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Sample records for channa punctatus bloch

  1. Cadmium induced histopathology in the olfactory epithelium of a snakehead fish, Channa punctatus (Bloch

    Directory of Open Access Journals (Sweden)

    Debraj Roy

    2013-10-01

    Full Text Available Histopathology on the olfactory organ of a snakehead fish, Channa punctatus (Bloch, 1793 were assessed after exposing the fish to 2.5 mg/L and 5mg/L of CdCl2 for 15 days, 30 days and 45 days. Cellular organization of the epithelium was affected severely with degeneration of sensory and supporting cells and hyperplasia of basal cells and mucous cells. Mucous cell proliferation indicates the upregulation of mucous secretion to protect the epithelium from toxic effect of cadmium. The olfactory epithelium was endowed with the multipotent basal cells which differentiate into sensory cells, supporting cells and other cell types of the epithelium during normal cells turn over and in the event of cell death.  However, due to cadmium exposure proliferating basal cells failed to differentiate into normal cells and the undifferentiated proliferated cell formed lump and intraepithelial lesion altering the composition of the entire epithelium. Present study indicates that in prolonged exposure to cadmium chloride olfactory functions of the fish might be impaired due to loss of all sensory cells.

  2. Impact of Triazophos on Ionic Regulation in the Blood of Freshwater Fish, Channa punctatus (Bloch)

    OpenAIRE

    Abdul Naveed; P. Venkateshwarlu; C. Janaiah

    2011-01-01

    The blood of fresh water, edible fish, Channa punctatus (=murrel) was exposed to sub lethal concentration of triazophos for 24, 48, 72 and 96 h to evaluate alterations in the levels of minerals i.e., sodium, potassium, chloride, calcium, inorganic phosphate, magnesium and iron. The increased chloride mineral along with sodium and potassium play an important role in neuromuscular excitability, acid-base balance and increased osmotic pressure of the fish. The decreased calcium is of great impor...

  3. Impact of Triazophos on Ionic Regulation in the Blood of Freshwater Fish, Channa punctatus (Bloch

    Directory of Open Access Journals (Sweden)

    Abdul Naveed

    2011-08-01

    Full Text Available The blood of fresh water, edible fish, Channa punctatus (=murrel was exposed to sub lethal concentration of triazophos for 24, 48, 72 and 96 h to evaluate alterations in the levels of minerals i.e., sodium, potassium, chloride, calcium, inorganic phosphate, magnesium and iron. The increased chloride mineral along with sodium and potassium play an important role in neuromuscular excitability, acid-base balance and increased osmotic pressure of the fish. The decreased calcium is of great importance in blood coagulation, muscle contraction and nerve transmission while decreased iron is an essential constituent of heame in hemoglobin of the fish. The increased magnesium participates in principal metabolic activities, in formation of bones and teeth. Inorganic phosphate acts as a major buffer and is the basis of energy exchange. Triazophos altered the activities of the macro minerals in C. punctatus during stress periods.

  4. Devicyprin induced gonadal impairment in a freshwater food fish, Channa punctatus (Bloch).

    Science.gov (United States)

    Srivastava, Rajesh K; Yadav, Kamlesh K; Trivedi, Sunil P

    2008-03-01

    Synthetic pyrethroids are the recent major class of broad spectrum, photostable, organic insecticides used in agricultural, domestic and veterinary applications and now account for more than 30% of global insecticide use. Cypermethrin is metabolized and eliminated significantly more slowly by fish than by mammals or birds, which may explain this compound's high toxicity in fish compared to other organisms. The present communication deals with histoanatomical alterations in the gonads of a local fresh water food fish, Channa punctatus exposed to 0.033 ppm (96 hr LC50 X 1/10) concentration of a synthetic pyrethroid, devicyprin (cypermethrin 25%) in aquatic medium of aged tap water for 15, 30 and 45 days respectively. In testis, exposure dependent histological damage has been observed in terms of vacuolization, condensation of spermatogonic cells, distortion of tubular epithelium, shrinkage of interstitial cells and general inflammatory responses. Longest exposure of 45 days has resulted in peculiar starry-sky appearance of the testicular tissue. Gross histo-anatomy of ovarian tissue reveals epithelial lesions, inflammatory responses, stromal hemorrhage, increased interstitium and shrinkage of yolk vesicles towards periphery These findings are quite suggestive of reproductive impairments leading to delayed gonadal maturity and adversely affecting processes of sperm production and ovulation and thus, the fish production. PMID:18831372

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

    Science.gov (United States)

    Mishra, Ashish K; Mohanty, Banalata

    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.

  6. 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.

  7. Arsenic-induced histopathology and synthesis of stress proteins in liver and kidney of Channa punctatus.

    Science.gov (United States)

    Roy, Sonali; Bhattacharya, Shelley

    2006-10-01

    As3+, considered effective for aquatic weed control, has been found to be harmful to several species of freshwater teleosts. Channa punctatus (Bloch) exposed for 14 days to nonlethal concentrations (1/20 LC50 and 1/10 LC50) of As2O3 were sampled on days 0, 1, 2, 7, and 14. Tissue disorientation, peliosis, and vacuolization accompanied by karyolysis, apoptosis, and necrosis of hepatocytes were significant on days 1, 2, and 7. In the kidney shrinkage of the glomerulus and increase in the Bowman's space were observed on days 1, 2, and 7. Irregularities in the renal tubule including apoptotic and necrotic cells were also common. Decreased intertubular space and enlargement of the height of the brush border cells were noteworthy. Corresponding with the histopathological lesions, dose-dependent disturbances in liver and renal functions and induction of heat shock protein 70 were significant at the early phase of arsenic treatment while metallothionein was induced at a later phase of treatment.

  8. Nitric oxide inhibited the melanophore aggregation induced by extracellular calcium concentration in snakehead fish, Channa punctatus.

    Science.gov (United States)

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

    2011-12-01

    We studied the role of nitric oxide (NO) and extra-cellular Ca(2+) on the melanophores in Indian snakehead teleost, Channa punctatus. Increase of Ca(2+) level in the external medium causes pigment aggregation in melanophores. This pigment-aggregating effect was found to be inhibited when the external medium contained spontaneous NO donor, sodium nitro prusside (SNP) at all the levels of concentration tested. Furthermore, it has been observed that SNP keeps the pigment in dispersed state even after increasing the amount of Ca(2+). In order to test whether NO donor SNP causes dispersion of pigments or not is checked by adding the inhibitor of nitric oxide synthase, N-omega-Nitro-L-arginine (L-NNA) in the medium. It has been noted that the inhibitor L-NNA blocked the effect of NO donor SNP causing aggregation of pigments. In that way NO is inhibiting the effect of extracellular Ca(2+), keeping the pigment dispersed.

  9. Chromosome breakages associated with 45S ribosomal DNA sequences in spotted snakehead fish Channa punctatus.

    Science.gov (United States)

    Singh, Mamta; Barman, Anindya Sundar

    2013-01-01

    It is well known that transcriptionally inactive rRNA genes are correlated with DNA hyper-methylation and histone hypo-methylation and there is clear evidence in humans that DNA and histone modification which alter chromatin structure are related to chromosome fragility. Very little is known about the biological cause of 45S rDNA fragility. In this report we characterized the chromosome breakage or gap associated with 45S rDNA in a fish species Channa punctatus. The rDNA mapping in C. punctatus, showed many chromosome breakages or gap formations, and all occurred exclusively in the 45S rDNA sites in anterior kidney cells. We observed that the number of chromosomes plus chromosome fragments was often more than the expected 32 in most cells. Total 67 % metaphase spread showed the expected or normal 32 chromosomes, while 33 % metaphase spread showed 33 and/or 34 chromosomes and/or chromosome fragments. The chromosome lesions observed in this study are very similar cytologically to that of fragile sites observed in human chromosomes. Possible causes for the spontaneous expression of fragile sites and their potential biological significance are also discussed in present report.

  10. Lead toxicity on non-specific immune mechanisms of freshwater fish Channa punctatus.

    Science.gov (United States)

    Paul, Nilantika; Chakraborty, Samujjwal; Sengupta, Mahuya

    2014-07-01

    Lead has no known role in the body that is physiologically relevant, and its harmful effects are myriad. Lead from the atmosphere and soil ends up in water bodies thus affecting the aquatic organisms. This situation has thus prompted numerous investigations on the effects of this metal on the biological functions of aquatic organisms, particularly on immune mechanisms in fish. This paper addresses the immunotoxicologic effects of lead acetate in intestinal macrophages of freshwater fish Channa punctatus. Fish were exposed to lead acetate (9.43mg/l) for 4 days. When checked for its effects on macrophages, it was noted that lead interfered with bacterial phagocytosis, intracellular killing capacity and cell adhesion as well as inhibited release of antimicrobial substances like nitric oxide (NO) and myeloperoxidase (MPO). On giving bacterial challenge with Staphylococcus aureus to intestinal macrophages of both control and lead treated groups, the macrophages showed significantly higher concentration of viable bacteria in the intracellular milieu in lead treated group as compared to control. We also report that in vivo exposure to lead acetate inhibits phagocytosis, which is evident from a reduced phagocytic index of treated group from that of the control. The amount of MPO and NO released by the control cells was also reduced significantly upon in vivo lead treatment. The property of antigenic adherence to the macrophage cell membrane, a vital process in phagocytosis, was significantly decreased in the treated group as compared to control. Severe damage in intestinal epithelium, disarrangement and fragmentation of mucosal foldings was observed in lead treated group when compared with the untreated group. The present results also showed decreased tumor necrosis factor-alpha (TNF-α) level upon metal exposure in sera as well as cell lysate of lead exposed fish thus, implicating both MAPK signaling pathways as well as NFκβ signaling. We thus conclude that lead affects

  11. Toxicity studies of butachlor to the freshwater fish Channa punctata (Bloch).

    Science.gov (United States)

    Tilak, K S; Veeraiah, K; Bhaskara Thathaji, P; Butchiram, M S

    2007-04-01

    The toxicity studies were conducted on the fish Channa punctata (Bloch) by employing static and continuous flow through systems, for the toxicant butachlor (technical grade+) and its commercial formulation+ (machete 50% EC). The LC50 values are 297.89 ppb and 247.46 ppb for 24 hr and 48 hr in static for technical and 636.45 and 546.09 for machete. In continuous flow through the values are 270.05, 233.52 to the technical and 567.85 and 481.49 respectively for machete. The tissues show qualitative accumulation and were quantitatively analysed by gas liquid chromatography (GLC).

  12. Induction of micronuclei and nuclear lesions in Channa punctatus following exposure to carbosulfan, glyphosate and atrazine.

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    Nwani, Christopher Didigwu; Nagpure, Naresh Sahebrao; Kumar, Ravindra; Kushwaha, Basdeo; Kumar, Pavan; Lakra, Wazir Singh

    2014-10-01

    The genotoxic effects of commonly used agricultural pesticides viz., carbosulfan, glyphosate, and atrazine, were evaluated in Channa punctatus (Pisces, Perciformes) using micronucleus (MN) test and induction of nuclear lesions (NL). The 96 h LC50 value were estimated by probit analysis as 0.27, 32.0 and 42.0 mg L(-1), respectively, for carbosulfan, glyphosate, and atrazine using semi-static bioassays. Based on these values, three sublethal test concentrations of carbosulfan (0.07, 0.13, 0.20 mg L(-1)), glyphosate (8.1, 16.3, 24.4 mg L(-1)) and atrazine (10.6, 21.2, 31.8 mg L(-1)) corresponding to ¼, ½ and ¾ of the LC50 of the pesticides respectively, were selected for exposure for 96 h. Peripheral blood samplings were taken at intervals of 24 h for assessment of MN and NL frequencies. Considerably higher genotoxic damage was induced by carbosulfan as compared to glyphosate and atrazine. There were significant effects (p < 0.01) of concentrations in all the treated groups. The induction of MN and NL was highest at 96 h pesticide exposure at all test concentrations. The nuclear abnormalities recorded in this study, such as blebbed-, lobed-, notched- and bi-nuclei, other than micronuclei, are indicators of genotoxic damage.

  13. Effect of cadmium and chromium on the intestinal absorption of glucose in the snakehead fish, Channa punctatus.

    Science.gov (United States)

    Sastry, K V; Sunita, K

    1982-02-01

    The effect of five concentrations of cadmium and chromium (10 mM, 1 mM, 0.1 mM, 0.01 mM and 0.001 mM) on the rate of absorption of glucose from the intestine of te snakehead fish, channa punctatus, was studied at 23 degrees C. All concentrations of cadmium decreased the rate of glucose transport. Maximum decrease was recorded with 10 mM of cadmium. The rate of transport decreased with an increase in the concentration of cadmium used. Chromium increased glucose absorption rate at all concentrations examined; the highest rate of absorption occurred at 0.001 mM of chromium.

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

    Science.gov (United States)

    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.

  15. Studies on biomarkers of oxidative stress and associated genotoxicity and histopathology in Channa punctatus from heavy metal polluted canal.

    Science.gov (United States)

    Javed, Mehjbeen; Ahmad, Irshad; Usmani, Nazura; Ahmad, Masood

    2016-05-01

    Some investigations were made on the Satha canal water and health of dwelling fish Channa punctatus at Satha village, district Aligarh (U.P). Metal bioaccumulation and induction of biomarkers such as lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST), reduced glutathione (GSH), DNA damage and histopathology are potential indicators of stress in C. punctatus exposed to effluents. In canal water Cr, Mn, Fe and Ni concentrations were exceeding the permissible limits set by both Bureau of Indian standards (BIS) and WHO. Fe (74%) was highly bioavailable and accumulated in all organs (gill, liver, kidney, muscle and integument). The highest metal pollution index (MPI) value of 53 was observed in gills and the lowest 6 in liver tissue. SOD and LPO were significantly higher in all tissues, whereas CAT, GST and GSH levels declined significantly compared to fish from the reference site. Concomitant damage to DNA was observed with significantly higher mean tail length in the exposed fish gill cells (19 μm) and in liver (12.7 μm) compared to reference fish (5 and 4 μm respectively). Histopathology in gill and liver also show significant damage. Therefore, it can be concluded that the sugar mill effluent has the potential to cause oxidative stress, DNA damage and histopathology in C. punctatus. This canal is a prime source of water and fish food to the local residents of the area. Therefore, the consumers may suffer adverse health effects like that in indicator organism. PMID:26943742

  16. Studies on biomarkers of oxidative stress and associated genotoxicity and histopathology in Channa punctatus from heavy metal polluted canal.

    Science.gov (United States)

    Javed, Mehjbeen; Ahmad, Irshad; Usmani, Nazura; Ahmad, Masood

    2016-05-01

    Some investigations were made on the Satha canal water and health of dwelling fish Channa punctatus at Satha village, district Aligarh (U.P). Metal bioaccumulation and induction of biomarkers such as lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST), reduced glutathione (GSH), DNA damage and histopathology are potential indicators of stress in C. punctatus exposed to effluents. In canal water Cr, Mn, Fe and Ni concentrations were exceeding the permissible limits set by both Bureau of Indian standards (BIS) and WHO. Fe (74%) was highly bioavailable and accumulated in all organs (gill, liver, kidney, muscle and integument). The highest metal pollution index (MPI) value of 53 was observed in gills and the lowest 6 in liver tissue. SOD and LPO were significantly higher in all tissues, whereas CAT, GST and GSH levels declined significantly compared to fish from the reference site. Concomitant damage to DNA was observed with significantly higher mean tail length in the exposed fish gill cells (19 μm) and in liver (12.7 μm) compared to reference fish (5 and 4 μm respectively). Histopathology in gill and liver also show significant damage. Therefore, it can be concluded that the sugar mill effluent has the potential to cause oxidative stress, DNA damage and histopathology in C. punctatus. This canal is a prime source of water and fish food to the local residents of the area. Therefore, the consumers may suffer adverse health effects like that in indicator organism.

  17. Gastroprotective Effect of Freeze Dried Stripped Snakehead Fish (Channa striata Bloch.) Aqueous Extract against Aspirin Induced Ulcerogenesis in Pylorus Ligated Rats

    OpenAIRE

    Mohammed Safwan Ali Khan; Abdul Manan Mat Jais; Javeed Hussain; Faiza Siddiqua; Gopala Reddy, A.; P. Shivakumar; Madhuri, D.

    2014-01-01

    Channa striata (Bloch.) is a fresh water fish belonging to the family Channidae. The stripped snakehead fish possesses wide range of medicinal properties. In view of traditional use of C. striata for wound healing, the present study was undertaken to investigate the beneficial effects of orally administered freeze dried aqueous extract of Channa striata (AECS) in experimentally induced gastric ulcers in Wistar rats. Aspirin induced ulcerogenesis in pyloric ligation model was used for the asse...

  18. Studies on the alterations in haematological indices, micronuclei induction and pathological marker enzyme activities in Channa punctatus (spotted snakehead) perciformes, channidae exposed to thermal power plant effluent

    OpenAIRE

    Javed, Mehjbeen; Ahmad, Irshad; Ahmad, Ajaz; Usmani, Nazura; Ahmad, Masood

    2016-01-01

    The present study was conducted to assess the toxicity of thermal power plant effluent containing heavy metals (Fe > Cu > Zn > Mn > Ni > Co > Cr) on haematological indices, micronuclei, lobed nuclei and activity of pathological marker enzymes [alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) and creatine kinase (CK)] in Channa punctatus. Total erythrocyte count (−54.52 %), hemoglobin (−36.98 %), packed cell volume (−36.25 %), mean corpuscular hemoglobin conce...

  19. 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)

    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 [14C]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

  20. Incidence and histopathology of encysted progenetic metacercaria of Clinostomum complanatum (Digenea:Clinostomidae) in Channa punctatus and its development in experimental host

    Institute of Scientific and Technical Information of China (English)

    PA Ahammed Shareef; SMA Abidi

    2012-01-01

    Objective: To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum (C. complanatum) in Channa punctatus (C. punctatus), associated histopathology and the experimental infection to laboratory chicken to obtain ovigerous adult worms. Methods:Live C. punctatus were brought from local fish market of Aligarh, India, dissected and examined on a monthly basis for the presence of C. complanatum cysts. For histochemistry, infected tissue sections with attached cysts were processed for haematoxylene and eosin staining. Cysts were aseptically fed to 4 day old leghorn chicken to obtain adult worms. Mechanically excysted metacercaria and the ovigerous adult worms were stained in carmine to prepare permanent slides. Results: One year survey for the infection of encysted progenetic metacercaria of C. complanatum in C. punctatus revealed the prevalence, intensity and abundance of 24.7%, 2.27 and 0.608, respectively. Histopathology showed heavy infiltration of immune cells at the site of cyst attachment and some tissue damage was also evident. Following feeding to experimental chicken, about 41.07%of the encysted metacercariae were able to excyst and migrate back to bucco-pharyngeal region where they tenaciously attached and fed on blood, and transformed into ovigerous adult worms from 62 hours onwards of post infection. Conclusions:The parasite is potentially pathogenic to the host, and the availability of a suitable intermediate host can be a contributing factor for the occurrence of C. complanatum metacercaria either in the excysted or encysted form, indicating loose host specificity and zoonotic potential.

  1. Seasonality of reproduction in male spotted murrel Channa punctatus: correlation of environmental variables and plasma sex steroids with histological changes in testis.

    Science.gov (United States)

    Basak, Reetuparna; Roy, Alivia; Rai, Umesh

    2016-10-01

    The present study was undertaken to develop a comprehensive understanding of how environmental cues and sex steroids relate with cyclic changes in spermatogenesis in freshwater spotted snakehead Channa punctatus that is nutritious and economically important. The seasonal histological changes in testis and annual profile of gonadosomatic index (GSI) of C. punctatus delineated the testicular cycle into four phases: regressed (December-March), preparatory (April-June), spawning (July and August) and postspawning (September-November). Among environmental variables, correlation and regression analyses exhibited an important relationship between photoperiod and testicular weight while role of rainfall was seen confined to spawning. The seasonal profile of plasma sex steroids when correlated with cyclic changes in spermatogenesis in spotted snakehead, testosterone (T) seems to be involved in controlling the major events of spermatogenesis from renewal of stem cells to spawning of spermatozoa. Another important androgen prevalent in teleosts, 11-ketotestosterone (11-KT), was high during preparatory phase, suggesting that 11-KT in addition to T plays an important role in progression of spermatogenesis and spermiation in C. punctatus. However, 11-KT was not seen to be associated with milt production and release of spermatozoa during spawning. Plasma profile of estradiol-17β (E2) during different reproductive phases revealed the involvement of E2 in repopulation of stem cells during postspawning phase and in maintaining quiescence of testis during regressed phase.

  2. Simple method for backyard production of snakehead (Channa striata Bloch) fry

    OpenAIRE

    Yaakov, W.A.A.W.; Ali, A. B.

    1992-01-01

    The snakehead (Channa striata ) is a common freshwater fish species in Malaysia. Details are given of a simple technique for breeding this species, suitable for small-scale farmers practising backyard aquaculture. Two techniques were used to induce spawning - the first used water level manipulation to simulate rain and the second used injected with human chorionic gonadotropic hormone. The former, more natural, spawning technique was found to provide a viable alternative for the small-scale f...

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

    International Nuclear Information System (INIS)

    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)

  4. Studies on the alterations in haematological indices, micronuclei induction and pathological marker enzyme activities in Channa punctatus (spotted snakehead) perciformes, channidae exposed to thermal power plant effluent.

    Science.gov (United States)

    Javed, Mehjbeen; Ahmad, Irshad; Ahmad, Ajaz; Usmani, Nazura; Ahmad, Masood

    2016-01-01

    The present study was conducted to assess the toxicity of thermal power plant effluent containing heavy metals (Fe > Cu > Zn > Mn > Ni > Co > Cr) on haematological indices, micronuclei, lobed nuclei and activity of pathological marker enzymes [alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) and creatine kinase (CK)] in Channa punctatus. Total erythrocyte count (-54.52 %), hemoglobin (-36.98 %), packed cell volume (-36.25 %), mean corpuscular hemoglobin concentration (-1.41 %) and oxygen (O2) carrying capacity (-37.04 %) declined significantly over reference fish, however total leukocyte count (+25.43 %), mean corpuscular hemoglobin (+33.52 %) and mean corpuscular volume (+35.49 %) showed elevation. High frequency of micronuclei (1133.3 %) and lobed nuclei (150 %) were observed in exposed fish which may indicate mutagenesis. Activities of pathological marker enzymes ALP, AST, ALT and CK increased significantly in serum of exposed fish. The ratio of ALT: AST in exposed fish was beyond 1 which indicates manifestation of pathological processes. These biomarkers show that fish have macrocytic hypochromic anemia. Leukocytosis showed general defence response against heavy metal toxicity and marker enzymes showed tissue degeneration. In conclusion, thermal power plant effluent has strong potential to induce micronuclei, tissue pathology, making the fish anemic, weak, stressed and vulnerable to diseases.

  5. Studies on the alterations in haematological indices, micronuclei induction and pathological marker enzyme activities in Channa punctatus (spotted snakehead) perciformes, channidae exposed to thermal power plant effluent.

    Science.gov (United States)

    Javed, Mehjbeen; Ahmad, Irshad; Ahmad, Ajaz; Usmani, Nazura; Ahmad, Masood

    2016-01-01

    The present study was conducted to assess the toxicity of thermal power plant effluent containing heavy metals (Fe > Cu > Zn > Mn > Ni > Co > Cr) on haematological indices, micronuclei, lobed nuclei and activity of pathological marker enzymes [alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) and creatine kinase (CK)] in Channa punctatus. Total erythrocyte count (-54.52 %), hemoglobin (-36.98 %), packed cell volume (-36.25 %), mean corpuscular hemoglobin concentration (-1.41 %) and oxygen (O2) carrying capacity (-37.04 %) declined significantly over reference fish, however total leukocyte count (+25.43 %), mean corpuscular hemoglobin (+33.52 %) and mean corpuscular volume (+35.49 %) showed elevation. High frequency of micronuclei (1133.3 %) and lobed nuclei (150 %) were observed in exposed fish which may indicate mutagenesis. Activities of pathological marker enzymes ALP, AST, ALT and CK increased significantly in serum of exposed fish. The ratio of ALT: AST in exposed fish was beyond 1 which indicates manifestation of pathological processes. These biomarkers show that fish have macrocytic hypochromic anemia. Leukocytosis showed general defence response against heavy metal toxicity and marker enzymes showed tissue degeneration. In conclusion, thermal power plant effluent has strong potential to induce micronuclei, tissue pathology, making the fish anemic, weak, stressed and vulnerable to diseases. PMID:27386247

  6. Gastroprotective Effect of Freeze Dried Stripped Snakehead Fish (Channa striata Bloch.) Aqueous Extract against Aspirin Induced Ulcerogenesis in Pylorus Ligated Rats.

    Science.gov (United States)

    Ali Khan, Mohammed Safwan; Mat Jais, Abdul Manan; Hussain, Javeed; Siddiqua, Faiza; Gopala Reddy, A; Shivakumar, P; Madhuri, D

    2014-01-01

    Channa striata (Bloch.) is a fresh water fish belonging to the family Channidae. The stripped snakehead fish possesses wide range of medicinal properties. In view of traditional use of C. striata for wound healing, the present study was undertaken to investigate the beneficial effects of orally administered freeze dried aqueous extract of Channa striata (AECS) in experimentally induced gastric ulcers in Wistar rats. Aspirin induced ulcerogenesis in pyloric ligation model was used for the assessment of antiulcer activity and Ranitidine (50 mg/kg) was employed as the standard drug. The various gastric parameters like volume of gastric juice, pH, free and total acidities, ulcer index, and levels of antioxidant enzymes like catalase, superoxide dismutase, and lipid peroxidation marker malondialdehyde were determined. AECS at concentrations of 40% and 50% w/v significantly decreased the volume of gastric juice and increased the levels of catalase while considerable decrease in free and total acidities and increase in superoxide dismutase were observed with the treatment of standard drug and AECS (50% w/v). All the test doses of AECS markedly decreased ulcer index and malondialdehyde compared to the standard drug whereas AECS 30% w/v did not alter volume of gastric juice, pH, free and total acidities, catalase, and superoxide dismutase. From these findings, it can be concluded that AECS is devoid of acid neutralizing effects at lower doses and possesses antisecretory and antiulcer activities and this could be related to its antioxidant mechanism.

  7. Gastroprotective Effect of Freeze Dried Stripped Snakehead Fish (Channa striata Bloch.) Aqueous Extract against Aspirin Induced Ulcerogenesis in Pylorus Ligated Rats.

    Science.gov (United States)

    Ali Khan, Mohammed Safwan; Mat Jais, Abdul Manan; Hussain, Javeed; Siddiqua, Faiza; Gopala Reddy, A; Shivakumar, P; Madhuri, D

    2014-01-01

    Channa striata (Bloch.) is a fresh water fish belonging to the family Channidae. The stripped snakehead fish possesses wide range of medicinal properties. In view of traditional use of C. striata for wound healing, the present study was undertaken to investigate the beneficial effects of orally administered freeze dried aqueous extract of Channa striata (AECS) in experimentally induced gastric ulcers in Wistar rats. Aspirin induced ulcerogenesis in pyloric ligation model was used for the assessment of antiulcer activity and Ranitidine (50 mg/kg) was employed as the standard drug. The various gastric parameters like volume of gastric juice, pH, free and total acidities, ulcer index, and levels of antioxidant enzymes like catalase, superoxide dismutase, and lipid peroxidation marker malondialdehyde were determined. AECS at concentrations of 40% and 50% w/v significantly decreased the volume of gastric juice and increased the levels of catalase while considerable decrease in free and total acidities and increase in superoxide dismutase were observed with the treatment of standard drug and AECS (50% w/v). All the test doses of AECS markedly decreased ulcer index and malondialdehyde compared to the standard drug whereas AECS 30% w/v did not alter volume of gastric juice, pH, free and total acidities, catalase, and superoxide dismutase. From these findings, it can be concluded that AECS is devoid of acid neutralizing effects at lower doses and possesses antisecretory and antiulcer activities and this could be related to its antioxidant mechanism. PMID:24977051

  8. On a New Species of Phyllodistomum Braun, 1899 (Digenea: Gorgoderidae, a Parasite of Fresh Water Fish, Channa Punctatus (Bl. from Betwa River, Bundelkhand Region Jhansi, U.P, India.

    Directory of Open Access Journals (Sweden)

    Jag Mohan Sen

    2014-04-01

    Full Text Available The present paper deals with a new species of genus Phyllodistum Braun, 1899. Phyllodistomum betwaensis sp.n. is reported from fresh water fish Channa punctatus (Bl. from Betwa river, Bundelkhand region,Jhansi. It differs from all the earlier reported species in having the body of fluke is spatulate and dorso-ventrally flattened; anterior portion of body is long and curved while posterior portion of body is broad; slightly curved, tubular oesophagus: ventral sucker oval and larger than oral sucker; testes, post-equatorial, inter-caecal, anterior testis is larger than posterior one and parallel to ovary; ovary, oval, just behind right vitelline lobe, parallel to anterior testis; vitelline lobes posterior-lateral to ventral sucker, oval. Right vitelline lobe is larger than left vitelline lobe; eggs are oval and non-operculated.

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

    Directory of Open Access Journals (Sweden)

    Dina Muthmainnah

    2013-12-01

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

  10. COMPARATIVE UTILIZATION IMPACT OF VARIOUS DIETARY LIPIDS, ON GROWTH INDICES, IN STRIPED MURREL, CHANNA STRIATUS (BLOCH FINGERLINGS

    Directory of Open Access Journals (Sweden)

    R. DAYAL

    2012-01-01

    Full Text Available A 84-day feeding trial was conducted to evaluate the utilization impact of dietary omega–3 HUFA as a dietary energy source by fingerlings of striped murrel, Channa striatus on the growth study and tissue composition. There were seven treatments (L3HUF, H3HUF, MUSOL, LINOL, MIXOL, SATOL and NATFO, each having two replicates, stocked with 100 fingerlings in circular plastic pools (300l capacity. The six feeds were formulated with basic ingredients (Soybean meal, 41%; soluble starch, 25%; Casein, 20%; carboxy-methyl-cellulose, 2%; papain, 0.5%; vitamin and mineral mix, 3.5% with iso-energetic (19.3 kJ/g, F1-F6 diets and results were compared with natural food fed fishes. The isocaloric diets were formulated from semi-purified ingredients with six different types of oil supplement which were fed to replicate groups of fishes ad libitum. Based on the protein efficiency ratio (PER, specific growth rate (SGR, average per day increment (PI and food conversion ratio (FCR, and, it was observed that C. striatus fingerlings utilized dietary lipid. The LINOL showing best growth performance followed by H3HUF, MUSOL on the basis of SGR and PER were significantly (P<0.05 influenced in striped murrel, Channa striatus. But lower SGR levels were obtained with diets containing L3HUF, MIXOL, SATOL and NATFO. This study suggests that the lipid from unsaturated origins could be effectively utilized by striped murrel fry with a better resultant growth.

  11. Estimation of length-weight relationship and condition factor of spotted snakehead Channa punctata (Bloch) under different feeding regimes.

    Science.gov (United States)

    Datta, Surjya Narayan; Kaur, Vaneet Inder; Dhawan, Asha; Jassal, Geeta

    2013-01-01

    Comparative study was conducted to observe the efficacy of different feeding regimes on growth of Channa punctata. Six iso- proteinous diets were prepared by using different agro industrial by-products. Maximum weight gain was recorded with diet having 66.75% rice bran, 11.50% mustard cake, 23.0% groundnut cake, 5% molasses, 1.5% vitamin-mineral mixture and 0.5% salt with specific growth rate of 0.408. The experimental fish recorded the value of exponent 'b' in the range of 2.7675 to 4.3922. The condition factor 'K' of all experimental fish was above 1.0 (1.094- 1.235) indicating robustness or well being of experimented fish.

  12. Precise age estimation from different ageing structures in the striped snakehead, Channa striata (Bloch,1793, collected from the river Ganga

    Directory of Open Access Journals (Sweden)

    Salman Khan

    2015-11-01

    Full Text Available In Channa striata (N=156; TL=17-60cm sampled from the river Ganga, the annuli laid on different ageing structures such as otoliths (whole and sectioned, scales, opercular bone and vertebrae were observed for age estimation. Standard procedures were followed to prepare and study the age structures. Age estimates obtained from different hard structures were analysed to calculate the parameters for precise age estimation viz., APE, CV and PA. The sectioned otoliths showed the highest (89.9% percentage of agreement between readers while least average percent error (1.20% and coefficient of variation (3.81% values between two readers. Thus sectioned otoliths were considered to be the most suitable method for estimating age in C. striata. When sectioned otoliths were compared with other bony structures, the highest percent agreement and lowest average percent error and coefficient of variation values were found between sectioned otoliths and whole otoliths age estimates.

  13. Establishment and characterization of a continuous cell line from thymus of striped snakehead, Channa striatus (Bloch 1793).

    Science.gov (United States)

    Sood, Neeraj; Chaudhary, D K; Pradhan, P K; Verma, D K; Raja Swaminathan, T; Kushwaha, B; Punia, P; Jena, J K

    2015-09-01

    The establishment and characterization of a continuous cell line from the thymus of air-breathing fish Channa striatus are described. The cell line, designated C. striatus thymus (CST), has been subcultured over 71 times and shows optimal growth at 28°C in Leibovitz's-15 (L-15) medium supplemented with 20% fetal bovine serum. The CST cells exhibited low plating efficiency which improved with increase in seeding density. The karyotype analysis revealed that CST cells have a normal diploid karyotype with 2n = 40. Partial amplification and sequencing of two mitochondrial genes, viz. 16S ribosomal RNA (rRNA) and cytochrome oxidase I, confirmed that the cell line originated from C. striatus. CST cells were successfully transfected indicating their potential application for expression of recombinant proteins. In immunocytochemical staining, CST cells showed characteristics of epithelial cells. These cells were sensitive to extracellular products of Vibrio cholerae MTCC 3904 as well as to heavy metal mercuric chloride. The CST cell line would be a useful tool in functional genomic studies such as RNA interference and gene knockout as well as for cytotoxicity studies.

  14. Characterization of serum immunoglobulin in channa striata (BLOCH) and kinetics of its response to Aeromonas hydrophila antigen.

    Science.gov (United States)

    Rauta, P R; Mohanty, J; Garnayak, S K; Sahoo, P K

    2013-01-01

    The immunoglobulin (Ig) from the serum of Channa striata was isolated by gel electroelution and characterized further to understand its nature and subsequent applications in studying the immune response. The purity of the sample was confirmed with the presence of a single band on native gradient PAGE and the molecular weight of ∼897 kDa was determined from the gel. In SDS-PAGE, C. striata Ig was reduced to produce two bands corresponding to H (heavy) (∼72 kDa) and L (light) (∼27 kDa) chain subunits. Polyclonal antiserum against the purified Ig was raised in a rabbit and adsorbed with 10% liver tissue homogenate of C. striata to enhance its specificity. By an indirect ELISA standardized using the adsorbed rabbit antiserum, the normal serum Ig concentration in C. striata was estimated to be 3.48 mg/mL. Further, a kinetic study of specific immunoglobulin response to formalin-killed Aeromonas hydrophila antigen was undertaken using another indirect ELISA, which showed a significant increase in serum immunoglobulin titer from day 2 onwards and reached its peak at day 14. Subsequently, the Ig titer was dropped from day 21 onwards till the completion of the experiment at day 42, although it was at a significantly higher level than the control. PMID:23656248

  15. TOXICOPATHOLOGICAL IMPACT OF SUB-LETHAL CONCENTRATION OF LEAD NITRATE ON THE AERIAL RESPIRATORY ORGANS OF ‘MURREL' CHANNA STRIATA (BLOCH, PISCES

    Directory of Open Access Journals (Sweden)

    R. Devi

    2007-09-01

    Full Text Available Sub-lethal toxicity of lead nitrate solution (46.25mg/L, 5% of 96h LC50 value on the air-breathing organ (suprabranchial chamber of Channa striata was analysed for 60 days. Because air-breathing organs of C. striata remain in direct contact with waterborne xenobiotics, any change in the aquatic ecosystem was directly reflected in them. Concentration of lead accumulation in the air-breathing organ fluctuated at different stages of exposure. Due to extensive secretory activity, the mucous cells very often got exhausted and disappeared followed by their regeneration. This causes periodic fluctuations in the density of the mucous cells. A significant increase in the gross DNA contents in relation to the respective control is noticed at many stages of exposure. Increases in the RNA and protein contents with simultaneous increase in the mucogenic activity of the mucous cells were also observed. The total lipid contents also showed a periodic fluctuation in their concentration.

  16. Sensitivity of brain cholinesterase activity to diazinon (BASUDIN 50EC) and fenobucarb (BASSA 50EC) insecticides in the air-breathing fish Channa striata (Bloch, 1793).

    Science.gov (United States)

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

    2006-05-01

    With the expansion of agricultural areas within the Mekong River Delta in Vietnam, a concurrent, dramatic increase has occurred in agrochemical usage. To date, little consideration has been given to the negative impacts of this agricultural activity on the aquatic resources of the region. Both acute toxicity and subacute effects on brain cholinesterase (ChE) of two of the most commonly used insecticides, diazinon and fenobucarb, on adult native snakehead (Channa striata) were evaluated in a static, nonrenewable system, the environmental parameters of which, such as dissolved oxygen, water temperature, and pH, fluctuated similarly to field conditions. Four levels of insecticides, from 0.008 to 0.52 mg/L (for diazinon) and from 0.11 to 9.35 mg/L (for fenobucarb), were tested to assess the effects on the brain ChE activity of the snakehead up to 30 and 10 d for diazinon and fenobucarb, respectively. Diazinon was highly toxic to this fish species, with a 96-h median lethal concentration (LC50) of only 0.79 mg/L, and it also caused long-term ChE inhibition, with activity still significantly inhibited by 30% after 30 d for the three highest concentrations. Fenobucarb was less toxic to this species, with a 96-h LC50 of 11.4 mg/L. Fenobucarb caused more rapid ChE inhibition but also rapid recovery. The results of the present study indicate an urgent need to regulate the usage of these pesticides in the Mekong River Delta. PMID:16704077

  17. Isolation of the bioactive compound(s) with antinociceptive activity in mice, from the fish Haruan, Channa striata

    OpenAIRE

    Mat Jais, M; Zakaria, Z; Mori, T.; McCahon, L; Croft, K.

    2014-01-01

    Note portant sur l'auteur Note portant sur l'auteur Note portant sur l'auteur Note portant sur l'auteur Note portant sur l'auteur Introduction A freshwater fish species haruan, Channa striata (Bloch 1793; syn. Channa striatus), is carnivorous and air breathing. The fish is indigenous to Malaysia and extracts are commonly used to induce postoperative wound healing, especially women following caesarean births. Haruan-based cream is also effective for exfoliation in dermatitis, such as sclerosis...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  19. The complete mitochondrial genome of Channa argus, Channa maculata and hybrid snakehead fish [Channa maculata (♀) × Channa argus (♂)].

    Science.gov (United States)

    Zhu, Shu-Ren; Ma, Ke-Yi; Xing, Zhi-Jun; Xie, Nan; Wang, Yu-Xi; Wang, Qun; Li, Jia-Le

    2013-06-01

    We sequenced and characterized the complete mitochondrial genome of Channa argus, Channa maculata and their hybrid [C. maculata (♀) and C. argus (♂)]. All the three mitochondrial genomes contained the typical complement of 13 protein-coding genes, 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs) and 1 control region. The entire mitochondrial DNA (mtDNA) molecule of C. maculata was 16,559 bp long while the complete mtDNA molecule of C. argus and hybrid snakehead fish was 16,558 bp long. This is the first report on the complete mitogenome sequence of C. maculata and hybrid snakehead fish.

  20. Trianchoratus longianchoratus sp. n. (Monogenea: Ancyrocephalidae: Heteronchocleidinae) from Channa lucius (Osteichthyes: Channidae) in Peninsular Malaysia.

    Science.gov (United States)

    Tan, W B; Lim, L H S

    2009-09-01

    One new and three previously described species of Trianchoratus Price et Berry, 1966 were collected from the gills of Channa lucius (Cuvier) and Channa striata (Bloch) from the Bukit Merah Reservoir, Perak and Endau-Rompin, Pahang, Peninsular Malaysia. They are Trianchoratus longianchoratus sp.n., T. malayensis Lim, 1986 and T. pahangensis Lim, 1986 from C. lucius, and T. ophicephali Lim, 1986 from C. striata. The new species differs from the Trianchoratus species hitherto described from channids and anabantoids in having two ventral anchors with a long curved inner root and one dorsal anchor with a curved inner root and lacking an outer root. A table summarizing the known species of heteronchocleidins (Trianchoratus, Eutrianchoratus and Heteronchocleidus) and Sundanonchus reported from fish hosts of different families (Channidae, Helostomatidae, Anabantidae and Osphronemidae) is provided. PMID:19827361

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:21167285

  3. Resonant Bloch-wave beatings.

    Science.gov (United States)

    Kartashov, Yaroslav V; Vysloukh, Victor A; Torner, Lluis

    2014-07-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  4. Resonant Bloch-wave beatings

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2014-01-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  5. Polychromatic optical Bloch oscillations.

    Science.gov (United States)

    Longhi, Stefano

    2009-07-15

    Bloch oscillations (BOs) of polychromatic beams in circularly curved optical waveguide arrays are smeared out owing to the dependence of the BO spatial period on the wavelength. Here it is shown that restoring of the self-imaging property of the array and approximate BOs over relatively broad spectral ranges can be achieved by the insertion of suitable lumped phase slips uniformly applied across the array.

  6. Bloch vectors for qudits

    Energy Technology Data Exchange (ETDEWEB)

    Bertlmann, Reinhold A; Krammer, Philipp [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)], E-mail: reinhold.bertlmann@univie.ac.at, E-mail: philipp.krammer@univie.ac.at

    2008-06-13

    We present three different matrix bases that can be used to decompose density matrices of d-dimensional quantum systems, so-called qudits: the generalized Gell-Mann matrix basis, the polarization operator basis and the Weyl operator basis. Such a decomposition can be identified with a vector-the Bloch vector, i.e. a generalization of the well-known qubit case-and is a convenient expression for comparison with measurable quantities and for explicit calculations avoiding the handling of large matrices. We present a new method to decompose density matrices via so-called standard matrices, consider the important case of an isotropic two-qudit state and decompose it according to each basis. In the case of qutrits we show a representation of an entanglement witness in terms of expectation values of spin-1 measurements, which is appropriate for an experimental realization.

  7. A theory of generalized Bloch oscillations.

    Science.gov (United States)

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

    2016-04-20

    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.

  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...... 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....

  9. Channa striatus capsules induces cytokine conversion in pulmonary tuberculosis patients

    Directory of Open Access Journals (Sweden)

    Novita Paliliewu

    2013-06-01

    Full Text Available Objective: This study aimed to investigate whether Channa striatus capsule induces sputum and cytokine conversion in pulmonary tuberculosis (TB patients. Methods: Randomized, placebo-controlled, double-blind pilot study was conducted to pulmonary TB patients who admitted to Department of Internal Medicine, Faculty of Medicine, University of Sam Ratulangi, Manado, North Sulawesi, Indonesia. A total of 36 pulmonary TB patients were randomly divided into two equal groups (n = 18 including one group received standart antituberculosis drugs plus Channa striatus capsule and another group received standart antituberculosis drugs plus placebo. Channa striatus capsule was given at a dose of 2 g each time, 3 times per day, for 12 weeks. The levels of tumor necrosis factor (TNF-α, interferon (IFN-γ, and interleukin (IL-10 were analyses using enzyme linked immunosorbent assay (ELISA method. Results: The rate of positive sputum smear decline was more pronounced in the Channa striatus group but did not reach statistically different value between groups. The levels of TNF-α, IFN-γ, and IL-10 were not significantly different in Channa striatus group compared to placebo group at baseline (week 0. But at week 12, the supplementation of Channa striatus capsule significantly decreased TNF-α, IFN-γ, and IL-10 levels compared to baseline. In placebo groups, there were no significant differences for IL-10 levels at week 12, but the levels of TNF-α and IFN-γ significantly decreased. Conclusion: Adjunctive supplementation of Channa striatus capsules accelerated the beneficial therapeutic effect of TB chemotherapy by improving cytokine response. [J Exp Integr Med 2013; 3(3.000: 237-242

  10. Observation of anharmonic Bloch oscillations.

    Science.gov (United States)

    Dreisow, Felix; Wang, Gang; Heinrich, Matthias; Keil, Robert; Tünnermann, Andreas; Nolte, Stefan; Szameit, Alexander

    2011-10-15

    We report on the experimental observation of Bloch oscillations of an optical wave packet in a lattice with second-order coupling. To this end, we employ zigzag waveguide arrays, in which the second-order coupling can be precisely tuned.

  11. Bloch oscillations in carbon nanotubes.

    Science.gov (United States)

    Jódar, Esther; Pérez-Garrido, Antonio; Rojas, Fernando

    2009-05-27

    Bloch oscillations arise when electrons are in a one-dimensional linear chain of atoms under a constant electric field. In this paper we show numerically that electrons in different types of carbon nanotubes show oscillations with a Bloch frequency proportional to the constant electric field applied along the nanotube axis. We show these oscillations, calculating the quadratic displacement as a function of the electric field. Because of the double periodicity of the nanotubes' geometry (the lattice constant and the lines of atoms) two frequencies appear, one twice the value of the other. These frequencies coincide perfectly with those predicted for a linear chain of atoms, taking into account the periodicity considered in each case.

  12. Optical analogue of electronic Bloch oscillations.

    Science.gov (United States)

    Sapienza, Riccardo; Costantino, Paola; Wiersma, Diederik; Ghulinyan, Mher; Oton, Claudio J; Pavesi, Lorenzo

    2003-12-31

    We report on the observation of Bloch oscillations in light transport through periodic dielectric systems. By introducing a linear refractive index gradient along the propagation direction the optical equivalent of a Wannier-Stark ladder was obtained. Bloch oscillations were observed as time-resolved oscillations in transmission, in direct analogy to electronic Bloch oscillations in conducting crystals where the Wannier-Stark ladder is obtained via an external electric field. The observed oscillatory behavior is in excellent agreement with transfer matrix calculations.

  13. Hybrid Bloch-Anderson localization of light

    CERN Document Server

    Stutzer, Simon; Vysloukh, Victor A; Konotop, Vladimir V; Nolte, Stefan; Torner, Lluis; Szameit, Alexander

    2013-01-01

    We investigate the interplay of Bloch oscillations and Anderson localization in optics. Gradual washing out of Bloch oscillations and the formation of nearly stationary averaged intensity distributions, which are symmetric for narrow and strongly asymmetric for broad input excitations, are observed experimentally in laser-written waveguide arrays. At large disorder levels Bloch oscillations are completely destroyed and both narrow and wide excitations lead to symmetric stationary averaged intensity distributions with exponentially decaying tails.

  14. Hybrid Bloch-Anderson localization of light.

    Science.gov (United States)

    Stützer, Simon; Kartashov, Yaroslav V; Vysloukh, Victor A; Konotop, Vladimir V; Nolte, Stefan; Torner, Lluis; Szameit, Alexander

    2013-05-01

    We investigate the interplay of Bloch oscillations and Anderson localization in optics. Gradual washing out of Bloch oscillations and the formation of nearly stationary averaged intensity distributions, which are symmetric for narrow and strongly asymmetric for broad input excitations, are observed experimentally in laser-written waveguide arrays. At large disorder levels Bloch oscillations are completely destroyed and both narrow and wide excitations lead to symmetric stationary averaged intensity distributions with exponentially decaying tails.

  15. Wave impedance retrieving via Bloch modes analysis

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Ha, S.; Sukhorukov, A.;

    2011-01-01

    The main bottleneck in the restoration of electromagnetic effective parameters is connected to the impedance retrieving. The S-parameters method gives the input (Bloch) impedance, which, being then used for permittivity and permeability determination, causes some fundamental physics prin......-ciples violation, like antiresonance behaviour with Im(ε) fundamental) Bloch mode. Then it is possible to determine the Bloch and wave impedances by the surface and volume aver-aging of the electromagnetic field...

  16. The Bloch Vector for N-Level Systems

    OpenAIRE

    Kimura, Gen

    2003-01-01

    We determine the set of the Bloch vectors for N-level systems, generalizing the familiar Bloch ball in 2-level systems. An origin of the structural difference from the Bloch ball in 2-level systems is clarified.

  17. Electric dipoles on the Bloch sphere

    CERN Document Server

    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.

  18. Bloch-Zener oscillations in binary superlattices.

    Science.gov (United States)

    Dreisow, F; Szameit, A; Heinrich, M; Pertsch, T; Nolte, S; Tünnermann, A; Longhi, S

    2009-02-20

    Bloch-Zener oscillations, i.e., the coherent superposition of Bloch oscillations and Zener tunneling between minibands of a binary lattice, are experimentally demonstrated for light waves in curved femtosecond laser-written waveguide arrays. Visualization of double-periodicity breathing and oscillation modes is reported, and synchronous tunneling leading to wave reconstruction is demonstrated.

  19. Bloch oscillations in atom interferometry

    CERN Document Server

    Cladé, Pierre

    2014-01-01

    In Paris, we are using an atom interferometer to precisely measure the recoil velocity of an atom that absorbs a photon. In order to reach a high sensitivity, many recoils are transferred to atoms using the Bloch oscillations technique. In this lecture, I will present in details this technique and its application to high precision measurement. I will especially describe in details how this method allows us to perform an atom recoil measurement at the level of $1.3 \\times 10^{-9}$. This measurement is used in the most precise determination of the fine structure constant that is independent of quantum electrodynamics.

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

    Science.gov (United States)

    Lefevre, Sjannie; Jensen, Frank B; Huong, Do T T; Wang, Tobias; Phuong, Nguyen T; Bayley, Mark

    2012-08-15

    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 mM. Effects of sub-lethal exposures to nitrite (0mM, 1.4mM, and 3.0mM) 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% of total Hb. Haematocrit and total Hb were unaffected by nitrite. Although the effects of nitrite exposure seemed minor in terms of plasma nitrite and metHb increases, ion balance was strongly affected. In the high exposure group, total osmolality decreased from 320 mOsm to 260 mOsm, and plasma sodium from 150 mM to 120 mM, while plasma chloride fell from 105 mM to 60mM and plasma bicarbonate rose from 12 mM in controls to 20mM in exposed fish. The extreme changes in ion balance in C. striata are different from the response reported in other fish, and further studies are needed to investigate the mechanism behind the observed changes in regulation.

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

    Science.gov (United States)

    Lefevre, Sjannie; Jensen, Frank B; Huong, Do T T; Wang, Tobias; Phuong, Nguyen T; Bayley, Mark

    2012-08-15

    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 mM. Effects of sub-lethal exposures to nitrite (0mM, 1.4mM, and 3.0mM) 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% of total Hb. Haematocrit and total Hb were unaffected by nitrite. Although the effects of nitrite exposure seemed minor in terms of plasma nitrite and metHb increases, ion balance was strongly affected. In the high exposure group, total osmolality decreased from 320 mOsm to 260 mOsm, and plasma sodium from 150 mM to 120 mM, while plasma chloride fell from 105 mM to 60mM and plasma bicarbonate rose from 12 mM in controls to 20mM in exposed fish. The extreme changes in ion balance in C. striata are different from the response reported in other fish, and further studies are needed to investigate the mechanism behind the observed changes in regulation. PMID:22516674

  2. First Bloch eigenvalue in high contrast media

    Science.gov (United States)

    Briane, Marc; Vanninathan, Muthusamy

    2014-01-01

    This paper deals with the asymptotic behavior of the first Bloch eigenvalue in a heterogeneous medium with a high contrast ɛY-periodic conductivity. When the conductivity is bounded in L1 and the constant of the Poincaré-Wirtinger weighted by the conductivity is very small with respect to ɛ-2, the first Bloch eigenvalue converges as ɛ → 0 to a limit which preserves the second-order expansion with respect to the Bloch parameter. In dimension two the expansion of the limit can be improved until the fourth-order under the same hypotheses. On the contrary, in dimension three a fibers reinforced medium combined with a L1-unbounded conductivity leads us to a discontinuity of the limit first Bloch eigenvalue as the Bloch parameter tends to zero but remains not orthogonal to the direction of the fibers. Therefore, the high contrast conductivity of the microstructure induces an anomalous effect, since for a given low-contrast conductivity the first Bloch eigenvalue is known to be analytic with respect to the Bloch parameter around zero.

  3. First Bloch eigenvalue in high contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Briane, Marc, E-mail: mbriane@insa-rennes.fr [Institut de Recherche Mathématique de Rennes, INSA de Rennes (France); Vanninathan, Muthusamy, E-mail: vanni@math.tifrbng.res.in [TIFR-CAM, Bangalore (India)

    2014-01-15

    This paper deals with the asymptotic behavior of the first Bloch eigenvalue in a heterogeneous medium with a high contrast εY-periodic conductivity. When the conductivity is bounded in L{sup 1} and the constant of the Poincaré-Wirtinger weighted by the conductivity is very small with respect to ε{sup −2}, the first Bloch eigenvalue converges as ε → 0 to a limit which preserves the second-order expansion with respect to the Bloch parameter. In dimension two the expansion of the limit can be improved until the fourth-order under the same hypotheses. On the contrary, in dimension three a fibers reinforced medium combined with a L{sup 1}-unbounded conductivity leads us to a discontinuity of the limit first Bloch eigenvalue as the Bloch parameter tends to zero but remains not orthogonal to the direction of the fibers. Therefore, the high contrast conductivity of the microstructure induces an anomalous effect, since for a given low-contrast conductivity the first Bloch eigenvalue is known to be analytic with respect to the Bloch parameter around zero.

  4. Magnetic Bloch oscillations in nanowire superlattice rings.

    Science.gov (United States)

    Citrin, D S

    2004-05-14

    The recent growth of semiconductor nanowire superlattices encourages hope that Bloch-like oscillations in such structures formed into rings may soon be observed in the presence of a time-dependent magnetic flux threading the ring. These magnetic Bloch oscillations are a consequence of Faraday's law; the time-dependent flux produces an electromotive force around the ring, thus leading to the Bloch-like oscillations. In the spectroscopic domain, generalized Wannier-Stark states are found that are manifestations of the emf-induced localization of the states.

  5. First Bloch eigenvalue in high contrast media

    OpenAIRE

    Briane, Marc; Vanninathan, Muthusamy

    2014-01-01

    16 pages International audience This paper deals with the asymptotic behavior of the first Bloch eigenvalue in a heterogeneous medium with a high contrast $\\varepsilon Y$-periodic conductivity. When the conductivity is bounded in $L^1$ and the constant of the Poincaré-Wirtinger weighted by the conductivity is very small with respect to $\\varepsilon^{-2}$, the first Bloch eigenvalue converges as $\\varepsilon\\to 0$ to a limit which preserves the second-order expansion with respect to the ...

  6. Bloch oscillations in optical dissipative lattices.

    Science.gov (United States)

    Efremidis, Nikolaos K; Christodoulides, Demetrios N

    2004-11-01

    We show that Bloch oscillations are possible in dissipative optical waveguide lattices with a linearly varying propagation constant. These oscillations occur in spite of the fact that the Bloch wave packet experiences coupling gain and (or) loss. Experimentally, this process can be observed in different settings, such as in laser arrays and lattices of semiconductor optical amplifiers. In addition, we demonstrate that these systems can suppress instabilities arising from preferential mode noise growth.

  7. Experimental observation of spectral Bloch oscillations.

    Science.gov (United States)

    Bersch, Christoph; Onishchukov, Georgy; Peschel, Ulf

    2009-08-01

    We report on the first, to our knowledge, experimental observation of spectral Bloch oscillations in an optical fiber employing the interaction between a probe signal and a traveling-wave periodic potential. The spectrum of weak probe pulses is shown to oscillate on account of their group-velocity mismatch to the periodic field. The behavior of a cw probe spectrum reveals the actual discrete nature of the effect. Recurrences of the spectrum after one and two Bloch periods are demonstrated.

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

    OpenAIRE

    Mita Borman; Ismot Ara; Mohammad Kamrujjaman; Md Rafiqun Nabi

    2015-01-01

    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...

  9. Resonant delocalization and Bloch oscillations in modulated lattices.

    Science.gov (United States)

    El-Ganainy, R; Christodoulides, D N; Rüter, C E; Kip, D

    2011-04-15

    We study the propagation of light in Bloch waveguide arrays exhibiting periodic coupling interactions. Intriguing wave packet revival patterns as well as beating Bloch oscillations are demonstrated. A new resonant delocalization phase transition is also predicted.

  10. 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.

  11. Observation of Bloch oscillations in molecular rotation

    CERN Document Server

    Floß, Johannes; Averbukh, Ilya Sh; Bucksbaum, Philip H

    2015-01-01

    The periodically kicked quantum rotor is known for non-classical effects such as quantum localisation in angular momentum space or quantum resonances in rotational excitation. These phenomena have been studied in diverse systems mimicking the kicked rotor, such as cold atoms in optical lattices, or coupled photonic structures. Recently, it was predicted that several solid state quantum localisation phenomena - Anderson localisation, Bloch oscillations, and Tamm-Shockley surface states - may manifest themselves in the rotational dynamics of laser-kicked molecules. Here, we report the first observation of rotational Bloch oscillations in a gas of nitrogen molecules kicked by a periodic train of femtosecond laser pulses. A controllable detuning from the quantum resonance creates an effective accelerating potential in angular momentum space, inducing Bloch-like oscillations of the rotational excitation. These oscillations are measured via the temporal modulation of the refractive index of the gas. Our results int...

  12. Fractional Bloch oscillations in photonic lattices.

    Science.gov (United States)

    Corrielli, Giacomo; Crespi, Andrea; Della Valle, Giuseppe; Longhi, Stefano; Osellame, Roberto

    2013-01-01

    Bloch oscillations, the oscillatory motion of a quantum particle in a periodic potential, are one of the most fascinating effects of coherent quantum transport. Originally studied in the context of electrons in crystals, Bloch oscillations manifest the wave nature of matter and are found in a wide variety of different physical systems. Here we report on the first experimental observation of fractional Bloch oscillations, using a photonic lattice as a model system of a two-particle extended Bose-Hubbard Hamiltonian. In our photonic simulator, the dynamics of two correlated particles hopping on a one-dimensional lattice is mapped into the motion of a single particle in a two-dimensional lattice with engineered defects and mimicked by light transport in a square waveguide lattice with a bent axis.

  13. Fractional Bloch oscillations in photonic lattices

    CERN Document Server

    Corrielli, Giacomo; Della Valle, Giuseppe; Longhi, Stefano; Osellame, Roberto; 10.1038/ncomms2578

    2013-01-01

    Bloch oscillations, the oscillatory motion of a quantum particle in a periodic potential, are one of the most fascinating effects of coherent quantum transport. Originally studied in the context of electrons in crystals, Bloch oscillations manifest the wave nature of matter and are found in a wide variety of different physical systems. Here we report on the first experimental observation of fractional Bloch oscillations, using a photonic lattice as a model system of a two-particle extended Bose-Hubbard Hamiltonian. In our photonic simulator, the dynamics of two correlated particles hopping on a one-dimensional lattice is mapped into the motion of a single particle in a two-dimensional lattice with engineered defects and mimicked by light transport in a square waveguide lattice with a bent axis.

  14. Bloch oscillations in complex crystals with PT symmetry.

    Science.gov (United States)

    Longhi, S

    2009-09-18

    Bloch oscillations in complex lattices with PT symmetry are theoretically investigated with specific reference to optical Bloch oscillations in photonic lattices with gain or loss regions. Novel dynamical phenomena with no counterpart in ordinary lattices, such as nonreciprocal Bloch oscillations related to violation of the Friedel's law of Bragg scattering in complex potentials, are highlighted.

  15. Terahertz Bloch oscillator with a modulated bias.

    Science.gov (United States)

    Hyart, Timo; Alexeeva, Natalia V; Mattas, Jussi; Alekseev, Kirill N

    2009-04-10

    Electrons performing Bloch oscillations in an energy band of a dc-biased superlattice in the presence of weak dissipation can potentially generate THz fields at room temperature. The realization of such a Bloch oscillator is a long-standing problem due to the instability of a homogeneous electric field in conditions of negative differential conductivity. We establish the theoretical feasibility of stable THz gain in a long superlattice device in which the bias is quasistatically modulated by microwave fields. The modulation waveforms must have at least two harmonics in their spectra.

  16. Observation of Bloch Oscillations in Molecular Rotation.

    Science.gov (United States)

    Floß, Johannes; Kamalov, Andrei; Averbukh, Ilya Sh; Bucksbaum, Philip H

    2015-11-13

    We report the observation of rotational Bloch oscillations in a gas of nitrogen molecules kicked by a periodic train of femtosecond laser pulses. A controllable detuning from the quantum resonance creates an effective accelerating potential in angular momentum space, inducing Bloch-like oscillations of the rotational excitation. These oscillations are measured via the temporal modulation of the refractive index of the gas. Our results introduce room-temperature laser-kicked molecules as a new laboratory for studies of localization phenomena in quantum transport.

  17. Morphological and genetic differences between cultured and wild populations of Channa striata in Viet Nam and its phylogenetic relationship with other Channa species

    Directory of Open Access Journals (Sweden)

    Ngoc-Tran Thi Nguyen

    2016-08-01

    Full Text Available The Channa genus includes important species for aquaculture and interesting targets for phylogenetic studies. In the Mekong Delta, Viet Nam, four species of this genus (Channa striata, C. micropeltes, C. lucius, and C. gachua are naturally distributed and other phenotypes that look like C. striata have been observed in aquaculture conditions. The taxonomic status of newly-observed phenotypes including “triangle-head” snakehead (THS and square-head snakehead (SHS is still controversial. This study compared morphological characteristics and Cytochrome C oxidase subunit I (COI sequences of different C. striata-like phenotypes and investigated the phylogenetic relationship of Channa species based on COI. Morphological results show that THS, SHS, and wild C. striata have similar ranges for meristic traits but differ in morphometric ratios, especially the shape of their head and length of their gut. Kimura-2P genetic distances among three phenotypes (0.0017- 0.0062 are equivalent to those of C. striata samples from Mainland Southeast Asian countries. The results indicate that THS and SHS belong to C. striata, and this species exhibits within-species diversity in both morphology and COI sequences. The phylogenetic analysis indicates that C. striata individuals form a monophyletic group and are genetically distinct from other Channa species in the Vietnamese Mekong Delta. Congeneric distances of four species range from 0.1836 to 0.2436, indicating high divergence among Channa species.

  18. Electronic Bloch oscillation in bilayer graphene gradient superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hemeng; Li, Changan; Song, Yun [Department of Physics, Beijing Normal University, Beijing 100875 (China); Ma, Tianxing, E-mail: txma@bnu.edu.cn [Department of Physics, Beijing Normal University, Beijing 100875 (China); Beijing Computational Science Research Center, Beijing 100084 (China); Wang, Li-Gang, E-mail: sxwlg@yahoo.com [Department of Physics, Zhejiang University, Hangzhou 310027 (China); Lin, Hai-Qing [Beijing Computational Science Research Center, Beijing 100084 (China)

    2014-08-18

    We investigate the electronic Bloch oscillation in bilayer graphene gradient superlattices using transfer matrix method. By introducing two kinds of gradient potentials of square barriers along electrons propagation direction, we find that Bloch oscillations up to terahertz can occur. Wannier-Stark ladders, as the counterpart of Bloch oscillation, are obtained as a series of equidistant transmission peaks, and the localization of the electronic wave function is also signature of Bloch oscillation. Furthermore, the period of Bloch oscillation decreases linearly with increasing gradient of barrier potentials.

  19. In silico analysis of Myoglobin in Channa striata.

    Science.gov (United States)

    Parveen, Farzana; Mishra, Vineet Kumar

    2014-01-01

    Myoglobin is a cytoplasmic hemoprotein, expressed solely in cardiac myocytes and oxidative skeletal muscle fibers, that reversibly binds O2 by its heme residue. Myoglobin is an essential oxygen-storage hemoprotein capable of facilitating oxygen transport and modulating nitric oxide homeostasis within cardiac and skeletal myocytes. Functionally, myoglobin is well accepted as an O2- storage protein in muscle, capable of releasing O2 during periods of hypoxia or anoxia. There is no evidence available regarding active sites, ligand binding sites, antigenic determinants and the ASA value of myoglobin in Channa striata. We further document the predicted active sites in the structural model with solvent exposed ASA residues. During this study, the model was built by CPH program and validated through PROCHECK, Verify 3D, ERRAT and ProSA for reliability. The active sites were predicted in the model with further ASA analysis of active site residues. The discussed information thus provides the predicted active sites, ligand binding sites, antigenic determinants and ASA values of myoglobin model in Channa striata. PMID:24516321

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

    International Nuclear Information System (INIS)

    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

  1. Ultrastructural features of spermatogenesis in Melanorivulus punctatus (Cyprinodontiformes: Rivulidae).

    Science.gov (United States)

    Cassel, Mônica; Ferreira, Adelina; Mehanna, Mahmoud

    2014-07-01

    Fish belonging to the family Rivulidae possess one of the most complex reproductive systems. Rivulus, a genus of freshwater fish in the Rivulidae family, was recently reclassified into five genera, including Melanorivulus. Its type species, M. punctatus, is widely distributed and probably represents a species complex. The ultrastructure of sperm has been broadly used in systematics, and we hereby describe the ultrastructural features of spermatogenesis in M. punctatus. Ten M. punctatus males were collected from the reservoir of Parque Estadual da Quineira, municipality of Chapada dos Guimarães, Mato Grosso, Brazil, and prepared for analysis by light microscopy and transmission electron microscopy. M. punctatus undergoes cystic spermatogenesis. Its cysts consist of groups of germ cells that are in synchronous development and are surrounded by cytoplasmic projections of Sertoli cells. With the breakdown of the cysts, the spermatozoa are released and their maturation is completed in the duct, where part of the cytoplasmic material is discarded through the vesicles. The mature spermatozoon is characterized by a spherical head with homogeneously condensed chromatin, a symmetric midpiece consisting of a pair of perpendicular centrioles, a ring of mitochondria, several vesicles, and one flagellum medial to the nucleus. Early stages of spermatogenesis show no peculiarities; however, in spermiogenesis, we observed that the spermatids remain interconnected by cytoplasmic bridges and have pockets of residual cytoplasm. The sperm is of the aquasperm type and is similar to that observed in the members of the family Rivulidae. The spermatozoa have a single flagellum that consists of a classic axoneme (9+2), as found in most groups of fish, despite the lateral extensions. PMID:24811986

  2. Fractional Bloch Oscillations in photonic lattices

    Directory of Open Access Journals (Sweden)

    Corrielli G.

    2013-11-01

    Full Text Available We present the photonic analogy of the Fractional Bloch Oscillations [1]: the oscillatory motion of interacting particles moving in a periodic potential, under the presence of a static force. The analogy is implemented with the propagation of classical light in a specially engineered photonic waveguides lattice, fabricated in fused silica substrate via femtosecond laser micromachining.

  3. Sandwich reactor lattices and Bloch's theorem

    International Nuclear Information System (INIS)

    The study of the neutron flux distribution in repetitive sandwiches of reactor material leads to results analogous to the 1-dimensional form of Bloch's theorem for the electronic structure in crystals. This principle makes it possible to perform analytically accurate homogenisations of sandwich lattices The method has been extended to cover multi group diffusion and transport theory. (author)

  4. Tunable Bloch Wave Resonances and Bloch Gaps in Uniform Materials with Reconfigurable Boundary Profiles

    Science.gov (United States)

    Pogrebnyak, Victor A.; Furlani, Edward P.

    2016-05-01

    We study wave propagation in uniform materials with periodic boundary profiles and introduce for the first time Bloch resonances and Bloch gaps. Bloch resonances are due to transverse phase matching, i.e., the coupling of two transverse standing waves corresponding to different harmonics. These are distinct from well-known Bragg resonances that result from longitudinal phase matching. We show that Bloch gaps can be engineered over the entire first Brillouin zone up to an infinite wavelength, i.e., kx=0 , where kx is the wave number in the direction of propagation. This is in contrast to Bragg gaps that open at a fixed wavelength, twice the period of the structure. Bloch resonances and gaps can be tuned by reconfiguring the boundary profile and we derive analytical expressions that predict these phenomena when the amplitude of the profile is small. The theory is fundamental as it broadly applies to wave phenomena that span the quantum to continuum scale with applications that range from condensed matter to acoustics. We validate the theory experimentally for the electromagnetic field at GHz frequencies. We also discuss potential photonic and electronic applications of the theory such as a white-light distributed feedback laser and a two-dimensional electron gas transistor.

  5. Tunable Bloch Wave Resonances and Bloch Gaps in Uniform Materials with Reconfigurable Boundary Profiles.

    Science.gov (United States)

    Pogrebnyak, Victor A; Furlani, Edward P

    2016-05-20

    We study wave propagation in uniform materials with periodic boundary profiles and introduce for the first time Bloch resonances and Bloch gaps. Bloch resonances are due to transverse phase matching, i.e., the coupling of two transverse standing waves corresponding to different harmonics. These are distinct from well-known Bragg resonances that result from longitudinal phase matching. We show that Bloch gaps can be engineered over the entire first Brillouin zone up to an infinite wavelength, i.e., k_{x}=0, where k_{x} is the wave number in the direction of propagation. This is in contrast to Bragg gaps that open at a fixed wavelength, twice the period of the structure. Bloch resonances and gaps can be tuned by reconfiguring the boundary profile and we derive analytical expressions that predict these phenomena when the amplitude of the profile is small. The theory is fundamental as it broadly applies to wave phenomena that span the quantum to continuum scale with applications that range from condensed matter to acoustics. We validate the theory experimentally for the electromagnetic field at GHz frequencies. We also discuss potential photonic and electronic applications of the theory such as a white-light distributed feedback laser and a two-dimensional electron gas transistor. PMID:27258880

  6. Bloch oscillations in plasmonic waveguide arrays.

    Science.gov (United States)

    Block, A; Etrich, C; Limboeck, T; Bleckmann, F; Soergel, E; Rockstuhl, C; Linden, S

    2014-05-12

    The combination of modern nanofabrication techniques and advanced computational tools has opened unprecedented opportunities to mold the flow of light. In particular, discrete photonic structures can be designed such that the resulting light dynamics mimics quantum mechanical condensed matter phenomena. By mapping the time-dependent probability distribution of an electronic wave packet to the spatial light intensity distribution in the corresponding photonic structure, the quantum mechanical evolution can be visualized directly in a coherent, yet classical wave environment. On the basis of this approach, several groups have recently observed discrete diffraction, Bloch oscillations and Zener tunnelling in different dielectric structures. Here we report the experimental observation of discrete diffraction and Bloch oscillations of surface plasmon polaritons in evanescently coupled plasmonic waveguide arrays. The effective external potential is tailored by introducing an appropriate transverse index gradient during nanofabrication of the arrays. Our experimental results are in excellent agreement with numerical calculations.

  7. Logarithmic Bloch space and its predual

    CERN Document Server

    Pavlović, Miroslav

    2011-01-01

    We consider the space $\\bk^1_{\\log^\\alpha}$, of analytic functions on the unit disk $\\D,$ defined by the requirement $\\int_\\D|f'(z)|\\phi(|z|)\\,dA(z)<\\infty,$ where $\\phi(r)=\\log^\\alpha(1/(1-r))$ and show that it is a predual of the "$\\log^\\alpha$-Bloch" space and the dual of the corresponding little Bloch space. We prove that a function $f(z)=\\sum_{n=0}^\\infty a_nz^n$ with $a_n\\downarrow 0$ is in $\\bk^1_{\\log^\\alpha}$ iff $\\sum_{n=0}^\\infty \\log^\\alpha(n+2)/(n+1)<\\infty$ and apply this to obtain a criterion for membership of the Libera transform of a function with positive coefficients in $\\bk^1_{\\log^\\alpha}.$ Some properties of the Ces\\'aro and the Libera operator are considered as well.

  8. Bloch oscillations of path-entangled photons.

    Science.gov (United States)

    Bromberg, Yaron; Lahini, Yoav; Silberberg, Yaron

    2010-12-31

    We show that when photons in N-particle path-entangled |N,0)+|0,N) or N00N states undergo Bloch oscillations, they exhibit a periodic transition between spatially bunched and antibunched states. The period of the bunching-antibunching oscillation is N times faster than the period of the oscillation of the photon density, manifesting the unique coherence properties of N00N states. The transition occurs even when the photons are well separated in space.

  9. Photonic Bloch oscillations of correlated particles.

    Science.gov (United States)

    Longhi, Stefano

    2011-08-15

    A photonic realization of Bloch oscillations (BOs) of two correlated electrons that move on a one-dimensional periodic lattice, based on spatial light transport in a square waveguide array with a defect line, is theoretically proposed. The signature of correlated BOs, such as frequency doubling of the oscillation frequency induced by particle interaction, can be simply visualized by monitoring the spatial path followed by an optical beam that excites the array near the defect line.

  10. Quantum state transfer via Bloch oscillations.

    Science.gov (United States)

    Tamascelli, Dario; Olivares, Stefano; Rossotti, Stefano; Osellame, Roberto; Paris, Matteo G A

    2016-05-18

    The realization of reliable quantum channels, able to transfer a quantum state with high fidelity, is a fundamental step in the construction of scalable quantum devices. In this paper we describe a transmission scheme based on the genuinely quantum effect known as Bloch oscillations. The proposed protocol makes it possible to carry a quantum state over different distances with a minimal engineering of the transmission medium and can be implemented and verified on current quantum technology hardware.

  11. A Refresher of the Original Bloch's Law Paper (Bloch, July 1885).

    Science.gov (United States)

    Gorea, Andrei

    2015-08-01

    In 1885, Adolphe-Moïse Bloch asked the following simple question "Is there a law describing the relationship between the duration of a light and its perceived intensity?" Based on a series of experiments using a Foucault regulator and a candle, Bloch concluded that "when the lighting duration varies from 0.00173 to 0.0518 seconds (…) the [visible] light is markedly in inverse proportion to its duration"-his famous law. As this law pertains to the more general and hotly debated question of accumulation of sensory information over time, it is timely to offer the public a full translation of Bloch's original paper (from French) and to present it within the context of contemporary research. PMID:27433317

  12. Inverse Bloch-oscillator: Strong Thz-photocurrent resonances at the Bloch frequency

    Energy Technology Data Exchange (ETDEWEB)

    Unterrainer, K.; Keay, B.J.; Wanke, M.C. [Univ. of California, Santa Barbara, CA (United States)] [and others

    1995-12-31

    We have observed resonant changes in the current-voltage characteristics of miniband semiconductor superlattices when the Bloch frequency is resonant with a terahertz field and its harmonics: the inverse Bloch oscillator effect. The resonant feature consists of a peak in the current which grows with increasing laser intensity accompanied by a decrease of the current at the low bias side. The peak position moves linearly with the laser frequency. When the intensity is increased further the first peak starts to decrease and a second peak at about twice the voltage of the first peak is observed due to a two photon resonance. At the highest intensities we observe up to a four photon resonance. A superlattice is expected to show negative differential conductance due to the strong nonparabolicity of the miniband. In this situation the carriers should undergo Bloch oscillations with a frequency {omega}{sub B} = eEd/h. Transient Bloch oscillations of photo excited carriers have been observed in time resolved Thz emission measurements. However, the possibility of Thz generation form a DC voltage biased superlattice is still under discussion. We have approached this problem by exploring the inverse Bloch oscillator effect in a superlattice excited by the Thz radiation form the UCSB FEL. The superlattice consists of 40 periods of 80{angstrom} GaAs wells and 20{angstrom} Al{sub 0.3}Ga{sub 0.7}As barriers. To couple the electric field of the Terahertz radiation parallel to the growth direction a coplanar bowtie antenna has been employed. Our results show clearly that the external radiation couples to Bloch oscillations in contrary to theoretical suggestions that Thz radiation would not couple to a uniform Wannier Stark ladder. We conclude that this result is intimately related to dissipation and line broadening of the otherwise identical states in the ladder: absorption appears above the Wannier Stark splitting ({omega}{sub B}<{omega}) and gain below ({omega}{sub B}>{omega}).

  13. Bloch's Theorem in the Context of Quaternion Analysis

    CERN Document Server

    Gürlebeck, K

    2012-01-01

    The classical theorem of Bloch (1924) asserts that if $f$ is a holomorphic function on a region that contains the closed unit disk $|z|\\leq 1$ such that $f(0) = 0$ and $|f'(0)| = 1$, then the image domain contains discs of radius $3/2-\\sqrt{2} > 1/12$. The optimal value is known as Bloch's constant and 1/12 is not the best possible. In this paper we give a direct generalization of Bloch's theorem to the three-dimensional Euclidean space in the framework of quaternion analysis. We compute explicitly a lower bound for the Bloch constant.

  14. Bloch oscillations in the presence of plasmons and phonons

    Science.gov (United States)

    Ghosh; Jonsson; Wilkins

    2000-07-31

    The coupling between Bloch oscillating electrons and longitudinal optical phonons in a superlattice leads to resonant phonon excitation but no gap in the Bloch-phonon spectrum. In addition, we predict a sharp transition from plasma to Bloch oscillations at nu(B) = 2nu(P). From a microscopic description with phenomenological dampings, we numerically map out the behavior of coupled Bloch-plasmon-phonon modes for a wide range of parameters, and mimic experimental conditions. Our results are in good agreement with recent experiments by Dekorsy et al. [Phys. Rev. Lett. 85, 1080 (2000)].

  15. Ernst Bloch:repensar la utopia

    Directory of Open Access Journals (Sweden)

    Enric Gil

    2003-07-01

    Full Text Available Aquest article, fruit del treball final de carrera de l'autor per a obtenir la llicenciatura en Humanitats de la UOC, presenta la figura i el pensament d'Ernst Bloch. Considerat el filòsof de la utopia, Bloch aborda aquest tema en totes les seves obres, d'una manera o d'una altra; a més, en la seva trajectòria intel·lectual hi ha una obsessió recurrent pels somnis d'una vida millor en les seves diferents perspectives. Pensador de primera línia, sovint ha estat oblidat i malentès, pel fet de ser considerat un irracionalista que convertia el marxisme en una religió o un marxista heterodox que s'allunyava del materialisme dialèctic per les seves reflexions sobre l'escatologia. La crítica postmodernista dels grans relats i el fracàs dels règims comunistes de l'Est provocaren l'abandó del marxisme i, per extensió, dels seus autors més rellevants.L'article comença amb una exposició general i sintètica dels conceptes de Bloch que apareixen a "El Principi Esperança", comprova el lligam amb la qüestió central de la utopia i desemboca en una reflexió sobre dues utopies del nostre temps que, tot i divergir dels continguts blochians, es troben en diàleg amb l'estructura general dels somnis somiats despert.

  16. Algorithm for generating goldstone and Bloch--Brandow diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Kaldor, U.

    1976-04-01

    An algorithm for the automatic generation of Goldstone and Bloch--Brandow diagrams, needed for diagrammatic perturbation expansions, is described (the Bloch--Brandow diagrams are required for degenerate perturbations). Diagrams are produced in sets, each set consisting of members related by exchanges about interaction lines. Only distinct connected diagrams are generated. Applications are described. 5 figures, 1 table.

  17. Improved Separability Criteria Based on Bloch Representation of Density Matrices.

    Science.gov (United States)

    Shen, Shu-Qian; Yu, Juan; Li, Ming; Fei, Shao-Ming

    2016-01-01

    The correlation matrices or tensors in the Bloch representation of density matrices are encoded with entanglement properties. In this paper, based on the Bloch representation of density matrices, we give some new separability criteria for bipartite and multipartite quantum states. Theoretical analysis and some examples show that the proposed criteria can be more efficient than the previous related criteria. PMID:27350031

  18. Bloch spaces on bounded symmetric domains in complex Banach spaces

    Institute of Scientific and Technical Information of China (English)

    DENG; Fangwen

    2006-01-01

    We give a definition of Bloch space on bounded symmetric domains in arbitrary complex Banach space and prove such function space is a Banach space. The properties such as boundedness, compactness and closed range of composition operators on such Bloch space are studied.

  19. Channa andrao, a new species of dwarf snakehead from West Bengal, India (Teleostei: Channidae).

    Science.gov (United States)

    Britz, Ralf

    2013-10-30

    Channa andrao, new species, from Lefraguri swamp, West Bengal, India, differs from all its congeners except, C. asiatica, C. bleheri and C. burmanica and the recently described C. hoaluensis and C. ninhbinhensis by the absence of pelvic fins. It can be distinguished from all other pelvic fin-less species of snakeheads by its colour pattern, and differs further in its number of vertebrae, dorsal- and anal-fin rays, and lateral-line scales from individual snakehead species in this complex. Channa andrao raises the number of snakehead species endemic to the Eastern Himalaya biodiversity hotspot to ten, representing almost one third of the known species in the genus.

  20. Synchronization of Bloch oscillations by a ring cavity.

    Science.gov (United States)

    Samoylova, M; Piovella, N; Robb, G R M; Bachelard, R; Courteille, Ph W

    2015-06-01

    We consider Bloch oscillations of ultracold atoms stored in a one-dimensional vertical optical lattice and simultaneously interacting with a unidirectionally pumped optical ring cavity whose vertical arm is collinear with the optical lattice. We find that the feedback provided by the cavity field on the atomic motion synchronizes Bloch oscillations via a mode-locking mechanism, steering the atoms to the lowest Bloch band. It also stabilizes Bloch oscillations against noise, and even suppresses dephasing due to atom-atom interactions. Furthermore, it generates periodic bursts of light emitted into the counter-propagating cavity mode, providing a non-destructive monitor of the atomic dynamics. All these features may be crucial for future improvements of the design of atomic gravimeters based on recording Bloch oscillations.

  1. Experimental observation of N00N state Bloch oscillations.

    Science.gov (United States)

    Lebugle, Maxime; Gräfe, Markus; Heilmann, René; Perez-Leija, Armando; Nolte, Stefan; Szameit, Alexander

    2015-09-22

    Bloch oscillations of quantum particles manifest themselves as periodic spreading and relocalization of the associated wave functions when traversing lattice potentials subject to external gradient forces. Albeit this phenomenon is deeply rooted into the very foundations of quantum mechanics, all experimental observations so far have only contemplated dynamics of one and two particles initially prepared in separable local states. Evidently, a more general description of genuinely quantum Bloch oscillations will be achieved on excitation of a Bloch oscillator by nonlocal states. Here we report the observation of Bloch oscillations of two-particle N00N states, and discuss the nonlocality on the ground of Bell-like inequalities. The time evolution of two-photon N00N states in Bloch oscillators, whether symmetric, antisymmetric or partially symmetric, reveals transitions from particle antibunching to bunching. Consequently, the initial states can be tailored to produce spatial correlations akin to those of bosons, fermions and anyons, presenting potential applications in photonic quantum simulation.

  2. Bloch-Like Oscillations in Finite Quantum Structures

    DEFF Research Database (Denmark)

    Duggen, Lars; Willatzen, Morten; Lassen, Benny;

    Inspired by several attempts to generate Bloch-like oscillations in different fields of physics [1,2], we examine a multitude of oscillator systems and interactions that lead to Bloch oscillations in finite quantum structures. A general requirement is the existence of a common period in the time...... of individual quantum wells and changing the coupling strength as a function of position. It is, furthermore, demonstrated that the application of a magnetic field to a structure of quantum wells may lead to the observation of Bloch oscillations (similar to Bloch oscillations stemming from the Stark effect......) and derive rather general mathematical relations between quantum systems that allow the existence of Bloch oscillations. References: [1]: G. Corrielli, A. Crespi, G. Della Valle, S. Longhi, and R. Osellame, Nature Communications 4, 1555 (2013) [2]: H. Sanchis-Alepuz, Y. A. Kosevich, and J. Sanchez...

  3. Short-term feed deprivation alters immune status of surface mucosa in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Short-term feed deprivation (or fasting) is a common occurrence in aquacultured fish species whether due to season, production strategies, or disease. In channel catfish (Ictalurus punctatus) fasting impacts susceptibility to several bacterial pathogens including Flavobacterium columnare, the causat...

  4. CONCURRENT EXPERIMENTAL Streptococcus SPP. INFECTIONS AND NATURAL PARASITISM IN CHANNEL CATFISH Ictalurus punctatus

    Science.gov (United States)

    Streptococcus iniae and S. agalactiae are usually not considered pathogens of channel catfish, Ictalurus punctatus, though concurrent infections may decrease catfish survival when infected with streptococcal organisms. Non-parasitized or naturally-parasitized channel catfish fry were challenged wit...

  5. On unorthodox solutions of the Bloch equations

    CERN Document Server

    Moroz, Alexander

    2012-01-01

    A systematic, rigorous, and complete investigation of the Bloch equations in time-harmonic driving classical field is performed. Our treatment is unique in that it takes full advantage of the partial fraction decomposition over real number field, which makes it possible to find and classify all analytic solutions. Torrey's analytic solution in the form of exponentially damped harmonic oscillations [Phys. Rev. {\\bf 76}, 1059 (1949)] is found to dominate the parameter space, which justifies its use at numerous occasions in magnetic resonance and in quantum optics of atoms, molecules, and quantum dots. The unorthodox solutions of the Bloch equations, which do not have the form of exponentially damped harmonic oscillations, are confined to rather small detunings $\\delta^2\\lesssim (\\gamma-\\gamma_t)^2/27$ and small field strengths $\\Omega^2\\lesssim 8 (\\gamma-\\gamma_t)^2/27$, where $\\gamma$ and $\\gamma_t$ describe decay rates of the excited state (the total population relaxation rate) and of the coherence, respectiv...

  6. Preliminary studies on cryopreservation of snakehead (Channa striata) embryos.

    Science.gov (United States)

    Mohd Sharifuddin, M; Siti Azizah, M N

    2014-08-01

    This paper reports the findings of the ongoing studies on cryopreservation of the snakehead, Channa striata embryos. The specific objective of this study was to collect data on the sensitivity of C. striata embryo hatching rate to low temperatures at two different developmental stages in the presence of four different cryoprotectants. Embryos at morula and heartbeat stages were selected and incubated in 1M dimethyl sulfoxide (Me2SO), 1M ethylene glycol (EG), 1M methanol (MeOH) and 0.1M sucrose solutions at different temperatures for a period of time. Embryos were kept at 24 °C (control), 15 °C, 4 °C and -2 °C for 5 min, 1h and 3h. Following these treatments, the embryos were then transferred into a 24 °C water bath until hatch to evaluate the hatching rate. The results showed that there was a significant decrease of hatching rate in both developmental stages following exposure to 4 °C and -2 °C at 1h and 3h exposure in each treatment. Heartbeat stage was more tolerant against chilling at -2 °C for 3h exposure in Me2SO followed by MeOH, sucrose and EG. Further studies will be conducted to find the best method to preserve embryos for long term storage.

  7. Study on pepsinogens and pepsins from snakehead (Channa argus).

    Science.gov (United States)

    Chen, Wei-Qin; Cao, Min-Jie; Yoshida, Asami; Liu, Guang-Ming; Weng, Wu-Yin; Sun, Le-Chang; Su, Wen-Jin

    2009-11-25

    Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish snakehead (Channa argus) by ammonium sulfate fractionation, anion exchange, and gel filtration. Two-dimensional gel electrophoresis and native-PAGE analysis revealed that their molecular masses were 37, 38, and 36 kDa and their isoelectric points 4.8, 4.4, 4.0, respectively. All of the pepsinogens converted into their active form pepsins under pH 2.0 by one-step pathway or stepwise pathway. The three pepsins showed maximal activity at pH 3.0, 3.5, and 3.0 with optimum temperature at 45, 40, and 40 degrees C, respectively, using hemoglobin as substrate. All of the pepsins were completely inhibited by pepstatin A, a typical aspartic proteinase inhibitor. The N-terminal amino acid sequences of the three pepsinogens were determined to the 34th, 25th, and 28th amino acid residues, respectively. Western blot analysis of the three PGs exhibited different immunological reactions.

  8. Preliminary studies on cryopreservation of snakehead (Channa striata) embryos.

    Science.gov (United States)

    Mohd Sharifuddin, M; Siti Azizah, M N

    2014-08-01

    This paper reports the findings of the ongoing studies on cryopreservation of the snakehead, Channa striata embryos. The specific objective of this study was to collect data on the sensitivity of C. striata embryo hatching rate to low temperatures at two different developmental stages in the presence of four different cryoprotectants. Embryos at morula and heartbeat stages were selected and incubated in 1M dimethyl sulfoxide (Me2SO), 1M ethylene glycol (EG), 1M methanol (MeOH) and 0.1M sucrose solutions at different temperatures for a period of time. Embryos were kept at 24 °C (control), 15 °C, 4 °C and -2 °C for 5 min, 1h and 3h. Following these treatments, the embryos were then transferred into a 24 °C water bath until hatch to evaluate the hatching rate. The results showed that there was a significant decrease of hatching rate in both developmental stages following exposure to 4 °C and -2 °C at 1h and 3h exposure in each treatment. Heartbeat stage was more tolerant against chilling at -2 °C for 3h exposure in Me2SO followed by MeOH, sucrose and EG. Further studies will be conducted to find the best method to preserve embryos for long term storage. PMID:24726775

  9. Description of Pallisentis (Brevitritospinus punctati n. sp. (Acantho¬cephala: Quadrigyridae from Channa punctatus in Ba¬reilly, Uttar Pradesh, India

    Directory of Open Access Journals (Sweden)

    Neelima GUPTA

    2015-12-01

    Full Text Available Background: The genus Pallisentis is an endoparasitic acanthocephalan inhabit­ing the intestinal walls. Hooks and spines of the worm are significant taxonomical and adaptive tools.Methods: The parasites were fixed, dehydrated and examined under Olym­pus BX 53 Microscope with DIC attachment, digital camera and CELLSENS imag­ing system [Light microscopy (LM] and fixed in 2% glutaraldehyde in 0.1 M cacodylate buffer, dehydrated, rotary-coated with gold palladium in NeoCoater 100-240V and examined in Neo JCM-6000 [scanning electron microscopy (SEM].Results: P. punctati n. sp. (prevalence 65.51%; mean intensity 3-6 par/host is de­scribed. Females almost twice as large as males; proboscis hooks small; collar spine rows similar [16] and constant in both sexes but number of spines per row greater in females [22] than males [14]; trunk spine rows 28-39 (spines per row 14-18 in females and 20-26 (spines per row 10-12 in males. spine length of females almost twice as long as males, spines extend up to posterior testis in males and ¾ of total body length in females, Saefftigen’s pouch present, nuclei in cement gland 10-11, seminal vesicle, bursa and egg size small. SEM indicated lack of micro sculptures, and spines embedded on pre-trunk and trunk. Sex-based differences apparent (hook sizes, greater number of spines per row and longer spines in pre-trunk and trunk of females. Male trunk spine was narrower and of lateral spine with characteristic hooked appearance.Conclusion: A new species of Pallisentis based on LM and SEM is described, sexual diversity in hook and spine structure is reported.

  10. Occurrence of Malabar Snakehead, Channa diplogramma (Perciformes: Channidae from River Valapattanam, Western Ghats of Kerala, India

    Directory of Open Access Journals (Sweden)

    Sajan Sajeevan

    2014-01-01

    Full Text Available We report the occurrence of Channa diplogramma in the Valapattanam River in March 2013 and this study adds to the species record of C. diplogramma in terms of diversity and range distribution in the River Valapattanam and South India.

  11. 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.

  12. Salutary value of haruan, the striped snakehead Channa striatus - a review.

    Science.gov (United States)

    Haniffa, Mohammed Abdul Kader; Sheela, Paul Asir Jeya; Kavitha, Kumaresan; Jais, Abdul Manan Mat

    2014-05-01

    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.

  13. Salutary value of haruan, the striped snakehead Channa striatus - a review

    Institute of Scientific and Technical Information of China (English)

    Mohammed Abdul Kader Haniffa; Paul Asir Jeya Sheela; Kumaresan Kavitha; Abdul Manan Mat Jais

    2014-01-01

    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.

  14. 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.

  15. Bloch inductance in small-capacitance Josephson junctions.

    Science.gov (United States)

    Zorin, A B

    2006-04-28

    We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/(omega)CB, an inductive term i(omega)LB. Similar to the known Bloch capacitance CB(q), the Bloch inductance LB(q) also depends periodically on the quasicharge, q, and its maximum value achieved at q=e(mod 2e) always exceeds the value of the Josephson inductance of this junction LJ(phi) at fixed phi=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described.

  16. Bloch-mode analysis for effective parameters restoration

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Andryieuski, Andrei; Ha, Sangwoo;

    2012-01-01

    We utilize the Bloch-mode analysis of periodic composite structures to introduce an approach for retrieving effective parameters of homogenized metamaterials. In the case of single-mode propagation we can restore a complex effective refractive index with a high accuracy. By further employing...... surface or volume averaging of the electromagnetic fields of the dominating (fundamental) Bloch modes we are able to determine the Bloch and wave impedances, leading to wave and material effective parameters, respectively. The approach is demonstrated on several examples. We focus our discussion...

  17. Bloch oscillations in chirped layered structures with metamaterials.

    Science.gov (United States)

    Davoyan, Arthur R; Shadrivov, Ilya V; Sukhorukov, Andrey A; Kivshar, Yuri S

    2008-03-01

    We analyze the Bloch oscillations of electromagnetic waves in chirped layered structures with alternating layers of negative-index metamaterial and conventional dielectric under the condition of the zero average refractive index. We consider the case when the chirp is introduced by varying the thickness of the layers linearly across the structure. We demonstrate that such structures can support three different types of the Bloch oscillations for electromagnetic waves associated with either propagating or evanescent guided modes. In particular, we predict a novel type of the Bloch oscillations associated with coupling between surface waves excited at the interfaces separating the layers of negative-index metamaterial and the layers of the conventional dielectric.

  18. Bloch oscillations of THz acoustic phonons in coupled nanocavity structures.

    Science.gov (United States)

    Lanzillotti-Kimura, N D; Fainstein, A; Perrin, B; Jusserand, B; Mauguin, O; Largeau, L; Lemaître, A

    2010-05-14

    Nanophononic Bloch oscillations and Wannier-Stark ladders have been recently predicted to exist in specifically tailored structures formed by coupled nanocavities. Using pump-probe coherent phonon generation techniques we demonstrate that Bloch oscillations of terahertz acoustic phonons can be directly generated and probed in these complex nanostructures. In addition, by Fourier transforming the time traces we had access to the proper eigenmodes in the frequency domain, thus evidencing the related Wannier-Stark ladder. The observed Bloch oscillation dynamics are compared with simulations based on a model description of the coherent phonon generation and photoelastic detection processes.

  19. Bloch oscillations in a one-dimensional spinor gas.

    Science.gov (United States)

    Gangardt, D M; Kamenev, A

    2009-02-20

    A force applied to a spin-flipped particle in a one-dimensional spinor gas may lead to Bloch oscillations of the particle's position and velocity. The existence of Bloch oscillations crucially depends on the viscous friction force exerted by the rest of the gas on the spin excitation. We evaluate the friction in terms of the quantum fluid parameters. In particular, we show that the friction is absent for integrable cases, such as an SU(2) symmetric gas of bosons or fermions. For small deviations from the exact integrability the friction is very weak, opening the possibility to observe Bloch oscillations.

  20. Unit quaternions and the Bloch sphere

    Science.gov (United States)

    Wharton, K. B.; Koch, D.

    2015-06-01

    The spinor representation of spin-1/2 states can equally well be mapped to a single unit quaternion, yielding a new perspective despite the equivalent mathematics. This paper first demonstrates a useable map that allows Bloch-sphere rotations to be represented as quaternionic multiplications, simplifying the form of the dynamical equations. Left-multiplications generally correspond to non-unitary transformations, providing a simpler (essentially classical) analysis of time-reversal. But the quaternion viewpoint also reveals a surprisingly large broken symmetry, as well as a potential way to restore it, via a natural expansion of the state space that has parallels to second order fermions. This expansion to ‘second order qubits’ would imply either a larger gauge freedom or a natural space of hidden variables.

  1. Bloch state tomography using Wilson lines.

    Science.gov (United States)

    Li, Tracy; Duca, Lucia; Reitter, Martin; Grusdt, Fabian; Demler, Eugene; Endres, Manuel; Schleier-Smith, Monika; Bloch, Immanuel; Schneider, Ulrich

    2016-05-27

    Topology and geometry are essential to our understanding of modern physics, underlying many foundational concepts from high-energy theories, quantum information, and condensed-matter physics. In condensed-matter systems, a wide range of phenomena stem from the geometry of the band eigenstates, which is encoded in the matrix-valued Wilson line for general multiband systems. Using an ultracold gas of rubidium atoms loaded in a honeycomb optical lattice, we realize strong-force dynamics in Bloch bands that are described by Wilson lines and observe an evolution in the band populations that directly reveals the band geometry. Our technique enables a full determination of band eigenstates, Berry curvature, and topological invariants, including single- and multiband Chern and Z₂ numbers. PMID:27230376

  2. Bloch state tomography using Wilson lines

    Science.gov (United States)

    Li, Tracy; Duca, Lucia; Reitter, Martin; Grusdt, Fabian; Demler, Eugene; Endres, Manuel; Schleier-Smith, Monika; Bloch, Immanuel; Schneider, Ulrich

    2016-05-01

    Topology and geometry are essential to our understanding of modern physics, underlying many foundational concepts from high-energy theories, quantum information, and condensed-matter physics. In condensed-matter systems, a wide range of phenomena stem from the geometry of the band eigenstates, which is encoded in the matrix-valued Wilson line for general multiband systems. Using an ultracold gas of rubidium atoms loaded in a honeycomb optical lattice, we realize strong-force dynamics in Bloch bands that are described by Wilson lines and observe an evolution in the band populations that directly reveals the band geometry. Our technique enables a full determination of band eigenstates, Berry curvature, and topological invariants, including single- and multiband Chern and Z2 numbers.

  3. Large momentum beam splitter using Bloch oscillations.

    Science.gov (United States)

    Cladé, Pierre; Guellati-Khélifa, Saïda; Nez, François; Biraben, François

    2009-06-19

    The sensitivity of an inertial sensor based on an atomic interferometer is proportional to the velocity separation of atoms in the two arms of the interferometer. In this Letter we describe how Bloch oscillations can be used to increase this separation and to create a large momentum transfer (LMT) beam splitter. We experimentally demonstrate a separation of 10 recoil velocities. Light shifts during the acceleration introduce phase fluctuations which can reduce the fringes contrast. We precisely calculate this effect and demonstrate that it can be significantly reduced by using a suitable combination of LMT pulses. We finally show that this method seems to be very promising to realize a LMT beam splitter with several tens of recoils and a very good efficiency.

  4. Bloch vector, disclination and exotic quantum holonomy

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atushi, E-mail: tanaka-atushi@tmu.ac.jp [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Cheon, Taksu [Laboratory of Physics, Kochi University of Technology, Tosa Yamada, Kochi 782-8502 (Japan)

    2015-09-04

    A topological formulation of the eigenspace anholonomy, where eigenspaces are interchanged by adiabatic cycles, is introduced. The anholonomy in two-level systems is identified with a disclination of the director (headless vector) of a Bloch vector, which characterizes eigenprojectors. The covering map structure behind the exotic quantum holonomy and the role of the homotopy classification of adiabatic cycles are elucidated. The extensions of this formulation to nonadiabatic cycles and N-level systems are outlined. - Highlights: • A topological formulation of the eigenspace anholonomy is proposed. • The covering map structure behind the anholonomy is identified. • The role of homotopy classification of adiabatic cycles is explained. • The anholonomy in two-level systems is associated with disclinations. • The present formulation offers an extension to nonadiabatic cycles.

  5. Estimates on Bloch constants for planar harmonic mappings

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Bloch constants for quasiregular harmonic mappings and open planar harmonic mappings are considered. Better estimates are obtained. The results, presented in this paper, improve the one made by Chen et al. and Grigoryan.

  6. Coupled bloch-phonon oscillations in semiconductor superlattices

    Science.gov (United States)

    Dekorsy; Bartels; Kurz; Kohler; Hey; Ploog

    2000-07-31

    We investigate coherent Bloch oscillations in GaAs/AlxGa1-xAs superlattices with electronic miniband widths larger than the optical phonon energy. In these superlattices the Bloch frequency can be tuned into resonance with the optical phonon. Close to resonance a direct coupling of Bloch oscillations to LO phonons is observed which gives rise to the coherent excitation of LO phonons. The density necessary for driving coherent LO phonons via Bloch oscillations is about 2 orders of magnitude smaller than the density necessary to drive coherent LO phonons in bulk GaAs. The experimental observations are confirmed by the theoretical description of this phenomenon [A.W. Ghosh et al., Phys. Rev. Lett. 85, 1084 (2000)].

  7. Calculation of the relativistic Bloch correction to stopping power

    Science.gov (United States)

    Ahlen, S. P.

    1982-01-01

    Bloch's technique of joining the nonrelativistic Bethe and Bohr stopping-power expressions by taking into account wave-packet effects for close collisions is extended to the relativistic case. It is found that Bloch's nonrelativistic correction term must be modified and that charge asymmetric terms appear. Excellent agreement is observed by comparing the results of these calculations to recent data on the stopping power of relativistic heavy ions.

  8. Isolation and multiplex genotyping of polymorphic microsatellite DNA markers in the snakehead murrel, Channa striata

    OpenAIRE

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

    2011-01-01

    Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae), a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07) was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. Thes...

  9. Kinetic characterization of Channa striatus muscle sarcoplasmic and myofibrillar protein hydrolysates

    OpenAIRE

    Ghassem, Masomeh; Fern, See Siau; Said, Mamot; Ali, Zainon Mohd; Ibrahim, Saadiah; Babji, Abdul Salam

    2011-01-01

    This study was conducted to evaluate the kinetic characteristics of proteolytic activity of proteases on Channa striatus protein fractions. Degree of hydrolysis (DH), amino acid composition and kinetic parameters of sarcoplasmic and myofibrillar proteins were investigated when incubated with proteinase K and thermolysin, separately. After 30 min incubation with proteases, a decrease in DH of sarcoplasmic protein was observed whereas, hydrolysis of myofibrillar protein with proteases took 2 h ...

  10. Therapeutic potential of the haruan (Channa striatus): from food to medicinal uses.

    Science.gov (United States)

    Mohd, Shafri M A; Abdul Manan, M J

    2012-04-01

    The haruan (Channa striatus) is an indigenous, predatory freshwater fish of Malaysia. It is a common food fish among the local populace with traditionally identified pharmacological benefits in treating wound and pain and in boosting energy of the sick. Channa striatus is also a subject of renewed interest in Malaysian folk medicine in the search for a better cure for diseases and ailments. Amino acids and fatty acids, found in high concentrations in the fish, might have contributed to its pharmacological properties. Important amino acids of the fish include glycine, lysine and arginine, while its fatty acids are arachidonic acid, palmitic acid and docosahexaenoic acid. They appear to effect their influence through the formation of several types of bioactive molecules. Extracts of the fish are produced from whole fish, roe, mucus and skin of the fish. This review updates research findings on potential uses of Channa striatus, beyond the traditional prescription as a wound healer, pain reliever and energy booster to include its properties as a ACE-inhibitor, anti-depressant and neuroregenerative agent. The fish appears to have wide-ranging medical uses and should be studied more intensively to unearth its other properties and mechanisms of action. PMID:23713236

  11. Bloch Oscillations of Einstein-Podolsky-Rosen States

    CERN Document Server

    Lebugle, Maxime; Heilmann, René; Perez-Leija, Armando; Nolte, Stefan; Szameit, Alexander

    2015-01-01

    Bloch Oscillations (BOs) of quantum particles manifest themselves as periodic spreading and re-localization of the associated wave functions when traversing lattice potentials subject to external gradient forces. Albeit BOs are deeply rooted into the very foundations of quantum mechanics, all experimental observations of this phenomenon so far have only contemplated dynamics of one or two particles initially prepared in separable local states, which is well described by classical wave physics. Evidently, a more general description of genuinely quantum BOs will be achieved upon excitation of a Bloch-oscillator lattice system by nonlocal states, that is, containing correlations in contradiction with local realism. Here we report the first experimental observation of BOs of two-particle Einstein-Podolsky-Rosen states (EPR), whose associated N-particle wave functions are nonlocal by nature. The time evolution of two-photon EPR states in Bloch-oscillators, whether symmetric, antisymmetric or partially symmetric, r...

  12. Landau-Zener Bloch Oscillations with Perturbed Flat Bands.

    Science.gov (United States)

    Khomeriki, Ramaz; Flach, Sergej

    2016-06-17

    Sinusoidal Bloch oscillations appear in band structures exposed to external fields. Landau-Zener (LZ) tunneling between different bands is usually a counteracting effect limiting Bloch oscillations. Here we consider a flat band network with two dispersive and one flat band, e.g., for ultracold atoms and optical waveguide networks. Using external synthetic gauge and gravitational fields we obtain a perturbed yet gapless band structure with almost flat parts. The resulting Bloch oscillations consist of two parts-a fast scan through the nonflat part of the dispersion structure, and an almost complete halt for substantial time when the atomic or photonic wave packet is trapped in the original flat band part of the unperturbed spectrum, made possible due to LZ tunneling.

  13. Funcionalidade de hidrolisados proteicos de cabrinha (Prionotus punctatus) obtidos a partir de diferentes proteases microbianas Functionality of bluewing searobin (Prionotus punctatus) protein hydrolysates obtained from different microbial proteases

    OpenAIRE

    Elessandra da Rosa Zavareze; Carolina Moroni Silva; Myriam Salas-Mellado; Carlos Prentice-Hernández

    2009-01-01

    The objective of this work was to study the influence of enzymes Alcalase, Flavourzyme and Novozym in the functional properties of hydrolysates of Bluewing searobin (Prionotus punctatus) minced. The hydrolysates of Bluewing searobin were evaluated for the chemical composition and the functional properties. The Novozym enzyme presented greater specific activity differing significantly from the enzymes Alcalase and Flavourzyme. The hydrolysates of Bluewing searobin presented protein content abo...

  14. 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.

  15. 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...

  16. COMPOSITION OPERATORS ON THE LITTLE BLOCH SPACE IN POLYDISCS

    Institute of Scientific and Technical Information of China (English)

    Zhou Zehua; Zhu Min; Shi Jihuai

    2005-01-01

    Let Un be the unit polydisc of Cn and φ = (φ1,…,φn) a holomorphic self map of Un. This paper shows that the composition operator Cφ induced by φ is bounded on the little Bloch space β0*(Un) if and only if φ∈β0*(Un) for every l=1,2,…,n, and also gives a sufficient and necessary condition for the composition operator Cφ to be compact on the little Bloch spaceβ0* (Un).

  17. Surface optical Bloch oscillations in semi-infinite waveguide arrays.

    Science.gov (United States)

    Chremmos, I D; Efremidis, N K

    2012-06-01

    We predict that surface optical Bloch oscillations can exist in semi-infinite waveguide arrays with a linear index variation, if the array parameters close to the boundary are appropriately perturbed. The perturbation is such that the surface states obtain the Wannier-Stark ladder eigenvalues of the unperturbed infinite array. The number of waveguides, whose parameters need to be controlled, decreases with increasing ratio of index gradient over coupling. The configuration can find applications as a "matched" termination of waveguide arrays to eliminate the distortion of Bloch oscillations due to reflection on the boundaries.

  18. Control of interaction-induced dephasing of Bloch oscillations.

    Science.gov (United States)

    Gustavsson, M; Haller, E; Mark, M J; Danzl, J G; Rojas-Kopeinig, G; Nägerl, H-C

    2008-02-29

    We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice. We quantify the dephasing in terms of the width of the quasimomentum distribution and measure its dependence on time for different interaction strengths which we control by means of a Feshbach resonance. For minimal interaction, the dephasing time is increased from a few to more than 20 thousand Bloch oscillation periods, allowing us to realize a BEC-based atom interferometer in the noninteracting limit.

  19. Optical BLOCH oscillations and Zener tunneling with nonclassical light.

    Science.gov (United States)

    Longhi, Stefano

    2008-11-01

    A quantum theory of optical Bloch oscillations and Zener tunneling (ZT) in arrays of coupled waveguides is theoretically presented, and the particlelike behavior of photons undergoing ZT is highlighted. In singly-periodic arrays excited by a photon-number-state input beam, each photon behaves as a classical particle which independently undergoes a coin-toss ZT event with a probability described by classical Zener theory. In binary arrays, excitation with two tilted beams enables us to observe the Hong-Ou-Mandel interference for two photons undergoing Bloch-Zener oscillations.

  20. Unidirectional optical Bloch oscillations in asymmetric waveguide arrays.

    Science.gov (United States)

    Kumar, Pradeep; Levy, Miguel

    2011-11-15

    We present an analytical proof of the existence of unidirectional optical Bloch oscillations in a waveguide array system. It is shown that the presence of nonreciprocity in the system allows for a complete normal-mode dephasing in one of the propagation directions, resulting in a unidirectional breakdown in Bloch oscillations. A model system consisting of an array of transversely magnetized asymmetric Si/SiO2 waveguides with a magneto-optic cover layer is presented. Large index contrasts between film and cover are critical for practical realizations.

  1. Superfluidity versus Bloch oscillations in confined atomic gases.

    Science.gov (United States)

    Büchler, H P; Geshkenbein, V B; Blatter, G

    2001-09-01

    We study the superfluid properties of (quasi) one-dimensional bosonic atom gases/liquids in traps with finite geometries in the presence of strong quantum fluctuations. Driving the condensate with a moving defect we find the nucleation rate for phase slips using instanton techniques. While phase slips are quenched in a ring resulting in a superfluid response, they proliferate in a tube geometry where we find Bloch oscillations in the chemical potential. These Bloch oscillations describe the individual tunneling of atoms through the defect and thus are a consequence of particle quantization.

  2. Generation of 1D interference patterns of Bloch surface waves

    Science.gov (United States)

    Kadomina, E. A.; Bezus, E. A.; Doskolovich, L. L.

    2016-09-01

    Interference patterns of Bloch surface waves with a period that is significantly less than the wavelength of incident radiation are formed using dielectric diffraction gratings located on the surface of photonic crystal. The simulation based on electromagnetic diffraction theory is used to demonstrate the possibility of high-quality interference patterns due to resonant enhancement of higher evanescent diffraction orders related to the excitation of the Bloch surface waves. The contrast of the interference patterns is close to unity, and the period is less than the period of the diffraction structure by an order of magnitude.

  3. PHYSIOLOGICALLY-BASED TOXICOKINETIC MODELING OF THREE WATERBORNE CHLOROETHANES IN CHANNEL CATFISH, ICTALURUS PUNCTATUS

    Science.gov (United States)

    A physiologically-based toxicokinetic model for fish was used to describe the uptake and disposition of three chlorinated ethanes in channel catfish (Ictalurus punctatus). atfish were simultaneously exposed to 1,1,2,2-tetrachloroethane (TCE), pentachloroethane (PCE), and hexachlo...

  4. RESPIRATORY-CARDIOVASCULAR PHYSIOLOGY AND CHLOROETHANE GILL FLUX IN THE CHANNEL CATFISH ICTALRUS PUNCTATUS

    Science.gov (United States)

    A fish respirometer-metabolism chamber was used to obtain in ivo respiratory-cardiovascular and chloroethane gill flux data on transected channel catfish (Ictalrus punctatus). ethods used for spinal transection, attachment of an oral membrane (respiratory mask), placement and att...

  5. 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...

  6. Comparative Oxygen Tolerance of Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus

    Science.gov (United States)

    Blue catfish (Ictalurus furcatus) have several advantages over channel catfish (I. punctatus) as commercial culture fish. They are more resistant to ESC, PGD, and CCVD, major diseases of channel catfish. They are very easy to seine, with a near-total harvest possible with one seine haul, and may ex...

  7. 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...

  8. 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...

  9. Comparison of the northern snakehead (Channa argus) and blotched snakehead (Channa maculata) and their reciprocal hybrids (C. maculata ♀ × C. argus ♂ and C. argus ♀ × C. maculata ♂) based on complete mitochondrial DNA sequences.

    Science.gov (United States)

    Xincheng, Zhang; Xinping, Zhu; Kunci, Chen; Jian, Zhao; Qing, Luo; Xiaoyou, Hong

    2015-01-01

    The complete mitochondrial DNA of Channa argus, Channa maculata, C. maculate ♀ × C. argus ♂ and C. argus ♀ × C. maculata ♂ were sequenced to characterize and compare their mitochondrial genomes. The lengths were 16,558, 16,559, 16,558 and 16,559 bp respectively. Start codon of 13 protein-coding genes was ATG, except that COI was GTG. The control region of the mitogenome were 907, 908, 907 and 908 bp in C. argus, C. maculata and their reciprocal hybrids (C. argus ♀ × C. maculata ♂ and C. maculate ♀ × C. argus ♂), respectively.

  10. Compact composition operators on the Bloch space in polydiscs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Let Un be the unit polydisc of Cn and =(1,…n) a holomorphicself-map of Un. As the main result of the paper, it shows that the composition operator Cφ is compact on the Bloch space β(Un) if and only if for every ε>0, there exists a δ>0, such thatwhenever dist((z),Un)<δ.

  11. Quantum Properties of Bloch Point as Nanosized Soliton in Ferromagnetics

    Directory of Open Access Journals (Sweden)

    M.Yu. Barabash

    2014-11-01

    Full Text Available It is established that magnetic soliton – Bloch point – has quantum properties which are manifested in the effects of tunneling and above-barrier reflection in a subhelium temperature range. The conditions of the given phenomena are determined.

  12. Topological optical Bloch oscillations in a deformed slab waveguide.

    Science.gov (United States)

    Longhi, Stefano

    2007-09-15

    Spatial Bloch oscillations of light waves of purely topological origin are theoretically shown to exist in weakly deformed slab waveguides. As the optical rays trapped in the deformed waveguide can roll freely, wave diffraction is strongly affected by the topology of the deformed surface, which can be tailored to simulate the effect of a tilted periodic refractive index.

  13. Interaction-induced decoherence of atomic BLOCH oscillations.

    Science.gov (United States)

    Buchleitner, Andreas; Kolovsky, Andrey R

    2003-12-19

    We show that the energy spectrum of the Bose-Hubbard model amended by a static field exhibits Wigner-Dyson level statistics. In itself a characteristic signature of quantum chaos, this induces the irreversible decay of Bloch oscillations of cold, interacting atoms loaded into an optical lattice, and provides a Hamiltonian model for interaction-induced decoherence.

  14. N-qubit states as points on the Bloch sphere

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, H; Messina, A, E-mail: harmak@gmail.co [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, via Archirafi 36, 90123 Palermo (Italy)

    2010-09-01

    We show how the Majorana representation can be used to express the pure states of an N-qubit system as points on the Bloch sphere. We compare this geometrical representation of N-qubit states with an alternative one, proposed recently by the present authors.

  15. Generalized Bloch spheres for m-qubit states

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Klaus [Dipartimento di Scienze Fisiche ed Astronomiche dell' Universita di Palermo, via Archirafi 36, 90123 Palermo (Italy); Sektion Physik, LMU, Muenchen, Theresienstrasse 37, 80333 Munich (Germany)

    2006-02-10

    m-qubit states are embedded in Cl{sub 2m} Clifford algebras. Their probability spectrum then depends on O(2m)- or O(2m + 1)-invariants, respectively. Parameter domains for O(2m(+1))-vector and -tensor configurations, generalizing the notion of a Bloch sphere, are derived.

  16. Lines crossing a tetrahedron and the Bloch group

    CERN Document Server

    Hutchinson, Kevin

    2011-01-01

    We consider a simple modification of the Chow group CH^2(Spec(k),3) using only linear subvarieties in affine spaces and show that it maps surjectively to the Bloch group B(k) for any infinite field k. We also describe the kernel of this map.

  17. Evaluation of a cohabitation challenge model in immunization trials for channel catfish, Ictalurus punctatus (Rafinesque), against Ichthyophthirius multifiliis

    Science.gov (United States)

    Calcein marking and cohabitation challenge have not been investigated in fish parasite research. This study evaluated a cohabitation challenge method in immunization trials against Ichthyophthirius multifiliis (Ich) using calcein, a fluorescent dye, to mark channel catfish Ictalurus punctatus (Rafi...

  18. Efficacy of euphorbia hirta latex as plant derived molluscicides against freshwater snails

    Directory of Open Access Journals (Sweden)

    Ram P. Yadav

    2011-04-01

    Full Text Available The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch (Channidae {Ophicephalidae}, which shares the habitat with these snails, but the LC90 (24h doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.

  19. Isolation and multiplex genotyping of polymorphic microsatellite DNA markers in the snakehead murrel, Channa striata

    Directory of Open Access Journals (Sweden)

    Amirul Firdaus Jamaluddin Jamsari

    2011-01-01

    Full Text Available Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae, a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07 was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. These novel markers would be useful for population genetic studies of the C. striata.

  20. [Parasite fauna of the snakehead Channa argus warpachowskii from Primorsky Krai].

    Science.gov (United States)

    Ermolenko, A V; Besprozvannykh, V V

    2008-01-01

    Parasite fauna of the snakehead Channa argus warpachowskii was studied in water bodies of Primorsky Krai. Thirty-one parasite species were recorded in this host from the studied area according to original and literary data. Most part of these species are host-specific parasites of snakehead originated from Chinese-Indian region or parasites having a wide host range and able to infest almost all freshwater fishes. Moreover, three brackishwater species of parasites were found in the fishes introduced into the rivers of the southern part of Primorsky Krai. The causes of this invasion are discussed.

  1. Complete sequence and characterization of mitochondrial genome in great snakehead, Channa marulius (Hamilton, 1822).

    Science.gov (United States)

    Singh, Rajeev K; Mohindra, Vindhya; Pathak, Abhinav; Lal, Kuldeep K; Jena, J K

    2015-06-01

    The complete nucleotide sequence of mitogenome of the great snakehead, Channa marulius (Channidae), was determined and found to be 16,569 base pairs in length. The content and arrangement of different genes on the mitogenome was found similar to other typical teleosts. The overall base composition of the L-strand was found to be T (19.1%), C (31.5%), A (34.8%) and G (14.6%). The control region was 915 nt long and without any repetitive region. The mitogenome sequence data would be useful for studying phylogenetic relationship of C. marulius with other perciform species.

  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. Isolation and multiplex genotyping of polymorphic microsatellite DNA markers in the snakehead murrel, Channa striata.

    Science.gov (United States)

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

    2011-04-01

    Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae), a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07) was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. These novel markers would be useful for population genetic studies of the C. striata.

  4. Isolation and multiplex genotyping of polymorphic microsatellite DNA markers in the snakehead murrel, Channa striata.

    Science.gov (United States)

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

    2011-04-01

    Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae), a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07) was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. These novel markers would be useful for population genetic studies of the C. striata. PMID:21734840

  5. Funcionalidade de hidrolisados proteicos de cabrinha (Prionotus punctatus obtidos a partir de diferentes proteases microbianas Functionality of bluewing searobin (Prionotus punctatus protein hydrolysates obtained from different microbial proteases

    Directory of Open Access Journals (Sweden)

    Elessandra da Rosa Zavareze

    2009-01-01

    Full Text Available The objective of this work was to study the influence of enzymes Alcalase, Flavourzyme and Novozym in the functional properties of hydrolysates of Bluewing searobin (Prionotus punctatus minced. The hydrolysates of Bluewing searobin were evaluated for the chemical composition and the functional properties. The Novozym enzyme presented greater specific activity differing significantly from the enzymes Alcalase and Flavourzyme. The hydrolysates of Bluewing searobin presented protein content above of 87% and excellent solubility, capacity of water retention, capacity of oil retention and emulsifying capacity.

  6. Lower Cambrian phosphatized Punctatus from southern Shaanxi and their ontogeny sequence

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Phosphatized and three-dimensionally preserved embryos and spherical fossils of metazoan recovered from the Kuanchuanpu Member, Dengying Formation in southern Shaanxi, China provide nice developmental sequence for the studies of origination, taxonomy, phylogenic evolution and developmental biology of early animals. Ontogeny of these larva fossils has not been systemically studied mainly due to their poor preservation and limited identification. The Kuanchuanpu Member, predominated by phosphorites and cherts, yields phosphatized animal embryos, particularly those of Olivooides and Punctatus which have high resolution in fine structures and different ontogeny developmental stages. An ontogenetic sequence of the Punctatus is established mainly base on its developmental transitions from body part to oral one, which is perfectly consistent with the embryonic ontogeny sequence proposed by Bengtson and Yue (1997). Furthermore, a new genus Quadrapyrgites gen. nov is erected to receive a larva with tetraradial body plan.

  7. Clonal structure affects the assembling behavior in the Japanese queenless ant Pristomyrmex punctatus

    Science.gov (United States)

    Nishide, Yudai; Satoh, Toshiyuki; Hiraoka, Tuyosi; Obara, Yoshiaki; Iwabuchi, Kikuo

    2007-10-01

    The queenless ant Pristomyrmex punctatus (Hymenoptera: Myrmicinae) has a unique society that differs from those of other typical ants. This species does not have a queen, and the workers lay eggs and produce their clones parthenogenetically. However, a colony of these ants does not always comprise members derived from a single clonal line. In this study, we examined whether P. punctatus changes its “assembling behavior” based on colony genetic structure. We prepared two subcolonies—a larger one comprising 200 individuals and a smaller one comprising 100 individuals; these subcolonies were established from a single stock colony. We investigated whether these subcolonies assemble into a single nest. The genetically monomorphic subcolonies (single clonal line) always fused into a single nest; however, the genetically polymorphic subcolonies (multiple clonal lines) did not tend to form a single colony. The present study is the first to demonstrate that the colony genetic structure significantly affects social viscosity in social insects.

  8. 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.

  9. Cytoarchitectonic study of the brain of a dwarf snakehead, Channa gachua (Ham.). I. The telencephalon.

    Science.gov (United States)

    Baile, Vidya V; Patle, Pratap J

    2011-12-01

    Cytoarchitectonic pattern of the telencephalon of a dwarf snakehead, Channa gachua, is studied by serial transverse sections of the brain (Kluver and Barrera staining). On the anteriormost extremity of the telencephalon, olfactory bulbs terminate that are sessile. The olfactory bulbs comprise four concentric layers, which from outside toward the center are olfactory nerve layer, a glomerular layer, mitral cell layer, and internal cell layer. Large terminal nerve ganglion cells are prominently visible in the dorsomedial position where the bulbs terminate on the telencephalon. In all, 24 nuclei are identified in the telencephalon on ventral and dorsal areas and are named according to their position. Ventral telencephalon exhibits 11 nuclei. On the dorsal telencephalon, there are 13 nuclei. These again are named according to their position on dorsal, ventral, median, lateral, or posterior part. This study reported for the first time in this fish will be useful in tracing the neuronal system of Channa gachua and subsequent studies of the functional aspects of these nuclei in the regulation of reproductive cycle of this species.

  10. Anderson wall and Bloch oscillations in molecular rotation

    CERN Document Server

    Floß, Johannes

    2014-01-01

    We describe a universal behavior of linear molecules excited by a periodic train of short laser pulses under quantum resonance conditions. In a rigid rotor the resonance causes an unlimited ballistic growth of the angular momentum. We show that the centrifugal distortion of rotating molecules eventually halts the growth, by causing Anderson localization beyond a critical value of the angular momentum -- the Anderson wall. Its position solely depends on the molecular rotational constants and lies in the range of a few tens of hbar. Below the wall, rotational excitation oscillates with the number of pulses due to a mechanism similar to Bloch oscillations in crystalline solids. We suggest optical experiments capable of observing the rotational Anderson wall and Bloch oscillations at ambient conditions with the help of existing laser technology.

  11. Bloch-Redfield equations for modeling light-harvesting complexes

    CERN Document Server

    Jeske, Jan; Plenio, Martin B; Huelga, Susana F; Cole, Jared H

    2014-01-01

    We challenge the commonly held view that Bloch-Redfield equations are a less powerful tool than phenomenological Lindblad equations for modeling exciton transport in photosynthetic complexes. This view predominantly originates from the misuse of the secular approximation. We provide a detailed description of how to model both coherent oscillations and several types of noise, giving explicit examples. All issues with non-positivity are overcome by a consistent straightforward physical noise model. Herein also lies the strength of the Bloch-Redfield approach because it facilitates the analysis of noise-effects by linking them back to physical parameters of the noise environment. This includes temporal and spatial correlations and the strength and type of interaction between the noise and the system of interest. Finally we analyze a prototypical dimer system as well as a 7-site Fenna-Matthews-Olson (FMO) complex in regards to spatial correlation length of the noise, noise strength, temperature and their connecti...

  12. Anderson wall and BLOCH oscillations in molecular rotation.

    Science.gov (United States)

    Floß, Johannes; Averbukh, Ilya Sh

    2014-07-25

    We describe a universal behavior of linear molecules excited by a periodic train of short laser pulses under quantum resonance conditions. In a rigid rotor, the resonance causes an unlimited ballistic growth of the angular momentum. We show that the centrifugal distortion of rotating molecules eventually halts the growth, by causing Anderson localization beyond a critical value of the angular momentum--the Anderson wall. Its position solely depends on the molecular rotational constants and lies in the range of a few tens of ℏ. Below the wall, rotational excitation oscillates with the number of pulses due to a mechanism similar to Bloch oscillations in crystalline solids. We suggest optical experiments capable of observing the rotational Anderson wall and Bloch oscillations at near-ambient conditions with the help of existing laser technology.

  13. Geometry of entangled states, Bloch spheres and Hopf fibrations

    Energy Technology Data Exchange (ETDEWEB)

    Mosseri, Remy [Groupe de Physique des Solides, CNRS UMR 7588, Universites Pierre et Marie Curie et Denis Diderot, Paris (France)]. E-mail: mosseri@gps.jussieu.fr; Dandoloff, Rossen [Laboratoire de Physique Theorique et Modelisation, CNRS-ESA 8089, Universite de Cergy-Pontoise, Cergy-Pontoise (France)]. E-mail: rossen.dandoloff@ptm.u-cergy.fr

    2001-11-30

    We discuss a generalization of the standard Bloch sphere representation for a single qubit to two qubits, in the framework of Hopf fibrations of high-dimensional spheres by lower dimensional spheres. The single-qubit Hilbert space is the three-dimensional sphere S{sup 3}. The S{sup 2} base space of a suitably oriented S{sup 3} Hopf fibration is nothing but the Bloch sphere, while the circular fibres represent the overall qubit phase degree of freedom. For the two-qubits case, the Hilbert space is a seven-dimensional sphere S{sup 7}, which also allows for a Hopf fibration, with S{sup 3} fibres and a S{sup 4} base. The most striking result is that suitably oriented S{sup 7} Hopf fibrations are entanglement sensitive. The relation with the standard Schmidt decomposition is also discussed. (author)

  14. Phosphatized Punctatus with mouthparts and its embryo fossils from the Lower Cambrian of Ningqiang, south Shaanxi, China

    Institute of Scientific and Technical Information of China (English)

    LIU Yunhuan; LI Yong; SHAO Tiequan; ZHU Zhixin; YU Bo; WANG Zhuo; ZHANG Wanqian; LI Rongxi

    2007-01-01

    The appearance of coelenterates marks the real beginning ofmetazoan evolution. It therefore has a prominent position in the origin and evolutionary history of organisms,and is also a pivotal question of evolutionary biology.Punctatus is an extinct, ancient marine animal from the early stage of the Cambrian explosion, occurring at. The lowermost Cambrian of both Kuanchuanpu (Ningqiang, Shaanxi) and Maidiping (Emei, Sichuan) areas. Punctatus has been studied for many years since the discovery of its fragments. System-atic and phylogenetic analysis has long been limited because of the rarity of complete specimens. In order to improve research into Punctatus, more than ten thousand globular fossils were recovered by means of "Chemistry Retting". On the basis of the study of these globular fossils, a series of Punctatus fossils with cone parts and finely preserved soft-tissue mouthparts and fossilized metazoan embryo were recovered. Through research on characteristics such as shape,modality and structure of these fossils symbiotic with Punctatus emeiensis, the author found many possible embryo fossils including the evidence of gastrula-stage animal fossils.The sequence of fetation might have appeared on the corol-liform oral region of Punctatus emeiensis. A study of the soft tissues, functional morphology and the sequence of embryo fossils shows evidence that Punctatus resembles coelenterate polyps in systematic classification. Perhaps it also represents an ancestor of the coelenterate with an original tentacle. A comparison with the real "tentacle animal" found in the Chengjiang Fauna, shows that the original tentacle is very tiny and its function range is limited. This reveals the primi-tive nature of the animal. Although the original tentacle is so small, it does exist, representing the first big step towards the real flexible tentacle with a strong function from the early evolving tentacle.

  15. Surface Bloch waves mediated heat transfer between two photonic crystals

    OpenAIRE

    Ben-Abdallah, Philippe; Joulain, Karl; Pryamikov, Andrey

    2010-01-01

    submitted to Applied Physics Letters We theoretically investigate the non-radiative heat transfer between two photonic crystals separated by a small gap in non-equilibrium thermal situation. We predict that the surface Bloch states coupling supported by these media can make heat exchanges larger than those measured at the same separation distance between two massive homogeneous materials made with the elementary components of photonic crystals. These results could find broad applications i...

  16. Experimental reconstruction of Wilson lines in Bloch bands

    OpenAIRE

    Li, Tracy; Duca, Lucia; Reitter, Martin; Grusdt, Fabian; Demler, Eugene; Endres, Manuel; Schleier-Smith, Monika; Bloch, Immanuel; Schneider, Ulrich

    2015-01-01

    Topology and geometry are essential to our understanding of modern physics, underlying many foundational concepts from high energy theories, quantum information, and condensed matter physics. In condensed matter systems, a wide range of phenomena stem from the geometry of the band eigenstates, which is encoded in the matrix-valued Wilson line for general multi-band systems. By realizing strong-force dynamics in Bloch bands that are described by Wilson lines, we observe an ev...

  17. Nonreciprocal Bloch oscillations in magneto-optic waveguide arrays.

    Science.gov (United States)

    Levy, Miguel; Kumar, Pradeep

    2010-09-15

    We show that nonreciprocal optical Bloch-like oscillations can emerge in transversely magnetized waveguide arrays in the presence of an effective index step between the waveguides. Normal modes of the system are shown to acquire different wavenumbers in opposite propagation directions. Significant differences in phase coherence and decoherence between these normal modes are presented and discussed. Nonreciprocity is established by imposing unequal vertical refractive index gradients at the substrate/core and core/cover interfaces in the presence of transverse magnetization.

  18. Acoustic Bloch oscillations in a two-dimensional phononic crystal.

    Science.gov (United States)

    He, Zhaojian; Peng, Shasha; Cai, Feiyan; Ke, Manzhu; Liu, Zhengyou

    2007-11-01

    We report the observation of acoustic Bloch oscillations at megahertz frequency in a two-dimensional phononic crystal. By creating periodically arrayed cavities with a decreasing gradient in width along one direction in the phononic crystal, acoustic Wannier-Stark ladders are created in the frequency domain. The oscillatory motion of an incident Gaussian pulse inside the sample is demonstrated by both simulation and experiment.

  19. Super Bloch Oscillation in a PT symmetric system

    CERN Document Server

    Turker, Z

    2016-01-01

    Wannier-Stark ladder in a PT symmetric system is generally complex that leads to amplified/damped Bloch oscillation. We show that a non-amplified wave packet oscillation with very large amplitude can be realized in a non-Hermitian tight binding lattice if certain conditions are satisfied. We show that pseudo PT symmetry guarantees the reality of the quasi energy spectrum in our system.

  20. Bloch oscillations of Bose-Einstein condensates: breakdown and revival.

    Science.gov (United States)

    Witthaut, D; Werder, M; Mossmann, S; Korsch, H J

    2005-03-01

    We investigate the dynamics of Bose-Einstein condensates in a tilted one-dimensional periodic lattice within the mean-field (Gross-Pitaevskii) description. Unlike in the linear case the Bloch oscillations decay because of nonlinear dephasing. Pronounced revival phenomena are observed. These are analyzed in detail in terms of a simple integrable model constructed by an expansion in Wannier-Stark resonance states. We also briefly discuss the pulsed output of such systems for stronger static fields.

  1. Damping of Bloch oscillations in the Hubbard model.

    Science.gov (United States)

    Eckstein, Martin; Werner, Philipp

    2011-10-28

    Using nonequilibrium dynamical mean-field theory, we study the isolated Hubbard model in a static electric field in the limit of weak interactions. Linear response behavior is established at long times, but only if the interaction exceeds a critical value, below which the system exhibits an ac-type response with Bloch oscillations. The transition from ac to dc response is defined in terms of the universal long-time behavior of the system, which does not depend on the initial condition.

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

    Directory of Open Access Journals (Sweden)

    Salomon J. Terreblanche

    2008-01-01

    Full Text Available This article explores the tension between history and salvation as theme in contemporary social and humanist philosophy. Special reference is made to Emmanuel Levinas’ work in order to delineate the scope of the questions involved, and to critically elucidate the position on history, death and hope in new-Marxist philosopher Ernst Bloch. The article then illuminates Levinas’ phenomenological account of fecundity, parenthood, patience and institutional justice as hopeful moments that are contained in his philosophy on history

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    We introduce an approach for retrieving effective parameters of metamaterials based on the Bloch-mode analysis of quasiperiodic composite structures. We demonstrate that, in the case of single-mode propagation, a complex effective refractive index can be assigned to the structure, being restored...... that this approach can be useful for retrieval of both material and wave effective parameters of a broad range of metamaterials....

  4. Bloch-Nordsieck cancellations beyond logarithms in heavy particle decays

    OpenAIRE

    Beneke, M.; Braun, Vladimir M.; Zakharov, V. I.

    1994-01-01

    We investigate the one-loop radiative corrections to the semileptonic decay of a charged particle at finite gauge boson mass. Extending the Bloch-Nordsieck cancellation of infrared logarithms, the subsequent non-analytic terms are also found to vanish after eliminating the pole mass in favor of a mass defined at short distances. This observation justifies the operator product expansion for inclusive decays of heavy mesons and implies that infrared effects associated with the summation of the ...

  5. Continuity, the Bloch-Torrey equation, and Diffusion MRI

    CERN Document Server

    Hall, Matt G

    2016-01-01

    The Bloch equation describes the evolution of classical particles tagged with a magnetisation vector in a strong magnetic field and is fundamental to many NMR and MRI contrast methods. The equation can be generalised to include the effects of spin motion by including a spin flux, which typically contains a Fickian diffusive term and/or a coherent velocity term. This form is known as the Bloch-Torrey equation, and is fundamental to MR modalities which are sensitive to spin dynamics such as diffusion MRI. Such modalities have received a great deal of interest in the research literature over the last few years, resulting in a huge range of models and methods. In this work we make make use of a more general Bloch-Torrey equation with a generalised flux term. We show that many commonly employed approaches in Diffusion MRI may be viewed as different choices for the flux terms in this equation. This viewpoint, although obvious theoretically, is not usually emphasised in the diffusion MR literature and points to inte...

  6. Orbital magnetism of Bloch electrons I. General formula

    International Nuclear Information System (INIS)

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

  7. The essential norms of composition operators between generalized Bloch spaces in the polydisc and their applications

    OpenAIRE

    Zhou Zehua; Liu Yan

    2006-01-01

    Let be the unit polydisc of and a holomorphic self-map of . , and denote the -Bloch space, little -Bloch space, and little star -Bloch space in the unit polydisc , respectively, where . This paper gives the estimates of the essential norms of bounded composition operators induced by between ( or ) and ( or ). As their applications, some necessary and sufficient conditions for the (bounded) composition operators to be compact from ( or ) into ( or ) are obtained.

  8. 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-dimensi......-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....

  9. Excitation of Bloch-like surface waves in quasi-crystals and aperiodic dielectric multilayers.

    Science.gov (United States)

    Koju, Vijay; Robertson, William M

    2016-07-01

    The existence of Bloch surface waves in periodic dielectric multilayer structures with a surface defect is well known. Not yet recognized is that quasi-crystals and aperiodic dielectric multilayers can also support Bloch-like surface waves. In this work, we numerically show the excitation of Bloch-like surface waves in Fibonacci quasi-crystals and Thue-Morse aperiodic dielectric multilayers using the prism coupling method. We report improved surface electric field intensity and penetration depth of Bloch-like surface waves in the air side in such structures compared to their periodic counterparts. PMID:27367064

  10. Channa aurantipectoralis, a new species of snakehead from Mizoram, north-eastern India (Teleostei: Channidae).

    Science.gov (United States)

    Lalhlimpuia, Denis Van; Lalronunga, Samuel; Lalramliana, Lalramliana

    2016-08-04

    Channa aurantipectoralis, a new species of snakehead of the C. gachua species group, is described from Karnaphuli drainage of Mizoram, India. The species is immediately distinguished from all other snakehead species by its unique coloration in life, specifically its brightly-coloured orange pectoral fins, which lack any spots or stripes; and by the presence of a dark V-shaped blotch on the dorsal surface of the head. It can be further distinguished from all other species of the genus by the combination of the following characters: presence of pelvic fins, a large scale on the ventral surface of the lower jaw, 51-64 lateral-line scales, 34-37 dorsal-fin rays, 23-25 anal-fin rays, 13-14 pectoral-fin rays, 5½-6½ /1/ 7½-8½ transverse scale rows, and the absence of scales on the gular region.

  11. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    Science.gov (United States)

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

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition.

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

    Science.gov (United States)

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

    2008-10-01

    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. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide.

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

    Science.gov (United States)

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

    2008-10-01

    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. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide. PMID:18514898

  14. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    Science.gov (United States)

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

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition. PMID:19054558

  15. Kinetic characterization of Channa striatus muscle sarcoplasmic and myofibrillar protein hydrolysates.

    Science.gov (United States)

    Ghassem, Masomeh; Fern, See Siau; Said, Mamot; Ali, Zainon Mohd; Ibrahim, Saadiah; Babji, Abdul Salam

    2014-03-01

    This study was conducted to evaluate the kinetic characteristics of proteolytic activity of proteases on Channa striatus protein fractions. Degree of hydrolysis (DH), amino acid composition and kinetic parameters of sarcoplasmic and myofibrillar proteins were investigated when incubated with proteinase K and thermolysin, separately. After 30 min incubation with proteases, a decrease in DH of sarcoplasmic protein was observed whereas, hydrolysis of myofibrillar protein with proteases took 2 h with an increase in DH. The major amino acids were glutamic acid (16.6%) in thermolysin- myofibrillar hydrolysate followed by aspartic acid (11.1%) in sarcoplasmic protein fraction with no enzyme treatment and lysine (10%) in thermolysin-myofibrillar hydrolysate. The apparent Michaelis constant of proteinase K was lower than thermolysin for both sarcoplasmic and myofibrillar proteins. However, rate of turnover and enzyme efficiency suggested that sarcoplasmic and myofibrillar proteins are suitable substrates for proteinase K and thermolysin hydrolytic reaction, respectively.

  16. 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. W...

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

    OpenAIRE

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

    2003-01-01

    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.

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

    International Nuclear Information System (INIS)

    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

  19. Quantum Group and Magnetic Translations. Bethe-Ansatz Solution for Bloch Electrons in a Magnetic Field

    OpenAIRE

    Wiegmann, P. B.; Zabrodin, A. V.

    1993-01-01

    We present a new approach to the problem of Bloch electrons in magnetic field,\\\\ by making explicit a natural relation between magnetic translations and the\\\\quantum group $U_{q}(sl_2)$. The approach allows to express the spectrum and\\\\\\ the Bloch function as solutions of the Bethe-Ansatz equations typical for com\\\\pletely integrable quantum systems

  20. Nonreciprocal Bloch Oscillations in Magneto-Optic Waveguide Arrays

    CERN Document Server

    Levy, Miguel

    2010-01-01

    We show that nonreciprocal optical Bloch-like oscillations can emerge in transversely magnetized waveguide arrays in the presence of an effective index step between the waveguides. Normal modes of the system are shown to acquire different wavenumbers in opposite propagation directions. Significant differences in phase coherence and decoherence between these normal modes are presented and discussed. Non-reciprocity is established by imposing unequal vertical refractive index gradients at the substrate/core, and core/cover interfaces in the presence of transverse magnetization.

  1. Heisenberg-Weyl Observables: Bloch vectors in phase space

    Science.gov (United States)

    Asadian, Ali; Erker, Paul; Huber, Marcus; Klöckl, Claude

    2016-07-01

    We introduce a Hermitian generalization of Pauli matrices to higher dimensions which is based on Heisenberg-Weyl operators. The complete set of Heisenberg-Weyl observables allows us to identify a real-valued Bloch vector for an arbitrary density operator in discrete phase space, with a smooth transition to infinite dimensions. Furthermore, we derive bounds on the sum of expectation values of any set of anticommuting observables. Such bounds can be used in entanglement detection and we show that Heisenberg-Weyl observables provide a first nontrivial example beyond the dichotomic case.

  2. 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

  3. Tunable photonic Bloch oscillations in electrically modulated photonic crystals.

    Science.gov (United States)

    Wang, Gang; Huang, Ji Ping; Yu, Kin Wah

    2008-10-01

    We exploit theoretically the occurrence and tunability of photonic Bloch oscillations (PBOs) in one-dimensional photonic crystals (PCs) containing nonlinear composites. Because of the enhanced third-order nonlinearity (Kerr-type nonlinearity) of composites, photons undergo oscillations inside tilted photonic bands, which are achieved by the application of graded external-pump electric fields on such PCs, varying along the direction perpendicular to the surface of layers. The tunability of PBOs (including amplitude and period) is readily achieved by changing the field gradient. With an appropriate graded pump ac or dc electric field, terahertz PBOs can appear and cover a terahertz band in an electromagnetic spectrum.

  4. Localization without recurrence and pseudo-Bloch oscillations in optics.

    Science.gov (United States)

    Longhi, Stefano

    2015-10-15

    Dynamical localization, i.e., the absence of secular spreading of a quantum or classical wave packet, is usually associated with Hamiltonians by the pure point spectrum, i.e., with a normalizable and complete set of eigenstates. Such systems always show quasi-periodic dynamics (recurrence). Here, we show, rather counter-intuitively, that dynamical localization can be observed in Hamiltonians with an absolutely continuous spectrum, where recurrence effects are forbidden. An optical realization of such a Hamiltonian is proposed based on beam propagation in a self-imaging optical resonator with a phase grating. Localization without recurrence in this system is explained in terms of pseudo-Bloch optical oscillations.

  5. Plasmonic Bloch oscillations in cylindrical metal-dielectric waveguide arrays.

    Science.gov (United States)

    Shiu, Ruei-Cheng; Lan, Yung-Chiang; Chen, Chin-Min

    2010-12-01

    This study investigates plasmonic Bloch oscillations (PBOs) in cylindrical metal-dielectric waveguide arrays (MDWAs) by performing numerical simulations and theoretical analyses. Optical conformal mapping is used to transform cylindrical MDWAs into equivalent chirped structures with permittivity and permeability gradients across the waveguide arrays, which is caused by the curvature of the cylindrical waveguide. The PBOs are attributed to the transformed structure. The period of oscillation increases with the wavelength of the incident Gaussian beam. However, the amplitude of oscillation is almost independent of wavelength.

  6. Localization without recurrence and pseudo-Bloch oscillations in optics

    CERN Document Server

    Longhi, Stefano

    2015-01-01

    Dynamical localization, i.e. the absence of secular spreading of a quantum or classical wave packet, is usually associated to Hamiltonians with purely point spectrum, i.e. with a normalizable and complete set of eigenstates, which show quasi-periodic dynamics (recurrence). Here we show rather counter-intuitively that dynamical localization can be observed in Hamiltonians with absolutely continuous spectrum, where recurrence effects are forbidden. An optical realization of such an Hamiltonian is proposed based on beam propagation in a self-imaging optical resonator with a phase grating. Localization without recurrence in this system is explained in terms of pseudo-Bloch optical oscillations.

  7. Quasi-BLOCH oscillations in curved coupled optical waveguides.

    Science.gov (United States)

    Joushaghani, Arash; Iyer, Rajiv; Poon, Joyce K S; Aitchison, J Stewart; de Sterke, C Martijn; Wan, Jun; Dignam, Marc M

    2009-10-01

    We report the observation of quasi-Bloch oscillations, a recently proposed, new type of dynamic localization in the spatial evolution of light in a curved coupled optical waveguide array. By spatially resolving the optical intensity at various propagation distances, we show the delocalization and final relocalization of the beam in the waveguide array. Through comparisons with other structures, we show that this dynamic localization is robust beyond the nearest-neighbor tight-binding approximation and exhibits a wavelength dependence different from conventional dynamic localization.

  8. Photon BLOCH oscillations in porous silicon optical superlattices.

    Science.gov (United States)

    Agarwal, V; del Río, J A; Malpuech, G; Zamfirescu, M; Kavokin, A; Coquillat, D; Scalbert, D; Vladimirova, M; Gil, B

    2004-03-01

    We report the first observation of oscillations of the electromagnetic field in an optical superlattice based on porous silicon. These oscillations are an optical equivalent of well-known electronic Bloch oscillations in crystals. Elementary cells of our structure are composed by microcavities whose coupling gives rise to the extended collective modes forming optical minigaps and minibands. By varying thicknesses of the cavities along the structure axis, we have created an effective electric field for photons. A very high quality factor of the confined optical state of the Wannier-Stark ladder may allow lasing in porous silicon-based superlattices.

  9. Plasmonic Bloch oscillations in monolayer graphene sheet arrays.

    Science.gov (United States)

    Fan, Yang; Wang, Bing; Huang, He; Wang, Kai; Long, Hua; Lu, Peixiang

    2014-12-15

    We investigate the spatial plasmonic Bloch oscillations (BOs) in the monolayer graphene sheet arrays (MGSAs) as the surface plasmon polaritons (SPPs) between graphene in the arrays experience weak coupling. In order to realize BOs, linear gradient of the potential is introduced by changing the chemical potentials of individual graphene sheets or the interlayer space between graphene. Numerical simulations show that the complete plasmonic BOs can be observed in the former MGSAs. However, only harmonic oscillations occur in the latter of varying interlayer space. Theoretical analysis based on the coupled-mode theory agrees well with the numerical simulations.

  10. Truncated-Bloch-wave solitons in optical lattices

    CERN Document Server

    Wang, Jiandong; Alexander, Tristram J; Kivshar, Yuri S

    2009-01-01

    We study self-trapped localized nonlinear states in the form of truncated Bloch waves in one-dimensional optical lattices, which appear in the gaps of the linear bandgap spectrum. We demonstrate the existence of families of such localized states which differ by the number of intensity peaks. These families do not bifurcate from the band edge, and their power curves exhibit double branches. Linear stability analysis demonstrates that in deep lattice potentials the states corresponding to the lower branches are stable, whereas those corresponding to the upper branches are unstable, independently of the number of peaks.

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

    OpenAIRE

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

    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 M...

  12. Evidence of geographical structuring in the Malaysian Snakehead, Channa striata based on partial segment of the CO1 gene

    OpenAIRE

    Abu Bakar Siti-Balkhis; Amirul Firdaus Jamaluddin Jamsari; Tan Shau Hwai; Zulfigar Yasin; Mohd Nor Siti-Azizah

    2011-01-01

    Channa striata, locally known as "haruan", is economically important in fisheries and aquaculture industries in several Asian countries. DNA sequencing, based on a partial segment of the Cytochrome oxidase c subunit 1 (CO1) gene, was used to determine genetic variation in C. striata samples from four different populations on the west coast of Peninsular Malaysia. The highest nucleotide and haplotype diversities were observed in the Linggi population (π = 0.0067, h = 0.835), and the lowes...

  13. Progress in Crossbreeding of Channa argus and Channa maculata and Biological Study on Their First Filial Generation%乌鳢(♂)×斑鳢(♀)杂交繁育及杂交子一代生物学研究进展

    Institute of Scientific and Technical Information of China (English)

    朱林; 谢楠; 朱树人; 郭水荣; 冯晓宇; 李应森

    2011-01-01

    杂交鳢是以鸟鳢(Channa argus)为父本,斑鳢(C.maculata)为母本杂交获得的子一代,相比亲本,具有牛长速度快、抗逆性强、成活率高、易驯食膨化颗粒饲料的优势.概括了近几年来国内外乌鳢(♂)×斑鳢(♀)杂交繁育历史、杂交繁育技术,同时对乌鳢(♂)x斑鳢(♀)杂交子一代的遗传特性、胚胎发育、生长性能、抗逆性、血液指标、肌肉营养成分等研究现状进行了总结.%Hybrid snakehead is the first filial generation crossbred by Channa argus (male parent) and Channa maculate (female parent). In comparison with parents, it grows in high speed, has a high survival rate, strong stress resistance and easily tames to feed puffed granule feedstuff. This paper summarized that the crossbreeding history and crossbreeding techniques of hybrid snakehead in China and abroad in recent years, and the genetic characteristics, embryonic development, growth performances, stress resistance, blood index, muscle nutrition of first filial generation crossbred by Channa argus and Channa maculate. This paper will supply some basis for germplasm innovation of Channa argus and scientific breeding of varieties.

  14. Local gravity measurement with the combination of atom interferometry and Bloch oscillations

    CERN Document Server

    Charrière, Renée; Zahzam, Nassim; Bidel, Yannick; Bresson, Alexandre

    2011-01-01

    We present a local measurement of gravity combining Bloch oscillations and atom interferometry. With a falling distance of 0.8 mm, we achieve a sensitivity of 2x10-7 g with an integration time of 300 s. No bias associated with the Bloch oscillations has been measured. A contrast decay with Bloch oscillations has been observed and attributed to the spatial quality of the laser beams. A simple experimental configuration has been adopted where a single retro-reflected laser beam is performing atoms launch, stimulated Raman transitions and Bloch oscillations. The combination of Bloch oscillations and atom interferometry can thus be realized with an apparatus no more complex than a standard atomic gravimeter.

  15. BOB.1 of the channel catfish, Ictalurus punctatus: Not a transcriptional coactivator?

    OpenAIRE

    Richard, Mara L. Lennard; Hikima, Jun-ichi; Wilson, Melanie R.; Miller, Norman W.; Cunningham, Charles; Warr, Gregory W.

    2008-01-01

    Expression of the immunoglobulin heavy chain (IGH) locus of the channel catfish (Ictalurus punctatus)is driven by the Eμ3′ enhancer, whose core region contains two octamer motifs and a μE5 site. Orthologues of the Oct1 and Oct2 transcription factors have been cloned in the channel catfish and shown to bind to the octamer motifs within the core enhancer. While catfish Oct2 is an activator of transcription, catfish Oct1 failed to drive transcription and may act as a negative regulator of IGH tr...

  16. Asymptotic Analysis of Quantum Dynamics in Crystals:the Bloch-Wigner Transform, Bloch Dynamics and Berry Phase

    Institute of Scientific and Technical Information of China (English)

    Weinan E; Jian-feng LU; Xu YANG

    2013-01-01

    We study the semi-classical limit of the Schr(o)dinger equation in a crystal in the presence of an external potential and magnetic field.We first introduce the Bloch-Wigner transform and derive the asymptotic equations governing this transform in the semi-classical setting.For the second part,we focus on the appearance of the Berry curvature terms in the asymptotic equations.These terms play a crucial role in many important physical phenomena such as the quantum Hall effect.We give a simple derivation of these terms in different settings using asymptotic analysis.

  17. Bloch-Zener oscillations in a tunable optical honeycomb lattice

    Energy Technology Data Exchange (ETDEWEB)

    Uehlinger, Thomas; Greif, Daniel; Jotzu, Gregor; Esslinger, Tilman [Institute for Quantum Electronics, ETH Zurich, 8093 Zurich (Switzerland); Tarruell, Leticia [Institute for Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland and LP2N, Universite Bordeaux 1, IOGS, CNRS, 351 cours de la Liberation, 33405 Talence (France)

    2013-12-04

    Ultracold gases in optical lattices have proved to be a flexible tool to simulate many different phenomena of solid state physics [1, 2]. Recently, optical lattices with complex geometries have been realized [3, 4, 5, 6, 7], paving the way to simulating more realistic systems. The honeycomb structure has recently become accessible in an optical lattice composed of mutually perpendicular laser beams. This lattice structure exhibits topological features in its band structure – the Dirac points. At these points, two energy bands intersect linearly and the particles behave as relativistic Dirac fermions. In optical lattices, Bloch oscillations [8] resolved both in time and in quasi-momentum space can be directly observed. We make use of such Bloch-Zener oscillations to probe the vanishing energy gap at the Dirac points as well as their position in the band structure. In small band gap regions, we observe Landau-Zener tunneling [7, 9] to the second band and the regions of maximum transfer can be identified with the position of the Dirac points.

  18. Bloch-Redfield equations for modeling light-harvesting complexes.

    Science.gov (United States)

    Jeske, Jan; Ing, David J; Plenio, Martin B; Huelga, Susana F; Cole, Jared H

    2015-02-14

    We challenge the misconception that Bloch-Redfield equations are a less powerful tool than phenomenological Lindblad equations for modeling exciton transport in photosynthetic complexes. This view predominantly originates from an indiscriminate use of the secular approximation. We provide a detailed description of how to model both coherent oscillations and several types of noise, giving explicit examples. All issues with non-positivity are overcome by a consistent straightforward physical noise model. Herein also lies the strength of the Bloch-Redfield approach because it facilitates the analysis of noise-effects by linking them back to physical parameters of the noise environment. This includes temporal and spatial correlations and the strength and type of interaction between the noise and the system of interest. Finally, we analyze a prototypical dimer system as well as a 7-site Fenna-Matthews-Olson complex in regards to spatial correlation length of the noise, noise strength, temperature, and their connection to the transfer time and transfer probability.

  19. The Quantum Noise of Ferromagnetic π-Bloch Domain Walls

    Directory of Open Access Journals (Sweden)

    Peter R. Crompton

    2009-09-01

    Full Text Available We quantify the probability per unit Euclidean-time of reversing the magnetization of a π-Bloch vector, which describes the Ferromagnetic Domain Walls of a Ferromagnetic Nanowire at finite-temperatures. Our approach, based on Langer’s Theory, treats the double sine-Gordon model that defines the π-Bloch vectors via a procedure of nonperturbative renormalization, and uses importance sampling methods to minimise the free energy of the system and identify the saddlepoint solution corresponding to the reversal probability. We identify that whilst the general solution for the free energy minima cannot be expressed in closed form, we can obtain a closed expression for the saddlepoint by maximizing the entanglement entropy of the system as a polynomial ring. We use this approach to quantify the geometric and non-geometric contributions to the entanglement entropy of the Ferromagnetic Nanowire, defined between entangled Ferromagnetic Domain Walls, and evaluate the Euclidean-time dependence of the domain wall width and angular momentum transfer at the domain walls, which has been recently proposed as a mechanism for Quantum Memory Storage.

  20. Comparative study on flesh quality of hybrid snakehead(Channa maculate ♀× Channa argus ♂)and Channa argus%杂交鳢(斑鳢♀×乌鳢♂)与乌鳢肌肉品质比较研究

    Institute of Scientific and Technical Information of China (English)

    邹礼根; 冯晓宇; 王宇希; 刘新轶; 郭水荣; 陈飞东

    2011-01-01

    为了评价杂交鳢(Channa maculate ♀×Channa argus ♂)与乌鳢(Channa argus)肌肉品质,实验选择规格基本相同的1+龄杂交鳢和乌鳢进行比较研究.研究从肌肉基本营养组成、游离氨基酸组成、物理特性指标、质构参数4个方面评价肌肉品质.在肌肉的基本营养组成方面,杂交鳢与乌鳢肌肉粗蛋白含量、灰分含量、粗脂肪含量基本相当,无显著性差异(P>0.05),杂交鳢肌肉水分含量比乌鳢显著性增加(P<0.05).在肌肉游离氨基酸含量方面,杂交鳢游离氨基酸总量、呈味氨基酸含量、必需氨基酸含量分别比乌鳢提高了 7.90%、9.19%、9.01%.在肌肉物理特性方面,与乌鳢相比,杂交鳢肌纤维直径和蒸煮过程肌肉失水率显著性变小(P<0.01),肌原纤维长度显著性增长(P<0.01).在质构参数方面,与乌鳢相比,杂交鳢肌肉弹性、硬度、咀嚼性显著降低(P<0.01),粘聚性显著性增加(P<0.01),恢复性无显著性差异(P>0.05).实验得出的结论是:杂交鳢蛋白质营养水平和质构参数所反映的肌肉品质与乌鳢接近;杂交鳢蛋白质氨基酸水平和物理特性所反映的肌肉品质优于乌鳢.%Hybrid snakehead (Channa maculate ♀ × Channa argus ♂ )and Channa argus with the nearly same standard were selected to study contrastively for evaluating their flesh quality.Then, muscle nutrients composition, free amino acid content, physical parameters and flesh texture parameters were determined to analyze the flesh quality.About muscle nutrients composition , there were no differences (P > 0.05 )in muscle crude protein , crude ash and crude fat between hybrid snakehead and Channa argus, but muscle moisture of hybrid snakehead was increased significantly ( P < 0.01 ).The contents of total free amino acids, flavor amino acids and essential amino acid of hybrid snakehead increased by 7.90%, 9.19% and 9.01%,respectively.About flesh physical index between hybrid

  1. 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.

  2. Metabolic responses of channel catfish (Ictalurus punctatus) exposed to phenol and post-exposure recovery.

    Science.gov (United States)

    Moraes, Fernanda D; Rossi, Priscila A; Figueiredo, Juliana S L; Venturini, Francine P; Cortella, Lucas R X; Moraes, Gilberto

    2016-05-31

    Metabolic adjustments were studied in channel catfish Ictalurus punctatus exposed to 1.5 mg L-1 of phe nol (10% LC50) for four days and recovered for seven days. Lower triacylglycerol (TGA) stores and increased muscle fat free acids (FFA) suggest fat catabolism in muscle. Remarkable liver FFA decrease (-31%) suggests liver fat catabolism as well. Increased muscular ammonia levels and ASAT (aspartate aminotransferase) and decreased plasma aminoacids suggest higher muscular amino acid uptake. Constant levels of glucose and increased liver glycogen stores, associated with lower amino acids in plasma, indicate gluconeogenesis from amino acids. This is supported by higher hepatic ALAT and ASAT. Higher hepatic LDH followed by lower plasma lactate may indicate that plasma lactate was also used as gluconeogenic substrate. Biochemical alterations were exacerbated during the post-exposure recovery period. Reduction in muscle and plasma protein content indicate proteolysis. A higher rate of liver fat catabolism was resulted from a remarkable decrease in hepatic TGA (-58%). Catabolic preference for lipids was observed in order to supply such elevated energy demand. This study is the first insight about the metabolic profile of I. punctatus to cope with phenol plus its ability to recover, bringing attention to the biological consequences of environmental contamination. PMID:27254449

  3. Metabolic responses of channel catfish (Ictalurus punctatus exposed to phenol and post-exposure recovery

    Directory of Open Access Journals (Sweden)

    Fernanda D. Moraes

    2016-06-01

    Full Text Available Metabolic adjustments were studied in channel catfish Ictalurus punctatus exposed to 1.5 mg L-1 of phe nol (10% LC50 for four days and recovered for seven days. Lower triacylglycerol (TGA stores and increased muscle fat free acids (FFA suggest fat catabolism in muscle. Remarkable liver FFA decrease (-31% suggests liver fat catabolism as well. Increased muscular ammonia levels and ASAT (aspartate aminotransferase and decreased plasma aminoacids suggest higher muscular amino acid uptake. Constant levels of glucose and increased liver glycogen stores, associated with lower amino acids in plasma, indicate gluconeogenesis from amino acids. This is supported by higher hepatic ALAT and ASAT. Higher hepatic LDH followed by lower plasma lactate may indicate that plasma lactate was also used as gluconeogenic substrate. Biochemical alterations were exacerbated during the post-exposure recovery period. Reduction in muscle and plasma protein content indicate proteolysis. A higher rate of liver fat catabolism was resulted from a remarkable decrease in hepatic TGA (-58%. Catabolic preference for lipids was observed in order to supply such elevated energy demand. This study is the first insight about the metabolic profile of I. punctatus to cope with phenol plus its ability to recover, bringing attention to the biological consequences of environmental contamination.

  4. Efficacy of crystalline lysine in alternative diets for pond-raised hybrid catfish, female Ictalurus punctatus X male Ictalurus furcatus

    Science.gov (United States)

    study was conducted to examine the efficacy of crystalline lysine in alternative diets for pond-raised hybrid catfish, ' Ictalurus punctatus × ' Ictalurus furcatus. Two 28% protein alternative diets supplemented with l-lysine HCl at the required level based on 62% (previously published value) or 10...

  5. Mitochondrial DNA variation in the East China Sea and Yellow Sea populations of swimming crab Ovalipes punctatus.

    Science.gov (United States)

    Zheng, Wei; Han, Zhiqiang; Chen, Guobao; Yu, Cungen; Gao, Tianxiang

    2015-08-01

    Swimming crab Ovalipes punctatus is a commercially important species in the East China Sea and Yellow Sea, but there is limited knowledge of its genetic population structure. The population genetic structure of O. punctatus in East China Sea and Yellow Sea was examined with a 658-bp segment of the mtDNA COI gene. A total of 60 individuals were collected from five locations and 48 haplotypes were obtained. Mean haplotype diversity and nucleotide diversity for the five populations were 0.9876 ± 0.0068 and 0.0074 ± 0.0041, respectively. Analysis of molecular variance (AMOVA) detected no significant differences at all hierarchical levels, and all FST values were non-significant, indicating that no significant population genetic structure exists in the East China Sea and Yellow Sea. These results supported the null hypothesis that O. punctatus within the East China Sea and Yellow Sea constitutes a panmictic mtDNA gene pool. Neutrality tests and mismatch distribution supported population expansion in this species, indicating that climate change could play an important role in affecting the demographic history of marine species. Strong dispersal capacity of larvae and adults, and ocean currents in the studied area could be the reasons for genetic homogeneity in this species in the East China Sea and Yellow Sea. Another explanation for the lack of phylogeographic structure in O. punctatus might reflect a recent range expansion after the last glacial maximum and insufficient time to attain migration-drift equilibrium.

  6. Impacts of Bolbophorus damnificus digenea: Bolbophoridae on production characteristics of channel catfish, Ictalurus punctatus, raised in experimental ponds

    Science.gov (United States)

    Bolbophorus damnificus was recognized as a threat to channel catfish, Ictalurus punctatus, production in Louisiana and Mississippi in 1997 and 1999, respectively. Severe to moderate outbreaks (=34% prevalence) are correlated to heavy losses, but impact of mild outbreaks with low prevalence (<33%) wa...

  7. Evaluation of corn distillers dried grains with solubles and brewers yeast in diets for channel catfish Ictalurus punctatus

    Science.gov (United States)

    A study was conducted to examine the use of distillers grains with solubles (DDGS), ethanol extracted DDGS (EDDGS), and brewers yeast in channel catfish, Ictalurus punctatus, diets. Diets containing these ingredients were compared with all-plant and fish meal control diets. Juvenile channel catfish ...

  8. Stable isotope analyses reveal the importance of seagrass beds as feeding areas for juvenile Myrophic punctatus in Florida

    Science.gov (United States)

    The feeding habits and habitats of the speckled worm eel Myrophis punctatus were studied on the mangrove edge of the Indian River Lagoon (Florida) using stomach contents and stable isotope analyses of carbon (δ13C) and nitrogen (δ15N). Stomach dietary analyses identified four tax...

  9. 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...

  10. 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...

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

    CERN Document Server

    Lermer, Matthias; Dunzer, Florian; Reitzenstein, Stephan; Höfling, Sven; Mørk, Jesper; Worschech, Lukas; Kamp, Martin; Forchel, Alfred

    2011-01-01

    We have employed Bloch-wave engineering to realize submicron diameter ultra-high quality factor GaAs/AlAs micropillars (MPs). The design features a tapered cavity in which the fundamental Bloch mode is subject to an adiabatic transition to match the Bragg mirror Bloch mode. The resulting reduced 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.

  12. Acoustic analogue of electronic BLOCH oscillations and resonant Zener tunneling in ultrasonic superlattices.

    Science.gov (United States)

    Sanchis-Alepuz, Helios; Kosevich, Yuriy A; Sánchez-Dehesa, José

    2007-03-30

    We demonstrate the existence of Bloch oscillations of acoustic fields in sound propagation through a superlattice of water cavities and layers of methyl methacrylate. To obtain the acoustic equivalent of a Wannier-Stark ladder, we employ a set of cavities with different thicknesses. Bloch oscillations are observed as time-resolved oscillations of transmission in a direct analogy to electronic Bloch oscillations in biased semiconductor superlattices. Moreover, for a particular gradient of cavity thicknesses, an overlap of two acoustic minibands occurs, which results in resonant Zener-like transmission enhancement.

  13. 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

    We have employed Bloch-wave engineering to realize submicron diameter ultra-high quality factor GaAs/AlAs micropillars (MPs). The design features a tapered cavity in which the fundamental Bloch mode is subject to an adiabatic transition to match the Bragg mirror Bloch mode. The resulting reduced...... 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....

  14. Inducing transport in a dissipation-free lattice with super Bloch oscillations.

    Science.gov (United States)

    Haller, Elmar; Hart, Russell; Mark, Manfred J; Danzl, Johann G; Reichsöllner, Lukas; Nägerl, Hanns-Christoph

    2010-05-21

    Particles in a perfect lattice potential perform Bloch oscillations when subject to a constant force, leading to localization and preventing conductivity. For a weakly interacting Bose-Einstein condensate of Cs atoms, we observe giant center-of-mass oscillations in position space with a displacement across hundreds of lattice sites when we add a periodic modulation to the force near the Bloch frequency. We study the dependence of these "super" Bloch oscillations on lattice depth, modulation amplitude, and modulation frequency and show that they provide a means to induce linear transport in a dissipation-free lattice.

  15. Computation and visualization of photonic quasicrystal spectra via Blochs theorem

    CERN Document Server

    Rodriguez, Alejandro W; Avniel, Yehuda; Johnson, Steven G

    2007-01-01

    Previous methods for determining photonic quasicrystal (PQC) spectra have relied on the use of large supercells to compute the eigenfrequencies and/or local density of states (LDOS). In this manuscript, we present a method by which the energy spectrum and the eigenstates of a PQC can be obtained by solving Maxwells equations in higher dimensions for any PQC defined by the standard cut-and-project construction, to which a generalization of Blochs theorem applies. In addition, we demonstrate how one can compute band structures with defect states in the higher-dimensional superspace with no additional computational cost. As a proof of concept, these general ideas are demonstrated for the simple case of one-dimensional quasicrystals, which can also be solved by simple transfer-matrix techniques.

  16. Engineering of slow Bloch modes for optical trapping

    Energy Technology Data Exchange (ETDEWEB)

    Milord, L.; Gerelli, E.; Jamois, C.; Harouri, A.; Benyattou, T., E-mail: taha.benyattou@insa-lyon.fr [Institut des Nanotechnologies de Lyon (INL), CNRS UMR5270, Université de Lyon, INSA-Lyon, Bât “Blaise Pascal,” 7 avenue Jean Capelle, Villeurbanne F-69621 (France); Chevalier, C.; Viktorovitch, P.; Letartre, X. [Institut des Nanotechnologies de Lyon (INL), CNRS UMR5270, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, Ecully F-69134 (France)

    2015-03-23

    In the present paper, we propose an approach based on slow Bloch mode microcavity that enables the optical trapping of small nanoparticles over a broad surface. A specific design based on a double-period photonic crystal is presented. It enables an easy coupling using a wide free-space Gaussian beam and the cavity Q factor can be tuned at will. Moreover, the microcavity mode is mainly localized within the photonic crystal holes, meaning that each hole of the microcavity behaves as efficient nanotweezers. Experimental studies have shown that 200 nm and 100 nm particles can be trapped within the microcavity, in a spatial region that corresponds to the size of one hole (200 nm wide). The experimental trap stiffness has been extracted. It shows that this approach is among the most performant ones if we take into account the size of the cavity.

  17. Landau-Lifhsitz-Bloch equation for exchange coupled grains

    CERN Document Server

    Vogler, Christoph; Bruckner, Florian; Suess, Dieter

    2014-01-01

    Heat assisted recording is a promising technique to further increase the storage density in hard disks. Multilayer recording grains with graded Curie temperature is discussed to further assist the write process. Describing the correct magnetization dynamics of these grains, from room temperature to far above the Curie point, during a write process is required for the calculation of bit error rates. We present a coarse grained approach based on the Landau-Lifshitz-Bloch (LLB) equation to model exchange coupled grains with low computational effort. The required temperature dependent material properties such as the zero-field equilibrium magnetization as well as the parallel and normal susceptibilities are obtained by atomistic Landau-Lifshitz-Gilbert (LLB) simulations. Each grain is described with one magnetization vector. In order to mimic the atomistic exchange interaction between the grains a special treatment of the exchange field in the coarse grained approach is presented.

  18. Coulomb blockade and BLOCH oscillations in superconducting Ti nanowires.

    Science.gov (United States)

    Lehtinen, J S; Zakharov, K; Arutyunov, K Yu

    2012-11-01

    Quantum fluctuations in quasi-one-dimensional superconducting channels leading to spontaneous changes of the phase of the order parameter by 2π, alternatively called quantum phase slips (QPS), manifest themselves as the finite resistance well below the critical temperature of thin superconducting nanowires and the suppression of persistent currents in tiny superconducting nanorings. Here we report the experimental evidence that in a current-biased superconducting nanowire the same QPS process is responsible for the insulating state--the Coulomb blockade. When exposed to rf radiation, the internal Bloch oscillations can be synchronized with the external rf drive leading to formation of quantized current steps on the I-V characteristic. The effects originate from the fundamental quantum duality of a Josephson junction and a superconducting nanowire governed by QPS--the QPS junction.

  19. 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.

  20. 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

  1. Randomized Controlled Trial on the Effect of Channa striatus Extract on Measurement of the Uterus, Pulsatility Index, Resistive Index of Uterine Artery and Superficial Skin Wound Artery in Post Lower Segment Caesarean Section Women.

    Directory of Open Access Journals (Sweden)

    Mohd Rizal Abu Bakar

    Full Text Available To compare the mean of anteroposterior (AP measurements of the uterus in longitudinal and oblique transverse planes, and the pulsatility index (PI and resistive index (RI of the uterine artery and superficial skin wound artery between patients taking Channa striatus and placebo.Channa striatus, also known as haruan, is a fresh water snakehead fish consumed in many parts of Southeast Asia. Channa striatus is also normally consumed by women postpartum to promote wound healing as well as to reduce post-operative pain.This study is a randomised, double blind, placebo-controlled study conducted in women after Lower Segment Caesarean Section (LSCS. Subjects were randomised to either a Channa striatus or a placebo group and were given a daily dosage of 500 mg of Channa striatus extract or 500 mg maltodextrin, respectively, for six weeks post LSCS. The anteroposterior measurements of the uterus in the longitudinal and oblique transverse planes, and the pulsatility index (PI and resistive index (RI of the uterine and superficial skin wound arteries were assessed using pelvic Gray-scale ultrasound and Doppler ultrasound at baseline (Day 3 and at two weeks, four weeks and six weeks post-operatively.Sixty-six subjects were randomised into the study with 33 in the Channa striatus group and 33 in the placebo group. No significant differences were detected in terms of the pulsatility index (PI and the resistive index (RI of the uterine and superficial skin wound arteries between the Channa striatus and placebo groups. However, in the Channa striatus group, the AP measurements of the uterus on the longitudinal and oblique transverse planes were significantly lower compared to the placebo group (p<0.05 and p<0.001, respectively.Daily intake of Channa striatus extract results in marked differences compared to placebo in terms of uterine involution and recovery in women post LSCS.www.isrctn.com 11960786.

  2. Randomized Controlled Trial on the Effect of Channa striatus Extract on Measurement of the Uterus, Pulsatility Index, Resistive Index of Uterine Artery and Superficial Skin Wound Artery in Post Lower Segment Caesarean Section Women

    Science.gov (United States)

    Abdul Karim, Ahmad Helmy; Nik Hussain, Nik Hazlina; Mohd Noor, Norhayati; Omar, Julia; Bin Bai @ Bae, Saringat; Wan Mahmood, Wan Haslindawani; Abdul Razak, Asrenee; Yunus, Rohaizan

    2015-01-01

    Aim To compare the mean of anteroposterior (AP) measurements of the uterus in longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine artery and superficial skin wound artery between patients taking Channa striatus and placebo. Background Channa striatus, also known as haruan, is a fresh water snakehead fish consumed in many parts of Southeast Asia. Channa striatus is also normally consumed by women postpartum to promote wound healing as well as to reduce post-operative pain. Methodology This study is a randomised, double blind, placebo-controlled study conducted in women after Lower Segment Caesarean Section (LSCS). Subjects were randomised to either a Channa striatus or a placebo group and were given a daily dosage of 500 mg of Channa striatus extract or 500 mg maltodextrin, respectively, for six weeks post LSCS. The anteroposterior measurements of the uterus in the longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine and superficial skin wound arteries were assessed using pelvic Gray-scale ultrasound and Doppler ultrasound at baseline (Day 3) and at two weeks, four weeks and six weeks post-operatively. Results Sixty-six subjects were randomised into the study with 33 in the Channa striatus group and 33 in the placebo group. No significant differences were detected in terms of the pulsatility index (PI) and the resistive index (RI) of the uterine and superficial skin wound arteries between the Channa striatus and placebo groups. However, in the Channa striatus group, the AP measurements of the uterus on the longitudinal and oblique transverse planes were significantly lower compared to the placebo group (p<0.05 and p<0.001, respectively). Conclusion Daily intake of Channa striatus extract results in marked differences compared to placebo in terms of uterine involution and recovery in women post LSCS. Trial Registration www.isrctn.com 11960786

  3. 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...

  4. 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...

  5. Stable BLOCH oscillations of cold atoms with time-dependent interaction.

    Science.gov (United States)

    Gaul, C; Lima, R P A; Díaz, E; Müller, C A; Domínguez-Adame, F

    2009-06-26

    We investigate Bloch oscillations of interacting cold atoms in a mean-field framework. In general, atom-atom interaction causes dephasing and destroys Bloch oscillations. Here we show that Bloch oscillations are persistent if the interaction is modulated harmonically with suitable frequency and phase. For other modulations, Bloch oscillations are rapidly damped. We explain this behavior in terms of collective coordinates whose Hamiltonian dynamics permits one to predict a whole family of stable solutions. In order to describe also the unstable cases, we carry out a stability analysis for Bogoliubov excitations. Using Floquet theory, we are able to predict the unstable modes as well as their growth rate, found to be in excellent agreement with numerical simulations.

  6. Spatiotemporal control of light by Bloch-mode dispersion in multi-core fibers

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Sukhorukov, A.A.; Neshev, D.N.;

    2008-01-01

    We study theoretically the dispersion properties of Bloch modes and nonlinearly-induced defect states in two-dimensional waveguide arrays. We define the conditions for achieving anomalous group-velocity dispersion and discuss possibilities for generation of spatiotemporal solitons....

  7. Band structure and Bloch states in birefringent 1D magnetophotonic crystals: An analytical approach

    CERN Document Server

    Lévy, M; Levy, Miguel; Jalali, Amir A

    2007-01-01

    An analytical formulation for the band structure and Bloch modes in elliptically birefringent magnetophotonic crystals is presented. The model incorporates both the effects of gyrotropy and linear birefringence generally present in magneto-optic thin film devices. Full analytical expressions are obtained for the dispersion relation and Bloch modes in a layered stack photonic crystal and their properties are analyzed. It is shown that other models recently discussed in the literature are contained as special limiting cases of the formulation presented herein.

  8. A dorsal fold in Gymnura micrura (Bloch and Scheneider, 1801 (Chondrichthyes: Gymnuridae

    Directory of Open Access Journals (Sweden)

    Jorge Luiz Silva Nunes

    2009-04-01

    Full Text Available This paper reports a dorsal fold which is a membranous structure located on the tail of two juvenile butterfly rays, Gymnura micrura (Bloch & Scheneider, 1801, caught through artisanal fishery in the shallow waters of Maranhão State (Brazil.Neste manuscrito registra-se uma nadadeira dorsal em dois espécimes juvenis de Gymnura micrura (Bloch and Scheneider, 1801 capturadas pela pesca artesanal em águas rasas do estado do Maranhão (Brasil.

  9. Weighted Composition Operators from Bergman-Type Spaces into Bloch Spaces

    Indian Academy of Sciences (India)

    Songxiao Li; Stevo Stević

    2007-08-01

    Let be an analytic self-map and be a fixed analytic function on the open unit disk in the complex plane $\\mathbb{C}$. The weighted composition operator is defined by $$u C_\\varphi f=u\\cdot p (f\\circ\\varphi), f\\in H(D).$$ Weighted composition operators from Bergman-type spaces into Bloch spaces and little Bloch spaces are characterized by function theoretic properties of their inducing maps.

  10. Bloch Oscillations of Two-Component Bose-Einstein Condensates in Optical Lattices

    Institute of Scientific and Technical Information of China (English)

    GU Huai-Qiang; WANG Zhi-Cheng; JIN Kang; TAN Lei

    2006-01-01

    @@ We study the Bloch oscillations of two-component Bose-Einstein condensates trapped in spin-dependent optical lattices. The influence of the intercomponent atom interaction on the system is discussed in detail Accelerated breakdown of the Bloch oscillations and revival phenomena are found respectively for the repulsive and attractive case. For both the cases, the system will finally be set in a quantum self-trapping state due to dynamical instability.

  11. Imaging of Bloch oscillations in erbium-doped curved waveguide arrays.

    Science.gov (United States)

    Chiodo, N; Della Valle, G; Osellame, R; Longhi, S; Cerullo, G; Ramponi, R; Laporta, P; Morgner, U

    2006-06-01

    We report a direct observation of Bloch-like dynamics of light in curved waveguide arrays manufactured in Er:Yb-doped phosphate glass by femtosecond laser writing. The green upconversion fluorescence emitted by excited erbium ions is exploited to image the flow of the guided pump light at approximately 980 nm along the array. Direct and clear evidence of periodic light breathing for single-waveguide excitation, closely related to Bloch oscillations, is reported.

  12. Photonic Bloch oscillations and Wannier-Stark ladders in exponentially chirped Bragg gratings.

    Science.gov (United States)

    Wilkinson, P B

    2002-05-01

    The formation of photonic Bloch oscillations and Wannier-Stark ladders is demonstrated in an exponentially chirped one-dimensional Bragg grating. The photonic Bloch oscillations are investigated using Hamiltonian optics, and direct analogies are made with electron dynamics in periodic potentials. The results of transfer matrix calculations are presented, which show the existence of a photonic Wannier-Stark ladder that should be detectable in experiments.

  13. Modified Bloch-Redfield Master Equation for Incoherent Excitation of Multilevel Quantum Systems

    OpenAIRE

    Tscherbul, Timur V.; Brumer, Paul

    2014-01-01

    We present an efficient theoretical method for calculating the time evolution of the density matrix of a multilevel quantum system weakly interacting with incoherent light. The method combines the Bloch-Redfield theory with a partial secular approximation for one-photon coherences, resulting in a master equation that explicitly exposes the reliance on transition rates and the angles between transition dipole moments in the energy basis. The modified Bloch-Redfield master equation allows an un...

  14. An extended q-deformed su(2) algebra and the Bloch electron problem

    OpenAIRE

    Fujikawa, Kazuo; KUBO, HARUNOBU

    1997-01-01

    It is shown that an extended q-deformed $su(2)$ algebra with an extra (``Schwinger '') term can describe Bloch electrons in a uniform magnetic field with an additional periodic potential. This is a generalization of the analysis of Bloch electrons by Wiegmann and Zabrodin. By using a representation theory of this q-deformed algebra, we obtain functional Bethe ansatz equations whose solutions should be functions of finite degree. It is also shown that the zero energy solution is expressed in t...

  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. The complete mitogenome of the snakehead Channa argus (Perciformes: Channoidei): genome characterization and phylogenetic implications.

    Science.gov (United States)

    Wang, Jialian; Yang, Guang

    2011-08-01

    To better understand the phylogenetic status of the snakehead, Channa argus, we determined its complete mitogenome sequence using long-polymerase chain reaction and the direct sequencing method. The complete mitogenome sequence was 16,559 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region (D-loop), the gene composition/order of which was identical to that observed in most other vertebrates. This was the first report of the mitogenome sequence in suborder Channoidei. Phylogenetic relationships of 14 perciform suborders based on mitogenome sequences were reconstructed using Bayesian inference and maximum likelihood methods. The results strongly supported the monophyly of Perciformes and the snakehead, as a representative species of suborder Channoidei, formed the most basal branch having sister relationship with the clade containing all other analyzed perciform fishes. The further phylogenetic analyses of six channid species, based on cytochrome b gene, suggested that two channid genera constituted reciprocally monophyletic clades. In addition, the relaxed molecular clock method was used to estimate divergence dates among major suborders of Perciformes and major species in Channoidei.

  17. Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water.

    Science.gov (United States)

    Nakkrasae, La-iad; Wisetdee, Khanitha; Charoenphandhu, Narattaphol

    2015-07-01

    NaCl-rich rock salt dissolved in natural water source leads to salinity fluctuation that profoundly affects freshwater ecosystem and aquatic fauna. The snakehead (Channa striata) can live in saline water, but the osmoregulatory mechanisms underlying this ability remain unclear. Herein, we found that exposure to salinities ≥ 10‰ NaCl markedly elevated plasma cortisol and glucose levels, and caused muscle dehydration. In a study of time-dependent response after being transferred from fresh water (0‰ NaCl, FW) to salt-dissolved brackish water (10‰ NaCl, SW), FW-SW, cortisol increased rapidly along with elevations of plasma glucose and lactate. Interestingly, plasma cortisol returned to baseline after prolonged exposure, followed by a second peak that probably enhanced the branchial Na(+)/K(+)-ATPase activity. Under SW-FW condition, Na(+)/K(+)-ATPase activity was not altered as compared to SW-adapted fish. In conclusion, salinity change, especially FW-SW, induced a stress response and hence cortisol release in C. striata, which might increase plasma glucose and lactate to energize the branchial Na(+)/K(+)-ATPase.

  18. ATPase 8/6 GENE BASED GENETIC DIVERSITY ASSESSMENT OF SNAKEHEAD MURREL, Channa striata (Perciformes, Channidae).

    Science.gov (United States)

    Baisvar, V S; Kumar, R; Singh, M; Singh, A K; Chauhan, U K; Nagpure, N S; Kushwaha, B

    2015-10-01

    The mitochondrial DNA (mtDNA) ATPase 8/6 gene has been used in phylogenetic as well as in phylogeographic studies along with other mtDNA markers. In this study, ATPase gene sequences were used to assess the genetic structuring and phylogeographic patterns in Channa striata. Out of 884 nucleotide positions generated in ATPase 8/6 genes, 76 were polymorphic. The study suggested 23 unique haplotypes from 67 individuals of nine populations collected from different riverine systems of India. The ATPase 8/6 sequence revealed highest haplotype as well as nucleotide diversities in Imphal River population and lowest diversities in Tapti River population. The pattern of genetic diversity and haplotype network indicated distinct mitochondrial lineages for Chaliyar population, whereas mismatch distribution strongly suggested a population expansion in mid pleistocene epoch (0.4 Mya) with distinct genetic structuring in C. striata. The baseline information on genetic variation and the population sub-structuring would facilitate conservation and management of this important snakehead murrel.

  19. Isolation and characterization of Aeromonas schubertii from diseased snakehead, Channa maculata (Lacepède).

    Science.gov (United States)

    Chen, Y F; Liang, R S; Zhuo, X L; Wu, X T; Zou, J X

    2012-06-01

    Pure bacterial cultures were isolated from diseased snakeheads, Channa maculata (Lacepède), suffering high mortality in a farm in Zhongshan, southern China. Three isolates, namely ZS20100725, ZS20100725-1 and ZS20100725-2, were identified as Aeromonas schubertii. All the isolates showed high 16S rRNA sequence similarities with A. schubertii. The isolates exhibited strong virulence to snakeheads in experimental challenges with LD(50) ranging between 1.4 × 10(4) and 6.4 × 10(6) CFU g(-1). Two of the isolates were positive for haemolysin, elastase, lipase and lecithinase by phenotypic determination, which was further confirmed by PCR amplification of the haemolysin and elastase genes. In sterile liquid medium, the best growth conditions of strain ZS20100725 were 30 °C, pH 7 and 0.5% salinity (w/v). Antibiotic susceptibility tests showed that strain ZS20100725 was susceptible to cefoxitin, cefoperazone and chloramphenicol. Furthermore, histopathology of diseased snakeheads infected with A. schubertii showed necrosis and congestion in liver, kidney and spleen and also damage to the cardiac muscle, intestine and gills.

  20. Effect of meal size on the specific dynamic action of the juvenile snakehead (Channa argus).

    Science.gov (United States)

    Wang, Qianqian; Wang, Wen; Huang, Qingda; Zhang, Yurong; Luo, Yiping

    2012-04-01

    The effect of meal size on the specific dynamic action (SDA) of the juvenile snakehead (Channa argus) was assessed at 25 °C. The fish were fed with test diets at meal sizes of 0.5, 1, 2, 3, 4, and 5% body mass and the postprandial oxygen consumption rate was determined at 1-h intervals until it returned to the pre-prandial level. The peak metabolic rate increased from 237.4 to 283.2 mg O(2) kg(-1) h(-1) as the relative meal size increased from 0.5% to 3% and leveled off at 4% and 5%. Factorial metabolic scope increased from 1.53 to 1.99 and SDA duration increased from 11.7 to 32.3h as the relative meal size increased from 0.5% to 5%. The relationship between SDA duration (D) and relative meal size (M) was described as: D=4.28 M+10.62 (r(2)=0.752, Psnakehead may adopt different feeding strategies when taking in different amounts of food.

  1. Genetic diversity based on SSR analysis of the cultured snakehead fish, Channa argus, (Channidae) in China.

    Science.gov (United States)

    Zhu, S-R; Li, J-L; Xie, N; Zhu, L-M; Wang, Q; Yue, G-H

    2014-02-13

    The snakehead fish Channa argus is an important food fish in China. We identified six microsatellite loci for C. argus. These six microsatellite loci and four other microsatellite markers were used to analyze genetic diversity in four cultured populations of C. argus (SD, JX, HN, and ZJ) and determine their relationships. A total of 154 alleles were detected at the 10 microsatellite loci. The average expected and observed heterozygosities varied from 0.70-0.84 and 0.69-0.83, respectively, and polymorphism information content ranged between 0.66 and 0.82 in the four populations, indicating high genetic diversity. Population JX deviated from mutation-drift equilibrium and may have experienced a recent bottleneck. Analysis of pairwise genetic differentiation revealed FST values that ranged from 0.028 to 0.100, which indicates a moderate level of genetic differentiation. The largest distances were observed between populations HN and SD, whereas the smallest distances were obtained between populations HN and JX. Genetic clustering analysis demonstrated that the ZJ and HN populations probably share the same origin. This information about the genetic diversity within each of the four populations, and their genetic relationships will be useful for future genetic improvement of C. argus through selective breeding.

  2. Establishment, characterization and viral susceptibility of 3 new cell lines from snakehead, Channa striatus (Blooch).

    Science.gov (United States)

    Zhao, Zhengshan; Montgomery-Brock, Dee; Lee, Cheng-Sheng; Lu, Yuanan

    2003-01-01

    Three cell lines were established from muscle (SHMS), heart (SHHT) and swim bladder (SHSB) of snakehead (Channa striatus). The cells grew initially at 25 degrees C in L15 medium supplemented with 20% fetal bovine serum and have been subcultured 13-18 times since their initiation on June 25, 2002. Growth of the snakehead cells was serum-dependent and plating efficiencies ranged from 22-29%. These snakehead cells grew well in RPMI 1640 and L-15 media, which are commonly used for cultivation of animal and mammalian cells and retained 95.9-96.6% cell viability following storage for 4 months in liquid nitrogen. Karyotyping indicated that these snakehead-derived cell lines remained diploid with a chromosome count of 44 at their early passage (passage 8-14). These cell lines were sensitive to CCV, VHSV, SVCV, IPN and SHRV; they were refractory to IHNV. These newly established cell lines are currently being used for the investigation of snakehead viral diseases in Hawaii and will be available for future isolation and study of snakehead viruses.

  3. ATPase 8/6 GENE BASED GENETIC DIVERSITY ASSESSMENT OF SNAKEHEAD MURREL, Channa striata (Perciformes, Channidae).

    Science.gov (United States)

    Baisvar, V S; Kumar, R; Singh, M; Singh, A K; Chauhan, U K; Nagpure, N S; Kushwaha, B

    2015-10-01

    The mitochondrial DNA (mtDNA) ATPase 8/6 gene has been used in phylogenetic as well as in phylogeographic studies along with other mtDNA markers. In this study, ATPase gene sequences were used to assess the genetic structuring and phylogeographic patterns in Channa striata. Out of 884 nucleotide positions generated in ATPase 8/6 genes, 76 were polymorphic. The study suggested 23 unique haplotypes from 67 individuals of nine populations collected from different riverine systems of India. The ATPase 8/6 sequence revealed highest haplotype as well as nucleotide diversities in Imphal River population and lowest diversities in Tapti River population. The pattern of genetic diversity and haplotype network indicated distinct mitochondrial lineages for Chaliyar population, whereas mismatch distribution strongly suggested a population expansion in mid pleistocene epoch (0.4 Mya) with distinct genetic structuring in C. striata. The baseline information on genetic variation and the population sub-structuring would facilitate conservation and management of this important snakehead murrel. PMID:27169232

  4. Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water.

    Science.gov (United States)

    Nakkrasae, La-iad; Wisetdee, Khanitha; Charoenphandhu, Narattaphol

    2015-07-01

    NaCl-rich rock salt dissolved in natural water source leads to salinity fluctuation that profoundly affects freshwater ecosystem and aquatic fauna. The snakehead (Channa striata) can live in saline water, but the osmoregulatory mechanisms underlying this ability remain unclear. Herein, we found that exposure to salinities ≥ 10‰ NaCl markedly elevated plasma cortisol and glucose levels, and caused muscle dehydration. In a study of time-dependent response after being transferred from fresh water (0‰ NaCl, FW) to salt-dissolved brackish water (10‰ NaCl, SW), FW-SW, cortisol increased rapidly along with elevations of plasma glucose and lactate. Interestingly, plasma cortisol returned to baseline after prolonged exposure, followed by a second peak that probably enhanced the branchial Na(+)/K(+)-ATPase activity. Under SW-FW condition, Na(+)/K(+)-ATPase activity was not altered as compared to SW-adapted fish. In conclusion, salinity change, especially FW-SW, induced a stress response and hence cortisol release in C. striata, which might increase plasma glucose and lactate to energize the branchial Na(+)/K(+)-ATPase. PMID:25899744

  5. Genomic and biological characterization of a new cypovirus isolated from Dendrolimus punctatus.

    Science.gov (United States)

    Zhou, Yin; Qin, Tongcheng; Xiao, Yuzhou; Qin, Fujun; Lei, Chengfeng; Sun, Xiulian

    2014-01-01

    A novel cypovirus (designated DpCPV-MC) was isolated from the pine moth Dendrolimus punctatus using serial in vivo cloning procedures. DpCPV-MC occurs in typical polyhedral occlusion bodies, containing a number of spherical virions. Laboratory bioassays indicated that the infectivity of DpCPV-MC against second-instar Spodoptera exigua larvae does not differ significantly from that of Dendrolimus punctatus cypovirus 1. Full-length amplification of the DpCPV-MC cDNAs identified 16 dsRNA genome segments. Each segment encodes one open reading frame with unique conserved terminal sequences at the 5' and 3' ends, which differ from those of all previously reported cypoviruses. On a phylogenetic tree based on the amino acid sequences of the polyhedrin of 19 cypovirus species, DpCPV-MC was closest to the type-4 cypoviruses. Homology searches showed that ten segments of DpCPV-MC (S1, S2, S3, S4, S5, S7, S8, S9, S12, and S13) encode putative CPV structural and nonstructural proteins, three segments (S6, S10 and S14) encode putative insect proteins or other viral proteins, and the other three segments (S11, S15, and S16) encode proteins that have no obvious sequence similarity to any known protein. Based on RNA secondary structures analysis, two segments of them (S11 and S16) were predicted to possibly transcript less efficiently than the other segments. We speculate that DpCPV-MC is composed of several genotypes. The ten CPV-related segments constantly exist in all genotypes, and one or two of the six CPV-unrelated segments co-exist with the ten CPV-related segments in one DpCPV-MC genotype, thus each virion contains no more than 12 segments. Based on our results and the literature, DpCPV-MC is a new cypovirus (Cypovirus 22, strain DpCPV-22).

  6. Genomic and biological characterization of a new cypovirus isolated from Dendrolimus punctatus.

    Directory of Open Access Journals (Sweden)

    Yin Zhou

    Full Text Available A novel cypovirus (designated DpCPV-MC was isolated from the pine moth Dendrolimus punctatus using serial in vivo cloning procedures. DpCPV-MC occurs in typical polyhedral occlusion bodies, containing a number of spherical virions. Laboratory bioassays indicated that the infectivity of DpCPV-MC against second-instar Spodoptera exigua larvae does not differ significantly from that of Dendrolimus punctatus cypovirus 1. Full-length amplification of the DpCPV-MC cDNAs identified 16 dsRNA genome segments. Each segment encodes one open reading frame with unique conserved terminal sequences at the 5' and 3' ends, which differ from those of all previously reported cypoviruses. On a phylogenetic tree based on the amino acid sequences of the polyhedrin of 19 cypovirus species, DpCPV-MC was closest to the type-4 cypoviruses. Homology searches showed that ten segments of DpCPV-MC (S1, S2, S3, S4, S5, S7, S8, S9, S12, and S13 encode putative CPV structural and nonstructural proteins, three segments (S6, S10 and S14 encode putative insect proteins or other viral proteins, and the other three segments (S11, S15, and S16 encode proteins that have no obvious sequence similarity to any known protein. Based on RNA secondary structures analysis, two segments of them (S11 and S16 were predicted to possibly transcript less efficiently than the other segments. We speculate that DpCPV-MC is composed of several genotypes. The ten CPV-related segments constantly exist in all genotypes, and one or two of the six CPV-unrelated segments co-exist with the ten CPV-related segments in one DpCPV-MC genotype, thus each virion contains no more than 12 segments. Based on our results and the literature, DpCPV-MC is a new cypovirus (Cypovirus 22, strain DpCPV-22.

  7. Snake venomics of Bothrops punctatus, a semiarboreal pitviper species from Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    Maritza Fernández Culma

    2014-01-01

    Full Text Available Bothrops punctatus is an endangered, semi-arboreal pitviper species distributed in Panamá, Colombia, and Ecuador, whose venom is poorly characterized. In the present work, the protein composition of this venom was profiled using the ‘snake venomics’ analytical strategy. Decomplexation of the crude venom by RP-HPLC and SDS-PAGE, followed by tandem mass spectrometry of tryptic digests, showed that it consists of proteins assigned to at least nine snake toxin families. Metalloproteinases are predominant in this secretion (41.5% of the total proteins, followed by C-type lectin/lectin-like proteins (16.7%, bradykinin-potentiating peptides (10.7%, phospholipases A2 (93%, serine proteinases (5.4%, disintegrins (38%, L-amino acid oxidases (3.1%, vascular endothelial growth factors (17%, and cysteine-rich secretory proteins (1.2%. Altogether, 6.6% of the proteins were not identified. In vitro, the venom exhibited proteolytic, phospholipase A2, and L-amino acid oxidase activities, as well as angiotensin-converting enzyme (ACE-inhibitory activity, in agreement with the obtained proteomic profile. Cytotoxic activity on murine C2C12 myoblasts was negative, suggesting that the majority of venom phospholipases A2 likely belong to the acidic type, which often lack major toxic effects. The protein composition of B. punctatus venom shows a good correlation with toxic activities here and previously reported, and adds further data in support of the wide diversity of strategies that have evolved in snake venoms to subdue prey, as increasingly being revealed by proteomic analyses.

  8. Complete Genome Sequence of the Highly Virulent Aeromonas schubertii Strain WL1483, Isolated from Diseased Snakehead Fish (Channa argus) in China.

    Science.gov (United States)

    Liu, Lihui; Li, Ningqiu; Zhang, Defeng; Fu, Xiaozhe; Shi, Cunbin; Lin, Qiang; Hao, Guijie

    2016-01-21

    We sequenced the complete genome of the highly virulent Aeromonas schubertii strain WL1483, which was isolated from diseased snakehead fish (Channa argus) in China. The full genome sequence of A. schubertii WL1483 is 4,400,034 bp, which encodes 4,376 proteins and contains 195 predicted RNA genes.

  9. A comparison between two-scale asymptotic expansions and Bloch wave expansions for the homogenization of periodic structures

    OpenAIRE

    Allaire, Grégoire; Briane, Marc; Vanninathan, Muthusamy

    2016-01-01

    in press International audience In this paper we make a comparison between the two-scale asymptotic expansion method for periodic homogenization and the so-called Bloch wave method. It is well-known that the homogenized tensor coincides with the Hessian matrix of the first Bloch eigenvalue when the Bloch parameter vanishes. In the context of the two-scale asymptotic expansion method, there is the notion of high order homogenized equation [5] where the homogenized equation can be improve...

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

    OpenAIRE

    Miller Norman W; Wilson Melanie R; Kruiswijk Corine P; Ross David A; Hikima Jun-ichi; Lennard Mara L; Warr Gregory W

    2007-01-01

    Abstract Background The enhancer (Eμ3') 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 μE5 site. An orthologue to the Oct2 transcription factor has previously been cloned in catfish and is a functionally active transcription factor. This study was undertaken to clone and characterize the Oct1 trans...

  11. Molecular cloning, expression and the adjuvant effects of interleukin-8 of channel catfish (Ictalurus Punctatus) against Streptococcus iniae

    OpenAIRE

    Erlong Wang; Jun Wang; Bo Long; Kaiyu Wang; Yang He; Qian Yang; Defang Chen; Yi Geng; Xiaoli Huang; Ping Ouyang; Weimin Lai

    2016-01-01

    Interleukin-8 (IL-8) as an important cytokine involving in inflammatory and immune response, has been studied as effective adjuvants for vaccines in mammals. However, there are fewer reports about the characterization and adjuvant effects of IL-8 in fish. In this study, cloning and sequence analysis of IL-8 coding region of channel catfish (Ictalurus punctatus) were conducted, mature IL-8(rtIL-8) was expressed and evaluated for its adjuvant effects on the immunoprotection of subunit vaccine e...

  12. Geometry of the generalized Bloch sphere for qutrit

    CERN Document Server

    Goyal, Sandeep K; Singh, Rajeev; Simon, Sudhavathani

    2011-01-01

    The geometry of the generalized Bloch sphere $\\Omega_3$, the state space of a qutrit is studied. Closed form expressions for $\\Omega_3$, its boundary $\\partial \\Omega_3$, and the set of extremals $\\Omega_3^{\\rm ext}$ are obtained by use of an elementary observation. These expressions and analytic methods are used to classify the 28 two-sections and the 56 three-sections of $\\Omega_3$ into unitary equivalence classes, completing the works of earlier authors. It is shown, in particular, that there are families of two-sections and of three-sections which are equivalent geometrically but not unitarily, a feature that does not appear to have been appreciated earlier. A family of three-sections of obese-tetrahedral shape whose symmetry corresponds to the 24-element tetrahedral point group $T_d$ is examined in detail. This symmetry is traced to the reduction of the adjoint representation of SU(3), the symmetry underlying $\\Omega_3$, into direct sum of the two-dimensional and the two (inequivalent) three-dimensional ...

  13. Floquet-Bloch theory for polymers in a periodic

    Science.gov (United States)

    Pablo Pedro, Ricardo; Tempel, David; Alexander-Katz, Alfredo

    2014-03-01

    Anderson localization in disordered systems predicts the localization of electronic wave functions and the resulting absence of diffusion. The phenomenon is much more general and has been observed in a variety of systems. In the case of the polymer, the behavior of it in a periodic potential is equivalent to the behavior of a quantum-machanicial particle in a periodic potential. According to this mapping our results for polymers in a periodic potential ara valid for localization of a quantum-mechanical particle in a periodic potential. Besides, one of our motivations for studying polymers in a periodic potential is because it reveals interesting aspects of a self-organization of the adsorbed polymers onto a surface with periodic potential. In order to describe the properties of time-periodic polymer system, we consider the potential time dependent which is periodic in time and space and we evaluate the solutions using the powerful nonperturbative Floquet-Bloch theory which is formulated for linear systems. Finally, we also consider a more interesting problem of when disorder is included in the time-periodic system, where localization of the wave function can occur.

  14. Non-Hermitian wave packet approximation of Bloch optical equations

    Energy Technology Data Exchange (ETDEWEB)

    Charron, Eric [Universite Paris-Sud, Institut des Sciences Moleculaires d' Orsay, ISMO, CNRS, F-91405 Orsay (France); Sukharev, Maxim [Department of Applied Sciences and Mathematics, Arizona State University, Mesa, Arizona 85212 (United States)

    2013-01-14

    We introduce a non-Hermitian approximation of Bloch optical equations. This approximation provides a complete description of the excitation, relaxation, and decoherence dynamics of ensembles of coupled quantum systems in weak laser fields, taking into account collective effects and dephasing. In the proposed method, one propagates the wave function of the system instead of a complete density matrix. Relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. As an application, we compute the numerical wave packet solution of a time-dependent non-Hermitian Schroedinger equation describing the interaction of electromagnetic radiation with a quantum nano-structure, and compare the calculated transmission, reflection, and absorption spectra with those obtained from the numerical solution of the Liouville-von Neumann equation. It is shown that the proposed wave packet scheme is significantly faster than the propagation of the full density matrix while maintaining small error. We provide the key ingredients for easy-to-use implementation of the proposed scheme and identify the limits and error scaling of this approximation.

  15. Geometry of the generalized Bloch sphere for qutrits

    Science.gov (United States)

    Goyal, Sandeep K.; Neethi Simon, B.; Singh, Rajeev; Simon, Sudhavathani

    2016-04-01

    The geometry of the generalized Bloch sphere Ω3, the state space of a qutrit, is studied. Closed form expressions for Ω3, its boundary ∂Ω3, and the set of extremals {{{Ω }}}3{{ext}} are obtained by use of an elementary observation. These expressions and analytic methods are used to classify the 28 two-sections and the 56 three-sections of Ω3 into unitary equivalence classes, completing the works of earlier authors. It is shown, in particular, that there are families of two-sections and of three-sections which are equivalent geometrically but not unitarily, a feature that does not appear to have been appreciated earlier. A family of three-sections of obese-tetrahedral shape whose symmetry corresponds to the 24-element tetrahedral point group T d is examined in detail. This symmetry is traced to the natural reduction of the adjoint representation of SU(3), the symmetry underlying Ω3, into direct sum of the two-dimensional and the two (inequivalent) three-dimensional irreducible representations of T d .

  16. 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...

  17. 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.

  18. Molecular cloning of rhamnose-binding lectin gene and its promoter region from snakehead Channa argus.

    Science.gov (United States)

    Jia, W Z; Shang, N; Guo, Q L

    2010-09-01

    Lectins are sugar-binding proteins that mediate pathogen recognition and cell-cell interactions. A rhamnose-binding lectin (RBL) gene and its promoter region have been cloned and characterized from snakehead Channa argus. From the transcription initiation site, snakehead rhamnose-binding lectin (SHL) gene extends 2,382 bp to the end of the 3' untranslated region (UTR), and contains nine exons and eight introns. The open reading frame (ORF) of the SHL transcript has 675 bp which encodes 224 amino acids. The molecular structure of SHL is composed of two tandem repeat carbohydrate recognition domains (CRD) with 35% internal identity. Analysis of the gene organization of SHL indicates that the ancestral gene of RBL may diverge and evolve by exon shuffling and gene duplication, producing new forms to play their own roles in various organisms. The characteristics of SHL gene 5' flanking region are the presence of consensus nuclear factor of interleukin 6 (NF-IL6) and IFN-gamma activation (GAS) sites. The results provide indirect evidence that up-regulation of SHL expression may be induced in response to inflammatory stimuli, such as lipopolysaccharide (LPS), interleukin 6 (IL-6), and interferon gamma (IFN-gamma). The transcript of SHL mRNA was expressed in the head kidney, posterior kidney, spleen, liver, intestine, heart, muscle, and ovary. No tissue-specific expressive pattern is different from reported STLs, WCLs, and PFLs, suggesting that different types of RBLs exist in species-specific fish that have evolved and adapted to their surroundings.

  19. Bloch Oscillation in a One-Dimensional Array of Small Josephson Junctions

    Science.gov (United States)

    Shimada, Hiroshi; Katori, Shunsuke; Gandrothula, Srinivas; Deguchi, Tomoaki; Mizugaki, Yoshinao

    2016-07-01

    A distinct Bloch nose was demonstrated in the current-voltage characteristics of a one-dimensional array of 20 small Josephson junctions. Arrays of direct-current superconducting quantum interference device (dc-SQUID) structures were used as leads to the array of junctions, and the environmental impedance was tuned with a magnetic field. The observed Bloch nose had a negative differential resistance of its magnitude of as large as 14.3 MΩ, a blockade voltage of 0.36 mV, and a decrease in voltage of 0.21 mV due to the Bloch oscillation, all of which are larger than those obtained in a single junction by more than one order. The observed Bloch oscillation was quantitatively described on the basis of the Bloch oscillation of each single junction in combination with the charge soliton model in a long array. Unexpected constant-current spikes, whose origin lay in the dc-SQUID in the leads, were also observed to be superposed on the current-voltage characteristics when the Coulomb blockade appeared.

  20. Experimental and theoretical demonstration of acoustic Bloch oscillations in porous silicon structures

    Energy Technology Data Exchange (ETDEWEB)

    Lazcano, Z.; Arriaga, J., E-mail: arriaga@ifuap.buap.mx [Instituto de Física, Benemérita Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110-A, Ciudad Universitaria, 72570 Puebla (Mexico); Aliev, G. N. [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2014-04-21

    We report the theoretical calculations and the experimental demonstration of acoustic Bloch oscillations and Wannier-Stark ladders in linear tilted multilayer structures based on porous silicon. The considered structures consist of layers with constant porosity alternated by layers with a linear gradient in the parameter η=1/v{sub L}{sup 2} along the growth direction in order to tilt the acoustic band gap. The purpose of this gradient is to mimic the tilted electronic miniband structure of a superlattice semiconductor under an external electric field. In this way, acoustic Wannier-Stark ladders of equidistant modes are formed and they were experimentally confirmed in the transmission spectrum around 1.2 GHz. Their frequency separation defines the period of the acoustic Bloch oscillations. We fabricated three different structures with the same thicknesses but different values in the η parameter to observe the effect on the period of the Bloch oscillations. We measured the acoustic transmission spectra in the frequency domain, and by using the Fourier transform, we obtained the transmission in the time domain. The transmission spectra of the fabricated samples show acoustic Bloch oscillations with periods of 27, 24, and 19 ns. The experimental results are in good agreement with the transfer matrix calculations. The observed phenomenon is the acoustic counterpart of the well known electronic Bloch oscillations.

  1. Probing the intrinsic optical Bloch-mode emission from a 3D photonic crystal.

    Science.gov (United States)

    Hsieh, Mei-Li; Bur, James A; Du, Qingguo; John, Sajeev; Lin, Shawn-Yu

    2016-10-14

    We report experimental observation of intrinsic Bloch-mode emission from a 3D tungsten photonic crystal at low thermal excitation. After the successful removal of conventional metallic emission (normal emission), it is possible to make an accurate comparison of the Bloch-mode and the normal emission. For all biases, we found that the emission intensity of the Bloch-mode is higher than that of the normal emission. The Bloch-mode emission also exhibits a slower dependence on [Formula: see text] than that of the normal emission. The observed higher emission intensity and a different T-dependence is attributed to Bloch-mode assisted emission where emitters have been located into a medium having local density of states different than the isotropic case. Furthermore, our finite-difference time-domain (FDTD) simulation shows the presence of localized spots at metal-air boundaries and corners, having intense electric field. The enhanced plasmonic field and local non-equilibrium could induce a strong thermally stimulated emission and may be the cause of our unusual observation. PMID:27606574

  2. 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.

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

    Science.gov (United States)

    Laude, Vincent; Moiseyenko, Rayisa P.; Benchabane, Sarah; Declercq, Nico F.

    2011-12-01

    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.

  4. 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.

  5. Observation of fractional Bloch band quantum Hall states in graphene/h-BN superlattices

    Science.gov (United States)

    Wang, Lei; Gao, Yuanda; Wen, Bo; Hone, James; Dean, Cory

    The Hofstadter energy spectrum provides a uniquely tunable system to study emergent topological order in the regime of strong interactions. Previous experiments, however, have been limited to low Bloch band fillings where only the Landau level index plays a role. Here we report measurements of high mobility graphene superlattices where the complete unit cell of the Hofstadter spectrum is accessible. We observe coexistence of conventional fractional quantum Hall effect (QHE) states together with the integer QHE states associated with the fractal Hofstadter spectrum. At large magnetic field, we observe signatures of another series of states, which appears at fractional Bloch filling index. These fractional Bloch band QHE states are not anticipated by existing theoretical pictures and point towards a distinct type of many-body state.

  6. Bloch mode synthesis: Ultrafast methodology for elastic band-structure calculations

    Science.gov (United States)

    Krattiger, Dimitri; Hussein, Mahmoud I.

    2014-12-01

    We present a methodology for fast band-structure calculations that is generally applicable to problems of elastic wave propagation in periodic media. The methodology, called Bloch mode synthesis, represents an extension of component mode synthesis, a set of substructuring techniques originally developed for structural dynamics analysis. In Bloch mode synthesis, the unit cell is divided into interior and boundary degrees-of-freedom, which are described, respectively, by a set of normal modes and a set of constraint modes. A combination of these mode sets then forms a reduced basis for the band structure eigenvalue problem. The reduction is demonstrated on a phononic-crystal model and a locally resonant elastic-metamaterial model and is shown to accurately predict the frequencies and Bloch mode shapes with a dramatic decrease in computation time in excess of two orders of magnitude.

  7. Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice.

    Science.gov (United States)

    Xu, Ye-Long; Fegadolli, William S; Gan, Lin; Lu, Ming-Hui; Liu, Xiao-Ping; Li, Zhi-Yuan; Scherer, Axel; Chen, Yan-Feng

    2016-01-01

    As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform. PMID:27095533

  8. Bloch bound states in the radiation continuum in a periodic array of dielectric rods

    CERN Document Server

    Bulgakov, Evgeny N

    2014-01-01

    We consider an infinite periodic array of dielectric rods in vacuum with the aim to demonstrate three types of a Bloch bound states in the continuum (BSC), symmetry protected with a zero Bloch vector, embedded into one diffraction channel with nonzero Bloch vector, and embedded into two and three diffraction channels. The first and second types of the BSC exist in a wide range of material parameters of the rods, while the third occurs only at a specific value of the radius of the rods. We show that the second type supports the power flux along the array. In order to find BSC we put forward an approach based on the expansion over the Hankel functions. We show how the BSC reveals itself in the scattering function when the singular BSC point is approached along a specific path in the parametric space.

  9. Non-destructive monitoring of Bloch oscillations in an optical cavity

    CERN Document Server

    Keßler, H; Venkatesh, B P; Georges, Ch; Hemmerich, A

    2016-01-01

    Bloch oscillations are a hallmark of coherent wave dynamics in periodic potentials. They occur as the response of quantum mechanical particles in a lattice if a weak force is applied. In optical lattices with their perfect periodic structure they can be readily observed and employed as a quantum mechanical force sensor, for example, for precise measurements of the gravitational acceleration. However, the destructive character of the measurement process in previous experimental implementations poses serious limitations for the precision of such measurements. In this article we show that the use of an optical cavity operating in the regime of strong cooperative coupling allows one to directly monitor Bloch oscillations of a cloud of cold atoms in the light leaking out of the cavity. Hence, with a single atomic sample the Bloch oscillation dynamics can be mapped out, while in previous experiments, each data point required the preparation of a new atom cloud. The use of a cavity-based monitor should greatly impro...

  10. Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice.

    Science.gov (United States)

    Xu, Ye-Long; Fegadolli, William S; Gan, Lin; Lu, Ming-Hui; Liu, Xiao-Ping; Li, Zhi-Yuan; Scherer, Axel; Chen, Yan-Feng

    2016-04-20

    As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform.

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

    CERN Document Server

    Wimmer, Martin; Christodoulides, Demetrios; Peschel, Ulf

    2016-01-01

    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 ...

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

    Science.gov (United States)

    Lermer, M; Gregersen, N; Dunzer, F; Reitzenstein, S; Höfling, S; Mørk, J; Worschech, L; Kamp, M; Forchel, A

    2012-02-01

    We have employed Bloch-wave engineering to realize submicron diameter high quality factor GaAs/AlAs micropillars (MPs). The design features a tapered cavity in which the fundamental Bloch mode is subject to an adiabatic transition to match the Bragg mirror Bloch mode. The resulting reduced scattering loss leads to record-high vacuum Rabi splitting of the strong coupling in MPs with modest oscillator strength quantum dots. A quality factor of 13, 600 and a splitting of 85  μeV with an estimated visibility v of 0.41 are observed for a small mode volume MP with a diameter d{c} of 850 nm.

  13. Visualization of Bloch surface waves and directional propagation effects on one-dimensional photonic crystal substrate.

    Science.gov (United States)

    Hung, Yu-Ju; Lin, I-Sheng

    2016-07-11

    This paper reports a novel approach to the direct observation of Bloch surface waves, wherein a layer of fluorescent material is deposited directly on the surface of a semi-infinite periodic layered cell. A set of surface nano-gratings is used to couple pumping light to Bloch surface waves, while the sample is rotated until the pumping light meets the quasi-phase matching conditions. This study investigated the directional propagation of waves on stripe and circular one-dimensional grating structures by analyzing the dispersion relationship of the first two eigen modes. Our results demonstrate the efficacy of the proposed scheme in visualizing Bloch surface waves, which could be extended to a variety of other devices. PMID:27410869

  14. Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice

    Science.gov (United States)

    Xu, Ye-Long; Fegadolli, William S.; Gan, Lin; Lu, Ming-Hui; Liu, Xiao-Ping; Li, Zhi-Yuan; Scherer, Axel; Chen, Yan-Feng

    2016-01-01

    As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform. PMID:27095533

  15. Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice

    Science.gov (United States)

    Xu, Ye-Long; Fegadolli, William S.; Gan, Lin; Lu, Ming-Hui; Liu, Xiao-Ping; Li, Zhi-Yuan; Scherer, Axel; Chen, Yan-Feng

    2016-04-01

    As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform.

  16. The Barkas-Effect Correction to Bethe-Bloch Stopping Power

    Science.gov (United States)

    Porter, L. E.

    A brief history of the discovery of the Barkas-effect correction to the Bethe-Bloch stopping power formula is presented, followed by a recounting of the initial theoretical calculations prepared as a quantitative explanation. A current version of the modified Bethe-Bloch formula is described in detail. An overview of the current capability to assess the validity of several existing formalisms for calculating the Barkas-effect correction term is provided, in the course of which discussion of numerous sources of uncertainty ensues. Finally, an opinion on the significance of this departure from Bethe-Bloch theory is offered, along with a presentation of a few recent developments and of some areas for focus in future exploration in the field of the stopping power of matter for charged particles.

  17. Production of antioxidant and antitumor metabolites by submerged cultures of Inonotus obliquus cocultured with Phellinus punctatus.

    Science.gov (United States)

    Zheng, Weifa; Zhao, Yanxia; Zheng, Xin; Liu, Yubing; Pan, Shenyuan; Dai, Yucheng; Liu, Fuming

    2011-01-01

    While Inonotus obliquus produces a diverse range of bioactive metabolites in its natural habitats, it accumulates less in its submerged cultures. We show here that coculture of I. obliquus with Phellinus punctatus resulted in less production of mycelial biomass but an increased accumulation of phenolic compounds, melanins, and lanostane-type triterpenoids. Metabolites increased in production by coculture include phelligridin C, phelligridin H, methyl inoscavin A, inoscavin C, inoscavin B, davallialactone, methyl davallialactone, foscoparianol D, 21,24-cyclopentalanosta-3β,21,25-triol-8-en, lanosta-7,9(11),23-triene-3β,22,25-triol, and inotodisaccharide and melanins. Metabolites from coculture also showed an increased potential for scavenging free radicals and inhibiting the proliferation of HeLa 229 cells. Davallialactone, methyl davallialactone, and minor phenolic components are the major contributors for scavenging DPPH and hydroxyl radical in monoculture, and phelligridin C, phelligridin H, methyl inoscavin A, inoscavin C, methyl davallialactone, foscoparianol D, and inotodisaccharide are those for scavenging the tested radicals in coculture. Lanostane-type triterpenoids indicated limited roles in scavenging free radicals. Nearly all the detected metabolites correlate positively with inhibiting proliferation of HeLa 229 cells. Thus, coculture of I. obliquus with other fungi seems to be a cost-effective strategy for upregulating biosynthesis of bioactive metabolites. PMID:20830471

  18. 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.

  19. Acute toxicity of nitrofurazone to channel catfish Ictalurus punctatus, and goldfish, Carassius auratus

    Energy Technology Data Exchange (ETDEWEB)

    Wise, M.L.; Stiebel, C.L.; Grizzle, J.M.

    1987-01-01

    Nitrofurazone (5-nitro-2-furaldehyde semicarbazone) is a nitrofuran, a group of organic compounds which have inhibitory activity against many Gram-negative and Gram-positive bacteria and against some protozoan parasites. Although not approved by the United States Food and Drug Administration for use with food fish, nitrofurazone has been found effective in fish against external and internal infections by various species of Aeromonas, Pseudomonas and myxobacteria and can be administered either as a food additive or as a bath treatment. Attempts to control the microsporidian parasite Pleistophora ovariae in golden shiners, Notemigonus crysoleucas, with nitrofurazone met with equivocal results. The following experiment was performed to determine acute toxicity, including lesions, of nitrofurazone to channel catfish, Ictalurus punctatus, and goldfish, carassius auratus, fingerlings. Toxicity of nitrofurazone to channel catfish was determined with low dissolved oxygen concentrations (2 mg/L) to simulate conditions frequently encountered in channel catfish culture. Information abut toxic levels of drugs and the lesions occurring in exposed fish is important to determine the safety of treatment levels and the effects of toxic concentrations.

  20. Short-term feed deprivation alters immune status of surface mucosa in channel catfish (Ictalurus punctatus.

    Directory of Open Access Journals (Sweden)

    Lisa Liu

    Full Text Available Short-term feed deprivation (or fasting is a common occurrence in aquacultured fish species whether due to season, production strategies, or disease. In channel catfish (Ictalurus punctatus fasting impacts susceptibility to several bacterial pathogens including Flavobacterium columnare, the causative agent of columnaris disease. As columnaris gains entry through the gills and skin of fish, we examined here changes in transcriptional regulation induced in these surface mucosal tissues due to short-term (7 day fasting. RNA-seq expression analysis revealed a total of 1,545 genes perturbed by fasting. Fasting significantly altered expression of critical innate immune factors in a manner consistent with lower immune fitness as well as dysregulating key genes involved in energy metabolism and cell cycling/proliferation. Downregulation of innate immune actors such as iNOS2b, Lysozyme C, and peptidoglycan recognition protein 6 is predicted to impact the delicate recognition/tolerance balance for commensal and pathogenic bacteria on the skin and gill. The highlighted expression profiles reveal potential mechanistic similarities between gut and surface mucosa and underscore the complex interrelationships between nutrition, mucosal integrity, and immunity in teleost fish.

  1. Female reproductive dynamics in a Maryland population of ringneck snakes (Diadophis punctatus)

    Science.gov (United States)

    Clark, D.R., Jr.; Bunck, C.M.; Hall, R.J.

    1997-01-01

    Adult female ringneck snakes (Diadophis punctatus) collected from a Maryland population during five successive summers laid a total of 50 clutches in which all eggs hatched successfully under laboratory conditions. Mean hatchling mass was not significantly related to female mass or clutch size when each was evaluated in separate analyses, but was significantly related to these factors when they were evaluated in a joint analysis. Mean hatchling masses of 0.6-1 g appear most adaptive; when females are large enough to produce 1-g eggs, the tendency is to produce a larger number of relatively smaller eggs. The relationship of clutch mass to female mass was unaffected by clutch size. Reproductive effort, measured as relative clutch mass (RCM, clutch mass/female mass), increased with age, as indicated by snout-vent length (SVL); also, the relationship of clutch mass to female mass indicated that clutches equaled a larger percentage as female mass increased. Clutch size averaged 3.55 eggs and ranged from 2 to 6. Clutches were laid from 17 June through 21 July (35 d), median 2 July. Clutches hatched during the 20-d interval 8-27 August (median August 18). Larger clutches were laid earlier in the season on average than smaller clutches. Incubation periods for clutches averaged 47 (range 42-51) d. Clutches laid later in the season averaged shorter incubation periods than clutches laid earlier.

  2. Construction and characterization of a BAC library from a gynogenetic channel catfish Ictalurus punctatus

    Directory of Open Access Journals (Sweden)

    Wilson Melanie

    2003-11-01

    Full Text Available Abstract A bacterial artificial chromosome (BAC library was constructed by cloning HindIII-digested high molecular weight DNA from a gynogenetic channel catfish, Ictalurus punctatus, into the vector pBeloBAC11. Approximately 53 500 clones were arrayed in 384-well plates and stored at -80°C (CCBL1, while clones from a smaller insert size fraction were stored at -80°C without arraying (CCBL2. Pulsed-field gel electrophoresis of 100 clones after NotI digestion revealed an average insert size of 165 kb for CCBL1 and 113 kb for CCBL2. Further characterization of CCBL1 demonstrated that 10% of the clones did not contain an insert. CCBL1 provides a 7.2-fold coverage of the channel catfish haploid genome. PCR-based screening demonstrated that 68 out of 74 unique loci were present in the library. This represents a 92% chance to find a unique sequence. These libraries will be useful for physical mapping of the channel catfish genome, and identification of genes controlling major traits in this economically important species.

  3. Quantum distance and the Euler number index of the Bloch band in a one-dimensional spin model.

    Science.gov (United States)

    Ma, Yu-Quan

    2014-10-01

    We study the Riemannian metric and the Euler characteristic number of the Bloch band in a one-dimensional spin model with multisite spins exchange interactions. The Euler number of the Bloch band originates from the Gauss-Bonnet theorem on the topological characterization of the closed Bloch states manifold in the first Brillouin zone. We study this approach analytically in a transverse field XY spin chain with three-site spin coupled interactions. We define a class of cyclic quantum distance on the Bloch band and on the ground state, respectively, as a local characterization for quantum phase transitions. Specifically, we give a general formula for the Euler number by means of the Berry curvature in the case of two-band models, which reveals its essential relation to the first Chern number of the band insulators. Finally, we show that the ferromagnetic-paramagnetic phase transition in zero temperature can be distinguished by the Euler number of the Bloch band.

  4. Atomic Bloch-Zener oscillations and Stückelberg interferometry in optical lattices.

    Science.gov (United States)

    Kling, Sebastian; Salger, Tobias; Grossert, Christopher; Weitz, Martin

    2010-11-19

    We report on experiments investigating quantum transport and band interferometry of an atomic Bose-Einstein condensate in an optical lattice with a two-band miniband structure, realized with a Fourier-synthesized optical lattice potential. Bloch-Zener oscillations, the coherent superposition of Bloch oscillations and Landau-Zener tunneling between the two bands, are observed. When the relative phase between paths in different bands is varied, an interference signal is observed, demonstrating the coherence of the dynamics in the miniband system. Measured fringe patterns of this Stückelberg interferometer allow us to interferometrically map out the band structure of the optical lattice over the full Brillouin zone.

  5. The intensive terahertz electroluminescence induced by Bloch oscillations in SiC natural superlattices.

    Science.gov (United States)

    Sankin, Vladimir; Andrianov, Alexandr; Petrov, Alexey; Zakhar'in, Alexey; Lepneva, Ala; Shkrebiy, Pavel

    2012-10-09

    : We report on efficient terahertz (THz) emission from high-electric-field-biased SiC structures with a natural superlattice at liquid helium temperatures. The emission spectrum demonstrates a single line, the maximum of which shifts linearly with increases in bias field. We attribute this emission to steady-state Bloch oscillations of electrons in the SiC natural superlattice. The properties of the THz emission agree fairly with the parameters of the Bloch oscillator regime, which have been proven by high-field electron transport studies of SiC structures with natural superlattices.

  6. Bloch-Zener oscillations across a merging transition of Dirac points.

    Science.gov (United States)

    Lim, Lih-King; Fuchs, Jean-Noël; Montambaux, Gilles

    2012-04-27

    Bloch oscillations are a powerful tool to investigate spectra with Dirac points. By varying band parameters, Dirac points can be manipulated and merged at a topological transition toward a gapped phase. Under a constant force, a Fermi sea initially in the lower band performs Bloch oscillations and may Zener tunnel to the upper band mostly at the location of the Dirac points. The tunneling probability is computed from the low-energy universal Hamiltonian describing the vicinity of the merging. The agreement with a recent experiment on cold atoms in an optical lattice is very good.

  7. Schrodinger cat states prepared by Bloch oscillation in a spin-dependent optical lattice

    CERN Document Server

    Wu, B J

    2011-01-01

    We propose to use Bloch oscillation of ultra-cold atoms in a spin-dependent optical lattice to prepare schrodinger cat states. Depending on its internal state, an atom feels different periodic potentials and thus has different energy band structures for its center-of-mass motion. Consequently, under the same gravity force, the wave packets associated with different internal states perform Bloch oscillation of different amplitudes in space and in particular they can be macroscopically displaced with respect to each other. In this way, a cat state can be prepared.

  8. Immunological role of C4 CC chemokine-1 from snakehead murrel Channa striatus.

    Science.gov (United States)

    Bhatt, Prasanth; Kumaresan, Venkatesh; Palanisamy, Rajesh; Chaurasia, Mukesh Kumar; Gnanam, Annie J; Pasupuleti, Mukesh; Arockiaraj, Jesu

    2014-02-01

    In this study, we have reported a cDNA sequence of C4 CC chemokine identified from snakehead murrel (also known as striped murrel) Channa striatus (named as CsCC-Chem-1) normalized cDNA library constructed by Genome Sequencing FLX™ Technology (GS-FLX™). CsCC-Chem-1 is 641 base pairs (bp) long that contain 438 bp open reading frame (ORF). The ORF encodes a polypeptide of 146 amino acids with a molecular mass of 15 kDa. The polypeptide contains a small cytokine domain at 30-88. The domain carries the CC motif at Cys(33)-Cys(34). In addition, CsCC-Chem-1 consists of another two cysteine residues at C(59) and C(73), which, together with C(33) and C(34), make CsCC-Chem-1 as a C4-CC chemokine. CsCC-Chem-1 also contains a 'TCCT' motif at 32-35 as CC signature motif; this new motif may represent new characteristic features, which may lead to some unknown function that needs to be further focused on. Phylogenitically, CsCC-Chem-1 clustered together with CC-Chem-1 from rock bream Oplegnathus fasciatus and European sea bass Dicentrarchus labrax. Significantly (P<0.05) highest gene expression was noticed in spleen and is up-regulated upon fungus (Aphanomyces invadans), bacteria (Aeromonas hydrophila) and virus (poly I:C) infection at various time points. The gene expression results indicate the influence of CsCC-Chem-1 in the immune system of murrel. Overall, the gene expression study showed that the CsCC-Chem-1 is a capable gene to increase the cellular response against various microbial infections. Further, we cloned the coding sequence of CsCC-Chem-1 in pMAL vector and purified the recombinant protein to study the functional properties. The cell proliferation activity of recombinant CsCC-Chem-1 protein showed a significant metabolic activity in a concentration dependent manner. Moreover, the chemotaxis assay showed the capability of recombinant CsCC-Chem-1 protein which can induce the migration of spleen leukocytes in C. striatus. However, this remains to be verified

  9. Molecular characterization, phylogeny and expression of a hepcidin gene in the blotched snakehead Channa maculata.

    Science.gov (United States)

    Gong, Li-cai; Wang, Hao; Deng, Li

    2014-05-01

    A hepcidin-like gene (cmHep) was cloned and characterized from the liver of the blotched snakehead Channa maculata. The complete cmHep cDNA was 756 bp in length, containing an open reading frame of 270 bp (encoding 89 amino acids), flanked by 210 bp and 276 bp of 5' and 3' untranslated regions, respectively. The deduced peptide of 89 amino acids consisted of 24 aa, 40 aa and 25 aa for signal peptide, prodomain and mature peptide, respectively. The mature peptide had eight cysteines at the identical conserved positions in common with most of other known hepcidins in vertebrates. cmHepc gene displayed a tripartite structure (three exons interrupted by two introns), which organisation was conserved between the blotched snakehead and other fish species. Phylogenetic analysis of hepcidins from C. maculata and other vertebrates showed that major phylogenetic grouping of fish hepcidin coincided with the current euteleosts classification, indicating the multiphyletic evolution of hepcidin in the teleosts. In the Acanthopterygii subclade, there were two distinct additional subclades named as HAMP-Ac1 and HAMP-Ac2. The blotched snakehead hepcidin was in the group HAMP-Ac1, which has the hypothetical iron regulatory sequence [Q-S/I-H-L/I-S/A] motif in N-terminal of mature peptide. The RT-PCR showed cmHep mRNA transcripts were widely distributed in all tissues tested in the blotched snakehead including the liver, gill, intestine, spleen, head kidney and peripheral white blood cell. The most abundant of cmHep mRNA was detected in liver. A significant up-regulation of cmHep expression was detected only in head kidney at 24h post-challenge with Vibrio parahaemolyticus in blotched snakehead adults, no significant differences found in liver, gill, intestine and spleen. The cmHep expression was up-regulated in spleen, head kidney and intestine at 24h post-injection with LPS in blotched snakehead juveniles, liver cmHep expression was not altered. Iron overloading and poly I

  10. Atividade alimentar diária da cabrinha Prionotus punctatus (Teleostei: Triglidae do litoral de Ubatuba, Brasil Diel feeding of searobin Prionotus punctatus (Telestei: Triglidae from coastal system off Ubatuba, Brazil

    Directory of Open Access Journals (Sweden)

    Lucy Satiko Hashimoto Soares

    1994-12-01

    Full Text Available Com o objetivo de se identificar a cronologia alimentar e comparar a composição dos conteúdos estomacais ao longo do dia foram obtidas amostras de Prionotus punctatus na plataforma interna ao largo de Ubatuba (SP, Brasil, durante o ciclo diário em janeiro/87, julho/88 e dezembro/88. As amostras foram obtidas com rede de arrasto de fundo, a intervalos de aproximadamente 3 horas. Através do acompanhamento da freqüência relativa dos graus de repleção, dos indicadores de repleção, do número médio de presas frescas evidenciou-se nitidamente que Prionotus punctatus possui hábito alimentar diurno com tendência vespertina, podendo-se levantar a hipótese de ritmo circadiano na atividade alimentar. A composição dos conteúdos consistiu, principalmente de jovens de siris Portunus spinicarpus no verão (janeiro/87 e dezembro/88, e de jovens de Portunidae e camarões Penaeidea (Sicyonidae e Pleoticus mullen no inverno (julho/88. A composição foi altamente similar durante a fase de atividade alimentar no inverno, enquanto que apresentou variação tanto no verão/87 quanto no verão/88.The feeding habits and the diel feeding periodicity of the searobin Prionotus punctatus were investigated at Ubatuba region (22º30'S in the western South Atlantic. The samples were collected during consecutive 3 h periods over 24 h in January, 1987 and July and December, 1988. The diel feeding activity analysis indicated that Prionotus punctatus was a daytime feeder with afternoon tendency, permitting to bring up the hypothesis of the Orcadian rythm. The main food items were Portunidae crabs in Summer, and Portunidae and Penaeidae shrimps in Winter. The diet composition was very similar during the feeding activity time in Winter (July 1988, whereas it showed some variation in Summer (January 1987 and December 1988.

  11. Evidence of geographical structuring in the Malaysian Snakehead, Channa striata based on partial segment of the CO1 gene.

    Science.gov (United States)

    Siti-Balkhis, Abu Bakar; Jamsari, Amirul Firdaus Jamaluddin; Hwai, Tan Shau; Yasin, Zulfigar; Siti-Azizah, Mohd Nor

    2011-07-01

    Channa striata, locally known as "haruan", is economically important in fisheries and aquaculture industries in several Asian countries. DNA sequencing, based on a partial segment of the Cytochrome oxidase c subunit 1 (CO1) gene, was used to determine genetic variation in C. striata samples from four different populations on the west coast of Peninsular Malaysia. The highest nucleotide and haplotype diversities were observed in the Linggi population (π = 0.0067, h = 0.835), and the lowest in the Timah Tasoh population (π = 0.0008, h = 0.286). Apart from Kajang-Linggi, which was insignificant, F(ST) values were significant (p < 0.05) in all pairwise-population comparisons. Consequently, it is inferred that genetic structuring C. striata populations in this region was largely shaped by a common origin, with secondary influences from geographical factors and isolation.

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

    Directory of Open Access Journals (Sweden)

    Li Min Song

    2013-01-01

    Full Text Available 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.

  13. 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.

  14. Genotyping of microsatellite markers to study genetic structure of the wild striped snakehead Channa striata in Malaysia.

    Science.gov (United States)

    Tan, M P; Jamsari, A F J; Siti Azizah, M N

    2016-05-01

    Genetic variability and differences in wild striped snakehead Channa striata from Malaysia were analysed by genotyping nine novel nuclear microsatellite loci. Analysis revealed moderate-to-high genetic diversity in most of the populations, indicative of large effective population sizes. The highly diversified populations are admixed populations and, therefore, can be recommended as potential candidates for selective breeding and conservation since they each contain most of the alleles found in their particular region. Three homogenous groups of the wild populations were identified, apparently separated by effective barriers, in accordance with contemporary drainage patterns. The highest population pairwise FST found between members of the same group reflects the ancient population connectivity; yet prolonged geographical isolation resulted in adaptation of alleles to local contemporary environmental change. A significant relationship between genetic distance and geographical isolation was observed (r = 0·644, P < 0·01). Anthropogenic perturbations indicated apparent genetic proximity between distant populations.

  15. Evidence of geographical structuring in the Malaysian Snakehead, Channa striata based on partial segment of the CO1 gene

    Directory of Open Access Journals (Sweden)

    Abu Bakar Siti-Balkhis

    2011-01-01

    Full Text Available Channa striata, locally known as "haruan", is economically important in fisheries and aquaculture industries in several Asian countries. DNA sequencing, based on a partial segment of the Cytochrome oxidase c subunit 1 (CO1 gene, was used to determine genetic variation in C. striata samples from four different populations on the west coast of Peninsular Malaysia. The highest nucleotide and haplotype diversities were observed in the Linggi population (π = 0.0067, h = 0.835, and the lowest in the Timah Tasoh population (π = 0.0008, h = 0.286. Apart from Kajang-Linggi, which was insignificant, F ST values were significant (p < 0.05 in all pairwise-population comparisons. Consequently, it is inferred that genetic structuring C. striata populations in this region was largely shaped by a common origin, with secondary influences from geographical factors and isolation.

  16. HISTOPATHOLOGICAL CHANGES IN THE GILLS OF CHANNA GACHUA, AN AIR BREATHING TELEOST AFTER SHORT TERM EXPOSURE OF HOSTATHION

    Directory of Open Access Journals (Sweden)

    jeebu kumar jha

    2014-09-01

    Full Text Available Gills are the prime organs for gaseous exchange and perform several other physiological functions including osmoregulation and excretion. Harmful effects of several insecticide on the gill histomorphology are well known. In this paper the effects of a commonly used insecticides on the gills of C.gachua is demonstrated. Channa gachua, a freshwater teleost was exposed to a broad spectrum organophosphate insecticide hostathion for 24, 48, 72 and 96h at 0.25, 0.30, 0.35 and 0.40ppm. 96h LC50 value was determined. The histological sections of gills of snake headed air breathing teleost examined under light microscope showed severe structural alterations like mucus cells hyperplasia, buldging of taste buds, formation of interlamellar bridge and sub epithelial spaces in the primary and secondary gill lamellae.

  17. Genotyping of microsatellite markers to study genetic structure of the wild striped snakehead Channa striata in Malaysia.

    Science.gov (United States)

    Tan, M P; Jamsari, A F J; Siti Azizah, M N

    2016-05-01

    Genetic variability and differences in wild striped snakehead Channa striata from Malaysia were analysed by genotyping nine novel nuclear microsatellite loci. Analysis revealed moderate-to-high genetic diversity in most of the populations, indicative of large effective population sizes. The highly diversified populations are admixed populations and, therefore, can be recommended as potential candidates for selective breeding and conservation since they each contain most of the alleles found in their particular region. Three homogenous groups of the wild populations were identified, apparently separated by effective barriers, in accordance with contemporary drainage patterns. The highest population pairwise FST found between members of the same group reflects the ancient population connectivity; yet prolonged geographical isolation resulted in adaptation of alleles to local contemporary environmental change. A significant relationship between genetic distance and geographical isolation was observed (r = 0·644, P < 0·01). Anthropogenic perturbations indicated apparent genetic proximity between distant populations. PMID:27027270

  18. Evidence of geographical structuring in the Malaysian Snakehead, Channa striata based on partial segment of the CO1 gene.

    Science.gov (United States)

    Siti-Balkhis, Abu Bakar; Jamsari, Amirul Firdaus Jamaluddin; Hwai, Tan Shau; Yasin, Zulfigar; Siti-Azizah, Mohd Nor

    2011-07-01

    Channa striata, locally known as "haruan", is economically important in fisheries and aquaculture industries in several Asian countries. DNA sequencing, based on a partial segment of the Cytochrome oxidase c subunit 1 (CO1) gene, was used to determine genetic variation in C. striata samples from four different populations on the west coast of Peninsular Malaysia. The highest nucleotide and haplotype diversities were observed in the Linggi population (π = 0.0067, h = 0.835), and the lowest in the Timah Tasoh population (π = 0.0008, h = 0.286). Apart from Kajang-Linggi, which was insignificant, F(ST) values were significant (p striata populations in this region was largely shaped by a common origin, with secondary influences from geographical factors and isolation. PMID:21931528

  19. 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

  20. INFLUENCED OF CYPERMETHRIN ON DNA, RNA AND RNA/DNA RATIO IN GILLS OF THE FRESHWATER FISH CHANNA STRIATA

    Directory of Open Access Journals (Sweden)

    Gracy A. Raksheskar

    2012-01-01

    Full Text Available In the present study the impact of subletal concentration of cypermethrin exposed to fresh water fish. The DNA, RNA and RNA/DNA ratio were estimated in gill of freshwater fish Channa striata. The sublethal concentration of cypermethrin (0.00078 µl/lit for 24, 48, 72 and 96 hours of different time intervals. The concentration of cypermethrin showed reduce level of DNA as 6.79, 15.77, 15.66, 15.36 in experimental and 15.20, 14.11, 12.16, 10.16 respectively for experimenntal RNA at different exposure period. Whereas the RNA/DNA ratio observed changed (2.23, 2.48, 2.27, 1.97 respectively at different exposure period as compares to control group.

  1. Influence of size, station time and satiation amount on prey handling time in Anabas testudineus (Bloch)

    OpenAIRE

    Sreekumari, T.; Aravindan, C.M.

    1993-01-01

    Satiation amount, satiation time and handling time of Anabas testudineus (Bloch), an air breathing predatory fish was experimentally estimated using guppy (Lebistes reticulatus) as prey. Weight of the fish and satiation time influenced prey handling time. As satiation time is related to the level of hunger, level of hunger was found to influence handling time of prey.

  2. Quantum Maxwell-Bloch equations for spontaneous emission in optical semiconductor devices

    OpenAIRE

    Hess, Ortwin; Hofmann, Holger F.

    1998-01-01

    We present quantum Maxwell-Bloch equations (QMBE) for spatially inhomogeneous optical semiconductor devices taking into account the quantum noise effects which cause spontaneous emission and amplified spontaneous emission. Analytical expressions derived from the QMBE are presented for the spontaneous emission factor beta and the far field pattern of amplified spontaneous emission in broad area quantum well lasers.

  3. Floquet-Bloch waves and suppression of vibrations in multi-scale fluid-solid systems

    CERN Document Server

    Carta, Giorgio; Movchan, Alexander B

    2016-01-01

    The paper presents a mathematical model for an industry inspired problem of vibration isolation applied to a cluster of elastic fluid-filled containers. We develop a systematic approach employing full fluid-solid interaction and Floquet-Bloch waves in periodic multi-scale systems. The analytical findings are accompanied by numerical simulations, including frequency response analyses and computations in the transient regime.

  4. 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

    in 1978 who also extended the conjecture to Bloch SU(2) spin-coherent states for every angular momentum $J$. This conjecture is proved here. We also recall our 1991 extension of the Wehrl map to a quantum channel from $J$ to $K=J+1/2, J+1, ...$, with $K=\\infty$ corresponding to the Wehrl map to classical...

  5. Dynamic localization and Bloch oscillations in the spectrum of a frequency mode-locked laser.

    Science.gov (United States)

    Longhi, Stefano

    2005-04-01

    It is shown that a frequency mode-locked laser with a sinusoidal sweep of modulation frequency around a mode-locking condition represents an ideal optical system for observing in the spectral domain the phenomena of dynamic localization and Bloch oscillations of electrons in an ideal solid placed in an external ac electric field.

  6. Dynamic Behavior and Quasi-energy Spectrum of Multiband Superlattice Bloch Electrons in Quantum Kicked Potential

    Institute of Scientific and Technical Information of China (English)

    OUYANG BiYao; ZHAO XianGeng; CHEN ShiGang; LIU Jie

    2001-01-01

    In this paper, we study the dynamic behavior and quasi-energy spectrum of multiband superlattice Bloch electrons in quantum kicked potential. We show analytically and numerically the avoided crossing and band suppression about the quasi-energy spectrum, the dynamic nonlocalization, and the electron oscillation behavior between two bands.

  7. Beam splitter and combiner based on Bloch oscillations in spatially modulated waveguide arrays

    CERN Document Server

    Zhang, Yiqi; Zhong, Weiping; Wen, Feng; Guo, Yang; Guo, Yao; Lu, Keqing; Zhang, Yanpeng

    2014-01-01

    We numerically investigate the light beam propagation in periodic waveguide arrays which are elaborately modulated with certain structures. We find that the light beam may split, coalesce, deflect, and be localized during propagation in these spatially modulated waveguide arrays. All the phenomena originate from Bloch oscillations, and supply possible method for fabricating on-chip beam splitters and beam combiners.

  8. Populating the Large-Wavevector Realm: Bloch Volume Plasmon Polaritons in Hyperbolic and Extremely Anisotropic Metamaterials

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Babicheva, Viktoriia; Orlov, A. A.;

    2014-01-01

    Optics of hyperbolic metamaterials is revisited in terms of large-wavevector waves, evanescent in isotropic media but propagating in presence of extreme anisotropy. Identifying the physical nature of these waves as Bloch volume plasmon polaritons, we derive their existence conditions and outline...... the strategy for tailoring their properties in multiscale metamaterials....

  9. Floquet-Bloch vs. Nicolson-Ross-Weir Extraction for Magneto-Dielectric Bragg Stacks

    DEFF Research Database (Denmark)

    Clausen, Niels Christian Jerichau; Arslanagic, Samel; Breinbjerg, Olav

    2014-01-01

    We extract and compare the permittivity and permeability from a dielectric and a magnetodielectric Bragg stack with the Floquet-Bloch (FB) method for the infinite stack and the Nicolson-Ross- Weir (NRW) method for the finite stack. While the extracted propagation constants are identical, the wave...

  10. Bloch Walls and Macroscopic String States in Bethe's Solution of the Heisenberg Ferromagnetic Linear Chain

    Science.gov (United States)

    Dhar, Abhishek; Sriram Shastry, B.

    2000-09-01

    We present a calculation of the lowest excited states of the Heisenberg ferromagnet in 1D for any wave vector. These turn out to be string solutions of Bethe's equations with a macroscopic number of particles in them. They are identified as generalized quantum Bloch wall states, and a simple physical picture is provided for the same.

  11. Bloch Walls and Macroscopic String States in Bethe's solution of the Heisenberg Ferromagnetic Linear Chain

    OpenAIRE

    Dhar, Abhishek; Shastry, B. Sriram

    2000-01-01

    We present a calculation of the lowest excited states of the Heisenberg ferromagnet in 1-d for any wave vector. These turn out to be string solutions of Bethe's equations with a macroscopic number of particles in them. These are identified as generalized quantum Bloch wall states, and a simple physical picture provided for the same.

  12. Uptake and distribution of technetium-99 by channel catfish Ictalarus punctatus (Rafinesque)

    International Nuclear Information System (INIS)

    An investigation was undertaken to study the uptake and distribution of Tc-99 by channel catfish Ictalarus punctatus (Rafinesque) under laboratory conditions. The major source of the radionuclide was water and not food. Fifty-four small fish (18--21 grams) were exposed to the radionuclide in groups of six in each one of nine to 20 gallon glass tanks containing a Tc-99 concentration of 0.00645 +- 0.0002 μCi/ml. The water temperature remained relatively constant at a value of 19.62 +- 0.270C. The exposure times were 2 hours, 8 hours, 1, 2, 4, 6, 10, 15, and 20 days for the nine groups of fish. Three fish from each tank were separated to be processed as whole body specimens and three were dissected for muscle, skin, gills, gastrointestinal tract, liver, and kidney. All samples were homogenized using a laboratory blender and digested in preparation for analysis, using perchloric acid (70%) and hydrogen peroxide (30%), at a temperature of 700C for 30 minutes. Water samples were also collected for radioassay. The analytical technique used in this study was internal liquid scintillation spectrometry. The uptake data were expressed as dpm/g and also as a concentration factor. Statistical analysis indicated significant increase in the radionuclide concentration in fish tissue with time. Statistically significant differences were also observed in the uptake among the different organs at a given time. The lowest concentration factor was achieved by the muscle followed by the skin, gills, kidney, gastrointestinal tract, and liver with the highest

  13. Seasonal and spatial dynamics of ectoparasite infestation of a threatened reptile, the tuatara (Sphenodon punctatus).

    Science.gov (United States)

    Godfrey, S S; Bull, C M; Nelson, N J

    2008-12-01

    The conservation of threatened vertebrate species and their threatened parasites requires an understanding of the factors influencing their distribution and dynamics. This is particularly important for species maintained in conservation reserves at high densities, where increased contact among hosts could lead to increased rates of parasitism. The tuatara (Sphenodon punctatus) (Reptilia: Sphenodontia) is a threatened reptile that persists at high densities in forests (approximately 2700 tuatara/ha) and lower densities in pastures and shrubland (ectoparasites (the tuatara tick, Amblyomma sphenodonti, and trombiculid mites, Neotrombicula sp.) in a mark-recapture study in three forest study plots from November 2004 to March 2007, and compared infestation levels among habitat types in March 2006. Tick loads were lowest over summer and peaked from late autumn (May) until early spring (September). Mating and engorgement of female ticks was highest over spring, and larval tick loads subsequently increased in early autumn (March). Nymphal tick loads increased in September, and adult tick loads increased in May. Our findings suggest the tuatara tick has a 2- or 3-year lifecycle. Mite loads were highest over summer and autumn, and peaked in March. Prevalences (proportion of hosts infected) and densities (estimated number of parasites per hectare) of ticks were similar among habitats, but tick loads (parasites per host) were higher in pastures than in forests and shrub. The prevalence and density of mites was higher in forests than in pasture or shrub, but mite loads were similar among habitats. We suggest that a higher density of tuatara in forests may reduce the ectoparasite loads of individuals through a dilution effect. Understanding host-parasite dynamics will help in the conservation management of both the host and its parasites. PMID:19120965

  14. Bioconcentration and endocrine disruption effects of diazepam in channel catfish, Ictalurus punctatus.

    Science.gov (United States)

    Overturf, C L; Overturf, M D; Huggett, D B

    2016-01-01

    Recently, the detection of pharmaceuticals in surface waters has increased worldwide. Pharmaceuticals are typically found in the environment at concentrations well below therapeutic levels in humans; however, their mechanisms of action may be largely unknown in non-target organisms, such as teleost species. Thus, chronic exposure to these types of compounds warrants further investigation. The goal of this study was to examine the potential for diazepam, a model benzodiazepine drug, to bioconcentrate in tissues of channel catfish and to examine its ability to interact with the endocrine system through modulation of steroid hormones and/or steroidogenic genes. To investigate the bioconcentration potential of diazepam, channel catfish (Ictalurus punctatus) were exposed to 1 ng/mL diazepam for seven days, followed by clean water for another seven days, using an abbreviated OECD 305 Fish Bioconcentration Test study design. This concentration of diazepam is well below environmentally relevant concentrations of diazepam (ng/L). To evaluate steroidogenic effects, fish were exposed to 1 ng/mL diazepam for seven days only. Steroid hormone concentrations were analyzed for various tissues, as well as expression of selected steroidogenic genes. Calculated bioconcentration factors for diazepam were well below regulatory threshold values in all tissues analyzed. No changes in steroid hormone concentration were detected in any tissue analyzed; however, the steroidogenic gene cytochrome P450 side chain cleavage (P450scc) was significantly down-regulated at day 5 and 3β-hydroxy steroid dehydrogenase (3β-HSD) was significantly down-regulated at day 7 in the gonad. These results indicate that although diazepam does not significantly bioconcentrate, low-level chronic exposure to diazepam may have the potential to interact with endocrine function by altering gene expression. PMID:26875913

  15. Ising and Bloch domain walls in a two-dimensional parametrically driven Ginzburg-Landau equation model with nonlinearity management

    DEFF Research Database (Denmark)

    Gaididei, Yu. B.; Christiansen, Peter Leth

    2008-01-01

    We study a parametrically driven Ginzburg-Landau equation model with nonlinear management. The system is made of laterally coupled long active waveguides placed along a circumference. Stationary solutions of three kinds are found: periodic Ising states and two types of Bloch states, staggered...... and unstaggered. The stability of these states is investigated analytically and numerically. The nonlinear dynamics of the Bloch states are described by a complex Ginzburg-Landau equation with linear and nonlinear parametric driving. The switching between the staggered and unstaggered Bloch states under...

  16. A redescription of grey pomfret Pampus cinereus (Bloch,1795) with the designation of a neotype (Teleostei:Stromateidae)

    Institute of Scientific and Technical Information of China (English)

    LIU Jing; LI Chunsheng; NING Ping

    2013-01-01

    Pampus cinereus (Bloch,1795) (Stromateidae),a species believed to be widely distributed throughout the Indo-Western Pacific region,was redescribed and a neotype was designated.The designation of a neotype was necessary because of ambiguous data in Bloch's original description and the loss of the original type specimen.Morphological data indicated that 10 recently-collected specimens from the coasts of southern China agreed well with Bloch's original description and figure ofP.cinereus.A neotype for this species was selected from among the 10 specimens,and a detailed description is presented in this paper.

  17. Some aspects in early life stage of snake head fish, Channa striatus larvae

    Directory of Open Access Journals (Sweden)

    Thumronk Amornsakun1*,

    2011-12-01

    Full Text Available The sexual maturity of female snake head fish, Channa striatus was studied by determining fecundity and gonadosomaticindex (GSI. It was found that the size at sexual maturity of female snake head fish was 26.45±3.07 cm (mean ± SD,n=10 in total length and 167.4±48.09 g in body weight. The eggs were floating and rounded. The fertilized eggs had a diameterof 588±20.43 m. The fecundity was 10,279.1±2,527.9 ova/fish and gonadosomatic index (GSI was 5.07±1.04 %.Newly hatched larvae of snake head fish were produced by induced spawning using chemical injection (Suprefactand Motilium. The sexually mature fishes were cultured in a fiber-glass tank (water volume 300 liters with the ratio of maleand female brooders 1:1. The fertilization rate, hatching out and hatching rate experiments were carried out using 3 15-literglass aquaria (water volume 10 liters each containing 1,000 eggs. It was found that the average fertilization rate was 76.50%,hatching out occurred of 28 hr 40 min and average hatching rate was 60.26 % at a water temperature of 26.5-29.0°C. Samplingof the newly-hatched larvae was done at 2-hour intervals, when 20 of them were randomly taken and preserved in 10%buffered formalin for later determination of yolk absorption time. Observation using a microscope revealed that newlyhatched larvae were 3.18±0.11 mm in total length and had yolk sacs of 1,279.71±196.10 m3 in volume. The yolk sacs werecompletely absorbed within 80 hr after hatching at a water temperature of 26.5-29.0°C. Up until full mouth development (startof feeding, 2-hourly samplings of twenty newly hatched larvae were taken from an aquarium for observation of the size ofmouth opening. All the larvae had open mouths about 52 hr after hatching (5.48±0.16 mm TL, and measured 324.30±144.60m in mouth opening.The feeding experiments were carried out using a 15-liter glass aquarium (water volume 10 liters containing 1,000larvae aged 1.5 days post-hatching (just before

  18. Stable isotope analyses reveal the importance of seagrass beds as feeding areas for juvenile Myrophis punctatus (Angulliformes: Ophichthidae) inthe coastal waters of Florida

    Science.gov (United States)

    The feeding habits and habitats of the speckled worm eel Myrophis punctatus were studied on the mangrove edge of the Indian River Lagoon (Florida) using stomach contents and stable isotope analyses of carbon (δ13C) and nitrogen (δ15N). Stomach dietary analyses identified four tax...

  19. Suspending mammalian LHRHa-injected channel catfish, Ictalurus punctatus in individual nylon-mesh bag reduces stress and improves reproductive performance

    Science.gov (United States)

    Hormone induced spawning of channel catfish held communally in tanks is a reliable method to produce channel catfish, Ictalurus punctatus ' x blue catfish, I. furcatus ' F1 hybrid catfish fry. However, mature catfish are crowded, and repeatedly handled during the process of induced ovulation. Repe...

  20. 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...

  1. 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...

  2. 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...

  3. SOLITONS: Optimal control of optical soliton parameters: Part 2. Concept of nonlinear Bloch waves in the problem of soliton management

    Science.gov (United States)

    Serkin, Vladimir N.; Belyaeva, T. L.

    2001-11-01

    It is shown that optical solitons in nonlinear fibre-optic communication systems and soliton lasers can be represented as nonlinear Bloch waves in periodic structures. The Bloch theorem is proved for solitons of the nonlinear Schrodinger equation in systems with the dispersion, the nonlinearity, and the gain (absorption coefficient) periodically changing over the length. The dynamics of formation and interaction, as well as stability of the coupled states of nonlinear Bloch waves are investigated. It is shown that soliton Bloch waves exist only under certain self-matching conditions for the basic parameters of the system and reveal a structural instability with respect to the mismatch between the periods of spatial modulation of the dispersion, nonlinearity or gain.

  4. Distribution and elimination of [14C] sarafloxacin hydrochloride from tissues of juvenile channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Gingerich, W.H.; Meinertz, J.R.; Dawson, V.K.; Gofus, J.E.; Delaney, L.J.; Bunnell, P.R.

    1995-01-01

    The distribution and loss of radioactivity from tissues were determined in 60 juvenile channel catfish (Ictalurus punctatus) following oral dosing with the candidate fish therapeutant Sarafin® ([14C] sarafloxacin hydrochloride) at 10 mg/kg for 5 consecutive days. Twelve groups of 5 fish each were sampled at selected times ranging from 3 to 240 h after the last dose was administered, The concentration and content of sarafloxacin-equivalent activity was determined in liver, gallbladder, kidney, skin, and skinless fillet by sample oxidation and liquid scintillation counting; content of sarafloxacin-equivalent activity was determined in stomach and anterior and posterior intestines, Skinless fillet tissues were also analyzed for sarafloxacin and for potential metabolites by gradient-elution high-performance liquid chromatography (HPLC) with in-line radiometric and fluorescence detection, Loss of radioactivity from the whole body conformed to a bimodal elimination pattern with a rapid initial phase (t1/2=11 h) and a slower secondary phase (t1/2=222 h). Tissue and contents of the gastrointestinal tract (i.e. stomach and anterior and posterior intestines) were a principal depot of activity during the first four sample times (3, 6, 12, and 24 h); the combined head, skeleton, and fins (i.e. residual carcass) were the principal depot of activity in samples taken after 24 h. Of those tissues sampled 3 h after the last dose, relative sarafloxacin concentration was greatest in the liver (4.06 μg equivalents/g) and least in the residual carcass (1.13 μg equivalents/g), Intermediate concentrations were found in the kidney (2.04 μg equivalents/g), skinless fillet (1.71 μg equivalents/ g), and the skin (1.51 μg equivalents/g). Concentrations of sarafloxacin-equivalent residues in edible skinless fillet were consistently among the lowest of all tissues examined. The highest mean concentration of parent-equivalent material in the fillet tissue was found 12 h after

  5. Raman fingerprints on the Bloch sphere of a spinor Bose-Einstein condensate

    Science.gov (United States)

    Schultz, Justin T.; Hansen, Azure; Murphree, Joseph D.; Jayaseelan, Maitreyi; Bigelow, Nicholas P.

    2016-10-01

    We explore the geometric interpretation of a diabatic, two-photon Raman process as a rotation on the Bloch sphere for a pseudo-spin-? system. The spin state of a spin-? quantum system can be described by a point on the surface of the Bloch sphere, and its evolution during a Raman pulse is a trajectory on the sphere determined by properties of the optical beams: the pulse area, the relative intensities and phases and the relative frequencies. We experimentally demonstrate key features of this model with a ?Rb spinor Bose-Einstein condensate, which allows us to examine spatially dependent signatures of the Raman beams. The two-photon detuning allows us to precisely control the spin density and imprinted relative phase profiles, as we show with a coreless vortex. With this comprehensive understanding and intuitive geometric interpretation, we use the Raman process to create and tailor as well as study and characterize exotic topological spin textures in spinor BECs.

  6. 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...

  7. A Refresher of the Original Bloch’s Law Paper (Bloch, July 1885)

    Science.gov (United States)

    2015-01-01

    In 1885, Adolphe-Moïse Bloch asked the following simple question “Is there a law describing the relationship between the duration of a light and its perceived intensity?” Based on a series of experiments using a Foucault regulator and a candle, Bloch concluded that “when the lighting duration varies from 0.00173 to 0.0518 seconds (…) the [visible] light is markedly in inverse proportion to its duration”—his famous law. As this law pertains to the more general and hotly debated question of accumulation of sensory information over time, it is timely to offer the public a full translation of Bloch’s original paper (from French) and to present it within the context of contemporary research. PMID:27433317

  8. Tilted resonators in a triangular elastic lattice: chirality, Bloch waves and negative refraction

    CERN Document Server

    Tallarico, Domenico; Movchan, Alexander B; Colquitt, Daniel J

    2016-01-01

    We consider a vibrating triangular mass-truss lattice whose unit cell contains a resonator of a triangular shape. The resonators are connected to the triangular lattice by trusses. Each resonator is tilted, i.e. it is rotated with respect to the triangular lattice's unit cell through an angle $\\vartheta_0$. This geometrical parameter is responsible for the emergence of a resonant mode in the Bloch spectrum for elastic waves and strongly affects the dispersive properties of the lattice. Additionally, the tilting angle $\\vartheta_0$ triggers the opening of a band gap at a Dirac-like point. We provide a physical interpretation of these phenomena and discuss the dynamical implications on elastic Bloch waves. The dispersion properties are used to design a structured interface containing tilted resonators which exhibit negative refraction and focussing, as in a "flat elastic lens".

  9. 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 ...

  10. Magneto-optical switching of Bloch surface waves in magnetophotonic crystals

    Science.gov (United States)

    Romodina, M. N.; Soboleva, I. V.; Fedyanin, A. A.

    2016-10-01

    Bloch-surface-wave (BSW) excitation controlled by Faraday rotation in one-dimensional magnetophotonic crystals is presented. Dispersion curves of the Bloch surface wave and waveguide modes of magnetophotonic crystals consisting of silicon dioxide and bismuth-substituted yttrium-iron-garnet (Bi:YIG) quarter-wavelength-thick layers are calculated using Berreman's 4×4 transfer matrix method. Enhanced Faraday rotation observed in the magnetophotonic crystals in the spectral vicinity of the BSW resonance enables the magneto-optical switching of BSWs. The excitation of the BSWs at the magnetophotonic crystal surface for p-polarized incident light is induced by magneto-optical activity in the Bi:YIG layers.

  11. Bloch oscillations as generators of polarons in a 1D crystal

    Science.gov (United States)

    Nazareno, H. N.; Brito, P. E. de

    2016-08-01

    The main purpose of this work is to characterize the kind of propagation/localization of carriers in a one-dimensional crystalline structure along the tight-binding model while the electron-phonon interaction is taken into account through a deformation potential and the system is under the action of a dc electric field. The lattice was treated in the classical formalism of harmonic vibrations. A remarkable effect is obtained due to the presence of the electric field. On one side the particle performs Bloch oscillations and at the same time it interacts with the lattice and as a result at each turning point of its trajectory phonons are generated that carry with them a fraction of the electronic wave packet, it is the polaron formation. This way the Bloch oscillations pump polarons into the system. We explain why the polaron is formed at returning points of the oscillations.

  12. Interplay between Point-Group Symmetries and the Choice of the Bloch Basis in Multiband Models

    Directory of Open Access Journals (Sweden)

    Qiang-Hua Wang

    2013-11-01

    Full Text Available We analyze the point-group symmetries of generic multiband tight-binding models with respect to the transformation properties of the effective interactions. While the vertex functions in the orbital language may transform non-trivially under point-group operations, their point-group behavior in the band language can be simplified by choosing a suitable Bloch basis. We first give two analytically accessible examples. Then, we show that, for a large class of models, a natural Bloch basis exists, in which the vertex functions in the band language transform trivially under all point-group operations. As a consequence, the point-group symmetries can be used to reduce the computational effort in perturbative many-particle approaches, such as the functional renormalization group.

  13. Suppression of space broadening of exciton polariton beams by Bloch oscillation effects

    CERN Document Server

    Duan, Xudong; Zhang, Yongyou

    2015-01-01

    We theoretically study the transport of exciton polaritons under different applied photon potentials. The relation between the photon potentials and the thickness of the cavity layer is calculated by the finite element simulation. The theoretical analysis and numerical calculation indicate that the cavity photon potential is proportional to the thickness of the cavity layer with the coefficient being about $1.8$ meV/nm. Further, the periodic and linear photon potentials are considered to control the transport of the exciton polaritons in weak- and strong-field pump situations. In both situations the periodic potential cannot by itself effectively suppress the scatterings of the disorder potentials of the cavity photons and excitons and the nonlinear exciton-exciton interaction. When the linear potential is added to the cavity photons, the polariton transport exhibits the Bloch oscillation behavior. Importantly, the polariton Bloch oscillation can strongly suppress the space broadening due to the disorder pote...

  14. Circularly polarized few-cycle optical rogue waves: rotating reduced Maxwell-Bloch equations.

    Science.gov (United States)

    Xu, Shuwei; Porsezian, K; He, Jingsong; Cheng, Yi

    2013-12-01

    The rotating reduced Maxwell-Bloch (RMB) equations, which describe the propagation of few-cycle optical pulses in a transparent media with two isotropic polarized electronic field components, are derived from a system of complete Maxwell-Bloch equations without using the slowly varying envelope approximations. Two hierarchies of the obtained rational solutions, including rogue waves, which are also called few-cycle optical rogue waves, of the rotating RMB equations are constructed explicitly through degenerate Darboux transformation. In addition to the above, the dynamical evolution of the first-, second-, and third-order few-cycle optical rogue waves are constructed with different patterns. For an electric field E in the three lower-order rogue waves, we find that rogue waves correspond to localized large amplitude oscillations of the polarized electric fields. Further a complementary relationship of two electric field components of rogue waves is discussed in terms of analytical formulas as well as numerical figures.

  15. Exciting Molecules Close to the Rotational Quantum Resonance: Anderson Wall and Rotational Bloch Oscillations.

    Science.gov (United States)

    Floß, Johannes; Averbukh, Ilya Sh

    2016-05-19

    We describe a universal behavior of linear molecules excited by a periodic train of short laser pulses under conditions close to the quantum resonance. The quantum resonance effect causes an unlimited ballistic growth of the angular momentum. We show that a disturbance of the quantum resonance, either by the centrifugal distortion of the rotating molecules or a controlled detuning of the pulse train period from the so-called rotational revival time, eventually halts the growth by causing Anderson localization beyond a critical value of the angular momentum, the Anderson wall. Below the wall, the rotational excitation oscillates with the number of pulses due to a mechanism similar to Bloch oscillations in crystalline solids. We suggest optical experiments capable of observing the rotational Anderson wall and Bloch oscillations at near-ambient conditions with the help of existing laser technology.

  16. Phase transition to spatial Bloch-like oscillation in squeezed photonic lattices

    CERN Document Server

    Nezhad, M Khazaei; Golshani, M; Mahdavi, S M; Langari, A

    2013-01-01

    We propose an exactly solvable waveguide lattice incorporating inhomogeneous coupling coefficient. This structure provides a classical analogue to the squeezed number and squeezed coherent intensity distribution in quantum optics where the propagation length plays the role of squeezed amplitude. The intensity pattern is obtained in a closed form for an arbitrary distribution of the initial beam profile. We have also investigated the phase transition to the spatial Bloch-like oscillations by adding a linear gradient to the propagation constant of each waveguides ($ \\alpha $). Our analytical results show that the Bloch-like oscillations appear above a critical value for the linear gradient of propagation constant ($ \\alpha > \\alpha_{c} $). The phase transition (in the propagation properties of the waveguide) is a result of competition between discrete and Bragg diffraction. Moreover, the light intensity decay algebraically along each waveguide at the critical point while it falls off exponentially below the cri...

  17. Delocalization-enhanced Bloch oscillations and driven resonant tunneling in optical lattices for precision force measurements

    CERN Document Server

    Tarallo, M G; Poli, N; Chiofalo, M L; Wang, F -Y; Tino, G M

    2012-01-01

    In this paper we describe and compare different methods used for accurate determination of forces acting on matter-wave packets in optical lattices. The quantum interference nature responsible for the production of both Bloch oscillations and coherent delocalization is investigated in detail. We study conditions for optimal detection of Bloch oscillation for a thermal ensemble of cold atoms with a large velocity spread. We report on the experimental observation of resonant tunneling in an amplitude-modulated (AM) optical lattice up to the sixth harmonic with Fourier-limited linewidth. We then explore the fundamental and technical phenomena which limit both the sensitivity and the final accuracy of the atomic force sensor at 10^{-7} precision level [1], with an analysis of the coherence time of the system and addressing few simple setup changes to go beyond the current accuracy.

  18. Reflectors and resonators for high-k bulk Bloch plasmonic waves in multilayer hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Lavrinenko, Andrei

    2012-01-01

    We propose proof-of-concept designs of Bragg reflectors and Fabry-Pe´rot resonators for large wave vector waves (Bloch bulk plasmon polaritons) in multilayer metal-dielectric hyperbolic metamaterials. The designs are based on hybrid multilayers having both subwavelength and wavelength-scale struc......We propose proof-of-concept designs of Bragg reflectors and Fabry-Pe´rot resonators for large wave vector waves (Bloch bulk plasmon polaritons) in multilayer metal-dielectric hyperbolic metamaterials. The designs are based on hybrid multilayers having both subwavelength and wavelength......-scale structuring. This multiscale approach is shown to be a promising platform for using bulk plasmonic waves in complex multilayer metamaterials as a new kind of information carriers....

  19. Measuring h /mCs and the Fine Structure Constant with Bragg Diffraction and Bloch Oscillations

    Science.gov (United States)

    Parker, Richard

    2016-05-01

    We have demonstrated a new scheme for atom interferometry based on large-momentum-transfer Bragg beam splitters and Bloch oscillations. In this new scheme, we have achieved a resolution of δα / α =0.25ppb in the fine structure constant measurement, which gives up to 4.4 million radians of phase difference between freely evolving matter waves. We suppress many systematic effects, e.g., Zeeman shifts and effects from Earth's gravity and vibrations, use Bloch oscillations to increase the signal and reduce the diffraction phase, simulate multi-atom Bragg diffraction to understand sub-ppb systematic effects, and implement spatial filtering to further suppress systematic effects. We present our recent progress toward a measurement of the fine structure constant, which will provide a stringent test of the standard model of particle physics.

  20. Modified Bloch-Redfield Master Equation for Incoherent Excitation of Multilevel Quantum Systems

    CERN Document Server

    Tscherbul, Timur V

    2014-01-01

    We present an efficient theoretical method for calculating the time evolution of the density matrix of a multilevel quantum system weakly interacting with incoherent light. The method combines the Bloch-Redfield theory with a partial secular approximation for one-photon coherences, resulting in a master equation that explicitly exposes the reliance on transition rates and the angles between transition dipole moments in the energy basis. The modified Bloch-Redfield master equation allows an unambiguous distinction between the regimes of quantum coherent vs. incoherent energy transfer under incoherent light illumination. The fully incoherent regime is characterized by orthogonal transition dipole moments in the energy basis, leading to a dynamical evolution governed by a coherence-free Pauli-type master equation. The coherent regime requires non-orthogonal transition dipole moments in the energy basis, and leads to the generation of noise-induced quantum coherences and population-to-coherence couplings. As a fi...

  1. Oxygen consumption and ammonia excretion of the searobin Prionotus punctatus (Scorpaeniformes, Triglidae at two different temperatures

    Directory of Open Access Journals (Sweden)

    Vicente Gomes

    1999-01-01

    Full Text Available Routine oxygen consumption and ammonia excretion were measured at 20ºC and 25ºC in the searobin Prionotus punctatus collected in Ubatuba region (22º30'S, SP, Brazil, in western South Atlantic, to investigate energy expenditure and losses through metabolic processes. IndividuaIs ranging from 1.00g to 88.47g and from 1.79g to 56.50g were used in experiments at 20ºC and 25ºC, respectively. At 20ºC and 25ºC, the averages of weight-specific oxygen consumption for the weight class of 1.00 - 10.00g, common to both temperatures, were 162.46µ 39.51 µ.10z/g/h and 200.47µ 92.46 µ.10z/g/h, respectively; for the weight class of 50.01 - 60.00g these values were 112.30 µ 22.84 µ.10z/g/h and 114.60 µ 20.36 µ.10zlg/h. At 20ºC and 25ºC, the averages of weight-specific ammonia excretion for the weight class of 1.00 to 1O.00g were 1.03 µ 0.37 fJ.M/g/h and 1.21 µ 0.65 µ.M/g/h, respectively; for the weight class of 50.01 -60.00g these values were 0.68 µ 0.13 fJ.M/g/h and 0.60 µ 0.22 µ.M/g/h. The energy budget for the species was calculated at both temperatures using the experimental data and a model for marine teleosts proposed in the literature.O consumo de oxigênio de rotina e a excreção de amônia de Prionotus punctatus coletados na região de Ubatuba (22º30'S, SP, Brasil, foram medidos a 20ºC e 25ºC, para avaliar os gastos e perdas de energia com os processos metabólicos. Foram utilizados indivíduos variando de 1,00g a 88,47g e de 1,79g a 56,50g, em experimentos a 20ºC e 25ºC, respectivamente. As médias de consumo específico de oxigênio a 20ºC e 25ºC para a classe de peso de 1,00 - 10,00g, comum a ambas as temperaturas, foram 162,46µ 39,51 µ.10z/g/h e 200,47 µ 92,46 µ.10z/g/h, respectivamente; para a classe de peso de 50,01 - 60,00g esses valores foram 112,30 µ 22,84 µ.10z/g/h e 114,60 µ 20,36 µ.10z/g/h. A 20ºC e 25ºC, as médias de excreção específica de amônia para a classe de peso de 1,00 a 10,00g foram 1

  2. Norm equivalence and composition operators between Bloch/Lipschitz spaces of the ball

    OpenAIRE

    Stević Stevo; Clahane Dana D

    2006-01-01

    For , let and denote, respectively, the -Bloch and holomorphic -Lipschitz spaces of the open unit ball in . It is known that and are equal as sets when . We prove that these spaces are additionally norm-equivalent, thus extending known results for and the polydisk. As an application, we generalize work by Madigan on the disk by investigating boundedness of the composition operator from to .

  3. Weighted Composition Operators from the Bloch Space to Weighted Banach Spaces on Bounded Homogeneous Domains

    Institute of Scientific and Technical Information of China (English)

    Robert F.Allen

    2014-01-01

    We study the bounded and the compact weighted composition operators from the Bloch space into the weighted Banach spaces of holomorphic functions on bounded homogeneous domains, with particular attention to the unit polydisk. For bounded homogeneous domains, we characterize the bounded weighted composition operators and determine the operator norm. In addition, we provide sufficient condi-tions for compactness. For the unit polydisk, we completely characterize the compact weighted composition operators, as well as provide ”computable” estimates on the operator norm.

  4. EXTENDED CES(A)RO OPERATORS ON THE BLOCH SPACE IN THE UNIT BALL OF Cn

    Institute of Scientific and Technical Information of China (English)

    胡璋剑

    2003-01-01

    The paper defines an extended Cesàro operator Tg with holomorphic symbolg in the unit ball B of Cn asWhere g(z)= ∑j=1∑n zj g/ zj is the radial derivative of g. In this paper, the author characterizes g for which Tg is bounded (or compact) on the Bloch spaceB and the little Blochspace B0.

  5. Genetic Diversity Analysis of Lates calcarifer (Bloch 1790) in Captive and Wild Populations Using RAPD Markers

    OpenAIRE

    Muthusamy RAJASEKAR; Muthusamy THANGARAJ; Thathiredypalli R. BARATHKUMAR; Jayachandran SUBBURAJ; Kaliyan MUTHAZHAGAN

    2012-01-01

    Lates calcarifer (Bloch 1790) is one of the major economically important cultivable fish species in India. In this study, three populations of L. calcarifer was selected to assess the genetic diversity. Of which, two wild (Mudaslodai, Muthupettai) and one captive (Mutukadu) population. The genetic diversity of three populations of this species was studied using Random Amplified Polymorphic DNA (RAPD) markers. Ten random primers were used for the assessment of their genetic diversity and const...

  6. Positiveness and Pauli exception principle in raw Bloch equations for quantum boxes

    OpenAIRE

    Bidégaray-Fesquet, Brigitte

    2010-01-01

    International audience The aim of this paper is to derive a raw Bloch model for the interaction of light with quantum boxes in the framework of a two-electron-species (conduction and valence) description. This requires a good understanding of the one-species case and of the treatment of level degeneracy. In contrast with some existing literature we obtain a Liouville equation which induces the positiveness and the boundedness of solutions, that are necessary for future mathematical studies...

  7. Positiveness and Pauli exception principle in raw Bloch equations for quantum boxes

    Science.gov (United States)

    Bidégaray-Fesquet, Brigitte

    2010-10-01

    The aim of this paper is to derive a raw Bloch model for the interaction of light with quantum boxes in the framework of a two-electron-species (conduction and valence) description. This requires a good understanding of the one-species case and of the treatment of level degeneracy. In contrast with some existing literature, we obtain a Liouville equation which induces the positiveness and the boundedness of solutions, that are necessary for future mathematical studies involving higher order phenomena.

  8. Positiveness and Pauli exception principle in raw Bloch equations for quantum boxes

    International Nuclear Information System (INIS)

    The aim of this paper is to derive a raw Bloch model for the interaction of light with quantum boxes in the framework of a two-electron-species (conduction and valence) description. This requires a good understanding of the one-species case and of the treatment of level degeneracy. In contrast with some existing literature, we obtain a Liouville equation which induces the positiveness and the boundedness of solutions, that are necessary for future mathematical studies involving higher order phenomena.

  9. Anti-Newtonian dynamics and self-induced Bloch oscillations of correlated particles

    CERN Document Server

    Longhi, Stefano

    2014-01-01

    We predict that two correlated particles hopping on a one-dimensional Hubbard lattice can show transient self-acceleration and self-induced Bloch oscillations as a result of anti-Newtonian dynamics. Self-propulsion occurs for two particles with opposite effective mass on the lattice and requires long-range particle interaction. A photonic simulator of the two-particle Hubbard model with controllable long-range interaction, where self-propulsion can be observed, is discussed.

  10. Sensitive measurement of forces at the micron scale using Bloch oscillations of ultracold atoms.

    Science.gov (United States)

    Carusotto, I; Pitaevskii, L; Stringari, S; Modugno, G; Inguscio, M

    2005-08-26

    We show that Bloch oscillations of ultracold fermionic atoms in the periodic potential of an optical lattice can be used for a sensitive measurement of forces at the micrometer length scale, e.g., in the vicinity of a dielectric surface. In particular, the proposed approach allows us to perform a local and direct measurement of the Casimir-Polder force which is, for realistic experimental parameters, as large as 10(-4) gravity.

  11. Freezing of nonlinear Bloch oscillations in the generalized discrete nonlinear Schrödinger equation.

    Science.gov (United States)

    Cao, F J

    2004-09-01

    The dynamics in a nonlinear Schrödinger chain in a homogeneous electric field is studied. We show that discrete translational invariant integrability-breaking terms can freeze the Bloch nonlinear oscillations and introduce new faster frequencies in their dynamics. These phenomena are studied by direct numerical integration and through an adiabatic approximation. The adiabatic approximation allows a description in terms of an effective potential that greatly clarifies the phenomena.

  12. Bloch oscillations and Zener tunneling in two-dimensional photonic lattices.

    Science.gov (United States)

    Trompeter, Henrike; Krolikowski, Wieslaw; Neshev, Dragomir N; Desyatnikov, Anton S; Sukhorukov, Andrey A; Kivshar, Yuri S; Pertsch, Thomas; Peschel, Ulf; Lederer, Falk

    2006-02-10

    We report on the first experimental observation of photonic Bloch oscillations and Zener tunneling in two-dimensional periodic systems. We study the propagation of an optical beam in a square lattice superimposed on a refractive index ramp. We observe oscillations of the beam inside the first Brilloin zone and tunneling of light from the first to the higher-order bands of the lattice band gap spectrum.

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

    OpenAIRE

    Laura Ghigliotti; Julius Nielsen; Jorgen Schou Christiansen; Eva Pisano

    2015-01-01

    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 unde...

  14. Maxwell-Bloch Equations Modeling of Ultrashort Optical Pulse Propagation in Semiconductor Materials

    Science.gov (United States)

    Goorjian, Peter M.; Agrawal, Govind, P.

    1997-01-01

    An algorithm has been developed that solves the semiconductor Maxwell-Bloch equations, without making the standard slowly-varying envelope (SVEA) and rotating-wave (RWA) approximations. It is applied to study the propagation of ultrashort pulses in semiconductor materials. The results include many-body effects due to the Coulomb interaction among the charge carriers as well as the nonlinear effects resulting from spectral hole-burning.

  15. Explicit Solutions of the Bethe Ansatz Equations for Bloch Electrons in a Magnetic Field

    OpenAIRE

    Hatsugai, Yasuhiro; Kohmoto, Mahito; Wu, Yong-Shi

    1994-01-01

    For Bloch electrons in a magnetic field, explicit solutions are obtained at the center of the spectrum for the Bethe ansatz equations of Wiegmann and Zabrodin. When the magnetic flux per plaquette is 1 / Q with Q an odd integer, distribution of the roots of the Bethe ansatz equation is uniform except at two points on the unit circle in the complex plane. For the semiclassical limit Q→∞, the wave function is

  16. Real-time protein aggregation monitoring with a Bloch surface wave-based approach

    Science.gov (United States)

    Santi, Sara; Barakat, Elsie; Descrovi, Emiliano; Neier, Reinhard; Herzig, Hans Peter

    2014-05-01

    The misfolding and aggregation of amyloid proteins has been associated with incurable diseases such as Alzheimer's or Parkinson's disease. In the specific case of Alzheimer's disease, recent studies have shown that cell toxicity is caused by soluble oligomeric forms of aggregates appearing in the early stages of aggregation, rather than by insoluble fibrils. Research on new strategies of diagnosis is imperative to detect the disease prior to the onset of clinical symptoms. Here, we propose the use of an optical method for protein aggregation dynamic studies using a Bloch surface wave based approach. A one dimension photonic crystal made of a periodic stack of silicon oxide and silicon nitride layers is used to excite a Bloch surface wave, which is sensitive to variation of the refractive index of an aqueous solution. The aim is to detect the early dynamic events of protein aggregation and fibrillogenesis of the amyloid-beta peptide Aβ42, which plays a central role in the onset of the Alzheimer's disease. The detection principle relies on the refractive index changes caused by the depletion of the Aβ42 monomer concentration during oligomerization and fibrillization. We demonstrate the efficacy of the Bloch surface wave approach by monitoring in real-time the first crucial steps of Aβ42 oligomerization.

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

    Science.gov (United States)

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

    2015-12-01

    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.

  18. Representability of Bloch states on Projector-augmented-wave (PAW) basis sets

    Science.gov (United States)

    Agapito, Luis; Ferretti, Andrea; Curtarolo, Stefano; Buongiorno Nardelli, Marco

    2015-03-01

    Design of small, yet `complete', localized basis sets is necessary for an efficient dual representation of Bloch states on both plane-wave and localized basis. Such simultaneous dual representation permits the development of faster more accurate (beyond DFT) electronic-structure methods for atomistic materials (e.g. the ACBN0 method.) by benefiting from algorithms (real and reciprocal space) and hardware acceleration (e.g. GPUs) used in the quantum-chemistry and solid-state communities. Finding a `complete' atomic-orbital basis (partial waves) is also a requirement in the generation of robust and transferable PAW pseudopotentials. We have employed the atomic-orbital basis from available PAW data sets, which extends through most of the periodic table, and tested the representability of Bloch states on such basis. Our results show that PAW data sets allow systematic and accurate representability of the PAW Bloch states, better than with traditional quantum-chemistry double-zeta- and double-zeta-polarized-quality basis sets.

  19. Dynamic scattering of electron vortex beams – A Bloch wave analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mendis, B.G., E-mail: b.g.mendis@durham.ac.uk

    2015-02-15

    Two important applications of electron vortex beams are in electron magnetic chiral dichroism (EMCD) measurements and nanoparticle manipulation. In both cases orbital angular momentum () transfer between the vortex beam and the specimen due to dynamic scattering is critical. In general the pendellösung consists of short and long wavelength oscillations. The former is due to interference between the tightly bound 1s and more dispersive non-1s Bloch states, while the latter is due to interference between the non-1s states. For EMCD experiments with ±ħ angular momentum beams, momentum transfer can be minimised by selecting the appropriate aperture size, so that the probe wavefunction approximately matches that of the 2p-type Bloch states. For manipulating nanoparticles with large angular momentum beams small apertures are required to excite the 1s state and thereby enhance the short wavelength oscillations in . This enables efficient momentum transfer to the specimen, provided the nanoparticle dimension corresponds to a minimum in the pendellösung. - Highlights: • Dynamic scattering of vortex beams is analysed using Bloch waves. • Fundamental origins of pendellösung oscillations are identified. • Effect on magnetic dichroism measurements and nanoparticle manipulation is discussed.

  20. Coherent amplification and noise in gain-enhanced nanoplasmonic metamaterials: a Maxwell-Bloch Langevin approach.

    Science.gov (United States)

    Pusch, Andreas; Wuestner, Sebastian; Hamm, Joachim M; Tsakmakidis, Kosmas L; Hess, Ortwin

    2012-03-27

    Nanoplasmonic metamaterials are an exciting new class of engineered media that promise a range of important applications, such as subwavelength focusing, cloaking, and slowing/stopping of light. At optical frequencies, using gain to overcome potentially not insignificant losses has recently emerged as a viable solution to ultra-low-loss operation that may lead to next-generation active metamaterials. Maxwell-Bloch models for active nanoplasmonic metamaterials are able to describe the coherent spatiotemporal and nonlinear gain-plasmon dynamics. Here, we extend the Maxwell-Bloch theory to a Maxwell-Bloch Langevin approach-a spatially resolved model that describes the light field and noise dynamics in gain-enhanced nanoplasmonic structures. Using the example of an optically pumped nanofishnet metamaterial with an embedded laser dye (four-level) medium exhibiting a negative refractive index, we demonstrate the transition from loss-compensation to amplification and to nanolasing. We observe ultrafast relaxation oscillations of the bright negative-index mode with frequencies just below the THz regime. The influence of noise on mode competition and the onset and magnitude of the relaxation oscillations is elucidated, and the dynamics and spectra of the emitted light indicate that coherent amplification and lasing are maintained even in the presence of noise and amplified spontaneous emission.

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

    Science.gov (United States)

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

    2015-12-07

    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.

  2. Dynamic scattering of electron vortex beams – A Bloch wave analysis

    International Nuclear Information System (INIS)

    Two important applications of electron vortex beams are in electron magnetic chiral dichroism (EMCD) measurements and nanoparticle manipulation. In both cases orbital angular momentum () transfer between the vortex beam and the specimen due to dynamic scattering is critical. In general the pendellösung consists of short and long wavelength oscillations. The former is due to interference between the tightly bound 1s and more dispersive non-1s Bloch states, while the latter is due to interference between the non-1s states. For EMCD experiments with ±ħ angular momentum beams, momentum transfer can be minimised by selecting the appropriate aperture size, so that the probe wavefunction approximately matches that of the 2p-type Bloch states. For manipulating nanoparticles with large angular momentum beams small apertures are required to excite the 1s state and thereby enhance the short wavelength oscillations in . This enables efficient momentum transfer to the specimen, provided the nanoparticle dimension corresponds to a minimum in the pendellösung. - Highlights: • Dynamic scattering of vortex beams is analysed using Bloch waves. • Fundamental origins of pendellösung oscillations are identified. • Effect on magnetic dichroism measurements and nanoparticle manipulation is discussed

  3. 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

    2011-01-01

    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.Nós examinamos 308 espécimes do blenídeo Omobranchus punctatus, de origem Indo-Pacífica, depositados em coleções de quatro museus. Os dados de distribuição foram analisados com o objetivo de avaliar a invasão das águas costeiras do Oceano Atlântico nas Américas do Sul e Central. Em sua área de distribuição original, O. punctatus ocorre em ambientes marinhos e estuarinos. Amostragens datadas de 1930 e de 2004 produziram 20 registros da espécie no Atlântico Oeste tropical, incluindo amostras do Panamá, Col

  4. Resting metabolism and heat increment of feeding in mandarin fish (Siniperca chuatsi) and Chinese snakehead (Channa argus).

    Science.gov (United States)

    Liu, J; Cui, Y; Liu, J

    2000-10-01

    Resting metabolism was measured in immature mandarin fish Siniperca chuatsi weighing 42.1-510.2 g and Chinese snakehead Channa argus weighing 41.5-510.3 g at 10, 15, 20, 25, 30 and 35 degrees C. Heat increment of feeding was measured in mandarin fish weighing 202.0 (+/-14.0) g and snakehead weighing 200.8 (+/-19.3) g fed swamp loach Misgurnus anguillicaudatus at 1% body weight per day at 28 degrees C. In both species, weight exponent in the power relationship between resting metabolism and body weight was not affected by temperature. The relationship between resting metabolism and temperature could be described by a power function. The temperature exponent was 1.39 in mandarin fish and 2.10 in snakehead (Psnakehead increased with temperature at a faster rate than in mandarin fish. Multiple regression models were used to describe the effects of body weight (W, g) and temperature (T, degrees C) on the resting metabolism (R(s), mg O(2)/h): lnR(s)=-5.343+0.772 lnW+1.387 lnT for the mandarin fish and lnR(s)=-7.863+0.801 lnW+2.104 lnT for the Chinese snakehead. The proportion of food energy channelled to heat increment was 8.7% in mandarin fish and 6.8% in snakehead.

  5. Phylogeographic pattern of the striped snakehead, Channa striata in Sundaland: ancient river connectivity, geographical and anthropogenic signatures [corrected].

    Science.gov (United States)

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

    2012-01-01

    A phylogeographic study of an economically important freshwater fish, the striped snakehead, Channa striata in Sundaland was carried out using data from mtDNA ND5 gene target to elucidate genetic patterning. Templates obtained from a total of 280 individuals representing 24 sampling sites revealed 27 putative haplotypes. Three distinct genetic lineages were apparent; 1)northwest Peninsular Malaysia, 2)southern Peninsular, east Peninsular, Sumatra and SW (western Sarawak) and 3) central west Peninsular and Malaysian Borneo (except SW). Genetic structuring between lineages showed a significant signature of natural geographical barriers that have been acting as effective dividers between these populations. However, genetic propinquity between the SW and southern Peninsular and east Peninsular Malaysia populations was taken as evidence of ancient river connectivity between these regions during the Pleistocene epoch. Alternatively, close genetic relationship between central west Peninsular Malaysia and Malaysian Borneo populations implied anthropogenic activities. Further, haplotype sharing between the east Peninsular Malaysia and Sumatra populations revealed extraordinary migration ability of C. striata (>500 km) through ancient connectivity. These results provide interesting insights into the historical and contemporary landscape arrangement in shaping genetic patterns of freshwater species in Sundaland.

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

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, Ryan [University of West Florida; Miller, Debra [University of Georgia; Vandersea, Mark [National Oceanic and Atmospheric Admin; Bevelhimer, Mark S [ORNL; Schofield, Pamela [U.S. Geological Survey; Bennett, Wayne [University of West Florida

    2010-02-01

    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.

  7. 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.

  8. Molecular identification and expression of the Foxl2 gene during gonadal sex differentiation in northern snakehead Channa argus.

    Science.gov (United States)

    Wang, Dan-Dan; Zhang, Gui-Rong; Wei, Kai-Jian; Ji, Wei; Gardner, Jonathan P A; Yang, Rui-Bin; Chen, Kun-Ci

    2015-12-01

    Channa argus is one of the most commercially important fish species in China. Studies show that males of C. argus grow faster than females at the same age. In order to explore the sex differentiation mechanism of C. argus, we isolated the full length of the sex-related gene Foxl2 cDNA and analysed its expression patterns during gonadal sex differentiation. Alignment of known Foxl2 amino acid sequences from vertebrates confirmed the conservation of the Foxl2 open reading frame, especially the forkhead domain and C-terminal region. Quantitative RT-PCR revealed that Foxl2 is predominantly expressed in brain, pituitary, gill and ovary, with its highest level in ovary but low levels in testis and other tissues, reflecting a potential role for Foxl2 in the brain-pituitary-gonad axis in C. argus. Our ontogenetic stage data showed that C. argus Foxl2 expression was significantly upregulated from 1 to 11 days posthatching (dph) and that the initiation of expression preceded the first anatomical ovarian differentiation (27 dph), suggesting that Foxl2 might play a potential role in early gonadal sex differentiation in C. argus. In addition, the Foxl2 protein was primarily located in granulosa cells surrounding the oocytes of mature C. argus, implying that Foxl2 may have a basic function in granulosa cell differentiation and the maintenance of oocytes.

  9. Phylogeographic pattern of the striped snakehead, Channa striata in Sundaland: ancient river connectivity, geographical and anthropogenic signatures [corrected].

    Directory of Open Access Journals (Sweden)

    Min Pau Tan

    Full Text Available A phylogeographic study of an economically important freshwater fish, the striped snakehead, Channa striata in Sundaland was carried out using data from mtDNA ND5 gene target to elucidate genetic patterning. Templates obtained from a total of 280 individuals representing 24 sampling sites revealed 27 putative haplotypes. Three distinct genetic lineages were apparent; 1northwest Peninsular Malaysia, 2southern Peninsular, east Peninsular, Sumatra and SW (western Sarawak and 3 central west Peninsular and Malaysian Borneo (except SW. Genetic structuring between lineages showed a significant signature of natural geographical barriers that have been acting as effective dividers between these populations. However, genetic propinquity between the SW and southern Peninsular and east Peninsular Malaysia populations was taken as evidence of ancient river connectivity between these regions during the Pleistocene epoch. Alternatively, close genetic relationship between central west Peninsular Malaysia and Malaysian Borneo populations implied anthropogenic activities. Further, haplotype sharing between the east Peninsular Malaysia and Sumatra populations revealed extraordinary migration ability of C. striata (>500 km through ancient connectivity. These results provide interesting insights into the historical and contemporary landscape arrangement in shaping genetic patterns of freshwater species in Sundaland.

  10. 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

    2010-01-25

    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.

  11. Molecular cloning and ontogenic mRNA expression of fatty acid desaturase in the carnivorous striped snakehead fish (Channa striata).

    Science.gov (United States)

    Jaya-Ram, Annette; Ishak, Sairatul Dahlianis; Enyu, Yee-Ling; Kuah, Meng-Kiat; Wong, Kah-Loon; Shu-Chien, Alexander Chong

    2011-04-01

    There is very little information on the capacity of freshwater carnivorous fish to biosynthesize highly unsaturated fatty acids (HUFA). The striped snakehead fish (Channa striata) is a carnivorous species cultured inland of several Southeast Asian countries due to its pharmaceutical properties in wound healing enhancement. We described here the full-length cDNA cloning of a striped snakehead fatty acid desaturase (fads), which is responsible for desaturation of unsaturated fatty acids in the HUFA biosynthesis. Bioinformatics analysis reveals a protein coding region with length of 445 amino acids containing all characteristic features of desaturase enzyme, including a cytochrome b5-domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. The striped snakehead fads amino acid sequence shares high similarity with known fads of other teleosts. The mRNA expression of striped snakehead fads also showed an ontogenic-related increase in expression in 0-20 days after hatch larva. Using ISH, we localized the presence of fads in larva brain, liver and intestinal tissues.

  12. Phylogeographic pattern of the striped snakehead, Channa striata in Sundaland: ancient river connectivity, geographical and anthropogenic signatures [corrected].

    Science.gov (United States)

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

    2012-01-01

    A phylogeographic study of an economically important freshwater fish, the striped snakehead, Channa striata in Sundaland was carried out using data from mtDNA ND5 gene target to elucidate genetic patterning. Templates obtained from a total of 280 individuals representing 24 sampling sites revealed 27 putative haplotypes. Three distinct genetic lineages were apparent; 1)northwest Peninsular Malaysia, 2)southern Peninsular, east Peninsular, Sumatra and SW (western Sarawak) and 3) central west Peninsular and Malaysian Borneo (except SW). Genetic structuring between lineages showed a significant signature of natural geographical barriers that have been acting as effective dividers between these populations. However, genetic propinquity between the SW and southern Peninsular and east Peninsular Malaysia populations was taken as evidence of ancient river connectivity between these regions during the Pleistocene epoch. Alternatively, close genetic relationship between central west Peninsular Malaysia and Malaysian Borneo populations implied anthropogenic activities. Further, haplotype sharing between the east Peninsular Malaysia and Sumatra populations revealed extraordinary migration ability of C. striata (>500 km) through ancient connectivity. These results provide interesting insights into the historical and contemporary landscape arrangement in shaping genetic patterns of freshwater species in Sundaland. PMID:23284881

  13. Molecular cloning and ontogenic mRNA expression of fatty acid desaturase in the carnivorous striped snakehead fish (Channa striata).

    Science.gov (United States)

    Jaya-Ram, Annette; Ishak, Sairatul Dahlianis; Enyu, Yee-Ling; Kuah, Meng-Kiat; Wong, Kah-Loon; Shu-Chien, Alexander Chong

    2011-04-01

    There is very little information on the capacity of freshwater carnivorous fish to biosynthesize highly unsaturated fatty acids (HUFA). The striped snakehead fish (Channa striata) is a carnivorous species cultured inland of several Southeast Asian countries due to its pharmaceutical properties in wound healing enhancement. We described here the full-length cDNA cloning of a striped snakehead fatty acid desaturase (fads), which is responsible for desaturation of unsaturated fatty acids in the HUFA biosynthesis. Bioinformatics analysis reveals a protein coding region with length of 445 amino acids containing all characteristic features of desaturase enzyme, including a cytochrome b5-domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. The striped snakehead fads amino acid sequence shares high similarity with known fads of other teleosts. The mRNA expression of striped snakehead fads also showed an ontogenic-related increase in expression in 0-20 days after hatch larva. Using ISH, we localized the presence of fads in larva brain, liver and intestinal tissues. PMID:21130179

  14. Phylogeographic Pattern of the Striped Snakehead, Channa striata in Sundaland: Ancient River Connectivity, Geographical and Anthropogenic Singnatures

    Science.gov (United States)

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

    2012-01-01

    A phylogeographic study of an economically important freshwater fish, the striped snakehead, Channa striata in Sundaland was carried out using data from mtDNA ND5 gene target to elucidate genetic patterning. Templates obtained from a total of 280 individuals representing 24 sampling sites revealed 27 putative haplotypes. Three distinct genetic lineages were apparent; 1)northwest Peninsular Malaysia, 2)southern Peninsular, east Peninsular, Sumatra and SW (western Sarawak) and 3) central west Peninsular and Malaysian Borneo (except SW). Genetic structuring between lineages showed a significant signature of natural geographical barriers that have been acting as effective dividers between these populations. However, genetic propinquity between the SW and southern Peninsular and east Peninsular Malaysia populations was taken as evidence of ancient river connectivity between these regions during the Pleistocene epoch. Alternatively, close genetic relationship between central west Peninsular Malaysia and Malaysian Borneo populations implied anthropogenic activities. Further, haplotype sharing between the east Peninsular Malaysia and Sumatra populations revealed extraordinary migration ability of C. striata (>500 km) through ancient connectivity. These results provide interesting insights into the historical and contemporary landscape arrangement in shaping genetic patterns of freshwater species in Sundaland. PMID:23284881

  15. Microcirculation of gills and accessory respiratory organs from the air-breathing snakehead fish, Channa punctata, C. gachua, and C. marulius.

    Science.gov (United States)

    Olson, K R; Roy, P K; Ghosh, T K; Munshi, J S

    1994-01-01

    Snakehead fish of the genus Channa have well-developed air-breathing organs (ABO) yet retain their gill arches for respiratory and non-respiratory functions. Alterations in the macrocirculation accompany inclusion of the ABO and appear to enhance gas exchange efficiency (Munshi et al., 1994. Anat. Rec. 238:77-91). In the present study, the microcirculatory anatomy of gill and ABO from two facultative air-breathing Channa, C. punctata and C. gachua, and one obligate air-breather, C. marulius, were examined in detail using scanning electron microscopy (SEM) of vascular corrosion replicas and fixed whole-sectioned tissue. The results show that the circulation in the filaments from the first, second, and third gill arches is similar to that found in water-breathing teleosts. Fourth gill arch microcirculation of C. punctata is not different from the other three, whereas in C. marulius, it has been greatly modified into a network of low-resistance vascular shunts, although remnants of an intralamellar filamental microcirculation remain. The vascular shunts are formed from extensions of afferent and efferent lamellar arterioles and the complete, or nearly complete, loss of a lamellar sinus. The vasculature of the ABO has been highly modified in all species into a coiled-spiral capillary network with a constricted aperture guarding a dilated capillary dome at the epithelial surface. Microvilli are found congregated on the aperture endothelium of C. punctata but they are virtually absent from C. marulius endothelium. Less than 15% of the ABO capillary surface appears to face the epithelium and thereby contributes directly to gas exchange. These findings suggest that the microvascular modifications observed in Channa entail more than a simple increase in the contact surface between ABO vessels and air and they may serve other unknown physiological functions.

  16. Molecular characterization of eight Indian Snakehead species (Pisces: Perciformes Channidae) using RAPD markers.

    Science.gov (United States)

    Bhat, Ajaz Ali; Haniffa, M A; Divya, P R; Gopalakrishnan, A; Milton, M James; Kumar, Raj; Paray, Bilal Ahmad

    2012-04-01

    Murrels (Perciformes; Channidei; Channidae) are unique group of freshwater air breathing fishes having a confined distribution to African and Asian continents. The phylogenetic relationship among eight Channid species viz. Channa aurantimaculata, Channa bleheri, Channa diplogramma, Channa gachua, Channa marulius, Channa punctatus, Channa stewartii and Channa striatus were investigated using RAPD markers. Eight random oligodecamers viz. OPAC03, OPAC05, OPAC07, OPAC09, OPAC19, OPA10, OPA11 and OPA16 were used to generate the RAPD profile. Estimates of Nei's (Genetics, 89:583-590, 1978) unbiased genetic distance (D) demonstrated sufficient genetic divergence to discriminate the samples of different species and the values ranged from 0.3292 to 0.800 The present RAPD analyses strongly substantiate the view of earlier morphological and osteological studies of Channid species, the closer association among species in "gachua" and "marulius" groups.

  17. 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)

  18. Artificial Propagations of Nine Mating Combinations among Channa argus,Channa maculate and Hybrid Snakehead%9种交配组合鳢的人工繁殖试验

    Institute of Scientific and Technical Information of China (English)

    龙敏明; 马建波; 周爱国; 曾运丁; 邹记兴

    2012-01-01

    运用人工催产的方法进行了9种交配组合鳢的人工繁殖试验,9种组合来源于乌鳢(Channa argus)、斑鳢(C.maculate)和杂交鳢(Hybrid snakehead)彼此之间的交配繁殖.结果表明,无论采用何种孵化方式,9种交配组合所产卵的受精率和孵化率高低顺序基本一致,且各组合间都存在显著差异.交配组合斑鳢(♀)×斑鳢(♂)、斑鳢(♀)×杂交鳢(♂)、杂交鳢(♀)×斑鳢(♂)及杂交鳢(♀)×杂交鳢(♂)在繁殖过程中,其受精率和孵化率高于其他组合,具有较强的繁殖优势,但其子代的生产性能优势还有待进一步研究.孵化方式对受精卵的发育与孵化有重大影响,其中以微流水孵化方式时的受精率和孵化率最高、孵化效果最好.雄亲鱼的重复催产次数会影响受精率及孵化率,一般以重复利用2~3次为宜.

  19. 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.

  20. 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. PMID:25023653

  1. Studies on extractive components of Channa argus%乌鳢抽出物成分的研究

    Institute of Scientific and Technical Information of China (English)

    陈舜胜; 陆颖华; 山中英明

    2006-01-01

    分析了乌鳢(Channa argus)即杀后背肉、腹肉、尾部肉、肝脏、生殖腺中ATP关联化合物、游离氨基酸、多胺、糖元及糖酵解中间代谢物、有机酸等的含量.ATP关联化合物在肌肉中的总量为7.5~8.0 μmol·g-1.ATP在背肉含量为3.9 μmol·g-1,腹肉为4.1 μmol·g-1,尾部肉为4.7 μmol·g-1.运动激烈的尾部肉ATP占63%,含量相当高.肝脏中有少量的腺苷与肌苷酸一起被检出,据此可认为ATP的分解存在两个途径.游离氨基酸总量在背肉中为436.0 mg·(100g)-1,腹肉中为405.0 mg·(100g)-1,尾部肉中为356.3 mg·(100g)-1.牛磺酸和甘氨酸为主要氨基酸,占68%~73%.丙氨酸和谷氨酸也相当高的含量检出.肌肉中的多胺检出为精胺和亚精胺,肝脏和生殖腺中有较高浓度的腐胺及亚精胺和精胺检出.即杀后糖元的量约占肌肉的0.5%,还有相当多的葡萄糖和6-磷酸葡萄糖的糖酵解中间代谢物以及其最终产物乳酸的大量检出.%In this study, ATP and its related compounds, free amino acids, polyamines and monoamines, glycogen and glycolytic intermediates and organic acid were analyzed in the dorsal, ventral and caudal muscles of snakehead Channa argus together with the liver and gonad immediately after death. Total levels of ATP and its related compounds in the muscle ranged from 7.5 μmol·g-1 to 8.0 μmol·g-1. ATP concentrations were 3.9,4.1 and 4.7 μmol·g-1 in the dorsal, ventral and caudal muscles, respectively. ATP level was high (63%) in the caudal muscle which moves hard. Small amounts of adenosine was detected in the liver together with inosinic acid. It can be considered that there exist two metabolic pathways of ATP degradation in the liver of snakehead. The total amounts of free amino acids were 436.0,405.0 and 356.3 mg·(100 g)-1 in the dorsal, ventral and caudal muscles. Taurine and glycine were major free amino acids and accounted for 68% to 73%. Alanine and glutamic acids were detected in

  2. 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.

  3. Weighted Composition Operators from α-Bloch Spaces to H∞%α-Bloch空间到H∞的加权复合算子

    Institute of Scientific and Technical Information of China (English)

    唐笑敏

    2007-01-01

    The article not only presents the boundedness and compactness of the weighted composition operator from α-Bloch spaces(or little α-Bloch spaces) to H∞, but also gives some estimates for the norm of the weighted composition operator.

  4. Determination of the orientation of pieces of zigzag-Bloch walls in bulk FeSi-single crystals by neutron small-angle scattering

    International Nuclear Information System (INIS)

    Small-angle scattering of neutrons allows the determination of the orientation of Bloch walls in the interior of bulk single crystals. The zigzag angle psi=280 of the 900 Bloch wall and its field dependence are measured. We also observe walls or wall pieces with psi=00. With 1800 walls we measure zigzag angles of psi approximately equal to 300. (orig.)

  5. 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

  6. Purification, characterization and cDNA cloning of a trypsin from the hepatopancreas of snakehead (Channa argus).

    Science.gov (United States)

    Zhou, Long-Zhen; Ruan, Mi-Mi; Cai, Qiu-Feng; Liu, Guang-Ming; Sun, Le-Chang; Su, Wen-Jin; Cao, Min-Jie

    2012-03-01

    A trypsin was purified from the hepatopancreas of snakehead (Channa argus) by ammonium sulfate fractionation and a series of column chromatographies including DEAE-Sepharose, Sephacryl S-200 HR and Hi-Trap Capto-Q. The molecular mass of the purified trypsin was about 22 kDa, as estimated by SDS-PAGE. The optimum pH and temperature of the purified trypsin were 9.0 and 40°C, respectively. The trypsin was stable in the pH range of 7.5-9.5 and below 45°C. The enzymatic activity was strongly inhibited by serine proteinase inhibitors, such as MBTI, Pefabloc SC, PMSF, LBTI and benzamidine. Peptide mass fingerprinting (PMF) of the purified protein obtained 2 peptide fragments with 25 amino acid residues and were 100% identical to the trypsinogen from pufferfish (Takifugu rubripes). The activation energy (Ea) of this enzyme was 24.65 kJ·M(-1). Apparent K(m) was 1.02 μM and k(cat) was 148 S(-1) for fluorogenic substrate Boc-Phe-Ser-Arg-MCA. A trypsinogen gene encoding 247 amino acid residues was further cloned on the basis of the sequence obtained from PMF and the conserved site peptide of trypsinogen together with 5'-RACE and 3'-RACE. The deduced amino acid sequence contains a signal peptide of 15 residues and an activation peptide of 9 amino acid residues with a mature protein of 223 residues. The catalytic triad His-64, Asp-107, Ser-201 and 12 Cys residues which may form 6 disulfide bonds were conserved. Compared with the PMF data, only 2 amino acid residues difference were identified, suggesting the cloned trypsinogen is quite possibly the precursor of the purified trypsin.

  7. Bloch oscillating transistor as the readout element for hot electron bolometers

    Science.gov (United States)

    Hassel, Juha; Seppä, Heikki; Lindell, Rene; Hakonen, Pertti

    2004-10-01

    In this paper we analyse the properties of the Bloch oscillating transistor as a preamplifier in cryogenic devices. We consider here especially the readout of hot electron bolometers (HEBs) based on Normal-Superconductor-Insulator tunnel junctions, but the results also apply more generally. We show that one can get an equivalent noise voltage below 1 nV/√Hz with a single BOT. By using N BOTs in a parallel array configuration, a further reduction by factor √N may be achieved.

  8. LDRD final report on Bloch Oscillations in two-dimensional nanostructure arrays for high frequency applications.

    Energy Technology Data Exchange (ETDEWEB)

    Lyo, Sungkwun Kenneth; Pan, Wei; Reno, John Louis; Wendt, Joel Robert; Barton, Daniel Lee

    2008-09-01

    We have investigated the physics of Bloch oscillations (BO) of electrons, engineered in high mobility quantum wells patterned into lateral periodic arrays of nanostructures, i.e. two-dimensional (2D) quantum dot superlattices (QDSLs). A BO occurs when an electron moves out of the Brillouin zone (BZ) in response to a DC electric field, passing back into the BZ on the opposite side. This results in quantum oscillations of the electron--i.e., a high frequency AC current in response to a DC voltage. Thus, engineering a BO will yield continuously electrically tunable high-frequency sources (and detectors) for sensor applications, and be a physics tour-de-force. More than a decade ago, Bloch oscillation (BO) was observed in a quantum well superlattice (QWSL) in short-pulse optical experiments. However, its potential as electrically biased high frequency source and detector so far has not been realized. This is partially due to fast damping of BO in QWSLs. In this project, we have investigated the possibility of improving the stability of BO by fabricating lateral superlattices of periodic coupled nanostructures, such as metal grid, quantum (anti)dots arrays, in high quality GaAs/Al{sub x}Ga{sub 1-x}As heterostructures. In these nanostructures, the lateral quantum confinement has been shown theoretically to suppress the optical-phonon scattering, believed to be the main mechanism for fast damping of BO in QWSLs. Over the last three years, we have made great progress toward demonstrating Bloch oscillations in QDSLs. In the first two years of this project, we studied the negative differential conductance and the Bloch radiation induced edge-magnetoplasmon resonance. Recently, in collaboration with Prof. Kono's group at Rice University, we investigated the time-domain THz magneto-spectroscopy measurements in QDSLs and two-dimensional electron systems. A surprising DC electrical field induced THz phase flip was observed. More measurements are planned to investigate this

  9. Experimental reconstruction of the Berry curvature in a topological Bloch band

    Science.gov (United States)

    Weitenberg, Christof; Flaeschner, Nick; Rem, Benno; Tarnowski, Matthias; Vogel, Dominik; Luehmann, Dirk-Soeren; Sengstock, Klaus

    2016-05-01

    Topological properties lie at the heart of many fascinating phenomena in solid state systems such as quantum Hall systems or Chern insulators. The topology can be captured by the distribution of Berry curvature, which describes the geometry of the eigenstates across the Brillouin zone. Employing fermionic ultracold atoms in a hexagonal optical lattice, we engineer the Berry curvature of the Bloch bands using resonant driving and measure it with full momentum resolution. Our results pave the way to explore intriguing phases of matter with interactions in topological band structures.

  10. Experimental reconstruction of the Berry curvature in a Floquet Bloch band

    Science.gov (United States)

    Fläschner, N.; Rem, B. S.; Tarnowski, M.; Vogel, D.; Lühmann, D.-S.; Sengstock, K.; Weitenberg, C.

    2016-05-01

    Topological properties lie at the heart of many fascinating phenomena in solid-state systems such as quantum Hall systems or Chern insulators. The topology of the bands can be captured by the distribution of Berry curvature, which describes the geometry of the eigenstates across the Brillouin zone. Using fermionic ultracold atoms in a hexagonal optical lattice, we engineered the Berry curvature of the Bloch bands using resonant driving and show a full momentum-resolved measurement of the ensuing Berry curvature. Our results pave the way to explore intriguing phases of matter with interactions in topological band structures.

  11. UGROŽENE VRSTE RIBA U SVIJETU: Mystus vittatus (Bloch, 1794) (Siluriformes: Bagridae)

    OpenAIRE

    Hossain, Yeamin

    2014-01-01

    Autohtona vrsta, Mystus vittatus (Bloch, 1794), pripadnik porodice Bagridae, široke je distribucije u azijskim zemljama, uključujući Bangladeš, Indiju, Pakistan, Šri Lanku, Nepal i Mianmar. Međutim, prirodne populacije ozbiljno opadaju zbog visokog ribolovnog pritiska, gubitka staništa, zagađenja, prirodnih katastrofa, sanacije močvara i prekomjernog poplavnog zamuljivanja pa se stoga nalazi se u kategoriji osjetljive vrste. U članku se predlažu mjere za očuvanje ostatka izolirane populacije ...

  12. Influence of Temperature on Equilibrium Separation Between Vertical Bloch Lines in OHBs in Garnet Bubble Films

    Institute of Scientific and Technical Information of China (English)

    SUN Hui-Yuan; HU Yun-Zhi; LIU Li-Hu

    2009-01-01

    The diameters of the ordinary hard bubbles (OHBs) and soft bubbles in epitaxial garnet films are measured under the microscope at various temperatures. It is found that the bubble diameters of OHBs increase with temperature, and it is concluded that the equilibrium separation between two neighbouring vertical Bloch lines (VBLs) Seq is widened with increasing temperature. At the same time, the results can be understood simply as that there are more VBLs in the domain walls of the first dumbbell domains (IDs) than those in walls of OH Bs at the same temperature.

  13. High sensitivity, low-systematics atom interferometers using Bragg diffraction and Bloch oscillations

    CERN Document Server

    Estey, Brian; Müller, Holger; Kuan, Pei-Chen; Lan, Shau-Yu

    2014-01-01

    We describe a new scheme for atom interferometry based on both large-momentum transfer Bragg beam splitters and Bloch oscillations. Combining the advantages of previous approaches to recoil-sensitive interferometers, we increase the signal and suppress a systematic phase shift caused by Bragg diffraction at least 60-fold, matching experiment to theory; the systematic shift can be eliminated from Mach-Zehnder interferometers. We demonstrate high contrast, interference with up to 4.4 million radians of phase difference between freely evolving matter waves, and a resolution of $\\delta \\alpha/\\alpha=0.33\\,$ppb$\\sqrt{\\rm 6h}$ available to measurements of the fine structure constant.

  14. Nontrivial Bloch oscillations in waveguide arrays with second-order coupling.

    Science.gov (United States)

    Wang, Gang; Huang, Ji Ping; Yu, Kin Wah

    2010-06-01

    Under the influence of the next-nearest-neighbor interaction, we theoretically investigate the occurrence of Bloch oscillations in zigzag waveguide arrays. Because of the special topological configuration of the lattice itself, the second-order coupling (SOC) can be enhanced significantly and leads to the band alteration beyond the nearest-neighbor model, i.e., the offset of minimum value from the band edge. Contrary to the behavior in the vanishing SOC, the oscillation patterns exhibit new features, namely, a double turning-back occurs when the beam approaches the band edge. Our results can be applied to some ordered-lattice systems.

  15. Bloch Oscillations of Cold Atoms in a Cavity: Effects of Quantum Noise

    CERN Document Server

    Venkatesh, B Prasanna

    2013-01-01

    In this communication we extend our theory of Bloch oscillations of cold atoms inside an optical cavity [Venkatesh et al., Phys. Rev. A 80, 063834 (2009)] to include the effects of quantum noise. By solving the coupled dynamics of linearized fluctuations about the atomic and optical meanfields, we are able to include the effects of quantum measurement backaction upon the atoms and ultimately examine how this influences the signal-to-noise ratio of a measurement of external forces using this system. One of the hurdles we overcome along the way is the proper treatment of fluctuations about time-dependent meanfields in the cold atom cavity-QED context.

  16. On-chip optical isolation via unidirectional Bloch oscillations in a waveguide array.

    Science.gov (United States)

    Kumar, Pradeep; Levy, Miguel

    2012-09-15

    We propose to use the unidirectionality of the optical Bloch oscillation phenomenon achievable in a magneto-optic asymmetric waveguide array to achieve optical isolation. At the 1.55 μm telecommunication wavelength, our isolator design exhibits an isolation ratio of 36 dB between forward- and backward-propagating waves. The proposed design consists of a waveguide array made in a silicon-on-insulator substrate with a magnetic garnet cover layer. A key role is played by the transverse-magnetic mode nonreciprocal phase shift effect.

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

    CERN Document Server

    Jiang, Chang; Zhou, Lan

    2012-01-01

    We consider the propagation of a quantized polarized light in a magneto-optically manipulated atomic ensemble with a tripod configuration. 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 quantum dynamics of the dark-state polariton by some experiment data from rubidium D1-line. It is found that one component propagates freely, however the wavepacket trajectory of the other component performs Bloch oscillations.

  18. Stopping and time reversal of light in dynamic photonic structures via Bloch oscillations.

    Science.gov (United States)

    Longhi, Stefano

    2007-02-01

    It is theoretically shown that storage and time reversal of light pulses can be achieved in a coupled-resonator optical waveguide by dynamic tuning of the cavity resonances without maintaining the translational invariance of the system. The control exploits the Bloch oscillation motion of a light pulse in the presence of a refractive index ramp, and it is therefore rather different from the mechanism of adiabatic band compression and reversal proposed by Yanik and Fan in recent works [Phys. Rev. Lett., 92, 083901 (2004); 93, 173903 (2004)].

  19. Long-living BLOCH oscillations of matter waves in periodic potentials.

    Science.gov (United States)

    Salerno, M; Konotop, V V; Bludov, Yu V

    2008-07-18

    The dynamics of matter waves in linear and nonlinear optical lattices subject to a spatially uniform linear force is studied both analytically and numerically. It is shown that by properly designing the spatial dependence of the scattering length it is possible to induce long-living Bloch oscillations of gap-soliton matter waves in optical lattices. This occurs when the effective nonlinearity and the effective mass of the soliton have opposite signs for all values of the crystal momentum in the Brillouin zone. The results apply to all systems modeled by the periodic nonlinear Schrödinger equation, including propagation of light in photonic and photorefractive crystals with tilted band structures.

  20. An Optical Parametric Amplifier in Photonic Crystals of Nondispersive Medium with Perfect Bloch Phase Matching

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-Xue(陈历学); KIM Dalwoo; SONG Ying-Lin(宋瑛琳); DING Wei-Qiang(丁卫强); LI Wen-Hui(李文惠); LIU Shu-Tian(刘树田)

    2004-01-01

    One-dimensional photonic crystal of second-order nonlinearity is studied. Among the three waves of the parametric interaction process of down-conversion with a nondispersive medium, two gap-edge localized modes and one travelling-mode are proposed, and an exact phase matching condition is realized using the periodic condition of the Bloch phase. Numerical simulation is implemented by the slow-envelope finite difference time domain method. In the case of a pulse wave pump of amplitude half-width 5.2 × 10-13 s, an intense optical parametric pulse with half-width about 5 × 10-14 s is observed.

  1. Extraction of optical Bloch modes in a photonic-crystal waveguide

    CERN Document Server

    Huisman, S R; Stobbe, S; Herek, J L; Lodahl, P; Vos, W L; Pinkse, P W H

    2011-01-01

    We perform phase-sensitive near-field scanning optical microscopy on photonic-crystal waveguides. The observed intricate field patterns are analyzed by spatial Fourier transformations, revealing several guided TE- and TM-like modes. Using the reconstruction algorithm proposed by Ha, et al. (Opt. Lett. 34 (2009)), we decompose the measured two-dimensional field pattern in a superposition of propagating Bloch modes. This opens new possibilities to study specific modes in near-field measurements. We apply the method to study the transverse behavior of a guided TE-like mode, where the mode extends deeper in the surrounding photonic crystal when the band edge is approached.

  2. EMUstack: An open source route to insightful electromagnetic computation via the Bloch mode scattering matrix method

    Science.gov (United States)

    Sturmberg, Björn C. P.; Dossou, Kokou B.; Lawrence, Felix J.; Poulton, Christopher G.; McPhedran, Ross C.; Martijn de Sterke, C.; Botten, Lindsay C.

    2016-05-01

    We describe EMUstack, an open-source implementation of the Scattering Matrix Method (SMM) for solving field problems in layered media. The fields inside nanostructured layers are described in terms of Bloch modes that are found using the Finite Element Method (FEM). Direct access to these modes allows the physical intuition of thin film optics to be extended to complex structures. The combination of the SMM and the FEM makes EMUstack ideally suited for studying lossy, high-index contrast structures, which challenge conventional SMMs.

  3. Explicit Solutions of the Bethe Ansatz Equations for Bloch Electrons in a Magnetic Field

    OpenAIRE

    Hatsugai, Yasuhiro; Kohmoto, Mahito; Wu, Yong-Shi

    1994-01-01

    For Bloch electrons in a magnetic field, explicit solutions are obtained at the center of the spectrum for the Bethe ansatz equations recently proposed by Wiegmann and Zabrodin. When the magnetic flux per plaquette is $1/Q$ where $Q$ is an odd integer, distribution of the roots is uniform on the unit circle in the complex plane. For the semi-classical limit, $ Q\\rightarrow\\infty$, the wavefunction obeys the power low and is given by $|\\psi(x)|^2=(2/ \\sin \\pi x)$ which is critical and unnormal...

  4. Quantum Group, Bethe Ansatz and Bloch Electrons in a Magnetic Field

    OpenAIRE

    Hatsugai, Y.; Kohmoto, M.; Wu, Y.-S.

    1995-01-01

    The wave functions for two dimensional Bloch electrons in a uniform magnetic field at the mid-band points are studied with the help of the algebraic structure of the quantum group $U_q(sl_2)$. A linear combination of its generators gives the Hamiltonian. We obtain analytical and numerical solutions for the wave functions by solving the Bethe Ansatz equations, proposed by Wiegmann and Zabrodin on the basis of above observation. The semi-classical case with the flux per plaquette $\\phi=1/Q$ is ...

  5. Nonlinear waves of the Hirota and the Maxwell-Bloch equations in nonlinear optics

    Institute of Scientific and Technical Information of China (English)

    Li Chuan-Zhong; He Jing-Song; K.Porseizan

    2013-01-01

    In this paper,considering the Hirota and the Maxwell-Bloch (H-MB) equations which are governed by femtosecond pulse propagation through a two-level doped fiber system,we construct the Darboux transformation of this system through a linear eigenvalue problem.Using this Daurboux transformation,we generate multi-soliton,positon,and breather solutions (both bright and dark breathers) of the H-MB equations.Finally,we also construct the rogue wave solutions of the above system.

  6. Surface acoustic BLOCH oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling in a solid.

    Science.gov (United States)

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

    2010-04-23

    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.

  7. Demonstration of photon Bloch oscillations and Wannier-Stark ladders in dual-periodical multilayer structures based on porous silicon.

    Science.gov (United States)

    Estevez, J Octavio; Arriaga, Jesús; Mendez-Blas, Antonio; Reyes-Ayona, Edgar; Escorcia, José; Agarwal, Vivechana

    2012-07-23

    : Theoretical demonstration and experimental evidence of photon Bloch oscillations and Wannier-Stark ladders (WSLs) in dual-periodical (DP) multilayers, based on porous silicon, are presented. An introduction of the linear gradient in refractive indices in DP structure, which is composed by stacking two different periodic substructures N times, resulted in the appearance of WSLs. Theoretical time-resolved reflection spectrum shows the photon Bloch oscillations with a period of 130 fs. Depending on the values of the structural parameters, one can observe the WSLs in the near infrared or visible region which may allow the generation of terahertz radiation with a potential applications in several fields like imaging.

  8. Combination of BLOCH oscillations with a Ramsey-Bordé interferometer: new determination of the fine structure constant.

    Science.gov (United States)

    Cadoret, Malo; de Mirandes, Estefania; Cladé, Pierre; Guellati-Khélifa, Saïda; Schwob, Catherine; Nez, François; Julien, Lucile; Biraben, François

    2008-12-01

    We report a new experimental scheme which combines atom interferometry with Bloch oscillations to provide a new measurement of the ratio h/mRb. By using Bloch oscillations, we impart to the atoms up to 1600 recoil momenta and thus we improve the accuracy on the recoil velocity measurement. The deduced value of h/mRb leads to a new determination of the fine structure constant alpha(-1) =137.03599945 (62) with a relative uncertainty of 4.6 x 10(-9). The comparison of this result with the value deduced from the measurement of the electron anomaly provides the most stringent test of QED.

  9. Derivation of a time dependent Schrödinger equation as the quantum mechanical Landau-Lifshitz-Bloch equation

    Science.gov (United States)

    Wieser, R.

    2016-10-01

    The derivation of the time dependent Schrödinger equation with transversal and longitudinal relaxation, as the quantum mechanical analog of the classical Landau-Lifshitz-Bloch equation, has been described. Starting from the classical Landau-Lifshitz-Bloch equation the transition to quantum mechanics has been performed and the corresponding von-Neumann equation deduced. In a second step the time Schrödinger equation has been derived. Analytical proofs and computer simulations show the correctness and applicability of the derived Schrödinger equation.

  10. Derivation of a time dependent Schrödinger equation as the quantum mechanical Landau-Lifshitz-Bloch equation.

    Science.gov (United States)

    Wieser, R

    2016-10-01

    The derivation of the time dependent Schrödinger equation with transversal and longitudinal relaxation, as the quantum mechanical analog of the classical Landau-Lifshitz-Bloch equation, has been described. Starting from the classical Landau-Lifshitz-Bloch equation the transition to quantum mechanics has been performed and the corresponding von-Neumann equation deduced. In a second step the time Schrödinger equation has been derived. Analytical proofs and computer simulations show the correctness and applicability of the derived Schrödinger equation. PMID:27494599

  11. Nonperturbative shell correction to the Bethe-Bloch formula for the energy losses of fast charged particles

    Science.gov (United States)

    Matveev, V. I.; Makarov, D. N.

    2011-09-01

    A simple method including nonperturbative shell corrections has been developed for calculating energy losses on complex atoms. The energy losses of fast highly charged ions on neon, argon, krypton, and xenon atoms have been calculated and compared with experimental data. It has been shown that the inclusion of the non-perturbative shell corrections noticeably improves agreement with experimental data as compared to calculations by the Bethe-Bloch formula with the standard corrections. This undoubtedly helps to reduce the number of fitting parameters in various modifications of the Bethe-Bloch formula, which are usually determined semiempirically.

  12. Dynamics of Bloch State Positronium Emission from MOF Targets Studied via Rydberg TOF Spectroscopy

    Science.gov (United States)

    Piñeiro Escalera, Alina; Jones, Adric; Mills, Allen

    2016-05-01

    Recent advances in the efficient production and detection of Rydberg positronium (Ps) have made it possible to perform energy- and angle- resolved time-of-flight (TOF) spectroscopy with Ps. We report here TOF measurements of Ps emission from the metal-oxide framework (MOF) targets, MOF-5 and ZIF-8. MOFs are a recently synthesized class of chemical structures, characterized by high long-range order and large surface area to volume ratios (i.e., they are highly porous and uniform, crystalline materials). Ps is found to be emitted predominantly in a series of monoenergetic peaks, providing clear evidence of Ps Bloch states. Measuring the relative populations of the monoenergetic peaks, as a function of implantation energy and target temperature, provides insight into the target-dependent dynamics of Bloch state Ps. Work supported by the U.S. National Science Foundation Grants No. PHY 1206100 and No. PHY 1040590 and the National Science Foundation Graduate Research Fellowship Progam (NSF-GRFP). DOE BES DE-FG02-13ER46972 (MOF-5 synthesis and characterization).

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

    CERN Document Server

    Osika, Edyta N; Ortmann, Lisa; Suárez, Noslen; Pérez-Hernández, Jose Antonio; Szafran, Bartłomiej; Ciappina, Marcelo F; Sols, Fernando; Landsman, Alexandra S; Lewenstein, Maciej

    2016-01-01

    Emission of high-order harmonics from solids provides a new avenue in attosecond science. On one hand, it allows to investigate fundamental processes of the non-linear response of electrons driven by a strong laser pulse in a periodic crystal lattice. On the other hand, it opens new paths toward efficient attosecond pulse generation, novel imaging of electronic wave functions, and enhancement of high-order harmonic generation (HHG) intensity. A key feature of HHG in a solid (as compared to the well-understood phenomena of HHG in an atomic gas) is the delocalization of the process, whereby an electron ionized from one site in the periodic lattice may recombine with any other. Here, we develop an analytic model, based on the localized Wannier wave functions in the valence band and delocalized Bloch functions in the conduction band. This Wannier-Bloch approach assesses the contributions of individual lattice sites to the HHG process, and hence addresses precisely the question of localization of harmonic emission...

  14. Partial secular Bloch-Redfield master equation for incoherent excitation of multilevel quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Tscherbul, Timur V., E-mail: ttscherb@chem.utoronto.ca; Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

    2015-03-14

    We present an efficient theoretical method for calculating the time evolution of the density matrix of a multilevel quantum system weakly interacting with incoherent light. The method combines the Bloch-Redfield theory with a partial secular approximation for one-photon coherences, resulting in a master equation that explicitly exposes the reliance on transition rates and the angles between transition dipole moments in the energy basis. The partial secular Bloch-Redfield master equation allows an unambiguous distinction between the regimes of quantum coherent vs. incoherent energy transfer under incoherent light illumination. The fully incoherent regime is characterized by orthogonal transition dipole moments in the energy basis, leading to a dynamical evolution governed by a coherence-free Pauli-type master equation. The coherent regime requires non-orthogonal transition dipole moments in the energy basis and leads to the generation of noise-induced quantum coherences and population-to-coherence couplings. As a first application, we consider the dynamics of excited state coherences arising under incoherent light excitation from a single ground state and observe population-to-coherence transfer and the formation of non-equilibrium quasisteady states in the regime of small excited state splitting. Analytical expressions derived earlier for the V-type system [T. V. Tscherbul and P. Brumer, Phys. Rev. Lett. 113, 113601 (2014)] are found to provide a nearly quantitative description of multilevel excited-state populations and coherences in both the small- and large-molecule limits.

  15. Singularity of the time-energy uncertainty in adiabatic perturbation and cycloids on a Bloch sphere.

    Science.gov (United States)

    Oh, Sangchul; Hu, Xuedong; Nori, Franco; Kais, Sabre

    2016-01-01

    Adiabatic perturbation is shown to be singular from the exact solution of a spin-1/2 particle in a uniformly rotating magnetic field. Due to a non-adiabatic effect, its quantum trajectory on a Bloch sphere is a cycloid traced by a circle rolling along an adiabatic path. As the magnetic field rotates more and more slowly, the time-energy uncertainty, proportional to the length of the quantum trajectory, calculated by the exact solution is entirely different from the one obtained by the adiabatic path traced by the instantaneous eigenstate. However, the non-adiabatic Aharonov-Anandan geometric phase, measured by the area enclosed by the exact path, approaches smoothly the adiabatic Berry phase, proportional to the area enclosed by the adiabatic path. The singular limit of the time-energy uncertainty and the regular limit of the geometric phase are associated with the arc length and arc area of the cycloid on a Bloch sphere, respectively. Prolate and curtate cycloids are also traced by different initial states outside and inside of the rolling circle, respectively. The axis trajectory of the rolling circle, parallel to the adiabatic path, is shown to be an example of transitionless driving. The non-adiabatic resonance is visualized by the number of cycloid arcs. PMID:26916031

  16. Creating full-Bloch Bose-Einstein condensates with Raman q-plates

    Science.gov (United States)

    Schultz, Justin T.; Hansen, Azure; Murphree, Joseph D.; Jayaseelan, Maitreyi; Bigelow, Nicholas P.

    2016-06-01

    A coherent two-photon optical Raman interaction in a pseudo-spin-1/2 Bose-Einstein condensate (BEC) serves as a q-plate for atoms, converting spin to orbital angular momentum. This Raman q-plate has a singular pattern in its polarization distribution in analogy to the singular birefringent q-plates used in singular optics. The vortex winding direction and magnitude as well as the final spin state of the BEC depend on the initial spin state and the topology of the optical Raman q-plate beams. Drawing on the mathematical and geometric foundations of singular optics, we derive the equivalent Jones matrix for this Raman q-plate and use it to create and characterize atomic spin singularities in the BEC that are analogous to optical C-point singularities in polarization. By tuning the optical Raman parameters, we can generate a coreless vortex spin texture which contains every possible superposition in a two-state system. We identify this spin texture as a full-Bloch BEC since every point on the Bloch sphere is represented at some point in the cross section of the atomic cloud. This spin-orbit interaction and the spin textures it generates may allow for the observation of interesting geometric phases in matter waves and lead to schemes for topological quantum computation with spinor BECs.

  17. Dynamic scattering of electron vortex beams--a Bloch wave analysis.

    Science.gov (United States)

    Mendis, B G

    2015-02-01

    Two important applications of electron vortex beams are in electron magnetic chiral dichroism (EMCD) measurements and nanoparticle manipulation. In both cases orbital angular momentum (〈Lz〉) transfer between the vortex beam and the specimen due to dynamic scattering is critical. In general the 〈Lz〉 pendellösung consists of short and long wavelength oscillations. The former is due to interference between the tightly bound 1s and more dispersive non-1s Bloch states, while the latter is due to interference between the non-1s states. For EMCD experiments with ±ħ angular momentum beams, momentum transfer can be minimised by selecting the appropriate aperture size, so that the probe wavefunction approximately matches that of the 2p-type Bloch states. For manipulating nanoparticles with large angular momentum beams small apertures are required to excite the 1s state and thereby enhance the short wavelength oscillations in 〈Lz〉. This enables efficient momentum transfer to the specimen, provided the nanoparticle dimension corresponds to a minimum in the 〈Lz〉 pendellösung.

  18. Bloch spin waves and emergent structure in protein folding with HIV envelope glycoprotein as an example

    Science.gov (United States)

    Dai, Jin; Niemi, Antti J.; He, Jianfeng; Sieradzan, Adam; Ilieva, Nevena

    2016-03-01

    We inquire how structure emerges during the process of protein folding. For this we scrutinize collective many-atom motions during all-atom molecular dynamics simulations. We introduce, develop, and employ various topological techniques, in combination with analytic tools that we deduce from the concept of integrable models and structure of discrete nonlinear Schrödinger equation. The example we consider is an α -helical subunit of the HIV envelope glycoprotein gp41. The helical structure is stable when the subunit is part of the biological oligomer. But in isolation, the helix becomes unstable, and the monomer starts deforming. We follow the process computationally. We interpret the evolving structure both in terms of a backbone based Heisenberg spin chain and in terms of a side chain based XY spin chain. We find that in both cases the formation of protein supersecondary structure is akin the formation of a topological Bloch domain wall along a spin chain. During the process we identify three individual Bloch walls and we show that each of them can be modelled with a precision of tenths to several angstroms in terms of a soliton solution to a discrete nonlinear Schrödinger equation.

  19. Raman fingerprints on the Bloch sphere of a spinor Bose-Einstein condensate

    CERN Document Server

    Schultz, Justin T; Murphree, Joseph D; Jayaseelan, Maitreyi; Bigelow, Nicholas P

    2016-01-01

    We explore the geometric interpretation of a diabatic, two-photon Raman process as a rotation on the Bloch sphere for a pseudo-spin-1/2 system. The spin state of a spin-1/2 quantum system can be described by a point on the surface of the Bloch sphere, and its evolution during a Raman pulse is a trajectory on the sphere determined by properties of the optical beams: the pulse area, the relative intensities and phases, and the relative frequencies. We experimentally demonstrate key features of this model with a $^{87}$Rb spinor Bose-Einstein condensate, which allows us to examine spatially dependent signatures of the Raman beams. The two-photon detuning allows us to precisely control the spin density and imprinted relative phase profiles, as we show with a coreless vortex. With this comprehensive understanding and intuitive geometric interpretation, we use the Raman process to create and tailor as well as study and characterize exotic topological spin textures in spinor BECs.

  20. Partial secular Bloch-Redfield master equation for incoherent excitation of multilevel quantum systems

    Science.gov (United States)

    Tscherbul, Timur V.; Brumer, Paul

    2015-03-01

    We present an efficient theoretical method for calculating the time evolution of the density matrix of a multilevel quantum system weakly interacting with incoherent light. The method combines the Bloch-Redfield theory with a partial secular approximation for one-photon coherences, resulting in a master equation that explicitly exposes the reliance on transition rates and the angles between transition dipole moments in the energy basis. The partial secular Bloch-Redfield master equation allows an unambiguous distinction between the regimes of quantum coherent vs. incoherent energy transfer under incoherent light illumination. The fully incoherent regime is characterized by orthogonal transition dipole moments in the energy basis, leading to a dynamical evolution governed by a coherence-free Pauli-type master equation. The coherent regime requires non-orthogonal transition dipole moments in the energy basis and leads to the generation of noise-induced quantum coherences and population-to-coherence couplings. As a first application, we consider the dynamics of excited state coherences arising under incoherent light excitation from a single ground state and observe population-to-coherence transfer and the formation of non-equilibrium quasisteady states in the regime of small excited state splitting. Analytical expressions derived earlier for the V-type system [T. V. Tscherbul and P. Brumer, Phys. Rev. Lett. 113, 113601 (2014)] are found to provide a nearly quantitative description of multilevel excited-state populations and coherences in both the small- and large-molecule limits.

  1. Nucleotide sequences of genome segments S6, S7 and S10 of Dendrolimus punctatus cypovirus 1.

    Science.gov (United States)

    Hong, J J; Duan, J L; Zhao, S L; Xu, H G; Peng, H Y

    2004-01-01

    The nucleotide sequences of genome segments S6, S7 and S10 of Dendrolimus punctatus cypovirus 1 Hunan I (DpCPV-HN(I)) and DpCPV-HN(I)-Se(3) (DpCPV-HN(I) passed three times in Spodoptera exigua) were determined. Segment S10 was 944 nucleotides in length and encoded a polyhedrin of 248 amino acids (28,439 Da). Only two nucleotide mutations were found between DpCPV-HN(I) S10 and DpCPV-HN(I)-Se3 S10, and the deduced amino acid sequences of the polyhedrin proteins were identical. Segment S7, 1 501 nucleotides, encoded a protein of 448 amino acids ( approximately 50 kDa; p50). Thirty-one nucleotide mutations were found between DpCPV-HN(I) S7 and DpCPV-HN(I)-Se3 S7, but these resulted in only four amino acid changes. DpCPV-HN(I) S6 encoded a protein of 561 amino acids (63,688 Da; p64). The amino acid sequence of p64, had a high leucine content (10%), and contained a leucine zipper motif and one ATP/GTP-binding site motif.

  2. Safety of aquaflor (florfenicol, 50% type a medicated article), administered in feed to channel catfish, Ictalurus punctatus

    Science.gov (United States)

    Gaikowski, Mark P.; Wolf, Jeffery C.; Endris, Richard G.; Gingerich, William H.

    2003-01-01

    Aquaflor, a feed premix containing the broad spectrum antibacterial agent florfenicol (50% w/w), is being developed for use to control enteric septicemia (ESC) in channel catfish Ictalurus punctatus caused by the gram-negative enterobacterium Edwardsiella ictaluri. The recommended dose of Aquaflor to control ESC is 10 mg/kg body weight (BW)/day for 10 days. The study objective was to determine the safety of Aquaflor administered in feed to channel catfish at doses of 0 (control), 10, 30, and 50 mg/kg BW/day for 20 consecutive days. Parameters evaluated included daily mortality, behavioral (appetite, distribution, flight/fright response), and water chemistry observations, initial and terminal weight measurements, and gross and microscopic pathology. Medicated feed consumption was 67-86% of target with group mean doses of 8.5 mg/kg BW/day, 24.6 mg/kg BW/day, and 34.9 mg/kg BW/day. There were no mortalities or clinically observable changes noted at any of the dose levels tested. Aquaflor-related changes were limited to the food consumption and histopathology data. Although Aquaflor-related decreased feed consumption was noted in the 30 and 50 mg/kg BW/day groups, there were no differences in fish growth among the treatment groups. Aquaflor-related histopathology findings were limited to a histomorphologically evident dose-dependent decrease in hematopoietic/lymphopoietic tissue in the anterior kidneys, posterior kidneys, and spleens of channel catfish.

  3. Phenotypic plasticity allows the Mediterranean parsley frog Pelodytes punctatus to exploit two temporal niches under continuous gene flow.

    Science.gov (United States)

    Jourdan-Pineau, Helene; David, Patrice; Crochet, Pierre-Andre

    2012-02-01

    Environmental changes, such as climate change, lead to the opening of new niches. In such situations, species that adapt to new niches can survive and/or expand their ranges. However, gene flow can hamper genetic adaptation to new environments. Alternatively, recent models have highlighted the importance of phenotypic plasticity in tracking environmental change. Here, we investigate whether phenotypic plasticity or genetic evolution (or both) allows an amphibian species to exploit two divergent climatic niches. In the Mediterranean region, the parsley frog Pelodytes punctatus breeds both in spring, as do most other species, and in autumn, a temporal niche not exploited by most other species, but which may become increasingly important with global warming. Conditions of development are dramatically different between the two seasons and deeply impact tadpole life-history traits. To determine whether these temporal niches are exploited by two genetically differentiated subpopulations, or whether the bimodal phenology arises in a panmictic population displaying plastic life-history traits, we use two complementary approaches. We measure both molecular genetic differentiation and quantitative-trait differentiation between spring and autumn cohorts, using microsatellites and common garden experiments, respectively. Seasonal cohorts were not genetically differentiated and differences in tadpole life history between cohorts were not maintained in laboratory conditions. We conclude that phenotypic plasticity, rather than genetic adaptation, allows Parsley frog to exploit two contrasting temporal niches.

  4. Molecular cloning, expression and the adjuvant effects of interleukin-8 of channel catfish (Ictalurus Punctatus) against Streptococcus iniae

    Science.gov (United States)

    Wang, Erlong; Wang, Jun; Long, Bo; Wang, Kaiyu; He, Yang; Yang, Qian; Chen, Defang; Geng, Yi; Huang, Xiaoli; Ouyang, Ping; Lai, Weimin

    2016-01-01

    Interleukin-8 (IL-8) as an important cytokine involving in inflammatory and immune response, has been studied as effective adjuvants for vaccines in mammals. However, there are fewer reports about the characterization and adjuvant effects of IL-8 in fish. In this study, cloning and sequence analysis of IL-8 coding region of channel catfish (Ictalurus punctatus) were conducted, mature IL-8(rtIL-8) was expressed and evaluated for its adjuvant effects on the immunoprotection of subunit vaccine encoding α-enolase (rENO) of Streptococcus iniae from several aspects in channel catfish. The results showed co-vaccination of rENO with rtIL-8 enhanced immune responses including humoral and cellular immunity, with higher relative percent survival(RPS,71.4%) compared with the moderate RPS of rENO alone(50%) against S. iniae infection at 4 week post vaccination. While rtIL-8 failed to maintain long-lasting immune protection, only with RPS of 26.67% in rENO + rtIL-8-vaccinated fish compared with that of rENO alone(20%) at 8 week, signifying that IL-8 hold promise for use as potential immunopotentiator in vaccines against bacterial infections in fish, whereas it is insufficient to extend the immunoprotection for long time, and further studies are required to understand the mechanisms of IL-8 used as an adjuvant and seek for more effective way to strengthen the adjuvanticity of IL-8. PMID:27373470

  5. Expression, Purification and Antibacterial Activity of NK-Lysin Mature Peptides from the Channel Catfish (Ictalurus punctatus

    Directory of Open Access Journals (Sweden)

    Shurui Cai

    2016-08-01

    Full Text Available Antimicrobial peptides (AMPs are small peptides and play important roles in host innate immune response against microbial invasion. Aquatic animals secrete different kinds of antimicrobial peptides which have antimicrobial activity towards microorganisms. NK-lysins, mature peptides produced by cytotoxic T lymphocytes and natural killer cells, are comprised of 74–78 amino acid residues, demonstrating broad-spectrum antimicrobial activity against bacteria, fungi, protozoa, and parasites. In this study, three distinct NK-lysin mature peptide (mNKLs, transcripts (76 amino acid residues cloned from the channel catfish (Ictalurus punctatus head kidney were ligated into plasmid vector pET-32a(+ to express the mNKLs fusion protein. The fusion protein was successfully expressed in E. coli Rosetta (DE3 under optimized conditions. After purification by affinity column chromatography, the fusion protein was successfully cleaved by enterokinase and released the peptide mNKLs. Tricine-SDS-PAGE results showed that mNKLs (approximately 8.6 kDa were successfully expressed. The purified peptide mNKLs exhibited antibacterial activity against Staphylococcus aureus and E. coli.

  6. Responses of channel catfish (Ictalurus punctatus) swim-up fry to dietary calcium in soft and hard water.

    Science.gov (United States)

    Scarpa, J; Gatlin, D M

    1993-12-01

    1. Responses of channel catfish (Ictalurus punctatus) swim-up fry to dietary calcium in soft ( 100 mg/l as CaCO3) water were determined by feeding purified egg-white diets containing 0, 0.5, 1.0, or 2.0% calcium from CaCO3 for 8 weeks. 2. Catfish fry fed the basal diet (0.03% Ca) in hard and soft water had lower whole-body ash and whole-body calcium concentrations but higher weight gain and survival than those fed calcium-supplemented diets. 3. Fry in soft water generally had lower whole-body ash, whole-body calcium, and survival, as well as a higher incidence of spinal deformities than fry in hard water. 4. Feeding higher levels of calcium to fry reared in soft water did not increase whole-body calcium levels or decrease spinal deformities to the levels observed for fry reared in hard water and fed supplemental calcium. 5. These data indicate that calcium derived solely from dietary or environmental sources was not sufficient for optimum health of channel catfish fry.

  7. The Effects of Sequential Environmental and Harvest Stressors on the Sensory Characteristics of Cultured Channel Catfish (Ictalurus Punctatus) Fillets.

    Science.gov (United States)

    Ciaramella, Michael A; Kim, Taejo; Avery, Jimmy L; Allen, Peter J; Schilling, M Wes

    2016-08-01

    Stress during fish culture alters physiological homeostasis and affects fillet quality. Maintenance of high-quality seafood is important to ensure the production of a marketable product. This study assessed how sequential stressors affect the sensory and quality characteristics of catfish (Ictalurus punctatus) fillets. Three stress trials were conducted where temperature (25 or 33 °C) and dissolved oxygen (DO, approximately 2.5 or >5 mg/L) were manipulated followed by socking and transport stress. After each stage of harvest (environmental stress, socking, and transport), fillet yield, consumer acceptability, descriptive evaluation, cook loss, tenderness, and pH were evaluated. Fillet yield decreased with increasing severity of environmental stress. Fillets from the severe stress treatment (33 °C, approximately 2.5 mg/L) received the highest acceptability scores (P 5 mg/L) were the least acceptable (P 6 on a 9 point scale). Socking and transport were identified to positively affect textural characteristics of catfish fillets. Although the effects observed were not likely to negatively impact consumer acceptance, a strict management plan should be followed to maintain consistency in the product and avoid changes in stressors that might alter quality more drastically. PMID:27333086

  8. Molecular cloning, expression and the adjuvant effects of interleukin-8 of channel catfish (Ictalurus Punctatus) against Streptococcus iniae.

    Science.gov (United States)

    Wang, Erlong; Wang, Jun; Long, Bo; Wang, Kaiyu; He, Yang; Yang, Qian; Chen, Defang; Geng, Yi; Huang, Xiaoli; Ouyang, Ping; Lai, Weimin

    2016-01-01

    Interleukin-8 (IL-8) as an important cytokine involving in inflammatory and immune response, has been studied as effective adjuvants for vaccines in mammals. However, there are fewer reports about the characterization and adjuvant effects of IL-8 in fish. In this study, cloning and sequence analysis of IL-8 coding region of channel catfish (Ictalurus punctatus) were conducted, mature IL-8(rtIL-8) was expressed and evaluated for its adjuvant effects on the immunoprotection of subunit vaccine encoding α-enolase (rENO) of Streptococcus iniae from several aspects in channel catfish. The results showed co-vaccination of rENO with rtIL-8 enhanced immune responses including humoral and cellular immunity, with higher relative percent survival(RPS,71.4%) compared with the moderate RPS of rENO alone(50%) against S. iniae infection at 4 week post vaccination. While rtIL-8 failed to maintain long-lasting immune protection, only with RPS of 26.67% in rENO + rtIL-8-vaccinated fish compared with that of rENO alone(20%) at 8 week, signifying that IL-8 hold promise for use as potential immunopotentiator in vaccines against bacterial infections in fish, whereas it is insufficient to extend the immunoprotection for long time, and further studies are required to understand the mechanisms of IL-8 used as an adjuvant and seek for more effective way to strengthen the adjuvanticity of IL-8. PMID:27373470

  9. Magnetic Bloch oscillations in the near-Ising antiferromagnet CoCl2#center dot#2D2O

    DEFF Research Database (Denmark)

    Christensen, N.B.; Lefmann, K.; Johannsen, I.;

    2000-01-01

    We have investigated the possible occurrence of magnetic Bloch oscillations in CoCl2 . 2D(2)O. We were unable to observe these oscillations at 20.0 K, just above T-N. In an attempt to explain this result, we studied spin waves in the a*-c* plane in order to estimate the effect of the interchain...

  10. Spontaneous emission of Bloch oscillation radiation under the competing influences of microcavity enhancement and inhomogeneous interface degradation

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, V. N. [Department of Theoretical Physics, Institute for Semiconductor Physics, NASU, Pr. Nauki 41, Kiev 03028 (Ukraine); Iafrate, G. J. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695-8617 (United States)

    2014-02-07

    A theory for the spontaneous emission (SE) of terahertz radiation for a Bloch electron traversing a single energy miniband of a superlattice (SL) in a cavity, while undergoing elastic scattering is presented. The Bloch electron is accelerated under the influence of a superimposed external constant electric field and an internal inhomogeneous electric field, while radiating into a microcavity. The analysis of the SE accounts for both the spectral structure of nonharmonic miniband components and the Bloch oscillation degradation effects arising from elastic scattering due to SL interface roughness. The interface roughness effects are decomposed into contributions arising from independent planar and cross-correlated neighboring planar interfaces; parametric numerical estimates show that the cross-correlated contribution to the SE relaxation rate is relatively small, representing less than roughly 10% of the total relaxation rate. It is shown that the degradation effects from SL interface roughness can be more than compensated for by the enhancements derived from microcavity-based tuning of the emission frequency to the cavity density of states peak. The theoretical approach developed herein has general applicability beyond its use for elastic scattering due to interface roughness. As well, the results obtained in this analysis can be useful in the development of SL-based Bloch-oscillator terahertz devices.

  11. COMPARATIVE STUDY OF WLR OF Channa striatus OF FRY- FINGERLING, GROW-OUTS AND ADULTS OF GANGETIC PLAINS

    Directory of Open Access Journals (Sweden)

    R.DAYAL

    2012-03-01

    Full Text Available In the present study the Weight – Length relationships (WLR are described for the three stages of life of the Snakehead, Saul, Channa striatus, collected from the districts of Barabanki, Lucknow and Unnao in Uttar Pradesh in 2008-09. Method used for analysis of fisheries data on the WLR is (W=aLb and this study reports the parameters ‘a’ and ‘b’ of the length–weight relationships for one hundred numbers of fry/ fingerlings, thirty-seven grow-out fishes and eighty-nine number of adult fishes collected from the same geographical area. The weight and total length of fry/ fingerlings ranged from 340 to 650 mg and 35 to 45 mm respectively (a=W/L3, 0.0060 to 0.0088; log W=log a + b*(log L, 3.92821 to 4.72919; b=(log W-log a/log L, 3.89643 to 4.11143. The recorded weight and total length of the grow-outs ranged between 9 to 93g and 10.9 to 25.4 cm respectively (a=W/L3, 0.0082 to 0.0146; log W=log a + b*(log L, 0.95424 to 1.96848; b= (log W-log a/log L, 3.0. In case of adults the weight and total length recorded ranged between 74 to 476g and 22.9 to 42.4 cm respectively (a=W/L3, 0.0054 to 0.0121; log W=log a + b*(log L, 2.39029 to 4.17039; b=(log W-log a/log L, 3.40747 to 3.95845. Since fishes were collected during the months of April - May, 2008 and November, 2009, the parameters estimated in this study are considered only for these seasons, because WLR are not constant over the entire year and vary according to factors such as temperature, food availability, feeding rate, gonadal development and spawning period. The result suggests that these fishes grow in a pattern from early life stage to adult if grown in the same environmental conditions.

  12. Dietary Prebiotics and Probiotics Influence the Growth Performance, Feed Utilisation, and Body Indices of Snakehead (Channa striata) Fingerlings.

    Science.gov (United States)

    Munir, Mohammad Bodrul; Hashim, Roshada; Abdul Manaf, Mohammad Suhaimee; Nor, Siti Azizah Mohd

    2016-08-01

    This study used a two-phase feeding trial to determine the influence of selected dietary prebiotics and probiotics on growth performance, feed utilisation, and morphological changes in snakehead (Channa striata) fingerlings as well as the duration of these effects over a post-experimental period without supplementation. Triplicate groups of fish (22.46 ±0.17 g) were raised on six different treatment diets: three prebiotics (0.2% β-glucan, 1% galacto-oligosaccharides [GOS], 0.5% mannan-oligosaccharides [MOS]), two probiotics (1% live yeast [Saccharomyces cerevisiae] and 0.01% Lactobacillus acidophilus [LBA] powder) and a control (unsupplemented) diet; there were three replicates for each treatment. All diets contained 40% crude protein and 12% crude lipid. Fish were fed to satiation three times daily. No mortalities were recorded during Phase 1; however, 14% mortality was documented in the control and prebiotic-amended fish during Phase 2. At the end of Phase 1, growth performance and feed utilisation were significantly higher (p<0.05) in the LBA-treated fish, followed by live yeast treatment, compared with all other diets tested. The performance of fish on the three prebiotic diets were not significantly different from one another but was significantly higher than the control diet. During Phase 2 (the post-feeding phase), fish growth continued until the 6th week for the probiotic-based diets but levelled off after four weeks for the fish fed the prebiotic diets. The feed conversion ratio (FCR) was higher in all treatments during the post-feeding period. The hepatosomatic index (HSI) did not differ significantly among the tested diets. The visceral somatic index (VSI) and intraperitoneal fat (IPF) were highest in the LBA-based diet and the control diet, respectively. The body indices were significantly different (p<0.05) between Phases 1 and 2. This study demonstrates that probiotic-based diets have a more positive influence on the growth, feed utilisation, and

  13. Cloning and characterization of interferon stimulated genes Viperin and ISG15,and their promoters from snakehead Channa argus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By suppression subtractive hybridization,rapid amplification of cDNA ends and gene walking methods,interferon stimulated genes (ISGs),Viperin and ISG15,and their promoters have been cloned and characterized from snakehead Channa argus.The Viperin cDNA was found to be 1474 nt and contain an open reading frame(ORF)of 1059 nt that translates into a putative peptide of 352amino acid(aa).The putative peptide of Viperin shows high identity to that in teleosts and mamals except for the N-terminal 70 aa.The ISG15 cDNA was found to be 758 nt and contain an ORF of 468 nt that translates into a putative peptide of 155 aa.The putative peptide of ISG15 is composed of two tandem repeats of ubiquitin-like(UBL)domains,and a canonical conjugation motif(LRGG)at C-terminal.Viperin and ISG15 promoter regions were characterized by the presence of interferon stimulating response elements(ISRE)and γ-IFN activation sites (GAS).ISRE is a feature of IFN-induced gene promoter and partially overlaps interferon regulatory factor (IRF)1 and IRF2 recognition sites.GAS is responsible for the γ-IFN mediated transcription.One conserved site for NF-kB was found in the promoter region of Viperin.This is the first report of conservative binding motif for NF-kB in accordance with the consensus sequence(GGGRNNYYCC)among teleost ISG promoters.Moreover,there were also TATA,CAAT and Spl transcription factor sites in Viperin and ISG15 promoters.In 5'untranslated region (UTR),snakehead ISG15 gene contains a single intron,which differs from Viperin gene.The transcripts of Vipeirn and ISG15 mRNA were mainly expressed in head kidney,posterior kidney,spleen and gill.The expression levels in liver were found to increase obviously in response to induction by IFN-inducer poly I:C.

  14. 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

  15. Bloch Brane

    CERN Document Server

    Bazeia, D

    2004-01-01

    We investigate a system described by two real scalar fields coupled with gravity in (4, 1) dimensions in warped spacetime involving one extra dimension. The results show that the parameter which controls the way the two scalar fields interact induces the appearence of thick brane which engenders internal structure, driving the energy density to localize inside the brane in a very specific way.

  16. Interaction-induced quantum phase revivals and evidence for the transition to the quantum chaotic regime in 1D atomic Bloch oscillations.

    Science.gov (United States)

    Meinert, F; Mark, M J; Kirilov, E; Lauber, K; Weinmann, P; Gröbner, M; Nägerl, H-C

    2014-05-16

    We study atomic Bloch oscillations in an ensemble of one-dimensional tilted superfluids in the Bose-Hubbard regime. For large values of the tilt, we observe interaction-induced coherent decay and matter-wave quantum phase revivals of the Bloch oscillating ensemble. We analyze the revival period dependence on interactions by means of a Feshbach resonance. When reducing the value of the tilt, we observe the disappearance of the quasiperiodic phase revival signature towards an irreversible decay of Bloch oscillations, indicating the transition from regular to quantum chaotic dynamics.

  17. A cytochemical study of the "chloride cells" in the skin of a fresh-water teleost (Channa striata (Bl.) Channidae, Pisces).

    Science.gov (United States)

    Banerjee, T K; Mittal, A K

    1975-01-01

    The chloride cells in the skin of Channa striata have been described. The cytoplasm of these cells is filled with acidophilic, osmiophilic and sudanophilic granules. The sudanophila is due to phospholipids. These cells give positive reaction for chloride ions and exhibit the presence of neutral mucopolysaccharides. The cytoplasm of these cells is packed with numerous mitochondria and exhibit high succinic dehydrogenase activity which may provide the energy needed for the active transportation of ions. Alkaline phosphatase activity could not be demonstrated in these cells. The presence of chloride cells in comparatively large numbers in the regions where the epidermis is thin is correlated as an adaptation for the increased efficiency of these cells for the transportation of ions so as to maintain the osmotic concentration of its body fluid which is higher than that of the surrounding medium. PMID:127502

  18. 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.

  19. Parámetros hemáticos en tres especies de peces (Ictalurus punctatus, Morone saxatilis y Micropterus salmoides) en condiciones de desnutrición

    OpenAIRE

    Francisco Javier Alvarez Mendoza; Elsa María Tamez Cantú; Jesús Montemayor Leal

    2013-01-01

    Se evaluó el efecto de la desnutrición sobre los parámetros hemáticos en tres especies de peces de agua dulce, Ictalurus punctatus, Morone saxatilis y Micropterus salmoides. Los parámetros hemáticos analizados fueron: Microhematocrito (Ht), Hemoglobina (Hb), Proteína Total del Plasma (PTP), y Recuento diferencial de leucocitos. Además se analizó el comportamiento del polígono de frecuencia de la longitud mayor de los eritrocitos. Se consideraron dos niveles de desnutrición: moderada (15 dí...

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

    International Nuclear Information System (INIS)

    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 60Co 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

  1. Modified-Bloch-equation description of EPR transient nutations and free induction decay in solids

    Energy Technology Data Exchange (ETDEWEB)

    Asadullina, N.Ya.; Asadullin, Ya.Ya. [Kazan State Technical University, Department of General Physics, Kazan (Russian Federation); Asadullin, T.Ya. [Kazan State Technical University, Department of General Physics, Kazan (Russian Federation). E-mail: atimur@physics.ktsu-kai.ru

    2001-04-09

    Based on the experimental work by Boscaino et al on the EPR transient nutations (TNs) and free induction decay (FID) in solids, we propose the modified Bloch equations (MBEs). In addition to the Tomita expression for power-dependent parameter T{sub 2u}, we give an original phenomenological expression for power-dependent parameter T{sub 2v} and tuning {delta}. Both analytical (in the form of a Torrey solution with these parameters) and numerical solutions of MBE are obtained for TN and for different FID regimes with very good agreement between theory and experiment. We also discuss the meaning and role of the instantaneous diffusion mechanism in the transient pulse experiments. (author)

  2. A Bloch decomposition-based stochastic Galerkin method for quantum dynamics with a random external potential

    Science.gov (United States)

    Wu, Zhizhang; Huang, Zhongyi

    2016-07-01

    In this paper, we consider the numerical solution of the one-dimensional Schrödinger equation with a periodic lattice potential and a random external potential. This is an important model in solid state physics where the randomness results from complicated phenomena that are not exactly known. Here we generalize the Bloch decomposition-based time-splitting pseudospectral method to the stochastic setting using the generalized polynomial chaos with a Galerkin procedure so that the main effects of dispersion and periodic potential are still computed together. We prove that our method is unconditionally stable and numerical examples show that it has other nice properties and is more efficient than the traditional method. Finally, we give some numerical evidence for the well-known phenomenon of Anderson localization.

  3. Electroweak corrections and Bloch-Nordsieck violations in 2-to-2 processes at the LHC

    Science.gov (United States)

    Stirling, W. J.; Vryonidou, E.

    2013-04-01

    We consider the effect of next-to-leading order (NLO) electroweak corrections to Standard Model 2 → 2 processes, taking into account the potentially large double logarithms originating from both real and virtual corrections. A study of the leading Sudakov logarithms is presented and Bloch-Nordsieck (BN) violations are discussed for processes at the CERN Large Hadron Collider. In particular, we focus on the processes Z/γ+jet and also the ratio of Z to γ production. This ratio is known to be insensitive to NLO QCD corrections but this is not expected to be the case for the electroweak corrections. We also comment on the effect of electroweak corrections and the presence of BN violation for QCD processes, in particular dijet production, and also for purely electroweak processes such as W + H and W + Z associated production.

  4. Electroweak corrections and Bloch-Nordsieck violations in 2-to-2 processes at the LHC

    CERN Document Server

    Stirling, W J

    2013-01-01

    We consider the effect of next-to-leading order (NLO) electroweak corrections to Standard Model 2-to-2 processes, taking into account the potentially large double logarithms originating from both real and virtual corrections. A study of the leading Sudakov logarithms is presented and Bloch-Nordsieck (BN) violations are discussed for processes at the CERN Large Hadron Collider. In particular, we focus on the processes Z/photon+jet and also the ratio of Z to photon production. This ratio is known to be insensitive to NLO QCD corrections but this is not expected to be the case for the electroweak corrections. We also comment on the effect of electroweak corrections and the presence of BN violation for QCD processes, in particular dijet production, and also for purely electroweak processes such as W + H and W + Z associated production.

  5. High tip angle approximation based on a modified Bloch-Riccati equation.

    Science.gov (United States)

    Boulant, Nicolas; Hoult, David I

    2012-02-01

    When designing a radio-frequency pulse to produce a desired dependence of magnetization on frequency or position, the small flip angle approximation is often used as a first step, and a Fourier relation between pulse and transverse magnetization is then invoked. However, common intuition often leads to linear scaling of the resulting pulse so as to produce a larger flip angle than the approximation warrants--with surprisingly good results. Starting from a modified version of the Bloch-Riccati equation, a differential equation in the flip angle itself, rather than in magnetization, is derived. As this equation has a substantial linear component that is an instance of Fourier's equation, the intuitive approach is seen to be justified. Examples of the accuracy of this higher tip angle approximation are given for both constant- and variable-phase pulses.

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

    International Nuclear Information System (INIS)

    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)

  7. Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch oscillations

    CERN Document Server

    Schubert, O; Langer, F; Urbanek, B; Lange, C; Huttner, U; Golde, D; Meier, T; Kira, M; Koch, S W; Huber, R

    2016-01-01

    Ultrafast charge transport in strongly biased semiconductors is at the heart of highspeed electronics, electro-optics, and fundamental solid-state physics. Intense light pulses in the terahertz (THz) spectral range have opened fascinating vistas: Since THz photon energies are far below typical electronic interband resonances, a stable electromagnetic waveform may serve as a precisely adjustable bias. Novel quantum phenomena have been anticipated for THz amplitudes reaching atomic field strengths. We exploit controlled THz waveforms with peak fields of 72 MV/cm to drive coherent interband polarization combined with dynamical Bloch oscillations in semiconducting gallium selenide. These dynamics entail the emission of phase-stable high-harmonic transients, covering the entire THz-to-visible spectral domain between 0.1 and 675 THz. Quantum interference of different ionization paths of accelerated charge carriers is controlled via the waveform of the driving field and explained by a quantum theory of inter- and in...

  8. Chirped dual periodic structures for photonic Bloch oscillations and Zener tunneling.

    Science.gov (United States)

    Estevez, J O; Arriaga, J; Reyes-Ayona, E; Agarwal, V

    2015-06-29

    Experimental evidence of photon Wannier-stark ladders (WSLs) and Zener tunneling (ZT) in one dimensional dual-periodical (DP) optical superlattices based on Porous Silicon (PSi), is presented. An introduction of linear gradient in physical thickness of the layers, composed of five stacks of two different periodic substructures, resulted in the appearance of four WSLs resonances and resonant Zener tunneling of nearest resonances of two consecutive WSLs. Theoretical analysis of time-resolved reflection spectra as a function of gradient reveals the presence of photonic Bloch oscillations (BOs) and an eventual tunneling at a specific value of linear gradient (20%), has been demonstrated through scattering maps. Measured reflection from different DP photonic structures confirm the presence of minibands, WSLs and ZT in the near infrared region.

  9. Bloch oscillations of ultracold atoms: a tool for a metrological determination of h/m Rb.

    Science.gov (United States)

    Battesti, Rémy; Cladé, Pierre; Guellati-Khélifa, Saïda; Schwob, Catherine; Grémaud, Benoît; Nez, François; Julien, Lucile; Biraben, François

    2004-06-25

    We use Bloch oscillations in a horizontal moving standing wave to transfer a large number of photon recoils to atoms with a high efficiency (99.5% per cycle). By measuring the photon recoil of 87Rb, using velocity-selective Raman transitions to select a subrecoil velocity class and to measure the final accelerated velocity class, we have determined h/m(Rb) with a relative precision of 0.4 ppm. To exploit the high momentum transfer efficiency of our method, we are developing a vertical standing wave setup. This will allow us to measure h/m(Rb) better than 10(-8) and hence the fine structure constant alpha with an uncertainty close to the most accurate value coming from the (g-2) determination.

  10. Backaction-driven transport of Bloch oscillating atoms in ring cavities.

    Science.gov (United States)

    Goldwin, J; Venkatesh, B Prasanna; O'Dell, D H J

    2014-08-15

    We predict that an atomic Bose-Einstein condensate strongly coupled to an intracavity optical lattice can undergo resonant tunneling and directed transport when a constant and uniform bias force is applied. The bias force induces Bloch oscillations, causing amplitude and phase modulation of the lattice which resonantly modifies the site-to-site tunneling. For the right choice of parameters a net atomic current is generated. The transport velocity can be oriented oppositely to the bias force, with its amplitude and direction controlled by the detuning between the pump laser and the cavity. The transport can also be enhanced through imbalanced pumping of the two counterpropagating running wave cavity modes. Our results add to the cold atoms quantum simulation toolbox, with implications for quantum sensing and metrology.

  11. Tunable hybridization at midzone and anomalous Bloch-Zener oscillations in optical waveguide ladders.

    Science.gov (United States)

    Zheng, Ming Jie; Wang, Gang; Yu, Kin Wah

    2010-12-01

    We have studied the optical oscillation and tunneling of light waves in optical waveguide ladders (OWLs) formed by two coupled planar optical waveguide arrays. For the band structure, a midzone gap is formed owing to band hybridization, and its wavenumber position can be tuned throughout the whole Brillouin zone, which is different from the Bragg gap. By imposing a gradient in the propagation constant in each array, Bloch-Zener oscillation (BZO) is realized with Zener tunneling between the bands occurring at the midzone, which is contrary to the common BZO with tunneling at the center or edge of the Brillouin zone. The occurrence of BZO is demonstrated by using the field-evolution analysis. The tunable hybridization at the midzone enhances the tunability of BZO in the OWLs. This Letter may offer new insights into the coherent phenomena in optical lattices.

  12. Optical Bloch oscillations and Zener tunneling of Airy beams in ionic-type photonic lattices.

    Science.gov (United States)

    Xiao, Fajun; Zhu, Weiren; Shang, Wuyun; Wang, Meirong; Zhang, Peng; Liu, Sheng; Premaratne, Malin; Zhao, Jianlin

    2016-08-01

    We report on the existence of optical Bloch oscillations (OBOs) and Zener tunneling (ZT) of Airy beams in ionic-type photonic lattices with a refractive index ramp. Different from their counterparts in uniform lattices, Airy beams undergoing OBOs show an alternatively switched concave and convex trajectory as well as a periodical revival of input beam profiles. Moreover, the ionic-type photonic lattice established in photorefractive crystal exhibits a reconfigurable lattice structure, which provides a flexible way to tune the amplitude and period of the OBOs. Remarkably, it is demonstrated that the band gap of the lattice can be readily controlled by rotating the lattice inducing beam, which forces the ZT rate to follow two significant different decay curves amidst decreasing index gradient. Our results open up new possibilities for all-optical switching, routing and manipulation of Airy beams.

  13. Quasiclassical analysis of Bloch oscillations in non-Hermitian tight-binding lattices

    CERN Document Server

    Graefe, E M; Rush, A

    2016-01-01

    Many features of Bloch oscillations in one-dimensional quantum lattices with a static force can be described by quasiclassical considerations for example by means of the acceleration theorem, at least for Hermitian systems. Here the quasiclassical approach is extended to non-Hermitian lattices, which are of increasing interest. The analysis is based on a generalised non-Hermitian phase space dynamics developed recently. Applications to a single-band tight-binding system demonstrate that many features of the quantum dynamics can be understood from this classical description qualitatively and even quantitatively. Two non-Hermitian and $PT$-symmetric examples are studied, a Hatano-Nelson lattice with real coupling constants and a system with purely imaginary couplings, both for initially localised states in space or in momentum. It is shown that the time-evolution of the norm of the wave packet and the expectation values of position and momentum can be described in a classical picture.

  14. Coexisting localized and extended optical Bloch states in a periodic deep wire array microcavity

    Science.gov (United States)

    Löchner, Franz J. F.; Mischok, Andreas; Brückner, Robert; Lyssenko, Vadim G.; Zakhidov, Alexander A.; Fröb, Hartmut; Leo, K.

    2015-09-01

    We embed periodic SiO2 wires in an organic microcavity, producing a rectangular potential by the different optical thicknesses of the active layer due to the additional SiO2 layer. By μ -photoluminescence spectroscopy, we observe the energy dispersion of the photons and obtain discrete localized below and extended Bloch states above the potential barrier, respectively, showing that electro-magnetic waves can behave like massive particles, such as electrons, in crystal lattices. We investigate the dependencies on wire width and period and use the Kronig-Penney model to describe the photon energy dispersion, including an "effective mass" of a photon propagating through a microcavity implying polarization splitting. We obtain excellent agreement between experiment, simulation and analytical calculation.

  15. Measuring the fine structure constant with Bragg diffraction and Bloch oscillations

    Science.gov (United States)

    Yu, Chenghui; Estey, Brian; Parker, Richard; Dudley, Jordan; Müller, Holger

    2016-05-01

    We have demonstrated a new scheme for atom interferometry based on large-momentum-transfer Bragg beam splitters and Bloch oscillations. In this new scheme, we have achieved a resolution of δα / α =0.25ppb in the fine structure constant measurement, which gives up to 4.4 million radians of phase difference between freely evolving matter waves. We have suppressed many systematic effects known in most atom interferometers with Raman beam splitters such as light shift, Zeeman effect shift as well as vibration. We have also simulated multi-atom Bragg diffraction to understand sub-ppb systematic effects, and implemented spatial filtering to further suppress systematic effects. We present our recent progress toward a measurement of the fine structure constant, which will provide a stringent test of the standard model of particle physics.

  16. Bloch waves in an arbitrary two-dimensional lattice of subwavelength Dirichlet scatterers

    CERN Document Server

    Schnitzer, Ory

    2016-01-01

    We study waves governed by the planar Helmholtz equation, propagating in an infinite lattice of subwavelength Dirichlet scatterers, the periodicity being comparable to the wavelength. Applying the method of matched asymptotic expansions, the scatterers are effectively replaced by asymptotic point constraints. The resulting coarse-grained Bloch-wave dispersion problem is solved by a generalised Fourier series, whose singular asymptotics in the vicinities of scatterers yield the dispersion relation governing modes that are strongly perturbed from plane-wave solutions existing in the absence of the scatterers; there are also empty-lattice waves that are only weakly perturbed. Characterising the latter is useful in interpreting and potentially designing the dispersion diagrams of such lattices. The method presented, that simplifies and expands on Krynkin & McIver [Waves Random Complex, 19 347 2009], could be applied in the future to study more sophisticated designs entailing resonant subwavelength elements di...

  17. Deformed Harmonic Oscillators for Metal Clusters and Balian-Bloch Theory

    CERN Document Server

    Bonatsos, D; Raychev, P P; Terziev, P A; Bonatsos, Dennis

    2003-01-01

    The predictions for the shell structure of metal clusters of the three-dimensional q-deformed harmonic oscillator (3D q-HO), utilizing techniques of quantum groups and having the symmetry Uq(3)$\\supset$SOq(3), are compared to the restrictions imposed by the periodic orbit theory of Balian and Bloch, of electrons moving in a spherical cavity. It is shown that agreement between the predictions of the two models is established through the introduction of an additional term to the Hamiltonian of the 3D q-HO, which does not influence the predictions for supershells. This term preserves the Uq(3)$\\supset$SOq(3) symmetry, while in addition it can be derived through a variational procedure, analogous to the one leading from the usual harmonic oscillator to the Morse oscillator by introducing the concept of the Variable Frequency Oscillator (VFO).

  18. Dynamics of cold bosons in optical lattices: effects of higher Bloch bands

    Science.gov (United States)

    Łącki, Mateusz; Delande, Dominique; Zakrzewski, Jakub

    2013-01-01

    The extended effective multiorbital Bose-Hubbard-type Hamiltonian which takes into account higher Bloch bands is discussed for boson systems in optical lattices, with emphasis on dynamical properties, in relation to current experiments. It is shown that the renormalization of Hamiltonian parameters depends on the dimension of the problem studied. Therefore, mean-field phase diagrams do not scale with the coordination number of the lattice. The effect of Hamiltonian parameters renormalization on the dynamics in reduced one-dimensional optical lattice potential is analyzed. We study both the quasi-adiabatic quench through the superfluid-Mott insulator transition and the absorption spectroscopy, that is, the energy absorption rate when the lattice depth is periodically modulated.

  19. 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.

  20. 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

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

    Directory of Open Access Journals (Sweden)

    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

  2. Transcriptome Display During Testicular Differentiation of Channel Catfish (Ictalurus punctatus) as Revealed by RNA-Seq Analysis.

    Science.gov (United States)

    Zeng, Qifan; Liu, Shikai; Yao, Jun; Zhang, Yu; Yuan, Zihao; Jiang, Chen; Chen, Ailu; Fu, Qiang; Su, Baofeng; Dunham, Rex; Liu, Zhanjiang

    2016-07-01

    Channel catfish (Ictalurus punctatus) has been recognized as a dominant freshwater aquaculture species in the United States. It is also a suitable model for studying the mechanisms of sex determination and differentiation because of its sexual plasticity and exhibition of both genetic and environmental sex determination. The testicular differentiation in male channel catfish normally starts between 90 and 102 days postfertilization (dpf), while the ovarian differentiation starts early from 19 dpf. As such, efforts to better understand the postponed testicular development at the molecular level are needed. Toward that end, we conducted transcriptomic comparison of gene expression of male and female gonads at 90, 100, and 110 dpf using high-throughput RNA-Seq. Transcriptomic profiles of male gonads on 90 and 100 dpf exhibited high similarities except for a small number of significantly up-regulated genes that were involved in development of germ cell-supporting somatic cells, while drastic changes were observed during 100-110 dpf, with a group of highly up-regulated genes that were involved in germ cells development, including nanog and pou5f1 Transcriptomic comparison between testes and ovaries identified male-preferential genes, such as gsdf, cxcl12, as well as other cytokines mediated the development of the gonad into a testis. Co-expression analysis revealed highly correlated genes and potential pathways underlying germ cell differentiation and spermatogonia stem cell development. The candidate genes and pathways identified in this study set the foundation for further studies on sex determination and differentiation in catfish as well as other teleosts. PMID:27307075

  3. Toxic effects of crotocaudin extracted from the medicinal plant Croton tiglium.

    Science.gov (United States)

    Yadav, Ram P; Singh, Ajay

    2010-01-01

    The compound crotocaudin extracted from the stem bark of the medicinal plant Croton tiglium Linn. was administered for 24 h or 96 h to the freshwater vector snail Lymnaea (Radix) acuminata Lamarck in order to test its toxicity. L. acuminata is the intermediate host of Fasciola hepatica and Fasciola gigantica which cause immense harm to man and his domestic animals. It was observed that the molluscicidal activity of crotocaudin against L. acuminata is time- as well as dose-dependent. There was a significant negative correlation among LC50 values and exposure periods, i.e. increasing the exposure time, the LC50 value of crotocaudin decreased from 5.37 microM (24 h) > 2.08 microM (48 h) > 1.36 microM (72 h) to 1.01 microM (96 h), respectively, against L. acuminata. The toxicological experiments to proof for environmental toxicity, if any, have also been carried out on the non-target freshwater fish Channa punctatus (Bloch) [Channidae (Ophicephalidae)], which shares the habitat with L. acuminata. The sublethal doses of crotocaudin (40% and 80% of LC50) administered over 24 h caused significant changes in the carbohydrate and nitrogenous metabolisms in nervous, hepatopancreas, and ovotestis tissues of Lymnaea acuminata. Channa punctatus was also exposed to sublethal doses of crotocaudin (40% and 80% of 24-h LC50 of L. acuminata) for 96 h which showed significant alterations in the metabolism in muscle, liver, and gonad tissues. After withdrawal of crotocaudin the snail tissues recovered in part after 7 days and the fish tissues completely. PMID:20653234

  4. Anatomical Observation on Skeletal System of Ictalurus punctatus%斑点叉尾鮰骨骼系统解剖观察

    Institute of Scientific and Technical Information of China (English)

    郭永军; 白东清; 张家全; 陈成勋; 李东芳; 邢克智

    2012-01-01

    The skeletal system components of Ictalurus punctatus were studied by means of boiling and the skeletal morphology was observed. By analyzing and dealing with the photoes of the integrated skeletal system and single skeletal system, it is summarized some corresponding skeletal characters. The results show that the skeletal system of Ictalurus punctatus was composed of 269 bones, including 40 bones in the district of neurocranium, 79 bones in the district of pharyngeal cranium, 52 bones in appendicular skeleton and 98 bones in the think, respectively. And there are hard spines.%采用常规煮沸剥离方法分析斑点叉尾鮰(Ictaluruspunctatus)骨骼系统的组成,得到了斑点叉尾鮰的完整骨骼标本和单个骨骼标本。对标本进行摄影、分析、处理,并总结出相应的骨骼特征。结果表明:斑点叉尾鮰骨骼系统由269块骨骼组成,其中脑颅区40块、咽颅区79块、附肢骨骼52块、躯干部98块,有鳍棘。

  5. Dieta do tucunaré-amarelo Cichla monoculus (Bloch & Schneider) (Osteichthyes, Cichlidae), no Reservatório de Lajes, Rio de Janeiro, Brasil Diet of Cichla monoculus (Bloch & Schneider) (Osteichthyes, Cichlidae) in Lajes' Reservoir, Rio de Janeiro, Brazil

    OpenAIRE

    Luciano Neves dos Santos; Alejandra Filippo Gonzalez; Francisco Gerson de Araújo

    2001-01-01

    The diet of Cichla monoculus (Bloch & Schneider, 1801) in Lajes's Reservoir, a major impoundment in Rio de Janeiro State, Brazil, was assessed, from fishes collected in 1994,1996 and 1999/2000. Gut contents in individuals was analyzed by the index of relative importance (IRI) which deals with numerical, gravimetrical and frequency of occurrence. Cichla monoculus showed a strong piscivorous habits feeding on Cichlidae, Characidae and Pimelodidae, in decreasing order of importance, with a remar...

  6. 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.

  7. Rogue-wave interaction of the generalized variable-coefficient Hirota–Maxwell–Bloch system in fiber optics

    International Nuclear Information System (INIS)

    In this paper, a generalized variable-coefficient Hirota–Maxwell–Bloch system is investigated, which can describe the propagation of optical solitons in an erbium-doped optical fiber. Higher-step generalized Darboux transformation and rogue-wave solutions are obtained. Rogue-wave interaction is analyzed as follows: (1) Variable coefficients in the system affect the shape, background and number of the wave crests and troughs of the first-step rogue waves for the modulus of the normalized slowly varying amplitude of the complex pulse envelope, modulus of the measure of the polarization of the resonant medium and extant population inversion; (2) Variable coefficients in the system affect the shape, background and number of the wave crests and troughs of the second-step rogue-wave interaction. Those phenomena can not be attained through the existing Hirota–Maxwell–Bloch system

  8. Bloch oscillation and Landau-Zener tunnelling in a modulated optical lattice in a photovoltaic photorefractive crystal

    Institute of Scientific and Technical Information of China (English)

    Zhang Bing-Zhi; Cui Hu; Li Xiang-Heng; She Wei-Long

    2009-01-01

    We theoretically study the beam dynamical hehaviour in a modulated optical lattice with a quadratic potential in a photovoltaic photorefractive crystal. We find that two different Bloch oscillation patterns appear for the excitation of both broad and narrow light beams. One kind of optical Landau-Zener tunnelling also appears upon the Bloch oscillation and can be controlled by adjusting the parameter of the optical lattice. Unlike the case of linear potential, the energy radiation due to Landau-Zener tunnelling can be confined in modulated lattices of this kind. For high input intensity levels, the Landau-Zener tunnelling is suppressed by the photovoltaic photorefractive nonlinearity and a symmetry breaking of beam propagation from the modulational instability appears.

  9. Simulação de sinais de RMN através das equações de Bloch

    Directory of Open Access Journals (Sweden)

    Tiago Bueno Moraes

    2014-01-01

    Full Text Available 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.

  10. On the zero-field orbital magnetic susceptibility of Bloch electrons in graphene-like solids: Some rigorous results

    CERN Document Server

    Savoie, Baptiste

    2012-01-01

    Starting with a nearest-neighbors tight-binding model, we rigorously investigate the bulk zero-field orbital susceptibility of a non-interacting Bloch electrons gas in graphene-like solids at fixed temperature and density of particles. In the zero-temperature limit and in the semiconducting situation, we derive a complete expression which holds for an arbitrary number of bands with possible degeneracies. In the particular case of a two-bands gapped model, all involved quantities are exactly written down. Besides the formula we obtain have the special feature to be suitable for numerical computations since it only involves the eigenvalues and associated eigenfunctions of the Bloch Hamiltonian, together with the derivatives (up to the second order) w.r.t. the quasi-momentum of the matrix-elements of the Bloch Hamiltonian. Finally we give a simple application for the two-bands gapped model by considering the case of a dispersion law which is linear w.r.t. the quasi-momentum in the gapless limit. Through this ins...

  11. Sulfonation of 17β-estradiol and inhibition of sulfotransferase activity by polychlorobiphenylols and celecoxib in channel catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    The sulfonation of 17β-estradiol (E2) by human liver and recombinant sulfotransferases is influenced by environmental contaminants such as hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs), which are potent inhibitors, and the therapeutic drug, celecoxib, which affects positional sulfonation of E2. In some locations, the aquatic environment is contaminated by PCBs, OH-PCBs and widely used therapeutic drugs. The objectives of this study were to investigate the sulfonation kinetics of E2 in liver cytosol from channel catfish (Ictalurus punctatus); to examine the effect of OH-PCBs on E2 sulfonation; and to determine if celecoxib altered the position of E2 sulfonation, as it does with human liver cytosol. E2 was converted to both 3- and 17-sulfates by catfish liver cytosol. At E2 concentrations below 1μM, formation of E2-3-sulfate (E2-3-S) predominated, but substrate inhibition was observed at higher concentrations. Rates of E2-3-S formation at different E2 concentrations were fit to a substrate inhibition model, with K'm and V'max values of 0.40+/-0.10μM and 91.0+/-4.7pmol/min/mg protein, respectively and Ki of 1.08+/-0.09μM. The formation of E2-17-S fit Michaelis-Menten kinetics over the concentration range 25nM to 2.5μM, with Km and Vmax values of 1.07+/-0.23μM and 25.7+/-4.43pmol/min/mg protein, respectively. The efficiency (Vmax/Km) of formation of E2-3-S was 9.8-fold higher than that of E2-17-S. Several OH-PCBs inhibited E2 3-sulfonation, measured at an E2 concentration of 1nM. Of those tested, the most potent inhibitor was 4'-OH-CB79, with two chlorine atoms flanking the OH group (IC50: 94nM). The inhibition of estrogen sulfonation by OH-PCBs may disrupt the endocrine system and thus contribute to the known toxic effects of these compounds. Celecoxib did not stimulate E2-17-S formation, as is the case with human liver cytosol, but did inhibit the formation of E2-3-S (IC50: 44μM) and to a lesser extent, E2-17-S (IC50: >160μM), suggesting the

  12. 鰤鱼诺卡氏菌对乌鳢血液指标的影响%Effect of Nocardia seriolea on Blood Indices of Channa argus

    Institute of Scientific and Technical Information of China (English)

    孙东雨; 沈理; 金珊; 缪燕萍; 赵青松; 陈寅儿

    2012-01-01

    应用浓度为106 cfu/mL的鰤鱼诺卡氏菌(Nocardia seriolea)菌悬液腹腔注射乌鳢,人工感染诺卡氏菌病.在感染后3 d、6 d、9 d、12 d、18 d和24 d时抽取乌鳢血液,检测乌鳢的血细胞数、血细胞脆性、溶菌酶、血清总蛋白、碱性磷酸酶、乳酸脱氢酶和尿素氮等指标.结果表明,与对照组相比,感染鰤鱼诺卡氏菌后乌鳢血细胞数呈先升高后降低的趋势,而血细胞脆性在各实验时间点均高于对照组;血清碱性磷酸酶呈先降低后升高趋势,血清溶菌酶、血清总蛋白和血清尿素氮等均呈先降低后增高再降低的趋势,血清乳酸脱氢酶活力显著增加.说明鰤鱼诺卡氏菌感染会引起乌鳢血液指标明显变化.%This study is to evaluate the influences of Nocardia seriolae on the haematological parameters of Channa argus. C. argus were injected intraperitoneally with 106 cfu/mL N. seriolae suspension. Blond samples were taken at 3 d, 6 d, 9 d, 12 d, 18 d and 24 d after that injection, then the number of erythrocyte, blood cell fragility, lysozyme, serum total protein, alkaline phosphatase, lactic dehydrogenase, urea nitrogen were tested. The results showed that compared with control group, the number of erythrocyte increased at first and then decreased, while blood cell fragility was higher than control group all the time. Alkaline phosphatase decreased at first and then increased. Lysozyme, serum total protein and urea nitrogen had the same tendency change that they all decreased at first and then increased and decreased again. The activity of lactic dehydrogenase increased significantly. These indicate that tissues of Channa argus, such as liver, kidney, heart and spleen, can be damaged seriously and the blood indices may change significantly when it is infected with N. seriolea.

  13. Shear Bloch waves and coupled phonon-polariton in periodic piezoelectric waveguides.

    Science.gov (United States)

    Piliposyan, D G; Ghazaryan, K B; Piliposian, G T

    2014-02-01

    Coupled electro-elastic SH waves propagating in a periodic piezoelectric finite-width waveguide are considered in the framework of the full system of Maxwell's electrodynamic equations. We investigate Bloch-Floquet waves under homogeneous or alternating boundary conditions for the elastic and electromagnetic fields along the guide walls. Zero frequency stop bands, trapped modes as well as some anomalous features due to piezoelectricity are identified. For mixed boundary conditions, by modulating the ratio of the length of the unit cell to the width of the waveguide, the minimum widths of the stop bands can be moved to the middle of the Brillouin zone. The dispersion equation has been investigated also for phonon-polariton band gaps. It is shown that for waveguides at acoustic frequencies, acousto-optic coupling gives rise to polariton behavior at wavelengths much larger than the length of the unit cell but at optical frequencies polariton resonance occurs at wavelengths comparable with the period of the waveguide. PMID:24139302

  14. The analysis of cytochrome b nucleotidic sequence for Carassius gibelio (Bloch, 1782

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    Lucian D. Gorgan

    2009-01-01

    Full Text Available The paper is part of a larger scale study for some genes` (Cytb, ND4L and D-loop nucleotidic structure identification by sequencing, to distinguish the structural differences and their exact length inase pairs. Research was carried out on individuals of Carassius gibelio (Bloch, 1782 (Actinopterygii,Cypriniformes from two different populations, Iezăreni and Movileni (Iaşi, from which dorsal musculartissue was sampled. Mitochondrial DNA (mtDNA isolation and purification was carried out automaticallyusing Promega’s Maxwell 16 (SEV module. Cytochrome b (cytb was multiplied by a two stage>polymerase chain reaction (PCR, using two sets of complementary primers (1 set for each fragment.Direct sequencing of PCR products revealed that the cytochrome b has one sequence of 1140bp. Theobtained sequences were subsequently compared with sequences of the same gene from otherindividuals within this species, towards identifying possible differences in the nucleotidic structure.Key Words: Carassius, cytocrhome b, mtDNA.

  15. 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.

  16. Genetic Diversity Analysis of Lates calcarifer (Bloch 1790 in Captive and Wild Populations Using RAPD Markers

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    Muthusamy RAJASEKAR

    2012-08-01

    Full Text Available Lates calcarifer (Bloch 1790 is one of the major economically important cultivable fish species in India. In this study, three populations of L. calcarifer was selected to assess the genetic diversity. Of which, two wild (Mudaslodai, Muthupettai and one captive (Mutukadu population. The genetic diversity of three populations of this species was studied using Random Amplified Polymorphic DNA (RAPD markers. Ten random primers were used for the assessment of their genetic diversity and construction of the dendrogram. A total of 589 scorable bands were obtained, 93.12% of them were polymorphic. The Nei�s gene diversity (H of two wild populations were more (0.0504 � 0.0670 and 0.0519 � 0.0953 than the captive population (0.0489 � 0.0850. The clustering pattern obtained by UPGMA method emphasized the wild populations were clustered in one clade and captive population was deviated into another clade. This study proved that RAPD analysis has the ability to discriminate L. calcarifer populations. Further molecular studies, comprising a higher number of molecular tools are still required to precisely evaluate the genetic structure of all seabass populations along the Indian coast.

  17. Grating-Coupling-Based Excitation of Bloch Surface Waves for Lab-on-Fiber Nanoprobes

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    Scaravilli, Michele; Cusano, Andrea; Galdi, Vincenzo

    2016-01-01

    In this paper, we investigate for the first time the possibility to excite Bloch surface waves (BSWs) on the tip of single-mode optical fibers. Within this framework, we first demonstrate the possibility to exploit a grating-coupling mechanism for on-tip excitation of BSWs, and highlight the flexibility of the proposed design as well as its intrinsic robustness to unavoidable fabrication tolerances. Subsequently, with a view towards label-free chemical and biological sensing, we present an optimized design to maximize the sensitivity (in terms of wavelength shift) of the arising resonances with respect to changes in the refractive properties of the surrounding environment. Numerical results indicate that the attained sensitivities are in line with those exhibited by state-of-the-art plasmonic nanoprobes, with the key advantage of exhibiting much narrower spectral resonances. This prototype study paves the way for a new class of miniaturized high-performance surface-wave fiber-optic devices for high-resolution...

  18. Differential geometric invariants for time-reversal symmetric Bloch-bundles: The "Real" case

    Science.gov (United States)

    De Nittis, Giuseppe; Gomi, Kiyonori

    2016-05-01

    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.

  19. 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.

  20. Photonic lattices in organic microcavities: Bloch states and control of lasing

    Science.gov (United States)

    Mischok, Andreas; Brückner, Robert; Fröb, Hartmut; Lyssenko, Vadim G.; Leo, Karl

    2015-09-01

    Organic microcavities comprising the host:guest emitter system Alq3:DCM offer an interesting playground to experimentally study the dispersion characteristics of laterally patterned microlasers due to the broad emission spectrum and large oscillator strength of the organic dye. By structuring of metallic or dielectric sublayers directly on top of the bottom mirror, we precisely manipulate the mode structure and influence the coherent emission properties of the device. Embedding silver layers into a microcavity leads to an interaction of the optical cavity-state in the organic layer and the neighboring metal which red-shifts the cavity resonance, creating a Tamm-plasmon-polariton state. A patterning of the metal can in turn be exploited to fabricate deep photonic wells of micron-size, efficiently confining light in lateral direction. In periodic arrays of silver wires, we create a Kronig-Penney-like optical potential in the cavity and in turn observe optical Bloch states spanning over several photonic wires. We modify the Kronig-Penney theory to analytically describe the full far-field emission dispersion of our cavities and show the emergence of either zero- , π-, or 2π- phase-locking in the system. By investigating periodic SiO2 patterns, we experimentally observe stimulated emission from the ground and different excited discrete states at room temperature and are able to directly control the laser emission from both extended and confined modes of the photonic wires at room-temperature.