth varied more intensively until the age-5, but it reduced with ageing and did not show high variability. The body weight most variable was in age-4 fish (Cv=9.62%. The noted insignificant deviations in the body weight growth rate of the right wing of the age series was due to stable predominance of females in the stock structure, which were characterized by a variability of the mean weight as a result of different development of gonads. The dynamics of the age-related changes in the condition factor indicated on a

  9. Suppression of error in qubit rotations due to Bloch-Siegert oscillation via the use of off-resonant Raman excitation

    International Nuclear Information System (INIS)

    Pradhan, Prabhakar; Cardoso, George C; Shahriar, M S

    2009-01-01

    The rotation of a quantum bit (qubit) is an important step in quantum computation. The rotation is generally performed using a Rabi oscillation. In a direct two-level qubit system, if the Rabi frequency is comparable to its resonance frequency, the rotating wave approximation is not valid, and the Rabi oscillation is accompanied by the so-called Bloch-Siegert oscillation (BSO) that occurs at twice the frequency of the driving field. One implication of the BSO is that for a given interaction time and Rabi frequency, the degree of rotation experienced by the qubit depends explicitly on the initial phase of the driving field. If this effect is not controlled, it leads to an apparent fluctuation in the rotation of the qubit. Here we show that when an off-resonant lambda system is used to realize a two-level qubit, the BSO is inherently negligible, thus eliminating this source of potential error.

  10. Multiple Bloch surface waves in visible region of light at the interfaces between rugate filter/rugate filter and rugate filter/dielectric slab/rugate filter

    Science.gov (United States)

    Ullah Manzoor, Habib; Manzoor, Tareq; Hussain, Masroor; Manzoor, Sanaullah; Nazar, Kashif

    2018-04-01

    Surface electromagnetic waves are the solution of Maxwell’s frequency domain equations at the interface of two dissimilar materials. In this article, two canonical boundary-value problems have been formulated to analyze the multiplicity of electromagnetic surface waves at the interface between two dissimilar materials in the visible region of light. In the first problem, the interface between two semi-infinite rugate filters having symmetric refractive index profiles is considered and in the second problem, to enhance the multiplicity of surface electromagnetic waves, a homogeneous dielectric slab of 400 nm is included between two semi-infinite symmetric rugate filters. Numerical results show that multiple Bloch surface waves of different phase speeds, different polarization states, different degrees of localization and different field profiles are propagated at the interface between two semi-infinite rugate filters. Having two interfaces when a homogeneous dielectric layer is placed between two semi-infinite rugate filters has increased the multiplicity of electromagnetic surface waves.

  11. Anachronism in the writing of History: ¿Error or Possibility? Some reflections about the concept of time in Carlo Ginzburg, Marc Bloch and Georges Didi-Huberman

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Chaves Maldonado

    2016-01-01

    Full Text Available In his unfinished and posthumously published book Apologie pour l’histoire, Marc Bloch bestowed on future historians a seminal legacy of critical reflections on the concept of time as the object of historical analysis. During the last decades, the concept of time in History has experienced a renewed interest by professional historians, in particular in reference to the category of anachronism. The Italian historian Carlo Ginzburg and the French art historian Georges Didi-Huberman are among those engaged in this debate. This article offers a reading of two works by these historians with the purpose of underlying the fundamental influence that Marc Bloch’s ideas on time had in Ginzburg and Didi-Hubermans’ critical interventions.

  12. Architecture and Bloch-Maxwell modelling of multi-mJ 100 fs fully-coherent soft X-ray laser based on X-ray CPA

    International Nuclear Information System (INIS)

    Zeitoun, Ph.; Oliva, E.; Fajardo, M.; Cheriaux, G.; Le, T. T. T.; Li, L.; Pitman, M.; Ros, D.; Sebban, S.; Velarde, P.

    2012-01-01

    By seeding amplifying plasmas pumped with the so-called Transient collisionnal excitation scheme, the amplified pulse seems to be limited to an energy of several 10's of μJ. Aiming to attain several mJ, we study the seeding of plasma pumped by long laser pulse. Thanks to our time-dependent Maxwell-Bloch code, we demonstrate that direct seeding with femtosecond pulse is inefficient. We also study the amplification of pulse train with the drawback of re-synchronizing the pulses. We proposed and studied the amplification of high harmonic seed stretched by a grating pair, amplified finally compressed. We consider off-axis diffraction on the gratings for maximizing their efficiency. Considering the phase deformation induced by the amplification and the spectral narrowing the final pulse is 230 fs in duration and 5 mJ.

  13. Histopathological alterations of the gills, liver and kidneys in Anabas Testudineus (Bloch) fish living in an unused lignite mine, Li District, Lamphun Povince, Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Saenphet, S.; Thaworn, W.; Saenphet, K. [Chiang Mai University, Chiang Mai (Thailand). Faculty of Science

    2009-09-15

    The acidity of mine water generally makes it toxic to most organisms. The gills, kidneys and livers of Anabas testudineus Bloch fish inhabiting the acidic water (pH 2-4) of an unused lignite mine in Li District, Lamphun Province, Thailand were examined and compared to those of farmed fish. Tissue abnormalities were found in all investigated organs. Deterioration and telangiectasia of gill filaments were found. Liver tissue revealed hemorrhages, blood congestion and necrotic cells with mononuclear cell infiltration. In addition, hypertrophy of the epithelial cells of the renal tubules with reduced lumens, aneurisms of the renal tubules, and contractions of the glomeruli in the Bowman's capsule were observed. These histopathological findings suggest the acidic water in this habitat causes severe damage to the internal organs of fish and consequently alter their physiological status. Since the water in this pond is utilized by local people, these findings highlight the need for adequate water treatment.

  14. The fish fauna in tropical rivers: The case of the Sorocaba river basin, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Welber Senteio Smith

    2003-09-01

    Full Text Available A survey was carried out on the fish species in the Sorocaba River basin, the main tributary of the left margin of the Tietê River, located in the State of São Paulo, Brazil. The species were collected with gill nets. After identification of the specimens, their relative abundance, weight and standard length were determined. Up to the present moment there are not any studies that focus this subject in this hydrographic basin. Fifty-three species, distributed in eighteen families and six orders were collected. Characiformes were represented by twenty-eight species, Siluriformes by seventeen species, the Gymnotiformes by three species, Perciformes and Cyprinodontiformes by two species, and the Synbranchiformes by one species. Among the collected species there were two exotic. The most abundant species were Astyanax fasciatus and Hypostomus ancistroides. In relation to total weight the most representative species were Hoplias malabaricus and Hypostomus ancistroides. Cyprinus carpio, Prochilodus lineatus, Schizodon nasutus and Hoplias malabaricus were the most representative species in relation to average weight. Largest standard length were recorded for Sternopygus macrurus, Steindachnerina insculpta, Eigenmannia aff. virescens and Cyprinus carpioSe realizó un análisis de las especies de peces de la cuenca del Río Sorocaba, el principal tributario de la margen izquierda del Río Tietê, localizado en el estado de Sao Paulo, Brasil. Las especies fueron recolectadas con redes agalleras. Luego de la identificación de los especímenes, fue determinada su abundancia relativa, peso, y longitud estandar. Hasta el presente, no hay ningún otro estudio que analice estos aspectos en dicha cuenca hidrográfica. Fueron recolectados 55 especies, distribuidas en 18 familias y 6 ordenes. Los Characiformes estuvieron representados por 28 especies, Siluriformes por 17 especies, Gymnotiformes por 3 especies, Perciformes y Cyprinodontiformes por 2 especies, y

  15. Comparative histology in the liver and spleen of three species of freshwater teleost

    Directory of Open Access Journals (Sweden)

    Camila F. Sales

    2017-03-01

    Full Text Available ABSTRACT We describe and compare the histology of liver and spleen ofGeophagus brasiliensis (Perciformes, Hypostomus francisci (Siluriformes and Hoplias aff. malabaricus (Characiformes, tropical freshwater fishes. InG. brasiliensisandH. aff. malabaricusthe hepatocytes were arranged in tubular form whereas in H. franciscithey cord-like. In all species, hepatocytes presented glycogen, but in G. brasiliensis and H. aff. malabaricus they showed strong stained for hemossiderin in the cytoplasm. InG. brasiliensis and H. aff. malabaricus, melanomacrophage centres (MMCs were associated to hepatic structures and only in G. brasiliensis was observed intrahepatic exocrine pancreas. The spleen, in all species, was characterized by red and white pulp without boundary between the two regions, but only in H. francisci was recorded nodular organization in splenic parenchyma. The G. brasiliensisandH. aff. malabaricuspresented in the white pulp MMCs linked mainly to ellipsoids. Besides, we observed large MMCs in the spleen in relation to liver of G. brasiliensis and H. aff. malabaricus. In liver, highest values of reticular fibers and collagen were observed inG. brasiliensis. In spleen, highest values of reticular fibers and collagen were recorded inH. aff. malabaricusandH. francisci, respectively. Histological differences confirm the hypothesis that the phylogenetic distance is reflected in liver and spleen.

  16. Characterization of anomalous relaxation using the time-fractional Bloch equation and multiple echo T2 *-weighted magnetic resonance imaging at 7 T.

    Science.gov (United States)

    Qin, Shanlin; Liu, Fawang; Turner, Ian W; Yu, Qiang; Yang, Qianqian; Vegh, Viktor

    2017-04-01

    To study the utility of fractional calculus in modeling gradient-recalled echo MRI signal decay in the normal human brain. We solved analytically the extended time-fractional Bloch equations resulting in five model parameters, namely, the amplitude, relaxation rate, order of the time-fractional derivative, frequency shift, and constant offset. Voxel-level temporal fitting of the MRI signal was performed using the classical monoexponential model, a previously developed anomalous relaxation model, and using our extended time-fractional relaxation model. Nine brain regions segmented from multiple echo gradient-recalled echo 7 Tesla MRI data acquired from five participants were then used to investigate the characteristics of the extended time-fractional model parameters. We found that the extended time-fractional model is able to fit the experimental data with smaller mean squared error than the classical monoexponential relaxation model and the anomalous relaxation model, which do not account for frequency shift. We were able to fit multiple echo time MRI data with high accuracy using the developed model. Parameters of the model likely capture information on microstructural and susceptibility-induced changes in the human brain. Magn Reson Med 77:1485-1494, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  17. Dynamics of Bloch oscillating transistor near bifurcation threshold and its applicability for common mode rejection capability of a differential pair BOT

    Science.gov (United States)

    Sarkar, Jayanta; Puska, Antti; Hassel, Juha; Hakonen, Pertti

    2014-03-01

    Bloch oscillating transistor (BOT) is mesoscopic current amplier based on a combination of a Josephson junction or a squid connected with a large resistor and a NIS junction. We have studied the dynamics of BOT near the bifurcation threshold. This is an important feature for an amplifier as this can be utilized to improve its performance characteristics. We have measured the I - V characteristics of the BOT with different base currents (IB) over a wide range of Josephson coupling energies (EJ) . The current gain (β) is found to be increasing with increasing IB and eventually diverging. We have found a record large β = 50 in our experiment. In order to determine the common mode rejection ratio (CMRR) of a differential pair BOT we have used two BOTs fabricated on the same chip. The common mode port is connected to the bases of the two BOTs and fed with varying voltages; simultaneously emitter currents of the two BOTs are recorded. In our experiment we found a 20dB of CMRR.

  18. Impact of Salinity on the Incubation Rate and the Performance during the Nursery Phase of Square Head Climbing Perch (Anabas testudineus Bloch, 1792

    Directory of Open Access Journals (Sweden)

    Le, DV.

    2016-01-01

    Full Text Available Square head climbing perch (Anabas testudineus Bloch, 1792 is a high quality fish without small bones. It grows in a wide range of temperatures (10-42 oC, pH (3.5-9.5 and salinity (up to 16%. As regards climate change, this species may become important for aquaculture in the Tam Giang-Cau Hai lagoon near Hue city. To optimise the quality of fingerlings, we analyzed the effect of salinity levels on hatching and nursing in three subsequent experiments. Fertilization, hatching, survival and growth rates for 30 days were determined at salinity levels 0%, 5%, 7%, 13% and 15%. Water temperature and pH varied between 22-29.5 oC and 7.3-7.8, respectively. Between 0-5%, fertilization ratio was 77% to 83% and highest at 5%, but this dropped to 0% when salinity increased; hatching ratio was larger than 90%, but decreased to 0% at 13-15%. Between 0-11%, hatching time of fertilized eggs was not affected by salinity levels. The ratio of deformation gradually increased above 5%. After hatching at either 0 or 5%, survival ratios for square head climbing perch were above 13% up to 5%, but dropped to 0% at 9%. The growth after 30 days of nursing was higher at 5 and 7% compared with that of 0 and 3%.

  19. Detection of cyprinid herpesvirus 2 in peripheral blood cells of silver crucian carp, Carassius auratus gibelio (Bloch), suggests its potential in viral diagnosis.

    Science.gov (United States)

    Wang, H; Xu, Lj; Lu, Lq

    2016-02-01

    Epidemics caused by cyprinid herpesvirus 2 (CyHV-2) in domestic cyprinid species have been reported in both European and Asian countries. Although the mechanisms remain unknown, acute CyHV-2 infections generally result in high mortality, and the surviving carps become chronic carriers displaying no external clinical signs. In this study, in situ hybridization analysis showed that CyHV-2 tended to infect peripheral blood cells during either acute or chronic infections in silver crucian carp, Carassius auratus gibelio (Bloch). Laboratory challenge experiments coupled with real-time PCR quantification assays further indicated that steady-state levels of the viral genomic copy number in fish serum exhibited a typical 'one-step' growth curve post-viral challenge. Transcriptional expression of open reading frames (ORF) 121, which was selected due to its highest transcriptional levels in almost all tested tissues, was monitored to represent the replication kinetics of CyHV-2 in peripheral blood cells. Similar kinetic curve of active viral gene transcription in blood cells was obtained as that of serum viral load, indicating that CyHV-2 replicated in peripheral blood cells as well as in other well-characterized tissues. This study should pave the way for designing non-invasive and cost-effective serum diagnostic methods for quick detection of CyHV-2 infection. © 2015 John Wiley & Sons Ltd.

  20. Solitons and rogue waves for a higher-order nonlinear Schroedinger-Maxwell-Bloch system in an erbium-doped fiber

    International Nuclear Information System (INIS)

    Su, Chuan-Qi; Gao, Yi-Tian; Yu, Xin; Xue, Long; Aviation Univ. of Air Force, Liaoning

    2015-01-01

    Under investigation in this article is a higher-order nonlinear Schroedinger-Maxwell-Bloch (HNLS-MB) system for the optical pulse propagation in an erbium-doped fiber. Lax pair, Darboux transformation (DT), and generalised DT for the HNLS-MB system are constructed. Soliton solutions and rogue wave solutions are derived based on the DT and generalised DT, respectively. Properties of the solitons and rogue waves are graphically presented. The third-order dispersion parameter, fourth-order dispersion parameter, and frequency detuning all influence the characteristic lines and velocities of the solitons. The frequency detuning also affects the amplitudes of solitons. The separating function has no effect on the properties of the first-order rogue waves, except for the locations where the first-order rogue waves appear. The third-order dispersion parameter affects the propagation directions and shapes of the rogue waves. The frequency detuning influences the rogue-wave types of the module for the measure of polarization of resonant medium and the extant population inversion. The fourth-order dispersion parameter impacts the rogue-wave interaction range and also has an effect on the rogue-wave type of the extant population inversion. The value of separating function affects the spatial-temporal separation of constituting elementary rogue waves for the second-order and third-order rogue waves. The second-order and third-order rogue waves can exhibit the triangular and pentagon patterns under different choices of separating functions.

  1. Natural outbreak of Streptococcus agalactiae (GBS) infection in wild giant Queensland grouper, Epinephelus lanceolatus (Bloch), and other wild fish in northern Queensland, Australia.

    Science.gov (United States)

    Bowater, R O; Forbes-Faulkner, J; Anderson, I G; Condon, K; Robinson, B; Kong, F; Gilbert, G L; Reynolds, A; Hyland, S; McPherson, G; Brien, J O'; Blyde, D

    2012-03-01

    Ninety-three giant Queensland grouper, Epinephelus lanceolatus (Bloch), were found dead in Queensland, Australia, from 2007 to 2011. Most dead fish occurred in northern Queensland, with a peak of mortalities in Cairns in June 2008. In 2009, sick wild fish including giant sea catfish, Arius thalassinus (Rüppell), and javelin grunter, Pomadasys kaakan (Cuvier), also occurred in Cairns. In 2009 and 2010, two disease epizootics involving wild stingrays occurred at Sea World marine aquarium. Necropsy, histopathology, bacteriology and PCR determined that the cause of deaths of 12 giant Queensland grouper, three wild fish, six estuary rays, Dasyatis fluviorum (Ogilby), one mangrove whipray, Himantura granulata (Macleay), and one eastern shovelnose ray, Aptychotrema rostrata (Shaw), was Streptococcus agalactiae septicaemia. Biochemical testing of 34 S. agalactiae isolates from giant Queensland grouper, wild fish and stingrays showed all had identical biochemical profiles. The 16S rRNA gene sequences of isolates confirmed all isolates were S. agalactiae; genotyping of selected S. agalactiae isolates showed the isolates from giant Queensland grouper were serotype Ib, whereas isolates from wild fish and stingrays closely resembled serotype II. This is the first report of S. agalactiae from wild giant Queensland grouper and other wild tropical fish and stingray species in Queensland, Australia. © 2012 Blackwell Publishing Ltd and State of Queensland.

  2. Influence of in-plane field on the stability of vertical Bloch lines in the walls of OHB at various bias fields

    International Nuclear Information System (INIS)

    Guo, G.X.; Wang, L.N.; Zhen, C.M.; Nie, X.F.

    2006-01-01

    The stability of vertical Bloch line (VBL) chains subjected to in-plane field (H ip ) was statistically studied for the ordinary hard bubbles (OHB) in garnet bubble films at various bias fields (H b ). The dumbbell domains were also investigated. We found that (H ip (1) ) IID ip (1) ) ID ip (1) ) OHB and (H ip (2) ) IID =(H ip (2) ) ID =(H ip (2) ) OHB when keeping H b unchanged. With the increasing of H b , the in-plane field H ip (1) , H ip * and H ip (2) all decrease, while the in-plane field range [H ip (1) , H ip * ] and [H ip (1) , H ip (2) ] become narrower. Here, H ip (1) is the initial critical in-plane field where VBLs in the walls of three types of hard domains are annihilated, H ip * stands for the in-plane field where the retention rate of three types of hard domains R reduces to zero, and H ip (2) is the lowest in-plane field where VBLs in their corresponding hard domains are annihilated completely

  3. Estimation of Tissue Distribution of mRNA Transcripts for Desaturase and Elongase Enzymes in Channa striata (Bloch, 1793 Fingerlings using PCR Technique

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    M. Aliyu-Paiko

    2013-06-01

    Full Text Available Fish species are varied in their capacity to biosynthesize n-3 highlyunsaturated fatty acids (HUFA such as eicosapentaenoic and docosahexaenoic acids (EPA & DHA that are crucial to the health and well-being of all higher vertebrates. Experts report that HUFA metabolism involves enzyme-mediated fatty acyl desaturation (FAD and elongation (FAE processes. In previous studies, different workers cloned, characterized, identified and reported several genes for FAD and FAE enzymes in different fish species such as Atlantic salmon, gilthead seabream, rainbow trout and zebrafish, and also demonstrated the up- and down-regulation in the activity of these enzymes in response to fluctuations in dietary HUFA. In this paper, we report on the expression of genes (mRNA transcripts for FAD and FAE enzymes in different tissues of Channa striata (Bloch, 1793 fingerling, to evaluate the tissues of the fish in which activity of both enzymes are high. To achieve this objective, we used conventional polymerase chain reaction (PCR technique to isolate and quantify the absolute copy number for each gene transcripts from 8 different tissues of the fish (reared with a commercial feed. Our estimate show that the distribution of the 2 enzyme transcripts were significantly (P < 0.05 higher in the liver and brain of C. striata than detected in the 6 other tissues evaluated (muscle, ovary, testis, intestine, kidney and skin. Subsequently, we discuss here extensively, the implication of this observation with respect to the use of vegetable oils (VO as substitute to fish oil (FO in diets for freshwater fish species.

  4. Adrenaline and triiodothyronine modify the iron handling in the freshwater air-breathing fish Anabas testudineus Bloch: role of ferric reductase in iron acquisition.

    Science.gov (United States)

    Rejitha, V; Peter, M C Subhash

    2013-01-15

    The effects of in vivo adrenaline and triiodothyronine (T(3)) on ferric reductase (FR) activity, a membrane-bound enzyme that reduces Fe(III) to Fe(II) iron, were studied in the organs of climbing perch (Anabas testudineus Bloch). Adrenaline injection (10 ng g(-1)) for 30 min produced significant inhibition of FR activity in the liver and kidney and that suggests a role for this stress hormone in iron acquisition in this fish. Short-term T(3) injection (40 ng g(-1)) reduced FR activity in the gills of fed fish but not in the unfed fish. Similar reduction of FR activity was also obtained in the intestine and kidney of fed fish after T(3) injection. Feeding produced pronounced decline in FR activity in the spleen but T(3) challenge in fed and unfed fish increased its activity in this iron storing organ and that point to the sensitivity of FR system to feeding activity. The in vitro effects of Fe on FR activity in the gill explants of freshwater fish showed correlations of FR with Na(+), K(+)-ATPase and H(+)-ATPase activities. Substantial increase in the FR activity was found in the gill explants incubated with all the tested doses of Fe(II) iron (1.80, 3.59 and 7.18 μM) and Fe(III) iron (1.25, 2.51 and 5.02 μM) and this indicate that FR and Na pump activity are positively correlated. On the contrary, substantial reduction of gill H(+)-ATPase activity was found in the gill explants incubated with Fe(II) iron and Fe(III) iron indicating that perch gills may not require a high acidic microenvironment for the reduction of Fe(III) iron. Accumulation of iron in the gill explants after Fe(III) iron incubation implies a direct relationship between Fe acquisition and FR activity in this tissue. The inverse correlation between FR activity and H(+)-ATPase activity in Fe(II) or Fe(III) loaded gills and the significant positive correlations of FR activity with total [Fe] content in the Fe(III) loaded gills substantiate that FR which shows sensitivity to sodium and proton pumps

  5. The taxonomic status of Japanese threadfin bream Nemipterus japonicus (Bloch, 1791) (Perciformes: Nemipteridae) with a redescription of this species from the south china sea based on morphology and DNA barcodes

    Science.gov (United States)

    Ning, Ping; Sha, Zhongli; Hebert, Paul D. N.; Russell, Barry

    2015-02-01

    Because of its importance as a food source, Nemipterus japonicus (Bloch, 1791) (Nemipteridae) or Japanese threadfin bream is the best studied of these taxa, and numerous investigations have examined its fisheries, its biology and biochemistry. Despite such intensive work, the taxonomic status of N. japonicus has never been seriously questioned and it is regarded as a common species, widely distributed throughout the Indo-Western Pacific Ocean. In fact, Bloch's description of the type specimen of N. japonicus has ambiguous collection data and lacks a designation for the type locality, though it is probably Java. In this paper, DNA barcode results based on COI gene support the existence of two geographically separated lineages of the Japanese threadfin bream, both being an Indian Ocean and western Pacific lineage, with 2.7% sequence divergence, and the results indicate a possible existing of some cryptic species. The two lineages also possess a diagnostic difference in their belly color, with specimens in the South China Sea having a silver belly, while those from the Indian Ocean isolate specimen have a yellow coloration. Based upon new collections from the South China Sea, this species from the western Pacific is morphologically redescribed and its details of DNA barcode diversity are shown for the future investigations.

  6. Diploposthe laevis (Bloch Jacobi (Eucestoda, Hymenolepididae from Netta peposaca (Vieillot (Aves: Anatidae: first record for the Neotropical Region and a new host Diploposthe laevis (Bloch Jacobi (Eucestoda: Hymenolepididae em Netta peposaca (Vieillot (Aves, Anatidae: primeiro registro para Região Neotropical e novo hospedeiro

    Directory of Open Access Journals (Sweden)

    Eliane F. da Silveira

    2008-03-01

    Full Text Available One hundred eight rosy-billed pochards, Netta peposaca (Vieillot, 1816, collected in Brazil and Argentina were examined for endoparasites. Collection sites included the municipalities of Santa Vitória do Palmar and Jaguarão, Rio Grande do Sul State, Brazil (wintering site and Alvear, Corrientes Province, northern Argentina (nesting site. Birds were frozen in dry ice after collection. During necropsy they were categorized according to sex and maturation, either adult or juvenile. The cestode Diploposthe laevis (Bloch Jacobi, 1896 was found (prevalence 68.5%, mean infection was 2. The mean prevalence of D. laevis in Alvear (25.9% was higher than found in Jaguarão and Santa Vitória do Palmar, Rio Grande do Sul (19%, and could be related to the nesting site and to the period when the birds may ingest a higher amount of food. This is the first record of a species of the genus Diploposthe in anatideans from South America, and the first record of the species in N. peposaca. Details of the cirrus pouch and vagina were described based on histological sections.Com o objetivo de conhecer a helmintofauna do marrecão, Netta peposaca (Vieillot, 1816, na América do Sul, 108 aves foram amostradas. Os pontos de captura foram os municípios de Santa Vitória do Palmar e Jaguarão, no Estado do Rio Grande do Sul, sul do Brasil (pólo de invernia, e em Alvear, Província de Corrientes, região norte da Argentina (pólo de nidificação, entre 2002 e 2004. As aves foram congeladas em gelo seco logo após o abate. Durante o procedimento de necropsia tiveram o sexo identificado, e foram classificadas de acordo com estado de maturação sexual, em juvenil e adulto. O cestóide Diploposthe laevis (Bloch Jacobi, 1896 foi encontrado com prevalência média de 68,5% e intensidade média de infecção de dois espécimes por hospedeiro. A prevalência média de D. laevis em Alvear (25,9% foi maior do que a encontrada em Jaguarão e Santa Vitória do Palmar, Rio Grande

  7. Influence of ammonia on forming the toxicity of waters from the surface sources of water supply determined on Carassius auratus gibelio (Bloch, 1782

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    Е. Arystarkhova

    2018-03-01

    Full Text Available Purpose. Determination of the influence of ammonia in waters from surface sources of water supply of Zhytomyr city on forming the toxicity of these waters determined by test-reactions of atypical motor activity of Carassius auratus gibelio (Bloch, 1782 with the use of the «time sampling» method during 2012–2014. Methodology. Biotesting was performed at the Municipal Enterprise "Zhytomyrvodokanal". Water samples were taken once a month time from the Teteriv river reservoirs and tap water network and then placed into aquaria (8 dm3 on a group. Control and experimental groups of fish were formed according to the following scheme: control group — samples of settled (24 hours tap water; experimental group D-1 — water samples from the Denyshivske reservoir; experimental group D-2 — water samples from the Vidsichne water intake. Test specimens were females of C. auratus gibelio. Biotesting was conducted using the «time sampling» method by keeping fish (n=30 in water for 12 hours. The toxicity indexes of waters were calculated on the basis of the following test-reactions: spiral-like and vector movements, jumping out from water, immobilization and death of fish. Statistical processing of study results were performed using cross-correlation and regression analysis in MS Excel 2007 and Statistica-6. Findings. The study showed an effect of ammonia on the toxicity of waters from reservoirs of the Teteriv river that was determined by atypical motor activity with the use of the «time sampling» method, which consisted in the instantaneous fixation of the number of individuals that favored one or another act of behavior. It was shown that females not adapted to the action of ammonia reacted to its concentration in water of more than 0.55 mg/dm3 by disorders in movements. Unlike fish of experience groups, only single pathological acts were observed in the control group. A positive moderate relationship, which had a tendency to an increase, was

  8. Compuestos organoclorados residuales en dos especies ícticas de la Ciénaga Grande del Bajo Sinú, Córdoba, Colombia

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    Edineldo Lans C

    2011-04-01

    Full Text Available Objetivo. Determinación de niveles de pesticidas organoclorados (POCs en especies ícticas, procedentes de la Ciénaga Grande del Bajo Sinú, Materiales y métodos. Se usó un cromatógrafo de gases (Perkin Elmer Autosystem XL con detector captura de electrones y columna capilar 5% de difenil y 95% de dimetilpolisiloxano, de 30 m, 0.25 mm de diámetro interno y 0.25 μm de espesor de película. Las especies estudiadas fueron: bocachico (Prochilodus magdalenae y moncholo (Hoplias malabaricus, durante las estaciones seca y húmeda. Resultados. El porcentaje de recuperación de los pesticidas determinados se registró entre 80 y 84%, mientras que los límites de detección y cuanficación fueron 0.02 a 0.18 ng/g y 0.2 a 1.8 ng/g respectivamente. La desviación estándar relativa permaneció por debajo del 7% en todos los casos. De los pesticidas organoclorados investigados, en las dos especies se detectaron el a-clordano, endrín y aldrín. Se observó que a medida que aumenta el peso y el tamaño del pez, aumenta la concentración de los plaguicidas en una de las especies. Los niveles de concentración de los POCs estuvieron en el intervalo de 0.35-3.75 y 0.48-5.49 ng/g para el moncholo (Hoplias malabaricus and bocachico (Prochilodus magdalenae respectivamente. Conclusiones. La frecuencia de aparición de POCs y los niveles detectados en las especies podrían ser consecuencia de actividades antropogénicas realizadas en los alrededores de la ciénaga. La correlación entre las medidas biométricas y la concentración depende de la especie íctica. Las concentraciones encontradas en las especies estudiadas, Hoplias malabaricus y Prochilodus magdalenae no representan toxicidad letal inmediata.

  9. Spatial synchrony of a highly endemic fish Assemblage (Segredo Reservoir, Iguaçu River, Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    W. M. Domingues

    Full Text Available In this study, patterns of spatial synchrony in population fluctuations (cross-correlation of an endemic fish assemblage of a Neotropical reservoir (Segredo Reservoir, Iguaçu River, Paraná State, Brazil were reported. First, the level of population synchrony for 20 species was estimated. Second, population synchrony was correlated, using the Mantel test, with geographical distances among sites (n = 11 and also environmental synchrony (temperature. Nine species presented significant correlations between spatial synchrony and geographic distances (Astyanax sp. b, Astyanax sp. c, Pimelodus sp., Hoplias malabaricus, Crenicichla iguassuensis, Hypostomus derbyi, Hypostomus myersi, Rhamdia branneri, and R. voulezi. Considering the ecology of the species and the significant relationship between population and environmental synchronies, it seems that environmental stochasticity is the most plausible hypothesis in explaining the observed synchrony patterns.

  10. Avaliação da perda de mercúrio total em peixe antes e após os processos de fritura e cocção Determination of mercury losses in fish after cooking

    Directory of Open Access Journals (Sweden)

    Aricelso Maia LIMAVERDE FILHO

    1999-01-01

    Full Text Available A perda de mercúrio contido em músculo de peixes (Piraíba, Brachyplatystoma ssp; Traíra, Hoplias malabaricus submetidos a dois distintos processos de cozimento foi investigada. Os resultados mostraram perdas variando entre 0 e 30% (base seca, indicando que a maior parte do mercúrio foi retida. Assim, tais processos não protegem as populações, que deles se utilizam, contra a exposição por ingestão ao mercúrio originariamente contido na amostra "in natura".Mercury losses from flesh fish after two cooking process were investigated. Results showed losses ranging from 0 to 30% (dry weight basis. Such result indicates that fish consuming populations are not protected from mercury exposition by the studied cooking processes.

  11. Ichthyofauna from the Emas National Park region: composition and structure

    Directory of Open Access Journals (Sweden)

    E. Benedito-Cecilio

    Full Text Available The relationship between habitats and the ichthyofauna composition in the Parque Nacional das Emas (PNE and adjacent areas (the Araguaia and Sucuriú rivers are provided and could be applied in determining the Park's future zoning. Samples of the ichthyofauna and limnological parameters were obtained during both dry (September 1999 and wet (December 1999 seasons. Ichthyofauna collections resulted in the capture of 4,740 specimens of 22 species. The most abundant species in the Araguaia River during the two sampling seasons were Astyanax sp. 2 and Hasemania sp. In the Sucuriú River and PNE, Astyanax scabripinnis cf. paranae and Hoplias aff. malabaricus were the most frequent species. The largest number of species and diversity index were recorded for the Araguaia River. However, sound management policies require more detailed studies on the fish communities of the Cerrado biome.

  12. Mercury Contamination in an Indicator Fish Species from Andean Amazonian Rivers Affected by Petroleum Extraction.

    Science.gov (United States)

    Webb, Jena; Coomes, Oliver T; Mainville, Nicolas; Mergler, Donna

    2015-09-01

    Elevated mercury (Hg) concentrations in fish from Amazonia have been associated with gold-mining, hydroelectric dams and deforestation but few studies consider the role of petroleum extraction. Hg levels were determined in fish samples collected in three river basins in Ecuador and Peru with contrasting petroleum exploitation and land-use characteristics. The non-migratory, piscivorous species, Hoplias malabaricus, was used as a bioindicator. The rate of Hg increase with body weight for this species was significantly higher on the Corrientes River, near the site of a recent oil spill, than on the other two rivers. In the absence of substantial deforestation and other anthropogenic sources in the Corrientes River basin, this finding suggests that oil contamination in Andean Amazonia may have a significant impact on Hg levels in fish.

  13. Records of new localities and hosts for crustacean parasites in fish from the eastern Amazon in northern Brazil.

    Science.gov (United States)

    Oliveira, Marcos Sidney Brito; Corrêa, Lincoln Lima; Oliveira Ferreira, Drielly; Neves, Lígia Rigor; Tavares-Dias, Marcos

    2017-06-01

    The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas , Cichla monoculus , Cichla ocellaris , Cichla jariina , Satanoperca jurupari , Leporinus friderici , Leporinus fasciatus , Hoplias malabaricus , Phractocephalus hemioliopterus , Serrasalmus altispinis , Pseudoplatystoma tigrinum and Potamotrygon motoro of the State Amapá and Pará, in northern Brazil. A total of 242 parasites, including Argulus elongatus , Argulus multicolor, Argulus juparanaensis , Argulus nattereri , Dolops discoidalis , Dolops longicauda , Braga patagonica , Braga fluviatilis , Livoneca guianensis and undetermined Lernaeidae, were collected from these hosts. The Argulus species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than D. discoidalis , was most abundant in the integument of A. gigas and P. tigrinum . Finally, the present study reported nine new hosts for the crustacean parasite species and expanded knowledge of the occurrence of some parasite species in the Jari River basin, in eastern Amazon.

  14. Myocardial T1 mapping at 3.0 tesla using an inversion recovery spoiled gradient echo readout and bloch equation simulation with slice profile correction (BLESSPC) T1 estimation algorithm.

    Science.gov (United States)

    Shao, Jiaxin; Rapacchi, Stanislas; Nguyen, Kim-Lien; Hu, Peng

    2016-02-01

    To develop an accurate and precise myocardial T1 mapping technique using an inversion recovery spoiled gradient echo readout at 3.0 Tesla (T). The modified Look-Locker inversion-recovery (MOLLI) sequence was modified to use fast low angle shot (FLASH) readout, incorporating a BLESSPC (Bloch Equation Simulation with Slice Profile Correction) T1 estimation algorithm, for accurate myocardial T1 mapping. The FLASH-MOLLI with BLESSPC fitting was compared with different approaches and sequences with regards to T1 estimation accuracy, precision and image artifact based on simulation, phantom studies, and in vivo studies of 10 healthy volunteers and three patients at 3.0 Tesla. The FLASH-MOLLI with BLESSPC fitting yields accurate T1 estimation (average error = -5.4 ± 15.1 ms, percentage error = -0.5% ± 1.2%) for T1 from 236-1852 ms and heart rate from 40-100 bpm in phantom studies. The FLASH-MOLLI sequence prevented off-resonance artifacts in all 10 healthy volunteers at 3.0T. In vivo, there was no significant difference between FLASH-MOLLI-derived myocardial T1 values and "ShMOLLI+IE" derived values (1458.9 ± 20.9 ms versus 1464.1 ± 6.8 ms, P = 0.50); However, the average precision by FLASH-MOLLI was significantly better than that generated by "ShMOLLI+IE" (1.84 ± 0.36% variance versus 3.57 ± 0.94%, P < 0.001). The FLASH-MOLLI with BLESSPC fitting yields accurate and precise T1 estimation, and eliminates banding artifacts associated with bSSFP at 3.0T. © 2015 Wiley Periodicals, Inc.

  15. Structure dynamics of a fish community over ten years of formation in the reservoir of the hydroelectric power plant in upper Uruguay River.

    Science.gov (United States)

    Schork, G; Zaniboni-Filho, E

    2017-11-01

    The objective of this study was to evaluate the structure of the fish assemblage in the ten years following the closing of the lake of the Itá Hydroelectric Power Plant. Seasonal collections were conducted from 2001 to 2010. During this period, 44,834 fish were captured, totaling 3,818.01 kg, among 8 orders, 24 families and 84 species. In general, profound changes were not observed in the fish assemblage in the ten years after the formation of the Itá lake. Few species changed in dominance over time, while many were rare in the environment. The ichthyofauna in the reservoir was dominated by small and medium size opportunist species that conduct short or no migratory movements. Among the most abundant, six species were responsible for more than 50% of the numeric representation: Steindachnerina brevipinna, Astyanax fasciatus, Apareiodon affinis, Hypostomus isbrueckeri, Iheringichthys labrosus and Loricariichthys anus. The increase in the representation of the later species stood out. The biomass was dominated by Steindachneridion scriptum, Prochilodus lineatus, I. laborsus, Schizodon nasutus, Hoplias malabaricus, Acestrorhynchus pantaneiro, Hoplias lacerdae, H. isbrueckeri and L. anus. Despite the presence of large migrators in the region of the reservoir, their vulnerability was revealed by the low numeric abundance and accidental capture. The k-dominance curve of numerical abundance and biomass indicates a moderately disturbed community, in which the representation of small species was also important to the amounts of biomass.

  16. Anatomy of the bucco-pharyngeal cavity of Salminus brasiliensis (Cuvier, 1817 (Pisces, Characidae, Salmininae

    Directory of Open Access Journals (Sweden)

    Eliane Menin

    2006-03-01

    Full Text Available The bucco-pharyngeal cavity of Salminus brasiliensis, an ichthyophagous species of fresh water, is anatomically adapted to predation. The wide buccal rift, the oral-aboral enlargement of the buccal cavity and the reduced thickness of the pharyngeal mastigatory apparatus favor the capture and deglutition of larger prey. In function of the oral and pharyngeal dentition type, pre-digestive food preparation does not occur. The pointed and curved teeth, together with the tongue which is relatively mobile, prevent the prey’s escape from the buccopharyngeal cavity. The passage of the food is facilitated by the absence of pronounced folds in the mucous membrane of this cavity and by the disposition of the oral and pharyngeal teeth. The characteristics of flat and thin lips, developed oral dentition, relatively mobile tongue, mucous membrane without folds, pharynx with denticules disposed in dentigerous areas and plates, and short and sharp gill-rackers are anatomical adaptations which are shared by S. brasiliensis and other ichthyophagous Characiformes species such as Salminus maxillosus, Salminus hilarii, Hoplias malabaricus, Hoplias lacerdae, Acestrorhynchus lacustris and Acestrorhynchus britskii. However, different to the mentioned species, except other Salmininae, S. brasiliensis possesses oral teeth of an unique type, present only in the jawbones and distributed in two series.

  17. Gill rakers in six teleost species: influence of feeding habit and body size

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    Ana Paula Gottlieb Almeida

    2013-12-01

    Full Text Available This study analyzed the structure of the gill rakers of Parapimelodus valenciennis and Parapimelodus nigribarbis (planktivorous, Serrasalmus maculatus and Hoplias malabaricus (piscivorous, Iheringichthys labrosus (benthophagous and Hypostomus commersonii (detritivorous and related it with the body size and feeding habits of these species. The species of Parapimelodus and H. commersonii showed long, filiform and closely spaced gill rakers, similar to those of species that use the gill rakers as a filter to assist in the retention of small particles. The widely spaced gill rakers of I. labrosus probably allow the retention of insect larvae, but not particles of inorganic matter. In H. malabaricus and S. maculatus the gill rakers are most likely related to prey capture and swallowing, as observed in other piscivorous species. In general, gill raker length and the distance between gill rakers have a positive relationship with fish length. The gill rakers show adaptations related to the diet of the fish, but morphological variation may occur even between species whose feeding habits are the same.

  18. Habitat preferences of common native fishes in a tropical river in Southeastern Brazil

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    Marcus Rodrigues da Costa

    Full Text Available We determined in this study the habitat preferences of seven native fish species in a regulated river in Southeastern Brazil. We tested the hypothesis that fishes differ in habitat preference and that they use stretches of the river differing in hydraulic characteristics and substrate type. We surveyed fishes in four 1-km long river stretches encompassing different habitat traits, where we also measured water depth, velocity, and substrate type. We investigated preference patterns of four Siluriformes (Loricariichthys castaneus, Hoplosternum littorale, Pimelodus maculatus, and Trachelyopterus striatulus and three Characiformes (Astyanax aff. bimaculatus, Oligosarcus hepsetus, and Hoplias malabaricus, representing approximately 70% of the total number of fishes and 64% of the total biomass. We classified fishes into four habitat guilds: (1 a slow-flowing water guild that occupied mud-sand substrate, composed of two Siluriformes in either shallow ( 8 m, L. castaneus waters; (2 a run-dwelling guild that occurs in deep backwaters with clay-mud substrate, composed of the Characiformes A. aff. bimaculatus and O. hepsetus; (3 a run-dwelling guild that occurs in sandy and shallow substrate, composed of T. striatulus; and (4 a fast-flowing guild that occurs primarily along shorelines with shallow mud bottoms, composed of H. malabaricus and P. maculatus. Our hypothesis was confirmed, as different habitat preferences by fishes appear to occur in this regulated river.

  19. BAFRA BALIK GÖLÜ'NDE YAŞAYAN HAVUZ BALIĞI,Carassius gibelio (BLOCH, 1782'NUN KONDİSYON FAKTÖRÜ VE BOY-AĞIRLIK İLİŞKİSİNİN BELİRLENMESİ

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    Derya BOSTANCI

    2009-02-01

    Full Text Available Özet: Bu çalışmada, Bafra Balık Gölü'ndeki Havuz balığının (Carassius gibelio kondisyon faktörü ve boy-ağırlık ilişkisini belirlemek amacıyla, Ocak 2000-Eylül 2002 tarihleri arasında aylık olarak örneklenen 173 birey incelenmiştir. Populasyonda 168 ♀ (% 97.11, 5 ♂ (% 2.89 birey bulunmaktadır. Populasyonun çatal boy dağılımı 16.9-30 cm arasında, ağırlık dağılımı ise 125-730 g arasında değişmiş, boy-ağırlık ilişkisi W = 0.0265 L2,978 olarak hesaplanmıştır. Kondisyon faktörü ise 1.976–3.776 arasında değişmiş ve ortalama kondisyon faktörü 2.494±0.018 olarak belirlenmiştir. Anahtar kelimeler: Carassius gibelio, Kondisyon faktörü, Boy-ağırlık ilişkisi, Bafra Balık Gölü DETERMINATION OF CONDITION FACTOR AND LENGTH-WEİGHT RELATIONSHIP OF THE CRUCIAN CARP, Carassıus gıbelıo (BLOCH, 1782 INHABITING BAFRA FISH LAKE Abstract: In this study, it is examined the crucian carp (Carassius gibelio which is captured by montly sampling during the period of January 2000 to September 2002 in the Bafra Fish Lake to investigate for the condition factor and length-weight relationship. There are 168 ♀ (% 97.11, 5 ♂ (% 2.89 specimens in the population. The fork length distribution from 16.9 to 30 cm and weight varied between of 125 to 730 g; length-weight relationship was calculated as W = 0.0265 L2.978. Condition factors varied from 1.976 to 3.776 and the mean condition factors were determined as 2.494±0.018. Key words: Carassius gibelio, Condition factor, Length-weight relationship, Bafra Fish Lake

  20. Zymosan-induced immune challenge modifies the stress response of hypoxic air-breathing fish (Anabas testudineus Bloch): Evidence for reversed patterns of cortisol and thyroid hormone interaction, differential ion transporter functions and non-specific immune response.

    Science.gov (United States)

    Simi, S; Peter, Valsa S; Peter, M C Subhash

    2017-09-15

    Fishes have evolved physiological mechanisms to exhibit stress response, where hormonal signals interact with an array of ion transporters and regulate homeostasis. As major ion transport regulators in fish, cortisol and thyroid hormones have been shown to interact and fine-tune the stress response. Likewise, in fishes many interactions have been identified between stress and immune components, but the physiological basis of such interaction has not yet delineated particularly in air-breathing fish. We, therefore, investigated the responses of thyroid hormones and cortisol, ion transporter functions and non-specific immune response of an obligate air-breathing fish Anabas testudineus Bloch to zymosan treatment or hypoxia stress or both, to understand how immune challenge modifies the pattern of stress response in this fish. Induction of experimental peritonitis in these fish by zymosan treatment (200ngg -1 ) for 24h produced rise in respiratory burst and lysozomal activities in head kidney phagocytes. In contrast, hypoxia stress for 30min in immune-challenged fish reversed these non-specific responses of head kidney phagocytes. The decline in plasma cortisol in zymosan-treated fish and its further suppression by hypoxia stress indicate that immune challenge suppresses the cortisol-driven stress response of this fish. Likewise, the decline in plasma T 3 and T 4 after zymosan-treatment and the rise in plasma T 4 after hypoxia stress in immune-challenged fish indicate a critical role for thyroid hormone in immune-stress response due to its differential sensitivity to both immune and stress challenges. Further, analysis of the activity pattern of ion-dependent ATPases viz. Na + /K + -ATPase, H + /K + -ATPase and Na + /NH 4 + -ATPase indicates a functional interaction of ion transport system with the immune response as evident in its differential and spatial modifications after hypoxia stress in immune-challenged fish. The immune-challenge that produced differential

  1. Eğirdir Gölü'nde Gümüşi Havuz Balığı, Carassius gibelio (Bloch, 1782 Avcılığında Kullanılan Monofilament Fanyalı Ağların Seçiciliği

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    Bayram KORKMAZ

    2014-09-01

    Full Text Available In this study, it has been investigated that the characteristics of the selectivity of monofilament trammel nets having 50, 55, 60 mm bar length. This study was carried out on prussian carp Carassius gibelio (Bloch,1782 caught in Lake Eğirdir. An indirect method developed by Holt (1963 was used for determining the selectivity parameters. Common selection factor as SF=4.753 and common standard deviation as SD=2.347 were calculated for monofilament trammel nets. Common selection factor used of the optimum catch lengths of prussian carp in 50, 55 and 60 mm bar length were 23.77; 26.14 and 28.52 cm respectively. The optimum catch lengths were compared with lenghts at first maturity of prussian carp in Lake Eğirdir. Trammel nets of this study do not cause the overfishing on the prussian carp stock

  2. Biology and ecomorphology of stream fishes from the rio Mogi-Guaçu basin, Southeastern Brazil

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    Katiane M. Ferreira

    Full Text Available The córrego Paulicéia is a direct tributary of the rio Mogi-Guaçu, located in Santa Rita do Passa Quatro, State of São Paulo, Southeastern Brazil. This stream runs inside a savannah-like (cerrado environment and it associated vegetation. Biological and ecomorphological aspects of its fish community were studied in three stretches of the stream, denominated herein as the upper, middle and lower courses. The fish fauna recorded in this study consisted of 15 species, belonging to five orders and nine families, based in a total of 715 collected individuals representing 1,450 kg of biomass. The most important abiotic factors related to the occurrence and distribution of the fish fauna were the substrate, current speed, and presence or absence of riparian vegetation. The analysis of 336 stomach contents of 13 species demonstrated that 65% of food items are autochthonous, 32% allochthonous, and 3% are of unknown origin. Four alimentary guilds could be identified, based on the predominant food items: omnivores with tendency to insectivory - Astyanax paranae, A. fasciatus and Piabina argentea; larvivores - Corydoras difluviatilis, Cetopsorhamdia iheringi, Phenacorhamdia tenebrosa, Characidium gomesi, Eigenmannia virescens, and Rhamdia quelen; periphyton feeders - Hisonotus sp., Hypostomus ancistroides and Synbranchus marmoratus; and piscivore - Hoplias malabaricus. Reproductions data are presented for Astyanax altiparanae and Hisontus sp. Three ecomorphological groups could be established, based on swimming, feeding, and microhabitat strategies: nektonic (A. fasciatus, A. paranae, Bryconamericus stramineus, P. argentea, H. malabaricus and Phallotorynus jucundus, benthic (C. gomesi, P. tenebrosa, C. iheringi, R. quelen, C. difluviatilis, H. ancistroides and Hisonotus sp., and necktobenthic (E. virescens and S. marmoratus.

  3. Larvicultura de trairão (Hoplias lacerdae em água doce e água salinizada

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    Ronald Kennedy Luz

    2002-04-01

    Full Text Available O experimento foi conduzido com o objetivo de desenvolver técnicas de manejo durante a larvicultura de trairão, realizando cultivos em água doce ou ligeiramente salinizada, utilizando náuplios de Artemia como alimento vivo. No início da alimentação exógena, oito dias após a eclosão, as larvas foram contadas e estocadas em 12 recipientes com volume útil de 1,5 L cada, dotados de sistema de aeração, numa densidade de 10 larvas/L, distribuídos dentro de três tanques de 130 L, contendo água com temperatura controlada (29,5ºC. Os tanques foram totalmente cobertos com lona plástica preta, mantendo o ambiente interno escuro, e descobertos somente para os manejos diários. As larvas foram submetidas a três tratamentos: cultivo em água doce; em água a 2‰ de salinidade; e em água a 4‰ de salinidade. Cada tratamento teve quatro repetições. A alimentação foi fornecida nas proporções diárias de 300 náuplios de Artemia/larva, do primeiro ao quinto dia, de 600 náuplios de Artemia/larva, do sexto ao décimo dia e de 900 náuplios de Artemia/larva, do décimo primeiro ao décimo quinto dia, divididos em três refeições. Ao final do experimento, foram avaliadas a sobrevivência, o crescimento (comprimento e peso, a taxa de crescimento específico e a taxa de resistência ao estresse. Após 15 dias de tratamento, não foram verificadas diferenças significativas entre os resultados das variáveis analisadas. As condições de cultivo mostraram-se eficientes, possibilitando altas taxas de sobrevivência (valores médios superiores a 91,6%, sendo a Artemia um alimento atrativo. Os níveis de salinidade utilizados não afetaram o desenvolvimento das larvas e alevinos.

  4. 23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

    CERN Multimedia

    Maximilien Brice

    2012-01-01

    23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

  5. EVALUATION OF FISH FAUNA STOCKS IN DAMS IN SOSSEGO MIME IN CANAÃ OF CARAJÁS (EASTERN AMAZON, CAPTURED WITH THE USE OF CAST NET BEFORE THE DEPOSIT OF TAILINGS

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    Ivan Furtado Junior

    2016-12-01

    Full Text Available This study aims to estimate the biomass of fish stocks in the area of the dam formed by tailings of Sossego mine in Canaã dos Carajás, captured with the use of cast nets for fish. The prospecting work was carried out during the period from 29 February to 6 March 2004, 6 months after closing the dam and immediately before the disposal of waste. The average values estimated for the capture per unit area covered by cast nets (CPUA and biomass were 8.4 g m-² and 16,922.7 kg, respectively. The most representative groups of fish were minnows, with 67.7% and discus with 24.8% of the total estimated biomass. The species caught were: Moenkhausia cf. sanctaefilomenae (redeye tetra fish, Tetragonopterus cf. argenteus (white tetra fish, Tetragonopterus chalceus (red tetra fish, Aequidens viridis (cichlasoma bimaculatum Crenicichla cincta (jacunda Hoplerythrinus unitaeniatus (jeju Curimata inornata (branquinha and Hoplias malabaricus (trahira. Keywords: fishing survey; yield per unit area; biomass; tailings dam.

  6. Hepatic retinoid levels in seven fish species (teleosts) from a tropical coastal lagoon receiving effluents from iron-ore mining and processing.

    Science.gov (United States)

    Pereira, Adriana A; van Hattum, Bert; Brouwer, Abraham

    2012-02-01

    The present study was undertaken to investigate the possible effects of Fe and trace element exposure on hepatic levels of retinoids in seven fish species. Concentrations of retinoids were measured in fish collected from a coastal lagoon in Brazil that receives effluents from an iron-ore mining and processing plant. Fish from nearby coastal lagoons were also included to assess possible differences related to chemical exposure. Results indicated considerable differences in hepatic retinoid composition among the various species investigated. The most striking differences were in retinol and derivative-specific profiles and in didehydro retinol and derivative-specific profiles. The Perciformes species Geophagus brasiliensis, Tilapia rendalli, Mugil liza, and Cichla ocellaris and the Characiforme Hoplias malabaricus were characterized as retinol and derivative-specific, while the Siluriformes species Hoplosternum littorale and Rhamdia quelen were didehydro retinol and derivative-specific fish species. A negative association was observed between Al, Pb, As, and Cd and hepatic didehydro retinoid levels. Fish with higher levels of hepatic Fe, Cu, and Zn showed unexpectedly significant positive correlations with increased hepatic retinol levels. This finding, associated with the positive relationships between retinol and retinyl palmitate with lipid peroxidation, may suggest that vitamin A is mobilized from other tissues to increase hepatic antioxidant levels for protection against oxidative damage. These data show significant but dissimilar associations between trace element exposure and hepatic retinoid levels in fish species exposed to iron-ore mining and processing effluents, without apparent major impacts on fish health and condition. Copyright © 2011 SETAC.

  7. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

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    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.

  8. Eficacia del control de larvas de vectores de la malaria con peces larvívoros nativos en San Martín, Perú

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    Elmer Rojas P

    2004-01-01

    Full Text Available Objetivo: Determinar la eficacia del control larvario de vectores de la malaria con peces larvívoros nativos en San Martín, Perú. Material y métodos: Estudio experimental que se llevó a cabo en las localidades de Yumbatos, Alianza y San Juan de Shanusi con ocho criaderos cada uno, identificándose las especies nativas Rivulus urophtalmus "chuina" y Pyrrulina brevis "achualillo" comparados con la eficacia ejercida por Poecilia reticulata "guppy". Se midieron variables como temperatura, pH, concentración de electrolitos en el agua, densidad de los peces y presencia de otros depredadores. Resultados: Los peces nativos alcanzaron una eficacia de 98% en el control de larvas de Anopheles, cuando se mantuvieron en densidades entre 10 y 15 peces/m²; estos peces alcanzan longitudes hasta de 8 cm, y tienen similar o mayor voracidad que Poecilia reticulata. Asimismo, se evidenció la existencia de peces depredadores, Hoplias malabaricus "fasaco" y Simbranchus marmoratus "atinga", los que se alimentan de estos peces pequeños. Conclusiones: Los peces nativos son eficaces para el control de larvas de Anopheles; asimismo, se deben tener en cuenta la existencia de otras especies depredadoras, así como la limpieza de la maleza de los criaderos para incrementar la eficacia del control.

  9. Reproductive strategies and genetic variability in tropical freshwater fish

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    Maria Dolores Peres Lassala

    2007-01-01

    Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

  10. Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

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    Izaias M Fernandes

    Full Text Available The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance and qualitative data (presence-absence. Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm, while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm. However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered.

  11. First record of the Indo-Pacific areolate grouper Epinephelus areolatus (Forsskål, 1775) (Perciformes: Epinephelidae) in the Mediterranean Sea.

    Science.gov (United States)

    Rothman, Shevy B S; Stern, Nir; Goren, Menachem

    2016-01-25

    The number of alien species in the Mediterranean Sea is steadily increasing and it seems that the pace has been accelerating since the turn of the century (Galil et al. 2014). In 2015 alone five additional fish species have been reported, Epinephelus geoffroyi (Klunzinger, 1870) (Golani et al. 2015); Stolephorus indicus (van Hasselt, 1823) (Fricke et al. 2015); Sardinella gibbosa (Bleeker, 1849) (Stern et al. 2015); Mobula japanica (Müller & Henle, 1841) (Capapé et al. 2015); and Cryptocentrus caeruleopunctatus (Rüppell, 1830) (Rothman & Goren 2015). Among the ca. 100 alien fish species reported from the Mediterranean to date (Galil & Goren 2014), five Indo-Pacific species belong to the genus Epinephelus Bloch, 1793: Epinephelus coioides (Hamilton, 1822), Epinephelus fasciatus (Forsskål, 1775), Epinephelus malabaricus (Bloch and Schneider, 1804) Epinephelus merra Bloch, 1793 (Golani et al. 2013a) and Epinephelus geoffroyi (Klunzinger, 1870) (Golani et al. 2015). Additional alien Epinephelus species reported from the Mediterranean are excluded for various reasons (Golani et al. 2013b). Here we report the finding of a sixth Indo-Pacific species of this genus along the Mediterranean coast of Israel.

  12. Bloch walls and the non-ideal bose gas spectrum

    International Nuclear Information System (INIS)

    Vitiello, S.A.S.

    1986-05-01

    The quasi-particle spectrum of non-ideal Bose gas with domain walls in the condensate is investigated. The existence of such a system is determined from solutions of Gross-Pitaevskii equation which represent many-soliton systems. The walls which make the condensate non-uniform are responsible for density and velocity fields ρ(x) and υ(x) repectively. In the laboratory, the Bogoliubov spectrum, supposed to be true for an uniform condensate at rest, is changed due to the velocity field to which the quasi-particles are submited. The spectrum in the laboratory frame is obtained by considering the Galileu invariance principle and the interaction energy between the quasi-particle and its medium. The importance in considering the last two facts is illustrated by the analyse of a constant density condensate which moves uniformly in the laboratory. The many-soliton spectrum configuration and structure function are studied by the Monte Carlo method. In an approximation that assumes the quasi-particle to be point like, the condensate can be treated as locally uniform. For each event the position x of a quasi-particle and its momentum in a frame with velocity υ(x) are determined. Thus, by a convenient Galileu transformation the energy spectrum in the laboratory an be obtained. The results show a phonon spectrum which splits in two branches in the high momenta region. In this region the lower energy branch exibiths a point of minimum. Analogies with the He II are explored. (author) [pt

  13. Biochemical composition of the alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

    Science.gov (United States)

    Sanaye, Sushant Vilas; Pawar, Ashwini Pandurang; Rivonker, Chandrasheker Umanath; Sreepada, Rayadurga Anantha; Ansari, Zakir Ali; Ram, Anirudh

    2017-11-01

    Considering the economic importance in traditional Chinese medicine (TCM) and lack of baseline information, we evaluated the proximate composition, fatty acid and amino acid profiles, trace element content and C:N ratio in the alligator pipefish, Syngnathoides biaculeatus. Amongst proximate principals, a crude protein formed the major biochemical component ((58.9±2.2)% dry weight). Mean percent concentrations (dry weight) of other components such as a total lipid (TL), ash and nitrogen-free extract measured were, (1.8±0.2)%, (19.2±2.2)% and (20.1±0.45)%, respectively. The fatty acid profile revealed the presence of 27 saturated fatty acids (SFA) with 13 straight-chained and 14 branched-chained, 28 unsaturated fatty acids (UFA) with 14 monounsaturated and 14 polyunsaturated and nine other minor fatty acids. Mean percent contributions of total SFAs and UFAs to TL were found to be (55.41±0.24)% and (44.05±0.25)%, respectively. Altogether, 16 different amino acids with an equal number of essential (EAA) and non-essential (NAA) ones were identified. Percent contributions by EAA and NAA to the total amino acid content were 38.11% and 61.89%, respectively. Trace metal concentrations in S. biaculeatus were generally low and their distribution followed the order, Mg>Fe>Zn>Mn>Cu>Cr>Ni>Hg>Co. The C:N ratio was (4.37±0.04)%. The profile of major biochemical constituents in alligator pipefish, S. biaculeatus revealed its potential use in TCM as well as a nutritional diet for human consumption. The results of the study would also form the basis for formulation and optimization of diets for the culture of S. biaculeatus.

  14. ( ucleus rofeno (Bloch s assay ofos to ) using y

    African Journals Online (AJOL)

    SAM

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  15. La pesca artesanal en la Cuenca del Plata (Argentina y sus implicancias en la conservación de la biodiversidad Artisanal fish at del Plata basin (Argentina and its implications for the biodiversity conservation

    Directory of Open Access Journals (Sweden)

    Juan Miguel Iwaszkiw

    2011-06-01

    Full Text Available El objetivo del presente trabajo es considerar distintos aspectos que surgen del análisis de las exportaciones pesqueras provenientes de la pesca comercial artesanal de la Cuenca del Plata, Argentina. Se trata de identificar aquellos impactos vinculados a las prácticas pesqueras sobre las poblaciones naturales involucradas y los compromisos relacionados con la conservación de la biodiversidad de la ictiofauna de la cuenca. Se analizan 17 años de datos de las pesquerías comerciales artesanales correspondientes al tramo argentino del río Paraná sobre registros oficiales de los productos pesqueros exportados para distintas especies durante el período 1994-2010. Los registros de los productos exportados expresados en toneladas en peso (ton se refieren particularmente a especies autóctonas de gran tamaño e interés comercial como el sábalo (Prochilodus lineatus, la boga (Leporinus obtusidens, la tararira (Hoplias malabaricus, el surubí (Pseudoplatystoma spp., el dorado (Salminus brasiliensis y el patí (Luciopimelodus pati, además de varias especies acompañantes en las capturas como bagres, armados y pejerreyes (Odontesthes bonariensis. Las exportaciones pesqueras muestran un incremento sumamente importante con un total de 331.517 ton para el período 1994-2010. La especie blanco de la pesquería es el sábalo con 88,77 % de las exportaciones totales y le siguen en orden de importancia la tararira con el 4,16 %, la boga con el 3,70 %, el patí con un 1,35 % y otras especies de menor captura. Los países de destino de los productos pesqueros son Brasil, Colombia, Bolivia y Nigeria, entre otros. Sin embargo, desde el 2003, Colombia compra en promedio el 50 % del total de las exportaciones pesqueras de la Argentina. El análisis de los datos históricos de las exportaciones pesqueras (1994-2010 evidencia la necesidad de implementar medidas mas claras sobre el control y manejo de los recursos pesqueros y las posibles implicancias derivadas

  16. Food resources used by three species of fish in the semi-arid region of Brazil

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    Márcio J. da Silva

    2010-01-01

    Full Text Available Temporary and semi-permanent aquatic habitats in semi-arid Brazil have been reported as important sites supporting a diverse fish fauna. As such, they must be able to trophically sustain fish species that feed at different trophic levels. This study aims to describe the diets of Astyanax aff. bimaculatus, Hoplias malabaricus and Prochilodus brevis in aquatic systems in semi-arid Brazil, providing evidence of the importance of these habitats as supporters of large consumers like fish. The diet of the three species studied was diverse, feeding on a range of food items, from microalgae to fish. Despite that, a few items were more important to each of the study species. These results and the relatively high rates of stomach fullness indicate that a diverse and abundant food range is available in the study sites, but species seem to select some food resources. The present study provides evidence that despite being highly variable, intermittent and semi-permanent aquatic systems in semi-arid Brazil are able to trophically sustain large consumers.Os ambientes aquáticos temporários e semi-permanentes do semiárido brasileiro tem sido mostrados como importantes sítios que possuem uma diversa fauna de peixes. Desta forma, esses ambientes devem ser capazes de sustentar, do ponto de vista trófico, populações de peixes que se alimentam em diversos níveis tróficos. O presente estudo tem como objetivo descrever o hábito alimentar de Astyanax aff. bimaculatus, Hoplias malabaricus e Prochilodus brevis em ambientes aquáticos do semiárido brasileiro, fornecendo evidências da importância desses habitats para manutenção da diversidade de consumidores como os peixes. A composição da dieta das espécies estudadas foi diversificada, já que alimentaram-se de uma variedade de classes de itens, desde microalgas até peixes. Apesar disso, alguns itens foram mais importantes para cada uma das três espécies. Estes resultados, e as altas taxas de reple

  17. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish Avaliação da ocorrência de fungos patogênicos em estruturas traumatogênicas de peixes fluviais

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.INTRODUÇÃO: Infecções fúngicas na pele humana (como a esporotricose podem se manifestar após traumatismos por peixes. O objetivo deste trabalho é procurar fungos patogênicos para o homem em peixes fluviais. MÉTODOS: Extração de arcadas dentárias Serrassalmus maculatus (piranha e Hoplias malabaricus (traíra, ferrões de Pimelodus maculatus (mandis, raios da nadadeira dorsal de Plagioscion spp. (corvina e Tilapia spp. para a realização do cultivo em agar Mycosel. Algumas culturas foram submetidas à extração de DNA para a identificação molecular pelo seqüenciamento da região ITS-5.8S do rDNA. RESULTADOS: As culturas mostraram que a maioria das

  18. Primeiro registro da utilização medicinal de recursos pesqueiros na cidade de São Félix, Estado da Bahia, Brasil - DOI: 10.4025/actascibiolsci.v27i2.1328 First account on the use of fishing resources as medicines in the city of São Félix, Bahia State, Brazil - DOI: 10.4025/actascibiolsci.v27i2.1328

    Directory of Open Access Journals (Sweden)

    Juliana Nascimento Andrade

    2005-03-01

    Full Text Available Este trabalho discute a utilização medicinal de recursos pesqueiros pelos moradores da cidade de São Félix, Estado da Bahia. O trabalho de campo foi realizado entre maio de 2004 a março de 2005, entrevistando-se 29 indivíduos de ambos os sexos com idades que variaram de 11 a 79 anos. As informações foram obtidas junto a pescadores e a suas famílias por meio de entrevistas abertas e semi-estruturadas. A maior parte das entrevistas foi gravada, usando-se micro-gravador, sempre com o consentimento dos informantes. As transcrições feitas em caderno de campo encontram-se mantidas no Laboratório de Etnobiologia da Universidade Estadual de Feira de Santana, Estado da Bahia. Espécimes de peixes foram coletados, identificados e depositados no Laboratório de Ictiologia da UEFS. Os resultados mostram que, no sistema de classificação etnoictiológico dos pescadores de São Félix, diferentes organismos não sistematicamente relacionados são incluídos no domínio etnozoológico “Peixe”. Por essa razão, sete etnoespécies de peixes foram citadas como recursos medicinais: bagre (Genidens genidens, camarão (Macrobrachium sp., cambotá (Callichthys sp., piau (Leporinus sp., piranha (Serrasalmus branditi, peixe-boi (Trichechus sp. e traíra (Hoplias malabaricus. Esses animais fornecem matérias-primas que são utilizadas na elaboração de medicamentos que visam tratar e/ou curar enfermidades diagnosticadas localmente. O registro escrito da medicina tradicional implica conservação da cultural local, além de permitir que os recursos zooterapêuticos possam ser avaliados quanto à provável existência de compostos biologicamente ativosThis article deals with the medicinal use of fishing resources by the inhabitants of São Félix, Bahia State. Fieldwork was carried out from May 2004 to March 2005 by interviewing 29 individuals of both sexes, whose ages ranged from 11 to 79 years old. Data were obtained by means of open-ended interviews

  19. Effects of experimental infections with larvae of Eustrongylides ignotus Jäegerskiold, 1909 and Contracaecum multipapillatum (Drasche, 1882 Baylis, 1920 in rabbits Efeitos de infecções experimentais em coelhos com larvas de Eustrongylides ignotus Jäegerskiold, 1909 e Contracaecum multipapillatum (Drasche, 1882 Baylis, 1920

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    L.A. Barros

    2004-06-01

    Full Text Available Rabbits were infected per os with 10 Eustrongylides ignotus L4 and with 50 Contracaecum multipapillatum L3 per rabbit, recovered from naturally infected freshwater fishes (Hoplias malabaricus in order to evaluate the patogenicity of these two nematode species in mammalian host. Two rabbits (20% infected with E. ignotus died before the fourth day post-inoculation (one after 51 and the other after 78 hours. Six rabbits (60% were inappetent until the fifth day following experimental inoculation. No clinical signs in rabbits inoculated with C. multipapillatum were observed; nevertheless, eight (80% animals were positive for this nematode species. Rabbits inoculated with E. ignotus, had gastric congestion with hematoma of the gastric wall in 60% of the cases. Peritoneum was congested in 20% of the animals with the presence of peritoneal abscess in 10% of the cases. All inoculated animals showed hyperemia of the gastric mucosa with hemorrhagic gastritis due to infections with E. ignotus. In C. multipapillatum inoculated animals, the hyperemia was followed by disruption of the epithelial mucosa in the sites of parasite attachment. In the gastric mucosa, miscellaneous leukocitary infiltrates, with multifocal necrosis reaching the submucosa in the infections with C. multipapillatum were observed under bright field microscopy. Perforating lesions in several organs, mainly in the gastric wall, pancreas and liver, always in the presence of a mixed inflammatory process, intensely fibrous, with hemorrhage and necrosis were observed in animals infected with E. ignotus.Coelhos foram infectados experimentalmente per os com 10 larvas L4 de Eustrogylides ignotus (n= 10 e 50 L3 de Contracaecum multipapillatum (n= 50 coletados em traíras (Hoplias malabaricus naturalmente parasitadas a fim de se avaliar a patogenicidade induzida por essas espécies de nematóides em mamíferos. Dois coelhos (20% infectados com E. ignotus morreram antes do quarto dia p

  20. Which is the best environment for the development of the early life stages of fish during the dry season? Qual o melhor ambiente para o desenvolvimento das fases jovens de peixes durante a estação seca?

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    André Luiz Henríques Esguícero

    2010-09-01

    Full Text Available AIM: The main objective of this study was to investigate the quality of habitats for early life stages of fish in the Jacaré-Guaçu River, during the dry phase; METHODS: For assessing the quality of the habitats for the development of early life stages, the relative condition factor was applied to the juveniles of five species of fishes, captured in four different habitats (reservoir, floodplain lake, main river, and tributary. The juveniles were caught in macrophytes of the littoral zone by a rectangular sieve, in the dry season of 2008 and 2009; RESULTS: The species Astyanax altiparanae thrived similarly in the four habitats, and A. fasciatus, Hyphessobrycon eques, Hoplias malabaricus and Serrapinnus notomelas, showed higher values of relative condition factors in the reservoir and in the lake. Among the species, A. fasciatus showed the highest values of the relative condition factor in these two habitats; CONCLUSIONS: It is likely that the complexity of the macrophytes' stands and the current velocity were the main factors influencing the development of juveniles. It was found that a lower current velocity can propitiated the establishment of a greater richness of macrophytes, which in turn can influence positively the development of fish juveniles. Moreover, a higher current velocity ends in a higher energy demand for swimming.OBJETIVO: O objetivo principal deste estudo foi investigar a qualidade dos habitats para as primeiras fases de vida dos peixes no Rio Jacaré-Guaçu, durante a estação seca; MÉTODOS: Para avaliar a qualidade dos hábitats para o desenvolvimento das primeiras fases, o fator de condição relativo foi aplicado aos juvenis de cinco espécies de peixes, capturados em quatro habitats diferentes (reservatório, lago de planície de inundação, canal principal e tributário. Os juvenis foram coletados em macrófitas litorâneas com uma peneira retangular, na estação seca de 2008 e 2009; RESULTADOS: Somente Astyanax

  1. Alternagin-C (ALT-C), a disintegrin-like protein from Rhinocerophis alternatus snake venom promotes positive inotropism and chronotropism in fish heart.

    Science.gov (United States)

    Monteiro, D A; Kalinin, A L; Selistre-de-Araujo, H S; Vasconcelos, E S; Rantin, F T

    2016-02-01

    Alternagin-C (ALT-C) is a disintegrin-like protein purified from the venom of the snake, Rhinocerophis alternatus. Recent studies showed that ALT-C is able to induce vascular endothelial growth factor (VEGF) expression, endothelial cell proliferation and migration, angiogenesis and to increase myoblast viability. This peptide, therefore, can play a crucial role in tissue regeneration mechanisms. The aim of this study was to evaluate the effects of a single dose of alternagin-C (0.5 mg kg(-1), via intra-arterial) on in vitro cardiac function of the freshwater fish traíra, Hoplias malabaricus, after 7 days. ALT-C treatment increased the cardiac performance promoting: 1) significant increases in the contraction force and in the rates of contraction and relaxation with concomitant decreases in the values of time to the peak tension and time to half- and 90% relaxation; 2) improvement in the cardiac pumping capacity and maximal electrical stimulation frequency, shifting the optimum frequency curve upward and to the right; 3) increases in myocardial VEGF levels and expression of key Ca(2+)-cycling proteins such as SERCA (sarcoplasmic reticulum Ca(2+)-ATPase), PLB (phospholamban), and NCX (Na(+)/Ca(2+) exchanger); 4) abolishment of the typical negative force-frequency relationship of fish myocardium. In conclusion, this study indicates that ALT-C improves cardiac function, by increasing Ca(2+) handling efficiency leading to a positive inotropism and chronotropism. The results suggest that ALT-C may lead to better cardiac output regulation indicating its potential application in therapies for cardiac contractile dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The Canal da Piracema at Itaipu Dam as a fish pass system

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    Sérgio Makrakis

    Full Text Available The Canal da Piracema is the longest (nearly 10 km fish pass system in the world. The construction of this fish pass was somehow controversial, because it connected two distinct ichthyofaunistic provinces. This study evaluated the ichthyofauna present in the Canal da Piracema and the abundance and distribution of long-distance migratory fish species along this fish pass system (evaluated possible selectivity. The Canal da Piracema was shown to be difficult to sample because of its environmental heterogeneity: artificial ponds, ladders and nature-like fish pass. To solve this problem, we used several fishing gears, adequate for the several biotopes present (unstructured and structured littoral were sampled with seining nets and electrofishing; lentic were sampled with gillnets and longlines (deeper areas; and rapid water areas were sampled with cast nets. The ichthyofauna of the Canal da Piracema followed the pattern for South America and the Paraná River, with a predominance of Characiformes and Siluriformes. The most representative families were Characidae, Anostomidae, Pimelodidae and Loricariidae. We captured 116 species (17 were long-distance migratory during the period studied. Small-sized species were predominant in unstructured and structured littoral areas, especially Bryconamericus exodon and Apareiodon affinis.The most abundant species was Hypostomus spp. in lentic areas, followed by Iheringichthys labrosus. Hoplias aff. malabaricus predominated in deeper lentic areas. Long-distance migratory species were abundant in rapid waters; they were Prochilodus lineatus and Leporinus elongatus. The sharp reduction in the number of species, including migratory ones, is an indication that the Canal da Piracema is selecting the species that ascend it. Therefore, the search for information on the efficiency of the various fish passes present in the Canal da Piracema is fundamental, to facilitate upward movements of fish. If this is reached, this

  3. Effects of trophic exposure to diclofenac and dexamethasone on hematological parameters and immune response in freshwater fish.

    Science.gov (United States)

    Ribas, João Luiz Coelho; Zampronio, Aleksander R; Silva de Assis, Helena C

    2016-04-01

    The aim of the present study was to evaluate the effects of diclofenac and dexamethasone on hematological parameters and immune response in the fish species Hoplias malabaricus after trophic exposure. Fish were fed twice every week with Astyanax sp., which were given an intraperitoneal inoculation with diclofenac (0 μg/kg, 0.2 μg/kg, 2.0 μg/kg, or 20.0 μg/kg) or dexamethasone (0.03 μg/kg, 0.3 μg/kg, or 3.0 μg/kg). After 12 doses, the hematological parameters and lipopolysaccharide-induced nitric oxide production by head kidney monocytic lineage were evaluated. Exposed fish also received 1 mg/kg of carrageenan intraperitoneal, and cell migration to the peritoneal cavity was evaluated after 4 h. Diclofenac and dexamethasone altered the red blood cell count, as well as hematocrit and hemoglobin levels. The total blood leukocyte count decreased in all groups. A significantly reduced carrageenan-induced leukocyte migration to the peritoneal cavity, particularly of polymorphonuclear cells, was observed at all tested doses, suggesting a possible immunosuppressive effect. The basal nitric oxide synthesis of head kidney cell cultures was reduced at the highest dose of diclofenac and was increased at the highest dose of dexamethasone. The lipopolysaccharide-stimulated nitric oxide production was reduced in all treatments, thus corroborating the immunosuppressive effect. Although some fish responses were variable for different drugs, the results suggested that trophic exposure to diclofenac and dexamethasone can lead to hematological changes and immunotoxic effects, causing negative impacts in aquatic organisms. © 2015 SETAC.

  4. Improved ROS defense in the swimbladder of a facultative air-breathing erythrinid fish, jeju, compared to a non-air-breathing close relative, traira.

    Science.gov (United States)

    Pelster, Bernd; Giacomin, Marina; Wood, Chris M; Val, Adalberto L

    2016-07-01

    The jeju Hoplerythrinus unitaeniatus and the traira Hoplias malabaricus are two closely related erythrinid fish, both possessing a two-chambered physostomous swimbladder. In the jeju the anterior section of the posterior bladder is highly vascularized and the swimbladder is used for aerial respiration; the traira, in turn, is a water-breather that uses the swimbladder as a buoyancy organ and not for aerial oxygen uptake. Observation of the breathing behavior under different levels of water oxygenation revealed that the traira started aquatic surface respiration only under severe hypoxic conditions and did not breathe air. In the jeju air-breathing behavior was observed under normoxic conditions, and the frequency of air-breathing was significantly increased under hypoxic conditions. Unexpectedly, even under hyperoxic conditions (30 mg O2 L(-1)) the jeju continued to take air breaths, and compared with normoxic conditions the frequency was not reduced. Because the frequently air-exposed swimbladder tissue faces higher oxygen partial pressures than normally experienced by other fish tissues, it was hypothesized that in the facultative air-breathing jeju, swimbladder tissue would have a higher antioxidative capacity than the swimbladder tissue of the water breathing traira. Measurement of total glutathione (GSSG/GSH) concentration in anterior and posterior swimbladder tissue revealed a higher concentration of this antioxidant in swimbladder tissue as compared to muscle tissue in the jeju. Furthermore, the GSSG/GSH concentration in jeju tissues was significantly higher than in traira tissues. Similarly, activities of enzymes involved in the breakdown of reactive oxygen species were significantly higher in the jeju swimbladder as compared to the traira swimbladder. The results show that the jeju, using the swimbladder as an additional breathing organ, has an enhanced antioxidative capacity in the swimbladder as compared to the traira, using the swimbladder only as a

  5. Air-breathing behavior, oxygen concentrations, and ROS defense in the swimbladders of two erythrinid fish, the facultative air-breathing jeju, and the non-air-breathing traira during normoxia, hypoxia and hyperoxia.

    Science.gov (United States)

    Pelster, Bernd; Wood, Chris M; Jung, Ellen; Val, Adalberto L

    2018-05-01

    The jeju Hoplerythrinus unitaeniatus and the traira Hoplias malabaricus are two neighboring genera from the family of erythrinid fish, both possessing a two-chambered physostomous swimbladder. In the jeju the anterior section of the posterior bladder is highly vascularized, and the swimbladder is used for aerial respiration; the traira, in turn, is a water-breather that uses the swimbladder as a buoyancy organ and not for aerial oxygen uptake. Measurement of swimbladder oxygen partial pressure (PO 2 ) of fish kept at 26 °C in normoxic, hyperoxic (28-32 mg O 2 L - 1 ) or hypoxic (1-1.5 mg O 2 L - 1 ) water revealed constant values in traira swimbladder. Under normoxic conditions in the jeju swimbladder PO 2 was higher than in traira, and the PO 2 significantly increased under hyperoxic conditions, even in the absence of air breathing. In jeju, air-breathing activity increased significantly under hypoxic conditions. Hypoxic air-breathing activity was negatively correlated to swimbladder PO 2 , indicating that the swimbladder was intensely used for gas exchange under these conditions. In traira, the capacity of the ROS defense system, as assessed by measurement of activities of enzymes involved in ROS degradation and total glutathione (GSH + GSSG) concentration, was elevated after 4 h of hyperoxic and/or hypoxic exposure, although swimbladder PO 2 was not affected. In jeju, experiencing a higher variability in swimbladder PO 2 due to the air-breathing activity, only a reduced responsiveness of the ROS defense system to changing environmental PO 2 was detected.

  6. Diferentes densidades de estocagem na larvicultura do trairão Hoplias lacerdae - DOI: 10.4025/actascibiolsci.v27i1.1366 Different stocking densities in trairão (Hoplias lacerdae larvae rearing - DOI: 10.4025/actascibiolsci.v27i1.1366

    Directory of Open Access Journals (Sweden)

    Maria Célia Portella

    2005-03-01

    Full Text Available O objetivo do experimento foi avaliar o efeito da densidade de estocagem na larvicultura do trairão. Larvas com sete dias de vida foram submetidas a quatro densidades de estocagem: 10, 30, 60 e 90 larvas/L. Foram utilizados 16 recipientes com volume útil de 5 L cada, dotados de aeração constante e dispostos em sistema de banho termostatizado. Cada tratamento teve quatro repetições. As unidades experimentais foram cobertas com lona plástica preta para manter o ambiente interno escuro, sendo descobertas somente para o manejo diário. Ao final do experimento, após 15 dias de alimentação com náuplios de Artemia, não foram encontradas diferenças significativas (P > 0,05 de crescimento dos animais nas diferentes densidades. Esse mesmo resultado também foi observado com relação às taxas de sobrevivência, de mortalidade e de canibalismo. A utilização da maior densidade de estocagem resultou em maior produção de larvas de trairão, possibilitando a criação mais intensiva da espécie nessa faseThis experiment was carried out to evaluate the effects of the stocking density on trairao larvae rearing. Seven days old larvae were submitted to four different stocking densities: 10, 30, 60 and 90 larvae/L. Sixteen vessels with 5 L each supplied with constant aeration were kept in a thermostatic bath. Each treatment had four replications. In order to keep the internal environment dark, all the experimental units were covered with a black plastic and it was uncovered only during the daily management. At the end of the experiment, after 15 days of feeding with Artemia nauplii, no significant differences were found (P > 0.05 on growth among the evaluated densities. The same results were also registered for the survival, mortality and cannibalism rates. Higher stocking density resulted in higher production of trairao larvae rearing, allowing intensive rearing of this species in this phase

  7. New records of philometrids (Nematoda: Philometridae) from marine fishes off Australia, including description of four new species and erection of Digitiphilometroides gen. n.

    Science.gov (United States)

    Moravec, Frantisek; Barton, Diane P

    2018-04-16

    The following six species of the Philometridae (Nematoda: Dracunculoidea) were recorded from marine fishes off the northern coast of Australia in 2015 and 2016: Philometra arafurensis sp. n. and Philometra papillicaudata sp. n. from the ovary and the tissue behind the gills, respectively, of the emperor red snapper Lutjanus sebae (Cuvier); Philometra mawsonae sp. n. and Dentiphilometra malabarici sp. n. from the ovary and the tissue behind the gills, respectively, of the Malabar blood snapper Lutjanus malabaricus (Bloch et Schneider); Philometra sp. from the ovary of the goldbanded jobfish Pristipomoides multidens (Day) (Perciformes: all Lutjanidae); and Digitiphilometroides marinus (Moravec et de Buron, 2009) comb. n. from the body cavity of the cobia Rachycentron canadum (Linnaeus) (Perciformes: Rachycentridae). Digitiphilometroides gen. n. is established based on the presence of unique digital cuticular ornamentations on the female body. New gonad-infecting species, P. arafurensis and P. mawsonae, are characterised mainly by the length of spicules (252-264 µm and 351-435 µm, respectively) and the structure of the gubernaculum, whereas P. papillicaudata is characterised mainly by the body length (70 mm) of gravid female, extent of the oesophageal gland, size of caudal projections and the location in the host. Dentiphilometra malabarici differs from congeners mainly in the arrangement of circumoral teeth (in a single row), extent of the oesophageal gland and the absence of sclerotised teeth or protuberances on the oesophageal lobes in the mouth. Digitiphilometroides marinus has not previously been reported from fishes in Australian waters.

  8. Complete mitochondrial genome of freshwater shark Wallago attu (Bloch & Schneider) from Indus River Sindh, Pakistan.

    Science.gov (United States)

    Laghari, Muhammad Younis; Lashari, Punhal; Xu, Peng; Zhao, Zixia; Jiang, Li; Narejo, Naeem Tariq; Xin, Baoping; Sun, Xiaowen; Zhang, Yan

    2016-01-01

    Complete mitochondrial genome of fresh water giant catfish, Wallago attu, was isolated by LA PCR (TakaRa LAtaq, Dalian, China); and sequenced by Sanger's method to obtain the complete mitochondrial genome. The complete mitogenome was 15,639 bp in length and contains 13 typical vertebrate protein-coding genes, 2 rRNA and 22 tRNA genes. The whole genome base composition was estimated to be 31.17% A, 28.15% C, 15.55% G and 25.12% T. The complete mitochondrial genome of catfish, W. attu, provides the fundamental tools for genetic breeding.

  9. GROWTH AND EXPLOITATION STATUS (Channa striata Bloch, 1793 IN LUBUK LAMPAM FLOODPLAINS, SOUTH SUMATERA

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    Zulkarnaen Fahmi

    2013-06-01

    Full Text Available Due to the economic importance of C. striata in Lubuk Lampam floodplains (Indonesia, this study is aimed to estimate the biological and population parameters required for proposing a future plan to sustain and manage this valuable fish resource. The growth, mortality and explotation ratio of Channa striata estimated by employing FiSATProgramme are reported. The parameters of Von Bertalanffy growth model of 1,529 sample fishes were estimated as K= 0.36/ year, L” = 72.98 cm and to = -0.52 year. The coefficients of total mortality (Z, natural mortality (M and fishing mortality (F were 1.72, 0.73 and 0.99 year-1 respectively. Relative yield per recruit analysis shows that the presentexploitation rate (E was 0.58. Yield per recruit can be maximized at the exploitation ratio of 0.5 and Lc/Linf values of 0.3. The Yield per recruit and biomass per recruit models indicated that, the fisheries status of C. striata in Lubuk Lampam floodplains exceed the limit reference point (Fmax, thus stock of this species in Lubuk Lampam floodplains is indicated being driving down.Reduction in fishing effort and increase number of selective fishing gears are suggested to sustain the fishery of Channa striata in Lubuk Lampam floodplains.

  10. Stock assessment of the lizardfish Saurida tumbil (Bloch, 1795 in Jizan fisheries, Saudi Arabia

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    Mohamed Hosny Gabr

    2017-06-01

    Full Text Available To evaluate the current stock status of the lizardfish Saurida tumbil in Jizan fisheries, growth parameters, mortality coefficients and size at first capture were determined. Otoliths collected from 623 specimens were used for age determination and back calculations of lengths at ages. The growth parameters of von Bertalanffy were estimated and found to be L∞ = 52.98 cm, K = 0.27 yr−1, and to = -0.84 yr. The mortality coefficients were estimated to be 1.365, 0.403 and 0.962 yr−1 for the total 'Z', natural 'M', and fishing 'F' mortality coefficient, respectively. The current exploitation rate 'Ecur' was 0.705 yr−1. The length at first capture 'Lc' was determined to be 25.1 cm. The relative yield and biomass per recruit were estimated, and the results showed that the exploitation rate is currently higher than Emax = 0.685 yr−1 and E0.1 = 0.551 yr−1 as biological reference points, which indicates that the stock of Saurida tumbil in Jizan fisheries is currently overexploited.

  11. Proof of an entropy conjecture for Bloch coherent spin states and its generalizations

    DEFF Research Database (Denmark)

    H. Lieb, Elliott; Solovej, Jan Philip

    2014-01-01

    Wehrl used Glauber coherent states to define a map from quantum density matrices to classical phase space densities and conjectured that for Glauber coherent states the mininimum classical entropy would occur for density matrices equal to projectors onto coherent states. This was proved by Lieb...

  12. Bloch-Wave Engineered Submicron Diameter Micropillars with Quality Factors Exceeding 10,000

    DEFF Research Database (Denmark)

    Hofling, S.; Lermer, M.; Gregersen, Niels

    2011-01-01

    Adiabatic design submicron diameter quantum-dot micropillars have been designed and implemented for cavity quantum electrodynamics experiments. Ultra-high experimental quality factors (>10,000) are obtained for submicron diameters and strong light-matter interaction is observed....

  13. Caloric densities of ingested food of Etroplus suratensis (Bloch) grown in a culture pond

    Digital Repository Service at National Institute of Oceanography (India)

    Sumitra-Vijayaraghavan; Krishnakumari, L.; Dhawan, R.M.; Royan, J.P.

    Analyses of stomach contents of E.suratensis indicated that it is principally a phytoplankton-detritus feeder. Biochemical analyses of the ingested food showed that of the total consumed food, 44% was contributed by ash content, while 56...

  14. Pinning of 1800 Bloch walls at etched nuclear tracks in LPE-grown iron garnet films

    International Nuclear Information System (INIS)

    Krumme, J.; Bartels, I.; Strocka, B.; Witter, K.; Schmelzer, C.; Spohr, R.

    1977-01-01

    For increasing the magnetic-wall coercivity H/sup w//sub c/ in liquid-phase epitaxial (LPE) ferrimagnetic garnet films of composition (Gd,Bi) 3 (Fe,Al,Ga) 5 O 12 , magnetic-wall ''traps'' are formed via bombardment by xenon ions with 180-MeV/ion energy and doses between 10 6 and 10 8 cm -2 . For efficient wall pinning, the width of the nuclear damage tracks associated with the ion trajectories in the film have been enlarged to about the wall width by using a selective (chemical) etchant that makes use of the drastically increased etching rate in the damaged track volume. Therefore, channels of cylindrical or prismatic cross section are created having a width of a few 10 2 to about 10 3 A and a length of more than 10 μm at the given etching conditions. The pinning capability of such channels can be further enhanced in films that are grown under planar compressive or tensile misfit strain. Then, strain relaxation occurs in the vicinity of these channels which results in steep gradients of the magnetic-wall energy via magnetostriction. These strain halos extend sufficiently beyond the channels so that efficient wall pinning is observed, even if the channel cross section is small compared with the wall width. Thermomagnetic compensation-point writing in LPE garnet film, that were treated accordingly, yield a pattern of stable magnetic domains of down to 8 μm in diameter in 3-μm-thick layers. The effect of etched nuclear tracks on the magnetic-wall coercivity can be interpreted satisfactorily with present models on H/sup w//sub c/

  15. A Bloch modal approach for engineering waveguide and cavity modes in two-dimensional photonic crystals

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Kristensen, Philip Trøst; Mørk, Jesper

    2014-01-01

    uses no external excitation and determines the quasi-normal modes as unity eigenvalues of the cavity roundtrip matrix. We demonstrate the method and the quasi-normal modes for two types of two-dimensional photonic crystal structures, and discuss the quasi-normal mode eld distributions and Q-factors...

  16. Controlled Population of Floquet-Bloch States via Coupling to Bose and Fermi Baths

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    Karthik I. Seetharam

    2015-12-01

    Full Text Available External driving is emerging as a promising tool for exploring new phases in quantum systems. The intrinsically nonequilibrium states that result, however, are challenging to describe and control. We study the steady states of a periodically driven one-dimensional electronic system, including the effects of radiative recombination, electron-phonon interactions, and the coupling to an external fermionic reservoir. Using a kinetic equation for the populations of the Floquet eigenstates, we show that the steady-state distribution can be controlled using the momentum and energy relaxation pathways provided by the coupling to phonon and Fermi reservoirs. In order to utilize the latter, we propose to couple the system and reservoir via an energy filter which suppresses photon-assisted tunneling. Importantly, coupling to these reservoirs yields a steady state resembling a band insulator in the Floquet basis. The system exhibits incompressible behavior, while hosting a small density of excitations. We discuss transport signatures and describe the regimes where insulating behavior is obtained. Our results give promise for realizing Floquet topological insulators.

  17. Bloch-wave engineering of quantum dot-micropillars for cavity quantum electrodynamics experiments

    DEFF Research Database (Denmark)

    Lermer, Matthias; Gregersen, Niels; Dunzer, Florian

    2012-01-01

    scattering loss leads to record-high visibility of the strong coupling in MPs with modest oscillator strength quantum dots. A quality factor of 13,600 and a Rabi splitting of 85 \\mueV with an estimated visibility v of 0.38 are observed for a small mode volume MP with a diameter dc of 850 nm....

  18. Wannier-Bloch approach to localization in high-harmonics generation in solids

    Czech Academy of Sciences Publication Activity Database

    Osika, E.N.; Chacon, A.; Ortmann, L.; Suarez, N.; Perez-Hernandez, J.A.; Szafran, B.; Ciappina, Marcelo F.; Sols, F.; Landsman, A.S.; Lewenstein, M.

    2017-01-01

    Roč. 7, č. 2 (2017), 1-14, č. článku 021017. ISSN 2160-3308 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : field * photoemission * spectroscopy * ionization Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 12.789, year: 2016

  19. Electronic states in crystals of finite size quantum confinement of bloch waves

    CERN Document Server

    Ren, Shang Yuan

    2017-01-01

    This book presents an analytical theory of the electronic states in ideal low dimensional systems and finite crystals based on a differential equation theory approach. It provides precise and fundamental understandings on the electronic states in ideal low-dimensional systems and finite crystals, and offers new insights into some of the basic problems in low-dimensional systems, such as the surface states and quantum confinement effects, etc., some of which are quite different from what is traditionally believed in the solid state physics community. Many previous predictions have been confirmed in subsequent investigations by other authors on various relevant problems. In this new edition, the theory is further extended to one-dimensional photonic crystals and phononic crystals, and a general theoretical formalism for investigating the existence and properties of surface states/modes in semi-infinite one-dimensional crystals is developed. In addition, there are various revisions and improvements, including us...

  20. A counter example to the Bloch-Nordsieck theorem for quark-gluon scattering

    International Nuclear Information System (INIS)

    Doria, R.M.; Cambridge Univ.

    1983-01-01

    Quark-massless quark and quark-gluon scattering are studied in the infrared region. In both cases it is shown that the infrared divergences do not cancel. This breaks the factorization theorems. We raise the question about how to use the impulse approximation for reactions that contain IR singularities. (orig.)

  1. A counter example of the Bloch Nordsiek theorem for the quark-gluon scattering

    International Nuclear Information System (INIS)

    Doria, R.M.

    Quark-massless quark and quark gluon scattering are studied in the Infrared region. In both cases is shown that the infrared divergences do not cancel. This breaks the factorization theorems. It is raised the question about how to use the impulse approximation for reactions that contain IR singularities. (Author) [pt

  2. Finding of triploid Carassius Gibelio (Bloch, 1780)(Cypriniformes, Cyprinidae), in Turkey

    Czech Academy of Sciences Publication Activity Database

    Kalous, Lukáš; Memis, D.; Bohlen, Jörg

    2004-01-01

    Roč. 28, č. 1 (2004), s. 77-79 ISSN 0399-0974 R&D Projects: GA ČR GA523/02/0460 Institutional research plan: CEZ:AV0Z5045916 Keywords : carassius gibelio * cyprinidae * Turkey Subject RIV: ED - Physiology Impact factor: 0.312, year: 2004

  3. Microbiological studies of irradiated dried mackerel (Cybium guttatum Bloch and Schnieder)

    International Nuclear Information System (INIS)

    Ahmed, M.; Joardar, S.K.; Bhuiya, A.D.; Islam, M.S.

    1985-01-01

    Microbiological studies of sun-dried mackerel fish, Cybium guttatum, were conducted by exposing the fish to doses of gamma-rays from 0.50 to 8.00 kGy at the storage temperatures of 10.20 and 30oC. The reduction of bacterial flora was determined both qualitatively and quantitatively. At 4 kGyone log cycle reduction of bacterial flora was achieved and at 8 kGy the reduction was nearly 2 log cycles. The irradiated samples were stored for two months and viable bacterial counts were taken. Except in a few cases, reduction in viable counts occurred. Bacterial isolates were made and both Mesophiles and Psychrophiles were identified. Micrococcus, Staphylococcus, Corymebacterium and some Bacillus were found to be the prominent groups in mesophiles, while Bacillus dominated in psychrophiles. Staphylococcus was found to be the most dominant bacterial flora in unirradiated samples, but they were highly affected by irradiation

  4. Age determination and feeding habits of Nemipterus japonicus (Bloch, 1791) in the northern Oman Sea

    OpenAIRE

    Afshari, M.; Valinassab, T.; Seifabadi, J.; Kamaly, E.

    2013-01-01

    Age determination and feeding habits of the Japanese threadfin bream, Nemipterus japonicus, was carried out in the northern Oman Sea (Chabahar area), based on 212 specimens collected between September 2009 and May 2010. The minimum and maximum fork length and body weight were measured as 145, 258 mm and 55.31, 288.12 g. The relationship between Body Weight (BW) and Fork Length (FL) for all individuals was estimated as BW= 0.0001×FL2.83 (r2 = 0.9425, n= 212). The Vacuity Index (VI) was 55.2% t...

  5. Antimicrobial activity of different tissues of snakehead fish Channa striatus (Bloch

    Directory of Open Access Journals (Sweden)

    Pravin Kumar N

    2012-05-01

    Full Text Available Objective: The aim of this study was to identify the presence of antimicrobial activity in different organs/tissues (gills, blood, skin, liver, intestine, kidney, tissue and ovary extract of snakehead fish Channa striatus. Methods: A total of 48 fractions from the organs and tissue extracts were obtained by solid-phase extraction and the fractions were assayed for antimicrobial activity. The screening of antimicrobial activity for all the fractions were tested against 8 human pathogens including Gram positive (Methicillin-resistant Staphylococcus aureus (MRSA, Staphylococcus aureus, Bacillus cereus and Gram negative bacteria (Salmonella enteritidis, Shigella flexneri, Acinetobacter baumanni, Escherichia coli, Klebsiella pneumoniae using the British Society for Antimicrobial Chemotherapy (BSAC standardized disc susceptibility test method. The activity was measured in terms of zone of inhibition in mm. Results: The results indicated that, among the 8 organs/tissues tested only blood and gills extract fractions (40 and 60 % ACN fraction showed inhibition against Escherichia coli and 60 % ACN fraction of gill extract showed inhibition against Salmonella enteritidis. Protein profile analysis by SDS-PAGE showed that antimicrobial activity of the partially purified blood and gill tissue extracts might be due to low molecular weight peptides. Conclusions: The present study showed that, gill and blood extracts of Channa striatus can be a potential source of an antimicrobial protein for specific human pathogens.

  6. Effect of three diets in the experimental culture of the common snook (Centropomus undecimalis Bloch, 1792

    Directory of Open Access Journals (Sweden)

    Carmen Polonía R

    2017-09-01

    Full Text Available Objective. To evaluate the effect of three diets on the growth of juvenile common snook (Centropomus undecimalis maintained in freshwater ponds Materials and methods. 108 juvenile of common snook were homogenous and randomly distributed in a pond, divided into 9 corrals of 50 m2. Three diets were applied (D1: commercial food for trout, 45% protein; D2: commercial food for cobia, 50% protein and D3: fresh fish, 17.52% protein. The experimental treatments were assigned in triplicate and diets were supplied in two daily doses. Biometrics were performed every 20 days to assess: weight, size, Length-Weight correlation, Feed Conversion Factor (FCA, Condition Factor (K, Specific Growth Rate (SGR and survival; during 120 days. The results were evaluated with a one-way ANOVA, when differences (p<0.05 were found the means were compared by test Median Mood, otherwise a pos-hoc test was performed (Tukey HSD. Results. Applying the test of Mood Median significant differences were found, showing the highest growth with D2, where values of SGR=0.65±0.09 g/day; FCA=3.76 and K=0.81±0.06. Survival was D1=51.4%, D2=50% and D3=77.8% without inferring statistically among the different diets. Conclusions. The culture of this species in freshwater ponds with commercial food for cobia, is viable in terms of growth and weight gain.

  7. Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch.

    Directory of Open Access Journals (Sweden)

    Kasi Marimuthu

    Full Text Available Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p0.05 in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish.

  8. Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch).

    Science.gov (United States)

    Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M Aminur; Subramaniam, Sreeramanan

    2013-01-01

    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (pbuprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (pbuprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish.

  9. Toxicity of Buprofezin on the Survival of Embryo and Larvae of African Catfish, Clarias gariepinus (Bloch)

    OpenAIRE

    Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M. Aminur; Subramaniam, Sreeramanan

    2013-01-01

    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatme...

  10. Discontinuous Galerkin Approximations for Computing Electromagnetic Bloch Modes in Photonic Crystals

    NARCIS (Netherlands)

    Lu, Zhongjie; Cesmelioglu, A.; van der Vegt, Jacobus J.W.; Xu, Yan

    We analyze discontinuous Galerkin finite element discretizations of the Maxwell equations with periodic coefficients. These equations are used to model the behavior of light in photonic crystals, which are materials containing a spatially periodic variation of the refractive index commensurate with

  11. Positronium bloch function, and trapping of positronium in vacancies, in ice

    International Nuclear Information System (INIS)

    Mogensen, O.E.; Eldrup, M.

    1977-08-01

    Positron annihilation techniques were used to study the behaviour of positronium (Ps) in pure light and heavy ice in the temperature interval -185 2 was extracted by very detailed computer analyses. A nearly-free-Ps theory, including phonon influence, could not explain the temperature dependence of /Asub(g vector)/ 2 . The Ps trapping in vacancies could not be explained in detail in terms of several models, including the simple 'trapping model'. A main difficulty was the fact that para-Ps and ortho-Ps are trapped at roughly the same amount at a certain vacancy concentration. Our results imply a high (several ppm) vacancy concentration at the melting point in ice in agreement with other independent estimates. This fact might introduce pronounced changes in currently accepted theories of the electrical properties of ice. (author)

  12. Effects of atrazine on endocrinology and physiology in juvenile barramundi, Lates calcarifer (Bloch).

    Science.gov (United States)

    Kroon, Frederieke J; Hook, Sharon E; Jones, Dean; Metcalfe, Suzanne; Osborn, Hannah L

    2014-07-01

    Exposure to certain environmental contaminants such as agricultural pesticides can alter normal endocrine and reproductive parameters in wild fish populations. Recent studies have found widespread pesticide contamination across the rivers that discharge into the Great Barrier Reef lagoon. Potential impacts on native fish species exposed to known endocrine disrupting chemicals such as atrazine, simazine, and diuron have not been assessed. In the present study, the authors examined the endocrine and physiological effects of short-term, acute exposure of environmentally relevant concentrations of analytical grade atrazine in juvenile barramundi (Lates calcarifer) in a controlled laboratory experiment. Expression of hepatic vitellogenin was not affected, supporting results of previous studies that showed that atrazine does not have a direct estrogenic effect via mediation of estrogen receptors. The lack of effect on brain cytochrome P19B (CYP19B) expression levels, combined with increases in testosterone (T) and 17β estradiol and a stable T:17β estradiol ratio, does not support the hypothesis that atrazine has an indirect estrogenic effect via modulation of aromatase expression. Gill ventilation rate, a measure of oxidative stress, did not change in contrast to other studies finding enhanced osmoregulatory disturbance and gill histopathology after atrazine exposure. To more closely reflect field conditions, the authors recommend that laboratory studies should focus more on examining the effects of commercial pesticide formulations that contain additional ingredients that have been found to be disruptive to endocrine function. © 2014 SETAC.

  13. Kuhu kadus antropoloogia? : ehk vajadus "inimloomuse" järele / Maurice Bloch ; tlk. Maarja Kaaristo

    Index Scriptorium Estoniae

    Bloch, Maurice

    2007-01-01

    Antropoloogia kui distsipliini akadeemilisest ajaloost, sotsiaal- ja kultuuriantropoloogia hariduse puudujääkidest. Antropoloogia põhilistest uurimisteemadest ja uurimisteooriatest: difusionismist, evolutsionismist ning funktsionalismist

  14. The quantum group, Harper equation and structure of Bloch eigenstates on a honeycomb lattice

    International Nuclear Information System (INIS)

    Eliashvili, M; Tsitsishvili, G; Japaridze, G I

    2012-01-01

    The tight-binding model of quantum particles on a honeycomb lattice is investigated in the presence of a homogeneous magnetic field. Provided the magnetic flux per unit hexagon is a rational of the elementary flux, the one-particle Hamiltonian is expressed in terms of the generators of the quantum group U q (sl 2 ). Employing the functional representation of the quantum group U q (sl 2 ), the Harper equation is rewritten as a system of two coupled functional equations in the complex plane. For the special values of quasi-momentum, the entangled system admits solutions in terms of polynomials. The system is shown to exhibit a certain symmetry allowing us to resolve the entanglement, and a basic single equation determining the eigenvalues and eigenstates (polynomials) is obtained. Equations specifying the locations of the roots of polynomials in the complex plane are found. Employing numerical analysis, the roots of polynomials corresponding to different eigenstates are solved and diagrams exhibiting the ordered structure of one-particle eigenstates are depicted. (paper)

  15. A Bloch mode expansion approach for analyzing quasi-normal modes in open nanophotonic structures

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Kristensen, Philip Trøst; Mørk, Jesper

    2014-01-01

    We present a new method for determining quasi-normal modes in open nanophotonic structures using a modal ex- pansion technique. The outgoing wave boundary condition of the quasi-normal modes is satisfied automatically without absorbing boundaries, representing a significant advantage compared...

  16. RÉGIMEN ALIMENTARIO DE SIETE ESPECIES ÍCTICAS EN EL EMBALSE DE LA HIDROELÉCTRICA URRÁ (CÓRDOBA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    V.J. Atencio-García

    2005-12-01

    Full Text Available El objeto del estudio fue evaluar el régimen alimentario de siete especies de peces que se han establecidoen el embalse de la Hidroeléctrica Urrá (HU. Se analizaron 453 estómagos, distribuidos así: 115 deperico (Tracheolypterus badeli cf, 111 de cacucho (Panaque gibbosus, 108 de yalúa (Cyphocharaxmagdalenae, 89 de mojarra amarilla (Caquetaia kraussii , 11 de moncholo (Hoplias malabaricus, 10 debarbul ( Pimelodus clarias y 9 de doncella ( Ageneoisus pardales . Los contenidos estomacales se evaluaronmediante frecuencia de ocurrencia (FO, frecuencia numérica (FN y el método gravimétrico (G. Sedeterminó la importancia de cada presa mediante el índice de categorización de presa (ICP y lasuperposición de dietas se analizó mediante el Índice de Morosita (IM. La distribución porcentual de loscontenidos estomacales de la yalúa mostró que el 95.5% correspondió al ítem detritus y el restante 4.5%a microlagas (Clorofitas y Bacillariofitas y protozoarios/rotíferos. La dieta del cacucho la conformaron enun 70.9% microalgas (Cianofitas, Clorofitas y Bacilariofitas y protozoarios/rotíferos y el restante 29.1%correspondieron al ítem detritus. Barbul (FO = 50%, FN = 46.2% y perico se alimentaron principalmentede insectos (FO = 73.9%, FN = 86.4%. La mojarra amarilla (FO = 87.1%, FN = 83.3%, doncella(FO = 92.3%, FN = 92.0% y moncholo (FO = 90.9%, FN = 90.9% prefieren peces como cachanita(Roeboides dayi y sardinas ( Astianax sp. Los resultados sugieren que yalúa es detritívoro iliófago, cacuchoes detritívoro, perico y barbul son carnívoros insectívoros y doncella, moncholo y mojarra amarilla soncarnívoros piscívoros.

  17. Influence of ecological factors and of land use on mercury levels in fish in the Tapajós River basin, Amazon.

    Science.gov (United States)

    Sampaio da Silva, D; Lucotte, M; Paquet, S; Davidson, R

    2009-05-01

    Mercury (Hg) contamination of riparian communities and of environmental compartments of the Amazon can be directly related to the occupation of the territory. The objective of this study was to identify the characteristics of aquatic environments that are associated with high levels of Hg in ichthyofauna. Our research aimed at determining the influence of variables related to fish ecology, types of aquatic environment, fishing activities by local riparian populations, and watershed use on the levels of contamination of ichthyofauna. Six sites were sampled during two distinct periods of the hydrological cycle: at the beginning of descending waters and during low waters. We focused on ten dominant fish species representing four trophic levels: Curimata inornata, Geophagus proximus, Schizodon vittatum, Leporinus fasciatus, Anostomoides laticeps, Hemiodus unimaculatus, Caenotropus labyrinthicus, Hoplias malabaricus, Plagioscion squamosissimus, Acestrorhynchus falcirostris. The study sites, which included lotic and lentic habitats, are exploited year-round by local riparian communities. Spatial variations in Hg contamination in ichthyofauna were determined by factorial analysis of variance taking into account fish diets, seasons, and sampling sites. Multiple regressions were used to check the influence of ecological and anthropogenic variables and variables related to watershed uses, on Hg levels in key species representing the four trophic groups. Each variable was checked independently. Next, multiple regressions were used to verify the concomitant influence of selected variables. Independently of the study site and the phase of the hydrologic cycle, fish Hg contamination followed the trend piscivores>omnivores>herbivores>detritivores. In all the aquatic study sites, Hg levels measured in predatory species were often higher than the 500 ng/g fresh weight threshold. Mean Hg levels in key species were significantly higher during descending waters in lotic environments

  18. Infección por Gnathostoma (Spirurida: Gnathostomatidae en Hoplias microlepis: prevalencia, correlación con la talla del pez, huéspedes e implicaciones para salud pública en Ecuador

    Directory of Open Access Journals (Sweden)

    Juan José Alava

    2009-12-01

    Conclusiones. La gnathostomiasis sigue siendo prevalente en la zona costera de Ecuador y el agente patógeno es aún encontrado en el huésped intermediario. Diversos mamíferos neotropicales estarían actuando como huésped reservorio definitivo en el ciclo biológico de Gnathostoma en Ecuador.

  19. Feeding ecology of stream-dwelling fishes from a coastal stream in the Southeast of Brazil

    Directory of Open Access Journals (Sweden)

    Rosana Mazzoni

    2007-07-01

    Full Text Available The relationship between ontogenetic variation of intestine length and feeding habits of five stream-dwelling fish species from the Ubatiba River were investigated. Analysed data were based on two size categories (juveniles and adults and two food categories (animal and vegetal. Diet composition of each size category revealed that Astyanax janeiroensis and Geophagus brasiliensis changed food preference throughout ontogeny and switched from omnivorous/carnivorous to omnivorous/herbivorous and from omnivorous/carnivorous to omnivorous, respectively. These changes were followed by ontogenetic changes in the Intestinal Coefficient (IC. No ontogenetic differences were registered for IC and food categories consumed by Hoplias malabaricus but significant differences in the size of consumed preys as well as positive correlation between fish size (predator and prey size was observed. Food items (within animal category consumed by the adult Pimelodella lateristriga were mainly based on allochthonous arthropods whereas juvenile individuals fed with the same intensity on allochthonous and autochthonous arthropods; both juveniles and adult individuals of Mimagoniates microlepis were mainly allochthonous feeders. Mean IC values of Pimelodella lateristriga and Mimagoniates microlepis did not change along body growth. Although changes in food category consumption were not common among all the studied species, changes in the resource exploitation strategy was a rule among them, except for Mimagoniates microlepis.Foi investigada a relação entre as variações ontogenéticas do comprimento do intestino e os hábitos alimentares de cinco espécies de peixes do rio Ubatiba, RJ. Os dados analisados foram baseados em duas categorias de tamanho (jovens e adultos de cada espécie e duas categorias de alimento (animal e vegetal. A composição da dieta de cada categoria de tamanho revelou que Astyanax janeiroensis e Geophagus brasiliensis mudaram a prefer

  20. Low-loss bloch wave guiding in open structures and highly compact efficient waveguide-crossing arrays

    Science.gov (United States)

    Popovic, Milos

    2011-03-08

    Low-loss waveguide structures may comprise a multimode waveguide supporting a periodic light intensity pattern, and attachments disposed at the waveguide adjacent low-intensity regions of the light intensity pattern.

  1. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    International Nuclear Information System (INIS)

    Mishra, Ashish K.; Mohanty, Banalata

    2009-01-01

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  2. Genetic evidence for gonochoristic reproduction in gynogenetic silver crucian carp (Carassius auratus gibelio bloch) as revealed by RAPD assays.

    Science.gov (United States)

    Zhou, L; Wang, Y; Gui, J F

    2000-11-01

    Sex evolution has been a debating focus in evolutionary genetics. In lower vertebrates of reptiles, amphibians, and fish, a species or a bioform reproduces either sexually or asexually but never both. A few species were found to consist of all females in fish. These all-female species can propagate by asexual reproduction modes, such as gynogenesis and hybridogenesis. However, the coexistence of sexuality and asexuality in a single species was recently noted only in a cyprinid fish silver crucian carp, Carassius auratus gibelio. This fish had been demonstrated to be capable of gynogenesis stimulated by sperm from other related species. Surprisingly, natural populations of this fish consist of a minor but significant portion (approx. 20%) of males. As different clones with specific phenotypic and genetic characteristics have been found, and RAPD markers specific to each clone have recently been identified, this fish offers many advantages for analyzing whether or not genetic recombination occurs between different clones. In this study, artificial propagation was performed in clone F and clone D. Ovulated eggs from clone F were divided into two parts and respectively inseminated with sperm from a clone D male and from a red common carp (Cyprinus carpio) male. The control clone D individuals were selected from gynogenetic offspring of clone D activated by sperm of red common carp. The phenotype and sex ratio in the experimental groups were also observed. Using RAPD molecular markers, which allow for reliable discrimination and genetic analysis of different clones, we have revealed direct molecular evidence for gonochoristic reproduction in the gynogenetic silver crucian carp and confirmed a previous hypothesis that the silver crucian carp might reproduce both gynogenetically and gonochoristically. Therefore, we conclude that the silver crucian carp possesses two reproductive modes, i.e., gynogenetic and gonochoristic reproduction. The response mechanism of two reproductive development modes may be the first discovery in vertebrates. Additionally, we discuss the evolutionary implication between gynogenetic and gonochoristic reproduction modes and the contribution of the minor proportion of males to genetic flexibility in the gynogenetic silver crucian carp.

  3. Reproduction mode of European Bitterling (Rhodeus amarus, Bloch, 1782) determined through rapid oocyte counts and size determination using digital imaging

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta

    2012-01-01

    Roč. 28, č. 5 (2012), s. 806-810 ISSN 0175-8659 R&D Projects: GA MŠk LC522; GA AV ČR KJB600930802 Institutional support: RVO:68081766 Keywords : bitterling * oocyte * size determibation Subject RIV: EG - Zoology Impact factor: 0.902, year: 2012

  4. DOE Zero Energy Ready Home Case Study: Amerisips Homes — Miller-Bloch Residence, Johns Island, SC

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-09-01

    For this DOE Zero Energy Ready Home that won a Custom Builder award in the 2014 Housing Innovation Awards, the builder uses structural insulated panels to construct the entire building shell, including the roof, walls, and floor of the home.

  5. Total phenolic content and in-vitro antioxidant activities from methanolic extract of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

    Digital Repository Service at National Institute of Oceanography (India)

    Sanaye, S.V.; Pise, N.M.; Pawar, A.P.; Parab, P.P.; Sreepada, R.A.; Pawar, H.B.; Murugan, A.

    -vitro antioxidant activities in terms of reducing power (RP), metal chelating activity (MCA), 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), inhibition of lipid peroxidation (LPX) and hydroxyl radical...

  6. Effect of soybean diet: Growth and conversion efficiencies of fingerling of stinging cat fish, Heteropneustes fossilis (Bloch

    Directory of Open Access Journals (Sweden)

    Muzzammil Iqbal Siddiqui

    2014-04-01

    Full Text Available Replacement of 15% protein from soybean meal in Diet II was feasible for the stinging cat fish, Heteropneustes fossilis and no significant differences in growth parameters were found in fish fed soybean meal-based diets compared to those fed control diet (Diet I. Live weight gain percent (165% obtained in fish fed soybean meal based diet was not significantly different to that achieved (171% in fish fed Diet I. Specific growth rate percent, SGR (2.79%, feed conversion ratio FCR (1.40 and protein efficiency ratio PER (1.79 recorded in fish fed Diet II were also more less comparable to those fed control diet. Mortality was not recorded in the period of the feeding trial. Body composition of the fish fed soybean meal based diet (Diet II was also comparable to that fed control diet. Significantly higher fat content was noted in fish fed Diet II. However, the protein contents were not changed in fish fed Diet I and II. Similarly, no significant differences (P > 0.05 in protein productive value were noted between the two groups. However, ash content differed significantly (P < 0.05 in fish fed Diet I and II. Although soybean meal-based diet depressed growth and feed conversion efficiencies of the fish to some extent, inclusion of soybean meal was found to be cost-effective alternative to fish meal.

  7. Full-angle Negative Reflection with An Ultrathin Acoustic Gradient Metasurface: Floquet-Bloch Modes Perspective and Experimental Verification

    KAUST Repository

    Liu, Bingyi; Zhao, Jiajun; Xu, Xiaodong; Zhao, Wenyu; Jiang, Yongyuan

    2017-01-01

    Metasurface with gradient phase response offers new alternative for steering the propagation of waves. Conventional Snell's law has been revised by taking the contribution of local phase gradient into account. However, the requirement of momentum

  8. Reproductive biology of Nemipterus japonicus (Bloch, 1791) from the coastal waters of Bintulu (South China Sea), Sarawak, Malaysia.

    Science.gov (United States)

    Nettely, T; Rajaee, A H; Denil, N A; Idris, M H; Nesarul, M H; Amin, S M Nurul; Hena, M K Abu

    2016-07-01

    Samples of threadfin breams Nemipterus japonicus were collected from a village in Kuala Nyalau and a fish landing centre at Bintulu from April 2013 to March 2014. A total of 360 individuals of N. japonicus (214 male and 146 female) were used in this reproductive study.? The total length (TL) of individuals were measured to the nearest 0.1 cm and body weight (BW) was recorded to the nearest 0.1 g. Month-wise distribution of the sexes was significantly higher for males in September and March, while in the month of May the number of females was significantly higher (X(2) = 6.53; P Sarawak.

  9. Ectoparasitic copepod infestation on a wild population of Neotropical catfish Sciades herzbergii Bloch, 1794: Histological evidences of lesions on host

    Directory of Open Access Journals (Sweden)

    Deborah Fogel

    2017-12-01

    Full Text Available We analyzed the infestation of the attached copepod species Lepeophtheirus sp on a wild population of Sciades herzbergii. The infestation and occurrence of attached copepods were related to body size, maturity and sex of host and the presence of lesions on fish skin were described. In 61 fish specimens (37 males and 24 females, total of 218 ectoparasitic copepods, including 204 mature and 14 immature stages were found. Copepods were attached to different regions of fish body without any regular pattern. The prevalence of infestation was 80.3% and intensity between 1 and 15 copepods/fish. No significant differences were found between sex or maturity and the presence of attached Lepeophtheirus sp. However, a contingency table including both sex and maturity status, and the total number of attached copepod per combined category showed a significant association. A positive correlation was found between body length of fish and intensity of infestation. Similarly, when comparing the infested fish according to group size, we found more copepods on larger individual. Attached copepods were associated with the presence of lesions visible to the naked eye. Histological analyses showed changes in cell architecture when sections of copepod-free tissues and attached copepods were compared. Keywords: Damages, Fish, Lepeophtheirus, lesions, Sea lice, Parasitism

  10. Toxicity of puffer fish: two species (Lagocephalus laevigatus, linaeus 1766 and Sphoeroides spengleri, Bloch 1785 from the Southeastern Brazilian coast

    Directory of Open Access Journals (Sweden)

    J. S. Oliveira

    2003-01-01

    Full Text Available In Brazil, where puffer fish are considered poisonous, there are few documented cases on human consumption and consequent poisoning. In this study, toxicity of two puffer fish species from the Brazilian coast was examined. Specimens of Sphoeroides spengleri and Lagocephalus laevigatus were caught in São Sebastião Channel (North coast of São Paulo State, Brazil between January 1996 and May 1997. Acidic ethanol extracts from muscle and skin plus viscera were tested for mice acute toxicity using the standard method of Kawabata. Polar extracts of S. spengleri showed high toxicity up to 946 MU/g. Extracts from L. laevigatus showed very low levels of toxicity, never exceeding 1.7 MU/g. All extracts from both species blocked amielinic nerve fiber evoked impulses of crustacean legs; this effect reverted on washing similar to the standard tetrodotoxin TTX. The aqueous extract solutions were partially purified using an ionic exchange column (Amberlit GC-50 followed by treatment with activated charcoal (Norit-A. The presence of TTX and their analogs in the semi-purified extracts were confirmed by HPLC and mass spectrometry (MALDI-TOF.

  11. Ammonium sulphate induced stress related alterations in the respiratory epithelium of the airbreathing organ of the catfish Heteropneustes fossilis (Bloch)

    Digital Repository Service at National Institute of Oceanography (India)

    Paul, V.I.; Banerjee, T.K.

    lamellae. Subsequently regeneration takes place each time as evidenced by the appearance of inflammatory tissue. Fusion of more than one secondary lamellae is also common. Regeneration also leads to uncontrolled hyperplasia of haphazardly arranged...

  12. Florence Hulak. Sociétes et mentalités. La science historique de Marc Bloch.

    Directory of Open Access Journals (Sweden)

    Renán Silva

    2016-01-01

    Full Text Available Hay obras de análisis histórico (y esta lo es, aunque en el campo de la epistemología de la historia que pueden resumirse fácilmente, bien sea por su contenido renovador, bien sea por sus equívocos y errores, o bien sea por su propio carácter rutinario (una más entre una cadena de libros previsibles en su enfoque y en sus resultados. Hay otras obras que solicitan, de quien se ocupa de ellas y trata de presentarlas ante una comunidad de lectores alejada de su lugar de producción y de recepción iniciales del texto, tan solo un sobrevuelo inicial, una mención de sus temas y propósitos centrales, un énfasis repetido sobre su significado e importancia, para animar a los lectores a que se interesen en el debate planteado por el libro de referencia y, sobre todo, a que no se deje pasar de largo una oportunidad de discusión que puede servir para refinar el planteamiento de problemas de los que se habla de manera repetida con actitud poco reflexiva, repetitiva y rutinaria. Creo que este es el caso del libro reciente de Florence Hulak, Sociétés et mentalités que queremos presentar aquí, a través de una reseña centrada simplemente en sus grandes temas, dejando para otros momentos el debate preciso (textos en mano y con multiplicadas referencias, ejemplos, contra ejemplos y argumentaciones sobre puntos concretos de los planteamientos de la autora.

  13. Effect of different cooking methods on proximate and mineral composition of striped snakehead fish (Channa striatus, Bloch).

    Science.gov (United States)

    Marimuthu, K; Thilaga, M; Kathiresan, S; Xavier, R; Mas, R H M H

    2012-06-01

    The effects of different cooking methods (boiling, baking, frying and grilling) on proximate and mineral composition of snakehead fish were investigated. The mean content of moisture, protein, fat and ash of raw fish was found to be 77.2 ± 2.39, 13.9 ± 2.89, 5.9 ± 0.45 and 0.77 ± 0.12% respectively. The changes in the amount of protein and fat were found to be significantly higher in frying and grilling fish. The ash content increased significantly whereas that of the minerals (Na, K, Ca, Mg, Fe, Zn and Mn) was not affected in all cooking methods. Increased in Cu contents and decreased in P contents were observed in all cooking methods except grilling. In the present study, the grilling method of cooking is found to be the best for healthy eating.

  14. Survival and growth responses of snakehead fish Channa striata Bloch. juvenile in aerated and unaerated acid sulfate water

    Directory of Open Access Journals (Sweden)

    , Purnamawati

    2017-07-01

    Full Text Available ABSTRACT  The aim of the research was to analyze survival rate, specific growth rate, albumin, and feed efficiency and physiological (blood glucose, cortisol, dan haemoglobin responses of snake head fish juvenil that reared at aerated and unaerated of tidal land water have been conducted in the laboratory. Experiments using completely randomized design with aerated and unaerated as a treatment, and each treatment has twelve replications. The snakehead fish juvenil wich length 2.4±0.2 cm and weight of 0.21±0.05 g reared in the aquarium that are size 30×25×35 cm (water volume 25 L with a stocking density 2 juvenile/L, for 40 days. The fishes were fed with commercial feed with protein content about 40%, feeding two times a day (morning and afternoon were at satiation. Replacement of water done every two days about 10% of the total water volume in the aquarium. The results showed that unaerated median significantly affected to biometric and physiological response of juvenile of snake head fish. The media un-aerated gives the best results shown by the higher value of survival (92%, specific growth rate (6.73%/ day, feed efficiency (78.22%, protein retention (41.91%, energy retention (30.81% value of albumin (6.60 g/100 mL and the haemoglobin (5.58 g/dL, and have the lowest value of cortisol (21.49 ng/L and blood glucose (43.36 mg/100 mL. Keywords: acid sulfate water, growth rate, aeration, Channa striata   ABSTRAK  Penelitian ini bertujuan untuk menganalisis respons kelangsungan hidup, pertumbuhan spesifik, albumin, dan efisiensi pakan dan fisiologis (kortisol, glukosa darah, dan hemoglobin juvenil ikan gabus yang dipelihara dengan dan tanpa aerasi pada media air rawa pasang surut. Penelitian menggunakan rancangan acak lengkap dengan aerasi dan tanpa aerasi sebagai perlakuan, dan masing-masing perlakuan memiliki 12 ulangan. Juvenil ikan gabus berukuran panjang 2,4±0,3 cm dan bobot 0,21±0,03 g dipelihara dalam akuarium 30×25×35 cm (volume 25 L dengan padat tebar 2 ekor/L, selama 40 hari. Ikan diberi pakan berupa pakan komersial dengan kadar protein ±40%, pemberian pakan dua kali sehari (pagi dan sore at satiation. Penggantian air dan penyiponan dilakukan dua hari sekali sebanyak 10% dari volume total dalam akuarium. Hasil penelitian menunjukkan bahwa perlakuan tanpa aerasi berpengaruh nyata terhadap respons biometrik dan fisiologis juvenil ikan gabus. Media tanpa aerasi memberikan hasil yang lebih baik ditunjukkan oleh kelangsungan hidup (92%, laju pertumbuhan spesifik (6,73%/ hari, efisiensi pakan (78,22%, retensi protein (41,91%, retensi energi (30,81%, kadar albumin (6,60 g/100 mL, dan hemoglobin (5,85 g/dL yang lebih tinggi, sedangkan kadar kortisol (219 ng/L dan glukosa darah (43,36 mg/100 mL yang terendah. Kata kunci: media sulfat masam, pertumbuhan, aerasi, Channa striata

  15. Hubungan panjang berat dan faktor kondisi ikan gabus (Channa striata Bloch, 1793 yang dibesarkan di rawa lebak, Provinsi Sumatera Selatan

    Directory of Open Access Journals (Sweden)

    Dina Muthmainnah

    2013-12-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui hubungan panjang berat dan faktor kondisi ikan gabus (Channa striata telah dipelihara di rawa lebak Sekayu Kabupaten Musi Banyuasin dan Mariana Kabupaten Banyuasin Provinsi Sumatera Selatan pada Mei hingga November 2013. Hasil penelitian menunjukkan hubungan panjang berat tidak menunjukkan perbedaan nyata antara rawa Sekayu dan Mariana dengan nilai b di bawah nilai 3 yang berarti pertumbuhan ikan gabus tersebut allometrik negatif. Ikan gabus yang dipelihara di rawa lebak Mariana menghasilkan faktor kondisi 0,884 lebih tinggi daripada di rawa lebak Sekayu 0,839, yang menunjukkan bahwa kondisi lingkungan rawa lebak Mariana lebih mendukung untuk pertumbuhan ikan gabus.

  16. A study of neurotoxicity of BHC in relation to residual accumulation on the brain tissue of Heteropneustes fossilis (Bloch).

    Science.gov (United States)

    Hazarika, Ranjit

    2003-01-01

    Neurotoxic effect of BHC, the organochlorine pesticide in Heteropneustes fossilis has been studied exposing at the dose concentrations of 1 ppm, 5 ppm and 10 ppm in lab aquarium for 96 hours over a period of one year. The results showed the behavioural abnormalities in different exposure concentrations such as dysfunction of endocrine gland, excretion of mucus, dispigmentation, sign of restlessness, erratic swimming with rapid jurkey movement, spiralling and convolution showing severe effect in central nervous system. Therefore an attempt has been made for monitoring of BHC residues viz. alpha, beta, gamma isomers in the brain tissue exposed to different sublethal concentrations using Gas liquid chromatography. The mean values of isomers were found to be 1.587 microg/gm for 1 ppm, 2.993 microg/gm for 5 ppm and 3.78 microg/gm for 10 ppm test group. Severe behavioural abnormalities were recorded at high dose concentration of pesticides with higher accumulation of pesticide residues in brain tissue.

  17. Confinement of Bloch surface waves in a graphene-based one-dimensional photonic crystal and sensing applications

    Science.gov (United States)

    Zou, Xiu-Juan; Zheng, Gai-Ge; Chen, Yun-Yun

    2018-05-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61203211 and 41675154), the Six Major Talent Peak Expert of Jiangsu Province, China (Grant No. 2015-XXRJ-014), and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20141483).

  18. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Ashish K. [Department of Zoology, University of Allahabad, Allahabad-211002 (India); Mohanty, Banalata, E-mail: drbana_mohanty@rediffmail.com [Department of Zoology, University of Allahabad, Allahabad-211002 (India)

    2009-09-01

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  19. Ectoparasitic copepod infestation on a wild population of Neotropical catfish Sciades herzbergii Bloch, 1794: Histological evidences of lesions on host.

    Science.gov (United States)

    Fogel, Deborah; Fuentes, José Luis; Soto, Luz Marina; Lafuente, Wilson; Moncayo-Estrada, Rodrigo; López, Carlos

    2017-12-01

    We analyzed the infestation of the attached copepod species Lepeophtheirus sp on a wild population of Sciades herzbergii . The infestation and occurrence of attached copepods were related to body size, maturity and sex of host and the presence of lesions on fish skin were described. In 61 fish specimens (37 males and 24 females), total of 218 ectoparasitic copepods, including 204 mature and 14 immature stages were found. Copepods were attached to different regions of fish body without any regular pattern. The prevalence of infestation was 80.3% and intensity between 1 and 15 copepods/fish. No significant differences were found between sex or maturity and the presence of attached Lepeophtheirus sp. However, a contingency table including both sex and maturity status, and the total number of attached copepod per combined category showed a significant association. A positive correlation was found between body length of fish and intensity of infestation. Similarly, when comparing the infested fish according to group size, we found more copepods on larger individual. Attached copepods were associated with the presence of lesions visible to the naked eye. Histological analyses showed changes in cell architecture when sections of copepod-free tissues and attached copepods were compared.

  20. Quantum mechanical description of the two fluid model of liquid /sup 4/He solving the Bloch equation

    International Nuclear Information System (INIS)

    Fung, P.C.W.; Lam, C.C.

    1986-01-01

    The authors apply the U-matrix theory recently developed (Lam and Fung, Phys. Rev. A, vol.27, p.1760, 1983) to study certain physical properties of liquid /sup 4/He across a range of temperatures including the lambda -point. They propose a model for the chemical potential mu which is constant above T/sub lambda / but is a function of T below T/sub lambda /. They have discovered that the super-particles 'emerge' mathematically due to the uncommutability of the Hamiltonians at different temperatures, leading to a quantum mechanical description of the two-fluid model. Using the two-particle potential function deduced from scattering data, they have calculated numerically the approximate values of the number density for a range of temperatures starting from T/sub lambda /, taking the hard-core diameter Delta , 'effective chemical potential' mu ' as parameters

  1. Accumulation effects in modulation spectroscopy with high-repetition-rate pulses: Recursive solution of optical Bloch equations

    Science.gov (United States)

    Osipov, Vladimir Al.; Pullerits, Tõnu

    2017-10-01

    Application of the phase-modulated pulsed light for advance spectroscopic measurements is the area of growing interest. The phase modulation of the light causes modulation of the signal. Separation of the spectral components of the modulations allows to distinguish the contributions of various interaction pathways. The lasers with high repetition rate used in such experiments can lead to appearance of the accumulation effects, which become especially pronounced in systems with long-living excited states. Recently it was shown that such accumulation effects can be used to evaluate parameters of the dynamical processes in the material. In this work we demonstrate that the accumulation effects are also important in the quantum characteristics measurements provided by modulation spectroscopy. In particular, we consider a model of quantum two-level system driven by a train of phase-modulated light pulses, organized in analogy with the two-dimensional spectroscopy experiments. We evaluate the harmonics' amplitudes in the fluorescent signal and calculate corrections appearing from the accumulation effects. We show that the corrections can be significant and have to be taken into account at analysis of experimental data.

  2. Effect of sublethal exposure of Cartap on hypothalamo-neurosecretory system of the freshwater spotted murrel, Channa punctatus (Bloch).

    Science.gov (United States)

    Mishra, D K; Bohidar, K; Pandey, A K

    2008-11-01

    In order to record the effect of carbamate pesticide on hypothalamus of Channa punctatus, fish were exposed to sublethal concentration (0.18 mg l(-1), 30% LC50 for 96 hr) of Cartap for 24, 48, 72 and 96 hr under static bioassay condition. Hypothalamo-neurosecretory complex of the murrel consisted mainly of nucleus preopticus (NPO), nucleus lateralis tuberis (NLT) and their axonal tracts. NPO is a paired structure situtated on either side of the third ventricle anterodorsal to the optic chiasma and looked inverted L-shape in the sagittal section. NPO is morphologically divisible into a dorsal pars magnocellularis (PMC) consisting of large neurons and ventral pars parvocellularis (PPC) formed of smaller neurosecretory cells. NLT cells are distributed in the infundibular floor adjacent to the pituitary stalk. Sublethal Cartap treatment induced an initial hypertrophy of the neurosecretory cells of NPO and NLT followed by loss of staining affinity as well as varying degrees of cytoplasmic vacuolization and necrosis. Herring bodies (HB) were also encountered in the neurohypophysis of the treated fishes.

  3. 18 octobre 2013 - Le Préfet de l’Ain L. Touvet signe le livre d'or avec le Directeur général du CERN R. Heuer et le Chef du Département Technologie F. Bordry. Photo de groupe, de gauche à droite: T. Kupisz, Secrétaire général de la sous préfecture de Gex; L. Miralles, Chef du Département Infrastructure et services généraux; F. Eder, Délégué aux Relations avec les Etats hôtes; S. Donnot, Sous-préfet de Gex; L. Touvet, Préfet de l'Ain; E. Sches, Sous-préfète de Nantua; E.Gröniger-Voss, Conseiller juridique du CERN; R. Heuer, Directeur général; F. Bordry, Chef du Département Technologie et P. Bloch, Chef du Département Physique.

    CERN Multimedia

    Anna Pantelia

    2013-01-01

    18 octobre 2013 - Le Préfet de l’Ain L. Touvet signe le livre d'or avec le Directeur général du CERN R. Heuer et le Chef du Département Technologie F. Bordry. Photo de groupe, de gauche à droite: T. Kupisz,\tSecrétaire général de la sous préfecture de Gex; L. Miralles, Chef du Département Infrastructure et services généraux; F. Eder, Délégué aux Relations avec les Etats hôtes; S. Donnot, Sous-préfet de Gex; L. Touvet, Préfet de l'Ain; E. Sches, Sous-préfète de Nantua; E.Gröniger-Voss, Conseiller juridique du CERN; R. Heuer, Directeur général; F. Bordry, Chef du Département Technologie et P. Bloch, Chef du Département Physique.

  4. Filamoeba sinensis sp. n., a second species of the genus Filamoeba Page, 1967, isolated from gills of Carassius gibelio (Bloch, 1782)

    Czech Academy of Sciences Publication Activity Database

    Dyková, Iva; Pecková, Hana; Fiala, Ivan; Dvořáková, Helena

    2005-01-01

    Roč. 44, č. 1 (2005), s. 75-80 ISSN 0065-1583 R&D Projects: GA AV ČR IAA6022202 Institutional research plan: CEZ:AV0Z60220518 Keywords : Filamoeba sinensis sp. n. * morphology * phylogeny Subject RIV: EA - Cell Biology Impact factor: 0.987, year: 2005

  5. Feeding ecology of juvenile dog snapper Lutjanus jocu (Bloch and Shneider, 1801 (Lutjanidae in intertidal mangrove creeks in Curuçá estuary (Northern Brazil

    Directory of Open Access Journals (Sweden)

    Dijane Pantoja Monteiro

    2009-12-01

    Full Text Available The diet and feeding ecology of juvenile dog snapper (Lutjanus jocu were investigated in 92 specimens collected in four intertidal mangrove creeks of Curuçá estuary, Northern Brazil, between September 2003 and July 2004. No significant differences in total length were found between the sampling months. Feeding intensity was high as indicated by high stomach fullness index and low vacuity index. The most important prey was Penaeidae, followed by Grapsidae and Porcellanidae. The diet of juvenile dog snapper showed clear seasonal differences. Specimens from dry season (September and November and dry / wet season transition (January, were specialists feeding exclusively on Penaeidae. However, the specimens from wet season (March and May and wet /dry season transition (July that consumed mainly Grapsidae, Penaeidae and Porcellanidae were generalist. These seasonal changes in diet could be related to variations in food availability.A dieta e a ecologia alimentar de juvenis de Lutjanus jocu foram verificadas em 92 espécimes coletados em quatro canais de maré do estuário do rio Curuçá, Norte do Brasil, entre setembro de 2003 e julho de 2004. O comprimento total dos peixes coletados não apresentou diferenças significativas entre os meses amostrados. A intensidade alimentar foi elevada conforme indicado pelos altos valores do índice de repleção estomacal e os baixos valores do índice de vacuidade. A presa mais importante foi Penaeidae, seguida por Grapsidae e Porcellanidae. A dieta de juvenis de L. jocu apresentou diferenças sazonais evidentes. Os espécimes da estação seca (setembro e novembro e transição seca/chuvosa (janeiro foram considerados especialistas alimentando-se exclusivamente de Penaeidae. No entanto, os espécimes da estação chuvosa (março e maio e da transição chuvosa/seca (julho, que alimentaram-se principalmente de Grapsidae, Penaeidae e Porcellanidae, foram considerados generalistas. Esta mudança sazonal na dieta poderia estar relacionada com a disponibilidade do alimento.

  6. The invariant polarisation-tensor field for deuterons in storage rings and the Bloch equation for the polarisation-tensor density

    International Nuclear Information System (INIS)

    Barber, D.P.

    2015-10-01

    I extend and update earlier work, summarised in an earlier paper (D.P. Barber, M. Voigt, AIP Conference Proceedings 1149 (28)), whereby the invariant polarisation-tensor field (ITF) for deuterons in storage rings was introduced to complement the invariant spin field (ISF). Taken together, the ITF and the ISF provide a definition of the equilibrium spin density-matrix field which, in turn, offers a clean framework for describing equilibrium spin-1 ensembles in storage rings. I show how to construct the ITF by stroboscopic averaging, I give examples, I discuss adiabatic invariance and I introduce a formalism for describing the effect of noise and damping.

  7. Histopathological changes induced by acute toxicity of mercuric chloride on the air-breathing organ (branchial diverticulum) of the life-fish Heteropneustes (= Saccobranchus) fossilis (BLOCH)

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, M.T. (Histochemistry and Histopathology Lab., Dept. of Zoology, Banaras Hindu Univ., Varanasi (India)); Banerjee, T.K. (Histochemistry and Histopathology Lab., Dept. of Zoology, Banaras Hindu Univ., Varanasi (India))

    1993-01-01

    Toxicity induced by 0.3 ppm (96 h LC[sub 50] value) mercuric chloride solution on the histomorphology of the innerlining of the air breathing organ (branchial diverticulum) of Heteropneustes fossilis has been described. The outer cell layers of the epithelial lining show cyclic necrosis leading to shedding with ultimate haemorrhage and drainage of blood into the lumen causing decrease in the number of blood islets. Simultaneously the epithelium regenerates causing hyperplasia of its cells and increased gas diffusion distance impairing normal aerial respiration. Also the number of foldings decreases and the secondary lamella like structures fuse together. This results in smoothening of the inner lining of the air sac. Later reappearance of the blood islets, secondary lamellae and foldings of the inner lining are observed along with the repair of the epithelium. Damage of the repaired inner lining follows again. (orig.)

  8. Abandoning the ship: spontaneous mass exodus of Clinostomum complanatum (Rudolphi, 1814) progenetic metecercariae from the dying intermediate host Trichogaster fasciatus (Bloch & Schneider, 1801).

    Science.gov (United States)

    Rizvi, Asim; Alam, Md Maroof; Parveen, Saltanat; Saleemuddin, M; Abidi, S M A

    2012-04-01

    The dramatic and spontaneous exodus of live Clinostomum complanatum progenetic metacercaria from the gill slits of the dying intermediate host, Trichogaster fasciatus is reported. Basic water parameter tests for dissolved oxygen, pH and temperature revealed slightly lower level of dissolved oxygen in tank water used for water change. To the best of our knowledge, it is the first report of a digenean metacercariae, en mass leaving their intermediate host, upon its death in search of an alternative host to support their survival and help in continuing their life cycle.

  9. Genetic variation in the mitochondrial genome of the giant grouper Epinephelus lanceolatus (Bloch, 1790 and its application for the identification of broodstock

    Directory of Open Access Journals (Sweden)

    Seng S. Cheng

    2015-11-01

    Full Text Available Mitochondrial DNA (mtDNA markers are ideal for the validation of maternal inheritance and the identification of brood-stock in aquaculture breeding programs. The complete mitochondrial genomes of 11 species of grouper are currently available at the GenBank. This study was directed towards the characterization of mtDNA loci which can be applied for identification of interspecific F1 hybrids developed from Epinephelus fuscoguttatus and Epinephelus lanceolatus in aquaculture breeding programs. DNA was extracted from the fin clip of one specimen of E. lanceolatus which the source of sperm for the artificial spawning of the interspecific F1 hybrid E. fuscoguttatus × E. lanceolatus. Specific primers were designed to amplify the DNA after comparative analysis of the mtDNA genomes available at the GenBank. The primers were applied to test for cross-amplification in F1 hybrids as well as in the maternal parent E. fuscoguttatus (Forsskål, 1775 and the genetically related species Epinephelus coioides and Epinephelus corallicola (Valenciennes, 1828. DNA sequence analysis revealed that the Malaysian variety of E. lanceolatus exhibited variation at 11 of the 13 ORFs when compared to the variety from Taiwan. A distinct segmented duplication was observed in the D-loop region which was determined to be unique to the E. lanceolatus specimen obtained from Sabah, Malaysia. Cross amplification of mtDNA loci in the groupers E. fuscoguttatus, E. coioides, E. corallicola and the F1 hybrid of E. fuscoguttatus × E. lanceolatus revealed distinct profiles for each of the species with a clear indication that mtDNA were inherited from the maternal parent of the F1 hybrid.. mtDNA loci can be applied by fish breeders to determine interspecific hybridization events.

  10. Female morphology of Philometra hyderabadensis Rasheed, 1963 (Nematoda: Philometridae), a little-known parasite of the catfish Wallago attu Bloch & Schneider in India, as revealed by SEM observations

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Chavan, S. P.

    2012-01-01

    Roč. 83, č. 2 (2012), s. 117-122 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional research plan: CEZ:AV0Z60220518 Keywords : Philometra * Wallago * India Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.260, year: 2012

  11. Isolation and identification of bacteria from marine market fish Scomberomorus guttatus (Bloch and Schneider, 1801) from Madurai district, Tamil Nadu, India.

    Science.gov (United States)

    Karthiga Rani, M; Chelladurai, G; Jayanthi, G

    2016-09-01

    The present study was conducted to evaluate the hygienic quality and freshness of fish Indo-pacific King Mackerel "Scomberomorus guttatus" through the investigation of the occurrence of bacteria which is an indicator for fish quality. Fishes were collected every fortnight from Madurai fish market on monthly twice of January 2014 to March 2014. Skin surface of the fish was examined. Escherichia coli, Proteus vulgaris, Bacillus subtilis, Klebsiella pneumonia, Pseudomonas aeruginosa and Staphylococcus aureus were identified by Biochemical tests (IMViC Tests). Among the six bacterial species E. coli and K. pneumonia were found in all the collected samples where as other bacterial species were not found. The result of this study revealed that raw fish sold in Madurai fish market has high contamination so the presence of the bacterial species has strongly suggested the urgent need to improve the quality control systems in Madurai fish market.

  12. Cytochrome b gene reveals panmixia among Japanese Threadfin Bream, Nemipterus japonicus (Bloch, 1791) populations along the coasts of Peninsular Malaysia and provides evidence of a cryptic species.

    Science.gov (United States)

    Lim, Hong-Chiun; Ahmad, Abu Talib; Nuruddin, Ahmad Adnan; Mohd Nor, Siti Azizah

    2016-01-01

    We evaluated genetic differentiation among ten presumed Japanese threadfin bream, Nemipterus japonicus populations along the coast of Peninsular Malaysia based on the partial sequence of the mitochondrial cytochrome b gene (982 bp). Genetic divergences (Kimura-2 parameter) ranged from 0.5% to 0.8% among nine of the ten populations while these nine populations were 4.4% to 4.6% diverged from the Kuala Besar population located at the Northeast coast. The constructed Neighbour Joining (NJ) phylogenetic trees based on haplotypes showed the Kuala Besar population forming an isolated cluster. The Analysis of Molecular Variance (AMOVA) of the ten populations a priori assigned into four regions, revealed that most of the variation occurred within population with a fairly low but significant level of regional differentiation (FST = 0.07, p 0.05 and FCT = 0.07, p Malaysia were panmictic. However, the Kuala Besar population, although morphologically identical was composed of a genetically discrete taxon from the rest. These findings are important contributions in formulating sustainable fishery management policies for this important fishery in Peninsular Malaysia.

  13. Some observations on the morphometry and biology of Psettodes erumei (Bloch) and Pseudorhombus arsius (Hamilton-Buchanan) from the Goa region

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    . erumei and the number of dorsal fin rays in P. arsius were relatively stable characters. Statistical interpretation of metric data indicated that there is direct relationship between the head length, depth of the body and total length...

  14. Interactive effects of ambient acidity and salinity on thyroid function during acidic and post-acidic acclimation of air-breathing fish (Anabas testudineus Bloch).

    Science.gov (United States)

    Peter, M C Subhash; Rejitha, V

    2011-11-01

    The interactive effects of ambient acidity and salinity on thyroid function are less understood in fish particularly in air-breathing fish. We, therefore, examined the thyroid function particularly the osmotic and metabolic competences of freshwater (FW) and salinity-adapted (SA; 20 ppt) air-breathing fish (Anabas testudineus) during acidic and post-acidic acclimation, i.e., during the exposure of fish to either acidified water (pH 4.2 and 5.2) for 48 h or clean water for 96 h after pre-exposure. A substantial rise in plasma T(4) occurred after acidic exposure of both FW and SA fish. Similarly, increased plasma T(3) and T(4) were found in FW fish kept for post-acidic acclimation and these suggest an involvement of THs in short-term acidic and post-acidic acclimation. Water acidification produced significant hyperglycaemia and hyperuremia in FW fish but not in SA fish. The SA fish when kept for post-acclimation, however, produced a significant hypouremia. In both FW and SA fish, gill Na(+), K(+)-ATPase activity decreased but kidney Na(+), K(+)-ATPase activity increased upon acidic acclimation. During post-acidic acclimation, gill Na(+), K(+)-ATPase activity of the FW fish showed a rise while decreasing its activity in the SA fish. Similarly, post-acidic acclimation reduced the Na(+), K(+)-ATPase activity of intestine but elevated its activity in the liver of SA fish. A higher tolerance of the SA fish to water acidification was evident in these fish as they showed tight plasma and tissue mineral status due to the ability of this fish to counteract the ion loss. In contrast, FW fish showed more sensitivity to water acidification as they loose more ions in that medium. The positive correlations of plasma THs with many tested metabolic and hydromineral indices of both FW and SA fish and also with water pH further confirm the involvement of THs in acidic and post-acidic acclimation in these fish. We conclude that thyroid function of this fish is more sensitive to environmental acidity than ambient salinity and salinity interference nullifies the toxic effect of water acidification. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Nitric oxide rectifies acid-base disturbance and modifies thyroid hormone activity during net confinement of air-breathing fish (Anabas testudineus Bloch).

    Science.gov (United States)

    Peter, Valsa S

    2013-01-15

    Nitric oxide (NO), a short-lived freely diffusible radical gas that acts as an important biological signal, regulates an impressive spectrum of physiological functions in vertebrates including fishes. The action of NO, however, on thyroid hormone status and its role in the integration of acid-base, osmotic and metabolic balances during stress are not yet delineated in fish. Sodium nitroprusside (SNP), a NO donor, was employed in the present study to investigate the role of NO in the stressed air-breathing fish Anabas testudineus. Short-term SNP treatment (1 mM; 30 min) interacted negatively with thyroid axis, as evident in the fall of plasma thyroxine in both stressed and non-stressed fish. In contrast, the cortisol responsiveness to NO was negligible. SNP challenge produced systemic alkalosis, hypocapnia and hyperglycemia in non-stressed fish. Remarkable acid-base compensation was found in fish kept for 60 min net confinement where a rise in blood pH and HCO(3) content occurred with a reduction in PCO(2) content. SNP challenge in these fish, on the contrary, produced a rise in oxygen load together with hypocapnia but without an effect on HCO(3) content, indicating a modulator role of NO in respiratory gas transport during stress response. SNP treatment reduced Na(+), K(+) ATPase activity in the gill, intestine and liver of both stressed and non-stressed fish, and this suggests that stress state has little effect on the NO-driven osmotic competence of these organs. On the other hand, a modulatory effect of NO was found in the kidney which showed a differential response to SNP, emphasizing a key role of NO in kidney ion transport and its sensitivity to stressful condition. H(+)-ATPase activity, an index of H(+) secretion, downregulated in all the organs of both non-stressed and stressed fish except in the gill of non-stressed fish and this supports a role for NO in promoting alkalosis. The data indicate that, (1) NO interacts antagonistically with T(4), (2) modifies respiratory gas transport and (3) integrates acid-base and osmotic actions during stress response in air-breathing fish. Collectively, this first evidence in fish indicate that NO can promote compensatory physiologic modification and that can reduce the magnitude of stress-induced acid-base and osmotic disturbance and that suggests a role for NO in the ease and ease response of this fish. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Toxicity of the Herbicide Atrazine: Effects on Lipid Peroxidation and Activities of Antioxidant Enzymes in the Freshwater Fish Channa Punctatus (Bloch

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    Satish Kumar Srivastava

    2010-08-01

    Full Text Available The present study was undertaken to evaluate the toxicity and effects of a commercial formulation of the herbicide atrazine (Rasayanzine on lipid peroxidation and antioxidant enzyme system in the freshwater air breathing fish Channa punctatus. The 12, 24, 48, 72 and 96 h LC50 of atrazine, calculated by probit analysis, were determined to be 77.091, 64.053, 49.100, 44.412 and 42.381 mg·L-1, respectively, in a semi static system with significant difference (p < 0.05 in LC10-90 values obtained for different times of exposure. In addition to concentration and time dependent decrease in mortality rate, stress signs in the form of behavioral changes were also observed in response to the test chemical. In fish exposed for 15 days to different sublethal concentrations of the herbicide (1/4 LC50 = ~10.600 mg·L-1, 1/8 LC50 = ~5.300 mg·L-1 and 1/10 LC50 = ~4.238 mg·L-1 induction of oxidative stress in the liver was evidence by increased lipid peroxidation levels. The antioxidants superoxide dismutase (SOD, catalase (CAT and glutathione reductase (GR responded positively in a concentration dependent pattern, thus, suggesting the use of these antioxidants as potential biomarkers of toxicity associated with contaminations exposure in freshwater fishes.

  17. Ambient salinity modifies the action of triiodothyronine in the air-breathing fish Anabas testudineus Bloch: effects on mitochondria-rich cell distribution, osmotic and metabolic regulations.

    Science.gov (United States)

    Peter, M C Subhash; Leji, J; Peter, Valsa S

    2011-04-01

    The hydromineral and metabolic actions of thyroid hormone on osmotic acclimation in fish is less understood. We, therefore, studied the short-term action of triiodothyronine (T(3)), the potent thyroid hormone, on the distribution and the function of gill mitochondria-rich (MR) cells and on the whole body hydromineral and metabolic regulations of air-breathing fish (Anabas testudineus) adapted to either freshwater (FW) or acclimated to seawater (SA; 30 g L(-1)). As expected, 24 h T(3) injection (100 ng g(-1)) elevated (Pfish, suggest an action of T(3) on gill MR cell migration, though the density of these cells remained unchanged after T(3) treatment. The ouabain-sensitive Na(+), K(+)-ATPase activity, a measure of hydromineral competence, showed increases (Pfish after T(3) administration, but inhibited (Pfish and not in the SA fish. Exogenous T(3) reduced glucose (Pfish, whereas these metabolites were elevated (Pfish, suggesting a modulatory effect of ambient salinity on the T(3)-driven metabolic actions. Our data identify gill MR cell as a target for T(3) action as it promotes the spatial distribution and the osmotic function of these cells in both fresh water and in seawater. The results besides confirming the metabolic and osmotic actions of T(3) in fish support the hypothesis that the differential actions of T(3) may be due to the direct influence of ambient salinity, a major environmental determinant that alters the osmotic and metabolic strategies of fish. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Continuous Transition between Brillouin-Wigner and Rayleigh-Schrödinger Perturbation Theory, Generalized Bloch Equation, and Hilbert Space Multireference Coupled Cluster

    Czech Academy of Sciences Publication Activity Database

    Pittner, Jiří

    2003-01-01

    Roč. 118, č. 24 (2003), s. 10876-10889 ISSN 0021-9606 R&D Projects: GA MŠk OC D23.001; GA ČR GA203/99/D009; GA AV ČR IAA4040108 Institutional research plan: CEZ:AV0Z4040901 Keywords : continuous transition * Brillouin-Wigner * Rayleigh-Schrödinger Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.950, year: 2003

  19. ANALISIS USAHA PENGOLAHAN KERUPUK IKAN GABUS (Channa Striata Bloch PESERTA PROGRAM PEMBERDAYAAN KONSULTAN KEUANGAN MITRA BANK (KKMB DI KALIMANTAN SELATAN (STUDI PEMBERDAYAAN KKMB DI KOTA BANJARMASIN

    Directory of Open Access Journals (Sweden)

    Muhammad Aini

    2016-06-01

                Results of the research showed that the technology performance of the snakehead crackers processing business had grown well in Banjarmasin City after participating in KKMB empowerment program, characterised by the increasing quantity and quality of production. Incomes of the snakehead crackers processors in Banjarmasin City after participating in program had increased, showed by the incomes increasing an average of 189.79% from before participating in program. Income of the snakehead crackers processors in Banjarmasin City was significantly affected by the processed fish volume, the amount of the loan capital and business scale, which the regression coefficient of the each variable was positive and valid on test level of 99%. The average difference between the supply and demand of 4,65 tons/year indicated that the snakehead crackers marketing in Banjarmasin City still had a large market opportunity to keep organised. The marketing channels of the snakehead crackers processed by program participants in Banjarmasin City were consist of three pattern of the marketing channels, i.e. producers to consumers directly, producers through the collectors the retailers, and producers through the retailers before distributed to consumers.

  20. Revision of the genus Centrophorus (Squaliformes: Centrophoridae): Part 1--Redescription of Centrophorus granulosus (Bloch & Schneider), a senior synonym of C. acus Garman and C. niaukang Teng.

    Science.gov (United States)

    White, William T; Ebert, David A; Naylor, Gavin J P; Ho, Hsuan-Ching; Clerkin, Paul; Veríssimo, Ana; Cotton, Charles F

    2013-01-01

    The genus Centrophorus is one of the most taxonomically complex and confusing elasmobranch groups. A revision of this group is currently underway and this first paper sets an important foundation in this process by redescribing the type species of the genus--Centrophorus granulosus. This taxon name has been previously applied to two different morphotypes: a large species > 1.5 m TL and a smaller species -1 m TL. Centrophorus acus and C. niaukang are the most commonly used names applied to the larger morphotype. The original description of C. granulosus was based on a large specimen of -1.5 m TL, but subsequent redescriptions were based on either of the large or small morphotypes. Centrophorus granulosus is herein redescribed as a large species and a neotype is designated. Centrophorus acus and C. niaukang are found to be junior synonyms of C. granulosus. Centrophorus granulosus is distinguishable from its congeners by its large size, dermal denticle shape, colouration and a number of morphological and biological characteristics. Ontogenetic changes in morphology, dentition and denticle shape for this species are described in detail.

  1. The effect of temperature on the embryonic development of barramundi, the Australian strain of Lates calcarifer (Bloch using current hatchery practices

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    Valentin Thépot

    2015-11-01

    Full Text Available Lates calcarifer (barramundi or Asian seabass has been farmed since the 1970s, yet despite its widespread culture little has been documented on the species’ embryonic development and particularly how development relates to temperature. This is particularly the case for the Australian L. calcarifer genetic strain. Accordingly, embryonic development of fertilised barramundi eggs incubated at 26, 28, 30, 32, 34 and 36 °C were followed from the time of incubation until hatching and the timing to reach key developmental stages and temperature-induced hatching success established. Eggs incubated at 26 and 36 °C did not survive past the first two hours post-fertilisation. Development of the Australian strain of L. calcarifer was observed to proceed similarly to those documented from Asia, however, differences were observed in the timing of major embryonic events among the two strains. Incubation trials showed that eggs maintained at 30 °C had the highest hatch rate (86.7%. The findings of this study are discussed and put in a commercial context with potential future research to further improve practices at the hatchery level.

  2. A new genus of proteocephalid tapeworm (Cestoda) from the marbled swamp eel Synbranchus marmoratus Bloch (Synbranchiformes: Synbranchidae) in the River Parana basin, Argentina

    Czech Academy of Sciences Publication Activity Database

    Arredondo, N.J.; Alves, Philippe Vieira; Gil de Pertierra, A.A.

    2017-01-01

    Roč. 64, MAY 5 (2017), č. článku 015. ISSN 1803-6465 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Proteocephalidae * Monticelliinae * taxonomy * morphology * phylogenetic analysis * freshwater * Neotropical Region Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.082, year: 2016

  3. Molecular and cytogenetic analyses of cryptic species within the Synbranchus marmoratus Bloch, 1795 (Synbranchiformes: Synbranchidae grouping: species delimitations, karyotypic evolution and intraspecific diversification

    Directory of Open Access Journals (Sweden)

    Ricardo Utsunomia

    Full Text Available The fish species Synbranchus marmoratushas been reported to exist as a species complex due to high intraspecific karyotypic variability in spite of the difficulty or impossibility to distinguish them using morphological traits alone. The goal of this work was to use cytogenetic and molecular methods to determine the species delimitations and understand the karyoevolution ofS. marmoratususing samples collected from distinct Brazilian localities. Among the analyzed specimens, a large degree of cytogenetic variation related to diploid numbers and karyotype structure was observed, with karyotypes showing 2n=42, 44 and 46 chromosomes. In addition, using sequences of three mitochondrial genes, the phylogenetic relationships between every sample with a known karyotype were determined, which revealed significant nucleotide divergence among the karyomorphs. Also, the analyses indicate that chromosomal rearrangements occurred independently within the distinct lineages of S. marmoratuscomplex, which resulted in the appearance of distinct karyotypic variants in a non-linear fashion related to diploid numbers and in the appearance of similar non-homologous chromosomes. Finally, the integration of both molecular cytogenetic and phylogenetic approaches allowed the determination of specific chromosomes possibly involved in rearrangements and a better understanding about the evolutionary processes involved in the differentiation ofSynbranchusgenus.

  4. Screening probiotic candidates for a mixture of probiotics to enhance the growth performance, immunity, and disease resistance of Asian seabass, Lates calcarifer (Bloch), against Aeromonas hydrophila.

    Science.gov (United States)

    Lin, Hsueh-Li; Shiu, Ya-Li; Chiu, Chiu-Shia; Huang, Shih-Ling; Liu, Chun-Hung

    2017-01-01

    Six bacteria, including, Lactobacillus casei M15, Lac. plantarum D8, Lac. pentosus BD6, Lac. fermentum LW2, Enterococcus faecium 10-10, and Bacillus subtilis E20, and one yeast, Saccharomyces cerevisiae P13 were selected as probiotics for Asian seabass, Lates calcarifer, by tracking the growth performance and disease resistance of fish against Aeromonas hydrophila in the first trial. The probiotic efficiency screening results showed that B. subtilis E20 and Lac. pentosus BD6, and S. cerevisiae P13 and Lac. fermentum LW2 respectively improved either the growth performance or disease resistance. Therefore, these four probiotics were then selected to prepare a probiotics mixture, and this was incorporated in equal proportions into diets for Asian seabass at levels of 0 (control), and 10 6 (MD6), 10 7 (MD7), 10 8 (MD8), and 10 9 (MD9) colony-forming units (cfu) (kg diet) -1 . A synergistic effect of the combined probiotics was investigated in this study, and the probiotics mixture was able to improve both the growth performance and health status of fish. After 56 days of feeding, fish fed the MD9 diet had a higher final weight and percentage of weight gain. In addition, protein contents in the dorsal muscle of fish fed the MD8 and MD9 diets were significantly higher compared to the control. For the pathogen challenge test, fish fed the MD7, MD8, and MD9 diets had significantly lower cumulative mortalities after A. hydrophila infection compared to those of fish fed the control and MD6 diets, which might have been due to increased respiratory bursts, decreased superoxide dismutase activity in leucocytes, and increased phagocytic activity. Therefore, we considered that the probiotics mixture could adequately provide probiotic efficiency for Asian seabass, and the diet containing 10 9  cfu (kg diet) -1 probiotic mixture is recommended to improve the growth and health status of Asian seabass. Copyright © 2016. Published by Elsevier Ltd.

  5. Physiologic implications of inter-hormonal interference in fish: lessons from the interaction of adrenaline with cortisol and thyroid hormones in climbing perch (Anabas testudineus Bloch).

    Science.gov (United States)

    George, Nimta; Peter, Valsa S; Peter, M C Subhash

    2013-01-15

    Adrenaline and cortisol, the major stress hormones, are known for its direct control on stress response in fish. Likewise, as an important stress modifier hormone, thyroid hormone has also been implicated in stress response of fish. We tested whether the hypothesis on the phenomenon of inter-hormonal interference, a process that explains the hormonal interactions, operates in fish particularly between adrenaline, cortisol and thyroid hormones. To achieve this goal, indices of acid-base, osmotic and metabolic regulations were quantified after adrenaline challenge in propranolol pre-treated air-breathing fish (Anabas testudineus). Short-term adrenaline (10 ng g(-1)) injection for 30 min produced a rise in plasma cortisol without affecting plasma T(3) and T(4). On the contrary, blocking of adrenaline action with a non-selective blocker, propranolol (25 ng g(-1)) for 90 min reduced plasma cortisol along with plasma T(4) and that indicate a possible interference of these hormones in the absence of adrenaline challenge. Similarly, a reduction in plasma T(3) was found after adrenaline challenge in propranolol pre-treated fish and that suggests a functional synergistic interference of adrenaline with T(3). Adrenaline challenge in these fish, however, failed to abolish this propranolol effect. The remarkable systemic hypercapnia and acidosis by propranolol pre-treatment were reversed by adrenaline challenge, pointing to a direct action of adrenaline on acid-base indices probably by a mechanism which may not require β-adrenergic receptor systems. Interestingly, the prominent adrenaline-induced hyperglycemia, hyperlactemia and hyperuremea were not altered by propranolol treatment. Similarly, adrenaline challenge promoted and propranolol reduced the osmotic competencies of the gills, kidneys and liver of this fish as evident in the sodium and proton pump activities. The modified physiologic actions of adrenaline and its modified interaction with THs and cortisol in blocked fish indicate an interaction of adrenaline with cortisol and THs. Our physiologic evidences thus support the hypothesis of the phenomenon of inter-hormonal interference. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae a buccal cavity parasite of the marine fish, Oligoplites saurus (Bloch & Schneider (Osteichthyes, Carangidae of Rio Grande do Norte State, Brazil Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae um parasito da cavidade bucal do peixe marinho, Oligoplites saurus (Bloch & Schneider (Osteichthyes, Carangidae do Estado do Rio Grande do Norte, Brasil

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    Vernon E. Thatcher

    2007-03-01

    Full Text Available Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae a buccal cavity parasite of the marine fish, Oligoplites saurus, is described on the basis of eight male specimens and one female. The fish hosts were captured in the coastal waters of Natal, Rio Grande do Norte State, Brazil. In the new species, the anterior margin of the cephalon is doubled ventrally over the bases of the antennae. In this respect, it resembles C. recifea Thatcher & Fonseca, 2005. It differs from that species, however, in being much smaller and having basal carinae on the pereopods 4 to 7 that are small and rounded (not large and pointed. Also, pleopods 2-4 lack the folds and pockets that are present in C. recifea. The new species can be distinguished from all known Cymothoa spp. by the mandibular palps which are entirely covered with small spines in adult males. The mancas of the new species resemble those of Cymothoa oestrum since they have elongate antennae but they are wider and have shorter uropods.Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae, um parasito da cavidade bucal do peixe marinho, Oligoplites saurus, é descrita baseada em oito espécimes machos e uma fêmea Os peixes foram capturados nas águas costeiras de Natal, Rio Grande do Norte, Brasil. Na nova espécie, a margem anterior do cefalon é dobrada ventralmente sobre as bases das antenas. Neste aspecto, ela assemelha-se a C. recifea Thatcher & Fonseca, 2005. Distingue-se dessa espécie, no entanto, pelo menor tamanho e pelas carinas dos pereópodos 4 a 7 que são relativamente pequenas e arredondadas (não grandes e ponte agudas. Aliás, os pleópodos 2-4 carecem das dobras e bolsos que são presentes em C. recifea. Cymothoa spinipalpa sp. nov. distingue-se de todas as demais espécies de Cymothoa por ter palpos mandibulares completamente cobertos por espinhos nos machos adultos. As mancas têm antenas compridas e por isso parecem com as de Cymothoa oestrum mas distinguem-se por serem mais largas e de terem urópodos mais curtos.

  7. Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus (Bloch & Schneider) (Osteichthyes, Carangidae) of Rio Grande do Norte State, Brazil Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) um parasito da cavidade bucal do peixe marinho, Oligoplites saurus (Bloch & Schneider) (Osteichthyes, Carangidae) do Estado do Rio Grande do Norte, Brasil

    OpenAIRE

    Vernon E. Thatcher; Gustavo S. de Araújo; José T. A. X. de Lima; Sathyabama Chellappa

    2007-01-01

    Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus, is described on the basis of eight male specimens and one female. The fish hosts were captured in the coastal waters of Natal, Rio Grande do Norte State, Brazil. In the new species, the anterior margin of the cephalon is doubled ventrally over the bases of the antennae. In this respect, it resembles C. recifea Thatcher & Fonseca, 2005. It differs from that species, however, in ...

  8. Diferenciação geográfica de Macrodon ancylodon (Bloch & Schneider, 1801 na costa brasileira, entre as latitudes 18º36'S e 32º10'S: etapa I The geographical differentiation of Macrodon ancylodon (Bloch & Schneider, 1801 in the Brazilian coast between Lat. 18º36'S and 32º10'S: phase I

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    Noriyoshi Yamaguti

    1979-06-01

    Full Text Available Multiple range tests according to Kramer, 1956 were performed on 3 meristic and 15 morphometric characters of "pescada-foguete" (Macrodon ancylodon samples collected off coast near Conceição da Barra (Espirito Santo State, Atafona, Macaé, Ubatuba cities, Bom Abrigo Island and Rio Grande do Sul State coast. It was also observed morphological differences in otoliths collected at each region. The number of statistical differences among samples and different morphological characteristics presented by otoliths suggested the existence of four populations along the studied area: (1 along Espírito Santo State coast; (2 near the region between Atafona and Macaé coasts; (3 along São Paulo, Paraná and north Santa Catarina States coasts and (4 along Rio Grande do Sul State coast. Probably the differentiation was caused by different environmental conditions observed among regions. Other papers about life history corroborate these results except for the Espírito Santo population about which there is no biological information up to the moment.

  9. Metabolic adjustments during semi-aestivation of the marble swamp eel (Synbranchus marmoratus, Bloch 1795 - a facultative air breathing fish Ajustes metabólicos do muçum (Synbranchus marmoratus, Bloch 1795 - um peixe de respiração aérea facultativa - durante semi-estivação

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    G. Moraes

    2005-05-01

    Full Text Available Metabolic changes, principally in intermediary metabolism and nitrogen excretion, were investigated in the marble swamp eel (Synbranchus marmoratus after 15 and 45 days of artificially induced semi-aestivation. Glucose, glycogen, lactate, pyruvate, free amino acids, triglycerides, ammonia, urea, and urate contents were determined in liver, kidney, white muscle, heart, brain, and plasma. Lactate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthase, ornithine carbamoyl transferase, and arginase enzymes were assayed. The teleost S. marmoratus maintained initial energetic demands by lipid oxidation. The course of normal oxidative processes was observed through tissue enzyme profiles. After the lipid stores were exhausted, the fish consumed body proteins. Constant values of hematocrit during induced semi-aestivation suggested that the water balance remained normal. Therefore, the surrounding water was probably did not trigger the semi-aestivation in this teleost. Decrease of ammonia and increase of renal urea synthesis after 45 days of semi-aestivation led to the assumption that an alternative form of eliminating ammonia exists. Metabolic changes entailed by starvation were proposed to explain the biosynthesis of small molecules involved in the semi-aestivation of S. marmoratus.Foram investigadas variações metabólicas em muçum (Synbranchus marmoratus após 15 e 45 dias de semi-estivação artificial induzida, com ênfase no metabolismo intermediário e excreção de nitrogênio. Glicose, glicogênio, lactato, piruvato, aminoácidos livres, triglicerídios, amônia, uréia e uratos foram determinados em fígado, rim, músculo branco, coração, cérebro, e plasma. As enzimas lactato desidrogenase, glutamato desidrogenase, malato desidrogenase, aspartato amino transferase, alanina amino transferase, glutamina sintetase, ornitina carbamil transferase e arginase foram ensaiadas. O teleósteo S. marmoratus manteve sua demanda energética inicial pela oxidação de lipídios. A seqüência normal dos processos oxidativos foi observada por meio do perfil enzimático. Após o consumo das reservas lipídicas, os peixes passaram a consumir proteína. Valores constantes de hematócrito durante a semi-estivação induzida sugeriu que o balanço de água foi mantido normal. Todavia, a água ambiental provavelmente não foi o sinal inicial da semi-estivação em S. marmoratus. A diminuição de amônia e o aumento da síntese de uréia renal após 45 dias de semi-estivação levaram a assumir que existe uma forma alternativa de eliminar amônia. As variações metabólicas conseqüentes do jejum prolongado foram propostas como responsáveis pela síntese de pequenas moléculas envolvidas na semi-estivação de S. marmoratus.

  10. Preliminary studies on nutritive and organoleptic properties in processed fish fillets obtained from Iran

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    Ali Aberoumand

    2014-06-01

    Full Text Available The effects of boiling, frying, and roasting methods on nutrients and properties some of marine fishes were studies. AOAC official methods were used for the analyses of the samples. Frying reduced the protein content of Nemipterus japonicas, while roasting reduced the protein content of Carangoides malabaricus and Saurida undosquamis. Fresh and fried C. malabaricus had 71.2% and 57.05% protein content, respectively, while N. japonicas had 57.39% and 47.51%, respectively. The highest oil content in C.malabaricus was 16.80%, followed by N.japonicus 12.80%; while the lowest oil content in S.undosquamis was 5.88%. N.japonicusis protein content reduced with frying. Some cooking methods used in the processing can have an effect on of fish nutrient composition. The texture of fried and boiled fish fillets significantly differ from that of the roasted fillets (p<0.05.

  11. Weighted composition operators from Bergman-type spaces into ...

    Indian Academy of Sciences (India)

    Weighted composition operators from Bergman-type spaces into Bloch spaces and little. Bloch spaces are characterized by function theoretic properties of their inducing maps. Keywords. Weighted composition operator; Bergman-type space; Bloch space. 1. Introduction. Let D be the open unit disk in the complex plane C.

  12. Effects of feeding level and feeding frequency on growth, feed efficiency and nitrogen and phosphorus loss in seabass (Lates calcarifer Bloch fed diets with defatted soybean meal partially replacing fishmeal

    Directory of Open Access Journals (Sweden)

    Srisook, S.

    2007-05-01

    Full Text Available Satun Coastal Fisheries Research and Development Center, Muang, Satun 3Feeding management is crucial for feed efficiency, nutrient utilization, growth of cultured aquatic species and the amount of organic waste produced. This study aimed at investigating effects of two levels offeeding at two feeding frequencies on growth performance, feed efficiency and nitrogen and phosphorus loss in Asian seabass when fed diets with defatted soybean meal (SBM replacing fish meal. Three diets were formulated to contain defatted SBM to replace fish meal at 0, 10 and 20% of fish meal protein. Each diet wasgiven to the fish at either 4% of body weight (BW or to satiation. At each feeding level, the fish were fed at two feeding frequencies, once and twice daily. Fish with an average initial weight of 2.04±0.06 g/fish werereared for twelve weeks in the flow through system. Growth of fish reduced with an increasing amount of defatted SBM incorporated in diets as observed in other carnivorous species. Within groups of fish fed thesame diet, different growth performance and feed efficiency differed due to both feeding level and frequency. Weight gain of fish that were fed diet with defatted SBM replacing 10% of fish meal protein (diet 2until satiation was not significantly different from fish fed fish meal based diet at 4% BW. Furthermore, feeding fish the former diet twice daily resulted in an improvement of FCR, PER and PPV of fish to those ofthe fish fed fish meal based diet at satiation twice daily. Nitrogen and phosphorus loss was affected by diet, feeding level and frequency. Fish fed diet 2 until satiation twice daily lost nitrogen and phosphorus in theamount similar to that of fish fed fish meal based diet until satiation.

  13. ESTRUCTURA DE LA MACROFAUNA DE INVERTEBRADOS PRESENTE EN LOS NIDOS DEL PEZ MALACANTHUS PLUMIERI (BLOCH, 1786 (PERCIFORMES: MALACANTHIDAE EN LA BAHÍA DE NENGUANGE, PARQUE NACIONAL NATURAL TAYRONA, MAR CARIBE COLOMBIANO

    Directory of Open Access Journals (Sweden)

    GUTIÉRREZ-SALCEDO JOSÉ MANUEL

    2007-12-01

    Full Text Available Se realizó la caracterización de la estructura de invertebrados presentes en losmontículos de nidos del pez Malacanthus plumieri durante el segundo semestre de2003, en la bahía de Nenguange, con el fin de establecer diferencias entre dos gruposde nidos diferenciados por su profundidad (5 y 17 m. Se colectaron en total 1760individuos pertenecientes a 152 especies de siete Phyla, la mayoría de las cualesse encuentra asociadas a sustratos rocosos, arrecifes, fondos blandos y cascajo.Por medio de un análisis ecológico multivariado, se estableció la estructura de lacomunidad, además, se calcularon los principales atributos ecológicos tales comoriqueza, abundancia, diversidad, uniformidad y equidad para cada uno de los gruposde nidos establecidos previamente. La caracterización de la comunidad mostró lapresencia de 32 especies generalistas (presentes en los dos grupos de nidos de lascuales Brachycarpus biunguiculatus, Micropanope spinipes y Synalpheus fritzmuelleri tienen una frecuencia relativa superior al 70% cada una. En la franja de los 5 m deprofundidad se colectaron, además de las generalistas, 39 especies características (ej.Mithrax sculptus y Mithrax forceps y 38 especies representadas por un solo individuo.En la franja de los 17 m de profundidad se presentaron 19 especies características(ej. Munida angulata y Petrolisthes galathinus y 24 especies representadas porun solo individuo. Los atributos ecológicos evaluados no mostraron diferenciassignificativas entre las dos franjas batimétricas; el índice de correlación tampocomostró una influencia directa entre el perímetro de los montículos y la estructura dela comunidad

  14. An in vivo analysis of Cr6+ induced biochemical, genotoxicological and transcriptional profiling of genes related to oxidative stress, DNA damage and apoptosis in liver of fish, Channa punctatus (Bloch, 1793).

    Science.gov (United States)

    Awasthi, Yashika; Ratn, Arun; Prasad, Rajesh; Kumar, Manoj; Trivedi, Sunil P

    2018-07-01

    Present study was designed to assess the hexavalent chromium (Cr 6+ ) mediated oxidative stress that induces DNA damage and apoptosis in adult fish, Channa punctatus (35 ± 3.0 g; 14.5 ± 1.0 cm; Actinopterygii). Fishes were maintained in three groups for 15, 30 and 45 d of exposure periods. They were treated with 5% (Group T1) and 10% (Group T2) of 96 h-LC 50 of chromium trioxide (Cr 6+ ). Controls were run for the similar duration. A significant (p < 0.05) increment in the activities of antioxidant enzymes, SOD and CAT in liver tissues of the exposed fish evinces the persistence of oxidative stress. A significant (p < 0.05) increase in induction of micronuclei (MN) coupled with transcriptional responses of target genes related to antioxidant enzymes, DNA damage and apoptosis (sod, cat, gsr, nox-1, p53, bax, bcl-2, apaf-1 and casp3a) establishes the impact of oxidative stress due to in vivo, Cr 6+ accumulation in liver as compared to control (0 mg/L), in a dose and exposure-dependent manner. Initially, the increased level of reactive oxygen species (ROS) in liver coincided with that of enhanced mRNA expression of antioxidant enzymes, sod, cat, gsr and nox-1 but, later, the overproduction of ROS, after 45 d of exposure of Cr 6+ , resulted in a significant (p < 0.05) up-regulation of p53. Our findings also unveil that the up-regulation of bax, apaf-1 and casp3a and down-regulation of bcl-2 are associated with Cr 6+ -induced oxidative stress mediated-apoptosis in liver of test fish. Aforesaid molecular markers can, thus, be efficiently utilized for bio-monitoring of aquatic regimes and conservation of fish biodiversity. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Effects of feeding level and feeding frequency on growth, feed efficiency and nitrogen and phosphorus loss in seabass (Lates calcarifer Bloch) fed diets with defatted soybean meal partially replacing fishmeal

    OpenAIRE

    Srisook, S.; Mahankich, S.; Tantikitti, C.; Onkong, S.

    2007-01-01

    Satun Coastal Fisheries Research and Development Center, Muang, Satun 3Feeding management is crucial for feed efficiency, nutrient utilization, growth of cultured aquatic species and the amount of organic waste produced. This study aimed at investigating effects of two levels offeeding at two feeding frequencies on growth performance, feed efficiency and nitrogen and phosphorus loss in Asian seabass when fed diets with defatted soybean meal (SBM) replacing fish meal. Three diets were formulat...

  16. The calculation of absorbed dose rate in freshwater fish from high background natural radioactivity areas

    International Nuclear Information System (INIS)

    Pereira, W.S.; Moraes, S.R.; Cavalcante, J.J.V.; Pinto, C.E.C.; Kelecom, A.

    2017-01-01

    Areas of increased radiation may expose biota to radiation doses greater than the world averages, and depending on the magnitude of the exposure causing biota damage. The region of the municipality of Caldas, MG, BR is considered a region of increased natural radioactivity. The present work aims to evaluate the exposure of biota to natural radionuclides in the region of Caldas, MG. In order to evaluate the biota exposure in the region, the concentrations of the natural radionuclides U nat , 226 Ra, 210 Pb and 232 Th and 228 Ra were evaluated in two species of fishes: lambari (Astymax spp.) And traíra (Hoplias spp.). The dose rates of the analyzed fish were: for Astymax spp of 0.08 μGy d -1 and for Hoplias spp of 0.12 μGy∙d -1 . With these dose rate values no measurable deleterious effects are expected in the species studied

  17. Hydrophylax bahuvistara, a new species of fungoid frog (Amphibia: Ranidae from peninsular India

    Directory of Open Access Journals (Sweden)

    Anand D. Padhye

    2015-09-01

    Full Text Available Hydrophylax bahuvistara, a new species of fungoid frog, is described from peninsular India. It can be separated from its congeners based on a combination of characters including wider head, outline of snout in dorsal view truncated, finger and toe tips without lateroventral groove, foot moderately webbed, metatarsals of 4th and 5th toes closely set, outer metatarsal tubercle small, foot length less than or equal to half of snout vent length, dorsal parts of shank without glandular folds and sparse horny spinules, and heels touch each other when the legs are folded at right angles to the body.  Genetically, H. bahuvistara forms a monophyletic group with H. malabaricus as a sister clade separated by a raw distance of 4.0 to 4.5% in the 16s rRNA gene.  Morphometrically, H. bahuvistara forms a significantly different cluster from H. malabaricus and H. gracilis in Discriminant Analysis.  

  18. The DD Cold Fusion-Transmutation Connection

    Science.gov (United States)

    Chubb, Talbot A.

    2005-12-01

    LENR theory must explain dd fusion, alpha-addition transmutations, radiationless nuclear reactions, and three-body nuclear particle reactions. Reaction without radiation requires many-body D Bloch+ periodicity in both location and internal structure dependencies. Electron scattering leads to mixed quantum states. The radiationless dd fusion reaction is 2-D Bloch+ -> {}4 He Bloch2+. Overlap between {}4 He Bloch2+ and surface Cs leads to alpha absorption. In the Iwamura et al. studies active deuterium is created by scattering at diffusion barriers.

  19. Modeling of optical fields in laser microcavities using a modal method

    DEFF Research Database (Denmark)

    Gregersen, Niels

    2013-01-01

    mechanism limiting the Q factor is the poor modal overlap between the cavity Bloch mode and the mirror Bloch mode. Also, the strong connement will generally lead to highly divergent far field patterns and thus low collection efficiency. In this scenario, Bloch-wave engineering [1] and the introduction...... of adiabatic transitions emerge as powerful design tools to control the optical mode. In the modal method, the eld is expanded on the eigenmodes of z-invariant layers and on the Bloch modes of periodic sections. Using mode matching at the interfaces, the method gives direct access to re ection and transmission...

  20. Coherent excitation of vibrational levels using ultra short pulses

    CSIR Research Space (South Africa)

    De Clercq, LE

    2009-07-01

    Full Text Available population in a specific vibrational level. We used two approaches to do this, in the one model we used Von Neumann’s equations and the other the Optical Bloch equations (OBE’s). In this poster presentation the Optical Bloch model was used to do...

  1. Dr. Yu Wang, Director, Natural Science Division, National Science Council, Taiwan

    CERN Document Server

    Patrice Loïez

    2001-01-01

    Photo 01: L. to r.: Dr. Philippe Bloch, CERN CMS ECAL Deputy Project Manager, Dr. Yu Wang, Dr. Etiennette Auffray, CERN, responsible of the CERN ECAL Regional Centre. Photo 02: L. to r.: Dr. Yu Wang, Dr. Philippe Bloch, Dr. Apollo GO, National Central University, Taiwan, Dr. Etiennette Auffray.

  2. Extended rate equations

    International Nuclear Information System (INIS)

    Shore, B.W.

    1981-01-01

    The equations of motion are discussed which describe time dependent population flows in an N-level system, reviewing the relationship between incoherent (rate) equations, coherent (Schrodinger) equations, and more general partially coherent (Bloch) equations. Approximations are discussed which replace the elaborate Bloch equations by simpler rate equations whose coefficients incorporate long-time consequences of coherence

  3. Roland Weber first part

    DEFF Research Database (Denmark)

    2016-01-01

    The Sooty bloch complex - species identity, infection biology and control options. Rubbery rot and Black summer rot - two new diseases of apple......The Sooty bloch complex - species identity, infection biology and control options. Rubbery rot and Black summer rot - two new diseases of apple...

  4. Almost periodic Hamiltonians: an algebraic approach

    International Nuclear Information System (INIS)

    Bellissard, J.

    1981-07-01

    We develop, by analogy with the study of periodic potential, an algebraic theory for almost periodic hamiltonians, leading to a generalized Bloch theorem. This gives rise to results concerning the spectral measures of these operators in terms of those of the corresponding Bloch hamiltonians

  5. Multidimensional periodic Schrödinger operator perturbation theory and applications

    CERN Document Server

    Veliev, Oktay

    2015-01-01

    The book describes the direct problems and the inverse problem of the multidimensional Schrödinger operator with a periodic potential. This concerns perturbation theory and constructive determination of the spectral invariants and finding the periodic potential from the given Bloch eigenvalues. The unique method of this book derives the asymptotic formulas for Bloch eigenvalues and Bloch functions for arbitrary dimension. Moreover, the measure of the iso-energetic surfaces in the high energy region is construct and estimated. It implies the validity of the Bethe-Sommerfeld conjecture for arbitrary dimensions and arbitrary lattices. Using the perturbation theory constructed in this book, the spectral invariants of the multidimensional operator from the given Bloch eigenvalues are determined. Some of these invariants are explicitly expressed by the Fourier coefficients of the potential. This way the possibility to determine the potential constructively by using Bloch eigenvalues as input data is given. In the ...

  6. Uso de biomarcador histopatológico em brânquias de Centropomus undecimalis (Bloch, 1972 na avaliação da qualidade da água do Parque Ecológico Laguna da Jansen, São Luís - MA

    Directory of Open Access Journals (Sweden)

    S.M. Cantanhêde

    2014-04-01

    Full Text Available Com o objetivo de analisar a intensidade das alterações histológicas em brânquias de Centropomus undecimalis para avaliar a qualidade da água do Parque Ecológico Laguna da Jansen, em São Luís, Estado do Maranhão, coletaram-se exemplares de peixes no período chuvoso de 2012 e amostras de água nos períodos seco de 2011 e chuvoso de 2012 para análises físico-química e bacteriológica. Os resultados mostraram que a maioria dos parâmetros físico-químicos e bacteriológicos estava de acordo com os valores estabelecidos pela Resolução do CONAMA nº 357 de 2005. As alterações histológicas observadas foram: elevação do epitélio lamelar; proliferação excessiva de células dos epitélios filamentar e lamelar causando fusão total ou parcial das lamelas; alteração da estrutura das lamelas; hiperplasia das células mucosas; ruptura do epitélio lamelar; espessamento descontrolado do tecido proliferativo filamentar e lamelar e aneurismas de vários tamanhos. Também foi observada a presença de parasito em alguns exemplares. O Índice de Alteração Histológica (IAH por indivíduo variou de 2 a 114. O valor médio do IAH obtido foi de 40,3, demonstrando que as brânquias dos indivíduos amostrados da espécie C. undecimalis apresentaram alterações de moderadas para severas no tecido. As alterações histológicas encontradas indicam que esses indivíduos desenvolveram mecanismos de defesa contra a ação de estressores presentes na água da laguna e a um provável desequilíbrio parasito-hospedeiro-ambiente associado à baixa qualidade do ambiente.

  7. Estrutura populacional de Poecilia vivípara Bloch & Schneider, 1801 (Atheriniformes, Poeciliidae do rio Ceará-Mirim - Rio Grande do Norte Populational structure of Poecilia vivipara Block & Schneider, 1801 (Atheriniformes, Poeciliidae of Ceará-Mirim river, State of Rio Grande do Norte

    Directory of Open Access Journals (Sweden)

    Renata Swany Soares Nascimento

    2000-05-01

    Full Text Available Com o propósito de elucidar aspectos da estrutura populacional de Poecilia vivipara do rio Ceará-Mirim, município de Poço Branco, Rio Grande do Norte, foram capturados 3.390 exemplares em coletas mensais, no período de junho de 1995 a maio de 1997, utilizando-se tarrafas e peneiras. A partir dos resultados obtidos, constatou-se que as fêmeas, em relação aos machos, predominaram na proporção de 8:1, considerando-se as análises total e sazonal. No que se refere à distribuição por classes de comprimento para os sexos separados, observou-se uma maior amplitude de comprimento das fêmeas em relação aos machos e ainda uma ausência de diferenças entre as estações chuvosa e seca. De acordo com os valores obtidos para o &Teta; (3,86, verificou-se, para a espécie, um crescimento do tipo alométrico positivo. Quanto à influência dos fatores abióticos, fotoperíodo, pluviosidade, temperatura e nível do rio, relacionados aos aspectos da estrutura populacional, não foram verificados resultados significativos que a confirmassemWith the aim of clarifying aspects of the populational structure of Poecilia vivipara in the Ceará-Mirim river, State of Rio Grande do Norte, a total of 3,390 specimens were captured in monthly collections June 1995 trough May 1997, using nets and sieves. Results showed that females, prevailed in the proportion of 8:1, in the whole period as well as seasonaly. The total length classes distribution for separate sexes indicated that females reaches greatest lengths than males with no difference between dry and rainy seasons. The species growth is of the alometric positive type as suggested by the &Teta; value (3,86. No correlation between abiotic factors (photoperiod duration, rainfall, temperature and river water level and the population structure was found

  8. Separable decompositions of bipartite mixed states

    Science.gov (United States)

    Li, Jun-Li; Qiao, Cong-Feng

    2018-04-01

    We present a practical scheme for the decomposition of a bipartite mixed state into a sum of direct products of local density matrices, using the technique developed in Li and Qiao (Sci. Rep. 8:1442, 2018). In the scheme, the correlation matrix which characterizes the bipartite entanglement is first decomposed into two matrices composed of the Bloch vectors of local states. Then, we show that the symmetries of Bloch vectors are consistent with that of the correlation matrix, and the magnitudes of the local Bloch vectors are lower bounded by the correlation matrix. Concrete examples for the separable decompositions of bipartite mixed states are presented for illustration.

  9. Optically Controlled Quantum Dot Spins for Scaleable Quantum Computing

    National Research Council Canada - National Science Library

    Steel, Duncan G

    2005-01-01

    .... Our main achievements include working with a model system based on the exciton optical Bloch vector where we demonstrated the first solid state quantum logic device and made the first demonstration...

  10. and Asian catfish, Clarias batrachus

    African Journals Online (AJOL)

    ALEX

    2013-02-27

    Feb 27, 2013 ... crossing Indian catfish, Heteropneustes fossilis (Bloch) and Asian catfish, Clarias batrachus (Linn.) by ... Extensive culture of H. fossilis is prevalent in India, but with less growth, when ..... Kligerman AD, Bloom SE (1977).

  11. Browse Title Index

    African Journals Online (AJOL)

    Items 51 - 100 of 286 ... Vol 1 (1998), Bloch's Theorem And Quasiperiodicity In The Theory Of Optical ... Vol 11 (2003), Block Coded Combined Shannon-Fano and GAC Codes ... in Mauritian Transport Sector for Cars and Dual Cars, Abstract PDF.

  12. The calculation of absorbed dose rate in freshwater fish from high background natural radioactivity areas; Cálculo de taxa de dose absorvida em peixes de água doce de áreas de radioatividade natural aumentada

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S.; Moraes, S.R.; Cavalcante, J.J.V.; Pinto, C.E.C. [Universidade Veiga de Almeida (UVA), Rio de Janeiro, RJ (Brazil); Kelecom, A. [Universidade Federal Fluminense (UFF), Niterói, RJ (Brazil)

    2017-07-01

    Areas of increased radiation may expose biota to radiation doses greater than the world averages, and depending on the magnitude of the exposure causing biota damage. The region of the municipality of Caldas, MG, BR is considered a region of increased natural radioactivity. The present work aims to evaluate the exposure of biota to natural radionuclides in the region of Caldas, MG. In order to evaluate the biota exposure in the region, the concentrations of the natural radionuclides U{sub nat}, {sup 226}Ra, {sup 210}Pb and {sup 232}Th and {sup 228}Ra were evaluated in two species of fishes: lambari (Astymax spp.) And traíra (Hoplias spp.). The dose rates of the analyzed fish were: for Astymax spp of 0.08 μGy d{sup -1} and for Hoplias spp of 0.12 μGy∙d{sup -1}. With these dose rate values no measurable deleterious effects are expected in the species studied.

  13. A new species of Probursata Bravo-Hollis, 1984 (Mogenea: Heteraxinidae: Heteraxininae) parasite of Oligoplites spp. (Osteichthyes: Carangidae) from the coast of the state of Rio de Janeiro, Brazil

    OpenAIRE

    Ricardo M. Takemoto; J. F. R. Amato; José Luis Luque

    1993-01-01

    Probursata brasiliensis n. sp., a gill filament parasite of carangid fishes, O. palometa (Cuvier), Oligoplites saurus (Bloch & Schneider), and O. saliens (Bloch), from the Brazilian coast, is described and illustrated. The new species differs from Probursata veraecrucis Bravo-Hollis, 1984, the type and only species of this genus by the presence of spines in the auricular expansions of the genital atrium, by the trifurcate supplementary process of the clamp's midsclerite, and by having a l...

  14. Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae) da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae)

    OpenAIRE

    Takemoto, Ricardo Massato; Universidade Estadual de Matingá; Luque, José Luis; UFRRJ; Luque, José Luis; UFRRJ

    2008-01-01

    Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833), O. saurus (Bloch & Schneider, 1801) and O. saliens (Bloch, 1793) (Osteichthyes: Carangidae) from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908) are given. Caligus oligoplitisi Carvalho, 1954 is considered a new jun...

  15. Monogeneans of leatherjackets, Oligoplites spp. (Osteichthyes: Carangidae), with the description of a new species of Metacamopia (Monogenea: Allodiscocotylidae) from the coast of the State of Rio de Janeiro, Brazil

    OpenAIRE

    Takemoto,Ricardo M; Amato,JFR; Luque,José Luis

    1996-01-01

    Metacamopia oligoplites n. sp., a gill filament parasite of carangid fishes of three species of Oligoplites Gill, O. palometa (Cuvier), O. saurus (Bloch & Schneider), and O. saliens (Bloch), from the coast of the State of Rio de Janeiro, Brazil, is described and illustrated. Metacamopia oligoplites n. sp. differs from M. indica by: the shape of the body; the pre-, para-, and post-germarial testes; vaginas lacking sclerotized structures; well-developed seminal receptacles; muscular sleeves...

  16. Dilation of non-quasifree dissipative evolution

    Energy Technology Data Exchange (ETDEWEB)

    Varilly, J C [Costa Rica Univ., San Jose. Escuela de Matematica

    1981-03-01

    A semigroup evolution for the 1/2-spin which admits a conservative dilation is known to be governed by a Bloch equation in a standard form. Here we construct a conservative dilation directly from the Bloch equation, thus yielding an example of a dilation scheme for an evolution which is not quasifree. Moreover, we show that this conservative evolution is never ergodic in the non-quasifree case.

  17. H.E. Mr Leonid A. Skotnikov, Ambassador, Permanent Representative of the Russian Federation to the United Nations and other International Organisations in Geneva

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Photo 01: H.E. Mr Leonid A. Skotnikov, Ambassador of the Russian Federation to the United Nations and other International Organisations in Geneva (centre) with (from left to right) V. Kaftanov, Ph. Bloch, N. Koulberg, F. Grishaev Photo 02: H.E. Mr Leonid A. Skotnikov, Ambassador of the Russian Federation to the United Nations and other International Organisations in Geneva (centre) with Ph. Bloch (behind the Ambassador, V. Kaftanov) visiting the crystal laboratory in building 27.

  18. Matter-wave dark solitons in optical lattices

    International Nuclear Information System (INIS)

    Louis, Pearl J Y; Ostrovskaya, Elena A; Kivshar, Yuri S

    2004-01-01

    We analyse the Floquet-Bloch spectrum of matter waves in Bose-Einstein condensates loaded into single-periodic optical lattices and double-periodic superlattices. In the framework of the Gross-Pitaevskii equation, we describe the structure and analyse the mobility properties of matter-wave dark solitons residing on backgrounds of extended nonlinear Bloch-type states. We demonstrate that interactions between dark solitons can be effectively controlled in optical superlattices

  19. The Laughter as Hope Principle

    Directory of Open Access Journals (Sweden)

    Mateus Domingues da Silva

    2015-04-01

    Full Text Available The work aims to establish a parallel between the concept of laughter and the Hope Principle of Ernst Bloch, differentiating their relationship between the pursuit of individual happiness, said to be ideological, deceptive and precarious, and the pursuit of collective happiness, altruistic, that despite utopian it is also true and real, just for being selfless and real because, as a collective expression, indicating concretely and politically, is a real possibility.Keywords: Laughter, Hope Principle, Ernest Bloch, altruism.

  20. The multiplication operators on some analytic function spaces of the ...

    Indian Academy of Sciences (India)

    Given f ∈ E1(Bn) we still denote by f (ξ) (ξ ∈ Sn) its admissible limit at the boundary which exists a.e. A ... BMOA is a Banach space under the following norm: || f ||2 ..... The same inequalities hold when ga is replaced by fa by the same observations. ... The case of the Bloch space and the weighted Bloch space. As in the ...

  1. Manipulating quantum information on the controllable systems or subspaces

    OpenAIRE

    Zhang, Ming; Xi, Zairong; Wei, Jia-Hua

    2010-01-01

    In this paper, we explore how to constructively manipulate qubits by rotating Bloch spheres. It is revealed that three-rotation and one-rotation Hamiltonian controls can be constructed to steer qubits when two tunable Hamiltonian controls are available. It is demonstrated in this research that local-wave function controls such as Bang-Bang, triangle-function and quadratic function controls can be utilized to manipulate quantum states on the Bloch sphere. A new kind of time-energy performance ...

  2. Klimti tööd tagasi saanud juudi pere müüb need maha

    Index Scriptorium Estoniae

    2006-01-01

    Klimti maalide "Kasemets/Pöögimets" (1901), "Adele Bloch-Bauer II" (1912), "Õunapuu" (1912) ja "Majad Unterachis Attersee ääres" (1916) õiguspäraseks omanikuks tunnistati Ferdinand Bloch-Baueri vennatütar Maria Altmann. Maalid müüakse sügisel. Praegu asuvad maalid New Yorgis saksa ja austria kunsti muuseumis Neue Galerie's

  3. Magnetic resonance described in the excitation dependent rotating frame of reference.

    Science.gov (United States)

    Tahayori, Bahman; Johnston, Leigh A; Mareels, Iven M Y; Farrell, Peter M

    2008-01-01

    An excitation dependent rotating frame of reference to observe the magnetic resonance phenomenon is introduced in this paper that, to the best of our knowledge, has not been used previously in the nuclear magnetic resonance context. The mathematical framework for this new rotating frame of reference is presented based on time scaling the Bloch equation after transformation to the classical rotating frame of reference whose transverse plane is rotating at the Larmor frequency. To this end, the Bloch equation is rewritten in terms of a magnetisation vector observed from the excitation dependent rotating frame of reference. The resultant Bloch equation is referred to as the time scaled Bloch equation. In the excitation dependent rotating frame of reference whose coordinates are rotating at the instantaneous Rabi frequency the observed magnetisation vector is a much slower signal than the true magnetisation in the rotating frame of reference. As a result the ordinary differential equation solvers have the ability to solve the time scaled version of the Bloch equation with a larger step size resulting in a smaller number of samples for solving the equation to a desired level of accuracy. The simulation results for different types of excitation are presented in this paper. This method may be used in true Bloch simulators in order to reduce the simulation time or increase the accuracy of the numerical solution. Moreover, the time scaled Bloch equation may be employed to determine the optimal excitation pattern in magnetic resonance imaging as well as designing pulses with better slice selectivity which is an active area of research in this field.

  4. Sound waves and dynamics of superfluid Fermi gases in optical lattices

    International Nuclear Information System (INIS)

    Zhang Aixia; Xue Jukui

    2009-01-01

    The sound waves, the stability of Bloch waves, the Bloch oscillation, and the self-trapping phenomenon in interacting two-component Fermi gases throughout the BEC-BCS crossover in one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) optical lattices are discussed in detail. Within the hydrodynamical theory and by using the perturbative and tight-binding approximation, sound speed in both weak and tight 1D, 2D, 3D optical lattices, and the criteria for occurrences of instability of Bloch waves and self-trapping of Fermi gases along the whole BEC-BCS crossover in tight 1D, 2D, 3D optical lattices are obtained analytically. The results show that the sound speed, the criteria for occurrences of instability of Bloch waves and self-trapping, and the destruction of Bloch oscillation are modified dramatically by the lattice parameters (lattice dimension and lattice strength), the atom density or atom number, and the atom interaction.

  5. Light quantum particles in a metallic environment

    International Nuclear Information System (INIS)

    Hedegad, P.

    1986-04-01

    The basic mechanism that limits the quantum behavior of light particles are fluctuations in the environment. We here develop a path integral formalism that accounts for the influence of the environment on the quantum motion of such particles. As our prime example we discuss a particle that moves in a tight binding band and interacts with an electron gas environment. This situation has received experimental attention recently in the case of muon diffusion in metals, and in the theoretical discussion of hydrogen on metal surfaces. It is shown that the adiabatic approximation, usually applied to such problems, does not apply. This has basically two consequences. At low temperatures we find that the particle moves in Bloch states with a renormalized (more narrow) band width. For higher temperatures (k B T > W ren ) the Bloch states acquire a lifetime that is shorter than K/W ren , which means a complete breakdown of the Bloch picture. (orig.)

  6. Mrs Hitler and her doctor.

    Science.gov (United States)

    Macleod, Sandy

    2005-12-01

    The doctor who attended the mother of Adolf Hitler in her terminal illness has been blamed as a cause of the Holocaust. The medical details recorded of this professional relationship are presented and discussed. Dr Bloch's medical care of Mrs Hitler was consistent with the prevailing medical practice of the management of fungating breast carcinoma. Indeed, the general practitioner's care and attention of the family appear to have been astute and supportive. There is nothing to suggest that Dr Bloch's medical care was other than competent. Doctors who have the (mis)fortune to professionally attend major figures of history may be unfairly viewed, despite their appropriate and adequate care.

  7. A new species of Probursata Bravo-Hollis, 1984 (Mogenea: Heteraxinidae: Heteraxininae parasite of Oligoplites spp. (Osteichthyes: Carangidae from the coast of the state of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo M. Takemoto

    1993-06-01

    Full Text Available Probursata brasiliensis n. sp., a gill filament parasite of carangid fishes, O. palometa (Cuvier, Oligoplites saurus (Bloch & Schneider, and O. saliens (Bloch, from the Brazilian coast, is described and illustrated. The new species differs from Probursata veraecrucis Bravo-Hollis, 1984, the type and only species of this genus by the presence of spines in the auricular expansions of the genital atrium, by the trifurcate supplementary process of the clamp's midsclerite, and by having a larger number of tests and clamps. This is the first record of the genus Probursata Bravo-Hollis, 1984, in the South Atlantic Ocean.

  8. Proposal for a source of polarized protons; Projet de source de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Abragam, A.; Winter, J. M. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay, BP2, Gif-sur-Yvette (France)

    1959-07-01

    Proposal for a source of polarized protons based on the theory of adiabatic fast passage due to F. Bloch. Reprint of a paper published in 'Physical review letters', vol 1, n. 10, 15 Nov 1958, p. 374-375 [French] On propose une methode nouvelle pour la realisation d'une source de protons polarises basee sur la theorie du passage adiabatique de F. Bloch. Reproduction d'un article publie dans 'Physical review letters', vol 1, n. 10, 15 nov 1958, p. 374-375.

  9. Engineering topological edge states in two dimensional magnetic photonic crystal

    Science.gov (United States)

    Yang, Bing; Wu, Tong; Zhang, Xiangdong

    2017-01-01

    Based on a perturbative approach, we propose a simple and efficient method to engineer the topological edge states in two dimensional magnetic photonic crystals. The topological edge states in the microstructures can be constructed and varied by altering the parameters of the microstructure according to the field-energy distributions of the Bloch states at the related Bloch wave vectors. The validity of the proposed method has been demonstrated by exact numerical calculations through three concrete examples. Our method makes the topological edge states "designable."

  10. Selection rule for Dirac-like points in two-dimensional dielectric photonic crystals

    KAUST Repository

    Li, Yan

    2013-01-01

    We developed a selection rule for Dirac-like points in two-dimensional dielectric photonic crystals. The rule is derived from a perturbation theory and states that a non-zero, mode-coupling integral between the degenerate Bloch states guarantees a Dirac-like point, regardless of the type of the degeneracy. In fact, the selection rule can also be determined from the symmetry of the Bloch states even without computing the integral. Thus, the existence of Dirac-like points can be quickly and conclusively predicted for various photonic crystals independent of wave polarization, lattice structure, and composition. © 2013 Optical Society of America.

  11. Quantum qubit measurement by a quantum point contact with a quantum Langevin equation approach

    International Nuclear Information System (INIS)

    Dong, Bing; Lei, X.L.; Horing, N.J.M.; Cui, H.L.

    2007-01-01

    We employ a microscopic quantum Heisenberg-Langevin equation approach to establish a set of quantum Bloch equations for a two-level system (coupled quantum dots) capacitively coupled to a quantum point contact (QPC). The resulting Bloch equations facilitate our analysis of qubit relaxation and decoherence in coupled quantum dots induced by measurement processes at arbitrary bias-voltage and temperature. We also examine the noise spectrum of the meter output current for a symmetric qubit. These results help resolve a recent debate about a quantum oscillation peak in the noise spectrum. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Review of the Indo-Pacific labrid fish genus Hemigymnus

    OpenAIRE

    Randall, John E.

    2013-01-01

    The labrid fish genus Hemigymnus Günther consists of three relatively large coral-reef species: the wide-ranging Indo-Pacific H. fasciatus (Bloch) and H. melapterus (Bloch), and H. sexfasciatus (Rüppell) of the Red Sea and Gulf of Aden, usually regarded as a synonym of H. fasciatus. It is treated here as a species, distinguished by color pattern, longer pelvic fins of the terminal male, and fewer gill rakers. These three fishes are generally found as solitary individuals over sand or sand-and...

  13. Entanglement of arbitrary superpositions of modes within two-dimensional orbital angular momentum state spaces

    International Nuclear Information System (INIS)

    Jack, B.; Leach, J.; Franke-Arnold, S.; Ireland, D. G.; Padgett, M. J.; Yao, A. M.; Barnett, S. M.; Romero, J.

    2010-01-01

    We use spatial light modulators (SLMs) to measure correlations between arbitrary superpositions of orbital angular momentum (OAM) states generated by spontaneous parametric down-conversion. Our technique allows us to fully access a two-dimensional OAM subspace described by a Bloch sphere, within the higher-dimensional OAM Hilbert space. We quantify the entanglement through violations of a Bell-type inequality for pairs of modal superpositions that lie on equatorial, polar, and arbitrary great circles of the Bloch sphere. Our work shows that SLMs can be used to measure arbitrary spatial states with a fidelity sufficient for appropriate quantum information processing systems.

  14. Comparison of spatial harmonics in infinite and finite Bragg stacks for metamaterial homogenization

    DEFF Research Database (Denmark)

    Clausen, Niels Christian Jerichau; Arslanagic, Samel; Breinbjerg, Olav

    2014-01-01

    Metamaterial homogenization may be based on the dominance of a single Floquet-Bloch spatial harmonic in an infinite periodic structure - with the dominance quantified in terms of the relative magnitude of the associated spatial harmonic Poynting vector. For the corresponding finite structure...... the field is not quasi-periodic and cannot be expanded in Floquet-Bloch spatial harmonics; however, a set of pseudo spatial harmonics can be defined and the dominance of a single such harmonic likewise be used to determine whether the structure can be homogenized. For three different lossless Bragg stack...

  15. A new phase coding method using a slice selection gradient for high speed flow velocity meaurements in NMR tomography

    International Nuclear Information System (INIS)

    Oh, C.H.; Cho, Z.H.; California Univ., Irvine

    1986-01-01

    A new phase coding method using a selection gradient for high speed NMR flow velocity measurements is introduced and discussed. To establish a phase-velocity relationship of flow under the slice selection gradient and spin-echo RF pulse, the Bloch equation was numerically solved under the assumption that only one directional flow exists, i.e. in the direction of slice selection. Details of the numerical solution of the Bloch equation and techniques related to the numerical computations are also given. Finally, using the numerical calculation, high speed flow velocity measurement was attempted and found to be in good agreement with other complementary controlled measurements. (author)

  16. Symmetry characterization of electrons and lattice excitations

    Directory of Open Access Journals (Sweden)

    Schober H.

    2012-03-01

    Full Text Available Symmetry concerns all aspects of a physical system from the electronic orbitals to structural and magnetic excitations. In this article we will try to elaborate the fundamental connection between symmetry and excitations. As excitations are manyfold in physical systems it is impossible to treat them exhaustively. We thus concentrate on the two topics of Bloch electrons and phonons. These two examples are complementary in the sense that Bloch electrons describe single particles in an external periodic potential while phonons exemplify a decoupled system of interacting particles. The way we develop the argument gives as by-product a short account of molecular orbitals and molecular vibrations.

  17. 29 March 2011 - Ninth President of Israel S.Peres welcomed by CERN Director-General R. Heuer who introduces Council President M. Spiro, Director for Accelerators and Technology S. Myers, Head of International Relations F. Pauss, Physics Department Head P. Bloch, Technology Department Head F. Bordry, Human Resources Department Head A.-S. Catherin, Beams Department Head P. Collier, Information Technology Department Head F. Hemmer, Adviser for Israel J. Ellis, Legal Counsel E. Gröniger-Voss, ATLAS Collaboration Spokesperson F. Gianotti, Former ATLAS Collaboration Spokesperson P. Jenni, Weizmann Institute G. Mikenberg, CERN VIP and Protocol Officer W. Korda.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    During his visit he toured the ATLAS underground experimental area with Giora Mikenberg of the ATLAS collaboration, Weizmann Institute of Sciences and Israeli industrial liaison office, Rolf Heuer, CERN’s director-general, and Fabiola Gianotti, ATLAS spokesperson. The president also visited the CERN computing centre and met Israeli scientists working at CERN.

  18. Divergence of dielectric permittivity near phase transition within ferroelectric domain boundaries

    Czech Academy of Sciences Publication Activity Database

    Márton, Pavel; Stepkova, Vilgelmina; Hlinka, Jiří

    2013-01-01

    Roč. 86, č. 1 (2013), s. 103-108 ISSN 0141-1594 R&D Projects: GA ČR GAP204/10/0616 Institutional support: RVO:68378271 Keywords : Bloch wall * domain boundary * BaTiO 3 * Ginzburg-Landau-Devonshire theory * permittivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.044, year: 2013

  19. On the "Critique of Everyday Life" to "Metaphilosophy": Henri Lefebvre's Philosophical-Political Legacy of the Cultural Revolution

    Science.gov (United States)

    Sünker, Heinz

    2014-01-01

    Henri Lefebvre (1901-91), philosopher and sociologist, is, together with Theodor W. Adorno, Max Horkheimer, Walter Benjamin and Ernst Bloch, one of the most relevant representatives of the first generation in Western Marxism. His engagement with Marxism led him to analyse everyday life in post-war France in order to decipher the possibilities of,…

  20. Errata Resonance, Vol.20, No.12, 2015. Rajaram Nityananda, Sun ...

    Indian Academy of Sciences (India)

    IAS Admin

    Resonance, Vol.20, No.12, 2015. Rajaram Nityananda, Sun, Sky and Clouds: Where Light and Matter Meet. Page 1121: The correct Figure 5 is reproduced below: Resonance, Vol.20, No.11, 2015. Anil Kumar, Felix Bloch (1905–1983). Page 956: Para 1, Line 5, 'also from Zürich' should be read as 'from nearby Bern'.

  1. Length-weight relationships of five fish species in Epe lagoon, Nigeria

    African Journals Online (AJOL)

    The fishes (Clarias gariepinus (Burch), Illisha africana Bloch), Chrysichthys nigrodigitatus (Lacepede), Chrysichthys walkeri (Gunther) and Ethmalosa fimbriata (Bowdich)) were obtained from fish landing site at Epe market from November 2001 to October 2002, and January to December 2003. The parameters a and b of the ...

  2. Les innocents et les coupables; Essai d'exégese

    NARCIS (Netherlands)

    Gadourek-Backer, Johanna Carina Augusta

    1963-01-01

    Apres la publication des nouvelles, Camus consacra une grande partie de ses loisirs a la documentation requise pour les Reflexions sur la guillotine. Elles parurent en 1957, avec des contributions d'Arthur Koestler et de M. Bloch, dans un volume intitulé Réflexions sur la peine capitale. Le livre ne

  3. Significance of X-ray imaging techniques in the study of ferro-or ferri-magnets

    International Nuclear Information System (INIS)

    Miltat, J.

    1983-01-01

    The subject is discussed under the headings: introduction; basic physics of Bloch wall statics (magnetization (a) parallel (b) perpendicular, to the surface); magnetostrictive strains; detectability of magnetostrictive strains by means of X-ray imaging techniques; interactions of individual lattice defects and moving walls (optical studies; X-ray studies); conclusion. (U.K.)

  4. Coulomb drag in multiwall armchair carbon nanotubes

    DEFF Research Database (Denmark)

    Lunde, A.M.; Jauho, Antti-Pekka

    2004-01-01

    surface. The cylindrical geometry of the nanotubes and the different parities of the Bloch states are accounted for in the evaluation of the effective Coulomb interaction between charges in the concentric nanotubes. We find a broad peak in rho(21) as a function of temperature at roughly T similar to 0.4T...

  5. Eelproov Musikvereinile ja "Turangalila-sümfoonia" / Igor Garšnek

    Index Scriptorium Estoniae

    Garšnek, Igor, 1958-

    2010-01-01

    Tallinna Filharmoonia hooaja avakontserdist 6. oktoobril Estonia kontserdisaalis, kus esinesid Tallinna Filharmoonikud ja Lisa Smirnova (klaver) Andres Mustoneni dirigeerimisel ja 8. oktoobril samas toimunud ERSO kontserdist Nikolai Aleksejevi dirigeerimisel, kavas Olivier Messiaeni "Turangalila-Sümfoonia", solistid Francois Weigel ja Thomas Bloch

  6. Schrödinger operators on a periodically broken zigzag carbon ...

    Indian Academy of Sciences (India)

    In this paper, we study the spectra of Schrödinger operators on zigzag carbon nanotubes, which are broken by abrasion or during refining process. Throughout this paper, we assume that the carbon nanotubes are broken periodically and we deal with one of those models. Making use of the Floquet–Bloch theory, we ...

  7. Self-similar solutions of certain coupled integrable systems

    CERN Document Server

    Chakravarty, S; Kent, S L

    2003-01-01

    Similarity reductions of the coupled nonlinear Schroedinger equation and an integrable version of the coupled Maxwell-Bloch system are obtained by applying non-translational symmetries. The reduced system of coupled ordinary differential equations are solved in terms of Painleve transcendents, leading to new exact self-similar solutions for these integrable equations.

  8. Self-similar solutions of certain coupled integrable systems

    International Nuclear Information System (INIS)

    Chakravarty, S; Halburd, R G; Kent, S L

    2003-01-01

    Similarity reductions of the coupled nonlinear Schroedinger equation and an integrable version of the coupled Maxwell-Bloch system are obtained by applying non-translational symmetries. The reduced system of coupled ordinary differential equations are solved in terms of Painleve transcendents, leading to new exact self-similar solutions for these integrable equations

  9. Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac ...

    African Journals Online (AJOL)

    Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac·eptive Preparation. Basil Bloch. Abstract. Experience with depot medroxyprogesterone acetate as a contraceptive preparation in 7 335 patients for a total of 38 714 months over a 3-year period is described. The discontinuation rate was 18.3% and the ...

  10. Geometric interpretation of four-wave mixing

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Steffensen, Henrik; Rottwitt, Karsten

    2013-01-01

    -like coordinates of the electric fields, which reduce the FWM dynamics to a closed two-dimensional surface, similar to the Bloch sphere of quantum electrodynamics or the Pointcare´ sphere in polarization dynamics. The coordinates are chosen so as to use the gauge invariance symmetries of the FWM equations which...

  11. Infrared phenomena in quantum electrodynamics : I. The physical one-electron states in the infrared region

    NARCIS (Netherlands)

    Haeringen, W. van

    In view of remaining obscurities and difficulties in existing treatments of the infrared divergences in quantum electrodynamics this problem has been considered anew. The approximate model introduced in 1937 by Bloch and Nordsieck is rediscussed. It is explicitly shown to be a good substitute for

  12. Decoupling Stimulus Duration from Brightness in Metacontrast Masking: Data and Models

    Science.gov (United States)

    Di Lollo, Vincent; Muhlenen, Adrian von; Enns, James T.; Bridgeman, Bruce

    2004-01-01

    A brief target that is visible when displayed alone can be rendered invisible by a trailing stimulus (metacontrast masking). It has been difficult to determine the temporal dynamics of masking to date because increments in stimulus duration have been invariably confounded with apparent brightness (Bloch's law). In the research reported here,…

  13. YBa2Cu3O7–La0.67Sr0.33MnO3 trilayers

    Indian Academy of Sciences (India)

    the near bulk value (~350 K) in films thicker than 200 Å, while thinner films show a slight drop in ... 1000 Oe field-cooled Ms(T) measurements (shown in figure 1) to the Bloch relation .... The solid lines in the inset are only guides to the eyes.

  14. Stopping powers of Zr, Pd, Cd, In and Pb for 6.5 MeV protons and mean excitation energies

    International Nuclear Information System (INIS)

    Ishiwari, R.; Shiomi, N.; Sakamoto, N.

    1983-01-01

    Stopping powers of Zr, Pd, Cd, In and Pb have been measured for 6.5 MeV protons. Mean excitation energies have been extracted from the stopping power data by taking into account Bloch correction and Z 1 3 correction. For the shell correction the Bonderup shell correction has been used. The results agree fairly well with those of other authors

  15. Re-Engineering the Stomatopod Eye, Nature’s Most Comprehensive Visual Sensor

    Science.gov (United States)

    2017-02-22

    evolutionary trajectory for the past 400 million years. We want to learn from this evolutionarily based design. As their closest existing, artificial...of the Anterior Cruciate Ligament. The American Journal of Sports Medicine 0363546514566192. T. Charanya, T. York, S. Bloch, G. Sudlow, R. Tang, W

  16. Debate, Research on E-Cigarettes Continues

    Science.gov (United States)

    Since they first began to be sold in North America in the mid-2000s, electronic cigarettes have been the subject of intense debate. NCI's Dr. Michele Bloch recently presented an update on some of the issues surrounding e-cigarettes.

  17. Magnetic phenomena in F.F.A.G. cyclotrons

    International Nuclear Information System (INIS)

    Beurtey, R.

    1957-01-01

    This study regroups and develops some experimental and theoretical results obtained with spiral tract cyclotrons. The method used has been studied previously by C. BLOCH, whom we thank for his helpful advice. We have tried to give the main useful results, which are also in accordance with the rather scarce experimental results obtained on spiral pole pieces. (author) [fr

  18. A Comparison of Implications in Orthomodular Quantum Logic—Morphological Analysis of Quantum Logic

    Directory of Open Access Journals (Sweden)

    Mitsuhiko Fujio

    2012-01-01

    Full Text Available Morphological operators are generalized to lattices as adjunction pairs (Serra, 1984; Ronse, 1990; Heijmans and Ronse, 1990; Heijmans, 1994. In particular, morphology for set lattices is applied to analyze logics through Kripke semantics (Bloch, 2002; Fujio and Bloch, 2004; Fujio, 2006. For example, a pair of morphological operators as an adjunction gives rise to a temporalization of normal modal logic (Fujio and Bloch, 2004; Fujio, 2006. Also, constructions of models for intuitionistic logic or linear logics can be described in terms of morphological interior and/or closure operators (Fujio and Bloch, 2004. This shows that morphological analysis can be applied to various non-classical logics. On the other hand, quantum logics are algebraically formalized as orhomodular or modular ortho-complemented lattices (Birkhoff and von Neumann, 1936; Maeda, 1980; Chiara and Giuntini, 2002, and shown to allow Kripke semantics (Chiara and Giuntini, 2002. This suggests the possibility of morphological analysis for quantum logics. In this article, to show an efficiency of morphological analysis for quantum logic, we consider the implication problem in quantum logics (Chiara and Giuntini, 2002. We will give a comparison of the 5 polynomial implication connectives available in quantum logics.

  19. Effective-mass analysis of Bose-Einstein condensates in optical lattices: Stabilization and levitation

    International Nuclear Information System (INIS)

    Pu, H.; Zhang, W.; Meystre, P.; Baksmaty, L.O.; Bigelow, N.P.

    2003-01-01

    We investigate the time evolution of a Bose-Einstein condensate in a periodic optical potential. Using an effective mass formalism, we study the equation of motion for the envelope function modulating the Bloch states of the lattice potential. In particular, we show how the negative effective-mass affects the dynamics of the condensate

  20. Alien fish species in upper Sakarya River and their distribution ...

    African Journals Online (AJOL)

    However, the fact that the flood plains have been reclaimed, excessive hunting, destruction of the ecologic balance and invasion of the area by the alien fish species threatens the fish stocks in Sakarya River. In this study, we aimed to determine the dispersion area of Carassius gibelio (Bloch, 1782), Oreochromis niloticus ...

  1. Investigations into homogenization of electromagnetic metamaterials

    DEFF Research Database (Denmark)

    Clausen, Niels Christian Jerichau

    This dissertation encompasses homogenization methods, with a special interest into their applications to metamaterial homogenization. The first method studied is the Floquet-Bloch method, that is based on the assumption of a material being infinite periodic. Its field can then be expanded in term...

  2. Physical education, sport and recreation: A triad pedagogy of hope ...

    African Journals Online (AJOL)

    Bloch (2009, 58), a previous advocate of Outcomes-based Education (OBE), states that schooling in SA is a national disaster. Quality holistic education that includes Physical Education (PE) and school sport should be the focal point of progress in developing countries. However, PE is worldwide in a political crisis and the ...

  3. Unified Approach to Universal Cloning and Phase-Covariant Cloning

    OpenAIRE

    Hu, Jia-Zhong; Yu, Zong-Wen; Wang, Xiang-Bin

    2008-01-01

    We analyze the problem of approximate quantum cloning when the quantum state is between two latitudes on the Bloch's sphere. We present an analytical formula for the optimized 1-to-2 cloning. The formula unifies the universal quantum cloning (UQCM) and the phase covariant quantum cloning.

  4. Work notice

    CERN Multimedia

    TS-FM

    2005-01-01

    Please note that work to repair the water mains on Route Bloch near Gate C will be carried out between 12 and 30 September 2005. The area between Route Bakker and Gate C will be closed to traffic during this period. You are kindly requested to comply with the road signs in place. Thank you for your understanding. TS-FM Group

  5. Infrared problem in non-Abelian gauge theory

    International Nuclear Information System (INIS)

    Yao, Y.

    1976-01-01

    I extend the Bloch--Nordsieck idea to show that in the lowest nontrivial order of radiative correction the fermion--fermion and gauge-meson--fermion scattering rates are finite, provided that they are averaged over the initial and summed over the final internal spin states. Questions of the physical gauge coupling and infrared slavery are discussed

  6. Author Details

    African Journals Online (AJOL)

    Sairkar, P. Vol 8, No 14 (2009) - Articles Genetic variability in Asparagus racemosus (Willd.) from Madhya Pradesh, India by random amplified polymorphic DNA Abstract PDF · Vol 8, No 17 (2009) - Articles RAPD analysis for genetic diversity of two populations of Mystus vittatus (Bloch) of Madhya Pradesh, India

  7. A Review of Group Systems Theory

    Science.gov (United States)

    Connors, Joanie V.; Caple, Richard B.

    2005-01-01

    The ability to see interpersonal and group processes beyond the individual level is an essential skill for group therapists (Crouch, Bloch & Wanlass, 1994; Dies, 1994; Fuhriman & Burlingame, 1994). In addition to interpersonal therapy models (e.g., Sullivan and Yalom), there are a number of systems theory models that offer a broad array of…

  8. Theory of the nuclear self-oscillator used to measure the earth's magnetic field; Theorie de l'auto-oscillateur nucleaire utilise pour la mesure du champ magnetique terrestre

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, Ionel

    1961-07-01

    After an energy assessment of the device, this note reports the development of theoretical formulations describing its operation. The author uses Bloch equations, addresses the rotating field produced by nuclear magnetisation, and discusses a steady solution. The next part discusses the field measurement precision, notably while assessing various noises. The sample is then presented.

  9. Bird of Passage at Four Universities

    Indian Academy of Sciences (India)

    IAS Admin

    ship in the Research Department of a telephone com- pany, `Mix and .... the way he could guide research students. He always .... On his advice Peierls left ..... ciple fill the Bloch states, giving us a metal or an insulator (Figures 1a and 1b),.

  10. RAPD analysis for genetic diversity of two populations of Mystus ...

    African Journals Online (AJOL)

    ) was applied to analyze the genetic variation of the 2 populations of Mystus vittatus (Bloch) of Madhya Pradesh, India. 10 random 10-mer primers were primarily scored in 3 individuals from each of the 2 locations. Five primers, which gave ...

  11. Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe carrier-carrier scattering dynamics in an inverted quantum well structure including the nonparabolic nature of the valance band. A solution of the semiconductor Bloch equations yields strong evidence to a large change in the temporal evolution of the carrier distributions compared to ...

  12. Selection of planes in nuclear magnetic resonance tomography

    International Nuclear Information System (INIS)

    Bonagamba, T.J.

    1986-01-01

    A prototype aiming to obtain images in nuclear magnetic resonance tomography was developed, by adjusting NMR spectrometer in the IFQSC Laboratory. The techniques for selecting planes were analysed by a set of computer codes, which were elaborated from Bloch equation solutions to simulate the spin system behaviour. Images were obtained using planes with thickness inferior to 1 cm. (M.C.K.)

  13. Significance of sterol structural specificity : desmosterol cannot replace cholesterol in lipid rafts

    NARCIS (Netherlands)

    Vainio, S.; Jansen, Maurice; Koivusalo, M.; Róg, T.; Karttunen, M.E.J.; Vattulainen, I.; Ikonen, E.

    2006-01-01

    Desmosterol is an immediate precursor of cholesterol in the Bloch pathway of sterol synthesis and an abundant membrane lipid in specific cell types. The significance of the difference between the two sterols, an additional double bond at position C24 in the tail of desmosterol, is not known. Here,

  14. Data systems and computer science space data systems: Onboard memory and storage

    Science.gov (United States)

    Shull, Tom

    1991-01-01

    The topics are presented in viewgraph form and include the following: technical objectives; technology challenges; state-of-the-art assessment; mass storage comparison; SODR drive and system concepts; program description; vertical Bloch line (VBL) device concept; relationship to external programs; and backup charts for memory and storage.

  15. Roundtrip matrix method for calculating the leaky resonant modes of open nanophotonic structures

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Kristensen, Philip Trøst; Mørk, Jesper

    2014-01-01

    We present a numerical method for calculating quasi-normal modes of open nanophotonic structures. The method is based on scattering matrices and a unity eigenvalue of the roundtrip matrix of an internal cavity, and we develop it in detail with electromagnetic fields expanded on Bloch modes...

  16. Near-Field Nanolasers based on Nonradiating Anapole Modes

    KAUST Repository

    Gongora, J. S. Totero

    2016-05-31

    By employing ab-initio simulations of Maxwell-Bloch equations with a source of quantum noise, we study a new laser concept based on photonic dark-matter nanostructures that emit only in the near-field, with no far-field radiation pattern.

  17. Nonlinear emission from dark anapole modes and route to all-dielectric metamaterial near-field lasers

    KAUST Repository

    Gongora, J. S. Totero

    2016-08-29

    By employing ab-initio simulations of Maxwell-Bloch equations with a source of quantum noise, we study a new laser concept based on photonic dark-matter nanostructures that emit only in the near-field, with no far-field radiation pattern

  18. Neutron scattering studies of low dimensional magnetic systems

    DEFF Research Database (Denmark)

    Hansen, Ursula Bengård

    investigated at low temperaturesand in a longitudinal magnetic eld using neutron spectroscopy. Here we observe thehybridisation of the magnon bound states, inherent to the low dimensional nature ofCoCl2 · 2D2O.At higher temperature, signatures which can be attributed to Magnetic Bloch Oscillationsis observed...

  19. Nonlinear emission from dark anapole modes and route to all-dielectric metamaterial near-field lasers

    KAUST Repository

    Gongora, J. S. Totero; Miroshnichenko, Andrey E.; Kivshar, Yuri S.; Fratalocchi, Andrea

    2016-01-01

    By employing ab-initio simulations of Maxwell-Bloch equations with a source of quantum noise, we study a new laser concept based on photonic dark-matter nanostructures that emit only in the near-field, with no far-field radiation pattern

  20. Near-Field Nanolasers based on Nonradiating Anapole Modes

    KAUST Repository

    Gongora, J. S. Totero; Miroshnichenko, Andrey E.; Kivshar, Yuri S.; Fratalocchi, Andrea

    2016-01-01

    By employing ab-initio simulations of Maxwell-Bloch equations with a source of quantum noise, we study a new laser concept based on photonic dark-matter nanostructures that emit only in the near-field, with no far-field radiation pattern.

  1. CERN's 25th Anniversary

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    A ceremony in the Main Auditorium on 23 June 1979 to mark the 25th Anniversary of CERN. A photo of the five Director-Generals of CERN, from left to right: John Adams, Willi Jentschke, Felix Bloch, Viki Weisskopf and Leon van Hove.

  2. Balts show strong notes in Grammy Awards

    Index Scriptorium Estoniae

    2005-01-01

    Los Angeleses 8. veebr. Grammy Awards nominantide seas läti laulja Elina Garanca, dirigendid Paavo Järvi (Schumann "Cello Concerto" and Bloch's "Schelomo") ja Maris Jansons. Eelmisel aastal pälvis Grammy teos Sibelius "Cantatas" (esitajad Ellerheina tütarlastekoor Ester Loitme juhatusel, Eesti Rahvusmeeskoor, ERSO, dirigendid Ants Soots ja Paavo Järvi)

  3. Homer: A Collection of Critical Essays. Twentieth Century Views Series.

    Science.gov (United States)

    Steiner, George, Ed.; Fagles, Robert, Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection includes essays by George Steiner, Leo Tolstoy, Ezra Pound, Erich Auerbach, Edwin Muir, Cedric H. Whitman, Albert B. Lord, W. H. Auden, Ernst Bloch, Georg Lukacs, C. Day Lewis, Gabriel Germain, Franz Kafka, Rachel Bespaloff, Robert…

  4. Method to map individual electromagnetic field components inside a photonic crystal

    NARCIS (Netherlands)

    Denis, T.; Reijnders, B.; Lee, J.H.H.; van der Slot, Petrus J.M.; Vos, Willem L.; Boller, Klaus J.

    2012-01-01

    We present a method to map the absolute electromagnetic field strength inside photonic crystals. We apply the method to map the dominant electric field component Ez of a two-dimensional photonic crystal slab at microwave frequencies. The slab is placed between two mirrors to select Bloch standing

  5. On the unambiguous determination of effective optical properties of periodic metamaterials: a one-dimensional case study

    DEFF Research Database (Denmark)

    Mortensen, Asger; Yan, Min; Sigmund, Ole

    2010-01-01

    We show how branch ambiguities in the extraction of effective parameters is arising as a direct consequence of the underlying Bloch state physics. The mutual importance of the different branches in general depends on the experimental context, and we show how the Fourier spectrum of the field inside...

  6. Quantum dynamical phenomena of independent electrons in semiconductor superlattices subject to a uniform electric field

    International Nuclear Information System (INIS)

    Bouchard, A.M.

    1994-01-01

    This report discusses the following topics: Bloch oscillations and other dynamical phenomena of electrons in semiconductor superlattices; solvable dynamical model of an electron in a one-dimensional aperiodic lattice subject to a uniform electric field; and quantum dynamical phenomena of electrons in aperiodic semiconductor superlattices

  7. Plasmonic fluorescence enhancement of DBMBF2 monomers and DBMBF2-toluene exciplexes using al-hole arrays

    NARCIS (Netherlands)

    Schmidt, T.M.; Bochenkov, V.E.; Espinoza, J.D.A.; Smits, E.C.P.; Muzafarov, A.M.; Kononevich, Y.N.; Sutherland, D.S.

    2014-01-01

    The optical properties of aluminum hole arrays fabricated via colloidal lithography were investigated. By tuning the hole diameter and hole spacing independently, their influence on the Bloch wave-surface plasmon polariton (BW-SPP) and localized surface plasmon resonances resonances (LSPR) could be

  8. THE WEIGHTED POINCARÉ DISTANCE IN THE HALF PLANE

    OpenAIRE

    Byun, Jisoo; Baek, Seung Min; Cho, Hong Rae; Lee, Han-Wool

    2014-01-01

    In this paper we introduce the weighted Poincaré distance and the induced distance by the weighted Bloch type space. We prove that the weighted Poincaré distance is identical to the inner distance generated by the induced distance.

  9. Optical bistability without the rotating wave approximation

    Energy Technology Data Exchange (ETDEWEB)

    Sharaby, Yasser A., E-mail: Yasser_Sharaby@hotmail.co [Physics Department, Faculty of Applied Sciences, Suez Canal University, Suez (Egypt); Joshi, Amitabh, E-mail: ajoshi@eiu.ed [Department of Physics, Eastern Illinois University, Charleston, IL 61920 (United States); Hassan, Shoukry S., E-mail: Shoukryhassan@hotmail.co [Mathematics Department, College of Science, University of Bahrain, P.O. Box 32038 (Bahrain)

    2010-04-26

    Optical bistability for two-level atomic system in a ring cavity is investigated outside the rotating wave approximation (RWA) using non-autonomous Maxwell-Bloch equations with Fourier decomposition up to first harmonic. The first harmonic output field component exhibits reversed or closed loop bistability simultaneously with the usual (anti-clockwise) bistability in the fundamental field component.

  10. Optical bistability without the rotating wave approximation

    International Nuclear Information System (INIS)

    Sharaby, Yasser A.; Joshi, Amitabh; Hassan, Shoukry S.

    2010-01-01

    Optical bistability for two-level atomic system in a ring cavity is investigated outside the rotating wave approximation (RWA) using non-autonomous Maxwell-Bloch equations with Fourier decomposition up to first harmonic. The first harmonic output field component exhibits reversed or closed loop bistability simultaneously with the usual (anti-clockwise) bistability in the fundamental field component.

  11. Multiscale mechanics of dynamical metamaterials

    NARCIS (Netherlands)

    Geers, M.G.D.; Kouznetsova, V.; Sridhar, A.; Krushynska, A.; Kleiber, M.; Burczynski, T.; Wilde, K.; Gorski, J.; Winkelmann, K.; Smakosz, L.

    2016-01-01

    This contribution focuses on the computational multi-scale solution of wave propagation phenomena in dynamic metamaterials. Taking the Bloch-Floquet solution for the standard elastic case as a point of departure, an extended scheme is presented to solve for heterogeneous visco-elastic materials. The

  12. Quasiconfigurations: an approach to effective forces

    International Nuclear Information System (INIS)

    Poves, A.; Pasquini, E.; Zuker, A.P.

    1978-01-01

    Many body effective operators appear naturally by dressing states through a perturbative unitary transformation. They have forms that differ from those obtained in the Bloch-Horowitz approach. The fsub(7/2)sup(n) problem is treated explicitly. Pandya's transforms are generalized

  13. Joint Force Quarterly. Number 12, Summer 1996

    Science.gov (United States)

    1996-08-01

    Editor Martin J. Peters, Jr. Production Coordinator Calvin B. Kelley Copy Editor The Typography and Design Division of the U.S. Government Printing...mirror imaging of the worst sort. Immediately after the defeat of France in 1940, historian Marc Bloch (a French reserve officer who observed the

  14. Ethical Ideologies: Do They Affect Shopping Behaviors and Perceptions of Morality?

    Science.gov (United States)

    Cho, Hyeon; Yoo, Jeong-Ju; Johnson, Kim K. P.

    2005-01-01

    Counterfeiting is a serious problem facing several industries, including the medical, agricultural, and apparel industries (Bloch, Bush, & Campbell, 1993). The authors investigated whether ethical viewpoints affect perceptions of the morality of particular shopping behaviors, attitudes toward counterfeit products, and intentions to purchase such…

  15. Introduction to spintronics

    CERN Document Server

    Bandyopadhyay, Supriyo

    2008-01-01

    The Early History of Spin Spin The Bohr Planetary Model and Space Quantization The Birth of "Spin" The Stern-Gerlach Experiment The Advent of Spintronics The Quantum Mechanics of Spin Pauli Spin Matrices The Pauli Equation and Spinors More on the Pauli Equation Extending the Pauli Equation - the Dirac Equation The Time Independent Dirac Equation Appendix The Bloch Sphere The Spinor and the "Qubit" The Bloch Sphere Concept Evolution of a Spinor Spin-1/2 Particle in a Constant Magnetic Field: Larmor Precession Preparing to Derive the Rabi Formula The Rabi Formula The Density Matrix The Density Matrix Concept: Case of a Pure State Properties of the Density Matrix Pure Versus Mixed State Concept of the Bloch Ball Time Evolution of the Density Matrix: Case of Mixed State The Relaxation Times T1 and T2 and the Bloch Equations Spin Orbit Interaction Spin Orbit Interaction in a Solid Magneto-Electric Sub-Bands in Quantum Confined Structures in the Presence of Spin-Orbit Interaction Dispersion Relations of Spin Resolv...

  16. Küünarnukk purustas 1,7 miljardit maksva maali / Aadu Hiietamm

    Index Scriptorium Estoniae

    Hiietamm, Aadu, 1954-

    2006-01-01

    Kunstikoguja Steve Wynn lõhkus Las Vegases kogemata Picasso maali "La Reve" ("Unistus"), mille ta oli otsustanud maha müüa 139 miljoni dollari eest. Senine rekordhind - 135 miljonit dollarit - maksti Gustav Klimti portreemaali "Adele Bloch-Bauer I" eest

  17. The Faraday effect revisited

    DEFF Research Database (Denmark)

    Cornean, Horia; Nenciu, Gheorghe

    2009-01-01

    This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant. The main mathematical tool is a regularized magnetic and geometric...

  18. Spectrum properties of electrons in solids

    International Nuclear Information System (INIS)

    Avron, J.

    1975-11-01

    The electron spectra in the one-particle Bloch model is discussed. The presence of hamiltonian bands is proved, especially for the Dirac and Schrodinger hamiltonians. The analyticity of the quasimomentum k is described as well as the stability of the bands in singular disturbances. (B.G.)

  19. Nonrandom variation in Poecilia marcellinoi n. sp. and P. salvatoris Regan, 1907 in El Salvador (Pisces, Poeciliidae)

    NARCIS (Netherlands)

    Poeser, Frederick N.

    1995-01-01

    A new species of the genus Poecilia Bloch & Schneider, 1801 is recorded from El Salvador. Morphological and meristic data of P. marcellinoi n. sp. and of the sympatric P. salvatoris Regan, 1907 are analysed. Intra- and interspecific variation are compared and correlated with environmental and

  20. Growth performance and body composition of giant trahira fingerlings fed diets with different protein and energy levels Crescimento e composição corporal de alevinos de trairão alimentados com diferentes níveis de proteína e energia nas dietas

    Directory of Open Access Journals (Sweden)

    Galileu Crovatto Veras

    2010-09-01

    Full Text Available The objective of this work was to determine the proper levels of protein and energy in diets of Hoplias lacerdae fingerlings. The dietary crude protein (CP and gross energy (GE levels for fingerlings of giant trahira were evaluated in a completely randomized 4x3 factorial design with 35, 39, 43 and 47% CP and 4,100, 4,300 and 4,500 kcal kg-1 of GE, and four replicates. The survival rate was 99.22%, and a linear improvement on the performance parameters was detected after increasing diet crude protein levels. Feed conversion ratio decreased with increasing levels of dietary protein and energy in the diets. A significant interaction between crude protein and gross energy was observed over body protein and mineral matter. Body lipid has increased linearly as gross energy in the diet increased. The retention of crude protein and energy showed a linear increasing with rising of crude protein levels in the diet. Crude protein level at 47% provides the best performance and energy retention, independently of the gross energy levels in the diet.O objetivo deste trabalho foi determinar os níveis apropriados de proteína e energia em dietas para alevinos de trairão (Hoplias lacerdae. Os níveis de proteína bruta (PB e energia bruta (EB foram avaliados em delineamento inteiramente casualizado em esquema fatorial 4x3, com 35, 39, 43 e 47% PB e 4.100, 4.300 e 4.500 kcal kg-1 de EB, e quatro repetições. A taxa de sobrevivência foi de 99,22%, e um aumento linear nos índices de desempenho foi detectado após aumento dos níveis de proteína bruta na dieta. A conversão alimentar decresceu com o aumento dos níveis de proteína e energia na dieta. Foi observada interação significativa entre a proteína e energia bruta sobre a proteína corporal e matéria mineral. O lipídeo corporal aumentou linearmente com o aumento da energia bruta das dietas. A retenção de proteína e energia bruta mostrou aumento linear com os níveis crescentes de proteína bruta

  1. Reactively sputtered epitaxial γ′-Fe4N films: Surface morphology, microstructure, magnetic and electrical transport properties

    KAUST Repository

    Mi, Wenbo

    2013-10-01

    Epitaxial γ′-Fe4N films with (1 0 0) and (1 1 0) orientations have been fabricated by reactive sputtering; these films were characterized by X-ray θ-2θ and φ scans, pole figures and high-resolution transmission electron microscopy. The film surface is very smooth as the film is less than 58 nm thick. The films exhibit soft ferromagnetism, and the saturation magnetization decreases with an increase in temperature, following Bloch\\'s spin wave theory. The films also exhibit a metallic conductance mechanism. Below 30 K, magnetoresistance (MR) is positive and increases linearly with the applied field in the high-field range. In the low-field range, MR increases abruptly. Above 30 K, MR is negative, and its value increases linearly with the applied field.

  2. Incoherent imaging using dynamically scattered coherent electrons

    International Nuclear Information System (INIS)

    Nellist, P.D.; Pennycook, S.J.

    1999-01-01

    We use a Bloch wave approach to show that, even for coherent dynamical scattering from a stationary lattice with no absorption, annular dark-field imaging in a scanning transmission electron microscope gives a direct incoherent structure image of the atomic-column positions of a zone-axis-aligned crystal. Although many Bloch waves may be excited by the probe, the detector provides a filtering effect so that the 1s-type bound states are found to dominate the image contrast for typical experimental conditions. We also find that the column intensity is related to the transverse kinetic energy of the 1s states, which gives atomic number, Z, contrast. The additional effects of phonon scattering are discussed, in particular the reasons why phonon scattering is not a prerequisite for transverse incoherence. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. TM-TE hybridization and tunable refraction in magnetophotonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Khanikaev, A.B. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, 1-1, Hibari-Ga-Oka, Toyohashi 441-8580 (Japan)]. E-mail: khanikaev@maglab.eee.tut.ac.jp; Inoue, M. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, 1-1, Hibari-Ga-Oka, Toyohashi 441-8580 (Japan); Granovsky, A.B. [Faculty of Physics, Lomonosov Moscow State University, Leninski Gory, Moscow 119992 (Russian Federation)

    2006-05-15

    In the present work we study the photonic band structure (PBS) and the polarization state of the Bloch eigenmodes of a two-dimensional magnetophotonic crystal (MPC) with square lattice formed from magneto-optically (MO) active cylinders. The refraction of light at the boundary of the MPC is analyzed. We found that both-the PBS and eigenmodes of the MPC-are most significantly altered by the MO activity in the vicinity of the degeneracies. For this case we demonstrated the possibility of an abrupt change in the propagation direction of light by the application of a magnetic field. For the Bloch wave vectors and frequencies corresponding to non-degenerate branches, the alteration of the PBS is shown to be negligible and eigenmodes almost completely coincide with linearly TE- and/or TM-polarized eigenmodes of the non-magnetic photonic crystal.

  4. TM-TE hybridization and tunable refraction in magnetophotonic crystals

    International Nuclear Information System (INIS)

    Khanikaev, A.B.; Inoue, M.; Granovsky, A.B.

    2006-01-01

    In the present work we study the photonic band structure (PBS) and the polarization state of the Bloch eigenmodes of a two-dimensional magnetophotonic crystal (MPC) with square lattice formed from magneto-optically (MO) active cylinders. The refraction of light at the boundary of the MPC is analyzed. We found that both-the PBS and eigenmodes of the MPC-are most significantly altered by the MO activity in the vicinity of the degeneracies. For this case we demonstrated the possibility of an abrupt change in the propagation direction of light by the application of a magnetic field. For the Bloch wave vectors and frequencies corresponding to non-degenerate branches, the alteration of the PBS is shown to be negligible and eigenmodes almost completely coincide with linearly TE- and/or TM-polarized eigenmodes of the non-magnetic photonic crystal

  5. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    enhanced in quantum confined lower-dimensional systems, where exciton and biexciton effects dominate the spectra even at room temperature. The coherent dynamics of excitons are at modest densities well described by the optical Bloch equations and a number of the dynamical effects known from atomic......Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  6. Study of the stopping power and straggling for alpha particles and protons in organic solids, liquids and gases

    International Nuclear Information System (INIS)

    Haque, A.K.M.; Mohammadi, A.; Nikjoo, H.

    1985-01-01

    The stopping power and straggling for 5.5 MeV alpha particles in liquid and vapour phases of water, methanol, ethanol, propanol, h-hexane, n-octane and cyclohexane, and those for low energy protons in ethylene, styrene and propylene and their polymers, have been measured. Range-energy data have been fitted with inverse stopping power functions to give the cross sections. In each case, five parameters have been adjusted to obtain the best fit. The value of chi-squared per degree of freedom has been calculated, together with the parameters. The theoretical stopping cross section has been considered employing the Bethe-Bloch expression together with various corrections (shell correction using Walske and Bichsel procedure, Z 1 3 contribution according to Ashley and Bloch correction based on Lindhard formalism). The existence of a phase effect has been clearly demonstrated for the stopping of both alpha particles and protons. (author)

  7. Mean excitation energy of polystyrene extracted from proton-stopping-power measurements

    International Nuclear Information System (INIS)

    Porter, L.E.

    1980-01-01

    The measured stopping power of polystyrene for 2.2- to 5.9-MeV protons has been analyzed with the Bloch projectile-z 4 correction term and a modified low-velocity projectile-z 3 term included in the Bethe-Bloch formula. When the full-strength Walske K-shell correction was utilized, the mean excitation energy corresponding to the best fit of the measurements was (71.1 +- 1.8) eV. This result was obtained for a value of the free parameter of the low-velocity projectile-z 3 effect formalism of 1.90 +- 0.05, whether or not a Walske L-shell correction was included

  8. Transitionless driving on adiabatic search algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sangchul, E-mail: soh@qf.org.qa [Qatar Environment and Energy Research Institute, Qatar Foundation, Doha (Qatar); Kais, Sabre, E-mail: kais@purdue.edu [Qatar Environment and Energy Research Institute, Qatar Foundation, Doha (Qatar); Department of Chemistry, Department of Physics and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-12-14

    We study quantum dynamics of the adiabatic search algorithm with the equivalent two-level system. Its adiabatic and non-adiabatic evolution is studied and visualized as trajectories of Bloch vectors on a Bloch sphere. We find the change in the non-adiabatic transition probability from exponential decay for the short running time to inverse-square decay in asymptotic running time. The scaling of the critical running time is expressed in terms of the Lambert W function. We derive the transitionless driving Hamiltonian for the adiabatic search algorithm, which makes a quantum state follow the adiabatic path. We demonstrate that a uniform transitionless driving Hamiltonian, approximate to the exact time-dependent driving Hamiltonian, can alter the non-adiabatic transition probability from the inverse square decay to the inverse fourth power decay with the running time. This may open up a new but simple way of speeding up adiabatic quantum dynamics.

  9. Clustering phenomena in nuclear matter below the saturation density

    International Nuclear Information System (INIS)

    Takemoto, Hiroki; Fukushima, Masahiro; Chiba, Satoshi; Horiuchi, Hisashi; Akaishi, Yoshinori; Tohsaki, Akihiro

    2004-01-01

    We investigate density-fluctuated states of nuclear matter as a result of clustering below the saturation density ρ 0 by description in terms of the Bloch function. The Bloch description has the advantage of a unified representation for a density-fluctuated state from an aggregate of uncorrelated clusters in extremely low-density regions to the plane-wave state of uniform matter in relatively high-density regions. We treat the density-fluctuated states due to α and 16 O clustering in symmetric nuclear matter and due to 10 He clustering in asymmetric nuclear matter. The density-fluctuated states develop as the density of matter decreases below each critical density around 0.2-0.4 ρ 0 which depends on what kind of effective force we use

  10. On the treatment of light-ion electronic stopping in dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Schiwietz, G. (Hahn-Meitner-Inst. Berlin GmbH, Div., FD (Germany)); Grande, P.L. (Hahn-Meitner-Inst. Berlin GmbH, Div., FD (Germany))

    1994-05-01

    A review is given on single-electron mechanisms and the corresponding theoretical approaches describing the electronic energy-transfer processes of light ions in gases and solids. Special emphasis is given to a discussion on the connection between exact Bloch-wave treatments and free-atom approximations. In the case of solids, perturbation theory is applied to the stopping of low-energy ions in the alkaline metals Li and Na. These calculations include Bloch wavefunctions of the Wigner-Seitz type obtained from a Hartree-Fock-Slater calculation and allow for a prediction of the mean energy loss under channeling conditions. Results of the most widely used local-density approximation are compared to data of our more complete perturbative treatment. Comparison is also made with recent LCAO calculations. (orig.)

  11. Axial channeling in electron diffraction

    International Nuclear Information System (INIS)

    Ichimiya, A.; Lehmpfuhl, G.

    1978-01-01

    Kossel patterns from Silicon and Niobium were obtained with a convergent electron beam. An intensity maximum in the direction of the zone axes [001] and [111] of Nb was interpreted as axial channeling. The intensity distribution in Kossel patterns was calculated by means of the Bloch wave picture of the dynamical theory of electron diffraction. Particularly zone axis patterns were calculated for different substance-energy combinations and they were compared with experimental observations. The intensity distribution in the calculated Kossel patterns was very sensitive to the model of absorption and it was found that a treatment of the absorption close to the model of Humphreys and Hirsch [Phil. Mag. 18, 115 (1968)] gave the best agreement with the experimental observations. Furthermore it is shown which Bloch waves are important for the intensity distribution in the Kossel patterns, how they are absorbed and how they change with energy. (orig.) [de

  12. Critical voltage effects in electron channeling patterns

    International Nuclear Information System (INIS)

    Farrow, R.C.

    1984-01-01

    Electron channeling patterns were used to study critical voltage effects in the metals molybdenum and tungsten. The purpose was to characterize both theoretically and experimentally how a critical voltage will affect the channeling pattern line shapes. The study focused on the second order critical voltage that results from the degeneracy between the Bloch wave states of the (110) and (220) reflections. Theoretical (110) series electron channeling pattern line profiles were calculated using the dynamical theory of Hirsch and Humphreys (1970). A 10 beam dynamical electron diffraction calculation was performed (using complex Fourier lattice potentials) to generate Bloch wave coefficients, excitation amplitudes, and absorption coefficients needed for determining backscattering coefficients and subsequent backscattered electron intensities. The theoretical model is applicable to electron diffraction at all energies since no high energy approximation or perturbation method was used

  13. Bandwidth broadening and asymmetric softening of collective spin waves in magnonic crystals

    International Nuclear Information System (INIS)

    Montoncello, F.; Giovannini, L.

    2014-01-01

    We investigate the dependence on the applied field of the frequency/wavevector dispersion relations of collective spin waves in arrays of dots, close to a magnetic transition. In particular, we focus on the low frequency “soft” modes in three different cases: end modes in the transition between two different saturated states in ellipses, fundamental mode in the saturated-to-vortex transition in disks, and gyrotropic mode in the vortex-to-saturated transition in disks. Noteworthy, the spin waves with nonzero Bloch wavevector along the direction of the applied field happen to soften earlier than spin waves with a Bloch wavevector along different directions, and this feature is responsible for an asymmetric broadening of the bandwidth along the different lattice directions. This is particularly useful in magnonic/spin-logic device research, if different binary digits are associated to modes with the same cell function but different propagation directions.

  14. A Higgs at 125.1 GeV and baryon mass spectra derived from a Common U(3) Lie group framework

    DEFF Research Database (Denmark)

    Trinhammer, Ole; Bohr, Henrik; Jensen, Mogens O Stibius

    2015-01-01

    Baryons are described by a Hamiltonian on an intrinsic U(3) Lie group configuration space with electroweak degrees of freedom originating in specific Bloch wave factors. By opening the Bloch degrees of freedom pairwise via a U(2) Higgs mechanism, the strong and electroweak energy scales become...... related to yield the Higgs mass 125.085+/-0.017 GeV and the usual gauge boson masses. From the same Hamiltonian we derive both the relative neutron to proton mass ratio and the N and Delta mass spectra. All compare rather well with the experimental values. We predict neutral flavour baryon singlets...... to be sought for in negative pions scattering on protons or in photoproduction on neutrons and in invariant mass like Σ+c(2455)D- from various decays above the open charm threshold, e.g. at 4499, 4652 and 4723 MeV. The fundamental predictions are based on just one length scale and the fine structure coupling...

  15. Magnetic phenomena in F.F.A.G. cyclotrons; Phenomenes magnetiques dans les cyclotrons F.F.A.G

    Energy Technology Data Exchange (ETDEWEB)

    Beurtey, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    This study regroups and develops some experimental and theoretical results obtained with spiral tract cyclotrons. The method used has been studied previously by C. BLOCH, whom we thank for his helpful advice. We have tried to give the main useful results, which are also in accordance with the rather scarce experimental results obtained on spiral pole pieces. (author) [French] Cette etude regroupe et developpe des resultats experimentaux et theoriques sur les cyclotrons 'spirales'. La methode employee est celle etudiee par C. BLOCH, que nous remercions vivement pour sa bienveillance et ses conseils. Nous avons essaye de donner les resultats essentiels a la fois utilisables et compatibles avec les resultats experimentaux peu nombreux sur les pieces polaires spiralees. (auteur)

  16. Excitonic magnet in external field: Complex order parameter and spin currents

    Science.gov (United States)

    Geffroy, D.; Hariki, A.; Kuneš, J.

    2018-04-01

    We investigate spin-triplet exciton condensation in the two-orbital Hubbard model close to half-filling by means of dynamical mean-field theory. Employing an impurity solver that handles complex off-diagonal hybridization functions, we study the behavior of excitonic condensate in stoichiometric and doped systems subject to external magnetic field. We find a general tendency of the triplet order parameter to lie perpendicular with the applied field and identify exceptions from this rule. For solutions exhibiting k -odd spin textures, we discuss the Bloch theorem, which, in the absence of spin-orbit coupling, forbids the appearance of spontaneous net spin current. We demonstrate that the Bloch theorem is not obeyed by the dynamical mean-field theory.

  17. Current stopping power analyses

    International Nuclear Information System (INIS)

    Porter, L.E.

    1983-01-01

    Modified Bethe-Bloch stopping power theory permits fairly accurate calculation of energy losses over a broad interval of projectile velocity v = νc insofar as several parameters appearing in the revised Bethe-Bloch formula have been corectly evaluated. Since the parameters cannot in general be ascertained by calculation from first principles, fits of theory to measurement remain the best method of evaluation. The parameters alluded to are: the target mean excitation energy; the shell correction scaling parameters; the composite single free parameter of the Barkas (projectile-z 3 ) effect correction formalism, and the strength of the correction term; the high velocity density effect correction parameter; and the low velocity charge state parameter. These parameters are discussed

  18. Simulating a topological transition in a superconducting phase qubit by fast adiabatic trajectories

    Science.gov (United States)

    Wang, Tenghui; Zhang, Zhenxing; Xiang, Liang; Gong, Zhihao; Wu, Jianlan; Yin, Yi

    2018-04-01

    The significance of topological phases has been widely recognized in the community of condensed matter physics. The well controllable quantum systems provide an artificial platform to probe and engineer various topological phases. The adiabatic trajectory of a quantum state describes the change of the bulk Bloch eigenstates with the momentum, and this adiabatic simulation method is however practically limited due to quantum dissipation. Here we apply the "shortcut to adiabaticity" (STA) protocol to realize fast adiabatic evolutions in the system of a superconducting phase qubit. The resulting fast adiabatic trajectories illustrate the change of the bulk Bloch eigenstates in the Su-Schrieffer-Heeger (SSH) model. A sharp transition is experimentally determined for the topological invariant of a winding number. Our experiment helps identify the topological Chern number of a two-dimensional toy model, suggesting the applicability of the fast adiabatic simulation method for topological systems.

  19. Hydrogenated amorphous silicon nitride photonic crystals for improved-performance surface electromagnetic wave biosensors.

    Science.gov (United States)

    Sinibaldi, Alberto; Descrovi, Emiliano; Giorgis, Fabrizio; Dominici, Lorenzo; Ballarini, Mirko; Mandracci, Pietro; Danz, Norbert; Michelotti, Francesco

    2012-10-01

    We exploit the properties of surface electromagnetic waves propagating at the surface of finite one dimensional photonic crystals to improve the performance of optical biosensors with respect to the standard surface plasmon resonance approach. We demonstrate that the hydrogenated amorphous silicon nitride technology is a versatile platform for fabricating one dimensional photonic crystals with any desirable design and operating in a wide wavelength range, from the visible to the near infrared. We prepared sensors based on photonic crystals sustaining either guided modes or surface electromagnetic waves, also known as Bloch surface waves. We carried out for the first time a direct experimental comparison of their sensitivity and figure of merit with surface plasmon polaritons on metal layers, by making use of a commercial surface plasmon resonance instrument that was slightly adapted for the experiments. Our measurements demonstrate that the Bloch surface waves on silicon nitride photonic crystals outperform surface plasmon polaritons by a factor 1.3 in terms of figure of merit.

  20. Broadband slow light in one-dimensional logically combined photonic crystals.

    Science.gov (United States)

    Alagappan, G; Png, C E

    2015-01-28

    Here, we demonstrate the broadband slow light effects in a new family of one dimensional photonic crystals, which are obtained by logically combining two photonic crystals of slightly different periods. The logical combination slowly destroys the original translational symmetries of the individual photonic crystals. Consequently, the Bloch modes of the individual photonic crystals with different wavevectors couple with each other, creating a vast number of slow modes. Specifically, we describe a photonic crystal architecture that results from a logical "OR" mixture of two one dimensional photonic crystals with a periods ratio of r = R/(R - 1), where R > 2 is an integer. Such a logically combined architecture, exhibits a broad region of frequencies in which a dense number of slow modes with varnishing group velocities, appear naturally as Bloch modes.

  1. Magnetization processes in amorphous R-Co/R'-Co/R-Co sandwiches (R, R'=Y, Nd, Gd, Er)

    International Nuclear Information System (INIS)

    Dieny, B.; Givord, D.; Ndjaka, J.M.B.; Alameda, J.M.

    1990-01-01

    Sandwiches consisting of three amorphous layers (R 0.33 ,Co 0.67 )( 1000 A / R ' 0.33 ,Co 0.67 ) 1000 A / (R 0.33 Co 0.67 ) 1000 A , have been prepared by dc triode sputtering (R, R' are rare-earth elements). The systems chosen are such that the bulk magnetization alternates from one layer to the next or the coercivity of each layer is significantly different. Magnetic transitions are observed under field. They have been quantitatively analyzed in terms of successive reversals of magnetization in the different layers. The creation or annihilation of planar Bloch walls parallel to the surface are associated with the magnetic transitions. The wall energy and wall width depend essentially on the competition between exchange energy and Zeeman energy. It is suggested that the existence of such Bloch walls may favor magnetization reversal in thin films by coherent processes

  2. An active learning approach to education in MRI technology for the biomedical engineering curriculum

    DEFF Research Database (Denmark)

    Hanson, Lars G.

    2012-01-01

    techniques but can also be used for student exercises which may significantly improve the understanding of MRI concepts. The presentation demonstrates software made for the first few minutes of MRI education but focuses mostly on the educational value of the more advanced Bloch Simulator. It is explored how...... sense expressed in the math is in focus. Unfortunately, the nuclear dynamics happen in four dimensions, and are therefore not well suited for illustration on blackboard. 3D movies are more appropriate, but they do not encourage active learning. The typical solution employed by educators is hand waving...... (literally), since arm motions can to a limited extent be used to illustrate nuclear dynamics. Many students find this confusing, however, and students who do not grasp the meaning during lectures, are left in a bad position. For this reason, educational software was developed over the last decade (the Bloch...

  3. Wave propagation in structured materials as a platform for effective parameters retrieving

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Ha, S.; Sukhorukov, A. A.

    MM slab can be considered as a semi-infinite medium. Modelling the one-directional (forward) propagation of the wave inside a metamaterial slab thick enough to avoid transition layers effects and reflection from the rear interface we are able to restore complex refractive index3. Getting the input...... established yet. In this contribution, we present an overview of our activity in EPs retrieving based on observation of wave propagation phenomena in thick (multilayer) MMs. We put a goal to develop a method which is unambiguous, but at the same time simple and straightforward. The idea is that thick enough...... utilization of the Bloch-mode analysis5. The idea is to perform the Bloch mode expansion6 of the field inside the metamaterial slab when it is illuminated with a plane wave incident from vacuum. Then we determine the effective refractive index from the propagation constant of the dominating (fundamental...

  4. Alpha-chain states in 4N-nuclei from 20Ne to 32S

    International Nuclear Information System (INIS)

    Merchant, A.C.; Rae, W.D.M.

    1992-01-01

    A 6α-chain state has recently been discovered in 24 Mg which is some 16--17 MeV above the 6α-breakup threshold and yet paradoxically only 4--5 MeV wide. This surprising discovery raises the question of the possible existence of Nα-chain states in other 4N-nuclei. The excitation energy of this 6α-chain state is very close to the value predicted by the Bloch-Brink cluster model. Therefore, to aid the experimental search for similar states in other nuclei, we present here predictions of the excitation energies of the Nα-chain state bandheads in the 4N-nuclei from 20 Ne to 32 S obtained using the Bloch-Brink cranked cluster model with the Brink-Boeker effective interaction and free variation of all parameters

  5. Impact of slow-light enhancement on optical propagation in active semiconductor photonic crystal waveguides

    DEFF Research Database (Denmark)

    Chen, Yaohui; de Lasson, Jakob Rosenkrantz; Gregersen, Niels

    2015-01-01

    We derive and validate a set of coupled Bloch wave equations for analyzing the reflection and transmission properties of active semiconductor photonic crystal waveguides. In such devices, slow-light propagation can be used to enhance the material gain per unit length, enabling, for example......, the realization of short optical amplifiers compatible with photonic integration. The coupled wave analysis is compared to numerical approaches based on the Fourier modal method and a frequency domain finite element technique. The presence of material gain leads to the build-up of a backscattered field, which...... is interpreted as distributed feedback effects or reflection at passive-active interfaces, depending on the approach taken. For very large material gain values, the band structure of the waveguide is perturbed, and deviations from the simple coupled Bloch wave model are found....

  6. Extraordinary Light-Trapping Enhancement in Silicon Solar Cell Patterned with Graded Photonic Super-Crystals

    Directory of Open Access Journals (Sweden)

    Safaa Hassan

    2017-12-01

    Full Text Available Light-trapping enhancement in newly discovered graded photonic super-crystals (GPSCs with dual periodicity and dual basis is herein explored for the first time. Broadband, wide-incident-angle, and polarization-independent light-trapping enhancement was achieved in silicon solar cells patterned with these GPSCs. These super-crystals were designed by multi-beam interference, rendering them flexible and efficient. The optical response of the patterned silicon solar cell retained Bloch-mode resonance; however, light absorption was greatly enhanced in broadband wavelengths due to the graded, complex unit super-cell nanostructures, leading to the overlap of Bloch-mode resonances. The broadband, wide-angle light coupling and trapping enhancement mechanism are understood to be due to the spatial variance of the index of refraction, and this spatial variance is due to the varying filling fraction, the dual basis, and the varying lattice constants in different directions.

  7. Integridad y desprecio. Motivos básicos de una concepción de la moral desde la teoría del reconocimiento

    Directory of Open Access Journals (Sweden)

    Hünneth, Axel

    1992-05-01

    Full Text Available Not available.

    Si se admite con Emst Bloch que la completa integridad del hombre, su dignidad, sólo se alcanza estableciendo una adecuada protección ante los distintos modos de ofensa y de desprecio personal, entonces eso significa a la inversa que la integridad de la persona humana depende constitutivamente de la experiencia de reconocimiento intersubjetivo. El presente texto quiere aclarar esa conexión premisa propia de una teoría normativa del reconocimiento recíproco, entre desprecio e integridad humana que Bloch sugirió pero no desarrolló, para así poder introducir una tesis fuerte de sociología moral: la experiencia del desprecio personal representa un impulso moral en el proceso de desarrollo de la sociedad, pues el progreso moral es el resultado de la lucha por el reconocimiento.

  8. Method to map one-dimensional electronic wave function by using multiple Brillouin zone angle resolved photoemission

    Directory of Open Access Journals (Sweden)

    Dong-Wook Lee

    2010-10-01

    Full Text Available Angle resolved photoemission spectroscopy (ARPES is a powerful tool to investigate electronic structures in solids and has been widely used in studying various materials. The electronic structure information by ARPES is obtained in the momentum space. However, in the case of one-dimensional system, we here show that we extract the real space information from ARPES data taken over multiple Brillouin zones (BZs. Intensities in the multiple BZs are proportional to the photoemission matrix element which contains information on the coefficient of the Bloch wave function. It is shown that the Bloch wave function coefficients can be extracted from ARPES data, which allows us to construct the real space wave function. As a test, we use ARPES data from proto-typical one-dimensional system SrCuO2 and construct the real space wave function.

  9. Generation of phase-covariant quantum cloning

    International Nuclear Information System (INIS)

    Karimipour, V.; Rezakhani, A.T.

    2002-01-01

    It is known that in phase-covariant quantum cloning, the equatorial states on the Bloch sphere can be cloned with a fidelity higher than the optimal bound established for universal quantum cloning. We generalize this concept to include other states on the Bloch sphere with a definite z component of spin. It is shown that once we know the z component, we can always clone a state with a fidelity higher than the universal value and that of equatorial states. We also make a detailed study of the entanglement properties of the output copies and show that the equatorial states are the only states that give rise to a separable density matrix for the outputs

  10. Geometric phase for N-level systems through unitary integration

    International Nuclear Information System (INIS)

    Uskov, D. B.; Rau, A. R. P.

    2006-01-01

    Geometric phases are important in quantum physics and are now central to fault-tolerant quantum computation. For spin 1/2, the Bloch sphere S 2 , together with a U(1) phase, provides a complete SU(2) description. We generalize to N-level systems and SU(N) in terms of a 2(N-1)-dimensional base space and reduction to a (N-1)-level problem, paralleling closely the two-dimensional case. This iteratively solves the time evolution of an N-level system and gives (N-1) geometric phases explicitly. A complete analytical construction of an S 4 Bloch-like sphere for two qubits is given for the Spin(5) or SO(5) subgroup of SU(4)

  11. Replacement of moist ingredients in the feed training of carnivorous fish

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Salaro

    2012-10-01

    Full Text Available The study evaluated the replacement of bovine heart by gelatin in the feed training of carnivorous fish, using giant trahira (Hoplias lacerdae as an experimental model. A completely randomized design with four treatments and five repetitions was employed. The treatments were composed of wet ingredients beef heart (control, gelatin diluted in water, gelatin diluted in beef heart broth, and gelatin diluted in water mixed with fish meal. The fish (3.22±0.03 cm and 0.57±0.01 g were conditioned to accept industrialized diets by the technique of gradual feed ingredients transition in the diet. Gains in weight and length, efficiency of feed training, specific growth rate, cannibalism, mortality and survival rates were evaluated. There was significant difference in weight and length gains and specific growth rate, whereby the use of bovine heart gave the best results. Greater efficiency of feed training was observed for fish fed diets containing beef heart and gelatin diluted in water mixed with fish meal. The high survival rates and the absence of significant differences among treatments for rates of cannibalism, mortality and survival indicate the feasibility of using gelatin as a moist ingredient in the feed training of carnivorous fish.

  12. Estudo dos vestígios de peixes dos sítios arqueológicos da área de influência da Usina Hidrelétrica Machadinho, Rio Grande do Sul, Brasil A study of fish traces taken from the archaeological sites of the areas surrounding the Machadinho Hydroelectric power station, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio Ricken

    2009-09-01

    Full Text Available The analysis of the material obtained in the rescue of archaeological sites in the area surrounding the Hydroelectric Plant of Machadinho, Rio Grande do Sul, revealed that a considerable amount of bones and fish scales incorporated in the alimentary remains. Using an osteological collection as reference, we identified remains of Salminus brasiliensis (Cuvier, 1816 (Characidae, Brycon orbignyanus (Valenciennes, 1849 (Characidae, Pogonopoma obscurum Quevedo & Reis, 2002 (Loricariidae, Hemiancistrus fuliginosus Cardoso & Malabarba, 1999, Prochilodus lineatus (Valenciennes, 1836 (Prochilodontidae, Schizodon sp. (Anostomidae, Leporinus sp. (Anostomidae, Hoplias sp. (Erythrinidae, Hypostomus sp. (Loricariidae and Crenicichla sp. (Cichlidae. Based on specimens from fish collections, regressions were obtained comparing the size of the pre-maxillary bone in Crenicichla spp. and the length of the pectoral fin spine of Hemiancistrus fuliginosus, Pogonopoma obscurum and Hypostomus spp, with the standard length and weight of corresponding specimens. The estimated size and weight of the specimens obtained from fish remains in the archaeological sites varied between 79.7-153.9 mm and 13.5-33.9 g for Hemiancistrus fuliginosus, 158.2-151.0 mm and 179.5-194.3 g for Pogonopoma obscurum, 117.1-166.2 mm and 86.6-93.1 g for Crenicichla spp., and 62.2-397.2 mm and 34-20.3 g for Hypostomus spp. Therefore using these estimates of standard lengths and weights it was possible to formulate a hypotheses on the fishing technology used by the inhabitants of these sites.

  13. Radiotherapy Proton Interactions in Matter

    OpenAIRE

    Gottschalk, Bernard

    2018-01-01

    A survey of physics useful to proton radiotherapy, centered on stopping, scattering and hard scatters: 1. Introduction 2. The fundamental formula dose = fluence x mass stopping power. Practical units, comments on effective stopping power. 3. Range: experimental definition, Beth-Bloch CSDA theory, range-energy tables and approximations, range straggling. 4. Multiple Coulomb Scattering: suggested reading, elements of Moliere theory, the Gaussian approximation, scattering power. 5. Hard scatters...

  14. Dollar Summary of Prime Contract Awards by State, Place, and Contractor, FY84, Part 5, (Ashton, Rhode Island-Sinclair, Wyoming).

    Science.gov (United States)

    1984-01-01

    BERGSTROM AIR FORCE CITY OF AUSTIN 4,745 4,745 CPT CORPORATION 66 66 CSR CONTRACTING INC 554 554 DAILEY...317 STARBUCK INDUSTRIAL PUMP SALES COM 147 147 RIDGE CONSTRUCTION CO INC 240 240 SIUSLAW CONSTRUCTION 352 352 SPOONER MECHANICAL CONTRS 226 226 TOTAL... STARBUCK 965 965 STEVENSON BLOCH LUMBER COMPANY 44 44 SUMNER SPACE TECH ENGINEERING INC 762 762 SUNNYSIDE INDEPENDENT FOOD PROCSSRS CORP 86 66 TACOMA

  15. Phase-space quantum mechanics study of two identical particles in an external oscillatory potential

    Science.gov (United States)

    Nieto, Luis M.; Gadella, Manuel

    1993-01-01

    This simple example is used to show how the formalism of Moyal works when it is applied to systems of identical particles. The symmetric and antisymmetric Moyal propagators are evaluated for this case; from them, the correct energy levels of energy are obtained, as well as the Wigner functions for the symmetric and antisymmetric states of the two identical particle system. Finally, the solution of the Bloch equation is straightforwardly obtained from the expressions of the Moyal propagators.

  16. The month of August - an Annales approach to the history of the Kowie: August 1881 to August 1914.

    OpenAIRE

    Hummel, H C

    1985-01-01

    • Opsomming: Die analities-historiese denkrigting in Frankryk, bekend as die Annalesskool, is deur Lucien Febvre en Marc Bloch tot stand gebring en meesterlik deur Fernand Braudel in sy klassieke werk oor die Middellandse Seegebied (1949) toegepas. Hierdie benadering geniet reeds wêreldwye aansien en navolging omdat dit die klem hoofsaaklik laat val op die soort geskiedenis wat nie op die tradisionele vlak of in gebaande weë lê nie. Gevolglik bied dit 'n uiters geskikte m...

  17. Reciprocal mass tensor : a general form

    International Nuclear Information System (INIS)

    Roy, C.L.

    1978-01-01

    Using the results of earlier treatment of wave packets, a general form of reciprocal mass tensor has been obtained. The elements of this tensor are seen to be dependent on momentum as well as space coordinates of the particle under consideration. The conditions under which the tensor would reduce to the usual space-independent form, are discussed and the impact of the space-dependence of this tensor on the motion of Bloch electrons, is examined. (author)

  18. Parasitic copepods on Oligoplites spp. (Osteichthyes, Carangidae from the Brazilian coastal zone, with the redescription of Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae

    Directory of Open Access Journals (Sweden)

    Ricardo Massato Takemoto

    2002-05-01

    Full Text Available Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 and O. saliens (Bloch, 1793 (Osteichthyes: Carangidae from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908 are given. Caligus oligoplitisi Carvalho, 1954 is considered a new junior synonym of C. robustus. Fishes of the genus Oligoplites are new host records for this species of copepod. Redescription and illustration of Tuxophorus caligodes Wilson, 1908, collected on the body surface of Oligoplites saliens, O. palometa and O. saurus, are provided.Quatro espécies de copépodes caligídeos, parasitos de Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 e O. saliens (Bloch, 1793 (Osteichthyes, Carangidae da Baia de Sepetiba, litoral do Estado do Rio de Janeiro, Brasil, são descritos. São apresentados o registro de novo hospedeiro e nova distribuição geográfica para Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 e Metacaligus rufus (Wilson, 1908. Caligus oligoplitisi Carvalho, 1954, é considerado novo sinônimo júnior de C. robustus. Tuxophorus caligodes Wilson, 1908, coletado na superfície do corpo de Oligoplites saliens, O. palometa e O. saurus é redescrito e ilustrado. Peixes do gênero Oligoplites são novos hospedeiros para estas espécies de copépodes.

  19. Secondary electron emission induced by channeled relativistic electrons in a (1 1 0) Si crystal

    International Nuclear Information System (INIS)

    Korotchenko, K.B.; Kunashenko, Yu P.; Tukhfatullin, T.A.

    2012-01-01

    A new effect that accompanies electrons channeled in a crystal is considered. This phenomenon was previously predicted was called channeling secondary electron emission (CSEE). The exact CSEE cross-section on the basis of using the exact Bloch wave function of electron channeled in a crystal is obtained. The detailed investigation of CSEE cross-section is performed. It is shown that angular distribution of electrons emitted due to CSEE has a complex form.

  20. Ambient Smell and the Retail Environment: Relating Olfaction Research to Consumer Behavior

    OpenAIRE

    Ward, Philippa; Davies, Barry; Kooijman, Dion

    2004-01-01

    This paper focuses on the use of ambient scent within retail environments, and investigates those mediating factors that help shape the emotional and behavioural responses that are stimulated. In doing so, it draws on the work of Mehrabian and Russell (1974), and attempts to contribute to the work on ambient scent in retailing by extending and elaborating the Gulas and Bloch (1995) model to encompass current research on human olfaction. The paper also introduces and specifically considers the...