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Sample records for channa punctatus bloch

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

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

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    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.

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

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    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.

  4. 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.

  5. 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).

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    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.

  6. Growth and liver histology of Channa punctatus exposed to a common biofertilizer.

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    Nath, S; Matozzo, V; Bhandari, D; Faggio, C

    2018-01-28

    Mustard oil cake (MOC) is widely used as biofertilizer in the field of agriculture and aquaculture. Channa punctatus was exposed to 0.42 g.L -1 sublethal concentration for 4, 7, 14, 21 and 28 days. Due to such exposure, body growth and histological changes in liver were observed. It was revealed that weight, length and breadth of fish were gradually increased with the days of exposure in compare to control fish, whereas, liver showed an increase in sinusoidal space and lipidosis during early days, followed by a recovery from the stress of MOC on the 28th day.

  7. Effect of bioactive compounds extracted from euphorbious plants on hematological and biochemical parameters of Channa punctatus

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    Jaya Shahi

    2011-10-01

    Full Text Available Channa punctatus was exposed to four different concentrations of Rutin, Taraxerol and Apigenin. Changes in some hematological parameters of Channa punctatus were assessed to determine the influence of these compounds on test fish. Fish were exposed to sublethal concentrations (80% of LC50 of 24h of these compounds for one week. Control fish were also administered for one week. Thereafter, blood samples were obtained from the control and experimental fish. Blood was assayed for selected hematological parameters (hematocrit, hemoglobin, red blood cell count, white blood cell count total plasma protein and plasma glucose concentration. The derived hematological indices of mean corpuscular hemoglobin concentration (MCHC, mean corpuscular hemoglobin (MCH and mean corpuscular volume (MCV were calculated. Sublethal concentrations of these compounds caused a dose dependent decrease in hemoglobin values coupled with a decrease in hematocrit values and red blood cell counts are an obvious indication of anemia. The total white blood cell counts and the differential white blood cell counts were decreased except for the lymphocytes, where there was a slight increase. Plasma protein and glucose were also lower in exposed fish when compared with control. The hematological indices MCH, MCHC, MCV were also lowered. The result from this study reveals high mortality rate and deleterious consequences on the health of fish subjected to acute exposure of Rutin, Taraxerol and Apigenin and therefore, should not be used directly in aquaculture without having the proper knowledge.

  8. Antibacterial properties of the skin mucus of the freshwater fishes, Rita rita and Channa punctatus.

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    Kumari, U; Nigam, A K; Mitial, S; Mitial, A K

    2011-07-01

    The skin mucus of Rita rita and Channa punctatus was investigated to explore the possibilities of its antibacterial properties. Skin mucus was extracted in acidic solvents (0.1% trifluoroacetic acid and 3% acetic acid) and in triple distilled water (aqueous medium). The antibacterial activity of the mucus extracts was analyzed, using disc diffusion method, against five strains of bacteria--the Gram-positive Staphylococcus aureus and Micrococcus luteus; and the Gram negative Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi. In both Rita rita and Channa punctatus, the skin mucus extracted in acidic solvents as well as in aqueous medium show antibacterial activity against Staphylococcus aureus and Micrococcus luteus. Nevertheless, the activity is higher in acidic solvents than that in aqueous medium. The acidic mucus extracts of Rita rita, show antibacterial activity against Salmonella typhi as well. The results suggest that fish skin mucus have bactericidal properties and thus play important role in the protection of fish against the invasion of pathogens. Fish skin mucus could thus be regarded as a potential source of novel antibacterial components.

  9. Alterations in the Erythrocyte Sedimentation Rate of Fresh Water Fish, Channa punctatus on exposure to Temperature Stress from Godavari River, Nanded

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    Jagtap, Ashwini Ravichandra; Mali, R. P.

    2013-01-01

    Out of various environmental factors that influence aquatic organisms, temperature is the most all-pervasive. The environmental temperature also affects blood vascular system of aquatic organisms. The present paper deals with the effect of temperature on the Erythrocyte Sedimentation Rate of freshwater fish, Channa punctatus. The freshwater fish, Channa punctatus, were collected from Godavari River, Nanded (Maharashtra). They were acclimated to laboratory condition. The fishes were exposed to...

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

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    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.

  11. Role of catecholamines and nitric oxide on pigment displacement of the chromatophores of freshwater snakehead teleost fish, Channa punctatus.

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    Biswas, Saikat P; Jadhao, Arun G; Palande, Nikhil V

    2014-04-01

    We are reporting for the first time that the catecholamines (adrenaline and noradrenaline) inhibit the effect of nitric oxide (NO) on melanosome dispersion in freshly isolated scales of the freshwater snakehead fish, Channa punctatus. We studied the effect of NO and catecholamines on the pigment displacement by observing the changes in the melanophore index. The scales when treated with solution containing NO donor sodium nitroprusside (SNP) showed dispersion of melanosomes, whereas NO synthase blocker N-omega-Nitro-L-arginine suppresses this action of SNP. Treatment with adrenaline and noradrenaline on the isolated scales caused aggregation of melanosomes. Scales treated with solution containing catecholamines and SNP resulted in aggregation of melanosomes suggesting that catecholamines mask the effect of SNP. These results suggest that the catecholamines are inhibiting the effect of NO and causing the aggregation of the melanosomes may be via surface receptors.

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

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    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

  13. Biological significance of [14C]phenol accumulation in different organs of a murrel, Channa punctatus, and the common carp, Cyprinus carpio

    International Nuclear Information System (INIS)

    Mukherjee, D.; Bhattacharya, S.; Kumar, V.; Moitra, J.

    1990-01-01

    Phenol, a ubiquitous component of industrial effluents, is a common pollutant of water resources and a serious threat to fish. The present work demonstrates that a significant amount of phenol is retained by various tissues of the common carp, Cyprinus carpio, and the snake-headed murrel, Channa punctatus. The rate of [ 14 C]phenol accumulation was higher carp than in the murrel. It is suggested that retention of phenol in the brain and ovary may seriously affect the reproductive potential of the fish

  14. 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.

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

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    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.

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

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    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.

  17. Ontogenetic changes and developmental adjustments in lactate dehydrogenase isozymes of an obligate air-breathing fish Channa punctatus during deprivation of air access.

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    Ahmad, Riaz; Hasnain, Absar-Ul

    2005-02-01

    In air-breathing snakehead Channa punctatus, Ldh-B is expressed at all ontogenetic and developmental stages, while Ldh-A is expressed temporally in pre-hatchlings 12-13 days ahead of bimodal respiration marked by air-breathing. Remarkable differences are observed in the LDH isozyme expression among various ontogenetic and developmental stages upon denying air access. When denied air access, water-breathing larvae show two distinct characteristics: (i) they survive longer than transitory air-breathers due to independence from air-breathing and (ii) there is more transient induction of Ldh-B than Ldh-A. Transition to bimodal breathing, which occurred post-hatching in 15-day old larvae, is coincidental with inducibility of Ldh-A and concomitant down-regulation of Ldh-B. Heart tissue from air-breathing adults denied air access shows a preferential expression of LDH-A subunit and slight down-regulation of LDH-B. Heterotetramers of A and B subunits participate in adjusting LDH levels among those stages which either precede air-breathing switchover, or are subsequent to this transition. The contribution of heterotetramers depends on the stage-specific levels of LDH homotetramers A(4) or B(4). Scaling of muscle mass during growth, tolerance to extended deprivation of air access and induction of Ldh-A are correlated. Response to restoring air contact indicated that advanced air-breathing stages of C. punctatus possess an inherent capacity to sense surface air. In kinetic properties, LDH isozymes of C. punctatus are teleost-like but species specificity is displayed in oxidative potential by cardiac muscle and in L-lactate reduction by skeletal muscle.

  18. Concentration of heavy metals n available fish species (bain, mastacembelus armatus; taki, channa punctatus and bele, glossogobius giuris) in the turag river, bangladesh

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    Afrin, R.; Younus, M.D.

    2015-01-01

    This study was conducted to assess the concentration level of heavy metals in three available fish species (Bain, Mastacembelus armatus; Taki, Channa punctatus and Bele, Glossogobius giuris) of the Turag river, Bangladesh during the months from January to March, 2014. In case of bio-concentration of heavy metals in fish, the levels of Pb, Cd, Cr, Cu and Fe ranged from 0.01-0.13 mg/kg, 0.001-0.02 mg/kg, 0.17-0.48 mg/kg, 0.30-0.74 mg/kg and 4.05-46.86 mg/kg, respectively while Hg was below detection level. These values indicate that the heavy metals were concentrated in fish flesh at a higher level than water. The highest values of Pb, Cd and Cr were found in Bain fish, Fe was found in Taki fish and Cu was found in Bele fish. Most of the heavy metals have crossed the permissible limits in fish, especially for the values of Cr, Cu and Fe. From the results of the present investigation, it can be concluded that the available fish species are harmful for their consumers. (author)

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

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    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.

  20. 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.

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

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    , 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

  2. Ictalurus punctatus

    African Journals Online (AJOL)

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    while the immersion of the protective effect of various immunization groups was not obvious. .... body in reagent, and then form a certain kind of immune complex .... Changes of total protein in serum of Ictalurus punctatus in each group. Groups.

  3. Biochemical modulation in male specimens of Channa punctatus ...

    African Journals Online (AJOL)

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    African Journal of Biotechnology Vol. 11(97), pp. 16365-16376, 4 ... food source in Asia pacific region (Hossain et al., 2008). This carnivorous ... small streams, ditches and lakes across Southern Asia. (Mohsin and ..... shrimp, Pandulus borealis, in relation to that of the euphasid, ... water. American Public Health Association.

  4. Monoclonal antibodies to snakehead, Channa striata immunoglobulins: detection and quantification of immunoglobulin-positive cells in blood and lymphoid organs.

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    Sood, Neeraj; Chaudhary, Dharmendra K; Rathore, Gaurav; Singh, Akhilesh; Lakra, W S

    2011-02-01

    Snakehead Channa striata is an important freshwater food fish in many Southeast Asian countries. Three monoclonal antibodies (C9, C10 and D10) were developed against purified serum immunoglobulins of Channa striata (Cs-Ig) and characterized. C9 and D10 MAbs were specific to heavy chain, while C10 MAb detected only unreduced Cs-Ig in western blotting. In competitive ELISA, C9 and C10 MAbs were specific to C. striata Ig and showed no cross reactivity with serum Ig of other fish species i.e. Channa punctatus, Channa marulius, Clarias batrachus and Labeo rohita. D10 MAb showed reactivity to serum Ig of C. striata and C. marulius. In FACS analysis of gated lymphocytes, the percentage of Ig+ cells detected by C9 MAb was 18.2%, 27.7% and 10.3% in blood, spleen and kidney, respectively (n=3, body weight 500-600 g). However, only a few cells (0.5%) were found to be Ig+ in thymus (n=5). C9 MAb was also successfully employed to demonstrate Ig+ cells in blood smears and formalin fixed sections of spleen and kidney. These findings suggest that the spleen plays an important role in humoral immunity as compared to head kidney. Further, these MAbs can be useful immunological tool in monitoring health status of cultured C. striata. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. 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)

  6. Haematological and ion regulatory effects of nitrite in the air-breathing snakehead fish Channa striata

    DEFF Research Database (Denmark)

    Lefevre, Sjannie; Jensen, Frank B.; Huong, Do T.T.

    2012-01-01

    M. Effects of sub-lethal exposures to nitrite (0 mM, 1.4 mM, and 3.0 mM) were determined during a 7-day exposure period. Plasma nitrite increased, but the internal concentration remained well below ambient levels. Extracellular nitrate rose by several mM, indicating that a large proportion of the nitrite...... taken up was converted to nitrate. Nitrite reacted with erythrocyte haemoglobin (Hb) causing methaemoglobin (metHb) to increase to 30% and nitrosylhaemoglobin (HbNO) to increase to 10% of total Hb. Both metHb and HbNO stabilised after 4 days, and functional Hb levels accordingly never fell below 60......The tolerance and effects of nitrite on ion balance and haematology were investigated in the striped snakehead, Channa striata Bloch 1793, which is an air-breathing fish with reduced gills of importance for aquaculture in South East Asia. C. striata was nitrite tolerant with a 96 h LC50 of 4.7 m...

  7. 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.

  8. 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....

  9. 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.

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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/

  17. 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

  18. 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

  19. 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.

  20. 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

  1. IKAN GABUS (Channa striata MANFAAT PENGEMBANGAN DAN ALTERNATIF TEKNIK BUDIDAYANYA

    Directory of Open Access Journals (Sweden)

    Nurbakti Listyanto

    2009-06-01

    Full Text Available Ikan gabus (Channa striata merupakan jenis ikan yang bernilai ekonomis. Di Indonesia penyebarannya antara lain di Sumatera, Jawa, Kalimantan, Sulawesi, dan Papua. Spesies ini memiliki rasa yang khas, tekstur daging tebal dan putih sehingga harganya pun cukup mahal baik dalam bentuk segar maupun kering (ikan asin. Selain itu, memiliki kandungan albumin yang diperlukan tubuh manusia dalam mengatasi berbagai penyakit terutama yang disebabkan berkurangnya jumlah protein darah. Ikan ini termasuk salah satu jenis ikan karnivora air tawar dikarenakan sifatnya yang gemar memangsa ikan-ikan kecil sebagai pakannya. Walaupun memiliki potensi strategis, serta kegunaan yang luas dalam industri pangan maupun farmasi, namun di Indonesia masih belum banyak dibudidayakan karena belum dikuasai teknik budidayanya. Pemeliharaan bersama ikan mujair di kolam, penggunaan campuran pakan buatan kaya nutrisi, serta pemanfaatan tanaman air dalam proses pemijahan merupakan alternatif budidaya yang perlu dikembangkan.

  2. Effect of zinc, copper and mercury on Channa marulius (Hamilton)

    Energy Technology Data Exchange (ETDEWEB)

    Khangarot, B.S.

    1981-01-01

    Static bioassay acute toxicity tests of zinc, copper and mercury were conducted to determine the median lethal concentrations (LC/sub 50/S) of a freshwater telcost Channa marulius (HAM.) The 96 h LC/sub 50/ for Zn/sup 2 +/ were 25.61 mg/l; 0.90 mg/l for Cu/sup 2 +/ and 0.314 mg/l for Hg/sup 2 +/. However, these values decreased at 240 h of exposure and were: 21.09 mg Zn/sup 2 +//l; 0.66 mg Cu/sup 2 +//l; and 0.31 mg Hg/sup 2 +//l. The relative potency ratio of Zn/Hg, Zn/Cu and Cu/Hg suggests that fish were most sensitive to Hg, followed by Cu and Zn ions. The acute toxicities of mixtures of Zn/sup 2 +/-Cu/sup 2 +/; Zn/sup 2 +/-Hg/sup 2 +/; Cu/sup 2 +/-Hg/sup 2 +/ and Zu/sup 2 +/-Cu/sup 2 +/-Hg/sup 2 +/ up to 48 h of exposure were also investigated. The additive index and ranges for Zn/sup 2 +/-Cu/sup 2 +/ were -0.241 for Zn-Hg; 0.285 for Cu-Hg; and -0.542 for Zn-Cu-Hg. All the mixtures tested showed a greater than additive toxicity because index ranges overlapped zero.

  3. Salutary value of haruan, the striped snakehead Channa striatus – a review

    Directory of Open Access Journals (Sweden)

    Mohammed Abdul Kader Haniffa

    2014-05-01

    Full Text Available Murrel namely Channa striatus or haruan contains all essential elements to maintain good health and to recover the lost energy after prolonged illness. The fatty acid composition (% of total fatty acid indicated the abundant presence of C16:0 fatty acid as 30% and the other major fatty acids were C22:6 (15%, C20:4 (19%, C18:1 (12% and C18:0 (15%. Haruan contains arachidonic acid (C20:4 as 19.0%, a precursor for prostaglandin and thromboxane biosyntheses. Both fatty and amino acids are important components for wound healing processes. Both the fillet and mucus extracts of haruan were found to exhibit a concentration dependent antinociceptive activity. In vitro antioxidant activity was higher in Channa roe protein hydrolysate than in Labeo roe protein hydrolysate in both DPPH radical scavenging and ferric reducing power. Protein content of roe concentrates (RPC was found to be 90.2% (Channa and 82.5% (Lates. Water absorption, oil absorption, foam capacity, stability and emulsifying capacity were found to be higher in Channa RPC than in Lates RPC. Characterization of protein hydrolysates from muscle and myofibrillar samples of haruan showed different kinetic and proteolytic activities. The skin extract of haruan influences the serotonergic receptor system thus they can function as an anti-depressant. Thus, haruan is the best example for food as medicine.

  4. Histo-morphology of the alimentary canal in two freshwater snakehead fish Channa punctata and Channa striata

    Directory of Open Access Journals (Sweden)

    Mita Borman

    2015-12-01

    Full Text Available The histo-morphological study of the alimentary canal of two carnivore freshwater snakehead fish Channa punctata and C. striata was carried out from October 2013 to July 2014. It revealed that three major parts like oesophagus, stomach and intestine composed of short thick-walled body. The oesophagus begins with buccopharynx. Structure and arrangement of both villiform and canine teeth on jaws in C. striata are more extendable and stronger than C. punctata and thereby made the former one more successful predator. The availability and arrangement pattern of mucous pits and taste bud pores in oesophagus are also prominent in C. striata. The TS of stomach of both the species has broad GM devoid of goblet mucous cells, but surface layer CC and basal layer GG open through gastric pits. The length of intestine (16.0 cm and intestinal pyloric caeca (5.5 cm in C. striata are larger than C. punctata (7.0 cm and 1.5 cm, respectively. However, the TS of intestinal Sr. 0.05 mm; MM. 0.8 mm; Mu 0.5 mm suggest in favour of carnivore habit of both the species.

  5. 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

  6. 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.

  7. 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...

  8. Xeroradiographic and radiographic anatomy of the channel catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    Smith, S.A.; Smith, B.J.

    1994-01-01

    The purpose of this study was to provide an anatomic reference for the channel catfish (Ictalurus punctatus) using xeroradiography† and conventional radiography. The entire body of three adult fish was radiographed using standard xeroradiographic and conventional radiographic techniques. Two xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate the normal skeletal and soft-tissue anatomy of the channel catfish

  9. INDUKSI HORMONAL MATURASI GONAD IKAN GABUS (Channa striata

    Directory of Open Access Journals (Sweden)

    Muhammad Hunaina Fariduddin Ath-thar

    2017-05-01

    Full Text Available Ikan gabus (Channa striata merupakan ikan lokal air tawar potensial untuk pengembangan budidaya di Indonesia. Sebagian besar produksi ikan gabus berasal dari tangkapan di alam yang menyebabkan menurunnya populasi ikan gabus. Domestikasi merupakan salah satu solusi dari masalah ini. Dewasa ini, ikan gabus telah dapat dipijahkan baik secara alami maupun buatan. Namun demikian produksi benih yang dihasilkan masih bergantung pada kondisi lingkungan. Tujuan penelitian adalah mendapatkan dosis oodev yang optimal untuk pematangan gonad ikan gabus, pemijahan alami, dan analisis performa pertumbuhan keturunan pertama. Jumlah larva yang dihasilkan dari pemijahan alami ikan gabus pada lingkungan ex situ adalah 1.250-5.000 ekor per induk. Berdasarkan pertambahan diameter dan fase kematangan telur, induksi hormon dengan dosis 1,5 mL/kg menunjukkan hasil terbaik dibandingkan perlakuan lain (perlakuan dosis 0,5 dan 1 mL/kg. Benih ikan gabus hasil pemijahan alami di luar habitat menunjukkan populasi Bogor memberikan performa pertumbuhan mutlak bobot (1,7 ± 0,06 g; laju pertumbuhan spesifik (2,6% ± 0,10%; dan sintasan (86,43% ± 1,32% lebih baik dibandingkan benih ikan gabus populasi Palembang. Striped snakehead (Channa striata is a market potential of local fish in Indonesia. Up to now (to date, the majority of production comes from natural catches. This condition, if continues, can lead to the decline in natural stock. Domestication offers a promising solution to help solve this problem. So far, natural spawning for seed production has been done succcesfully. However, continuity of fish supply is still very much dependent on environmental factors. The present study aimed to investigate the optimal hormone dosage for inducing gonad maturation, natural spawning and to analyze growth performance of fry resulted from natural spawning. Striped snakehead broodstock from Palembang and Bogor were induced with three dosages of oodev (consisted of Pregnant Mare

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. DINAMIKA POPULASI IKAN GABUS (Channa striata DI RAWA DANAU PANGGANG, KALIMANTAN SELATAN

    Directory of Open Access Journals (Sweden)

    Dini Sofarini

    2018-04-01

    Full Text Available The province of South Kalimantan has the largest peat swamp that is named Danau Panggang Swamp with an area of 5,390.7 Ha. This swamp has ecological, economic and potential functions of a large fishery resource. The purposes of this study are to evaluate the exploitation rate of Snake Head Fish (Channa striata in Danau Panggang Swamp, by population dynamic analysis using FISAT program of Von Bertalanffy method.  The results showed that the growth pattern of Snake Head Fish (Channa striata has the tendency to grow negative allometric with 63.4 cm of long infifer (L¥, growth rate (k 0.15 per year, theoretical age at the time of the fish is equal to 0 (t0 is -1.48257 years. While the natural mortality rate (M was 0.43, the mortality rate due to catch (F of 0.69/year and the total mortality rate  (Z of 1.12/year, and the rate of exploitation value E = 0.62.  These results indicated that the exploitation rate of Head Snake Fish (Channa striata in Danau Panggang swamp has a tendency to overfishing.

  16. Two molecular markers based on mitochondrial genomes for varieties identification of the northern snakehead (Channa argus) and blotched snakehead (Channa maculata) and their reciprocal hybrids.

    Science.gov (United States)

    Xincheng, Zhang; Kunci, Chen; Xinping, Zhu; Jian, Zhao; Qing, Luo; Xiaoyou, Hong; Wei, Li; Fengfang, Xiao

    2015-08-01

    The northern snakehead (Channa argus) and blotched snakehead (Channa maculata) and their reciprocal hybrids have played important roles in the Chinese freshwater aquaculture industry, with an annual production in China exceeding 400 thousand tons. While these are popular aquaculture breeds in China, it is not easy to identify northern snakehead, blotched snakehead, and their hybrids. Thus, a method should be developed to identify these varieties. To distinguish between the reciprocal hybrids (C. argus ♀ × C. maculata ♂ and C. maculata ♀ × C. argus ♂), the mitochondrial genome sequences of northern snakehead and blotched snakehead and their reciprocal hybrids were compared. Following the alignment and analysis of mtDNA sequences of northern snakehead, blotched snakehead and their hybrids, two pairs of specific primers were designed based on identified differences ranging from 12S rRNA to 16S rRNA gene. The BY1 primers amplified the same bands in the blotched snakehead and the hybrid (C. maculata ♀ × C. argus ♂), while producing no products in northern snakehead and the hybrid (C. argus ♀ × C. maculata ♂). Amplification with WY1 yielded the opposite results. Then, 30 individuals per fish were randomized to verify the primers, and the results showed that the primers were specific for breeds, as intended. The specific primers can not only simply distinguish between two kinds of hybrids, but also rapidly identify the two parents. This study provides a method of molecular marker identification to identify reciprocal hybrids.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Characteristics of chitinase isolated from different part of snakehead fish (Channa striata) digestive tract

    Science.gov (United States)

    Baehaki, A.; Lestari, S. D.; Wahidman, Y.; Gofar, N.

    2018-01-01

    Naturally, snakehead fish (Channa striata) is a prodigious carnivore feeding mainly on live animals, including small shrimp. Based on its feeding habits, the digestrive tracts of snakehead is considered as auspicious source of various enzumes including chitinase. The purpose of this study was to partially characterize chitinase enzyme isolated from digestive tract of snakehead fish. Two parts of digestive tract, stomach and intestine were used as enzymes’ source. The results showed that chitinase activity from the stomach was higher than chitinase activity from the intestine. The pH and temperature optimum of chitinase activity from digestive tract (the stomach and the intestine) were 6.0 and 70 °C, respectively.

  2. Brain cholinesterase response in the snakehead fish (Channa striata) after field exposure to diazinon

    DEFF Research Database (Denmark)

    van Cong, Nguyen; Phuong, Nguyen Thanh; Bayley, Mark

    2008-01-01

    The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most...... commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days...

  3. 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.)

  4. 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.

  5. 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)

  6. 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.

  7. 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)

  8. Diagnosis and interrelationships of fishes of the genus Channa Scopoli (Teleostei: Channidae of northeastern India

    Directory of Open Access Journals (Sweden)

    W. Vishwanath

    2009-02-01

    Full Text Available Diagnostic characters of nine species of the genus Channa Scopoli of northeastern India are given. Examination of morphological and osteological characters revealed that the fish under study comprised two phylectic groups: marulius and gachua. The Marulius group is characteristic by having a very prominent V-shaped sharp isthmus, cephalic sensory pores arranged in groups, absence of scales on the lower jaw, a sharp prominent spinelike hypurapophysis, more branchial toothplates than epibranchial, and an elongated urostyle. The Gachua group is characterized by a U-shaped isthmus, cephalic sensory pores evenly arranged in a single row, the presence of one or two large cycloid scales on each side of the lower jaw, absence of a sharp prominent spine-like hypurapophysis, absence or presence of one tooth plate in the epibranchial, and absence of an elongated urostyle. An elongated bone is present in between two last hemal spines of all species examined. A key to known species of Channa of northeastern India is also given

  9. Identification and Expression Profiling of Chemosensory Genes in Dendrolimus punctatus Walker

    Directory of Open Access Journals (Sweden)

    Su-fang Zhang

    2017-07-01

    Full Text Available Dendrolimus punctatus Walker is a serious pest affecting conifers in southern China. As extensive pesticide spraying is currently required to control D. punctatus, new control strategies are urgently needed. Chemosensory genes represent potential molecular targets for development of alternative pest control strategies, and the expression characteristics of these genes provide an indication of their function. To date, little information is available regarding chemosensory genes in D. punctatus or their expression profiles at different development stages and in various tissues. Here, we assembled and analyzed the transcriptomes of D. punctatus collected at different developmental stages and in a range of organs, using next-generation sequencing. A total of 171 putative chemosensory genes were identified, encoding 53 odorant binding proteins, 26 chemosensory proteins, 60 odorant receptors (OR, 12 gustatory receptors (GR, 18 ionotropic receptors (IR, and 2 sensory neuron membrane proteins (SNMPs. Expression analysis indicated that the antennae possess the largest number of highly expressed olfactory genes and that olfactory gene expression patterns in the eggs, larvae, and head were similar to one another, with each having moderate numbers of highly expressed olfactory genes. Fat body, ovary, midgut, and testis tissues also had similar olfactory gene expression patterns, including few highly expressed olfactory genes. Of particular note, we identified only two pheromone binding proteins and no pheromone receptors in D. punctatus, similar to our previous findings in Dendrolimus houi and Dendrolimus kikuchii, suggesting that insects of the Dendrolimus genus have different pheromone recognition characteristics to other Lepidopteran insects. Overall, this extensive expression profile analysis provides a clear map of D. punctatus chemosensory genes, and will facilitate functional studies and the development of new pest control methods in the future.

  10. A case of partial xanthism in a marblefish Aplodactylus punctatus (Teleostei: Aplodactylidae) from southern Peru

    OpenAIRE

    Béarez, Philippe; Treviño, Hugo Treviño; Huamani, Isaac

    2006-01-01

    Se reporta por primera vez en Ilo, sur del Perú, una jerguilla amarilla (Aplodactylus punctatus). Esa condición de tener una piel de color amarillo se denomina xantismo. Este registro, único, corresponde probablemente a una extensión hacia el norte del rango de distribución de la «jerguilla reina», conocida de la costa central de Chile. A yellow skinned jerguilla (Aplodactylus punctatus) is reported for the first time from Ilo, Southern Peru. This condition of skin, in which yellow colorat...

  11. 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

  12. 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)

  13. Effect of feeding silkworm on growth performance and feed efficiency of snakehead (Channa striata)

    Science.gov (United States)

    Firmani, U.; Lono

    2018-04-01

    The snakehead, Chana striata is a carnivorous freshwater fish and widely distributed in Asia. High demand of this fish has been triggering many aquaculturist to culture C. stiata. Feed was the important factor for fish growth. Silkworm has high protein content, low fat and can be used as natural feed for finfish. This study investigate the silkworm feed in C. striata. The treatment of this research were A (100 % pellet); B (100 % silkworm); C (combination of 75 % pellet and 25 % silkworm); D (combination of 50 % pellet and 50 % silkworm); and E (combination of 25 % pellet and 75 % silkworm). The variables measured in this study were relatif growth, specific growth rate, feed efficiency, feed conversion ratio, and survival rate. The result show that silkworm gave the high growth performance, feed efficiency and survival rate of the snakehead (Channa striata) compared with the control.

  14. PENDUGAANPARAMETERPERTUMBUHAN,MORTALITAS DANUKURAN PERTAMAMATANGGONAD IKAN GABUS (Channa striata DI RAWABANJIRAN SUNGAIMUSI

    Directory of Open Access Journals (Sweden)

    Syarifah Nurdawati

    2015-12-01

    Full Text Available Ikan gabus merupakan salah satu jenis ikan ekonomis penting yang banyak dimanfaatkan sebagai bahan baku produk olahan. Habitat ikan gabus di SungaiMusi yaitu banyak dijumpai di rawa banjiran seperti lebak-lebak di SungaiMeriak, Sungai Semuntul dan hutan rawa Danau Cala. Penelitian dilakukan dari bulan Februari–Desember 2010 dengan tujuan untukmengetahui pertumbuhan, mortalitas, laju pertumbuhan dan ukuran pertama matang gonad. Hasil penelitian menunjukkan bahwa selama 11 bulan penelitian didapatkan sampel ikan gabus sebanyak 2.303 ekor dengan kisaran nilai tengah panjang antara 20 - 500 mm, Ikan gabus betina pertama matang gonad berukuran panjang 210 mm sedangkan ikan gabus jantan pada ukuran 185 mm. Dari analisa Ford-Walford diperoleh nilai parameter pertumbuhan dengan panjang asimtotik ikan gabus (L sebesar 575,9 mm, koefisien pertumbuhan (K sebesar 0,173 per tahun dan umur teorits (t0 sebesar - 0,07 per tahun sehingga diperoleh persamaan pertumbuhan Von Bertalanffy untuk ikan gabus adalah Lt = 575,9 (1-e-0,173(t +0,07. Dugaan laju kematian alami (M sebesar 0,25 per tahun dan laju kematian karena penangkapan (F sebesar 0,51 per tahun. Laju eksploitasi (E ikan gabus sebesar 0,67 per tahun atau sudah melebihi nilai eksploitasi optimumyaitu 0,50. The snakehead fishis considered to be an important food fish.The fishes arewidely used asraw material refined products. Habitat of Channa striata in floodplain of Musi River, there are in Meriak River, Semuntul River and in plood plain of Cala lake. Estimation of population parameters and size at the firstmaturity of female and male snakehead (Channa striata has been conducted from February 2010 to December 2010. The purpose is to estimate fish population parameters quantitatively including growth of snakehead. The first sexual maturity and natural mortality (M, fishing mortality (Z and exploitation rates (E of snakehead.The results of this study showed that 11 month study period we

  15. KITOSAN CANGKANG UDANG WINDU SEBAGAI PENGAWET FILLET IKAN GABUS (Channa striata

    Directory of Open Access Journals (Sweden)

    sri - wahyuni

    2014-06-01

    Full Text Available Kitosan berpeluang besar digunakan sebagai bahan pengawet alami pada produk perikanan karenamemiliki aktivitas antimikrob. Penelitian ini bertujuan untuk mengetahui karakteristik kitosan asalkulit udang windu dan pengaruhnya terhadap aktivitas mikrob pembusuk, nilai gizi, organoleptik danmasa simpan fi llet ikan gabus segar. Kitosan diisolasi dari kulit udang windu dan dikarakterisasi, laludigunakan sebagai bahan pengawet pada fi llet daging ikan gabus segar dengan konsentrasi 0; 1; 1,5; dan2%. Penyimpanan dilakukan pada suhu ruang selama 10, 15, 20, dan 25 jam. Perlakuan larutan kitosan1,5% mampu memperpanjang masa simpan fi llet daging ikan gabus karena mampu mengurangi kadarair dan laju pertumbuhan bakteri pembusuk, mempertahankan kadar protein terhadap daging fi llet ikangabus hingga penyimpanan 20 jam.Kata kunci: antimikrob, bahan pengawet, ikan gabus (Channa striata, kitosan

  16. 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....

  17. Distribution of the portunid crab Ova/ipes punctatus (De Haan) in ...

    African Journals Online (AJOL)

    (De Haan) in Algoa Bay and salinity and temperature tolerances of its ... The three-spot swimming crab Ovalipes punctatus is commonly found in surf zones off ..... recorded in the Sundays River or Swartkops River estuaries. (p.E.D. Winter and ...

  18. Stress Effects in Channel Catfish (Ictalurus punctatus) Fry on Pond Survival

    Science.gov (United States)

    Results from previous studies suggested that channel catfish (Ictalurus punctatus) fry that were housed in very high traffic areas from hatch until reaching 9 g in size were able to survive experimental challenge with Edwardsiella ictaluri better than siblings who were hatched and raised in very low...

  19. Streptococcal Arthritis, Osteolysis, Myositis, and Spinal Meningitis in Channel Catfish Ictalurus punctatus Broodstock

    Science.gov (United States)

    This report details findings of an investigation into complaints by commercial fingerling producers of low-grade mortalities, poor reproductive success, emaciation, skin lesions, and severely arched backs among broodstock of channel catfish Ictalurus punctatus. Gross lesions involved the jaw, fin ba...

  20. Molecular Cloning and Sequencing of Hemoglobin-Beta Gene of Channel Catfish, Ictalurus Punctatus Rafinesque

    Science.gov (United States)

    : Hemoglobin-y gene of channel catfish , lctalurus punctatus, was cloned and sequenced . Total RNA from head kidneys was isolated, reverse transcribed and amplified . The sequence of the channel catfish hemoglobin-y gene consists of 600 nucleotides . Analysis of the nucleotide sequence reveals one o...

  1. The Case Against Using Organic Fertilizers in Channel Catfish Ictalurus punctatus Nursery Ponds

    Science.gov (United States)

    This paper reviews the assumed advantages and disadvantages of organic fertilizers and presents the case that the risks outweigh the benefits for channel catfish, Ictalurus punctatus, nursery pond fertilization. Under certain conditions, organic fertilizers may be beneficial to provide forage for z...

  2. Oxygen requirements of separated hybrid catfish female Ictalurus punctatus male I. furcatus eggs

    Science.gov (United States)

    Channel catfish Ictalurus punctatus egg masses require ambient water with over 95% air saturation to maintain maximum oxygen consumption as they near hatch. Since hybrid catfish eggs (channel catfish ' X blue catfish I. furcatus ') are often kept separated after fertilization by the addition of full...

  3. Developing a low cortisol responsive line of channel catfish, Ictalurus punctatus

    Science.gov (United States)

    Nagaraj G. Chatakondi and Brian C. Peterson USDA ARS Warmwater Aquaculture Research Unit, 141 Experiment Station Road, Stoneville, MS 38776. nagaraj.chatakondi@ars.usda.gov Channel catfish, Ictalurus punctatus is the most important farm-raised aquacultured species in the USA. Stressors in aquacultu...

  4. Evidence of birth-and-death evolution of 5S rRNA gene in Channa species (Teleostei, Perciformes).

    Science.gov (United States)

    Barman, Anindya Sundar; Singh, Mamta; Singh, Rajeev Kumar; Lal, Kuldeep Kumar

    2016-12-01

    In higher eukaryotes, minor rDNA family codes for 5S rRNA that is arranged in tandem arrays and comprises of a highly conserved 120 bp long coding sequence with a variable non-transcribed spacer (NTS). Initially the 5S rDNA repeats are considered to be evolved by the process of concerted evolution. But some recent reports, including teleost fishes suggested that evolution of 5S rDNA repeat does not fit into the concerted evolution model and evolution of 5S rDNA family may be explained by a birth-and-death evolution model. In order to study the mode of evolution of 5S rDNA repeats in Perciformes fish species, nucleotide sequence and molecular organization of five species of genus Channa were analyzed in the present study. Molecular analyses revealed several variants of 5S rDNA repeats (four types of NTS) and networks created by a neighbor net algorithm for each type of sequences (I, II, III and IV) did not show a clear clustering in species specific manner. The stable secondary structure is predicted and upstream and downstream conserved regulatory elements were characterized. Sequence analyses also shown the presence of two putative pseudogenes in Channa marulius. Present study supported that 5S rDNA repeats in genus Channa were evolved under the process of birth-and-death.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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)

  11. Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River catchment

    Science.gov (United States)

    Densmore, Christine L.; Iwanowicz, L.R.; Henderson, A.P.; Iwanowicz, D.D.; Odenkirk, J.S.

    2016-01-01

    The Northern snakehead, Channa argus (Cantor), is a non-native predatory fish that has become established regionally in some temperate freshwater habitats within the United States. Over the past decade, Northern snakehead populations have developed within aquatic ecosystems throughout the eastern USA, including the Potomac River system within Virginia, Maryland and Washington, D.C. Since this species was initially observed in this region in 2002, the population has expanded considerably (Odenkirk & Owens 2007). In the Chesapeake Bay watershed, populations of Northern snakehead exist in the lower Potomac River and Rappahannock Rivers on the Western shore of the Bay, and these fish have also been found in middle or upper reaches of river systems on the Eastern shore of the Bay, including the Nanticoke and Wicomico Rivers among others. Over the past several years, many aspects of Northern snakehead life history in the Potomac River have been described, including range and dispersal patterns, microhabitat selection and diet (Lapointe, Thorson & Angermeier 2010; Saylor, Lapointe & Angermeier 2012; Lapointe, Odenkirk & Angermeier 2013). However, comparatively little is known about their health status including susceptibility to parasitism and disease and their capacity to serve as reservoirs of disease for native wildlife. Although considered hardy by fisheries biologists, snakehead fish have demonstrated susceptibility to a number of described piscine diseases within their native range and habitat in Asia. Reported pathogens of significance in snakehead species in Asia include snakehead rhabdovirus (Lio-Po et al. 2000), aeromonad bacteria (Zheng, Cao & Yang 2012), Nocardia (Wang et al. 2007) andMycobacterium spp. (Chinabut, Limsuwan & Chantatchakool 1990; ). Mycobacterial isolates recovered from another snakehead species (Channa striata) in the previous studies have included M. marinum and M. fortuitum, as identified through molecular

  12. 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

  13. 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.

  14. Un caso de xantismo parcial en Aplodactylus punctatus (Teleostei: Aplodactylidae del sur de Perú

    Directory of Open Access Journals (Sweden)

    Philippe Béarez

    2006-10-01

    Full Text Available Se reporta por primera vez en Ilo, sur del Perú, una jerguilla amarilla (Aplodactylus punctatus. Esa condición de tener una piel de color amarillo se denomina xantismo. Este registro, único, corresponde probablemente a una extensión hacia el norte del rango de distribución de la «jerguilla reina», conocida de la costa central de Chile.

  15. Seasonal meso- and microhabitat selection by the northern snakehead (Channa argus) in the Potomac river system

    Science.gov (United States)

    Lapointe, N.W.R.; Thorson, J.T.; Angermeier, P.L.

    2010-01-01

     The northern snakehead (Channa argus) is a large piscivorous fish that is invasive in eastern Europe and has recently been introduced in North America. We examined the seasonal habitat selection at meso- and microhabitat scales using radio-telemetry to increase understanding of the ecology of this species, which will help to inform management decisions. After the spawning season (postspawn season, September–November), northern snakeheads preferred offshore Eurasian water-milfoil (Myriophyllum spicatum) beds with shallow water (∼115 cm) and soft substrate. In the winter (November–April), these fish moved to deeper water (∼135 cm) with warmer temperatures, but habitat selection was weak at both scales. Northern snakeheads returned to shallower water (∼95 cm) in the prespawn season (April–June) and used milfoil and other cover. Habitat selection was the strongest at both meso- and microhabitat scales during the spawning season (June–September), when fish preferred macrophytes and cover in shallow water (∼88 cm). Our results help to identify habitats at the risk of invasion by northern snakeheads. We suggest that control efforts and future research focus on shallow waters, and take into consideration the seasonal habitat preferences.

  16. Does air-breathing meet metabolic demands of the juvenile snakehead, Channa argus, in multiple conditions

    Directory of Open Access Journals (Sweden)

    Yongli Li

    2017-05-01

    Full Text Available The objective of this study was to examine how the respiratory metabolism of the snakehead Channa argus changed when it shifted from breathing water to breathing air, and how increased metabolic demands caused by temperature, feeding, and exhaustive exercise affect its survival in air. The results demonstrated that the oxygen consumption rate (MO2 of the snakehead was lower for aerial respiration than aquatic respiration by 12.1, 24.5 and 20.4% at 20, 25, and 30°C, respectively. Survival time was significantly shortened with increasing temperature and was negatively correlated with the resting MO2 in air (MO2Air. No obvious feeding metabolic response was observed in the snakeheads fed at 1% and 3% body mass levels while breathing air. The maximum MO2Air of the snakehead after exhaustive exercise was significantly higher than the resting MO2Air of the control group. The results suggest that the snakehead could survive out of water by breathing air for varying lengths of time, depending on ambient temperature and metabolic demand. Additionally, some degree of metabolic depression occurs in the snakehead when breathing air. The metabolic demand associated with exercise in the snakehead, but not that associated with feeding, can be supported by its capacity for breathing air to some extent.

  17. ACE inhibition and antioxidant activity of different part of Channa striata prepared by various cooking method

    Science.gov (United States)

    Chasanah, E.; Budiari, S.; Thenawijaya, M.; Palupi, N. S.

    2018-03-01

    Channa striata (snakehead) extract has been known possessing positive activity, one of which is the ability to inhibit Angiotensin Converting Enzyme (ACE) activity in vitro. Aims of this study were to determine the effect of cooking and parts of C. striata, i.e. meat/fillet, gonad, skin, gill against the ACE inhibition activity and antioxidant activity in vitro. Heat processing methods used were direct boiling and indirect boiling and steamed at 100 °C for 10 min. ACE inhibition activity was analyzed using hippuryl-L-histidyl-L-leucine (HHL) as substrate and antioxidant activity was analyzed using DPPH method. The result shows that the higher the concentration of the extract (5 %, 20 %, 35 % and 50 %), the higher the antioxidant activity. The highest antioxidant activity was shown by gonad followed by meat extract, skin, and gill. Cooking treatment affected antioxidant activity, being the detrimental treatment were steam and direct boiling. The egg/gonad of C. striata showed the highest capability to inhibit ACE activity followed by meat/fillet, gill and skin. In concentration of 10 mg, extract of C. striata gonad was comparable to captopril, a commercial hypertension drug. While uncooked fillet showed the highest ACE inhibition activity followed by indirect boiling, direct boiling and steaming.

  18. FORMULATION OF AEROSOL CONCENTRATES CONTAINING HARUAN (Channa striatus FOR WOUND DRESSING

    Directory of Open Access Journals (Sweden)

    FEBRIYENTI

    2008-01-01

    Full Text Available The objective of this research was to formulate an aerosol concentrate containing haruan (Channa striatus water extract that would produce a thin film when sprayed onto a wound and could be used for wound dressing. The aerosol concentrates were formulated with various polymer and plasticiser mixtures and tested in dispersion systems. The polymers evaluated were hydroxypropyl methylcellulose (HPMC, carboxymethylcellulose sodium (CMC Sodium, acacia, tragacanth, chitosan, gelatine and gelatine (bloom 151–160, all at concentrations of 2%. The plasticisers evaluated were polyethylene glycol (PEG 400 and 4000, glycerine, propylene glycol, and triacetin. Films were prepared from film-forming dispersions by casting techniques. Film-forming dispersions were characterised in terms of pH, density, surface tension, rheological properties, particle size distribution, and tackiness. Based on these evaluations, HPMC was chosen as the best polymer. It produced a film with the expected qualities and was easy to reproduce in the form of dispersions or as thin transparent films. Glycerine was judged as the most appropriate plasticiser because it produced the concentrate having the desired qualities and properties expected from an aerosol concentrate

  19. PCR-RFLP analysis of mitochondrial DNA cytochrome b gene among Haruan (Channa striatus) in Malaysia.

    Science.gov (United States)

    Rahim, Mohamamd Hafiz Abdul; Ismail, Patimah; Alias, Rozila; Muhammad, Norwati; Mat Jais, Abdul Manan

    2012-02-15

    Haruan (Channa striatus) is in great demand in the Malaysian domestic fish market. In the present study, mtDNA cyt b was used to investigate genetic variation of C. striatus among populations in Peninsular Malaysia. The overall population of C. striatus demonstrated a high level of haplotype diversity (h) and a low-to-moderate level of nucleotide diversity (π). Analysis of molecular variance (AMOVA) results showed a significantly different genetic differentiation among 6 populations (F(ST)=0.37566, P=0.01). Gene flow (Nm) was high and ranged from 0.32469 to infinity (∞). No significant relationship between genetic distance and geographic distance was detected. A UPGMA tree based on the distance matrix of net interpopulation nucleotide divergence (d(A)) and haplotype network of mtDNA cyt b revealed that C. striatus is divided into 2 major clades. The neutrality and mismatch distribution tests for all populations suggested that C. striatus in the study areas had undergone population expansion. The estimated time of population expansion in the mtDNA cyt b of C. striatus populations occurred 0.72-6.19 million years ago. Genetic diversity of mtDNA cyt b and population structure among Haruan populations in Peninsular Malaysia will be useful in fisheries management for standardization for Good Agriculture Practices (GAP) in fish-farming technology, as well as providing the basis for Good Manufacturing Practices (GMP). Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Transcriptome Characterization of Dendrolimus punctatus and Expression Profiles at Different Developmental Stages.

    Directory of Open Access Journals (Sweden)

    Cong-Hui Yang

    Full Text Available The pine moth Dendrolimus punctatus (Walker is a common insect pest that confers serious damage to conifer forests in south of China. Extensive physiology and ecology studies on D. punctatus have been carried out, but the lack of genetic information has limited our understanding of the molecular mechanisms behind its development and resistance. Using RNA-seq approach, we characterized the transcriptome of this pine moth and investigated its developmental expression profiles during egg, larval, pupal, and adult stages. A total of 107.6 million raw reads were generated that were assembled into 70,664 unigenes. More than 30% unigenes were annotated by searching for homology in protein databases. To better understand the process of metamorphosis, we pairwise compared four developmental phases and obtained 17,624 differential expression genes. Functional enrichment analysis of differentially expressed genes showed positive correlation with specific physiological activities of each stage, and these results were confirmed by qRT-PCR experiments. This study provides a valuable genomic resource of D. punctatus covering all its developmental stages, and will promote future studies on biological processes at the molecular level.

  1. 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.

  2. 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

  3. 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...

  4. Investigating hsp Gene Expression in Liver of Channa striatus under Heat Stress for Understanding the Upper Thermal Acclimation

    Directory of Open Access Journals (Sweden)

    Gopal Krishna Purohit

    2014-01-01

    Full Text Available Changes in hsp gene expression profiles in murrel Channa striatus experimentally exposed to temperature stress (36°C for 4, 15, and 30 days were investigated; fish collected from aquaculture ponds and maintained in laboratory at the pond temperature (25 ± 1°C served as control. Channa collected from a hot spring runoff (36°C was included in the study to examine the hsp profiles beyond 30 days of exposure. Gene expression analyses of a battery of hsps in liver tissues were carried out by quantitative RT-PCR and protein expressions were analyzed by immunoblotting. hsps could be grouped into three clusters based on similarity in response to heat stress: hsp70, hsp78, and hsp60, whose transcript level continued to increase with duration of exposure; hsp90 and hsp110 that increased to a much higher level and then decreased; hsp27 and hsp47 that did not significantly vary as compared to control. The results suggest that Hsp70, Hsp78, and Hsp60 are involved in thermal acclimation and long term survival at high temperature. Fish living in the hot spring runoff appears to continuously express hsps that can be approximated by long term induction of hsps in farmed fish if temperature of their environment is raised to 36°C.

  5. 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...

  6. 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.

  7. 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.

  8. Antiulcer activity of methanol-chloroform extract of Channa striatus fillet.

    Science.gov (United States)

    Azemi, Ahmad Khusairi; Abd Rahim, Mohd Hafiz; Mamat, Siti Syariah; Mat Jais, Abdul Manan; Zakaria, Zainul Amiruddin

    2018-01-01

    Channa striatus (Haruan) is Malaysian freshwater fish that is traditionally used to treat ailments related to wound and also ulcers. The aimed of the present study was to determine the mechanisms of anti-ulcer activity of chloroform: methanol extract of C. striatus fillet (CMCS) in rats. The antiulcer profile of CMCS, given orally in the doses of 50, 250 and 500mg/kg, was assessed using the ethanol- and indomethacin-induced gastric ulcer models. The mechanisms of antiulcer of CMCS were determined as follows; i) the antisecretory activity of CMCS was measured using the pyloric ligation rat model, and; ii) the role of nitric oxide (NO) and sulfhydryl compounds in the modulation of CMCS antiulcer activity were determined by pre-treating the rats with L -NAME or NEM, respectively, followed by the pre-treatment of rats with CMCS before subjecting the animals to the ethanol-induced gastric ulcer model. From the results obtained, CMCS exerted significant (P<0.05) antiulcer activity in both models of gastric ulcer wherein the macroscopic and microscopic analysis of the stomach supported the antiulcer claim. With regard to its antisecretory effect, CMCS did not change the volume and pH, but reduce the total acidity only at the lower doses of the gastric juice. Moreover, CMCS demonstrated antiulcer activity was reversed by NEM, but not affected by L-NAME. In conclusion, CMCS shows antiulcer activity that is modulated via its cytoprotective, but not antisecretory effect, and in the presence of sulfhysryl compounds, but not NO.

  9. Antidepressant-like effect of aqueous extract of Channa striatus fillet in mice models of depression.

    Science.gov (United States)

    Saleem, A M; Taufik Hidayat, M; Mat Jais, A M; Fakurazi, S; Moklas, Mohamad; Sulaiman, M R; Amom, Z

    2011-07-01

    Channa (C.) striatus (Malay-Haruan), is a fresh water snakehead fish, consumed as a rejuvenating diet in post-parturition period in local Malay population. The aqueous extract of C. striatus fillet (AECSF) was reported to act through serotonergic receptor system in a previous study. There is no scientific report on neuropharmacological effects of C. striatus. Based on these data, the antidepressant-like effect of C. striatus was evaluated in mice models of depression. AECSF was prepared by steaming the fillets as described previously. Antidepressant activity was studied in male ICR mice using forced swimming test (FST) and tail suspension test (TST). Open-field test was used to evaluate any psychomotor stimulant activity. AECSF was administered intraperitoneally at the concentrations of 30%, 40% and 50% w/v at the dosage of 10 ml/kg. Amitriptyline (10 mg/kg) was used as positive control. All the three concentrations of AECSF (30%, 40% and 50% w/v) significantly reduced the immobility time (p open-field test. AECSF produced significant reduction of immobility time in both FST and TST. Amitriptyline produced a significant reduction of immobility time in both FST and TST similar to previous findings. The AECSF produced a dose-dependent decrease in locomotor activity in the open-field test. This hypolocomotion effect indicated the absence of any psychomotor stimulant activity thereby supporting the antidepressant-like effect of the AECSF. The pharmacological mechanisms of the observed antidepressant-like effect and hypolocomotion effect are not understood from our study. Hence, further studies are required.

  10. 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)

  11. 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.

  12. 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...

  13. 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

  14. Emergence of Edwardsiella piscicida in farmed channel femal, Ictalurus punctatus X blue male, Ictalurus furcatus, hybrid catfish cultured in Mississippi

    Science.gov (United States)

    here is a trend toward the increased incidence and prevalence of Edwardsiella piscicida septicemia in US catfish aquaculture, particularly in channel ', Ictalurus punctatus, × blue ', I. furcatus, hybrid catfish. From 2013 to 2017, a total of 3242 disease case submissions were made to the Aquatic Re...

  15. Evaluation of potassium permanganate against an experimental subacute infection of Flavobacterium columnare in channel catfish, Icatlurus punctatus

    Science.gov (United States)

    The efficacy of potassium permanganate (KMnO4) as a prophylactic and therapeutic treatment for subacute infection of Flavobacterium columnare was demonstrated in experimentally infected channel catfish, Ictalurus punctatus. Catfish experimentally infected with F. columnare to mimic a subacute infec...

  16. Effect of supplemental taurine on juvenile channel catfish Ictalurus punctatus growth and survival after challenge with Edwardsiella ictaluri

    Science.gov (United States)

    Juvenile channel catfish, Ictalurus punctatus, were fed a basal diet that contained major protein (soybean meal, cottonseed meal) and energy (ground corn grain) ingredients that were derived from plant sources. Plant-source ingredients are considered to be low (taurine content. In add...

  17. Characterization of an Oct1 orthologue in the channel catfish, Ictalurus punctatus: A negative regulator of immunoglobulin gene transcription?

    NARCIS (Netherlands)

    Lennard, M.L.; Hikima, J.I.; Ross, D.A.; Kruiswijk, C.P.; Wilson, M.R.; Miller, N.W.; Warr, G.W.

    2007-01-01

    Background - The enhancer (E¿3') of the immunoglobulin heavy chain locus (IGH) of the channel catfish (Ictalurus punctatus) has been well characterized. The functional core region consists of two variant Oct transcription factor binding octamer motifs and one E-protein binding ¿E5 site. An

  18. First Southeast U.S. records for Lacconotus punctatus Leconte (Coleoptera: Mycteridae), an early seasonal canopy specialist?

    Science.gov (United States)

    Michael Ulyshen; Scott Horn; James Hanula

    2010-01-01

    A recent project carried out within the Oconee River watershed in northeastern Georgia produced six specimens of Lacconotus punctatus LeConte, a species formerly known only from the northeastern United States (New Hampshire, Ohio, Pennsylvania, Michigan) and Canada (Ontario, Québec, Nova Scotia) ( Majka and Selig 2006, and references therein). Georgia represents a new...

  19. Feeding ecology of Hypostomus punctatus Valenciennes, 1840 (Osteichthyes, Loricariidae in a costal stream from Southeast Brazil

    Directory of Open Access Journals (Sweden)

    R. Mazzoni

    Full Text Available In the present study we aimed to compare the feeding ecology of Hypostomus punctatus from a coastal stream from Southeast Brazil with data previously published for the same study site before environmental changes. Feeding preferences were assessed through a sample of 138 specimens (67 from the dry and 71 from the rainy season using the Index of Alimentary Importance (IAi. We registered five different food items (detritus, plant fragments, Diatoms, Chloroficeae and Cianobacteries composing the species diet. Detritus was the most abundant one both during the rainy and dry seasons (IAirainny = 90.34 and IAidry = 96.30. No significant differences were registered for the volume of food items consumed during the rainy and dry seasons. The Frequency of Occurrence analysis showed that four (detritus, plant fragments, Diatoms and Chloroficeae among the five all other consumed ones, were always frequent. Comparing our own results with those available for the study site, we suggest that the feeding habit of H. punctatus has changed according to environmental changes and that the species diet is strongly dependent upon environmental conditions.

  20. Determinação do sexo em catfish de canal (Ictalurus punctatus utilizando endoscopia

    Directory of Open Access Journals (Sweden)

    Fernando Souza Mendonça De Lima

    2011-06-01

    Full Text Available A identificação precoce do sexo em peixes é um procedimento importante para o desenvolvimento de estratégias que facilitem o manejo no plantel de reprodutores. A endoscopia pode ser utilizada para essa identificação, embora em peixes seu uso ainda seja restrito. Diante disso, o objetivo deste trabalho foi validar o uso do endoscópio rígido via poro urogenital para determinação do sexo do catfish de canal (Ictalurus punctatus. O equipamento utilizado foi um endoscópio Multipurpose Rigid™ 30º com 2,7 mm de diâmetro e 18 cm de comprimento. Foram examinados 60 peixes com peso variando entre 86 e 1.032 gramas nos quais foi introduzido o endoscópio via poro genital e, logo em seguida, eutanaziados para confirmação do sexo. Amostras de tecido gonadal foram coletadas para avaliação histológica do estádio de maturação e confirmação do sexo. Os resultados mostraram que dos 60 peixes examinados, 57 tiveram confirmação positiva do sexo via endoscopia, o que corresponde a 95% da amostra. A utilização da endoscopia para determinação do sexo em I. punctatus via poro genital é viável.

  1. AMINO ACID COMPOSITION OF SNAKEHEAD FISH (CHANNA STRIATUS OF VARIOUS SIZES OBTAINED AT DIFFERENT TIMES OF THE YEAR

    Directory of Open Access Journals (Sweden)

    LAY-HARN GAM

    2005-01-01

    Full Text Available Snakehead fish (Channa striatus or Haruan is one of the favourite fresh water fish in the Asia-Pacific countries. The fish has been traditionally used to heal wounds. The amino acid composition of wild type Haruan was analyzed in this study. The most abundant amino acid in Haruan was glutamic acid, followed by aspartic acid, lysine, arginine, leucine, alanine, valine, threonine and glycine, in a decreasing order. The Haruan caught during rainy season was found to contain higher amount of total amino acids. The essential amino acids made up 56% of its total amino acids content. Furthermore, each of the essential amino acids (except lysine was found in higher quantity compared to other types of fishes. Haruan was found significantly rich in arginine, an important constituent in the process of wound healing. The amino acid composition of Haruan indicates that the fish is an excellent source of dietary protein for human.

  2. Ovulation time and ovulated eggs count of sneakehead Channa striata induced by prostaglandin 2α with different doses

    Directory of Open Access Journals (Sweden)

    Frits Jamlaay

    2016-02-01

    Full Text Available ABSTRACT Snakehead fish Channa striata is one of freshwater commodity which has high economic value. Nowadays, snakehead fish stock mostly comes from wild capture. Artificial spawning with hormonal induction is usually used to improve broodstock efficiency, as well as the quality and quantity of fish seed production. Purpose of this study was to determine the effectiveness of prostaglandin 2α (PGF2α hormone on ovulation time and count of ovulated eggs. This experiment used 30–40 cm broodstock with 600–900 g body weight. Fishes were acclimated for one week in a container and then injected with different doses of PGF2α, namely: control without PGF2α (P1, 0.5 mL/kg (P2; 0.7mL/kg (P3; and 0.9 mL/kg (P4. Each treatment consisted of three fishes as replication. Ovulation time was observed until 72 hours post injection. The results showed that PGF2α injected broodstoks ovulated faster (9.17–12.24 hours post injection than control P1 (22.67 hours, while among PGF2α injected fishes were the same. Furthermore, count of ovulated eggs from PGF2α induced broodstocks were higher than control P1, and the highest (2,860 eggs was obtained in treatment 0.9 mL/kg. Thus, PGF2α at dose of 0.9 mL/kg can be used to induce eggs ovulation of snakehead fish and to increase count of ovulated eggs. Keywords: PGF2α, ovulation time, ovulated eggs count, Channa striata  ABSTRAK Ikan gabus Channa striata merupakan salah satu komoditas air tawar yang mempunyai nilai ekonomi tinggi. Saat ini, pemenuhan kebutuhan hanya bergantung pada hasil penangkapan di alam. Cara pemijahan buatan dengan induksi hormon biasanya digunakan untuk efisiensi penggunaan induk serta peningkatan kualitas dan kuantitas benih ikan yang dihasilkan. Tujuan dari penelitian ini adalah untuk menguji efektivitas hormon prostaglandin 2α (PGF2α terhadap waktu ovulasi dan jumlah telur ikan gabus yang diovulasikan. Penelitian ini menggunakan induk ikan gabus berukuran 30–40 cm dengan bobot

  3. Characterisation of Asian Snakehead Murrel Channa striata (Channidae) in Malaysia: An Insight into Molecular Data and Morphological Approach

    Science.gov (United States)

    Song, Li Min; Munian, Kaviarasu; Abd Rashid, Zulkafli; Bhassu, Subha

    2013-01-01

    Conservation is imperative for the Asian snakeheads Channa striata, as the species has been overfished due to its high market demand. Using maternal markers (mitochondrial cytochrome c oxidase subunit 1 gene (COI)), we discovered that evolutionary forces that drove population divergence did not show any match between the genetic and morphological divergence pattern. However, there is evidence of incomplete divergence patterns between the Borneo population and the populations from Peninsular Malaysia. This supports the claim of historical coalescence of C. striata during Pleistocene glaciations. Ecological heterogeneity caused high phenotypic variance and was not correlated with genetic variance among the populations. Spatial conservation assessments are required to manage different stock units. Results on DNA barcoding show no evidence of cryptic species in C. striata in Malaysia. The newly obtained sequences add to the database of freshwater fish DNA barcodes and in future will provide information relevant to identification of species. PMID:24396312

  4. 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.

  5. 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).

  6. Using 1-D 1H and 2-D 1H J-resolved NMR metabolomics to understand the effects of anemia in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Anemia is a widespread hematological disorder in vertebrates. In channel catfish (Ictalurus punctatus), anemia is a persistent problem in culture environments, however, its causes and physiological impacts are not well understood. To better understand the symptoms and characterize associated biomark...

  7. Using 1-D and 2-D J-resolved 1H-NMR metabolomics to understand the effects of anemia in channel catfish Ictalurus punctatus

    Science.gov (United States)

    Anemia is a widespread hematological disorder in vertebrates. In channel catfish (Ictalurus punctatus), anemia is a persistent problem in culture environments, however, its causes and physiological impacts are not well understood. To better understand the symptoms and characterize associated biomark...

  8. 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.

  9. 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....

  10. 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

  11. 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.

  12. 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

  13. 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....

  14. 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)

  15. Henneguya exilis Kudo associated with granulomatous branchitis of channel catfish Ictalurus punctatus (Rafinesque).

    Science.gov (United States)

    Duhamel, G E; Kent, M L; Dybdal, N O; Hedrick, R P

    1986-07-01

    Outbreaks of a chronic branchitis in channel catfish Ictalurus punctatus (Rafinesque) were observed on four fish farms throughout the state of California from November 1982 to April 1984. Severe granulomatous inflammation of the gill filaments with necrosis of the cartilage of the gill ray and diffuse epithelial hyperplasia, resulting in extensive fusion of gill lamellae, was present on histologic examination of gill specimens from 35 out of 44 fish examined. Numerous, small trophozoites morphologically consistent with presporogonic myxosporean parasites were consistently associated with the inflammatory process. Mature spores of Henneguya exilis Kudo were present in large numbers in gill specimens from two fish and only occasionally in 22 others. Similar cases referred to as "Hamburger Gill Disease" or "proliferative gill disease" have been known to occur in the south-central United States. This report describes the morphologic changes of this condition and discusses its possible pathogenesis.

  16. Resurrecting embryos of the tuatara, Sphenodon punctatus, to resolve vertebrate phallus evolution.

    Science.gov (United States)

    Sanger, Thomas J; Gredler, Marissa L; Cohn, Martin J

    2015-10-01

    The breadth of anatomical and functional diversity among amniote external genitalia has led to uncertainty about the evolutionary origins of the phallus. In several lineages, including the tuatara, Sphenodon punctatus, adults lack an intromittent phallus, raising the possibility that the amniote ancestor lacked external genitalia and reproduced using cloacal apposition. Accordingly, a phallus may have evolved multiple times in amniotes. However, similarities in development across amniote external genitalia suggest that the phallus may have a single evolutionary origin. To resolve the evolutionary history of amniote genitalia, we performed three-dimensional reconstruction of Victorian era tuatara embryos to look for embryological evidence of external genital initiation. Despite the absence of an intromittent phallus in adult tuataras, our observations show that tuatara embryos develop genital anlagen. This illustrates that there is a conserved developmental stage of external genital development among all amniotes and suggests a single evolutionary origin of amniote external genitalia. © 2015 The Author(s).

  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. KOMBINASI INJEKSI sGNRH-a + ad , PADA KETINGGIAN AIR YANG BERBEDA UNTUK PEMIJAHAN SNAKEHEAD , Channa Striata DI WADAH BUDIDAYA

    Directory of Open Access Journals (Sweden)

    Untung Bijaksana

    2016-06-01

    Full Text Available Penelitian ini bertujuan untuk melihat efektivitas sGnRH-a+ad dan ketinggian air yang berbeda pada pemijahan ikan snakehead, Channa striata dalam tangki concreat. Penelitian ini dilakukan di Laboratorium Basah Program Studi Budidaya Perairan Fakultas Perikanan Universitas Lambung Mangkurat . Ada dua faktor utama sebagai perlakuan yaitu: Faktor A = dosis sGnRH -a + ad dengan tiga tingkat ( A1 = 0,2 ml / kg , A2 = 0,4 ml / kg , A3 = 0,6 ml / kg dan faktor B = tinggi air dengan tiga tingkat ( B1 = 15 cm; B2 = 20 cm; B3 = 25 cm   diulang 4 kali untuk mendapatkan 36 unit percobaan. Pengamatan dilakukan pada parameter : berat badan, berat gonad, berat hati , estradiol - 17β , diameter telur, IGS, IHS, fekunditas, pemupukan dan derajat penetasan. Terdapat Hubungan yagn sangat erat atara parameter pengamatan IGS dan IHS.  Perlakuan yang diberikan waktu laten diperoleh kisaran  antara 12 jam sampai 25 jam, fekunditas antara 5047-5072 butir, derajat fertilisasi antara 60-60,3 persen dan 76,6 derajat fertilisasi antara 83,9 persen.  Perkembangan setelah menetas mencapai panjang tubuh 3,5 mm dan 45,5 mm pada hari 20 . This study aims to look at the effectiveness of injection of sGnRH-a + ad and height of water on fish spawning snakehead, Channa striata in the concreat tank. The research was conducted at the Wet Laboratory Aguaculture Departement Faculty of Fisheries University of Lambung Mangkurat. There are two main factors as treatment namely: Factor A = dose of sGnRH-a + ad with three levels (A1 = 0.2 ml / kg; A2 = 0.4 ml / kg; A3 = 0.6 ml / kg and factor B = height of water with three levels (B1 = 15 cm; B2 = 20 cm; B3 = 25 cm made repeated 4 times to obtain 36 units of the experiment. Observations made on the parameters: body weight, gonad weight, liver weight, estradiol-17β, egg diameter, IGS, IHS, fecundity, fertilization and hatching degrees. The strongest relationship obtained from the treatment of observational parameter is IGS and IHS. Of

  7. Ictalurus punctatus

    African Journals Online (AJOL)

    user

    PLGA microspheres vaccine by double emulsion evaporation maltophilia. It was prepared to support the completion of the .... of the polyving alcohol (PVA bought from SIGMA) solution and churn by 1100 r/min, evaporating under ordinary temperature ...... turtle pond water quality. In Shanghai Fisheries University, Shanghai.

  8. Is the red spotted green frog Hypsiboas punctatus (Anura: Hylidae) selecting its preys? The importance of prey availability.

    Science.gov (United States)

    López, Javier A; Scarabotti, Pablo A; Medrano, María C; Ghirardi, Romina

    2009-09-01

    The study of the feeding ecology of amphibians is an old issue in herpetology. Notwithstanding, the lack of food resources data in many studies of amphibians feeding has lead to partial understanding of frog feeding strategies. In this study we evaluate the trophic selectivity of a red spotted green frog (Hypsiboas punctatus) population from a Middle Paraná River floodplain pond in Argentina, and discuss the importance of prey availability data when interpreting results from diet analysis. We analyzed the gut contents of 47 H. punctatus adults and compared frog's diet with the environmental food resources. Prey availability was estimated by systematically seep-netting the microhabitat where anurans were localized foraging. We identified 33 taxonomic categories from gastrointestinal contents. Numerically, the most important prey categories were dipterans, followed by hemipterans, homopterans and coleopterans. The diet similarity between males and females was high and no statistical differences in diet composition were found. The most abundant food resources in the environment were dipterans, coleopterans, homopterans and collembolans. In order to assess whether frogs were selecting their preys, we calculated Pianka's niche overlap index and Jacobs' electivity index comparing gut contents to prey availability data. Trophic niche overlap was medium but significantly higher than expected by chance. The electivity index indicated that H. punctatus foraged dipterans slightly above their environmental abundance. Among the secondary preys, hemipterans were foraged selectively, homopterans were consumed in the same proportion to their occurrence in the environment, coleopterans were foraged quite under their availability and collembolans were practically ignored by frogs. Without food resources data, H. punctatus could be classified as a specialist feeder, but dipterans also were quite abundant in the environment. Our results show that H. punctatus fit better as a

  9. The Effect of Channa striatus (Haruan Extract on Pain and Wound Healing of Post-Lower Segment Caesarean Section Women

    Directory of Open Access Journals (Sweden)

    Siti Zubaidah Ab Wahab

    2015-01-01

    Full Text Available Channa striatus has been consumed for decades as a remedy to promote wound healing by women during postpartum period. The objectives of this study were to compare postoperative pain, wound healing based on wound evaluation scale (WES, wound cosmetic appearance based on visual analogue scale (VAS scores and patient satisfaction score (PSS, and safety profiles between C. striatus group and placebo group after six weeks of lower segment caesarean section (LSCS delivery. A randomised, double-blind, placebo-controlled study was conducted. Subjects were randomised in a ratio of 1 : 1 into either the C. striatus group (500 mg daily or placebo group (500 mg of maltodextrin daily. 76 subjects were successfully randomised, with 38 in the C. striatus group and 35 in the placebo group. There were no significant differences in postoperative pain p=0.814 and WES p=0.160 between the C. striatus and placebo groups. However, VAS and PSS in the C. striatus group were significantly better compared with the placebo group (p=0.014 and p<0.001, resp.. The safety profiles showed no significant differences between the groups. In conclusion, six-week supplementation of 500 mg of C. striatus extract showed marked differences in wound cosmetic appearance and patient’s satisfaction and is safe for human consumption.

  10. Exiguobacterium mediated arsenic removal and its protective effect against arsenic induced toxicity and oxidative damage in freshwater fish, Channa striata

    Directory of Open Access Journals (Sweden)

    Neha Pandey

    2015-01-01

    Full Text Available Arsenic is a toxic metalloid existing widely in the environment, and its removal from contaminated water has become a global challenge. The use of bacteria in this regard finds a promising solution. In the present study, Exiguobacterium sp. As-9, which is an arsenic resistant bacterium, was selected with respect to its arsenic removal efficiency. Quantification of arsenic in the water treated with bacterium showed that Exiguobacterium efficiently removed up to 99% of arsenic in less than 20 h. In order to reveal the possible effect of this bacterium in removal of arsenic from water and protecting fishes from the detrimental effects of arsenic, we initiated a range of studies on fresh water fish, Channa striata. It was observed that the fishes introduced into bacteria treated water displayed no symptoms of arsenic toxicity which was marked by a decreased oxidative damage, whereas the fishes exposed to arsenic revealed a significant (p < 0.05 increase in the oxidative stress together with the elevated levels of malondialdehyde. Determination of the bioaccumulation of arsenic in the liver tissues of C. striata using hydride generation atomic absorption spectrophotometry (HG-AAS revealed an increased As(III accumulation in the fishes exposed to arsenic whereas the arsenic level in the control and bacteria treated fishes were found below the detectable limit. In conclusion, this study presents the strategies of bacterial arsenic removal with possible directions for future research.

  11. The influence of snakehead (Channa striata) fish extract to increase hyperglycemic mice fertility based on spermatogenic cell composition

    Science.gov (United States)

    Hidayati, Dewi; Abdulgani, Nurlita; Ashuri, Nova Maulidina; Sa'adah, Noor Nailis; Lukitasari, Maharani

    2017-06-01

    Reproductive dysfunction is recognized as a consequence of diabetes mellitus. Previous study revealed that snakehead (Channa striata) fish extract can repairing the pancreas histological structure which by that decreasing the blood glucose levels. Further research was conducted to determine the influence of snakehead fish extract (SHFE) to increasing the fertility of hyperglycemic mice based on spermatogenic cell composition. Twenty five adult mice (Mus musculus) were induced intraperitoneally to be hyperglycemic using alloxan monohydrate single dose of 190 mg/kg body weight. Hyperglycemic mice treated orally for 14 days using SHFE which grouped into five treatment dosages. Testicular histology were prepared using the paraffin methods and stained with Haematoxylin and Eosin. According to ANOVA and Tukey's test, it was found that spermatogenic cells population as well as its composition in the testis of mice that treated with SHFE are significantly higher than hyperglichemic mice. The highest dose of SHFE (0.15 ml/day), showed highest spermatogenic cell. All hyperglichemic mice that treated with SHFE exhibited the ratio composition of spermatogonia: spermatocytes: spermatids as same as with control (healthy mice) i.e. 1:1:3 respectively.

  12. Individual growth and reproductive behavior in a newly established population of northern snakehead (Channa argus), Potomac River, USA

    Science.gov (United States)

    Landis, Andrew M. Gascho; Lapointe, Nicolas W. R.; Angermeier, Paul L.

    2010-01-01

    Northern snakehead (Channa argus) were first found in the Potomac River in 2004. In 2007, we documented feeding and reproductive behavior to better understand how this species is performing in this novel environment. From April to October, we used electrofishing surveys to collect data on growth, condition, and gonad weight of adult fish. Growth rates of young were measured on a daily basis for several weeks. Mean length-at-age for Potomac River northern snakehead was lower than for fish from China, Russia, and Uzbekistan. Fish condition was above average during spring and fall, but below average in summer. Below-average condition corresponded to periods of high spawning activity. Gonadosomatic index indicated that females began spawning at the end of April and continued through August. Peak spawning occurred at the beginning of June when average temperatures reached 26°C. Larval fish growth rate, after the transition to exogenous feeding, was 2.3 (SD ± 0.7) mm (total length, TL) per day. Although Potomac River northern snakehead exhibited lower overall growth rates when compared to other populations, these fish demonstrated plasticity in timing of reproduction and rapid larval growth rates. Such life history characteristics likely contribute to the success of northern snakehead in its new environment and limit managers’ options for significant control of its invasion.

  13. Epizootic ulcerative syndrome caused by Aphanomyces invadans in captive bullseye snakehead Channa marulius collected from south Florida, USA

    Science.gov (United States)

    Saylor, Ryan K.; Miller, Debra L.; Vandersea, Mark W.; Bevelhimer, Mark S.; Schofield, Pamela J.; Bennett, Wayne A.

    2010-01-01

    Epizootic ulcerative syndrome (EUS) caused by the oomycete Aphanomyces invadans is an invasive, opportunistic disease of both freshwater and estuarine fishes. Originally documented as the cause of mycotic granulomatosis of ornamental fishes in Japan and as the cause of EUS of fishes in southeast Asia and Australia, this pathogen is also present in estuaries and freshwater bodies of the Atlantic and gulf coasts of the USA. We describe a mass mortality event of 343 captive juvenile bullseye snakehead Channa marulius collected from freshwater canals in Miami-Dade County, Florida. Clinical signs appeared within the first 2 d of captivity and included petechiae, ulceration, erratic swimming, and inappetence. Histological examination revealed hyphae invading from the skin lesions deep into the musculature and internal organs. Species identification was confirmed using a species-specific PCR assay. Despite therapeutic attempts, 100% mortality occurred. This represents the first documented case of EUS in bullseye snakehead fish collected from waters in the USA. Future investigation of the distribution and prevalence of A. invadans within the bullseye snakehead range in south Florida may give insight into this pathogen-host system.

  14. Antidepressant-Like Effect of Lipid Extract of Channa striatus in Postpartum Model of Depression in Rats

    Directory of Open Access Journals (Sweden)

    Mohamed Saleem Abdul Shukkoor

    2017-01-01

    Full Text Available Postpartum depression affects 15% of women. Channa striatus, a freshwater fish, is consumed in local Malay population as a rejuvenating diet during postpartum period. This study evaluated the antidepressant-like effect of lipid extract of C. striatus fillet and its mechanism of action in female Sprague-Dawley rats in postpartum model of depression. The rats were ovariectomized and treated with high dose of progesterone and estradiol benzoate for 23 days to have hormone-simulated pregnancy. The day 24 and afterwards were considered as the postpartum period. During the postpartum period, lipid extract was administered at 125, 250, and 500 mg/kg through intraperitoneal route for 15 days. Fluoxetine (10 mg/kg was used as the positive control. On postpartum day 15, the animals were tested in forced swimming test (FST and open field test (OFT followed by biochemical analysis. Withdrawal of hormone administration during the postpartum period induced depressive-like behavior in FST. Administration of lipid extract reversed that depressive-like behavior at 125, 250, and 500 mg/kg in FST. In OFT, it decreased the exploratory activity. The mechanism of the antidepressant-like effect may be mediated through the decrease in plasma corticosterone, increase in plasma oxytocin, and decrease in nuclear factor-kappa B in prefrontal cortex of rats.

  15. Studies on the epidemiology and histopathology of Euclinostomum heterostomum (Trematoda; Digenea infection in Channa punctata from North India

    Directory of Open Access Journals (Sweden)

    Shareef P. A. Ahammed

    2015-09-01

    Full Text Available A survey on the occurrence and epidemiology of the encysted progenetic metacercariae of Euclinostomum heterostomum infection in Channa punctata in the Aligarh region of North India revealed a mean prevalence, intensity, and abundance of 18.61, 1.52, and 0.38%, respectively, during the period from April 2011 to March 2012. Liver, kidney, peritoneum, muscle, and ovary were found to be infected with this parasite, and the later three are reported for the first time in this fish species. The histopathology of the infected tissues indicated the following at the host-parasite interface: tissue damage, infiltration of immune cells into the cyst wall, chronic inflammatory responses, and granulomatous lesions. The infected liver showed degeneration of hepatocytes, cytoplasmic vacuolation, nuclear alterations, mallory body formation, fibrosis, and necrosis. The pathology of the infected kidney included distortion and dilation of renal tubules, vacuolar degeneration, hypertrophy and hyperplasia of tubular epithelial cells, occlusion of tubules, fibrosis, hemorrhage, and congestion of glomeruli. The infected muscle demonstrated comparatively fewer pathological changes confined only to the circumference of the cyst wall. The ovary displayed the least changes. The conclusions drawn from the study are that the large metacercarial cysts formed by E. heterostomum in the vital organs of the economically important fish C. punctata could result in the impairment of fish physiology and health, thereby affecting their productivity and quality for human consumption.

  16. 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

  17. Effects of water salinity on hatching of egg, growth and survival of larvae and fingerlings of snake head fish, Channa striatus

    Directory of Open Access Journals (Sweden)

    Thumronk Amornsakun

    2017-04-01

    Full Text Available A study on the effect of water salinity ranging from 0-30 ppt on hatching success of snake head fish, Channa striatus was conducted in a 15-liter glass aquarium (water volume 10 liters containing 500 eggs for various levels of water salinity. Fertilization rates at 0, 5, 10, 11, 12, 13 and 14 ppt were 69.33, 72.67, 71.33, 72.67, 82.00, 73.33 and 10.67%, respectively. The fertilization rate at 12-13 ppt salinity was significantly (P0.05 among 0, 5 and 10 ppt.

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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 ...

  7. 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)

  8. 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.

  9. 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)

  10. 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

  11. Paraoxonase activity in sera from Piaractus mesopotamicus Holmberg (Characidae and Hypostomus punctatus Valenciennes (Siluridae

    Directory of Open Access Journals (Sweden)

    Vera Lucia F. Cunha Bastos

    1998-01-01

    Full Text Available A paraoxonase activity present in serum of two Brazilian fish species was consistently assayed at pH 8.5 using 7.5 mM paraoxon final concentration. The paraoxonase activity was more activated by 0.5 M NaCl in serum of Piaractus mesopotanricus Holmberg, 1887 (pacu than in serum of Hypostomus punctatus Valenciennes, 1840 (cascudo. Apparent values of K M were 3.3 x 10-3 M for cascudo and pacu paraoxonase activity in the presence of 0.5 M NaCl. Apparent maximum velocity values calculated in the presence of 0.5 M NaCl were 6.1 and 6.5 nmole/min/mL of serum for cascudo and pacu, respectively. Vmax/K M ratio values of determinations in the presence and absence of 0.5 M NaCl showed that NaCl had a more evident effect on increasing the affinity of serum paraoxonase for paraoxon in pacu serum. Young specimens of pacu showed a marked decreased paraoxonase serum activity when kept in tanks treated with 0.25 ppm methyl-parathion.

  12. Population structure of the Korean gizzard shad, Konosirus punctatus (Clupeiformes, Clupeidae) using multivariate morphometric analysis

    Science.gov (United States)

    Myoung, Se Hun; Kim, Jin-Koo

    2016-03-01

    The gizzard shad, Konosirus punctatus, is one of the most important fish species in Korea, China, Japan and Taiwan, and therefore the implementation of an appropriate population structure analysis is both necessary and fitting. In order to clarify the current distribution range for the two lineages of the Korean gizzard shad (Myoung and Kim 2014), we conducted a multivariate morphometric analysis by locality and lineage. We analyzed 17 morphometric and 5 meristic characters of 173 individuals, which were sampled from eight localities in the East Sea, the Yellow Sea and the Korean Strait. Unlike population genetics studies, the canonical discriminant analysis (CDA) results showed that the two morphotypes were clearly segregated by the center value "0" of CAN1, of which morphotype A occurred from the Yellow Sea to the western Korean Strait with negative values, and morphotype B occurred from the East Sea to the eastern Korean Strait with positive values even though there exists an admixture zone in the eastern Korean Strait. Further studies using more sensitive markers such as microsatellite DNA are required in order to define the true relationship between the two lineages.

  13. [Spectral features analysis of Pinus massoniana with pest of Dendrolimus punctatus Walker and levels detection].

    Science.gov (United States)

    Xu, Zhang-Hua; Liu, Jian; Yu, Kun-Yong; Gong, Cong-Hong; Xie, Wan-Jun; Tang, Meng-Ya; Lai, Ri-Wen; Li, Zeng-Lu

    2013-02-01

    Taking 51 field measured hyperspectral data with different pest levels in Yanping, Fujian Province as objects, the spectral reflectance and first derivative features of 4 levels of healthy, mild, moderate and severe insect pest were analyzed. On the basis of 7 detecting parameters construction, the pest level detecting models were built. The results showed that (1) the spectral reflectance of Pinus massoniana with pests were significantly lower than that of healthy state, and the higher the pest level, the lower the reflectance; (2) with the increase in pest level, the spectral reflectance curves' "green peak" and "red valley" of Pinus massoniana gradually disappeared, and the red edge was leveleds (3) the pest led to spectral "green peak" red shift, red edge position blue shift, but the changes in "red valley" and near-infrared position were complicated; (4) CARI, RES, REA and REDVI were highly relevant to pest levels, and the correlations between REP, RERVI, RENDVI and pest level were weak; (5) the multiple linear regression model with the variables of the 7 detection parameters could effectively detect the pest levels of Dendrolimus punctatus Walker, with both the estimation rate and accuracy above 0.85.

  14. First record of Trichodina heterodentata (Ciliophora: Trichodinidae from channel catfish, Ictalurus punctatus cultivated in Brazil

    Directory of Open Access Journals (Sweden)

    ML. Martins

    Full Text Available This study characterises morphologically Trichodina heterodentata Duncan, 1977 from channel catfish, Ictalurus punctatus (Rafinesque, 1818 in the State of Santa Catarina, Brazil. Body and gill smears were air-dried at room temperature, impregnated with silver nitrate and/or stained with Giemsa. Ten characteristics were selected to compare the present material with other morphological characterisations of T. heterodentata. Prevalence rate was 100%, mean intensity 89,333.70 (3,125 to 299,100 parasites per host. Trichodina heterodentata was considered medium-sized trichodinid with mean body diameter 59.4 ± 8.5 μm, denticulate ring 38.5 ± 4.5 μm, adhesive disc 60.2 ± 6.7 μm diameter and 24.4 ± 1.6 denticles. In relation to previous reports of T. heterodentata this material resembles in 90% of the analysed characters. This work confirms the biometrical variation that exists in the different populations of T. heterodentata. A list of hosts and comparative measurements of T. heterodentata are presented and the channel catfish is considered a new host.

  15. 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.

  16. 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.

  17. 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

  18. Cytotoxicity, genotoxicity and oxidative stress of malachite green on the kidney and gill cell lines of freshwater air breathing fish Channa striata.

    Science.gov (United States)

    Majeed, S Abdul; Nambi, K S N; Taju, G; Vimal, S; Venkatesan, C; Hameed, A S Sahul

    2014-12-01

    The cytotoxicity, genotoxicity and oxidative stress of malachite green (MG) was investigated using the fish Channa striata kidney (CSK) and Channa striata gill (CSG) cell lines. Five concentrations ranging from 0.001 to 10 μg mL(-1) were tested in three independent experiments. Cytotoxicity was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Rhodamine 123 and Alamar Blue. The mitochondrial changes and apoptosis of MG-exposed cells were observed by Rhodamine 123 and acridine orange/ethidium bromide (AO/EB) staining, respectively. In vitro potential DNA damaging effect of MG was tested using comet assay. Mitochondrial damage, apoptosis and DNA fragmentation increased in a concentration-dependent manner. Additionally, DNA electrophoretic mobility experiments were carried out to study the binding effect of MG to double-stranded DNA (dsDNA) of cells. DNA shift mobility experiments showed that MG is capable of strongly binding to linear dsDNA causing its degradation. Biochemical parameters such as lipid peroxidation (MDA), catalase (CAT) activity and reduced glutathione (GSH) levels were evaluated after exposure to MG. In CSK and CSG cell lines exposed to MG for 48 h, a significant increase in lipid peroxidation, which might be associated with decreased levels of reduced glutathione and catalase activity in these cell lines (p < 0.001), was observed.

  19. Notes on social wasps of the group of Mischocyttarus(Omega punctatus (Ducke, with description of six new species (Hymenoptera, Vespidae, Polistinae

    Directory of Open Access Journals (Sweden)

    Orlando Tobias Silveira

    2015-09-01

    Full Text Available ABSTRACTA revision of the taxonomic status and an identification key for wasp species of the genus Mischocyttarus related to M. punctatus (Ducke, 1904 are presented here. Six new species are proposed (M. tayrona Silveira sp. nov.; M. anchicaya Silveira sp. nov.; M. caxiuana Silveira sp. nov.; M. verissimoi Silveira sp. nov.; M. rodriguesi Silveira sp. nov.; M. ryani Silveira sp. nov., raising to nine the number of species in the M. punctatus group. The highest diversity of the group concentrates in northern South America, in Andean areas and Amazonia. New information concerning the very peculiar nests of these wasps is also given.

  20. Hierarchical demographic approaches for assessing invasion dynamics of non-indigenous species: An example using northern snakehead (Channa argus)

    Science.gov (United States)

    Jiao, Y.; Lapointe, N.W.R.; Angermeier, P.L.; Murphy, B.R.

    2009-01-01

    Models of species' demographic features are commonly used to understand population dynamics and inform management tactics. Hierarchical demographic models are ideal for the assessment of non-indigenous species because our knowledge of non-indigenous populations is usually limited, data on demographic traits often come from a species' native range, these traits vary among populations, and traits are likely to vary considerably over time as species adapt to new environments. Hierarchical models readily incorporate this spatiotemporal variation in species' demographic traits by representing demographic parameters as multi-level hierarchies. As is done for traditional non-hierarchical matrix models, sensitivity and elasticity analyses are used to evaluate the contributions of different life stages and parameters to estimates of population growth rate. We applied a hierarchical model to northern snakehead (Channa argus), a fish currently invading the eastern United States. We used a Monte Carlo approach to simulate uncertainties in the sensitivity and elasticity analyses and to project future population persistence under selected management tactics. We gathered key biological information on northern snakehead natural mortality, maturity and recruitment in its native Asian environment. We compared the model performance with and without hierarchy of parameters. Our results suggest that ignoring the hierarchy of parameters in demographic models may result in poor estimates of population size and growth and may lead to erroneous management advice. In our case, the hierarchy used multi-level distributions to simulate the heterogeneity of demographic parameters across different locations or situations. The probability that the northern snakehead population will increase and harm the native fauna is considerable. Our elasticity and prognostic analyses showed that intensive control efforts immediately prior to spawning and/or juvenile-dispersal periods would be more effective

  1. Molecular and functional roles of 6C CC chemokine 19 in defense system of striped murrel Channa striatus.

    Science.gov (United States)

    Arockiaraj, Jesu; Bhatt, Prasanth; Harikrishnan, Ramasamy; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah

    2015-08-01

    In this study, we have reported the molecular information of chemokine-19 (Chem19) from striped murrel Channa striatus (Cs). CsCC-Chem19 cDNA sequence was 555 base pair (bp) in length which is 68bp 5' untranslated region (UTR), 339bp translated region and 149bp 3' UTR. The translated region is encoded for a polypeptide of 112 amino acids. CsCC-Chem19 peptide contains a signal sequence between 1 and 26 and an interleukin (IL) 8 like domain between 24 and 89. The multiple sequence alignment showed a 'DCCL' motif, an indispensable motif present in all CC chemokines which was conserved throughout the evolution. Phylogenetic tree showed that CsCC-Chem19 formed a cluster with chemokine 19 from fishes. Secondary structure of CsCC-Chem19 revealed that the peptide contains maximum amount of coils (61.6%) compared to α-helices (25.9%%) and β-sheet (12.5%). Further, 3D analysis indicated that the cysteine residues at 33, 34, 59 and 75 making the disulfide bridges as 33 = 59 and 34 = 75. Significantly (P coding region of CsCC-Chem19, recombinant CsCC-Chem19 protein was produced. The recombinant CsCC-Chem19 protein induced the cellular proliferation and respiratory burst activity of C. striatus peripheral blood leukocytes (PBL) in a concentration dependent manner. Moreover, the chemotactic activity showed that the recombinant CsCC-Chem19 significantly (P < 0.05) enhanced the movement of PBL of C. striatus. Conclusively, CsCC-Chem19 is a 6C CC chemokine having an ability to perform both inflammatory and homeostatic functions. However, further research is necessary to understand the potential of 6C CC chemokine 19 of C. striatus, particularly their regulatory ability on different cellular components in the defense system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Cyclic variations of gonad development of an air-breathing fish, Channa striata in the lentic and lotic environments

    Directory of Open Access Journals (Sweden)

    Nasim Al Mahmud

    2016-03-01

    Full Text Available Abstract The study was conducted to know the cyclic changes in gonadal maturation and to investigate the developmental stages of oocytes and testicular germ cells of an air-breathing fish, Channa striata. Fish were sampled monthly from lentic and lotic environments of three geographical locations of Bangladesh from December to November and the histological analysis of their gonad was done to evaluate the objectives. The highest mean GSI was 5.95 ± 0.20 for female in July and 0.14 ± 0.01 for male also in July showing that the gonadal development reached its peak during this month. The highest mean oocyte diameter was 1257.50 ± 24.17 μm observed in July implying that the oocyte reached maturity in this month. Histological study of ovary revealed the evidence of early yolk granule stage and late yolk granule stage from April to July. In case of male four stages of spermatogenesis were distinguished and spermatozoa were highly abundant in June and July. So the monthly pooled values of GSI and the analysis of gonadal histology indicated that the peak breeding season of C. striata occurred in July in the lentic and lotic environments. Samples collected from lentic and lotic habitats are suggestive of no difference in the development of the gonad. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of C. striata in its natural habitat.

  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. Evaluation of the therapeutic effect of potassium permanganate at early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    The efficacy of potassium permanganate (KMnO4) against early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus) was evaluated. Fish were experimentally challenged, by waterborne exposure for 2 h to F. columnare after cutaneous abrasion, an...

  5. Effects of feeding frequency on apparent energy and nutrient digestibility/availability of channel catfish, Ictalurus punctatus, reared at optimal and suboptimal temperatures

    Science.gov (United States)

    This study examined the effects of feeding frequency (daily versus every other day [EOD]) on nutrient digestibility/availability of channel catfish, Ictalurus punctatus, reared at optimal (30 C) and suboptimal (24 C) temperatures. A 28% protein practical diet was used as the test diet, and chromic o...

  6. Development of phytoplankton communities and common off-flavors in a biofloc technology system used to culture channel catfish Ictalurus punctatus

    Science.gov (United States)

    The use of biofloc technology production systems continues to increase in the aquaculture industry worldwide. Recent research demonstrated that outdoor biofloc systems can be used to produce high yields of channel catfish (Ictalurus punctatus). However, studies have not yet been performed to deter...

  7. Development of phytoplankton communities and common off-flavors in a biofloc technology system used for the culture of channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    The use of biofloc technology production systems continues to increase in the aquaculture industry worldwide. Recent research demonstrated that outdoor biofloc systems can be used to produce high yields of channel catfish (Ictalurus punctatus). However, studies have not yet been performed to deter...

  8. Pond-raised hybrid catfish, male Ictalurus punctatus X female Ictalurus furcatus, do not respond to microbial phytase “super-dosing”

    Science.gov (United States)

    Two experiments were conducted in consecutive years to evaluate responses of hybrid catfish, male Ictalurus punctatus X female Ictalurus furcatus, to “super-dosing” of 6-phytase added to existing commercial catfish feeds. In each experiment, two diets with or without a phytase super-dose (2,500 and ...

  9. Invasion of the Indo-Pacific blenny Omobranchus punctatus (Perciformes: Blenniidae on the Atlantic Coast of Central and South America

    Directory of Open Access Journals (Sweden)

    Oscar Lasso-Alcalá

    Full Text Available We examined 308 specimens of the Indo-Pacific blenniid Omobranchus punctatus deposited in four museum collections, and analyzed data on their collection locations to assess its invasion on the Atlantic coast of Central and South America. This species occurs in shoreline estuarine and marine habitats in the Indo-West Pacific. Previous sampling and recent records in the Tropical West Atlantic from 1930 to 2004 produced 20 records for: Panamá, Colombia, Venezuela, Trinidad and Brazil. In this work, we provide data on 17 new records for the Gulfs of Venezuela and Paria in Venezuela, as well as four records for Maranhão and Pará states in NE Brazil. The temporal pattern of collections (1930 - 2009 and the proximity of most localities to ports and zones of ship traffic indicate that O. punctatus was initially introduced to the Atlantic by ships travelling from India to Trinidad. Within Brazil the introduction is linked to shipping connected to petroleum platforms. In Maranhão and Pará the introduction may have occurred as a result of fish sheltering in fouling on hulls of ships moving between ports around the mouth of the Amazon River. Alternatively, the spread of this species along of the American coast may reflect the expansion of the range of O. puntactus through larval dispersal in northward flowing currents. We recommend monitoring of this introduced species, and studies of its ecology in West Atlantic areas.

  10. Antifungal activity of the pygidial gland secretion of Laemostenus punctatus (Coleoptera: Carabidae) against cave-dwelling micromycetes

    Science.gov (United States)

    Nenadić, Marija; Ljaljević-Grbić, Milica; Stupar, Miloš; Vukojević, Jelena; Ćirić, Ana; Tešević, Vele; Vujisić, Ljubodrag; Todosijević, Marina; Vesović, Nikola; Živković, Nemanja; Ćurčić, Srećko

    2017-06-01

    The antifungal potential of the pygidial gland secretion of the troglophilic ground beetle Laemostenus punctatus from a cave in Southeastern Serbia against cave-dwelling micromycetes, isolated from the same habitat, has been investigated. Eleven collected samples were analyzed and 32 isolates of cave-dwelling fungi were documented. A total of 14 fungal species were identified as members of the genera Aspergillus, Penicillium, Alternaria, Cladosporium, Rhizopus, Trichoderma, Arthrinium, Aureobasidium, Epicoccum, Talaromyces, and Fusarium. Five isolates were selected for testing the antifungal activity of the pygidial gland secretion: Talaromyces duclauxi, Aspergillus brunneouniseriatus, Penicillium sp., Rhizopus stolonifer, and Trichoderma viride. The microdilution method has been applied to detect minimal inhibitory concentrations (MICs) and minimal fungicidal concentrations (MFCs). The most sensitive isolate was Penicillium sp., while the other isolates demonstrated a high level of resistance to the tested agent. L. punctatus has developed a special mechanism of producing specific compounds that act synergistically within the secretion mixture, which are responsible for the antifungal action against pathogens from the cave. The results open opportunities for further research in the field of ground beetle defense against pathogens, which could have an important application in human medicine, in addition to the environmental impact, primarily.

  11. 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.

  12. 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)

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. Dietary supplementation of Zeolite on growth performance, immunological role, and disease resistance in Channa striatus against Aphanomyces invadans.

    Science.gov (United States)

    Jawahar, Suntharam; Nafar, Adil; Vasanth, Krishnan; Musthafa, Mohamed Saiyad; Arockiaraj, Jesu; Balasundaram, Chellam; Harikrishnan, Ramasamy

    2016-04-01

    Epizootic Ulcerative Syndrome (EUS) caused by Aphanomyces invadans which is a primary fungal parasitic pathogen, inflicts serious economic loss in tropical freshwater fish including snakehead murrel, Channa striatus. In the present study with an aim to circumvent the adverse effects of the traditional measures in graded levels (2%, 4%, and 6%) of Zeolite enriched diet on growth performance, hematology, immunological response, and disease resistance in C. striatus against A. invadans is reported. The final weight (FW), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and average daily gain (ADG) were significantly high in infected fish fed with 4% or 6% Zeolite incorporated diets on 4th week. The maximum survival rates (SR) of 96% and 98% were observed when fed with 2% or 4% diets on 4th week. Similarly, the white blood cell (WBC), red blood cell (RBC), hematocrit (Hct), mean corpuscular volume (MCV), and mean corpuscular haemoglobin concentration (MCHC) were significantly high when fed with any Zeolite enriched diet. However, the haemoglobin (Hb) and mean corpuscular haemoglobin (MCH) were significantly high with 4% and 6% Zeolite diets. The total protein and globulin were significantly high with 4% and 6% diets; the albumin, glucose, cholesterol, and triglyceride were significantly elevated with any enriched diet. The 4% and 6% Zeolite diets significantly enhanced the phagocytic activity on 2nd week but the 2% diet could increase it on 4th week. The respiratory burst (RB) activity, complement activity, and lymphocyte proliferation level were significantly enhanced with 4% and 6% Zeolite diets on weeks 1 and 2 while with 2% diet on 4th week. All enriched diets significantly increased the lysozyme activity during the experimental period. Superoxide anion (SOA) production significantly enhanced with 6% diet on weeks 1 and 2 whereas with 2% diet on week 4. Lower cumulative mortality of 10% and 15% was found with 4% and 6

  1. 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.

  2. CEPF Western Ghats Special Series: Length-weight and length-length relationship of three species of snakehead fish, Channa diplogramma, C. marulius and C. striata from the riverine reaches of Lake Vembanad, Kerala, India.

    Directory of Open Access Journals (Sweden)

    A. Ali

    2013-09-01

    Full Text Available The length-weight relationship (LWR and length-length relationships (LLR of three snakehead fishes, Channa diplogramma, C. marulius and C. striata, exploited by small-scale fishers in the riverine reaches of Lake Vembanad, Kerala were studied using the allometric growth equation Y = aXb. Our analysis shows that the LWR of C. diplogramma and C. marulius is nonisometric with exponents much smaller than the cubic value (b = 3, while that of C. striata is isometric. Channa marulius showed a definite change in LWR with size, with smaller fish growing with positive allometric exponents (b greater than 3 and larger individuals having negative allometric relationship (b less than 3, indicating a possible age-related change in growth pattern. In the case of LLR, all three snakehead species showed non-isometric growth patterns. The caudal fin did not grow substantially with increasing fish length.

  3. 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.

  4. Plant Natural compounds with antibacterial activity towards common pathogens of pond-cultured channel catfish (Ictalurus punctatus).

    Science.gov (United States)

    Schrader, Kevin K

    2010-07-01

    The bacteria Edwardsiella ictaluri and Flavobacterium columnare cause enteric septicemia and columnaris disease, respectively, in channel catfish (Ictalurus punctatus). Natural therapeutants may provide an alternative to current management approaches used by producers. In this study, a rapid bioassay identified plant compounds as potential therapeutants. Chelerythrine chloride and ellagic acid were the most toxic toward E. ictaluri, with 24-h IC50 of 7.3 mg/L and 15.1 mg/L, respectively, and MIC of 2.1 mg/L and 6.5 mg/L, respectively. Chelerythrine chloride, ellagic acid, β-glycyrrhetinic acid, sorgoleone, and wogonin were the most toxic towards two genomovars of F. columnare, and wogonin had the strongest antibacterial activity (MIC = 0.3 mg/L).

  5. 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

  6. 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.

  7. 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.

  8. 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...

  9. 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-...

  10. Localization of water channels in the skin of two species of desert toads, Anaxyrus (Bufo) punctatus and Incilius (Bufo) alvarius.

    Science.gov (United States)

    Shibata, Yuki; Takeuchi, Hiro-Aki; Hasegawa, Takahiro; Suzuki, Masakazu; Tanaka, Shigeyasu; Hillyard, Stanley D; Nagai, Takatoshi

    2011-09-01

    Anuran amphibians obtain water by osmosis across their ventral skin. A specialized region in the pelvic skin of semiterrestrial species, termed the seat patch, contains aquaporins (AQPs) that become inserted into the apical plasma membrane of the epidermis following stimulation by arginine vasotocin (AVT) to facilitate rehydration. Two AVT-stimulated AQPs, AQP-h2 and AQP-h3, have been identified in the epidermis of seat patch skin of the Japanese tree frog, Hyla japonica, and show a high degree of homology with those of bufonid species. We used antibodies raised against AQP-h2 and AQP-h3 to characterize the expression of homologous AQPs in the skin of two species of toads that inhabit arid desert regions of southwestern North America. Western blot analysis of proteins gave positive results for AQP-h2-like proteins in the pelvic skin and also the urinary bladder of Anaxyrus (Bufo) punctatus while AQP-h3-like proteins were found in extracts from the pelvic skin and the more anterior ventral skin, but not the urinary bladder. Immunohistochemical observations showed both AQP-h2- and AQP-h3-like proteins were present in the apical membrane of skin from the pelvic skin of hydrated and dehydrated A. punctatus. Further stimulation by AVT or isoproterenol treatment of living toads was not evident. In contrast, skin from hydrated Incilius (Bufo) alvarius showed very weak labeling of AQP-h2- and AQP-h3-like proteins and labeling turned intense following stimulation by AVT. These results are similar to those of tree frogs and toads that occupy mesic habitats and suggest this pattern of AQP expression is the result of phylogenetic factors shared by hylid and bufonid anurans.

  11. 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

  12. PERBAIKAN STATUS GIZI ANAK BALITA DENGAN INTERVENSI BISKUIT BERBASIS BLONDO, IKAN GABUS (Channa striata, DAN BERAS MERAH (Oryza nivara

    Directory of Open Access Journals (Sweden)

    Slamet Widodo

    2016-01-01

    Full Text Available ABSTRACTThe objective of this study was to analyze the influence of blondo, snakehead fish flour and brown rice flour-based biscuit on the improvement of the nutritional status of anthropometric and serum albumin in malnourished children aged 3-5 years old. The design of this study was Randomized Controlled Trial (RCT with single blind pre-post study. The total subjects were 50 underfive children and divided into two groups. They were given the biscuits for 90 days. Before intervention, the body weight and serum albumin level of subjects were measured. The analysis method were paired t-test. The result showed that the difference between baseline and endline in control group for energy was 20.8±3.9 kcal, treatment group was 45.6±8.6 kcal, endline in control group for protein was 9.5±1 g, and treatment group was 16.6±2.4 g. The changing of weight in the control group from 11.7±0.8 kg increase to 13.3±1.1 kg, the weight of treatment group from 11.7±0.7 kg increase to 13.6±1.0 kg. The increasing of albumin level in the control group was 0.3±0.1 g/dL, and treatment group was 1.0±0.2 g/dL. The increase of weight for age and albumin level after consuming nutritious biscuits can increase and normalize the nutritional status of the malnourished children. It is concluded that intervention of the formulated biscuits for 90 days could increase the nutritional status (weight for age and weight for height and the serum albumin level in the 3-5 years old malnourished children.Keywords: albumin, biscuit, blondo, brown rice flour, malnutrition, snakehead fish flourABSTRAKTujuan penelitian adalah menganalisis pengaruh biskuit berbasis blondo, ikan gabus (Channa striata, dan beras merah (Oryza nivara terhadap perbaikan status gizi antropometri dan serum albumin anak gizi kurang usia 3-5 tahun. Desain penelitian Randomized Controlled Trial (RCT Single Blind Pre-post Study. Jumlah subjek 50 balita terbagi menjadi dua kelompok yaitu kelompok perlakuan dan

  13. 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)

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. An assessment of morphometric indices, blood chemistry variables and an energy meter as indicators of the whole body lipid content in Micropterus dolomieu, Sander vitreus and Ictalurus punctatus

    Science.gov (United States)

    Mesa, Matthew G.; Rose, Brien P.

    2015-01-01

    The effectiveness of several non-lethal techniques as indicators of total lipid content in smallmouth bass Micropterus dolomieu, walleye Sander vitreus and channel catfish Ictalurus punctatus was investigated. The techniques included (1) the Fulton and relative condition factors, (2) relative mass, (3) plasma indicators of nutritional status (alkaline phosphatase, calcium, cholesterol, protein, triglycerides and glucose) and (4) readings from a hand-held, microwave energy meter. Although simple linear regression analysis showed that lipid content was significantly correlated with several predictor variables in each species, the r2 values for the relations ranged from 0·17 to 0·50 and no single approach was consistent for all species. Only one model, between energy-meter readings and lipid content in I. punctatus, had an r2 value (0·83) high enough to justify using it as a predictive tool. Results indicate that no single variable was an accurate and reliable indicator of whole body lipid content in these fishes, except the energy meter for I. punctatus.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. Diet of non-native northern snakehead (Channa argus) compared to three co-occurring predators in the lower Potomac River, USA

    Science.gov (United States)

    Ryan K. Saylor,; Nicolas W.R. Laointe,; Angermeier, Paul

    2012-01-01

    Introductions of large, non-native, carnivorous fishes continue to occur worldwide and represent a substantial management concern to global biodiversity. One of the most recent non-native fishes to successfully establish in North America is the northern snakehead (Channa argus), found in the lower Potomac River catchment. Dispersal of the northern snakehead throughout this system has been well documented since its original discovery in May 2004; however, little is known about the foraging habits of this species and its interactions with co-occurring predators. Here, we quantify northern snakehead diet in comparison with the diets of naturalised largemouth bass (Micropterus salmoides), and native American eel (Anguilla rostrata) and yellow perch (Perca flavescens) collected from tidal freshwaters bordering Virginia and Maryland near Fort Belvoir, Virginia. Over 97% of northern snakehead gut contents were fishes, with fundulid and centrarchid species consumed most frequently. Dietary overlap was biologically significant only between northern snakehead and largemouth bass. Aquatic invertebrates were >10 times more common in native predator diets, reducing dietary overlap with northern snakehead. Ontogenic shifts in adult northern snakehead diet were also detected, which may be explained by optimal foraging rather than true prey specificity. Northern snakehead may be occupying a novel niche based on a piscivorous diet, therefore limiting competition with resident predators in the lower Potomac River. Further research into interactions between largemouth bass and northern snakehead is needed to inform management decisions and understand the ecological impacts of this non-native species.

  18. The Effectiveness Test of Oil Phase Ointment Containing Snakehead Fish (Channa striata Extract on Open Stage II Acute Wounded Wistar Strain Male Rats

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    Fransisca Daisa

    2017-08-01

    Full Text Available The snakehead (Channa striata contained fatty acids omega-3 and omega-6 are useful as nutrients in accelerating the wound healing process. This study aims to determine the effectiveness of the oil phase extract ointment snakehead in the healing of acute wounds open stage II. Testing the effectiveness of wound healing using 6 groups: normal, gel bioplacenton (positive control, ointment base (negative control, ointments snakehead extract oil phase concentration of 10; 20 and 40% of the 4 rats with acute wounds open stage II and observation until day 16 injury. The area of the wound was measured with the image J program Macbiophotonic, calculated% healing power, and AUC values. A statistical test to the total AUC values per rat with SPSS for Windows 22.0 program using One Way ANOVA and Post-hoc LSD test. The results showed a significant difference in the negative group with ointment concentration of 20% (p <0.05. The treatment group phase ointment fish oil extract is effective for wound healing is best to have a concentration of 20% for percentage of wound healing power of 97.157% and the average AUC value of 865.683% of the day.

  19. Novel tetra-nucleotide microsatellite DNA markers for assessing the evolutionary genetics and demographics of Northern Snakehead (Channa argus) invading North America

    Science.gov (United States)

    King, Timothy L.; Johnson, Robin L.

    2011-01-01

    We document the isolation and characterization of 19 tetra-nucleotide microsatellite DNA markers in northern snakehead (Channa argus) fish that recently colonized Meadow Lake, New York City, New York. These markers displayed moderate levels of allelic diversity (averaging 6.8 alleles/locus) and heterozygosity (averaging 74.2%). Demographic analyses suggested that the Meadow Lake collection has not achieved mutation-drift equilibrium. These results were consistent with instances of deviations from Hardy–Weinberg equilibrium and the presence of some linkage disequilibrium. A comparison of individual pair-wise distances suggested the presence of multiple differentiated groups of related individuals. Results of all analyses are consistent with a pattern of multiple, recent introductions. The microsatellite markers developed for C. argus yielded sufficient genetic diversity to potentially: (1) delineate kinship; (2) elucidate fine-scale population structure; (3) define management (eradication) units; (4) estimate dispersal rates; (5) estimate population sizes; and (6) provide unique demographic perspectives of control or eradication effectiveness.

  20. Genetic structure of the snakehead murrel, Channa striata (channidae) based on the cytochrome c oxidase subunit I gene: Influence of historical and geomorphological factors.

    Science.gov (United States)

    Jamsari, Amirul Firdaus Jamaluddin; Jamaluddin, Jamsari Amirul Firdaus; Pau, Tan Min; Siti-Azizah, Mohd Nor

    2011-01-01

    Nucleotide sequences of a partial cytochrome c oxidase subunit I gene were used to assess the manner in which historical processes and geomorphological effects may have influenced genetic structuring and phylogeographic patterns in Channa striata. Assaying was based on individuals from twelve populations in four river systems, which were separated into two regions, the eastern and western, of the biodiversely rich state of Perak in central Peninsular Malaysia. In 238 specimens, a total of 368-bp sequences with ten polymorphic sites and eleven unique haplotypes were detected. Data on all the twelve populations revealed incomplete divergence due to past historical coalescence and the short period of separation. Nevertheless, SAMOVA and F(ST) revealed geographical structuring existed to a certain extent in both regions. For the eastern region, the data also showed that the upstream populations were genetically significantly different compared to the mid- and downstream ones. It is inferred that physical barriers and historical processes played a dominant role in structuring the genetic dispersal of the species. A further inference is that the Grik, Tanjung Rambutan and Sungkai are potential candidates for conservation and aquaculture programmes since they contained most of the total diversity in this area.

  1. Genetic structure of the snakehead murrel, Channa striata (channidae based on the cytochrome c oxidase subunit I gene: influence of historical and geomorphological factors

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    Jamsari Amirul Firdaus Jamaluddin

    2011-01-01

    Full Text Available Nucleotide sequences of a partial cytochrome c oxidase subunit I gene were used to assess the manner in which historical processes and geomorphological effects may have influenced genetic structuring and phylogeographic patterns in Channa striata. Assaying was based on individuals from twelve populations in four river systems, which were separated into two regions, the eastern and western, of the biodiversely rich state of Perak in central Peninsular Malaysia. In 238 specimens, a total of 368-bp sequences with ten polymorphic sites and eleven unique haplotypes were detected. Data on all the twelve populations revealed incomplete divergence due to past historical coalescence and the short period of separation. Nevertheless, SAMOVA and F ST revealed geographical structuring existed to a certain extent in both regions. For the eastern region, the data also showed that the upstream populations were genetically significantly different compared to the mid- and downstream ones. It is inferred that physical barriers and historical processes played a dominant role in structuring the genetic dispersal of the species. A further inference is that the Grik, Tanjung Rambutan and Sungkai are potential candidates for conservation and aquaculture programmes since they contained most of the total diversity in this area.

  2. Uji Efektivitas Penyembuhan Luka Akut Stadium II Terbuka Kombinasi Fase Air-Minyak Ekstrak Ikan Gabus (Channa striata Dalam Sediaan Salep Pada Tikus Jantan Galur Wistar

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    Mohamad Andrie

    2017-08-01

    Full Text Available The snakehead (Channa striata extract contains albumin (in its water phase and omega-3 and omega-6 (in its oil phase which have been proven to be effective in wound healing process. This research was aimed to determine wound healing effect of snakehead extract-containing ointment on 6 groups of male Wistar rats. The rat’s skin was wounded to produce acute stage II opened wound, the ointment was applied for sixteen days, and wound healing process was observed. The width of the wound was measured by using Macbiophotonic Image J program. The AUC results of each groups from smallest to largest were normal group (702.84% x day, negative group (749.56% x day, positive group (765.146% x day, water phase-containing ointment 10% group (795.146% x day, oil phase-containing ointment 10% (837.282% x day, and water-oil-phase combination ointment 10% (874.901% x day. The data were analyzed using One-Way ANOVA and Post-Hoc LSD test. The result of this research showed significant differences (p<0.05 between groups of water-oil phase combination of snakehead extract ointment with a negative control group. This result showed that ointment containing water-oil phase combination of snakehead extract had wound healing effect on acute stage II opened wound.

  3. Growth and contribution of stocked channel catfish, Ictalurus punctatus (Rafinesque, 1818): the importance of measuring post-stocking performance

    Science.gov (United States)

    Stewart, David R.; Long, James M.

    2015-01-01

    In this study it was sought to quantify post-stocking growth, survival, and contribution of advanced size (178 mm total length [TL]) channel catfish Ictalurus punctatus fingerlings, something rarely done. Channel catfish populations were evaluated before (May 2010) and after (May to August 2011 and 2012) stocking. Relative abundance, stocking contribution, and growth were different (P stocked in Lake Lone Chimney, stocking contribution was lower (3–35%), and average length and weight of stocked fish by age-2 reached 230 mm TL and 85 g, whereas the stocking contribution (84–98%) and growth in length (340 mm TL) and weight (280 g) were higher by age-2 in Lake Greenleaf. Given these unambiguous differences of post-stocking performance, benchmark metrics that represent population-level information such as relative abundance and average length and weight of the sample masked these significant differences, highlighting the importance of marking hatchery-fish and then following them through time to determine the effectiveness of stocking. These results suggest that stock enhancement programmes would benefit from studies that quantify post-stocking performance of hatchery fish.

  4. 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.

  5. 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

  6. 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.

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

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    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.

  8. 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

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

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    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.

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

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    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

  11. 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.

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

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    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.

  13. Análisis comparativo del uso de Ictalurus punctatus (Rafinesque, 1818) y Cyprinus carpio (Linnaeus, 1758) en la elaboración de hamburguesas

    OpenAIRE

    Cerón-Ortiz, Ana Nallely; Castillo-Martínez, Elías; Ángeles-Monroy, Miguel Ángel

    2016-01-01

    Resumen: El estudio realizó un análisis comparativo de la utilización de la carne de bagre (I. punctatus) y carpa (C. carpio) para la elaboración de hamburguesas, considerando el impacto de la especie en la factibilidad de manufactura, la aceptación organoléptica, el valor nutricional, el contenido de microorganismos y el costo de las mismas. Los resultados indican que el grado de frescura de la carne y la inocuidad del proceso evitaron la presencia de microorganismos patógenos en el producto...

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

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    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.

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

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    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.

  16. Ultra-structural and histochemical analysis of channel catfish (Ictalurus punctatus liver treated with fumonisin B1

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    Rejane Maria Cirra Scaff

    2008-04-01

    Full Text Available The histopathological effects of fumonisin B1 (FB1 injected intraperitoneally (IP, was evaluated in catfish (Ictalurus punctatus. Fishes were divided into four Groups. Groups II, III and IV were treated IP with FB1 injections of 1; 5 and 10 mg/kg bw/day, respectively, during 21 days. At the 7th, 14th and 21st day, fishes were sacrificed. The livers were hystologicaly analysed by the light and transmission electronic microscopy. Livers from the 7th day showed organelles alterations, particularly in the granular endoplasmatic reticle, mitochondria, nucleus and nucleolus mediated by FB1 doses. The occurrence of processes involved in the necrosis and apoptosis was detected. At the highest FB1 dose,the livers presented an intense response with an accentuate tissue disorganization, absence of cell limits and intense cytoplasm vacuolization. The image analysis showed the occurrence of necrosis in some areas, characterized by fully broken or swollen cells. The apoptosis was observed as the cytoplasm contraction and the chromatin formed masses concentrated in the edge of the nucleus. There was strong evidence that the numerous hepatocytes in the liver from the fishes under the toxic dose of FBs were selectively removed by the apoptosis process.Os efeitos histopatológicos da fumonisina B1 (FB1 foram avaliados quando a toxina foi aplicada intraperitoneal (IP em bagre (Ictalurus punctatus. Os peixes foram divididos em 4 Grupos, sendo que os Grupos II, III e IV foram tratados com FB1 em injeções IP nas concentrações de 1; 5 e 10 mg/kg p.c./dia, respectivamente, durante 21 dias. No 7º, 14ºe 21º dia de tratamento, amostras de peixe de cada Grupo foram sacrificadas. Os figados foram analisados histopatologicamente por microscopia de luz e de transmissão eletrônica. Desde o dia 7 de coleta, os fígados apresentaram alterações em diversas organelas, principalmente no retículo endoplasmático, citoplasma, núcleo e nucléolo mediadas pelas doses de FB

  17. Major Histocompatibility Complex Genes Map to Two Chromosomes in an Evolutionarily Ancient Reptile, the Tuatara Sphenodon punctatus.

    Science.gov (United States)

    Miller, Hilary C; O'Meally, Denis; Ezaz, Tariq; Amemiya, Chris; Marshall-Graves, Jennifer A; Edwards, Scott

    2015-05-07

    Major histocompatibility complex (MHC) genes are a central component of the vertebrate immune system and usually exist in a single genomic region. However, considerable differences in MHC organization and size exist between different vertebrate lineages. Reptiles occupy a key evolutionary position for understanding how variation in MHC structure evolved in vertebrates, but information on the structure of the MHC region in reptiles is limited. In this study, we investigate the organization and cytogenetic location of MHC genes in the tuatara (Sphenodon punctatus), the sole extant representative of the early-diverging reptilian order Rhynchocephalia. Sequencing and mapping of 12 clones containing class I and II MHC genes from a bacterial artificial chromosome library indicated that the core MHC region is located on chromosome 13q. However, duplication and translocation of MHC genes outside of the core region was evident, because additional class I MHC genes were located on chromosome 4p. We found a total of seven class I sequences and 11 class II β sequences, with evidence for duplication and pseudogenization of genes within the tuatara lineage. The tuatara MHC is characterized by high repeat content and low gene density compared with other species and we found no antigen processing or MHC framework genes on the MHC gene-containing clones. Our findings indicate substantial differences in MHC organization in tuatara compared with mammalian and avian MHCs and highlight the dynamic nature of the MHC. Further sequencing and annotation of tuatara and other reptile MHCs will determine if the tuatara MHC is representative of nonavian reptiles in general. Copyright © 2015 Miller et al.

  18. Exploring the binding properties and structural stability of an opsin in the chytrid Spizellomyces punctatus using comparative and molecular modeling

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    Steven R. Ahrendt

    2017-04-01

    Full Text Available Background Opsin proteins are seven transmembrane receptor proteins which detect light. Opsins can be classified into two types and share little sequence identity: type 1, typically found in bacteria, and type 2, primarily characterized in metazoa. The type 2 opsins (Rhodopsins are a subfamily of G-protein coupled receptors (GPCRs, a large and diverse class of seven transmembrane proteins and are generally restricted to metazoan lineages. Fungi use light receptors including opsins to sense the environment and transduce signals for developmental or metabolic changes. Opsins characterized in the Dikarya (Ascomycetes and Basidiomycetes are of the type 1 bacteriorhodopsin family but the early diverging fungal lineages have not been as well surveyed. We identified by sequence similarity a rhodopsin-like GPCR in genomes of early diverging chytrids and examined the structural characteristics of this protein to assess its likelihood to be homologous to animal rhodopsins and bind similar chromophores. Methods We used template-based structure modeling, automated ligand docking, and molecular modeling to assess the structural and binding properties of an identified opsin-like protein found in Spizellomyces punctatus, a unicellular, flagellated species belonging to Chytridiomycota, one of the earliest diverging fungal lineages. We tested if the sequence and inferred structure were consistent with a solved crystal structure of a type 2 rhodopsin from the squid Todarodes pacificus. Results Our results indicate that the Spizellomyces opsin has structural characteristics consistent with functional animal type 2 rhodopsins and is capable of maintaining a stable structure when associated with the retinaldehyde chromophore, specifically the 9-cis-retinal isomer. Together, these results support further the homology of Spizellomyces opsins to animal type 2 rhodopsins. Discussion This represents the first test of structure/function relationship of a type 2 rhodopsin

  19. The effects of L-arginine, D-arginine, L-name and methylene blue on channa striatus-induced peripheral antinociception in mice.

    Science.gov (United States)

    Zakaria, Zainul Amiruddin; Sulaiman, Mohd Rosian; Somchit, Muhammad Nazrul; Jais, Abdul Manan Mat; Ali, Daud Israf

    2005-08-03

    To determine the involvement of nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway in aqueous supernatant of haruan (Channa striatus) fillet (ASH) antinociception using the acetic acid-induced abdominal constriction test. The ASH was prepared by soaking fresh haruan fillet in chloroform:methanol (CM) (2/1 (v/v)) for 72 h followed by evaporation of the upper layer supernatant to remove any solvent residues. The supernatant was then subjected to a freeze-drying process (48 h) followed by doses preparation. Subcutaneous (SC) administration of ASH alone (0.170, 0.426 and 1.704 mg/kg) exhibited a dose-dependent antinociception. On the other hand, 20 mg/kg (SC) of L-arginine and MB exhibited a significant nociception and antinociception, while D-arginine and L-NAME did not produce any effect at all. Pre-treatment with L-arginine was found to significantly reverse the three respective doses of ASH antinociception; pre-treatment with D-arginine did not produce any significant change in the ASH activity; pre-treatment with L-NAME only significantly increased the 0.170 and 0.426 mg/kg ASH antinociception; and pre-treatment with MB significantly enhanced the respective doses of ASH antinociception, respectively. Furthermore, co-treatment with L-NAME significantly enhanced the L-arginine reversal effect on 0.426 mg/kg ASH antinociception. In addition, MB significantly reversed the L-arginine nociception on 0.426 mg/kg ASH. These finding suggest ASH antinociception involves the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. The presence of NO was found to reverse ASH antinociceptive activity while blocking of cGMP system enhanced it.

  20. 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)

  1. 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.

  2. 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.

  3. Invasion and Colonisation of a Tropical Stream by an Exotic Loricariid Fish: Indices of Gradual Displacement of the Native Common Pleco (Hypostomus punctatus) by the Red Fin Dwarf Pleco (Parotocinclus maculicauda) over Fifteen Years.

    Science.gov (United States)

    Mazzoni, Rosana; Costa da Silva, Raquel; Pinto, Míriam Plaza

    2015-01-01

    The introduction of invasive species represents a major threat to the integrity of stream-dwelling fish populations worldwide, and this issue is receiving increasing attention from scientists, in particular because of potential impact on biodiversity. In this study, we analysed the dispersal of an exotic loricariid fish the red fin dwarf pleco (Parotocinclus maculicauda) in a stream of the Atlantic Forest biome in coastal south-eastern Brazil and evaluated the effects of this invasion on the native loricariid common pleco (Hypostomus punctatus). Specimens were collected at eight sites located along the course of the stream over a 15-year period. The distribution and density of the two species were determined by the Successive Removal Method. The introduction of P. maculicauda occurred in the medium sector of the stream, and during the course of the study, the species dispersed to new sites further upstream. By the end of the study, it was found at all points upstream from the original site. Hypostomus punctatus was registered at all sample sites both before and after the introduction of P. maculicauda, but its density decreased at all upstream sites after the arrival of the exotic species. Our analysis shows that colonisation by P. maculicauda seems to have a negative effect on H. punctatus densities. The maintenance of H. punctatus densities at the sites not colonised by P. maculicauda reinforces the conclusion that the colonisation of the stream by the exotic species had deleterious effects on the density of the resident H. punctatus populations, either by direct or indirect action.

  4. Invasion and Colonisation of a Tropical Stream by an Exotic Loricariid Fish: Indices of Gradual Displacement of the Native Common Pleco (Hypostomus punctatus by the Red Fin Dwarf Pleco (Parotocinclus maculicauda over Fifteen Years.

    Directory of Open Access Journals (Sweden)

    Rosana Mazzoni

    Full Text Available The introduction of invasive species represents a major threat to the integrity of stream-dwelling fish populations worldwide, and this issue is receiving increasing attention from scientists, in particular because of potential impact on biodiversity. In this study, we analysed the dispersal of an exotic loricariid fish the red fin dwarf pleco (Parotocinclus maculicauda in a stream of the Atlantic Forest biome in coastal south-eastern Brazil and evaluated the effects of this invasion on the native loricariid common pleco (Hypostomus punctatus. Specimens were collected at eight sites located along the course of the stream over a 15-year period. The distribution and density of the two species were determined by the Successive Removal Method. The introduction of P. maculicauda occurred in the medium sector of the stream, and during the course of the study, the species dispersed to new sites further upstream. By the end of the study, it was found at all points upstream from the original site. Hypostomus punctatus was registered at all sample sites both before and after the introduction of P. maculicauda, but its density decreased at all upstream sites after the arrival of the exotic species. Our analysis shows that colonisation by P. maculicauda seems to have a negative effect on H. punctatus densities. The maintenance of H. punctatus densities at the sites not colonised by P. maculicauda reinforces the conclusion that the colonisation of the stream by the exotic species had deleterious effects on the density of the resident H. punctatus populations, either by direct or indirect action.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Experimental induction of motile Aeromonas septicemia in channel catfish (Ictalurus punctatus by waterborne challenge with virulent Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Dunhua Zhang

    2016-05-01

    Full Text Available Motile Aeromonas septicemia (MAS, caused by virulent clonal isolates of Aeromonas hydrophila (vAh, is emerging as a major disease in catfish (Ictalurus punctatus aquaculture in the Southeastern United States. Predisposing conditions leading to vAh infection in catfish were however largely unknown. The objective of this study was to investigate factors that predispose catfish to vAh infection and establish a waterborne challenge model that mimics natural occurrence of MAS. Results of this study indicated that wounding on the fish body surface was one of the key factors that predisposed catfish to vAh infection via waterborne route. Relatively uniform wounds were created by clipping part of the fish adipose fin. Adipose fin clipped (Af-clipped fish behaved normally in terms of swimming and feeding and no mortality occurred in the control treatment (a mock challenge. When subjected to challenge in vAh-infected water, Af-clipped fish were highly susceptible, showing typical symptoms of MAS observed in the field. The mortality rate of Af-clipped fish was significantly associated with vAh concentration, challenge time and water temperature. About 90% mortality occurred within 48 h when Af-clipped fish were challenged for 1 h with vAh at the concentration of 2 × 107 colony forming units per mL of water (27 ± 1 °C. The waterborne challenge model was further tested using four field isolates including A. hydrophila and A. veronii. All vAh isolates caused about 90% mortality of Af-clipped fish and one isolate of Aeromonas veronii caused no mortality under the same challenge conditions. The waterborne challenge model described in this study would facilitate urgently-needed studies of MAS prevention (such as wound avoidance and healing and control (such as prophylactic vaccination; antibiotics treatment and probiotics screening. Keywords: Adipose fin, Channel catfish, Motile Aeromonas septicemia, Virulent Aeromonas hydrophila, Waterborne challenge

  12. 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

  13. 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

  14. POTENTIAL FOR GREAT EGRETS (ARDEA ALBA) TO TRANSMIT A VIRULENT STRAIN OF AEROMONAS HYDROPHILA AMONG CHANNEL CATFISH (ICTALURUS PUNCTATUS) CULTURE PONDS.

    Science.gov (United States)

    Jubirt, Madison M; Hanson, Larry A; Hanson-Dorr, Katie C; Ford, Lorelei; Lemmons, Scott; Fioranelli, Paul; Cunningham, Fred L

    2015-07-01

    Aeromonas hydrophila is a gram-negative, rod-shaped, facultative, anaerobic bacterium that is ubiquitous in freshwater and slightly brackish aquatic environments and infects fish, humans, reptiles, and birds. Recent severe outbreaks of disease in commercial channel catfish (Ictalurus punctatus) aquaculture ponds have been associated with a highly virulent A. hydrophila strain (VAH), which is genetically distinct from less-virulent strains. The epidemiology of this disease has not been determined. Given that A. hydrophila infects birds, we hypothesized that fish-eating birds may serve as a reservoir for VAH and spread the pathogen by flying to uninfected ponds. Great Egrets (Ardea alba) were used in this transmission model because these wading birds frequently prey on farmed catfish. Great Egrets that were fed VAH-infected catfish shed VAH in feces demonstrating their potential to spread VAH.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Transgenic loblolly pine (Pinus taeda L.) plants expressing a modified delta-endotoxin gene of Bacillus thuringiensis with enhanced resistance to Dendrolimus punctatus Walker and Crypyothelea formosicola Staud.

    Science.gov (United States)

    Tang, Wei; Tian, Yingchuan

    2003-02-01

    A synthetic version of the CRY1Ac gene of Bacillus thuringiensis has been used for the transformation of loblolly pine (Pinus taeda L.) using particle bombardment. Mature zygotic embryos were used to be bombarded and to generate organogenic callus and transgenic regenerated plants. Expression vector pB48.215 DNA contained a synthetic Bacillus thuringiensis (B.t.) CRY1Ac coding sequence flanked by the double cauliflower mosaic virus (CaMV) 35S promoter and nopaline synthase (NOS) terminator sequences, and the neomycin phosphotransferase II (NPTII) gene controlled by the promoter of the nopaline synthase gene was introduced into loblolly pine tissues by particle bombardment. The transformed tissues were proliferated and selected on media with kanamycin. Shoot regeneration was induced from the kanamycin-resistant calli, and transgenic plantlets were then produced. More than 60 transformed plants from independent transformation events were obtained for each loblolly pine genotype tested. The integration and expression of the introduced genes in the transgenic loblolly pine plants was confirmed by polymerase chain reactions (PCR) analysis, by Southern hybridization, by Northern blot analysis, and by Western blot analysis. Effective resistance of transgenic plants against Dendrolimus punctatus Walker and Crypyothelea formosicola Staud was verified in feeding bioassays with the insects. The transgenic plants recovered could represent a good opportunity to analyse the impact of genetic engineering of pine for sustainable resistance to pests using a B. thuringiensis insecticidal protein. This protocol enabled the routine transformation of loblolly pine plants that were previously difficult to transform.

  5. Salt Sensitive Tet-Off-Like Systems to Knockdown Primordial Germ Cell Genes for Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus.

    Science.gov (United States)

    Li, Hanbo; Su, Baofeng; Qin, Guyu; Ye, Zhi; Alsaqufi, Ahmed; Perera, Dayan A; Shang, Mei; Odin, Ramjie; Vo, Khoi; Drescher, David; Robinson, Dalton; Zhang, Dan; Abass, Nermeen; Dunham, Rex A

    2017-05-31

    Repressible knockdown approaches were investigated for transgenic sterilization in channel catfish, Ictalurus punctatus . Two primordial germ cell (PGC) marker genes, nanos and dead end , were targeted for knockdown, and an off-target gene, vasa , was monitored. Two potentially salt sensitive repressible promoters, zebrafish adenylosuccinate synthase 2 (ADSS) and zebrafish racemase (Rm), were each coupled with four knockdown strategies: ds-sh RNA targeting the 5' end (N1) or 3' end (N2) of channel catfish nanos , full-length cDNA sequence of channel catfish nanos for overexpression (cDNA) and ds-sh RNA targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with sodium chloride as the repressor compound. Spawning rates of full-sibling P₁ fish exposed or not exposed to the constructs as treated and untreated embryos were 93% and 59%, respectively, indicating potential sterilization of fish and repression of the constructs. Although the mRNA expression data of PGC marker genes were inconsistent in P₁ fish, most F₁ individuals were able to downregulate the target genes in untreated groups and repress the knockdown process in treated groups. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but more data from F₂ or F₃ are needed for evaluation.

  6. Salt Sensitive Tet-Off-Like Systems to Knockdown Primordial Germ Cell Genes for Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus

    Directory of Open Access Journals (Sweden)

    Hanbo Li

    2017-05-01

    Full Text Available Repressible knockdown approaches were investigated for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC marker genes, nanos and dead end, were targeted for knockdown, and an off-target gene, vasa, was monitored. Two potentially salt sensitive repressible promoters, zebrafish adenylosuccinate synthase 2 (ADSS and zebrafish racemase (Rm, were each coupled with four knockdown strategies: ds-sh RNA targeting the 5′ end (N1 or 3′ end (N2 of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA and ds-sh RNA targeting channel catfish dead end (DND. Each construct had an untreated group and treated group with sodium chloride as the repressor compound. Spawning rates of full-sibling P1 fish exposed or not exposed to the constructs as treated and untreated embryos were 93% and 59%, respectively, indicating potential sterilization of fish and repression of the constructs. Although the mRNA expression data of PGC marker genes were inconsistent in P1 fish, most F1 individuals were able to downregulate the target genes in untreated groups and repress the knockdown process in treated groups. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but more data from F2 or F3 are needed for evaluation.

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

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

  9. 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)

  10. 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.

  11. 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)

  12. 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.)

  13. Identification and analysis of genome-wide SNPs provide insight into signatures of selection and domestication in channel catfish (Ictalurus punctatus.

    Directory of Open Access Journals (Sweden)

    Luyang Sun

    Full Text Available Domestication and selection for important performance traits can impact the genome, which is most often reflected by reduced heterozygosity in and surrounding genes related to traits affected by selection. In this study, analysis of the genomic impact caused by domestication and artificial selection was conducted by investigating the signatures of selection using single nucleotide polymorphisms (SNPs in channel catfish (Ictalurus punctatus. A total of 8.4 million candidate SNPs were identified by using next generation sequencing. On average, the channel catfish genome harbors one SNP per 116 bp. Approximately 6.6 million, 5.3 million, 4.9 million, 7.1 million and 6.7 million SNPs were detected in the Marion, Thompson, USDA103, Hatchery strain, and wild population, respectively. The allele frequencies of 407,861 SNPs differed significantly between the domestic and wild populations. With these SNPs, 23 genomic regions with putative selective sweeps were identified that included 11 genes. Although the function for the majority of the genes remain unknown in catfish, several genes with known function related to aquaculture performance traits were included in the regions with selective sweeps. These included hypoxia-inducible factor 1β. HIFιβ.. and the transporter gene ATP-binding cassette sub-family B member 5 (ABCB5. HIF1β. is important for response to hypoxia and tolerance to low oxygen levels is a critical aquaculture trait. The large numbers of SNPs identified from this study are valuable for the development of high-density SNP arrays for genetic and genomic studies of performance traits in catfish.

  14. Gametogenesis and reproductive cycle of Melanorivulus aff. punctatus (Boulenger, 1895 (Cyprinodontiformes, Rivulidae in Chapada dos Guimarães, Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Monica Cassel

    Full Text Available The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulus aff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male gonads presented themselves as capable of reproducing, characterized by the presence of undifferentiated and differentiated spermatogonia, spermatocytes organized into cysts, spermatids in cysts whose wall was thicker and the spermatozoa was free in the lumen and the duct. This can indicate a continuous reproductive cycle with split spermiation. The females had gonads in the development stage from May to September with undifferentiated and differentiated oogonias and early oocytes always facing the lumen, abundant pre-vitellogenic and vitellogenic oocytes and some atresias. In the phase capable of spawning, observed from October to March, the mature oocytes are abundant, there are many post-ovulatory complexes and some atresia in advanced stage. The regression, observed in some individuals from February to April, is characterized by ovaries with many atresias and post-ovulatory complexes. The same results were found in the quantitative assessments. Therefore, it may be characterized as discontinuous cycle with split spawning. Thus, the reproductive cycle of this species can be characterized as continuous for males and discontinuous for females, which have a most intense phase of reproduction

  15. 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

  16. 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.)

  17. Tributyltin modulates 3,3',4,4',5-pentachlorobiphenyl (PCB-126)-induced hepatic CYP1A activity in channel catfish, Ictalurus punctatus.

    Science.gov (United States)

    Rice, C D; Roszell, L E

    1998-10-09

    Many harbor estuaries and their tributaries are contaminated with halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). Planar congeners of these two classes initiate their toxic effects, including reproductive, developmental, and immunological dysfunction, primarily through the cytosolic arylhydrocabon receptor (Ahr). However, only rarely are aquatic environments contaminated with Ahr-binding contaminants alone. Instead, most are impacted by a variety of pollutants in mixture. Tributyltin (TBT), a common antifouling biocide, is also found in many harbor estuaries and their tributaries. Several reports indicate that TBT inhibits the cytochrome P-4501A system of fish, at least in vitro, and our recent studies with rodents indicate that TBT potentiates PCB-induced CYP1A. However, the effects of TBT on xenobiotic-induced CYP1A activity in aquatic organisms has been virtually unexplored. To this end, channel catfish, Ictalurus punctatus, were exposed to 3,3'4,4',5-pentachlorobiphenyl (PCB-126, PeCB), TBT, or both in combination, with corn oil (CO) serving as the carrier control. Immunoreactive CYP1A protein and ethoxyresorufin O-deethylase (EROD) activity were measured after (1) a single dose of 0.01, 0. 1, or 1 mg/kg of each or both in combination, and (2) 6 injections of 0.017, 1.7, or 17 microg/kg of each (or in combination) given every 3 d over a 16-d period to yield a cumulative dose of 0.01, 0.1, or 1 mg/kg. As expected, PeCB alone, but not TBT, greatly induced these two CYP1A parameters. Low and middle doses of TBT (0.01 and 0.1 mg/kg), but not the high dose, potentiated PeCB-induced activity at these same doses. This effect of TBT was even more pronounced in the repeated exposure study. Furthermore, EROD activity did not always reflect CYP1A protein induction; enzyme activity was inhibited by TBT at doses that potentiated protein induction (0.01 and 0.1 mg/kg). In summary, TBT potentiates PeCB-induced CYP1A in channel catfish at

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Method for aquatic multiple species toxicant testing: acute toxicity of 10 chemicals to 5 vertebrates and 2 invertebrates. [Pimephales promelas; Carassius auratus; Ictalurus punctatus; Lepomis macrochirus; Salmo gairdneri; Orconectes immunis; Aplexa hypnorum

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, G.L.; Holcombe, G.W.

    1985-01-01

    A method was developed to simultaneously ascertain 96 h LC/sub 50/ values for seven freshwater species in a single flow through test with measured concentrations. It allows interspecific comparisons, easy determination of the most sensitive species, and cuts cost of labor, materials and chemical analysis for measured concentration tests. Species tested included fathead minnows Pimephales promelas, goldfish Carassius auratus, channel catfish Ictalurus punctatus, bluegill Lepomis macrochirus, rainbow trout Salmo gairdneri, crayfish Orconectes immunis and snails Aplexa hypnorum. Compounds tested were pentachlorophenol, 2-chloroethanol, 2,4-pentanedione, hexachloroethane, ..cap alpha..-bromo-2',5'-dimethoxyacetophenone, benzaldehyde, 1,3-dichloro-4,6-dinitro-benzene, dursban, sevin and cadmium chloride. The LC/sub 50/ values from these multiple species tests compared favourably with those determined using single species tests at this laboratory, usually within 20%.

  5. Electrophoretic pattern of blood serum proteins of some of the vertebrates of Pakistan

    International Nuclear Information System (INIS)

    Shakoori, Abdul Rauf; Zaheer, Saleem Akhtar; Ahmad, Muhammad Salih.

    1976-01-01

    The electrophoretic pattern of blood serum proteins of some of the common fishes e.g. Catla catla, Cirrhina mrigala, Channa punctatus, Channa marulius, Wallago attu, Heterop-neustes fossilis; amphibia e.g., Rana tigrina, Rana cyanophlyctis, Bufo melanostictus; reptiles e.g. Varanus bengalensis, Uromastix hardwickii; birds e.g. Columba livia, Gallus domesticus, Passer domestica, Anas platyrhynchos; and mammals e.g. Homo sapiens, Mus musculus, Lepus cuniculus have been described. The mobility of proteins of blood sera has been studied over cellulose acetate paper and then a comparative pattern analysed

  6. 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.

  7. 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.

  8. 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%.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Biodiversity in floodplains with special reference to artificial stocking

    OpenAIRE

    Hossain, M.S.; Ehshan, M.A.; Mazid, M.A.; Rahman, S.; Razzaque, A.

    2000-01-01

    A five years investigation on fish biodiversity in connection with artificial stocking was conducted in three south-western floodplains of Bangladesh from 1992 to 1996. The ten top most available and ten rarest fish species were identified. Puntius sp., Channa punctatus, Mystus sp., Anabus testudinius, Ambasis sp., Colisha sp. and Macrobrachium sp. etc. were the most common available species. On the other hand, Mystus aor, Notopterus chitala, Clupisoma garua, Aplocheilus panchax, Ctenophmyngo...

  14. 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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. 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.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    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

  19. STATUS REPRODUKSI IKAN GABUS, Channa striata Blkr (Reproduction status snakehead, Channa striata

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    Untung Bijaksana

    2017-02-01

    Full Text Available Research aimed to evaluate the reproduction status of snakehead in concrete tank  and in natural swamp aquatic. Seven indicators can be made by knowing the snakehead status indicator reproduction so that breeding manipulation in concrete tank can be done. The seven indicators were gonadosomatic indexs, hevatosomatic indexs, body weight, liver weight, gonade weight, egg diameter, fecundity and estradiol-17β concentrations. Result measurement of the gonadosomatic indexs of the snakehead in natural swamp aquatic show in Agust month was 3,3 ± 0.09 and hevatosomatic indexs was 1,1 ± 0.05 in Agust month. For gonadosomatic indexs and  hevatosomatic indexs in concrete tank in April month was 3.6 ± 0.09 and Januari month was 1.0 ± 0.08, respectively. Result of measurement the fecundity and egg diameter of the snakehead in concrete tank in Pebruary month was 2978.3 ± 7.64 and 1.3 ± 0.00 mm respectively, The fecundity and egg diameter of the snakehead in natural swamp aquatic in Januari month was 3080.0 ± 7.91 and Nopember and December was 1.5 ± 0.04 mm respectively. The estradiol-17β concentration of the snakehead in swamp aquatic show the higest concentration in natural aquatic. Average concentration estradiol-17β in natural aquatic in Juni month was 85.3 ± 9.37 pg/ml until December was 169.2 ± 6.22 pg/ml. In concrete tank from 80.5 ± 5.17 pg/ml in Juli until  118.3 ± 6.78 pg/ml in April. In general it is concluded that the reproduction status of snakehead was similar  between in concrete tank and natural swamp aquatic. Enviroment ”trigger” was the limited factor in finally gonade maturation.

  20. Evaluation of butachlor for control of some submerged macrophytes along with its impact on biotic components of freshwater system

    Directory of Open Access Journals (Sweden)

    A. Chattopadhyay, S. Adhikari, S. P. Adhikary, S. Ayyappan

    2006-04-01

    Full Text Available In this investigation, the efficacy of the herbicide butachlor, (N-butoxymethyl-2 chloro-21, 61 diethyl acetanilide was tested against few common submerged macrophytes namely Hydrilla (Hydrilla verticillata (L. Royale, Najas (Najas minor All., Nechamandra (Nechamandra alternifolia (Roxb. Thwaites and Ottelia (Ottelia alismoides (L. Pers. of freshwater fish ponds. Almost complete decay of Hydrilla, Nechamandra and Ottelia was achieved at 7.5 L of active ingredient/ha/m butachlor within 15 days while the herbicide showed no negative effect on Najas. However at the same concentration of butachlor, total mortality of zooplankton and water fern Azolla (Azolla caroliniana Lamarck occurred within seven days. In case of few freshwater fish species like Rohu (Labeo rohita, Channa (Channa punctatus, Anabas (Anabas testitudineus and Heteropneustes (Heteropneustes fossilis, total mortality occurred upto 90 days after application of the same dose of butachlor but fish survived beyond 120 days of herbicide application indicating degradation of the herbicides.

  1. 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.

  2. 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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

  4. 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

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

    Directory of Open Access Journals (Sweden)

    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

  6. 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.

  7. 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

  8. 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.

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

    African Journals Online (AJOL)

    SAM

    eus assay. T. s a useful to and can be y, profenofos, chemicals o ural farming aterbodies. Th onment has b ... ty of p tatus ( ucleus. N. S. Nagp ational Bureau. U.P., India. ent of Zoology .... and may b ni et al. 2006) ond to toxic an allow the y hazardous. NA per cell, t d the low m .... Saleh KA, Alshehri MA (2011). The intensity ...

  10. Komposisi Kimia, Kadar Albumin Dan Bioaktivitas Ekstrak Protein Ikan Gabus (Channa Striata) Alam Dan Hasil Budidaya

    OpenAIRE

    Ekowati Chasanah; Mala Nurilmala; Ayu Ratih Purnamasari; Diini Fithriani

    2015-01-01

    Khasiat kesehatan ikan gabus (C. striata) telah dikenal secara luas dan saat ini C. striata telah digunakan sebagai bahan baku industri produk suplemen. Tingginya permintaan akan produk suplemen tersebut menimbulkan masalah pada ketersediaan C. striata yang sebagian besar ditangkap dari sungai dan danau sebagai tempat hidupnya. Ikan gabus budidaya dipercaya memiliki kualitas tidak sebaik ikan gabus alam.Tujuan penelitian ini adalah untuk mendapatkan informasi mengenai komposisi kimia, termasu...

  11. Komposisi Kimia, Kadar Albumin Dan Bioaktivitas Ekstrak Protein Ikan Gabus (Channa Striata Alam Dan Hasil Budidaya

    Directory of Open Access Journals (Sweden)

    Ekowati Chasanah

    2015-12-01

    Full Text Available Khasiat kesehatan ikan gabus (C. striata telah dikenal secara luas dan saat ini C. striata telah digunakan sebagai bahan baku industri produk suplemen. Tingginya permintaan akan produk suplemen tersebut menimbulkan masalah pada ketersediaan C. striata yang sebagian besar ditangkap dari sungai dan danau sebagai tempat hidupnya. Ikan gabus budidaya dipercaya memiliki kualitas tidak sebaik ikan gabus alam.Tujuan penelitian ini adalah untuk mendapatkan informasi mengenai komposisi kimia, termasuk albumin dan potensi ekstrak protein kasar ikan gabus alam dan hasil budidaya sebagai antioksidan dan anti hipertensi. Hasil analisis menunjukkan bahwa ikan gabus alam dan hasil budidaya memiliki kadar protein yang tidak berbeda secara nyata, tetapi berbeda pada kadar air, abu, dan lemak. Ikan gabus alam memiliki kadar lemak dan abu lebih rendah tetapi kadar air lebih tinggi dibanding ikan gabus budidaya. Ikan dari kedua sumber memiliki bagian yang dapat dimakan atau edible portion (EP sebesar 36%,dengan kadar mineral makro (Na, K, Ca dan mikro (Zn, Fe pada ikan hasil budidaya lebih tinggi dibanding kedua kelompok mineral pada ikan gabus alam. Kadar albumin ikan gabus alam lebih tinggi daripada kadar albumin ikan gabus budidaya. Namun demikian, hasil analisis asam amino menunjukkan bahwa ikan gabus hasil budidaya memiliki kuantitas asam amino yang lebih tinggi daripada ikan gabus alam. Asam amino non essensial dominan adalah alanin, asam aspartat, glisin, alloisoleusin, prolin, dan glutamin, sedangkan asam amino esensial didominasi oleh leusin, lisin, dan fenilalanin. Kedua ikan gabus yang diperoleh dari tempat yang berbeda tersebut memiliki bioaktivitas sebagai antioksidan yang lemah, namun berpotensi sebagai antihipertensi (penghambat Angiotensin Converting Enzyme (ACE dengan kekuatan 1/10 kekuatan kontrol obat hipertensi captopril.

  12. Komposisi Kimia, Kadar Albumin dan Bioaktivitas Ekstrak Protein Ikan Gabus (Channa striata Alam dan Hasil Budidaya

    Directory of Open Access Journals (Sweden)

    Ekowati Chasanah

    2015-12-01

    Full Text Available Khasiat kesehatan ikan gabus (C. striata telah dikenal secara luas dan saat ini C. striata telah digunakan sebagai bahan baku industri produk suplemen. Tingginya permintaan akan produk suplemen tersebut menimbulkan masalah pada ketersediaan C. striata yang sebagian besar ditangkap dari sungai dan danau sebagai tempat hidupnya. Ikan gabus budidaya dipercaya memiliki kualitas tidak sebaik ikan gabus alam.Tujuan penelitian ini adalah untuk mendapatkan informasi mengenai komposisi kimia, termasuk albumin dan potensi ekstrak protein kasar ikan gabus alam dan hasil budidaya sebagai antioksidan dan anti hipertensi. Hasil analisis menunjukkan bahwa ikan gabus alam dan hasil budidaya memiliki kadar protein yang tidak berbeda secara nyata, tetapi berbeda pada kadar air, abu, dan lemak. Ikan gabus alam memiliki kadar lemak dan abu lebih rendah tetapi kadar air lebih tinggi dibanding ikan gabus budidaya. Ikan dari kedua sumber memiliki bagian yang dapat dimakan atau edible portion (EP sebesar 36%,dengan kadar mineral makro (Na, K, Ca dan mikro (Zn, Fe pada ikan hasil budidaya lebih tinggi dibanding kedua kelompok mineral pada ikan gabus alam. Kadar albumin ikan gabus alam lebih tinggi daripada kadar albumin ikan gabus budidaya. Namun demikian, hasil analisis asam amino menunjukkan bahwa ikan gabus hasil budidaya memiliki kuantitas asam amino yang lebih tinggi daripada ikan gabus alam. Asam amino non essensial dominan adalah alanin, asam aspartat, glisin, alloisoleusin, prolin, dan glutamin, sedangkan asam amino esensial didominasi oleh leusin, lisin, dan fenilalanin. Kedua ikan gabus yang diperoleh dari tempat yang berbeda tersebut memiliki bioaktivitas sebagai antioksidan yang lemah, namun berpotensi sebagai antihipertensi (penghambat Angiotensin Converting Enzyme (ACE dengan kekuatan 1/10 kekuatan kontrol obat hipertensi captopril.

  13. Recovery And Valorization Of Snakehead Fish Channa Striata Surimi Wash Water As Stock Albumin Tablet

    Directory of Open Access Journals (Sweden)

    Ikbal Syukroni

    2017-11-01

    Full Text Available Surimi washing process is aimed to concentrate the myofibril protein by removing catepsin enzyme fat pigment blood and sarcoplasmic protein which is soluble in wash water. The soluble subtances cause trouble environment if it was untreated. In addition recovery protein will give benefit both in reducing trouble environment and utilizing soluble protein as sources of albumin protein. The objectives of research were to recover albumin from snakehead fish surimi wash water and to valorize as stock albumin tablet. Recovery of albumin use 0.05 m ultrafiltration membrane and the valorization of albumin tablets was by direct compression. The protein band with molecular weight of 67.741 kDa on the retentate was detected as albumin. Concentration of protein recover by ultrafiltration membrane increased 89.98 and the albumin content 3.50.4 gdl. Based on the result of chemical composition and microbiology analysis albumin of snakehead surimi wash water appropriate with Indonesia National Standard SNI quality requirement about snakehead fish albumin extract. The best formulation in the preparation of surimi wash water albumin tablet was by using corn starch excipients with uniformity weight value 410.39 0.09 g hardness value 7.65 0.8 Kp uniformity size of tablet with diameter 1 cm and thickness 0.59 cm friability value 2.3 and disintregation time of the tablet is 2 minutes 16 second.

  14. Maternal Transfer of Vitamin C in Channel Catfish (Ictalurus Punctatus) Effects Reproduction and Progeny Performance

    Science.gov (United States)

    Two routes of maternal transfer of vitamin C in channel catfish female broodfish prior to spawning were explored as a strategy to incorporate the vitamin to determine its effect on reproduction and subsequent performance of the progeny. Accumulation of vitamin C was higher (p<0.05) in ovarian tissu...

  15. Bioaccumulation factor for 32P measured in bluegill, Lepomis macrochirus, and catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    Kahn, B.; Turgeon, K.S.; Martini, D.K.; Dunkerly, S.J.; el-Shinawy, R.M.; Wilson, M.D.

    1987-01-01

    The ratio of the bioaccumulation factors for 32 P and phosphorus was determined for edible tissue in two species of freshwater fish by measuring the specific activity ( 32 P activity per milligram phosphorus) in muscle relative to feed. The 32 P tracer was added to the feed at a uniform level throughout the study. Feeding was at two levels: ad libitum and at a lower but constant intake per body weight. In the main experiment, bluegill were maintained in a large flow-through tank and sacrificed at approximately weekly intervals for 51 d of 32 P accumulation and 28 d of depuration to compare the specific activity with values predicted with a calculational model. In experiments performed in smaller aquaria, the specific activity in bluegill and catfish muscle was compared at two feeding levels and two temperatures. In addition, unfed fish were exposed to 32 P in water at a known specific activity to determine the extent of phosphorus uptake directly from water. The pattern of specific activity increase and decrease in fish muscle during the accumulation/depuration experiment was consistent with a one-compartment model, so that specific activity ratios at steady state could be predicted from measurements during relatively brief exposures. On this basis, the ratio of the bioaccumulation factors of 32 P and phosphorus in fish feeding ad libitum was 0.081 for bluegill and 0.17 for catfish. Hence, at a mean phosphorus bioaccumulation factor of 70,000, the factors for 32 P are 6000 and 12,000, respectively. The ratios were less at lower phosphorus intakes associated with lower feeding rates; moreover, the lesser value for bluegill occurred at a much lower phosphorus intake than by catfish

  16. Evasion of mucosal defenses during Aeromonas hydrophila infection of channel catfish (Ictalurus punctatus) skin

    Science.gov (United States)

    The mucosal surfaces of fish serve as the first-line of defense against the myriad of aquatic pathogens present in the aquatic environment. The immune repertoire functioning at these interfaces is still poorly understood. The skin, in particular, must process signals from several fronts, sensing and...

  17. Pentachlorophenol-Induced Cytotoxic, Mitogenic, and Endocrine-Disrupting Activities in Channel Catfish, Ictalurus punctatus

    Directory of Open Access Journals (Sweden)

    Paul B. Tchounwou

    2004-09-01

    Full Text Available Pentachlorophenol (PCP is an organochlorine compound that has been widely used as a biocide in several industrial, agricultural, and domestic applications. Although it has been shown to induce systemic toxicity and carcinogenesis in several experimental studies, the literature is scarce regarding its toxic mechanisms of action at the cellular and molecular levels. Recent investigations in our laboratory have shown that PCP induces cytotoxicity and transcriptionally activates stress genes in human liver carcinoma (HepG2 cells [1]. In this research, we hypothesize that environmental exposure to PCP may trigger cytotoxic, mitogenic, and endocrine-disrupting activities in aquatic organisms including fish. To test this hypothesis, we carried out in vitro cultures of male channel catfish hepatocytes, and performed the fluorescein diacetate assay (FDA to assess for cell viability, and the Western Blot analysis to assess for vitellogenin expression following exposure to PCP. Data obtained from FDA experiments indicated a strong dose-response relationship with respect to PCP cytotoxicity. Upon 48 hrs of exposure, the chemical dose required to cause 50% reduction in cell viability (LD50 was computed to be 1,987.0 + 9.6 μg PCP/mL. The NOAEL and LOAEL were 62.5 + 10.3 μg PCP/mL and 125.0+15.2 μg PCP/mL, respectively. At lower levels of exposure, PCP was found to be mitogenic, showing a strong dose- and time-dependent response with regard to cell proliferation. Western Blot analysis demonstrated the potential of PCP to cause endocrine-disrupting activity, as evidenced by the up regulation of the 125-kDa vitellogenin protein the hepatocytes of male channel catfish.

  18. IMMUNOTOXICITY IN CHANNEL CATFISH, ICTALURUS PUNCTATUS, FOLLOWING ACUTE EXPOSURE TO TRIBUTYLTIN. (R823881)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus).

    Science.gov (United States)

    Regnault, Sophie; Jones, Marc E H; Pitsillides, Andrew A; Hutchinson, John R

    2016-05-01

    The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial. © 2016 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  20. Sequence genomic organization and expression of two channel catfish Ictalurus punctatus Ghrelin receptors

    Science.gov (United States)

    Two ghrelin receptor (GHS-R) genes were isolated from channel catfish tissue and a bacterial artificial chromosome (BAC) library. The two receptors were characterized by determining tissue distribution, ontogeny of receptor mRNA expression, and effects of exogenous homologous ghrelin administration ...

  1. Effect of supplemental taurine on juvenile channel catfish Ictalurus punctatus growth

    Science.gov (United States)

    Taurine is a beta-amino sulfur amino acid found in most animal tissues. It has many important biological functions in mammals including membrane stabilization, antioxidation, cellular osmoregulation, detoxification, neuromodulation, and brain and eye development. Taurine supplementation in juvenil...

  2. Effect of supplemental taurine on juvenile channel catfish Ictalurus punctatus growth performance

    Science.gov (United States)

    Taurine is a beta-amino sulfur amino acid found in most animal tissues that has many important biological functions including bile salt conjugation, cellular osmoregulation, neuromodulation, calcium signaling. The benefits of supplementing diets with taurine are just beginning to be realized in a n...

  3. Plasma cortisol stress response in channel catfish, Ictalurus punctatus influences susceptibility to Edwardeseilla ictaluri

    Science.gov (United States)

    Cortisol is a primary stress hormone in fish as its plasma variations correlate with the occurrence of various stressful situations. Past studies have demonstrated that fish subjected to handling stress or poor water quality had a reduced ability to resist pathogens. Channel catfish fingerlings th...

  4. Ontogeny of the cortisol stress response in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Cortisol is a glucocorticoid hormone which is an endocrine signaling molecule in all vertebrates and acts through intracellular glucocorticoid receptors (GR). Cortisol affects many biological functions including immunity, stress, growth, ion homeostasis, and reproduction. The objective of this stu...

  5. Nucleic acids digestion by enzymes in the stomach of snakehead (Channa argus) and banded grouper (Epinephelus awoara).

    Science.gov (United States)

    Liu, Yu; Zhang, Yanfang; Jiang, Wei; Wang, Jing; Pan, Xiaoming; Wu, Wei; Cao, Minjie; Dong, Ping; Liang, Xingguo

    2017-02-01

    Dietary nucleic acids (NAs) were important nutrients. However, the digestion of NAs in stomach has not been studied. In this study, the digestion of NAs by enzymes from fish stomach was investigated. The snakehead pepsins (SP) which were the main enzymes in stomach were extracted and purified. The purity of SP was evaluated by SDS-PAGE and HPLC. The snakehead pepsin 2 (SP2) which was the main component in the extracts was used for investigating the protein and NAs digestion activity. SP2 could digest NAs, including λ DNA and salmon sperm DNA. Interestingly, the digestion could be inhibited by treatment of alkaline solution at pH 8.0 and pepstatin A, and the digestion could happen either in the presence or absence of hemoglobin (Hb) and BSA as the protein substrates. Similarly, the stomach enzymes of banded grouper also showed the NAs digestion activity. NAs could be digested by the stomach enzymes of snakehead and banded grouper. It may be helpful for understanding both animal nutrition and NAs metabolic pathway.

  6. DISTRIBUSI NITROGEN DAN FOSFOR PADA BUDIDAYA IKAN GABUS (Channa striata DENGAN APLIKASI ECENG GONDOK (Eichhornia crassipes DAN PROBIOTIK

    Directory of Open Access Journals (Sweden)

    Adang Saputra

    2018-01-01

    Full Text Available Permasalahan yang dihadapi pembudidaya ikan dengan sistem intensif adalah meningkatnya limbah yang terakumulasi pada air dan sedimen. Limbah budidaya ikan pada umumnya berupa padatan dan nutrien terlarut pada air terutama nitrogen dan fosfor. Tujuan penelitian ini adalah mengkaji distribusi nitrogen total dan fosfor total pada budidaya ikan gabus secara intensif yang diberi eceng gondok Eichhornia crassipes dan probiotik (Pseudomonas aeruginosa dan Achromobacter insuavis. Penelitian dirancang menggunakan rancangan acak lengkap dengan perlakuan pemberian kombinasi eceng gondok dan probiotik (A, pemberian eceng gondok (B, dan pemberian probiotik (C, masing-masing perlakuan diulang tiga kali. Benih ikan gabus yang digunakan berukuran panjang 14,74 ± 0,01 cm dan bobot 25,53 ± 0,09 g dengan padat tebar 175 ekor/kolam (50 ekor/m3. Selama 90 hari masa pemeliharaan, ikan gabus diberi pakan berupa pelet dengan kandungan protein sekitar 30%. Jumlah pemberian pakan 5% dari biomassa dengan frekuensi pemberian empat kali dalam sehari (pagi, siang, sore, dan malam. Hasil penelitian menunjukkan nitrogen dan fosfor pada budidaya ikan gabus terdistribusi pada eceng gondok, sedimen, air, dan ikan. Eceng gondok menyerap nitrogen dan fosfor paling tinggi (P<0,05 dibandingkan air, ikan, dan sedimen. Laju pertumbuhan spesifik bobot (4,37 ± 0,01%/hari dan biomassa (1,88 ± 0,01 g ikan gabus tertinggi dicapai pada pemberian kombinasi eceng gondok dan probiotik. Hasil ini dapat dijadikan landasan untuk pengelolaan limbah nitrogen dan fosfor pada budidaya ikan gabus secara intensif. One of the problems in intensive aquaculture system is the the accumulation of waste in the water and sediment. Aquaculture wastes are discharged into the water in form of solids and dissolved nutrients which mostly consisted of nitrogen and phosphorus. The purpose of this study was to study the dynamics of total nitrogen and phosphorus in an intensive aquaculture media supplied with water hyacinth and probiotics (Pseudomonas aeruginosa and Achromobacter insuavis. The study was designed using a completely randomized design with treatment combinations of water hyacinth with probiotic (A, water hyacinth (B, and probiotic (C. Each treatment consisted of three replications. The seeds of snakehead used had body length of 14.74 ± 0.01 cm and weight 25.53 ± 0.09 g, stocked in ponds with stocking density of 175 individuals/pond (50 individuals/m3. During 90 days of rearing, the fish were fed with pellet with protein content of 30%. The amount of feeding was 5% of the biomass with feeding frequency of four times a day (morning, afternoon, evening, and night. The results showed that the produced nitrogen and phosphorus in the snakehead cultivation were distributed to water hyacinth, sediment, water, and fish. Water hyacinth absorbed most of the nitrogen and phosphorus compared to water, fish, and sediment. Higher specific growth rate (4.37 ± 0.01%/day and biomass (1.88 ± 0.01 g of snakehead were achieved in combination of water hyacinth and probiotic treatment. These results can be used as a basis for the management of nitrogen and phosphorus wastes in an intensive fish farming.

  7. INTERVENSI FOLICLE STIMULATING HORMONE (FSH DALAM PROSES REMATURASI INDUK IKAN GABUS HARUAN Channa Striata Blkr DIDALAM WADAH BUDIDAYA

    Directory of Open Access Journals (Sweden)

    Akhmad Ridha Fani

    2016-06-01

    Full Text Available Snakehead and other fish species in waters of the swamp doing spawning at the beginning or in the middle of the rainy season. Gonadal maturation process so as to return time is limited. Aquaculture development is highly dependent on the availability of seeds that meet the timeliness, quality and quantity. The seeds can be produced continuously if supported by the availability of mature broodstock with good quality eggs. Some research about the role of hormones and or the use of stimulants to the success in support of gonad development and spawning, such as; Siam Jambal fish, Pangasius hypophthalmus (Ernawati 1999, Catfish, Clarias batrachus (Zairin et al. 2001, and catfish, Hemibagrus nemurus (Supriyadi 2005. By because they were with potential memamfaatkan folicle Stimulating Hormone (FSH that serves as the control at the start of the reproductive cycle up to ovulation and spermiasi in fish. The aim of this study was to determine the effect of the injection folicle Stimulating Hormone (FSH in the parent rematurisasi catfish. Results from the start 17007-52327 item, 0,63-1,07mm egg diameter, IGS range of 4, 13 to 8.50%, and ranged from 0.86 2.4% IHS. Based on the results of the study injection folicle Stimulating Hormone (FSH capable mepersingkat rematurasi processing time.

  8. KERAGAMAN FENOTIPE TRUSS MORFOMETRIK DAN GENOTIPE IKAN GABUS (Channa striata DARI JAWA BARAT, SUMATERA SELATAN, DAN KALIMANTAN TENGAH

    Directory of Open Access Journals (Sweden)

    Irin Iriana Kusmini

    2015-12-01

    Full Text Available Ikan gabus di Indonesia awalnya hanya terdapat di Barat garis Wallace (Sumatera, Jawa, dan Kalimantan yang kemudian diintroduksi ke Indonesia bagian Timur. Ikan gabus termasuk ke dalam deretan ikan air tawar sebagai sumber daya genetik untuk menunjang diversifikasi usaha budidaya. Guna menyukseskan program diversifikasi tersebut, maka perlu diketahui keragaman genetik ikan gabus dari Jawa Barat, Sumatera Selatan, dan Kalimantan Tengah agar dapat direkomendasikan sebagai dasar pemuliaan. Tujuan penelitian ini untuk menganalisis keragaman dan kekerabatan antara populasi ikan gabus dari Jawa Barat, Sumatera Selatan, dan Kalimantan tengah. Metode penelitian dilakukan dengan analisis fenotipe terhadap 16 ekor ikan sampel dari masing-masing daerah tersebut, sedangkan untuk analisis keragaman genotipe masing-masing digunakan 10 ekor ikan dari setiap daerah. Analisis tersebut dilakukan melalui truss morfometrik dan RAPD dengan primer OPA-10, OPA-11, dan OPA-15. Hasil penelitian menunjukkan keragaman berdasarkan truss morfometrik dan hasil PCR ikan gabus asal Sumatera Selatan lebih tinggi dibandingkan Kalimantan Tengah dan Jawa Barat. Kekerabatan ikan gabus Kalimantan Tengah lebih dekat dengan ikan gabus Sumatera Selatan dibandingkan dengan ikan gabus Jawa Barat. Hasil penelitian ini dapat dijadikan sebagai informasi untuk pertimbangan dalam program pemuliaan.

  9. KERAGAMAN FENOTIPE TRUSS MORFOMETRIK DAN GENOTIPE IKAN GABUS (Channa striata) DARI JAWA BARAT, SUMATERA SELATAN, DAN KALIMANTAN TENGAH

    OpenAIRE

    Irin Iriana Kusmini; Vitas Atmadi Prakoso; Kusdiarti Kusdiarti

    2015-01-01

    Ikan gabus di Indonesia awalnya hanya terdapat di Barat garis Wallace (Sumatera, Jawa, dan Kalimantan) yang kemudian diintroduksi ke Indonesia bagian Timur. Ikan gabus termasuk ke dalam deretan ikan air tawar sebagai sumber daya genetik untuk menunjang diversifikasi usaha budidaya. Guna menyukseskan program diversifikasi tersebut, maka perlu diketahui keragaman genetik ikan gabus dari Jawa Barat, Sumatera Selatan, dan Kalimantan Tengah agar dapat direkomendasikan sebagai dasar pemuliaan. Tuju...

  10. Antidepressant-Like Effect of Lipid Extract of Channa striatus in Chronic Unpredictable Mild Stress Model of Depression in Rats

    Directory of Open Access Journals (Sweden)

    Mohamed Saleem Abdul Shukkoor

    2016-01-01

    Full Text Available This study evaluated the antidepressant-like effect of lipid extract of C. striatus in chronic unpredictable mild stress (CUMS model of depression in male rats and its mechanism of action. The animals were subjected to CUMS for six weeks by using variety of stressors. At the end of CUMS protocol, animals were subjected to forced swimming test (FST and open field test followed by biochemical assay. The CUMS protocol produced depressive-like behavior in rats by decreasing the body weight, decreasing the sucrose preference, and increasing the duration of immobility in FST. The CUMS protocol increased plasma corticosterone and decreased hippocampal and prefrontal cortex levels of monoamines (serotonin, noradrenaline, and dopamine and brain-derived neurotrophic factor. Further, the CUMS protocol increased interleukin-6 (in hippocampus and prefrontal cortex and nuclear factor-kappa B (in prefrontal cortex but not in hippocampus. The lipid extract of C. striatus (125, 250, and 500 mg/kg significantly (p<0.05 reversed all the above parameters in rats subjected to CUMS, thus exhibiting antidepressant-like effect. The mechanism was found to be mediated through decrease in plasma corticosterone, increase in serotonin levels in prefrontal cortex, increase in dopamine and noradrenaline levels in hippocampus and prefrontal cortex, increase in BDNF in hippocampus and prefrontal cortex, and decrease in IL-6 and NF-κB in prefrontal cortex.

  11. Bacterial Diversity in the Digestive Tracts of Four Indian Air-Breathing Fish Species Investigated by PCR Based Denaturing Gradient Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Suxu He

    Full Text Available ABSTRACT An investigation was conducted to identify the allochthonous microbiota (entire intestine and the autochthonous microbiota in proximal intestine (PI and distal intestine (DI of four species of Indian air-breathing fish (climbing perch; Anabas testudineus, murrel; Channa punctatus, walking catfish; Clarias batrachus and stinging catfish; Heteropneustes fossilis by PCR based denaturing gradient gel electrophoresis (DGGE. High similarities of the allochthonous microbiota were observed between climbing perch and murrel, walking catfish and stinging catfish, indicating similar food behavior. The autochthonous microbiota of PI and DI from climbing perch and murrel revealed more similarity, than the result obtained from walking catfish and stinging catfish. The autochthonous microbiota of climbing perch and murrel were similar with regard to the allochthonous microbiota, but no such similarity was observed in case of walking catfish and stinging catfish. The fish genotype and intestinal bacteria are well matched and show co-evolutionary relationship. Three fish species has its unique bacteria; autochthonous Enterobacter cloacae, Edwardsiella tarda and Sphingobium sp. in DI of climbing perch, Pseudomonas sp.; allochthonous and autochthonous in PI of walking catfish and uncultured bacterium (EU697160.1, uncultured bacterium (JF018065.1 and uncultured bacterium (EU697160.1 for stinging catfish. In murrel, no unique bacteria were detected.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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...

  15. 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....

  16. 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...

  17. 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/

  18. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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....

  1. 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

  2. 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...

  3. 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.)

  4. 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

  5. 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

  6. 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

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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)

  14. 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.

  15. 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

  16. 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)

  17. 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...

  18. Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish

    Directory of Open Access Journals (Sweden)

    Seyedeh F. Afzali

    2015-09-01

    Full Text Available Aim: Epizootic ulcerative syndrome (EUS causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups. Materials and Methods: Snakehead, Channa striata (Bloch, 1793; snakeskin gourami, Trichopodus pectoralis (Regan, 1910; koi carp, Cyprinus carpio (Linnaeus, 1758; broadhead catfish, Clarias macrocephalus (Günther, 1864; goldfish, Carassius auratus (Linnaeus, 1758; climbing perch, Anabas testudineus (Bloch, 1792; and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758 were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701. The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program. Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01. Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of

  19. Spatial and seasonal variations on Henneguya exilis prevalence on cage intensive cultured channel catfish (Ictalurus punctatus, in Tamaulipas, Mexico

    Directory of Open Access Journals (Sweden)

    Jaime Luis Rábago-Castro

    2013-03-01

    Full Text Available Diseases are of particular importance for aquaculture worldwide, particularly in intensive culture. In Mexico, intensive culture of channel catfish is mainly done in floating cages. The aim of the present study was to determine the presence of the myxozoan Henneguya and the effect of site, period and host length on its prevalence in cage-cultured channel catfish. Over a year, fish were examined on six different sites. Results showed the presence of Henneguya exilis in all the farms. However, no significant effects were observed for site and season on prevalence, nor was there a correlation between host length and infection prevalence.

  20. Edwardsiella ictaluri Encodes an Acid Activated Urease that is Required for Intracellular Replication in Channel Catfish Ictalurus punctatus Macrophages

    Science.gov (United States)

    Genomic analysis indicated that Edwardsiella ictaluri encodes a putative ureasepathogenicity island containing 9 open reading frames, including urea and ammonium transporters. In vitro studies with the wild-type E. ictaluri and a ureG::kan urease mutant strain indicated that E. ictaluri is significa...

  1. Iron status of channel catfish Ictalurus punctatus affected by channel catfish anemia and response to parenteral iron

    Science.gov (United States)

    Originally reported in 1983, channel catfish anemia (CCA), also ‘white lip’ or ‘no blood,’ is a major idiopathic disease affecting commercial production in the Mississippi Delta region of the USA. Affected individuals are characterized by lethargy, anorexia, extreme pallor, and packed cell volumes o...

  2. Impact of feed additives on surface mucosal health and columnaris susceptibility in channel catfish fingerlings, Ictalurus punctatus.

    Science.gov (United States)

    Zhao, Honggang; Li, Chao; Beck, Benjamin H; Zhang, Ran; Thongda, Wilawan; Davis, D Allen; Peatman, Eric

    2015-10-01

    One of the highest priority areas for improvement in aquaculture is the development of dietary additives and formulations which provide for complete mucosal health and protection of fish raised in intensive systems. Far greater attention has been paid to dietary impact on gut health than to protective effects at other mucosal surfaces such as skin and gill. These exterior surfaces, however, are important primary targets for pathogen attachment and invasion. Flavobacterium columnare, the causative agent of columnaris disease, is among the most prevalent of all freshwater disease-causing bacteria, impacting global aquaculture of catfish, salmonids, baitfish and aquaria-trade species among others. This study evaluated whether the feeding of a standard catfish diet supplemented with Alltech dietary additives Actigen(®), a concentrated source of yeast cell wall-derived material and/or Allzyme(®) SSF, a fermented strain of Aspergillus niger, could offer protection against F. columnare mortality. A nine-week feeding trial of channel catfish fingerlings with basal diet (B), B + Allzyme(®) SSF, B + Actigen(®) and B + Actigen(®)+Allzyme(®) SSF revealed good growth in all conditions (FCR additives may provide protection extending beyond the gut to surface mucosa. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of nutrient restriction and re-feeding on calpain family genes in skeletal muscle of channel catfish (Ictalurus punctatus.

    Directory of Open Access Journals (Sweden)

    Elena Preziosa

    Full Text Available BACKGROUND: Calpains, a superfamily of intracellular calcium-dependent cysteine proteases, are involved in the cytoskeletal remodeling and wasting of skeletal muscle. Calpains are generated as inactive proenzymes which are activated by N-terminal autolysis induced by calcium-ions. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we characterized the full-length cDNA sequences of three calpain genes, clpn1, clpn2, and clpn3 in channel catfish, and assessed the effect of nutrient restriction and subsequent re-feeding on the expression of these genes in skeletal muscle. The clpn1 cDNA sequence encodes a protein of 704 amino acids, Clpn2 of 696 amino acids, and Clpn3 of 741 amino acids. Phylogenetic analysis of deduced amino acid sequences indicate that catfish Clpn1 and Clpn2 share a sequence similarity of 61%; catfish Clpn1 and Clpn3 of 48%, and Clpn2 and Clpn3 of only 45%. The domain structure architectures of all three calpain genes in channel catfish are similar to those of other vertebrates, further supported by strong bootstrap values during phylogenetic analyses. Starvation of channel catfish (average weight, 15-20 g for 35 days influenced the expression of clpn1 (2.3-fold decrease, P<0.05, clpn2 (1.3-fold increase, P<0.05, and clpn3 (13.0-fold decrease, P<0.05, whereas the subsequent refeeding did not change the expression of these genes as measured by quantitative real-time PCR analysis. Calpain catalytic activity in channel catfish skeletal muscle showed significant differences only during the starvation period, with a 1.2- and 1.4- fold increase (P<0.01 after 17 and 35 days of starvation, respectively. CONCLUSION/SIGNIFICANCE: We have assessed that fasting and refeeding may provide a suitable experimental model to provide us insight into the role of calpains during fish muscle atrophy and how they respond to changes in nutrient supply.

  4. Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens.

    Science.gov (United States)

    Iwanowicz, Luke R; Stafford, James L; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W; Blazer, Vicki S

    2014-09-01

    Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines. Published by Elsevier Ltd.

  5. A study on Polonium-210 distribution in the Koraiyar river ecosystem, Tiruchirappalli - India

    International Nuclear Information System (INIS)

    Krishnamoorthy, R.; Syed Mohamed, H.E.; Raja, P.; Shahul Hameed, M.M.; Shahul Hameed, P.

    2004-01-01

    The present work reports the distribution of naturally occurring alpha emitting radionuclide 210 Po in the environmental matrices of Koraiyar river. Koraiyar is a seasonal river and it is situated 5 Km West of Tiruchirappalli. Environmental samples such as water, sediment, plankton, weeds (Eichhornia crassipes), crab (Barytelphusa jacguemonti), gastropods (Pila virens and Bellamya dissimilis) and fishes (Anabas testudineus, Catla catla, Clarias batrachus, Channa punctatus, Macrognathus acculeatus, Mystus vittatus and Oreochromis mossambicus) were collected and subjected to the analyses of 210 Po activity. The concentration of 210 Po in water sample and sediment sample was 0.75 mBq/l and 3.1 Bq/Kg respectively. The roots and shoots of aquatic weeds and plankton sample showed concentration of 3.4, 1.2 and 22.2 Bq/Kg respectively. The concentration of 210 Po in crab muscle and exoskeleton was 43.92 Bq/Kg and 11.34 Bq/Kg respectively. In soft tissue of gastropods the 210 Po activity ranged from 38.16 (B. dissimilis) to 88.74 Bq/Kg (P. virens) and 2.9 to 9.45 Bq/Kg in shell. The 210 Po activity in fishes ranged from 8.87 (Macrognathus acculeatus) to 45.29 (Clarias batrachus) Bq/Kg in muscle and 4.76 to 25.09 Bq/Kg in bone. Concentration factor of 210 Po in edible portion of fish from river water ranged from 1.3 x 10 3 to 6.0 x 10 4 . Among the samples analysed P. virens accumulated higher concentrations of 210 Po and it could serve as a bioindicator organism in the absence of any bivalve mollusc. (author)

  6. Formulation of Emergency Food in Biscuit-Form Made From Proso Millet Flour (Panicum miliaceum) and Snakehead Fish (Channa striata) -Tempeh Flour Koya

    Science.gov (United States)

    Anandito, R. B. K.; Kurniawan, S. R.; Nurhartadi, E.; Siswanti

    2018-02-01

    Indonesia is a natural disaster-prone country. Food availability appears as the post-disaster main problem. Emergency food is an effort to overcome it. An ideal emergency food is expected to have a complete nutritional composition. Fulfilling macronutrient needs, proso millet flour and snakehead fish-tempeh flour koya were being used in this research. The objective of this research was to determine the formulation of emergency food in biscuit form made from proso millet flour and snakehead fish-tempeh flour koya based on its sensory, chemical and physical properties. This research was using a completely randomized design with one factor affecting. The variations of proso millet flour and snakehead fish-tempeh flour koya composition were 100:0 ; 80:20 ; 60:40 ; and 40:60. All treatments were carried out sensory evaluation using hedonic test, proximate analysis, calories analysis using bomb calorimetry methods. and physical analysis using texture profile analyzer. The compensatory model was used to determine the best formula based on all parameters. The result indicated that the best biscuit formula had compositions of proso millet flour 80% and snakehead fish-tempeh flour koya 20%. It had a brownish color, not-strong-fishy aroma, a strong-enough bitter aftertaste and crunchy texture. Chemical analysis showed that its moisture, ash, protein, fat, carbohydrate and total calories content were 1,146%; 4,827%; 12,536%; 26,325%; 56,312% and 5,033 kcal/gram, respectively. The physical analysis shows that its hardness and fracturability values were 8,037 N and 2,403 N, respectively.

  7. Potential of Glutathione Antioxidant in the Hippocampus Repair: Preliminary Study on Bioactive Materials Antiaging of Snakehead Fish (Channa striata in Animal Models of Aging

    Directory of Open Access Journals (Sweden)

    Sunarno Sunarno

    2014-12-01

    Full Text Available Snakehead fish meat contains active ingredients with anti-aging potential that serves as a precursor of glutathione. The ability of glutathione as an antiaging opportunities in the utilization of fish meat, especially snakehead fish. Snakehead fish meat contains several important amino acids, such as glutamine, cysteine​​, and glycine so the potential to be developed for the production of food that is nutritious and healthy. This study examines the essential amino acid composition of the antioxidant glutathione precursors found in snakehead fish from Rawa Pening Central Java to increase glutathione in the body and brain. The results showed that every 100g of snakehead fish meat from Rawa Pening containing glutamine (32.39%, cysteine ​​(6.61%, and glycine (9.69%. Snakehead fish meat extract given at a dose of 30 ml/kg/day in both types of animal models of aging effect on the increase in the content of glutathione and glutathione precursors, both in blood and hippocampus. Increased glutathione precursor of the most high to low, respectively glutamine, glycine, and cysteine​​. Availability of essential amino acids can support increased glutathione in the brain. This is indicated by an increase in glutathione hippocampus in both animal models, both on chronological aging or aging due to oxidative stress, respectively (0.822 and 0.359 mol/g bb compared to control tissue.

  8. 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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Determination of niclosamide residues in rainbow trout (Oncorhynchus mykiss) and channel catfish (Ictalurus punctatus) fillet tissue by high-performance liquid chromatography

    Science.gov (United States)

    Schreier, Theresa M.; Dawson, V.K.; Cho, Yirang; Spanjers, N.J.; Boogaard, M.A.

    2000-01-01

    Bayluscide [the ethanolamine salt of niclosamide (NIC)] is a registered piscicide used in combination with 3-(trifluoromethyl)-4-nitrophenol (TFM) to control sea lamprey populations in streams tributary to the Great Lakes. A high-performance liquid chromatography (HPLC) method was developed for the determination of NIC residues in muscle fillet tissues of fish exposed to NIC and TFM during sea lamprey control treatments. NIC was extracted from fortified channel catfish and rainbow trout fillet tissue with a series of acetone extractions and cleaned up on C-18 solid-phase extraction cartridges. NIC concentrations were determined by HPLC with detection at 360 and 335 nm for rainbow trout and catfish, respectively. Recovery of NIC from rainbow trout (n = 7) fortified at 0.04 mu g/g was 77 +/- 6.5% and from channel catfish (n = 7) fortified at 0.02 mu g/g was 113 +/- 11%. NIC detection limit was 0.0107 mu g/g for rainbow trout and 0.0063 mu g/g for catfish. Percent recovery of incurred radioactive residues by this method from catfish exposed to [C-14]NIC was 89.3 +/- 4.1%. Percent recoveries of NIC from fortified storage stability tissue samples for rainbow trout (n = 3) analyzed at 5 and 7.5 month periods were 78 +/- 5.1 and 68 +/- 2.4%, respectively. Percent recoveries of NIC from fortified storage stability tissue samples for channel catfish (n = 3) analyzed at 5 and 7.5 month periods were 88 +/- 13 and 76 +/- 21%, respectively.

  9. The effect of temperature on the mucosal IgM antibody response to DNP-KLH in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Bath immersion remains a practical route for immunizing against disease in channel catfish; however research efforts in this area have revealed variable results when activating mucosal Ab responses with different antigens. This is likely due to a number of factors including the individual species, ...

  10. Interaction of xenobiotics with estrogen receptors α and β and a putative plasma sex hormone-binding globulin from channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Gale, William L.; Patino, Reynaldo; Maule, Alec G.

    2004-01-01

    Estrogens are important regulators of physiological functions. Although environmental contaminants (xenoestrogens) which interfere with estrogen signaling are of increasing concern, there is only limited information about their ability to interact with estrogen-binding proteins (SHBG) or receptors (ER). Recombinant ER?? and ?? were obtained after transient transfection of COS-7 cells with channel catfish ER cDNA. Plasma from adult female channel catfish was the source of SHBG. Tritiated estradiol ( 3H-E2) was used in standard radioligand-binding assays to characterize the binding properties of channel catfish SHBG (ccfSHBG) and to estimate the inhibition constants for various estrogenic compounds. Binding of 3H-E2 to ccfSHBG was saturable and of high affinity with a Kd (??SE) of 1.9??0.14nM and a Bmax of 14.3??2.4pmol/mg protein (n=3 assays). Additionally, ccfSHBG displayed binding specificity for androgens and estrogens. Endosulfan, 4-nonylphenol, and 4-octylphenol displaced 3H-E2 binding to ccfSHBG albeit only at very high concentrations, whereas dieldrin and atrazine showed little displacement activity even at the highest concentrations used. The synthetic estrogen ethynylestradiol had higher affinity than E2 for ccfSHBG. This finding differs from results with human and rainbow trout SHBG. The alkylphenolic compounds (4-octylphenol and 4-nonylphenol) displayed some ability to displace 3H-E2 binding from ER?? and ?? at high concentrations, but dieldrin and atrazine had little binding activity for both ER subtypes and endosulfan for ER??. The xenobiotics tested generally showed equivalent or greater affinity for ER?? than ER??, whereas natural estrogens had much greater affinity for ER?? than ER??. These observations suggest that results of studies using fish tissue ER extracts must be interpreted with caution, since both ER subtypes may be present, and that the binding of xenoestrogens to SHBG must be taken into account for proper assessment of endocrine disruption caused by environmental contaminants.

  11. Stable carbon isotope ratios as indicators of marine versus terrestrial inputs to the diets of wild and captive tuatara (Sphenodon punctatus)

    International Nuclear Information System (INIS)

    Cree, A.; Cartland-Shaw, L.; Tyrrell, C.; Lyon, G.L.

    1999-01-01

    Stable carbon isotope analysis was used to examine feeding relationships of wild tuatara on Stephens Island and captive tuatara in New Zealand institutions. We first measured delta 13 C in three food items of wild tuatara. Pectoral muscle of fairy prions (a seabird eaten seasonally by tuatara) was significantly enriched in 13 C compared with whole bodies of wild insects (darkling beetles and tree weta). Values for delta 13 C in blood cells varied significantly among wild tuatara of different life-history stages. Male tuatara were more enriched in 13 C than were females or juveniles, suggesting that males prey more heavily on seabirds. Insect foods of captive tuatara varied dramatically in delta/sup 13/C; this is attributed to differential consumption of plant material derived from the C 3 and C 4 photosynthetic pathways. Blood cells from four different groups of captive tuatara differed significantly in delta 13 C. This was perhaps related to assimilation of insects with different delta 13 C values, and cannot be attributed to differences in seabird predation as captive tuatara do not have access to seabirds. For wild tuatara on Stephens Island, stable carbon isotope analysis provides support for the dietary information available from behavioural observations, gut analyses and measurements of plasma composition. (author). 47 refs., 1 tab., 2 figs

  12. TRIBUTYLTIN (TBT) MODULATES 3,3'4,4',5-PENTACHLOROBIPHENYL (PCB-126)-INDUCED HEPATIC CYP1A ACTIVITY IN CHANNEL CATFISH, ICTALURUS PUNCTATUS. (R823881)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Enhancement effects of dietary wheat distiller's dried grains with solubles on growth, immunology, and resistance to Edwardsiella ictaluri challenge of channel catfish, Ictalurus punctatus

    Science.gov (United States)

    This study evaluated the effects of the inclusion of wheat distiller’s dried grains with solubles (WDDGS) at levels of 0 (control), 10, 20, 30 and 40% without (diets 2-5) and with (diets 6-9) lysine supplementation, as substitutes of soybean meal and corn meal mixture on growth, body composition, he...

  14. Effectiveness of copper sulfate, potassium permanganate, and peracetic acid to reduce mortality and infestation of Ichthyobodo nector in channel catfish Ictalurus punctatus (Rafinesque 1818)

    Science.gov (United States)

    Ichthyobodo necator is a single celled bi-flagellate parasite, and in high density can causes significant mortality in young fish. Copper sulfate (CuSO4), potassium permanganate (KMnO4) and peracetic acid (PAA) were evaluated for effectiveness against ichthyobodosis. Treatments were: untreated con...

  15. Effects of dietary sweet potato leaf meal on the growth, non-specific immune responses, total phenols and antioxidant capacity in channel catfish (Ictalurus punctatus).

    Science.gov (United States)

    Lochmann, Rebecca T; Islam, Shahidul; Phillips, Harold; Adam, Zelalem; Everette, Jace

    2013-04-01

    Traditional energy sources in catfish diets have become costly, and economical alternatives are needed. Sweet potato leaves are underutilised agricultural by-products that provide energy and substantial amounts of phenols, which affect animal and human health. There is little information on the effects of these compounds on catfish, or the capacity of catfish to accumulate dietary phenols. Catfish enriched with phenols have marketing potential as functional foods. This study investigated the effects of diets with sweet potato leaf meal (SPLM) on growth performance, health and total phenolic compounds in catfish. SPLM was substituted for wheat middlings in three diets fed to groups of juvenile catfish for 10 weeks. Weight gain, feed conversion, survival, alternative complement activity and lysozyme activity were similar among diets. Haematocrit was lower in fish fed diets with SPLM, but within the normal range. Total phenols and antioxidant capacity in the whole body were similar among treatments. SPLM was an effective energy source for catfish up to the maximum level tested (230 g kg(-1) diet). SPLM did not enhance total phenols in catfish, but there were no apparent antinutritional effects of the meal on catfish growth, health or survival. © 2012 Society of Chemical Industry.

  16. COMPARISON OF POND AND RACEWAY PRODUCTION METHODS ON TEXTURE OF CHANNEL CATFISH (Ictalurus punctatus) FILLETS, SHOWING A DEPENDENCY ON SIZE AND FILLET POSITION

    Science.gov (United States)

    The objective of this study was to compare the effect of the production environment (pond vs in-pond raceway) on the chemical composition, color, and textural properties of channel catfish fillets. Compositional analysis consisted of percent moisture, lipid, protein, and ash content. Additional sa...

  17. Estádios evolutivos de tripanossomas de Hipostomus punctatus Valenciennes (Osteichthyes, Loricariidae em infecção natural de Batracobdella gemmata Blanchard (Hirudinea, Glossiphoniidae Evolutive stages of tripanosomes of Hipostomus punctatus Valenciennes (Osteichthyes, Loricariidae in natural infection of Batracobdella gemmata Blanchard (Hirudinea, Glossiphoniidae

    Directory of Open Access Journals (Sweden)

    Marta D'Agosto

    1993-01-01

    Full Text Available Seventeen leeches obtained from armoured catfish (Hypostomus punclatus Valenciennes, 1840 infected with Trypanosoma spp. were examined. It was observed the presence of tripomastigotes, epimastigotes and amastigotes forms as well as dividing forms in the proboscis and in the stomach, different from the ones found in the vertebrate host as regards the morfometric features and developing forms. The examination of the contents of rectum did not show tripanosomes. These facts seem to demonstrate that Batracobdella gemmata (Blanchard, 1900 is an invertebrate host of trypanosomes and the transmission is done by means of inoculation.

  18. Applications of bioactive material from snakehead fish (Channa striata) for repairing of learning-memory capability and motoric activity: a case study of physiological aging and aging-caused oxidative stress in rats

    Science.gov (United States)

    Sunarno, Sunarno; Muflichatun Mardiati, Siti; Rahadian, Rully

    2018-05-01

    Physiological aging and aging due to oxidative stress are a major factor cause accelerated brain aging. Aging is characterized by a decrease of brain function of the hippocampus which is linked to the decline in the capability of learning-memory and motoric activity. The objective of this research is to obtain the important information about the mechanisms of brain antiaging associated with the improvement of hippocampus function, which includes aspects of learning-memory capability and motoric activity as well as mitochondrial ultrastructure profile of hippocampus cornu ammonis cells after treated by fish snakehead fish extract. Snakehead fish in Rawa Pening Semarang District allegedly holds the potential of endemic, which contains bioactive antiaging material that can prevent aging or improve the function of the hippocampus. This research has been conducted using a completely randomized design consisting of four treatments with five replications. The treatments were including rats with physiological aging or aging due to oxidative stress which was treated and without treated with meat extract of snakehead fish. The research was divided into two stages, i.e., determining of learning-memory capability, and determining motoric activity. The measured-parameters are time response to find feed, distance travel, time stereotypes, ambulatory time, and resting time. The result showed that the snakehead fish meat extract might improve function hippocampus, both in physiological aging or aging due to oxidative stress. The capability of learning and memory showed that the rats in both conditions of aging after getting treatment of meat extract of snakehead fish could get a feed in the fourth arm maze faster than rats untreated snakehead fish meat extract. Similarly, the measurement of the distance traveled, time stereotypes, ambulatory time, and resting time showed that rats which received treatment of meat extract of snakehead fish were better than the untreated rats. To conclude, the meat extract of snakehead fish can be used as antiaging material to improve the function of the hippocampus, to improve the capability of learning and memory, to improve motoric activity, and to prevent aging. These findings are expected to provide comprehensive information for the development of antiaging research as an effort to improve public health and to improve learning-memory capability and motoric activity.

  19. Study of HMG-CoA Reductase Inhibition Activity of the Hydrolyzed Product of Snakehead Fish (Channa striata) Skin Collagen with 50 kDa Collagenase from Bacillus licheniformis F11.4.

    Science.gov (United States)

    Virginia, Agnes; Rachmawati, Heni; Riani, Catur; Retnoningrum, Debbie S

    2016-01-01

    Bioactive peptides produced from enzymatic hydrolysis fibrous protein have been proven to have several biological activities. Previous study showed that the hydrolysis product of snakehead fish skin collagen with 26 kDa collagenase from Bacillus licheniformis F11.4 showed HMG-CoA (HMGR) inhibition activity. The aim of this research was to determine the ability of the hydrolysis product produced from snakehead fish skin collagen hydrolysed by 50 kDa collagenase from B. licheniformis F11.4 in inhibiting HMGR activity. Snakehead fish skin collagen was extracted using an acid method and collagenase was produced from B. licheniformis F11.4 using half-strength Luria Bertani (LB) medium containing 5% collagen. Crude collagenase was concentrated and fractionated using the DEAE Sephadex A-25 column eluted with increasing gradient concentrations of NaCl. Collagen, collagenase, and fractions were analyzed using SDS-PAGE and collagenolytic activity was analyzed by the zymography method. Collagenase with 50 kDa molecular weight presented in fraction one was used to hydrolyze the collagen. The reaction was done in 18 hours at 50°C. The hydrolysis product using 3.51 μg collagen and 9 ng collagenase showed 25.8% inhibition activity against pravastatin. This work shows for the first time that the hydrolysis product of snakehead fish skin collagen and 50 kDa collagenase from B. licheniformis F11.4 has potential as an anticholesterol agent.

  20. 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

  1. 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.

  2. 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.

  3. 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.)

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. gross morphological study of placenta in preeclampsia

    African Journals Online (AJOL)

    2017-06-12

    Jun 12, 2017 ... A cross-sectional study was carried out on preeclampsia mothers who gave birth at ... maternal and fetal surfaces (Ashfaq, Janjua, and. Channa, 2005). A term .... causing loss and fibrosis of parenchyma tissue. These changes ...

  5. 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

    Directory of Open Access Journals (Sweden)

    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.

  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

    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 ...

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

    Directory of Open Access Journals (Sweden)

    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.

  9. THE EFFECTS OF DIETARY EXPOSURES TO TRIBUTYLTIN (TBT) AND 3,3',4,4',5-PENTACHLORBIPHENYL (PCB-126) ON HEPATIC CYP1A AND IMMUNE FUNCTION IN CHANNEL CATFISH, ICTALURUS PUNCTATUS. (R823881)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  10. CIRCULATING LYSOZYME AND HEPATIC CYP1A ACTIVITIES DURING A CHRONIC DIETARY EXPOSURE TO TRIBUTYLTIN (TBT) AND 3,3 ',4,4 ',5-PENTACHLOROBIPHENYL (PCB-126) MIXTURES IN CHANNEL CATFISH, ICTALURUS PUNCTATUS. (R823881)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  11. The effect of pesticides on fish fauna of Bhopal lower lake (M. P.)

    African Journals Online (AJOL)

    kishor

    Significant histological alteration in gill. 2. Labeo rohita. Chlorophyrifos. Biochemical changes of total protein and glycogen observed. 3. Puntius punctatus. Endosulfan and. Diazinon. Affect of arginine and tryptophane showing the interaction of pesticides with cellular proteins depletion. 4. Puntius punctatus. Endosulfan and.

  12. osmoregulation by means of a hitherto unsuspected osmoregulatory ...

    African Journals Online (AJOL)

    and may be concerned with the maintenance of a constant haemolymph osmotic pressure in the antero-lateral regions of the haemocoel, but tpis requires more critical study. There is considerable difference between the abilities of C. punctatus and· P. chabrus to tolerate hypotonic external media. C. punctatus can survive ...

  13. 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.

  14. 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.

  15. 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

  16. 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...

  17. the functional morphology of the fore-gut of three species of ...

    African Journals Online (AJOL)

    and related forms, however, is considerable, but no attempt has been made to review it. ... the crab C. punctatus is a general scavenger which eats large pieces of food, ... A morphological and functional description of a generalised decapod ...

  18. A new species of the Heteromerous genus Leiochrinus, Westwood

    NARCIS (Netherlands)

    Neervoort van de Poll, J.R.H.

    1886-01-01

    Nitidus; capite prothoraceque rufo, prothorace in medio vitta lata nigra ornato; antennis nigris; scutello parvo, triangularis nigro; elytris violaceis; subtus niger, prosterno rufo pedibusque brunneis; supra omnino densissime sed delicatissime punctatus. Tarsi articulo penultimo simplici,

  19. Toxicity of peracetic acid to fish: Variation among species and impact of water chemistry

    DEFF Research Database (Denmark)

    Straus, David L.; Meinelt, Thomas; Liu, Dibo

    2017-01-01

    , Ictalurus punctatus; golden shiner, Notemigonus crysoleucas; goldfish, Carassius auratus; grass carp, Ctenopharyngodon idella; largemouth bass, Micropterus salmoides; rainbow trout, Oncorhynchus mykiss; sunshine bass, Morone chrysops × M. saxatilis; and walleye, Sander vitreus. Median lethal concentration...

  20. Heavy metals concentration in various tissues of two freshwater ...

    African Journals Online (AJOL)

    Heavy metals like cadmium, zinc, copper, chromium, lead and mercury were measured in the various tissues of Labeo rohita and Channa striatus and in the water samples collected from ... The values of heavy metals concentration in the present study are within the maximum permissible levels for drinking water and fish.

  1. Abundances and Habitat Sensitivities of Some River Fishes in ...

    African Journals Online (AJOL)

    Freshwater fishes from a diverse array of 11 families, some dominated by marine species and others containing only a few species, were collected by electrofishing from 84 locations on small rivers in central Thailand and their abundances related to habitat characteristics. Abundances were largest for Channa gachua, ...

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. 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...

  8. 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

  9. 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 ...

  10. Endosulfan residues in fish from the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Nashriyah Mat; Sabri Junoh; Nuriati Nurdin

    2002-01-01

    A study was carried out in the recycled and the non-recycled areas of the Muda rice agroecosystem to determine the residue level of endosulfan in rice field fish. Snakehead or haruan (Channa striata), climbing perch or puyu (Anabas testudineus), walking catfish or keli (Clariasspp.) and snakeskin gouramy or sepat siam (Trichogasterpectoralis) were sampled and the tissues analysed using Gas Liquid Chromatography. Endosulfan sulphate metabolite was a ubiquitous residue in all fish at levels ranging from 0.0065 μg/g to 0.9837 μg/g of tissue wet weight whilst α-isomer was detected at a much lower concentration followed by β-isomer. In Channa striata, endosulfan total residue (α+β+sulphate) was accumulated in fish tissues sampled at ACRBD4 (non-recycled) site followed by Blok 14 (recycled) site. Endosulfan residue concentration did not coincide with water recycling practice nor changes in EROD enzyme activity. (Author)

  11. PROPORSI BAGIAN TUBUH DAN KADAR PROKSIMAT IKAN GABUS PADA BERBAGAI UKURAN

    OpenAIRE

    Ruddy - Suwandi; - - nurjanah; margaretha - winem

    2014-01-01

    Ikan gabus (Channa striata) merupakan jenis ikan air tawar yang sudah banyak dikenal oleh masyarakat Indonesia. Ikan gabus hidup di muara sungai, danau, rawa, dan dapat pula hidup di air kotor dengan kadar oksigen rendah. Ikan gabus belum banyak dibudidayakan secara luas dan belum banyak dimanfaatkan sebagai produk olahan ikan. Informasi mengenai proporsi tubuh ikan gabus masih kurang dan belum banyak dikaji. Penelitian ini bertujuan untuk menentukan proporsi bagian-bagian tubuh ikan dan komp...

  12. Molecular tracing of white muscardine in the silkworm, Bombyx mori (Linn.) II. Silkworm white muscardine is not caused by artificial release or natural epizootic of Beauveria bassiana in China.

    Science.gov (United States)

    Chen, Xue; Huang, Cui; He, Lingmin; Zhang, Shengli; Li, Zengzhi

    2015-02-01

    The fungal pathogen Beauveria bassiana causes serious economic losses in sericulture. Its origin is usually attributed to the release of B. bassiana insecticides against pine caterpillars (Dendrolimus punctuatus). In the present study, 488 B. bassiana isolates obtained from silkworm (Bombyx mori) collected from 13 Chinese provinces, and 327 B. bassiana isolates obtained from D. punctatus collected from 9 provinces, were analyzed for population genetic structure using the ISSR technique based on genetic distance. A UPGMA dendrogram clustered them into three independent clades: two B. mori clades and one D. punctatus clade. A 3-D principal component analysis further divided them into two completely independent host groups, revealing high host-specificity. This suggested that white muscardine occurring in B. mori populations throughout southern China was not caused by any B. bassiana strain either naturally prevailing in D. punctatus populations or by any strain artificially released as a fungal insecticide against D. punctatus. We further investigated the genetic differentiation coefficient Gst and gene flow between B. mori-pathogenic and D. punctatus-pathogenic B. bassiana isolates from across China and from five provinces inhabited by both B. mori and D. punctatus. The Gst value across China was computed as 0.410, while the values of the five provinces ranged from 0.508 to 0.689; all above 0.25, which is the threshold for significant genetic differentiation. This suggests that B. bassiana strains isolated from the two different hosts maintained their respective heredity without a convergent homogenization trend, and reduces the possibility that the host range of the caterpillar isolates could expand and enhance their virulence in B. mori. These findings indicate that the use of B. bassiana does not threaten the safety of sericulture. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Diadophis Puntatus Puntatus (Southern Ring-neck Snake) Predation

    Science.gov (United States)

    Gotte, Steve W.

    2016-01-01

    DIADOPHIS PUNCTATUS PUNCTATUS (Southern Ring-necked Snake). PREDATION. Here I present the first record of Buteo lineatus (Red-shouldered Hawk) predator on a Diadophis p. punctatus. At ca. 1100h on l2 February2 013,I observed a B. lineatus eating a katydid in Corkscrew Swamp Sanctuary (26.2730'N, 81.6079"W;WGS 84), Collier Co., Florida, USA. The hawk was in a Pond Cypress tree on the edge of a small prairie bordered on one side by a cypress swamp and by pine woodland on the other. Immediately upon consuming the katydid, the hawk flew to the ground ca. 1.5 m from an elevated boardwalk to grab an adult D. punctatus. It then flew with the snake in its talons to a branch 3 m high ca. l0 m from the boardwalk. The hawk stretched and otherwise manipulated the struggling snake (Fig.1) before consuming the still moving snake. Although snakes are a well-known component of B. lineatus diet (Clark1 987A. Field Guide to the Hawks of North America. Houghton Mifflin Co. Boston, Massachusetts 198 pp.), I found only one literature reference to Red-shouldered Hawks eating Ring-neck Snakes (Fisher 1893.Hawks and Owls of the United States in their Relation to Agriculture. U.S. Dept. Agric., Div Ornith. Mamm. Bull. 3). That specimen was from Canton, New York (taken 26 Oct IBBB) and would be a D. p. edwardisii (Northern Ring-necked Snake), while the snake reported on here is a Diadophis p. punctatus (USNM Herp Image 2847a -c). Based on evidence presented by Fontanella et al. (2008. Mol. Phylogenet Evol.46:1049-1070), D. p. edwardisii and D. p. punctatus are likely different species.

  14. 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.

  15. 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

  16. Records of the endemic and threatened catfish, Hemibagrus punctuates from the southern Western Ghats with notes on its distribution, ecology and conservation status

    Directory of Open Access Journals (Sweden)

    A. Ali

    2013-07-01

    Full Text Available The Nilgiri Mystus, Hemibagrus punctatus, a rare bagrid catfish endemic to the Western Ghats, has been currently listed in the IUCN Red List, as Critically Endangered with a possibility that it could be extinct. The last validated record of H. punctatus was known to be in 1998, and several surveys since then have not been able to collect the species from its native range. In this paper, we provide information on new records of this rare catfish from the Western Ghats after a period of 14 years, and discuss its distribution, ecology and conservation. An updated conservation assessment of this species following the IUCN Red List Criteria is also provided.

  17. 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.

  18. African Zoology - Vol 19, No 4 (1984)

    African Journals Online (AJOL)

    Fish community structures in Zostera and non-Zostera regions of the Kromme estuary, St Francis Bay · EMAIL ... Distribution of the portunid crab Ovalipes punctatus (De Haan) in Algoa Bay and salinity and temperature tolerances of its zoeae ...

  19. Potential roles of fish, birds, and water in swamp privet (Forestiera acuminata) seed dispersal

    Science.gov (United States)

    Susan B. Adams; Paul B. Hamel; Kristina Connor; Bryce Burke; Emile S. Gardiner; David Wise

    2007-01-01

    Forestiera acuminata (swamp privet) is a common wetland shrub/small tree native to the southeastern United States. We examined several possible dispersal avenues for the plant. We tested germination of seeds exposed to various treatments, including passage through Ictalurus punctatus (Channel Catfi sh) guts, and conducted other...

  20. Effects of Ichthyophthirius multifiliis parasitism on the survival, hematology and bacterial load in channel catfish previously exposed to Edwardsiella ictaluri

    Science.gov (United States)

    The effect of Ichthyophthirius multifiliis (Ich) parasitism on survival, hematology and bacterial load in channel catfish, Ictalurus punctatus, previously exposed to Edwardsiella ictaluri was studied. Fish were exposed to E. ictaluri one day prior to Ich in the following treatments: 1)- infected by...

  1. The effect of temperature and salinity on oxygen consumption in the ...

    African Journals Online (AJOL)

    The aquatic oxygen consumption of the estuarine brachyuran crab, Cyclograpsus punctatus, was investigated after a 24-hour acclimation period at different temperature (12.5, 20, 30°C) and salinity (9, 17.5, 35, and 44‰) combinations . Salinity had no significant effect on oxygen consumption at 12.5 and 20°C in both large ...

  2. Destiny-yield relationship for channel catfish reared in a biofloc technology production system

    Science.gov (United States)

    The effect of stocking density on yield of stocker channel catfish and water quality in a biofloc technology production system was studied in this completely randomized design experiment. Fingerling channel catfish (Ictalurus punctatus; 48.0 g/fish, 17.8 cm/fish) were stocked into nine continuously ...

  3. Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa

    NARCIS (Netherlands)

    Vergoossen, JMJ

    1999-01-01

    Fish microfossils were extracted from an erratic. The taxa from the rich microvertebrate fauna of late Pridolian (latest Silurian) age ( P. punctatus Zone) are listed. A full description is given of two new Gomphonchus taxa, G. mediocostatus and G. boekschoteni. On the basis of old and new material,

  4. Treating a natural outbreak of columnaris in channel catfish with copper sulfate and potassium permanganate

    Science.gov (United States)

    An F. Columnare-exclusive epizootic occurred in fingerling channel catfish (Ictalurus punctatus) during normal tank culture practices at SNARC. Fish were transferred to the ultra low-flow system and 2.1 mg/L copper sulfate or 3 mg/L potassium permanganate was administered; an untreated control was ...

  5. Comparative effects of copper sulfate or potassium permanganate on channel catfish concurrently infected with Flavobacterium columnare and Ichthyobodo necator

    Science.gov (United States)

    An opportunistic study was conducted to determine the effects of two chemical therapeutants on channel catfish (CCF) Ictalurus punctatus concurrently infected Flavobacterium columnare and Ichthyobodo necator. Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were investigated for their abil...

  6. Effectiveness of copper sulfate and potassium permanganate on channel catfish infected with Flavobacterium columnare

    Science.gov (United States)

    Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were evaluated for their effectiveness to curtail mortality and decrease bacterial load in fish tissues and water in channel catfish Ictalurus punctatus naturally infected with Flavobacterium columnare, the causative agent of columnaris. Fis...

  7. Potassium permanganate is not an effective pond disinfectant to control Dero digitata

    Science.gov (United States)

    Proliferative gill disease (PGD) is a major problem in cultured channel catfish, Ictalurus punctatus. This parasite requires Dero digitata to complete its life cycle. It is believed potassium permanganate disinfects ponds and reduces D. digitata populations, but this practice has not been verified...

  8. Impact of Copper Sulfate on Plankton in Channel Catfish Nursery Ponds

    Science.gov (United States)

    Many fish culturists are interested in applying copper sulfate pentahydrate (CSP) to channel catfish, Ictalurus punctatus, nursery ponds as a prophylactic treatment for trematode infection and proliferative gill disease by killing snails and Dero sp., respectively, before stocking fry. However, copp...

  9. Food habits of Bald Eagles breeding in the Arizona desert

    Science.gov (United States)

    Teryl G. Grubb

    1995-01-01

    Of 1814 foraging attempts, prey captures, or nest deliveries by Bald Eagles (Haliaeetus leucocephalus) in 14 Arizona breeding areas during 1983-1985, 1471 observations were identifiable to at least class: fish (76%), mammal (18%), bird (4%), and reptile/amphibian (2%). Forty-five species were recorded: catfish (Ictalurus punctatus, Pylodictis olivaris), suckers (...

  10. Can reduced stocking rates and natural forage utilization produce market sized catfish from fingerlings in one growing season

    Science.gov (United States)

    The purpose of this study was to determine the feasibility of growing marketable channel catfish Ictalurus punctatus from pond-run fingerlings (15.9 g/fish) using low stocking densities (7,413 or 14,826 fish/ha) and electrified bug lights to enhance natural forage available to fish. Even at low sto...

  11. Utilization of the termite Hodotermes mossambicus (Hagen) by ...

    African Journals Online (AJOL)

    Five species of primarily nocturnal geckos (Ptenopus garrulus maculatus, Chondrodactylus angulifer angulifer, Pachydactylus bibronii, P. mariquensis latirosths and P. punctatus) collected near Keetmanshoop, South West Africa on the night of 3 October 1987 were found to contain large numbers of the harvester termite ...

  12. Dietary copper effects survival of channel catfish challenged with Flavobacterium columnare

    Science.gov (United States)

    Columnaris disease is one of the most important bacterial diseases of channel catfish, Ictalurus punctatus, commercially grown in the US. Copper sulfate (CuSO4) has also been shown to be both therapeutic and prophylactic as a water treatment for columnaris disease. As copper is an essential dietar...

  13. Review of the South American characiform fish genus Chilodus, with description of a new species, C. gracilis (Pisces, Characiformes, Chilodontidae)

    NARCIS (Netherlands)

    Isbrücker, I.J.H.; Nijssen, H.

    1988-01-01

    Examination of 291 specimens of Chilodus, a genus of South American fresh water fishes, yielded the presence of three species, viz.: C. punctatus, C. zunevei, and C. gracilis. Of the first species the lectotype is designated. The type material of C. zunevei is lost; new material enabled a

  14. Effect of stocking biomass on solids, phytoplankton communities, common off-flavors, and production parameters in a channel catfish biofloc technology production system

    Science.gov (United States)

    The effect of initial channel catfish (Ictalurus punctatus, Rafinesque, 1818) fingerling biomass (1.4, 1.8, or 2.3 kg m-3) on phytoplankton communities, common off-flavors, and stocker catfish production parameters was evaluated in biofloc technology production tanks. Stocker catfish size (145.5 – 1...

  15. Efficacy of Sodium Carbonate Peroxyhydrate as A Catfish Egg Disinfectant and Comparison to Hydrogen Peroxide

    Science.gov (United States)

    Two experiments were conducted to evaluate the efficacy of sodium carbonate peroxyhydrate (SCP) for improving channel catfish Ictalurus punctatus hatching success when used as a prophylactic chemotherapeutant during egg incubation. In the first experiment, efficacy of SCP was evaluated in 379-L, al...

  16. 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...

  17. 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).

  18. 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.

  19. 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...

  20. 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...