Sample records for ohmi papenfuss gracilariales
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Xie, Xiujun; Wang, Guangce; Pan, Guanghua; Gao, Shan; Xu, Pu; Zhu, Jianyi
2010-04-28
Red algae are primitive photosynthetic eukaryotes, whose spores are ideal subjects for studies of photosynthesis and development. Although the development of red alga spores has received considerable research attention, few studies have focused on the detailed morphological and photosynthetic changes that occur during the early development of tetraspores of Gracilaria vermiculophylla (Ohmi) Papenfuss (Gracilariales, Rhodophyta). Herein, we documented these changes in this species of red algae. In the tetraspores, we observed two types of division, cruciate and zonate, and both could develop into multicellular bodies (disks). During the first 84 hours, tetraspores divided several times, but the diameter of the disks changed very little; thereafter, the diameter increased significantly. Scanning electron microscopy observations and analysis of histological sections revealed that the natural shape of the disk remains tapered over time, and the erect frond grows from the central protrusion of the disk. Cultivation of tissue from excised disks demonstrated that the central protrusion of the disk is essential for initiation of the erect frond. Photosynthetic (i.e., PSII) activities were measured using chlorophyll fluorescence analysis. The results indicated that freshly released tetraspores retained limited PSII photosynthetic capabilities; when the tetraspores attached to a substrate, those capabilities increased significantly. In the disk, the PSII activity of both marginal and central cells was similar, although some degree of morphological polarity was present; the PSII photosynthetic capabilities in young germling exhibited an apico-basal gradient. Attachment of tetraspores to a substrate significantly enhanced their PSII photosynthetic capabilities, and triggered further development. The central protrusion of the disk is the growth point, may have transfer of nutritive material with the marginal cells. Within the young germling, the hetero-distribution of PSII
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Directory of Open Access Journals (Sweden)
Gao Shan
2010-04-01
Full Text Available Abstract Background Red algae are primitive photosynthetic eukaryotes, whose spores are ideal subjects for studies of photosynthesis and development. Although the development of red alga spores has received considerable research attention, few studies have focused on the detailed morphological and photosynthetic changes that occur during the early development of tetraspores of Gracilaria vermiculophylla (Ohmi Papenfuss (Gracilariales, Rhodophyta. Herein, we documented these changes in this species of red algae. Results In the tetraspores, we observed two types of division, cruciate and zonate, and both could develop into multicellular bodies (disks. During the first 84 hours, tetraspores divided several times, but the diameter of the disks changed very little; thereafter, the diameter increased significantly. Scanning electron microscopy observations and analysis of histological sections revealed that the natural shape of the disk remains tapered over time, and the erect frond grows from the central protrusion of the disk. Cultivation of tissue from excised disks demonstrated that the central protrusion of the disk is essential for initiation of the erect frond. Photosynthetic (i.e., PSII activities were measured using chlorophyll fluorescence analysis. The results indicated that freshly released tetraspores retained limited PSII photosynthetic capabilities; when the tetraspores attached to a substrate, those capabilities increased significantly. In the disk, the PSII activity of both marginal and central cells was similar, although some degree of morphological polarity was present; the PSII photosynthetic capabilities in young germling exhibited an apico-basal gradient. Conclusions Attachment of tetraspores to a substrate significantly enhanced their PSII photosynthetic capabilities, and triggered further development. The central protrusion of the disk is the growth point, may have transfer of nutritive material with the marginal cells. Within
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Sfriso, A.; Wolf, M. A.; Maistro, S.; Sciuto, K.; Moro, I.
2012-12-01
Gracilaria vermiculophylla (Ohmi) Papenfuss, an invasive Rhodophyta recently recorded in the Po Delta lagoons (May 2008), was also found in the Venice lagoon in March 2009 and successively in Pialassa della Baiona (Emilia-Romagna Region) in May 2009. The species has colonized the eutrophic and confined areas of Venice by pleustophytic tangled populations (5-15 kg fwt m-2), replacing the allochthonous species whereas it is absent in the areas characterized by low nutrient availability and high water exchange. In contrast, in the Po Delta lagoons and in Pialassa della Baiona it is present everywhere, also with high water renewal, because of the eutrophication caused by the Po river and the industrial area of Ravenna. This study presents the autoecology and distribution of G. vermiculophylla in the above environments, according to their different eutrophication status, showing its relationship with physico-chemical parameters and nutrient concentrations in water column, pore-water, surface sediments and particulate matter collected by traps in a station of the Venice lagoon (Teneri) sampled monthly during one year. Furthermore, we give new information on its morphology and the high dimorphism between female and male gametophytes and tetrasporophytes.
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Study of an instability of the PEP-II positron beam (Ohmi effect and Multipactoring)
Energy Technology Data Exchange (ETDEWEB)
Heifets, S A [Stanford Linear Accelerator Center, Menlo Park, CA (United States)
1996-08-01
The processes defining the density distribution of the photoelectrons are quite complicated. In this study, a simplified model of the instability was used to get a quick estimate of the growth rate of the instability and the relative importance of the parameters, as has been done in Ohmi`s paper. The production rate and dynamics of the photoelectrons are studied for the PEP-II parameters. The growth rate of the transverse instability driven by the primary photoelectrons is of the order of 0.7 msec for the PEP-II parameters. The multipactoring at resonance currents cannot produce large electron density due to the final energy spread caused by the finite bunch length and the intrinsic energy spread of the secondary electrons. Production of the secondary electrons may lead to large average densities. The ion can be produced in electron collisions with the residual gas with density of the order of the electron density. (G.K.)
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Study of an instability of the PEP-II positron beam (Ohmi effect and multipactoring)
International Nuclear Information System (INIS)
Heifets, S.A.
1995-11-01
The paper is organized in the following way. First, Ohmi effect induced by direct flow of primary photoelectrons is studied for the PEP-II parameters. The production rate and kinematics take into account the antechamber of the LER. We discuss the effect of the secondary emission of electrons in the AL chamber, where the yield is larger than one. Resonance multipactoring is considered, and then the average density of the secondary electrons is estimated taking into account the space-charge effect and the interaction with the beam. We show that in the extreme case there is a self-consistent regime similar to the regime of the space-charge dominated cathode. Finally, the rate of ion production by accumulated electrons and the possibility of the ion induced pressure instability is discussed
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DEFF Research Database (Denmark)
Höffle, Hannes; Thomsen, M.S.; Holmer, M.
2011-01-01
The present study tested for density-dependent effects of the invasive drift macroalgae Gracilaria vermiculophylla (Ohmi) Papenfuss on growth and survival of the native eelgrass, Zostera marina L., under different temperature levels. Three weeks laboratory experiments were conducted in Odense......, Denmark, combining three algae densities (control, low 1.9 kg WW m2, high 4.5 kg WW m2) with typical Danish summer temperatures (18 C) and elevated temperatures (21 C and 27 C). There was a significant effect of temperature on shoot survival with on average 68% mortality in the high temperature treatment...... but almost no mortality at the two lower temperatures. The higher mortality was probably caused by high sulphide levels in the sediment pore water (0.6 mmol l1 at 18 C compared to 3.7 mmol l1 at 27 C). Above-ground growth of the surviving shoots was also significantly affected by temperature, with leaf...
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Directory of Open Access Journals (Sweden)
Plastino Estela M.
1999-01-01
Full Text Available Agar is the most valuable phycocoloid in the world market. Currently, about half of its production is obtained from the red alga Gracilaria (Gracilariales, Rhodophyta. Consequently, this genus has been the subject of many studies worldwide. A common green color variant of G. domingensis (Kützing Sonder ex Dickie was found in a natural population on the northeastern coast of Brazil. Crosses were performed to determine the mode of color inheritance. The results can be interpreted as the expression of a pair of codominant alleles, where the green and red phenotypes are homozygous, and the heterozygotes present a brownish color. Heterozygous tetrasporophytes, at least until they are 4-5 cm long, exhibit a parental influence on the female gametophyte, since the reddish-brown or greenish-brown color is dependent on the female parent color (red or green. Mixed reproductive phases, as well as specimens with patches of different colors bearing spermatangia or cystocarps, were observed in laboratory cultures. Gametophytes that resulted from in situ germination of meiospores were also observed, and could be easily detected when red or green gametophytes were grown on brown tetrasporophytes.
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Directory of Open Access Journals (Sweden)
Filemon Jalu N Putra
2014-12-01
Full Text Available Gracilaria verrucosa (Hudson Papenfuss has great potential to be farmed in the water resources in Indonesia. As natural resource, the weed has a major contribution in the field of industry both for human food and health. Efforts have been done intensively to increase the production capacity to meet the market demand especially gelatin, both national and international market. One of them is the application of plasma corona irradiation treatments on the weed to improve developmental pathways. The concept of plasma irradiation performed at atmospheric conditions may impact on nitrogen intrusion pathway that is important element in the growth of the weed. The aims of this study are to assess the potential impact of plasma irradiation in improving the growth of G. verrucosa and thus increase their biomass production. The treatments were done using five different duration of plasma irradiation, which were 2, 4, 6, 8, and 10 minutes at a 0,5mA stable source of voltage and 8kV of electrical current. Observations of growth rate include thallus length and biomass of G. verrucosa , that was observed every week for 28 days. The result showed that the growth of weed exhibited better than those without radiation. The best growth was reached in the group of treatment of 8 minutes irradiation, exhibited 65,91g of biomass and 9.5515% growth rate and length of thallus reached 22,33 cm and daily growth rate of 2.9759%. The lowest growth of the weed occurred in the treatment of 10 minutes irradiation, which was 44,82 g biomass, 8.123% growth rate, 17,13 cm thallus length with a daily growth rate of 1.9942%
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Directory of Open Access Journals (Sweden)
Fernanda Ramlov
2011-05-01
Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.
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Directory of Open Access Journals (Sweden)
Fernanda Ramlov
2011-04-01
Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.
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DEFF Research Database (Denmark)
Thomsen, Mads S.; Stæhr, Peter Anton; Nyberg, Cecilia D.
2007-01-01
Gracilaria vermiculophylla, a red macroalga from the West Pacific, was discovered in western Germany (the Wadden Sea) in 2002 and has since also been observed in Sweden (from about 70 km south to about 80 km north of Göteborg), Denmark (Wadden Sea, Horsens Fjord, Limfjorden, Vejle Fjord, Holckenh......Gracilaria vermiculophylla, a red macroalga from the West Pacific, was discovered in western Germany (the Wadden Sea) in 2002 and has since also been observed in Sweden (from about 70 km south to about 80 km north of Göteborg), Denmark (Wadden Sea, Horsens Fjord, Limfjorden, Vejle Fjord......-bottom estuaries and bays, typically in association with ubiquitous native invertebrates (lugworms, tube-building worms, mussels, cockles, snails). The invertebrates provide substratum for holdfast attachment and thalli incorporation, most likely increasing the stability of local G. vermiculophylla populations. We...
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Höffle, H.; Thomsen, M. S.; Holmer, M.
2011-03-01
The present study tested for density-dependent effects of the invasive drift macroalgae Gracilaria vermiculophylla (Ohmi) Papenfuss on growth and survival of the native eelgrass, Zostera marina L., under different temperature levels. Three weeks laboratory experiments were conducted in Odense, Denmark, combining three algae densities (control, low 1.9 kg WW m -2, high 4.5 kg WW m -2) with typical Danish summer temperatures (18 °C) and elevated temperatures (21 °C and 27 °C). There was a significant effect of temperature on shoot survival with on average 68% mortality in the high temperature treatment but almost no mortality at the two lower temperatures. The higher mortality was probably caused by high sulphide levels in the sediment pore water (0.6 mmol l -1 at 18 °C compared to 3.7 mmol l -1 at 27 °C). Above-ground growth of the surviving shoots was also significantly affected by temperature, with leaf elongation rates being negatively affected, while the leaf plastochrone interval increased. Relative growth rate was significantly higher at 21 °C than at 18 °C or 27 °C, whereas rhizome elongation was significantly lowest at 27 °C. Elemental sulphur content in the plant tissues increased significantly with temperature and was up to 34 times higher (S 0 in rhizomes) at 27 °C compared to the lower temperatures. In contrast to the temperature effects, cover by G. vermiculophylla did not cause significant effects on any seagrass responses. However, there was a (non-significant) negative effect of algal cover at the highest temperature, where the seagrass is already stressed. The latter results suggest that more studies should test for interaction effects between temperature and other anthropogenic stressors given that temperature is predicted to increase in the near future.
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African Journals Online (AJOL)
Items 751 - 800 of 1050 ... ... Seasonal changes in phytoplankton biomass on the Western Agulhas bank, ... (Gracilariales, Rhodophyta) from Western Australia, Abstract ... species in the Tsitsikamma National Park no-take marine reserve, Abstract.
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Digital Repository Service at National Institute of Oceanography (India)
Dhargalkar, V.K.
th Symp. on Polar Biology, Nat. Inst. Pf Polar Research. Tokyo. Mem. natn. lnst. polar Res. Tokyo(Spec.Issue).32: l12-116. Papenfuss, G. F. 1964. Catalogue and bibliography of Antarctic and sub- antarctic benthic marine algae. Am. Geophys. Union...
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African Journals Online (AJOL)
Mwaluma, J. Vol 3, No 2 (2004) - Articles Taxonomic Challenges and Distribution of Gracilarioid Algae (Gracilariales, Rhodophyta) in Tanzania Abstract PDF · Vol 3, No 2 (2004) - Articles Composition, Abundance and Distribution of Brachyuran Larvae in Mida creek, Kenya Abstract PDF. ISSN: 0856-860X. AJOL African ...
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African Journals Online (AJOL)
Fotedar, R. Vol 33, No 1 (2011) - Articles Seasonal variations of agar extracted from different life stages of Gracilaria cliftonii (Gracilariales, Rhodophyta) from Western Australia Abstract. ISSN: 1814-232X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about ...
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Characterisation of botanical starches as potential substitutes of ...
African Journals Online (AJOL)
user
2015-02-16
Feb 16, 2015 ... African Journal of Biotechnology. Full Length ..... absorbance, e is the molar absorptivity with units of L mol-1 cm-1, b is the path length of the ... 0.5 ml was drawn to be mixed with 0.5 ml of de-Ionized water followed by adding 5 ml ..... seaweed Gracilaria dura (Gracilariales, Rhodophyta). Bioresour. Technol.
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Gracilaria chilensis(Gracilariales, Rhodophyta
Directory of Open Access Journals (Sweden)
Maximiliano D. Garcia
2007-01-01
Full Text Available Gracilaria chilensis es un alga roja agarófita perteneciente a la clase Florideophyceae. En este estudio se describe la formación de pelos en talos mantenidos en cultivo en agua de mar enriquecida, bajo condiciones controladas de luz y temperatura. La inducción de los pelos fue realizada colocando porciones de talos en un medio de cultivo carente de compuestos nitrogenados. Se emplearon técnicas de microscopía óptica y electrónica de transmisión y barrido. Los pelos se desarrollan a partir de células corticales ovoides grandes. Estas células formadoras de pelos (CFPs son multinucleadas, poseen pequeños plástidos y una abundante red de retículo endoplasmático de disposición apical. La formación de los pelos comienza con el desarrollo de una protuberancia, inicialmente cubierta por una pared multilaminar, la cual se rompe junto con la pared del talo, con la consecuente elongación de la protuberancia. El pelo queda establecido cuando se produce una citocinesis en la base de la protuberancia, formándose una conexión citoplasmática obliterada o pit plug asimétrica entre la base del pelo y la CFP. Los pelos son unicelulares, poseen una vacuola y numerosos núcleos. Tienen un crecimiento activo dejando, al caerse, una cicatriz de forma concéntrica en la pared. Se compara este proceso con el descrito en otras especies de la clase. En medios de cultivo carentes de nitrógeno, el crecimiento del talo de G. chilensis fue menor, aumentando el número de pelos.
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Menyoal Etika Jurnalisme Kontemporer: Belajar dari OhmyNews
Directory of Open Access Journals (Sweden)
Yohanes Widodo
2017-01-01
Full Text Available This article explores journalism ethics, credibility and objectivity on contemporary journalism platforms (blog, online journalism and citizen journalism by case study of Ohmynews— a citizen journalism developed in South Korea. To answer the challenge of citizen journalism in relation with credibility and objectivity on contemporary journalism, at least there are three solutions. First, by developing education and training for citizen journalism. Second, by building collaboration between professional journalism and citizen. Third, in their task, journalist must based on nine journalism elements. So, media idealism as social control and education for society can be practiced
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Menyoal Etika Jurnalisme Kontemporer: Belajar dari OhmyNews
Yohanes Widodo
2017-01-01
This article explores journalism ethics, credibility and objectivity on contemporary journalism platforms (blog, online journalism and citizen journalism) by case study of Ohmynews— a citizen journalism developed in South Korea. To answer the challenge of citizen journalism in relation with credibility and objectivity on contemporary journalism, at least there are three solutions. First, by developing education and training for citizen journalism. Second, by building collaboration between pro...
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Development of In Vitro Correlate Assays of Immunity to Infection with Yersinia Pestis
2007-05-01
cynomolgus macaques (CM) and African green (Chlorocebus aethiops) monkeys (AGM) vaccinated s.c. three times at 4-week intervals with the F1-V fusion...Yersinia pestis in African green monkeys . Arch. Pathol. Lab. Med. 120:156–163. 15. Faure, K., J. Fujimoto, D. W. Shimabukuro, T. Ajayi, N. Shime, K...A. Kuwae, C. Sasakawa, and S. Imajoh-Ohmi. 1999. Shigella flexneri YSH6000 induces two types of cell death, apoptosis and oncosis, in the
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Morpho-anatomy of stypopodium zonale (phaeophycota) from the coast of karachi, pakistan
International Nuclear Information System (INIS)
Abbas, A.; Shameel, M.
2014-01-01
A brown alga Stypopodium zonale (Lamouroux) Papenfuss (Dictyotales) was collected from Manora and Buleji, the coastal areas near Karachi (Pakistan) during March 2006-April 2009 and investigated for its morphology, anatomy and reproductive structures. This is the first detailed study on the Pakistani specimens of this species from these points of view, where presence or absence of intercellular spaces, cell-wall thickness of different cells and structure of surface cells were examined. In this connection the apical, middle and basal parts of the thallus were investigated anatomically. (author)
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Potential antiradical and alpha-glucosidase inhibitors from Ecklonia maxima (Osbeck) Papenfuss.
Rengasamy, Kannan R R; Aderogba, Mutalib A; Amoo, Stephen O; Stirk, Wendy A; Van Staden, Johannes
2013-11-15
Alpha-glucosidase inhibitors play a potential role in the treatment of type 2 diabetes by delaying glucose absorption in the small intestine. Ecklonia maxima, a brown alga which grows abundantly on the west coast of South Africa, is used to produce alginate, animal feed, nutritional supplements and fertilizer. The crude aqueous methanol extract, four solvent fractions and three phlorotannins: 1,3,5-trihydroxybenezene (phloroglucinol) (1), dibenzo [1,4] dioxine-2,4,7,9-tetraol (2) and hexahydroxyphenoxydibenzo [1,4] dioxine (eckol) (3) isolated from E. maxima were evaluated for antiradical and alpha-glucosidase inhibitory activities. All the phlorotannins tested had strong antioxidant activities on DPPH free radicals with EC50 values ranging from 0.008 to 0.128μM. Compounds 2 and 3 demonstrated stronger antioxidant activity and an alpha-glucosidase inhibitory property than positive controls. These results suggest that E. maxima could be a natural source of potent antioxidants and alpha-glucosidase inhibitors. This study could facilitate effective utilization of E. maxima as an oral antidiabetic drug or functional food ingredient with a promising role in the formulation of medicines and nutrition supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Flavo E. S. de Sousa
2012-06-01
Full Text Available This study was designed to select potential areas for cultivation of the seaweed Gracilaria birdiae Plastino & E.C. Oliveira (Gracilariales, Rhodophyta on the coast of Rio Grande do Norte state, Brazil. The Geographic Information System (GIS and multi-criteria evaluation (MCE were used to identify the most suitable areas. The Analytical Hierarchical Process (AHP was applied to establish MCE weights, thereby generating viable areas for species cultivation. From a total of 3316.82 ha, around 53.67% (1780.06 ha were indicated as highly suitable areas, 40.93% (1357.58 ha as moderately suitable and 5.40% (179.18 ha as scarcely suitable for seaweed cultivation. Seven areas (1084.62 ha are located on the northern coast and 20 (2232.20 ha on the eastern coast. The results show that GIS can be used as an effective instrument for selecting seaweed cultivation areas.
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From Reader to Writer: Citizen Journalism as News Produsage
Bruns, Axel
Today, participatory or citizen journalism - journalism which enables readers to become writers - exists online and offline in a variety of forms and formats, operates under a number of editorial schemes, and focuses on a wide range of topics from the specialist to the generic and the micro-local to the global. Key models in this phenomenon include veteran sites Slashdot and Indymedia, as well as news-related weblogs; more recent additions into the mix have been the South Korean OhmyNews, which in 2003 was “the most influential online news site in that country, attracting an estimated 2 million readers a day” (Gillmor, 2003a, p. 7), with its new Japanese and international offshoots, as well as the Wikipedia with its highly up-to-date news and current events section and its more recent offshoot Wikinews, and even citizen-produced video news as it is found in sites such as YouTube and Current.tv.
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Mendes, Luiz Fernando; Stevani, Cassius Vinicius; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Colepicolo, Pio
2014-01-01
The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism.
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Directory of Open Access Journals (Sweden)
George E. C. de Miranda
2012-08-01
Full Text Available The success of seaweed cultivation depends on the scientific control of the tolerance limits and the optimal physiological conditions that affect the spore germination and the early development of algal species. In order to establish cultivation techniques for spores of Hidropuntia caudata (J. Agardh Gurgel & Fredericq, the effects of irradiance, salinity, and temperature on the carpospore germination and carposporeling development were evaluated under laboratory conditions. Five photon flux densities (PFD, from 18 to 200 µmol photons m-2s-1, six salinity values (from 7 to 55 psu, and four temperatures (from 20 ºC to 35 ºC were investigated. The level of irradiance caused significant differences in the growth, in the following order: 200±5 > 100±5 62.5±2.5 > 30±1.5 > 18±1 µmol of photons m-2s-1, but they did not inhibit the carposporeling development. Maximum growth occurred under 35 psu, while at 15 psu the formation of carposporeling erect axis was limited. The optimal temperature for growth was 25 ºC, while at 35 ºC the spores died. These results show the importance of previous knowledge on the tolerance limits and optimal conditions for sporeling development of H. caudata for the implementation of an aquaculture program.
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Directory of Open Access Journals (Sweden)
George E. C. de Miranda
2012-06-01
Full Text Available The success of seaweed cultivation depends on the scientific control of the tolerance limits and the optimal physiological conditions that affect the spore germination and the early development of algal species. In order to establish cultivation techniques for spores of Hidropuntia caudata (J. Agardh Gurgel & Fredericq, the effects of irradiance, salinity, and temperature on the carpospore germination and carposporeling development were evaluated under laboratory conditions. Five photon flux densities (PFD, from 18 to 200 µmol photons m-2s-1, six salinity values (from 7 to 55 psu, and four temperatures (from 20 ºC to 35 ºC were investigated. The level of irradiance caused significant differences in the growth, in the following order: 200±5 > 100±5 62.5±2.5 > 30±1.5 > 18±1 µmol of photons m-2s-1, but they did not inhibit the carposporeling development. Maximum growth occurred under 35 psu, while at 15 psu the formation of carposporeling erect axis was limited. The optimal temperature for growth was 25 ºC, while at 35 ºC the spores died. These results show the importance of previous knowledge on the tolerance limits and optimal conditions for sporeling development of H. caudata for the implementation of an aquaculture program.
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Ferreres, Federico; Lopes, Graciliana; Gil-Izquierdo, Angel; Andrade, Paula B.; Sousa, Carla; Mouga, Teresa; Valentão, Patrícia
2012-01-01
Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn. Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration, characteristic of the process. PMID:23222802
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dos Santos, Rodrigo W; Schmidt, Éder C; Bouzon, Zenilda L
2013-02-01
The agarophyte macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie is widely distributed along the Brazilian coast. While this species produces agarana, it is more important in the human diet. Therefore, the present study aimed to evaluate the biological effects of cadmium on its morphology and cellular organization. To accomplish this, the effects of cadmium in apical segments of G. domingensis were examined in vitro. Over a period of 16 days, the segments were cultivated and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1), with cadmium treatments in doses of 100, 200 and 300 μM. The samples were processed for light, transmission and scanning electron microscopy. Histochemical analyses included Toluidine Blue for acidic polysaccharides, Coomassie Brilliant Blue for total protein, and Periodic Acidic Schiff for neutral polysaccharides. In all cadmium treatments, cytochemical analysis showed 1) metachromatic granulation in vacuole and lenticular thickness of the cell wall, 2) a higher concentration of cytoplasmic organelles, and 3) an increase in the number of floridean starch grains. Cadmium also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and vacuole volume, as well as the destruction of chloroplast internal organization and increased number of plastoglobuli. In addition, treated plants showed a gradual increase in surface roughness, apparently the result of cadmium absorption. Taken together, these findings strongly suggested that cadmium negatively affects the agarophyte G. domingensis, posing a threat to the vitality of this plant species as a supplement in the human diet.
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Directory of Open Access Journals (Sweden)
José Bonomi Barufi
2015-03-01
Full Text Available Gracilaria species are the main source of agar worldwide. Since laboratory cultivation is an important means of sustaining such production, this study aimed to assess the influence of two fundamental strategies of physiological algae adjustment, photoacclimation and photomorphogenesis, on G. birdiae physiology. Specifically, the effects of different spectral light qualities on reproduction, growth, and pigment content in two distinct photoperiods (8 and 14 hours were examined. Tetrasporophytes and gametophytes were submitted to different light qualities: white, green, red, and blue over the course of nine weeks. At the end of this period, chlorophyll a, allophycocyanin, phycocyanin, and phycoerythrin contents were analysed. Gametophytes showed reproductive structures only under monochromatic radiation. A stimulatory effect on tetrasporangium differentiation was mainly observed under red light, but this high fertility was negatively correlated with growth rate, i.e. algae cultivated under red light showed the lowest growth rate. However, while growth rates were higher in algae exposed to white light, they were similar to those observed in algae subjected to green light and 14 hours of daylight. PE was the predominant pigment, irrespective of light quality. Phycocyanin and phycoerythrin concentration increased when algae were cultivated under green and blue light. Therefore, considering future management prospects for G. birdiae mariculture, we suggest that red light could be utilized as a reproductive inductor to produce tetraspores. Furthermore, if the aim is to achieve high phycoerythrin content, continuous blue light could be applied during a short photoperiod. Indeed, the combination of different wavelengths could allow better economic resource exploitation.
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2013-01-01
Background Gracilaria changii (Xia et Abbott) Abbott, Zhang et Xia, a red algae commonly found in the coastal areas of Malaysia is traditionally used for foods and for the treatment of various ailments including inflammation and gastric ailments. The aim of the study was to investigate anti-inflammatory, gastroprotective and anti-ulcerogenic activities of a mass spectrometry standardized methanolic extract of Gracilaria changii. Methods Methanolic extract of Gracilaria changii (MeOHGCM6 extract) was prepared and standardized using mass spectrometry (MS). Anti-inflammatory activities of MeOHGCM6 extract were examined by treating U937 cells during its differentiation with 10 μg/ml MeOHGCM6 extract. Tumour necrosis factors-α (TNF-α) response level and TNF-α and interleukin-6 (IL-6) gene expression were monitored and compared to that treated by 10 nM betamethasone, an anti-inflammatory drug. Gastroprotective and anti-ulcerogenic activities of MeOHGCM6 extract were examined by feeding rats with MeOHGCM6 extract ranging from 2.5 to 500 mg/kg body weight (b.w.) following induction of gastric lesions. Production of mucus and gastric juice, pH of the gastric juice and non-protein sulfhydryls (NP-SH) levels were determined and compared to that fed by 20 mg/kg b.w. omeprazole (OMP), a known anti-ulcer drug. Results MS/MS analysis of the MeOHGCM6 extracts revealed the presence of methyl 10-hydroxyphaeophorbide a and 10-hydroxypheophytin a, known chlorophyll proteins and several unidentified molecules. Treatment with 10 μg/ml MeOHGCM6 extract during differentiation of U937 cells significantly inhibited TNF-α response level and TNF-α and IL-6 gene expression. The inhibitory effect was comparable to that of betamethasone. No cytotoxic effects were recorded for cells treated with the 10 μg/ml MeOHGCM6 extract. Rats fed with MeOHGCM6 extract at 500 mg/kg b.w. showed reduced absolute ethanol-induced gastric lesion sizes by > 99% (p < 0.05). This protective effect was comparable to that conferred by OMP. The pH of the gastric mucus decreased in dose-dependent manner from 5.51 to 3.82 and there was a significant increase in NP-SH concentrations. Conclusions Results from the study, suggest that the mass spectrometry standardized methanolic extract of Gracillaria changii possesses anti-inflammatory, gastroprotective and anti-ulcerogenic properties. Further examination of the active constituent of the extract and its mechanism of action is warranted in the future. PMID:23497105
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Directory of Open Access Journals (Sweden)
Marcella A. A. Carneiro
2011-04-01
Full Text Available The reproductive phenology and thallus length of Gracilaria birdiae were studied over a period of 12 months in a natural bed in Northeastern Brazil. Fertile specimens of G. birdiae were observed during the entire study period. Tetrasporophytes were the most common with an annual mean of 80.1±5.6%, followed by cystocarpic plants (9.3±3.4%, male gametophytes (8.3±3.6% and infertile plants (2.2±3.4%. Only male gametophytes and infertile plants showed a variation in occurrence frequency during the year (p<0.05. With respect to thallus length, a distinct seasonal variation was observed for all reproductive stages (p<0.05, with the highest values recorded during the rainy season (March to August and the lowest in the dry season (September to February. The results demonstrate that the size of individuals in this population is significantly affected by the periodic changes in the environment caused by rainfall regimes and hydrodynamism.
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Ho, Chai-Ling; Lee, Wei-Kang; Lim, Ee-Leen
2018-03-01
Agar and agarose have wide applications in food and pharmaceutical industries. Knowledge on the genome of red seaweeds that produce them is still lacking. To fill the gap in genome analyses of these red algae, we have sequenced the nuclear and organellar genomes of an agarophyte, Gracilaria changii. The partial nuclear genome sequence of G. changii has a total length of 35.8Mb with 10,912 predicted protein coding sequences. Only 39.4% predicted proteins were found to have significant matches to protein sequences in SwissProt. The chloroplast genome of G. changii is 183,855bp with a total of 201 open reading frames (ORFs), 29 tRNAs and 3 rRNAs predicted. Five genes: ssrA, leuC and leuD CP76_p173 (orf139) and pbsA were absent in the chloroplast genome of G. changii. The genome information is valuable in accelerating functional studies of individual genes and resolving evolutionary relationship of red seaweeds. Copyright © 2017 Elsevier Inc. All rights reserved.
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José Bonomi Barufi; Félix L. Figueroa; Estela M. Plastino
2015-01-01
Las especies del género Gracilaria son la principal fuente de agar en el mundo. El desarrollo de técnicas de cultivo en laboratorio es importante para mejorar la producción, y por ello, este estudio tuvo como objetivo la evaluación de la influencia de dos estrategias de ajuste fisiológico de las algas, la fotoaclimatación y la fotomorfogénesis en G. birdiae. De modo más específico, se evaluaron los efectos de diferentes calidades espectrales de luz sobre la reproducción, crecimiento y conteni...
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Zhong, Mingqin; Yin, Pinghe; Zhao, Ling
2017-04-01
The objective of the present work was to evaluate the toxic effect of nonylphenol (NP) on the antioxidant response and antitumor activity of Gracilaria lemaneiformis. An obvious oxidative damage was observed in this study. The thallus exposed to NP showed 1.2-2.0-fold increase in lipid peroxide and displayed a maximum level of 16.58 μmol g -1 Fw on 0.6 mg L -1 for 15-day exposure. The activities of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) enhanced significantly by 1.1-3.2-fold and subsequently diminished at the high concentrations and prolonged exposure. The results of DNA damage in comet assay also supported that NP was obviously toxic on G. lemaneiformis with increasing the percentage of tail DNA in a dose-dependent manner. Furthermore, the ethanol extract of G. lemaneiformis (EEGL) did exhibit antitumor potential against HepG-2 cells. While decreased in cell inhibition, ROS generation, apoptosis, and caspase-3 in HepG-2 cells treated with the EEGL were observed when G. lemaneiformis was exposed to NP for 15 days, and which were related to exposure concentration of NP. These suggested that NP has strongly toxic effect on the antitumor activity of G. lemaneiformis. The results revealed in this study imply that macroalgae can be useful biomarkers to evaluate marine pollutions.
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Sports activities enhance the prevalence of rhinitis symptoms in schoolchildren.
Kusunoki, Takashi; Takeuchi, Jiro; Morimoto, Takeshi; Sakuma, Mio; Mukaida, Kumiko; Yasumi, Takahiro; Nishikomori, Ryuta; Heike, Toshio
2016-03-01
To evaluate the association between sports activities and allergic symptoms, especially rhinitis, among schoolchildren. This longitudinal survey of schoolchildren collected data from questionnaires regarding allergic symptoms based on the International Study of Asthma and Allergies in Childhood (ISAAC) program and sports participation that were distributed to the parents of children at all 12 public primary schools in Ohmi-Hachiman City, Shiga Prefecture, Japan. Data were collected annually from 2011 until 2014, when the children reached 10 years of age. Blood samples were obtained in 2014, and the levels of immunoglobulin (Ig)E specific to four inhalant allergens were measured. Data from 558 children were analyzed. At 10 years of age, prevalence of asthma and eczema did not differ significantly, while rhinitis was significantly higher (p = 0.009) among children who participated in sports. Prevalence of rhinitis increased as the frequency or duration of sports participation increased (p sports (p = 0.03). Among those who participated in continuous sports activities, the prevalence of rhinitis was significantly higher with prolonged eczema (p = 0.006). Sports activities did not increase sensitization to inhalant allergens. Sports activities enhance the prevalence of rhinitis in schoolchildren. Prolonged eczema, together with sports participation, further promotes the symptoms. The mechanisms of these novel findings warrant further investigation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Jiang, Heng; Zou, Dinghui; Chen, Weizhou; Yang, Yufeng
2017-11-01
The branches and mass of Gracilaria lemaneiformis increase with growth season, and the thalli sink to deeper depths with increasing biomass density during maricultivation. The changing depth and algal mat density may affect the physiology of the algae. In the present study, the photosynthetic behaviors regarding different biomass densities in G. lemaneiformis thalli collected from different stocking depths were determined, to examine how photosynthesis of this farmed alga was affected by the growth depths and algal mat densities. Our results showed that the chlorophyll a (Chl a), carotenoids (Car), phycoerythrin (PE) contents, and irradiance-saturated maximum photosynthetic rates (P max ) of the deeper layer-grown algae were significantly increased relative to the surface layer-grown algae. The P max , apparent photosynthetic efficiency (α) and dark respiration rate (R d ) of G. lemaneiformis thalli, were reduced, whereas the irradiance saturation points (I k ) were increased, with the increasing algal mat density. We proposed that appropriate measures are needed to trade off the stocking depth and biomass density, in an effort to maintain a relative high photosynthetic productivity during G. lemaneiformis maricultivation.
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Organization of plastid genomes in the freshwater red algal order Batrachospermales (Rhodophyta).
Paiano, Monica Orlandi; Del Cortona, Andrea; Costa, Joana F; Liu, Shao-Lun; Verbruggen, Heroen; De Clerck, Olivier; Necchi, Orlando
2018-02-01
Little is known about genome organization in members of the order Batrachospermales, and the infra-ordinal relationship remains unresolved. Plastid (cp) genomes of seven members of the freshwater red algal order Batrachospermales were sequenced, with the following aims: (i) to describe the characteristics of cp genomes and compare these with other red algal groups; (ii) to infer the phylogenetic relationships among these members to better understand the infra-ordinal classification. Cp genomes of Batrachospermales are large, with several cases of gene loss, they are gene-dense (high gene content for the genome size and short intergenic regions) and have highly conserved gene order. Phylogenetic analyses based on concatenated nucleotide genome data roughly supports the current taxonomic system for the order. Comparative analyses confirm data for members of the class Florideophyceae that cp genomes in Batrachospermales is highly conserved, with little variation in gene composition. However, relevant new features were revealed in our study: genome sizes in members of Batrachospermales are close to the lowest values reported for Florideophyceae; differences in cp genome size within the order are large in comparison with other orders (Ceramiales, Gelidiales, Gracilariales, Hildenbrandiales, and Nemaliales); and members of Batrachospermales have the lowest number of protein-coding genes among the Florideophyceae. In terms of gene loss, apcF, which encodes the allophycocyanin beta subunit, is absent in all sequenced taxa of Batrachospermales. We reinforce that the interordinal relationships between the freshwater orders Batrachospermales and Thoreales within the Nemaliophycidae is not well resolved due to limited taxon sampling. © 2017 Phycological Society of America.
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Growth-promoting effects of a seaweed concentrate at various pH and water hardness conditions
Directory of Open Access Journals (Sweden)
Georgina D. Arthur
2013-11-01
Full Text Available Kelpak® – a liquid seaweed concentrate made from the kelp Ecklonia maxima (Osbeck Papenfuss – is used as a natural biostimulant to promote rooting and improve yield in crops. Plant–soil environmental conditions and the chemistry of water used for irrigation may affect the efficiency of Kelpak. The effect of pH (pH 4.5, 6.5 and 8.5 and water hardness (200 mg/L and 400 mg/L Ca2+ on the growth-promoting ability of Kelpak was assessed using the mungbean rooting bioassay and in a pot trial with Swiss chard. Kelpak promoted rooting in all the treatments in the mungbean bioassay with maximum rooting generally achieved with 20% Kelpak. With 20% Kelpak, the addition of 200 mg/L and 400 mg/L Ca2+ decreased rooting at pH 4.5, increased rooting at pH 6.5 and did not affect rooting at pH 8.5. A similar trend was observed in the pot trial with Swiss chard: leaf and root (fresh weight and pigment content (chl a, chl b and carotenoids improved with the addition of 200 mg/L Ca2+ + 5% Kelpak at pH 6.5 or pH 8.5, while Kelpak was able to partially mask the negative effect of 200 mg/L Ca2+ at pH 4.5. These results suggest that while Kelpak is most effective in neutral pHs, it can be used to promote plant growth in a wide range of pH and water hardness conditions.
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Carotenogenesis diversification in phylogenetic lineages of Rhodophyta.
Takaichi, Shinichi; Yokoyama, Akiko; Mochimaru, Mari; Uchida, Hiroko; Murakami, Akio
2016-06-01
Carotenoid composition is very diverse in Rhodophyta. In this study, we investigated whether this variation is related to the phylogeny of this group. Rhodophyta consists of seven classes, and they can be divided into two groups on the basis of their morphology. The unicellular group (Cyanidiophyceae, Porphyridiophyceae, Rhodellophyceae, and Stylonematophyceae) contained only β-carotene and zeaxanthin, "ZEA-type carotenoids." In contrast, within the macrophytic group (Bangiophyceae, Compsopogonophyceae, and Florideophyceae), Compsopogonophyceae contained antheraxanthin in addition to ZEA-type carotenoids, "ANT-type carotenoids," whereas Bangiophyceae contained α-carotene and lutein along with ZEA-type carotenoids, "LUT-type carotenoids." Florideophyceae is divided into five subclasses. Ahnfeltiophycidae, Hildenbrandiophycidae, and Nemaliophycidae contained LUT-type carotenoids. In Corallinophycidae, Hapalidiales and Lithophylloideae in Corallinales contained LUT-type carotenoids, whereas Corallinoideae in Corallinales contained ANT-type carotenoids. In Rhodymeniophycidae, most orders contained LUT-type carotenoids; however, only Gracilariales contained ANT-type carotenoids. There is a clear relationship between carotenoid composition and phylogenetics in Rhodophyta. Furthermore, we searched open genome databases of several red algae for references to the synthetic enzymes of the carotenoid types detected in this study. β-Carotene and zeaxanthin might be synthesized from lycopene, as in land plants. Antheraxanthin might require zeaxanthin epoxydase, whereas α-carotene and lutein might require two additional enzymes, as in land plants. Furthermore, Glaucophyta contained ZEA-type carotenoids, and Cryptophyta contained β-carotene, α-carotene, and alloxanthin, whose acetylenic group might be synthesized from zeaxanthin by an unknown enzyme. Therefore, we conclude that the presence or absence of the four enzymes is related to diversification of carotenoid
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Health Applications for Corporate Health Management.
Steigner, Guido; Doarn, Charles R; Schütte, Michael; Matusiewicz, David; Thielscher, Christian
2017-05-01
Many corporate organizations around the world are looking at new ways to improve the health and well-being of their employees. Many have begun to use m-health approaches and unique applications (apps) to provide assistance. In Germany, both m-health and occupational health management (OHM) are growing quickly. Therefore, we hypothesized that the combination-apps usage in OHM-is growing as well. We studied the usage of health apps in large corporations for health management of employed individuals. To understand the environment in Germany, a two-part study was conducted. First, an extensive literature search was done and second, interviews were conducted with 12 of the 20 biggest companies' health management representatives. Using key search terms, 5,445 peer-reviewed journal articles traced with German databases and on PubMed were reviewed. Interestingly and somewhat surprising to the authors, none of them covered our specific topic. Interviews were conducted with 60% of the companies indicated. Only 3 out of 12 companies use apps. Four companies are piloting apps. With one exception, apps cover well-known areas such as food coaching, physical motion, smoking cessation, stress prevention, and other health-related subjects. One app used sensors in work clothing to prevent unhealthy motion. With a few exceptions, there has been no evaluation of the utility and utilization of apps. Current app usage in corporate health management in Germany is surprisingly low. Apps need to be better evaluated. Main obstacles-which could be resolved in the future-are legal restrictions (especially on data security), the lack of company-owned smart phones, misfit of apps and corporate health strategy, a lack of app evaluation, and high app prices.
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Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoung Ho; Hong, Hye Ran; Niaz, Zeeshan; Wei, Huihui; Du, Qingwei; Peng, Chong; Mi, Ping; Que, Zhou
2016-06-01
There is potential for bicarbonate to improve crop yields and economic efficiency of marine algae. However, few studies have focused on the effect of bicarbonate on the growth, photosynthesis, and enzyme activity associated with carbon utilization, especially in commercial macroalgae. Here, the addition of bicarbonate (up to 420 mg L(-1)) to macroalgal cultures has been evaluated for Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae with respect to growth rate, photosynthetic activity, carbonic anhydrase activity, and biochemical composition. The results showed that the effects of NaHCO3 on growth, chlorophyll a, phycoerythrin, photosynthetic oxygen evolution, photochemical parameters of PSI and PSII, carbonic anhydrase activity, and nitrogen content were significant (P 336 mg L(-1) for Gp. lemaneiformis and >420 mg L(-1) for the other two species). Moreover, species-specific differences induced by supplementation with bicarbonate were discovered during culture. Optimal concentrations of NaHCO3 used in this study were 252 mg L(-1) for Gp. lemaneiformis and 336 mg L(-1) for G. vermiculophylla and G. chouae. These results suggest that an adequate supplementation of sodium bicarbonate is a viable strategy for promoting growth and photosynthetic activity in some macroalgae as well as for improving biochemical composition. The study will help to accelerate the growth rate of algae and improve the quality of thalli, and will also be useful for enhancing the understanding of carbon utilization in macroalgae.
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Ng, Poh-Kheng; Lin, Showe-Mei; Lim, Phaik-Eem; Liu, Li-Chia; Chen, Chien-Ming; Pai, Tun-Wen
2017-01-06
The chloroplast genome of Gracilaria firma was sequenced in view of its role as an economically important marine crop with wide industrial applications. To date, there are only 15 chloroplast genomes published for the Florideophyceae. Apart from presenting the complete chloroplast genome of G. firma, this study also assessed the utility of genome-scale data to address the phylogenetic relationships within the subclass Rhodymeniophycidae. The synteny and genome structure of the chloroplast genomes across the taxa of Eurhodophytina was also examined. The chloroplast genome of Gracilaria firma maps as a circular molecule of 187,001 bp and contains 252 genes, which are distributed on both strands and consist of 35 RNA genes (3 rRNAs, 30 tRNAs, tmRNA and a ribonuclease P RNA component) and 217 protein-coding genes, including the unidentified open reading frames. The chloroplast genome of G. firma is by far the largest reported for Gracilariaceae, featuring a unique intergenic region of about 7000 bp with discontinuous vestiges of red algal plasmid DNA sequences interspersed between the nblA and cpeB genes. This chloroplast genome shows similar gene content and order to other Florideophycean taxa. Phylogenomic analyses based on the concatenated amino acid sequences of 146 protein-coding genes confirmed the monophyly of the classes Bangiophyceae and Florideophyceae with full nodal support. Relationships within the subclass Rhodymeniophycidae in Florideophyceae received moderate to strong nodal support, and the monotypic family of Gracilariales were resolved with maximum support. Chloroplast genomes hold substantial information that can be tapped for resolving the phylogenetic relationships of difficult regions in the Rhodymeniophycidae, which are perceived to have experienced rapid radiation and thus received low nodal support, as exemplified in this study. The present study shows that chloroplast genome of G. firma could serve as a key link to the full resolution of
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Canary: an atomic pipeline for clinical amplicon assays.
Doig, Kenneth D; Ellul, Jason; Fellowes, Andrew; Thompson, Ella R; Ryland, Georgina; Blombery, Piers; Papenfuss, Anthony T; Fox, Stephen B
2017-12-15
or a Docker image at https://github.com/PapenfussLab/Canary under a GPL-3.0 License.
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Simulation of the interaction of positively charged beams and electron clouds
International Nuclear Information System (INIS)
Markovik, Aleksandar
2013-01-01
The incoherent (head-tail) effect on the bunch due to the interaction with electron clouds (e-clouds) leads to a blow up of the transverse beam size in storage rings operating with positively charged beams. Even more the e-cloud effects are considered to be the main limiting factor for high current, high-brightness or high-luminosity operation of future machines. Therefore the simulation of e-cloud phenomena is a highly active field of research. The main focus in this work was set to a development of a tool for simulation of the interaction of relativistic bunches with non-relativistic parasitic charged particles. The result is the Particle-In-Cell Program MOEVE PIC Tracking which can track a 3D bunch under the influence of its own and external electromagnetic fields but first and foremost it simulates the interaction of relativistic positively charged bunches and initially static electrons. In MOEVE PIC Tracking the conducting beam pipe can be modeled with an arbitrary elliptical cross-section to achieve more accurate space charge field computations for both the bunch and the e-cloud. The simulation of the interaction between positron bunches and electron clouds in this work gave a detailed insight of the behavior of both particle species during and after the interaction. Further and ultimate goal of this work was a fast estimation of the beam stability under the influence of e-clouds in the storage ring. The standard approach to simulate the stability of a single bunch is to track the bunch particles through the linear optics of the machine by multiplying the 6D vector of each particle with the transformation matrices describing the lattice. Thereby the action of the e-cloud on the bunch is approximated by a pre-computed wake kick which is applied on one or more points in the lattice. Following the idea of K.Ohmi the wake kick was pre-computed as a two variable function of the bunch part exiting the e-cloud and the subsequent parts of a bunch which receive a
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Directory of Open Access Journals (Sweden)
Keith M. Bayha
2017-10-01
morphology-based phylogenies. A paraphyletic Chrysaora raises systematic questions at the genus level for Pelagiidae; accepting the validity of the recently erected genus Mawia, as well as past genera, will require the creation of additional pelagiid genera. Historical review of the species-delineating genetic and morphological differences indicates that Chrysaora quinquecirrha Desor 1848 applies to the U.S. Coastal Atlantic Chrysaora species (U.S. Atlantic sea nettle, while the name C. chesapeakei Papenfuss 1936 applies to the U.S. Atlantic estuarine and Gulf of Mexico Chrysaora species (Atlantic bay nettle. We provide a detailed redescription, with designation of a neotype for Chrysaora chesapeakei, and clarify the description of Chrysaora quinquecirrha. Since Caribbean Chrysaora are genetically similar to Chrysaora chesapeakei, we provisionally term them Chrysaora c.f. chesapeakei. The presence of Mawia benovici off the coast of Western Africa provides a potential source region for jellyfish introduced into the Adriatic Sea in 2013.
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Selected working papers[Nuclear data activities
Energy Technology Data Exchange (ETDEWEB)
NONE
2002-08-01
/126 (reply to WPs 2002-15, 16); WP 2002-29, Comments and Recommendations of Working Groups 1-3 of the INDC Meeting, Vienna, 14-17 May 2002 (see report on that meeting); WP 2002-30, SyGRD (System of Graph Reading) by JCPRG (H. Ohmi); WP 2002-32, The JEFF-3.0 General Purpose Library (A. Nouri); WP 2002-33, NEA Data Bases; WP 2002-32 WebTrends (NEA web statistics); WP 2002-35, NEA Computer Network (P. Nagel)
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International Nuclear Information System (INIS)
2002-01-01
/126 (reply to WPs 2002-15, 16); WP 2002-29, Comments and Recommendations of Working Groups 1-3 of the INDC Meeting, Vienna, 14-17 May 2002 (see report on that meeting); WP 2002-30, SyGRD (System of Graph Reading) by JCPRG (H. Ohmi); WP 2002-32, The JEFF-3.0 General Purpose Library (A. Nouri); WP 2002-33, NEA Data Bases; WP 2002-32 WebTrends (NEA web statistics); WP 2002-35, NEA Computer Network (P. Nagel)
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Focal Mechanism of Semi-Volcanic Deep Low-Frequency Earthquakes in Eastern Shimane
Aso, N.; Ohta, K.; Ide, S.
2012-12-01
Many deep low-frequency earthquakes (LFEs) occur near the island arc Mohorovicic discontinuities and far from both active volcanoes and plate boundaries. They are quite similar to volcanic LFEs beneath active volcanoes, which infers some fluid movement in the source region, and we regard them as "semi-volcanic" LFEs [Aso et al., 2011; 2012 (submitted)]. Several previous studies determined the focal mechanisms of volcanic and semi-volcanic LFEs using a small portion of information of the waveforms. Although the estimated focal mechanisms are various, they may not necessary support the variety of the actual physical process, owing to the large determination error [e.g., Nishidomi and Takeo, 1996; Ohmi and Obara, 2002; Nakamichi et al., 2003]. Here we determine the focal mechanisms by waveform inversion for LFEs in eastern Shimane in western Japan, where many LFEs occurred in a quiet region. The locations are also close to the fault plane of the 2000 western Tottori earthquake of Mw6.6, and right beneath Yokota volcano, which is a Quaternary volcanic cluster. We estimated the focal mechanisms of semi-volcanic LFEs in eastern Shimane by moment tensor inversion. The data are velocity seismograms at five stations of Hi-net near the epicenters. For each seismogram, we extracted a 1.5-second time window beginning from 0.2 seconds before the arrivals of either P-wave in a vertical component or S-wave in a horizontal component. The arrival time of each phase is picked manually first, and then corrected to minimize the variance between observed and synthetic waveforms. The local site amplification is estimated using far-field body waves from deep intraslab earthquakes, and collected for each seismogram. The synthetic waveforms were calculated using the discrete wavenumber integration method developed by Takeo [1985] for a horizontally layered structure. For 38 LFEs, which are equal to or larger than M1.2 (JMA magnitude) and recorded at all five stations, the focal mechanisms
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Godet, Alexis; Bodin, Stéphane; Adatte, Thierry; Föllmi, Karl B.
2010-05-01
In the last decades, the anthropogenic increase pCO2atm has been considered as one of the main contributors for the decline of modern coral reefs, and nearly 60% of these marine ecosystems are presently threatened (Bryant et al., 1998). Interactions between anthropogenic change and reef growth can, however, not be reduced to a single factor, and it is essential to look at the Earth's history to understand and counterbalance. During the Early Cretaceous, enhanced pCO2atm may have been responsible, at least in part, for the demise of the carbonate platform along the northern margin of the Tethys through climatic feedback mechanisms. From the Hauterivian to the Early Aptian, increased rainfalls are documented from the clay-mineral association, by a change from a smectite-dominated (most of the Hauterivian), to a kaolinite-dominated assemblage (latest Hauterivian up to the early Late Barremian). This switch is dated to the Pseudothurmannia ohmi ammonozone in the Vocontian Trough of southeastern France (Angles section, Godet et al., 2008). It is immediately followed in time by major nutrient input, as is illustrated by the substantial increase in phosphorus accumulation rates (PAR), not only in this section, but also in the Ultrahelvetic area of Switzerland and in the Umbria-Marche basin of Italy (Bodin et al., 2006). On the other hand, the remainder of the Hauterivian is characterized by PAR mean values characteristic of mesotrophic conditions, whereas the Late Barremian witnesses the return to oligotrophic environments (lower PAR values). Synchronously, these perturbations are mirrored on the platform by changes in the type of carbonate ecosystems. Indeed, a stronger continental runoff, and a subsequent input in the oceanic domain of nutrients (e.g., phosphorus) and clastic material modified marine palaeoenvironmental conditions and triggered changes in ecosystems. A unique archive of the Early Cretaceous carbonate platform is preserved in the Helvetic Alps, where the