Sample records for chaetoceros calcitrans paulsen

  1. Efficient solvent extraction of antioxidant-rich extract from a tropical diatom,Chaetoceros calcitrans (Paulsen) Takano 1968

    Su Chern Foo; Fatimah Md Yusoff; Maznah Ismail; Mahiran Basri; Nicholas Mun Hoe Khong; Kim Wei Chan; Sook Kun Yau


    Objective:To compare thein vitro antioxidant capacity of a diatom,Chaetoceros calcitrans (C. calcitrans) extracted using six types of solvents. Methods:Each extract was evaluated in terms of extraction yield, total carotenoid, fucoxanthin content, total phenolic and antioxidant capacities (DPPH• andABTS•+ scavenging activity and iron chelating activity). Results: The methanol extract exhibited the highest yield [(22.71 ± 0.96) g/100 g dry weight (DW)], total carotenoid [(4.46 ± 0.36) mg/g DW], total phenolic [(2.49 ± 0.08) mg gallic acid equivalents/g DW] and second highest fucoxanthin content [(2.08 ± 0.03) mg fucoxanthin/g DW] as compared to other solvent extracts. Methanolic extract also exhibited significantly higher (P Conclusions: Methanol was the recommended solvent for the production of antioxidant rich extract fromC. calcitrans. Both carotenoids and phenolic acids were found to be positively correlated to the antioxidant capacities ofC. calcitrans. Lead bioactives confirmed by subsequent high performance liquid chromatography studies were fucoxanthin, gallic acid and protocatechuic acid.

  2. Efficient solvent extraction of antioxidant-rich extract from a tropical diatom,Chaetoceros calcitrans (Paulsen) Takano 1968简

    Su; Chern; Foo; Fatimah; Md.Yusoff; Maznah; Ismail; Mahiran; Basri; Nicholas; Mun; Hoe; Khong; Kim; Wei; Chan; Sook; Kun; Yau


    Objective: To compare the in vitro antioxidant capacity of a diatom, Chaetoceros calcitrans(C. calcitrans) extracted using six types of solvents.Methods: Each extract was evaluated in terms of extraction yield, total carotenoid,fucoxanthin content, total phenolic and antioxidant capacities(DPPH and ABTS +scavenging activity and iron chelating activity).Results: The methanol extract exhibited the highest yield [(22.71 ± 0.96) g/100 g dry weight(DW)], total carotenoid [(4.46 ± 0.36) mg/g DW], total phenolic [(2.49 ± 0.08) mg gallic acid equivalents/g DW] and second highest fucoxanthin content [(2.08 ± 0.03) mg fucoxanthin/g DW] as compared to other solvent extracts. Methanolic extract also exhibited significantly higher(P < 0.05) scavenging(DPPH, ABTS +) and iron chelating activities.Conclusions: Methanol was the recommended solvent for the production of antioxidant rich extract from C. calcitrans. Both carotenoids and phenolic acids were found to be positively correlated to the antioxidant capacities of C. calcitrans. Lead bioactives confirmed by subsequent high performance liquid chromatography studies were fucoxanthin, gallic acid and protocatechuic acid.


    Cahya Laila Oktaviana Putri


    Full Text Available Besi termasuk unsur yang esensial bagi makhluk hidup. Pada tumbuhan termasuk algae, besi berperan sebagai penyusun sitokrom dan klorofil. Selain itu, besi juga berperan dalam sistem enzim dan transfer elektron pada proses fotosintesis. Namun, belum diketahui konsentrasi yang tepat untuk pengunaannya oleh algae sehingga diperlukan penelitian yang dapat mengetahui konsentrasi pemakaian FeCl3 untuk perkembangan algae terutama untuk C. calcitrans. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pemberian FeCl3 terhadap kepadatan C. calcitran sehingga dapat mengetahui konsentrasi FeCl3 yang paling baik terhadap kepadatan C. calcitran. Serta untuk Mengetahui kepadatan C. calcitran berdasarkan hari. Penelitian ini diawali dengan menyetock C. calcitran hingga kepadatan 400 ribu sel/ml kemudian dilanjutkan dengan mengkultur C. calcitran pada toples yang telah dibuat sama parameternya kecuali pemberian FeCl3 sesuai dengan perlakuan. Untuk menganalisa pengaruh pemberian FeCl3 pada konsentrasi yang bebeda terhadap kepadatan C. calcitrans digunakan analisa sidik ragam (ANOVA dua langkah dengan bantuan software SPSS 12 dan dilakukan uji lanjut Tukey (Multiple Comparisons untuk melihat perlakuan yang berbeda dengan membandingkan berbagai hasil perlakuan. Pada konsentrasi FeCl3 0 mg/l berbeda nyata (P<0,05 sedangkan konsentrai FeCl3 0,02 mg/l, 0,2  mg/l, 2 mg/l berbeda signifikan terhadap kepadatan C. calcitrans sehingga hanya konsentrasi FeCl3 0 mg/l yang mempengaruhi kepadatan C. calcitrans. Ini disebabkan karena pemberian konsentrasi terlalu sedikit dan selisih konsentrasi yang kecil sehingga tidak mempengaruhi kepadatan C. calcitrans. Sedangkan untuk hari  diperoleh hari ke-1 dan ke-7 merupakan hari yang signifikan terhadap kepadatan C. calcitrans.  Kata Kunci : Chaetoceros calcitrans, FeCl3 dan kepadatan

  4. Proximate composition analysis posterior to the cryopreservation of Chaetoceros calcitrans

    Joan Salas-Leiva


    Full Text Available Objective. The effect of cryopreservation on the proximate composition of microalgae Chaetoceros calcitrans was evaluated. Materials and methods. C. calcitrans was cultured and cryopreserved using 5% (v/v dimethylsulfoxide as cryoprotectant. The freezing was controlled at a rate of 3°C/min, up to -60°C and then the microalgae were immersed in liquid nitrogen (-196°C. After storage in liquid nitrogen, microalgae were rapidly thawed out and subcultured. The percentage of proteins, lipids and carbohydrates was analyzed using absorption spectrophotometry and the organic matter was studied by gravimetric analysis. Results. There was no significant variation between the proximate composition of C. calcitrans cryopreserved and the controls (p>0.05. Conclusion. Our results show that, despite low cell recovery after the preservation of this organism at low temperatures, there is no apparent loss of nutritional characteristics caused by the storing process at low temperatures.

  5. A comparative study on growth performance and biochemical composition of mixed culture of Isochrysis galbana and Chaetoceros calcitrans with monocultures

    Phatarpekar, P.V.; Sreepada, R.A.; Pednekar, C.; Achuthankutty, C.T.

    The growth performance, biochemical composition and nutritive value of the mixed culture of Isochrysis galbana and Chaetoceros calcitrans, grown in batch cultures under laboratory conditions was compared with those in monoculture conditions...

  6. Phytoremediation of Cd2+ by Marine Phytoplanktons, Tetracelmis chuii and Chaetoceros calcitrans

    Sjahrul, M


    The use of marine phytoplankton, Tetracelmis chuii and Chaetoceros calcitrans as phytoremediator has already been reported. However their use as phytoremediator on the cadmium polluted marine has not yet well understood. Therefore, this study was conducted to evaluate the influence of the Cd2+ concentration, interacting time, and medium pH on accumulation of Cd2+ in the phytoplankton. Methods of analysis and data collection were carried out on 1) the growth rate, the number of phy...

  7. Production of Biodiesel from Lipid of Phytoplankton Chaetoceros calcitrans through Ultrasonic Method

    Raymond Kwangdinata; Indah Raya; Muhammad Zakir


    A research on production of biodiesel from lipid of phytoplankton Chaetoceros calcitrans through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extracti...

  8. Nutritional Content of Artemia sp. Fed with Chaetoceros calcitrans and Skeletonema costatum



    Full Text Available Artemia sp. is a natural food with high protein content, especially amino acid. Nowadays, Indonesia still relies on import for its supply. Hence, the utilization of local Artemia sp. as an alternative to the imported product is recommended as it contains more protein and less expensive. The advantages of local Artemia sp. is its better crystal quality as it is still fresh. It also provides better income for salt farmers because waste water from salt farm can be used to culture Artemia sp.. This research is aimed at determining the quality of locally-produced Artemia sp., by evaluation of its essential amino acid and fatty acid profiles after treatments. Our results indicated that Artemia sp. cysts with good quality were produced after 8 hours and Artemia sp. reaches a hatching rate of 1,320,000 cysts (95% after 27 hours. We also found an indication that the best feed concentration was a mix of 60% Chaetoceros calcitrans with 40% Skeletonema costatum. Fatty acid profile analyses showed that the highest SAFA (12.86% and PUFA (29.91% were gained after feeding with Chaetoceros calcitrans, whereas the highest HUFA (4.93% was gained after feeding with Skeletonemacostatum. Essential amino acid profile analyses revealed the highest content of amino acid (18912.62 ppm was after feeding with a combination of Chaetoceros calcitrans and Skeletonema costatum. Finally, the proper water quality during research was at 25-30 oC of temperature, 30-31 ppt of salinity, pH 7.8-8.9, and DO was at 3.0-4.4 mg/L.

  9. Production of Biodiesel from Lipid of Phytoplankton Chaetoceros calcitrans through Ultrasonic Method

    Raymond Kwangdinata


    Full Text Available A research on production of biodiesel from lipid of phytoplankton Chaetoceros calcitrans through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extraction method using ethanol 96%, while biodiesel synthesis was carried out by transesterification reaction using methanol and KOH catalyst under sonication. Weight of biodiesel yield per biomass Chaetoceros calcitrans is 35.35%. Characterization of biodiesel was well carried out in terms of physical properties which are density and viscosity and chemical properties which are FFA content, saponification value, and iodine value. These values meet the American Society for Testing and Materials (ASTM D6751 standard levels, except for the viscosity value which was 1.14 g·cm−3.

  10. Toxicity of mercury and copper to marine phytoplankton, Dunaliella salina, Tetraselmis sp. and Chaetoceros calcitrans

    Chomrung, A.


    Full Text Available Static 96-hour phytoplankton growth tests were carried out to measure the toxicity of mercury (Hg and copper (Cu on growth (cell density and chlorophyll a content of three marine phytoplankton species: Dunaliella salina, Tetraselmis sp. and Chaetoceros calcitrans. The experiments were carried out at a temperature of 27±1ºC, using natural seawater (salinity 30 psu filtered with a 0.4 μ polycarbonate membrane, under continuous illumination of 3800±200 lux and they were repeated three times for each metal. Resultsshowed that C. calcitrans was the most sensitive species to Hg and Cu, followed by Tetraselmis sp. and D. salina, respectively. In addition, Hg was found to be more toxic to the three species than Cu. The mean IC50 values of Hg on growth of D. salina, Tetraselmis sp. and C. calcitrans were 0.277, 0.144 and 0.043 mg L-1, respectively, while those of Cu were 1.132, 0.270 and 0.090 mg L-1, respectively.

  11. Índice de desarrollo y supervivencia de larvas del camarón azul Litopenaeus stylirostris (Stimpson, 1871), alimentadas con diferentes concentraciones de Chaetoceros calcitrans (Paulsen)

    Daniel E Godínez; Arnulfo H Díaz; María del C Gallo


    Se llevaron a cabo ensayos alimenticios con larvas del camarón azul (Litopenaeus stylirostris) utilizando cuatro diferentes concentraciones de la microalga Chaetoceroscalcitrans (30000, 60000, 90000 y 120000 cél/ml), con una concentración constante por tratamiento de 10000 cél/ml de Tetraselmis suecica y seis nauplios por ml de Artemia franciscana recién eclosionada. El período de prueba se inició a partir del sub estadio zoea 1 y concluyó hasta la aparición de misis 3. En cada ensayo fueron...

  12. The Paulsen Problem in Operator Theory

    Casazza, Peter G.; Cahill, Jameson


    The Paulsen Problem in Hilbert space frame theory has proved to be one of the most intractable problems in the field. We will help explain why by showing that this problem is equivalent to a fundamental, deep problem in operator theory. Along the way we will give a new exact computation for chordal distances, we will give a generalization of these problems and we will spell out exactly the complementary versions of the problem.

  13. [A Stomoxys calcitrans outbreak on a dairy farm].

    Betke, P; Schultka, H; Ribbeck, R


    In late summer and autumn of 1982 Stomoxys calcitrans disturbed cattle on a dairy farm and scourged the people working there. Both actively and passively Stomoxys calcitrans got into the cowsheds from its nearby breeding sites on open silos. The successful fly control combined sanitary measures with the application of pyrethrum insecticide aerosol. PMID:3717689

  14. Growth and proximate composition of the Chaetoceros calcitrans f. pumilus under different temperature, salinity and carbon dioxide levels

    Raghavan, G.; Haridevi, C.K.; Gopinathan, C.P.

    . Carbohydrates were increased while lipids and protein decreased at the highest salinity (35 + or - 0.9). These results should be taken into consideration when evaluating the dietary value of this micro alga for aquaculture....

  15. Effects of twelve pesticides on larvae of oysters (Crassostrea gigas) and on two species of unicellular marine algae (Isochrysis galbana and Chaetoceros calcitrans)

    His, Edouard; Seaman, Matthias


    The effects of seven herbicides, four insecticides and one molluscicide were tested at concentrations of up to 10 mg/l on larvae of oysters, Crassostrea gigas (9 days exposure), and on laboratory cultures of the algae Isochrysis galbana and Chaeloceros calcilrans (21 days exposure). Ali of the pesticides tested had significant toxic effects on at least one of the test organisms. The strongest effects were those of lindane and isoproturon on survival and growth of C.gigas larvae, and of iso...

  16. Populational dynamics of Stomoxys calcitrans (Linneaus) (Diptera: Muscidae) in three biocenosis, Minas Gerais, Brazil.

    Rodríguez-Batista, Z; Leite, R C; Oliveira, P R; Lopes, C M L; Borges, L M F


    Populational flux of the adult phase of Stomoxys calcitrans was observed in the municipal district of Pedro Leopoldo, Minas Gerais, Brazil. Three biocenoses were selected for the study: stable agrobiocenosis, pastural agrobiocenosis and eubiocenosis. The occurrence and the populational flux of the insects, using the Magoon trap for their capture, were established. For each trap located in different biocenoses, a crossbred calf (Bos taurusxBos indicus) approximately 6-month-old was used as "live bait," exposed weekly for 48h in the traps. Of the three agrobiocenoses studied, the stable agrobiocenosis contributed the greatest number of specimens of. S. calcitrans captured, corresponding to 96.9% of the total flies of this species collected. S. calcitrans shows seasonal behavior for approximately 6 months (spring and summer being the rainiest months of the year). The population peaked during the months of November and December. During the months of July and August, there was no capture of flies. PMID:15908125

  17. Stable Fly, Stomoxys calcitrans (L.), Dispersal and Governing Factors.

    Showler, Allan T; Osbrink, Weste L A


    Although the movement of stable fly, Stomoxys calcitrans (L.), has been studied, its extent and significance has been uncertain. On a local scale (farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within distance dispersal (>13 km) is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one "lineage", the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock. PMID:26816486

  18. The stable fly (Stomoxys calcitrans) (Diptera: Muscidae) recorded from the Faroes

    Nielsen, Søren Achim; Bloch, Dorete

    can reproduce all the year in the byres. Both sexes are blood feeding and attack vertebrates with preference for cattle and other ungulates. By high fly population the biting activity can result in reduction of milk and bodyweight in the livestock. S. calcitrans was probably introduced into the Faroes...

  19. Geographic distribution of stomoxyine flies (Diptera: Muscidae) and diurnal activity of Stomoxys calcitrans in Thailand.

    Muenworn, Vithee; Duvallet, Gerard; Thainchum, Krajana; Tuntakom, Siripun; Tanasilchayakul, Somchai; Prabaripai, Atchariya; Akratanakul, Pongthep; Sukonthabhirom, Suprada; Chareonviriyaphap, Theeraphap


    Stomoxyine flies (Stomoxys spp.) were collected in 10 localities of Thailand using the Vavoua traps. These localities represented four major ecological settings, as follows: small local dairy farms, large industrial dairy farms, a national park, and one elephant conservation area. Three species of stable flies were identified in the following proportions: Stomoxys calcitrans (91.5%), Stomoxys indicus (7.9%), and Stomoxys sitiens (0.6%). The number of flies collected differed significantly among collection sites (chi2 = 360.15, df=3, P flies was captured in dairy farms. Seasonal and daily activity of S. calcitrans was observed during a 1-yr period at two selected locations (Dairy Farming Promotion Organization of Thailand and Khao Kheow Open Zoo). S. calcitrans was more abundant during the rainy season (March-September), but was not associated with the total rainfall (r2 = 0.0002, P > 0.05). Peak of daily flight activity of males S. calcitrans was at 1000 and 1600 h, whereas females showed an increase of activity all along the day until 1600 h. A better understanding of stomoxyine fly behavior related to patterns of daily activity will facilitate and improve the efficiency of fly control measures in private and government sectors. PMID:20939373

  20. Effects of Reserpine on Reproduction and Serotonin Immunoreactivity in the Stable Fly Stomoxys Calcitrans (L.)

    Biogenic amines are known to play critical roles in key insect behaviors such as feeding and reproduction. This study documents the effects of reserpine on mating and egg-laying behaviors of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), which is one of the most economically significa...

  1. Efficacy of knightstick traps and sticky wraps for attraction and capture of stable flies (Stomoxys calcitrans)

    The stable fly, Stomoxys calcitrans, is known as a noxious pest of livestock, particularly cattle, in many countries of the world. However, this blood-feeding fly can also pestiferous around pets and companion animals maintained outdoors. Two groups of animals, dogs and horses, are major hosts for s...

  2. Sugarcane stems as larval habitat for the stable fly (Stomoxys calcitrans in sugarcane plantations

    Paulo H.D. Cançado


    Full Text Available Outbreaks of stable fly, Stomoxys calcitrans, cause losses for livestock producers located near sugarcane mills in Brazil, especially in southern Mato Grosso do Sul. The sugarcane mills are often pointed by local farmers as the primary source of these outbreaks; some mills also joined the farmers in combating the flies. Brazilian beef cattle production has great economic importance in similar level to bio-fuel production as ethanol. In this context, the wide-ranging knowledge on the biology and ecology of the stable fly, including larval habitats and their reproduction sites is extremely important for further development of control programs. This paper aims to report the occurrence and development of S. calcitrans larvae inside sugarcane stems in three municipalities of Mato Grosso do Sul. The sugarcane stems give protection against bad weather conditions and insecticide application. In this way, for sustainable sugarcane growth specific research concerning this situation should be conducted.

  3. Surtos por Stomoxys calcitrans em gado de corte no Mato Grosso do Sul

    Antonio Thadeu M Barros


    Full Text Available A expansão da indústria sucroalcooleira tem levado à instalação de usinas de álcool em áreas tradicionalmente ocupadas pela pecuária de corte na região Centro-Oeste do País. Surtos pela mosca-dos-estábulos (Stomoxys calcitrans em bovinos Nelore têm sido relatados nos últimos dois anos em Mato Grosso do Sul, associados a estas usinas. Visitas em propriedades pecuárias e usinas foram realizadas em meados de novembro 2009, ao final de surtos por S. calcitrans ocorridos nos municípios de Angélica e Ponta Porã, MS. Entrevistas, observações e coletas de imaturos de dípteros foram realizadas nos locais e o material entomológico coletado foi levado ao laboratório para posterior emergência. Elevadas infestações pela mosca-dos-estábulos e comportamento de agrupamento dos bovinos foram observados. Sítios de reprodução foram encontrados nos locais e a emergência de S. calcitrans foi constatada nas amostras coletadas tanto nas fazendas como nas usinas. O conjunto de informações, observações in loco e resultados das amostragens possibilitaram realizar uma abordagem epidemiológica preliminar sobre a dinâmica dos referidos surtos por S. calcitrans e discutir potenciais fatores de risco.

  4. Sugarcane stems as larval habitat for the stable fly (Stomoxys calcitrans) in sugarcane plantations

    Paulo H.D. Cançado; Taciany Ferreira; Eliane M. Piranda; Cleber O. Soares


    Outbreaks of stable fly, Stomoxys calcitrans, cause losses for livestock producers located near sugarcane mills in Brazil, especially in southern Mato Grosso do Sul. The sugarcane mills are often pointed by local farmers as the primary source of these outbreaks; some mills also joined the farmers in combating the flies. Brazilian beef cattle production has great economic importance in similar level to bio-fuel production as ethanol. In this context, the wide-ranging knowledge on the biology a...

  5. Stomoxys calcitrans as possible vector of Trypanosoma evansi among camels in an affected area of the Canary Islands, Spain

    Noé Francisco Rodríguez


    Full Text Available Introduction Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. Methods One Nzi trap was placed on a camel farm located in the infected area for a period of one year. Results Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. Conclusions Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.

  6. Extensive Chaetoceros curvisetus bloom in relation to water quality in Port Blair Bay, Andaman Islands.

    Begum, Mehmuna; Sahu, Biraja Kumar; Das, Apurba Kumar; Vinithkumar, Nambali Valsalan; Kirubagaran, Ramalingam


    Blooming of diatom species Chaetoceros curvisetus (Cleve, 1889) was observed in Junglighat Bay and Haddo Harbour of Port Blair Bay of Andaman and Nicobar Islands during June 2010. Physico-chemical parameters, nutrient concentrations and phytoplankton composition data collected from five stations during 2010 were classified as bloom area (BA) and non-bloom area (NBA) and compared. Elevated values of dissolved oxygen were recorded in the BA, and it significantly varied (p parametric multidimensional scaling (nMDS) ordinations; cluster analysis powered by SIMPROF test also grouped the stations as BA and NBA. PMID:25838063

  7. Desponte dos ramos da videira e seu efeito na qualidade dos frutos de 'Merlot' sobre os porta-enxertos 'Paulsen 1103' e 'Couderc 3309' Shoot topping on Merlot grapevines grafted on Paulsen 1103 and Couderc 3309 and its effects on the quality of grapes

    Alberto Fontanella Brighenti


    Full Text Available A produção de uvas viníferas nas regiões de altitude do Estado de Santa Catarina é recente e existem poucos dados de pesquisa sobre o comportamento das diferentes cultivares neste local. Os objetivos do trabalho foram testar o efeito de diferentes níveis de desponte do dossel vegetativo e avaliar a influência de dois porta-enxertos nas características dos frutos produzidos. O experimento foi realizado em São Joaquim-SC (28º17'38" S e 49º55'54" W, a uma altitude média de 1.250 m, na Vinícola Villa Francioni, com a cultivar Merlot enxertada em 'Paulsen 1103' e 'Couderc 3309'. Os tratamentos consistiram no desponte em diferentes níveis, mantendo as áreas foliares de 4,5; 2,5; 2,0 e 1,5 m² kg-1 de uva em dois porta-enxertos. Foram avaliados número de bagas por cacho, diâmetro de bagas, pH, sólidos solúveis totais, antocianinas, índice de polifenóis totais, comprimento e peso de cacho. As plantas enxertadas em 'Paulsen 1103' apresentaram a máxima eficiência para o nível de desponte de 3,4 m² kg-1de uva, já as plantas enxertadas sobre 'Couderc 3309' apresentaram a máxima eficiência com a manutenção de uma área foliar de 3,0 m² kg-1 de uva. Os diferentes porta-enxertos não interferiram nos compostos fenólicos dos frutos. No ciclo de 2005/06, Couderc 3309 produziu frutos com maiores teores de sólidos solúveis totais e, no ciclo de 2006/07, produziu cachos mais pesados.The production of grapevines in regions of high altitude of Santa Catarina state is recent and there are few data on the behavior of different cultivars. The objective of this work was to verify the effect of different levels of shoot topping and evaluate the influence of two rootstocks on the characteristics of the fruit produced. The experiment was conducted in the city of São Joaquim, Santa Catarina state (28º17'38" S and 49º55'54" W, in an altitude of 1.250m, at Villa Francioni Vineyards, with Merlot grapevine grafted on Paulsen 1103 and Couderc

  8. Temperature-dependent functional response of Spalangia cameroni (Perkins) (Hymenoptera: Pteromalidae), a parasitoid of Stomoxys calcitrans (L.) (Diptera: Muscidae)

    Skovgård, Henrik; Nachman, Gösta


    The effects of host density, temperature, and burial depths on the functional response of the synovigenic parasitoid Spalangia cameroni (Perkins) attacking pupae of the stable fly Stomoxys calcitrans (L.) were examined. Five temperatures (15, 20, 25, 30, and 35 degrees C), six host densities (2, ...

  9. Use of secondary sewage water as a culture medium for Chaetoceros gracilis and Thalassiosira Sp (Chrysophyceae in laboratory conditions

    Rauquírio André Albuquerque Marinho da Costa


    Full Text Available Experiments were carried out in order to test the efficiency of additions of secondary sewage as a culture medium for Chaetoceros gracilis and Thalassiosira sp (Chrysophyceae under laboratory conditions. These algae were cultivated in sea water with concentrations of 10%, 20%, 30% and 40% of wastewater. The results were compared with those obtained by the nutritive medium f2 of Guillard (1975. The best results in terms of cellular densities were observed at 40% additions. There were significant differences (significance levels of 5% between the nutritive medium f2 and the 40% additions for both the species. Maximum cellular densities observed for all additions tested were, 4,125.00 x 10³ cells/ml for Chaetoceros gracilis on the ninth day and 834.00 x 10³ cells/ml for Thalassiosira sp on the fifth day. Biomass was higher in the nutritive medium f2 than in the other treatments, reaching average values of 2,363μg/ml for Chaetoceros gracilis. At all experimental units, the best results were registered at 40% addition for Chaetoceros gracilis, where average values of 0.768μg/ml were observed on the fifth day, and at 30% additions for Thalassiosira sp where 0.883μg/ml were observed on the thirteenth day. It was concluded that secondary sewage could be used as a culture medium for the species tested here, after large scale tests.

  10. Effect of Low ph on Carbohydrate Production by a Marine Planktonic Diatom (Chaetoceros muelleri)

    Rising carbon dioxide (CO2) concentrations in the atmosphere due to human activity are causing the surface ocean to become more acidic. Diatoms play a pivotal role in biogeochemical cycling and ecosystem function in the ocean. ph affected the quantum efficiency of photosystem II and carbohydrate metabolism in a planktonic diatom (Chaetoceros muelleri), representative of a widely distributed genus. In batch cultures grown at low ph, the proportion of total carbohydrate stored within the cells decreased and more dissolved carbohydrates were exuded from the cells into the surrounding medium. Changes in productivity and the way in which diatoms allocate carbon into carbohydrates may affect ecosystem function and the efficiency of the biological carbon pump in a low ph ocean.

  11. Effect of Low pH on Carbohydrate Production by a Marine Planktonic Diatom (Chaetoceros muelleri

    Daniel C. O. Thornton


    Full Text Available Rising carbon dioxide (CO2 concentrations in the atmosphere due to human activity are causing the surface ocean to become more acidic. Diatoms play a pivotal role in biogeochemical cycling and ecosystem function in the ocean. pH affected the quantum efficiency of photosystem II and carbohydrate metabolism in a planktonic diatom (Chaetoceros muelleri, representative of a widely distributed genus. In batch cultures grown at low pH, the proportion of total carbohydrate stored within the cells decreased and more dissolved carbohydrates were exuded from the cells into the surrounding medium. Changes in productivity and the way in which diatoms allocate carbon into carbohydrates may affect ecosystem function and the efficiency of the biological carbon pump in a low pH ocean.

  12. The study on the effect of NO on the growth of Chaetoceros curvisetus

    ZHANG Zhengbin; WU Zhenzhen; LIU Chunying; XING Lei


    This article studied nitric oxide (NO) effect on the growth of Chaetoceros curvisetus in chemistry for the first time. Nitric oxide was added into the media with 4 different nutrient concentrations f/2, f/50, f/100, and f/200 when the alga was growing. The growth of C. curvisetus could be obviously promoted or inhibited during the cultivation process in NO enriched media of different concentrations.The growth curve in such media showed a sharp single peak that is the optimal NO concentration for the alga growth, which is consistent with the influence of NO on the growth of high plants. In addition, C.curvisetus can produce NO by itself during the growth. Therefore, using NO could effectively regulate the algae growth, which is important in real tide control and remediation.

  13. Global diversity of two widespread, colony-forming diatoms of the marine plankton, Chaetoceros socialis (syn. C. radians) and Chaetoceros gelidus sp. nov.

    Chamnansinp, Atchaneey; Li, Yang; Lundholm, Nina; Moestrup, Øjvind


    Marine phytoplankton samples containing diatoms of the Chaetoceros socialis group were collected from Thailand, China, Denmark, and Greenland, and cells were isolated into culture for light and electron microscopy and DNA sequencing of D1-D3 of the LSU rDNA. Species of this lineage are characterized by three short and one long setae extending from each cell, the long setae from several cells joining into a common center to form large colonies, which are sometimes visible with the naked eye. Phylogenetic analyses including sequences from other parts of the world revealed segregation into three groups. Most sequences fell into two large clades, one comprising material from cold waters, whereas the other contained material from warmer waters. Strain CCMP 172 from the Strait of Georgia, Washington State, USA, formed a separate group. The warm-water species included Chinese and Thai material and therefore probably also material from the type locality of C. socialis, Hong Kong. It is characterized by all setae being covered by spines and the setae extending from the valve at some distance from the margin. In the resting spores, both valves are ornamented with spines. The cold-water material is characterized by three spiny and one mostly smooth long setae, and the setae extend from the valve near the margin. Both valves of the resting spore are smooth. This material is described as C. gelidus sp. nov. C. radians, described from the Baltic in 1894, is considered a synonym of C. socialis. CCMP172 is in many ways intermediate and probably constitutes a separate species. The published evidence on this globally distributed and sometimes bloom-forming group of species indicates higher species diversity than presently thought. PMID:27007633

  14. Nutrient compositions of cultured Skeletonema costatum, Chaetoceros curvisetus, and Thalassiosira nordenskiöldii

    Pan, Shengjun; Shen, Zhiliang; Liu, Wenping; Han, Xiaotian; Miao, Hui; Ma, Haiqing


    We cultured different-sized fractions of dominant phytoplankton species, Skeletonema costatum, Chaetoceros curvisetus, and Thalassiosira nordenskiöldii, collected in different sea areas in various seasons, and measured and compared their C, N, P, Si contents. The N content of these species is similar, while the C, P, and Si contents of S. costatum from eutrophic Changjiang (Yangtze River) estuary are higher than those from Jiaozhou Bay (JZB), particularly the content of Si. The C, N, P, and Si contents of cultured phytoplankton in JZB increase with size fraction augmentation, and the percentages of C, N, and P follow the same trend, while the percentage of Si remain constant. Moreover, S. costatum from small-sized fraction assimilated Si more easily than C. curvisetus and T. nordenskiöldii, which is explained by the dominance of S. costatum under the conditions of low SiO3-Si concentration in JZB. The C, N, P, and Si contents of cultured S. costatum collected during summer and winter are higher, which is consistent with the phytoplankton blooming seasons in JZB. The SiO3-Si concentration of seawater during spring restrain the growth of phytoplankton, supported by the fact that the N, P, and Si contents and their ratios in cells of cultured S. costatum are low in spring season.

  15. Optimization of Alkaline Flocculation for Harvesting of Scenedesmus quadricauda #507 and Chaetoceros muelleri #862

    Shuhao Huo


    Full Text Available A response surface methodology (RSM was used to evaluate the effects of pH and microalgal biomass concentration (BC on alkaline flocculating activity for harvesting one freshwater green algae Scenedesmus quadricauda #507 and one marine diatom Chaetoceros muelleri #862. The pH value and BC were in range of 9.0–12.0 and 0.20–2.30 g/L, respectively. Very high regression coefficient between the variables and the response indicates excellent evaluation of experimental data by second-order regressions. Optimum conditions for flocculating activity were estimated as follows: (i pH 11.6, BC 0.54 g/L for strain #507 and (ii pH 11.5, BC 0.42 g/L for strain #862. The maximum flocculating activity was around 94.7% and 100%, respectively. Furthermore, the addition of synthetic ocean water (SOW to the freshwater #507 culture can increase the flocculating activity from 82.13%–88.79% in low algae concentration (0.52 g/L and 82.92%–95.60% in high concentration (2.66 g/L.

  16. Produção de mudas de videira cv. Bordô/Paulsen 1103 pela enxertia de mesa com estratificação

    Lari Maroli


    Full Text Available O emprego de práticas adequadas na implantação do vinhedo, principalmente o uso de mudas enxertadas com boa sanidade, é fator essencial para o sucesso da viticultura. O objetivo do trabalho foi testar temperatura de estratificação, uso do ácido indolbutírico (AIB, tipo e época de enxertia para produção de mudas da cultivar Bôrdo/Paulsen 1103 por enxertia de mesa com estratificação. No primeiro e no segundo experimentos, as estacas do porta-enxerto foram tratadas com AIB antes e após a estratificação, respectivamente. Ambos os experimentos foram conduzidos em blocos ao acaso, em esquema fatorial de 3 x 2 (temperaturas de estratificação: 19º; 24º e 29ºC x tipo enxertia: garfagem de topo e tipo Ômega, com quatro repetições, constituída por 10 unidades de observação cada. O terceiro experimento foi em blocos ao acaso, em esquema fatorial 4 x 2 (época de enxertia: maio, junho, julho e agosto x temperatura de estratificação: 19ºC e 24ºC, com quatro repetições de 20 unidades de observação cada. A técnica de enxertia empregada foi de garfagem de topo, com aplicação de AIB 2.000 mg L-1 após a saída da estratificação. Concluiu-se que a enxertia tipo garfagem de topo apresentou melhores resultados que o tipo Ômega. Recomenda-se a aplicação de AIB após estratificação. As temperaturas de 19ºC e 24ºC no período de estratificação favorecem a sobrevivência em relação a 29ºC. Com a realização da enxertia em meados de julho, e a utilização da temperatura de 19ºC na estratificação, pode-se obter elevada sobrevivência (86%, acompanhada de melhor desenvolvimento vegetativo e radicial.

  17. Mechanical transmission of Bacillus anthracis by stable flies (Stomoxys calcitrans) and mosquitoes (Aedes aegypti and Aedes taeniorhynchus).

    Turell, M J; Knudson, G B


    We evaluated the potential of stable flies, Stomoxys calcitrans, and two species of mosquitoes, Aedes aegypti and Aedes taeniorhynchus, to transmit Bacillus anthracis Vollum 1B mechanically. After probing on Hartley guinea pigs with a bacteremia of ca. 10(8.6) CFU of B. anthracis per ml of blood, individual or pools of two to four stable flies or mosquitoes were allowed to continue feeding on either uninfected guinea pigs or A/J mice. All three insect species transmitted lethal anthrax infect...

  18. Analysis of expressed sequence tags from a significant livestock pest, the stable fly (Stomoxys calcitrans), identifies transcripts with a putative role in chemosensation and sex-determination

    The stable fly, Stomoxys calcitrans, is one of the most significant pests of livestock in the United States. We are interested in the identification of targets for the development of novel control for this pest species, focusing on those molecules that play a role in successful feeding and reproduc...


    Interpretations of chlorophyll a fluorescence data are based largely on application with green algae and higher plants. This study evaluated the interpretation of fluorescence data for a unicellular marine diatom. Chaetoceros sp. was grown in 4-liter batch cultures on a 16:8, L:D...

  20. Repellency to Stomoxys calcitrans (Diptera: Muscidae) of plant essential oils alone or in combination with Calophyllum inophyllum nut oil.

    Hieu, Tran Trung; Kim, Soon-Il; Lee, Sang-Guei; Ahn, Young-Joon


    The repellency to female Stomoxys calcitrans (L.) (Diptera: Muscidae) of 21 essential oils (EOs) alone or in combination with Calophyllum inophyllum L. (Clusiaceae) nut oil (tamanu oil) was examined using an exposed human hand bioassay. Results were compared with those of commonly used repellent N,N-diethyl-3-methylbenzamide (DEET). In tests with six human male volunteers at a dose of 0.5 mg/cm2, patchouli (protection time [PT], 3.67 h) was the most effective EO but less active than DEET (4.47 h), as judged by the PT to first bite. Very strong repellency also was produced by clove bud, lovage root, and clove leaf EOs (PT, 3.50-3.25 h), whereas strong repellency was obtained from thyme white EO (2.12 h). Thyme red, oregano, and geranium EOs exhibited moderate repellency (PT, 1.24-1.11 h). At 0.25 mg/cm2, protection time of clove bud, clove leaf, and lovage root EOs (PT, approximately equal to 1 h) was shorter than that of DEET (2.17 h). An increase in the protection time was produced by binary mixtures (PT, 2.68-2.04 h) of five EOs (clove bud, clove leaf, thyme white, patchouli, and savory) and tamanu oil (0.25:2.0 mg/cm2) compared with that of either the constituted essential oil or tamanu oil alone (PT, 0.56 h). The protection time of these binary mixtures was comparable with that of DEET. With the exception of savory EO, the other EOs, tamanu oil, and binary mixtures did not induce any adverse effects on the human volunteers at 0.5 mg/cm2. Thus, binary mixtures of essential oils and tamanu oil described merit further study as potential repellents for protection from humans and domestic animals from biting and nuisance caused by S. calcitrans. PMID:20695272

  1. Modulation of Medium-Chain Fatty Acid Synthesis in Synechococcus sp. PCC 7002 by Replacing FabH with a Chaetoceros Ketoacyl-ACP Synthase

    Gu, Huiya; Jinkerson, Robert E.; Davies, Fiona K.; Sisson, Lyle A.; Schneider, Philip E.; Posewitz, Matthew C.


    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novo assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase III increased MCFA synthesis up to fivefold. The level of increase is dependent on promoter strength and culturing conditions. PMID:27303412

  2. Induction of protease release of the resistant diatom Chaetoceros didymus in response to lytic enzymes from an algicidal bacterium.

    Paul, Carsten; Pohnert, Georg


    Marine lytic bacteria can have a substantial effect on phytoplankton and are even capable to terminate blooms of microalgae. The bacterium Kordia algicida was reported to lyse cells of the diatom Skeletonema costatum and several other diatoms by a quorum sensing controlled excretion of proteases. However the diatom Chaetoceros didymus is fully resistant against the bacterial enzymes. We show that the growth curve of this diatom is essentially unaffected by addition of bacterial filtrates that are active against other diatoms. By monitoring proteases from the medium using zymography and fluorescence based activity assays we demonstrate that C. didymus responds to the presence of the lytic bacteria with the induced production of algal proteases. These proteases exhibit a substantially increased activity compared to the bacterial counterparts. The induction is also triggered by signals in the supernatant of a K. algicida culture. Size fractionation shows that only the >30 kD fraction of the bacterial exudates acts as an inducing cue. Implications for a potential induced defense of the diatom C. didymus are discussed. PMID:23469204

  3. Induction of protease release of the resistant diatom Chaetoceros didymus in response to lytic enzymes from an algicidal bacterium.

    Carsten Paul

    Full Text Available Marine lytic bacteria can have a substantial effect on phytoplankton and are even capable to terminate blooms of microalgae. The bacterium Kordia algicida was reported to lyse cells of the diatom Skeletonema costatum and several other diatoms by a quorum sensing controlled excretion of proteases. However the diatom Chaetoceros didymus is fully resistant against the bacterial enzymes. We show that the growth curve of this diatom is essentially unaffected by addition of bacterial filtrates that are active against other diatoms. By monitoring proteases from the medium using zymography and fluorescence based activity assays we demonstrate that C. didymus responds to the presence of the lytic bacteria with the induced production of algal proteases. These proteases exhibit a substantially increased activity compared to the bacterial counterparts. The induction is also triggered by signals in the supernatant of a K. algicida culture. Size fractionation shows that only the >30 kD fraction of the bacterial exudates acts as an inducing cue. Implications for a potential induced defense of the diatom C. didymus are discussed.

  4. Determinação das exigências térmicas de Stomoxys calcitrans (L. (Diptera, Muscidae, em condições de laboratório Determination of thermal requirements of Stomoxys calcitrans (L. (Diptera, Muscidae, under laboratory conditions

    M. Aguiar-Valgode


    Full Text Available The biology immature stage of Stomoxys calcitrans (L. was studied in the laboratory under four constant temperature. The study was carried out in biological incubators at 20, 25, 30 and 35-C; 65 ñ 10% relative humidity and 14 hours of photophase. The most favorable temperature for developing eggs, larval and pupal was 25-C, while 35-C proved to be harmful for a normal developing of S. calcitrans in larval stage. The incubation periods for egg were 69.90, 42.58, 26.10, 21.78 hours and 2.91, 1.77, 1.08, 0.90 days at 20, 25, 30, 35-C, respectively . The larval stage was 18.40, 11.63, 8.55 days and, the pupal stage, 8.60, 4.54, 3.60 days at 20, 25, 30-C, respectively. Threshold temperatures for males were a little higher than for females, however, this difference was lesser than 1-C. On the other hand, the quantity of energy (GD for developing females was a little higher than for males. No difference was observed between the two methods used for calculating the above mentioned biological parameters of S. calcitrans.

  5. Temperature benefits the photosynthetic performance of the diatoms Chaetoceros gracilis and Thalassiosira weissflogii when exposed to UVR.

    Halac, S R; Villafañe, V E; Helbling, E W


    The aim of this study was to assess the combined effects of temperature and UVR on the photosynthesis performance of two diatoms -Chaetoceros gracilis and Thalassiosira weissflogii. In particular, we evaluated the role of UVR in inducing photoinhibition and the potential mitigation of this negative effect by an increase in temperature. Cultures were pre-acclimated at two temperatures - 18°C and 23°C - and exposed to different radiation treatments - UVR+PAR (280-700nm); UV-A+PAR (315-700nm) and PAR only (400-700nm) under two temperatures: 18°C (local surface summer water temperature) and 23°C (simulating a potential increase estimated by the year 2100). Exposure to natural solar radiation resulted in UVR-induced photoinhibition that was significantly higher in T. weissflogii than in C. gracilis. Both species benefited from the higher temperature (23°C) resulting in a lower photoinhibition as compared to samples exposed at 18°C. Inter-specific differences were determined in regard to the heat dissipation processes (NPQ) which were higher at high temperatures, and much more evident in C. gracilis than in T. weissflogii. The analyses of inhibition and recovery rates under different irradiances indicate that the balance between negative (inhibition) and positive (repair-dissipation) effects shifted towards a more positive balance with increasing temperature. Our results highlight for a beneficial effect of temperature on photosynthesis performance during exposure to UVR, although important inter-specific differences are found, probably due to differences in cell size as well as in their distribution within the oceanic realm (i.e., coastal versus oceanic species). PMID:20692849

  6. Toxicity of Zanthoxylum piperitum and Zanthoxylum armatum oil constituents and related compounds to Stomoxys calcitrans (Diptera: Muscidae).

    Hieu, Tran Trung; Kim, Soon-Il; Ahn, Young-Joon


    Zanthoxylum plants (Rutaceae) have drawn attention because they contain insecticidal principles against insects. An assessment was made of the insecticidal and acetylcholinesterase (AChE) inhibitory activities of Zanthoxylum piperitum steam distillate and Zanthoxylum armatum seed oil, their 28 constituents, and eight structurally related compounds against female stable fly, Stomoxys calcitrans (L.). Results were compared with those of two organophosphorus insecticides chlorpyrifos and dichlorvos. Potent fumigant toxicity was observed with cuminaldehyde, thymol, (1S)-(-)-verbenone, (-)-myrtenal, carvacrol, (S)-(Z)-verbenol, Zanthoxylum piperitum steam distillate, cuminyl alcohol, Zanthoxylum armatum seed oil, piperitone, (-)-(Z)-myrtanol, and citronellal (LC50, 0.075-0.456 microg/cm3). However, they were five orders of magnitude less toxic than either chlorpyrifos or dichlorvos. An in vitro bioassay using female fly heads indicates that strong AChE inhibition was produced by citronellyl acetate, alpha-pinene, thymol, carvacrol, and alpha-terpineol (1.20-2.73 mM), but no direct correlation between fly toxicity and AChE inhibition by the test compounds was observed. Structure-activity relationships indicate that structural characteristics, such as carbon skeleton, degrees of saturation and types of functional groups, and vapor pressure parameter, appear to play a role in determining toxicities of the test monoterpenoids to stable flies. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on Z. piperitum and Z. armatum oil-derived materials as potential insecticides for the control of stable fly populations. PMID:23025190

  7. Efficacy of the entomopathogenic fungi Metarhizium anisopliae in the control of infestation by stable flies Stomoxys calcitrans (L.), under natural infestation conditions.

    Cruz-Vazquez, C; Carvajal Márquez, J; Lezama-Gutiérrez, R; Vitela-Mendoza, I; Ramos-Parra, M


    The objective of this study was to evaluate the efficacy of an isolate of Metarhizium anisopliae applied by aspersion to control of Stomoxys calcitrans flies in dairy cattle naturally infested. Was applied by aspersion an aqueous formulation of M. anisopliae sensu lato (Ma134), at a concentration of 1×10(8)conidia/ml, four times with seven day intervals, on a group of eight Holstein cows; a control group of eight Holstein cows, received a water solution with Tween 80 (0.1%). The average number of flies per animal was estimated one day before each application, and then daily counts were done in both groups. The effectiveness of the formulation was calculated using the Abbott's formula. At the same time, defensive behaviors of stamp/kicks and tail movements were evaluated daily, estimating relative frequency per hour. The Ma134 formulation had an infestation control efficacy of 73%, taking into consideration the four study weeks. The population reduction effect was observed since the first week post-application (p<0.05), and the effect increased with the subsequent applications. Defensive behaviors were reduced beginning from the first application, reaching a reduction of 66% and 70%, respectively, during the four weeks of study. These results demonstrated the effectiveness of the formulation to control infestation by S. calcitrans, as well as reduce defensive behaviors which involves the infestation. PMID:26209932

  8. Kuidas ennast ise juhtida / Susanne Paulsen

    Paulsen, Susanne


    Rosenecki biotagasiside-eksperdid õpetavad, kuidas inimene võib oma keha üksnes tahtejõu abil mõjutada. Aju-arvuti-liidese kaudu on võimalik mõjutada selliseid haigusi nagu hüperaktiivsus, epilepsia ja migreen

  9. Activity and relative abundance of hymenopterous parasitoids that attack puparia of Musca domestica and Stomoxys calcitrans (Diptera: Muscidae) on confined pig and cattle farms in Denmark

    Skovgård, H; Jespersen, J B


    A survey was conducted on 84 pig and cattle farms in Denmark between August and October 1996 and 1997. The aim was to describe the activity and relative abundance of parasitoids (Hymenoptera: Pteromalidae and Ichneumonidae) that attack puparia of Musca domestica Linnaeus and Stomoxys calcitrans...... (Linnaeus). In total, seven pteromalid species were recovered: Spalangia cameroni Perkins, S. nigripes Curtis, S. subpunctata Förster, Muscidifurax raptorGirault & Sanders, Pachycrepoideus vindemiae (Rondani), Urolepis rufipes(Ashmead) and Nasonia vitripennis (Walker), an ichneumonid Phygadeuon fumator......Gravenhorst, a diapriid Trichopria sp., and a staphylinid Aleocharasp. This is the first time that U. rufipes has been recorded in Europe. Spalangia cameroni and M. raptor were the most frequently recorded species in all regions of the country, and accounted for the main parasitism of Musca domesticaand Stomoxys...

  10. Diversity of Stomoxys spp. (Diptera: Muscidae) and diurnal variations of activity of Stomoxys indicus and S. calcitrans in a farm, in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand.

    Keawrayup, S; Duvallet, G; Sukonthabhirom, S; Chareonviriyaphap, T


    A study of species diversity of Stomoxys spp. and diurnal variations of activity of the most abundant was performed during a one year period at a local dairy cattle farm in Wang Nam Khiao District, Nakhon Ratchasima Province, Thailand. Four species of stomoxyine flies were morphologically identified, including Stomoxys indicus Picard 1908, S. calcitrans (Linnaeus 1758), S. sitiens Rondani 1873 and S. uruma Shinonaga and Kanao 1966. The most common species were S. indicus (50.2%) and S. calcitrans (49.5%). S. sitiens and S. uruma were found in small proportions (flies captured was significantly different among the three seasons with the greatest number in the rainy season (mean = 66%; df = 2, P fly behavior, especially the daily flight activity, can assist in prioritization and design of appropriate vector prevention and control strategies. PMID:22910668

  11. Ocorrência de Spalangia endius Walker, 1839 (Hymenoptera, Pteromalidae em pupas de Musca domestica L. e Stomoxys calcitrans L. (Diptera, Muscidae no sul do Rio Grande do Sul

    R.K Brandão


    Full Text Available It was reported the occurrence of Spalangia endius Walker, 1839 (Hymenoptera, Pteromalidae as a parasitoid of pupae of Musca domestica Linnaeus, 1758 (Diptera, Muscidae and Stomoxys calcitrans Linnaeus, 1758 (Diptera, Muscidae in the extreme Southern of Brazil. The collection of pupae was performed in January and February, 2008. The pupae of M. domestica and S. calcitrans were collected from bovine feces using the flotation method. The pupae were individualized in glass tubes and maintained in acclimatized chamber at 27±2ºC with relative air humidity > 70% until the emergence of the flies or the parasitoids. The referred occurrence consists in the first report to Rio Grande do Sul.

  12. 旋链角毛藻和中肋骨条藻间的他感作用%Allelopathic effects between Chaetoceros curvisetus and Skeletonema costatum

    张议文; 王江涛


    选择两种常见硅藻——中肋骨条藻(Skeletonema costatum)和旋链角毛藻(Chaetoceros curvisetus)为研究对象,采用滤液培养的方法考察二者之间的他感效应,结果表明:f/2全营养培养条件下,旋链角毛藻指数后期无藻细胞滤液对中肋骨条藻的生长有显著抑制作用,抑制率随旋链角毛藻滤液比例的增大而增大,他感效应随作用时间消退后,中肋骨条藻生长速率提高,且随着旋链角毛藻滤液比例的增大,中肋骨条藻的细胞粒径有减小的趋势;中肋骨条藻指数后期无藻细胞滤液对旋链角毛藻的生长速率和细胞粒径均无影响,表明中肋骨条藻对旋链角毛藻无他感作用.本实验结果可为下一步提取他感物质、研究他感作用机理提供实验基础.%The two common types of diatom, respectively Chaetoceros curvisetus and Skeletonema costatum, were chosen to observe and study the allelopathic effect between them by means of cell-free filtrate culture. The observation showed that under the condition of enriched , cell-free filtrate of the C. curvisetus culture inhibited the growth of 5. costatum significantly in the later exponential growth phase. The inhibition rate was related to the proportion of C. curvisetus cell-free filtrate in the culture, in addition the diameter of S. costatum was affected as well. Allelochemical degraded as time went on, and then the relative growth rate of 5. costatum was increased. There was no influence on the relative growth rate and diameter of S. costatum by enriched C. cumsetus cell-free Citrate in the end of exponential growth phase, which showed that there was not allelopathic effect of S. costatum on C. curuisetus. The results provided the experimental basis for extracting allelochemical and researching allelopathic mechanism later.

  13. Evaluation of genotoxic responses of Chaetoceros tenuissimus and Skeletonema costatum to water accommodated fraction of petroleum hydrocarbons as biomarker of exposure.

    Desai, S R; Deasi, S R; Verlecar, X N; Ansari, Z A; Jagtap, T G; Sarkar, A; Vashistha, Deepti; Dalal, S G


    Genotoxic responses towards chronic exposure of Chaetoceros tenuissimus and Skeletonema costatum to water accommodated fraction of petroleum hydrocarbons (WAF-P) were evaluated as biomarkers of petroleum hydrocarbons pollution. The DNA damage caused by water accommodated fraction of petroleum hydrocarbons was assessed in terms of the DNA integrity measured by alkaline unwinding assay. The comparative study of the growth pattern of C. tenuissimus with respect to DNA integrity and the DNA strand breaks in different concentrations of WAF-P showed sufficient tolerance. However, its toxicity increased proportionately with exposure to elevated levels of WAF-P. Although DNA damage in S. costatum was similar to C. tenuissimus, its tolerance level to WAF-P was at least 5 times lower than that of C. tenuissimus indicating its high sensitivity to petroleum hydrocarbons. Active growth was exhibited by C. tenuissimus between 10 and 20% WAF-P (ranging from 0.59 to 1.18mg/L petroleum hydrocarbons) which can be related to the polluted regions only, suggesting the tolerant nature of this organism. Considering the degree of sensitivity to petroleum products and good growth under laboratory conditions, these two diatoms could be recommended as model species for evaluating ecogenotoxic effects of wide range of petroleum hydrocarbon pollutants using alkaline unwinding assays. PMID:20096916

  14. Isolation and characterization of a single-stranded DNA virus infecting the marine diatom Chaetoceros sp. strain SS628-11 isolated from western Japan.

    Kei Kimura

    Full Text Available Diatoms are significant organisms for primary production in the earth's aquatic environment. Hence, their dynamics are an important focus area in current studies. Viruses are a great concern as potential factors of diatom mortality, along with other physical, chemical, and biological factors. We isolated and characterized a new diatom virus (Csp07DNAV that lyses the marine planktonic diatom Chaetoceros sp. strain SS628-11. This paper examines the physiological, morphological, and genomic characteristics of Csp07DNAV. The virus was isolated from a surface water sample that was collected at Hiroshima Bay, Japan. It was icosahedral, had a diameter of 34 nm, and accumulated in the nuclei of host cells. Rod-shaped virus particles also coexisted in the host nuclei. The latent period and burst size were estimated to be <12 h and 29 infectious units per host cell, respectively. Csp07DNAV had a closed circular single-stranded DNA genome (5,552 nucleotides, which included a double-stranded region and 3 open reading frames. The monophyly of Csp07DNAV and other Bacilladnavirus group single-stranded DNA viruses was supported by phylogenetic analysis that was based on the amino acid sequence of each virus protein. On the basis of these results, we considered Csp07DNAV to be a new member of the genus Bacilladnavirus.

  15. Biological control of house flies Musca domestica and stable flies Stomoxys calcitrans(Diptera: Muscidae) by means of inundative releases of Spalangia cameroni(Hymenoptera: Pteromalidae).

    Skovgård, H; Nachman, G


    The efficacy of the pupal parasitoid Spalangia cameroni Perkins as a biological control agent was tested against house flies Musca domestica Linnaeus and stable flies Stomoxys calcitrans (Linnaeus) in one dairy cattle and two pig installations in Denmark. Weekly releases of S. cameroni from April through to September-October 1999 and 2000 resulted in significant suppressions of house fly populations to below nuisance level, whereas no effect on stable flies was found. Parasitism was significantly higher in the release years compared to the control years, but was below 25% averaged over the fly season for each farm. A statistical model based on a functional relationship between the innate capacity of increase of the two fly species and three explanatory variables (air temperature, fly density and parasitism) provided a fairly good fit to data with the abundances of house flies and stable flies explained mostly by temperature, but intra- and interspecific competition, and parasitism had a significant effect as well. Overall, the model was capable of explaining 14% and 6.6% of the total variation in data for house fly and stable fly, respectively. Spalangia cameroni was the predominant parasitoid to emerge from exposed house fly pupae, but from mid summer onwards Muscidifurax raptor Girault & Sanders (Hymenoptera: Pteromalidae) was also quite common. The study indicated that biological control of house flies can be an efficient alternative to chemical control. PMID:15541194

  16. Interaction Effects of Light, Temperature and Nutrient Limitations (N, P and Si on Growth, Stoichiometry and Photosynthetic Parameters of the Cold-Water Diatom Chaetoceros wighamii.

    Kristian Spilling

    Full Text Available Light (20-450 μmol photons m(-2 s(-1, temperature (3-11 °C and inorganic nutrient composition (nutrient replete and N, P and Si limitation were manipulated to study their combined influence on growth, stoichiometry (C:N:P:Chl a and primary production of the cold water diatom Chaetoceros wighamii. During exponential growth, the maximum growth rate (~0.8 d(-1 was observed at high temperature and light; at 3 °C the growth rate was ~30% lower under similar light conditions. The interaction effect of light and temperature were clearly visible from growth and cellular stoichiometry. The average C:N:P molar ratio was 80:13:1 during exponential growth, but the range, due to different light acclimation, was widest at the lowest temperature, reaching very low C:P (~50 and N:P ratios (~8 at low light and temperature. The C:Chl a ratio had also a wider range at the lowest temperature during exponential growth, ranging 16-48 (weight ratio at 3 °C compared with 17-33 at 11 °C. During exponential growth, there was no clear trend in the Chl a normalized, initial slope (α* of the photosynthesis-irradiance (PE curve, but the maximum photosynthetic production (P(m was highest for cultures acclimated to the highest light and temperature. During the stationary growth phase, the stoichiometric relationship depended on the limiting nutrient, but with generally increasing C:N:P ratio. The average photosynthetic quotient (PQ during exponential growth was 1.26 but decreased to <1 under nutrient and light limitation, probably due to photorespiration. The results clearly demonstrate that there are interaction effects between light, temperature and nutrient limitation, and the data suggests greater variability of key parameters at low temperature. Understanding these dynamics will be important for improving models of aquatic primary production and biogeochemical cycles in a warming climate.

  17. A comparison of morphological and molecular-based surveys to estimate the species richness of Chaetoceros and Thalassiosira (bacillariophyta, in the Bay of Fundy.

    Sarah E Hamsher

    Full Text Available The goal of this study was to compare the ability of morphology and molecular-based surveys to estimate species richness for two species-rich diatom genera, Chaetoceros Ehrenb. and Thalassiosira Cleve, in the Bay of Fundy. Phytoplankton tows were collected from two sites at intervals over two years and subsampled for morphology-based surveys (2010, 2011, a culture-based DNA reference library (DRL; 2010, and a molecular-based survey (2011. The DRL and molecular-based survey utilized the 3' end of the RUBISCO large subunit (rbcL-3P to identify genetic species groups (based on 0.1% divergence in rbcL-3P, which were subsequently identified morphologically to allow comparisons to the morphology-based survey. Comparisons were compiled for the year (2011 by site (n = 2 and by season (n = 3. Of the 34 taxa included in the comparisons, 50% of taxa were common to both methods, 35% were unique to the molecular-based survey, and 12% were unique to the morphology-based survey, while the remaining 3% of taxa were unidentified genetic species groups. The morphology-based survey excelled at identifying rare taxa in individual tow subsamples, which were occasionally missed with the molecular approach used here, while the molecular methods (the DRL and molecular-based survey, uncovered nine cryptic species pairs and four previously overlooked species. The last mentioned were typically difficult to identify and were generically assigned to Thalassiosira spp. during the morphology-based survey. Therefore, for now we suggest a combined approach encompassing routine morphology-based surveys accompanied by periodic molecular-based surveys to monitor for cryptic and difficult to identify taxa. As sequencing technologies improve, molecular-based surveys should become routine, leading to a more accurate representation of species composition and richness in monitoring programs.

  18. Impact of elevated CO2 concentrations on the growth and ultrastructure of non-calcifying marine diatom (Chaetoceros gracilis F.Schütt

    Hanan M. Khairy


    Full Text Available The impacts of different CO2 concentrations on the growth, physiology and ultrastructure of noncalcifying microalga Chaetoceros gracilis F.Schütt (Diatom were studied. We incubated Ch. gracilis under different CO2 concentrations, preindustrial and current ambient atmospheric concentrations (285 and 385 μatm, respectively or predicted year-2100 CO2 levels (550, 750 and 1050 μatm in continuous culture conditions. The growth of Ch. gracilis measured as cell number was decreased by increasing the pCO2 concentration from nowadays concentration (385 μatm to 1050 μatm. The lowest percentage changes of oxidizable organic matter, nitrite, nitrate, phosphate and silicate were recorded at a higher pCO2 (1050 μatm, and this is in consistence with the lowest recorded cell number indicating unsuitable conditions for the growth of Ch. gracilis. The minimum cell numbers obtained at higher levels of CO2 clearly demonstrate that, low improvement occurred when the carbon level was raised. This was confirmed by a highly negative correlation between cell number and carbon dioxide partial pressure (r = −0.742, p ⩽ 0.05. On the other hand, highest growth rate at pCO2 = 385 μatm was also confirmed by the maximum uptake of nutrient salts (NO3 = 68.96 μmol.l−1, PO4 = 29.75 μmol.l−1, Si2O3 = 36.99 μmol.l−1. Total protein, carbohydrate and lipid composition showed significant differences (p ⩽ 0.05 at different carbon dioxide concentrations during the exponential growth phase (day 8. Transmission Electron Microscopy of Ch. gracilis showed enlargement of the cell, chloroplast damage, disorganization and disintegration of thylakoid membranes; cell lysis occurs at a higher CO2 concentration (1050 μatm. It is concluded from this regression equation and from the results that the growth of Ch. gracilis is expected to decrease by increasing pCO2 and increasing ocean acidification.

  19. Effect of alternative mediums on production and proximate composition of the microalgae Chaetoceros muelleri as food in culture of the copepod Acartia sp. Efecto de medios alternativos sobre la producción y composición proximal de la microalga Chaetoceros muelleri como alimento en cultivo del copépodo Acartia sp.

    Luis R Martínez-Córdova


    Full Text Available Microalgae Chaetoceros muelleri was cultured in three different mediums consisting on an agricultural fertilizer (Agr-F, aquacultural fertilizer (Aq-F and a conventional medium (F/2, control. These microalgae were later used as natural food to culture the copepod Acartia sp. The productive response and chemical proximate composition of microalgae and copepods were monitored. Growth rate and final cell concentration were higher in microalgae cultured in Agr-F compared to the control. In addition, the final biomass and cellular concentration were also the highest in Agr-F. Microalgae from Agr-F and Aq-F had higher carbohydrate and lower protein contents than those in the control. No differences in lipid and ash contents were observed. Regarding copepod production, higher densities and fecundity indexes were observed for those fed with microalgae previously cultured in Agr-F and Aq-F, compared to the control. The adult-nauplii ratio was also higher in copepods fed on microalgae from Agr-F compared to Aq-F and control. Copepods fed on Agr-F and Aq-F microalgae, had higher protein content compared to those fed on control microalgae; carbohydrates were higher in copepods fed on Agr-F as compared to Aq-F microalgae. No differences in lipid and ash contents were registered. Agr-F and Aq-F were adequate alternative mediums to produce C. muelleri, which produced higher quality microalgae that increased the copepod production.La microalga Chaetoceros muelleri fue cultivada en tres medios diferentes basados en un fertilizante agrícola (Agr-F, un fertilizante acuícola (Aq-F y un medio convencional (F/2, control. Éstas microalgas fueron posteriormente utilizadas como alimento natural para cultivar el copépodo Acartia sp. La respuesta productiva y la composición proximal de las microalgas y copépodos fueron monitoreadas. La tasa de crecimiento y concentración final de células fueron mayores en la microalga cultivada en Agr-F, comparada con el control

  20. Control Químico de la Mosca de los Establos, Stomoxys Calcitrans (L y Otros Insectos Asociados con Estipes de Palma Africana en Descomposición

    Ureta Sandino Eduardo


    Full Text Available En ensayos para determinar el efecto del diazinon 1% I.A. (ingrediente activo; bromophos 1 % I.A.; dieldrin 0.5% I.A., 2% I.A. y methomyl 0.1 % I.A. sobre larvas de Stomoxys calcilrans y otros insectos asociados con tipes de palma africana (Elaeis guineensis en descomposición, se encontró que los tratamientos con diazinon 1% I.A. y bromophos 1% I.A. fueron los más efectivos para impedir la proliferación en éstos de las larvas de Slomoxys calcilralls. Ambos insecticidas protegieron eficientemente los estipes por lo menos durante dos semanas. El dieldrin al 0.5% I. A. y 2% I. A., aunque inferior al bromophos 1% I.A. y al diazinon 1% I.A. también fue efectivo para impedir la proliferación de larvas de la mosca en los troncos de palma africana en descomposición. El tratamiento con methomyl 0.1 % I. A. al parecer no impidió la multiplicación de las larvas en los estipes, según pudo observarse en muestras tomadas a las dos semanas de haber sido aplicado el producto. El diazinon 1% I.A: bromophos 1 % I.A.; dieldrin 0.5% I.A. y 2% I.A., aparentemente fueron eficaces para controlar los adultos de Limnobaris calandriformis y Metamasius hemipterus, los cuales eran atraídos en grandes cantidades a los trozos de tallo de palma recién rajada, así como también impidieron la proliferación en éstos de las larvas de los dípteros Ormidea obesa y Hermelia sp./Abstract Several tests were carried out to determine the effectiveness of diazinon 1% I.A., bromophos 1% I.A., dieldrin 0.5 and 2% I.A., and methomyl 0.1 % on larvae of the stable fly, Stomoxys calcitrans, and other insects associated with dead trunks of the oil palm (Elaeis guineesis.The results showed by the author indicate that diazinon and bromophos were the most effective materials tested. Both insecticides protected well the dead trunks for at least two weeks. Dieldrin (both doses although less efficient than diazinon, was also effective in preventing the development of great numbers of

  1. Comparison of acute toxicity of process chemicals used in the oil refinery industry, tested with the diatom Chaetoceros gracilis, the flagellate Isochrysis galbana, and the zebra fish, Brachydanio rerio

    Chemicals under the trade names Nalco 537-DA, Nalco 625, Nalco 7607, Nalco 5165, Ivamin, and technical monoethanolamine are used extensively in the oil refinery industry. Aquatic toxicity tests were conducted using zebra fish fry (Brachydanio rerio) and the unicellular algae Isochrysis galbana (a flagellate) and Chaetoceros gracilis (a diatom). Inhibition of cell division, chlorophyll content, and 14CO2 uptake in the algae were sensitive end points. The effective concentrations (EC50s) of growth inhibition were 0.1 mg/L (Ivamin; I. galbana), 0.8 mg/L (Nalco 7607; I. galbana), 6 mg/L (Nalco 625; I. galbana), 10 mg/L (Nalco 5165; C. gracilis), and 15 mg/L (Nalco 537-DA; C. gracilis). The lethal concentrations (LC50s) (96 h) toward zebra fish fry was 1 mg/L for Nalco 7607, 6.5 mg/L for Nalco 537-DA, 7.1 mg/L for Nalco 625, and 20 mg/L for Ivamin 803. Monoethanolamine had an LC50 higher than 5,000 mg/L. Nalco 5165 was not tested on fish fry. The heartbeat frequency of fish embryos was reduced by 2.5 mg/L Nalco 537-DA, but this was an insensitive end point for the other chemicals

  2. Toxicity of lead and cadmium to tropical marine phytoplankton

    Jensen, Susanne Dal; Panutrakul, Suwanna; Nyholm, Niels


    Toxicity of Pb and Cd to three tropical, marine phytoplankton species isolated from the Andaman Sea off Phuket Thailand were determined. The phytoplankton species included one diatom, Chaetoceros calcitrans, one green alga, Chlorella sp., and one chrysophyte, Dunaliella tertiolecta. The test method...

  3. Évaluation de la toxicité de pesticides sur quatre niveaux trophiques marins : microalgues, échinoderme, bivalves et poisson

    Amara, Anis


    This work aims to study the effects of a few pesticides and one adjuvant on marine organisms, representatives of four trophic levels : micro-algae, echinoderm, bivalves and fish. Analysis of the pollu-sensitivity was based on the utilisation of existing bio-assays or adapted to this study.Phytotoxic assessments were conducted on three phytoplanktonic species (Chaetoceros calcitrans, Isochrysis aff. Galbana et Tetraselmis suecica) using the fungicide epoxiconazole and the adjuvant nonylphenol....

  4. Growth and survival larvae of Argopecten nucleus fed with different microalgae diets

    Yenia Katerine Carreño Hernández


    Full Text Available The influence of the diet on larval growth of the scallops Argopecten nucleus was studied, testing six microalgae diets composed by single-algae and mixed diets of the species Isochrysis galbana, Chaetoceros calcitrans y Tetraselmis suecica, handling a concentration per mL equivalent to 40000 cells of I. galbana and the response through the variables surviving, growth, appearance of the eye spot and state of condition (full, half-full and empty larvae was measured. The diets containing I. galbana showed greater results over all the measured variables, with regard to those where it was not present. In particular, the mixed diet I. galbana + C. calcitrans presented superiority over all variables, although in the most cases was statistically similar to I. galbana + C. calcitrans + T. suecica, I. galbana + T. suecica and I. galbana alone. For the opposite, the diets with the lowest results were C. calcitrans and C. calcitrans +T. suecica. The results obtained are principally attributed to the nutritional composition mainly of high unsaturated fatty acids (HUFA of each microalgae and each mixture supply, which is discussed in detail.

  5. Mercury-induced genotoxicity in marine diatom (Chaetoceros tenuissimus)

    Sarker, S.; Desai, S.R.; Verlecar, X.N.; Sarker, M.S.; Sarkar, A.

    . tenuissimus cells. Grover et al. (2001) observed similar repair of DNA damage in rat peripheral blood leucocytes at an HgCl2 level of 43.2 ng g −1 after a 48-h exposure period. It was previously shown that, when phytoplankton was exposed to heavy metals... correlation between the metal concentration in water and plankton growth (Senthilnathan and Balasubramanian 1999). Interestingly, an inhibition was observed in cell population and chlorophyll a (chl a) concen- tration in Dunaliella minuta when exposed...

  6. Evolution of phytoplankton cultures after ultraviolet light treatment

    Introducing invasive species in new environments through ballast water is a specific problem of contamination and has recently become one of the main concerns of Maritime Organizations. Ultraviolet-C radiation (UV-C) is a technological alternative to prevent this maritime pollution. This study addresses the effect of UV-C on different phytoplankton cultures and also the ability to recover following exposure to damage. A UV-C low-pressure lamp irradiates the cultures. The distance from the source and the thickness of the layer prevent part of the energy from reaching the culture and the disinfective process is diminished. Some cultures such as Chlorella autotrophica and Chaetoceros calcitrans can easily recover from UV-C damage. However, Phaeocystis globosa does not have this ability. C. calcitrans forms cysts and exhibits two different behaviours depending on the dose applied.

  7. Interactive effect of elevated pCO2 and temperature on the larval development of an inter-tidal organism, Balanus amphitrite Darwin (Cirripedia: Thoracica)

    Baragi, L.V.; Anil, A.C.

    of the suitable food type (Barnes and Barnes, 1958). The growth rate of an organism is also influenced by the food quality and quantity (Moyse, 1963). Several studies have reported that the rising pCO2/reduced pH change the nutritional quality (Burkhardt et al... on the nutritional quality of the diatom (Chaetoceros calcitrans) which is used as feed for the rearing of barnacle larvae. In this experiment the growth of this diatom was measured in terms of cell numbers; and the nutritional quality was measured in terms...

  8. Stable isotopic analysis of Barnacle larvae and their faecal pellets to evaluate the ingested food

    Gaonkar, C.A.; Anil, A.C.

    ). 15N enrichment in the laboratory reared larvae fed with Chaetoceros calcitrans diet was about 1.42‰ which was slightly lower. Though the δ15N ratios of the consumers are known to be heavier by about 3-4‰ than their presumed diet (Michener... and Schell, 1994), the laboratory experiments have shown lower trophic enrichment values for 15N, with mean differences in δ15N between diet and their consumers being lower in marine (1.48‰) than in freshwater (2.82‰) organisms (Vanderklift and Ponsard...

  9. Invention of outdoor closed type photobioreactor for microalgae

    For efficient mass production of microalgae, we invented a novel photobioreactor that uses aeration for mixing. To select better chamber shapes for a photobioreactor, two aspects of its performance were numerically simulated, mixing and light reception. Two shapes survived the computational filters and were tested by cultivating Chlorococum littorale. One of them attained 20.5 g/m2/day in dry weight in the winter days in Japan. Recently, this figure was overwritten by the performance of 37.3 g/m2/day for Chaetoceros calcitrans with the maximum cell density of 2.5 g/L

  10. Caregivers' experiences of the South African judicial system after the reporting of child sexual abuse / N.L. Paulsen.

    Paulsen, Nicole


    Child sexual abuse (CSA) is found to occur in alarming proportions worldwide. In South Africa, children represent almost half of the victims of known sexual abuse, and this is becoming a great concern, even being described as a silent epidemic. This alarming fact as well as the researcher’s experiences as a social worker in this field, resulted in her reviewing literature, in order to gain further insight into the current situation in South Africa. It was discovered that the number of success...

  11. Phytochemical screening of twelve species of phytoplankton isolated from Arabian Sea coast

    Sushanth Vishwanath Rai


    Full Text Available Objective: To analyze the phytochemicals in twelve species of marine phytoplankton. Methods: Total phenolic content of methanol extract was estimated by the Folin-Ciocalteu method. Total flavonoid content of the methanol extarct was determined by aluminium chloride method. Chlorophylls, β-carotene and astaxanthin were estimated by acetone extraction method. Vitamin C was determined by dinitrophenyl-hydrazine method. Phycobiliproteins such as allophycocyanin, phycocyanin and phycoerythrin in the aqueous extracts were determined. Results: Total phenolics varied from 5.41 mg gallic acid equivalents/g dry weight (DW in Phormidium corium (P. corium to 17.37 mg gallic acid equivalents/g DW in Oscillatoria fremyii (O. fremyii. Total flavonoids ranged between 0.74 mg quercetin equivalent/g DW in P. corium and 9.87 mg quercetin equivalent/g DW in Nannochloropsis oceanica. Chlorophyll-a pigment was high in Chaetoceros calcitrans (C. calcitrans (15.51 mg/g DW and low in P. corium (1.08 mg/g DW. Chlorophyll-c ranged between 0.07 mg/g DW in Nannochloropsis oceanica and 4.62 mg/g DW in C. calcitrans. High contents of β-carotene and astaxanthin were found in C. calcitrans and low in P. corium which ranged from 0.33 to 10.03 mg/g DW and 0.18 to 3.85 mg/g DW, respectively. Vitamin C content varied from 0.50 mg/g DW in C. calcitrans to 1.51 mg/g DW in Phormidium tenue. O. fremyii showed highest total phycobiliproteins of 317.05 mg/g DW. High contents of allophycocyanin and phycocyanin were found in O. fremyii, whereas high contents of phycoerythrin were found in Oscillatoria sancta. All the three phycobiliproteins were low in Chroococcus turgidus. Conclusions: Marine phytoplankton are one of the natural sources providing novel biologically active compounds with potential for pharmaceutical applications.

  12. Effect of sonication frequency on the disruption of algae.

    Kurokawa, Masaki; King, Patrick M; Wu, Xiaoge; Joyce, Eadaoin M; Mason, Timothy J; Yamamoto, Ken


    In this study, the efficiency of ultrasonic disruption of Chaetoceros gracilis, Chaetoceros calcitrans, and Nannochloropsis sp. was investigated by applying ultrasonic waves of 0.02, 0.4, 1.0, 2.2, 3.3, and 4.3MHz to algal suspensions. The results showed that reduction in the number of algae was frequency dependent and that the highest efficiency was achieved at 2.2, 3.3, and 4.3MHz for C. gracilis, C. calcitrans, and Nannochloropsis sp., respectively. A review of the literature suggested that cavitation, rather than direct effects of ultrasonication, are required for ultrasonic algae disruption, and that chemical effects are likely not the main mechanism for algal cell disruption. The mechanical resonance frequencies estimated by a shell model, taking into account elastic properties, demonstrated that suitable disruption frequencies for each alga were associated with the cell's mechanical properties. Taken together, we consider here that physical effects of ultrasonication were responsible for algae disruption. PMID:26964936

  13. The culture of pearl oysters, Pinctada fucata (Gould, 1850 in Phuket with temperature shock method and survival rates on various feeds

    Rativat, V.


    Full Text Available Marine pearl farming at Phuket Island has exploited natural pearl oysters. In order to obtain sufficient pearl oysters, Pinctada fucata (Gould, 1850, the oyster cultivation was carried out to determine appropriate kinds of food and types of spat collectors. The male and female oysters were stimulated to spawn with this temperature shock method (treated with 32ºC and then with 26ºC. The fertilized eggs developed into the stages of polar body, cleavage, blastula, gastrula, trochophore and then D-shape larvae. At the ageof 19-26 hrs. the larvae were fed with three kinds of food: Isochrysis galbana, Chaetoceros calcitrans and the mixture of 1:1 I. galbana and C. calcitrans. Upon the first 30 days, shell lengths of the spats fed with I. Galbana, C. calcitrans and the mixture were 422.00±59.32, 221.33±12.46 and 347.33±67.98 μg, respectively. The 26-29th day spat stage settled to the collectors: saran net, plastic plates and wavy tile. Number of spats settling to saran net was the highest. But after being moved into the sea for 30 days, the survival rate was89.06% which was lower than for those settling to plastic plates (93.29% and wavy tile (93.99%.

  14. Effects of iron limitation on photosynthesis and carbohydrate metabolism in the Antarctic diatom Chaetoceros brevis (Bacillariophyceae)

    van Oijen, T; van Leeuwe, MA; Gieskes, WWC; de Baar, HJW


    Iron, one of the structural elements of organic components that play an essential role in photosynthesis and nitrogen assimilation of plants, is available at extremely low concentrations in large parts of the Southern Ocean's surface waters. We tested the hypothesis that photosynthesis is the primar

  15. Genotoxicity of cadmium in marine diatom Chaetoceros tenuissimus using the alkaline Comet assay

    Desai, S.R.; Verlecar, X.N.; Nagarajappa; Goswami, U.

    /L and 12th day at 7.5 mg/L concentrations. At lower Cd concentrations (4.5 mg/L and below) the damage was below 30% till the last day. This suggested that higher Cd levels have early damaging effects on cell nuclear material and that % injury increases...

  16. Lipid extraction methods from microalgal biomass harvested by two different paths: screening studies toward biodiesel production.

    Ríos, Sergio D; Castañeda, Joandiet; Torras, Carles; Farriol, Xavier; Salvadó, Joan


    Microalgae can grow rapidly and capture CO2 from the atmosphere to convert it into complex organic molecules such as lipids (biodiesel feedstock). High scale economically feasible microalgae based oil depends on optimizing the entire process production. This process can be divided in three very different but directly related steps (production, concentration, lipid extraction and transesterification). The aim of this study is to identify the best method of lipid extraction to undergo the potentiality of some microalgal biomass obtained from two different harvesting paths. The first path used all physicals concentration steps, and the second path was a combination of chemical and physical concentration steps. Three microalgae species were tested: Phaeodactylum tricornutum, Nannochloropsis gaditana, and Chaetoceros calcitrans One step lipid extraction-transesterification reached the same fatty acid methyl ester yield as the Bligh and Dyer and soxhlet extraction with n-hexane methods with the corresponding time, cost and solvent saving. PMID:23434816

  17. Photosynthetic characteristics of five high light and low light exposed microalgaea as measured with 14C-uptake and oxygen electrode techniques

    Grobbelaar, J.U.; Schanz, F.; Dubinsky, Z.; M. M. Tilzer; Burger-Wiersma, T; Rijkeboer, M.; Lemoalle, Jacques; Falkowski, P. G.


    #Tetraselmis suecica$, #Thalassiosira pseudonana$, #Chaetoceros calcitrans$, #Isochrysis galbana$ et #Microcystis sp.$ ont été utilisées pour déterminer leurs capacités d'adaptation et pour tester les différences entre les deux méthodes de mesure. Les cultures avaient été exposées à un éclairement fort (HL) ou à un éclairement faible (LL) pendant deux jours avant l'expérience. L'efficacité de la conversion de la lumière (...) et l'activité photosynthétique spécifique maximale par unité de chl...

  18. Workshop on The Functional Analysis of Quantum Information Theory : a Collection of Notes Based on Lectures by Gilles Pisier, K. R. Parthasarathy, Vern Paulsen and Andreas Winter

    Gupta, Ved Prakash; Sunder, V S


    This book provides readers with a concise introduction to current studies on operator-algebras and their generalizations, operator spaces and operator systems, with a special focus on their application in quantum information science. This basic framework for the mathematical formulation of quantum information can be traced back to the mathematical work of John von Neumann, one of the pioneers of operator algebras, which forms the underpinning of most current mathematical treatments of the quantum theory, besides being one of the most dynamic areas of twentieth century functional analysis. Today, von Neumann’s foresight finds expression in the rapidly growing field of quantum information theory. These notes gather the content of lectures given by a very distinguished group of mathematicians and quantum information theorists, held at the IMSc in Chennai some years ago, and great care has been taken to present the material as a primer on the subject matter. Starting from the basic definitions of operator space...

  19. Phytochemical screening of twelve species of phytoplankton isolated from Arabian Sea coast

    Sushanth Vishwanath Rai; Madaiah Rajashekhar


    Objective:To analyze the phytochemicals in twelve species of marine phytoplankton. Methods: Total phenolic content of methanol extract was estimated by the Folin-Ciocalteu method. Total flavonoid content of the methanol extarct was determined by aluminium chloride method. Chlorophylls,β-carotene and astaxanthin were estimated by acetone extraction method. Vitamin C was determined by dinitrophenyl-hydrazine method. Phycobiliproteins such as allophycocyanin, phycocyanin and phycoerythrin in the aqueous extracts were determined. Results: Total phenolics varied from 5.41 mg gallic acid equivalents/g dry weight (DW) in Phormidium corium (P. corium) to 17.37 mg gallic acid equivalents/g DW inOscillatoria fremyii(O. fremyii). Total flavonoids ranged between 0.74 mg quercetin equivalent/g DW inP. corium and 9.87 mg quercetin equivalent/g DW inNannochloropsis oceanica. Chlorophyll-a pigment was high inChaetoceros calcitrans(C. calcitrans)(15.51 mg/g DW) and low inP. corium (1.08 mg/g DW). Chlorophyll-c ranged between 0.07 mg/g DW inNannochloropsis oceanica and 4.62 mg/g DW inC. calcitrans. High contents ofβ-carotene and astaxanthin were found inC. calcitrans and low inP. corium which ranged from 0.33 to 10.03 mg/g DW and 0.18 to 3.85 mg/g DW, respectively. Vitamin C content varied from 0.50 mg/g DW inC. calcitrans to 1.51 mg/g DW inPhormidium tenue.O. fremyii showed highest total phycobiliproteins of 317.05 mg/g DW. High contents of allophycocyanin and phycocyanin were found inO. fremyii, whereas high contents of phycoerythrin were found inOscillatoria sancta. All the three phycobiliproteins were low inChroococcus turgidus. Conclusions: Marine phytoplankton are one of the natural sources providing novel biologically active compounds with potential for pharmaceutical applications.

  20. The regrowth of phytoplankton cultures after UV disinfection

    Highlights: ► Phytoplankton cultures were placed in a rich medium after UV-C irradiation. ► Flow cytometry and PAM were used for determining cell viability. ► The behavior differs from that of cultures kept in their original environment. ► Chlorella autotrophica recovers between 5 and 10 days after the treatment. ► Phaeocystis globosa shows only a slight recovery for low-dose UV-radiation exposure. - Abstract: This study addresses how cultures of three phytoplankton species –Chaetoceros calcitrans, Chlorella autotrophica and Phaeocystis globosa – can recover from the effects of UV-C exposure if the cells are placed in a rich medium. Flow cytometry and pulse amplitude modulation (PAM) were used to determine cell recovery after UV treatment. The recovery of C. calcitrans was complete 9 days after treatment. For C. autotrophica, the recovery was noticeable 5 days after treatment. P. globosa only recovered if the UV dose did not exceed 7.3 × 105 μWs/cm2. The recovery of the UV-treated cultures introduced to a regrowth medium, compared with the recovery of the irradiated cultures kept in their original environment, had two main characteristics: cell recovery was slower but was more efficient. This pattern of recovery has very important implications for real ballast water management systems because such systems discharge treated water into the environment

  1. Efficiency of traps for Stomoxys calcitrans and Stomoxys niger niger on Reunion Island.

    Gilles, J; David, J-F; Duvallet, G; De La Rocque, S; Tillard, E


    The main objective of this study was to compare the trapping efficiency of two Alsynite sticky traps (modified Williams and modified Broce) and two phtalogen blue cloth traps (Vavoua and Nzi) to be used in an integrated control programme of Stomoxys spp. (Diptera: Muscidae) on Reunion Island. Mean daily catches of these flies on two dairy farms differed significantly between the four types of trap. The Broce trap was the least efficient and had the lowest specificity for Stomoxys spp. The Vavoua, Nzi and Williams traps performed significantly better but could not be ranked on the basis of the numbers of Stomoxys caught because their respective performances differed between farms. Given the various practical criteria, it is concluded that, as control tools, blue cloth traps (Vavoua and Nzi) have practical advantages over the Williams trap. The Vavoua trap, which is less expensive and easier to use for farmers, seems adequate to complement other methods of fly control on Reunion Island. PMID:17373948

  2. Pollen recovered from the exoskeleton of stable flies, Stomoxys calcitrans (L.) in Gainesville, Florida

    Stable flies are pestiferous blood feeding flies that attack animals and humans. Besides consuming blood, these flies will also visit flowers to take nectar meals. When feeding on nectar, flies become coated with pollen which can be used to identify flowers used by the flies. Recently, flies cove...

  3. Effects of iron availability on pigment signature and biogenic silica production in the coastal diatom Chaetoceros gracilis

    Biswas, H.; Bandyopadhyay, D.

    activated a strong photoprotection mechanism by maximising the conversion of diadinoxanthin to diatoxanthin and by increasing overall amount of photoprotective pigments relative to light harvesting pigments. The xanthophyll cycle comprising of diadinoxanthin...

  4. Contact and spatial repellency from catnip essential oil, Nepeta cataria, against stable fly, Stomoxys calcitrans, and other filth flies

    Presenting brief summaries of our significant findings on: 1). Development of an in vitro bioassay for screening/discovering biting fly repellents, 2). Strong repellency found from catnip oil and its ingredient compounds, nepetalactones against four filth fly species; 3). Feeding deterrency, oviposi...

  5. Biogenic amines in the stable fly Stomoxys calcitrans L. (Diptera: Muscidae): tissue localization and roles in feeding and reproduction

    Biogenic amines, such as serotonin (5-hdroxytryptamine [5-HT]) and octopamine (OA), play critical roles as neurotransmitters and neuromodulators that control or modulate many behaviors in insects, such as feeding and reproduction. Neurons immunoreactive (IR) to 5-HT and OA were detected in the centr...

  6. Filtration and respiration rates of the short-necked clam Paphia undulata (Born, 1778 (Mollusca, Pelecypoda: Veneridae under laboratory conditions

    Laureen Morillo Manalo


    Full Text Available The filtration and respiration rates of various size classes (35-39.99, 40-44.99,45-49.99, 50-54.99 and 55-59.99 mm of the short-necked clam Paphia undulata were measured in the laboratory. The effects of three light regimes (0 lux, 172.22 lux and 645.83 lux, three microalgal species (Isochrysis galbana, Tetraselmis tetrahele and Chaetoceros calcitrans and four microalgal concentrations (10, 25, 50 and 100 x 104 cells ml-1 on filtration rates were investigated. Mean filtration rate was highest (0.57 ± 0.04 Lh-1ind.-1 under total darkness. This can be attributed to the natural environment of this species which is characterized by silty substrate and low visibility. Filtration was also highest in the microalga Isochrysis galbana (0.67 ± 0.05. Rates initially increased from low to moderate microalgal concentrations (25 x 104 cells ml-1 and decreased at higher concentrations. Filtration generally decreased with increase in clam size. Light intensity, microalgal species and microalgal concentration showed significant effects on filtration. Respiration of fed clams was higher (0.138 ± 0.026 ml O2h-1ind.-1 than unfed clams (0.053± 0.025 ml O2h-1 nd.-1 and increased with clam size.

  7. Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effecti...

  8. Evaluation of genotoxic responses of Chaetoceros tenuissimus and Skeletonema costatum to water accommodated fraction of petroleum hydrocarbons as biomarker of exposure

    Desai, S.R.; Verlecar, X.N.; Ansari, Z.A.; Jagtap, T.G.; Sarkar, A.; Vashistha, D.; Dalal, S.G.

    their toxicity. Photo-oxidation is an important mechanism in this respect. Greatly increased toxicity has been reported to algae by photo- oxidised hydrocarbons (Lacaze and Viledonde, 1976; Skjoldal et al., 1982). Aromatic compounds get 13 readily photo... time. Because of the polar and the non-polar nature, they are concentrated more by organisms and have a deleterious effect on the cell membrane, which could lead to death of the cell (Larson et al., 1979). Thus, photo-oxidation products might have...

  9. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    Mastitis is a common illness of dairy cattle and is very costly, economically, to the dairy farmer. Thus, there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH4-inhibitors nitroethane (2 mg/m...

  10. Effects of the methane-inhibitors nitrate, nitroethane, lauric acid, Lauricidin**R and the Hawaiian marine algae, Chaetoceros, on ruminal fermentation in vitro

    The effects of several methane-inhibitors on rumen fermentation were compared during three 24 h consecutive batch cultures of ruminal microbes in the presence of nonlimiting amounts of hydrogen. After the initial incubation series, methane production was reduced greater than 92% from that of nontre...

  11. Copper addition helps alleviate iron stress in a coastal diatom: Response of Chaetoceros gracilis from the Bay of Bengal to experimental Cu and Fe addition

    Biswas, H.; Bandyopadhyay, D.; Waite, A.

    sedimentation of biomass within the bottles. Based on earlier growth rate measurements, sampling were executed during the maximum growth phase on day 3 of the incubation. All bottles were returned to the clean laboratory for further sampling and analysis. 2....3 Sample Analysis: For total Chl-a determination, 100 mL of the experimental sample from each treatment was filtered onto GF/F filters and kept in -20ºC until analysis. Later, filters were soaked overnight in 5 mL N,N- 6    Dimethyl formamide following...

  12. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as causative agents of mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effective while...

  13. Spatial distribution, seasonality and trap preference of stable fly, Stomoxys calcitrans L. (Diptera: Muscidae), adults on a 12-hectare zoological park

    Ose, Gregory A; Hogsette, Jerome A


    Although this study was originally designed to compare the efficacy of two different stable fly traps within 10 sites at a 12-ha zoological park, seasonal and spatial population distribution data were simultaneously collected. The two traps included an Alsynite fiberglass cylindrical trap (AFT) and a blue-black cloth target modified into a cylindrical trap (BCT). Both traps were covered with sticky sleeves to retain the attracted flies. Paired trap types were placed at sites that were 20–100 ...

  14. Effect of mutual interference on the ability of Spalangia cameroni (Hymenoptera: Pteromalidae) to attack and parasitize pupae of Stomoxys calcitrans (Diptera: Muscidae)

    Skovgård, Henrik; Nachman, Gösta


    h. The number of pupae that were attacked and the number successfully parasitized increased with the parasitoid density and reached a maximum of similar to 70 and 50, respectively. Parasitoid-induced mortality (PIM) was about 20 pupae, irrespective of parasitoid density. The per capita rates of...... attack, successful parasitism and parasitoid-induced mortality declined monotonously with parasitoid density. Progeny sex ratio was female biased for all parasitoid densities, but declined significantly with increasing parasitoid density from similar to 70% females at the lowest density to similar to 60......% at the highest. Mutual interference was incorporated into a functional response model to predict the attack rate and the rate of successful parasitism at different temperatures, host densities and parasitoid densities. The model explained 93.5% of the variation in the observed number of attacked...

  15. Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

    Gaonkar, Chetan A.; Anil, Arga Chandrashekar


    Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in feeding studies of various organisms. In this study we standardised the gut fluorescence method using laboratory-reared barnacle larvae (Balanus amphitrite) fed with mono-algal diet Chaetoceros calcitrans, a unicellular diatom at a cell concentration of 2 × 105 cells ml-1. The gut fluorescence of IV-VI instar nauplii was found to be 370(±12) ng chlorophyll a larva-1 and in faecal pellets it was 224(±63) ng chlorophyll a larva-1. A phaeopigment concentration in larval gut was found to be 311(±13) ng larva-1 and in faecal pellets it was 172(±61) ng larva-1. The study also analysed larval samples collected from the field during different seasons from a tropical environment influenced by monsoons (Dona Paula bay, Goa, west coast of India), with characteristic temporal variations in phytoplankton abundance and diversity. Gut fluorescence of larvae obtained during the post-monsoon season was consistently higher when compared to the pre-monsoon season, suggesting the predominance of autotrophic forms in the larval gut during the post-monsoon season. Whereas, the low gut fluorescence obtained during the pre-monsoon season indicated the ingestion of food sources other than autotrophs. Such differences observed in the feeding behaviour of larvae could be due to differential availability of food for the larvae during different seasons and indicate the capability of larvae to feed on wide range of food sources. This study shows the value of the fluorescence method in feeding studies of planktotrophic organisms and in the evaluation of ecosystem dynamics.

  16. Molecular characterization and immunolocalization of the olfactory co-recepter Orco from two blood-feeding muscid flies, the stable fly (Stomoxys calcitrans, L.) and the horn fly (Haematobia irritans irritans, L.)

    Olafson, Pia Untalan


    Biting flies are economically important, blood-feeding pests of medical and veterinary significance. Chemosensory-based biting fly behaviors, such as host/nutrient source localization and ovipositional site selection, are intriguing targets for the development of supplemental control strategies. In an effort to expand our understanding of biting fly chemosensory pathways, transcripts encoding the highly conserved insect odorant co-receptor (Orco) were isolated from two representative biting f...

  17. Population Dynamics of Stable Flies Stomoxys calcitrans (Diptera: Muscidae) at an Organic Dairy Farm in Denmark based on a Mark-recapture with Destructive Sub-Sampling

    Skovgård, H.; Nachman, G.


    of a modified version of Bailey's triple catch method. In both years, the abundance of flies peaked in July. Using a statistical model, we were able to explain 86.6% of the variation in the per capita growth rate r as a function of current temperature, precipitation, and population size. Omitting precipitation...... from the model, it still explained 69.3%. The model predicts that stable flies have a temperature optimum at 21.8°C, and that no development will take place when temperatures inside the stable are below 10.2°C or above 33.5°C. At the optimal temperature the intrinsic rate of natural increase is 0.070 d......-1. The per capita dilution rate increased with temperature and decreased with population size, whereas no effect of these factors on the per capita loss rate could be shown. Mean adult survival time was estimated to 6.3 d with 95% CL ranging from 4.3 to 11.1 d. The study points at the possibility...

  18. Screening of High-quality Feed Microalgae in Cultivation of Juvenile Intertidal Shellfish, Sinonovacula constricta%缢蛏稚贝优质微藻饵料的筛选

    马斌; 周海波; 徐继林; 周成旭; 严小军


    为了筛选缢蛏稚贝的合适饵料及其最优组合投饵方式,比较了8种常见饵料微藻单种投喂和混合投喂对缢蛏稚贝生长的影响.结果显示:单种投喂时,角毛藻和金藻饵料效果最佳,云微藻和XSWG仅次于角毛藻和金藻,对于规格较大的缢蛏稚贝扁藻饵料效果较佳,而对于规格较小的缢蛏稚贝其饵料效果并不太好,这5种微藻都可以作为缢蛏稚贝培育过程中的优良饵料选择:微绿球藻、巴夫藻饵料效果较差,不是缢蛏的良好饵料;而A5不仅对缢蛏稚贝没有饵料效果还具有一定的毒害作用.选择优良饵料微藻进行混合投喂,其效果要优于单种投喂;混合投喂时,一些单种投喂饵料效果不佳的微藻品种可以作为优质饵料不足时的补充;对缢蛏稚贝有毒害作用的微藻品种绝对不能作为混合投喂时的饵料选择.%In order to select the appropriate feed and optimum combinational feeding methods of juvenile shellfish, Sinonovacula constricta, the feeding effects of eight common microalgae are compared in this study. The best feeding effects are found in Chaetoceros calcitrans and Isochrysis galbana, followed by YW0980 and XSWG., through feeding with single microalgae. The feeding result of Platymonas helgolandica on juvenile Sinonovacula with larger size is more effective than those with smaller size. All of the five feed microalgae above can be used as good choices during the cultivation of juvenile Sinonovacula. Poor results are identified in Pavlova viridis and Nannochloropsis oculata, which are found to be the inappropriate feed for juvenile Sinonovacula. However, not only little feed effect but also some toxic effect is noted in the microalgae named A5. Relative to those feeding with single microalgae the better effects are achieved in mixed feeding with high-quality microalgae. The experimental results of feeding with the mixed microalgae show that the poor

  19. The Expert Ceiling in Epistemological Beliefs

    Barnard, Lucy


    Paulsen and Wells (1998) stated that, "it seems unlikely that substantial differences in epistemological beliefs across domains would persist in studies of faculty or other more advanced experts," (p. 380). This statement implies the existence of an upper limit or ceiling effect in the epistemological beliefs among experts. Faculty members are…


    Paulsen, Steve and Kevin Summers. In press. EMAP: Myths, Hobgoblins and Crusades (Abstract). To be presented at EMAP Symposium 2004: Integrated Monitoring and Assessment for Effective Water Quality Management, 3-7 May 2004, Newport, RI. 1 p. (ERL,GB R980). The Environment...

  1. Making Cooperative Learning Work in the College Classroom: An Application of the "Five Pillars" of Cooperative Learning to Post-Secondary Instruction

    Jones, Karrie A.; Jones, Jennifer L.


    Cooperative learning is viable yet generally underutilized method of instruction at the college level (Paulsen and Faust, 2008). This paper highlights the work of teacher educator Dr. Paul J. Vermette in his implementation of cooperative learning based practices in a graduate level Multicultural education course. In analyzing the "Five…

  2. Planktonic diatoms of the Zuari estuary, Goa (west coast of India)

    Redekar, P.D.; Wagh, A.B.

    and 30 (13 genera) Centrales. The common diatoms observed were Chaetoceros borealis, C. decipiens, Biddulphia regia, B. sinensis, Coscinodiscus conscinnus, C. subtilis, C. grani, Navicula inflexa, N. oblonga, Amphora turgida, A. ovalis, Nitzschia sigma...

  3. Abundance of bacterial and diatom fouling on various surfaces


    , Coscinodiscus sp, Fragilaria sp, Liemophora sp, Chaetoceros sp and Rhizoselenia sp. Pennate forms were more dominant as compared to the centrales. The mucilaginous fibrillar material entrapping bacteria and diatoms formed a two-tiered layer on study surfaces...

  4. Seasonality and composition of phytoplankton in the Arabian Sea

    Sawant, S.S.; Madhupratap, M.

    population when three seasons were combined, followed by cyanobacteria (7%) and dinoflagellate (6%). The common diatoms were Nitzschia sp., N. seriata, N. longissima, Thalassiothrix spp., Rhizosolenia spp. and Chaetoceros spp. Some diatoms like Fragilaria sp...

  5. Vigour Health: the ASC-Series launch in Canada

    Danielsen, David M.; Fredriksen, Joakim; Nordli, Espen; Nøstberg, Bjørn R.


    This report is part of the authors’ bachelor degree in International Marketing and analyzes the Canadian vitamins and dietary supplements (VDS) industry. Based on this analysis, the authors will be proposing how Vigour can enter the market. Vigour Health was founded in 2006 by Omar Paulsen Bekheet and John Ivar Andre and the goal was to introduce a new lifestyle concept that should be inventive in its approach. Vigour utilizes raw materials from the northern parts of Norway, an...

  6. Organizational Communication and Media

    Tække, Jesper


     The paper reflects an interest in the relation between organizational communication and media. It tries to answer the question, how we can observe the relationship between organizational communication and media. It is a work-in-progress which tries to combine organizational studies inspired of Niklas Luhmann (Tække & Paulsen 2008, Tække 2008a) with analysis of how organizations communicate in and about media. Using systems theory and form theory, it puts forward a theoretical framework a...

  7. Efficacy and Safety of Catnip (Nepeta cataria) as a Novel Filth Fly Repellent

    The essential oil of catnip (Nepeta cataria) has recently been reported as an alternative mosquito repellent on mosquitoes both topically and spatially. The present study reports that catnip oil resulted in an average repellency of 96% in feeding against stable fly (Stomoxys calcitrans) and 79% to t...

  8. Development and oviposition preference of house flies and stable flies (Diptera: Muscidae) in six substrates from Florida equine facilities

    House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), common pests on equine facilities, were studied in the laboratory to determine their oviposition preferences and larval development on six substrates commonly found on equine facilities. The substrates...

  9. Effect of biogenic amines on the mating and egg-laying behaviors in the stable fly

    The stable fly Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most significant biting fly pests affecting livestock.The annual economic damage to the U.S. cattle industry is estimated at over one billion US dollars. Biogenic amines are known to play critical roles in feeding and reprodu...

  10. External morphology of stable fly (Diptera: Muscidae) larvae

    Scanning electron microscopy was used to examine the external morphology of first-, second-, and third-instar stable flies (Stomoxys calcitrans (L.)). In the cephalic region, the antennae, labial lobe, and maxillary palpi are morphologically similar among instars. Antennae comprise a prominent ante...

  11. Comparison of the Olfactory Preferences of Four Species of Filth Fly Pupal Parasitoid Species (Hymenoptera: Pteromalidae) for Hosts in Equine and Bovine Manure

    House flies (Musca domestica L.) and stable flies (Stomoxys calcitrans (L.)) (Diptera: Muscidae) are common pests in equine and cattle facilities. Pupal parasitoids primarily in the genera Spalangia and Muscidifurax (Hymenoptera: Pteromalidae) can be purchased for biological control of these flies. ...

  12. Freeze dried blood and development of an artificial diet for blood feeding arthropods

    The goals of the research were to determine the biochemical differences between freeze dried bovine and porcine blood relative to their nutritional value to Glossina palpalis palpalis and Stomoxys calcitrans and to develop an artificial diet for mass rearing these flies. Freeze dried bovine and porcine blood were found to differ in their amino acid content; total dietary lipids did not significantly differ, but some notable exceptions were found in fatty acid content. Both sonication and addition of foetal bovine serum to freeze dried bovine blood improved its nutritional value for G. p. palpalis. A two component, semi-defined artificial diet was developed for G. p. palpalis and S. calcitrans. The College Station diet consisted of lipid contaminated bovine haemoglobin (BHb) and bovine serum albumin (BSA). To conduct dietary deletion tests, a process was developed for preparing large quantities of ultrapure lipid free bovine haemoglobin. S. calcitrans fed on lipid free BHb plus BSA had zero fecundity. Lipids were re-added to the protein diet in three forms: (1) lipid contaminated BHb, (2) pure erythrocyte ghosts, and (3) pure lipids. It was found that membrane lipid from the erythrocyte is required by S. calcitrans. A defined artificial diet consisting of lipid free BHb, BSA, sphingomyelin, phosphatidyl ethanolamine, phosphatidyl serine and cholesterol gave normal adult survival, as well as near normal fecundity and percentage egg hatch for S. calcitrans. Knowing the identity of the lipids, it is now possible to prepare dietary formulations to alleviate dependency on the blood proteins BHb and BSA. (author). 34 refs, 1 fig., 15 tabs

  13. Produção e qualidade de uvas de mesa 'Sugraone' sobre diferentes porta-enxertos no Submédio do Vale do São Francisco Production and quality of table grapes 'Sugraone' on different rootstocks in the São Francisco River Valley

    Patrícia Coelho de Souza Leão


    Full Text Available O presente trabalho teve como objetivos avaliar o comportamento agronômico da cultivar de uva de mesa sem sementes Sugraone sobre quatro porta-enxertos nas condições do Submédio do Vale do São Francisco. O experimento foi conduzido em um vinhedo comercial no município de Sento Sé-BA durante quatro ciclos de produção (2002 à 2004, em sistema de condução do tipo latada e irrigação por gotejamento. Os tratamentos consistiram de quatro cultivares de porta-enxerto ('Paulsen 1103', 'SO4', 'Harmony' e '420A', utilizando-se delineamento experimental em blocos ao acaso. Foram obtidas maiores produções por planta e vigor vegetativo sobre o porta-enxerto 'Paulsen 1103'. Também observou-se uma tendência de maior massa de cachos, massa e tamanho de bagas sobre este porta-enxerto, embora tenham ocorrido variações entre os ciclos de produção. O porta-enxerto exerceu influência sobre o teor de sólidos solúveis totais, mas não afetou a acidez total e a relação SST/ATT dos frutos.The present work aimed to evaluate the agronomic performance of the seedless grape cultivar Sugraone on four rootstocks in the São Francisco Valley. The trial was carried out in a commercial vineyard in Sento Sé, State of Bahia for four seasons (2002 to 2004. The treatments were four cultivars of rootstock ('Paulsen 1103', 'SO4', 'Harmony' and '420A', using a randomized block design. The highest yield per plant and vegetative vigor were obtained on the rootstock Paulsen 1103. Also there was a tendency for higher mass of bunches, mass and size of berries on the same rootstock, although there were variations between seasons. The rootstock showed positive influence on the content of soluble solids, but did not affect the total acidity and TSS/TA. Young plants of grapevine cv. Sugraone showed good agronomic performance on Paulsen 1103, but it is important to continue the studies for a larger number of years to recommend their use in the São Francisco Valley.

  14. [Ingestion and digestion of seven species of microalgae by larvae of Strombus gigas (Mesogastropoda: Strombidae)].

    Patiño Súarez, V; Aldana Aranda, D


    The potential nutritional value of seven microalgal diets as measured by their ingestibility and digestibility to queen conch Strombus gigas larvae was tested with 30 day old larvae reared at 28 degrees C and fed at 1000 cells x ml(-1). The algae were Tetraselmis suecica, Tetraselmis chuii Isochrysis aff. galbana, Dunaliella tertiolecta, Chlamydomonas coccoides, Chaetoceros sp. and Thalassiosira fluviatilis. Ingestion and digestion were measured by the four nutritional stages studied with epifluorescence microscopy with live larvae. Temporal and absolute indices showed that larvae fed Chaetoceros sp. and T. fluviatilis had lower ingestion and digestion levels. The other algae are recommend to feed S. gigas larvae. PMID:15266796

  15. Feeding behaviour of salp Thalia democratica (Thaliacea)

    Nair, S.R.S.; Achuthankutty, C.T.; Bhattathiri, P.M.A.; Madhupratap, M.

    The salp Thalia democratica was found to feed on Chaetoceros sp. continuously during the entire experimental period of 24 hours. The rate of consumption (0.09-0.16% animal sup(-1) h sup(-1)), however, did not differ significantly. Faecal output also...

  16. Quantitative grain density autoradiography and the intraspecific distribution of primary productivity in phytoplankton

    Analysis of a method of grain density autoradiography demonstrates that reliable measurements of the primary productivity of individual phytoplankton species can be obtained with this technique. Grain density autoradiography is particularly useful for providing an estimate of the intraspecific distribution of primary productivity. As an example, the productivity distribution of the marine diatom Chaetoceros curvisetus became positively skewed during a period of population decline

  17. Cultivation of shear stress sensitive and tolerant microalgal species in a tubular photobioreactor equipped with a centrifugal pump

    Michels, M.H.A.; Goot, van der A.J.; Vermuë, M.H.; Wijffels, R.H.


    The tolerance to shear stress of Tetraselmis suecica, Isochrysis galbana, Skeletonema costatum, and Chaetoceros muelleri was determined in shear cylinders. The shear tolerance of the microalgae species strongly depends on the strain. I. galbana, S. costatum, and C. muelleri exposed to shear stress b

  18. Observations on feeding behaviour and survival rates in the estuarine calanoid copepods Acartia spinicauda and Heliodiaptomus cinctus (Crustacea: Copepoda: Calanoida)

    Srivastava, Y.; Fernandes, Brenda; Goswami, S.C.; Goswami, U.; Achuthankutty, C.T.

    to feed on T. gracilis (90.08%) as compared to S. costatum (55.87%). A combined feed of Isochrysis galbana (50%) and Chaetoceros sp. (50%) was found to be most satisfactory in case of H. cinctus as there was no mortality till the 8th day and only 57...

  19. Trocas gasosas de mudas de videira, obtidas por dois porta-enxertos, submetidas à deficiência hídrica Gas exchange of vine cuttings obtained from two graftings submitted to water deficiency

    Claudia Rita de Souza


    Full Text Available Este trabalho teve como objetivo avaliar o efeito da deficiência hídrica e de dois porta-enxertos nas trocas gasosas de mudas de videira cultivadas em vasos, nas condições de casa de vegetação. Utilizou-se como copa a 'Niágara Rosada' (Vitis labrusca, e como porta-enxertos, o 101-14 (V. riparia e o 1103 Paulsen (V. rupestris x V. berlandieri. Doze dias após a suspensão da rega, o potencial hídrico foliar da combinação 'Niágara Rosada'/101-14 apresentou os menores valores (-2,80 MPa em relação à 'Niágara Rosada'/1103 Paulsen (-2,10 MPa nas plantas não-irrigadas, enquanto o teor relativo de água variou apenas entre os tratamentos hídricos. Com a evolução do estresse hídrico, houve uma sensível redução nas trocas gasosas da cultivar 'Niágara Rosada', que apresentaram valores próximos de zero, devido ao fechamento dos estômatos, sem diferenças entre os porta-enxertos. Somente após 12 dias sem rega, os porta-enxertos influenciaram a eficiência no uso da água e eficiência fotoquímica do fotossistema II, onde a 'Niágara Rosada' enxertada sobre o 101-14 apresentou valores inferiores ao 1103 Paulsen. Entretanto, durante o período de suspensão da rega, os porta-enxertos não influenciaram as trocas gasosas da cultivar 'Niágara Rosada', e apresentaram comportamento semelhante em condições de baixa disponibilidade hídrica.The present work aimed to evaluate the water deficiency effect and two graftings on the gas exchange of vine cuttings under greenhouse conditions. 'Niágara Rosada' (Vitis labrusca was used as scion, and 101-14 (V. riparia x V. rupestris and 1103 Paulsen (V. rupestris x V. berlandieri were used as rootstocks. Twelve days after watering suspension, the leaf water potential of the combination 'Niágara Rosada'/101-14 showed lower (-2.80 MPa in relation to 'Niágara Rosada'/1103 Paulsen (-2.10 MPa in the non-irrigated plants, while relative water content altered only among watering levels. With the

  20. Disponibilidade hídrica, radiação solar e fotossíntese em videiras 'Cabernet Sauvignon' sob cultivo protegido Water supply, solar radiation and photosynthesis in 'Cabernet Sauvignon' grapevines under plastic covering

    Clenilso Sehnen Mota; Cassandro Vidal Talamini do Amarante; Henrique Pessoa dos Santos; Jackson Adriano Albuquerque


    O objetivo deste trabalho foi avaliar os efeitos da cobertura de videira 'Cabernet Sauvignon' com lona plástica translúcida sobre a disponibilidade de luz e água, a concentração foliar de clorofila e a fotossíntese. As plantas com cinco anos de idade foram conduzidas em sistema 'Y' sobre porta-enxerto Paulsen 1103. O experimento seguiu o delineamento em blocos ao acaso, com dois tratamentos (plantas sem e com cobertura plástica) e quatro repetições de 15 plantas (unidade experimental). A cobe...

  1. On non-trivial barrier solutions of the dividend problem for a diffusion under constant and proportional transaction costs

    Bai, Lihua


    In Bai and Paulsen (SIAM J. Control optim. 48, 2010) the optimal dividend problem under transaction costs was analyzed for a rather general class of diffusion processes. It was divided into several subclasses, and for the majority of subclasses the optimal policy is a simple barrier policy; whenever the process hits an upper barrier $\\bar{u}^*$, reduce it to $\\bar{u}^*-\\xi$ through a dividend payment. After transaction costs, the shareholder receives $k\\xi-K$. It was proved that a simple barrier strategy is not always optimal, and here these more difficult cases are solved. The optimal solutions are rather complicated, but interesting.

  2. Raleio de cachos em vinhedos de altitude e qualidade do vinho da cultivar Syrah Cluster thinning in high altitude vineyards and wine quality from the cultivar Syrah

    Leonardo Cury da Silva; Leo Rufato; Aike Anneliese Kretzschmar; José Luiz Marcon Filho


    O objetivo deste trabalho foi avaliar o efeito de diferentes intensidades de raleio de cachos de uvas (Vitis vinifera L.), em vinhedos de altitude, sobre a evolução dos compostos fenólicos durante a maturação da uva. O experimento foi conduzido em São Joaquim, SC, a uma altitude média de 1.230 m, em videiras da cv.Syrah, enxertadas sobre 'Paulsen 1103', conduzidas em espaldeira, em duplo cordão esporonado, espaçadas em 3x1,2 m, com cobertura antigranizo. Os tratamentos de raleio foram definid...

  3. Bildung in the Digital Medium Environment

    Tække, Jesper; Paulsen, Michael Eric

    We are living in a period where new social structures arise in the communicative space and wake of digital media. This means that we must try to adapt to a changing social world within all social arenas like economy, work-life, love relations and last but not least education. The question...... in education today and tomorrow. The paper draws on empirical findings from the Socio Media Education experiment, a Danish action research project in an upper secondary school from 2011-214 (Tække & Paulsen 2013a, 2015a, 2016a, 2016b)....

  4. 80 aastat tagasi : Jaanuar 1928 / Mati Märtin

    Märtin, Mati


    Muusikasündmustest 80 aastat tagasi: Noorte Meeste Kristliku Ühing andis loengkontserte, Tallinna Kaarli kirikus tuli ettekandele A.Dvoraki "Stabat Mater" (juhatas Johannes Paulsen, esinesid Jekeli lauluselts, Estonia sümfooniaorkester ja solistid Olga Torokoff-Tiedeberg, J. Badendiesk-Inger, Arnold Vissmann ja Karl Viitol), trükist ilmus Johannes Jürgensoni (Juhan Jürme) "12 vaimulikku laulu" (kirjastajaks Tallinna Kaarli Lauluselts), 50. surma-aastapäeva puhul meenutati kirikumuusikut Johann August Hagenit, meenutati Keila muusikameest Jakob Maabergi

  5. Avaliação de substratos para inoculação micorrízica e aclimatização de dois porta-enxertos de videira micropropagados Evaluation of substrates for mycorrhization and weaning of two micropropagated grapevine rootstocks

    Josy Moraes Zemke


    Full Text Available O objetivo deste trabalho foi selecionar substratos favoráveis à associação micorrízica na produção de mudas micropropagadas de porta-enxertos de videira. Os porta-enxertos SO4 e Paulsen 1103 foram aclimatizados por três semanas em bandejas alveoladas, contendo seis substratos (à base de solo, composto termofílico, casca de arroz carbonizada, vermiculita, areia e um substrato comercial, com e sem inoculação micorrízica. No final da aclimatização e dez semanas depois, avaliaram-se a colonização micorrízica, a matéria seca de parte aérea e o comprimento radicular das plantas. A intensidade de colonização micorrízica variou em razão dos porta-enxertos e dos substratos utilizados na aclimatização, havendo interação significativa entre os dois fatores. O substrato comercial proporcionou a maior produção de biomassa, mas promoveu a menor colonização micorrízica em todos os porta-enxertos. As combinações mais favoráveis de produção de biomassa vegetal e de taxa de colonização micorrízica ocorreram no porta-enxerto Paulsen 1103, no substrato à base de solo, composto termofílico e areia e, no porta-enxerto SO4, no substrato à base de solo, composto termofílico e vermiculita.The aim of this work was to select substrates conductive to the establishment of arbuscular mycorrhizas in the production of micropropagated grapevine rootstocks. Micropropagated SO4 and Paulsen 1103 rootstock plantlets were weaned for three weeks in trays with mycorrhizal fungal- inoculated or uninoculated substrates (prepared with soil, compost, calcined rice hulls, vermiculite and sand, besides a commercial substrate. At the end of the weaning period and ten weeks after, shoot and root growth and mycorrhizal root colonization were evaluated. Mycorrhizal root colonization varied according to the rootstock and substrates, with a significant interaction between these factors. The commercial substrate was associated with the highest increase

  6. Determination of callusing performance and vine sapling characteristics on different rootstocks of ‘Merzifon Karası’ grape variety (Vitis vinifera L.)

    Bülent KÖSE; ÇELIK, Hüseyin; Karabulut, Besim


    Grafted vines are the only option while establishing vineyards over the sites contaminated with phylloxera. Furthermore, grafted vines used to establish new vineyards should be well-developed, healthy and compatible with the scions. In this research, we aimed to find out the most suitable rootstock for ‘Merzifon Karası’ using ten rootstocks (140 Ruggeri, 110 R, 99 R, 41B, 5C, 5BB, SO4, 1103 Paulsen 140 Ruggeri and Rupestris du Lot) in 2010 and 2011. The effects on the callusing performance, g...

  7. Thermal requirement and phenology of different cultivars of Vitis labrusca on different rootstocks

    Luciane Bertoletti Barros


    Full Text Available The knowledge of phenological stages and thermal requirement are important in vineyard management because provides information for production and quality of the grapes. This study had the objective to evaluate phenology and thermal demand of the grape cultivars Bordô, Concord, and BRS Carmem on rootstocks Paulsen 1103, IAC 766, and VR 043-43. The experiment was conducted in a family owned vineyard in Campo Largo, Paraná State, Brazil. The vineyard was carried out on ridges with semi-trellis in ‘T’ systems conducting (Geneva Double Curtain trellis. The evaluations were assessed during the production cycles of 2011/2012 and 2012/2013. The phenology was evaluated with a scale of 13 phenological stages. The thermal demand was defined by calculating the degree-days accumulation (DD from bud swelling until harvest stage. The cultivar BRS Carmem had the longest cycle, being influenced by the rootstock, IAC 766 e Paulsen 1103 showed opposite results for cycle time. The cultivar Concord was more stable; there was no influence of rootstock on the cycle or of the thermal demand on the two harvests. The duration of the phenological cycle in 2012/2013 was lower than on the first harvest. Thermal requirement of ‘BRS Carmem’ was influenced by tree different rootstocks, ‘Concord’ was not influenced, and the results to ‘Bordô’ were not consistent.

  8. Insights into aerosol formation chemistry from comprehensive gas-phase precursor measurement in the TRAPOZ chamber experiments; an overview

    Carr, Timo; Wyche, Kevin; Monks, Paul S.; Camredon, Marie; Alam, Mohammed S.; Bloss, William J.; Rickard, Andrew R.


    Aerosols have a profound affect on the environment on local, regional and even global levels, with impacts including adverse health effects, (Alfarra, Paulsen et al. 2006) visibility reduction, cloud formation, direct radiative forcing (Charlson, Schwartz et al. 1992) and an important role in influencing the climate due to their contribution to important atmospheric processes (Baltensperger, Kalberer et al. 2005; Alfarra, Paulsen et al. 2006). The Total Radical Production from the OZonolysis of alkenes (TRAPOZ) project was used to study the gas phase and radical chemistry along with secondary organic aerosol (SOA) formation for a number of different alkenes and terpenes. In order to better the scientific knowledge regarding the oxidation mechanisms of terpene and alkene species along with radical and SOA formation, the experiments were conducted under varying conditions controlled and monitored by the EUropean PHOto REactor (EUPHORE) simulation chamber in Valencia, Spain. A vast number of instruments enabled a detailed examination of the chemistry within oxidation of each precursor. However the work here will focus on the results obtained from the University of Leicester Chemical Ionisation Reaction Time-of-Flight Mass Spectrometer (CIR-TOF-MS). With regard to the gas phase chemistry an analysis of the degradation of the precursor Volatile Organic Compounds (VOCs) and evolution of certain gas phase species in each experiment has been presented and discussed.

  9. Dimethylsulfoniopropionate (DMSP) cell quota of key Southern North Sea spring diatoms and Phaeocystis globosa.

    Speeckaert, Gaëlle; Gypens, Nathalie; Lancelot, Christiane; Borges, Alberto V.


    Dimethylsulfide (DMS) in the ocean results of complex transformations of dimethylsulfoniopropionate (DMSP) produced by phytoplankton under different controls, including microbial transformation pathways. The phytoplankton composition is an important factor of variability due to the species dependence of the DMSP production and conversion to DMS. To better appraise the link between phytoplankton diversity and the DMS(P) cycling in the Southern North Sea we present measurements of the DMSP cell quota of key spring phytoplankton species (Skeletonema costatum, Thalassiosira rotula, Rhizosolenia delicatula, Asterionella glacialis, Nitzschia closterium, Chaetoceros debilis, Chaetoceros socialis and Phaeocystis globosa) isolated from the North Sea and maintained in non-limiting and axenic laboratory culture conditions. Results are discussed with regards to literature data and hypothesis currently used in DMS(P) biogeochemical models.

  10. Continuous harvesting of microalgae by new microfluidic technology for particle separation.

    Hønsvall, Birgitte K; Altin, Dag; Robertson, Lucy J


    A new microfluidic chip based on a trilobite structure, designed for continuously concentrating particles in moving fluids, was investigated as a pre-concentration method for microalgal harvesting. The chip has a 5-μm gap limit and was tested for concentrating the microalgae Rhodomonas baltica, Chaetoceros sp. and Thalassiosira weissflogii. The chip was able to concentrate rigid cells and to sort them according to size. However, optimization with respect to cell properties, such as size and flexibility, needs further work. Although no clogging of the chip was seen for R. baltica and Chaetoceros sp., production of exopolymers by T. weissflogii made harvesting challenging for this species. The Trilobite™ microfluidic chip appears to be a promising tool for pre-concentrating microalgae that are difficult to harvest due to their repelling properties or small size. PMID:26512859

  11. Toxic effects of oil and dispersant on marine microalgae.

    Garr, Amber L; Laramore, Susan; Krebs, William


    To better understand the potential impacts of the deepwater horizon oil spill on lower trophic level food sources, a series of toxicological laboratory experiments were conducted with two microalgae species. The acute toxicity of oil (tar mat and MC252 crude oil), dispersant (Corexit 9500A), and dispersed oil on growth inhibition (IC50) and motility of Isochrysis galbana and Chaetoceros sp. were determined. There was no impact on cell division (growth) for microalgae exposed to both oil types and mean motility of I. galbana never dropped below 79 %. However, the addition of dispersant inhibited cell division and motility within 24 h, with Chaetoceros sp. being more susceptible to sublethal effects than I. galbana. These results highlight microalgae sensitivity to the use of dispersants in bioremediation processes, which may be a concern for long-term impacts on fisheries recruitment. PMID:25283369

  12. Diatom associations in shelf waters off Paraná State, Southern Brazil: annual variation in relation to environmental factors

    Luciano Felício Fernandes; Frederico Pereira Brandini


    The seasonal variation of diatoms in the inshore waters off Paraná State, Southern Brazil was investigated to analyse their temporal dynamics and to detect the main environmental constraints of the planktonic community. Biomass peaks occurred from May to August and from December to March. Among the microplanktonic diatoms, Cerataulina pelagica, Chaetoceros spp., Dactyliosolen fragilissimus, Guinardia striata, Lauderia annulata, Leptocylindrus spp., Pseudo-nitzschia cf. delicatissima, P. austr...

  13. Seasonal changes in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas: General trends based on field survey data 1959-2009

    Yang, Shu; Han, Xiurong; Zhang, Chuansong; Sun, Baiye; Wang, Xiulin; Shi, Xiaoyong


    The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll- a concentration in surface seawater was between 0.4 and 8.5 μg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level (including the nutrient supply from the terrestrial runoffs) was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that diatoms were the main phytoplankton in this area, and Skeletonema costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends: 1) Skeletonema (mainly S. costatum) was dominant throughout the year; and 2) seasonal succession trends were Coscinodiscus (spring) → Chaetoceros (summer and autumn) → Coscinodiscus (winter). The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas: average annual phytoplankton biomass and dinoflagellate

  14. The effects of eight single microalgal diets on sex-ratio and gonad development throughout European flat oyster (Ostrea edulis L.) conditioning

    Gonzales, Ricardo; Quillien, Virgile; Robert, Rene


    To determine the effects of food quality on Ostrea edulis reproduction, European flat oysters were conditioned during two sets of experiments, carried out in spring and autumn, during 40 days at 19 degrees C, in 50 l transparent flow-through tanks, in triplicate, and fed constantly at 900 mu m(3) mu l(-1), with eight different types of microalgae. Four species were fed per group of trials: Isochrysis affinis galbana, Chaetoceros gracilis, Skeletonema marinoi, and Tetraselmis suecica were fed ...

  15. Study On The Phytoplankton And Seasonal Variation Of Lake Simenit (Terme - Samsun, Turkey)

    , Elif Ersanlı; Gönülol, Arif


    The composition and seasonal variations of phytoplankton in Lake Simenit were studied between june 2000 to may 2001. 175 taxa belonging to the Cyanoprokaryota, Bacillariophyta, Chlorophyta, Cryptophyta, Dinophyta, Euglenophyta and Xanthophyta divisions were identified. In the phytoplankton species belonging to the genera of Chaetoceros, Cyclotella, Cocconeis, Scenedesmus, Anabaena, Euglena, Trachelomonas caused water blooms in certain months. The Lake water was light alkaline and it was vari...

  16. Effect of Rhodomonas salina addition to a standard hatchery diet during the early ontogeny of the scallop Pecten maximus

    Tremblay, Rejean; Cartier, Simon; Miner, Philippe; Pernet, Fabrice; Quere, Claudie; Moal, Jeanne; Muzellec, Marie-louise; Mazuret, Michel; Samain, Jean-francois


    The main objective of this study was to identify algal diets that maximize the survival and growth and alter the biochemical content of Pecten maximus larvae with the aim of improving metamorphosis. We also evaluated the potential of the cryptophyceae Rhodomonas salina as a food source for these larvae. Two flagellates, Isochrysis aff. galbana (T) and Pavlova lutheri (P), and two diatoms, Chaetoceros gracilis (C) or Skeletonema costatum (S), were tested as two ternary diets, namely PTC and PT...

  17. Influence of one selected Tisochrysis lutea strain rich in lipids on Crassostrea gigas larval development and biochemical composition

    Da Costa, F.; Petton, Bruno; Mingant, Christian; Bougaran, Gael; Rouxel, Catherine; Quere, Claudie; Wikfors, Gary H.; Soudant, Philippe; Robert, Rene


    Effects of a remarkably high overall lipid Tisochrysis lutea strain (T+) upon gross biochemical composition, fatty acid (FA), sterol and lipid class composition of Crassostrea gigas larvae were evaluated and compared with a normal strain of Tisochrysis lutea (T) and the diatom Chaetoceros neogracile (Cg). In a first experiment, the influence of different single diets (T, T+ and Cg) and a bispecific diet (TCg) was studied, whereas, effects of monospecific diets (T and T+) and bispecific diets ...

  18. Not all calcite ballast is created equal: Differing effects of foraminiferan tests and coccoliths on the aggregation and sinking of diatoms

    De La Rocha, C. L.; Schmidt, K.; Gallinari, M.; Cortese, G.


    There is a strong correlation between sinking fluxes of CaCO3 biominerals and particulate organic carbon (POC), leading to suggestions that sinking fluxes of CaCO3 might control the amount of POC reaching the deep sea. Research has shown that CaCO3 (which is considerably denser than both seawater and particulate organic matter), in the form of coccoliths produced by coccolithophores, can be incorporated into phytoplankton aggregates, reducing their size and POC content but significantly increasing their sinking velocity (W, in m d-1). Coccoliths are, however, not the only form of CaCO3 common in the water column. The tests of foraminiferans represent roughly half of the global flux of CaCO3 to the seafloor and it is unclear what role they play in "carrying" POC to depth. Tests of foraminiferans are commonly large and heavily calcified enough to sink with velocities of 1 km per day. Foraminiferan tests should not accumulate organic matter, as the resulting aggregate should fall apart when subject to the hydrodynamic shear associated with such rapid sinking. To investigate this, thick cultures of the marine diatom Chaetoceros gracilis were placed into 4.5 L cylindrical tanks. Added to the tanks was either no CaCO3, 4.5 mg L-1 of coccoliths, or 4.5 mg L-1 of foraminiferan tests > 250 μm. The tanks were then placed on roller tables to simulate sinking through the water column. Incubation was done in the dark at 16°C for 2 days. Aggregates formed in all treatments. Aggregates in the Chaetoceros-only tanks were the largest and contained the most POC per aggregate. Aggregates in the coccolith tanks were smaller but had higher sinking velocities for their equivalent spherical diameter (ESD, in mm) (W = 678(ESD) + 173; r2 = 0.52) Foraminiferan tests in the foraminiferan tanks absorbed visible but minor amounts of organic matter and sank extremely rapidly (400-700 m d-1). However, most of the POC in the foraminiferan tanks occurred in aggregates that did not contain

  19. Cell transformation mediated by the Epstein-Barr virus G protein-coupled receptor BILF1 is dependent on constitutive signaling

    Lyngaa, Rikke Birgitte; Nørregaard, K.; Kristensen, Martin; Kubale, V.; Rosenkilde, M.M.; Kledal, Thomas N


    Epstein-Barr virus (EBV) open reading frame BILF1 encodes a seven trans-membrane (TM) G protein-coupled receptor that signals with high constitutive activity through G alpha(i) (Beisser et al., 2005; Paulsen et al., 2005). In this paper, the transforming potential of BILF1 is investigated in vitro...... an intermediately active triple-mutated receptor possessed an intermediate transforming potential. Furthermore, BILF1 expression induced vascular endothelial growth factor secretion in a constitutively active manner. In nude mice, BILF1 promoted tumor formation in 90% of cases, ORF74 (from Kaposi......'s sarcoma-associated herpes virus) in 100% of cases, whereas the signaling-deficient receptor resulted in tumor establishment in 40% of cases. These data suggest that BILF1, when expressed during EBV infection, could indeed be involved in the pathogenesis of EBV-associated diseases and malignancies...

  20. From Analog to Digital Medias in Early Childhood Education

    Brandt, Erika Zimmer


    in a mixed-methods design based on field observation and interviews (Frederiksen, Gundelach and Skovgaard Nielsen 2014) Paradigm, methodology and methods Special sensitivity is directed towards how the dialog between children and educators develops, when they use tablets in educational practice. Ethical......Research aims: The aim of the study is to explore how the encounters between children and their educators alter when the media changes from analog to digital. Relationship to previous research works Tablets and other handheld, electronic devices has become part of everyday life in kindergartens....... Research shows that there are both potential pedagogical difficulties and possibilities connected to using digital media (ex. Thestrup 2015, Tække and Paulsen 2014) Theoretical and conceptual framework: The study is a single case study of an educational experiment (Flyvbjerg 2006). It is carried out...

  1. Synchronous correlation matrices and Connes' embedding conjecture

    Dykema, Kenneth J.; Paulsen, Vern


    In the work of Paulsen et al. [J. Funct. Anal. (in press); preprint arXiv:1407.6918">arXiv:1407.6918], the concept of synchronous quantum correlation matrices was introduced and these were shown to correspond to traces on certain C*-algebras. In particular, synchronous correlation matrices arose in their study of various versions of quantum chromatic numbers of graphs and other quantum versions of graph theoretic parameters. In this paper, we develop these ideas further, focusing on the relations between synchronous correlation matrices and microstates. We prove that Connes' embedding conjecture is equivalent to the equality of two families of synchronous quantum correlation matrices. We prove that if Connes' embedding conjecture has a positive answer, then the tracial rank and projective rank are equal for every graph. We then apply these results to more general non-local games.

  2. Videira 'Syrah' sobre diferentes porta-enxertos em ciclo de inverno no sul de Minas Gerais

    Frederico Alcântara Novelli Dias; Renata Vieira da Mota; Ana Carolina Fávero; Eduardo Purgatto; Tânia Misuzu Shiga; Claudia Rita de Souza; Rodrigo Meirelles de Azevedo Pimentel; Murillo de Albuquerque Regina


    O objetivo deste trabalho foi avaliar a influência de porta-enxertos sobre as características agronômicas, ecofisiológicas e qualitativas da videira 'Syrah' manejada por meio da técnica da dupla poda. As videiras foram enxertadas nos porta-enxertos 'SO4', '110 Richter' e '1103 Paulsen', e sustentadas em sistema espaldeira sem irrigação. Foram avaliadas as características ecofisiológicas, de produção e de composição físico-química das bagas maduras em três safras (2007, 2008 e 2010). Os porta-...

  3. How to Steer and Lead Educational Processes in a Digital Medium Environment?

    Tække, Jesper

    This paper is about challenges to steering and leadership of educational interaction in classrooms provided by the new medium environment that comes with digital media. In the new medium environment, the old way of steering what is going on in the classroom appears not to work any more since...... Education (SME), which has worked with possibilities and problems in regard to the digital medium revolution’s disruption of the Danish upper secondary school (Tække & Paulsen 2015a, b, 2014, 2013a, b, c, 2012)....... it was developed in the image of the industrial society and based on a closed classroom. Now with the digital media and wireless networks the classroom is opened and the old way of organizing teaching has become inadequate: The students are disturbed by the new media, instead of learning through them. Inspired...

  4. Synchronous correlation matrices and Connes’ embedding conjecture

    Dykema, Kenneth J., E-mail: [Department of Mathematics, Texas A& M University, College Station, Texas 77843-3368 (United States); Paulsen, Vern, E-mail: [Department of Mathematics, University of Houston, Houston, Texas 77204 (United States)


    In the work of Paulsen et al. [J. Funct. Anal. (in press); preprint arXiv:1407.6918], the concept of synchronous quantum correlation matrices was introduced and these were shown to correspond to traces on certain C*-algebras. In particular, synchronous correlation matrices arose in their study of various versions of quantum chromatic numbers of graphs and other quantum versions of graph theoretic parameters. In this paper, we develop these ideas further, focusing on the relations between synchronous correlation matrices and microstates. We prove that Connes’ embedding conjecture is equivalent to the equality of two families of synchronous quantum correlation matrices. We prove that if Connes’ embedding conjecture has a positive answer, then the tracial rank and projective rank are equal for every graph. We then apply these results to more general non-local games.

  5. Organizational Communication and Media

    Tække, Jesper

      The paper reflects an interest in the relation between organizational communication and media. It tries to answer the question, how we can observe the relationship between organizational communication and media. It is a work-in-progress which tries to combine organizational studies inspired...... of Niklas Luhmann (Tække & Paulsen 2008, Tække 2008a) with analysis of how organizations communicate in and about media. Using systems theory and form theory, it puts forward a theoretical framework and a strategy for analysing organisational communication in and about media. The medium aspect is inspired...... is a possible framework to draw the two disciplines together in, because it is a theory about the relation between the social and the media it is based on. First the paper sum up the Luhmann inspired theory about organizations, fleshing out how organizations are thought to communicate in and about media and how...

  6. First survey of seasonal abundance and daily activity of Stomoxys spp. (Diptera: Muscidae) in Kamphaengsaen Campus, Nakornpathom province, Thailand.

    Masmeatathip, R; Gilles, J; Ketavan, C; Duvallet, G


    The seasonal changes and the daily activity of Stomoxyine species (Diptera: Muscidae) were examined, using Vavoua traps, in a dairy and a beef cattle farm in Nakhonpathom province, Thailand during July 2004 to June 2005. Over this period, Stomoxys calcitrans was the most commonly trapped species, followed by S. sitiens and S. indica. For the later species, this is the first report of its presence in Thailand. A total of 80 % of flies were captured during the rainy season from May to October and 20 % during the dry season from November to April. No major difference of fly density was observed between the dairy and the beef cattle farm. The activity pattern of S. calcitrans was diurnal with a peak between 08:00 am to 10:00 am and another less marked one in the afternoon. The activity pattern of S. sitiens and S. indica was mainly crepuscular with 2 peaks, early in the morning (06:00 a.m.) and late in the afternoon (6:00 p.m.). Those species are important pests of livestock in Thailand, where they are known as a mechanical vector of trypanosomes. A better knowledge of their ecology is a prerequisite for more efficient control measures. PMID:17007217

  7. Efecto de diferentes dietas de microalgas sobre la supervivenci y crecimiento de Apocyclops aff. panamensis (Marsh, 1913 (Copépodo: Cyclopoida cultivado bajo condiciones controladas de laboratorio - Effect of different diets from microalga on supervivenci and growth of Apocyclops aff. panamensis (Marsh, 1913 (Copépodo: Cyclopoida cultivated under controlled conditions of laboratory

    Elifonso Isiordia Perez,


    Full Text Available El presente trabajo fue realizado Julio 2001 con el propósito de evaluar el efecto de diferentes dietas de microalgas sobre la supervivencia y crecimiento (desarrollo de Apocyclops aff. Panamensis. El experimento duró 15 días y se realizó en las instalaciones del Instituto de Ciencias del Mar y Limnología (UNAM Unidad académica Mazatlán Sinaloa. El sistema consistió en un acuario de fibra de vidrio (50x30x40 al cual se agregó 4 litros de agua dulce filtrada 5µ se colocó un termostato para presentar condiciones controladas de temperatura (28ºC, así mismo se mantuvo constante el fotoperiodo (8 horas luz. En el interior del acuario se colocó 1 gradilla con 35 tubos de ensayo con 6 ml de agua salada a 32 ‰ filtrada con luz ultravioleta. Los copépodos fueron colectados en la boca del estero el Yugo Mazatlán, Sinaloa, transportados y aclimatados durante 15 minutos. La siembra consistió en colocar 20 nauplios en estadio II en cada tubo de ensayo. Los tratamientos que se aplicaron como alimento fueron: Chaetoceros sp. + Nannocloropsis sp. (50%:50% (T1, Isochrysis sp. + Nannocloropsis sp. (50%:50% (T2, Chaetoceros sp. + Isochrysis sp. (50%:50% (T3, Chaetoceros sp. (100% (T4, Isochrysis sp. (100% (T5, Nannocloropsis sp. (100% (T6, Chaetoceros sp. + Isochrysis sp. + Nannocloropsis sp. (1:1:1 (T7 cada uno con 5 repeticiones. La densidad de microalgas a suministrar para el presente experimento fue de 50,000 células / mililitro. Al finalizar el estudio solo los copépodos que lograron una supervivencia del 15% hasta copepodito 5 fueron los alimentados con Nanocloropsis sp. (100% y la mayor longitud (0.83 mm se presentó en copépodos alimentados con Chaetoceros sp. (100%, De acuerdo a los resultados se concluye que para lograr mayor crecimiento y supervivencia en el cultivo de copépodos Apocyclops aff. Panamensis se recomienda usar estos tratamientos como alimento. The present work was made July 2001 in order to evaluate the effect of

  8. Intensive aggregate formation with low vertical flux during an upwelling-induced diatom bloom

    Kiørboe, Thomas; Tiselius, P.; Mitchell-Innes, B.;


    The surfaces of most pelagic diatoms are sticky at times and may therefore form rapidly settling aggregates by physical coagulation. Stickiness and aggregate formation may be particularly adaptive in upwelling systems by allowing the retention of diatom populations in the vicinity of the upwelling...... center. We therefore hypothesized that upwelling diatom blooms are terminated by aggregate formation and rapid sedimentation. We monitored the development of a maturing diatom (mainly Chaetoceros spp.) bloom in the Benguela upwelling current during 7 d in February. Chlorophyll concentrations remained...

  9. Effects of BDE-47 on the antioxidase activities of four species of marine microalgae%BDE-47对4种海洋微藻抗氧化酶活性的影响

    孟范平; 李卓娜; 赵顺顺; 刘娇


    运用实验生态学和生物化学的方法,研究了不同质量浓度的2,2',4,4'-四溴联苯醚(BDE-47)对海水小球藻Chlorellaautotropica,牟氏角毛藻Chaetoceros muelleri,中肋骨条藻Skeletonema costatum和赤潮异弯藻Heterosigam akashiwo的抗氧化酶活性的影响.结果表明:在实验设定质量浓度范围内(0.1~2.5 μg·L~(-1)),4种微藻的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)均能出现一定的应激活性,以减少BDE-47胁迫对藻细胞自身的危害,但是酶活增加的幅度却有很大不同.与赤潮异弯藻和中肋骨条藻相比,海水小球藻和牟氏角毛藻的SOD和CAT对BDE-47具有较高的敏感性.4种海洋微藻的SOD和CAT对BDE-47的敏感性顺序依次为:海水小球藻>牟氏角毛藻>中肋骨条藻>赤潮异弯藻.因此,海水小球藻的SOD和CAT可以作为指示海洋环境中BDE-47污染水平的生物标志物.%The toxic effects of 2,2',4,4'-tetrabrominated biphenyl ether (BDE-47) at various concentrations on the activities of anti-oxidases in four species of marine microalgae (Chlorella autotropica, Chaetoceros muelleri, Heterosigam akashiwo and Skeletonema costatum) were examined through experimental ecology and biochemica1 methods. The results indicated that both SOD and CAT activities in the four species were enhanced in various degree to alleviate the oxidative damage from BDE-47 in the concentration range of 0.1~2.5μg·L~(-1). Compared with Heterosigam akashiwo and Skeletonema costatum, Chlorella autotropica and Chaetoceros muelleri were more sensitive to BDE-47 concerning SOD and CAT activities. The sensitivity of the four marine microalgae species to BDE-47 was in the order of Chlorella autotropica > Chaetoceros muelleri > Skeletonema costatum > Heterosigam akashiwo. Therefore, SOD and CAT in Chlorella autotropica could be used as the biomarkers to indicate pollution level of BDE-47 in marine environment.

  10. Efficiency of copper and cupronickel substratum to resist development of diatom biofilms

    Patil, J.S; Anil, A.C.

    for initial days i.e. up to 2 days (Fig. 3a and b). Cluster analyses of the species for all days revealed thatin the case of Cu (6 species - day 1 and 2, 11 species - day 3 and 4) and Cu-Ni (7, 9, 5 and 8 species for days 1, 2, 3 and 4 respectively) species.... pu + + + 4 B. rhombus (Ehrenberg) Smith, W. Bd. rh + + + + + 5 Cerataulina pelagica (Cleve) Hendy Ce. pe + 6 Chaetoceros curvisetus Cleve Ch. cu + + + + + + 7 C. diversus Ehrenberg Ch. dv + 8 C. lorenzianus Grunow Ch. lr + 9 Climacodium...

  11. The community structure and the seasonal changes of phytoplankton in Dayao Bay in Dalian Coast from 2006 to 2007%2006-2007年大连大窑湾海区浮游植物的群落结构及其季节变化

    赵文; 魏洪祥; 郭凯


    于2006年10月至2007年10月,逐月采样研究了大窑湾海区浮游植物的种类组成、密度以及物种多样性.调查结果表明:共发现浮游植物5门42属75种,其中硅藻31属59种,甲藻8属13种,金藻1属1种,蓝藻1属1种,黄藻门1属1种;大窑湾海区浮游植物的生态类型几乎都为温带近岸性物种,个别为暖海性物种或大洋性物种;硅藻在种数和密度上均占优势,主要优势种为旋链角毛藻Chaetoceros curvisetus、中心圆筛藻Coscinodiscus centralis、星脐圆筛藻Coscinodiscus asteromphalus、浮动弯角藻Eucampia zoodicacus、波氏直链藻Melosira borreri、具毒冈比甲藻Gambierdiscus toxicus、刚毛根管藻Rhizosolenia setigera、尖刺拟菱形藻Nitzschia pungens、柔弱角毛藻Chaetoceros debilis;浮游植物密度在2007年的3月和7月出现春、秋两个高峰期,多样性指数为0.36-3.17,平均值为1.65,表明该海区属于中度污染.%The abundance, species composition and biodiversity of phytoplankton were studied in Dayao Bay in Dalian coast from October 2006 to October 2007. A total of 75 species (excluding unidentified ones) , 42 genera and 5 phyla were found in the survey area, including59 species, and 31 genera belonging to Bacillariophyta,8 genera and 13 species belonging to Dinophyta, 1 species and 1 genera belong to Chrysophyta, 1 species belonging to Cyanophyta, and 1 species belonging to Xanthophyta. The dominant species were found in bacillariophyta including Chaetoceros curvisetus, Coscinodiscus centralis, Coscinodiscus asteromphalus, Eucampia zoodkacus, Melosira borreri, Gambierdiscus toxicus, Rhizosolenia, Nitzschia pungens, and Chaetoceros debilis. The cell abundance peaks were observed in March and July of 2007, and the species diversity index was changed from 0.36 to 3.17 with an average of 1.65, indicating that the water quality in this area is meso-pollution.

  12. Humus de lombriz Eisenia foetida para cultivar dos microalgas marinas como alimento de larvas de camarón

    Guerra Aznay, M.


    Para evaluar el extracto líquido de humus de lombriz roja californiana Eisenia foetida como un nuevo medio alternativo de cultivo de las microalgas Tetraselmis tetrathele y Chaetoceros muelleri, se probaron cuatro diluciones (EH50, EH200, EH350 y EH500 mL) empleando como control al medio f/2 Guillard (MG). Las concentraciones celulares de T. tetrathele no mostraron diferencias (p>0.05) entre el tratamiento MG y el tratamiento EH200 mL. Los valores medios ± DS fueron de...

  13. Alternativa de biofertilizante como medio de cultivo para el crecimiento poblacional de dos microalgas marinas empleadas en la camaronicultura

    Guerra Aznay, M.; Pérez Jar, L.; Leal Lorenzo, S.; Jaime Ceballos, B.; Jiménez Cabrera, R.; Pérez Díaz, S.; Bobadilla González, J.


    Con el propósito de evaluar el humus de lombriz roja californiana Eisenia foetida como biofertilizante para el crecimiento poblacional de dos microalgas marinas, fueron cultivadas Tetraselmis tetrathele y Chaetoceros muelleri en agua de mar enriquecida con cuatro diluciones (50; 200; 350 y 500 mL) de extracto líquido de humus. La especie T. tetrathele, cultivada en la dilución de 200 mL, no mostró diferencias con el patrón medio f/2 Guillard para los parámetros: concentración celu...

  14. Water relations of field-grown grapevines in the São Francisco Valley, Brazil, under different rootstocks and irrigation strategies Relações hídricas de videiras cultivadas no Vale do São Francisco sob diferente porta-enxertos e estratégias de irrigação

    Claudia Rita de Souza


    Full Text Available There is an increased demand for high quality winegrapes in the São Francisco Valley, a new wine producing area in Brazil. As the grape quality is closely linked to the soil water status, understanding the effects of rootstock and irrigation management on grapevine water relations is essential to optimize yield and quality. This study was carried out to investigate the effects of irrigation strategies and rootstocks on water relations and scion vigour of field-grown grapevines in Petrolina, Pernambuco state, Brazil. The cultivars used as scions are Moscato Canelli and Syrah, both grafted onto IAC 572 and 1103 Paulsen rootstocks. The following water treatments were used: deficit irrigation, with holding water after veraison; and partial root-zone drying, supplying (100% of crop evapotranspiration of the water loss to only one side of the root system after fruit set, alternating the sides periodically (about 24 days. In general, all treatments had values of pre-dawn leaf water potential higher than -0.2 MPa, suggesting absence of water stress. The vine water status was more affected by rootstock type than irrigation strategies. Both cultivars grafted on IAC 572 had the highest values of midday leaf water potential and stem water potential, measured on non-transpiring leaves, which were bagged with both plastic sheet and aluminum foil at least 1 h before measurements. For both cultivars, the stomatal conductance (g s, transpiration (E and leaf area index (LAI were also more affected by roostsotck type than by irrigation strategies. The IAC 572 rootstock presented higher g s, E and LAI than the 1103 Paulsen. Differences in vegetative vigor of the scion grafted onto IAC 572 rootstocks were related to its higher leaf specific hydraulic conductance and deeper root system as compared to the 1103 Paulsen, which increased the water-extraction capability, resulting in a better vine water status.Existe aumento na demanda por vinhos de alta qualidade no

  15. Fungal parasites infect marine diatoms in the upwelling ecosystem of the Humboldt current system off central Chile.

    Gutiérrez, Marcelo H; Jara, Ana M; Pantoja, Silvio


    This is the first report of fungal parasitism of diatoms in a highly productive coastal upwelling ecosystem, based on a year-round time series of diatom and parasitic Chytridiomycota abundance in the Humboldt Current System off Chile (36°30.80'S-73°07.70'W). Our results show co-variation in the presence of Skeletonema, Thalassiosira and Chaetoceros diatoms with attached and detached chytrid sporangia. High abundance of attached sporangia was observed during the austral spring, coinciding with a predominance of Thalassiosira and Skeletonema under active upwelling conditions. Towards the end of austral spring, a decreasing proportion of attached sporangia was accompanied by a decline in abundance of Skeletonema and Thalassiosira and the predominance of Chaetoceros, suggesting specificity and host density dependence of chytrid infection. The new findings on fungal parasitism of diatoms provide further support for the inclusion of Fungi in the current model of the role played by the marine microbial community in the coastal ocean. We propose a conceptual model where Fungi contribute to controlling the dynamics of phytoplankton populations, as well as the release of organic matter and the transfer of organic carbon through the pelagic trophic web in coastal upwelling ecosystems. PMID:26914416

  16. Quantification of diatom gene expression in the sea by selecting uniformly transcribed mRNA as the basis for normalization.

    Kang, Lee-Kuo; Tsui, Feng-Hsiu; Chang, Jeng


    To quantify gene expressions by quantitative reverse transcription-PCR (Q-RT-PCR) in natural diatom assemblages, it is necessary to seek a biomass reference specific to the target species. Two housekeeping genes, TBP (encoding the TATA box-binding protein) and EFL (encoding the translation elongation factor-like protein), were evaluated as candidates for reference genes in Q-RT-PCR assays. Transcript levels of TBP and EFL were relatively stable under various test conditions including growth stages, light-dark cycle phases, and nutrient stresses in Skeletonema costatum and Chaetoceros affinis, and TBP expression was more stable than that of EFL. Next, the sequence diversity of diatom assemblages was evaluated by obtaining 32 EFL and 29 TBP homologous gene fragments from the East China Sea (ECS). Based on sequence alignments, EFL and TBP primer sets were designed for Chaetoceros and Skeletonema groups in the ECS. An evaluation of primer specificity and PCR efficiency indicated that the EFL primer sets performed better. To demonstrate the applicability of EFL primer sets in the ECS, they were employed to measure mRNA levels of the FcpB (fucoxanthin-chlorophyll protein) gene in diatoms. The results correctly revealed prominent diel variations in FcpB expression and confirmed EFL as a good reference gene. PMID:22706063

  17. 三沙湾渔业水域理化因子与赤潮生物的关系研究%Distribution features and relation of red tide organisms environment factors in Sansha Bay



    根据2009年和2010年4~10月份对三沙湾海域生态环境调查,共鉴定浮游植物118种,其中硅藻门有36属93种,甲藻门12属25种,主要的优势种为中肋骨条藻(Skeletonema costatum)、诺氏海链藻(Thalassiosira nordenskiotdi)、具槽直链藻(Melosira sulcata)、旋链角毛藻(Chaetoceros curvisetus)、冕孢角毛藻(Chaetoceros subsecumdus)、柔弱拟菱形藻(Pseudo-nitzschia delicatissma)及东海原甲藻(Prorocentrum donghaiense).回归相关性分析表明,湾内浮游植物的分布季节和丰度受到多种环境理化因子的影响,水体pH、DO、COD、Chl-a对赤潮发生期间环境状况及赤潮的发生和发展具有明显的指示作用;尤其在6~8月间与赤潮生物细胞数之间存在显著性相关关系.

  18. Assessment of endemic microalgae as potential food for Artemia franciscana culture

    Juan M Pacheco-Vega


    Full Text Available In this study, five microalgal strains were isolated from Bahía de La Paz, Baja California Sur, Mexico and identified as Grammatophora sp., Navícula sp., Rhabdonema sp., Schizochytrium sp., and Nitzschia sp., and their evaluation as potential food for Artemia franciscana. The isolated strains were cultured outdoors and harvested after four days. Chaetoceros muelleri was cultured under laboratory conditions and used as control. The protein, lipid, and carbohydrate composition and the fatty acid profiles of the strains were determined by gas chromatography. To assess the effect of microalgal strains on A. franciscana, decapsulated cysts were cultured at outdoor conditions in 15 L containers. The experiment was conducted for twelve days. Samples from the five different feeding treatments were taken at the beginning and end of the experiment to assess number, size, and weight of Artemia larvae. Treatment with Rhabdonema sp. showed larvae with a lower percentage of polyunsaturated fatty acids (PUFAs while Grammatophora sp. showed those with the greatest PUFA proportion, even more than those fed Chaetoceros muelleri (control. Larvae consuming Schizochytrium sp. had no docosahexanoic (DHA nor eicosapentaenoic (EPA fatty acid content. Growth and survival of A. franciscana did not show significant differences among feed treatments, except when it was fed Nitzschia sp., showing lower survival and dry weight. Treatment based on Schizochytrium sp. and Rhabdonema sp. had a greater A. franciscana size but reduced dry weight; additional tests including two or more algal species for every treatment should be carried out to determine the best yield.

  19. Discrimination of phytoplankton classes using characteristic spectra of 3D fluorescence spectra

    Zhang, Qian-Qian; Lei, Shu-He; Wang, Xiu-Lin; Wang, Lei; Zhu, Chen-Jian


    The discrimination of phytoplankton classes using the characteristic fluorescence spectra extracted from three-dimensional fluorescence spectra was investigated. Single species cultures of 11 phytoplankton species, representing 5 major phytoplankton divisions, were used. The 3D fluorescence spectra of the cultures grown at different temperatures (20 and 15 °C) and illumination intensities (140, 80 and 30 μM m -2 s -1) were measured and their feature extraction methods were explored. Ordering Rayleigh and Raman scattering data as zero, the obtained excitation-emission matrices were processed by both singular value decomposition (SVD) and trilinear decomposition methods. The resulting first principal component can be regarded as the characteristic spectrum of the original 3D fluorescence spectrum. The analysis shows that such characteristic spectra have a discriminatory capability. At different temperatures, the characteristic spectra of Isochrysis galbana, Platymonas helgolanidica and Skeletonema costatuma have high degrees of similarity to their own species samples, while the spectra similarities of Alexandrium tamarense, Prorocentrum dentatum, Pseudo-nitzschia pungens, Chaetoceros curvisetus, Ch. Debilis, Ch. Didymus and Synechococcus sp. are not as significant as the other three species. C. curvisetus, Ch. Debilis and Ch. Didymus, belonging to genus Chaetoceros, have identical spectra and cannot be discriminated at all. Regarding all six diatom species as one class, the average discriminant error rate is below 9%. It is worth mentioning that the diatom class can be distinguished from A. tamarense and P. dentatum, which belong to Dinophyta.

  20. Genetic sexing strains for four species of insects

    Genetic sexing strains were assembled by using classical genetic and cytogenetic techniques for four medically important species of insects. Male linked reciprocal translocations were used to impose pseudolinkage of sex and selectable genes (shown in parentheses) for Anopheles albimanus (propoxur resistance), Anopheles quadrimaculatus sp. A (malathion resistance), Stomoxys calcitrans (dieldrin resistance; malathion resistance, and black pupa), and Musca domestica (black pupa). These strains would be of great value in implementation of the sterile insect technique for control of these species because the females can either be killed in the egg stage (in the case of insecticide resistance as the selectable gene) or they can be separated from the males and thus excluded from releases. (author). 13 refs

  1. Exploratory trial to determine the efficacy of the PYthon and the PYthon Magnum slow-release insecticide ear tags for the control of midges (Culicoides spp.), attacking sheep and cattle and flies attacking cattle.

    Goosen, H; de Vries, P J T; Fletcher, M G


    This study investigated the prophylactic action of the chemical combination zeta-cypermethrin and piperonyl butoxide, administered by means of slow-release insecticide-impregnated ear tags, against biting midges (Culicoides spp) attacking sheep and against midges, horn flies (Haematobia irritant), stable flies (Stomoxys calcitrans), and houseflies (Musca domestica) attacking cattle. Treated sheep and cattle were protected 100 percent against blood-feeding midges for two months and there was a clear reduction in the number of midges collected from treated animals. Three days after the ear tags were attached to cattle, the number of horn flies on the cattle was reduced to practically zero and remained at a low level until the end of the trial (day 85). There was also a strong reduction in the numbers of stable flies and houseflies counted. PMID:22930983

  2. Transferability of HIV by arthropods supports the hypothesis about transmission of the virus from apes to man

    Eigen, Manfred; Kloft, Werner; Brandner, Gerhard


    The primate Pan troglodytes troglodytes, a chimpanzee subspecies, has recently been defined as a natural animal host of the human immunodeficiency virus (HIV). Apes are traditionally hunted in Africa and are offered for sale in open-air meat markets. The bloody carcasses are regularly covered with blood-feeding flies, amongst them possibly the stable fly (Stomoxys calcitrans L.), a cosmopolitically occurring biting fly. This fly is the effective vector for the retrovirus causing equine leukemia. According to laboratory experiments, the infectivity of ingested HIV is not reduced in the regurgitates of this fly. These findings are combined to explain the mechanism for a possible primary transmission of HIV from ape to man.

  3. Behavioural responses of stable flies to cattle manure slurry associated odourants.

    Tangtrakulwanich, K; Albuquerque, T A; Brewer, G J; Baxendale, F P; Zurek, L; Miller, D N; Taylor, D B; Friesen, K A; Zhu, J J


    Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundance of stable flies increased significantly in grasslands or crop fields when cattle manure slurry was applied. Major volatile compounds emanating from manure slurry were collected and identified. Behavioural responses of stable flies to those compounds were investigated in laboratory bioassays and field-trapping studies. Results from olfactometer assays revealed that phenol, p-cresol and m-cresol were attractive to adult stable flies. When tested individually, attraction was higher with lower dosages. Stable flies were most attracted to blends of phenol and m-cresol or p-cresol. Traps with binary blend lures caught more stable flies in field trials as well. PMID:25557192

  4. Salivary gland hypertrophy virus of house flies in Denmark: Prevalence, host range, and comparison with a Florida isolate

    Geden, C. J.; Steenberg, T.; Lietze, V.-U.;


    House flies (Musca domestica) infected with Musca domestica salivary gland hypertrophy virus (MdSGHV) were found in fly populations collected from 12 out of 18 Danish livestock farms that were surveyed in 2007 and 2008. Infection rates ranged from 0.5% to 5% and averaged 1.2%. None of the stable...... flies (Stomoxys calcitrans), rat-tail maggot flies (Eristalis tenax) or yellow dung flies (Scathophaga stercoraria) collected from MdSGHV-positive farms displayed characteristic salivary gland hypertrophy (SGH). In laboratory transmission tests, SGH symptoms were not observed in stable flies, flesh...... flies (Sarcophaga bullata), black dump flies (Hydrotaea aenescens), or face flies (Musca autumnalis) that were injected with MdSGHV from Danish house flies. However, in two species (stable fly and black dump fly), virus injection resulted in suppression of ovarian development similar to that observed in...

  5. Dicty_cDB: Contig-U09065-1 [Dicty_cDB

    Full Text Available ection 1... 36 8.7 10 ( CU280045 ) S.lycopersicum DNA sequence from clone SL_MboI-98... 38 8.8 5 ( AY068783 ) Schmidtea mediterran...lone list U09065 List of clone(s) est1= SFH875F ,1,470 est2= SFH875Z ,471,1180 Translated Amino Acid sequence cwptgia...348( CR382131 |pid:none) Yarrowia lipolytica strain CLIB... 129 7e-31 CU633900_534( CU633900 |pid:none) Podospora ans...... 118 5e-28 CU928171_8( CU928171 |pid:none) Kluyveromyces thermotolerans strai....mRNA fo... 42 0.033 EZ048843_1( EZ048843 |pid:none) TSA: Stomoxys calcitrans SC-4-2-3 ... 42 0.033 AE014297_

  6. Dihydronepetalactones deter feeding activity by mosquitoes, stable flies, and deer ticks.

    Feaster, John E; Scialdone, Mark A; Todd, Robin G; Gonzalez, Yamaira I; Foster, Joseph P; Hallahan, David L


    The essential oil of catmint, Nepeta cataria L., contains nepetalactones, that, on hydrogenation, yield the corresponding dihydronepetalactone (DHN) diastereomers. The DHN diastereomer (4R,4aR,7S,7aS)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 1) was evaluated as mosquito repellent, as was the mixture of diastereomers {mostly (4S,4aR,7S,7aR)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 2} present after hydrogenation of catmint oil itself. The repellency of these materials to Aedes aegypti L. and Anopheles albimanus Wiedemann mosquitoes was tested in vitro and found to be comparable to that obtained with the well-known insect repellent active ingredient N,N-diethyl-3-methylbenzamide (DEET). DHN 1 and DHN 2 also repelled the stable fly, Stomoxys calcitrans L., in this study. DHN 1, DHN 2, and p-menthane-3,8-diol (PMD), another natural monoterpenoid repellent, gave comparable levels of repellency against An. albimanus and S. calcitrans. Laboratory testing of DHN 1 and DHN 2 using human subjects with An. albimanus mosquitoes was carried out. Both DHN 1 and DHN 2 at 10% (wt:vol) conferred complete protection from bites for significant periods of time (3.5 and 5 h, respectively), with DHN2 conferring protection statistically equivalent to DEET. The DHN 1 and DHN 2 diastereomers were also efficaceous against black-legged tick (Ixodes scapularis Say) nymphs. PMID:19645285

  7. Controle químico da forma galícola da filoxera Daktulosphaira vitifoliae (Fitch, 1856 (Hemiptera: Phylloxeridae na cultura da videira Chemical control of grape phylloxera Daktulosphaira vitifoliae (Fitch, 1856 leaf form (Hemiptera: Phylloxeridae on vineyards

    Marcos Botton


    Full Text Available A filoxera Daktulosphaira vitifoliae (Fitch, 1856 (Hemiptera: Phylloxeridae é considerada a principal praga da videira. O inseto se alimenta da parte aérea e raízes sendo que os maiores prejuízos são observados em raízes de Vitis vinifera cultivada como pé-franco. O dano nas folhas é importante em viveiros, quando o ataque ocorre nos ramos utilizados como porta-enxertos, resistentes à forma radícola. Este trabalho foi realizado com o objetivo de selecionar inseticidas que possam ser empregados como substitutos aos fosforados e piretróides no manejo da forma galícola da filoxera. Os inseticidas imidacloprid, thiamethoxam, acephate, abamectin, deltamethrin e fenitrothion, foram avaliados em condições de campo, sob infestação natural, em plantas matrizes do porta-enxerto Paulsen 1103. Imidacloprid (Provado 200 SC, 40mL 100L-1 e thiamethoxam (Actara 250 WG, 30g 100L-1 reduziram as injúrias causadas pela forma galícola da filoxera nos ponteiros em nível superior a 90%, proporcionando controle superior aos inseticidas deltamethrin (Decis 25 CE, 40mL 100L-1 e fenitrothion (Sumithion 500 CE, 150 mL/100L considerados referência no controle do inseto. Os inseticidas acephate (Orthene 750 BR, 100g 100L-1 e abamectin (Vertimec 18 CE, 80mL 100L-1 não foram eficientes.Grape phylloxera Daktulosphaira vitifoliae (Fitch, 1856 (Hemiptera: Phylloxeridae is the main grape pest. Adults and nymphs feeds on leaves and roots but major damage is observed on roots of own rooted Vitis vinifera. Damage on leaves is important in root stock nurseries where chemical control is necessary. This study was conducted to evaluate insecticides to control the leaf form in a Paulsen 1103 nursery in field condictions. Imidacloprid (Provado 200 SC, 40mL 100L-1 and thiamethoxam (Actara 250 WG, 30g 100L-1 reduced foliar damage in more than 90%, providing better control than deltamethrin (Decis 25 CE, 40mL 100L-1 and fenitrothion (Sumithion 500 CE, 150mL 100L-1 current

  8. Sparse Matrix Decompositions and Graph Characterizations

    Khare, Kshitij


    The question of when zeros (i.e., sparsity) in a positive definite matrix $A$ are preserved in its Cholesky decomposition, and vice versa, was addressed by Paulsen et al. in the Journal of Functional Analysis (85, pp151-178). In particular, they prove that for the pattern of zeros in $A$ to be retained in the Cholesky decomposition of $A$, the pattern of zeros in $A$ has to necessarily correspond to a chordal (or decomposable) graph associated with a specific type of vertex ordering. This result therefore yields a characterization of chordal graphs in terms of sparse positive definite matrices. It has also proved to be extremely useful in probabilistic and statistical analysis of Markov random fields where zeros in positive definite correlation matrices are intimately related to the notion of stochastic independence. Now, consider a positive definite matrix $A$ and its Cholesky decomposition given by $A = LDL^T$, where $L$ is lower triangular with unit diagonal entries, and $D$ a diagonal matrix with positive...

  9. Note: A top-view optical approach for observing the coalescence of liquid drops

    Wang, Luhai; Zhang, Guifu; Wu, Haiyi; Yang, Jiming; Zhu, Yujian


    We developed a new device that is capable of top-view optical examination of the coalescence of liquid drops. The device exhibits great potential for visualization, particularly for the early stage of liquid bridge expansion, owing to the use of a high-speed shadowgraph technique. The fluid densities of the two approaching drops and that of the ambient fluid are carefully selected to be negligibly different, which allows the size of the generated drops to be unlimitedly large in principle. The unique system design allows the point of coalescence between two drops to serve as an undisturbed optical pathway through which to image the coalescence process. The proposed technique extended the dimensionless initial finite radius of the liquid bridge to 0.001, in contrast to 0.01 obtained for conventional optical measurements. An examination of the growth of the bridge radius for a water and oil-tetrachloroethylene system provided results similar to Paulsen's power laws of the inertially limited viscous and inertial regimes. Furthermore, a miniscule shift in the center of the liquid bridge was detected at the point of crossover between the two regimes, which can be scarcely distinguished with conventional side-view techniques.

  10. Pruning management of Chardonnay grapevines at high altitude in Brazilian southeast

    Tania dos Reis Mendonça


    Full Text Available ABSTRACT The agronomical responses of Chardonnay, a variety indicated for sparkling wine production, is influenced by the vineyard management and the edaphoclimatic conditions of the region. The objective of this study was to evaluate the effects of two pruning types (Royat and double Guyot on vegetative and reproductive development of Chardonnay vine growing at high altitude in the Brazilian southeastern region. The experiment was carried out in a commercial vineyard located at 1,280 m of altitude in Divinolândia, São Paulo State, Brazil. The Chardonnay vines (clone 96, grafted onto 1103 Paulsen rootstock and trained in a vertical shoot positioning trellis system, were assessed. Vegetative vigor, bud fruitfulness, production and physicochemical composition of grapes were evaluated during 2014 and 2015 growing seasons. The Royat pruning induced higher vegetative vigor and increased the bud fruitfulness, the cluster number and the productivity of Chardonnay vine when compared to Guyot pruning. Even though the increase on yield was observed, there was no effect of pruning type on grape final quality. Therefore, the choice of pruning method in function of variety genetic characteristics and their interaction with environment can optimize the vineyard profitability. In the Brazilian southeast, the Royat system is the most suitable one to grow Chardonnay for sparkling wines production.

  11. 厦门东侧海域浮游植物的种类组成与分布%Species composition and distribution of phytoplankton in eastern Xiamen waters

    杨清良; 林更铭; 蔡秉及


    共鉴定厦门东侧海域浮游植物43属111种.其主体是广温性种类(56种),占浮游植物总种数的50%.主要优势种的季节性演替明显.四季浮游植物的平均细胞总量达36 500千个/m3,最重要的优势种是旋链角毛藻(Chaetoceros curvisetus)(占总量的53.3%)和中肋骨条藻(Skeletonema costatum)(占20.0%).浮游植物的繁盛时期在春、夏两季,但高峰期出现在春季,不同于相邻的厦门外港和厦门西港.

  12. Ecological composition and distribution of the diatoms from the Laguna Superior, Oaxaca, Mexico.

    Moreno-Ruiz, José Luis; Tapia-Garcia, Margarito; Licea, Sergio; Figueroa-Torres, María Guadalupe; Esquivel, Alfonso; Herrera-Galindo, Jorge Eduardo; González-Fernández, José Manuel; González-Macias, Maria Del Carmen


    A taxonomic study of diatoms was carried out in a tropical coastal lagoon. Material for this study consists of water samples obtained from February-March 1992 to November-December 2000. Qualitative and quantitative analyses showed the presence of 373 taxa of which the families Bacillariaceae (67 species) and Chaetocerotaceae (37 species) were the most abundant groups. The species Skeletonema costatum, Chaetoceros curvisetus, Coscinodiscus radiatus var. radiatus, Ditylum brightwellii, Thalassiosira eccentrica and Entomoneis alata were found associated with moderate water quality and forming blooms. In addition, a regional comparison between Mexico and South America of the identified species is given. For practical handling, indicative values obtained from their ecological composition are incorporated as well as a code of the floristic list. Achecklist of the species and their occurrence are given. PMID:22315822

  13. Seasonal distribution and correlates of transparent exopolymer particles (TEP) in the waters surrounding mangroves in the Sundarbans

    Chowdhury, Chumki; Majumder, Natasha; Jana, Tapan Kumar


    In situ concentration of transparent exopolymer particles (TEP) are usually associated with phytoplankton dominated by diatoms and their release of precursor polysaccharide material in the aquatic system. Here, we present temporal data on TEP variation and related habitat parameters for waters surrounding mangroves in the Sundarbans located at the coastal boundary of the Ganges River delta. Over three study years (2009-2011), TEP concentration was highest during the post-monsoon period and was mainly a function of phytoplankton production. The most common diatom species (by percentage of relative abundance) were Skeletonema cf. costatum (Cleve 1873), Ditylum brightwellii (Gosse 1850), and Chaetoceros sp. During the post-monsoon, when phytoplankton was abundant TEP/Chl-a ratio was relatively low and as nutrients depleted from water, phytoplankton biomass declined subsequently, increasing mean TEP/Chl-a ratio in the pre-monsoon.

  14. Diatom associations in shelf waters off Paraná State, Southern Brazil: annual variation in relation to environmental factors

    Luciano Felício Fernandes


    Full Text Available The seasonal variation of diatoms in the inshore waters off Paraná State, Southern Brazil was investigated to analyse their temporal dynamics and to detect the main environmental constraints of the planktonic community. Biomass peaks occurred from May to August and from December to March. Among the microplanktonic diatoms, Cerataulina pelagica, Chaetoceros spp., Dactyliosolen fragilissimus, Guinardia striata, Lauderia annulata, Leptocylindrus spp., Pseudo-nitzschia cf. delicatissima, P. australis, Rhizosolenia spp., Skeletonema costatum and Thalassionema nitzschioides were dominant species. Nanoplanktonic diatoms were dominated by Naviculaceae, Nitzschia spp., Thalassiosira spp. and Chaetoceros cf. tenuissimus. Concentrations of most of the species decreased during and just after the blooms of Phaeocystis pouchetii in September and of Coscinodiscus wailesii in April. Based on cluster analysis and interpretations of the environmental parameters monitored, six diatom associations were discerned. Four main environmental factors were attributed as the determinants for the grouping: (a the stronger influence of the tropical oligotrophic waters of the Brazil Current in spring/summer, (b the alternation between dry and rainy (nutrient-richer seasons, (c the influence of subantarctic waters mixed with coastal ones in fall/winter, bringing cold species and promoting the growth of autochthonous species, and (d the blooms of nanoplanktonic (Phaeocystis and microplanktonic (C. wailesii species.A variação sazonal das diatomáceas em águas neríticas do estado do Paraná, Sul do Brasil, foi investigada para analisar sua dinâmica temporal e detectar as principais forçantes ambientais da comunidade planctônica. Picos de biomassa ocorreram de Maio a Agosto e de Dezembro a Março. As espécies dominantes foram Cerataulina pelagica, Chaetoceros spp., Dactyliosolen fragilissimus, Guinardia striata, Lauderia annulata, Leptocylindrus spp., Pseudo-nitzschia cf


    Lifanchuk A. V.


    Full Text Available In this article we present data on the effect of addition of mineral nutrition elements in the structure of the phytoplankton community in the north-eastern part of the Black Sea in the different seasons. Experimental studies have shown that the increase in biomass of microalgae occurs at the simultaneous addition of nitrogen and phosphorus in the accumulative cultures. In the spring can get biomass Emiliania huxleyi, P.pseudodelicatissima, Chaetoceros curvisetus and Skeletonema costatum, in the summer – E. huxleyi, C. curvisetus, P.pseudodelicatissima, S.costatum, Thalassionema nitzschioides, Leptocylindrus danicus, Dactyliosolen fragilissimus, Proboscia alata, Pseudosolenia calcar-avis, in the autumn - C. curvisetus, S.costatum, Th. nitzschioides, L. danicus, D. fragilissimus

  16. The evaluation of fish farming impact by nutrient content and chlorophyll A in Mala Lamljana bay

    Jelic-Mrcelic Gorana


    Full Text Available This paper offers a brief review of the impacts of fish farming on the nutrient content and chlorophyll a in Mala Lamljana Bay, Croatia. Local loading of nitrogen and phosphorous compounds in fish farms can be very significant and can represent the largest source of N and P in a given area. Low N and P concentrations, low chlorophyll a concentration and a great variety of phytoplankton species were found in the bay, despite the high nutrient loading during the long history of farming in the bay. The phytoplankton community consisted mostly of diatoms and partly of dinoflagellates. Skeletonema costatum and Chaetoceros compressus were the dominant species (90% in summer chlorophyll, which is typical for Middle Adriatic oligotrophic coastal waters. Nevertheless, further studies are required to determine changes in water column factors and planktonic communities in this area.

  17. Microzooplankton Grazing Impact on Phytoplankton Blooms in the Coastal Seawater of the Southern Crimea (Black Sea

    L.V. Stelmakh


    Full Text Available The investigation of seasonal dynamics of microzooplankton specific grazing rate was carried out in the near-shore sea off the southern Crimea (Black Sea during 2006~2007 and 2010. It is shown that microzooplankton grazing depended on the abundance and quality of prey. The favorite prey items were diatoms Skeletonema costatum and Chaetoceros spp. When microzooplankton grazed less than 80% of the primary production, the peaks of phytoplankton biomass were recorded in this study. The average annual removal of primary production by microzooplankton was estimated as weighty as 65%. Such estimated values indicate the key role of the microzooplankton in exporting matter and energy from phytoplankton to higher trophic levels.

  18. The influence of extracellular compounds produced by selected Baltic cyanobacteria, diatoms and dinoflagellates on growth of green algae Chlorella vulgaris

    Żak, Adam; Kosakowska, Alicja


    Secondary metabolites produced by bacteria, fungi, algae and plants could affect the growth and development of biological and agricultural systems. This natural process that occurs worldwide is known as allelopathy. The main goal of this work was to investigate the influence of metabolites obtained from phytoplankton monocultures on the growth of green algae Chlorella vulgaris. We selected 6 species occurring in the Baltic Sea from 3 different taxonomic groups: cyanobacteria (Aphanizomenon flos-aquae; Planktothrix agardhii), diatoms (Thalassiosira pseudonana; Chaetoceros wighamii) and dinoflagellates (Alexandrium ostenfeldii; Prorocentrum minimum). In this study we have demonstrated that some of selected organisms caused allelopathic effects against microalgae. Both the negative and positive effects of collected cell-free filtrates on C. vulgaris growth, chlorophyll a concentration and fluorescence parameters (OJIP, QY, NPQ) have been observed. No evidence has been found for the impact on morphology and viability of C. vulgaris cells.

  19. Simulated terrestrial runoff triggered a phytoplankton succession and changed seston stoichiometry in coastal lagoon mesocosms.

    Deininger, A; Faithfull, C L; Lange, K; Bayer, T; Vidussi, F; Liess, A


    Climate change scenarios predict intensified terrestrial storm runoff, providing coastal ecosystems with large nutrient pulses and increased turbidity, with unknown consequences for the phytoplankton community. We conducted a 12-day mesocosm experiment in the Mediterranean Thau Lagoon (France), adding soil (simulated runoff) and fish (different food webs) in a 2 × 2 full factorial design and monitored phytoplankton composition, shade adaptation and stoichiometry. Diatoms (Chaetoceros) increased four-fold immediately after soil addition, prymnesiophytes and dinoflagellates peaked after six- and 12 days, respectively. Soil induced no phytoplankton shade adaptation. Fish reduced the positive soil effect on dinoflagellates (Scripsiella, Glenodinium), and diatom abundance in general. Phytoplankton community composition drove seston stoichiometry. In conclusion, pulsed terrestrial runoff can cause rapid, low quality (high carbon: nutrient) diatom blooms. However, bloom duration may be short and reduced in magnitude by fish. Thus, climate change may shift shallow coastal ecosystems towards famine or feast dynamics. PMID:27209121

  20. Pyrolytic characteristics of biodiesel prepared from lipids accumulated in diatom cells with growth regulation.

    Cheng, Jun; Feng, Jia; Ge, Tingting; Yang, Weijuan; Zhou, Junhu; Cen, Kefa


    Dynamic compositions of lipids accumulated in two diatoms Chaetoceros gracilis and Nitzschia closterium cultured with nitrogen and silicon deprivation were studied. It was found that short-chain fatty acids (C14-C16) content was much higher than long-chain fatty acids (C18-C20) content in lipids of two diatoms. The pyrolytic characteristics of biodiesel made from two diatoms and two plant seeds were compared by thermogravimetric analysis. The highest activation energy of 46.68 kJ mol(-1) and the minimum solid residue of 25.18% were obtained in the pyrolysis of biodiesel made from C. gracilis cells, which were cultured with 0.5 mmol L(-1) of nitrogen (no silicon) and accumulated the minimum polyunsaturated fatty acid (C20:5). The pyrolysis residue percentage of C. gracilis biodiesel was lower than that of N. closterium biodiesel and higher than those of plant (Cormus wilsoniana and Pistacia chinensis) biodiesels. PMID:25782618

  1. Persistent blooms of surf diatoms along the pacific coast U. S. A. I. physical characteristics of the coastal region in relation to the distribution and abundance of the species

    Garver, J.L.; Lewin, J.


    The surf diatom populations at thirteen beaches along the Oregon and Washington coast were studied from June 1977 through August 1978. Chaetoceros armatum T. West and Asterionella socialis Lewin and Norris, the two species responsible for the blooms, were present in the surf along beaches between Point Grenville, Washington, and Cape Blanco, Oregon. On the basis of the cell densities of these two species, the beaches were arranged into four distinct groups. Discriminant analysis showed that the four groups could also be completely separated by three discriminant functions composed of four physical variables: offshore bottomslope, per cent chlorite, per cent montmorillonite and beach length. The absence of surf diatoms at two beaches south of Cape Blanco can probably be explained by the unsuitable physical conditions along the coast south of the Cape.

  2. Phenotypic plasticity of southern ocean diatoms: key to success in the sea ice habitat?

    Olivia Sackett

    Full Text Available Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseudo-nitzschia subcurvata exhibited phenotypic plasticity in response to salinity and temperature regimes experienced during the seasonal formation and decay of sea ice. The degree of phenotypic plasticity, in terms of changes in macromolecular composition, was highly species-specific and consistent with each species' known distribution and abundance throughout sea ice, meltwater and pelagic habitats, suggesting that phenotypic plasticity may have been selected for by the extreme variability of the polar marine environment. We argue that changes in diatom macromolecular composition and shifts in species dominance in response to a changing climate have the potential to alter nutrient and energy fluxes throughout the Southern Ocean ecosystem.

  3. A triphase red tide in Tong'an Bay of Xiamen Seas and its causes analysis%厦门同安湾海域一次三相型赤潮及其成因分析



    通过监视监测2011年7月26日-8月7日发生在厦门同安湾的赤潮,对赤潮发生时的水文气象、化学、生物因子等进行分析。结果表明,本次赤潮为三相混合型赤潮,赤潮生物为中肋骨条藻(Skeletonema costatum)、血红哈卡藻(Akashiwo sanguinea)和角毛藻(Chaetoceros sp.),赤潮最大面积为105km2。水体的富营养化、持续的高温天气和小潮期水体的相对稳定是本次赤潮发生的基本条件,"洛坦"台风的气压影响以及降雨导致的盐度急剧下降是此次赤潮的诱因。%A red tide in Tong'an Bay of Xiamen Seas during July 26th to August 7th in 2011 was reported in this paper. Hydrological meteorological, chemistry and biological factors were analyzed in the occurrence of red tide. The results showed that this red tide with the area of 105 km2 was a hybrid triphase red tide, and the red tide species included Skeletonema costatum, Akashiwo sanguinea, Chaetoceros sp. The basic conditions of this tide were eutrophication, continuous high air temperature and the stable water body of neap tide, the air pressure due to "Luotan" typhoon and sharp decline of salinity due to rainfall also contributed to this red tide.

  4. [Analysis on characteristics of red tide in Fujian coastal waters during the last 10 years].

    Li, Xue-Ding


    There were 161 red tide events collected during the last 10 years from 2001 to 2010 in Fujian coastal waters. Comprehensive analysis was performed using statistical methods and the results indicated the following characteristics of the temporal and spatial distribution of red tide in Fujian coastal waters: (1) Outbreaks of red tide often occurred between April and September, and the peak period was in May and June. Most red tide events lasted for 2 to 4 days, and the affected area was below 50 square kilometers. The first outbreak of red tide tended to occur earlier in recent years, and the lasting time became longer. (2) There were 20 species of organisms causing the red tides in Fujian coastal waters, among which 10 species were Bacillariophyta, 9 species were Dinophyta and 1 species was Protozoa. Prorocentrum donghaiense was the most frequent cause of red tides, followed by Noctiluca scintillans, Skeletonema costatum and Chaetoceros sp.. The species caused red tides obeyed the succession law and there were always new species involved. (2) In terms of spatial distribution, outbreaks of red tides mainly occurred in the coastal waters of Ningde, Fuzhou and Xiamen. The species causing red tides were Prorocentrum donghaiense and Noctiluca in the coastal waters in the north of Pingtan, Fujian Province, Skeletonema costatum and Chaetoceros in the coastal waters in the south of Pingtan, Fujian Province. The comprehensive analysis of the characteristics of red tides during the last 10 years is expected to provide scientific and reasonable basis for the prevention, reduction and forecast of red tides in Fujian coastal waters. PMID:23002593

  5. Temporal variation of diatom benthic propagules in a monsoon-influenced tropical estuary

    Patil, Jagadish S.; Anil, Arga Chandrashekar


    Temporal variations in the diatom benthic propagule (DBP) community and their role in the phytoplankton community in a monsoon-affected tropical estuary, Zuari estuary, Goa (India) are presented. The DBP from the sediments was enumerated using an extinction dilution method (most probable number method), which allows estimation of resting stages through examination of germinated vegetative cells in culture. The DBP community was dominated by planktonic species belonging to the genera Skeletonema, Fragilariopsis, Thalassiosira, and Chaetoceros. Benthic propagules (BPs) of Skeletonema costatum and Fragilariopsis sp. were dominant throughout the year. Between these two species, only S. costatum showed a linear relationship between the BP and planktonic cells, indicating that this species is particularly important in coupling of pelagic and benthic ecosystems. During the onset and restart of monsoon after an intermittent break, water column was stratified, with a low-salinity layer arising from riverine discharge and precipitation at the surface and relatively cold, saline, low-oxygen waters at the bottom. Stratification favored blooming of S. costatum and Fragilariopsis sp. in nutrient-rich surface and bottom waters, respectively. The decline in these blooms ensuing nitrate depletion and salinity change resulted in an increased abundance of BP. Chaetoceros bloom was observed during the monsoon break as well as during non-monsoon period and on both the occasions the decline in bloom was coupled with freshwater discharge. During the non-monsoon season, Thalassiosira blooms were encountered subsequent to high nitrate inputs. These findings suggest that in such shallow tropical regions, physical processes during monsoon (freshwater discharge) and non-monsoon seasons (currents, waves and tides) cause resuspension of diatom BP. Since light is not a limiting factor for germination in such regions, the blooming of resuspended BP depends on nutrient availability.

  6. The effects of spring-neap tide on the phytoplankton community development in the Jiaozhou Bay,China

    LIU Dongyan; SUN Jun; LIU Zhe; CHEN Hongtao; WEI Hao; ZHANG Jing


    The development of the phytoplankton community was studied in the Jiaozhou Bay during the spring to neap tide in August 2001, through three cruises and a 15 d continuous observation. This investigation indicates that diatom cell abundance increased sharply following the end of a spring tide, from 9 cells/cm3 to a peak of 94 cells/cm3. The dominant species composition and abundance show a quick species sequence from spring to neap tide, and the dominant species at the start phase is Skeletomena costatum, then changes to Chaetoceros curvisetus, finally it changes to Eucampia zodiacus. Silicate concentration increases during spring tide, as a result of nutrient replenishment from the water-sediment interface, its initial average concentration in neap tide is 1.39 μmol/dm3 and reached the peak average concentration of 8.40 μmol/dm3 in spring tide. But the nitrogen concentration dropped due to dilution by the low nitrogen seawater from the Huanghai Sea, its initial average concentration in neap tide is 67 μmol/dm3 and decreased to the average concentration of 54 μmol/dm3 in spring tide. The degree of silicon limitation was decreased and phytoplankton, especially diatoms, responds immediately after nutrient replenishment in the water column. Skeletonmea costatum, as one of the dominant species in the Jiaozhou Bay, shows a quicker response to nutrient availability than Eucampia zodiacus and Chaetoceros curvisetus. It is proposed that dominant species composition and water column stability synchronously determine the development of phytoplankton summer blooms in the Jiaozhou bay.

  7. The research of relationships between phytoplankton and environmental factors in artificial reef area of Haizhou Bay%海州湾人工鱼礁区浮游植物与环境因子关系的研究

    杨柳; 张硕; 孙满昌; 张虎


    By using canonical correspondence analysis (CCA), this paper studied the relationship between phytoplankton species and its environmental factors.The species-environment biplots were drawn based on the result of CCA.The result showed that total inorganic nitrogen, water temperature and transparency were the most important factors influencing the distribution of phytoplankton species.The distribution of main dominant phytoplankton species Chaetoceros muelleri and Eucompia zoodiacus correlated strongly with phosphate.CCA can be a useful tool to understand the spatial distribution of phytoplankton species in marine ecosystems.%于2008年对海州湾人工鱼礁区进行了3个航次的理化因子和生物资源调查,应用CANOCO4.5软件对获得的浮游植物数据和环境因子数据进行典范对应分析(canonical correspondence analysis),作出物种与环境因子关系的二维排序图.根据环境因子与排序轴的相关系数,认为影响这一海区浮游植物分布的主要环境因子依次为总无机氮、水温和透明度.主要浮游植物优势种牟勒氏角毛藻(Chaetoceros muelleri)和浮动弯角藻(Eucampia zoodiacus)的分布与磷酸盐密切相关,这些优势种在鱼礁区和对照区数量上的差异导致了鱼礁区浮游植物数量要高于对照区.

  8. Some thermal effects of a simulated entrainment regime on marine plankton

    Six species of diatoms, various life stages of seven species of zooplankters, and the demersal eggs of a fish were subjected to laboratory simulations of the maximum thermal regime predicted for the Maine Yankee Atomic Power Plant. Each organism was tested from the ambient temperature(s) (AT) at which they occurred normally. These ranged from 3 to 200C. The simulated thermal regime (STR) consisted of a nearly instantaneous temperature rise (usually 140C) above AT followed by a controlled return to AT over a 3-hr period. Chaetoceros laciniosus, which suffered a complete mortality, was the only diatom species sensitive to the STR from a 3 or 150C AT. Chaetoceros lorenzianus and Skeletonema costatum, not sensitive to the STR from an AT of 150C, were sensitive from an AT of 200C; although mortalities were not complete, the lag phase preceding exponential growth in treated cultures was usually prolonged. The zooplankters and fish eggs tested from AT's of 3, 5, or 100C were not sensitive to the STR. However, zoea of the decapod crab Cancer irroratus, not sensitive to the STR from a 100C AT, were sensitive from a 150C AT. The data suggested that other factors, including crowding, salinity, and duration of exposure, may have complicated the zoea results at the 150C AT. Nauplii of the calanoid copepod, Eurytemora herdmani were all killed when tested from a 200C AT, but not from a 100C AT. Females of the archiannelid, Dinophilus conklini were tested from an AT of 200C with inconclusive results, which suggested these organisms may be sensitive to the STR from this AT. Polychaete nectochaetes and juveniles, the most tolerant group tested, showed no sensitivity to the STR from AT's ranging from 3 to 200C. (U.S.)

  9. Automatic cell object extraction of red tide algae in microscopic images

    Yu, Kun; Ji, Guangrong; Zheng, Haiyong


    Extracting the cell objects of red tide algae is the most important step in the construction of an automatic microscopic image recognition system for harmful algal blooms. This paper describes a set of composite methods for the automatic segmentation of cells of red tide algae from microscopic images. Depending on the existence of setae, we classify the common marine red tide algae into non-setae algae species and Chaetoceros, and design segmentation strategies for these two categories according to their morphological characteristics. In view of the varied forms and fuzzy edges of non-setae algae, we propose a new multi-scale detection algorithm for algal cell regions based on border- correlation, and further combine this with morphological operations and an improved GrabCut algorithm to segment single-cell and multicell objects. In this process, similarity detection is introduced to eliminate the pseudo cellular regions. For Chaetoceros, owing to the weak grayscale information of their setae and the low contrast between the setae and background, we propose a cell extraction method based on a gray surface orientation angle model. This method constructs a gray surface vector model, and executes the gray mapping of the orientation angles. The obtained gray values are then reconstructed and linearly stretched. Finally, appropriate morphological processing is conducted to preserve the orientation information and tiny features of the setae. Experimental results demonstrate that the proposed methods can eff ectively remove noise and accurately extract both categories of algae cell objects possessing a complete shape, regular contour, and clear edge. Compared with other advanced segmentation techniques, our methods are more robust when considering images with different appearances and achieve more satisfactory segmentation eff ects.

  10. Écologie des stomoxes (Diptera : Muscidae au Gabon. I – Premier inventaire dans différentes zones écologiques

    Mavoungou J.F.


    Full Text Available Les stomoxes (Stomoxys spp. sont des diptères hématophages, vecteurs potentiels de divers agents pathogènes. Comme ceux de la région afrotropicale en général, les stomoxes du Gabon demeurent mal connus. Pour ces raisons, une enquête entomologique a été conduite de façon transversale dans huit localités représentatives des diverses zones écologiques du Gabon. L’enquête est basée sur l’utilisation de pièges Vavoua. Divers facteurs environnementaux pouvant influer sur les captures ont été relevés et inclus dans une analyse canonique des correspondances. Au total, 15 966 stomoxes, appartenant à sept espèces ou sous-espèces, ont été capturés. Les densités apparentes (DAP, exprimées en nombre de stomoxes par piège et par jour, sont importantes dans les localités de Franceville (41, Bakoumba (40, Makokou (25 et Mouila (21. Les espèces les plus abondantes sont Stomoxys n. niger (33,4 % de l’ensemble des captures, S. transvittatus (33 % puis S. calcitrans (17 %. Les principaux facteurs qui expliquent la variabilité des captures sont le degré d’anthropisation du milieu, le faciès botanique (savane ou forêt, la présence de la faune sauvage et domestique et la nature de la couverture végétale du sol. S. calcitrans et S. n. niger sont abondants dans les zones où la présence humaine est manifeste. S. xanthomelas est inféodé aux zones forestières. S. transvittatus, S. omega, et S. inornatus sont des espèces ubiquistes. S. niger bilineatus se retrouve dans les zones de savane.

  11. Condições meteorológicas e tipo de solo na composição da uva 'Cabernet Sauvignon' Weather and soil effects on the composition of 'Cabernet Sauvignon' grape

    Rodrigo Vieira Luciano


    Full Text Available O objetivo deste trabalho foi avaliar os efeitos das condições meteorológicas e do tipo de solo sobre características físico-químicas e compostos fenólicos da uva 'Cabernet Sauvignon' (Vitis vinifera. O experimento foi realizado em vinhedo implantado em 2003, enxertado sobre o porta-enxerto 'Paulsen 1103' e conduzido no sistema espaldeira. No vinhedo, foram selecionados dois solos: Cambissolo Háplico e Cambissolo Húmico. O efeito das condições meteorológicas (precipitação e temperatura mínima e máxima do ar foi avaliado nas safras 2008/2009, 2009/2010 e 2010/2011. Foram determinados os atributos físicos e químicos dos solos, os teores de sólidos solúveis, a acidez titulável e o pH do mosto, bem como o índice de polifenóis totais e dos teores de antocianinas e de taninos da uva. Os fatores solo e as condições meteorológicas (safras foram arranjados em esquema fatorial 2x3. Com exceção do teor de polifenóis totais, as condições meteorológicas e o tipo de solo afetam as características físico-químicas da uva 'Cabernet Sauvignon', com efeito mais pronunciado das condições meteorológicas do que do tipo de solo. Menores precipitações e maiores amplitudes térmicas favorecem o acúmulo de sólidos solúveis na uva 'Cabernet Sauvignon'. Maiores precipitações favorecem o aumento da acidez do mosto.The objective of this work was to evaluate the effects of weather and soil type on the physicochemical characteristics and phenolic compounds of the 'Cabernet Sauvignon' grape (Vitis vinifera. The experiment was carried out in a vineyard established in 2003, grafted onto 'Paulsen 1103', and conducted in the cordon system. Two soils were selected in the vineyard: Typic Dystrudepts and Pachic Humudepts. The effect of weather (rainfall, and minimum and maximum temperature was evaluated in the seasons 2008/2009, 2009/2010, and 2010/2011. Soil physical and chemical properties, soluble solids, titratable acidity and pH of the

  12. Produtividade e composição físico-química de bagas de cultivares de uva em distintos porta-enxertos Productivity and physicochemical composition of berries of grapevine cultivars grafted onto different rootstocks

    Renata Vieira da Mota


    Full Text Available O objetivo deste trabalho foi avaliar a influência de nove porta-enxertos na produção e composição química das bagas de uvas de mesa e de processamento durante o período de 2006 a 2008 em Caldas, MG. As cultivares Niágara Rosada e Folha de Figo foram enxertadas sobre 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' e 'RR 101-14' e submetidas ao delineamento em blocos ao acaso com dez tratamentos (nove porta-enxertos e o pé-franco e quatro repetições. Ambas cultivares apresentaram maior produção sobre 'IAC 572', porém com prejuízo para a qualidade das bagas que apresentaram menor relação sólidos solúveis/acidez, menor teor de antocianinas e de compostos fenólicos e maior acidez. A absorção de potássio foi mais dependente do porta-enxerto em 'Niágara Rosada'; a maior absorção foi com os porta-enxertos 'IAC 766' e 'Traviú'. Videiras enxertadas sobre '196-17' apresentaram o menor teor de potássio nas bagas. 'Niágara Rosada' apresentou produção de 9 kg por planta e elevada relação sólidos solúveis/acidez sobre 'RR 101-14', '420 A' e 'Gravesac'. Entretanto, 'Gravesac' proporcionou maior concentração de antocianinas. 'Folha de Figo' enxertada em '196-17' apresentou elevado teor de sólidos solúveis, antocianinas e fenólicos nas cascas e menor teor de acidez e fenólicos nas sementes, além de produção de 5 kg por planta, estatisticamente semelhante aos porta-enxertos mais produtivos.This work aimed at evaluating the influence of nine rootstocks on the productivity and chemical composition of table and processing grapes from 2006 to 2008 in Caldas, MG. The cultivars Niagara Rosada and Folha de Figo were grafted onto 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' and 'RR 101-14' and submitted to a randomized block design with ten treatments (nine rootstocks and ungrafted plant with four replicates. Both cultivars had higher yields

  13. Efeito do porta-enxerto no teor de nutrientes em tecidos da videira "cabernet sauvignon" Effect of rootstock on nutrient content of 'cabernet sauvignon' grapevine tissues

    Alberto Miele


    Full Text Available A nutrição mineral da videira constitui-se em importante fator para a qualidade dos vinhos. Devido a isso, avaliou-se o efeito de porta-enxertos no teor de nutrientes em diferentes tecidos da videira 'Cabernet Sauvignon' (Vitis vinifera L. na Serra Gaúcha. o experimento foi conduzido durante o ciclo vegetativo de 2004/2005, com os porta-enxertos Rupestris du lot, 101-14, 3309, 420A, Kober 5BB, 161-49, So4 e Paulsen 1103, enxertados em 1993 com a cv. 'Cabernet Sauvignon'. o delineamento experimental foi em blocos ao acaso, com oito tratamentos e três repetições, sendo quatro plantas/parcela. Coletaram-se folhas - separando-se os pecíolos dos limbos -, cachos - separando-se as bagas das ráquis - e ramos, os quais foram posteriormente secados em estufa e pesados. Analisaram-se os nutrientes n, P, K, Ca e Mg. os resultados mostram que houve efeito significativo do porta-enxerto nos teores de N, P, K, Ca e Mg no limbo, pecíolo, ráquis e baga da videira 'Cabernet Sauvignon' e que este efeito variou em função do nutriente e do tecido considerado. Entretanto, não houve efeito significativo do porta-enxerto no teor desses nutrientes no ramo da videira. Além disso, a ordem de grandeza do teor dos nutrientes variou em função do tecido avaliado. Assim, os teores de n e de Ca foram maiores no limbo; os de P e K, na ráquis; e o de Mg, no pecíolo.Grapevine mineral nutrition is an important factor influencing wine quality. For this, the effect of rootstocks on the nutrient content in different tissues of 'Cabernet Sauvignon' grapevines (Vitis vinifera L. grown in the Serra Gaúcha region was evaluated. The experiment was carried out during the 2004/2005 vegetative cycle with the rootstocks Rupestris du Lot, 101-14, 3309, 420A, Kober 5BB, 161-49, SO4, and Paulsen 1103. The experimental design was in randomized blocks, with eight treatments, three replicates, four plants/plot. leaves - petioles were separated from the limbs -, clusters - berries

  14. Influência da altitude na qualidade das uvas 'Chardonnay' e 'Pinot Noir' em Minas Gerais Altitude influence on the quality of 'Chardonnay' and 'Pinot Noir' grapes in the state of Minas Gerais

    Murillo de Albuquerque Regina


    Full Text Available No Sul e Sudeste brasileiros, o excesso de chuvas durante o período de maturação afeta negativamente a qualidade dos vinhos tintos. Por outro lado, estas regiões possuem potencial para a elaboração de espumantes, uma vez que, para a elaboração desta bebida, a uva é colhida antes de completar o amadurecimento. No Estado de Minas Gerais, as condições de verão chuvoso estão presentes em todas as regiões de potencial vitícola, e a variação de altitude entre elas pode exercer influência na composição das uvas. Desta forma, este estudo buscou avaliar o potencial de maturação de uvas 'Chardonnay' e 'Pinot Noir' destinadas à elaboração de espumantes em dois locais de Minas Gerais: Cordislândia (873m e Caldas (1.150m. As plantas foram enxertadas sobre 1.103 Paulsen e conduzidas em espaldeira. Foram avaliados os teores de sólidos solúveis totais, acidez total, ácidos málico e tartárico, e pH do mosto, tamanho e massa das bagas, compostos fenólicos nas cascas e sementes, antocianinas na casca e açúcares solúveis nas bagas, em duas safras consecutivas. As bagas apresentaram maior tamanho e massa quando cultivadas em Caldas. As uvas colhidas em Cordislândia apresentaram maior grau de maturação, sendo observados maior pH, maiores teores de glicose e frutose, e quantidade inferior de acidez e fenólicos totais nas sementes. Os maiores teores de ácido málico presentes nas uvas provenientes de Caldas sugerem que esta região pode ser mais indicada à produção de uvas para elaboração de vinhos espumantes.In the southern and southeastern of Brazil, the excessive rainfall during the maturation period negatively affects the quality of red wines. On the other hand, these regions have great potential for the development of sparklings since that for the elaboration of this drink, the grape is harvested before complete its maturation. In the state of Minas Gerais, the conditions of rainy summer season are present in all

  15. Raleio de cachos em vinhedos de altitude e qualidade do vinho da cultivar Syrah Cluster thinning in high altitude vineyards and wine quality from the cultivar Syrah

    Leonardo Cury da Silva


    Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes intensidades de raleio de cachos de uvas (Vitis vinifera L., em vinhedos de altitude, sobre a evolução dos compostos fenólicos durante a maturação da uva. O experimento foi conduzido em São Joaquim, SC, a uma altitude média de 1.230 m, em videiras da cv.Syrah, enxertadas sobre 'Paulsen 1103', conduzidas em espaldeira, em duplo cordão esporonado, espaçadas em 3x1,2 m, com cobertura antigranizo. Os tratamentos de raleio foram definidos de modo a se ter redução da produtividade em 13,3, 26,6 e 40% em relação à produtividade do tratamento controle sem raleio, estimada em 15 Mg ha-1. Os tratamentos foram ajustados quando 50% das bagas encontravam-se em "véraison". Odelineamento foi o de blocos ao acaso, com quatro repetições e 40 plantas por tratamento. As avaliações foram feitas nas safras 2005/2006 e 2006/2007. Avaliou-se a evolução dos compostos fenólicos durante as oito semanas antecedentes à colheita. O raleio de cachos aumentou o conteúdo de antocianinas quando a produtividade estimada foi de 12 Mg ha-1, e melhorou a composição fenólica das bagas, atributos esses favoráveis à produção de vinhos tintos finos de qualidade.The objective of this work was to evaluate the effect of different intensities of cluster thinning in mountain vineyards cv.Syrah on the evolution of phenolic compounds, during grape maturation. The experiment was carried out in the 2005/2006 and 2006/2007 crop seasons, at São Joaquim, SC, Brazil, at an average altitude of 1,230 m, on 'Syrah' grapevines that had been grafted on 'Paulsen 1103' root stock and trained out in vertical trellis system, spaced in 3x1.2 m and protected against hail. The cluster thinning was adjusted in the "veraison" corresponded to 15 Mg ha-1 (control, 13 Mg ha-1, 11 Mg ha-1 and 9 Mg ha-1, in a complete randomized blocks. The evolution of phenolic compounds was evaluated during the eight antecedent weeks to the

  16. An innovative pot system for monitoring the effects of water stress on grapevines and grape quality

    Puccioni, Sergio; Leprini, Marco; Mocali, Stefano; Perria, Rita; Priori, Simone; Storchi, Paolo; Zombardo, Alessandra; Costantini, Edoardo


    The advantage of a pot system is the possibility to control many variables and factors with a large number of replicates, obtaining statistically significant results in only one year of experimentation. An innovative pot system for the monitoring of grapevine water stress was set up. The system consists of 99 pots of 70 liters, filled by 3 different soils collected from premium vineyards of the Chianti Classico district (Tuscany). The soils showed different texture (clay-loam, loam and sandy-loam), different gravel and carbonate content, and different available water capacity (AWC). The same soils had been field monitored for grapevine water stress; therefore it was possible to compare the grapevine behaviour both in pot and in field conditions. The grapevine cultivar was Pinot noir clone ENTAV 115, which can be used to investigate the genetic expression in response to environmental factors, since its genome has been sequenced. Different rootstocks theses were compared: not grafted, 1103 Paulsen and M101-14. Each combination rootstock-soil was repeated 9 times. Every pot was equipped for drip irrigation and with electrodes for soil moisture determination by TDR. A non-stop automated control unit recorded meteorological data (temperature and rainfalls), soil temperature and water potential on 9 selected pots. These 9 selected pots were also used to calibrate a model for soil water volume/tension curve. Soil, leaves and grapes samples from each pot were collected for microbial community determination, through NGS analysis. A preliminary study was based on testing the ability of the system to simulate the natural growing conditions of the grapevines. Therefore the grape performances of the potted plants were compared to those of plants cultivated in the vineyards where the soils were taken. In July 2015 three levels of water supply were tested during 5 weeks (up to veraison) in order to study the effects of water stress on the plants and the grape. Later, all the pots

  17. Condições meteorológicas e tipo de solo na composição da uva 'Cabernet Sauvignon'

    Rodrigo Vieira Luciano


    Full Text Available O objetivo deste trabalho foi avaliar os efeitos das condições meteorológicas e do tipo de solo sobre características físico-químicas e compostos fenólicos da uva 'Cabernet Sauvignon' (Vitis vinifera. O experimento foi realizado em vinhedo implantado em 2003, enxertado sobre o porta-enxerto 'Paulsen 1103' e conduzido no sistema espaldeira. No vinhedo, foram selecionados dois solos: Cambissolo Háplico e Cambissolo Húmico. O efeito das condições meteorológicas (precipitação e temperatura mínima e máxima do ar foi avaliado nas safras 2008/2009, 2009/2010 e 2010/2011. Foram determinados os atributos físicos e químicos dos solos, os teores de sólidos solúveis, a acidez titulável e o pH do mosto, bem como o índice de polifenóis totais e dos teores de antocianinas e de taninos da uva. Os fatores solo e as condições meteorológicas (safras foram arranjados em esquema fatorial 2x3. Com exceção do teor de polifenóis totais, as condições meteorológicas e o tipo de solo afetam as características físico-químicas da uva 'Cabernet Sauvignon', com efeito mais pronunciado das condições meteorológicas do que do tipo de solo. Menores precipitações e maiores amplitudes térmicas favorecem o acúmulo de sólidos solúveis na uva 'Cabernet Sauvignon'. Maiores precipitações favorecem o aumento da acidez do mosto.

  18. Den norske EPOC-satellitten: støtte til kunnskapsbaserte beslutninger

    Susan Munabi-Babigumira


    Full Text Available Systematiske oversikter fra det internasjonale Cochrane-samarbeidet er en viktig kilde til oppsummert kunnskap for beslutningstakere i helsevesenet. Den norske satellitten av Cochrane Effective Practice and Organisation of Care (EPOC Review Group har base i Seksjon for global helse, Nasjonalt kunnskapssenter for helsetjenesten, og fokuserer på tiltak som retter seg mot helsesystemer og helsetjenesten i lav- og mellominntektsland. Den norske EPOC-satellitten gir redaksjonell støtte til forfattere som skriver Cochraneoversikter om effekter av slike tiltak, og bidrar dermed til at systematiske oversikter blir utarbeidet og brukt. Behovet for oppsummert kunnskap, skreddersydd for ulike sammenhenger og ulike sluttbrukere, er stort. Ikke minst gjelder det i lav- og mellominntektsland der ressursene er begrenset, og der gode prioriteringer er spesielt viktig.Munabi-Babigumira S, Johansen M, Paulsen E. The Norwegian EPOC-satellite: Support for evidenceinformed decisions. Nor J Epidemiol 2013; 23 (2: 211-214.ENGLISH SUMMARYSystematic reviews from the Cochrane Collaboration are an important source of summarised evidence for decision makers in health care. The Norwegian satellite of the Cochrane Effective Practice and Organisation of Care (EPOC Review Group has its base at the Global Health Unit in the Norwegian Knowledge Centre for the Health Services, and focuses on interventions targeting health systems and services in lowand middle-income countries. The Norwegian EPOC-satellite provides editorial support to authors who write systematic reviews on the effects of such interventions, and contributes to building the capacity for producing and using systematic reviews. The need for summarised evidence, tailored for various settings and various end users, is large. This is particularly important for low- and middle income countries, where resources are limited and it is important to identify the right priorities.

  19. Could be the future climate change an opportunity for the winegrowers? The case study of Aglianico wine in southern Italy.

    Bonfante, Antonello; Basile, Angelo; Dragonetti, Giovanna; De Lorenzi, Francesca; De Mascellis, Roberto; Gambuti, Angelita; Giorio, Pasquale; Guida, Giampiero; Manna, Piero; Minieri, Luciana; Oliva, Marco; Orefice, Nadia; Terribile, Fabio


    Water deficit is a limiting factor to yield production and crop adaptation to future climate conditions. This is true for crops addressed mainly for biomass production (e.g. maize, wheat, etc.) but not for those where the quality is relevant. Specifically, in grapevine water stress (mid or limited) - occurring during specific phenological phases - is a factor to produce good quality wines. It induces for example the production of anthocyanins and aroma precursors. Therefore, the water stress, due to the future increase of temperature and the rainfall decrease, could represent an opportunity to increase winegrowers' incomes. The study was carried out in Campania region (Southern Italy), in an area vocated to high quality wines production (ZOVISA project: Viticultural zoning at farm scale) The study was realized in two different soils (calcisol and cambisol), under the same climate, on Aglianico cultivar, standard clone population on 1103 Paulsen rootstocks placed along a slope of 90 m length with 11% of gradient. The agro-hydrological model SWAP was calibrated and applied to estimate soil-plant water status at the various crop phenological phases for three vintages (2011-2013). Crop water stress index (CWSI) - estimated by the model - was related to physiological measurements (e.g leaf water potential), grape bunches measurements (e.g. sugar content) and wine quality (e.g. tannins). For both soils, the correlation between measurements and CWSI were high (e.g. -0.97** with sugar; 0.895* with anthocyanins in the skins). Then, the model was applied to future climate condition (2021-2051) obtained from statistical downscaling of GCM in order to estimate the effect of the climate on CWSI and hence on vine quality. The results show that the effects of the climate change on the vine quality is dependent by the soil, being relevant to the cambisol and less pronounced to the calcisol, with an expected improvement of wine quality in the cambisol.

  20. Desempenho vitivinícola da Cabernet Sauvignon sobre diferentes porta-enxertos em região de altitude de Santa Catarina Viticultural performance of cabernet sauvignon grafted on different rootstocks in high altitude regions of Santa Catarina state

    Alberto Fontanella Brighenti


    Full Text Available Apesar de os porta-enxertos serem usados primariamente como uma forma de resistência a pragas, eles são uma ligação entre o solo e a copa, e desempenham um papel importante na adaptação da videira a fatores ambientais. O objetivo deste trabalho foi avaliar três porta-enxertos e dois sistemas de condução na produtividade do vinhedo, no crescimento da copa e nas características físicas dos frutos. O experimento foi conduzido em um vinhedo experimental da Epagri - Estação Experimental de São Joaquim, localizada no município de Painel (28°01'02"S e 50°08'57"O, altitude 1.200 m. O trabalho foi executado com a cultivar Cabernet Sauvignon, enxertada sobre Paulsen 1.103 (Vitis berlandieri x Vitis rupestris, Couderc 3309 (Vitis riparia x Vitis rupestris e 1.014-14 Mgt (Vitis riparia x Vitis rupestris, em dois sistemas de condução, espaldeira e manjedoura, com cinco anos de idade, no espaçamento de 3,0 x 1,5 m. O experimento foi avaliado nas safras de 2007/08 e 2008/09. Os tratamentos porta-enxerto e sistema de condução foram arranjados em um fatorial (3 x 2. O delineamento utilizado foi o de blocos ao acaso, com quatro blocos e 20 plantas por parcela. Foram avaliados a área foliar, a produtividade médias das plantas, o índice de Ravaz, o peso de material podado, o peso de cachos, peso de 50 bagas, o número de bagas por cacho, o diâmetro das bagas, os teores de sólidos solúveis, a acidez total, o pH, os teores de antocianinas, o índice de polifenóis totais e os taninos. Plantas enxertadas em Paulsen 1103 apresentaram as menores produtividades e as maiores áreas foliares. 3.309C é o porta-enxerto menos vigoroso e interfere de maneira positiva na frutificação efetiva, pois produz maior número de bagas por cacho e bagas mais pesadas. Os porta-enxertos 1.103P e 101-14 Mgt, apresentam os melhores resultados para antocianinas.Rootstocks are a link between the soil and the scion, they play an important role in vine adaptation

  1. Performance of painted plywood and cloth Nzi traps relative to Manitoba and greenhead traps for tabanids and stable flies.

    Mihok, Steve; Carlson, David A


    Experiments were conducted to adapt the cloth Nzi trap to a format suitable for fixed applications in biting fly sampling or control. Catches of tabanids [Tabanus L., Chrysops (Meigen), and Hybomitra Enderlein], and stable flies [Stomoxys calcitrans (L.)] in painted plywood traps were compared with those in standard phthalogen blue cloth traps, and in similarly painted cloth traps. The Manitoba horse fly trap and the Tabanus nigrovittatus Macquart "greenhead" box trap were used as additional standards during one tabanid season. Shiny features of traps reduced catches, e.g., paint on cloth instead of wood, or use of aluminum screening instead of netting. Nevertheless, appropriately painted plywood Nzi traps caught as many biting flies as did standard cloth Nzi traps, if paint finishes were matte, and with the use of phthalogen blue colorants. Nzi traps collected about the same tabanid fauna as the Manitoba and T. nigrovittatus traps, but with improved catches of Chrysops and Tabanus. Recommendations are provided on appropriate color matching, and selection of readily-available materials for trap construction. PMID:17461091

  2. The repellency of lemongrass oil against stable flies, tested using video tracking.

    Baldacchino, Frédéric; Tramut, Coline; Salem, Ali; Liénard, Emmanuel; Delétré, Emilie; Franc, Michel; Martin, Thibaud; Duvallet, Gérard; Jay-Robert, Pierre


    Lemongrass oil (Cymbopogon citratus) is an effective repellent against mosquitoes (Diptera: Culicidae) and house flies (Diptera: Muscidae). In this study, its effectiveness was assessed on stable flies (Diptera: Muscidae) in laboratory conditions. First, we demonstrated that lemongrass oil is an active substance for antennal olfactory receptor cells of Stomoxys calcitrans as indicated by a significant increase in the electroantennogram responses to increasing doses of lemongrass oil. Feeding-choice tests in a flight cage with stable flies having access to two blood-soaked sanitary pads, one of which was treated with lemongrass oil, showed that stable flies (n = 24) spent significantly more time in the untreated zone (median value = 218.4 s) than in the treated zone (median value = 63.7 s). No stable flies fed on the treated pad, whereas nine fed on the untreated pad. These results suggest that lemongrass oil could be used as an effective repellent against stable flies. Additional studies to confirm its spatial repellent and feeding deterrent effects are warranted. PMID:23759542

  3. Descriptive epidemiology of insects infesting domestic sheep (ovis aries) of district toba tek singh, punjab, pakistan

    During a cross-sectional prospective epidemiological survey, a total of 2412 sheep were screened for the prevalence of insects. Out of which, 333 (13.80%) were harbored for insects including lice (36.57%), fleas (3.23%) and flies (1.62%). Among the identified species of lice, Haematopinus spp. (44.14%) was predominant followed in order by Damalinia ovis (26.42%) and Linognathus spp. (17.71%). The flea Ctenocepahlides (Ct). felis was more common (4.50%) than Ct. canis (3.30%). Stomoxys calcitrans (3.90%) was the only prevalent specie of fly in the study area. Infestation rate was higher in young sheep (72.68%) as compared to adults (27.32%) and level of infestation was significantly higher in females (75.37%) than males (24.62%). Amongst various breeds of sheep, Cholistani (19.81%) had the highest prevalence followed by Kajli (13.49%), Thalli (12.94%) and Lohi (11.80%). Prevalence of flies (37%) and lice (47%) was highest in December and January, respectively; whereas,that of fleas (39%) reached a peak in April. Among various associated determinants, stall feeding, closed housing, tethered animals and non-cemented floor were found positively associated (P<0.05) with insect infestation. The results showed that insect abundance and the variety of genera were wide in this part of Pakistan. This also causes concern over the emergence of insect-borne diseases in domestic animals. (author)

  4. Reproductive capacity and longevity of stable flies maintained on different kinds of blood.

    DuToit, G D


    An investigation was made into some lesser known aspects of the biology of the stable fly, Stomoxys calcitrans, in order to find a basis for possible means of natural control of the pest on dairy farms. The reaction of adults to different kinds of blood was tested. Diets investigated were bovine blood alternated with ovine blood, bovine blood alternated with pig's blood, bovine blood alternated with manure filtrate, bovine blood alone, ovine blood alone, pig's blood alone and manure filtrate alone. Adults could not servive on manure filtrate alone. Flies in the other treatments exhibited no marked differences as regards duration of pre-mating-, pre-oviposition- and oviposition periods. There were, however, differences in the number of eggs laid. Females maintained on bovine blood alone produced most eggs i.e. 2,3 times as many as those laid by females fed on pig's blood alone. The latter were the poorest producers. Viability and incubation period of eggs did not appear to be affected by the kind of blood fed to the adults. Flies, however, lived longer when supplied with bovine blood and died sooner when maintained on pig's blood. PMID:1223286

  5. Suppressing immature house and stable flies in outdoor calf hutches with sand, gravel, and sawdust bedding.

    Schmidtmann, E T


    Sand, gravel, sawdust, and pine shavings were used as bedding in outdoor calf hutches and compared with straw relative to the density of immature (maggot) house flies, Musca domestica, and stable flies, Stomoxys calcitrans. In 6-wk field trials, average densities of house and stable fly maggots in concrete mix sand ranged from only .3 to 1.6 and 0 to .1 maggots/L, respectively; pea size gravel bedding also strongly suppressed densities from less than .1 to .3 and less than .1 to .1 maggots/L, respectively. These densities represent reductions of 76 to greater than 99% relative to straw bedding, but both sand and gravel compacted and became soiled with calf feces, which resulted in unacceptable bedding sanitation and foul odors. Densities of house and stable fly maggots in pine shavings did not differ from those in straw bedding. Nevertheless, in sawdust bedding, maggot density was limited to averages of 1.4 to 8.3 house and 9.8 to 11.8 stable fly maggots/L; this represented reductions of 45 to 91% relative to straw. In a follow-up trial, house and stable fly maggot densities in sawdust averaged 11.3 and 43.9 maggots/L, respectively, reductions of 77 and 46%. These findings suggest that bedding calf hutches with sawdust during warm weather can be useful as an ecologically sound approach to controlling muscoid fly populations on dairy farms. PMID:1757634

  6. Use of radioisotopes to elucidate the role of regurgitation for direct transfer of parasites or disease agents between host organisms through arthropod vectors

    In the context of the transmission of parasites and disease agents by bloodfeeding arthropods, the hitherto neglected phenomenon of regurgitation is of the greatest importance. It makes possible the direct transfer of ingested blood, together with these disease agents, within the shortest period of time after intake without the interaction of any circulative or transformative processes in the vector. Owing to such direct transmission from host to host, the epidemiology of vector borne diseases (e.g. arbo-viruses or certain protozoan diseases such as trypanosomiasis, leishmaniosis or even malaria) is influenced by additional factors. Regurgitative transmission should be considered in programmes of eradication and procedures of quarantine or isolation. We have examined the occurrence of regurgitation in a systematic way with the use of tracer techniques, in combination with other methods. The main arthropods are ticks (especially Ornithodoros moubata Murray), bloodsucking Hemiptera (e.g. Triatoma phyllosoma Burmeister), bloodsucking Muscidae (mainly Stomoxys calcitrans L.) and also mosquitoes. As can be shown with aphid, in which THO was used as a tracer, immediate transmission occurs in stable flies and soft ticks after labelling with 32P and 14C, and it can even be quantified. Also, the output of saliva secreted into and collected from the crop must be regarded as regurgitation rather than salivation. Since it can mix with previously ingested food (blood plus disease agents), this type of regurgitation can also contribute to the transmission of diseases by arthropods. (author). 23 refs, 3 figs, 2 tabs

  7. Use of isotopes as model substances to elucidate the mode of transmission of pathogens to animals and plants by arthropod vectors

    Experimental work was begun with J.F. Butler and L.A. DuBose on the biting flies Stomoxys calcitrans (L.) and Haematobia irritans (L.), which are important ectoparasites of livestock. Several possible mechanisms for the transmission of pathogenic materials to animals were defined, using radioisotopes: (1) mechanical transmission from contaminated mouthparts; (2) transfer through regurgitation; (3) transfer via saliva; (4) transfer through the alimentary tract. A generalized scheme was developed for the paths of uptake and excretion of radioisotopes through the organism of insects. First, experiments applied this model to blood-feeding arthropods such as the stable fly and hornfly, tsetse flies, sheep keds (Melophagus ovinus L.), mosquitoes (Culex sp., Aedes sp.), Triatoma infestans Klug (Hemiptera, Triatomidae), and the tick Ornithodorus moubata Murray. Very similar principles and possibilities for the transfer of pathogens also appear to apply to plant-sucking aphids (vectors of virus diseases in plants) as to blood-feeding arthropods. Regurgitation found in biting flies, appears in ticks as well as in Triatomidae and tsetse flies (in the last two only under stress conditions) and could even be observed in aphids. Thus, aphids and certain biting arthropods can immediately transfer pathogens after feeding on an infected host plant or animal, on migrating to another host, findings mainly possible through using radioisotopes. The results on aphids include discussion of the ingestion-egestion hypothesis of noncirculative virus transmission, described by Harris in 1977

  8. House and Stable Fly Seasonal Abundance, Larval Development Substrates, and Natural Parasitism on Small Equine Farms in Florida.

    Machtinger, E T; Leppla, N C; Hogsette, J A


    House flies, Musca domestica Linnaeus, and stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), are common pests on horse farms. The successful use of pupal parasitoids for management of these pests requires knowledge of seasonal fluctuations and biology of the flies as well as natural parasitism levels. However, these dynamics have not been investigated on small equine farms. A 1-year field study began in July 2010, in north central Florida, to determine adult fly population levels and breeding areas on four small equine farms. Weekly surveillance showed that pest flies were present year-round, though there were differences in adult population levels among farms and seasons. Fly development was not confirmed on two of the four small farms, suggesting that subtle differences in husbandry may adversely affect the development of immature flies. In six substrates previously identified as the most common among the farms, stable fly puparia were found overwhelmingly in hay mixed with equine manure and house fly puparia were found in fresh pine shavings mixed with equine manure. Natural parasitism was minimal as expected, but greatest numbers of natural parasitoids collected were of the genus Spalangia. Differences in adult and immature fly numbers recovered emphasizes the need for farm owners to confirm on-site fly development prior to purchase and release of biological control agents. Additionally, due to the low natural parasitism levels and domination of parasitism by Spalangia cameroni, augmentative releases using this species may be the most effective. PMID:26902468

  9. Repellency of a wax-based catnip-oil formulation against stable flies.

    Zhu, Junwei J; Dunlap, Christopher A; Behle, Robert W; Berkebile, Dennis R; Wienhold, Brian


    Stable flies, Stomoxys calcitrans (L.), are one of the most serious livestock pests, which cause significant economic loss in the cattle industry. Current practices for managing stable flies are limited to costly sanitation techniques and unsustainable insecticide applications. The present study reports the initial efforts using catnip essential oil as a spatial repellent and the results of field trials using a wax-based formulation to repel stable flies in the cattle feedlot. Electroantennograms showed that catnip oil and its ingredient compounds elicit significant antennal responses from both sexes of stable flies. Catnip oil and ZE- and EZ-nepetalactone showed repellent activity in a single cage olfactormeter study. No behavioral activity was observed from another ingredient compound, caryophyllene. A laboratory dispersal bioassay also showed that stable flies avoided areas treated with catnip oil. Using a solid phase microextraction (SPME) method, the atmospheric concentration of catnip active ingredient compounds (nepetalactones) absorbed by SPME fiber in treated areas was detected at 4 times higher than those in control areas. Application of wax-based catnip pellets in cattle feedlots resulted in >99% repellency of stable flies in treated areas, compared with that in nontreated areas. However, the repellent efficacy of the formulation only lasted 3 h. This is the first study demonstrating the potential application of a plant-based repellent formulation that may be used as an alternative method against stable flies. PMID:21058736

  10. Reassessment of the potential economic impact of cattle parasites in Brazil.

    Grisi, Laerte; Leite, Romário Cerqueira; Martins, João Ricardo de Souza; Barros, Antonio Thadeu Medeiros de; Andreotti, Renato; Cançado, Paulo Henrique Duarte; León, Adalberto Angel Pérez de; Pereira, Jairo Barros; Villela, Humberto Silva


    The profitability of livestock activities can be diminished significantly by the effects of parasites. Economic losses caused by cattle parasites in Brazil were estimated on an annual basis, considering the total number of animals at risk and the potential detrimental effects of parasitism on cattle productivity. Estimates in U.S. dollars (USD) were based on reported yield losses among untreated animals and reflected some of the effects of parasitic diseases. Relevant parasites that affect cattle productivity in Brazil, and their economic impact in USD billions include: gastrointestinal nematodes - $7.11; cattle tick (Rhipicephalus (Boophilus) microplus) - $3.24; horn fly (Haematobia irritans) - $2.56; cattle grub (Dermatobia hominis) - $0.38; New World screwworm fly (Cochliomyia hominivorax) - $0.34; and stable fly (Stomoxys calcitrans) - $0.34. The combined annual economic loss due to internal and external parasites of cattle in Brazil considered here was estimated to be at least USD 13.96 billion. These findings are discussed in the context of methodologies and research that are required in order to improve the accuracy of these economic impact assessments. This information needs to be taken into consideration when developing sustainable policies for mitigating the impact of parasitism on the profitability of Brazilian cattle producers. PMID:25054492

  11. Detection of West Nile virus in stable flies (Diptera: Muscidae) parasitizing juvenile American white pelicans.

    Johnson, Gregory; Panella, Nicholas; Hale, Kristina; Komar, Nicholas


    Stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), an economically important pest of livestock and humans, were observed parasitizing prefledged American white pelicans, Pelecanus erythrorhynchos (Pelecaniformes: Pelecanidae), in a pelican breeding colony in northeastern Montana where die-offs attributed to West Nile virus (family Flaviviridae, genus Flavivirus, WNV) have occurred since 2002. Engorged and unengorged flies were collected off nine moribund chicks. Of 29 blood-engorged flies testing positive for vertebrate DNA, all 29 contained pelican DNA. Virus isolation was performed on 60 pools (1,176 flies) of unengorged flies using Vero cell plaque assay. Eighteen pools were positive for WNV for an estimated infection rate of 18.0 per 1,000 flies. Fifty-four percent (36/67) of abdomens from blood-engorged flies tested positive for WNV. Pelican viremia levels from the blood-engorged fly abdomens revealed that at least one of the ill pelicans circulated a viremia capable of infecting Culex mosquito vectors. Stable flies may be involved in WNV transmission within the pelican breeding colony by serving as either a mechanical vector or as a source for oral infection if ingested by predators. PMID:21175073

  12. Diatom thanatocoenosis in a middle Galician Ría: Spatial patterns and their relationship to the seasonal diatom cycle in the water column and hydrographic conditions

    Bernárdez, Patricia; Prego, Ricardo; Varela, Manuel; Francés, Guillermo


    Modern diatom distribution patterns in the surface sediment of the Ferrol Ría and their relationship to the hydrography and diatom patterns in the water column were studied to determine the hydrographic influence on the record of these biogenic components. Diatom abundance in the water column was assessed for different oceanographic periods and compared with the biosiliceous sedimentary record. Very low abundances were found in the water column during the winter, whereas in spring and summer, diatoms proliferated. Chaetoceros spp. formed the bulk of the water column community during spring and summer, followed by Thalassionema nitzschioides and Rhizosolenia spp. Nitzschia longissima represented a significant portion of the winter assemblage, together with Paralia sulcata and benthic taxa . Leptocylindrus danicus, N. longissima and Skeletonema costatum characterized the autumn campaign, when stratification of the waters occurs, with L. danicus being especially abundant in the outer ría. Seasonal hydrographic and associated productivity patterns govern the abundance and assemblage of the diatoms preserved in surface sediments. Samples located in the inner ría area and its margins exhibited the highest abundances of diatoms, and were primarily dominated by benthic species. The freshwater group, crysophycean cysts and phytoliths were present in the landward stations influenced by river runoff. The middle ría was characterized by P. sulcata and Thalassiosira spp., with minor occurrences of the benthic and freshwater group. Chaetoceros R.S., L. danicus R.S. and T. nitzschioides typified the outer ría, an assemblage that corresponds to nutrient-rich coastal areas of high productivity influenced by oceanic waters, demonstrating the impact of oceanic waters flowing into the embayment due to enhanced tidal mixing through the narrow channel. Therefore, sediment diatom assemblages reflect diatom production patterns in the water column of the Ría. However, we must proceed

  13. O microfitoplâncton das águas costeiras do litoral Fluminense (estado do Rio de Janeiro: lista de especies e aspectos ecológicos Microphytoplankton from coastal waters of Rio de Janeiro: species composition and ecological aspects

    Nadja M. Lins da Silva


    Full Text Available O microfitoplâncton das águas costeiras entre Cabo Frio e Rio de Janeiro foi coletado durante as operações PLATAFORMA IV, V e VI do AvPqOc SO OLIVEIRA (DGN nos meses de outubro de 1984 e janeiro e março de 1985, As variações qualitativas e quantitativas foram analisadas em função das condições hidrológicas por meio de um tratamento estatístico multivariado dos dados. O fenômeno de ressurgência, responsável seja pelo afloramento da Água Central do Atlântico Sul, seja pela formação de uma termo-clina na camada eufótica, é o fator de terminante do crescimento algal que começa com especies de pequeno porte (Skeletonema costatum, Nitzschia spp e evolui para uma maior diversidade com especies dos gêneros Guinardia, Rhizosolenia, Chaetoceros, Thalassiothrix. Em condição de estratificação da coluna d'agua notou-se a influência das aguas da Baía de Guanabara, com forte crescimento de Skeletonema costatum, e uma grande quantidade de detritos associados a algas cianofíceas e formas nanoplanctônicas.Phytoplankton of the coastal water between Cabo Frio and Rio de Janeiro were studied at the upwelling season (October, January and Maroh. Qualitative and quantitative variations are analized in function of the hydrological conditions by means of a multivariate statistical treatment of data. Cabo Frio upwelling is responsible for occurrence of a thermocline in the euphotic layer which induces phytoplankton growth, beginning by small-sized species (Nitzschia spp, Skeletonema costatum and evoluting to highest diversity and quantity of different microphytoplanktonic forms (Guinardia, Rhizosolenia, Chaetoceros, Thalassiothrix. When water column is sharply stratified, we observe Guanabara Bay influence, with high growth of Skeletonema costatum and high quantity of detritus together with blue-green algae and nanoplanktonic forms.

  14. Effects of simulated benthic fluxes on phytoplankton dynamic and photosynthetic parameters in a mesocosm experiment (Bay of Brest, France)

    Claquin, Pascal; NÍ Longphuirt, Sorcha; Fouillaron, Pierre; Huonnic, Pierre; Ragueneau, Olivier; Klein, Cécile; Leynaert, Aude


    Benthic faunal activity and density play an important role in determining the rates of benthic nutrient fluxes, which enrich the water column and contribute to phytoplankton growth. The intensity of nutrient fluxes in the Bay of Brest depends on the density of the invasive gastropod, Crepidula fornicata. In order to study the impact of benthic fluxes on phytoplankton dynamics, realistic daily nutrient inputs simulating various densities of C. fornicata were added to six enclosures during three weeks. The increase in fertilization intensity influenced the phytoplankton biomass. A succession from Chaetoceros spp. to Pseudo-nitzschia spp. and Leptocylindrus danicus was observed in all enclosures, but the dynamics of successions were different. Pseudo-nitzschia spp. was favored in the three more fertilized enclosures, while Chaetoceros spp. persisted longer in less enriched enclosures. Despite an apparent nitrogen limitation, the quantum efficiency of PSII (F v/F m) was high (>0.5) and stable in all enclosures. The maximal photosynthetic capacity (P Bmax) was also invariable and oscillated around an average value of 2.23 mg C (mg Chl a) -1 h -1. The stability of F v/F m and P Bmax observed at different nutrient input intensities demonstrates that the daily inputs maintained the physiological balance of the microalgae. The maximal light utilization efficiency (α) and the light saturation parameter (E k) were also quite stable after day 8, which reveals that photosynthetic parameters were driven by growth constraints due to nutrient availability and not by incident light or species successions. We suggest that our results correspond to an "E k independent variation" regulation. We propose that such regulation of photosynthetic parameters appears when there are frequent nutrient additions which do not allow replete nutrient conditions to be reached but lead to physiological equilibrium. Thanks to our results we can understand how even low benthic fluxes, by supporting

  15. A preliminary study on phytoplankton community of Yantai Taozi Bay in autumn%烟台套子湾海域秋季浮游植物群落的初步研究

    宁璇璇; 纪灵; 王刚; 夏炳训; 丁琳


    根据2010年11月的调查数据,对套子湾海域浮游植物的群落结构进行了初步研究.共鉴定浮游植物3门24属43种,主要为温带近岸性和广布性种.其中,硅藻门20属35种,占总种数的81.40%,以圆筛藻属(Coscinodiscus)和角毛藻属(Chaetoceros)的种类为主;甲藻类3属7种,占总种数的16.28%,由角藻属(Ceratium)、多甲藻属(Peridinium)及夜光藻(Noctiluca scintillans)组成;金藻门只有小等刺硅鞭藻(Dictyocha fibula)1种.浮游植物细胞丰度的平面分布主要由浮游硅藻的分布决定,其高值区位于套子湾北部湾口和西北部区域.多样性分析表明,该海域浮游植物群落结构比较稳定.聚类分析发现浮游植物基本可归为4大类群,不同群落类型间的组成呈显著性差异.%Features of phytoplankton community were studied, based on the survey data of Taozi Bay in autumn, 2010. The results showed that 43 phytoplankton species were identified altogether, belonging to 3 phyla with 24 genera, in which 81.40% were Bacillariophyta and 16.28% were Dinophyta. In Bacillariophyta, Coscinodiscus and Chaetoceros were the dominant groups in terms of species number while Dinophyta was composed of Ceratium, Peridinium and Noctiluca scintillans. In Chrysophta, only Dictyocha fibula was identified. The horizontal distribution of phytoplankton was mainly determined by the diatom distribution pattern. It was high in the north and northwest of Taozi Bay. Analysis of Shannon-Wiener index, Margalef index and Pielou index showed the community structure was stable. The species at 14 stations were grouped into four ecotypes with cluster analysis, and One-Way ANOSIM test of four cruises revealed significant differences in both global and for pairwise test.

  16. Fitoplancton del Parque Nacional Las Tablas de Daimiel. III. Diatomeas y clorofitas

    Rojo, Carmen


    Full Text Available Las Tablas de Daimiel National Park is an important semi-arid wetland, biodiversity reserve, that is experiencing an accelerated eutrophication process and dramatic hydrological changes in recent years. This paper reports the taxonomy, dynamics and ecology of 9 planktonic diatoms (2 centric, 7 pennate and 37 chlorophytes (24 coccoids. 8 flageflated and 5 species of other groups which were found from 1996 to 1998. Despite the higher diversity of Chlorococcales, diatoms made a major contribution to algal biomass. Most species are typical of eutrophic systems and some are salinity indicators (Chaetoceros muelleri. Scenedesmus quadricauda, Cyclotella meneghiniana and Nitzschia acicularis were the most common species. Pteromonas limnetica is a new record for Spain. There was a remarkable decrease in phytoplankton density and a 50 % species substitution in comparison to the drier period 1992-1993. Species distribution through the wetland was very heterogeneous spatially and temporally, without any pattern.El Parque Nacional Las Tablas de Daimiel es un humedal semiárido, importante como reserva de biodiversidad, que sufre un acelerado proceso de eutrofización y profundos cambios hidrológicos. En este trabajo se describen la taxonomía, la dinámica y la ecología de las 9 diatomeas (2 centrales, 7 pennadas y las 37 clorofitas (24 cocales, 8 flageladas y 5 especies de otros grupos recolectadas entre los años 1996-1998. La mayor parte de las especies son características de ambientes eutróñcos y algunas son indicadoras de salinidad (Chaetoceros muelleri. Las especies más abundantes fueron Scenedesmus quadricauda, Cyclotella meneghiniana y Nitzschia acicularis. Pteromonas limnetica es primera cita española. Con respecto al período de sequía de 1992-1993, se constata una considerable disminución en la densidad fitoplanctónica y una sustitución de especies del 50 %• Se observó una gran heterogeneidad espaciotemporal en la distribuci

  17. Pigment signatures of some diatoms isolated from China seas


    The photosynthetic pigments of 12 species (14 strains) of cultured diatoms from six genera under specific conditions were examined by the HPLC. The diatom genera were Skeletonema, Thalassiosira, Chaetoceros, Nitzschia, Phaeodactylum and Meuniera. All strains were isolated from China seas and most of them were from the Jiaozhou Bay, China. Fifteen pigments were identified and eight of them were various chlorophyll a derivatives. Chlorophyll a, c2 and c1 and the carotenoids fucoxanthin, diadinoxanthin, diatoxanthin and β,β-carotene existed in all species. The ratios of each pigment to chlorophyll a were compared with the results in literatures. The pigment ratios of this study generally fall within the ranges reported by the literatures although the maximum ratio of fucoxanthin to chlorophyll a was higher and the ratios of chlorophyll c and diatoxanthin to chlorophyll a were low. The pigment ratios are useful to understanding the pigment signatures of diatoms in the Jiaozhou Bay, China, and to setting up the chemotaxonomic method ofphytoplankton in these sea areas.

  18. Growth of microalgae in autotrophic stationary systems

    Paulo Cunha


    Full Text Available In this paper we evaluate the growth of nine marine microalgae species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp. and one freshwater species (Chlorella vulgaris under stationary autotrophy conditions, using erlenmeyers fl asks with 800mL of culture medium exposed to constant light intensities providing a photon flux density of about 150μmol.m-2.s-1 and 25±2oC temperature and constant air flow. The experiment was carried out in a controlled environment considering a block delineating randomized over time with three replicates. The Nannochloropsis oculata showed the highest value of maximum cellular density, but with a longer period of time and a lower growth rate. This was probably due to its tiny cell size, demanding a large number of cells per volume to attain its optimum conditions for light, nutrients, water and atmospheric carbon dioxide. In addition, in spite of showing one of the lowest values of maximum cellular density, Thalassiosira fluviatilis was the species that reached its maximum in a short period of time at the highest growth rate. Chlorella vulgaris was the only freshwater species tested and it showed the poorest performance for all the variables analyzed in the current study.

  19. Paradoxical effects of temperature and solar irradiance on the photodegradation state of killed phytoplankton.

    Amiraux, Rémi; Jeanthon, Christian; Vaultier, Frédéric; Rontani, Jean-François


    The aim of this paper was to study the effects of temperature and irradiance on the photodegradation state of killed phytoplankton cells. For this purpose, killed cells of the diatom Chaetoceros neogracilis RCC2022 were irradiated (photosynthetically active radiation) at 36 and 446 J · s(-1)  · m(-2) (for the same cumulative dose of irradiation energy) and at two temperatures (7°C and 17°C). Analyses of specific lipid tracers (fatty acids and sterols) revealed that low temperatures and irradiances increased photooxidative damages of monounsaturated lipids (i.e., palmitoleic acid, cholesterol and campesterol). The high efficiency of type II photosensitized degradation processes was attributed to: (i) the relative preservation of the sensitizer (chlorophyll) at low irradiances allowing a longer production of singlet oxygen and (ii) the slow diffusion rate of singlet oxygen through membranes at low temperatures inducing more damages. Conversely, high temperatures and irradiances induced (i) a rapid degradation of the photosensitizer and a loss of singlet oxygen by diffusion outside the membranes (limiting type II photosensitized oxidation), and (ii) intense autoxidation processes degrading unsaturated cell lipids and oxidation products used as photodegradation tracers. Our results may explain the paradoxical relationship observed in situ between latitude and photodegradation state of phytoplankton cells. PMID:26992328

  20. A biological source of oceanic alkyl nitrates

    Dahl, E. E.; Lewis, C. B.; Velasco, F. L.; Escobar, C.; Kellogg, D.; Velcamp, M.


    Alkyl nitrates are an important component of reactive nitrogen in the troposphere. The oceans are a source of alkyl nitrates to the atmosphere, however the source of alkyl nitrates in the oceans is unknown. It has been demonstrated that the reaction of alkyl peroxy radicals (ROO) with nitric oxide (NO) produces alkyl nitrates in the aqueous phase. We hypothesize that alkyl nitrates may be formed by organisms through the same reaction and therefore biological production could be a source of alkyl nitrates to the troposphere. This work focuses on the production of alkyl nitrates by the diatoms Chaetoceros muelleri and Thalassiosira weisfloggi. Using chemostats, we measure alkyl nitrates formed under nitrate limited conditions. We also use triggers and inhibitors of nitric oxide formation to determine if alkyl nitrate formation is affected by changes in NO production. To date, the rates of production of alkyl nitrates in our cultures, lead us to estimate a production rate on the order of femtomolar/day for C1-C3 alkyl nitrates by diatom species in the equatorial Pacific Ocean. This suggests that diatoms may contribute to the overall ocean source of alkyl nitrates; however, it is possible that other types of phytoplankton, such as cyanobacteria, that are more abundant in the open ocean, may contribute to a greater extent.

  1. Bioavailability of riverine dissolved organic matter to phytoplankton in the marine coastal waters

    Jurgensone, Iveta; Aigars, Juris


    Nutrient inputs from catchments with intensive agriculture are mostly dominated by inorganic nutrients, whereas the contribution of organic nutrients from catchments with natural forests can be considerable but there is a pooere understanding of this nutrient source. Consequently this study investigated spring, summer and autumn phytoplankton community responses to enrichment by riverine dissolved organic matter (DOM). Dissolved organic substances were extracted from the Daugava River, fractionated into three molecular size classes: 1) 5-100 kDa, 2) 100-1000 kDa, and 3) >1000 kDa, and added to a microcosm with natural assemblages from the Gulf of Riga. During the spring the phytoplankton community was dominated (97%) by diatoms and the species composition did not change over the course of the experiment. Specific species and functional groups of the summer and autumn phytoplankton communities responded positively to these treatments. Small-celled cyanobacteria and Monoraphidium contortum responded to almost all size fractions of DOM for the summer and autumn experiments. Oocystis spp. characteristic for the summer and Chaetoceros wighamii, Cyclotella spp., Thalassiosira baltica for the autumn responded to treatment by two and three size classes of organic substances, respectively, while Merismopedia spp. shifted from one food source to another during the summer experiment.

  2. MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

    Villacorte, Loreen O.


    Pretreatment with microfiltration (MF) or ultrafiltration (UF) membranes has been proposed for seawater reverse osmosis (SWRO) plants to address operational issues associated with algal blooms. Here, we investigated the MF/UF rejection and fouling potential of algal organic matter (AOM) released by common species of bloom-forming marine (Alexandrium tamarense and Chaetoceros affinis) and freshwater (Microcystis sp.) algae. Batch culture monitoring of the three algal species illustrated varying growth pattern, cell concentration, AOM released and membrane fouling potential. The high membrane fouling potential of the cultures can be directly associated (R2>0.85) with AOM such as transparent exopolymer particle (TEP) while no apparent relationship with algal cell concentration was observed. The AOM comprised mainly biopolymers (e.g., polysaccharides and proteins) and low molecular weight organic compounds (e.g., humic-like substances). The former were largely rejected by MF/UF membranes while the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans-membrane pressure (δP) over time, characterised by pore blocking followed by cake filtration with enhanced compression as illustrated by an exponential progression of δP. © 2015 Elsevier B.V.

  3. Impacta of CO2 enrichment on growth and photosynthesis in freshwater and marine diatoms

    HU Hanhua; GAO Kunshan


    The physiological responses of Nitzschia palea Kiitzing, a freshwater diatom, to elevated CO2 were investigated and compared with those of a marine diatom, Chaetoceros muelleri Lemmermann previously reported. Elevated CO2 concentration to 700 μl/L increased the dissolved inorganic carbon (DIC) and lowered the pH in the cultures of N. palea, thus enhancing the growth by 4%-20% during the whole growth period. High CO2-grown N. palea cells showed lower levels of dark respiration rates and higher Ik values. Light-saturated photosynthetic rates and photosynthetic efficiencies decreased in N. palea with the doubling CO2 concentration in airflow to the bottom of cultures, although the doubling CO2 concentration in airflow to the surface cultures had few effects on these two photosynthetic parameters. N. palea cells were found to be capable of using HCO3- in addition to gaseous CO2, and the CO2 enrichment decreased their affinity for HCO3- and CO2. Although doubled CO2 level would enhance the biomass of N. palea and C. muelleri to different extents, compared with the marine diatom, it had a significant effect on the specific growth rates of N. palea. In addition, the responses of photosynthetic parameters of N. palea to doubled CO2 concentration were almost opposite to those of C. muelleri.

  4. Headspace solid-phase microextraction with on-fiber derivatization for the determination of aldehydes in algae by gas chromatography-mass spectrometry.

    Ma, Jiping; Xiao, Ronghui; Li, Jinhua; Li, Jie; Shi, Benzhang; Liang, Yanjuan; Lu, Wenhui; Chen, Lingxin


    A simple, fast, sensitive and cost-effective method based on headspace solid-phase microextraction (HS-SPME) with on-fiber derivatization coupled with gas chromatography-mass spectrometry was developed for the determination of six typical aldehydes, 2E-hexenal, heptanal, 2E-heptenal, 2E,4E-heptadienal, 2E-decenal and 2E,4E-decadienal in laboratory algae cultures. As derivatization reagent, O-2,3,4,5,6-(pentafluorobenzyl) hydroxylamine hydrochloride, was loaded onto the poly(dimethylsiloxane)/divinylbenzene fiber for aldehydes on-fiber derivatization prior to HS-SPME. Various influence factors of extraction efficiency were systematically investigated. Under optimized extraction conditions, excellent method performances for all the six aldehydes were attained, such as satisfactory extraction recoveries ranging from 67.1 to 117%, with the precision (relative standard deviation) within 5.3-11.1%, and low detection limits in the range of 0.026-0.044 μg/L. The validated method was successfully applied for the analysis of the aldehydes in two diatoms (Skeletonema costatum and Chaetoceros muelleri), two pyrrophytas (Prorocentrum micans and Scrippsiella trochoidea) and Calanus sinicus eggs (feeding on the two diatoms above). PMID:21567947

  5. 2007年春夏季锦州湾浮游植物群落结构特征%Community structure of phytoplankton in Jinzhou Bay in spring and summer 2007

    杨世民; 李岿然; 白洁


    研究了2007年春季和夏季辽宁省锦州湾16个大面站网采浮游植物的群落结构特征.共检出浮游植物4门38属59种,在两个季节的调查中硅藻在物种数量和细胞丰度上占绝对优势.春季平均细胞丰度为5.44×104/m3,主要优势种为中肋骨条藻Skeletonema costatum和具槽帕拉藻Paralia sulcata;夏季平均细胞丰度为9.73×104/m3,主要优势种为扭链角毛藻Chaetoceros tortissimus和劳氏角毛藻C.lorenzianus.锦州湾春季细胞丰度高值区位于湾西部和东南部;夏季细胞丰度则呈现西高东低的分布趋势.两季节浮游植物的Shannon-Wiener指数值均较高,表明锦州湾春夏季浮游植物群落结构较稳定.

  6. Interactions of the algicidal bacterium Kordia algicida with diatoms: regulated protease excretion for specific algal lysis.

    Carsten Paul

    Full Text Available Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors.

  7. 20th century fluctuations in the abundance of siliceous microorganisms preserved in the sediments of the Puyuhuapi Channel (44° S, Chile Fluctuaciones en la abundancia de microorganismos silíceos preservados en los sedimentos del canal Puyuhuapi (44° S, Chile, durante el siglo XX



    Full Text Available We present a 100-year reconstruction of siliceous export production from sediments of the Puyuhuapi Channel (44° S, 70° W in the Chilean fjords. We use accumulation rates and concentrations of diatoms and silicoflagellates, organic carbon (Corg and biogenic opal (SiOPAL as proxies of export production, and fluctuations in the contribution of freshwater diatoms as proxies of rainfall in the hinterland and river runoff. Box core sediments collected at two sites within the Puyuhuapi Channel were analyzed: Station 35 (at the head of the fjord; 56 m water depth and Station 40 (in the middle of the Channel; 270 m water depth. Surface sedimentation rates were 0.75 cm yr-1 at Station 35 and 0.25 cm yr-1 at Station 40. SiOPAL content averaged ~ 4 % at both sites. Diatom accumulation rates as well as the contribution of freshwater diatoms were higher at the head of the fjord (1.59 10(10 valves m-2 yr-1 and 22 %, respectively than in its middle (1.08 10(10 valves m_2 yr_1 and 14 %, respectively. Diatom abundances were two orders of magnitude higher than silicoflagellate contribution at both sites. In general, diatoms typical of high nutrient environments characterize the Puyuhuapi Channel sediments: at both sites, spores of the genus Chaetoceros dominated the diatom assemblage (> 40 % of total diatoms; spores of Chaetoceros radicans/cinctus, Ch. constrictus/vanheurcki, Ch. debilis and Ch. diadema. Downcore analysis reveals an overall increase in the production of siliceous microorganisms from the late 19th century to the early 1980s, and then a decrease until the late-1990s. We associate a decrease in freshwater diatom contribution since the mid-1970s which we associate with a concomitant decline in rainfall in the Chilean fjords. We suggest that this decline is related to the global atmospheric and oceanic warming of the past ~ 25 yearsSe presenta una reconstrucción de 100 años de la productividad silícea exportada en sedimentos del canal Puyuhuapi

  8. Structure of late summer phytoplankton community in the Firth of Lorn (Scotland) using microscopy and HPLC-CHEMTAX

    Brito, Ana C.; Sá, Carolina; Mendes, Carlos R.; Brand, Tim; Dias, Ana M.; Brotas, Vanda; Davidson, Keith


    The Firth of Lorn is at the mouth of one of Scotland's largest fjordic sea lochs, Loch Linnhe. This sea loch, which is fed by a number of other inner lochs, supplies a significant flow of freshwater, which frequently causes the stratification of the water column. To investigate how environmental conditions influence the spatial distribution of phytoplankton in this region water samples were collected for phytoplankton (pigments and microscopy), and other environmental variables including nutrients. Chemotaxonomy was used to estimate the contribution of different taxonomic groups to total chlorophyll a (phytoplankton biomass index). Good agreement was obtained between chemotaxonomy and microscopy data. The highest levels of chlorophyll a (˜2.6 mg m-3) were found in the vicinity of Oban Bay, where cryptophytes, the most abundant group, dinoflagellates and other flagellates thrived in the stratified water column. Centric diatoms, mainly Chaetoceros sp. and Skeletonema costatum, were associated with NH4 and SiO2 concentrations and stratification, while pennate diatoms, mainly Cylindrotheca sp. and Nitzchia sp., were found to be associated with NO3 + NO2 and high surface mixed layer depths. Four diatom groups were identified in accordance to their surface to volume ratios, as well as their affinity to environmental parameters (nutrients) and turbulence. This study used a combination of physico-chemical data, classical microscopy methods (appropriate for large cells > 20 μm) and HPLC-CHEMTAX approaches (for large and small cells) to evaluate the distribution of phytoplankton functional groups in a fjordic coastal area.

  9. A suggested local regions in the Southern Gulf of Mexico using a diatom database (1979-2002) and oceanic hidrographic features.

    Licea, Sergio; Zamudio, Ma E; Moreno-Ruiz, J L; Luna, R


    A diatom data-base of 255 species obtained from 14 oceanographic cruises (14801 entries of 647 sampling sites) together with the analysis of oceanic features were used to establish four local regions in the southern Gulf of Mexico. In addition, common species for each region were designated. This study is based on the application of cluster analysis and the species frequency data. Material for this undertaking consisted of water and net samples obtained between June 1979 and December 2002. Results show that the most frequent species (> 40%) were: Asterionellopsis glacialis, Bacteriastrum delicatulum, B. hyalinum, Chaetoceros affinis, C. coarctatus, C. compresus, C. curvisetus, C. danicus, C. decipiens, C. diversus, C. lorenzianus, C. pelagicus, C. peruvianus, Coscinodiscus radiatus, Cylindrotheca closterium, Guinardia flaccida, Hemiaulus hauckii, H. membranaceus, H. sinensis, Leptocylindrus danicus, Neocalyptrella robusta, Nitzschia bicapitata, Pleurosigma diverse-striatum, Proboscia alata, Pseudo-nitzschia pungens, Pseudosolenia calcar-avis, Rhizosolenia imbricata, R. setigera, Skeletonema costatum, Thalassionema bacillare, T frauenfeldii, T nitzschioides and Thalassiosira eccentrica. The species composition for each region and season are discussed. Itis concluded that sampling site assemblages are related to oceanographic conditions. A total list of species composition is given, forty-seven species taxa being new records for this area. PMID:22315823

  10. Interactions of the algicidal bacterium Kordia algicida with diatoms: regulated protease excretion for specific algal lysis.

    Paul, Carsten; Pohnert, Georg


    Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors. PMID:21695044

  11. 南麂列岛海洋自然保护区浮游植物生态研究%Ecological study on netzphytoplankton in Nanji marine nature reserve area

    张晓辉; 周燕; 张成; 余俊; 卢毅军


    研究了南麂列岛海洋自然保护区浮游植物物种组成、数量分布、多样性指数及其与营养盐、浮游动物的关系.经鉴定,共发现浮游植物86种,隶属于33属.网样浮游植物平均密度为194.00×104个/m3,水样浮游植物平均密度为4.98×104个/m3,优势类群有角毛藻(Chaetoceros sp.)、角藻(Ceratuym sp.)、中肋骨条藻(Skeletonema costatum)、红色裸甲藻(Akashiwo sanyuineum)等.网样浮游植物多样性平均指数为2.28,水样浮游植物多样性平均指数为2.17.根据浮游植物组成特点,将其分为两个生态类群:近岸性和广布性类群,外海性类群.


    Sushanth Vishwanath Rai


    Full Text Available The seasonal variation of the hydrographic variables and phytoplankton species in the Arabian Sea waters of the Kerala coast, Southern India was investigated during different seasons. The variables such as pH, temperature, salinity, turbidity and chlorophyll-a contents of water were found to be high during pre-monsoon season and the dissolved oxygen content was minimal. The concentration of nutrients viz., nitrate, phosphate, silicate varied independently. In the study a total of 53 species of phytoplankton were recorded. Their density was higher during the post-monsoon season than during other seasons and the diatoms were found to be the dominant species. The major phytoplankton in terms of frequency and abundance were the species namely, Biddulphia mobiliensis, Chaetoceros curvisetus, Licmophora abbreviata, Skeletonema costatum, Prorocentrum micans and Oscillatoria sp. They showed significant positive correlation with pH, temperature, salinity, nitrate, phosphate and chlorophyll-a contents, whereas turbidity, dissolved oxygen and silicate exhibited significant negative correlation. The Principal Component Analysis (PCA developed two principal components with 84.74% of total variability in the water quality which separated pre- and post-monsoon periods from the monsoon season on axis I, and pre-monsoon and monsoon periods from post-monsoon on axis II.

  13. 胶州湾赤潮生物种类及其生态分布特征%Harmful algae bloom species in Jiaozhou Bay and the features of distribution

    韩笑天; 邹景忠; 张永山


    近年来,胶州湾赤潮发生频繁,对海水养殖业、海洋环境乃至人类健康与安全都构成威胁,作者根据 1997年 6~ 9月和 1998年 4~ 9月采于胶州湾东北部富营养化海域的样品及有关历史资料,报道了赤潮生物 69种, 其中已发生过的赤潮种类有 7种,分析了中肋骨条藻 Skeletonema costatum、圆筛藻 Coscinodiscus sp.、冰河拟星杆藻(日本星杆藻) Asterionellopsis glacialis、劳氏角毛藻 Chaetoceros lorenzianus、红色中缢虫 Mesodinium rubrum等主要赤潮生物的生态分布特征.

  14. [Yearly Changes of Phytoplankton Community in the Ecology-monitoring Area of Changli, Hebei in Summer].

    Liang, Xiao-lin; Yang, Yang; Wang, Yu-liang; Zhang, Yue-ming; Zhao, Zhi-nan; Han, Xiao-qing; Zhang, Jian-da; Gao, Wei-ming


    Based on the investigation of phytoplankton and water body nutrient concentration in the ecology-monitoring area of Changli in summer from 2005 to 2013, the phytoplankton community structure was analyzed. The result showed that in recent 9 years, 3 phyla including 23 families, 39 genera and 105 species of phytoplankton were identified, in which 85.7% were diatoms and 13.3% were dinoflagellate. Only one species was found belonging to golden algae. There was great difference in dominant species among different years. According to the value of dominance, there were Coscinodiscus radiatus, Coscinodiscus debilis, Rhizosolenia styliformis, Cerataulina bergoni, Coscinodiscus wailesii, Thalassiosira sp., Ceratium tripos, Chaetoceros lorenzianus, Skeletonema costatum. The cell abundance was decreased yearly. The Shannon-Wiener index of phytoplankton community ranged from 0.015 to 3.889, and the evenness index ranged from 0.009 to 1, which showed little yearly change. And phytoplankton species were unevenly distributed among the 19 sites, there were relatively low amount of dominant species, but the dominance was relatively high. Canonical Correspondence Analysis (CCA) results of the phytoplankton community and its environmental factors showed that the environmental factors influencing the change of phytoplankton community structure in summer included water temperature, nutrients (TP, TN and NO3(-) -N, NH4(+)-N) and salinity, and the structural change was the result of the interactions of different environmental factors. PMID:26164906

  15. Phytoplankton taxonomy based on CHEMTAX and microscopy in the northwestern Black Sea

    Eker-Develi, Elif; Berthon, Jean-François; Canuti, Elisabetta; Slabakova, Natalya; Moncheva, Snejana; Shtereva, Galina; Dzhurova, Boryana


    Abundance and carbon biomass of different phytoplankton groups obtained by microscopy were compared with taxonomy derived from pigment measurements and CHEMTAX analysis of samples collected in June 2006 in the NW Black Sea. The diatom Chaetoceros curvisetus was dominant in terms of carbon biomass based on cell volume at inshore stations, while the coccolithophore Emiliania huxleyi was prevalent at offshore. Emiliania huxleyi reached bloom abundance of 3.3 × 106 cells L- 1. The chlorophyll a (chl a) concentration within phytoplankton groups as allocated by CHEMTAX was in agreement with microscopy derived carbon biomasses of the taxonomic groups diatoms, dinoflagellates and cryptophytes only. Carbon biomass of less abundant phytoplankton taxa (cyanophytes, euglenophytes and chlorophytes) did not correlate with group-specific chl a. It was not possible to detect E. huxleyi bloom by CHEMTAX analysis probably due to much higher biomass of other species containing 19'-hexanoyloxyfucoxanthin. Nutrient concentrations were generally high in the waters where diatom and dinoflagellates dominated the community but low in the area of E. huxleyi bloom. A good correlation between total carbon biomass of phytoplankton and chl a was found and the estimated C:chl a ratio of phytoplankton varied between 36 and 256 (in average 124 ± 50).

  16. High interglacial diatom paleoproductivity in the westernmost Indo-Pacific Warm Pool during the past 130,000 years

    Romero, Oscar E.; Mohtadi, Mahyar; Helmke, Peer; Hebbeln, Dierk


    A wealth of sedimentary records aimed at reconstructing late Quaternary changes in productivity and temperature have been devoted to understanding linkages between the Indo-Pacific Warm Pool (IPWP) and other distant oceanic areas. Most of these reconstructions are based, however, on biogeochemical and sedimentological proxies, with comparatively less attention devoted to microfossils. A high-resolution (cycle. The diatom record provides evidence that diatom paleoproductivity was highest during interglacials, primarily due to the input of lithogenics and nutrients following the rise in sea level after full glacials. In addition, the co-variation of total diatom concentration and Northern Hemisphere forcing for Marine Isotope Stage 5 suggests a direct response of diatom productivity and upwelling intensity to boreal summer insolation. Temporal shifts of the diverse diatom community at site GeoB10038-4 correspond well with the present-day seasonal monsoon pattern and the strengthening and weakening phases of upwelling along the southern coast of Sumatra. Resting spores ofChaetoceros, typical of nutrient-rich waters, were dominant during periods of highest diatom paleoproductivity and responded to the strengthening of the SE monsoon, while diatoms of oligotrophic to mesotrophic waters characterized intermonsoon periods. The close correspondence between the dominance of upwelling diatoms and the boreal summer insolation resembles the present-day dynamics of diatom production. The observed interglacial highs and glacial lows of diatom productivity at site GeoB10038-4 is a unique pattern in the late Quaternary tropics.

  17. Deglacial diatom productivity and surface ocean properties over the Bermuda Rise, northeast Sargasso Sea

    Gil, Isabelle M.; Keigwin, Lloyd D.; Abrantes, Fatima G.


    Diatom assemblages document surface hydrographic changes over the Bermuda Rise. Between 19.2 and 14.5 ka, subtropical diatom species and Chaetoceros resting spores dominate the flora, as in North Atlantic productive regions today. From 16.9 to 14.6 ka, brackish and fresh water diatoms are common and their contribution is generally coupled with total diatom abundance. This same interval also contains rare grains of ice-rafted debris. Coupling between those proxies suggests that successive discharge of icebergs might have stimulated productivity during Heinrich event 1 (H1). Iceberg migration to the subtropics likely created an isolated environment involving turbulent mixing, upwelled water, and nutrient-rich meltwater, supporting diatom productivity in an otherwise oligotrophic setting. In addition, the occurrence of mode water eddies likely brought silica-rich waters of Southern Ocean origin to the euphotic zone. The persistence of lower-salinity surface water beyond the last ice rafting suggests continued injection of fresh water by cold-core rings and advection around the subtropical gyre. These results indicate that opal productivity may have biased estimates of meridional overturning based on 231Pa/230Th ratios in Bermuda Rise sediments during H1.

  18. Evaluación del crecimiento y supervivencia en larvas de camarón blanco Litopenaeus vannamei usando como fuente de alimento microalgas vivas y congeladas

    Elifonso Isiordia Pérez:


    Full Text Available Resumen matraces de 1.5 litros de capacidad con 5 El objetivo del presente rabajo fue evaluar el eplicas cada tratamiento. La densidad de efecto de una dieta monoalgal a base de dos microalgas a suministrar fue de 50,000 células presentaciones Tetraselmis sp. (vivas y / mililitro. Conforme mudaban de estadio se congeladas:producto comercial: INLAND hacía conteo de organismos vivos y se media Seafarm® en la supervivencia y crecimiento longitud El mayor porcentaje de supervivencia en larvas de camarón blanco Litopenaeus y crecimiento se registró en las larvas vannamei en estadios larvales desde limentadas con Tetraselmis sp. vivas (97.3 Protozoea 1 (PZ1 a Protozoea 3 (PZ3. El ±4.6 en PZI, 94.1 ± 2.13 en PZ2 y 30.7±12.6 experimento se realizó en las instalaciones del en PZ3. Sin embargo este resultado no es Centro de Investigación en Alimentación y comparable a los obtenidos con otras especies Desarrollo (CIAD, Unidad Mazatlán Sinaloa. El de microalgas como Chaetoceros muelleri e estudio se realizó bajo condiciones controladas Isochrysis galbana. de temperatura (28°C, salinidad (35‰ y fotoperiodo (12 h luz / oscuridad. Se sembraron 150 organismos en nauplio V en

  19. Compositional Similarities and Differences between Transparent Exopolymer Particles (TEP) from two Marine Bacteria and two Marine Algae: Significance to Surface Biofouling

    Li, Sheng


    Transparent-exopolymer-particles (TEP) have been recently identified as a significant contributor to surface biofouling, such as on reverse osmosis (RO) membranes. TEP research has mainly focused on algal TEP/TEP precursors while limited investigations have been conducted on those released by bacteria. In this study, TEP/TEP precursors derived from both algae and bacteria were isolated and then characterized to investigate their similarities and/or differences using various advanced analytical techniques, thus providing a better understanding of their potential effect on biofouling. Bacterial TEP/TEP precursors were isolated from two species of marine bacteria (Pseudidiomarina homiensis and Pseudoalteromonas atlantica) while algal TEP/TEP precursors were isolated from two marine algae species (Alexandrium tamarense and Chaetoceros affinis). Results indicated that both isolated bacterial and algal TEP/TEP precursors were associated with protein-like materials, and most TEP precursors were high-molecular-weight biopolymers. Furthermore all investigated algal and bacterial TEP/TEP precursors showed a lectin-like property, which can enable them to act as a chemical conditioning layer and to agglutinate bacteria. This property may enhance surface biofouling. However, both proton nuclear magnetic resonance (NMR) spectra and the nitrogen/carbon (N/C) ratios suggested that the algal TEP/TEP precursors contained much less protein content than the bacterial TEP/TEP precursors. This difference may influence their initial deposition and further development of surface biofouling.

  20. Effect of diet quality on mussel biomarker responses to pollutants.

    González-Fernández, Carmen; Lacroix, Camille; Paul-Pont, Ika; Le Grand, Fabienne; Albentosa, Marina; Bellas, Juan; Viñas, Lucía; Campillo, Juan A; Hegaret, Helene; Soudant, Philippe


    The effect of the quality of two microalgal species on select biological and biochemical responses used as indicators of pollution were assessed. Mussels were conditioned for 6 weeks with the diatom Chaetoceros neogracile and the dinoflagellate Heterocapsa triquetra, chosen for being two clearly different types of primary production quality that differ in both biometric and biochemical characteristics. After dietary conditioning, the mussels were exposed to a polycyclic aromatic hydrocarbon, fluoranthene (FLU), for 1 week followed by 1 week of depuration. Results showed higher FLU accumulation in mussels fed on C. neogracile compared to those fed on H. triquetra. Concomitantly, a greater impact of this toxicant was observed in the biomarker responses of mussels fed on C. neogracile. These mussels showed an increase in the percentage of dead hemocytes, an activation of phagocytosis and ROS production of hemocytes after exposure. Some enzymatic activities also increased upon FLU exposure (superoxide dismutase -SOD-, catalase -CAT-, and glutathione reductases -GR-) and after depuration (glutathione-s-transferase -GST-). Results suggest that FLU exposure as well as food quality influence biomarker responses, with higher values of SOD, CAT and GR in non-exposed mussels fed on C. neogracile. In addition, upon exposure to the same FLU concentration, GR response varied according to dietary conditioning, suggesting that diet could act as a confounding factor in biomarker responses to pollution. Consequently, trophic conditions should be considered in marine pollution monitoring programs for a better interpretation of biomarker responses. PMID:27300503

  1. Accumulation of tritium in aquatic organisms through a food chain with three trophic levels

    Accumulation of tritium in aquatic organisms was estimated through a model food chain such as; tritiated water (THO) → diatoms → brine shrimps → Japanese killifish. Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where tritium accumulation took place from tritiated water without tritiated diets. Brine shrimps and Japanese killifish, which grew from larvae to adult in tritiated sea water with feeding on tritiated diets (model food chain), had the R value at 0.70 and 0.67 respectively, indicating that more tritium accumulation in consumer populations with tritiated diets than those without tritiated diets. In addition, the R values of each organ of Japanese killifish, of DNA and the nucleotides purified from brine shrimps growing under the condition with or without our model food chain were measured to estimate the tritium distribution in the body or various components of the organism. These results did not indicate the seeking characteristic of tritium to some specific organs of compounds. (author)

  2. Application of a laser fluorometer for discriminating phytoplankton species

    Chen, Peng; Pan, Delu; Mao, Zhihua


    A portable laser-induced fluorescence system for discriminating phytoplankton species has been developed. It consists of a high pulsed repetition frequency (10-kHz) microchip laser at 405 nm, a reflective fluorescent probe and a broadband micro spectrometer. The measured fluorescent spectra were overlapped by various fluorescent components, and were then decomposed by a bi-Gaussian mixture model. A spectral shape description index was designed to characterize fluorescent spectral shapes for descriminating the phytoplankton species cultured in our laboratory. Using clustering analysis, the samples of eight phytoplankton species belonging to two divisions of Bacillariophyta and Dinophyta were divided into six categories: 1) Chaetoceros debilis, Thalassiosira rotula; 2) Prorocentrum donghaiense, Prorocentrum dentatum; 3) Gymnodinium simplex; 4) Alexandrium tamarense; 5) Karenia mikimotoi; and 6) Akashiwo sanguinea. The phytoplankton species belonging to Bacillariophyta were well separated from those belonging to Dinophyta. In addition, the phytoplankton species belonging to Dinophyta were successfully distinguished from each other at genus level. The portable system is expected to be used both in vivo and in the field.


    Sanda Skejić


    Full Text Available The aim of this study was to establish phytoplankton composition at the sea bream (Sparus aurata and sea bass (Dicentrarchus labrax fish farm in the middle Adriatic Sea. The investigation was performed from September 2005 to September 2006 at a station located in Maslinova Bay at the island of Brač. Considering the whole research period, diatoms generally prevailed in terms of abundance while dinoflagellates were particularly abundant in June. Number of species of diatoms in comparison to dinoflagellates through the investigated period was similar. From 111 species of phytoplankton found, there were 55 species of Bacillariophyceae (diatoms, 47 species of Dinophyta (dinoflagellates, 5 species of Prymnesiophyceae, 3 Chrysophyceae and 1 Euglenophyta. Among the diatoms, the majority of species belonged to genus Chaetoceros. The most represented dinoflagellate genera were Oxytoxum and Gymnodinium. There were no considerable differences in phytoplankton composition with respect to different depths, but seasonal influence was significant. Biodiversity and abundance ranges of phytoplankton species indicated good water conditions and there were no evident alterations induced by the increased release of nutrients.

  4. Cadmium and zinc capture capacity by bacteria, microalgae and yeast

    María Elena Carballo


    Full Text Available The elimination of toxic heavy metals present in wa-tery solutions has been performed with the employ-ment of biosorbent materials coming from microbial sources, considering the capacities they have for the metallic ions uptake. Microbial sivings to deter-mine metal uptake level is the base in order to find appropriate biosorbents for its application in this process, aspect that has been the principal objective in the present work. The cadmium and zinc uptake capacity was evaluated in different microorganisms such as Gram positive and Gram negative bacterias, phototrophic bacteria, microalgae and yeasts. The capture levels of both metals were variable among the strains, which indicate different uptake capaci-ties of cadmium and zinc. The best biosorbents from 64 analyzed microorganisms were: isolated bacteria CB-M4 y A-6, Pseudomonas mendocina, Anabaena sp. PCC 7120, Anabaena variabilisATCC 29413, Chloroglocopsis fritschii, Chaetoceros ceratospho-rus, Tetraselmis suesica,isolated microalgae CM3, CM5, CM6 y CMV and the strains 10 and 12 of the yeast Saccharomyces cerevisiae.

  5. A metabolic profile in Ruditapes philippinarum associated with growth-promoting effects of alginate hydrolysates

    Yamasaki, Yasuhiro; Taga, Shigeru; Kishioka, Masanobu; Kawano, Shuichi


    The aim of this study is to demonstrate the growth-promoting effect of alginate hydrolysates (AHs) on the Manila clam Ruditapes philippinarum, and to verify the physiological change occurring within a living R. philippinarum stimulated by AHs. We show that growth of clams was dramatically promoted by supplementing a diet of the diatom Chaetoceros neogracile with AHs at 4 mg/mL. Furthermore, metabolomics indicates that each state of starvation, food satiation, and sexual maturation have a characteristic pattern. In the groups given AHs in addition to C. neogracile in particular, excess carbohydrate was actively utilized for the development of reproductive tissue. In contrast, it appeared that clams in the groups given C. neogracile only were actively growing, utilizing their adequate carbohydrate resources. Meanwhile, the unfed groups have slowed growth because of the lack of an energy source. Hence, supplementation of AHs in addition to the algal diet may be an inexpensive way to shorten the rearing period of R. philippinarum. Moreover, metabolomics can evaluate the growth condition of R. philippinarum in a comprehensive way, and this approach is crucially important for not only the development of a mass culture method but also for the conservation of the clam resource in the field.

  6. Distribution of diatoms in the water and surface sediments of southern South China Sea

    LU Jun; CHEN Muhong; CHEN Zhong


    The relationship of species and abundance between the diatoms in the water and sediments from the southern South China Sea (SCS) were discussed, and the key environmental controlling factors were also investigated. Studies show that the diatom abundance is high in both water and sediments in the southeast part of the southern SCS and the varying trend is similar, while in the northwest part, the abundance is low, and the varying trend is different. The dominant diatom species are Thalassionema nitzschioides and Nitzschia bicapitata in water, and T. nitzschioides and Chaetoceros messanensis in sediments. The diatom species of small size and thin shell in water are more than in the sediments, while the diatom species of large size and thick shell in water are less. The percentage of species T. nitzschioides is higher in water of southeast part than in that of northwest part, but it is similar in sediments of both areas. It is shown that the southwest monsoon is the important factor influencing diatom abundance and T. nitzschioides percentage,and when the southwest monsoon is well developed,the distribution of diatom abundance and T. nitzschioides percentage are consistent in both water and sediments of the study area.

  7. Microbenthic community structure and trophic status of sediments in the Mar Piccolo of Taranto (Mediterranean, Ionian Sea).

    Rubino, F; Cibic, T; Belmonte, M; Rogelja, M


    This study aimed to assess the benthic ecosystem trophic status in a heavily polluted marine area and the response of the microbenthic community to multiple and diffuse anthropogenic impacts, integrating information coming from the active and resting (plankton's cysts) components of microbenthos. Two sampling campaigns were carried out in the period 2013-2014 and four sampling sites at different levels of industrial contamination were chosen within the first and second inlet of the Mar Piccolo of Taranto. The chemical contamination affected to a higher extent the active microbenthos than the resting one. In the central part of the first inlet, characterised by more marine features, thrives a very rich and biodiverse microbenthic community. In contrast, at the polluted site near the military navy arsenal, extremely low densities (9576 ± 1732 cells cm(-3)) were observed for active microbenthos, but not for the resting community. Here, the high level of contamination selected for tychopelagic diatom species, i.e., thriving just above the surface sediments, while the other life forms died or moved away. Following the adoption of a 10 μm mesh, for the first time, resting spores produced by small diatoms of the genus Chaetoceros were found. Our results further indicate that although the Mar Piccolo is very shallow, the benthic system is scarcely productive, likely as a consequence of the accumulated contaminants in the surface sediments that probably interfere with the proper functioning of the benthic ecosystem. PMID:26511257

  8. Bacterial and protist community changes during a phytoplankton bloom

    Pearman, John K.


    The present study aims to characterize the change in the composition and structure of the bacterial and microzooplankton planktonic communities in relation to the phytoplankton community composition during a bloom. High-throughput amplicon sequencing of regions of the 16S and 18S rRNA gene was undertaken on samples collected during a 20 day (d) mesocosm experiment incorporating two different nutrient addition treatments [Nitrate and Phosphate (NPc) and Nitrate, Phosphate and Silicate (NPSc)] as well as a control. This approach allowed us to discriminate the changes in species composition across a broad range of phylogenetic groups using a common taxonomic level. Diatoms dominated the bloom in the NPSc treatment while dinoflagellates were the dominant phytoplankton in the control and NPc treatment. Network correlations highlighted significant interactions between OTUs within each treatment including changes in the composition of Paraphysomonas OTUs when the dominant Chaetoceros OTU switched. The microzooplankton community composition responded to changes in the phytoplankton composition while the prokaryotic community responded more to changes in ammonia concentration.

  9. Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

    Villacorte, Loreen O.


    Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems. The goal of this study is to understand the production, composition and membrane rejection of these organic materials using different characterisation techniques. Two common species of bloom-forming freshwater and marine algae were cultivated in batch cultures for 30days and the productions of TEP and other organic matter were monitored at different growth phases. TEP production of the marine diatom, Chaetoceros affinis, produced 6-9 times more TEP than the freshwater blue-green algae, Microcystis. The organic substances produced by both algal species were dominated by biopolymeric substances such as polysaccharides (45-64%) and proteins (2-17%) while the remaining fraction comprises of low molecular weight refractory (humic-like) and/ or biogenic organic substances. MF/UF membranes mainly rejected the biopolymers but not the low molecular weight organic materials. MF membranes (0.1-0.4 lm) rejected 42-56% of biopolymers, while UF membranes (10-100 kDa) rejected 65-95% of these materials. Further analysis of rejected organic materials on the surface of the membranes revealed that polysac-charides and proteins are likely responsible for the fouling of MF/UF systems during an algal bloom situation. © 2013 Desalination Publications.

  10. Phylogenetic analysis of microalgae based on highly abundant proteins using mass spectrometry.

    Lee, Hae-Won; Roh, Seong Woon; Cho, Kichul; Kim, Kil-Nam; Cha, In-Tae; Yim, Kyung June; Song, Hye Seon; Nam, Young-Do; Oda, Tatsuya; Chung, Young-Ho; Kim, Soo Jung; Choi, Jong-Soon; Kim, Daekyung


    The blooms of toxic phototrophic microorganisms, such as microalgae and cyanobacteria, which are typically found in freshwater and marine environments, are becoming more frequent and problematic in aquatic systems. Due to accumulation of toxic algae, harmful algal blooms (HABs) exert negative effects on aquatic systems. Therefore, rapid detection of harmful microalgae is important for monitoring the occurrence of HABs. Mass spectrometry-based methods have become sensitive, specific techniques for the identification and characterization of microorganisms. Matrix-assisted laser desorption/ionization (MALDI) with time-of-flight (TOF) mass spectrometry (MS) allows us to measure a unique molecular fingerprint of highly abundant proteins in a microorganism and has been used for the rapid, accurate identification of bacteria and fungi in clinical microbiology. Here, we tested the specificity of MALDI-TOF MS using microalgal strains (Heterocapsa, Alexandrium, Nannochloropsis, Chaetoceros, Chlorella, and Dunaliella spp.). Our research suggested that this method was comparable in terms of the rapid identification of microalgea to conventional methods based on genetic information and morphology. Thus, this efficient mass spectrometry-based technique may have applications in the rapid identification of harmful microorganisms from aquatic environmental samples. PMID:25476355