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Sample records for copepod fecal pellets

  1. Degradation of copepod fecal pellets

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Iversen, Morten

    2008-01-01

    Copepod fecal pellets are often degraded at high rates within the upper part of the water column. However, the identity of the degraders and the processes governing the degradation remain unresolved. To identify the pellet degraders we collected water from Oresund (Denmark) approximately every...... second month from July 2004 to July 2005. These water samples were divided into 5 fractions (pellet degradation rate and species composition of the plankton from triplicate incubations of each fraction and a known, added...... amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

  2. Feeding on copepod fecal pellets: a new trophic role of dinoflagellates as detritivores

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Moldrup, M.; Berge, T.;

    2011-01-01

    Recent field studies indicate that dinoflagellates are key degraders of copepod fecal pellets. This study is the first to publish direct evidence of pellet grazing by dinoflagellates. Feeding and growth on copepod fecal pellets were studied for both heterotrophic (4 species) and mixotrophic...... dinoflagellates (3 species) using a combination of classic incubation experiments and video recordings of feeding behavior. Fecal pellets were produced by adult Acartia tonsa feeding on Rhodomonas salina. Two mixotrophic species (Karlodinium armiger, a gymnodinoid dinoflagellate, Gy1) and all heterotrophic...... dinoflagellates (Gyrodinium dominans, Gyrodinium spirale, Diplopsalis lenticula, Protoperidinium depressum) studied fed on fecal pellets. Using natural concentrations of dinoflagellates and copepod fecal pellets, average ingestion rates of 0.2 and 0.1 pellets cell−1 d−1 and clearance rates of between 0.2 and 0...

  3. High turnover rates of copepod fecal pellets due to Noctiluca scintillans grazing

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2003-01-01

    Copepod fecal pellet production and vertical flux, as well as vertical distributions of copepods, fecal pellets and the heterotrophic dinoflagellate Noctiluca scintillans were monitored in an upwelling plume off the coast of Brazil during 5 d in austral spring. Less than half (20 to 45......%) of the pellets produced in the overlying water column reached sediment traps positioned at 30 to 60 m depth, and specific sinking losses computed from steady-state considerations varied inversely with trap depth between 0.3 and 2.9 d-1. Total specific losses varied between 0.6 and 16 d-1, and the major part...... as the latter aged, up to 5 x 105 cells m-2, and fecal pellets occurred commonly in the food vacuoles of N. scintillans. Specific fecal pellet remineralization rates were linearly related to the abundance of N. scintillans. This relation can be quantitatively accounted for if N. scintillans clears the water...

  4. Effects of salinity on egg and fecal pellet production, development and survival, adult sex ratio and total life span in the calanoid copepod, Acartia tonsa: a laboratory study

    Science.gov (United States)

    Shayegan, Majid; Esmaeili Fereidouni, Abolghasem; Agh, Naser; Jani Khalili, Khosrow

    2016-07-01

    The effects of salinity on the copepod, Acartia tonsa in terms of daily egg production rate (EPR), hatching success, fecal pellet production rate (FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods (seven consecutive days). Results show EPR was affected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females (long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages (56.7% and 52.2%, respectively) were significantly observed at two salinities of 13 and 20 compared to that at 35 (25%). Total longevity of females was not affected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.

  5. Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct measurements of ballasting by opal and calcite

    DEFF Research Database (Denmark)

    Ploug, H.; Iversen, M.H.; Koski, Marja;

    2008-01-01

    sp., T. weissflogii, and E. huxleyi, respectively. The average carbon-specific respiration rate was 0.15 d(-1) independent on diet (range: 0.08-0.21 d(-1)). Because of ballasting of opal and calcite, sinking velocities were significantly higher for pellets produced on T. weissflogii (322 +/- 169 m d...

  6. Fecal pellets: role in sedimentation of pelagic diatoms.

    Science.gov (United States)

    Schrader, H J

    1971-10-01

    Membrane-enclosed fecal pellets of planktonic herbivores were sampled at several depths in the Baltic Sea (459 meters deep) and off Portugal (4000 meters deep) by means of a Simonsen multinet. Pellets contained mainly empty shells of planktonic diatoms and silicoflagellates. Two kinds of fecal pellets were found, those with the remains of one species (for example, Thalassiosira baltica) and those with the remains of several species (for example, Chaetoceros, Achnanthes, and Thalassiosira). Siliceous skeletons were protected from dissolution during settling by a membrane around the pellet.

  7. Defecation of dimethylsulfoniopropionate (DMSP) by the copepod Acartia tonsa as functions of ambient food concentration and body DMSP content

    DEFF Research Database (Denmark)

    Tang, K.W.

    2001-01-01

    The dimethylsulfoniopropionate (DMSP) defecation rate of Acartia tonsa (calanoid copepod)feeding on Tetraselmis impellucida (prasinophyte) was correlated with food concentration and copepod body DMSP content. Copepod fecal pellets represent a highly concentrated source of DMSP and thus play an im...... an important role in DMSP flux and microbial processes in the ocean.......The dimethylsulfoniopropionate (DMSP) defecation rate of Acartia tonsa (calanoid copepod)feeding on Tetraselmis impellucida (prasinophyte) was correlated with food concentration and copepod body DMSP content. Copepod fecal pellets represent a highly concentrated source of DMSP and thus play...

  8. DMSP-consuming bacteria associated with the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Tang, K.W.; Visscher, P.T.; Dam, H.G.

    2001-01-01

    DMSP-consuming bacteria (DCB) were recovered from the body and fecal pellets of the copepod Acartia tonsa (Dana). The most probable number of DCB associated with starved A. tonsa was 9.2 X 10(2) cells copepod(-1). The abundance of DCB recovered from the copepod body increased to 1.6-2.8 X 10...

  9. Zooplankton fecal pellets, marine snow, phytodetritus and the ocean's biological pump

    Science.gov (United States)

    Turner, Jefferson T.

    2015-01-01

    The 'biological pump' is the process by which photosynthetically-produced organic matter in the ocean descends from the surface layer to depth by a combination of sinking particles, advection or vertical mixing of dissolved organic matter, and transport by animals. Particulate organic matter that is exported downward from the euphotic zone is composed of combinations of fecal pellets from zooplankton and fish, organic aggregates known as 'marine snow' and phytodetritus from sinking phytoplankton. Previous reviews by Turner and Ferrante (1979) and Turner (2002) focused on publications that appeared through late 2001. Since that time, studies of the biological pump have continued, and there have been >300 papers on vertical export flux using sediment traps, large-volume filtration systems and other techniques from throughout the global ocean. This review will focus primarily on recent studies that have appeared since 2001. Major topics covered in this review are (1) an overview of the biological pump, and its efficiency and variability, and the role of dissolved organic carbon in the biological pump; (2) zooplankton fecal pellets, including the contribution of zooplankton fecal pellets to export flux, epipelagic retention of zooplankton fecal pellets due to zooplankton activities, zooplankton vertical migration and fecal pellet repackaging, microbial ecology of fecal pellets, sinking velocities of fecal pellets and aggregates, ballasting of sinking particles by mineral contents, phytoplankton cysts, intact cells and harmful algae toxins in fecal pellets, importance of fecal pellets from various types of zooplankton, and the role of zooplankton fecal pellets in picoplankton export; (3) marine snow, including the origins, abundance, and distributions of marine snow, particles and organisms associated with marine snow, consumption and fragmentation of marine snow by animals, pathogens associated with marine snow; (4) phytodetritus, including pulsed export of

  10. Electrochemical fecal pellet sensor for simultaneous real-time ex vivo detection of colonic serotonin signalling and motility

    Science.gov (United States)

    Morris, Rachel; Fagan-Murphy, Aidan; MacEachern, Sarah J.; Covill, Derek; Patel, Bhavik Anil

    2016-03-01

    Various investigations have focused on understanding the relationship between mucosal serotonin (5-HT) and colonic motility, however contradictory studies have questioned the importance of this intestinal transmitter. Here we described the fabrication and use of a fecal pellet electrochemical sensor that can be used to simultaneously detect the release of luminal 5-HT and colonic motility. Fecal pellet sensor devices were fabricated using carbon nanotube composite electrodes that were housed in 3D printed components in order to generate a device that had shape and size that mimicked a natural fecal pellet. Devices were fabricated where varying regions of the pellet contained the electrode. Devices showed that they were stable and sensitive for ex vivo detection of 5-HT, and no differences in the fecal pellet velocity was observed when compared to natural fecal pellets. The onset of mucosal 5-HT was observed prior to the movement of the fecal pellet. The release of mucosal 5-HT occurred oral to the fecal pellet and was linked to the contraction of the bowel wall that drove pellet propulsion. Taken, together these findings provide new insights into the role of mucosal 5-HT and suggest that the transmitter acts as a key initiator of fecal pellet propulsion.

  11. Coprophagy in copepods and in a natural zooplankton community

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Kiørboe, Thomas

    Sediment trap studies have revealed that often only a minor fraction of the zooplankton fecal pellet production leave the upper ocean, and it has been suggested that copepod grazing on pellets (coprophagy) is the reason for this. A simple model is here used to estimate rate of coprophagy from lab...... 5 % of the fecal pellet production in the upper 50 m was lost as flux below 50 m depth. Estimates of coprophagy rates showed, however, that the zooplankton community > 200 um could account for only a few percent of the fecal pellet loss. Thus, plankton organisms

  12. DMSP-consuming bacteria associated with the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Tang, K.W.; Visscher, P.T.; Dam, H.G.

    2001-01-01

    DMSP-consuming bacteria (DCB) were recovered from the body and fecal pellets of the copepod Acartia tonsa (Dana). The most probable number of DCB associated with starved A. tonsa was 9.2 X 10(2) cells copepod(-1). The abundance of DCB recovered from the copepod body increased to 1.6-2.8 X 10(4) a...... Elsevier Science B.V. All rights reserved....

  13. Seasonal and diel patterns in sedimentary flux of krill fecal pellets recorded by an echo sounder

    KAUST Repository

    Røstad, Anders

    2013-11-01

    We used a moored upward-facing 200 kHz echo sounder to address sedimentation of fecal pellets (FPs) from dielly migrating Meganyctiphanes norvegica. The echo sounder was located on the bottom at 150 m depth in the Oslofjord, Norway, and was cabled to shore for continuous measurements during winter and spring. Records of sinking pellets were for the first time observed with an echo sounder. Seasonal patterns of sedimentation of krill FPs were strongly correlated with data from continuous measurement of fluorescence, which illustrate the development of the spring bloom. Sedimenting particles were first observed as fluorescence values started to increase at the end of February and continued to increase until the bloom suddenly culminated at the end of March. This collapse of the bloom was detected on the echo sounder as a pulse of slowly sinking acoustic targets over a 2 d period. Prior to this event, there was a strong diel pattern in sedimentation, which correlated, with some time lag, with the diel migration of krill foraging at night near the surface. Pellet average sinking speeds ranged between 423 m d−1 and 804 m d−1, with a strong relation to pellet target strength, which is an acoustic proxy for size. This novel approach shows that echo sounders may be a valuable tool in studies of vertical pellet flux and, thereby, carbon flux, providing temporal resolution and direct observation of the sedimentation process, which are not obtained from standard methods.

  14. Effects of Harpacticus sp. (Harpacticoida, copepod) grazing on dimethylsulfoniopropionate and dimethylsulfide concentrations in seawater

    Science.gov (United States)

    Yu, Juan; Tian, Ji-Yuan; Yang, Gui-Peng

    2015-05-01

    We conducted 9 d and 24 h ingestion experiments to investigate the effects of copepod grazing on the concentrations of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in seawater. Data from the 9 d trial showed that copepod Harpacticus sp. (Harpacticoida, copepod) grazing increased DMS (0-20%) and dissolved DMSP (DMSPd) (0-128%) apparently, accompanied by a significant reduction of particulate DMSP (DMSPp) in algal culture (0-30%). Ingestion rates (IRs) and pellet production rates (PPRs) of Harpacticus sp. varied with diet species (Platymonas subcordiformis (PS), Nitzschia closterium (NC), Skeletonema costatum (SC), Isochrysis galbana (IG), Prymnesium parvum (PP) or Heterosigma akashiwo (HA)), algal concentration, salinity and temperature. Harpacticus sp. fed on PP showed the lowest IRs (female/male, 0.72/0.53 × 104cells copepod- 1 h- 1) and PPRs (female/male, 0.75/0.5 pellets copepod- 1 h- 1), accompanied with the largest amounts of DMS and DMSPd,p (sum of DMSPd and DMSPp). IRs, PPRs, DMS and DMSPf (DMSP in fecal pellet) increased with the increase of food concentration and peaked at 25 × 104 cells mL- 1I. galbana. High salinity decreased IRs, PPRs, DMS and DMSPf and increased DMSPz (DMSP in copepod body) and DMSPd,p. IRs, PPRs, DMS and DMSPf increased with the increase of temperature from 15 to 25 °C, whereas DMSPz and DMSPd,p contents decreased. Pearson correlation analysis results showed that DMS concentrations presented positive relationships with IRs in algal concentration, salinity and temperature experiments (r = 0.746; P < 0.01). The contribution of DMSPz, DMSPf, DMS and DMSPd,p concentration to the total amounts (DMSPz + DMSPf + DMS + DMSPd,p) was 4-37%, 3-36%, 8-42% and 9-89%, respectively, indicating that DMSP was transferred to copepod tissue and fecal pellet via grazing. Our results are helpful for further understanding of the role of copepod grazing on DMS biogeochemical cycle.

  15. Rates of ingestion and their variability between individual calanoid copepods: Direct observations

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.; Lewis, K.D. [Skidaway Inst. of Oceanography, Savannah, GA (United States); Bundy, M.H. [Skidaway Inst. of Oceanography, Savannah, GA (United States)]|[Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany). Inst. fuer Fernerkundung (IFE); Metz, C. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany). Inst. fuer Fernerkundung (IFE)

    1995-12-01

    The goals of this study were to determine rates of ingestion and fecal pellet release, and their variability, for individual planktonic copepods over extended periods of time (>20 min). Ingestions and rejections of individual cells of the diatom Thalassiosira eccentrica by a adult females of the calanoid Paracalanus aculeatus were directly quantified by observing individual copepods continuously at cell concentrations ranging from 0.1 to 1.2 mm{sup 3} l{sup {minus}1}. Average ingestion rates increased with increasing food concentration, but were not significantly different between 0.3 and 1.0 mm{sup 3} l{sup {minus}1} (9.8 and 32.7 {mu}g Cl{sup {minus}1}) of T.eccentrica. Rates of cell rejections were low and similar at 0.1 and 0.3. but were significantly higher at 1.0 mm{sup 3} l{sup {minus}1}. The coefficients of variation for average ingestion rates of individual copepods hardly differed between food concentrations, ranging from 17 to 22%, and were close to those for average fecal pellet release intervals which ranged from 15 to 21%. A comparison between individuals at each food concentration found no significant differences at 1.0; at 0.1 and 0.3 mm{sup 3} l{sup {minus}1}, respectively, ingestion rates of four out of five females did not differ significantly from each other. Average intervals between fecal pellet releases were similar at 0.3 and 1.0 mm{sup 3} l{sup {minus}1}. Fecal pellet release intervals between individuals were significantly different at each food concentration; these significant differences were attributed to rather narrow ranges of pellet release intervals of each individual female. Potential sources/causes of variability in the sizes and rates of copepods in the ocean are evaluated.

  16. Impacts of ontogenetically migrating copepods on downward carbon flux in the western subarctic Pacific Ocean

    Science.gov (United States)

    Kobari, Toru; Steinberg, Deborah K.; Ueda, Ai; Tsuda, Atsushi; Silver, Mary W.; Kitamura, Minoru

    2008-07-01

    To evaluate the impacts of ontogenetically (seasonally) migrating copepods on carbon transport to the mesopelagic zone, we investigated depth distribution, population structure, and feeding activity of the ontogentic copepod community in the western subarctic Pacific Ocean from day-night pairs of zooplankton samples down to 1000 m during the VERtical Transport In the Global Ocean (VERTIGO) program. Over the 31 July-16 August 2005 study period, the biomass of Neocalanus cristatus and Neocalanus plumchrus predominated in the near surface waters, while Neocalanus flemingeri was already dormant at depth. We observed a strong diel migration for Metridia pacifica, and a seasonal downward migration for Eucalanus bungii. Based on gut pigment analysis, ingestion rate of the copepod community was 214-375 mg C m -2 day -1, which was equal to 26-37% of the concurrent primary production. However, comparison of grazing estimated from gut pigments to calculated carbon demand of the copepod community indicates that phytoplankton comprised 37-59% of the ingested carbon. Thus, the copepod community appears to have also relied on detritus and microzooplankton for their nutrition, likely because primary production during this time was dominated by picophytoplankton too small to be grazed by these large copepods. Fecal pellet flux by the copepod community was estimated to account for 141-223% of the sedimentary particulate organic carbon (POC) flux at 150 m, suggesting considerable fragmentation and consumption of pellets in the upper layers. Fecal pellets alone were adequate to meet copepod carbon demand in the surface 0-150 m layer. Active carbon flux by diel migration of M. pacifica (respiration, egestion, and mortality) was 4-17 mg C m -2 day -1, equal to 6-44% of sedimentary POC flux at 150 m. Active carbon flux by N. flemingeri ontogenetic migration (i.e., respiration and mortality at depth) contributed 246 mg C m -2 year -1, equal to 9% of sedimentary POC flux at 1000 m. The

  17. Effect of starch source in pelleted concentrates on fecal bacterial communities in Thoroughbred mares

    Science.gov (United States)

    High starch concentrates are often added to equine diets to meet digestible energy requirements of some horses, such as broodmares. Starch source has been shown to affect fecal bacterial communities of horses when fed cereal grains with little to no processing. Others suggest that grain processing, ...

  18. How much crude oil can zooplankton ingest? Estimating the quantity of dispersed crude oil defecated by planktonic copepods.

    Science.gov (United States)

    Almeda, Rodrigo; Connelly, Tara L; Buskey, Edward J

    2016-01-01

    We investigated and quantified defecation rates of crude oil by 3 species of marine planktonic copepods (Temora turbinata, Acartia tonsa, and Parvocalanus crassirostris) and a natural copepod assemblage after exposure to mechanically or chemically dispersed crude oil. Between 88 and 100% of the analyzed fecal pellets from three species of copepods and a natural copepod assemblage exposed for 48 h to physically or chemically dispersed light crude oil contained crude oil droplets. Crude oil droplets inside fecal pellets were smaller (median diameter: 2.4-3.5 μm) than droplets in the physically and chemically dispersed oil emulsions (median diameter: 6.6 and 8.0 μm, respectively). This suggests that copepods can reject large crude oil droplets or that crude oil droplets are broken into smaller oil droplets before or during ingestion. Depending on the species and experimental treatments, crude oil defecation rates ranged from 5.3 to 245 ng-oil copepod(-1) d(-1), which represent a mean weight-specific defecation rate of 0.026 μg-oil μg-Ccopepod(1) d(-1). Considering a dispersed crude oil concentration commonly found in the water column after oil spills (1 μl L(-1)) and copepod abundances in high productive coastal areas, copepods may defecate ∼ 1.3-2.6 mg-oil m(-3) d(-1), which would represent ∼ 0.15%-0.30% of the total dispersed oil per day. Our results indicate that ingestion and subsequent defecation of crude oil by planktonic copepods has a small influence on the overall mass of oil spills in the short term, but may be quantitatively important in the flux of oil from surface water to sediments and in the transfer of low-solubility, toxic petroleum hydrocarbons into food webs after crude oil spills in the sea.

  19. Exposure to crude oil micro-droplets causes reduced food uptake in copepods associated with alteration in their metabolic profiles.

    Science.gov (United States)

    Hansen, Bjørn Henrik; Altin, Dag; Nordtug, Trond; Øverjordet, Ida Beathe; Olsen, Anders J; Krause, Dan; Størdal, Ingvild; Størseth, Trond R

    2017-03-01

    Acute oil spills and produced water discharges may cause exposure of filter-feeding pelagic organisms to micron-sized dispersed oil droplets. The dissolved oil components are expected to be the main driver for oil dispersion toxicity; however, very few studies have investigated the specific contribution of oil droplets to toxicity. In the present work, the contribution of oil micro-droplet toxicity in dispersions was isolated by comparing exposures to oil dispersions (water soluble fraction with droplets) to concurrent exposure to filtered dispersions (water-soluble fractions without droplets). Physical (coloration) and behavioral (feeding activity) as well as molecular (metabolite profiling) responses to oil exposures in the copepod Calanus finmarchicus were studied. At high dispersion concentrations (4.1-5.6mg oil/L), copepods displayed carapace discoloration and reduced swimming activity. Reduced feeding activity, measured as algae uptake, gut filling and fecal pellet production, was evident also for lower concentrations (0.08mg oil/L). Alterations in metabolic profiles were also observed following exposure to oil dispersions. The pattern of responses were similar between two comparable experiments with different oil types, suggesting responses to be non-oil type specific. Furthermore, oil micro-droplets appear to contribute to some of the observed effects triggering a starvation-type response, manifested as a reduction in metabolite (homarine, acetylcholine, creatine and lactate) concentrations in copepods. Our work clearly displays a relationship between crude oil micro-droplet exposure and reduced uptake of algae in copepods.

  20. Owl Pellets.

    Science.gov (United States)

    Thompson, Craig D.

    1987-01-01

    Provides complete Project WILD lesson plans for 20-45-minute experiential science learning activity for grades 3-7 students. Describes how students construct a simple food chain through examination of owl pellets. Includes lesson objective, method, background information, materials, procedure, evaluation, and sources of owl pellets and posters.…

  1. Injection of Deuterium Pellets

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, P.; Andersen, S. A.

    1984-01-01

    A pellet injection system made for the TFR tokamak at Fontenay-aux-Roses, Paris is described. 0.12-mg pellets are injected with velocities of around 600-700 m/s through a 5-m long guide tube. Some details of a new light gas gun are given; with this gun, hydrogen pellets are accelerated...

  2. The chemical ecology of copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Selander, Erik

    2014-01-01

    for the functioning of the marine food web, much is still unknown. We synthesize current knowledge about chemical ecology of copepods including foraging, survival and reproduction. We also compile information on the sensory apparatus and new analytical approaches that may facilitate the identification of signal...... molecules. The review illustrates the importance of chemical interactions in many aspects of copepod ecology and identifies gaps in our knowledge, such as the lack of identified infochemicals and electrophysiological studies to confirm the function of sensory structures. We suggest approaches...

  3. The chemical ecology of copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Selander, Erik

    2014-01-01

    for the functioning of the marine food web, much is still unknown. We synthesize current knowledge about chemical ecology of copepods including foraging, survival and reproduction. We also compile information on the sensory apparatus and new analytical approaches that may facilitate the identification of signal...... molecules. The review illustrates the importance of chemical interactions in many aspects of copepod ecology and identifies gaps in our knowledge, such as the lack of identified infochemicals and electrophysiological studies to confirm the function of sensory structures. We suggest approaches...

  4. Importance of bacteria and protozooplankton for faecal pellet degradation* This work is a contribution to the Arctos Network and Conflux project.

    Directory of Open Access Journals (Sweden)

    Nathalie Morata

    2014-06-01

    Full Text Available The degradation mechanisms of faecal pellets are still poorly understood, although they determine their contribution to vertical fluxes of carbon. The aim of this study was to attempt to understand the microbial (bacteria and protozooplankton degradation of faecal pellets by measuring the faecal pellet carbon-specific degradation rate (FP-CSD as an indicator of pellet degradation. ‘In situ’ and ‘culture’ pellets (provided by the grazing of copepods in in situ water and in a culture of Rhodomonas sp. respectively were incubated in seawater from the chlorophyll a maximum and 90 m depth, and in filtered seawater. When microbes were abundant (at the chlorophyll a maximum, they significantly increased FP-CSD. In addition, culture pellets had a higher FP-CSD than in situ pellets, suggesting that the results obtained with culture pellets should be treated with caution when trying to extrapolate to natural field conditions.

  5. Toxicity of nickel in the marine calanoid copepod Acartia tonsa: Nickel chloride versus nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Academic Centre for Innovation and Development in the Food Industry (CAISIAL), Università degli Studi di Napoli Federico II, 80055 Portici (Italy); Vitiello, V. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Casals, E. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Puntes, V.F. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona (Spain); Iamunno, F. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Pellegrini, D. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Changwen, W. [Zhejiang Ocean University, 1 Rd. South Haida, Lincheng New Area, Dinghai District Zhoushan City, 316022 (China); Benvenuto, G. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Buttino, I., E-mail: isabella.buttino@isprambiente.it [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy)

    2016-01-15

    }, showed EC{sub 50} of 0.164 and 0.039 mg L{sup −1}, respectively. Overall, A. tonsa is more sensitive to NiCl{sub 2} than NiNPs with EC{sub 50} being one order of magnitude higher for NiNPs. Finally, we exposed adult copepods for 4 days to NiCl{sub 2} and NiNPs (chronic exposure) to study the effect on fecundity in terms of daily egg production and naupliar viability. Egg production is not affected by either form of nickel, whereas egg viability is significantly reduced by 0.025 mg L{sup −1} NiCl{sub 2} and by 8.5 mg L{sup −1} NiNPs. At NiNP concentration below the acute EC{sub 50} (17 mg L{sup −1}) only 9% of embryos hatched after 4 days. Interestingly, the percentage of naupliar mortality (>82%) observed in the semichronic test at the nominal concentration of 10 mg L{sup −1} NiNPs corresponding to almost 0.10 mg L{sup −1} of dissolved Ni, was similar to that recorded at the same Ni salt concentration. Electron microscopical analyses revealed that A. tonsa adults ingest NiNPs and excrete them through fecal pellets. To the best of our knowledge, this is the first study investigating the toxicity of two different forms of Ni on the reproductive physiology of the copepod A. tonsa and showing the ability of the calanoid copepod to ingest nanoparticles from seawater.

  6. Pellet microfossils: Possible evidence for metazoan life in Early Proterozoic time.

    Science.gov (United States)

    Robbins, E I; Porter, K G; Haberyan, K A

    1985-09-01

    Microfossils resembling fecal pellets occur in acid-resistant residues and thin sections of Middle Cambrian to Early Proterozoic shale. The cylindrical microfossils average 50 x 110 mum and are the size and shape of fecal pellets produced by microscopic animals today. Pellets occur in dark gray and black rocks that were deposited in the facies that also preserves sulfide minerals and that represent environments analogous to those that preserve fecal pellets today. Rocks containing pellets and algal microfossils range in age from 0.53 to 1.9 gigayears (Gyr) and include Burgess Shale, Greyson and Newland Formations, Rove Formation, and Gunflint Iron-Formation. Similar rock types of Archean age, ranging from 2.68 to 3.8 Gyr, were barren of pellets. If the Proterozoic microfossils are fossilized fecal pellets, they provide evidence of metazoan life and a complex food chain at 1.9 Gyr ago. This occurrence predates macroscopic metazoan body fossils in the Ediacaran System at 0.67 Gyr, animal trace fossils from 0.9 to 1.3 Gyr, and fossils of unicellular eukaryotic plankton at 1.4 Gyr.

  7. Mobile Biomass Pelletizing System

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Mason

    2009-04-16

    This grant project examines multiple aspects of the pelletizing process to determine the feasibility of pelletizing biomass using a mobile form factor system. These aspects are: the automatic adjustment of the die height in a rotary-style pellet mill, the construction of the die head to allow the use of ceramic materials for extreme wear, integrating a heat exchanger network into the entire process from drying to cooling, the use of superheated steam for adjusting the moisture content to optimum, the economics of using diesel power to operate the system; a break-even analysis of estimated fixed operating costs vs. tons per hour capacity. Initial development work has created a viable mechanical model. The overall analysis of this model suggests that pelletizing can be economically done using a mobile platform.

  8. Fundamentals of Biomass pellet production

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

    2005-01-01

    Pelletizing experiments along with modelling of the pelletizing process have been carried out with the aim of understanding the fundamental physico-chemical mechanisms that control the quality and durability of biomass pellets. A small-scale California pellet mill (25 kg/h) located with the Biomass...

  9. What makes pelagic copepods so successful?

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2011-01-01

    Three features that are unique or almost unique to pelagic copepods among zooplankton may account for their numerical dominance in the pelagic realm of the oceans: (i) the torpedo-shaped body, the sensory armed antennules and the ‘gearing’ of the muscle motor make pelagic copepods very efficient...

  10. Modeling pellet impact drilling process

    OpenAIRE

    Kovalev, Artem Vladimirovich; Ryabchikov, Sergey Yakovlevich; Isaev, Evgeniy Dmitrievich; Ulyanova, Oksana Sergeevna

    2016-01-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling t...

  11. Pelletizing properties of torrefied spruce

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

    2011-01-01

    to moisture uptake, microbiological decay and easy to comminute into small particles. The present study focused on the pelletizing properties of spruce torrefied at 250, 275 and 300 °C. The changes in composition were characterized by infrared spectroscopy and chemical analysis. The pelletizing properties......, with hemicelluloses being most sensitive to thermal degradation. The chemical changes had a negative impact, both on the pelletizing process and the pellet properties. Torrefaction resulted in higher friction in the press channel of the pellet press and low compression strength of the pellets. Fracture surface...

  12. Owl Pellet Paleontology

    Science.gov (United States)

    McAlpine, Lisa K.

    2013-01-01

    In this activity for the beginning of a high school Biology 1 evolution unit, students are challenged to reconstruct organisms found in an owl pellet as a model for fossil reconstruction. They work in groups to develop hypotheses about what animal they have found, what environment it inhabited, and what niche it filled. At the end of the activity,…

  13. Spliced leader RNA trans-splicing discovered in copepods

    Science.gov (United States)

    Yang, Feifei; Xu, Donghui; Zhuang, Yunyun; Yi, Xiaoyan; Huang, Yousong; Chen, Hongju; Lin, Senjie; Campbell, David A.; Sturm, Nancy R.; Liu, Guangxing; Zhang, Huan

    2015-12-01

    Copepods are one of the most abundant metazoans in the marine ecosystem, constituting a critical link in aquatic food webs and contributing significantly to the global carbon budget, yet molecular mechanisms of their gene expression are not well understood. Here we report the detection of spliced leader (SL) trans-splicing in calanoid copepods. We have examined nine species of wild-caught copepods from Jiaozhou Bay, China that represent the major families of the calanoids. All these species contained a common 46-nt SL (CopepodSL). We further determined the size of CopepodSL precursor RNA (slRNA; 108-158 nt) through genomic analysis and 3‧-RACE technique, which was confirmed by RNA blot analysis. Structure modeling showed that the copepod slRNA folded into typical slRNA secondary structures. Using a CopepodSL-based primer set, we selectively enriched and sequenced copepod full-length cDNAs, which led to the characterization of copepod transcripts and the cataloging of the complete set of 79 eukaryotic cytoplasmic ribosomal proteins (cRPs) for a single copepod species. We uncovered the SL trans-splicing in copepod natural populations, and demonstrated that CopepodSL was a sensitive and specific tool for copepod transcriptomic studies at both the individual and population levels and that it would be useful for metatranscriptomic analysis of copepods.

  14. Optimal mate choice patterns in pelagic copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Eliassen, Sigrun; Kiørboe, Thomas

    2013-01-01

    The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits......, and recent laboratory experiments identified some selected morphological traits. Here, we use a ‘life history-based’ model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities...... typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can...

  15. Table-top pellet injector (TATOP) for impurity pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Szepesi, Tamás, E-mail: szepesi.tamas@wigner.mta.hu [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Herrmann, Albrecht [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Kocsis, Gábor; Kovács, Ádám; Németh, József [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Ploeckl, Bernhard [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-10-15

    Highlights: • A portable pellet injector for solid state pellets was designed. • Aims to study ELM triggering potential of impurity pellets. • Aims for multi-machine comparison of pellet–plasma interaction. • Max. pellet speed: 450 m/s, max. rate: 25 Hz. • Pellet size: 0.5–1.5 mm (diameter). - Abstract: A table-top pellet injector (TATOP) has been designed to fulfill the following scientific aims: to study the ELM triggering potential of impurity pellets, and to make pellet injection experiments comparable over several fusion machines. The TATOP is based on a centrifugal accelerator therefore the complete system is run in vacuum, ensuring the compatibility with fusion devices. The injector is able to launch any solid material (stable at room temperature) in form of balls with a diameter in the 0.5–1.5 mm range. The device hosts three individual pellet tanks that can contain e.g. pellets of different materials, and the user can select from those without opening the vacuum chamber. A key element of the accelerator is a two-stage stop cylinder that reduces the spatial scatter of pellets exiting the acceleration arm below 6°, enabling the efficient collection of all fired pellets. The injector has a maximum launch speed of 450 m/s. The launching of pellets can be done individually by providing TTL triggers for the injector, giving a high level of freedom for the experimenter when designing pellet trains. However, the (temporary) firing rate cannot be larger than 25 Hz. TATOP characterization was done in a test bed; however, the project is still in progress and before application at a fusion oriented experiment.

  16. Fecal microbiota transplant

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007703.htm Fecal microbiota transplant To use the sharing features on this page, please enable JavaScript. Fecal microbiota transplantation (FMT) helps to replace some of the "bad" ...

  17. From a single pellet press to a bench scale pellet mill - Pelletizing six different biomass feedstocks

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Shang, Lei; Sárossy, Zsuzsa

    2016-01-01

    The increasing demand for biomass pellets requires the investigation of alternative raw materials for pelletizetion. In the present paper, the pelletization process of fescue, alfalfa, sorghum, triticale, miscanthus and willow is studied to determine if results obtained in a single pellet press...

  18. Observing copepods through a genomic lens

    Directory of Open Access Journals (Sweden)

    Johnson Stewart C

    2011-09-01

    Full Text Available Abstract Background Copepods outnumber every other multicellular animal group. They are critical components of the world's freshwater and marine ecosystems, sensitive indicators of local and global climate change, key ecosystem service providers, parasites and predators of economically important aquatic animals and potential vectors of waterborne disease. Copepods sustain the world fisheries that nourish and support human populations. Although genomic tools have transformed many areas of biological and biomedical research, their power to elucidate aspects of the biology, behavior and ecology of copepods has only recently begun to be exploited. Discussion The extraordinary biological and ecological diversity of the subclass Copepoda provides both unique advantages for addressing key problems in aquatic systems and formidable challenges for developing a focused genomics strategy. This article provides an overview of genomic studies of copepods and discusses strategies for using genomics tools to address key questions at levels extending from individuals to ecosystems. Genomics can, for instance, help to decipher patterns of genome evolution such as those that occur during transitions from free living to symbiotic and parasitic lifestyles and can assist in the identification of genetic mechanisms and accompanying physiological changes associated with adaptation to new or physiologically challenging environments. The adaptive significance of the diversity in genome size and unique mechanisms of genome reorganization during development could similarly be explored. Genome-wide and EST studies of parasitic copepods of salmon and large EST studies of selected free-living copepods have demonstrated the potential utility of modern genomics approaches for the study of copepods and have generated resources such as EST libraries, shotgun genome sequences, BAC libraries, genome maps and inbred lines that will be invaluable in assisting further efforts to

  19. Intermittent swarming of copepods in Versova mangrove, Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; Nair, V.R.

    suggested as an adaptive advantage for feeding, propagation, protection and dispersal by currents. Copepod swarms are usually monospecific and are composed of adult and late stage copepodites. While studying the copepod composition of Versova mangrove...

  20. Fecal Transplants: What Is Being Transferred?

    Directory of Open Access Journals (Sweden)

    Diana P Bojanova

    2016-07-01

    Full Text Available Fecal transplants are increasingly utilized for treatment of recurrent infections (i.e., Clostridium difficile in the human gut and as a general research tool for gain-of-function experiments (i.e., gavage of fecal pellets in animal models. Changes observed in the recipient's biology are routinely attributed to bacterial cells in the donor feces (~1011 per gram of human wet stool. Here, we examine the literature and summarize findings on the composition of fecal matter in order to raise cautiously the profile of its multipart nature. In addition to viable bacteria, which may make up a small fraction of total fecal matter, other components in unprocessed human feces include colonocytes (~107 per gram of wet stool, archaea (~108 per gram of wet stool, viruses (~108 per gram of wet stool, fungi (~106 per gram of wet stool, protists, and metabolites. Thus, while speculative at this point and contingent on the transplant procedure and study system, nonbacterial matter could contribute to changes in the recipient's biology. There is a cautious need for continued reductionism to separate out the effects and interactions of each component.

  1. Copepods and fishes in the Brazilian Amazon

    Science.gov (United States)

    Thatcher, Vernon E.

    1998-06-01

    The Amazon basin comprises the largest river ecosystem in the world (7 million km 2) with annual high and low water peaks and a constant temperature near 29°C. Some 2000 fish species and 40 species of free-living copepods are known to occur in Amazonia. The free-living forms serve as food for most larval fishes and some adults, but they also transmit several parasites including representatives of the nematode family Camallanidae. About three dozen species of parasitic copepods have been described from the Brazilian Amazon. Females of Amazonian parasitic copepods are found on skin, gill filaments, gill rakers or within the nasal fossae. Parasitic copepods are found on fishes that are from a few millimeters long up to those over 2 m in length and they are usually quite host specific. All have body pigmentation in different patterns and colors (frequently blues, such as cerulean, cobalt, spectrum, smalt or campanula). It is suggested that the coloration serves to attract specific host fish. Copepods have evolved adaptations for attachment and feeding, especially in the second antennae and endopods. Examples of progenesis, phoresis and commensalism are shown. Some species produce pathology such as a tourniquet effect, hyperplasia, blood loss and anemia, and can kill fishes by limiting their respiration.

  2. Feeding ecology of the copepod Lucicutia aff. L. grandis near the lower interface of the Arabian Sea oxygen minimum zone

    Science.gov (United States)

    Gowing, Marcia M.; Wishner, Karen F.

    sinking to the sea floor. They also modify sinking carbon in several ways: enhancing pelagic-abyssal coupling of carbon from cyanobacteria, eliminating part of the deep-sea microbial loop by direct consumption of bacterial aggregates, and redistributing particulate manganese and iron from association with suspended cells or aggregates to containment in rapidly sinking fecal pellets. Lucicutia aff. L. grandis can be viewed as representative of deep-dwelling detritivorous mesozooplankton. Assessing the magnitude of the effects of such organisms on carbon flux in the Arabian Sea will require data on feeding rates.

  3. Population dynamics and life history strategies of the dominant copepods in a sub-arctic Greenlandic fjord

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Nielsen, Torkel Gissel

    Investigations of the Arctic and Sub-Arctic pelagic food web have previously focused on the copepod genus Calanus, as they often dominate the mesozooplankton community and serve as a lipid rich food source for higher trophic levels. However, if night samples are considered a different food web...... might emerges with the omnivorous copepod Metridia spp. in a major role. Biology of Metridia is practically unknown but deviates from Calanus e.g. Metridia does not hibernate but stays active yearlong benefiting from being omnivore. In the present study abundance, depth distribution, and egg and pellet...... hibernating Calanus. M. longa might thereby also have a central role in the lipid rich food chain which is a distinct feature for Arctic and Sub-Arctic ecosystems...

  4. Pelleting of feed for broiler chickens: Factors affecting pellet quality

    Directory of Open Access Journals (Sweden)

    Daniel José Antoniol Miranda

    2011-01-01

    Full Text Available The efficiency of the pellet can be translated by the quality of the pellet which is defined as the proportion of intact pellets that come to feeders for chickens, i.e., its resistance to breakage between the feed mill and farms. The use of diets with a higher percentage of intact pellets results in better performance of birds when compared with the feed rations. The main factors that affect pellet quality are: characteristics of pelleting, the feed composition, particle size, pelleting temperature, moisture and steam injection. From a nutritional standpoint, one can consider that the smaller the particle size of food increased their contact with the digestive juices, which aids digestion and absorption of nutrients. However, finely ground lead to less stimulation and growth of intestinal ephitellium. But from the standpoint of production of feed, the larger the particle size of ingredients largest economy with energy and greater efficiency (tons / hour milling. Because of this, it is suggested that the particle sizes used vary between 500 and 700 ìm to not to cause loss of performance of the birds, nor the income from the factory. Increased energy, through the addition of oils and fats, have much influence on performance parameters of broilers and the quality of the pellet produced. The presence of oils and / or fat, depending on the amount, on its hydrophoby characteristic, causing damage to the particles aggregation acting as a lubricant between food particles and the matrix of pelleting, decreasing the pelleting pressure and its gelatinization, resulting into poor quality pellets.

  5. Fundamentals of Biomass pellet production

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

    2005-01-01

    to pelletize a 60% (wt) pine + 40% (wt) beech mixture but not a 40% (wt) pine + 60% (wt) beech mixture. Addition of 3% (wt) rape oil or 3% (wt) Wafolin did not facilitate the pelletizing process of beech. However, it was found that the addition of polymer-rich compounds such as brewers spent grains...... tests are needed, it appears that the addition of small amounts of brewers spent grains increases the quality of the pellets. A model is presented which describes the pelletizing pressure variation along the press channels of the die. Equations based on differential control volumes are set up...

  6. Prey detection in a cruising copepod

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Kiørboe, Thomas

    2012-01-01

    Small cruising zooplankton depend on remote prey detection and active prey capture for efficient feeding. Direct, passive interception of prey is inherently very inefficient at low Reynolds numbers because the viscous boundary layer surrounding the approaching predator will push away potential prey....... Yet, direct interception has been proposed to explain how rapidly cruising, blind copepods feed on non-motile phytoplankton prey. Here, we demonstrate a novel mechanism for prey detection in a cruising copepod, and describe how motile and non-motile prey are discovered by hydromechanical and tactile...

  7. Prey detection in a cruising copepod

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Kiørboe, Thomas

    2012-01-01

    Small cruising zooplankton depend on remote prey detection and active prey capture for efficient feeding. Direct, passive interception of prey is inherently very inefficient at low Reynolds numbers because the viscous boundary layer surrounding the approaching predator will push away potential prey....... Yet, direct interception has been proposed to explain how rapidly cruising, blind copepods feed on non-motile phytoplankton prey. Here, we demonstrate a novel mechanism for prey detection in a cruising copepod, and describe how motile and non-motile prey are discovered by hydromechanical and tactile...

  8. A plea for the use of copepods in freshwater ecotoxicology

    DEFF Research Database (Denmark)

    Kulkarni, Devdutt; Gergs, André; Hommen, Udo

    2013-01-01

    . However, very little is known about the ecotoxicology of freshwater copepods. To enable a more realistic risk higher tier environmental risk assessment, we recommend considering freshwater copepods as part of the hazard assessment process. This could include the establishment of laboratory experiments...... consequences concerning the vulnerability of such species to exposure with contaminants. We aimed to highlight the importance of copepods in ecology and to underline the need to include freshwater copepods in ecotoxicology. We carried out a literature search on copepods and Daphnia in ecology and ecotoxicology...

  9. Pellet injector research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Schuresko, D.D.; Milora, S.L.; Combs, S.K.; Foster, C.A.; Fisher, P.W.; Argo, B.E.; Barber, G.C.; Foust, C.R.; Gethers, F.E.; Gouge, M.J.

    1987-01-01

    Several advanced plasma fueling systems are under development at the Oak Ridge National Laboratory (ORNL) for present and future magnetic confinement devices. These include multishot and repeating pneumatic pellet injectors, centrifuge accelerators, electrothermal guns, a Tritium Proof-of-Principle experiment, and an ultrahigh velocity mass ablation driven accelerator. A new eight-shot pneumatic injector capable of delivering 3.0 mm, 3.5 mm, and 4.0 mm diameter pellets at speeds up to 1500 m/s into a single discharge has been commissioned recently on the Tokamak Fusion Test reactor. The so-called Deuterium Pellet Injector (DPI) is a prototype of a Tritium Pellet Injector (TPI) scheduled for use on TFTR in 1990. Construction of the TPI will be preceded by a test of tritium pellet fabrication and acceleration using a 4 mm bore ''pipe gun'' apparatus. A new repeating pneumatic pellet injector capable of 2.7 mm, 4 mm, and 6 mm operation is being installed on the Joint European Torus to be used in ORNL/JET collaborative pellet injection studies. A 1.5 m centrifuge injector is being developed for application on the Tore Supra experiment in 1988. The new device, which is a 50% upgrade of the prototype centrifuge used on D-III, features a pellet feed mechanism capable of producing variable-size pellets (1.5 to 3.0 mm diameter) optimally shaped to survive acceleration stresses. Accelerating pellets to velocities in excess of 2 km/s is being pursued through two new development undertakings. A hydrogen plasma electrothermal gun is operational at 2 km/s with 10 mg hydrogen pellets; this facility has recently been equipped with a pulsed power supply capable of delivering 1.7 kJ millisecond pulses to low impedence arc loads.

  10. A plea for the use of copepods in freshwater ecotoxicology.

    Science.gov (United States)

    Kulkarni, Devdutt; Gergs, André; Hommen, Udo; Ratte, Hans Toni; Preuss, Thomas G

    2013-01-01

    Standard species used in ecological risk assessment are chosen based on their sensitivity to various toxicants and the ease of rearing them for laboratory experiments. However, this mostly overlooks the fact that species in the field that may employ variable life-history strategies, which may have consequences concerning the vulnerability of such species to exposure with contaminants. We aimed to highlight the importance of copepods in ecology and to underline the need to include freshwater copepods in ecotoxicology. We carried out a literature search on copepods and Daphnia in ecology and ecotoxicology to compare the recognition given to these two taxa in these respective fields. We also conducted a detailed analysis of the literature on copepods and their current role in ecotoxicology to characterize the scale and depth of the studies and the ecotoxicological information therein. The literature on the ecology of copepods outweighed that in ecotoxicology when compared with daphnids. Copepods, like other zooplankton, were found to be sensitive to toxicants and important organisms in aquatic ecosystems. The few studies that were conducted on the ecotoxicology of copepods mainly focused on marine copepods. However, very little is known about the ecotoxicology of freshwater copepods. To enable a more realistic risk higher tier environmental risk assessment, we recommend considering freshwater copepods as part of the hazard assessment process. This could include the establishment of laboratory experiments to analyse the effects of toxicants on copepods and the development of individual-based models to extrapolate effects across species and scenarios.

  11. Owl Pellets and Crisis Management.

    Science.gov (United States)

    Anderson, Tom

    2002-01-01

    Describes a press conference that was used as a "teachable moment" when owl pellets being used for instructional purposes were found to be contaminated with Salmonella. The incident highlighted the need for safe handling of owl pellets, having a crisis management plan, and the importance of conveying accurate information to concerned parents.…

  12. Colloquium on diatom-copepod interactions

    DEFF Research Database (Denmark)

    Paffenhofer, G.A.; Ianora, A.; Miralto, A.;

    2005-01-01

    From 3 to 6 November 2002, a colloquium was convened at the Benthos Laboratory of the Stazione Zoologica Anton Dohrn on Ischia, Italy, with the goal of evaluating the present status of the effects of diatoms on their main consumers, planktonic copepods, and to develop future research strategies...

  13. The microbiome of North Sea copepods

    Science.gov (United States)

    Gerdts, G.; Brandt, P.; Kreisel, K.; Boersma, M.; Schoo, K. L.; Wichels, A.

    2013-12-01

    Copepods can be associated with different kinds and different numbers of bacteria. This was already shown in the past with culture-dependent microbial methods or microscopy and more recently by using molecular tools. In our present study, we investigated the bacterial community of four frequently occurring copepod species, Acartia sp., Temora longicornis, Centropages sp. and Calanus helgolandicus from Helgoland Roads (North Sea) over a period of 2 years using DGGE (denaturing gradient gel electrophoresis) and subsequent sequencing of 16S-rDNA fragments. To complement the PCR-DGGE analyses, clone libraries of copepod samples from June 2007 to 208 were generated. Based on the DGGE banding patterns of the two years survey, we found no significant differences between the communities of distinct copepod species, nor did we find any seasonality. Overall, we identified 67 phylotypes (>97 % similarity) falling into the bacterial phyla of Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The most abundant phylotypes were affiliated to the Alphaproteobacteria. In comparison with PCR-DGGE and clone libraries, phylotypes of the Gammaproteobacteria dominated the clone libraries, whereas Alphaproteobacteria were most abundant in the PCR-DGGE analyses.

  14. A trait database for marine copepods

    DEFF Research Database (Denmark)

    Brun, Philipp Georg; Payne, Mark; Kiørboe, Thomas

    2017-01-01

    The trait-based approach is gaining increasing popularity in marine plankton ecology but the field urgently needs more and easier accessible trait data to advance.We compiled trait information on marine pelagic copepods, a major group of zooplankton, from the published literature and from experts...

  15. Algal toxins alter copepod feeding behavior.

    Directory of Open Access Journals (Sweden)

    Jiarong Hong

    Full Text Available Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  16. Moving behavior of pellets in a pellet shaft furnace

    Institute of Scientific and Technical Information of China (English)

    梁儒全; 赫冀成

    2008-01-01

    The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model experiment shows that the downward movement of pellets can be regarded as plug flow approximately inside the furnace except for the lower region of cooling zone due to the influence of the drained hopper.The top model experiment reveals that the pellet sizes increase along the moving direction because of the percolation phenomenon,which results in a decrease of the resistance coefficient and an increase of the gas flow rate from the furnace wall toward the furnace center.

  17. The pellet handbook: the production and thermal utilisation of pellets

    National Research Council Canada - National Science Library

    Obernberger, Ingwald; Thek, Gerold

    2010-01-01

    "Biomass pellets are a suitable fuel type for a wide range of applications, from stoves and central heating systems up to large-scale plants, and with practically complete automation in all these capacities...

  18. Simulation of Pellet Ablation

    Science.gov (United States)

    Parks, P. B.; Ishizaki, Ryuichi

    2000-10-01

    In order to clarify the structure of the ablation flow, 2D simulation is carried out with a fluid code solving temporal evolution of MHD equations. The code includes electrostatic sheath effect at the cloud interface.(P.B. Parks et al.), Plasma Phys. Contr. Fusion 38, 571 (1996). An Eulerian cylindrical coordinate system (r,z) is used with z in a spherical pellet. The code uses the Cubic-Interpolated Psudoparticle (CIP) method(H. Takewaki and T. Yabe, J. Comput. Phys. 70), 355 (1987). that divides the fluid equations into non-advection and advection phases. The most essential element of the CIP method is in calculation of the advection phase. In this phase, a cubic interpolated spatial profile is shifted in space according to the total derivative equations, similarly to a particle scheme. Since the profile is interpolated by using the value and the spatial derivative value at each grid point, there is no numerical oscillation in space, that often appears in conventional spline interpolation. A free boundary condition is used in the code. The possibility of a stationary shock will also be shown in the presentation because the supersonic ablation flow across the magnetic field is impeded.

  19. Effect of Sawdust Characteristics on Pelletizing Properties and Pellet Quality

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, Robert; Thyrel, Mikael; Lestander, Torbjoern; Jonsson, Carina [Swedish Univ of Agricultural Science, Umeaa (Sweden). Unit of Biomass Technology and Chemistry; Sjoestroem, Michael [Univ. of Umeaa (Sweden). Dept. of Chemistry

    2006-07-15

    Sawdust of pine and spruce from sawmills is the most common raw material for pellet production in Sweden today. Experiences from pellet plants indicate that raw material properties like wood species, storage time (maturity), growing latitude and moisture content influence the pelletizing properties and the pellet quality. However, no systematic investigation where the above mentioned parameters were studied in combination with pelletizing parameters like die length and steam treatment has been reported so far. In this paper the pelletizing of sawdust using a reduced factorial design with six parameters is described. The independent parameters studied were wood species (pine, spruce), growing latitude (57, 64 deg N), storage time (fresh, 140 days), moisture content (9 %, 12 %), die length (55 mm, 65 mm) and steam treatment (2,0 kg/h, 6,0 kg/h). The pelletizing parameters measured during the experiments were i.e. die temperature, energy consumption, Pellets temperature, while the main pellet quality parameters were bulk density, durability, fines and moisture content. All results were evaluated by using multivariate data analysis. The results can be summarized as follows: Bulk density: The two-factor interaction between moisture content and steam treatment affected the bulk density most significantly. The best response was obtained at either high moisture content and low steam treatment or vice versa. In addition, the results showed that long storage time influenced the bulk density positively. durability: Storage time is the most significant factor for the durability; long storage results in higher durability. Even for the durability the two-factor interaction between moisture content and steam treatment is of great importance. fines: The amount of fines is to a large extent determined by the two-factor interaction between moisture content and steam treatment together with the storage time. The amount of fines is also affected by wood species and growing latitude

  20. Economic feasibility of copepod production for commercial use

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw; Nielsen, Rasmus; Nielsen, Max

    2015-01-01

    of producing copepods for commercial application. This is the first empirical study to investigate the economic feasibility of copepod production for commercial use. To this end, a standard cost-benefit analysis based on a prototype production facility of Acartia tonsa (Dana) eggs at Roskilde University...... production for marine finfish aquaculture. Furthermore, the study also highlights the economic benefits of production and utilization of copepods on productivity and species diversification in marine finfish aquaculture....

  1. Handling of Deuterium Pellets for Plasma Refuelling

    DEFF Research Database (Denmark)

    Jensen, Peter Bjødstrup; Andersen, Verner

    1982-01-01

    The use of a guide tube technique to inject pellets in pellet-plasma experiments is described. The effect of the guide tube on the mass and speed of a slowly moving pellet ( nu approximately 150 m s-1) is negligible. To improve the divergence in trajectories of the pellets on leaving the guide tube...... a specially formed brass slide has been developed, which improves the aiming accuracy by a factor of 10. A simple method for determining the mass of larger pellets by means of a plate capacitor through which the pellets are shot is described. A method for small pellets as well has been investigated...

  2. 46 CFR 148.04-21 - Coconut meal pellets (also known as copra pellets).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Coconut meal pellets (also known as copra pellets). 148.04-21 Section 148.04-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS... § 148.04-21 Coconut meal pellets (also known as copra pellets). (a) Coconut meal pellets; (1)...

  3. COPEPOD: The Coastal & Oceanic Plankton Ecology, Production, & Observation Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal & Oceanic Plankton Ecology, Production, & Observation Database (COPEPOD) provides NMFS scientists with quality-controlled, globally distributed...

  4. Fecal Incontinence in Children

    Science.gov (United States)

    ... children and teens in our Learning Center . FAQs Prevalence Causes of Incontinence Childbirth and Delivery Neurologic Disease or Injury Colorectal Cancer Other Contributing Factors Fecal Incontinence in Children Reporter's ...

  5. Ocean acidification challenges copepod phenotypic plasticity

    Science.gov (United States)

    Vehmaa, Anu; Almén, Anna-Karin; Brutemark, Andreas; Paul, Allanah; Riebesell, Ulf; Furuhagen, Sara; Engström-Öst, Jonna

    2016-11-01

    Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ˜ 365-1231 µatm) and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm) or quality (C : N) weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

  6. Copepod Foraging on the Basis of Food Nutritional Quality: Can Copepods Really Choose?

    Science.gov (United States)

    Isari, Stamatina; Antό, Meritxell; Saiz, Enric

    2013-01-01

    Copepods have been considered capable of selective feeding based on several factors (i.e., prey size, toxicity, and motility). However, their selective feeding behaviour as a function of food quality remains poorly understood, despite the potential impact of such a process on copepod fitness and trophodynamics. In this study, we aimed to evaluate the ability of copepods to feed selectively according to the nutritional value of the prey. We investigated the feeding performance of the calanoid copepod Acartia grani under nutritionally distinct diets of the dinoflagellate Heterocapsa sp. (nutrient-replete, N-depleted and P-depleted) using unialgal suspensions and mixtures of prey (nutrient-replete vs. nutrient-depleted). Despite the distinct cell elemental composition among algal treatments (e.g., C:N:P molar ratios) and the clear dietary impact on egg production rates (generally higher number of eggs under a nutrient-replete diet), no impact on copepod feeding rates was observed. All unialgal suspensions were cleared at similar rates, and this pattern was independent of food concentration. When the prey were offered as mixtures, we did not detect selective behaviour in either the N-limitation (nutrient-replete vs. N-depleted Heterocapsa cells) or P-limitation (nutrient-replete vs. P-depleted Heterocapsa cells) experiments. The lack of selectivity observed in the current study contrasts with previous observations, in which stronger nutritional differences were tested. Under normal natural circumstances, nutritional differences in natural prey assemblages might not be sufficiently strong to trigger a selective response in copepods based on that factor alone. In addition, our results suggest that nutritional quality might depend not only on the growing conditions but also on the inherent taxonomical properties of the prey. PMID:24386411

  7. FEEDING AND REPRODUCTIVE ACTIVITY OF THE COPEPODS Drepanopus forcipatus AND Calanus australis DURING LATE SUMMER ON THE SOUTHERN PATAGONIAN SHELF (ARGENTINA, 47°-55°S

    Directory of Open Access Journals (Sweden)

    Julieta Carolina Antacli

    2014-12-01

    Full Text Available Drepanopus forcipatus and Calanus australis are key planktonic copepods on the southern Patagonian shelf. Their feeding and reproductive patterns and population status were investigated during late summer, when environmental conditions may be critical. The presence of food in the gut and food-pellet length were recorded in adult females and the most abundant copepodite stages. Diet composition was also studied in adult females. Female reproductive status was evaluated by gonad staging. Despite generally low feeding conditions and decreasing seasonal temperature, both copepods fed to some degree. The most numerous copepodites and adult females of both species showed similarly low feeding activity. About half of the adult females of the two species and C5s of C. australis contained food in their guts, but the proportion of fed C4-females of D. forcipatus was much lower. All copepods were generally feeding at low or intermediate levels. Gonad stage distribution and population structure showed low but still ongoing reproduction in both species. Gut content findings suggest a preference for smaller nanoplanktonic particles, especially dinoflagellates by D. forcipatus, and for autotrophic prey, particularly large diatoms by C. australis. The feeding and reproduction patterns of the two copepods were likely influenced by the distributions of potential food resources and temperature.

  8. Complementary effects of torrefaction and co-pelletization: Energy consumption and characteristics of pellets.

    Science.gov (United States)

    Cao, Liang; Yuan, Xingzhong; Li, Hui; Li, Changzhu; Xiao, Zhihua; Jiang, Longbo; Huang, Binbin; Xiao, Zhihong; Chen, Xiaohong; Wang, Hou; Zeng, Guangming

    2015-06-01

    In this study, complementary of torrefaction and co-pelletization for biomass pellets production was investigated. Two kinds of biomass materials were torrefied and mixed with oil cake for co-pelletization. The energy consumption during pelletization and pellet characteristics including moisture absorption, pellet density, pellet strength and combustion characteristic, were evaluated. It was shown that torrefaction improved the characteristics of pellets with high heating values, low moisture absorption and well combustion characteristic. Furthermore, co-pelletization between torrefied biomass and cater bean cake can reduce several negative effects of torrefaction such as high energy consumption, low pellet density and strength. The optimal conditions for energy consumption and pellet strength were torrefied at 270°C and a blending with 15% castor bean cake for both biomass materials. The present study indicated that compelmentary performances of the torrefaction and co-pelletization with castor bean cake provide a promising alternative for fuel production from biomass and oil cake.

  9. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  10. Copepods use chemical trails to find sinking marine snow aggregates

    DEFF Research Database (Denmark)

    Lombard, Fabien; Koski, Marja; Kiørboe, Thomas

    2013-01-01

    Copepods are major consumers of sinking marine particles and hence reduce the efficiency of the biological carbon pump. Their high abundance on marine snow suggests that they can detect sinking particles remotely. By means of laboratory observations, we show that the copepod Temora longicornis ca...

  11. Re-assessing copepod growth using the Moult Rate method

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Keister, J. E.; Richardson, A. J.

    2014-01-01

    Estimating growth and production rates of mesozooplankton, and copepods in particular, is important in describing flows of material and energy though pelagic systems. Over the past 30 years, the Moult Rate (MR) method has been used to estimate juvenile copepod growth rates in ∼40 papers. Yet the ...

  12. Mortality of marine planktonic copepods : global rates and patterns

    DEFF Research Database (Denmark)

    Hirst, A.G.; Kiørboe, Thomas

    2002-01-01

    Using life history theory we make predictions of mortality rates in marine epi-pelagic copepods from field estimates of adult fecundity, development times and adult sex ratios. Predicted mortality increases with temperature in both broadcast and sac spawning copepods, and declines with body weight...

  13. Propulsion efficiency and imposed flow fields of a copepod jump

    DEFF Research Database (Denmark)

    Jiang, H.; Kiørboe, Thomas

    2011-01-01

    velocity vectors pointing towards the copepod; such a flow field may inform the predator of the whereabouts of the escaping copepod prey. High Froude propulsion efficiency (0.94–0.98) was obtained for individual power stroke durations of all simulated jumps. This is unusual for small aquatic organisms...

  14. A mathematical model to predict the size of the pellets formed in freeze pelletization techniques: parameters affecting pellet size.

    Science.gov (United States)

    Cheboyina, Sreekhar; O'Haver, John; Wyandt, Christy M

    2006-01-01

    A mathematical model was developed based on the theory of drop formation to predict the size of the pellets formed in the freeze pelletization process. Further the model was validated by studying the effect of various parameters on the pellet size such as viscosity of the pellet forming and column liquids, surface/interfacial tension, density difference between pellet forming and column liquids; size, shape, and material of construction of the needle tips and temperatures maintained in the columns. In this study, pellets were prepared from different matrices including polyethylene glycols and waxes. The column liquids studied were silicone oils and aqueous glycerol solutions. The surface/interfacial tension, density difference between pellet forming and column liquids and needle tip size were found to be the most important factors affecting pellet size. The viscosity of the column liquid was not found to significantly affect the size of the pellets. The size of the pellets was also not affected by the pellet forming liquids of low viscosities. An increase in the initial column temperature slightly decreased the pellet size. The mathematical model developed was found to successfully predict the size of the pellets with an average error of 3.32% for different matrices that were studied.

  15. Fecal Occult Blood Test and Fecal Immunochemical Test

    Science.gov (United States)

    ... Visit Global Sites Search Help? Fecal Occult Blood Test and Fecal Immunochemical Test Share this page: Was this page helpful? Also ... Test Common Questions Ask Us Related Pages The Test How is it used? When is it ordered? ...

  16. Does copepods influence dusky grouper (Epinephelus marginatus early development?

    Directory of Open Access Journals (Sweden)

    Monica Mateus

    2014-06-01

    Full Text Available Good knowledge on the development of early life stages is essential for successful conservation programs of threatened fish species. Diet and rearing system affects early life survival and juvenile quality. Copepods are the natural food of fish larvae in the wild possessing high nutritional value, when compared with live feeds used in aquaculture (rotifers and artemia, and a wide range of size classes. Rearing systems with low water column disturbance and low larval densities enhanced the survival of fragile fish larvae. The aim of this work is to evaluate the effect of the introduction of copepods in the diet of early dusky grouper larvae reared in controlled mesocosm systems using larval development and juvenile quality as indicators. Two feeding protocols were tested, one composed only by rotifers (Brachionus plicatilis, brine shrimp (Artemia spp. and dry feed and the other supplemented with copepods (Paracartia grani from mouth opening (2 day after hatching - DAH to 8 DAH. Feeding behavior, growth, survival, skeletal malformations and digestive enzymes activity was assessed at different developmental stages. The addition of copepods to the early larvae diet of dusky grouper resulted in faster development and higher survival rates. Larvae fed with copepods improved their development. At 20 DAH all larvae reared at the mesocosm with copedods were already at the stage of post-flexion while in the system without copepods this stage was attained later. At 25 DAH only 64% of the larvae were in post flexion in the mesoscosm without copepods. At 30 DAH larvae supplemented with copepods attained an acidic digestion (high specific activity of pepsin earlier than at the system without copepods. In this last system alkaline digestion (trypsin specific activity, characteristic of early larval stages, was significantly higher reinforcing the faster development of larvae fed with copepods. In both systems the incidence of skeletal malformations was low.

  17. [Fecal microbiota transplantation].

    Science.gov (United States)

    Šturdík, Igor; Hlavatý, Tibor; Payer, Juraj

    2016-02-01

    Fecal microbiota transplantation (FMT) is a therapeutic method, in which the fecal microflora from healthy donors is transmitted to the patient to restore the healthy microbial composition of the gut. In the recent years, there is a growing interest in the therapeutic potential of FMT in various diseases. The standard FMT protocols do not exist. Procedures of FMT vary in several aspects such as donor selection, preparation of fecal material, preparation of the recipient and administration way. FMT appears to be the most successful in the treatment of recurrent Clostridium difficile infection (CDI), randomized controlled studies reported 90 % success rate. There is a limited evidence for FMT as a treatment of ulcerative colitis. FMT has been also studied as treatment of diseases with impaired gut microbiota, such as cardiovascular, autoimmune and metabolic diseases. Many unanswered questions with regard to FMT remain and further research is needed.

  18. Gaining Control Over Fecal Incontinence.

    Science.gov (United States)

    Gump, Kendra; Schmelzer, Marilee

    2016-01-01

    Strategies that improve the regularity and efficiency of defecation can eliminate or minimize episodes of fecal incontinence. The medical-surgical nurse's role in identifying patients with fecal incontinence is discussed, along with various treatments to control bowel elimination.

  19. Interactions of Pellet with Reactor Relevant Plasma

    Institute of Scientific and Technical Information of China (English)

    PENGLilin; DENGBaiquan; YANJiancheng

    2003-01-01

    Extended algorithm has been developed for ablation rate calculations of Li, Be, B impurity pellets and five combinations of solid isotopic hydrogenic H2, HD, D2, DT, T2 pellets. Numerical calculations have been performed for reactor relevant plasma.

  20. DEVELOPMENT OF A CASSAVA PELLETING MACHINE

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Department of Mechanical Engineering, Michael Okapra University of Agriculture, Umudike, Abia State. ... ples of hand operations for pelleting food includes the rolling of modles .... the hopper, transmission and pelleting unit.

  1. Pellet fired appliances. Market survey. 7. rev. ed.; Pelletheizungen. Marktuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    The market survey under consideration reports on pellet central heating systems and pellet fired appliances. The main chapters of this market survey are concerned to: (1) Information on wood pellets and pellet fired appliances; (2) Information about the interpretation of the market survey; (3) Survey of all compared pellet fired appliances with respect to the nominal power; (4) Price lists of pellet fired appliances and pellet central heating systems; (5) Type sheets of the compared pellet fired appliances and pellet central heating systems. Finally, this brochure contains the addresses of the produces and distribution partners of pellet fired appliances and pellet central heating systems.

  2. A trait database for marine copepods

    Science.gov (United States)

    Brun, Philipp; Payne, Mark R.; Kiørboe, Thomas

    2017-02-01

    The trait-based approach is gaining increasing popularity in marine plankton ecology but the field urgently needs more and easier accessible trait data to advance. We compiled trait information on marine pelagic copepods, a major group of zooplankton, from the published literature and from experts and organized the data into a structured database. We collected 9306 records for 14 functional traits. Particular attention was given to body size, feeding mode, egg size, spawning strategy, respiration rate, and myelination (presence of nerve sheathing). Most records were reported at the species level, but some phylogenetically conserved traits, such as myelination, were reported at higher taxonomic levels, allowing the entire diversity of around 10 800 recognized marine copepod species to be covered with a few records. Aside from myelination, data coverage was highest for spawning strategy and body size, while information was more limited for quantitative traits related to reproduction and physiology. The database may be used to investigate relationships between traits, to produce trait biogeographies, or to inform and validate trait-based marine ecosystem models. The data can be downloaded from PANGAEA, http://dx.doi.org/10.1594/PANGAEA.862968" target="_blank">doi:10.1594/PANGAEA.862968.

  3. Numerical simulation of a self-propelled copepod during escape

    Science.gov (United States)

    Sotiropoulos, Fotis; Borazjani, Iman; Malkiel, Edwin; Katz, Josef

    2008-11-01

    Obtaining the 3D flow field, forces, and power is essential for understanding the high accelerations of a copepod during the escap. We carry out numerical simulations to study a free swimming copepod using the sharp-interface immersed boundary, fluid-structure interaction (FSI) approach of Borazjani et al. (J Compu Phys, 2008, 227, p 7587-7620). We use our previous tethered copepod model with a realistic copepod-like body, including all the appendages with the appendages motion prescribed from high-resolution, cinematic dual digital holography. The simulations are performed in a frame of reference attached to the copepod whose velocity is calculated by considering the forces acting on the copepod. The self-propelled simulations are challenging due to the destabilizing effects of the large added mass resulting from the low copepod mass and fast acceleration during the escape. Strongly-coupled FSI with under-relaxation and the Aitken acceleration technique is used to obtain stable and robust FSI iterations. The computed results for the self-propelled model are analyzed and compared with our earlier results for the tethered model.

  4. Molecular and microscopic evidence of viruses in marine copepods.

    Science.gov (United States)

    Dunlap, Darren S; Ng, Terry Fei Fan; Rosario, Karyna; Barbosa, Jorge G; Greco, Anthony M; Breitbart, Mya; Hewson, Ian

    2013-01-22

    As dominant members of marine mesozooplankton communities, copepods play critical roles in oceanic food webs and biogeochemical cycling. Despite the ecological significance of copepods, little is known regarding the causes of copepod mortality, and up to 35% of total copepod mortality cannot be accounted for by predation alone. Viruses have been established as ecologically important infectious agents in the oceans; however, viral infection has not been investigated in mesozooplankton communities. Here we used molecular and microscopic techniques to document viral infection in natural populations of the calanoid copepods Acartia tonsa (Dana) and Labidocera aestiva (Wheeler) in Tampa Bay, FL. Viral metagenomics revealed previously undocumented viruses in each species, named Acartia tonsa copepod circo-like virus (AtCopCV) and Labidocera aestiva copepod circo-like virus (LaCopCV). LaCopCV was found to be extremely prevalent and abundant in L. aestiva populations, with up to 100% prevalence in some samples and average viral loads of 1.13 × 10(5) copies per individual. LaCopCV transcription was also detected in the majority of L. aestiva individuals, indicating viral activity. AtCopCV was sporadically detected in A. tonsa populations year-round, suggesting temporal variability in viral infection dynamics. Finally, virus-like particles of unknown identity were observed in the connective tissues of A. tonsa and L. aestiva by transmission electron microscopy, demonstrating that viruses were actively proliferating in copepod connective tissue as opposed to infecting gut contents, parasites, or symbionts. Taken together, these results provide strong independent lines of evidence for active viral infection in dominant copepod species, indicating that viruses may significantly influence mesozooplankton ecology.

  5. Production and use of copepods in marine fish larviculture

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Norsker, N.H.

    1997-01-01

    substratum. Two such systems were compared in terms of area productivity and the use of ammonia excretion as a means for controlling feeding of the copepods was investigated. Finally, the potential benefits of the use of copepods as live food for marine fish larvae are discussed. (C) 1997 Elsevier Science B.V...... swimming behaviour in terms of vertical distribution in a typical fish larval tank and the use of T. holothuriae nauplii as live food for first-feeding turbot larvae were investigated. It was possible to cultivate harpacticoid copepods in shallow trays or in continuous bioreactors with large area...

  6. Does copepod size determine food consumption of particulate feeding fish?

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Koski, Marja; Rindorf, Anna

    2014-01-01

    on adult particulate feeding fish is unknown. In the present study, we investigated the hypothesis that the availability of the large copepods determines food consumption and growth conditions of lesser sandeel (Ammodytes marinus) in the North Sea. Analysis of stomach content suggested that food...... consumption is higher for fish feeding on large copepods, and additional calculations revealed how handling time limitation may provide part of the explanation for this relationship. Comparing stomach data and zooplankton samples indicated that lesser sandeel actively target large copepods when...

  7. Power from Pellets Technology and Applications

    CERN Document Server

    Döring, Stefan

    2013-01-01

    This book provides a practical description of the technology of pellet production on the basis of renewable sources as well as the utilization of pellets. The author explains what kinds of biomass are usable in addition to wood, how to produce pellets and how to use pellets to produce energy. Starting with the basics of combustion, gasification and the pelletizing process, several different technologies are described. The design, planning, construction and economic efficiency are discussed as well. The appendix gives useful advice about plant concepts, calculations, addresses, conversion tables and formulas.

  8. Imaging fecal incontinence

    Energy Technology Data Exchange (ETDEWEB)

    Fuchsjaeger, Michael H. E-mail: michael.fuchsjaeger@univie.ac.at; Maier, Andrea G

    2003-08-01

    Fecal incontinence is the inability to defer release of gas or stool from the anus and rectum by mechanisms of voluntary control. It is an important medical disorder affecting the quality of life of up to 20% of the population above 65 years. The most common contributing factors include previous vaginal deliveries, pelvic or perineal trauma, previous anorectal surgery, and rectal prolapse. Many physicians lack experience and knowledge related to pelvic floor incontinence disorders, but advancing technology has improved this knowledge. Increased experience with endoanal ultrasound and endoanal magnetic resonance imaging have given us a better understanding not only of the anatomy of the anal canal but also of the underlying morphological defects in fecal incontinence. Current imaging methods are emphasized and recent literature is reviewed.

  9. Strategies for success: Copepods in a seasonal world

    DEFF Research Database (Denmark)

    Sainmont, Julie

    by a short, productive spring blooms, but with relatively little food and harsh conditions for the rest of the year. Due to their world-wide dominance in biomass, and their importance in the food webs, copepods are fairly well studied. However, the success of their complex life-history strategies remain open......Amongst the zooplankton community, copepods display complex and diverse life history strategies, which could explain their wide success in the world ocean. Specically, in temperate and high latitude ecosystems, copepods are subject to \\boom and bust" conditions where annual cycles are punctuated...... scientic questions, in particular, how these are attuned to environmental conditions, and how these may be compromised by climate change. Due to their ability to concentrate lipids in their small bodies, copepods are indeed of great ecological signicance as they are an important link between phytoplankton...

  10. The fluid dynamics of swimming by jumping in copepods

    DEFF Research Database (Denmark)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-01-01

    Copepods swim either continuously by vibrating their feeding appendages or erratically by repeatedly beating their swimming legs resulting in a series of small jumps. The two swimming modes generate different hydrodynamic disturbances and therefore expose the swimmers differently to rheotactic...... limited and temporally ephemeral owing to jump-impulsiveness and viscous decay. In contrast, continuous steady swimming generates two well-extended long-lasting momentum jets both in front of and behind the swimmer, as suggested by the well-known steady stresslet model. Based on the observed jump-swimming...... kinematics of a small copepod Oithona davisae, we further showed that jump-swimming produces a hydrodynamic disturbance with much smaller spatial extension and shorter temporal duration than that produced by a same-size copepod cruising steadily at the same average translating velocity. Hence, small copepods...

  11. The fluid dynamics of swimming by jumping in copepods

    DEFF Research Database (Denmark)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-01-01

    Copepods swim either continuously by vibrating their feeding appendages or erratically by repeatedly beating their swimming legs resulting in a series of small jumps. The two swimming modes generate different hydrodynamic disturbances and therefore expose the swimmers differently to rheotactic...... limited and temporally ephemeral owing to jump-impulsiveness and viscous decay. In contrast, continuous steady swimming generates two well-extended long-lasting momentum jets both in front of and behind the swimmer, as suggested by the well-known steady stresslet model. Based on the observed jump-swimming...... kinematics of a small copepod Oithona davisae, we further showed that jump-swimming produces a hydrodynamic disturbance with much smaller spatial extension and shorter temporal duration than that produced by a same-size copepod cruising steadily at the same average translating velocity. Hence, small copepods...

  12. Distribution of pelagic harpacticoid copepods from the Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Haridas, P.; Rao, T.S.S.

    Pelagic harpacticoid copepods have been studied from the International Indian Ocean Expedition collections. Macrosetella gracilis and Miracia efferata were the most common species of harpacticoids with high densities near land masses. Other three...

  13. Development of copepod nauplii to copepodites

    DEFF Research Database (Denmark)

    Andersen, Henrik Rasmus; Wollenberger, Leah; Halling-Sørensen, Bent;

    2001-01-01

    of the 17 test compounds had 50% lethal concentration to 50% effective concentration (EC50) ratios higher than 10. The results suggest that naupliar development, as a parameter, is able to detect hormonal disrupters in addition to other chemicals that have other specific modes of action.......Test compounds including natural hormones, endocrine disrupters, environmentally occurring compounds, and reference compounds were tested for acute toxicity and inhibitory effect on larval development in the copepod Acartia tonsa. Three compounds, 17a-ethinylestradiol, p-octylphenol, and tamoxifen......, known for their differing effects on the vertebrate estrogen system, were potent inhibitors of naupliar development. Other estrogens, 17b-estradiol, estrone, and bisphenol A, had little potency. Testosterone and progesterone did not inhibit development, but the antiandrogen flutamide had inhibitory...

  14. Properties of enteric coated sodium valproate pellets.

    Science.gov (United States)

    Bruce, L Diane; Petereit, Hans-Ulrich; Beckert, Thomas; McGinity, James W

    2003-10-02

    The influence of subcoat application and micro-environmental pH on the dissolution properties of enteric coated sodium valproate pellets was investigated. The pellets were prepared by solution-layering or wet-mass extrusion-spheronization methods. In order to pass the USP enteric test, the solution-layered and wet-mass extruded pellets required 35 and 25% weight gain of Eudragit L 30D-55, respectively. The application of a subcoat of either Methocel-E5 (HPMC) or Opadry AMB to the pellets resulted in a delay in sodium valproate release in 0.1N HCl. Further delay in drug release was observed when citric acid was present in a HPMC subcoat or when added to the core pellet formulation. The amount of drug released from coated pellets was a function of the level of citric acid in the pellet core or subcoat and subsequent micro-environmental pH of the pellets. Citric acid exerted a plasticizing effect on the enteric polymer film and improved film formation and polymer coalescence. When greater than 10% (w/w) citric acid was present in the pellets, a decrease in drug content was observed due to the conversion of sodium valproate to the volatile compound, valproic acid. Pellets containing less than 10% (w/w) citric acid maintained potency during processing.

  15. Copepod flow modes and modulation: a modelling study of the water currents produced by an unsteadily swimming copepod

    OpenAIRE

    2007-01-01

    Video observation has shown that feeding-current-producing calanoid copepods modulate their feeding currents by displaying a sequence of different swimming behaviours during a time period of up to tens of seconds. In order to understand the feeding-current modulation process, we numerically modelled the steady feeding currents for different modes of observed copepod motion behaviours (i.e. free sinking, partial sinking, hovering, vertical swimming upward and horizontal swimming backward or fo...

  16. Hydrothermal pretreatment of biomass for pellet production

    Energy Technology Data Exchange (ETDEWEB)

    Tooyserkani, Z. [British Columbia Univ., Vancouver, BC (Canada). Clean Energy Research Centre, Biomass and Bioenergy Research Group

    2010-07-01

    This presentation discussed innovative technologies for the production of wood pellets using the hydrothermal pre-treatment of biomass. Conventional techniques use low-cost mill residues, such as saw dust and shavings, as feedstock to produce durable, low-ash pellets. However, mill residues are becoming less available as a result of fewer saw mills, increased pellet production, and increased competition for saw dust. Advanced techniques use mixed biomass such as logging residue as feedstock, creating pellets that are durable for handling and long-term storage, of a higher energy density for transport and mixing with coal for co-firing, and a choice feedstock for biofuels. Advanced pellet production uses steam explosion/pre-treatment in which biomass receives a short-term high-pressure steam treatment followed by sudden decompression. Mild torrefaction seems to have positive feedback, and steam-treated pellets are durable with superior hydrophobicity. 3 figs., 3 tabs.

  17. Pellet-plasma interactions in tokamaks

    DEFF Research Database (Denmark)

    Chang, C.T.

    1991-01-01

    The ablation of a refuelling pellet of solid hydrogen isotopes is governed by the plasma state, especially the density and energy distribution of the electrons. On the other hand, the cryogenic pellet gives rise to perturbations of the plasma temperature and density. Based on extensive experimental...... data, the interaction between the pellet and the plasma is reviewed. Among the subjects discussed are the MHD activity, evolution of temperature and density profiles, and the behaviour of impurities following the injection of a pellet (or pellets). The beneficial effect of density peaking on the energy...... of the plasma. The appearance of striations and the curving of the pellet trajectory are discussed in detail. The possibility is described for using these observations to study the plasma current-density distribution as well as the existence of suprathermal electrons....

  18. Screw Extruder for Pellet Injection System

    Directory of Open Access Journals (Sweden)

    Sharadkumar K. Chhantbar

    2014-05-01

    Full Text Available Solid hydrogenic pellets are used as fuel for fusion energy reactor. A technique for continuous production of solid hydrogen and its isotopes by a screw extruder is suggested for the production of an unlimited number of pellets. The idea was developed and patented by PELIN laboratories, Inc. (Canada. A Gifford McMahon cryocooler is used for the generation of solid hydrogenic fluid pellets. Requirements of the pellets is depends upon the energy to be produced by tokamak. This review paper focuses on the model for the screw extruder for solidification of hydrogen ice having high injection reliability.

  19. Capabilities of nitrogen admixed cryogenic deuterium pellets

    Energy Technology Data Exchange (ETDEWEB)

    Sharov, Igor; Sergeev, Vladimir [SPU, Saint-Petersburg (Russian Federation); Lang, Peter; Ploeckl, Bernhard; Cavedon, Marco [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kocsis, Gabor; Szepesi, Tamas [Wigner RCP RMI, Budapest (Hungary); Collaboration: ASDEX Upgrade Team

    2015-05-01

    Operation at high core density with high energy confinement - as foreseen in a future fusion reactor like DEMO - is being investigated at ASDEX Upgrade tokamak. The efficiency of pellet fuelling from the high-field side usually increases with increasing injection speed. Due to the fragile nature of the deuterium ice, however, the increment of pellet mass losses and subsequent pellet fragmentations take place when the speed is increased. Studies show, that admixing of a small amount of nitrogen (N{sub 2}) into D{sub 2} gas can be favorable for the mechanical stability of pellets. This might be helpful for deeper pellet penetration. Besides, seeding by N{sub 2} can enhance plasma performance due to both increasing the energy confinement time and reducing the divertor heat load in the envisaged ELMy H-mode plasma scenario. Fuelling efficiency of N{sub 2}-admixed solid D{sub 2} pellets and their nitrogen seeding capabilities were investigated. It was found that both the overall plasma density increase and the measured averaged pellet penetration depth were smaller in case of the admixed (1% mol. in the gas resulting in about 0.8% in the ice) pellet fuelling. Possibility of the N{sub 2}-seeding by admixed pellets was confirmed by CXRS measurements of N{sup 7+} content in plasma.

  20. Pelletizing properties of torrefied wheat straw

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Nielsen, Niels Peter; Hansen, Hans Ove;

    2013-01-01

    of wheat straw have been analyzed. Laboratory equipment has been used to investigate the pelletizing properties of wheat straw torrefied at temperatures between 150 and 300 °C. IR spectroscopy and chemical analyses have shown that high torrefaction temperatures change the chemical properties of the wheat...... straw significantly, and the pelletizing analyses have shown that these changes correlate to changes in the pelletizing properties. Torrefaction increase the friction in the press channel and pellet strength and density decrease with an increase in torrefaction temperature....

  1. Incontinencia fecal del adulto

    OpenAIRE

    2011-01-01

    El propósito de esta revisión es actualizar los conocimientos sobre esta patología, destacando su evolución clínica, estudio y tratamiento, aspectos que ameritan un enfoque multidisciplinario, ya que, además de su compleja fisiopatología, puede asociarse a incontinencia urinaria y prolapso de los tres compartimentos de la pelvis. La incontinencia fecal (IF) constituye una patología altamente prevalente que afecta al menos un 2% de la población y hasta el 45% de los pacientes en casas de repos...

  2. [Fecal microbiota transplantation: review].

    Science.gov (United States)

    Barbut, F; Collignon, A; Butel, M-J; Bourlioux, P

    2015-01-01

    Fecal microbiota transplantation (FMT) has gained an increasing medical interest, since the recognition of the role of disturbed microbiota in the development of various diseases. To date, FMT is an established treatment modality for multiple recurrent Clostridium difficile infection (RCDI), despite lack of standardization of the procedure. Persisting normalization of the disturbed colonic microbiota associated with RCDI seems to be responsible for the therapeutic effect of FMT. For other diseases, FMT should be considered strictly experimental, only offered to patients in an investigational clinical setting. Although the concept of FMT is appealing, current expectations should be damped until future evidence arises. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Ecology and Distribution of Copepods from the Salt Pan Ecosystems of Mumbai, West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; NaveenKumar, K.R.; Nair, V.R.

    Ecology, distribution and diversity of Copepod collected from two salt pans of Mumbai, India, are presented. Copepods, the mai zooplankton components, consisted mainly of Bestiolina similis, Acartia southwelli, Oithona sp., O. similis, O. hebes...

  4. Distribution and diversity of copepods in the Mandovi-Zuari estuarine system, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Copepod species number dwindled sharply during the rainy season (June to September) except in Zuari Estuary where comparatively more saline conditions were recorded (1.33 to 29.84 ppt) Postmonsoon period (October to January) was characterised with copepod...

  5. Distribution of copepods from the polluted and unpolluted regions off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; JiyalalRam, M.J.; Desai, B.N.

    genera of copepods recorded, Paracalanus, Acrocalanus, Acartia, and Oithona were the most common. The polluted regions of Mahim and Thana creek were characterised by the dominance of Paracalanus, Oithona and Acartia. The generic diversity of copepods...

  6. Micromorphology of pelletized soil conditioners

    Science.gov (United States)

    Hirsch, Florian; Dietrich, Nils; Knoop, Christine; Raab, Thomas

    2017-04-01

    Soil conditioners produced by anaerobic digestion and subsequent composting of organic household waste, bear the potential to improve unproductive farmland together with a reduced input risk of unwanted pollutants into the soils. Within the VeNGA project (http://www.biogas-network.de/venga), soil conditioners from anaerobically digested organic household waste are tested for their potential to increase plant growth in glasshouse and field experiments. Because the production techniques of these soil conditioners may influence their physical and chemical behaviour in the soil, two different techniques for pelletizing the soil conditioners where applied. We present findings from a pot experiment with cereal that has been sampled after two months for micromorphological analyses. We visualize the decomposition and the physical behaviour of the soil conditioners. Pellets produced in an agglomeration mixer result in dense balls, that are only slightly decomposed after the trial. But the soil conditioners created under pressure in a screw extruder are rich in voids and have the potential of retaining more soil water.

  7. Status and recommendations on marine copepod cultivation for use as live feed

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Frouël, Stéphane; Sichlau, Mie Hylstofte

    2011-01-01

    Copepods are important crustaceans studied because of their key role in ecology, trophic biology, fisheries management, in modeling the flow of energy and matter, ecotoxicology, aquaculture and aquarium trade. This paper discusses various aspects of the state of knowledge of copepod culture at la...... of probiotics for improving the fitness of copepod cultures; and 6) encourage copepod producers/retailers to use/develop an efficient sales and marketing strategy....

  8. Fecal microbiota composition and frailty

    NARCIS (Netherlands)

    van Tongeren, SP; Slaets, JPJ; Harmsen, HJM; Welling, GW

    2005-01-01

    The relationship between fecal microbiota composition and frailty in the elderly was studied. Fecal samples from volunteers with high frailty scores showed a significant reduction in the number of lactobacilli (26-fold). At much higher population levels, both the Bacteroides/Prevotella (threefold) a

  9. Fecal microbiota composition and frailty

    NARCIS (Netherlands)

    van Tongeren, SP; Slaets, JPJ; Harmsen, HJM; Welling, GW

    2005-01-01

    The relationship between fecal microbiota composition and frailty in the elderly was studied. Fecal samples from volunteers with high frailty scores showed a significant reduction in the number of lactobacilli (26-fold). At much higher population levels, both the Bacteroides/Prevotella (threefold)

  10. History repeats itself: genomic divergence in copepods.

    Science.gov (United States)

    Renaut, Sébastien; Dion-Côté, Anne-Marie

    2016-04-01

    Press stop, erase everything from now till some arbitrary time in the past and start recording life as it evolves once again. Would you see the same tape of life playing itself over and over, or would a different story unfold every time? The late Steven Jay Gould called this experiment replaying the tape of life and argued that any replay of the tape would lead evolution down a pathway radically different from the road actually taken (Gould 1989). This thought experiment has puzzled evolutionary biologists for a long time: how repeatable are evolutionary events? And if history does indeed repeat itself, what are the factors that may help us predict the path taken? A powerful means to address these questions at a small evolutionary scale is to study closely related populations that have evolved independently, under similar environmental conditions. This is precisely what Pereira et al. (2016) set out to do using marine copepods Tigriopus californicus, and present their results in this issue of Molecular Ecology. They show that evolution can be repeatable and even partly predictable, at least at the molecular level. As expected from theory, patterns of divergence were shaped by natural selection. At the same time, strong genetic drift due to small population sizes also constrained evolution down a similar evolutionary road, and probably contributed to repeatable patterns of genomic divergence.

  11. Hydrocarbon contamination decreases mating success in a marine planktonic copepod.

    Directory of Open Access Journals (Sweden)

    Laurent Seuront

    Full Text Available The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1% impacts (i the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics.

  12. Hydrocarbon contamination decreases mating success in a marine planktonic copepod.

    Science.gov (United States)

    Seuront, Laurent

    2011-01-01

    The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1%) impacts (i) the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii) the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF) significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics.

  13. Copepod assemblages in a highly complex hydrographic region

    Science.gov (United States)

    Berasategui, A. D.; Menu Marque, S.; Gómez-Erache, M.; Ramírez, F. C.; Mianzan, H. W.; Acha, E. M.

    2006-02-01

    Community structure and diversity patterns of planktonic copepods were investigated for the Southwestern Atlantic Ocean between 34 and 41°S. Our objectives were (1) to define copepod assemblages, (2) to accurately identify their association to different water masses/hydrodynamic regimes, (3) to characterize the assemblages in terms of their community structure, and (4) to test if frontal boundaries between water masses separate copepod assemblages. Biogeographic patterns were investigated using multivariate analysis (cluster and ANOSIM analyses). Biodiversity patterns were examined using different univariate indexes (point species richness and taxonomic distinctness). Five regions of similar copepod assemblages were defined for our study area each one corresponding to different environments (freshwater, estuarine, continental shelf, Malvinas and Brazil current assemblages). These assemblages have major community structure differences. In spite of the complex oceanographic scenario of our study area, that can lead us to expect a pattern of copepod communities with diffuse boundaries, we found a strong spatial correspondence between these limits and the presence of permanent frontal structures.

  14. Effect of pelleting on efficacy of sericea lespedeza hay as a natural dewormer in goats.

    Science.gov (United States)

    Terrill, T H; Mosjidis, J A; Moore, D A; Shaik, S A; Miller, J E; Burke, J M; Muir, J P; Wolfe, R

    2007-05-15

    Resistance of gastrointestinal nematodes (GIN) to anthelmintic treatment has increased pressure to find alternative, non-chemical control methods. Feeding hay of the high condensed tannin (CT) forage sericea lespedeza [SL; Lespedeza cuneata (Dum-Cours.) G. Don.] to sheep and goats has reduced GIN fecal egg count (FEC) and worm numbers in the abomasum and small intestines. This effect has been reported with both unground (long) and ground hay. Pelleting of ground hay increases ease of storage, transport, and feeding, but heating during the pelleting process could reduce biological activity of CT. Eighteen naturally GIN-infected 5-6-month-old Kiko-Spanish cross bucks were fed pelleted and ground SL hay and ground bermudagrass [BG; Cynodon dactyon (L.) Pers.] hay diets (n=6 per treatment) in a confinement trial. The bucks were fed the ground BG hay (75% of daily intake) plus a pelleted 16% CP commercial goat chow (25% of daily intake) for 3 weeks, after which they were assigned to treatment groups based upon FEC, 12 animals were switched to ground and pelleted SL hay plus goat chow for 4 weeks, and then all animals were fed the BG ration for one additional week. Throughout the trial, feces and blood were collected from individual animals weekly to determine FEC and blood packed cell volume (PCV), respectively. All goats were slaughtered at the end of the trial, with adult worms in the abomasum and small intestines recovered, counted, and identified to species. Both forms of SL hay reduced (P<0.05) FEC in goats relative to BG hay-fed animals, with a greater reduction in goats fed the SL pellets. There was no effect on PCV until the final sampling date, when the SL pellet-fed goats' PCV increased (P<0.05) compared with the other treatments. Feeding pelleted SL reduced (P<0.05) abomasal worms, primarily Haemonchus contortus, relative to the BG hay-fed goats. Worm numbers in the goats fed ground SL hay were intermediate. Pelleting SL hay enhanced its efficacy against

  15. Economic cost of fecal incontinence.

    Science.gov (United States)

    Xu, Xiao; Menees, Stacy B; Zochowski, Melissa K; Fenner, Dee E

    2012-05-01

    Despite its prevalence and deleterious impact on patients and families, fecal incontinence remains an understudied condition. Few data are available on its economic burden in the United States. The aim of this study was to quantify per patient annual economic costs associated with fecal incontinence. A mail survey of patients with fecal incontinence was conducted in 2010 to collect information on their sociodemographic characteristics, fecal incontinence symptoms, and utilization of medical and nonmedical resources for fecal incontinence. The analysis was conducted from a societal perspective and included both direct and indirect (ie, productivity loss) costs. Unit costs were determined based on standard Medicare reimbursement rates, national average wholesale prices of medications, and estimates from other relevant sources. All cost estimates were reported in 2010 US dollars. This study was conducted at a single tertiary care institution. The analysis included 332 adult patients who had fecal incontinence for more than a year with at least monthly leakage of solid, liquid, or mucous stool. The primary outcome measured was the per patient annual economic costs associated with fecal incontinence. The average annual total cost for fecal incontinence was $4110 per person (median = $1594; interquartile range, $517-$5164). Of these costs, direct medical and nonmedical costs averaged $2353 (median, $1176; interquartile range, $294-$2438) and $209 (median, $75; interquartile range, $17-$262), whereas the indirect cost associated with productivity loss averaged $1549 per patient annually (median, $0; interquartile range, $0-$813). Multivariate regression analyses suggested that greater fecal incontinence symptom severity was significantly associated with higher annual direct costs. This study was based on patient self-reported data, and the sample was derived from a single institution. Fecal incontinence is associated with substantial economic cost, calling for more

  16. Refractory Pellet for Hot Blast Stove

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Peng Xigao

    2011-01-01

    1 Scope This standard specifies the term,definition,classification,specification,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of refractory pellet for hot blast stove.This standard is applicable to refractory pellet for hot blast stove.

  17. Hydrogen Pellet-Rotating Plasma Interaction

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard; Øster, Flemming

    1977-01-01

    Spectroscopic measurements on the interaction between solid hydrogen pellets and rotating plasmas are reported. It was found that the light emitted is specific to the pellet material, and that the velocity of the ablated H-atoms is of the order of l0^4 m/s. The investigation was carried out...

  18. Lab and Bench-Scale Pelletization of Torrefied Wood Chips

    DEFF Research Database (Denmark)

    Shang, Lei; Nielsen, Niels Peter K.; Stelte, Wolfgang

    2013-01-01

    Combined torrefaction and pelletization is used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. In the present study, a single-pellet press tool was used to screen for the effects of pellet die temperature, moisture...... up from single-pellet press to bench-scale pelletizer. Tuning moisture content or increasing the die temperature did not ease the pellet production of torrefied wood chips significantly. The addition of rapeseed oil as a lubricant reduced the static friction by half and stabilized pellet production...... content, additive addition, and the degree of torrefaction on the pelletizing properties and pellet quality, i.e., density, static friction, and pellet strength. Results were compared with pellet production using a bench-scale pelletizer. The results indicate that friction is the key factor when scaling...

  19. Estimating shot distance from limited pellets pattern.

    Science.gov (United States)

    Plebe, Alessio; Compagnini, Domenico

    2012-10-10

    Several methods are available for shooting range estimation based on pellets pattern on the target that have a remarkable degree of accuracy. The task is usually approached working under the assumption that the entire distribution of pellets is available for examination. These methods fail, however, when the victim has been hit by a portion of the pattern only. The problem can be solved with reasonable accuracy when there are areas of void in the victim that are adjacent to the area struck by pellets. This study presents a method that can be used in precisely this type of situation, allowing the estimation of shot distance in cases of partial pellet patterns. It is based on collecting distributions in test shots at several distances, and taking samples in the targets, constrained by the shape of the void and the pellet hit areas. Statistical descriptors of patterns are extracted from such samples, and fed into a neural network classifier, estimating shot ranges of distance.

  20. [Fecal microbiota transplantation].

    Science.gov (United States)

    García-García-de-Paredes, Ana; Rodríguez-de-Santiago, Enrique; Aguilera-Castro, Lara; Ferre-Aracil, Carlos; López-Sanromán, Antonio

    2015-03-01

    Bacteria can no longer be seen as an enemy. Nowadays, there is enough evidence to place the microbiota as a key element in human homeostasis. Despite initial skepticism, fecal microbiota transplantation (FMT) is a real therapeutic alternative for patients with recurrent Clostridium difficile infection. Moreover, this procedure has shown promising results in ulcerative colitis and other non-gastrointestinal disorders. There is still a lack of knowledge and clinical trials with long- term follow-up. Therefore, the available data should be interpreted with caution. In this document we provide a detailed review of the literature on the intestinal microbiota and FMT. Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

  1. Scaling of fecundity, growth and development in marine planktonic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Sabatini, M.

    1995-01-01

    We compiled information from the literature on female and egg sizes and maximum egg production, growth and developmental rates in marine planktonic copepods. While specific growth and developmental rates are invariant with body mass, weight- specific fecundity scales with female body mass(-0.......26) in both broadcast-spawning and egg-carrying copepods. Egg sizes increase with female size and, consequently, egg production rates (no. of eggs female(-1) d(-1)) are constant with size. Developmental rates were similar among egg-carrying and broadcast-spawning copepods, but the latter grow faster by 30...... to 50% and have weight-specific fecundities that are 2.5 times and egg production rates that are 7.5 times those of the former, Nauplii develop faster (by a factor of 2) but grow slower (by 20 to 40%) than copepodites in both spawning types. The main demographic implications of these findings are (1...

  2. Rapid enzymatic response to compensate UV radiation in copepods.

    Directory of Open Access Journals (Sweden)

    María Sol Souza

    Full Text Available Ultraviolet radiation (UVR causes physical damage to DNA, carboxylation of proteins and peroxidation of lipids in copepod crustaceans, ubiquitous and abundant secondary producers in most aquatic ecosystems. Copepod adaptations for long duration exposures include changes in behaviour, changes in pigmentation and ultimately changes in morphology. Adaptations to short-term exposures are little studied. Here we show that short-duration exposure to UVR causes the freshwater calanoid copepod, Eudiaptomus gracilis, to rapidly activate production of enzymes that prevent widespread collateral peroxidation (glutathione S-transferase, GST, that regulate apoptosis cell death (Caspase-3, Casp-3, and that facilitate neurotransmissions (cholinesterase-ChE. None of these enzyme systems is alone sufficient, but they act in concert to reduce the stress level of the organism. The interplay among enzymatic responses provides useful information on how organisms respond to environmental stressors acting on short time scales.

  3. Fuel pellets from biomass: The importance of the pelletizing pressure and its dependency on the processing conditions

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Holm, Jens K.; Sanadi, Anand R.

    2011-01-01

    The aim of the present study was to identify the key factors affecting the pelletizing pressure in biomass pelletization processes. The impact of raw material type, pellet length, temperature, moisture content and particle size on the pressure build up in the press channel of a pellet mill...... was studied using a single pellet press unit. It was shown that the pelletizing pressure increased exponentially with the pellet length. The rate of increase was dependent on biomass species, temperature, moisture content and particle size. A mathematical model, predicting the pelletizing pressure......, was in good accordance with experimental data. It was shown that increasing the temperature resulted in a decrease of the pelletizing pressure. Infrared spectra taken from the pellets surface, indicated hydrophobic extractives on the pellet surface, for pellets produced at higher temperatures. The extractives...

  4. Speed of the internal pellet target in CSRm

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Pellet target is one of the main candidate targets in CSRm (cooler storage ring’s main ring) for hadron physics studies. Pellet speed is an important physical parameter for the target. Larger pellet speed could shorten the interacting time interval between the pellet and the cyclotron beam, and thus results in a small temperature variation for the pellet. This could make the pellet facility work in a stable condition. A fluid dynamic simulation was carried out for the pellet speed, and it was found that the maximum speed for the target pellet may be restricted to about 100 m/s even if all working parameters were set to their optimal values.

  5. Copepod recruitment and food composition : Do diatoms affect hatching success?

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Kiørboe, Thomas

    1996-01-01

    Laboratory experiments were conducted to differentiate between factors controlling the hatching success of copepod eggs. Factors that could affect viability of eggs; viz food quality, female condition and external factors were investigated. In a series of experiments the copepod Acartia tonsa Dana...... was fed several different diets while egg production and hatching success were monitored. The diet was analysed for fatty acid content as an indicator of food quality. Both egg production and hatching were found to be affected by the nutritional quality of the food. Hatching was also highly dependent...

  6. Addition of sodium bicarbonate to complete pelleted diets fed to dairy calves.

    Science.gov (United States)

    Wheeler, T B; Wangsness, P J; Muller, L D; Griel, L C

    1980-11-01

    During two trials, 35 and 27 Holstein calves were fed ad libitum complete, pelleted diets containing either 35% alfalfa (Trial 1) or 35% grass (Trial 2) hay from birth to 12 wk of age. Calves in Trial 1 were fed one of the following diets: control, control + 3.5% sodium chloride, or control + 5% sodium bicarbonate. In Trial 2, diets were: control, control + 5% sodium bicarbonate, or control + 5% sodium bicarbonate + loose, chopped grass hay. Intake of dry matter, gain in body weight, ruminal pH, or fecal starch did not differ. Calves fed sodium bicarbonate in Trial 1 but not 2 had a reduced feed efficiency compared with control and supplemented diets. In Trial 1 added sodium bicarbonate did not alter intake or digestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water indigestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water indigestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water intake in Trial 2. Incidence of free-gas bloat was higher in calves fed sodium bicarbonate in both trials. Addition of sodium bicarbonate to complete pelleted diets containing 35% alfalfa or 35% grass hay appeared to have no benefit for young, growing dairy calves in performance and health.

  7. A Review of Pellets from Different Sources

    Directory of Open Access Journals (Sweden)

    Teresa Miranda

    2015-03-01

    Full Text Available The rise in pellet consumption has resulted in a wider variety of materials for pellet manufacture. Thus, pellet industry has started looking for alternative products, such as wastes from agricultural activities, forestry and related industries, along with the combination thereof, obtaining a broad range of these products. In addition, the entry into force of EN ISO 17225 standard makes wood pellet market (among other types possible for industry and household purposes. Therefore, wastes that are suitable for biomass use have recently increased. In this study, the main characteristics of ten kinds of laboratory-made pellets from different raw materials were analyzed. Thus, we have focused on the most limiting factors of quality standards that determine the suitability for biomass market, depending on the kind of pellet. The results showed considerable differences among the analyzed pellets, exceeding the limits established by the standard in almost all cases, especially concerning ash content and N and S composition. The requirements of the studied standard, very demanding for certain factors, disable the entry of these densified wastes in greater added value markets.

  8. A centrifuge CO2 pellet cleaning system

    Science.gov (United States)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-03-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  9. Pelletization of fine coals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, K.V.S.

    1995-12-31

    Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

  10. Nitrogen-fixing bacteria associated with copepods in coastal waters of the North Atlantic Ocean.

    Science.gov (United States)

    Scavotto, Rosemary E; Dziallas, Claudia; Bentzon-Tilia, Mikkel; Riemann, Lasse; Moisander, Pia H

    2015-10-01

    The community composition of N2 -fixing microorganisms (diazotrophs) was investigated in copepods (primarily Acartia spp.) in parallel to that of seawater in coastal waters off Denmark (Øresund) and New England, USA. The unicellular cyanobacterial diazotroph UCYN-A was detected from seawater and full-gut copepods, suggesting that the new N contributed by UCYN-A is directly transferred to higher trophic levels in these waters. Deltaproteobacterial and Cluster 3 nifH sequences were detected in > 1 μm seawater particles and full-gut copepods, suggesting that they associate with copepods primarily via feeding. The dominant communities in starved copepods were Vibrio spp. and related Gammaproteobacteria, suggesting they represent the most permanent diazotroph associations in the copepods. N2 fixation rates were up to 3.02 pmol N copepod(-1) day(-1). Although at a typical copepod density in estuarine waters, these volumetric rates are low; considering the small size of a copepod, these mesozooplanktonic crustaceans may serve as hotspots of N2 fixation, at 12.9-71.9 μmol N dm(-3) copepod biomass day(-1). Taken together, diazotroph associations range from more permanent attachments to copepod feeding on some groups. Similar diazotroph groups detected on the eastern and western Atlantic Ocean suggest that these associations are a general phenomenon and play a role in the coastal N cycles. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Directory of Open Access Journals (Sweden)

    Simin Hu

    Full Text Available Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected

  12. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Science.gov (United States)

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

  13. Growth performance of calves fed microbially enhanced soy protein in pelleted starters.

    Science.gov (United States)

    Senevirathne, N D; Anderson, J L; Gibbons, W R; Clapper, J A

    2017-01-01

    Our objective was to determine effects of feeding calves pelleted starters with microbially enhanced (fungi-treated) soy protein (MSP) in replacement of soybean meal (SBM) with different milk replacers (MR). Thirty-six Holstein calves (2 d old; 24 females, 12 males) in individual hutches were used in a 12-wk randomized complete block design study. Treatments were (1) MSP pellets with MR formulated for accelerated growth (28% crude protein, 18% fat; MSPA), (2) SBM pellets with MR formulated for accelerated growth (SBMA), and (3) MSP pellets with conventional MR (20% crude protein, 20% fat; MSPC). Pellets were similar except for 23% MSP or 23% SBM (dry matter basis). Pellets and water were fed ad libitum throughout the study. Feeding rates of MR on a dry matter basis were 0.37kg twice daily during wk 1, 0.45kg twice daily during wk 2 to 5, and 0.45kg once daily during wk 6. Intakes were recorded daily. Body weights, frame size measurements, and jugular blood samples were collected 2 d every 2 wk at 3 h after the morning feeding. Fecal grab samples were collected 5 times per d for 3 d during wk 12 and then composited by calf for analysis of apparent total-tract digestibility of nutrients using acid detergent insoluble ash as an internal marker. Total and starter pellet dry matter intake were greatest for calves fed SBMA and least for MSPC. Calves had similar average daily gain among treatments, but there was a treatment by week interaction and during the last few weeks of the study calves on MSPC had less body weight compared with MSPA or SBMA. Gain-to-feed ratio was similar among treatments; however, there was a treatment by week interaction. Serum glucose was similar among treatments. Plasma urea nitrogen was greatest for calves fed MSPA and least for MSPC. Plasma concentrations of IGF-1 were greatest for calves fed SBMA. Plasma concentrations of triglycerides were greatest for calves fed MSPC. Plasma concentrations of β-hydroxybutyrate had a treatment by time

  14. Specific probiotics or 'fecal transplantation'.

    Science.gov (United States)

    Kruis, Wolfgang

    2012-01-01

    The intestinal ecosystem consists mainly of the enteric flora and to a large extent determines intestinal but also extraintestinal health and disease. General alterations and specific molecular changes of intestinal bacteria cause local as well as systemic immune reactions. Nonantibiotic treatment of the enteric flora has a long tradition and spans a range of different interventions from nutrition to specific probiotics and complete fecal transplantation. When comparing therapy to specific probiotics and fecal transplantation, several aspects need to be considered, like biological consequences, safety and therapeutic evidence. The introduction of probiotics into therapy occurred more than hundred years ago. In contrast, experiences with fecal transplantation are more recent and more limited. Safety issues have not been definitively clarified. Because of the different biological activities of probiotics and fecal transplantation, it can be hypothesized that they may play different roles in the treatment of various diseases. More research is needed before the details, safety and therapeutic effects of bacteriotherapy for IBD become sufficiently clear.

  15. Copepod guts as biogeochemical hotspots in the sea

    DEFF Research Database (Denmark)

    Tang, Kam W.; Glud, Ronnie N.; Glud, Anni;

    2011-01-01

    , with a steep gradient from the anal opening to the metasome region. The central metasome region was completely anoxic. Food remains in the gut led to a lower oxygen level, and a diatom diet induced a stronger oxygen gradient than a cryptophyte diet. The acidic and suboxic–anoxic environments of the copepod gut...

  16. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati...

  17. Linkage between copepods and bacteria in the North Atlantic Ocean

    NARCIS (Netherlands)

    De Corte, D.; Lekunberri, I.; Sintes, E.; Garcia, J.A.L.; Gonzalez, S.; Herndl, G.J.

    2014-01-01

    Copepods and bacteria are fundamental components of the pelagic food web andplay a major role in biogeochemical cycles. Marine bacteria have a free-living or particleattachedlifestyle, but as members of the microbial food web, the only biotic interaction of bacteriais commonly assumed to be with

  18. Propagation of planktonic copepods: production and mortality of eggs

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, Flemming; Tiselius, Peter

    1988-01-01

    Data on fecundity and egg mortality of neritic copepods were collected in various seasons, areas and under various hydrographical conditions. On a seasonal basis variations in fecundity (F) were related to temperature rather than to the abundance of phytoplankton (P). However, a strong correlatio...

  19. The copepod Calanus spp. (Calanidae) is repelled by polarized light.

    Science.gov (United States)

    Lerner, Amit; Browman, Howard I

    2016-10-20

    Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addition, the transparency of these copepods, as they might be seen by polarization insensitive vs. sensitive visual systems, was measured. Calanus spp. exhibited negative polarotaxis with a preference ratio of 1.9:1. Their transparency decreased from 80% to 20% to 30% in the unpolarized, partially polarized, and electric (e-) vector orientation domains respectively - that is, these copepods would appear opaque and conspicuous to a polarization-sensitive viewer looking at them under conditions rich in polarized light. Since the only difference between the two plankton traps was the polarization cue, we conclude that Calanus spp. are polarization sensitive and exhibit negative polarotaxis at low light intensities (albeit well within the sensitivity range reported for copepods). We hypothesize that Calanus spp. can use polarization vision to reduce their risk of predation by polarization-sensitive predators and suggest that this be tested in future experiments.

  20. The copepod Calanus spp. (Calanidae) is repelled by polarized light

    Science.gov (United States)

    Lerner, Amit; Browman, Howard I.

    2016-10-01

    Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addition, the transparency of these copepods, as they might be seen by polarization insensitive vs. sensitive visual systems, was measured. Calanus spp. exhibited negative polarotaxis with a preference ratio of 1.9:1. Their transparency decreased from 80% to 20% to 30% in the unpolarized, partially polarized, and electric (e-) vector orientation domains respectively - that is, these copepods would appear opaque and conspicuous to a polarization-sensitive viewer looking at them under conditions rich in polarized light. Since the only difference between the two plankton traps was the polarization cue, we conclude that Calanus spp. are polarization sensitive and exhibit negative polarotaxis at low light intensities (albeit well within the sensitivity range reported for copepods). We hypothesize that Calanus spp. can use polarization vision to reduce their risk of predation by polarization-sensitive predators and suggest that this be tested in future experiments.

  1. Vibrio elicits targeted transcriptional responses from copepod hosts.

    Science.gov (United States)

    Almada, Amalia A; Tarrant, Ann M

    2016-06-01

    Copepods are abundant crustaceans that harbor diverse bacterial communities, yet the nature of their interactions with microbiota are poorly understood. Here, we report that Vibrio elicits targeted transcriptional responses in the estuarine copepod Eurytemora affinis We pre-treated E. affinis with an antibiotic cocktail and exposed them to either a zooplankton specialist (Vibrio sp. F10 9ZB36) or a free-living species (Vibrio ordalii 12B09) for 24 h. We then identified via RNA-Seq a total of 78 genes that were differentially expressed following Vibrio exposure, including homologs of C-type lectins, chitin-binding proteins and saposins. The response differed between the two Vibrio treatments, with the greatest changes elicited upon inoculation with V. sp. F10 We suggest that these differentially regulated genes play important roles in cuticle integrity, the innate immune response, and general stress response, and that their expression may enable E. affinis to recognize and regulate symbiotic vibrios. We further report that V. sp. F10 culturability is specifically altered upon colonization of E. affinis These findings suggest that rather than acting as passive environmental vectors, copepods discriminately interact with vibrios, which may ultimately impact the abundance and activity of copepod-associated bacteria.

  2. Copepod guts as biogeochemical hotspots in the sea

    DEFF Research Database (Denmark)

    Tang, Kam W.; Glud, Ronnie N.; Glud, Anni

    2011-01-01

    The environmental conditions inside the gut of Calanus hyperboreus and C. glacialis were measured with microelectrodes. An acidic potential hydrogen (pH) gradient was present in the gut of C. hyperboreus, and the lowest pH recorded was 5.40. The gut pH of a starved copepod decreased by 0.53 after...

  3. Copepod carcasses as microbial hot spots for pelagic denitrification

    DEFF Research Database (Denmark)

    Glud, Ronnie N.; Grossart, Hans-Peter; Larsen, Morten

    2015-01-01

    Copepods are exposed to a high non-predatory mortality and their decomposing carcasses act as microniches with intensified microbial activity. Sinking carcasses could thereby represent anoxic microenvironment sustaining anaerobic microbial pathways in otherwise oxic water columns. Using non-invas...

  4. Macroevolutionary patterns of sexual size dimorphism in copepods

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Kiørboe, Thomas

    2014-01-01

    , and their female-biased SSD is greater than in many free-living families. However, other parasitic copepods which do not appear to have obvious differences in sex-based mate searching risks also show similar or even more extreme SSD, therefore suggesting other factors can drive the observed extremes....

  5. Linkage between copepods and bacteria in the North Atlantic Ocean

    NARCIS (Netherlands)

    De Corte, D.; Lekunberri, I.; Sintes, E.; Garcia, J.A.L.; Gonzalez, S.; Herndl, G.J.

    2014-01-01

    Copepods and bacteria are fundamental components of the pelagic food web andplay a major role in biogeochemical cycles. Marine bacteria have a free-living or particleattachedlifestyle, but as members of the microbial food web, the only biotic interaction of bacteriais commonly assumed to be with the

  6. Copepod feeding currents : flow patterns, filtration rates and energetics

    NARCIS (Netherlands)

    van Duren, LA; Stamhuis, EJ; Videler, JJ

    2003-01-01

    Particle image velocimetry was used to construct a quasi 3-dimensional image of the flow generated by the feeding appendages of the calanoid copepod Temora longicornis. By scanning layers of flow, detailed information was obtained on flow velocity and velocity gradients. The flow around feeding T. l

  7. Cyclopoid copepods (Lichomolgidae) from octocorals at Eniwetok Atoll

    NARCIS (Netherlands)

    Humes, Arthur G.

    1973-01-01

    This report of lichomolgid copepods found for the first time associated with octocorals in the Pacific Ocean includes six species, two of them new. Paramolgus eniwetokensis n. sp. and Paramolgus ostentus n. sp. are associated with Lobophytum pauciflorum (Ehrenberg). New host records include Acanthom

  8. Copepod swarm in the Campbell Bay (Andaman Sea)

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Rao, T.S.S.

    During the 68th cruise of R.V.Gaveshani, an unusual abundance of calanoid copepods of family Pontellidae was observed in the Campbell Bay (lat.6 degrees 30'-6 degrees 59'N and long 93 degrees 56'-94 degrees 15'E) Swarm density (25974 to 138420/m 3...

  9. Hydrogen Uptake of DPB Getter Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, L N; Schildbach, M A; Herberg, J L; Saab, A P; Weigle, J; Chinn, S C; Maxwell, R S; McLean II, W

    2008-05-30

    The physical and chemical properties of 1,4-diphenylbutadiyne (DPB) blended with carbon-supported Pd (DPB-Pd/C) in the form of pellets during hydrogenation were investigated. A thermogravimetric analyzer (TGA) was employed to measure the kinetics of the hydrogen uptake by the DPB getter pellets. The kinetics obtained were then used to develop a semi-empirical model, based on gas diffusion into solids, to predict the performance of the getter pellets under various conditions. The accuracy of the prediction model was established by comparing the prediction models with independent experimental data on hydrogen pressure buildup in sealed systems containing DPB getter pellets and subjected to known rates of hydrogen input. The volatility of the hydrogenated DPB products and its effects on the hydrogen uptake kinetics were also analyzed.

  10. Kinetic depletion model for pellet ablation

    Energy Technology Data Exchange (ETDEWEB)

    Kuteev, Boris V. [State Technical Univ., St. Petersburg (Russian Federation)

    2001-11-01

    A kinetic model for depletion effect, which determines pellet ablation when the pellet passes a rational magnetic surface, is formulated. The model predicts a moderate decrease of the ablation rate compared with the earlier considered monoenergy versions [1, 2]. For typical T-10 conditions the ablation rate reduces by a reactor of 2.5 when the 1-mm pellet penetrates through the plasma center. A substantial deceleration of pellets -about 15% per centimeter of low shire rational q region; is predicted. Penetration for Low Field Side and High Field Side injections is considered taking into account modification of the electron distribution function by toroidal magnetic field. It is shown that Shafranov shift and toroidal effects yield the penetration length for HFS injection higher by a factor of 1.5. This fact should be taken into account when plasma-shielding effects on penetration are considered. (author)

  11. The effect of polycarbophil on the gastric emptying of pellets.

    Science.gov (United States)

    Khosla, R; Davis, S S

    1987-01-01

    The influence of the putative bioadhesive, polycarbophil, on the gastric emptying of a pellet formulation, has been investigated in three fasted subjects. The pellets were radiolabelled with technetium-99m. Gastric emptying was measured using the technique of gamma scintigraphy. The pellets emptied from the stomach rapidly and in an exponential manner. Polycarbophil did not retard the gastric emptying of the pellets.

  12. Development of Boron Carbide Pellet for CEFR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Many shielding subassemblies which contain B4C absorber material are arranged outside the reflecting subassemblies in China experimental fast reactor (CEFR). A hot press process has been adopted for preparing B4C pellet. The B4C powder is synthesized by boric acid and carbon black. The B4C pellet is fabricated by cold press, hot press and sintering, precision working, cleaning surface and drying. Among those processes, hot press process is very important because of its

  13. Development of advanced LWR fuel pellet technology

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kun Woo; Kang, K.W.; Kim, K. S.; Yang, J. H.; Kim, Y. M.; Kim, J. H.; Bang, J. B.; Kim, D. H.; Bae, S. O.; Jung, Y. H.; Lee, Y. S.; Kim, B. G.; Kim, S. H

    2000-03-01

    A UO{sub 2} pellet was designed to have a grain size of larger than 12 {mu}m, and a new duplex design that UO{sub 2}-Gd{sub 2}O{sub 3} is in the core and UO{sub 2}-Er{sub 2}O{sub 3} in the periphery was proposed. A master mixing method was developed to make a uniform mixture of UO{sub 2} and additives. The open porosity of UO{sub 2} pellet was reduced by only mixing AUC-UO{sub 2} powder with ADU-UO{sub 2} or milled powder. Duplex compaction tools (die and punch) were designed and fabricated, and duplex compacting procedures were developed to fabricate the duplex BA pellet. In UO{sub 2} sintering, the relations between sintering variables (additive, sintering gas, sintering temperature) and pellet properties (density, grain size, pore size) were experimentally found. The UO{sub 2}-U{sub 3}O{sub 8} powder which is inherently not sinterable to high density could be sintered well with the aid of additives. U{sub 3}O{sub 8} single crystals were added to UO{sub 2} powder, and homogeneous powder mixture was pressed and sintered in a reducing atmosphere. This technology leads to a large-grained pellet of 12-20 {mu}m. In UO{sub 2}-Gd{sub 2}O{sub 3} sintering, the relations between sintering variables (additives, sintering gas) and pellet properties (density, grain size) were experimentally found. The developed technology of fabricating a large-grained UO{sub 2} pellet has been optimized in a lab scale. Pellet properties were investigated in the fields of (1) creep properties, (2) thermal properties, (3) O/M ratios and (4) unit cell lattice. (author)

  14. Use of pelleted sericea lespedeza (Lespedeza cuneata) for natural control of coccidia and gastrointestinal nematodes in weaned goats.

    Science.gov (United States)

    Kommuru, D S; Barker, T; Desai, S; Burke, J M; Ramsay, A; Mueller-Harvey, I; Miller, J E; Mosjidis, J A; Kamisetti, N; Terrill, T H

    2014-08-29

    Infection with Eimeria spp. (coccidia) can be devastating in goats, particularly for young, recently-weaned kids, resulting in diarrhea, dehydration, and even death. Feeding dried sericea lespedeza [SL; Lespedeza cuneata (Dum.-Cours.) G. Don.] to young goats has been reported to reduce the effects of internal parasites, including gastrointestinal nematodes (GIN) but there have been no reports of the effects of feeding this forage on Eimeria spp. in goats. Two confinement feeding experiments were completed on recently-weaned intact bucks (24 Kiko-cross, Exp. 1; 20 Spanish, Exp. 2) to determine effects of SL pellets on an established infection of GIN and coccidia. The bucks were assigned to 1 of 2 (Exp. 1) or 3 (Exp. 2) treatment groups based upon the number of Eimeria spp. oocysts per gram (OPG) of feces. In Exp. 1, the kids were fed 1 of 2 pelleted rations ad libitum; 90% SL leaf meal+10% of a liquid molasses/lignin binder mix and a commercial pellet with 12% crude protein (CP) and 24% acid detergent fiber (n=12/treatment group, 2 animals/pen). For Exp. 2, treatment groups were fed (1) 90% SL leaf meal pellets from leaves stored 3 years (n=7), (2) 90% SL pellets from leaf meal stored less than 6 months, (n=7), and the commercial pellets (n=6) ad libitum. For both trials, fecal and blood samples were taken from individual animals every 7 days for 28 days to determine OPG and GIN eggs per gram (EPG) and packed cell volume (PCV), respectively. In Exp. 2, feces were scored for consistency (1=solid pellets, 5=slurry) as an indicator of coccidiosis. In Exp. 1, EPG (Pgoats on the SL pellet diet compared with animals fed the control pellets. The OPG and EPG remained lower in treatment than control animals until the end of the trial. In Exp. 2, goats fed new and old SL leaf meal pellets had 66.2% and 79.2% lower (Pgoats. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Quality of pellets from torrefied biomass and pellets torrefied at different temperatures

    DEFF Research Database (Denmark)

    Shang, Lei; Dahl, Jonas; Ahrenfeldt, Jesper;

    facility to do torrefaction before co-firing. In this study, both ways were utilized to produce torrefied pellets. The quality of these pellets have been characterized for higher heating value (HHV), energy consumption during grinding, mechanical durability and equilibrium moisture content (EMC) under...

  16. Effect of biomaterial characteristics on pelletizing properties and biofuel pellet quality

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, Robert; Thyrel, Mikael; Lestander, Torbjoern A. [Unit of Biomass Technology and Chemistry, Swedish University of Agricultural Sciences, Box 4097, SE-904 03 Umeaa (Sweden); Sjoestroem, Michael [Department of Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden)

    2009-09-15

    Sawdust of conifers as a by-product from saw mills is the most commonly used biomaterial for pellet production in Sweden today. Experiences from the biofuel pellet industry indicate that different biomaterial properties influence the final pellet quality. A systematic study was conducted where five factors were varied according to a two level fractional factorial design. The factors were: tree species (Scots pine, Norway spruce); origin of growth-place (latitudes 57 and 64 N); storage time of sawdust (0 and 140 days), moisture content (9 and 12%) and steam treatment (2 and 6 kg/h). The measured responses bulk density and mechanical durability represented the pellet quality while the press current and the fines produced in the pelletizing process were measures of the pelletizing property. The results showed that low moisture content and long storage time resulted in increased bulk densities and press currents. For mechanical durability and fines, a long storage time and intermediate moisture contents were found favourable. In addition, indications were found that the reduction of fatty and resin acids during the storage also influenced the pelletizing properties and the pellet quality. (author)

  17. The enhanced ASDEX Upgrade pellet centrifuge launcher

    Science.gov (United States)

    Plöckl, B.; Lang, P. T.

    2013-10-01

    Pellets played an important role in the program of ASDEX Upgrade serving both for investigations on efficient particle fuelling and high density scenarios but also for pioneering work on Edge Localised Mode (ELM) pacing and mitigation. Initially designed for launching fuelling pellets from the magnetic low field side, the system was converted already some time ago to inject pellets from the magnetic high field side as much higher fuelling efficiency was found using this configuration. In operation for more than 20 years, the pellet launching system had to undergo a major revision and upgrading, in particular of its control system. Furthermore, the control system installed adjacent to the launcher had to be transferred to a more distant location enforcing a complete galvanic separation from torus potential and a fully remote control solution. Changing from a hybrid system consisting of PLC S5/S7 and some hard wired relay control to a state of the art PLC system allowed the introduction of several new operational options enabling more flexibility in the pellet experiments. This article describes the new system architecture of control hardware and software, the operating procedure, and the extended operational window. First successful applications for ELM pacing and triggering studies are presented as well as utilization for the development of high density scenarios.

  18. Studies on preparation of aceclofenac pellets by centrifugal granulator

    Directory of Open Access Journals (Sweden)

    Zibin GAO

    Full Text Available To prepare aceclofenac pellets by centrifugal granulation. Using 90~100 g of starch pellets as the core pellets,100 g of aceclofenac mixed with 50 g of microcrystalline cellulose(MCC and 4 g talc, methyl cellulose (HPMC as binder,the aceclofenac pellets were prepared by centrifugal granulation .And evaluate the quality of the pellets. The aceclofenac pellets had high yield and less losses,the pellets had a partical size of 0.70~0.88 mm(18~24 mesh)and had uniform particle size .the moisture ,drug content and dissolution meet the requirement . Aceclofenac pellets were prepared by the process of centrifugal granulation .The preparation prescription and process parameters were optimized by single factor method .and the pellets meet the standard requirements.

  19. Fecal microbiota transplantation: in perspective.

    Science.gov (United States)

    Gupta, Shaan; Allen-Vercoe, Emma; Petrof, Elaine O

    2016-03-01

    There has been increasing interest in understanding the role of the human gut microbiome to elucidate the therapeutic potential of its manipulation. Fecal microbiota transplantation (FMT) is the administration of a solution of fecal matter from a donor into the intestinal tract of a recipient in order to directly change the recipient's gut microbial composition and confer a health benefit. FMT has been used to successfully treat recurrent Clostridium difficile infection. There are preliminary indications to suggest that it may also carry therapeutic potential for other conditions such as inflammatory bowel disease, obesity, metabolic syndrome, and functional gastrointestinal disorders.

  20. Host-specific and pH-dependent microbiomes of copepods in an extensive rearing system

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Castro Mejia, Josue Leonardo; Hansen, Lars Hestbjerg

    2015-01-01

    gradient gel electrophoresis (DGGE) analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which...... furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes....

  1. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas

    Science.gov (United States)

    Sasaki, Hiroko; Matsuno, Kohei; Fujiwara, Amane; Onuka, Misaki; Yamaguchi, Atsushi; Ueno, Hiromichi; Watanuki, Yutaka; Kikuchi, Takashi

    2016-08-01

    The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll a concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic-benthic-type ecosystem to a pelagic-pelagic type.

  2. Host-specific and pH-dependent microbiomes of copepods in an extensive rearing system

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Castro Mejia, Josue Leonardo; Hansen, Lars Hestbjerg;

    2015-01-01

    gradient gel electrophoresis (DGGE) analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which...... furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes....

  3. CDC Study Finds Fecal Contamination in Pools

    Science.gov (United States)

    ... Communication (404) 639-3286 CDC study finds fecal contamination in pools A study of public pools done ... The E. coli is a marker for fecal contamination. Finding a high percentage of E. coli-positive ...

  4. Home Use Tests: Fecal Occult Blood

    Science.gov (United States)

    ... Procedures In Vitro Diagnostics Home Use Tests Fecal Occult Blood Share Tweet Linkedin Pin it More sharing ... test kit to measure the presence of hidden (occult) blood in your stool (feces). What is fecal ...

  5. Decline in biodiversity of copepods in coastal waters of Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; Nair, V.R.

    and diversity of copepods increased in Makupa creek, Mombasa where dumping of domestic and industrial waste was rampant. ]2'49'E s.e: s.r N + O.S 1.0 1.S .N, KAMATHH' 4 •• •N, KHIM .DP .N, o· o· .M, .M, CUNDERI oM, 0' 42' .5, .5, .5, 41' 1 N '70 7S 80 ss Fig. 1... per day (mId) of industrial waste. The projected daily domestic waste water flow for greater Mumbai for 1985 and 2005 are respectively 1350 and 2000 mid. Copepods were studied during pre-monsoon and post-monsoon periods along with relevant water...

  6. Host-Specific and pH-Dependent Microbiomes of Copepods in an Extensive Rearing System.

    Directory of Open Access Journals (Sweden)

    Alf Skovgaard

    Full Text Available Copepods are to an increasing extent cultivated as feed for mariculture fish larvae with variable production success. In the temperate climate zone, this production faces seasonal limitation due to changing abiotic factors, in particular temperature and light. Furthermore, the production of copepods may be influenced by biotic factors of the culture systems, such as competing microorganisms, harmful algae, or other eukaryotes and prokaryotes that may be non-beneficial for the copepods. In this study, the composition of bacteria associated with copepods was investigated in an extensive outdoor copepod production system. Light microscopy and scanning electron microscopy revealed that bacteria were primarily found attached to the exoskeleton of copepods although a few bacteria were also found in the gut as well as internally in skeletal muscle tissue. Through 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes.

  7. Predation vulnerability of planktonic copepods: consequences of predator foraging strategies and prey sensory abilities

    DEFF Research Database (Denmark)

    Viitasalo, M; Kiørboe, T; Flinkman, J.;

    1998-01-01

    We investigated the vulnerability of 2 copepod species (Eurytemora affinis and Temora longicornis) to predation by predators with different foraging modes, three-spined stickleback Gasterosteus aculeatus juveniles and mysid shrimps Neomysis integer. Copepods were videofilmed escaping from predators...... of the sticklebacks was higher than that of mysids. In the case of sticklebacks foraging on E. affinis, copepod reaction distance was significantly correlated with stickleback approaching speed; sticklebacks captured a copepod only if they were able to slowly approach to within a strike distance of...

  8. Characteristics of pellet injected discharges in TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Finken, K.H. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, Assocition Euratom-KFA, 52425 Juelich (Germany); Sato, K.N. [National Institute for Fusion Science, Nagoya 464-01 (Japan); Akiyama, H. [Kumamoto University, Kumamoto 860 (Japan); Fuchs, G.; Jaspers, R. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, Assocition Euratom-KFA, 52425 Juelich (Germany); Kogoshi, S. [Science University of Tokyo, Noda 278 (Japan); Koslowski, H.R.; Mank, G. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, Assocition Euratom-KFA, 52425 Juelich (Germany); Sakakita, H.; Sakamoto, M. [National Institute for Fusion Science, Nagoya 464-01 (Japan); Sander, M.; Soltwisch, H. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, Assocition Euratom-KFA, 52425 Juelich (Germany)

    1995-09-01

    Pellets injected into the TEXTOR tokamak lead to a density profile peaking which is strongest at low plasma current and weakest at high current independent of {ital B}{sub {ital T}}. After the injection two types of density oscillations are excited, the first type follows immediately the injection and the second one is excited with a delay of more than ten milliseconds. The oscillations are also observed in runaway discharges; the synchrotron light from the relativistic electrons drops after the pellet injection and is subsequently modulated due to a trapping of the runaways in magnetic islands. First Faraday measurements have been performed indicating that the distribution of the plasma current is not measurably modified by the pellet. {copyright} {ital 1995 American Institute of Physics.}

  9. Contrasting ecosystem-effects of morphologically similar copepods.

    Directory of Open Access Journals (Sweden)

    Blake Matthews

    Full Text Available Organisms alter the biotic and abiotic conditions of ecosystems. They can modulate the availability of resources to other species (ecosystem engineering and shape selection pressures on other organisms (niche construction. Very little is known about how the engineering effects of organisms vary among and within species, and, as a result, the ecosystem consequences of species diversification and phenotypic evolution are poorly understood. Here, using a common gardening experiment, we test whether morphologically similar species and populations of Diaptomidae copepods (Leptodiaptomus ashlandi, Hesperodiaptomus franciscanus, Skistodiaptomus oregonensis have similar or different effects on the structure and function of freshwater ecosystems. We found that copepod species had contrasting effects on algal biomass, ammonium concentrations, and sedimentation rates, and that copepod populations had contrasting effects on prokaryote abundance, sedimentation rates, and gross primary productivity. The average size of ecosystem-effect contrasts between species was similar to those between populations, and was comparable to those between fish species and populations measured in previous common gardening experiments. Our results suggest that subtle morphological variation among and within species can cause multifarious and divergent ecosystem-effects. We conclude that using morphological trait variation to assess the functional similarity of organisms may underestimate the importance of species and population diversity for ecosystem functioning.

  10. Fuel Pellets Production from Biodiesel Waste

    Directory of Open Access Journals (Sweden)

    Kawalin Chaiyaomporn

    2010-01-01

    Full Text Available This research palm fiber and palm shell were used as raw materials to produce pelletised fuel, and waste glycerol were used as adhesive to reduce biodiesel production waste. The aim of this research is to find optimum ratio of raw material (ratio of palm fiber and palm shell, raw material size distribution, adhesive temperature, and ratio of ingredients (ratio of raw material, waste glycerol, and water. The optimum ratio of pelletized fuel made only by palm fiber was 50:10:40; palm fiber, water, and waste glycerol respectively. In the best practice condition; particle size was smaller than 2 mm, adhesive glycerol was heated. From the explained optimum ratio and ingredient, pelletizing ratio was 62.6%, specific density was 982.2 kg/m3, heating value was 22.5 MJ/kg, moisture content was 5.9194%, volatile matter was 88.2573%, fix carbon content was 1.5894%, and ash content was 4.2339% which was higher than the standard. Mixing palm shell into palm fiber raw material reduced ash content of the pellets. The optimum raw material ratio, which minimizes ash content, was 80 to 20 palm fiber and palm shell respectively. Adding palm shell reduced ash content to be 2.5247% which was higher than pelletized fuel standard but followed cubed fuel standard. At this raw material ratio, pelletizing ratio was 70.5%, specific density was 774.8 kg/m3, heating value was 19.71 MJ/kg, moisture content was 9.8137%, volatile matter was 86.2259%, fix carbon content was 1.4356%, and compressive force was 4.83 N. Pelletized fuel cost at optimum condition was 1.14 baht/kg.

  11. Considerations on the DEMO pellet fuelling system

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P.T., E-mail: peter.lang@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Day, Ch. [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Fable, E. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Igitkhanov, Y. [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Köchl, F. [Association EURATOM-Ö AW/ATI, Atominstitut, TU Wien, 1020 Vienna (Austria); Mooney, R. [Culham Centre for Fusion Energy, Culham Science Centre, Oxfordshire OX14 3DB (United Kingdom); Pegourie, B. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Ploeckl, B. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Wenninger, R. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); EFDA, Garching (Germany); Zohm, H. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-10-15

    Graphical abstract: - Highlights: • Considerations are made for a core particle fuelling system covering all DEMO requirements. • Particle deposition beyond the pedestal top is needed to achieve efficient fuelling. • Conventional pellet technology enabling launching from the torus inboard side can be used. • Efforts have been taken for integrating a suitable pellet guiding system into the EU DEMO model. • In addition, further techniques bearing potential for advanced fuelling performance are considered. - Abstract: The Demonstration Fusion Power Reactor DEMO is the step foreseen to bridge the gap between ITER and the first commercial fusion power plant. One key element in the European work plan for DEMO is the elaboration of a conceptual design for a suitable core particle fuelling system. First considerations for such a system are presented in this contribution. Following the well-considered ITER solution, most analysis performed in this study assumes conventional pellet technology will be used for the fuelling system. However, taking advantage of the less compressed time frame for the DEMO project, several other techniques thought to bear potential for advanced fuelling performance are considered as well. In a first, basic analysis all actuation parameters at hand and their implications on the fuelling performance were considered. Tentative transport modeling of a reference scenario strongly indicates only particles deposited inside the plasma pedestal allow for efficient fuelling. Shallow edge fuelling results in an unbearable burden on the fuel cycle. Sufficiently deep particle deposition seems technically achievable, provided pellets are launched from the torus inboard at sufficient speed. All components required for a DEMO pellet system capable for high speed inboard pellet launch are already available or can be developed in due time with reasonable efforts. Furthermore, steps to integrate this solution into the EU DEMO model are taken.

  12. Bowel Control Problems (Fecal Incontinence)

    Science.gov (United States)

    ... medical test results. In addition to a general medical history, the health care provider may ask the following questions: When did fecal ... delivery hemorrhoids and rectal prolapse rectocele inactivity ... on a person’s medical history, physical exam, and medical test results. Treatment ...

  13. International Trade of Wood Pellets (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-05-01

    The production of wood pellets has increased dramatically in recent years due in large part to aggressive emissions policy in the European Union; the main markets that currently supply the European market are North America and Russia. However, current market circumstances and trade dynamics could change depending on the development of emerging markets, foreign exchange rates, and the evolution of carbon policies. This fact sheet outlines the existing and potential participants in the wood pellets market, along with historical data on production, trade, and prices.

  14. Development of the centrifugal pellet injector for JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, Kaname; Hiratsuka, Hajime; Ichige, Hisashi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    2001-03-01

    For core fueling of JT-60U plasmas, a repetitive pellet injector which centrifugally accelerates D{sub 2} cubic pellets using a straight rod has been developed. This centrifugal pellet injector can eject trains of up to 40 cubic pellets at frequencies of 1-10 Hz and velocities of 0.3-1.0 km/s. The average pellet mass is 3.6x10{sup 20} atoms/pellet below 0.7 m/s. Key techniques for the development were a mesh structured acceleration component for removing gas sublimated from the pellet and a funnel with an appropriate angle connected just behind the acceleration chamber for introducing the pellet to plasma without destruction. Using the mesh structured components, the horizontal angular distribution of pellets ejected became narrow, because irregular pellet motion caused by sublimated gas was reduced. To investigate the performance of the injector, pellet injection experiments from the low magnetic field side (LFS) were conducted using ohmic heating plasmas. Central fueling and enhanced fueling rate have been observed. D{alpha} intensity around the divertor region was reduced in a pellet injection plasma compared to gas puffing, indicating low recycling rate was maintained with the pellet injection. (author)

  15. Decay rate of reindeer pellet-groups

    Directory of Open Access Journals (Sweden)

    Anna Skarin

    2008-06-01

    Full Text Available Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus. During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus tidigare. I omr

  16. Analysis of the parasitic copepod species richness among Mediterranean fish

    Science.gov (United States)

    Raibaut, André; Combes, Claude; Benoit, Françoise

    1998-06-01

    The Mediterranean ichthyofauna is composed of 652 species belonging to 405 genera and 117 families. Among these, 182 were studied for their parasitic copepods. The analysis of all the works conducted on these crustacea yielded 226 species distributed in 88 genera and 20 families. For each fish species we have established a file providing the species name of the fish, its family, its geographical distribution within the Mediterranean and some of its bio-ecological characteristics. Within each file, all the parasitic copepod species reported on each host species were listed. This allowed to know the species richness (SR) of these hosts. We thus produced 182 files within which 226 copepod species are distributed. A program was created under the Hypercard software, in order to analyse our data. Two parameters were studied. The first one is the mean species richness (MSR), which corresponds to the mean of the different SR found on the different host species. The second is the parasite-host ratio (P/H), which is the ratio of the number of copepod species by the number of host species. These parameters are calculated by our program for all the 182 species of Mediterranean fishes retained in our investigation, on the first hand, and, on the second hand, for one particular group of fish species. We used the following variables to investigate their correlations with copepod species richness: taxonomy—fish families, genera and species; biometry—maximal size of the adult fish; eco-ethology—mode of life (benthic, pelagic or nectonic), displacements (sedentary, migratory with environmental change, or migratory without environmental change), behaviour (solitary or gregarious). Other variables (colour, food, reproduction, abundance, distribution area) were also analysed but did not reveal any clear correlation. Providing that our study does not rely on quantitative (prevalence, intensity) but qualitative basis our aim was only to reveal some tendencies. These tendencies are

  17. Plastic pellets on the Caranzalem beach sands, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    Postmonsoonal survey of Caranzalem beach, Goa, India indicated the presence of plastic pellets. These pellets varied in shape, size and number, and are considered to be contaminants of marine environment...

  18. Influence of consumption on pellets production in Austria

    Directory of Open Access Journals (Sweden)

    Vasiljević Aleksandar

    2008-01-01

    Full Text Available Results of the research on pellet production in Austria as well as the influence of consumption on the production are presented. In that sense, the functional relation between pellet production and pellet consumption obtained by modeling method has been given. The basic elements and trends on pellet market are shown and the summary of other factors influencing pellet production in Austria are explained. The choice of Austria as a market to carry out research is due to the fact that Austria is a leader in Europe in pellet production and consumption and its experiences could be significant for the formation of the market and energy policy in Serbia. This adds to the fact that pellet market, as well as the policy in the field of renewable sources of energy (including pellets, in Serbia are still at the very beginning.

  19. Foreign metallic pellet in the heart

    Institute of Scientific and Technical Information of China (English)

    AN Yong; XIAO Ying-bin; ZHONG Qian-jin

    2007-01-01

    @@ Foreign bodies in the heart are a rare but serious form of cardiac injury. The objects usually are sharp pointed. Such as acupuncture needles,sewing needles, coat hangers, fragments of Kirschner wires, pins, etc. 1 We report a patient with a metallic pellet lodged in the heart, which was accurately diagnosed and successfully removed.

  20. Development of D2 Pellet Injectors

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, S. A.; Nordskov Nielsen, A.

    1985-01-01

    A versatile extrusion-type pneumatic gun is described. The extrusion nozzle/gun barrel system can easily be exchanged to produce pellets in the diameter range 0.4—2.0 mm. Velocities in the range 0.1—1.35 km/s are obtained by adjusting the propeller gas pressure. It is proposed that this gun type ...

  1. Pelletized Asphalt for Airfield Damage Repair

    Science.gov (United States)

    2009-08-01

    14, 2008. Gulf Asphalt Contractor (GAC), Panama City, FL, provided all labor , material (with the exception of pelletized asphalt) and equipment for...produced. Benefits include: reduced transportation, traffic disruption, operating costs, and labor costs, while increased productivity and... Mercado , E. A., A. Epps Martin, E. S. Park, C. Spiegelman, and C. J. Glover, “Factors Affecting Binder Properties between Production and Construction

  2. Co-gasification of pelletized wood residues

    Energy Technology Data Exchange (ETDEWEB)

    Carlos A. Alzate; Farid Chejne; Carlos F. Valdes; Arturo Berrio; Javier De La Cruz; Carlos A. Londono [Universidad Nacional de Colombia, Antioquia (Colombia). Grupo de Termodinamica Aplicada y Energias Alternativas

    2009-03-15

    A pelletization process was designed which produces cylindrical pellets 8 mm in length and 4 mm in diameter. These ones were manufactured using a blend of Pinus Patula and Cypress sawdust and coal in proportions of 0%, 5%, 10%, 20%, and 30% v/v of coal of rank sub-bituminous extracted from the Nech mine (Amaga-Antioquia). For this procedure, sodium carboxymethyl cellulose (CMC) was used as binder at three different concentrations. The co-gasification experiments were carried out with two kinds of mixtures, the first one was composed of granular coal and pellets of 100% wood and the second one was composed of pulverized wood and granular coal pellets. All samples were co-gasified with steam by using an electrical heated fluidized-bed reactor, operating in batches, at 850{sup o}C. The main components of the gaseous product were H{sub 2}, CO, CO{sub 2}, CH{sub 4}, and N{sub 2} with approximate quantities of 59%, 6.0%, 20%, 5.0%, and 9.0% v/v, respectively, and the higher heating values ranged from between 7.1 and 9.5 MJ/Nm{sup 3}.

  3. Isotope Effects of Solid Hydrogenic Pellet Ablation in Fusion Plasma

    Institute of Scientific and Technical Information of China (English)

    PENGLilin; DENGBaiquan; YANJiancheng; WANGXiaoyu

    2003-01-01

    The isotope effects of ablation processes in fusion plasma for five combinations of solid isotopic hydrogenic pellets H2, HD, D2,DT, T2 have been first time studied. The resuits show that the modifications caused by isotope effects for pellet erosion speeds range from 1 for hydrogen pellet down to 0. 487 for tritium pellet and are not negligible in ablation rate calculations. These effects lead to deeper mass deposition and improved core fueling efficiency.

  4. Parasites and diseases in marine copepods: Challenges for future mass-production of live feed for fish larva production

    DEFF Research Database (Denmark)

    Skovgaard, Alf

    Copepods are the natural food for many marine fish larvae, and the use of cultured copepods as life feed is, therefore, becoming increasingly important as more marine fish species are being produced in aquaculture. Large-scale cultivation of copepods may be challenged by diseases and parasites...

  5. Recommended feeding regime and light climate in live feed cultures of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Steensbjerg Bjørbæk, Niels; Rayner, Thomas Allan

    2017-01-01

    Understanding and optimising the parameters that controls the success for copepod cultures are the foundation for large scaled copepod cultures. Many underlying copepod culture parameters are already quantified and comprehended, but there is a lack in knowledge of optimising feeding regimes for c...

  6. Permeability of wood pellets in the presence of fines

    Energy Technology Data Exchange (ETDEWEB)

    Yazdanpanah, F. [University of British Columbia, Vancouver; Lau, A.K. [University of British Columbia, Vancouver; Sokhansanj, Shahabaddine [ORNL; Lim, C. Jim [University of British Columbia, Vancouver; Melin, Staffan [University of British Columbia, Vancouver; Bi, X.T. [University of British Columbia, Vancouver; Afzal, M [University of New Brunswick

    2010-03-01

    Broken pellets and fines are produced during mechanical handlings of wood pellets. The resistance to air flow was measured for clean pellets and for pellets mixed with 1 to 20% broken pellets (fines). A pellet diameter was 6 mm. The lengths ranged from from 6 to 12 mm. Clean pellets were defined as particles that remained on a 4 mm screen. A typical sieve analysis showed 30% of the mass of particles passed through the 4 mm screen were smaller than 1 mm. The airflow rates used in the experiment ranged from 0.004 to 0.357 ms-1. The corresponding pressure drop ranged from 1.9 Pa m-1 to 271 Pa m-1 for clean pellets and from 4.8 to 1100 Pa m 1 for pellets mixed with 10% fines. The pressure drop increased for pellets mixed with increasing fines content. Coefficients of Hukill and Ives equation were estimated for clean pellets and a multiplier was defined to calculate pressure drop for pellets mixed with fines.

  7. Owl Pellet Analysis--A Useful Tool in Field Studies

    Science.gov (United States)

    Medlin, G. C.

    1977-01-01

    Describes a technique by which the density and hunting habits of owls can be inferred from their pellets. Owl pellets--usually small, cylindrical packages of undigested bone, hair, etc.--are regurgitated by a roosting bird. A series of activities based on owl pellets are provided. (CP)

  8. Transonic ablation flow regimes of high-Z pellets

    CERN Document Server

    Kim, Hyoungkeun; Parks, Paul

    2015-01-01

    In this letter, we report results of numerical studies of the ablation of argon and neon pellets in tokamaks and compare them with theoretical predictions and studies of deuterium pellets. Results demonstrate the influence of atomic physics processes on the pellet ablation process.

  9. Sensory capabilities and food capture of two small copepods, Paracalanus parvus and Pseudocalanus sp

    DEFF Research Database (Denmark)

    Tiselius, Peter; Saiz, Enric; Kiørboe, Thomas

    2013-01-01

    Detection, handling, and selection of prey are key features of suspension-feeding copepods. Using high-speed video, we determined detection distances and durations of all elements of the food gathering process in two small calanoid copepods, Paracalanus parvus and Pseudocalanus sp. Animals were f...

  10. Copepod egg production, moulting and growth rates and secondary production in the Skagerrak in August 1988

    DEFF Research Database (Denmark)

    Peterson, W.T.; Tiselius, P.; Kiørboe, Thomas

    1991-01-01

    Measurements of hydrography, chlorophyll, moulting rates of juvenile copepods and egg production rates of adult female copepods were made at eight stations along a transect across the Skagerrak. The goals of the study were to determine (i) if there were correlations between spatial variations in ...

  11. Perceiving the algae: How feeding-current feeding copepods detect their nonmotile prey

    DEFF Research Database (Denmark)

    Goncalves, Rodrigo J.; Kiørboe, Thomas

    2015-01-01

    Feeding-current feeding copepods detect and capture prey individually, but the mechanism by which nonmotile prey is detected has been unclear. Early reports that copepods detect phytoplankton prey at distances of one body length or more led to the hypothesis that solutes leaking from the prey wou...

  12. Do inactivated Microbial Preparations Improve Life History Traits of the Copepod Acartia tonsa?

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Rabarimanantsoa, Tahina; Frouel, Stéphane

    2011-01-01

    production and hatching success, HS). This was carried out because the use of copepods as live prey in aquaculture could increase the number of fish successfully raised through their entire life cycle. However, the availability of copepods is limited by their difficulty to be effectively raised. Our results...

  13. Consequences of acclimation to Microcystis on the selective feeding behavior of the calanoid copepod Eudiaptomus gracilis

    NARCIS (Netherlands)

    Ger, K.A.; Panosso, R.; Lürling, M.F.L.L.W.

    2011-01-01

    We tested the hypothesis that calanoid copepods would adapt to extended periods of Microcystis exposure by increasing selective feeding on alternative food. Copepod (Eudiaptomus gracilis) clearance rates were compared before and after a 5-d acclimation to Microcystis aeruginosa using paired food mix

  14. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine f...

  15. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    2013-01-01

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine...

  16. Different microbiomes associated with the copepods Acartia tonsa and Temora longicornis from the same marine environment

    DEFF Research Database (Denmark)

    Dorosz, Julia; Castro-Mejia, Josue Leonardo; Hansen, Lars Hestbjerg

    2016-01-01

    Microbiomes of the neritic copepod species Acartia tonsa and Temora longicornis collected in coastal Danish waters were investigated by use of 16S rRNA gene-Amplicon highthroughput sequencing. In contrast to current assumptions and findings, microbiomes of the 2 copepod species from the same envi...

  17. Prymnesium parvum exotoxins affect the grazing and viability of the calanoid copepod Eurytemora affinis

    DEFF Research Database (Denmark)

    Sopanen, S.; Koski, Marja; Uronen, P.

    2008-01-01

    The calanoid copepod Eurytemora affinis from the northern Baltic Sea was exposed to cell-free filtrates of the toxic haptophyte Prymnesium parvum as well as to cell mixtures of P. parvum and Rhodomonas salina. To test the effects of P. parvum exudates and allelopathy on selective grazers, copepods...

  18. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.;

    2012-01-01

    and a high concentration of hydrophobic waxes on its outer surface that may limit the pellet strength. The present work studies the impact of the lignin glass transition on the pelletizing properties of wheat straw. Furthermore, the effect of surface waxes on the pelletizing process and pellet strength...... are investigated by comparing wheat straw before and after organic solvent extraction. The lignin glass transition temperature for wheat straw and extracted wheat straw is determined by dynamic mechanical thermal analysis. At a moisture content of 8%, transitions are identified at 53°C and 63°C, respectively....... Pellets are pressed from wheat straw and straw where the waxes have been extracted from. Two pelletizing temperatures were chosen—one below and one above the glass transition temperature of lignin. The pellets compression strength, density, and fracture surface were compared to each other. Pellets pressed...

  19. Optimization of backfill pellet properties AASKAR DP2 - Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Linus; Sanden, Torbjoern [Clay Technology AB, Lund (Sweden)

    2012-12-15

    Bentonite pellets are planned to be used as a part of the backfill in the Swedish spent nuclear fuel deep repository concept KBS-3. This report describes testing and evaluation of different backfill pellet candidates. The work completed included testing of both pellet material and pellet type. The materials tested were sourced from India (ASHA), Greece (IBECO, 2 products) and Wyoming USA (MX-80 clay). The majority of the tests were completed on the ASHA clay as well as the IBECO-RWC-BF products, with only limited testing of the others. The pellets tested were manufactured using both extrusion and roller compaction techniques and had different sizes and geometries. The following tests have been performed and are presented in this report: 1. General tests. Water content, bulk density and dry density have been determined for both the pellet filling and the individual pellets. The compressibility of the pellet filling was tested with CRS-tests and the strength of the individual pellets was tested with a special compression test. The water content varied from 11.3% to 18.7% and was highest for the extruded pellets. The dry density was somewhat higher for the roller-compacted pellets and their compressibility was lower. The strength of the individual pellets was generally higher for the extruded pellets. 2. Erosion. The pellet filling will be exposed to groundwater inflow when installed in the tunnel. This flow could possibly cause significant erosion on the pellet filling. Erosion tests have been performed with comparisons in erosion resistance made on the various material- and pellet-types. The influence of variations in water salinity and flow rates was also tested. The IBECO extruded 6- and 10- mm diameter rods and the compacted Posiva spec.-A pellet filling seem to have the lowest tendency to erode. It is also the IBECO extruded pellet filling that withstands variations in water salinity and flow rates best. 3. Water storing capacity. The pellet filling

  20. Probability Models for the Distribution of Copepods in Different Coastal Ecosystems Along the Straits of Malacca

    Science.gov (United States)

    Matias-Peralta, Hazel Monica; Ghodsi, Alireza; Shitan, Mahendran; Yusoff, Fatimah Md.

    Copepods are the most abundant microcrustaceans in the marine waters and are the major food resource for many commercial fish species. In addition, changes in the distribution and population composition of copepods may also serve as an indicator of global climate changes. Therefore, it is important to model the copepod distribution in different ecosystems. Copepod samples were collected from three different ecosystems (seagrass area, cage aquaculture area and coastal waters off shrimp aquaculture farm) along the coastal waters of the Malacca Straits over a one year period. In this study the major statistical analysis consisted of fitting different probability models. This paper highlights the fitting of probability distributions and discusses the adequateness of the fitted models. The usefulness of these fitted models would enable one to make probability statements about the distribution of copepods in three different ecosystems.

  1. Active prey selection in two pelagic copepods feeding on potentially toxic and non-toxic dinoflagellates

    DEFF Research Database (Denmark)

    Schultz, Mette; Kiørboe, Thomas

    2009-01-01

    Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower but compar......Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower...... but comparable to those at which they cleared the slightly larger G. instriatum when the two dinoflagellates were offered separately. However, when feeding on mixtures of the two prey species, the clearance rates on K. mikimotoi were substantially reduced in both copepods while their clearances of G. instiatum...

  2. Modeling Dynamic Fracture of Cryogenic Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Paul [General Atomics, San Diego, CA (United States)

    2016-06-30

    This work is part of an investigation with the long-range objective of predicting the size distribution function and velocity dispersion of shattered pellet fragments after a large cryogenic pellet impacts a solid surface at high velocity. The study is vitally important for the shattered pellet injection (SPI) technique, one of the leading technologies being implemented at ORNL for the mitigation of disruption damage on current tokamaks and ITER. The report contains three parts that are somewhat interwoven. In Part I we formulated a self-similar model for the expansion dynamics and velocity dispersion of the debris cloud following pellet impact against a thick (rigid) target plate. Also presented in Part I is an analytical fracture model that predicts the nominal or mean size of the fragments in the debris cloud and agrees well with known SPI data. The aim of Part II is to gain an understanding of the pellet fracturing process when a pellet is shattered inside a miter tube with a sharp bend. Because miter tubes have a thin stainless steel (SS) wall a permanent deformation (dishing) of the wall is produced at the site of the impact. A review of the literature indicates that most projectile impact on thin plates are those for which the target is deformed and the projectile is perfectly rigid. Such impacts result in “projectile embedding” where the projectile speed is reduced to zero during the interaction so that all the kinetic energy (KE) of the projectile goes into the energy stored in plastic deformation. Much of the literature deals with perforation of the target. The problem here is quite different; the softer pellet easily undergoes complete material failure causing only a small transfer of KE to stored energy of wall deformation. For the real miter tube, we derived a strain energy function for the wall deflection using a non-linear (plastic) stress-strain relation for 304 SS. Using a dishing profile identical to the linear Kirchkoff-Love profile (for lack

  3. Fecal transplant policy and legislation.

    Science.gov (United States)

    Vyas, Dinesh; Aekka, Apoorva; Vyas, Arpita

    2015-01-07

    Fecal microbiota transplantation (FMT) has garnered significant attention in recent years in the face of a reemerging Clostridium difficile (C. difficile) epidemic. Positive results from the first randomized control trial evaluating FMT have encouraged the medical community to explore the process further and expand its application beyond C. difficile infections and even the gastrointestinal domain. However promising and numerous the prospects of FMT appear, the method remains limited in scope today due to several important barriers, most notably a poorly defined federal regulatory policy. The Food and Drug Administration has found it difficult to standardize and regulate the administration of inherently variable, metabolically active, and ubiquitously available fecal material. The current cumbersome policy, which classifies human feces as a drug, has prevented physicians from providing FMT and deserving patients from accessing FMT in a timely fashion, and subsequent modifications seem only to be temporary. The argument for reclassifying fecal material as human tissue is well supported. Essentially, this would allow for a regulatory framework that is sufficiently flexible to expand access to care and facilitate research, but also appropriately restrictive and centralized to ensure patient safety. Such an approach can facilitate the advancement of FMT to a more refined, controlled, and aesthetic process, perhaps in the form of a customized and well-characterized stool substitute therapy.

  4. 46 CFR 148.04-9 - Fishmeal or scrap, ground or pelletized; fishmeal or scrap, ground and pelletized (mixture).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Fishmeal or scrap, ground or pelletized; fishmeal or scrap, ground and pelletized (mixture). 148.04-9 Section 148.04-9 Shipping COAST GUARD, DEPARTMENT OF... Additional Requirements for Certain Material § 148.04-9 Fishmeal or scrap, ground or pelletized; fishmeal...

  5. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Directory of Open Access Journals (Sweden)

    M. De Troch

    2013-02-01

    Full Text Available Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean. Nematodes were found as most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1 if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2 whether initial (normoxia feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect but also of primary producers (indirect effect, with important implications for the recovery phase.

  6. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Directory of Open Access Journals (Sweden)

    M. De Troch

    2013-06-01

    Full Text Available Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean. Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1 if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2 whether initial (normoxia feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect but also of primary producers (indirect effect, with important implications for the recovery phase.

  7. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Science.gov (United States)

    De Troch, M.; Roelofs, M.; Riedel, B.; Grego, M.

    2013-06-01

    Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.

  8. Astaxanthin production in marine pelagic copepods grazing on two different phytoplankton diets

    Science.gov (United States)

    Van Nieuwerburgh, Lies; Wänstrand, Ingrid; Liu, Jianguo; Snoeijs, Pauli

    2005-02-01

    The red carotenoid astaxanthin is a powerful natural antioxidant of great importance in aquatic food webs where it is abundant in eggs and body tissues of fish and crustaceans. Little is known about the impact of the phytoplankton diet on astaxanthin production in copepods, its major pelagic producers. We followed the transfer of carotenoids from phytoplankton to copepods in a mesocosm experiment on the northern Atlantic coast (Norway) and recorded the astaxanthin production in copepods. Wild copepods grazed on nutrient-manipulated phytoplankton blooms, which differed in community composition and nutrient status (nitrogen or silicate limitation). The copepod pigments consisted mainly of free astaxanthin and mono- and diesters of astaxanthin. We found no significant difference in astaxanthin production per copepod individual or per unit C depending on the phytoplankton community. However, in the mesocosms astaxanthin per unit C decreased compared with natural levels, probably through a lower demand for photoprotection by the copepods in the dense phytoplankton blooms. The total astaxanthin production per litre was higher in the silicate-limited mesocosms through increased copepod density. Pigment ratio comparisons suggested that the copepod diet here consisted more of diatoms than in the nitrogen-limited mesocosms. Silicate-saturated diatoms were less grazed, possibly because they could invest more in defence mechanisms against their predators. Our study suggests that the production of astaxanthin in aquatic systems can be affected by changes in nutrient dynamics mediated by phytoplankton community composition and copepod population growth. This bottom-up force may have implications for antioxidant protection at higher trophic levels in the food web.

  9. Copepod feeding study in the upper layer of the tropical South China Sea

    Science.gov (United States)

    Tseng, Li-Chun; Dahms, Hans-Uwe; Chen, Qing-Chao; Hwang, Jiang-Shiou

    2009-12-01

    The South China Sea (SCS) is the world’s largest marginal sea being notable for vertical mixing at various scales resulting in a sequence of chemical and biological dynamics in surface waters. We investigated the ingestion, gut content, evacuation and clearance rates of copepods collected from six stations (including a South East Asia Time Series station) along a transect line in the tropical of a SCS cruise during September 27, 1999 to October 2, 1999. The goal of the present study was to understand the feeding ecology of copepods in the upper water layers (0-5 m) of the northern SCS during autumn. We measured the gut pigment contents of 33 copepod species by the gut fluorescence method. The gut chlorophyll a values of most small size copepods (danae (7.07 ng Chl a individual-1). The gut pigment contents of 33 copepod species (including 70 samples and 1,290 individuals) estimated is negatively correlated with seawater temperature (Pearson correlation r = -0.292, P = 0.014) and is positively correlated with the chlorophyll a concentration of ambient waters (Pearson correlation r = 0.243, P = 0.043). Mean gut pigment content, ingestion and clearance rates (from 80 samples and 1,468 individuals) show that larger copepods (>2 mm) had significantly higher values than medium sized copepods (1-2 mm) and smaller sized copepods. The present study shows that the performance of feeding on phytoplankton was variable in different sized copepod groups, suggesting that copepods obtained in the tropical area of the southeastern Taiwan Strait might be opportunistic feeders.

  10. Simulation of peeling-ballooning modes with pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S. Y. [College of Physical Science and Technology, Sichuan University, 610064 Chengdu (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Huang, J.; Sun, T. T.; Tang, C. J. [College of Physical Science and Technology, Sichuan University, 610064 Chengdu (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Wang, Z. H. [Southwestern Institute of Physics, Chengdu 610041 (China)

    2014-11-15

    The influence of pellet ablation on the evolution of peeling-ballooning (P-B) modes is studied with BOUT++ code. The atoms coming from pellet ablation can significantly reshape the plasma pressure profile, so the behaviors of P-B modes and edge localized mode (ELM) are modified dramatically. This paper shows that the energy loss associated with an ELM increases substantially over that without the pellet, if the pellet is deposited at the top of the pedestal. On the contrary, for pellet deposition in the middle of the pedestal region the ELM energy loss can be less.

  11. Quality properties of fuel pellets from forest biomass

    Energy Technology Data Exchange (ETDEWEB)

    Lehtikangas, P.

    1999-07-01

    Nine pellet assortments, made of fresh and stored sawdust, bark and logging residues (a mixture of Norway spruce and Scots pine) were tested directly after production and after 5 months of storage in large bags (volume about 1 m{sup 3} loose pellets) for moisture content, heating value and ash content. Dimensions, bulk density, density of individual pellets and durability were also determined. Moreover, sintering risk and contents of sulphur, chlorine, and lignin of fresh pellets were determined. It is concluded that bark and logging residues are suitable raw materials for pellets production, especially regarding durability and if the ash content is controlled. Pellets density had no effect on its durability, unlike lignin content which was positively correlated. The pellets had higher ash content and lower calorific heating value than the raw materials, probably due to loss of volatiles during drying. In general, the quality changes during storage were not large, but notable. The results showed that storage led to negative effects on durability, especially on pellets made of fresh materials. The average length of pellets was decreased due to breakage during storage. Microbial growth was noticed in some of the pellet assortments. Pellets made out of fresh logging residues were found to be weakest after storage. The tendency to reach the equilibrium with the ambient moisture content should be taken into consideration during production due to the risk of decreasing durability.

  12. Tabletting behaviour of pellets of a series of porosities--a comparisonbetween pellets of two different compositions.

    Science.gov (United States)

    Nicklasson, F; Johansson, B; Alderborn, G

    1999-04-01

    The tabletting behaviour of pellets prepared from a 4:1 mixture of dicalcium phosphate dihydrate (DCP) and microcrystalline cellulose (MCC) was studied and compared with the tabletting behaviour of pellets made solely from microcrystalline cellulose (results from an earlier study by Johansson et al.). A series of pellets with porosities in the range 26-55% were prepared and tabletted at applied pressures of 25-200 MPa. Tablets were also formed from lubricated pellets. The degree of compression during compaction was calculated, and the porosity and tensile strength of the tablets and their permeability to air flow were determined. The porosity of the pellets was found to significantly affect the tabletting behaviour of the DCP/MCC pellets. However, the relationship between pellet porosity and tablet data for the DCP/MCC pellets was different from that for the MCC pellets. The DCP/MCC pellets were generally less prone to a reduction in volume during tabletting, and the pore structure of the DCP/MCC tablets was more closed. It was concluded that the DCP/MCC pellets were more rigid and underwent a different mode of deformation during tabletting than the MCC pellets. This mode of deformation was characterised by a more limited bulk deformation and a more extensive surface deformation at the pellet surfaces. The DCP/MCC pellets tended to give tablets of a lower mechanical strength. They were also less sensitive to lubrication in terms of their compactability, which may be explained either by less surface coverage by the lubricant before compression or rupture of the lubricant film during compression caused by the more extensive surface deformation of DCP/MCC pellets.

  13. High-rate behaviour of iron ore pellet

    Directory of Open Access Journals (Sweden)

    Gustafsson Gustaf

    2015-01-01

    Full Text Available Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  14. Reprint of: Pelletizing properties of torrefied wheat straw

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Nielsen, Niels Peter K.; Hansen, Hans Ove;

    2013-01-01

    Combined torrefaction and pelletization are used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. However, pelletization of torrefied biomass can be challenging and in this study the torrefaction and pelletizing properties...... of wheat straw have been analyzed. Laboratory equipment has been used to investigate the pelletizing properties of wheat straw torrefied at temperatures between 150 and 300 °C. IR spectroscopy and chemical analyses have shown that high torrefaction temperatures change the chemical properties of the wheat...... straw significantly, and the pelletizing analyses have shown that these changes correlate to changes in the pelletizing properties. Torrefaction increase the friction in the press channel and pellet strength and density decrease with an increase in torrefaction temperature....

  15. Tritium pellet injection sequences for TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, W.A.; Milora, S.L.; Attenberger, S.E.; Singer, C.E.; Schmidt, G.L.

    1983-01-01

    Tritium pellet injection into neutral deuterium, beam heated deuterium plasmas in the Tokamak Fusion Test Reactor (TFTR) is shown to be an attractive means of (1) minimizing tritium use per tritium discharge and over a sequence of tritium discharges; (2) greatly reducing the tritium load in the walls, limiters, getters, and cryopanels; (3) maintaining or improving instantaneous neutron production (Q); (4) reducing or eliminating deuterium-tritium (D-T) neutron production in non-optimized discharges; and (5) generally adding flexibility to the experimental sequences leading to optimal Q operation. Transport analyses of both compression and full-bore TFTR plasmas are used to support the above observations and to provide the basis for a proposed eight-pellet gas gun injector for the 1986 tritium experiments.

  16. Pellet integrity and swelling of lithium ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hollenberg, G.W.

    1987-01-01

    The objective of this effort is to determine the swelling and pellet integrity of Li/sub 2/O, Li/sub 4/SlO/sub 4/, Li/sub 2/ZrO/sub 3/, and LiAlO/sub 2/ after irradiation in a fast neutron fluence. Differences in the pellet integrity of lithium ceramics irradiated in the EBR-II reactor were observed to be related to the level of thermal strains within the ceramics which resulted from differences in thermal conductivity and thermal expansion of the solids. Swelling in Li/sub 2/O was found to be significantly greater than that of Li/sub 2/ZrO/sub 3/, LiAlO/sub 2/, and Li/sub 4/SlO/sub 4/ at high temperatures. At 500/sup 0/C, Li/sub 2/O exhibited axial shrinkage which resulted in overall volumetric shrinkage of the pellets which is not presently understood. The high temperature swelling of Li/sub 2/O is thought to be caused by the high helium retention in this solid.

  17. Surface properties of beached plastic pellets.

    Science.gov (United States)

    Fotopoulou, Kalliopi N; Karapanagioti, Hrissi K

    2012-10-01

    The presence of pollutants on plastic debris is an emerging environmental hot topic. Understanding the surface alteration of plastics while in the marine environment increases our understanding of the pollutant-plastic debris interaction. Plastic pellets are widely distributed throughout the world oceans. Eroded and virgin polyethylene (PE) and polypropylene (PP) pellets were studied for their surface properties to better understand the interaction between plastic and compounds in marine environment. Surface properties such as point of zero charge, surface area and pore volume, surface topography, functional groups and acid-base behavior are important factors which affect sorption. Virgin plastic pellets had homogeneous smooth surfaces that do not have any acid-base behavior. Eroded PE demonstrates an altered surface that at seawater pH acquires a negative charge due to ketone groups. The uneven surface and possible functional groups could have been formed from the erosion processes while floating at the sea surface and might explain the interaction of eroded plastics with microbes and metals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Producing bio-pellets from sunflower oil cake for use as an energy source

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Yuichi; Kato, Hitoshi; Kanai, Genta; Togashi, Tatsushi [National Agricultural Research Center (Japan)], E-mail: kobay@affrc.go.jp

    2008-07-01

    Pellet fuels were produced from ground sunflower oil cake using a pelletizer. The length, hardness, and powder characteristics of dried pellets depend on the initial water content of the oil cake. The appropriate values of water contents were 19.9 - 21.0% w.b. Oil cake pellets were found to contain 6.07% ash and 20.99 MJ/kg caloric value, which are within the standard range of wood pellets. Combustion experiments using a commercial pellet stove demonstrate that oil cake pellets burn as well as wood pellets. Oil cake pellets are useful as a fuel alternative to wood pellets. (author)

  19. Temperature effects on copepod egg hatching: does acclimatization matter?

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Kozmér, A.;

    2010-01-01

    This report investigates female sizes, egg sizes and egg hatching rates in relation to temperature for the near-shore calanoid copepod Acartia tonsa cultured at 6, 9, 14 and 24°C for several generations to achieve acclimatization. Inverse size relationships of eggs and females were revealed...... with increasing temperature. Eggs produced at 6°C were 85 ± 4 µm in diameter, but decreased to 80 ± 3 µm at 24°C. Female cephalothorax length was 840 ± 52 and 692 ± 39 µm at 9 and 24°C, respectively. Parallel hatching experiments were performed between non-acclimatized and acclimatized cultures across a range...... of temperatures reflecting natural conditions in Danish waters. A greater fraction of eggs enter quiescence as temperature declines. Eggs were able to hatch at temperatures as low as 1.5°C. Final egg hatching success increased with temperature. Acclimatization of the copepods resulted in a lower maximum hatching...

  20. Circular polarization of transmitted light by sapphirinidae copepods.

    Directory of Open Access Journals (Sweden)

    Yuval Baar

    Full Text Available Circularly polarized light, rare in the animal kingdom, has thus far been documented in only a handful of animals. Using a rotating circular polarization (CP analyzer we detected CP in linearly polarized light transmitted through epipelagic free living Sapphirina metallina copepods. Both left and right handedness of CP was detected, generated from specific organs of the animal's body, especially on the dorsal cephalosome and prosome. Such CP transmittance may be generated by phase retardance either in the muscle fibers or in the multilayer membrane structure found underneath the cuticle. Although the role, if any, played by circularly polarized light in Sapphirinidae has yet to be clarified, in other animals it was suggested to take part in mate choice, species recognition, and other forms of communication.Planktonic Sapphirinidae copepods were found to circularly polarize the light passing through them. Circular polarization may be created by unique, multilayered features of the membrane structure found under their cuticle or by organized muscle fibers.

  1. Impacts of intraguild predation on Arctic copepod communities

    Directory of Open Access Journals (Sweden)

    Karolane Dufour

    2016-09-01

    Full Text Available Communities of large copepods form an essential hub of matter and energy fluxes in Arctic marine food webs. Intraguild predation on eggs and early larval stages occurs among the different species of those communities and it has been hypothesized to impact its structure and function. In order to better understand the interactions between dominant copepod species in the Arctic, we conducted laboratory experiments that quantified intraguild predation between the conspicuous and omnivorous Metridia longa and the dominant Calanus hyperboreus. We recorded individual egg ingestion rates for several conditions of temperature, egg concentration and alternative food presence. In each of these experiments, at least some females ingested eggs but individual ingestion rates were highly variable. The global mean ingestion rate of M. longa on C. hyperboreus eggs was 5.8 eggs ind-1 d-1, or an estimated 37% of M. longa daily metabolic need. Among the different factors tested and the various individual traits considered (prosome length, condition index, only the egg concentration had a significant and positive effect on ingestion rates. We further explored the potential ecological impacts of intraguild predation in a simple 1D numerical model of C. hyperboreus eggs vertical distribution in the Amundsen Gulf. Our modelling results showed an asymmetric relationship in that M. longa has little potential impact on the recruitment of C. hyperboreus (< 3% egg standing stock removed by IGP at most whereas the eggs intercepted by the former can account for a significant portion of its metabolic requirement during winter (up to a third.

  2. Prey detection and prey capture in copepod nauplii.

    Directory of Open Access Journals (Sweden)

    Eleonora Bruno

    Full Text Available Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed video to describe the detection and capture of phytoplankton prey by the nauplii of two ambush feeding species (Acartia tonsa and Oithona davisae and by the nauplii of one feeding-current feeding species (Temora longicornis. We demonstrate that the ambush feeders both detect motile prey remotely. Prey detection elicits an attack jump, but the jump is not directly towards the prey, such as has been described for adult copepods. Rather, the nauplius jumps past the prey and sets up an intermittent feeding current that pulls in the prey from behind towards the mouth. The feeding-current feeding nauplius detects prey arriving in the feeding current but only when the prey is intercepted by the setae on the feeding appendages. This elicits an altered motion pattern of the feeding appendages that draws in the prey.

  3. Paternal inheritance of the primary sex ratio in a copepod.

    Science.gov (United States)

    Voordouw, M J; Robinson, H E; Anholt, B R

    2005-09-01

    Uniparentally inherited genetic elements are under strong selection to manipulate sex determination in their host and shift the host sex ratio towards the transmitting sex. For any sex-ratio trait, lineage analysis and quantitative genetics are important tools for characterizing the mode of inheritance (biparental vs. maternal vs. paternal) thereby narrowing the field of possible sex-determining mechanisms (e.g. polygenic, sex chromosomes with meiotic drive, cytoplasmic microorganisms). The primary sex ratio of the harpacticoid copepod, Tigriopus californicus is often male-biased and is highly variable among full sib families. We found that this extra-binomial variation for the primary sex ratio is paternally but not maternally transmitted in T. californicus. Paternal transmission of the primary sex ratio has been well documented in the haplo-diploid hymenoptera but is relatively rare in diplo-diploid organisms. If the sex-ratio trait is paternally transmitted in other closely related harpacticoid copepods it would explain why male biased primary sex ratios are so common in this group.

  4. The kinematics of swimming and relocation jumps in copepod nauplii

    DEFF Research Database (Denmark)

    Borg, Marc Andersen; Bruno, Eleonora; Kiørboe, Thomas

    2012-01-01

    Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella, and cop......Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella......, and copepodites are equipped with highly specialized swimming legs. In some species the nauplius may also propel itself more slowly through the water by beating and rotating the appendages in a different, more complex pattern. We use high-speed video to describe jumping and swimming in nauplii of three species...... larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when...

  5. Bioaccumulation and trophic transfer of dioxins in marine copepods and fish

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qiong [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Yang Liuyan [School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2011-12-15

    Despite the great concerns about dioxins in the marine environments, the biokinetics and bioaccumulation of these compounds in marine organisms remains little known. Using radioactive tracers the aqueous uptake, dietary assimilation efficiency, and elimination of dioxins were measured in marine phytoplankton, copepods and seabream. The calculated uptake rate constant of dioxins decreased with increasing trophic levels, whereas the dietary assimilation efficiency (AE) was 28.5-57.6% in the copepods and 36.6-70.2% in the fish. The dietary AE was highly dependent on the food concentrations and food type. The elimination rate constant of dioxin in the copepods varied with different exposure pathways as well as food concentration and food type. Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish. Aqueous uptake can be an important pathway only when the bioconcentration of dioxins in the phytoplankton was low. - Highlights: > Radiotracer was used to quantify the biokinetics of dioxins in a marine food chain. > Aqueous uptake rate of dioxins decreased with increasing trophic levels. > Dietary assimilation efficiencies were comparable between the copepods and the fish. > Both food type and density significantly affected the dietary assimilation of dioxins. > Diet was the predominant pathway for dioxin accumulation in marine copepods and fish. - Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish.

  6. Seasonal variability of planktonic copepods (Copepoda: Crustacea in a tropical estuarine region in Brazil

    Directory of Open Access Journals (Sweden)

    Cristina de Oliveira Dias

    2009-12-01

    Full Text Available The Caravelas River estuary and adjacent coastal region were studied during the rainy and dry seasons of 2003-2004 to assess the copepod community structure. Abiotic and biotic parameters were measured, and the total density, frequency and percentage of copepod taxa were determined for each sampling period. Copepod densities showed significant differences between sampling periods, with higher densities in the rainy seasons (Mean: 90,941.80 ind.m-3; S.D.: 26,364.79. The sampling stations located to the north and south, in the coastal region adjacent to the Caravelas River estuary presented the lowest copepod density values. The copepod assemblage was composed mainly of estuarine and estuarine/coastal copepods. The seasonal variations in temperature and salinity influenced the abundance of species during the rainy and dry seasons, with the following dominant species alternating: Paracalanus quasimodo Bowman, 1971 in the rainy season of 2003, Parvocalanus crassirostris Dahl, 1894 in the dry season of 2003 and Acartia lilljeborgii Giesbrecht, 1892 in the rainy and dry seasons of 2004. Non-parametric multidimensional scaling indicated differences in copepod assemblages between sampling periods, but not between sampling stations.

  7. Evaluation of Mechanical Parameters of Pellets

    Directory of Open Access Journals (Sweden)

    Ľubomír Kubík

    2016-01-01

    Full Text Available The paper dealt with the evaluation of mechanical properties of the cylinder wheat straw, rapeseed straw and 50/50 % mixed wheat and rapeseed straw pellet samples. The pellets were made by the granulating machine MGL 200 (Kovonovak. The compressive loading curves of dependencies of stress on strain were realised by the test stand Andilog Stentor 1000 (Andilog Technologies, Vitrolles, France. Certain mechanical parameters were determined, namely the initial force (force at 10 % of compress strain, force in maximum of loading curve, strain in maximum of loading curve, initial stress (stress at 10 % of compression strain, stress in maximum of loading curve and modulus of elasticity. Mean value of the initial force was maximal for mixed straw pellet samples 52.49 N. Mean values of the initial force of the wheat straw samples and the rapeseed straw samples were smaller and almost identical 43.58 N and 43.12 N. Mean values of the initial stress of loading curve, of the wheat straw samples reached 1.46 MPa, the rapeseed straw samples reached value 1.40 MPa and the mixed straw samples reached value 1.63 MPa. Mean value of the force in maximum of loading curve was also maximal for mixed straw pellet samples 213.26 N. Mean values of the force in maximum of loading curve of the wheat straw samples reached 178.11 N. The rapeseed straw samples reached value 95.95 N and the mixed straw samples reached value 213.26 N. Mean values of the stress in maximum of loading curve, of the wheat straw samples reached 5.93 MPa, the rapeseed straw samples reached value 3.11 MPa and the mixed straw samples reached value 7.10 MPa Mean values of the modulus of elasticity, of the wheat straw samples reached 18.27 MPa, the rapeseed straw samples reached value 13.08 MPa and the mixed straw samples reached value 14.97 MPa. Significant correlations of the mechanical parameters pellet samples were observed among initial force and initial stress and modulus of elasticity

  8. [Response of copepod community characteristics to environmental factors in the Backshore Wetland of Expo Garden, Shanghai].

    Science.gov (United States)

    Chen, Li-Jing; Wu, Yan-Fang; Jing, Yu-Xiang; Wang, Cong; Zhang, Yin-Jiang

    2012-11-01

    The Backshore Wetland of Expo Garden was the emphasis of the World Expo construction project in Shanghai in 2010, China programming district. We carried out studies on the community structure and spatial-temporal variation of copepod from September 2009 to August 2010. Statistical Product and Service Solutions (SPSS) was used for relevant statistical analysis between physicochemical parameters and copepod standing crop. Canonical correspondence analysis (CCA) was applied to further explore the correlation between copepod species and environmental parameters using CANOCO 4.5. A total of 23 copepod species in 11 genera, 6 families were identified. 5 dominant species of copepod were recorded during the survey period. They were Eucyclops serrulatus, Thermocyclops taihokuensis, Mesocyclops leuckarti, Thermocyclops brevifurcatus and Microcyclops varicans. The annual mean density of copepod was (8.6 +/- 16.6) ind x L(-1) and the biomass was (0.083 6 +/- 0.143 1) mg x L(-1). The standing crop of copepod had its first peak in July, the second in October and the bottom in January. The highest trophic level was measured at Site 1, decreasing along the flowing direction of the water current, and the lowest level was found at Site 10. The Margelf index remained low in winter and spring, but was increased in summer and autumn. The community structure of copepod was analyzed in relation to water quality parameters by canonical correspondence analysis (CCA). Water temperature, pH, nitrate nitrogen, nitrite nitrogen, TN, TP and dissolved oxygen were strongly correlated with the copepod community structure.

  9. Permeability of wood pellets in the presence of fines.

    Science.gov (United States)

    Yazdanpanah, F; Sokhansanj, S; Lau, A K; Lim, C J; Bi, X; Melin, S; Afzal, M

    2010-07-01

    Broken pellets and fines are produced when pellets are handled. The resistance to air flow was measured for clean pellets and for pellets mixed with 1-20% broken pellets (fines). A pellet diameter was 6mm. The lengths ranged from 6 to 12 mm. Clean pellets were defined as particles that remained on a 4mm screen. A typical sieve analysis showed 30% of the mass of particles that passed through the 4mm screen was smaller than 1mm. The airflow rates used in the experiment ranged from 0.004 to 0.357 ms(-1). The corresponding pressure drop ranged from 1.9 to 271 Pam(-1) for clean pellets, from 4.8 to 1100 Pam(-1) for 10% fines content, and from 7.9 to 1800 Pam(-1) for 20% fines content. Coefficients of Hukill and Ives' equation were estimated for clean pellets and a multiplier was defined to calculate pressure drop for pellets mixed with fines.

  10. Cryogenic pellet production developments for long-pulse plasma operation

    Energy Technology Data Exchange (ETDEWEB)

    Meitner, S. J.; Baylor, L. R.; Combs, S. K.; Fehling, D. T.; McGill, J. M.; Duckworth, R. C.; McGinnis, W. D.; Rasmussen, D. A. [Oak Ridge National Laboratory, 1Bethel Valley Rd Oak Ridge, TN 37831 (United States)

    2014-01-29

    Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at a rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.

  11. Influences on particle shape in underwater pelletizing processes

    Energy Technology Data Exchange (ETDEWEB)

    Kast, O., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Musialek, M., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Geiger, K., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de [Institut für Kunststofftechnik, University of Stuttgart (Germany)

    2014-05-15

    Underwater pelletizing has gained high importance within the last years among the different pelletizing technologies, due to its advantages in terms of throughput, automation, pellet quality and applicability to a large variety of thermoplastics. The resulting shape and quality of pellets, however, differ widely, depending on material characteristics and effects not fully understood yet. In an experimental set-up, pellets of different volumes and shapes were produced and the medium pellet mass, the pellet surface and the bulk density were analyzed in order to identify the influence of material properties and process parameters. Additionally, the shaping kinetics at the die opening were watched with a specially developed camera system. It was found that rheological material properties correlate with process parameters and resulting particle form in a complex way. Higher cutting speeds were shown to have a deforming influence on the pellets, leading to less spherical s and lower bulk densities. More viscous materials, however, showed a better resistance against this. Generally, the viscous properties of polypropylene proofed to be dominant over the elastic ones in regard to their influence on pellet shape. It was also shown that the shapes filmed at the die opening and the actual form of the pellets after a cooling track do not always correlate, indicating a significant influence of thermodynamic properties during the cooling.

  12. RECENT DEVELOPMENTS IN BIOMASS PELLETIZATION – A REVIEW

    Directory of Open Access Journals (Sweden)

    Wolfgang Stelte,

    2012-07-01

    Full Text Available The depletion of fossil fuels and the need to reduce greenhouse gas emissions has resulted in a strong growth of biomass utilization for heat and power production. Attempts to overcome the poor handling properties of biomass, i.e. its low bulk density and inhomogeneous structure, have resulted in an increasing interest in biomass densification technologies, such as pelletization and briquetting. The global pellet market has developed quickly, and strong growth is expected for the coming years. Due to an increase in demand for biomass, the traditionally used wood residues from sawmills and pulp and paper industry are not sufficient to meet future needs. An extended raw material base consisting of a broad variety of fibrous residues from agriculture and food industries, as well as thermal pre-treatment processes, provides new challenges for the pellet industry. Pellet production has been an established process for several decades, but only in the past five years has there been significant progress made to understand the key factors affecting pelletizing processes. A good understanding about the pelletizing process, especially the processing parameters and their effect on pellet formation and bonding are important for process and product optimization. The present review provides a comprehensive overview of the latest insights into the biomass pelletization processes, such as the forces involved in the pelletizing processes, modeling, bonding, and adhesive mechanisms. Furthermore, thermal pretreatment of the biomass, i.e. torrefaction and other thermal treatment to enhance the fuel properties of biomass pellets are discussed.

  13. Vertical distribution, grazing and egg production of calanoid copepods during winter-spring in Gullmarsfjorden

    DEFF Research Database (Denmark)

    Titelman, J.; Tiselius, P.

    1998-01-01

    The vertical distribution of copepods in relation to their potential food was examined in Gullmarsfjorden, Sweden (58 degrees 15.6' N, 11 degrees 27.2' E). Plankton distributions were determined from bottle samples at 5 m intervals on four occasions; 30 January, 28 February, 7 March and 10 April...... were superfluous throughout the water column. Copepods and ciliates were never correlated. Ingestion as determined from gut fluorescence and egg production analyses suggested a higher degree of herbivory during the spring bloom than before and after. There was potential for copepod predation control...

  14. Female-biased sex ratios in marine pelagic copepods: Comment on Gusmao et al. (2013)

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Bonnet, D; Conway, DVP

    2013-01-01

    Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important errors...... in their citation of our paper and briefly highlight where future work is needed in order to attribute the causes of strong sex ratio skew seen in some copepod families...

  15. Prolonged release matrix pellets prepared by melt pelletization. I. Process variables

    DEFF Research Database (Denmark)

    Thomsen, L.J.; Schaefer, T.; Sonnergaard, Jørn

    1993-01-01

    A melt pelletization process was investigated in an 8 litre laboratory scale high shear mixer using a formulation with paracetamol, glyceryl monostearate 40-50, and microcrystalline wax. The effects of jacket temperature, product temperature during massing, product load, massing time and impeller...... speed were investigated by means of factorially designed experiments. The maximum yield of pellets in the range of 500-1400 μm was found to approx. 90%. For process conditions preventing deposition of moist mass, the process was found to be reproducible. Impeller speed and massing time were found...

  16. Fecal Continence Revisited : The Anal External Sphincter Continence Reflex

    NARCIS (Netherlands)

    Broens, Paul M. A.; Penninckx, Freddy M.; Boix Ochoa, Jose

    2013-01-01

    BACKGROUND: None of the current theories on fecal incontinence can explain fecal continence adequately. OBJECTIVE: This study aims to evaluate the mechanism controlling fecal continence. DESIGN: Anal electrosensitivity, anorectal pressures, and rectal pressure volumetry tests were performed in 17

  17. Endoluminal magnetic resonance imaging in fecal incontinence

    NARCIS (Netherlands)

    E. Rociu (Elena)

    2000-01-01

    textabstractFecal incontinence is a chronic disability, has serious emotional impact and increased risk for social isolation. Imaging has become important in the diagnostic work-up of fecal incontinence. The research described in this thesis continues the line of efforts to improve the quality and t

  18. Microstructure of bentonite in iron ore green pellets.

    Science.gov (United States)

    Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas

    2014-02-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.

  19. Manufacture of Regularly Shaped Sol-Gel Pellets

    Science.gov (United States)

    Leventis, Nicholas; Johnston, James C.; Kinder, James D.

    2006-01-01

    An extrusion batch process for manufacturing regularly shaped sol-gel pellets has been devised as an improved alternative to a spray process that yields irregularly shaped pellets. The aspect ratio of regularly shaped pellets can be controlled more easily, while regularly shaped pellets pack more efficiently. In the extrusion process, a wet gel is pushed out of a mold and chopped repetitively into short, cylindrical pieces as it emerges from the mold. The pieces are collected and can be either (1) dried at ambient pressure to xerogel, (2) solvent exchanged and dried under ambient pressure to ambigels, or (3) supercritically dried to aerogel. Advantageously, the extruded pellets can be dropped directly in a cross-linking bath, where they develop a conformal polymer coating around the skeletal framework of the wet gel via reaction with the cross linker. These pellets can be dried to mechanically robust X-Aerogel.

  20. MULTIPARTICULATE DRUG DELIVERY SYSTEM: PELLETIZATION THROUGH EXTRUSION AND SPHERONIZATION

    Directory of Open Access Journals (Sweden)

    Anshuli Sharma

    2013-02-01

    Full Text Available Pharmaceutical invention and research are increasingly focusing on delivery systems which enhance desirable therapeutic objectives while minimising side effects. Recent trends indicate that multiparticulate drug delivery systems are especially suitable for achieving controlled or delayed release oral formulations with low risk of dose dumping, flexibility of blending to attain different release patterns as well as reproducible and short gastric residence time. Pelletization is a technique used to prepare fine powders into pellets used as multiparticulate drug delivery systems. There are different pelletization techniques used to prepare pellets. Extrusion and spheronization is one of them used to prepare pellets drug loaded beads/pellets for extended release or sustained release oral formulations such as tablets and capsules.

  1. Microstability analysis of pellet fuelled discharges in MAST

    CERN Document Server

    Garzotti, L; Roach, C M; Valovic, M; Dickinson, D; Naylor, G; Romanelli, M; Scannell, R; Szepesi, G

    2014-01-01

    Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density and temperature profiles relax towards their quasi-steady-state shape. Microinstabilities influence plasma confinement and will play a role in determining the evolution of the profiles in pellet fuelled plasmas. In this paper we present the microstability analysis of pellet fuelled H-mode MAST plasmas. Taking advantage of the unique capabilities of the MAST Thomson scattering system and the possibility of synchronizing the eight lasers with the pellet injection, we were able to measure the evolution of the post-pellet electron density and temperature profiles with high temporal and spatial resolution. These profiles, together with ion temperature profiles measured using a charge exchange diagnostic, were used to produce equilibria suitable for microstability analysis of th...

  2. Mechanical durability and combustion characteristics of pellets from biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Gil, M.V.; Oulego, P.; Casal, M.D.; Pevida, C.; Pis, J.J.; Rubiera, F. [CSIC, Oviedo (Spain)

    2010-11-15

    Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10-30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (<20%) with chestnut and pine sawdusts did not decrease pellet durability. The biomass/biomass blends presented combustion profiles similar to those of the individual raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends.

  3. Making Sense of Protists – aspects of phototaxis and chemo sensory behavior

    DEFF Research Database (Denmark)

    Moldrup, Morten

    . This is maintained although the expected peak in the near UV range is missing probably due to some sort of shading/filtering of harmful UV radiation. Interestingly, the phototaxis could be temporarily overruled by tactile stimuli. After physical contact with the light guide the cells escaped the area. They may do...... this as some sort of predator avoidance. Field studies have indicated that dinoflagellates are key degraders of copepod fecal pellets in the sea, however, direct evidence of pellet feeding by dinoflagellates have not been published prior to this study. Feeding and growth of dinoflagellates on copepod fecal...

  4. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    Science.gov (United States)

    Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

    1988-01-01

    Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

  5. Use of porous aluminosilicate pellets for drug delivery.

    Science.gov (United States)

    Byrne, R S; Deasy, P B

    2005-06-01

    Three pelletized porous aluminosilicate ceramics were obtained commercially and their potential to act as extended release drug delivery systems was assessed. The pellets were drug loaded using a vacuum impregnation technique. Factors such as the concentration of the loading solution and the porosity and bulk density of the ceramic influenced the drug loading. The release of drug from the pellets was extended as the drug was entrapped within their porous interior. The rate of release was influenced by the porous microstructure of the pellets and the physicochemical properties of the drug. Extrusion-spheronization was used to prepare pellets similar to the porous ceramics. The pellet formulations contained an aluminosilicate clay mineral (kaolin or halloysite), ethylcellulose 100 cps, ethanol and varying quantities of sucrose. The latter two components acted as pore forming agents. Diltiazem HCl was loaded into the pellets and its release was extended. The release rate could be modified by changing the quantity of sucrose included in the initial formulation, as this influenced the porous microstructure of the pellets. In halloysite-based products the release was further extended due to entrapment of the drug within the halloysite microtubules. Porous kaolin-based pellets were also prepared by cryopelletization. This involved freezing droplets of an aqueous suspension containing kaolin, sodium silicate solution and sodium lauryl sulphate. The resulting pellets were freeze-dried, which removed ice from them to leave pores behind. The pellets gave extended drug release with the release rate being influenced by the porous microstructure of the pellets and their microclimate pH.

  6. Calcium phosphate precipitation modeling in a pellet reactor

    OpenAIRE

    Montastruc, Ludovic; Azzaro-Pantel, Catherine; Cabassud, Michel; Biscans, Béatrice

    2002-01-01

    The calcium phosphate precipitation in a pellet reactor can be evaluated by two main parameters: the phosphate conversion ratio and the phosphate removal efficiency. The conversion ratio depends mainly on the pH. The pellet reactor efficiency depends not only on pH but also on the hydrodynamical conditions. An efficiency model based on a thermochemical precipitation approach and an orthokinetic aggregation model is presented. In this paper, the results show that optimal conditions for pellet ...

  7. Sintering of wax for controlling release from pellets.

    Science.gov (United States)

    Singh, Reena; Poddar, S S; Chivate, Amit

    2007-09-14

    The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100 degrees C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

  8. Microstructure of Bentonite in Iron Ore Green Pellets

    OpenAIRE

    Bhuiyan, Iftekhar U.; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P.E.; Hedlund, Jonas

    2017-01-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam ...

  9. Standard specification for nuclear-grade aluminum oxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification applies to pellets of aluminum oxide that may be ultimately used in a reactor core, for example, as filler or spacers within fuel, burnable poison, or control rods. In order to distinguish between the subject pellets and “burnable poison” pellets, it is established that the subject pellets are not intended to be used as neutron-absorbing material. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

  10. Solid phase extraction and metabolic profiling of exudates from living copepods

    DEFF Research Database (Denmark)

    Selander, Erik; Heuschele, Jan; Nylund, Göran M.

    2016-01-01

    Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding or induce defensive traits in prey organisms. However, little is known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we...... describe the development of a closed loop solid phase extraction setup that allows for extraction of exuded metabolites from live copepods. We captured exudates from male and female Temora longicornis and analyzed the content with high resolution LC-MS. Chemometric methods revealed 87 compounds...... that constitute a specific chemical pattern either qualitatively or quantitatively indicating copepod presence. The majority of the compounds were present in both female and male exudates, but nine compounds were mainly or exclusively present in female exudates and hence potential pheromone candidates...

  11. Composition and physical state of phospholipids in calanoid copepods from India and Norway

    Digital Repository Service at National Institute of Oceanography (India)

    Farkas, T.; Storebakken, T.; Bhosle, N.B.

    the adaptation of membrane lipids with seawater temperatures Phospholipid vesicles obtained from the tropic copepods proved more rigid than those from C finmarchicus, as assessed by diphenylhexatriene fluorescence polarization techniques In each case, there were...

  12. Toxicity of selected pesticides to the groundwater copepod Parastenocaris germanica (Crustacea)

    NARCIS (Netherlands)

    Notenboom J; Boessenkool JJ; ECO

    1994-01-01

    De toxiciteit van negen verschillende bestrijdingsmiddelen of afbraakproducten voor de grondwater copepod Parstenocaris germanica is onderzocht. De onderzochte stoffen zijn geselecteerd vanwege hun potentieel gevaar voor grondwater bewonende metazoen. Niet alle experimenten lieten een duidelijke

  13. Coexistence and succession of copepod species in the Mandovi and Zuari estuaries, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    correlated or associated either over space or time. The pattern of copepod succession based on species dominance revealed three main types with successional sequence of high saline species (greater than 30 ppt), low saline species (greater than 5 ppt...

  14. Studies of community structure and seasonal dynamics of planktonic copepods in saline-alkaline ponds

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen; DONG Shuanglin

    2005-01-01

    Species abundance and seasonal succession of copepods in aline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8-9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taihokuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds. ponds.

  15. Eradication of Aedes aegypti from a village in Vietnam, using copepods and community participation

    National Research Council Canada - National Science Library

    Vu, SN; Nguyen, TY; Kay, BH; Marten, GG; Reid, JW

    1998-01-01

    In northern Vietnam, copepods of the genus Mesocyclops were used for biological control of Aedes aegypti, the principal vector of dengue viruses, by inoculation into wells, large cement tanks, ceramic...

  16. Sex Conversion Induced by Hydrostatic Pressure in the Marine Copepod Tigriopus californicus.

    Science.gov (United States)

    Vacquier, V D; Belser, W L

    1965-12-17

    High hydrostatic pressure applied to the naupliar larval stages of the marine copepod Tigriopus californicus converts some individuals that would have become males into females. The copepodid stages are not sensitive to pressureinduced conversion.

  17. SWIMMING BEHAVIOR OF DEVELOPMENTAL STAGES OF THE CALANOID COPEPOD TEMORA-LONGICORNIS AT DIFFERENT FOOD CONCENTRATIONS

    NARCIS (Netherlands)

    VANDUREN, LA; VIDELER, JJ

    1995-01-01

    The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food

  18. Recent advances within intensive Recirculated Aquaculture System cultivation of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Højgaard, Jacob Kring; Drillet, Guillaume;

    2014-01-01

    Danish aquaculture has within recent years focused upon rearing of new marine fish species. A major challenge for rearing of marine fish species is relevant diets for their fish larvae. Copepods and their larvae stage “nauplii” are well documented as the ideal live feed for a variety of marine...... and the nauplii can be feed to marine fish larvae. A restriction is that copepod cultures for producing eggs are after 30 years of research still not stable and in large enough scale for bulk production of eggs. Recently a unique copepod Recirculated Aquaculture System (RAS) at Roskilde University (Denmark......) was constructed as a part of the IMPAQ project “IMProvement of AQuaculture high quality fish fry production”. We present recent advance within RAS culture for copepods, and lesson learned from rearing the specie. Further we present physical and biological culture restrictions in terms of water quality (NH3...

  19. Free-living copepods of the Arabian Sea: Distributions and research perspectives

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.

    11500 known species in this subclass. This paper briefly outlines the distribution, abundances and general feeding habitats of free-living copepods from the Arabian Sea. The role of taxonomy in biodiversity studies, estimates of grazing and production...

  20. On the occurrence of endoparasites from copepods of the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    Occurrence of endoparasitic dinoflagellates belonging to the genera, Blastodinium, parasitizing the coelomic cavity of their host, copepods was investigated. Infection by these species seems to be harmful to the host. Parasitized individuals showed...

  1. First evidence of tumor-like anomaly infestation in Copepods from the central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Bhandare, C.; Ingole, B.S.

    attack, especially to ectoparasites like Ellobiopsis sp. These ectoparasites attack the host and feed on their body fluids which may lead to the death of the host. This study emphasis the consequences of parasitic infection in dominant planktonic copepods...

  2. Motility of copepod nauplii and implications for food encounter

    DEFF Research Database (Denmark)

    Titelman, Josefin; Kiørboe, Thomas

    2003-01-01

    Velocity differences drive all encounter processes. Therefore, knowledge of both prey and predator motility are essential in order to understand feeding behavior and predict food acquisition rates. Here, we describe and quantify the motility behavior of young and old naupliar stages of 6 copepods...... of tracks, speeds, durations and frequencies of events as well as time budgets. Motility mode often changes drastically during naupliar ontogeny. Crudely, nauplii can be divided into those moving with a jump-sink type of motility of various frequencies (1 min(-1) to 3 s(-1)) and those swimming...... with a smoother glide of varying continuity. We apply observed time budgets and behavior-specific speeds in simple models to examine mechanisms of food encounter. The motility of all nauplii may account for clearance rates reported in the literature, but through different mechanisms. Smoothly swimming nauphi...

  3. Magnetic light cloaking control in the marine planktonic copepod Sapphirina

    Science.gov (United States)

    Kashiwagi, H.; Mizukawa, Y.; Iwasaka, M.; Ohtsuka, S.

    2017-05-01

    We investigated the light cloaking behavior of the marine planktonic copepod Sapphirina under a magnetic field. Optical interferences in the multi-laminated guanine crystal layer beneath the dorsal body surface create a brilliant structural color, which can be almost entirely removed by changing the light reflection. In the investigation, we immersed segments of Sapphirina in seawater contained in an optical chamber. When the derived Sapphirina segments were attached to the container surface, they were inert to magnetic fields up to 300 mT. However, when the back plate segments were attached to the substrate at a point, with most of the plate floating in the seawater, the plate rotated oppositely to the applied magnetic field. In addition, the brilliant parts of the Sapphirina back plate rotated backward and forward by changing the magnetic field directions. Our experiment suggests a new model of an optical micro-electro-mechanical system that is controllable by magnetic fields.

  4. Heritability of sex tendency in a harpacticoid copepod, Tigriopus californicus.

    Science.gov (United States)

    Voordouw, Maarten J; Anholt, Bradley R

    2002-09-01

    Systems with genetic variation for the primary sex ratio are important for testing sex-ratio theory and for understanding how this variation is maintained. Evidence is presented for heritable variation of the primary sex ratio in the harpacticoid copepod Tigriopus californicus. Variation in the primary sex ratio among families cannot be accounted for by Mendelian segregation of sex chromosomes. The covariance in sex phenotype between full-sibling clutches and between mothers and offspring suggests that this variation has a polygenic basis. Averaged over four replicates, the full-sibling heritability of sex tendency is 0.13 +/- 0.040; and the mother-offspring heritability of sex tendency is 0.31 +/- 0.216. Genetic correlations in the sex phenotype across two temperature treatments indicate large genotype-by-temperature interactions. Future experiments need to distinguish between zygotic, parental, or cytoplasmic mechanisms of sex determination in T. californicus.

  5. Optimal swimming strategies in mate searching pelagic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2008-01-01

    Male copepods must swim to find females, but swimming increases the risk of meeting predators and is expensive in terms of energy expenditure. Here I address the trade-offs between gains and risks and the question of how much and how fast to swim using simple models that optimise the number...... of lifetime mate encounters. Radically different swimming strategies are predicted for different feeding behaviours, and these predictions are tested experimentally using representative species. In general, male swimming speeds and the difference in swimming speeds between the genders are predicted...... and observed to increase with increasing conflict between mate searching and feeding. It is high in ambush feeders, where searching (swimming) and feeding are mutually exclusive and low in species, where the matured males do not feed at all. Ambush feeding males alternate between stationary ambush feeding...

  6. The kinematics of swimming and relocation jumps in copepod nauplii.

    Directory of Open Access Journals (Sweden)

    Christian Marc Andersen Borg

    Full Text Available Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella, and copepodites are equipped with highly specialized swimming legs. In some species the nauplius may also propel itself more slowly through the water by beating and rotating the appendages in a different, more complex pattern. We use high-speed video to describe jumping and swimming in nauplii of three species of pelagic copepods: Temora longicornis, Oithona davisae and Acartia tonsa. The kinematics of jumping is similar between the three species. Jumps result in a very erratic translation with no phase of passive coasting and the nauplii move backwards during recovery strokes. This is due to poorly synchronized recovery strokes and a low beat frequency relative to the coasting time scale. For the same reason, the propulsion efficiency of the nauplii is low. Given the universality of the nauplius body plan, it is surprising that they seem to be inefficient when jumping, which is different from the very efficient larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when feeding, which results in a higher feeding efficiency than that of a nauplius cruising through the water.

  7. Propulsion and perception in intermediate Re regimes: aquatic microcrustacean copepod responses to wake structures.

    Science.gov (United States)

    Yen, J.; Pender Healy, L. A.; Heaphy, M.

    2016-02-01

    Flow sensing by the mechanoreceptive cuticular arrays of sensors on copepods has been shaped by over 400 million years of evolution and plays an important role in predator avoidance, foraging, mating, and rheotaxis. These 3D wakes are produced by animal propulsive activities and contain cues that guide these key survival responses. We have demonstrated that the fluid mechanical and chemical information retained in the hydrodynamic envelope can be interpreted by suitable sensor arrays; copepod sensor arrays are capable of perceiving minute differences in wake structures. Temora longicornis, a coastal marine copepod, and Hesperodiaptomus shoshone, a high-alpine freshwater lake copepod, track laminar trails. High-speed videography coupled with high-magnification Schlieren optics enabled us to visualize the deformation of the trail signal and the propulsive movements of the male copepod. Males followed the trail mimic and our observations show clear differences between the marine and freshwater species. Comparative analyses reveal tracking mechanisms that differ in sensor location with respect to the trail and locomotory kinematics. Copepods perform directed motions that lead them to a stimulus source in the absence of other collimating stimuli. Tracking by the copepod around the trail allows it to have one or numerous sensors inside and outside the trail to facilitate edge detection using spatial sampling. The advantage of this remarkable behavior of following trails fast and accurately is to encounter mates or food patches more frequently, thus contributing to population recruitment and energy transfer up the trophic food web. Precise mate and food finding strategies found for pelagic copepods may be a key adaptation, promoting survival in these open-ocean planktonic populations.

  8. Biofeedback therapy for fecal incontinence.

    Science.gov (United States)

    Goldenberg, D A; Hodges, K; Hershe, T; Jinich, H

    1980-10-01

    Operant conditioning offers a new therapeutic modality for fecal incontinence. Our experience with biofeedback therapy in six male and six female patients (ages 12-78 years) is presented. Incontinence was associated with a surgical procedure in six patients and with a medical condition in six patients. Rectosphincteric manometry was performed using a three balloon technic, with one balloon positioned in the rectum as a distending stimulus and the others at the internal and external sphinchters. Pressure responses to measured volumes of rectal distention were displayed on a polygraph. Rectosphincteric reflexes and sensory thresholds for rectal distention were determined. Patients were then encouraged to elevate sphinchter pressures while observing their manometric responses. Follow-up of 10-96 weeks showed ten patients had good responses, with complete continence in six patients. Nine of 10 responders required only one treatment session. Operant conditioning is a valuable technic in properly selected patients with an 80% probability of success.

  9. Comparison of Ontology Reasoners: Racer, Pellet, Fact++

    Science.gov (United States)

    Huang, T.; Li, W.; Yang, C.

    2008-12-01

    In this paper, we examine some key aspects of three of the most popular and effective Semantic reasoning engines that have been developed: Pellet, RACER, and Fact++. While these reasonably advanced reasoners share some notable similarities, it is ultimately the creativity and unique nature of these reasoning engines that have resulted in the successes of each of these reasoners. Of the numerous dissimilarities, the most obvious example might be that while Pellet is written in Java, RACER employs the Lisp programming language and Fact++ was developed using C++. From this and many other distinctions in the system architecture, we can understand the benefits of each reasoner and potentially discover certain properties that may contribute to development of an optimal reasoner in the future. The objective of this paper is to establish a solid comparison of the reasoning engines based on their system architectures, features, and overall performances in real world application. In the end, we expect to produce a valid conclusion about the advantages and problems in each reasoner. While there may not be a decisive first place among the three reasoners, the evaluation will also provide some answers as to which of these current reasoning tools will be most effective in common, practical situations.

  10. Antibiotic-induced change of bacterial communities associated with the copepod Nitocra spinipes.

    Directory of Open Access Journals (Sweden)

    Anna Edlund

    Full Text Available Environmental pressures, such as physical factors, diet and contaminants may affect interactions between microbial symbionts and their multicellular hosts. Despite obvious relevance, effects of antimicrobial contaminants on host-symbiont relations in non-target aquatic organisms are largely unknown. We show that exposure to antibiotics had negative effects on survival and juvenile development of the copepod Nitocra spinipes and caused significant alterations in copepod-associated bacterial communities. The significant positive correlations between indices of copepod development and bacterial diversity indicate that disruption of the microflora was likely to be an important factor behind retarded juvenile development in the experimental animals. Moreover, as evidenced by ribotype distribution in the bacterial clone libraries, the exposure to antibiotics caused a shift in dominance from Betaproteobacteria to Cardinium bacteria; the latter have been shown to cause reproductive manipulations in various terrestrial arthropods. Thus, in addition to providing evidence that the antibiotic-induced perturbation of the microbial community associates with reductions in fitness-related traits of the host, this study is the first record of a copepod serving as a host for endosymbiotic Cardinium. Taken together, our results suggest that (1 antimicrobial substances and possibly other stressors can affect micobiome and symbiont-mediated interactions in copepods and other hosts, and (2 Cardinium endosymbionts may occur in other copepods and affect reproduction of their hosts.

  11. Effects of UV radiation on the RNA/DNA ratio of Copepods from Antarctica and Chile

    Institute of Scientific and Technical Information of China (English)

    Paulo F. Lagos; M. Jesús Valdés; Karen Manríquez

    2015-01-01

    The effect of ultraviolet (UV) radiation on marine organisms has been an important focus of recent research, with depletion of the ozone layer resulting in increased UV radiation at high latitudes. Several studies have identiifed negative impacts of UV radiation on the biology of zooplanktonic organisms. This study used the RNA/DNA ratio as a measure of stress in copepod assemblages from Fíldes Bay in Antarctica and Quintay Bay on the central coast of Chile, two areas with high UV radiation but different photobiologic histories. Controlled time-light experiments were performed with copepods from the two locations, exposing them to white light, UV light, or darkness. The results showed different responses to UV radiation. Copepods from Fíldes Bay showed a slow metabolic response to UV radiation after 4 and 8 h of exposure. Copepods from Quintay Bay showed a fast metabolic response after 4 h of exposure (4 orders of magnitude higher than that for Fíldes Bay copepods) followed by a rapid return toward baseline after 8 h of exposure. These different responses probably relfect the time the copepod assemblages have been exposed to increased UV radiation and the extent of adaptive stress responses to cope with that increased UV radiation. The results of this study show that the RNA/DNA ratio is a useful indicator of the physiologic status of marine organisms and is a useful tool to measure the effects of changing environmental conditions on marine ecosystems, such as those associated with global climate change.

  12. Alternative Methods for Marine Harpacticoid Copepod, Macrosetella gracilis Production in Marine Fish Larviculture

    Directory of Open Access Journals (Sweden)

    N. Jeyaraj

    2014-01-01

    Full Text Available Sustainable aquaculture depends upon eco-friendly, economically and socially viable culture systems. The recycling of organic wastes for plankton culture serves the dual purpose of cleaning the environment and providing economic benefits. There has been no experimentation to measure the effect of organic manure for the aquaculture of copepods, it may be reduced time and labor cost. Hence, the present experiment was conducted to evaluate the mass culture feasibility of Harpacticoid copepod, Macrosetella gracilis using a different organic manures viz., cow dung, poultry manure, goat manure and mixture of these three (1:1:1 ratio at 500 g for each tank manures were decomposed for twelve days before the inoculation of copepod. Twenty adult copepod M. gracilis were inoculated. The peak density was found on 10-14th day of at all doses, among these four doses, significantly higher numbers of organisms 4213.33±213.48 ind. L-1 were found in the cow dung followed by the poultry manure, goat manure and mixed doses 2350.66±148.20; 1573.60±121.41; 995±102, respectively. The number of organisms was ground very low in mixed doses than other doses. Water quality analyses of culture system was no significantly different among the treatments especially pH and salinity. Cow dung manure is therefore recommended for quick and high production of copepod, M. gracilis which invariably reduces the high cost of expensive algae feed for copepod.

  13. High-quality RNA extraction from copepods for Next Generation Sequencing: A comparative study.

    Science.gov (United States)

    Asai, Sneha; Ianora, Adrianna; Lauritano, Chiara; Lindeque, Penelope K; Carotenuto, Ylenia

    2015-12-01

    Despite the ecological importance of copepods, few Next Generation Sequencing studies (NGS) have been performed on small crustaceans, and a standard method for RNA extraction is lacking. In this study, we compared three commonly-used methods: TRIzol®, Aurum Total RNA Mini Kit and Qiagen RNeasy Micro Kit, in combination with preservation reagents TRIzol® or RNAlater®, to obtain high-quality and quantity of RNA from copepods for NGS. Total RNA was extracted from the copepods Calanus helgolandicus, Centropages typicus and Temora stylifera and its quantity and quality were evaluated using NanoDrop, agarose gel electrophoresis and Agilent Bioanalyzer. Our results demonstrate that preservation of copepods in RNAlater® and extraction with Qiagen RNeasy Micro Kit were the optimal isolation method for high-quality and quantity of RNA for NGS studies of C. helgolandicus. Intriguingly, C. helgolandicus 28S rRNA is formed by two subunits that separate after heat-denaturation and migrate along with 18S rRNA. This unique property of protostome RNA has never been reported in copepods. Overall, our comparative study on RNA extraction protocols will help increase gene expression studies on copepods using high-throughput applications, such as RNA-Seq and microarrays. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. A Lagrangian model of Copepod dynamics: clustering by escape jumps in turbulence

    CERN Document Server

    Ardeshiri, Hamidreza; Schmitt, François G; Souissi, Sami; Toschi, Federico; Calzavarini, Enrico

    2016-01-01

    Planktonic copepods are small crustaceans that have the ability to swim by quick powerful jumps. Such an aptness is used to escape from high shear regions, which may be caused either by flow per- turbations, produced by a large predator (i.e. fish larvae), or by the inherent highly turbulent dynamics of the ocean. Through a combined experimental and numerical study, we investigate the impact of jumping behaviour on the small-scale patchiness of copepods in a turbulent environment. Recorded velocity tracks of copepods displaying escape response jumps in still water are here used to define and tune a Lagrangian Copepod (LC) model. The model is further employed to simulate the behaviour of thousands of copepods in a fully developed hydrodynamic turbulent flow obtained by direct numerical simulation of the Navier-Stokes equations. First, we show that the LC velocity statistics is in qualitative agreement with available experimental observations of copepods in tur- bulence. Second, we quantify the clustering of LC...

  15. Observation on Marine Copepod - Appendicularian Naturally Changing Concentrations Along Southwest Coast of India

    Directory of Open Access Journals (Sweden)

    Jean J. JOSE

    2012-11-01

    Full Text Available Patterns of copepod - appendicularian distribution were studied along the Mangalore coastal waters (12�50�49� N; 74�48�50� E of the Arabian Sea to understand the food and feeding relationship existing among these groups. Sampling was conducted during pre-monsoon, monsoon and post-monsoon extending from January 2009 to December 2010. The copepod and appendicularian community was sampled with a 60 ?m net to include the smallest species and their developmental stages. Copepod biomass, especially calanoids, was substantially high throughout the study. Seasonal mean results showed that the small-sized copepods (calanoids, harpacticoida and cyclopoids dominated in terms of biomass and production. Calanoids found in abundance included Acartia, Centropages, Calanus, Eucalanus and Labidocera. Cyclopoid and Harpacticoid copepods genera dominated included Oithona, Oncaea and Microsetella, Macrosetella. Appendicularian species diversity was represented by Oikopleura fusiformis, O. dioica and its juveniles represented as Oikopleura sp. Total chlorophyll (chlorophyll a ranging between 10 and 20 mg m-3 indicated the eutrophic state as well as productivity prevailing during the study period. Principal component analysis (PCA indicated the routine and opportunistic seasonal grazers and establishes a phytoplankton - appendicularia - copepod - fish food chain relationship along Mangalore coast.

  16. Observation on Marine Copepod - Appendicularian Naturally Changing Concentrations Along Southwest Coast of India

    Directory of Open Access Journals (Sweden)

    Jean J. JOSE

    2012-11-01

    Full Text Available Patterns of copepod - appendicularian distribution were studied along the Mangalore coastal waters (125049 N; 744850 E of the Arabian Sea to understand the food and feeding relationship existing among these groups. Sampling was conducted during pre-monsoon, monsoon and post-monsoon extending from January 2009 to December 2010. The copepod and appendicularian community was sampled with a 60 ?m net to include the smallest species and their developmental stages. Copepod biomass, especially calanoids, was substantially high throughout the study. Seasonal mean results showed that the small-sized copepods (calanoids, harpacticoida and cyclopoids dominated in terms of biomass and production. Calanoids found in abundance included Acartia, Centropages, Calanus, Eucalanus and Labidocera. Cyclopoid and Harpacticoid copepods genera dominated included Oithona, Oncaea and Microsetella, Macrosetella. Appendicularian species diversity was represented by Oikopleura fusiformis, O. dioica and its juveniles represented as Oikopleura sp. Total chlorophyll (chlorophyll a ranging between 10 and 20 mg m-3 indicated the eutrophic state as well as productivity prevailing during the study period. Principal component analysis (PCA indicated the routine and opportunistic seasonal grazers and establishes a phytoplankton - appendicularia - copepod - fish food chain relationship along Mangalore coast.

  17. Fuel pellets from biomass - Processing, bonding, raw materials

    Energy Technology Data Exchange (ETDEWEB)

    Stelte, W.

    2011-12-15

    The present study investigates several important aspects of biomass pelletization. Seven individual studies have been conducted and linked together, in order to push forward the research frontier of biomass pelletization processes. The first study was to investigate influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding mechanisms within a biomass pellet, which indicate that different mechanisms are involved depending on biomass type and pelletizing conditions. Interpenetration of polymer chains and close intermolecular distance resulting in better secondary bonding were assumed to be the key factors for high mechanical properties of the formed pellets. The outcome of this study resulted in study four and five investigating the role of lignin glass transition for biomass pelletization. It was demonstrated that the softening temperature of lignin was dependent on species and moisture content. In typical processing conditions and at 8% (wt) moisture content, transitions were identified to be at approximately 53-63 deg. C for wheat straw and about 91 deg. C for spruce lignin. Furthermore, the effects of wheat straw extractives on the pelletizing properties and pellet stability were investigated. The sixth and seventh study applied the developed methodology to test the pelletizing properties of thermally pre-treated (torrefied) biomass from spruce and wheat straw. The results indicated that high torrefaction temperatures above 275 deg

  18. Moving fecal microbiota transplantation into the mainstream.

    Science.gov (United States)

    Orenstein, Robert; Griesbach, Cheryl L; DiBaise, John K

    2013-10-01

    In recent years, fecal microbiota transplantation (aka fecal transplantation, fecal bacteriotherapy, FMT) has become increasing utilized to treat recurrent and refractory Clostridium difficile infection (CDI). Almost 600,000 cases of CDI occur each year in the United States. Of these, an estimated 15,000 patients have a recurrence. The management of recurrent disease has been challenging for patients and clinicians. Increasingly, FMT has been recognized as an effective option for these patients. This article explores why FMT has reemerged as a practical therapeutic modality. In the process, the logistics by which the procedure is performed and the factors that may affect quality, safety, and patient outcomes will be described.

  19. Investigation Characteristics of Uranium Pellets from Different Reactor Types

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Yan; ZHU; Liu-chao; ZHAO; Xing-hong; JIANG; Xiao-yan; WANG; Tong-xing; ZHAO; Yong-gang

    2015-01-01

    Investigation of nuclear material properties is crucial to attribute the nuclear material.Pellets are targeted products in the nuclear fuel cycle and are among the most important materials in nuclear forensics.In this paper,nuclear material properties were obtained in three UO2 pellets samples which

  20. Ablation of Hydrogen Pellets in Hydrogen and Helium Plasmas

    DEFF Research Database (Denmark)

    Jørgensen, L W; Sillesen, Alfred Hegaard; Øster, Flemming

    1975-01-01

    Measurements on the interaction between solid hydrogen pellets and rotating plasmas are reported. The investigations were carried out because of the possibility of refuelling fusion reactors by the injection of pellets. The ablation rate found is higher than expected on the basis of a theory...

  1. Fuel Pellets from Biomass. Processing, Bonding, Raw Materials

    DEFF Research Database (Denmark)

    Stelte, Wolfgang

    in an increasing interest in biomass densification technologies, such as pelletization and briquetting. The global pellet market has developed quickly, and strong growth is to be expected for the coming years. Due to an increasing demand for biomass, the traditionally used wood residues from sawmills and pulp...

  2. Wood pellet market and trade: A global perspective

    NARCIS (Netherlands)

    Goh, C.S.; Cocchi, M.; Junginger, H.M.; Marchal, D.; Thrän, D.; Hennig, C.; Heinimo, J.; Nikolaisen, L.; Schouwenberg, P.P.; Bradley, D.; Hess, R.F.; Jacobson, J.; Ovard, L.; Deutmeyer, M.

    2013-01-01

    This perspective provides an overview of wood pellet markets in a number of countries of high signifi cance, together with an inventory of market factors and relevant past or existing policies. In 2010, the estimated global wood pellet production and consumption were close to 14.3 Mt (million metric

  3. Wood pellet market and trade: A global perspective

    NARCIS (Netherlands)

    Goh, C.S.; Cocchi, M.; Junginger, H.M.; Marchal, D.; Thrän, D.; Hennig, C.; Heinimo, J.; Nikolaisen, L.; Schouwenberg, P.P.; Bradley, D.; Hess, R.F.; Jacobson, J.; Ovard, L.; Deutmeyer, M.

    2013-01-01

    This perspective provides an overview of wood pellet markets in a number of countries of high signifi cance, together with an inventory of market factors and relevant past or existing policies. In 2010, the estimated global wood pellet production and consumption were close to 14.3 Mt (million

  4. Quality of Pelleted Olive Cake for Energy Generation

    Directory of Open Access Journals (Sweden)

    Radmilo Čolović

    2012-03-01

    Full Text Available Olive cake is by-product of olive oil production. This material cannot be stored in original condition for a long time because it has high water content and relatively high portion of oil that causes rapid deterioration. Thus it is necessary to investigate possible methods of remediation of such by-product, where utilization for energy generation presents a useful option. Several studies have been conducted on energy generation from olive cake, however not one that includes pelleting as a pre-treatment. Therefore, the aim of this paper was to determine the chemical composition of different cultivars of olive cake, to produce pellets, and determine their basic quality parameters. The pellets obtained from olive cake had mainly satisfactory results regarding their quality in comparison to standards for fuel pellets. It should be kept in mind that these standards are manly for wood pellets, and therefore some lower criteria could be applied for olive cake and such biomass. The highest amount of residual oil and the lowest amount of protein was found in cultivar ‘Buža’ and produced pellets had the smallest abrasion index (8.15%. Other cultivars had lower oil and higher protein content, and abrasion index higher than 10%. For these cultivars preparation of material (conditioning and/or binder adding prior to pelleting is necessary. Higher heating value (HHV and lower heating value (LHV were not significantly influenced by different chemical composition of cultivars, thus attention should be paid on their influence on pelleting process.

  5. FIBRE FLAX PREPLANT TREATMENT BASED ON SEED PELLETING AND ELECTROTECHNICS

    Directory of Open Access Journals (Sweden)

    Spiridonov A. B.

    2013-10-01

    Full Text Available The method of fibre flax preplant seed treatment that includes pelleting in bionanosuspension and influence of electrophysical fields on the pellet is described in the article. Due to given treatment technology it is possible to increase the crop capacity and engineering performance of the flax production

  6. Wood pellet market and trade: A global perspective

    NARCIS (Netherlands)

    Goh, C.S.; Cocchi, M.; Junginger, H.M.; Marchal, D.; Thrän, D.; Hennig, C.; Heinimo, J.; Nikolaisen, L.; Schouwenberg, P.P.; Bradley, D.; Hess, R.F.; Jacobson, J.; Ovard, L.; Deutmeyer, M.

    2013-01-01

    This perspective provides an overview of wood pellet markets in a number of countries of high signifi cance, together with an inventory of market factors and relevant past or existing policies. In 2010, the estimated global wood pellet production and consumption were close to 14.3 Mt (million metric

  7. Development of A Revolving Die and Roller Fish Feed Pelletizer

    Directory of Open Access Journals (Sweden)

    Theresa K. Kaankuka

    2013-02-01

    Full Text Available A revolving die and roller type pelletizing machine was designed and constructed to produce fish feed pellets for small scale fish farmers. The major components of the pelletizer were the hopper, rollers, a flat die, shaft, discharge tray, frame, V-belt, V-pulley and electric motor. These components were designed based on strength and rigidity. An electric motor drives the die by a shaft connected to its pulley. The rotation of the die initiates the rotation of the rollers which pick up the feed material and compress it into the die holes to form pellets. The pelletizing machine was tested at two speed levels of 507 and 761 rpm and at three moisture content (MC levels (wet basis of 20, 25 and 30�20At 30�0MC, highest pellet output of 34.3 kg/hr and 40.4 kg/hr were obtained for die speeds of 507 and 761 rpm respectively. Higher pellet output obtained from die speed of 761 rpm could be as a result of the production of higher heat which resulted in proper gelatinization of the carbohydrate in the compounded feed. The gelatinized starch acts as a binding agent and this reduces crumbling during pelleting. The small and medium scale fish farmer can operate the machine because of its simplicity and this will alleviate the problem of sourcing for imported fish feed.

  8. Pellet Enhanced Performance on the HL-2A Tokamak

    Institute of Scientific and Technical Information of China (English)

    DING Xuan-Tong; LIU Yi; ZHOU Yan; PAN Yu-Dong; CUI Zheng-Ying; HUANG Yuan; LIU Ze-Tian; SHI Zhong-Bing; JI Xiao-Quan; XIAO Wei-Wen; LIU Yong; YANG Qing-Wei; YAN Long-Wen; ZHU Gen-Liang; XIAO Zheng-Gui; LIU De-Quan; CAO Zeng; GAO Qing-Di; LONG Yong-Xing

    2006-01-01

    @@ Enhanced confinement has been achieved by the centre fuelling of pellet injection on the HL-2A tokamak. The energy confinement time increases from 50ms to 140ms after the pellet injection. Experimental results show that the improvement of the confinement is related to the decrease of the electron heat transport.

  9. Paraformaldehyde pellet not necessary in vacuum-pumped maple sap system

    Science.gov (United States)

    H. Clay Smith; Carter B. Gibbs

    1970-01-01

    In a study of sugar maple sap collection through a vacuum-pumped plastic tubing system, yields were compared between tapholes in which paraformaldehyde pellets were used and tapholes without pellets, Use of the pellets did not increase yield.

  10. Response of marine copepods to a changing tropical environment: winners, losers and implications.

    Science.gov (United States)

    Chew, Li Lee; Chong, Ving Ching

    2016-01-01

    Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985-86 and 2014-15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica). Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons) were unaffected. Centropages

  11. Response of marine copepods to a changing tropical environment: winners, losers and implications

    Directory of Open Access Journals (Sweden)

    Li Lee Chew

    2016-05-01

    Full Text Available Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15 interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI design. Copepods were identified to species, and results were interpreted by univariate (ANOVA and multivariate (PERMANOVA, PCO analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica. Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons were unaffected

  12. 21 CFR 866.5180 - Fecal calprotectin immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fecal calprotectin immunological test system. 866....5180 Fecal calprotectin immunological test system. (a) Identification. A fecal calprotectin... measure, by immunochemical techniques, fecal calprotectin in human stool specimens. The device is...

  13. In vivo evaluation of matrix pellets containing nanocrystalline ketoprofen.

    Science.gov (United States)

    Vergote, G J; Vervaet, C; Van Driessche, I; Hoste, S; De Smedt, S; Demeester, J; Jain, R A; Ruddy, S; Remon, J P

    2002-06-20

    The aim of this study was to evaluate the in-vivo behaviour of matrix pellets formulated with nanocrystalline ketoprofen after oral administration to dogs. No significant differences in AUC-values were seen between pellet formulations containing nanocrystalline or microcrystalline ketoprofen and a commercial ketoprofen formulation (reference: Rofenid 200 Long Acting). C(max) of the formulations containing nano- or microcrystalline ketoprofen was significantly higher compared to reference, whereas t(max) was significantly lower. The in-vivo burst release observed for the spray dried nanocrystalline ketoprofen matrix pellets was reduced following compression of the pellets in combination with placebo wax/starch pellets. These matrix tablets sustained the ketoprofen plasma concentrations during 5.6 and 5.4 h for formulations containing nano- and microcrystalline ketoprofen, respectively.

  14. ["Piggyback" shot: ballistic parameters of two simultaneously discharged airgun pellets].

    Science.gov (United States)

    Frank, Matthias; Schönekess, Holger C; Grossjohann, Rico; Ekkernkamp, Axel; Bockholdt, Britta

    2014-01-01

    Green and Good reported an uncommon case of homicide committed with an air rifle in 1982 (Am. J. Forensic Med. Pathol. 3: 361-365). The fatal wound was unusual in that two airgun pellets were loaded in so-called "piggyback" fashion into a single shot air rifle. Lack of further information on the ballistic characteristics of two airgun pellets as opposed to one conventionally loaded projectile led to this investigation. The mean kinetic energy (E) of the two pellets discharged in "piggyback" fashion was E = 3.6 J and E = 3.4 J, respectively. In comparison, average kinetic energy values of E = 12.5 J were calculated for conventionally discharged single diabolo pellets. Test shots into ballistic soap confirmed the findings of a single entrance wound as reported by Green and Good. While the ballistic background of pellets discharged in "piggyback" fashion could be clarified, the reason behind this mode of shooting remains unclear.

  15. Modeling of biofuel pellets torrefaction in a realistic geometry

    Directory of Open Access Journals (Sweden)

    Artiukhina Ekaterina

    2016-01-01

    Full Text Available Low temperature pyrolysis also known as torrefaction is considered as a promising pretreatment technology for conversion of biomass into a solid biofuel with enhanced properties in terms of lower moisture and volatile matter content, hydrophobicity and increased heating value. A thermal treatment leads to a non-uniform temperature field and chemical reactions proceeding unevenly within the pellets. However the temperature is assumed to be uniform in the pellets in the majority of models. Here we report on the model of single pellet biomass torrefaction, taking into account the heat transfer and chemical kinetics in the realistic geometry. The evolution of temperature and material density in the non-stationary thermo-chemical process is described by the system of non-linear partial differential equations. The model describing the high-temperature drying of biomass pellet was also introduced. The importance of boundary effects in realistic simulations of biomass pellets torrefaction is underlined in this work.

  16. Fabrication of very high density fuel pellets of thorium dioxide

    Science.gov (United States)

    Shiratori, Tetsuo; Fukuda, Kosaku

    1993-06-01

    Very high density ThO 2 pellets were prepared without binders and lubricants from the ThO 2 powder originated by the thorium oxalate, which was aimed to simplify the fabrication process by skipping a preheat treatment. The as-received ThO 2 powder with a surface area of 4.56 m 2/g was ball-milled up to about 9 m 2/g in order to increase the green pellet density as high as possible. Both of the single-sided and the double-sided pressing were tested in the range from 2 to 5 t/cm 2 in the green pellet formation. Sintering temperature was such low as 1550°C. The pellet prepared in this experiment had a very high density in the range from about 96 to 98% TD without any cracks, in which a difference of the pellet density was not recognized in the single-sided pressing methods.

  17. Analysis of pellet properties with use of artificial neural networks.

    Science.gov (United States)

    Mendyk, Aleksander; Kleinebudde, Peter; Thommes, Markus; Yoo, Angelina; Szlęk, Jakub; Jachowicz, Renata

    2010-11-20

    The objective was to prepare neural models identifying relationships between formulation characteristics and pellet properties based on algorithmic approach of crucial variables selection and neuro-fuzzy systems application. The database consisted of information about 227 pellet formulations prepared by extrusion/spheronization method, with various model drugs and excipients. Cheminformatic description of excipients and model drugs was employed for numerical description of pellet formulations. Initial numbers of neural model inputs were up to around 3000. The inputs reduction procedure based on sensitivity analysis allowed to obtain less than 40 inputs for each model. The reduced models were subjects of fuzzy logic implementation resulting in logical rules tables providing human-readable rule sets applicable in future development of pellet formulations. Neural modeling enhanced knowledge about pelletization process and provided means for future computer-guided search for the optimal formulation.

  18. Deposition of fuel pellets injected into tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, L.R.; Jernigan, T.C. [Oak Ridge National Lab., TN (United States); Hsieh, C. [General Atomics, San Diego, CA (United States)

    1998-06-01

    Pellet injection has been used on tokamak devices in a number of experiments to provide plasma fueling and density profile control. The mass deposition of these fuel pellets defined as the change in density profile caused by the pellet, has been found to show an outward displacement of the ablated material from that expected by mapping the theoretical ablation rate onto the flux surfaces. This suggests that fast transport of the pellet ablatant occurs during the flow along field lines that may be driven by {del}B drift effects. A comparison of the deposition of pellets from different machines shows similar behavior. Initial results from alternative injection locations designed to take advantage of the outward ablatant drift is presented.

  19. Fecal Transplant Shows Early Promise Against Autism

    Science.gov (United States)

    ... 163263.html Fecal Transplant Shows Early Promise Against Autism Small study found giving healthy gut bacteria to ... study suggests a novel treatment for kids with autism: Give these young patients a fresh supply of ...

  20. Fecal Microbiota Transplantation: Clinical and experimental studies

    NARCIS (Netherlands)

    van Nood, E.

    2015-01-01

    In this thesis, several aspects of donor feces infusion, also called Fecal Microbiota Transplantation (FMT), are investigated. Historically, FMTs are given mainly for antibiotic associated diarrhea, caused by the anaerobic bacteria Clostridium difficile. Clostridium difficile infections (CDI) are mo

  1. Torrefaction Processing of Human Fecal Waste Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New technology is needed to collect, stabilize, safen, recover useful materials, and store human fecal waste for long duration missions. The current SBIR Phase I...

  2. Fecal Microbiota Transplantation: Just a Fancy Trend?

    Science.gov (United States)

    Vandenplas, Yvan; Pierard, Denis; De Greef, Elisabeth

    2015-07-01

    The risks and advantages of the administration of fecal material of healthy people to patients are heavily debated. In adults, recurrent Clostridium difficile has become an accepted indication. In addition to all of the possible indications, many other questions need to be answered before pediatric indications and recommendations can be established. Optimal donor selection, fresh versus frozen stools versus capsules containing only microbiota, volume, and route of administration are just a few examples of the areas with missing data to allow in formulating recommendations for fecal microbiota or fecal material administration in children. A careful but not-too-complex regulation is the first priority in order to minimize the risk of administration of fecal slurry from unselected donors at home without medical supervision.

  3. Highly Efficient Fecal Waste Incinerator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Volume reduction is a critical element of Solid Waste Management for manned spacecraft and planetary habitations. To this end, the proposed fecal waste incinerator...

  4. U.S. Pellet Industry Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Corrie I. Nichol; Jacob J. Jacobsen; Richard D. Boardman

    2011-06-01

    This report is a survey of the U.S. Pellet Industry, its current capacity, economic drivers, and projected demand for biomass pellets to meet future energy consumption needs. Energy consumption in the US is projected to require an ever increasing portion of renewable energy sources including biofuels, among which are wood, and agrictulrual biomass. Goals set by federal agencies will drive an ever increasing demand for biomass. The EIA projections estimate that renewable energy produced by 2035 will be roughly 10% of all US energy consumption. Further analysis of the biofuels consumption in the US shows that of the renewable energy sources excluding biofuels, nearly 30% are wood or biomass waste. This equates to roughly 2% of the total energy consumption in the US coming from biomass in 2009, and the projections for 2035 show a strong increase in this amount. As of 2009, biomass energy production equates to roughly 2-2.5 quadrillion Btu. The EIA projections also show coal as providing 21% of energy consumed. If biomass is blended at 20% to co-fire coal plants, this will result in an additional 4 quadrillion Btu of biomass consumption. The EISA goals aim to produce 16 billion gal/year of cellulosic biofuels, and the US military has set goals for biofuels production. The Air Force has proposed to replace 50% of its domestic fuel requirements with alternative fuels from renewable sources by 2016. The Navy has likewise set a goal to provide 50% of its energy requirements from alternative sources. The Department of Energy has set similarly ambitious goals. The DOE goal is to replace 40% of 2004 gasoline use with biofuels. This equates to roughly 60 billion gal/year, of which, 45 billion gal/year would be produced from lignocellulosic resources. This would require 530 million dry tons of herbaceous and woody lignocellulosic biomass per year.

  5. Circular economy in drinking water treatment: reuse of ground pellets as seeding material in the pellet softening process.

    Science.gov (United States)

    Schetters, M J A; van der Hoek, J P; Kramer, O J I; Kors, L J; Palmen, L J; Hofs, B; Koppers, H

    2015-01-01

    Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research.

  6. Testing phenanthrene distribution properties of virgin plastic pellets and plastic eroded pellets found on lesvos island beaches (Greece)

    OpenAIRE

    Hrissi K. Karapanagioti; Klontza, Irene

    2008-01-01

    Testing phenanthrene distribution properties of virgin plastic pellets and plastic eroded pellets found on lesvos island beaches (Greece) correspondance: Corresponding author. (Karapanagioti, Hrissi K.) (Karapanagioti, Hrissi K.) Department of Chemistry--> , University of Patras--> , Rio--> - GREECE (Karapanagioti, Hrissi K.) GREECE (Karapanagioti, Hrissi K.) Marine Sciences Departmen...

  7. Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

    Science.gov (United States)

    Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

    2012-01-01

    Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

  8. Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

    Directory of Open Access Journals (Sweden)

    Jan Michels

    2015-03-01

    Full Text Available Copepods are dominant members of the marine zooplankton. Their diets often comprise large proportions of diatom taxa whose silicified frustules are mechanically stable and offer protection against grazers. Despite of this protection, many copepod species are able to efficiently break even the most stable frustule types. This ability requires specific feeding tools with mechanically adapted architectures, compositions and properties. When ingesting food, the copepods use the gnathobases of their mandibles to grab and, if necessary, crush and mince the food items. The morphology of these gnathobases is related to the diets of the copepods. Gnathobases of copepod species that mainly feed on phytoplankton feature compact and stable tooth-like structures, so-called teeth. In several copepod species these gnathobase teeth have been found to contain silica. Recent studies revealed that the siliceous teeth are complex microscale composites with silica-containing cap-like structures located on chitinous exoskeleton sockets that are connected with rubber-like bearings formed by structures with high proportions of the soft and elastic protein resilin. In addition, the silica-containing cap-like structures exhibit a nanoscale composite architecture. They contain some amorphous silica and large proportions of the crystalline silica type α-cristobalite and are pervaded by a fine chitinous fibre network that very likely serves as a scaffold during the silicification process. All these intricate composite structures are assumed to be the result of a coevolution between the copepod gnathobases and diatom frustules in an evolutionary arms race. The composites very likely increase both the performance of the siliceous teeth and their resistance to mechanical damage, and it is conceivable that their development has favoured the copepods’ dominance of the marine zooplankton observed today.

  9. Bloom-forming cyanobacteria support copepod reproduction and development in the Baltic Sea.

    Science.gov (United States)

    Hogfors, Hedvig; Motwani, Nisha H; Hajdu, Susanna; El-Shehawy, Rehab; Holmborn, Towe; Vehmaa, Anu; Engström-Öst, Jonna; Brutemark, Andreas; Gorokhova, Elena

    2014-01-01

    It is commonly accepted that summer cyanobacterial blooms cannot be efficiently utilized by grazers due to low nutritional quality and production of toxins; however the evidence for such effects in situ is often contradictory. Using field and experimental observations on Baltic copepods and bloom-forming diazotrophic filamentous cyanobacteria, we show that cyanobacteria may in fact support zooplankton production during summer. To highlight this side of zooplankton-cyanobacteria interactions, we conducted: (1) a field survey investigating linkages between cyanobacteria, reproduction and growth indices in the copepod Acartia tonsa; (2) an experiment testing relationships between ingestion of the cyanobacterium Nodularia spumigena (measured by molecular diet analysis) and organismal responses (oxidative balance, reproduction and development) in the copepod A. bifilosa; and (3) an analysis of long term (1999-2009) data testing relationships between cyanobacteria and growth indices in nauplii of the copepods, Acartia spp. and Eurytemora affinis, in a coastal area of the northern Baltic proper. In the field survey, N. spumigena had positive effects on copepod egg production and egg viability, effectively increasing their viable egg production. By contrast, Aphanizomenon sp. showed a negative relationship with egg viability yet no significant effect on the viable egg production. In the experiment, ingestion of N. spumigena mixed with green algae Brachiomonas submarina had significant positive effects on copepod oxidative balance, egg viability and development of early nauplial stages, whereas egg production was negatively affected. Finally, the long term data analysis identified cyanobacteria as a significant positive predictor for the nauplial growth in Acartia spp. and E. affinis. Taken together, these results suggest that bloom forming diazotrophic cyanobacteria contribute to feeding and reproduction of zooplankton during summer and create a favorable growth

  10. Characterization and analysis of ribosomal proteins in two marine calanoid copepods

    Science.gov (United States)

    Yang, Feifei; Xu, Donghui; Zhuang, Yunyun; Huang, Yousong; Yi, Xiaoyan; Chen, Hongju; Liu, Guangxing; Zhang, Huan

    2016-11-01

    Copepods are among the most abundant and successful metazoans in the marine ecosystem. However, genomic resources related to fundamental cellular processes are still limited in this particular group of crustaceans. Ribosomal proteins are the building blocks of ribosomes, the primary site for protein synthesis. In this study, we characterized and analyzed the cDNAs of cytoplasmic ribosomal proteins (cRPs) of two calanoid copepods, Pseudodiaptomus poplesia and Acartia pacifica. We obtained 79 cRP cDNAs from P. poplesia and 67 from A. pacifica by cDNA library construction/sequencing and rapid amplification of cDNA ends. Analysis of the nucleic acid composition showed that the copepod cRP-encoding genes had higher GC content in the protein-coding regions (CDSs) than in the untranslated regions (UTRs), and single nucleotide repeats (>3 repeats) were common, with "A" repeats being the most frequent, especially in the CDSs. The 3'-UTRs of the cRP genes were significantly longer than the 5'-UTRs. Codon usage analysis showed that the third positions of the codons were dominated by C or G. The deduced amino acid sequences of the cRPs contained high proportions of positively charged residues and had high pI values. This is the first report of a complete set of cRP-encoding genes from copepods. Our results shed light on the characteristics of cRPs in copepods, and provide fundamental data for further studies of protein synthesis in copepods. The copepod cRP information revealed in this study indicates that additional comparisons and analysis should be performed on different taxonomic categories such as orders and families.

  11. Market development of wood pellets and pellet heatings; Marktentwicklung von Holzpellets und Pelletheizungen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J. [Deutscher Energie Pellet-Verband e.V., Mannheim (Germany)

    2005-07-01

    The latest analysis of the German pellet market shows that the uptrend expected by the branch has indeed started. Supported by the spasmodic development of the prices for fossile energies and the consumers becoming uncertain, pellet heatings experienced a significant rise in demand over the past 12 months. They could increase their share in the German heating market to 2% thus almost doubling their results of the previous year. Furthermore, we see that the market in Germany which up to now had shown a rather uneven development is increasingly becoming more leveled and more and more specialized firms offer pellet heating systems. And the regional availability of the fuels is also continuously improving. This makes the branch's expected further stable growth for the next year seem achievable. Nevertheless, the experiences of the firms acting on the market also show that the efforts for increasing the market shares must not looseend. Meanwhile, it seems to be more important than ever to carry out joint market activities in order to overcome existing deficiencies in information and to awaken the existing market potential.

  12. Statistical analysis and modeling of pelletized cultivation of Mucor circinelloides for microbial lipid accumulation.

    Science.gov (United States)

    Xia, Chunjie; Wei, Wei; Hu, Bo

    2014-04-01

    Microbial oil accumulation via oleaginous fungi has some potential benefits because filamentous fungi can form pellets during cell growth and these pellets are easier to harvest from the culture broth than individual cells. This research studied the effect of various culture conditions on the pelletized cell growth of Mucor circinelloides and its lipid accumulation. The results showed that cell pelletization was positively correlated to biomass accumulation; however, pellet size was negatively correlated to the oil content of the fungal biomass, possibly due to the mass transfer barriers generated by the pellet structure. How to control the size of the pellet is the key to the success of the pelletized microbial oil accumulation process.

  13. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering Sea and Chukchi Sea

    Science.gov (United States)

    Sasaki, H.; Matsuno, K.; Fujiwara, A.; Onuka, M.; Yamaguchi, A.; Ueno, H.; Watanuki, Y.; Kikuchi, T.

    2015-11-01

    The advection of warm Pacific water and the reduction of sea-ice extent in the western Arctic Ocean may influence the abundance and distribution of copepods, i.e., a key component in food webs. To understand the factors affecting abundance of copepods in the northern Bering Sea and Chukchi Sea, we constructed habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods, separately, using generalized additive models. Copepods were sampled by NORPAC net. Vertical profiles of density, temperature and salinity in the seawater were measured using CTD, and concentration of chlorophyll a in seawater was measured with a fluorometer. The timing of sea-ice retreat was determined using the satellite image. To quantify the structure of water masses, the magnitude of pycnocline and averaged density, temperature and salinity in upper and bottom layers were scored along three axes using principal component analysis (PCA). The structures of water masses indexed by the scores of PCAs were selected as explanatory variables in the best models. Large Arctic copepods were abundant in the water mass with high salinity water in bottom layer or with cold/low salinity water in upper layer and cold/high salinity water in bottom layer, and small Arctic copepods were abundant in the water mass with warm/saline water in upper layer and cold/high salinity water in bottom layers, while Pacific copepods were abundant in the water mass with warm/saline in upper layer and cold/high salinity water in bottom layer. All copepod groups were abundant in areas with deeper depth. Although chlorophyll a in upper and bottom layers were selected as explanatory variables in the best models, apparent trends were not observed. All copepod groups were abundant where the sea-ice retreated at earlier timing. Our study might indicate potential positive effects of the reduction of sea-ice extent on the distribution of all groups of copepods in the Arctic Ocean.

  14. An oral controlled release matrix pellet formulation containing nanocrystalline ketoprofen.

    Science.gov (United States)

    Vergote, G J; Vervaet, C; Van Driessche, I; Hoste, S; De Smedt, S; Demeester, J; Jain, R A; Ruddy, S; Remon, J P

    2001-05-21

    A controlled release pellet formulation using a NanoCrystal colloidal dispersion of ketoprofen was developed. In order to be able to process the aqueous NanoCrystal colloidal dispersion into a hydrophobic solid dosage form a spray drying procedure was used. The in vitro dissolution profiles of wax based pellets loaded with nanocrystalline ketoprofen are compared with the profiles of wax based pellets loaded with microcrystalline ketoprofen and of a commercial sustained release ketoprofen formulation. Pellets were produced using a melt pelletisation technique. All pellet formulations were composed of a mixture of microcrystalline wax and starch derivatives. The starch derivatives used were waxy maltodextrin and drum dried corn starch. Varying the concentration of drum dried corn starch increased the release rate of ketoprofen but the ketoprofen recovery remained problematic. To increase the dissolution yield surfactants were utilised. The surfactants were either added during the production process of the NanoCrystal colloidal dispersion (sodium laurylsulphate) or during the pellet manufacturing process (Cremophor RH 40). Both methods resulted in a sustained but complete release of nanocrystalline ketoprofen from the matrix pellet formulations.

  15. Developments of repetitive pneumatic pipe-gun pellet injector

    Energy Technology Data Exchange (ETDEWEB)

    Sudo, Shigeru [National Inst. for Fusion Science, Nagoya (Japan); Viniar, I.

    1997-05-01

    A pellet injector of repetitive pneumatic pipe-gun type has been designed for advanced plasma fueling applications. This new concept is estimated to be able to reduce the time for pellet formation by an in situ technique from 3 - 5 minutes to 2 - 10 seconds. The basic idea of the new approach to pellet formation is to supply a hydrogen isotope pellet through a copper porous unit into a pipe-gun-type barrel. Two modes are possible: (1) to push liquid hydrogen isotope through a porous unit and re-freezing inside of the barrel, (2) to push solid hydrogen isotope through a porous unit to the inside of the barrel. This principle provides a continuous injection of an unlimited amount of pellets. For demonstration of the proof-of-principle, several experiments have been carried out. Hydrogen pellets of 3 mm in diameter and 3 to 10 mm in length were accelerated to 1.2 km/s at a rate of 1 pellet per 10 - 34 s with a manually controlled injector operation. (author)

  16. Use of the copepod Oithona hebes as a bioencapsulator of essential fatty acids

    Directory of Open Access Journals (Sweden)

    Marcia Vanacor Barroso

    2015-09-01

    Full Text Available AbstractThe advantages of using copepods in aquaculture include nutritional superiority, high digestibility and broad spectrum of sizes, with the possibility of bioencapsulation of nutrients, probiotics and medicines. This study aimed to compare the effects of feeding copepods with a microalgae diet and two commercial inert diets on the copepod culture performance and their fatty acid profile. Wild copepods were collected in the estuarine system of Piraquê-açu River, Aracruz, Espírito Santo, Brazil, with a conical net of 60 cm in diameter and 200 μm mesh with a blind cup end, towed through the subsurface layer at a speed of 1 knot for 5 minutes. Once collected, the material was sieved in order to select only Oithona hebes. The experiment was conducted in nine cylindrical-conical tanks with a 60 L capacity, salinity of 25.8 ± 1.3, temperature of 25.5 ± 0.5 ºC and weak aeration, stocked with a density of 1.5 copepod/mL. Treatments were made in triplicate and consisted of: Treatment 1 (Control fed with microalgae Chaetoceros gracilis and Nannochloropsis oculata (1:1 with 50,000 cells.mL-1each; Treatment 2 with S.Parkle® INVE (1g.million-1; and Treatment 3 with freeze-dried spirulina (1g.million-1. The mean final population was compared by a Tukey test (p < 0.05. Results showed higher population growth for copepods treated with S.parkle, which was the only treatment that presented copepodites. S.parkle was a good source of total lipids (9.54 g.100g-1 dry weight, high availability of DHA, EPA and had a good DHA:EPA:ARA ratio of 12.4:3.4:1.0. Copepods that were fed S.parkle had the highest DHA levels and a DHA:EPA:ARA ratio of 15.4:2.2:1.0. This study showed that S.parkle is a good inert food for rearing the copepod O. hebes, demonstrating the ability of copepods to bioencapsulate nutrients, allowing their transfer in the food chain.

  17. Characterization of fly ash ceramic pellet for phosphorus removal.

    Science.gov (United States)

    Li, Shiyang; Cooke, Richard A; Wang, Li; Ma, Fang; Bhattarai, Rabin

    2017-03-15

    Phosphorus has been recognized as a leading pollutant for surface water quality deterioration. In the Midwestern USA, subsurface drainage not only provides a pathway for excess water to leave the field but it also drains out nutrients like nitrogen (N) and phosphorus (P). Fly ash has been identified as one of the viable materials for phosphorus removal from contaminated waters. In this study, a ceramic pellet was manufactured using fly ash for P absorption. Three types of pellet with varying lime and clay proportions by weight (type 1: 10% lime + 30% clay, type 2: 20% lime + 20% clay, and type 3: 30% lime + 10% clay) were characterized and evaluated for absorption efficiency. The result showed that type 3 pellet (60% fly ash with 30% lime and 10% clay) had the highest porosity (14%) and absorption efficiency and saturated absorption capacity (1.98 mg P/g pellet) compared to type 1 and 2 pellets. The heavy metal leaching was the least (30 μg/L of chromium after 5 h) for type 3 pellet compared to other two. The microcosmic structure of pellet from scanning electron microscope showed the type 3 pellet had the better distribution of aluminum and iron oxide on the surface compared other two pellets. This result indicates that addition of lime and clay can improve P absorption capacity of fly ash while reducing the potential to reduce chromium leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Overview of recent developments in pellet injection for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephen Kirk, E-mail: combssk@ornl.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6169 (United States); Baylor, L.R.; Meitner, S.J.; Caughman, J.B.O.; Rasmussen, D.A. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6169 (United States); Maruyama, S. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Status of the ITER pellet injection system. Black-Right-Pointing-Pointer Fueling requirements for ITER. Black-Right-Pointing-Pointer Summarizes the design/operating parameters and highlights recent developments. Black-Right-Pointing-Pointer Benefits of plasma fueling by the injection of pellets, composed of frozen hydrogen isotopes and millimeters in size, into magnetically confined plasmas (core fueling). Black-Right-Pointing-Pointer ELM mitigation with pellets (ELM pacing). - Abstract: Pellet injection is the primary fueling technique planned for core fueling of ITER burning plasmas. Also, the injection of relatively small pellets to purposely trigger rapid small edge localized modes (ELMs) has been proposed as a possible solution to the heat flux damage from larger natural ELMs likely to be an issue on the ITER divertor surfaces. The ITER pellet injection system is designed to inject pellets into the plasma through both inner and outer wall guide tubes. The inner wall guide tubes will provide high throughput pellet fueling while the outer wall guide tubes will be used primarily to trigger ELMs at a high frequency (>15 Hz). The pellet fueling rate of each injector is to be up to 120 Pa m{sup 3}/s, which will require the formation of solid D-T at a volumetric rate of {approx}1500 mm{sup 3}/s. Two injectors are to be provided for ITER at the startup with a provision for up to six injectors during the D-T phase. The required throughput of each injector is greater than that of any injector built to date, and a novel twin-screw continuous extrusion system is being developed to meet the challenging design parameters. Status of the development activities is presented, highlighting recent progress.

  19. Revealing accumulation zones of plastic pellets in sandy beaches.

    Science.gov (United States)

    Moreira, Fabiana T; Balthazar-Silva, Danilo; Barbosa, Lucas; Turra, Alexander

    2016-11-01

    Microplastics such as pellets are reported worldwide on sandy beaches, and have possible direct and indirect impacts on the biota and physical characteristics of the habitats where they accumulate. Evaluations of their standing stock at different spatial scales generate data on levels of contamination. This information is needed to identify accumulation zones and the specific beach habitats and communities that are likely to be most affected. Standing stocks of plastic pellets were evaluated in 13 sandy beaches in São Paulo state, Brazil. The sampling strategy incorporated across-shore transects from coastal dunes and backshores, and vertical profiles of the accumulated pellets down to 1 m depth below the sediment surface. Accumulation zones were identified at regional (among beaches) and local (between compartments) scales. At the regional scale pellet density tended to increase at beaches on the central and southwestern coast, near ports and factories that produce and transport the largest amounts of pellets in the country. At the local scale coastal dunes showed larger accumulations of pellets than backshores. For both compartments pellets tended to occur deeper in areas where standing stocks were larger. Most of the pellets were concentrated from the surface down to 0.4 m depth, suggesting that organisms inhabiting this part of the sediment column are more exposed to the risks associated with the presence of pellets. Our findings shed light on the local and regional scales of spatial variability of microplastics and their consequences for assessment and monitoring schemes in coastal compartments. Copyright © 2016. Published by Elsevier Ltd.

  20. Blower Gun pellet injection system for W7-X

    Energy Technology Data Exchange (ETDEWEB)

    Dibon, M., E-mail: mathias.dibon@ipp.mpg.de [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Baldzuhn, J.; Beck, M. [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Cardella, A. [Lehrstuhl für Nukleartechnik, TU Munich, Boltzmannstr. 15, 85748 Garching (Germany); Köchl, F. [Atominstitut, TU Wien, 1020 Vienna (Austria); Kocsis, G. [Wigner RCP, RMI, P.O. Box 49, H-1525 Budapest-114 (Hungary); Lang, P.T. [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Macian-Juan, R. [Lehrstuhl für Nukleartechnik, TU Munich, Boltzmannstr. 15, 85748 Garching (Germany); Ploeckl, B. [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Szepesi, T. [Wigner RCP, RMI, P.O. Box 49, H-1525 Budapest-114 (Hungary); Weisbart, W. [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-10-15

    Highlights: • Operational principle of the ASDEX Upgrade Blower Gun. • Guiding tube properties for pellet guiding according to the requirements of W7-X. • Diagnostics for the characterization of the injection system. • Experimental procedure to investigate the performance of the Blower Gun. • Results concerning pellet speeds, mass loss, delivery efficiency and exit angle. - Abstract: Foreseen to perform pellet investigations in the new stellarator W7-X, the former ASDEX Upgrade Blower Gun was revised and revitalized. The systems operational characteristics have been surveyed in a test bed. The gun is designed to launch cylindrical pellets with 2 mm diameter and 2 mm length, produced from frozen deuterium D{sub 2}, hydrogen H{sub 2} or a gas mixture consisting of 50% H{sub 2} and 50% D{sub 2}. Pellets are accelerated by a short pulse of pressurized helium propellant gas to velocities in the range of 100–250 m/s. Delivery reliabilities at the launcher exit reach almost unity. The initial pellet mass is reduced to about 50% during the acceleration process. Pellet transfer to the plasma vessel was investigated by a first mock up guiding tube version. Transfer through this S-shaped stainless steel guiding tube (inner diameter 8 mm; length 6 m) containing two 1 m curvature radii was investigated for all pellet types. Tests were performed applying repetition rates from 2 Hz to 50 Hz and propellant gas pressures ranging from 0.1 to 0.6 MPa. For both H{sub 2} and D{sub 2}, low overall delivery efficiencies were observed at slow repetition rates, but stable efficiencies of about 90% above 10 Hz. About 10% of the mass is eroded while flying through the guiding tube. Pellets exit the guiding tube with an angular spread of less than 14°.

  1. Copepod Behavior in ``Cryptic Blooms'' of Toxic Algae

    Science.gov (United States)

    True, A. C.; Webster, D. R.; Weissburg, M. J.; Yen, J.

    2014-11-01

    Copepods,Acartia tonsa and Temora longicornis, were exposed to thin layers of exudates from the toxic dinoflagellate Karenia brevis (1 - 10,000 cells/mL) (i.e. models of ``cryptic blooms'' of toxic phytoplankton). Planar laser-induced fluorescence (PLIF) was used to quantify the spatiotemporal structure of the layer allowing for correlation of behavioral responses with toxin levels. Both species explicitly avoided the exudate layer and the vicinity of the layer. Measures of path kinematics (swimming speed, turn frequency) by location (in-layer vs. out-of-layer) and exposure (pre-contact vs. post-contact) revealed some similarities, but also significant differences, in trends for each species. A. tonsa significantly increases swimming speed and swimming speed variability in the exudate layer and post-contact, whereas T. longicornis slightly increases both in-layer and slightly reduces both post-contact. Both species increase turn frequency in-layer and post-contact with increasing K. brevis exudate concentration. Path fracticality indicates that A. tonsatrajectories became more diffuse/sinuous and T. longicornis trajectories became more linear/ballistic (trending effects). Regression analyses revealed that the rate of change of behavior with increasing exudate concentration for A. tonsa was thrice to fifty times that of T. longicornis. Toxic K. brevis can essentially eliminate top-down grazer control ,another sinister means by which it gains a competitive advantage over the local phytoplankton taxa.

  2. Spatial distribution of copepods along the salinity gradient of Perai river estuary, Penang, Malaysia.

    Science.gov (United States)

    Johan, I; Maznah, W O Wan; Mashhor, M; Abu Hena, M K; Amin, S M N

    2012-07-01

    Investigation on copepod communities in Perai river estuary was conducted from November 2005 to May 2006. Five stations were established for monthly sampling and were located from the river mouth to the upper reaches of the river. Copepod samples were collected from vertical tows using a standard zooplankton net. The Perai river estuary was slightly stratified and salinity decreases significantly from the mouth of the river towards the upper reaches of the river. A total of 28 species of copepods were recorded and comprised of 14 families, Paracalanidae, Oithonidae, Corycaeidae, Acartiidae, Calanidae, Centropagidae, Eucalanidae, Pontellidae, Pseudodiaptomidae, Tortanidae, Ectinosomatidae, Euterpinidae, Clausidiidae and Cyclopidae. A total of 10 species showed high positive affiliation towards salinity (R > 0.60), Acartia spinicauda, Euterpina acutifrons, Microsetella norvegica, Oithona nana, Oithona simplex, Paracalanus crassirostris, Paracalanus elegans, Paracalanus parvus, Pseudodiaptomus sp. and Hemicyclops sp. The copepod species Pseudodiaptomus dauglishi were negatively affiliated towards salinity (R = -0.71). The copepod assemblages classified into two distinct groups according to salinity regimes, euryhaline-polyhaline group (25 marine affiliated species) and oligohaline-mesohaline group (3 freshwater affiliated species).

  3. Hydrodynamic and Sensory Factors Governing Response of Copepods to Simulated Predation by Balaenid Whales

    Directory of Open Access Journals (Sweden)

    Alexander J. Werth

    2012-01-01

    Full Text Available Predator/prey interactions between copepods and balaenid (bowhead and right whales were studied with controlled lab experiments using moving baleen in still water and motionless baleen in flowing water to simulate zooplankton passage toward, into, and through the balaenid oral cavity. Copepods showed a lesser escape response to baleen and to a model head simulating balaenid oral hydrodynamics than to other objects. Copepod escape response increased as water flow and body size increased and was greatest at distances ≥10 cm from baleen and at copepod density = 10,000 m−3. Data from light/dark experiments suggest that escape is based on mechanoreception, not vision. The model head captured 88% of copepods. Results support previous research showing hydrodynamic effects within a whale’s oral cavity create slight suction pressures to draw in prey or at least preclude formation of an anterior compressive bow wave that could scatter or alert prey to the presence of the approaching whale.

  4. Climate change affects low trophic level marine consumers: warming decreases copepod size and abundance.

    Science.gov (United States)

    Garzke, Jessica; Ismar, Stefanie M H; Sommer, Ulrich

    2015-03-01

    Concern about climate change has re-ignited interest in universal ecological responses to temperature variations: (1) biogeographical shifts, (2) phenology changes, and (3) size shifts. In this study we used copepods as model organisms to study size responses to temperature because of their central role in the pelagic food web and because of the ontogenetic length constancy between molts, which facilitates the definition of size of distinct developmental stages. In order to test the expected temperature-induced shifts towards smaller body size and lower abundances under warming conditions, a mesocosm experiment using plankton from the Baltic Sea at three temperature levels (ambient, ambient +4 °C, ambient -4 °C) was performed in summer 2010. Overall copepod and copepodit abundances, copepod size at all life stages, and adult copepod size in particular, showed significant temperature effects. As expected, zooplankton peak abundance was lower in warm than in ambient treatments. Copepod size-at-immature stage significantly increased in cold treatments, while adult size significantly decreased in warm treatments.

  5. Pontellid copepods, Labidocera spp., affected by ocean acidification: A field study at natural CO2 seeps.

    Science.gov (United States)

    Smith, Joy N; Richter, Claudio; Fabricius, Katharina E; Cornils, Astrid

    2017-01-01

    CO2 seeps in coral reefs were used as natural laboratories to study the impacts of ocean acidification on the pontellid copepod, Labidocera spp. Pontellid abundances were reduced by ∼70% under high-CO2 conditions. Biological parameters and substratum preferences of the copepods were explored to determine the underlying causes of such reduced abundances. Stage- and sex-specific copepod lengths, feeding ability, and egg development were unaffected by ocean acidification, thus changes in these physiological parameters were not the driving factor for reduced abundances under high-CO2 exposure. Labidocera spp. are demersal copepods, hence they live amongst reef substrata during the day and emerge into the water column at night. Deployments of emergence traps showed that their preferred reef substrata at control sites were coral rubble, macro algae, and turf algae. However, under high-CO2 conditions they no longer had an association with any specific substrata. Results from this study indicate that even though the biology of a copepod might be unaffected by high-CO2, Labidocera spp. are highly vulnerable to ocean acidification.

  6. The effect of Fucus vesiculosus on the grazing of harpacticoid copepods on diatom biofilms

    Science.gov (United States)

    De Troch, M.; Chepurnov, V. A.; Vincx, M.; Ólafsson, E.

    2008-10-01

    The effect of Fucus vesiculosus on the functional traits of three harpacticoid copepod species ( Tigriopus brevicornis, Paramphiascella fulvofasciata and Microarthridion littorale) was studied. These copepods are likely to be important grazers on biofilms consisting mainly of diatoms. Several microcosms were created using diatom cultures ( Navicula phyllepta and Seminavis robusta) and vegetative thalli of Fucus, with the biofilm associated, collected from the field. The diatoms were enriched in the stable carbon 13C to facilitate tracing in the harpacticoids. The biofilm on the Fucus was labeled through impregnation of the Fucus leaves in 13C enriched seawater. In all treatments a measurable uptake of diatoms was found for the three copepod species. All copepods showed a low uptake of labeled material when only Fucus thalli were available. The grazing on the benthic diatoms was negatively affected by the presence of the Fucus thalli in the case of P. fulvofasciata. One species, T. brevicornis, grazed efficiently both on sedimentary and epiphytic biofilms. We hereby proved experimentally that benthic harpacticoid copepods are able to switch their food uptake under different habitat/food circumstances. This variety of food uptake is an illustration of the so-called 'niche complementarity effect' that lies at the basis of diverse communities.

  7. RNA-Based Methods Increase the Detection of Fecal Bacteria and Fecal Identifiers in Environmental Waters

    Science.gov (United States)

    We evaluated the use of qPCR RNA-based methods in the detection of fecal bacteria in environmental waters. We showed that RNA methods can increase the detection of fecal bacteria in multiple water matrices. The data suggest that this is a viable alternative for the detection of a...

  8. Fecal calprotectin in coeliac disease.

    Science.gov (United States)

    Capone, Pietro; Rispo, Antonio; Imperatore, Nicola; Caporaso, Nicola; Tortora, Raffaella

    2014-01-14

    We would like to share with the readers the results of our experience in 50 celiac disease (CD) patients, enrolled between September 2012 and April 2013, who were referred to our third-level CD Unit. The fecal calprotectin (FC) concentration of 50 adults with newly diagnosed CD was compared to that of a control group of 50 healthy subjects. FC level was determined by enzyme linked immunosorbent assay with diagnostic cut-off of 75 μg/g. In addition, we tried to correlate the FC level with symptoms, histological severity of CD (Marsh grade) and level of tissue transglutaminase antibodies (aTg) in CD patients. Finally, FC level was increased in five CD patients and in four controls (10% vs 8%, P = NS); mean FC concentration of patients and controls were 57.7 (SD ± 29.1) and 45.1 (SD ± 38.4) respectively. Furthermore, no significant correlation was seen between FC levels and symptoms/Marsh grade/aTg. The five CD patients did not show inflammatory lesions (e.g., ulcers, erosions) at upper endoscopy. The four healthy controls with positive FC were followed-up for further six months; in this observational period they did not show clinical signs of any underlying disease. On these bases, we think that FC is not able to investigate the subclinical inflammatory changes of active CD and FC should be considered a useless tool in the diagnostic work-up of uncomplicated CD but it should be accompanied by aTg when ruling out organic disease in patients with irritable bowel syndrome.

  9. Fecal calprotectin in coeliac disease

    Science.gov (United States)

    Capone, Pietro; Rispo, Antonio; Imperatore, Nicola; Caporaso, Nicola; Tortora, Raffaella

    2014-01-01

    We would like to share with the readers the results of our experience in 50 celiac disease (CD) patients, enrolled between September 2012 and April 2013, who were referred to our third-level CD Unit. The fecal calprotectin (FC) concentration of 50 adults with newly diagnosed CD was compared to that of a control group of 50 healthy subjects. FC level was determined by enzyme linked immunosorbent assay with diagnostic cut-off of 75 μg/g. In addition, we tried to correlate the FC level with symptoms, histological severity of CD (Marsh grade) and level of tissue transglutaminase antibodies (aTg) in CD patients. Finally, FC level was increased in five CD patients and in four controls (10% vs 8%, P = NS); mean FC concentration of patients and controls were 57.7 (SD ± 29.1) and 45.1 (SD ± 38.4) respectively. Furthermore, no significant correlation was seen between FC levels and symptoms/Marsh grade/aTg. The five CD patients did not show inflammatory lesions (e.g., ulcers, erosions) at upper endoscopy. The four healthy controls with positive FC were followed-up for further six months; in this observational period they did not show clinical signs of any underlying disease. On these bases, we think that FC is not able to investigate the subclinical inflammatory changes of active CD and FC should be considered a useless tool in the diagnostic work-up of uncomplicated CD but it should be accompanied by aTg when ruling out organic disease in patients with irritable bowel syndrome. PMID:24574734

  10. The forest-pellets era; Zeitalter der Waldpellets

    Energy Technology Data Exchange (ETDEWEB)

    Niederhaeusern, A.

    2010-07-01

    This article takes a look at the production of wood pellets for heating purposes using wood taken directly from forests. Waste wood from sawmills is also used to produce the pellets. The article takes a look at the supplies of raw material and the processing necessary to turn the four to six meter long logs into wood-chippings. Also, mobile shredders that produce wood-chips directly in the forests are mentioned. The 24-hour operation of the installations is discussed. Further matters examined included the drying of the wood chippings and the grey energy balance of the final product, the wood pellets. Co-operation with energy utilities is also examined.

  11. Cleaning By Blasting With Pellets Of Dry Ice

    Science.gov (United States)

    Fody, Jody

    1993-01-01

    Dry process strips protective surface coats from parts to be cleaned, without manual scrubbing. Does not involve use of flammable or toxic solvents. Used to remove coats from variety of materials, including plastics, ceramics, ferrous and nonferrous metals, and composites. Adds no chemical-pollution problem to problem of disposal of residue of coating material. Process consists of blasting solid carbon dioxide (dry ice) pellets at surface to be cleaned. Pellets sublime on impact and pass into atmosphere as carbon dioxide gas. Size, harness, velocity, and quantity of pellets adjusted to suit coating material and substrate.

  12. Fast imaging of intact and shattered cryogenic neon pellets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui, E-mail: zwang@lanl.gov [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Combs, S. K.; Baylor, L. R.; Foust, C. R.; Lyttle, M. S.; Meitner, S. J.; Rasmussen, D. A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-11-15

    Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100-µm- and sub-µs-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of µm to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development.

  13. Fast Imaging of Intact and Shattered Cryogenic Neon Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui [Los Alamos National Laboratory (LANL); Combs, Stephen Kirk [ORNL; Baylor, Larry R [ORNL; Foust, Charles R [ORNL; Lyttle, Mark S [ORNL; Meitner, Steven J [ORNL; Rasmussen, David A [ORNL

    2014-01-01

    Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100- m- and sub- s-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of m to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development.

  14. Fast imaging of intact and shattered cryogenic neon pellets.

    Science.gov (United States)

    Wang, Zhehui; Combs, S K; Baylor, L R; Foust, C R; Lyttle, M S; Meitner, S J; Rasmussen, D A

    2014-11-01

    Compact condensed-matter injection technologies are increasingly used in magnetic fusion. One recent application is in disruption mitigation. An imaging system with less-than-100-µm- and sub-µs-resolution is described and used to characterize intact and shattered cryogenic neon pellets. Shattered pellets contain fine particles ranging from tens of µm to about 7 mm. Time-of-flight analyses indicate that pellets could slow down if hitting the wall of the guide tube. Fast high-resolution imaging systems are thus useful to neon and other condensed-matter injector development.

  15. Seasonal variation and longitudinal distribution of copepods in the main river area of the Three Gorges Reservoir

    Institute of Scientific and Technical Information of China (English)

    Jianliang YAO; Junzeng XUE; Dengyuan WANGt; Qinghua CAI; Xiangfei HUANG; Jiankang LIU

    2008-01-01

    The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake (res-ervoir) ecosystem after impoundment in June 2003. We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem. From Jiangjin to Maoping, eight copepod species were collected and classified into Calanoida (2), Harpacticoida (1), and Cyclopoida (5). Among them, Mesocyclops pehpeiensis, M. leuckarti and Sinocalanus dorrii had a relatively wide distribution. No distinct dif-ference in species number was found among the sampling sites, but the species composition was different. Species composition, distribution and density of copepods showed significant seasonal variations. In addition, cope-pod density showed an obvious gradient with the distance from the reservoir dam: the nearer to the dam, the denser the copepods.

  16. Physiological response of the intertidal copepod Tigriopus japonicus experimentally exposed to cadmium

    Directory of Open Access Journals (Sweden)

    Emadeldeen H. Mohammed

    2011-01-01

    Full Text Available The intertidal harpacticoid copepod Tigriopus japonicus is a benthic copepod and has beencommonly used in ecotoxicology and environmental genomics studies as a marine model species. In thisstudy, Laboratory experiments were conducted to investigate the effects of cadmium (Cd on survival,development, growth and reproductive performance of T.japonicus. Our results indicated that Cd wassignificantly affected adult survival and development, but not those of nauplii. Despite the reduction inadult female total body length, Cd was not significantly affected copepod growth. Concerning T.japonicusreproduction response, Cd was significantly reduced the number of nauplii produced at 10 μg L-1. Thus,survival, development and reproduction in T.japonicus as a model test species could be effectivephysiological markers to monitor marine metal pollution and to assess population response.

  17. Sex, sex-ratios, and the dynamics of pelagic copepod populations

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2006-01-01

    within this group. Winter population sizes are well predicted by the critical density required for population persistence which, in turn, is closely related to the body-size-dependent mate-search capacity. Thus, the different requirements for mating lead in the first case to a more opportunistic......I examine how the population biology of pelagic copepods depends on their mating biology using field data and a simple demographic model. Among calanoid copepods, two distinct patterns emerge. Firstly, copepods that lack seminal receptacle and require repeated mating to stay fertilized have near...... equal adult sex ratios in field populations. Winter population densities are orders of magnitude less than the critical population density required for population persistence, but populations survive winter seasons as resting eggs in the sediment. Population growth in these species is potentially high...

  18. Fecal DNA Screening in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Suzanne Richter

    2008-01-01

    Full Text Available Colorectal cancer (CRC is the third most common type of cancer diagnosed in Canada, and is the leading cause of cancer-related deaths in nonsmokers. Although CRC is considered to be 90% curable if detected early, the majority of patients present with advanced stage III or IV disease. An effective screening test may significantly decrease disease burden. The present paper examines the rationale and potential of fecal DNA testing as an alternative and adjunct to other CRC screening tests. The most efficacious fecal DNA test developed to date has a sensitivity and specificity of 87.5% and 82%, respectively. The approach has a higher positive predictive value than the currently used fecal occult blood test and offers a noninvasive option to patients. It is not reliant on the presence of bleeding, which may be intermittent or altogether absent. The test is now commercially available and is supported by a number of American insurers. Current challenges include cost reduction and demonstration of mortality benefit in a rigorous clinical trial. Despite current challenges, fecal DNA testing is worth pursuing. Both the American Gastroenterological Society and the American Cancer Society maintain that molecular testing is in its infancy but is promising. Fecal DNA testing has the potential to be an exciting addition to the current armament of CRC screening options.

  19. Gas Flow Distribution in Pelletizing Shaft Furnace

    Institute of Scientific and Technical Information of China (English)

    CAI Jiu-ju; DONG Hui; WANG Guo-sheng; YANG Jun

    2006-01-01

    Through thermal test, cold state experiment, analysis and simulation of thermal process, the gas flow distribution in pelletizing shaft furnace (PSF) was discussed. The results show that there are five flowing trends; among them, the downward roasting gas and the upward cooling gas are the most unsteady, which influence flow distribution greatly. Among the operating parameters, the ratio of inflow is a key factor affecting the flow distribution. The roasting and cooling gases will entirely flow into the roasting zone and internal vertical air channels (IVAC), respectively, if the ratio of inflow is critical. From such a critical operating condition increasing roasting gas flow or decreasing cooling gas flow, the roasting gas starts flowing downwards so as to enter the inside of IVAC; the greater the ratio of inflow, the larger the downward flowrate. Among constructional parameters, the width of roasting zone b1, width of IVAC b2 and width of cooling zone b3, and the height of roasting zone h1, height of soaking zone h2 and height of cooling zone h3 are the main factors affecting flow distribution. In case the ratio of b2/b1, or h3/h2, or h1/h2 is increased, the upward cooling gas tends to decrease while the downward roasting gas tends to increase with a gradual decrease in the ratio of inflow.

  20. Methane rich gasification of wood pellets

    Directory of Open Access Journals (Sweden)

    Joka Magdalena

    2016-01-01

    Full Text Available In the work there are shown the results of experimental studies on methane rich gasification of pinewood pellets in Bio-CONOx technology. The experiment was carried out on a laboratory scale gasifier (5 kW, which design features allow producing a high quality gas with a high methane content. In the results there was identified the impact of the quantity of Bio-CONOx on the amount of flammable gas compounds (methane, hydrogen and carbon monoxide in the synthesis gas and the gas calorific value. The additive was added in 10,20,30 and 50% concentrations to the gasifier chamber. It has been shown that increasing the amount of the additive has a positive effect on the calorific value of the synthesis gas (Fig.1,2. Gas with a high content of methane (and high calorific value was obtained from gasification of biomass with a 50% addition of Bio-CONOx. There was also examined the proportion of blowing air (gasifying medium for which the properties of obtained syngas were the best.

  1. Backfilling of deposition tunnels: Use of bentonite pellets

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (Canada)); Sanden, Torbjoern (Clay Technology AB (Sweden)); Jonsson, Esther (Swedish Nuclear Fuel and Waste Mangaement Co. (Sweden)); Hansen, Johanna (Posiva Oy (Finland))

    2011-02-15

    The state of knowledge related to use of bentonite pellets as part of backfill or other gap filling components in repository applications is reviewed. How the pellets interact with adjacent sealing materials and the surrounding rock mass is a critical aspect in determining backfill behaviour. The key features and processes that determine how the pellet component of the KBS-3V deposition tunnel backfill will behave are discussed and recommendations related to what additional information needs to be developed are provided. Experiences related to pellet material composition, size, shape, placement options and more importantly, the density to which they can be placed all indicate that there are significant limitations to the achievable as-placed density of bentonite pellet fill. Low as-placed density of the pellet fill component of the backfill is potentially problematic as the outermost regions of tunnel backfill will be the first region of the backfill to be contacted by water entering the tunnels. It is also through this region that initial water movement along the length of the deposition tunnels will occur. This will greatly influence the operations in a tunnel, especially with respect to situations where water is exiting the downstream face of still open deposition tunnels. Pellet-filled regions are also sensitive to groundwater salinity, susceptible to development of piping features and subsequent mechanical erosion by through flowing water, particularly in the period preceding deposition tunnel closure. A review of the experiences of various organisations considering use of bentonite-pellet materials as part of buffer or backfill barriers is provided in this document. From this information, potential options and limitations to use of pellets or pellet-granule mixtures in backfill are identified. Of particular importance is identification of the apparent upper-limits of dry density to which such materials can to be placed in the field. These bounds will

  2. Modeling of thermal conductivity of stainless-steelmaking dust pellets

    Institute of Scientific and Technical Information of China (English)

    彭兵; 彭及; 余笛

    2004-01-01

    The thermal conductivity of stainless-steelmaking dust pellets, an important parameter for the direct recycling of the dust, is naturally of interest to metallurgists. The measurement of central temperature and surface temperature was taken in a furnace. The physical model and calculation model for the heating process were set up to check the thermal conductivity of the dust pellets. The physical structure parameters δ and λ of the basic unit are 0.92 and 0.45 based on the calculation. The temperature in the pellet can be expressed in a linear equation a5 Tp =a1 TN +a2 TM +a4. This is convenient to determine the central temperature of a pellet in the direct recycling process.

  3. Effects of pelletized anticoagulant rodenticides on California quail

    Science.gov (United States)

    Blus, L.J.; Henny, C.J.; Grove, R.A.

    1985-01-01

    A moribund, emaciated California quail (Callipepla californica) that was found in an orchard in the state of Washington had an impacted crop and gizzard. Pellets containing the anticoagulant chlorophacinone (Rozol, RO) were in the crop; the gizzard contents consisted of a pink mass of paraffin that was selectively accumulated from the paraffinized pellets. The plasma prothrombin time of 28 sec was near that determined for control quail. The signs of RO intoxication seen in the moribund wild quail were duplicated in captive quail given ad libitum diets of either RO or another paraffinized chlorophacinone pellet (Mr. Rat Guard II, MRG). This left little doubt that paraffin impaction of the gizzard was the primary problem. All captive quail fed RO or MRG pellets showed no increases in prothrombin times compared to control values, died in an emaciated condition, and had gizzards impacted with paraffin.

  4. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content.

    Directory of Open Access Journals (Sweden)

    Jessica Garzke

    Full Text Available Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1-5 and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA and arachidonic acid (ARA to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts.

  5. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content

    Science.gov (United States)

    Hansen, Thomas; Ismar, Stefanie M. H.; Sommer, Ulrich

    2016-01-01

    Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1–5) and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA) and arachidonic acid (ARA) to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts. PMID:27224476

  6. Feed Pellet and Corn Durability and Breakage During Repeated Elevator Handling

    Science.gov (United States)

    Pelleting of animal feeds is important for improved feeding efficiency and for convenience of handling. Pellet quality impacts the feeding benefits for the animals and pellet integrity during handling. To determine the effect of repeated handling on feed pellet breakage and durability, a 22.6-t (100...

  7. Quality of Wood Pellets Produced in British Columbia for Export

    Energy Technology Data Exchange (ETDEWEB)

    J. S. Tumuluru; S. Sokhansanj; C. J. Lim; T. Bi; A. Lau; S. Melin; T. Sowlati; E. Oveisi

    2010-11-01

    Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. The sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.

  8. QUALITY OF WOOD PELLETS PRODUCED IN BRITISH COLUMBIA FOR EXPORT

    Energy Technology Data Exchange (ETDEWEB)

    Tumuluru, J.S. [Idaho National Laboratory (INL); Sokhansanj, Shahabaddine [ORNL; Lim, C. Jim [University of British Columbia, Vancouver; Bi, X.T. [University of British Columbia, Vancouver; Lau, A.K. [University of British Columbia, Vancouver; Melin, Staffan [University of British Columbia, Vancouver; Oveisi, E. [University of British Columbia, Vancouver; Sowlati, T. [University of British Columbia, Vancouver

    2010-11-01

    Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. The sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.

  9. Digestibility of pelleted rations containing diverse potato flour and urea

    Directory of Open Access Journals (Sweden)

    Isabel Martinele

    2015-11-01

    Full Text Available The aim of this study was to evaluate ruminal in situ degradability and in vitro digestibility of dry matter (DM in concentrate supplements containing diverse potato flour pelletized with urea (0%, 4%, 8%, and 12% DM. Samples of feeds were incubated for 0, 2, 4, 8, 12, 24, 36, and 48h in the rumen of four fistulated sheep. Level of urea added had no significant effect (P>;0.05 on the soluble fraction (a or potentially degradable fraction (b of the pellets and ranged from 2.1% to 12.2% and 72.9% to 87.5%, respectively. Quadratic effects (P=0.03 of the rate of degradation of fraction "b" ranged from 4.75% h-1to 7.39% h-1; the estimated maximum value at 7.4% h-1was obtained when 5.9% urea was added to the pellet. Quadratic effects (P≤0.02 of the level of urea added to the pellets on the effective degradability (ED of DM were evaluated after considering rumen passage rates of 2.5% h-1and 8% h-1; the maximum values of ED calculated under these rumen passage rates were estimated at 6.3% to 7.3% urea in the pellets. The in vitro digestibility of DM of the pellets showed a quadratic effect (P=0.02 at different levels of urea, with a maximum value of 96.9% achieved when 7.9% urea was added to the pellets. Our results suggest that the addition of 6-8% urea to pelleted feed promotes an increase in the in vitro digestibility and ED of DM.

  10. Pellet-clad interaction in water reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The aim of this seminar is was to draw up a comprehensive picture of the pellet clad interaction and its impact on the fuel rod. This document is a detailed abstract of the papers presented during the following five sessions: industrial goals, fuel material behaviour in PCI situation, cladding behaviour relevant to PCI, in pile rod behaviour and modelling of the mechanical interaction between pellet and cladding. (A.L.B.)

  11. Determination of organochlorine pesticides adsorbed on plastic pellets

    OpenAIRE

    2016-01-01

    In the past years, several studies have revealed the presence of organic contaminants at concentrations from sub ng g–1 to mg g–1 on/in plastic pellets found in coastal environment worldwide [1,2,3]. Plastic pellets are actually industrial raw material, typically in the shape of small granules with a diameter of a few mm. They are categorized as microplastics (< 5 mm). They can be unintentionally lost in the environment during manufacturing and transport. They can subsequently ...

  12. Induction of domoic acid production in the toxic diatom Pseudo-nitzschia seriata by calanoid copepods

    DEFF Research Database (Denmark)

    Tammilehto, Anna; Nielsen, Torkel Gissel; Krock, B.

    2015-01-01

    in the presence ofthe copepods. This response was chemically mediated without physical contact between the organismssuggesting that it was induced by potential waterborne cues from the copepods or changes in waterchemistry. Domoic acid production may be related to defense against grazing in P. seriata although...... it wasnot shown in the present study. To evaluate if the induction of domoic acid production was mediatedby the chemical cues from damaged P. seriata cells, live P. seriata cells were exposed to a P. seriata cellhomogenate, but no effect was observed. Chain formation in P. seriata was affected only when...

  13. Use of phytoplankton pigments in estimating food selection of three marine copepods

    DEFF Research Database (Denmark)

    Oechsler-Christensen, B.; Jonasdottir, Sigrun; Henriksen, P.

    2012-01-01

    . Traditional grazing experiments were carried out in parallel with pigment analysis in experiments where the copepod A. tonsa was exposed to a mixture of food organisms. The results demonstrated that the two methods gave similar results with regard to food selection and that with certain precautions, pigment......Experiments were carried out to test the use of algal pigments in zooplankton grazing studies with a special emphasis on estimation of food selection. The results demonstrated that pigment composition of the phytoplankton food was reflected closely in the three copepod species Centropages typicus...... analysis can be successfully used in food selection studies...

  14. Clostridium difficile Infection and Fecal Microbiota Transplant.

    Science.gov (United States)

    Liubakka, Alyssa; Vaughn, Byron P

    2016-07-01

    Clostridium difficile infection (CDI) is a major source of morbidity and mortality for hospitalized patients. Although most patients have a clinical response to existing antimicrobial therapies, recurrent infection develops in up to 30% of patients. Fecal microbiota transplant is a novel approach to this complex problem, with an efficacy rate of nearly 90% in the setting of multiple recurrent CDI. This review covers the current epidemiology of CDI (including toxigenic and nontoxigenic strains, risk factors for infection, and recurrent infection), methods of diagnosis, existing first-line therapies in CDI, the role of fecal microbiota transplant for multiple recurrent CDIs, and the potential use of fecal microbial transplant for patients with severe or refractory infection. ©2016 American Association of Critical-Care Nurses.

  15. Formulation and characterization of self emulsifing pellets of carvedilol

    Directory of Open Access Journals (Sweden)

    Vikas Bhandari

    2015-09-01

    Full Text Available The purpose of present study was aimed at developing self emulsifying drug delivery system in liquid and then in pellet form that would result in improved solubility, dissolution and permeability of the poorly water soluble drug carvedilol. Pellets were prepared using extrusion-spheronization technique incorporating liquid SEDDS (carvedilol, capmul MCM EP, cremophore EL, tween 20, propylene glycol, adsorbents ( and crospovidone, microcrystalline cellulose and binder (povidone K-30. Ternary phase diagram was constructed to identify different oil-surfactant-cosurfactant mixtures according to the proportion of each point in it. The optimal CAR-SEDDS pellets showed a quicker redispersion with a droplet size of the reconstituted microemulsion being 160.47 nm, which was almost unchanged after solidification. SEM analysis confirmed good spherical appearance of solid pellets; DSC and XRD analysis confirmed that there was no crystalline carvedilol in the pellets. Pellets were then capable of transferring lipophilic compounds into the aqueous phase and significantly enhancing its release with respect to pure drug.

  16. Development and validation of a railgun hydrogen pellet injector model

    Energy Technology Data Exchange (ETDEWEB)

    King, T.L. [Univ. of Houston, TX (United States). Dept. of Electrical and Computer Engineering; Zhang, J.; Kim, K. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering

    1995-12-31

    A railgun hydrogen pellet injector model is presented and its predictions are compared with the experimental data. High-speed hydrogenic ice injection is the dominant refueling method for magnetically confined plasmas used in controlled thermonuclear fusion research. As experimental devices approach the scale of power-producing fusion reactors, the fueling requirements become increasingly more difficult to meet since, due to the large size and the high electron densities and temperatures of the plasma, hypervelocity pellets of a substantial size will need to be injected into the plasma continuously and at high repetition rates. Advanced technologies, such as the railgun pellet injector, are being developed to address this demand. Despite the apparent potential of electromagnetic launchers to produce hypervelocity projectiles, physical effects that were neither anticipated nor well understood have made it difficult to realize this potential. Therefore, it is essential to understand not only the theory behind railgun operation, but the primary loss mechanisms, as well. Analytic tools have been used by many researchers to design and optimize railguns and analyze their performance. This has led to a greater understanding of railgun behavior and opened the door for further improvement. A railgun hydrogen pellet injector model has been developed. The model is based upon a pellet equation of motion that accounts for the dominant loss mechanisms, inertial and viscous drag. The model has been validated using railgun pellet injectors developed by the Fusion Technology Research Laboratory at the University of Illinois at Urbana-Champaign.

  17. Modeling operation mode of pellet boilers for residential heating

    Science.gov (United States)

    Petrocelli, D.; Lezzi, A. M.

    2014-11-01

    In recent years the consumption of wood pellets as energy source for residential heating lias increased, not only as fuel for stoves, but also for small-scale residential boilers that, produce hot water used for both space heating and domestic hot water. Reduction of fuel consumption and pollutant emissions (CO, dust., HC) is an obvious target of wood pellet boiler manufacturers, however they are also quite interested in producing low- maintenance appliances. The need of frequent maintenance turns in higher operating costs and inconvenience for the user, and in lower boiler efficiency and higher emissions also. The aim of this paper is to present a theoretical model able to simulate the dynamic behavior of a pellet boiler. The model takes into account many features of real pellet boilers. Furthermore, with this model, it is possible to pay more attention to the influence of the boiler control strategy. Control strategy evaluation is based not only on pellet consumption and on total emissions, but also on critical operating conditions such as start-up and stop or prolonged operation at substantially reduced power level. Results are obtained for a residential heating system based on a wood pellet boiler coupled with a thermal energy storage. Results obtained so far show a weak dependence of performance in terms of fuel consumption and total emissions on control strategy, however some control strategies present some critical issues regarding maintenance frequency.

  18. Advanced turbine/CO{sub 2} pellet accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Foster, C.A.; Fisher, P.W.

    1994-09-01

    An advanced turbine/CO{sub 2} pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory. The program, sponsored by Warner Robins Air Logistics Center, Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air sandblast pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies. Applications include removal of epoxy-based points from aircraft and the cleaning of surfaces contaminated with toxic, hazardous, or radioactive substances. The lack of a secondary contaminated waste stream is of great benefit.

  19. Roll pelleting. Evaluation of a new technique for producing pellets from bioash suitable for forest nutrient; Valspelletering. Utvaerdering och uppfoeljning av pilotprojekt omfattande ny teknik foer framstaellning av pellets foer aaterfoering av bioaska till skogsmark

    Energy Technology Data Exchange (ETDEWEB)

    Windelhed, Kjell [Sycon Teknikkonsult AB, Stockholm (Sweden)

    2000-05-01

    Roll pelleting has earlier been tested in laboratory scale as a technique for processing wood ash to a product suitable to be spread into forest and thereby returning mineral nutrients to forest soils. The roll pelleting technique for producing pellets has, in this project, been evaluated in full scale. A container-based pelleting machine has been tested during nine months in AssiDomaen Froevi and Stora Enso Fors. Totally about 1500 tons of pellets were produced. The project started with a laboratory leach study. This study showed that pellets produced in a laboratory pelleting machine has a very low leach rate, in fact so low that the pellets seems possible to be spread on clearcuts. The pelleting machine was designed for a capacity of 5 tons per hour but the test indicated that production of 10 tons per hour was possible. The evaluation showed that this technique is suitable for producing pellets intended for returning nutrients to forest soils. However, it is important to start with a well humidified wood ash and to connect the control system for the humidification mixer with the pelleting machine to get an automatic system. Further, spreading of the pellets with a common disc spreader has been tested. The test turned out successful.

  20. Miocene cyclopid copepod from a saline paleolake in Mojave, California

    Directory of Open Access Journals (Sweden)

    Maria Hołyńska

    2016-06-01

    Full Text Available There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene–early Eocene; (ii Eocene termination of the Thulean land connection might have resulted in the

  1. Testing phenanthrene distribution properties of virgin plastic pellets and plastic eroded pellets found on Lesvos island beaches (Greece).

    Science.gov (United States)

    Karapanagioti, Hrissi K; Klontza, Irene

    2008-05-01

    Plastic pellets have been characterized as toxic pollutant carriers throughout the world oceans and coastal zones. However, their sorptive properties are not yet well understood. In the present study, virgin pellets and plastic eroded pellets (PEP) are used to elucidate their distribution characteristics through distribution kinetic studies. Distribution occurs through diffusion into the pellet for all materials (polyethylene, polyoxymethylene, and PEP) except polypropylene (PP). Although diffusion into the polymer happens with similar rates for both freshwater and saltwater external solutions, apparent diffusion is dependent on the solution salinity because it results in higher equilibrium distribution coefficients. Distribution coefficient into the PEP is higher and diffusion is slower than into the virgin materials. This is attributed to increased crystallinity of the PEP due to weathering. PP demonstrates diffusion rates that are increased by salinity and is apparently faster than into the other polymers suggesting a surface diffusion process.

  2. Tumour-like anomaly of copepods-an evaluation of the possible causes in Indian marine waters.

    Science.gov (United States)

    Jagadeesan, L; Jyothibabu, R

    2016-04-01

    Globally, tumour-like anomalies (TLA) in copepods and the critical assessment of their possible causes are rare. The exact causative factor and ecological consequences of TLA in copepods are still unclear and there is no quantitative data available so far to prove conclusively the mechanism involved in developing TLA in copepods. TLA in copepods are considered as a potential threat to the well-being of the aquatic food web, which prompted us to assess these abnormalities in Indian marine waters and assess the possible etiological agents. We carried out a focused study on copepods collected from 10 estuarine inlets and five coastal waters of India using a FlowCAM, advanced microscopes and laboratory-incubated observations. The analysis confirmed the presence of TLA in copepods with varying percentage of incidence in different environments. TLA was recorded in 24 species of copepods, which constituted ~1-15 % of the community in different environments. TLA was encountered more frequently in dominant copepods and exhibited diverse morphology; ~60 % was round, dark and granular, whereas ~20 % was round/oval, transparent and non-granular. TLA was mostly found in the dorsal and lateral regions of the prosome of copepods. The three suggested reasons/assumptions about the causes of TLA such as ecto-parasitism (Ellobiopsis infection), endo-parasitism (Blastodinium infection) and epibiont infections (Zoothamnium and Acineta) were assessed in the present study. We did find infections of endo-parasite Blastodinium, ecto-parasite Ellobiopsis and epibiont Zoothamnium and Acineta in copepods, but these infectious percentages were found <1.5 % to the total density and most of them are species specific. Detailed microscopical observations of the samples collected and the results of the incubation experiments of infected copepods revealed that ecto-parasitism, endo-parasitism and epibiont infections have less relevance to the formation of TLA in copepods. On the other hand

  3. Methods to ensure optimal off-bottom and drill bit distance under pellet impact drilling

    OpenAIRE

    Kovalev, Artem Vladimirovich; Isaev, Evgeniy Dmitrievich; Vagapov, A. R.; Urnish, V. V.; Ulyanova, Oksana Sergeevna

    2016-01-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rock for various purposes. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The paper presents the surve...

  4. Fecal microbiota transplantation inducing remission in Crohn's colitis and the associated changes in fecal microbial profile.

    Science.gov (United States)

    Kao, Dina; Hotte, Naomi; Gillevet, Patrick; Madsen, Karen

    2014-08-01

    Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the intestine of unclear etiology. Increasing evidence has pointed to intestinal dysbiosis as a potential factor in a genetically susceptible individual. Fecal microbiota transplantation (FMT) has been used to treat inflammatory bowel disease with variable degrees of success. Herein, we report a patient with Crohn's colitis, previously failing an immunosuppressant, who achieved clinical, endoscopic, and histologic remission after a single fecal microbiota transplantation infusion. We have further characterized the changes in the fecal microbiota associated with this observation.

  5. Measurement of persistent organic pollutants (POPs) in plastic resin pellets from remote islands: toward establishment of background concentrations for International Pellet Watch.

    Science.gov (United States)

    Heskett, Marvin; Takada, Hideshige; Yamashita, Rei; Yuyama, Masaki; Ito, Maki; Geok, Yeo Bee; Ogata, Yuko; Kwan, Charita; Heckhausen, Angelika; Taylor, Heidi; Powell, Taj; Morishige, Carey; Young, Doug; Patterson, Hugh; Robertson, Bryson; Bailey, Elizabeth; Mermoz, Jorge

    2012-02-01

    Plastic resin pellets collected from remote islands in the Pacific, Atlantic, and Indian Oceans and the Caribbean Sea were analyzed for polychlorinated biphenyls (PCBs), dichloro-diphenyltrichloroethane and its degradation products (DDTs), and hexachlorocyclohexanes (HCHs). Concentrations of PCBs (sum of 13 congeners) in the pellets were 0.1-9.9 ng/g-pellet. These were 1-3 orders of magnitude smaller than those observed in pellets from industrialized coastal shores. Concentrations of DDTs in the pellets were 0.8-4.1 ng/g-pellet. HCH concentrations were 0.6-1.7 ng/g-pellet, except for 19.3 ng/g-pellet on St. Helena, where current use of lindane is likely influence. This study provides background levels of POPs (PCBspollutants on plastic debris.

  6. Influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers fed on wheat-based diets.

    Science.gov (United States)

    Abdollahi, M R; Ravindran, V; Wester, T J; Ravindran, G; Thomas, D V

    2013-06-01

    1. The influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers given wheat-based diets was examined from 10 to 42 d of age. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two pellet diameters (3 and 4.76 mm) and two pellet lengths (3 and 6 mm). From 0 to 9 d of age, all birds were offered a common starter diet pelleted with a 3-mm diameter die and 3-mm length. Broiler grower (d 10 to 21) and finisher (d 22 to 42) diets, based on wheat, were formulated and then subjected to the 4 different treatments. 2. In grower diets, increasing pellet diameter and pellet length reduced the gelatinised starch (GS) content of the diets. In finisher diets, GS content of 3-mm diameter pellets did not change with increasing pellet length but decreased in 4.76-mm diameter pellets. 3. In grower and finisher diets, increments in intact pellet weight, pellet durability index and pellet hardness with increasing pellet length were greater in 3-mm diameter pellets than those with 4.76-mm diameter. 4. Increasing pellet length from 3 to 6 mm increased apparent metabolisable energy values. Neither the interaction nor main effects were significant for the ileal digestibility of nitrogen and starch. 5. During the grower period (d 10 to 21), birds given pellets of 6-mm length had greater body-weight gain than those given 3-mm length pellets. Feeding 6-mm length pellets decreased feed per body-weight gain compared to 3-mm length pellets. During the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods, while different pellet lengths had no effect on feed per body-weight gain values at 3-mm pellet diameter, increasing the pellet length decreased feed per body-weight gain at 4.76-mm pellet diameter. 6. Increasing pellet diameter and pellet length reduced the relative length of duodenum. Birds given 3-mm diameter pellets had heavier proventriculus compared to

  7. Roasting Properties of Pellets With Iron Concentrate of Complex Mineral Composition%Roasting Properties of Pellets With Iron Concentrate of Complex Mineral Composition

    Institute of Scientific and Technical Information of China (English)

    FAN Jian-jun; QIU Guan-zhou; JIANG Tao; GUO Yu-feng; CAI Mei-xia

    2011-01-01

    Investigation was conducted on roasting properties of pellets with an iron concentrate of complex mineral composition. The results indicated that the pellets of complex mineral composition concentrate required higher pre- heating temperature and longer pr

  8. Effects of dietary fiber on gastrointestinal transit time, fecal properties and fat absorption in rats.

    Science.gov (United States)

    Munakata, A; Iwane, S; Todate, M; Nakaji, S; Sugawara, K

    1995-08-01

    The gastrointestinal transit time of food was determined by x-ray fluoroscopy using barium sulfate in rats fed with diets of various dietary fiber contents, and the effects of dietary fiber on the transit time, properties of feces, and fat absorption were examined. In 4- and 16-month-old rats fed with the diet for 3 and 15 month, respectively, the transit time of the cecum and colon in those receiving 20 and 40% wheat bran diets was shortened compared with that in the 0% group. The fecal pellet number and volume increased as the wheat bran content of the diet increased. In another experiments, the daily total fat excretion was found to be the greatest in rats receiving 15% pectin diet, followed by rats receiving 15% cellulose and non-fiber diets, respectively. These results suggest that shortening of the transit time through the cecum and colon with increase of fecal volume and suppression of fat absorption all participate in the mechanism of the inhibitory action of wheat bran on carcinogenesis and on the development of diverticulum of the large intestine.

  9. Comparison of novel granulated pellet-containing tablets and traditional pellet-containing tablets by artificial neural networks.

    Science.gov (United States)

    Huang, Ying; Yao, Qinghe; Zhu, Chune; Zhang, Xuan; Qin, Lingzhen; Wang, Qinruo; Pan, Xin; Wu, Chuanbin

    2015-01-01

    Novel granulated pellets technique was adopted to prepare granulated pellet-containing tablets (GPCT). GPCT and traditional pellet-containing tablets (PCT) were prepared according to 29 formulations devised by the Design Expert 7.0, with doxycycline hydrochloride as model drug, blends of Eudragit FS 30D and Eudragit L 30D-55 as coating materials, for the comparison study to confirm the superiority of GPCT during compaction. Eudragit FS 30D content, coating weight gain, tablet hardness and pellet size were chosen as influential factors to investigate the properties and drug release behavior of tablets. The correlation coefficients between the experimental values and the predicted values by artificial neural networks (ANNs) for PCT and GPCT were 0.9474 and 0.9843, respectively, indicating the excellent prediction of ANNs. The similarity factors (f2) for release profiles of GPCT and the corresponding original pellets were higher than those of PCT, suggesting that the excipient layer of granulated pellets absorbed the compressing force and protected the integrity of coating films during compaction.

  10. Wood pellets and work environment; Traepiller og arbejdsmiljoe

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.

    2012-07-01

    The project aim was to evaluate the working environment in the production, transport and use of wood pellets. Furthermore, obtained knowledge and guidelines should be disseminated to relevant audiences. The first aim was achieved by making dust measurements at various relevant locations and analyze the results. Several technical problems regarding the measurements occurred during the project. In general, the manual handling of pellets often is a short-term task, which limits the amount of dust that can be collected on the sampling filter. The solution to this problem could be the use of in situ monitoring equipment, however, this technic did not work well for wood dust. Dissemination is mainly done by publishing the findings and guidelines on the webpage www.fyrmedpiller.dk. The result shows that there are widespread dust problems associated with the use and handling of pellets. The result may have been expected in the wood pellet industry, which has been reluctant to support this project. Legislation on the working environment has set a threshold limit for the dust concentration in the air on max 1 mg of dust per cubic meters of air over a working day and in over shorter periods this limit may be doubled. These threshold values were exceeded in many cases. Brief overview: The production of pellets takes place in a very dusty working environment, but the specific pelletizing and bagging processes only produce limited amounts of dust. The dust problems are major in the large warehouses where the handling of the raw material for the pellets increases the dust concentration in the air to levels that by far exceeds the legal threshold values. The work is mainly carried out from the cabin of different machines e.g. loaders and bobcats. It turns out that the average dust concentration in these cabins with filters also exceeds the threshold values. The transports of wood pellets include loading, unloading and delivery of loose pellets, all situations that are critical

  11. Experimental Evaluation of Koala Scat Persistence and Detectability with Implications for Pellet-Based Fauna Census

    Directory of Open Access Journals (Sweden)

    Romane H. Cristescu

    2012-01-01

    Full Text Available Establishing species distribution and population trends are basic requirements in conservation biology, yet acquiring this fundamental information is often difficult. Indirect survey methods that rely on fecal pellets (scats can overcome some difficulties but present their own challenges. In particular, variation in scat detectability and decay rate can introduce biases. We studied how vegetation communities affect the detectability and decay rate of scats as exemplified by koalas Phascolarctos cinereus: scat detectability was highly and consistently dependent on ground layer complexity (introducing up to 16% non-detection bias; scat decay rates were highly heterogeneous within vegetation communities; exposure of scats to surface water and rain strongly accelerated scat decay rate and finally, invertebrates were found to accelerate scat decay rate markedly, but unpredictably. This last phenomenon may explain the high variability of scat decay rate within a single vegetation community. Methods to decrease biases should be evaluated when planning scat surveys, as the most appropriate method(s will vary depending on species, scale of survey and landscape characteristics. Detectability and decay biases are both stronger in certain vegetation communities, thus their combined effect is likely to introduce substantial errors in scat surveys and this could result in inappropriate and counterproductive management decisions.

  12. Effect of Dietary Starch Source and Concentration on Equine Fecal Microbiota.

    Directory of Open Access Journals (Sweden)

    Brittany E Harlow

    Full Text Available Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only, HC (high corn, HO (high oats, LC (low corn, LO (low oats, and LW (low pelleted wheat middlings. Horses received an all-forage diet (2 wk; d -14 to d -1 before the treatment diets (2 wk; d 1 to 14. Starch was introduced gradually so that horses received 50% of the assigned starch amount (high = 2 g starch/kg BW; low = 1 g starch/kg BW by d 4 and 100% by d 11. Fecal samples were obtained at the end of the forage-only period (S0; d -2, and on d 6 (S1 and d 13 (S2 of the treatment period. Cellulolytics, lactobacilli, Group D Gram-positive cocci (GPC, lactate-utilizers and amylolytics were enumerated. Enumeration data were log transformed and analyzed by repeated measures ANOVA. There were sample day × treatment interactions (P 0.05. All treatments except LO resulted in increased amylolytics and decreased cellulolytics, but the changes were larger in horses fed corn and wheat middlings (P < 0.05. Feeding oats resulted in increased lactobacilli and decreased GPC (P < 0.05, while corn had the opposite effects. LW had increased lactobacilli and GPC (P < 0.05. The predominant amylolytic isolates from HC, LC and LW on S2 were identified by 16S RNA gene sequencing as Enterococcus faecalis, but other species were found in oat fed horses. These results demonstrate that starch source can have a differential effect on the equine fecal microbiota.

  13. Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

    Directory of Open Access Journals (Sweden)

    Stefanie Wolfram

    Full Text Available Polyunsaturated aldehydes (PUAs are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

  14. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Science.gov (United States)

    Guo, Zhiling; Liu, Sheng; Hu, Simin; Li, Tao; Huang, Yousong; Liu, Guangxing; Zhang, Huan; Lin, Senjie

    2012-01-01

    Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA)-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups), six (containing 99% of all the sequences) belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus), and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  15. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Directory of Open Access Journals (Sweden)

    Zhiling Guo

    Full Text Available Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups, six (containing 99% of all the sequences belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus, and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  16. 78 FR 12763 - Fecal Microbiota for Transplantation; Public Workshop

    Science.gov (United States)

    2013-02-25

    ... HUMAN SERVICES Food and Drug Administration Fecal Microbiota for Transplantation; Public Workshop AGENCY... ``Fecal Microbiota for Transplantation.'' The purpose of the public workshop is to exchange information... fecal microbiota for transplantation (FMT). ] Date and Time: The public workshop will be held on May...

  17. Glucagon-like peptide (GLP-1) is involved in the central modulation of fecal output in rats.

    Science.gov (United States)

    Gülpinar, M A; Bozkurt, A; Coşkun, T; Ulusoy, N B; Yegen, B C

    2000-06-01

    In addition to its insulinotropic action, exogenously administered glucagon-like peptide (GLP-1) inhibits gastropancreatic motility and secretion via central pathways. The aims of the present study were to evaluate the effects of exogenous GLP-1-(7-36) amide on fecal output and to investigate the role of endogenous GLP-1 on stress-induced colonic activity. With the use of a stereotaxic instrument, adult male Sprague-Dawley rats weighing 200-250 g were fitted with stainless steel cerebroventricular guide cannulas under ketamine anesthesia. A group of rats were placed in Bollman-type cages to induce restraint stress. Fecal output monitored for 2 h was increased significantly by intracerebroventricular GLP-1 to 500, 1, 000, and 3,000 pmol/rat (P corticotropin-releasing factor receptor antagonist astressin (10 microg/rat icv). The significant increase in fecal pellet output induced by restraint stress was also decreased by both intracerebroventricular exendin (10 nmol/rat) and astressin (10 microg/rat; Pmotility via its own receptor and that GLP-1 is likely to be a candidate brain-gut peptide that acts as a physiological modulator of stress-induced colonic motility.

  18. Therapeutic potential of fecal microbiota transplantation

    NARCIS (Netherlands)

    Smits, L.P.; Bouter, K.E.C.; Vos, de W.M.; Borody, T.J.; Nieuwdorp, M.

    2013-01-01

    There has been growing interest in the use of fecal microbiota for the treatment of patients with chronic gastrointestinal infections and inflammatory bowel diseases. Lately, there has also been interest in its therapeutic potential for cardiometabolic, autoimmune, and other extraintestinal conditio

  19. [Biofeedback effectiveness in patients with fecal incontinence].

    Science.gov (United States)

    Guerra-Mora, José Raúl; Buenrostro-Acebes, José María; Erciga-Vergara, Nancy; Zubieta-O'Farrill, Gregorio; Castillo-Calcáneo, Juan de Dios; Mosqueda, Maria Elena; Monroy-Argumedo, Montserrat; González-Alvarado, Carlos; Villanueva-Saenz, Eduardo

    2015-01-01

    Fecal incontinence is defined as an involuntary bowel movement through the anal canal in inadequate time and place. There are different types of therapies for the management of fecal incontinence, being biofeedback therapy one of the most effective techniques. The aim of this study was to evaluate the necessary number of sessions of biofeedback electromyographyc therapy to achieve the maximum sphincteric complex contraction. Descriptive, retrospective and longitudinal study. 65 patients with fecal incontinence were included. Weekly electromyographyc biofeedback therapies were applied, with a maximum of 6, in which the sphincteric complex contraction was measured. A two ways Friedman analysis was made to determine the significant differences between the sessions. A total of 65 patients were evaluated for fecal incontinence. The values for pelvic floor contraction were significantly higher in the third session, and did not show any significant difference in posterior sessions. The maximum contraction of the sphicnteric complex was achieved in the third weekly biofeedback session, without any significant differences in the posterior sessions.

  20. Therapeutic potential of fecal microbiota transplantation

    NARCIS (Netherlands)

    Smits, L.P.; Bouter, K.E.C.; Vos, de W.M.; Borody, T.J.; Nieuwdorp, M.

    2013-01-01

    There has been growing interest in the use of fecal microbiota for the treatment of patients with chronic gastrointestinal infections and inflammatory bowel diseases. Lately, there has also been interest in its therapeutic potential for cardiometabolic, autoimmune, and other extraintestinal conditio

  1. Fecal microbiota transplantation and donor standardization.

    Science.gov (United States)

    Owens, Casey; Broussard, Elizabeth; Surawicz, Christina

    2013-09-01

    Clostridium difficile diarrhea is a common and severe infectious disease. Antibiotics, which are standard initial treatment, are less effective for treating refractory or recurrent infection. Fecal microbiota transplantation, where healthy donor stool is transplanted into a patient, is an alternative to antibiotic therapy that requires standardization for donors and patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The use of chlorine dioxide for the inactivation of copepod zooplankton in drinking water treatment.

    Science.gov (United States)

    Lin, Tao; Chen, Wei; Cai, Bo

    2014-01-01

    The presence of zooplankton in drinking water treatment system may cause a negative effect on the aesthetic value of drinking water and may also increase the threat to human health due to they being the carriers of bacteria. Very little research has been done on the effects of copepod inactivation and the mechanisms involved in this process. In a series of bench-scale experiments we used a response surface method to assess the sensitivity of copepod to inactivation when chlorine dioxide (ClO₂) was used as a disinfectant. We also assessed the effects of the ClO₂dosage, exposure time, organic matter concentration and temperature. Results indicated that the inactivation rate improved with increasing dosage, exposure time and temperature, whereas it decreased with increasing organic matter concentration. Copepod inactivation was more sensitive to the ClO₂dose than that to the exposure time, while being maintained at the same Ct-value conditions. The activation energy at different temperatures revealed that the inactivation of copepods with ClO₂was temperature-dependent. The presence of organic matter resulted in a lower available dose as well as a shorter available exposure time, which resulted in a decrease in inactivation efficiency.

  3. Resting egg production induced by food limitation in the calanoid copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Hansen, Benni W.; Kiørboe, Thomas

    2011-01-01

    Three populations of the copepod Acartia tonsa, two from the Baltic Sea and one from the U.S. East Coast, were compared for resting egg production at conditions of saturating and limiting food availability. All three populations produced eggs that hatched within 72 h when incubated at 17°C (subit...

  4. Extreme temperature and oil contamination shape the relative abundance of copepod species in the Arctic

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    is of north Atlantic origin. Pyrene is one of the most toxic components of crude oil to marine copepods. The temperatures of 2, 6 and 10°C represent the mean sea water temperature, the 4°C increase in mean temperature by 2100 as predicted by IPCC scenario RCP8.5 (2013) and the extreme sea water temperature...

  5. Reading the copepod personal ads : increasing encounter probability with hydromechanical signals

    NARCIS (Netherlands)

    van Duren, LA; Stamhuis, EJ; Videler, JJ

    1998-01-01

    Females of the calanoid copepod Temora longicornis react to chemical exudates of male conspecifics with little hops, quite distinct from their normal smooth uniform swimming motion. These hops possibly serve to create a hydrodynamical signal in the surrounding water, to increase encounter probabilit

  6. First records of parasitic copepods (Crustacea, Siphonostomatoida) from marine fishes in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Soh, H Y; Hwang, U W; Chang, C Y; Myoung, J G

    2015-06-01

    The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided.

  7. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    ., 1999. Economic and social issues of biodiversity loss in Cochin backwaters. The Kerala Research Programme on Local Level Devel- opment, Report. Bastos, A.D., Silveira, M.S.C., Laureˆnia, M.B.A., Ernesto, H., 1996. Influence of the copepod Mesocyclops...

  8. Effects of copepod size on fish growth: A model based on data for North Sea sandeel

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Jørgensen, C.; Fiksen, Ø.

    2015-01-01

    mechanistic models from relevant data: (1) a model of the bioenergetics and stomach filling/evacuation dynamics, and (2) a Holling type II functional response model that encompasses visual range from basic principles. The model predicts that going from a situation where large Calanus copepods (2 mm) dominate...

  9. Escape from viscosity : the kinematics and hydrodynamics of copepod foraging and escape swimming

    NARCIS (Netherlands)

    van Duren, LA; Videler, JJ

    2003-01-01

    Feeding and escape swimming in adult females of the calanoid copepod. Temora lopgicornis Muller were investigated and compared. Swimming velocities were calculated using a 3-D filming setup., Foraging velocities ranged between 2 and 6 min s(-1), while maximum velocities of up to 80 mm s(-1) were rea

  10. Role of dispersants of oil on copepods in high arctic areas

    DEFF Research Database (Denmark)

    Gustavson, Kim; Nørregaard, Rasmus Dyrmose; Møller, Eva Friis

    2013-01-01

    The purpose of the project is to increase the knowledge on the effects of using dispersants on oil spills in high arctic areas: more precisely, to investigate accumulation in and effects on high arctic copepods. Such knowledge is crucial for performing a robust net environmental benefit analysis...

  11. Trophic interactions and productivity of copepods as live feed from tropical Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

    Blanda, Elisa; Drillet, Guillaume; Huang, Cheng-Chien

    2015-01-01

    of phytoplankton available in the ponds was high (value of chlorophyll a in average 97.7 ± 10.9 μg L− 1) and dominated by diatoms, flagellates and pico-algae. The estimated abundance and biomass of adult copepods and copepodites of P. annandalei was on average 93 ± 40 individuals L− 1 and 214 ± 98 μg C L− 1...... to enable a correct description of the copepods ecology and a preliminary evaluation of the status of the pond management; and (III) provide advices for improved management leading towards a higher and more stable output of P. annandalei. Copepods were experiencing prey ad libitum since the quantity......, respectively. P. annandalei's specific growth rate in the ponds, thus the secondary productivity, was 0.89 ± 0.1 d− 1 (average ± S.D.). The average harvest (21 kg of copepods wet weight per pond every second to fifth day), was a relatively low quantity to satisfy the demand of the fish farmers, especially...

  12. Ostrincola breviseti n. sp., a copepod parasite of an oyster from Penang, Malaysia

    NARCIS (Netherlands)

    Ho, Ju-shey; Kim, Il-Hoi

    1990-01-01

    A new species of poecilostomatoid copepod, Ostrincola breviseti, is described from the mantle cavity of the oyster, Saccostrea cucullata (Born), collected at Penang, Malaysia. The new species is distinguished by the short terminal setae on leg 5. The species of Ostrincola are discussed in terms of t

  13. A parameter for detecting estrogenic exposure in the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Andersen, Henrik Rasmus; Halling-Sørensen, Bent; Kusk, Kresten Ole

    1999-01-01

    in a steeper maturation profile. The proposed endpoint was identified by exposing copepods to the natural estrogen 17 beta-estradiol and the antropogenic estrogen bisphenol A. Both compounds produced significant effects at 23 and 20 mu g/L respectively. Since bisphenol A is traditionally believed to be less...

  14. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the

  15. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Visser, Andre; Richardson, Katherine

    2015-01-01

    Significance Every autumn across the North Atlantic, large numbers of zooplankton copepods migrate from the surface waters into the ocean's interior to hibernate at depths of 600–1,400 m. Through this migration, they actively transport lipid carbon to below the permanent thermocline, where it is ...

  16. Feeding season duration and the relative success of capital and income spawning copepods

    DEFF Research Database (Denmark)

    Sainmont, Julie; Varpe, Øystein; Andersen, Ken Haste;

    to the spring bloom, using only its reserves accumulated the previous year (capital breeder). The success of these two strategies is related to the length of the spring bloom, the only source of nutrients for these copepods. We use an individual based model to approach the question of income versus capital...

  17. Non-consumptive effects of predator presence on copepod reproduction: insights from a mesocosm experiment

    DEFF Research Database (Denmark)

    Heuschele, Jan; Ceballos, Sara; Borg, Marc Andersen;

    2014-01-01

    Reproduction in planktonic animals depends on numerous biotic and abiotic factors. One of them is predation pressure, which can have both direct consumptive effects on population density and sex ratio, and non-consumptive effects, for example on mating and migration behaviour. In copepods, predat...

  18. The parasitic copepod Lernaeocera branchialis negatively affects cardiorespiratory function in Gadus morhua

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Seth, H.; Axelsson, M.

    2014-01-01

    The parasitic copepod Lernaeocera branchialis had a negative effect on cardiorespiratory function in Atlantic cod Gadus morhua such that it caused pronounced cardiac dysfunction with irregular rhythm and reduced stroke amplitude compared with uninfected fish. In addition, parasite infection...... depressed the postprandial cardiac output and oxygen consumption...

  19. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the sterna

  20. Distribution of calanoid copepods in the Arabian sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.

    . Numerical abundance was high in the shelf stations. Secondary production considered in terms of copepod density showed the ratio 2:1 between the Arabian Sea and Bay of Bengal. The water column from the top layer of thermocline to surface was dominated...

  1. Synopsis of lichomolgid copepods (Poecilostomatoida) associated with soft corals (Alcyonacea) in the tropical Indo-Pacific

    NARCIS (Netherlands)

    Humes, A.G.

    1990-01-01

    A synopsis of the 97 species of lichomolgid copepods known to be associated with tropical IndoPacific shallow-water alcyonaceans is given (Madagascar, New Caledonia, Moluccas, Philippines, and Enewetak Atoll). One new genus and 29 new species are included, distributed among the lichomolgid genera Ac

  2. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes...

  3. Spatio-temporal distribution and production of calanoid copepods in the central Baltic Sea

    DEFF Research Database (Denmark)

    Hansen, F.C.; Möllmann, Christian; Schutz, U.

    2006-01-01

    The aim of our study was the exploration of species-specific distribution and production patterns of dominant copepods in the Central Baltic Sea (Bornholm Basin). Spatio-temporal distribution, egg and secondary production were studied by means of net-sampling and egg production experiments from A...

  4. Physiological improvement in the copepod Eurytemora affinis through thermal and multi-generational selection

    DEFF Research Database (Denmark)

    Souissi, Anissa; Souissi, Sami; Hansen, Benni Winding

    2016-01-01

    . First two different copepod lines were obtained after long-term culture at constant cold (7°C) and warm (20°C) temperatures. Then both populations were transferred to a higher temperature of 24°C appropriate for aquaculture use and followed during five generations. During the first two generations (F1–F...

  5. New hypogean cyclopoid copepods (Crustacea) from the Yucatán Peninsula, Mexico

    NARCIS (Netherlands)

    Fiers, Frank; Reid, Janet W.; Iliffe, Thomas M.; Suárez-Morales, Eduardo

    1996-01-01

    Four previously unknown hypogean species of cyclopoid copepods were collected in cenotes and wells of the Yucatán Peninsula, Mexico. Diacyclops chakan sp. n. and D. puuc sp. n. differ from their congeners in combining 3-segmented swimming legs, 11-segmented antennules, and legs 1-4 endopodite

  6. Increased tolerance to oil exposure by the cosmopolitan marine copepod Acartia tonsa.

    Science.gov (United States)

    Krause, Kamille Elvstrøm; Dinh, Khuong V; Nielsen, Torkel Gissel

    2017-12-31

    Oil contamination is an environmental hazard to marine ecosystems, but marine organism tolerance to oil after many generations of exposure remains poorly known. We studied the effects of transgenerational oil exposure on fitness-related traits in a cosmopolitan neritic copepod, Acartia tonsa. Copepods were exposed to an oil compound, the PAH pyrene, at concentrations of 1, 10, 100 and 100+(the saturated pyrene concentration in seawater)nM over two generations and measured survival, sex ratio, size at maturity, grazing rate and reproductive success. Exposure to the pyrene concentration of 100+nM resulted in 100% mortality before adulthood in the first generation. At the pyrene concentration of 100nM, pyrene reduced grazing rate, increased mortality, reduced the size of females and caused lower egg production and hatching success. Importantly, we found strong evidence for increased tolerance to pyrene exposure in the second generation: the reduction in size at maturity of females was less pronounced in the second generation and survival, egg production and hatching success were recovered to control levels in the second generation. The increased tolerance of copepods to oil contamination may dampen the direct ecological consequences of a coastal oil spill, but it raises the concern whether a larger fraction of oil components accumulated in survived copepods, may be transferred up the food web. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. A simple device for culturing marine calanoid copepods and notes on the biology of

    NARCIS (Netherlands)

    Yassen, S.T.

    1973-01-01

    A simple device for culturing marine calanoid copepods is described. Calanus helgolandicus Pacificus, Acartia clausi Giesbrecht, Temora longicornis Muller, and Eurytemora hirundoides Nordquist, were reared in this device. The latter had been bred in the laboratory for

  8. SWIMMING BEHAVIOR OF DEVELOPMENTAL STAGES OF THE CALANOID COPEPOD TEMORA-LONGICORNIS AT DIFFERENT FOOD CONCENTRATIONS

    NARCIS (Netherlands)

    VANDUREN, LA; VIDELER, JJ

    1995-01-01

    The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food concentration

  9. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes. E...

  10. Blind dating - mate finding in planktonic copepods. III. Hydromechanical communication in Acartia tonsa

    DEFF Research Database (Denmark)

    Bagoien, E.; Kiørboe, Thomas

    2005-01-01

    Mate-finding behaviour in the marine copepod Acartia tonsa was examined by video analysis. A. tonsa appears to depend on hydromechanical signals in the location of mates, detected at distances of up to 5 or 7 mm. Series of up to 7 or 8 synchronised hops in closely situated individuals, interpreted...

  11. New hypogean cyclopoid copepods (Crustacea) from the Yucatán Peninsula, Mexico

    NARCIS (Netherlands)

    Fiers, Frank; Reid, Janet W.; Iliffe, Thomas M.; Suárez-Morales, Eduardo

    1996-01-01

    Four previously unknown hypogean species of cyclopoid copepods were collected in cenotes and wells of the Yucatán Peninsula, Mexico. Diacyclops chakan sp. n. and D. puuc sp. n. differ from their congeners in combining 3-segmented swimming legs, 11-segmented antennules, and legs 1-4 endopodite segmen

  12. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the sterna

  13. Blind dating - mate finding in planktonic copepods. III. Hydromechanical communication in Acartia tonsa

    DEFF Research Database (Denmark)

    Bagoien, E.; Kiørboe, Thomas

    2005-01-01

    Mate-finding behaviour in the marine copepod Acartia tonsa was examined by video analysis. A. tonsa appears to depend on hydromechanical signals in the location of mates, detected at distances of up to 5 or 7 mm. Series of up to 7 or 8 synchronised hops in closely situated individuals, interpreted...

  14. Influence of LAS on marine calanoid copepod population dynamics and potential reproduction

    DEFF Research Database (Denmark)

    Christoffersen, Kirsten; Hansen, Benni Winding; Johansson, Liselotte Sander

    2003-01-01

    The toxicity of linear alkyl benzene sulfonate (LAS) to marine invertebrates is well documented under laboratory conditions using single-species tests. It is less known how LAS affects natural populations of aquatic organisms. We hypothesised that LAS was more toxic to the calanoid copepod Acarti...

  15. Biochemical composition of the promising live feed tropical calanoid copepod Pseudodiaptomus annandalei (Sewell 1919) cultured in Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

    Rayner, Thomas Allan; Jørgensen, Niels O. G.; Blanda, Elisa

    2015-01-01

    The use of copepods as live feed has shown good potential, and in Taiwan copepods are harvested specifically as live feed for fin-fish production. The calanoid copepod Pseudodiaptomus annandalei is a species found typically in Taiwanese aquaculture and in the rest of the Indo-Pacific region...... combined relative abundance of 21.8% of total fatty acid content. The fatty acid C20:4 n − 6 (ARA) was present in adult females and late stage nauplii. Overall, P. annandalei demonstrated good trophic transfer capabilities of HUFAs. Discrepancies between adult female and seston fatty acid profiles indicate...

  16. Proteocephalidean larvae (Cestoda in naturally infected cyclopid copepods of the upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    Dina Lúcia Morais Falavigna

    2003-01-01

    Full Text Available The occurrence, prevalence and infection intensity of proteocephalidean larvae in naturally infected intermediate hosts of the Upper Paraná River floodplain are reported. A total of 5,206 zooplanktonic and benthic organisms were analyzed, namely cyclopid (2,621 and calanoid (1,479 copepods, cladocerans (704, rotifers (307, chironomid larvae (41 and ostracods (54. Eight cyclopid copepods - two copepodids, one male and five females - comprising 0.3% of the cyclopid copepods examined, were naturally infected. The male infected belonged to a species of Paracyclops, and the females to Paracyclops sp., Thermocyclops minutus and Mesocyclops longisetus.

  17. Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill

    Science.gov (United States)

    Tumuluru, Jaya Shankar; Conner, Craig C.; Hoover, Amber N.

    2016-01-01

    A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 °C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was 510 kg/m3 and >98%, respectively, and the percent fine particles generated was reduced to <3%. PMID:27340875

  18. Influence of flux additives on iron ore oxidized pellets

    Institute of Scientific and Technical Information of China (English)

    FAN Xiao-hui; GAN Min; JIANG Tao; YUAN Li-shun; CHEN Xu-ling

    2010-01-01

    Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes the wet drop strength decrease firstly,and then increase with further increase of additive dosage.Ca(OH)2 affects the bentonite properties at the beginning,but the binding property of Ca(OH)2 will be main when the dosage is higher.The other four additives decrease the drop strength for their disadvantageous physical properties.For preheated pellets,no mater what kind of additive is added,the compressive strength will be decreased because of unmineralized additives.For roasted pellets,calcium additives can form binding phase of calcium-ferrite,and suitable liquid phase will improve recrystallization of hematite,but excessive liquid will destroy the structure of pellets,so the compressive strength of pellet increases firstly and then drops.When adding magnesium additives,the strength will be decreased because of the oxidation of magnetite retarded by MgO.

  19. Modifying ability of titanium-based pelleted master alloys

    Science.gov (United States)

    Bazhin, V. Yu.; Savchenkov, S. A.; Kosov, Ya. I.

    2017-05-01

    The problem of enhancing the quality of pressed titanium master alloys is discussed to increase the rate and degree of dissolution of their components and to ensure the formation of a fine-grained structure in aluminum alloys. A technology of producing a pelleted titanium master alloy for effective correction of the chemical composition of an aluminum alloy in casting is developed and tested. Incoming inspection of the component composition and the flux distribution in the volume of pressed pellets of various manufacturers is performed. The rate of dissolution of pressed powder master alloys in the aluminum melt is studied, and their modifying ability is estimated after studying the microstructures of cast blanks. Molasses is used as a binder in a pelleted master alloy. As a result, we achieved a uniform flux distribution over the pellet volume and the formation of uniform pores after annealing as compared pelleted master alloys of other manufacturers. The fabricated alloying briquettes have higher strength characteristics and their dissolution rate in the aluminum melt is higher than those of analogs by 15-20%.

  20. Studies on implementation of pellet tracking in hadron physics experiments

    Directory of Open Access Journals (Sweden)

    Pyszniak A.

    2014-01-01

    Full Text Available A system for optical tracking of frozen hydrogen microsphere targets (pellets has been designed. It is intended for the upcoming hadron physics experiment PANDA at FAIR, Darmstadt, Germany. With such a tracking system one can reconstruct the positions of the individual pellets at the time of a hadronic interaction in the offline event analysis. This gives information on the position of the primary interaction vertex with an accuracy of a few 100 µm, which is very useful e.g. for reconstruction of charged particle tracks and secondary vertices and for background suppression. A study has been done at the WASA detector setup (Forschungszentrum Jülich, Germany to check the possibility of classification of hadronic events as originating in pellets or in background. The study has been done based on the instantaneous rate a Long Range TDC which was used to determine if a pellet was present in the accelerator beam region. It was clearly shown that it is possible to distinguish the two event classes. Also, an experience was gained with operation of two synchronized systems operating in different time scales, as it will also be the case with the optical pellet tracking.

  1. Kinetics of isothermal reduction of stainless steelmaking dust pellets

    Institute of Scientific and Technical Information of China (English)

    PENG Ji(彭及); PENG Bing(彭兵); YU Di(余笛); TANG Mo-tang(唐谟堂); SONG Hai-chen(宋海琛); J.Lobel; J. A. Kozinski

    2004-01-01

    The stainless steelmaking dust pellets were reduced in isothermal temperature condition simulating the direct recycling practice in the stainless steel production and the kinetics of the reduction process was investigated.The pellets were formed after mixing the dust with carbon as the reducing agent and dolomite as the binder and smelting flux. An electric furnace was used to heat the pellets and an electrical microbalance was used to check the mass of the pellets in the reduction process. The reduction rate was calculated according to the data of pellet mass change in consideration of the evaporation of moisture, zinc and lead at high temperature. The results of the experiments show that the reduction process is in two consecutive stages. The reduction kinetic models were set up for each stage and the kinetic parameters such as activation energy and frequency factor were determined. The apparent activation energy of the first stage is 21.69 kJ/mol, and this stage is controlled by chemical reaction. The apparent activation energy of the second stage is 17.35 kJ/mol, and this stage is controlled by the diffusion of carbon monoxide through the resultants of reaction.

  2. Blower Gun pellet injection system for W7-X

    Energy Technology Data Exchange (ETDEWEB)

    Dibon, Mathias; Baldzuhn, Juergen; Beck, Michael; Lang, Peter; Ploeckl, Bernhard; Weisbart, Wolfgang [MPI fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Cardella, Antonio; Macian-Juan, Rafael [Lehrstuhl fuer Nukleartechnik, TU Munich, Boltzmannstr. 15, 85748 Garching (Germany); Koechl, Florian [Association EURATOM-OeAW/ATI, Atominstitut, TU Wien, 1020 Vienna (Austria); Kocsis, Gabor; Szepesi, Tamas [Wigner RCP, RMI, EURATOM Association, P.O.Box 49, H-1525 Budapest-114 (Hungary)

    2014-07-01

    Foreseen to serve for the new stellarator W7-X for pellet investigations, the former ASDEX Upgrade Blower Gun was revised and revitalized in a test bed. The gun is able now to launch cylindrical pellets of 2 mm diameter and 2 mm length, produced from frozen Deuterium (D{sub 2}) or Hydrogen (H{sub 2}). Pellets are accelerated by a short pulse of pressurized helium propellant gas to velocities in the range of 100-250 m/s. Delivery reliabilities at the launcher exit close to unity are achieved. For pellet transfer to the plasma vessel a first mock up guiding tube version was investigated. Transfer through this S-shaped (inner diameter 8 mm; length 6 m) stainless steel guiding tube containing two 1 m curvature radii was investigated for both H{sub 2} and D{sub 2} pellets. Tests were performed applying repetition rates from 2 Hz to 50 Hz and propellant gas pressures ranging from 1 bar to 6 bar. For both H{sub 2} and D{sub 2}, low overall delivery efficiencies were observed at slow repetition rates, but stable efficiencies of about 90% above 10 Hz.

  3. Massive Pellet and Rupture Disk Testing for Disruption Mitigation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephen Kirk [ORNL; Meitner, Steven J [ORNL; Baylor, Larry R [ORNL; Caughman, John B [ORNL; Commaux, Nicolas JC [ORNL; Fehling, Dan T [ORNL; Foust, Charles R [ORNL; Jernigan, Thomas C [ORNL; McGill, James M [ORNL; Parks, P. B. [General Atomics; Rasmussen, David A [ORNL

    2009-01-01

    Injection of massive quantities of noble gases or D2 has proven to be effective at mitigating some of the deleterious effects of disruptions in tokamaks. Two alternative methods that might offer some advantages over the present technique for massive gas injection are shattering massive pellets and employing close-coupled rupture disks. Laboratory testing has been carried out to evaluate their feasibility. For the study of massive pellets, a pipe gun pellet injector cooled with a cryogenic refrigerator was fitted with a relatively large barrel (16.5 mm bore), and D2 and Ne pellets were made and were accelerated to speeds of ~600 and 300 m/s, respectively. Based on the successful proof-of-principle testing with the injector and a special double-impact target to shatter pellets, a similar system has been prepared and installed on DIII-D and should be ready for experiments later this year. To study the applicability of rupture disks for disruption mitigation, a simple test apparatus was assembled in the lab. Commercially available rupture disks of 1 in. nominal diameter were tested at conditions relevant for the application on tokamaks, including tests with Ar and He gases and rupture pressures of ~54 bar. Some technical and practical issues of implementing this technique on a tokamak are discussed.

  4. Pyrolysis Model of Single Biomass Pellet in Downdraft Gasifier

    Institute of Scientific and Technical Information of China (English)

    薛爱军; 潘继红; 田茂诚; 伊晓璐

    2016-01-01

    By coupling the heat transfer equation with semi-global chemical reaction kinetic equations, a one-dimensional, unsteady mathematical model is developed to describe the pyrolysis of single biomass pellet in the pyrolysis zone of downdraft gasifier. The simulation results in inert atmosphere and pyrolysis zone agree well with the published experimental results. The pyrolysis of biomass pellets in pyrolysis zone is investigated, and the results show that the estimated convective heat transfer coefficient and emissivity coefficient are suitable. The mean pyro-lysis time is 15.22%, shorter than that in inert atmosphere, and the pellet pyrolysis process in pyrolysis zone belongs to fast pyrolysis. Among the pyrolysis products, tar yield is the most, gas the second, and char the least. During pyrolysis, the temperature change near the center is contrary to that near the surface. Pyrolysis gradually moves inwards layer by layer. With the increase of pyrolysis temperature and pellet diameter, the total pyrolysis time, tar yield, char yield and gas yield change in different ways. The height of pyrolysis zone is calculated to be 1.51—3.51 times of the characteristic pellet diameter.

  5. Quality effects caused by torrefaction of pellets made from Scots pine

    DEFF Research Database (Denmark)

    Shang, Lei; Nielsen, Niels Peter K.; Dahl, Jonas

    2012-01-01

    The purpose of the study was to investigate the influence of torrefaction on the quality of Scots pine pellets. Pellet samples were torrefied at 230, 250 and 270°C for 1h in nitrogen atmosphere. Higher heating value (HHV) was increased from 18.37MJkg−1 to 24.34MJkg−1. The energy to crush a pellet...... the pellet samples in a bench scale disc mill. Particle size distribution measurements after grinding indicated a significant increase of small particles (diameterca. 2mm). To further analyze the effect on strength, the mechanical durability of pellets was tested according to wood pellet standards, EN 15210......-1. The results have shown a good correlation between pellet durability and compression strength, and indicated that the pellet durability can be estimated based on compression strength data of about 25 pellets....

  6. Steatorrhea cannot be excluded where there is a fecal weight below 0.200 kg per day and a high fecal consistency

    DEFF Research Database (Denmark)

    Thirup, P

    1998-01-01

    We surveyed one year's results of fecal fat (feces alifatic carboxylates) analyses, which are used in the diagnosis of malabsorption (steatorrhea), by calculating the relationship between fecal fat, fecal weight (fecal mass excretion rate) and fecal consistency (in terms of the volume of water...

  7. Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export

    Science.gov (United States)

    Rembauville, M.; Blain, S.; Armand, L.; Quéguiner, B.; Salter, I.

    2015-06-01

    The biological composition of the material exported to a moored sediment trap located under the winter mixed layer of the naturally fertilized Kerguelen Plateau in the Southern Ocean was studied over an annual cycle. Despite iron availability in spring, the annual particulate organic carbon (POC) export (98.2 mmol m-2) at 289 m was low, but annual biogenic silica export was significant (114 mmol m-2). This feature was related to the abundance of empty diatom cells and the ratio of full to empty cells exerted a first-order control in BSi : POC export stoichiometry of the biological pump. Chaetoceros Hyalochaete spp. and Thalassiosira antarctica resting spores were responsible for more than 60% of the annual POC flux that occurred during two very short export events of 80%). The seasonal progression of faecal pellet types revealed a clear transition from small spherical shapes (small copepods) in spring, to larger cylindrical and ellipsoid shapes in summer (euphausiids and large copepods) and finally to large tabular shapes (salps) in autumn and winter. We propose in this high-biomass, low-export (HBLE) environment that small but highly silicified and fast-sinking resting spores are able to bypass the intense grazing pressure and efficient carbon transfer to higher trophic levels that are responsible for the low fluxes observed the during the remainder of the year. More generally our study also provides a statistical framework linking the ecological succession of diatom and zooplankton communities to the seasonality of carbon and silicon export within an iron-fertilized bloom region in the Southern Ocean.

  8. Effect of ocean acidification on the nutritional quality of phytoplankton for copepod reproduction

    Science.gov (United States)

    Meyers, M.; Cochlan, W. P.; Kimmerer, W.; Carpenter, E. J.

    2016-02-01

    Phytoplankton are the oceans' primary producers of essential polyunsaturated fatty acids (PUFA), which provide marine organisms with nutrients needed for health and reproduction. It is hypothesized that future ocean acidification (OA) conditions could change the availability of phytoplankton PUFAs for ecologically significant predators such as copepods, affecting their reproductive success. Three species of phytoplankton (Rhodomonas salina, Skeletonema marinoi, Prorocentrum micans) were cultured under present-day (400ppm CO2, pH 8.1) and predicted future (1000ppm CO2, pH 7.8) oceanic conditions. For four days, female Acartia tonsa copepods were fed a phytoplankton mixture from either the present-day or predicted-future treatment. To assess changes in phytoplankton PUFA content, fatty acid profiles were analyzed via capillary gas chromatography. Copepod egg production (EP), hatching success (HS), and egg viability (EV) were determined to assess copepod reproductive success. Fatty acid analysis shows essential PUFAs comprise a smaller percentage of total fatty acids in phytoplankton cultured under high pCO2 (Rho 21.5%; Ske 14.1%; Pro 14.4%) compared to those cultured under present-day pCO2 (Rho 28.8%, Ske 32.7%, Pro 39.3%). Copepod reproduction data demonstrate that females fed phytoplankton cultured under high pCO2 have significantly lower EP (μ=14.3 eggs female-1), HS (μ=35.8%), and EV (μ=12.5%) compared to reproductive success of females fed phytoplankton cultured under present-day CO2 (EP μ=27.0 eggs female-1; HS μ=91.5%; EV μ=96.6%). This study demonstrates that OA can change the nutritional quality of primary producers, which can affect the reproductive success of fundamental secondary consumers.

  9. Optimization of a multi-parameter model for biomass pelletization to investigate temperature dependence and to facilitate fast testing of pelletization behavior

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Stelte, Wolfgang; Posselt, Dorthe;

    2011-01-01

    and error” experiments and personal experience. However in recent years the utilization of single pellet press units for testing the biomass pelletizing properties has attracted more attention. The present study outlines an approach where single pellet press testing is combined with modeling to mimic......Pelletization of biomass residues increases the energy density, reduces storage and transportation costs and results in a homogeneous product with well-defined physical properties. However, raw materials for fuel pellet production consist of ligno-cellulosic biomass from various resources...

  10. Control System of Pellet Injector on the HT-7 Tokamak

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper the control system of the pellet injector is introduced in detail and the system mainly includes two parts: the present and the remote control system. The present control system controls the injector and provides the interface to the remote system. And the remote control system has acquired present signals with analog input card and perform the actions through digit output card, it also has an interface for Windows programming easily used by the operators when carrying out the pellet injection experiments. Through several HT-7 campaigns, the remote control system has been validated to be feasible and reliable and has made successful shots for studying the interactions between the pellets and plasma.

  11. Standard specification for sintered (Uranium-Plutonium) dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This specification covers finished sintered and ground (uranium-plutonium) dioxide pellets for use in thermal reactors. It applies to uranium-plutonium dioxide pellets containing plutonium additions up to 15 % weight. This specification may not completely cover the requirements for pellets fabricated from weapons-derived plutonium. 1.2 This specification does not include (1) provisions for preventing criticality accidents or (2) requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aware of and conform to all applicable international, federal, state, and local regulations pertaining to possessing, processing, shipping, or using source or special nuclear material. Examples of U.S. government documents are Code of Federal Regulations Title 10, Part 50Domestic Licensing of Production and Utilization Facilities; Code of Federal Regulations Title 10, Part 71Packaging and Transportation of Radioactive Material; and Code of Federal Regulations Tit...

  12. COMPRESSION AND SPRINGBACK PROPERTIES OF HARDWOOD AND SOFTWOOD PELLETS

    Directory of Open Access Journals (Sweden)

    Amarnath Dhamodaran,

    2012-07-01

    Full Text Available A multiple linear regression analysis was carried out to predict the length of pellets under compression in the die based on moisture, temperature, pressure, hold time, and their interaction terms. Excellent correlations were obtained in the dependency of the considered parameters on length of compressed material inside the die. Springback characteristics based on axial changes after the compaction process were analyzed. The expansion for hardwood pellets (16.28% was found to be lowest at particle size 0.150 to 0.300 mm with 8% moisture (w.b, 60 °C, 139.3 MPa pressure, and a hold time of 15S. The expansion for softwood pellets (20.56% was lowest with particle size 0.300 to 0.425 mm, at 8% moisture (w.b, 70 °C, 159.2 MPa, and a hold time of 30S.

  13. FORMULATION AND EVALUATION OF SUSTAINED RELEASE PELLETS OF TRAMADOL HYDROCHLORIDE

    Directory of Open Access Journals (Sweden)

    Baskara Haripriya

    2013-02-01

    Full Text Available The aim of the present research is to develop and evaluate a better sustained release multiple unit pellets (MUP formulation of Tramadol hydrochloride. Dissolution and diffusion controlled systems have classically been of primary importance in oral delivery of medication because of their relative ease of production and cost compared with other methods of sustained or controlled delivery. Most of these systems are solids, although a few liquids and suspension have been recently introduced. The present work aimed at developing SR pellets of Tramadol HCl by Wurster process. FTIR studies showed no unacceptable extra peaks which confirm the absence of chemical interaction between the drug and polymer. Angle of repose, tapped density, bulk density values for the formulations were within the range which indicates that pellets prepared by Wurster process were satisfactory for further studies. The percentage drug content of Tramadol was determined by extraction with methanol and analyzed by using UV-visible spectrophotometer at 271nm.

  14. Formation of particulate matter monitoring during combustion of wood pellete with additives

    Science.gov (United States)

    Palacka, Matej; Holubčík, Michal; Vician, Peter; Jandačka, Jozef

    2016-06-01

    Application additives into the material for the production of wood pellets achieve an improvement in some properties such as pellets ash flow temperature and abrasion resistance. Additives their properties influence the course of combustion, and have an impact on the results of issuance. The experiment were selected additives corn starch and dolomite. Wood pellets were produced in the pelleting press and pelletizing with the additives. Selected samples were tested for the production of particulate matter (PM) during their direct burn. The paper analyzing a process of producing wood pellets and his effect on the final properties.

  15. Efficacy of the Nematophagous Fungus ARF18 in Alginate-clay Pellet Formulations Against Heterodera glycines

    OpenAIRE

    Kim, D. G.; Riggs, R. D.

    1995-01-01

    Dry alginate-clay pellets containing mycelium of ARF18 were added to sandy soil in greenhouse tests to determine the formulation's efficacy in the suppression of Heterodera glycines. Pellet formulation variables included quantity of mycelium per pellet (0.0-3.9%), pellet size (2.3 or 8.3 mg), pellet application rate per unit soil (0.4 or 1.0% based on dry soil weight), and pellet storage (0 or 90 days). All of these variables affected efficacy. Nematode suppression was greatest (95%) with 8.3...

  16. Market review. Pellet wood gasification boiler / combination boiler. 8. ed.; Marktuebersicht. Scheitholzvergaser-/Kombikessel

    Energy Technology Data Exchange (ETDEWEB)

    Uth, Joern

    2012-01-15

    In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) reports on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

  17. Pellet wood gasification boiler / Combination boiler. Market review. 7. ed.; Scheitholzvergaser-/Kombikessel. Marktuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Uth, Joern

    2010-08-15

    In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) report on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

  18. Investigation for the quality factors on the tablets containing medicated pellets

    Directory of Open Access Journals (Sweden)

    Xueying Tan

    2016-09-01

    Full Text Available Sustained and controlled pellets are considered as one of the ideal dosage forms. Due to the large coverage area of pellets, loaded drugs can be absorbed completely in the body and bioavailability is improved correspondingly. Coated pellets-containing tablet is a special oral formulation consisting of various pellets with different release rate. Desired rate of drug release rate can be achieved by adjusting the proportion of pellets. However, this formulation faces strict requirements in the process of preparation. Several factors will influence release behavior of tablets, including pellet cores, coating, and tabletting. Therefore, these factors will be investigated sufficiently in this review to provide valuable information for manufacturing process.

  19. Development of wood pellets market in South East Europe

    Directory of Open Access Journals (Sweden)

    Glavonjić Branko D.

    2015-01-01

    Full Text Available The paper presents the results of researching wood pellets market in nine countries in South East Europe and Slovakia. Objective of the research was to observe the actual situation regarding the number of producers, size of installed capacities, production volume, foreign trade flows and existing problems and obstacles which significantly limit the sustainable development of wood pellets market in the selected countries. Selection of such an objective results from the fact that according to the stated elements there are no sufficiently reliable data, wherefore this region is a huge gap in numerous reports of international and national organizations and institutions. Results of the conducted research show that in the middle of 2014, 245 producers were engaged in wood pellets production in South East Europe and Slovakia, 116 of which were located in Bulgaria and Serbia. Most of the producers of wood pellets has installed capacities of 1,000-5,000 tons annually, while only 18 factories in the entire region have the installed capacity over 30,000 tons/year. Observed collectively in all stated countries, the total installed capacities for wood pellets production were 2.2 million tons in 2013 and the realized production was 1.36 million tons. The largest part of the produced amounts of wood pellets in this region is exported. 1.06 million tons were exported from the region in 2013, which is 77.9% of the realized production. Such high export is the result of the underdevelopment of the local market (Slovenia is the only exception and the problems which exist and limit its faster development in most countries.

  20. Hydro-mechanical behaviour of bentonite pellet mixtures

    Science.gov (United States)

    Hoffmann, C.; Alonso, E. E.; Romero, E.

    Granular mixtures made of high-density pellets of bentonite are being evaluated as an alternative buffer material for waste isolation. Ease of handling is an often-mentioned advantage. The paper described the experimental program performed to characterize the hydro-mechanical behaviour of compacted pellet’s mixtures used in the engineered barrier (EB) experiment. The material tested in the laboratory was based in the pellet’s mixtures actually used for the emplacement of the EB in situ experiment. Grain size distribution was adjusted to a maximum pellet size compatible with the specimen’s dimensions. Dry densities of statically compacted specimens varied in most of the cases in the range: 1.3-1.5 Mg/m 3. Pellets had a very high dry density, close to 2 Mg/m 3. The outstanding characteristic of these mixtures is its discontinuous porosity. Pore sizes of the compacted pellets vary around 10 nm. However the inter-pellet size of the pores is four to five orders of magnitude higher. This double porosity and the highly expansive nature of the pellets controlled all the hydraulic and mechanical properties of the mixture. Tests performed include infiltration tests using different water injection rates and mechanisms of water transfer (in liquid and vapour phases), suction controlled oedometer tests and swelling pressure tests. The interpretation of some of the tests performed required backanalysis procedures using a hydro-mechanical (HM) computer code. Material response was studied within the framework of the elastoplastic constitutive model proposed by Alonso et al. [Alonso, E.E., Gens, A., Josa, A., 1990. A constitutive model for partially saturated soils. Géotechnique 40 (3), 405-430] (Barcelona Basic Model, BBM). Parameters for the model were identified and also a set of hydraulic laws necessary to perform coupled HM analysis.

  1. Penetrating facial injury with an "Airsoft" pellet: a case report.

    Science.gov (United States)

    Strong, Ben; Coady, Martin

    2014-11-01

    Airsoft is a recreational combat sport that originated in Japan in the 1970s and is currently increasing in popularity in the UK. Participants use air or electrically powered weapons to fire small plastic pellets at a controlled pressure. UK law strictly regulates the maximum muzzle velocity and the type of ammunition used in these weapons. A search of published papers found several reports of penetrating ocular injuries caused by Airsoft pellets, but no reports of penetrating injuries to other areas of the body. We report the case of a 25-year-old man who sustained a penetrating injury to the cheek after being shot with an Airsoft weapon.

  2. Development of machine vision system for PHWR fuel pellet inspection

    Energy Technology Data Exchange (ETDEWEB)

    Kamalesh Kumar, B.; Reddy, K.S.; Lakshminarayana, A.; Sastry, V.S.; Ramana Rao, A.V. [Nuclear Fuel Complex, Hyderabad, Andhra Pradesh (India); Joshi, M.; Deshpande, P.; Navathe, C.P.; Jayaraj, R.N. [Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh (India)

    2008-07-01

    Nuclear Fuel Complex, a constituent of Department of Atomic Energy; India is responsible for manufacturing nuclear fuel in India . Over a million Uranium-di-oxide pellets fabricated per annum need visual inspection . In order to overcome the limitations of human based visual inspection, NFC has undertaken the development of machine vision system. The development involved designing various subsystems viz. mechanical and control subsystem for handling and rotation of fuel pellets, lighting subsystem for illumination, image acquisition system, and image processing system and integration. This paper brings out details of various subsystems and results obtained from the trials conducted. (author)

  3. Control System for the NSTX Lithium Pellet Injector

    Energy Technology Data Exchange (ETDEWEB)

    P. Sichta; J. Dong; R. Gernhardt; G. Gettelfinger; H. Kugel

    2003-10-27

    The Lithium Pellet Injector (LPI) is being developed for the National Spherical Torus Experiment (NSTX). The LPI will inject ''pellets'' of various composition into the plasma in order to study wall conditioning, edge impurity transport, liquid limiter simulations, and other areas of research. The control system for the NSTX LPI has incorporated widely used advanced technologies, such as LabVIEW and PCI bus I/O boards, to create a low-cost control system which is fully integrated into the NSTX computing environment. This paper will present the hardware and software design of the computer control system for the LPI.

  4. Quality of Pelleted Olive Cake for Energy Generation

    Directory of Open Access Journals (Sweden)

    Tea Brlek

    2014-02-01

    Full Text Available Normal 0 21 false false false SR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olive cake is by-product of olive oil production. This material cannot be stored in original condition for a long time because it has high water content and relatively high portion of oil that causes rapid deterioration. Thus it is necessary to investigate possible methods of remediation of such by-product, where utilization for energy generation presents a useful option. Several studies have been conducted on energy generation from olive cake, however not one that includes pelleting as a pre-treatment. Therefore, the aim of this paper was to determine the chemical composition of different cultivars of olive cake, to produce pellets, and determine their basic quality parameters. The pellets obtained from olive cake had mainly satisfactory results regarding their quality in comparison to standards for fuel pellets. It should be kept in mind that these standards are manly for wood pellets, and therefore some lower criteria could be applied for olive cake and such biomass. The highest amount of residual oil and the lowest amount of protein was found in cultivar ‘Buža’ and produced pellets had the smallest abrasion index (8.15%. Other cultivars had lower oil and higher protein content, and abrasion index

  5. Heat-resistant bacterial phytase in broiler pelleted diets

    Directory of Open Access Journals (Sweden)

    TC de F Carlos

    2015-03-01

    Full Text Available The objective of the study was to evaluate the effects of a heat-resistant bacterial phytase added to pelleted diets on mineral digestibility, live performance, carcass traits, and bone quality of broilers. Three treatments were evaluated: Positive control; negative control, with 0.10 points reduction in calcium level and 0.15 points reduction in available phosphorus level; and negative control + phytase at 500 FTU/kg. Mineral digestibility and bone quality results demonstrated that the evaluated phytase resisted pelleting as it increased the utilization of the minerals present in the diet.

  6. Automated explosive pellet manufacturing using a PDP-14 programmable controller

    Energy Technology Data Exchange (ETDEWEB)

    Page, D.O.

    1976-10-29

    A Digital Equipment Corporation PDP-14 Industrial Programmable Controller was employed to provide automatic, closed-loop control for an explosive pellet manufacturing system at Mound Laboratory. Programmable controllers allow the application of sophisticated and flexible control, through programming. Advantages of the PDP-14 controller are ease of installation and maintenance, capability for modular expansion, and immunity to electrical noise. Safety requirements were met by using new techniques for adapting electrical equipment to a hazardous environment and by locating the PDP-14 remotely outside the explosive area. Another advantage of the new explosion proofing (EP) methods/equipment was that they produced a minimum of clutter on the controlled explosive pellet manufacturing system.

  7. Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

    DEFF Research Database (Denmark)

    Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

    Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... (photobioreactor - PBR). There is an increasing interest in using closed PBRs for algae cultivation since this culture system provides a better control of cultivation conditions and enables higher algae productivity. Among the marine microalgae, the cryptophyte Rhodomonas salina is one of the optimal feed...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...

  8. First record of the Calanoid Copepod Pseudodiaptomus serricaudatus (Scott, T. 1894), (Copepoda: Calanoida: Pseudodiaptomidae) in the equatorial Indian ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Rebello, V.; Narvekar, J.; Gadi, P.; Venenkar, A.; Gauns, M.; PrasannaKumar, S.

    , Pondicherry University, Port Blair, Andaman 3Happy Home Apartment, Near Canara Bank, Fatorda, Margao, Goa-403602 Abstract Pseudodiaptomus serricaudatus (Scott, T. 1894), a planktonic copepod belonging to the family Pseudodiaptomidae, though has...

  9. Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics.

    Science.gov (United States)

    Araujo, Adriana V; Dias, Cristina O; Bonecker, Sérgio L C

    2017-02-15

    We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of "Estuarine Quality Paradox". Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Influence of algal diet on feeding and egg-production of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Jensen, Johanne

    1990-01-01

    Threshold concentration, retention efficiency and egg-production in the calanoid copepod Acartia tonsa Dana were examined using the algal species Isochrysis galbana clone T-iso, Dunalietta tertiolecta Butcher, Rhodomonas baltica Karsten, Ditylum brightwellii Grunow and Thalassiosira weissflogii...

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    Experiments were conducted on the calanoid copepods, Acartia spinicauda (Acartiidae) and Heliodiaptomus cinctus (Diaptomidae) in order to determine food preference and survival rates respectively. Adults of A. spinicauda were fed monocultures...

  12. Pelletizing/reslurrying as a means of distributing and firing clean coal

    Energy Technology Data Exchange (ETDEWEB)

    Conkle, H.N.

    1992-06-09

    Work in this quarter focused on completing (1) the final batch of pilot-scale disk pellets, (2) storage, handling, and transportation evaluation, (3) pellet reslurrying and atomization studies, and (4) cost estimation for pellet and slurry production. Disk pelletization of Elkhorn coal was completed this quarter. Pellets were approximately 1/2- to 3/4-in. in diameter. Pellets, after thermal curing were strong and durable and exceeded the pellet acceptance criteria. Storage and handling tests indicate a strong, durable pellet can be prepared from all coals, and these pellets (with the appropriate binder) can withstand outdoor, exposed storage for at least 4 weeks. Pellets in unexposed storage show no deterioration in pellet properties. Real and simulated transportation tests indicate truck transportation should generate less than 5 percent fines during transport. Continuous reslurrying testing and subsequent atomization evaluation were performed this quarter in association with University of Alabama and Jim Walter Resources. Four different slurries of approximately 55-percent-solids with viscosities below 500 cP (at 100 sec{sup {minus}1}) were prepared. Both continuous pellet-to-slurry production and atomization testing was successfully demonstrated. Finally, an in depth evaluation of the cost to prepare pellets, transport, handle, store, and convert the pellet into Coal Water Fuel (CWF) slurries was completed. Cost of the pellet-CWF option are compared with the cost to directly convert clean coal filter cake into slurry and transport, handle and store it at the user site. Findings indicate that in many circumstances, the pellet-CWF option would be the preferred choice. The decision depends on the plant size and transportation distance, and to a lesser degree on the pelletization technique and the coal selected.

  13. Pellet cloud characterisation, scaling and estimation of the material- and temperature distribution inside the cloud

    Science.gov (United States)

    Cseh, G.; Kocsis, G.; Lang, P. T.; Plöckl, B.; Szepesi, T.; Veres, G.; The ASDEX Upgrade Team

    2017-01-01

    Using spatially calibrated images of fast visible cameras, a database was established containing pellet cloud images and the related pellet- and plasma parameters. Using this database, two scalings were derived for the cloud size along the magnetic field lines as a function of pellet speed and ablation rate (first case) and pellet speed, pellet volume, plasma temperature and plasma density (second case). Using the images—based on the number of radiation maxima—the four main cloud shapes were also categorized. The isotope effect (the effect of hydrogen pellets in hydrogen or helium plasma) was also investigated with particular attention devoted to the cloud characteristics. Finally, a synthetic diagnostic—which simulates the measurement system and produces a synthetic pellet cloud image based on the output of the pellet cloud simulation—was developed to reveal the underlying density- and temperature distributions of the observed pellet cloud images. Using this synthetic diagnostic, one of the main identified cloud shapes was reconstructed. Our goal is to derive a scaling law for the toroidal extension of the pellet cloud at different pellet- and plasma conditions, to give a more reliable input for the pellet ELM triggering simulations and using these two results—a better understanding of the pellet-caused pressure perturbation.

  14. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, L.R., E-mail: BaylorLR@ornl.gov [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37830-8050 (United States); Lang, P.T. [Max Plank Institute für Plasmaphysik, EURATOM Association., Boltzmannstr. 2, 85748 Garching (Germany); Allen, S.L. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Combs, S.K.; Commaux, N. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37830-8050 (United States); Evans, T.E. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Fenstermacher, M.E. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Huijsmans, G. [ITER Organization, CS 90 046, 13067 St. Paul lez Durance Cedex (France); Jernigan, T.C. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37830-8050 (United States); Lasnier, C.J. [Lawrence Livermore National Laboratory, 700 East Ave, Livermore, CA 94550 (United States); Leonard, A.W. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Loarte, A. [ITER Organization, CS 90 046, 13067 St. Paul lez Durance Cedex (France); Maingi, R. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Maruyama, S. [ITER Organization, CS 90 046, 13067 St. Paul lez Durance Cedex (France); Meitner, S.J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37830-8050 (United States); Moyer, R.A. [University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0417 (United States); Osborne, T.H. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States)

    2015-08-15

    The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.

  15. [Research progress of fecal microbiota transplantation].

    Science.gov (United States)

    Dai, Ting; Tang, Tongyu

    2015-07-01

    Intestinal microbial ecosystem is the most complex and the largest micro-ecosystem of the mammals. The use of antibiotics can lead to a lot of major changes of the flora, making the intestinal flora damaged and impacted, even developing Clostridium difficile infection. Fecal microbiota transplantation (FMT) as a special organ transplant therapy, which can rebuild the intestinal flora, has raised the clinical concerns. It has been used in the refractory Clostridium difficile, inflammatory bowel disease, irritable bowel syndrome, chronic fatigue syndrome, and some non-intestinal diseases related to the metabolic disorders. But this method of treatment has not become a normal treatment, and many clinicians and patients can not accept it. This paper reviews relevant literature in terms of origin, indications, mechanism, production process, current situation and future research, and provide a reference for the clinical application of the treatment of fecal microbiota transplantation.

  16. Donor Considerations in Fecal Microbiota Transplantation.

    Science.gov (United States)

    Barnes, Danielle; Park, K T

    2017-03-01

    Tremendous acceleration has been made in understanding the gut microbiota in the past decade and, with it, further understanding of the pathologic role of dysbiosis and the use of fecal microbiota transplantation (FMT) as therapy. FMT has been studied in many disease states including the most common indication of Clostridium difficile infection (CDI), though many questions regarding stool donor selection remain. Though traditionally, one donor has provided stool for one patient, research is underway to explore many donor selection considerations from the use of pooled donor stool to selection of a high diversity donor. It is well-known that dietary intake shapes the gut microbiota and the potential implications of this on FMT donor selection are being explored. Though further high-quality research is needed, optimizing the fecal microbiota inoculum holds great promise.

  17. Ethical aspects of Fecal Microbiota Transplantation (FMT).

    Science.gov (United States)

    Daloiso, V; Minacori, R; Refolo, P; Sacchini, D; Craxì, L; Gasbarrini, A; Spagnolo, A G

    2015-09-01

    The importance of human microbiota in preserving human organism healthy is nowadays well acknowledged. The alteration of the microbiota can be the consequence of a persistent use of antibiotics or immunosuppressive medications or abdominal irradiation or surgery, wrong diet, or can be caused by surgery or anatomical condition. These alterations can cause many infections and diseases that today can be treated with Fecal Microbiota Transplantation (FMT), also called Bacteriotherapy, that is the administration of a fecal solution from a donor into the intestinal tract of a recipient. Although to date, FMT appears to be safe and without serious adverse effects, there are some ethical issues that are worthy to be investigated. The aim of this article is to highlight these issues in order to give some notes for a better implementation of this particular clinical practice.

  18. Copepod grazing and their impact on phytoplankton standing stock and production in a tropical coastal water during the different seasons

    Digital Repository Service at National Institute of Oceanography (India)

    Jagadeesan, L.; Jyothibabu, R.; Arunpandi, N.; Parthasarathi, S.

    structure (Bautista and Harris 1992; Lee et al. 2012). Calanoid copepods showed both positive electivity on micro and nano plankton fractions (Fig.4) during low phytoplankton standing stock periods (Pre-Monsoon and Post-Monsoon), whereas they showed... on phytoplankton biomass are variable, ranging from <10% to 30% to standing stock (Morales et al. 1991; Bautista and Harris 1992; Dagg 1995; Froneman 2000; Grunewald et al. 2002; Li et al. 2003; Kibirige and Perisinotto 2003). Copepods normally consumed <30...

  19. The fecal microbiome in cats with diarrhea.

    Directory of Open Access Journals (Sweden)

    Jan S Suchodolski

    Full Text Available Recent studies have revealed that microbes play an important role in the pathogenesis of gastrointestinal (GI diseases in various animal species, but only limited data is available about the microbiome in cats with GI disease. The aim of this study was to evaluate the fecal microbiome in cats with diarrhea. Fecal samples were obtained from healthy cats (n = 21 and cats with acute (n = 19 or chronic diarrhea (n = 29 and analyzed by sequencing of 16S rRNA genes, and PICRUSt was used to predict the functional gene content of the microbiome. Linear discriminant analysis (LDA effect size (LEfSe revealed significant differences in bacterial groups between healthy cats and cats with diarrhea. The order Burkholderiales, the families Enterobacteriaceae, and the genera Streptococcus and Collinsella were significantly increased in diarrheic cats. In contrast the order Campylobacterales, the family Bacteroidaceae, and the genera Megamonas, Helicobacter, and Roseburia were significantly increased in healthy cats. Phylum Bacteroidetes was significantly decreased in cats with chronic diarrhea (>21 days duration, while the class Erysipelotrichi and the genus Lactobacillus were significantly decreased in cats with acute diarrhea. The observed changes in bacterial groups were accompanied by significant differences in functional gene contents: metabolism of fatty acids, biosynthesis of glycosphingolipids, metabolism of biotin, metabolism of tryptophan, and ascorbate and aldarate metabolism, were all significantly (p<0.001 altered in cats with diarrhea. In conclusion, significant differences in the fecal microbiomes between healthy cats and cats with diarrhea were identified. This dysbiosis was accompanied by changes in bacterial functional gene categories. Future studies are warranted to evaluate if these microbial changes correlate with changes in fecal concentrations of microbial metabolites in cats with diarrhea for the identification of potential diagnostic or

  20. Norfloxacin binds to human fecal material.

    Science.gov (United States)

    Edlund, C; Lindqvist, L; Nord, C E

    1988-01-01

    Earlier studies have reported very high (120 to 2,700 mg/kg) concentrations of norfloxacin in feces after therapeutic doses. MICs for fecal microorganisms are with few exceptions far below these levels. Nevertheless, clinical investigations show that the main part of the aerobic gram-positive and the anaerobic microflora remains unaffected after norfloxacin administration. In this study, the binding of [14C]norfloxacin to fecal material was analyzed. The binding of a group of nonlabeled quinolones to feces and the interactions between Enterococcus faecium, Bacteroides fragilis, and norfloxacin were also investigated. The results showed that norfloxacin has the ability to bind to feces. The specific binding was reversible, saturated after 90 min of incubation at 37 degrees C, and increased linearly with fecal concentration. Scatchard plots and nonlinear regression computer analyses revealed two different binding classes. The primary specific binding had a dissociation constant (KD) of 1.0 microM and a maximal binding capacity (Bmax) of 0.12 mumol/g of feces. The KD and Bmax of the secondary, more unspecific binding were 450 microM and 11.8 mumol/g of feces, respectively. The binding of unlabeled ciprofloxacin, enoxacin, ofloxacin, pefloxacin, and norfloxacin to feces was comparable to that of [14C]norfloxacin. The results of norfloxacin binding to suspensions of B. fragilis suggested that the main part of the binding is to the bacterial fraction of feces. In the presence of 8.0 g (dry weight) of B. fragilis per liter, the MBC of norfloxacin for E. faecium increased from 8 to 256 micrograms/ml. The finding of the present study indicated that binding of norfloxacin to feces may explain the paradox of high fecal concentrations of norfloxacin versus the actual effect on the normal gastrointestinal microflora. PMID:2854456

  1. Trophic Cascading of Medusae on the Relationships between Copepods and Diatoms in a Subtropical Coastal Ecosystem

    Directory of Open Access Journals (Sweden)

    Jia-Lu Chung

    2009-01-01

    Full Text Available To investigate the spatial and temporal variation of phytoplankton and copepods, eight seasonal cruises (January 2005 ~ Oc to ber 2006 were conducted in a subtropical coast site that encom passed 19 sampling stations. The results in dicated that the temperature (18.4 - 29.7°C varied more than 10°C seasonally, while nutrient concentrations (ni trate: 0.4 - 6.3 mM, phosphate: 0.1 - 0.8 mM, and silicate 2.1 - 12.1 mM were in versely corre lated with temperature. Diatoms (2792 - 1602437 cells m-3 constituted > 90% of the phytoplankton as semblages and dinoflagellates (226 - 10029 cells m-3 represented only ~10% of the algaebiomass. Copepod abun dance (8 - 1031 ind. m-3 varied positively with that of diatom and tempeature. Therelative abundance of Temora spp. (1 - 712 ind. m-3 varied from 69% in summer; that of Paracalanus spp. (0.1 - 176 ind. m-3 were > 25% in spring and au tumn and Calanus spp. (0.5 - 24 ind. m-3 dom i nated in win ter and spring, but ac counted for only ~10% of the to tal copepods. Both di a tom den sity and copepod abun dance were positively correlated with temperature, indicating these two plank tongroups were left bot tom-up control. The copepod abun dance positively co-aried with diatoms in 2005, but not in 2006. Fur ther sea son-to-sea son analysis showed that the diatomvs. copepodratios changed positively only when the medusa abun dance changed greatly (> 40-fold between consecutive sea sons. During periods when the medusa abundance varied less than 10-fold between seasons, there is no relationship between the ratios and the medusa abun dance. This study suggests that the stability of the medusa abundance from season to season could be important in regulating the ecological linkage between diatoms and their predators ¡V copepods.

  2. Copepod omnivory in the North Water Polynya (Baffin Bay) during autumn: spatial patterns in lipid composition

    Science.gov (United States)

    Stevens, Catherine J.; Deibel, Don; Parrish, Christopher C.

    2004-11-01

    To deduce spatial patterns in copepod lipid composition and feeding strategy (i.e., degree of omnivory) in the North Water Polynya (Baffin Bay), three dominant species were sampled extensively over a broad geographical area (∼75-78°N; 77-69°W). Calanus hyperboreus CV, C. glacialis CV and Metridia longa females were collected in shallow and deep strata at 16 stations during autumn 1999 (August-October). Principal components analysis (PCA) revealed that all species fed omnivorously in the southeastern (SE) region of the polynya. Here, copepods generally had elevated levels of carnivorous (e.g., 18 : 1 (n - 9)), dinoflagellate (e.g., 18 : 4 (n - 3) ; 22 : 6 (n - 3)) and bacterial fatty acid markers (e.g., odd-numbered and/or branched; 18:1(n - 7)). Copepods in the SE contained low proportions of diatom (e.g., 16 : 4 (n - 1) ; 20 : 5 (n - 3)) and phytoplankton (e.g., polyunsaturated fatty acids) markers, relative to animals from northwest stations. Values of the omnivory index 'UC' (i.e., unsaturation coefficient) were also low in SE copepods, which implied reduced phytoplankton ingestion. Spatial patterns in seston fatty acid composition resembled the dietary signatures in that dinoflagellate and bacterial indices were highest in SE waters. Estimates of primary production, particulate organic carbon, carbon to chlorophyll ratios, and abundances of diatoms, dinoflagellates and bacteria, provided further evidence of the importance of the microbial loop at SE stations. Comparable spatial patterns in feeding strategy were observed in both sampling layers, indicating that copepods from the entire water column were feeding on a similar food source. Several interesting species-specific trends also emerged from the PCA. In general, C. hyperboreus fed the most herbivorously, followed by C. glacialis and M. longa. C. glacialis showed a stronger connection to the microbial food web than the other two species, and M. longa fed herbivorously throughout much of the polynya

  3. Fecal Molecular Markers for Colorectal Cancer Screening

    Directory of Open Access Journals (Sweden)

    Rani Kanthan

    2012-01-01

    Full Text Available Despite multiple screening techniques, including colonoscopy, flexible sigmoidoscopy, radiological imaging, and fecal occult blood testing, colorectal cancer remains a leading cause of death. As these techniques improve, their sensitivity to detect malignant lesions is increasing; however, detection of precursor lesions remains problematic and has generated a lack of general acceptance for their widespread usage. Early detection by an accurate, noninvasive, cost-effective, simple-to-use screening technique is central to decreasing the incidence and mortality of this disease. Recent advances in the development of molecular markers in faecal specimens are encouraging for its use as a screening tool. Genetic mutations and epigenetic alterations that result from the carcinogenetic process can be detected by coprocytobiology in the colonocytes exfoliated from the lesion into the fecal matter. These markers have shown promising sensitivity and specificity in the detection of both malignant and premalignant lesions and are gaining popularity as a noninvasive technique that is representative of the entire colon. In this paper, we summarize the genetic and epigenetic fecal molecular markers that have been identified as potential targets in the screening of colorectal cancer.

  4. Therapeutic potential of fecal microbiota transplantation.

    Science.gov (United States)

    Smits, Loek P; Bouter, Kristien E C; de Vos, Willem M; Borody, Thomas J; Nieuwdorp, Max

    2013-11-01

    There has been growing interest in the use of fecal microbiota for the treatment of patients with chronic gastrointestinal infections and inflammatory bowel diseases. Lately, there has also been interest in its therapeutic potential for cardiometabolic, autoimmune, and other extraintestinal conditions that were not previously considered to be associated with the intestinal microbiota. Although it is not clear if changes in the microbiota cause these conditions, we review the most current and best methods for performing fecal microbiota transplantation and summarize clinical observations that have implicated the intestinal microbiota in various diseases. We also discuss case reports of fecal microbiota transplantations for different disorders, including Clostridium difficile infection, irritable bowel syndrome, inflammatory bowel diseases, insulin resistance, multiple sclerosis, and idiopathic thrombocytopenic purpura. There has been increasing focus on the interaction between the intestinal microbiome, obesity, and cardiometabolic diseases, and we explore these relationships and the potential roles of different microbial strains. We might someday be able to mine for intestinal bacterial strains that can be used in the diagnosis or treatment of these diseases. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  5. Fecal microbiota transplantation for gastrointestinal diseases.

    Science.gov (United States)

    Matsuoka, Katsuyoshi; Mizuno, Shinta; Hayashi, Atsushi; Hisamatsu, Tadakazu; Naganuma, Makoto; Kanai, Takanori

    2014-01-01

    Fecal microbiota transplantation (FMT) is a treatment to restore the normal microbial composition of the gut by introducing fecal microbiota obtained from a healthy donor into a diseased individual. There has been a growing interest in the use of FMT as a treatment of various diseases including Clostridium difficile infection (CDI), inflammatory bowel disease, and irritable bowel syndrome. Despite the increasing application of FMT, there are no standard protocols. Many aspects of FMT procedures vary regarding donor selection, preparation of fecal materials, recipient preparation, and route of administration. FMT is most successful in treating recurrent CDI. A randomized controlled trial reported a success rate of approximaetly 90%. Ulcerative colitis (UC) is a potentially good indication for FMT, although limited evidence is available on the use of FMT for the treatment of UC. Only several small case series have been reported, and the results in terms of efficacy are inconsistent. FMT can also be used to treat diseases other than gastrointestinal disorders in which the gut microbiota is disturbed, e.g., cardiovascular diseases, autoimmune diseases, and metabolic disorders. There remain many unanswered questions with regard to FMT, and more research is required in this field.

  6. [Biological process of phosphorus turnover in surface water body of Xiamen Harbor. II: Grazing pressure of copepod on phytoplankton].

    Science.gov (United States)

    Yang, Wei-di; Yang, Qing; Lin, Yuan-shao; Cao, Wen-qing

    2008-12-01

    To understand the roles of copepod in the biogeochemical cycling of phosphorus, gut fluorescence method was applied to examine in situ the grazing rate of copepod on the phytoplankton in Xiamen Time Station (XMTS) in May, August and November 2005 and March 2006. In the meanwhile, the abundance and species composition of copepod were investigated, and the grazing pressure of copepod on the phytoplankton was estimated. The results showed that the annual average grazing rate of copepod was 55.53 microg x m(-3) x d(-1), being the highest (108.98 microg x m(-3) x d(-1)) in autumn and the lowest (7.18 microg x m(-3) x d(-1)) in summer. Based on the estimation from our experimental data, the daily grazing rate of copepod populations on the phytoplankton in Xiamen Harbor was, on annual average, about 1.81% of the phytoplankton's standing stock, with the values in spring, summer, autumn, and winter being 3.22%, 0.06%, 3.52% and 0.46%, respectively.

  7. RNA-seq based whole transcriptome analysis of the cyclopoid copepod Paracyclopina nana focusing on xenobiotics metabolism.

    Science.gov (United States)

    Lee, Bo-Young; Kim, Hui-Su; Choi, Beom-Soon; Hwang, Dae-Sik; Choi, Ah Young; Han, Jeonghoon; Won, Eun-Ji; Choi, Ik-Young; Lee, Seung-Hwi; Om, Ae-Son; Park, Heum Gi; Lee, Jae-Seong

    2015-09-01

    Copepods are among the most abundant taxa in marine invertebrates, and cyclopoid copepods include more than 1500 species and subspecies. In marine ecosystems, planktonic copepods play a significant role as food resources in the food web and sensitively respond to environmental changes. The copepod Paracylopina nana is one of the planktonic brackish water copepods and considered as a promising model species in ecotoxicology. We sequenced the whole transcriptome of P. nana using RNA-seq technology. De novo sequence assembly by Trinity integrated with TransDecoder produced 67,179 contigs including putative alternative spliced variants. A total of 12,474 genes were identified based on BLAST analysis, and gene sequences were most similar to the sequences of the branchiopod Daphnia. Gene Ontology and KEGG pathway analysis showed that most transcripts annotated were involved in pathways of various metabolisms, immune system, signal transduction, and translation. Considering numbers of sequences and enzymes involved in the pathways, particularly attention was paid to genes potentially involved in xenobiotics biodegradation and metabolism. With regard to xenobiotics metabolism, various xenobiotic metabolizing enzymes such as oxidases, dehydrogenases, and transferases were obtained from the annotated transcripts. The whole transcriptome analysis of P. nana provides valuable resources for future studies of xenobiotics-related metabolism in this marine copepod species.

  8. UV imaging of Multiple Unit Pellet System (MUPS) tablets: A case study of acetylsalicylic acid stability

    DEFF Research Database (Denmark)

    Novikova, Anna; Carstensen, Jens Michael; Rades, Thomas

    2017-01-01

    The applicability of multispectral ultraviolet (UV) imaging in combination with multivariate image analysis was investigated to monitor API degradation within multiple unit pellet system (MUPS) tablets during storage. For this purpose, acetylsalicylic acid (ASA) layered pellets were coated...

  9. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    Science.gov (United States)

    Siriwardane, Ranjani V.

    1997-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  10. Durable regenerable sorbent pellets for removal of hydrogen sulfide coal gas

    Science.gov (United States)

    Siriwardane, Ranjani V.

    1999-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  11. Can adult and juvenile European rabbits be differentiated by their pellet sizes?

    Science.gov (United States)

    Delibes-Mateos, Miguel; Rouco, Carlos; Villafuerte, Rafael

    2009-03-01

    Recently, a new method for differentiating juvenile and adult rabbits based on faecal pellet size was published. According to this method, pellets >6 mm diameter are inferred to be deposited by adults, while those kittens. In this study, we designed a simple experiment to test the accuracy of this methodology. Twelve adult rabbits were housed in individual outdoor cages and their pellets were removed every day for 10 consecutive days. Pellets were separated using a sieve according to their size and counted. Results showed that adult rabbits produce pellets >6 mm diameter in the same proportion as those 6 mm, whereas others deposit mostly pellets <6 mm in size. Our findings demonstrate that pellet size is unsuitable for aging wild rabbits. Field biologists should therefore be cautious when employing the pellet size method of age determination in other wild animals in the absence of validating studies.

  12. Pellet Fueling, ELM pacing, and Disruption Mitigation Technology Development for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, Larry R [ORNL; Combs, Stephen Kirk [ORNL; Foust, Charles R [ORNL; Jernigan, Thomas C [ORNL; Meitner, S. J. [Oak Ridge National Laboratory (ORNL); Parks, P. B. [General Atomics; Caughman, John B [ORNL; Maruyama, S. [ITER International Team, Garching, Germany; Qualls, A L [ORNL; Rasmussen, David A [ORNL; ThomasJr., C. E. [Third Dimension Technologies, LLC, Knoxville, TN

    2009-01-01

    Plasma fueling with pellet injection, pacing of edge localized modes (ELMs) by small frequent pellets, and disruption mitigation with gas jets or injected pellets are some of the most important technological capabilities needed for successful operation of ITER. Tools are being developed at Oak Ridge National Laboratory that can be employed on ITER to provide the necessary core pellet fueling and the mitigation of ELMs and disruptions. Here we present progress on the development of the technology to provide reliable high throughput inner wall pellet fueling, pellet ELM pacing with high frequency small pellets, and disruption mitigation with gas jets and pellets. Examples of how these tools can be employed on ITER are discussed.

  13. Comments on Pellet Ablation in Hot Plasmas and the Problem of Magnetic Shielding

    DEFF Research Database (Denmark)

    Chang, C. T.

    1979-01-01

    Clarifications are provided concerning the consistency of a previously formulated magnetic nozzle model in connection with pellet ablation.......Clarifications are provided concerning the consistency of a previously formulated magnetic nozzle model in connection with pellet ablation....

  14. Modelling the role of pellet crack motion in the (r-θ) plane upon pellet-clad interaction in advanced gas reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, T.A. [Centre for Nuclear Engineering & Department of Materials, Imperial College London, Exhibition Rd., London SW7 2AZ (United Kingdom); Ball, J.A. [EDF Energy, Barnett Way, Gloucester GL4 3RS (United Kingdom); Wenman, M.R., E-mail: m.wenman@imperial.ac.uk [Centre for Nuclear Engineering & Department of Materials, Imperial College London, Exhibition Rd., London SW7 2AZ (United Kingdom)

    2017-04-01

    Highlights: • Finite element modelling of pellet relocation in the (r-θ) plane of nuclear fuel. • ‘Soft’ and ‘hard’ PCI have been predicted in a cracked nuclear fuel pellet. • Stress concentration in the cladding ahead of radial pellet cracks is predicted. • The model is very sensitive to the coefficient of friction and power ramp duration. • The model is less sensitive to the number of cracks assumed. - Abstract: A finite element model of pellet fragment relocation in the r-θ plane of advanced gas-cooled reactor (AGR) fuel is presented under conditions of both ‘hard’ and ‘soft’ pellet-clad interaction. The model was able to predict the additional radial displacement of fuel fragments towards the cladding as well as the stress concentration on the inner surface resulting from the azimuthal motion of pellet fragments. The model was subjected to a severe ramp in power from both full power and after a period of reduced power operation; in the former, the maximum hoop stress in the cladding was found to be increased by a factor of 1.6 as a result of modelling the pellet fragment motion. The pellet-clad interaction was found to be relatively insensitive to the number of radial pellet crack. However, it was very sensitive to both the coefficient of friction used between the clad and pellet fragments and power ramp duration.

  15. Standard Specification for Nuclear Grade Zirconium Oxide Pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This specification applies to pellets of stabilized zirconium oxide used in nuclear reactors. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

  16. ANALYSIS OF THERMAL-CHEMICAL CHARACTERISTICS OF BIOMASS ENERGY PELLETS

    Directory of Open Access Journals (Sweden)

    Zorica Gluvakov

    2014-09-01

    Full Text Available In modern life conditions, when emphasis is on environmental protection and sustainable development, fuels produced from biomass are increasingly gaining in importance, and it is necessary to consider the quality of end products obtained from biomass. Based on the existing European standards, collected literature and existing laboratory methods, this paper presents results of testing individual thermal - chemical properties of biomass energy pellets after extrusion and cooling the compressed material. Analysing samples based on standard methods, data were obtained on the basis of which individual thermal-chemical properties of pellets were estimated. Comparing the obtained results with the standards and literature sources, it can be said that moisture content, ash content and calorific values are the most important parameters for quality analysis which decide on applicability and use-value of biomass energy pellets, as biofuel. This paper also shows the impact of biofuels on the quality of environmental protection. The conclusion provides a clear statement of quality of biomass energy pellets.

  17. The Magnetic Shielding Effect of a Re-Fuelling Pellet

    DEFF Research Database (Denmark)

    Chang, C. T.

    1975-01-01

    The magnetic shielding effect of a refuelling pellet is considered by first briefly reviewing the existing balloon model. The limitation of the model is pointed out and discussed. Since solid deuterium is an insulator and the ablated plasma is expected to be cold and dense, it is felt...... that the existence of a field-free balloon is questionable; rather some field will be trapped by the pellet. On the assumption that the flow of the ablated plasma is governed by a flexible magnetic nozzle, it is shown that the reduction of the ablation rate of the pellet is not due to the exclusion of the field...... by a balloon, but to the reduction of the ablated plasma pressure through the trapping of the field inside the nozzle. The model also indicates that the penetration of a mm-size pellet into the centre of a low-β reactor might be possible, provided an injection speed around 104 m centerdots−1 can be attained...

  18. Standard specification for nuclear-Grade boron carbide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This specification applies to boron carbide pellets for use as a control material in nuclear reactors. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

  19. Assessment of Biomass Pelletization Options for Greensburg, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Haase, S.

    2010-05-01

    This report provides an overview of a technical report on an assessment NREL conducted in Greensburg, Kansas, to identify potential opportunities to develop a biomass pelletization or briquetting plant in the region. See NREL/TP-7A2-45843 for the Executive Summary of this report.

  20. Microgasification cookstoves and pellet fuels from waste biomass: A ...

    African Journals Online (AJOL)

    Lotter;Msola Hunter;Straub

    fuels consist: traditional (charcoal), fossil (LPG), and sustainable ... If ICTs such as pellet systems are to be counted on to reduce .... their users stop char combustion for saving biochar due to the extra work .... The very limited laboratory resources at our disposal ..... Summary of biomass supply and consumption in. Tanzania.

  1. Model analysis for combustion characteristics of RDF pellet

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fundamental studies of the combustion characteristics and the de-HCl behavior of a single refuse-derived fuel(RDF) pellet were carried out to explain the de-HCl phenomena of RDF during fluidized bed combustion and to provide data for the development of high efficiency power generation technology using RDF previously. For further interpreting the devolatilization and the char combustion processes of RDF quantitatively, an unsteady combustion model for single RDF pellet, involving reaction rates, heat transfer and oxygen diffusion in the RDF pellet, was developed. Comparisons of simulation results with experimental data for mass loss of the RDF samples made from municipal solid waste, wood chips and poly-propylene when they were heated at 10K/min or put into the furnace under 1073K show the verifiability of the model. Using this model, the distributions of the temperature and the reaction ratio along the radius of RDF pellet during the devolatilization process and the char combustion process were presented, and discussion about the inference of heating rate on the combustion characteristics were performed.

  2. Small-Scale Pellet Heating Systems from Consumer Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, K.; Gustavsson, L. [Mid Sweden Univ., Oestersund (Sweden). Ecotechnology

    2006-07-15

    A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic.

  3. DEVELOPMENT AND EVALUATION OF CLOZAPINE PELLETS FOR CONTROLLED RELEASE

    Directory of Open Access Journals (Sweden)

    D.V. Gowda

    2012-08-01

    Full Text Available This research work was done to design oral controlled release matrix pellets of water insoluble drug Clozapine, using blend of Hydroxypropyl cellulose and glyceryl palmito stearate as as matrix polymers, methyl crystalline cellulose as spheronizer enhancer,sodium lauryl sulphate as pore forming agent. Clozapine formulations developed by the pellitization technique by drug loaded pellets were characterized with regard to the drug content, size distribution, Scanning electron microscopy, differential scanning calorimetry, fourier transform infrared spectroscopy and Xray Diffraction study. Stability studies were carried out on the optimized formulation for aperiod of 90 days, 40 ± 2 oC and 75 ± 5% relative humidity. The drug content was in the range of 95.34 – 98.12 %. The mean particle size of drug loaded pellets was in the range 1018 to 1065 mm. SEM photographs and calculated sphericity factor confirms that the prepared formulations were spherical in nature. The drug loaded pellets were stable and compatible as confirmed by DSC and FTIR studies. XRD patterns revealed the crystalline nature of pure clozapine. Loose surface crystal study indicated that crystalline clozapine was observed in all formulation and more clear in formulation A5. Higher amount of clozapine released was observed from formulation A5 and Syclop® 25 mg tablet as compared to all other formulations and mechanism of drug release followed Fickian diffusion. It can be concluded that formulation A5 is an ideal formulation for once a day administration.

  4. NTA 8080 analysis of the JaLo pellet chain

    NARCIS (Netherlands)

    Poppens, R.P.

    2011-01-01

    JaLo Biopellets Twente intends to harvest biomass from landscape elements and turn that into pellets for energy purposes. The sustainability of these future operations was assessed through a specially developed sustainability framework consisting of several tools. This NTA 8080 study takes the JaLo

  5. Analytical model of neutral gas shielding for hydrogen pellet ablation

    Energy Technology Data Exchange (ETDEWEB)

    Kuteev, Boris V.; Tsendin, Lev D. [State Technical Univ., St. Petersburg (Russian Federation)

    2001-11-01

    A kinetic gasdynamic scaling for hydrogen pellet ablation is obtained in terms of a neural gas shielding model using both numerical and analytical approaches. The scaling on plasma and pellet parameters proposed in the monoenergy approximation by Milora and Foster dR{sub pe}/dt{approx}S{sub n}{sup 2/3}R{sub p}{sup -2/3}q{sub eo}{sup 1/3}m{sub i}{sup -1/3} is confirmed. Here R{sub p} is the pellet radius, S{sub n} is the optical thickness of a cloud, q{sub eo} is the electron energy flux density and m{sub i} is the molecular mass. Only the numeral factor is approximately two times less than that for the monoenergy approach. Due to this effect, the pellet ablation rates, which were obtained by Kuteev on the basis of the Milora scaling, should be reduced by a factor of 1.7. Such a modification provides a reasonable agreement (even at high plasma parameters) between the two-dimensional kinetic model and the one-dimensional monoenergy approximation validated in contemporary tokamak experiments. As the could (in the kinetic approximation) is significantly thicker than that for the monoenergy case as well as the velocities of the gas flow are much slower, the relative effect of plasma and magnetic shielding on the ablation rate is strongly reduced. (author)

  6. Pellet in the stomach:Where did it come from?

    Institute of Scientific and Technical Information of China (English)

    Baris Dogu Yildiz; Barlas Sulu

    2012-01-01

    Gunshot might have unexpected findings in the victim owing to the ballistics of the injury. The trajectory of the bullet plays a central role in the surprising findings in gunshot injuries. We are presenting a case with pellets seen in the stomach after a gunshot.

  7. Pellet in the stomach: Where did it come from?

    Directory of Open Access Journals (Sweden)

    Baris Dogu Yildiz

    2012-01-01

    Full Text Available Gunshot might have unexpected findings in the victim owing to the ballistics of the injury. The trajectory of the bullet plays a central role in the surprising findings in gunshot injuries. We are presenting a case with pellets seen in the stomach after a gunshot.

  8. Environmental footprints of British Columbia wood pellets from a simplified life cycle analysis

    OpenAIRE

    Pa, Ann; Craven, Jill S.; Xiaotao T. Bi; Melin, Staffan; Sokhansanj, Shahab

    2012-01-01

    Purpose: Environmental footprints of wood pellets produced in British Columbia (BC) of Canada are to be estimated based on industry surveys and published emission factor data. Method: The streamlined life cycle analysis starts from raw material acquisition and ends at port Rotterdam in Europe for exported pellets or North Vancouver port for domestically used pellets. The raw materials used for pellet production are dry and wet sawmill residues, and allocations are based on dry mass....

  9. Performance of a domestic pellet boiler as a function of operational loads: Part-2

    Energy Technology Data Exchange (ETDEWEB)

    Verma, V.K.; De Ruyck, J. [Department Mechanical Engineering, Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel (Belgium); Bram, S. [Department Mechanical Engineering, Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel (Belgium); Department of Industrial Sciences and Technology, Erasmushogeschool Brussel, Nijverheidskaai 170, 1070 Brussel (Belgium); Gauthier, G. [Unite de Thermodynamique et Turbomachines (TERM), Universite Catholique de Louvain (U.C.L.), 1348 Louvain-la-Neuve (Belgium)

    2011-01-15

    Emissions and efficiency of a pellet boiler (40 kW) at nominal load were compared with emissions and efficiency at reduced load, while fired with six biomass pellets. The pellets include reed canary grass (Phalaris arundinacea), pectin waste from citrus shells (Citrus reticulata), sunflower husk (Helianthus annuus), peat, wheat straw (Triticum aestivum) and wood pellets. The measurements of emissions comprised of carbon monoxide (CO), nitrogen oxides (NO{sub x}), sulphur oxides (SO{sub x}) and flue dust mass concentrations (using DINplus and isokinetic sampling techniques). Emissions varied as a function of operational loads, for each type of pellets. The CO emissions were insignificant with reed canary grass (RCG), citrus pectin waste (CPW) and straw pellets at nominal load, however, at reduced load same pellets emitted 1.9, 4.0 and 7.4 times higher CO than wood pellets, respectively. Peat pellets emitted maximum CO at nominal load (4221.1 mgNm{sup -3}, 12.6 times higher than wood pellets) however; at reduced load CO emission was insignificant. The highest NO{sub x} emissions were reported with CPW, which were 3.4 and 4.6 times higher than wood pellets at nominal load and reduced load, respectively. Dust emissions were highest with sunflower husk and lowest with RCG pellets, at both operational modes. The best performance was reported with wood pellets, followed by RCG and pectin pellets, however, wood pellets combustion emitted 1.7 and 2.0 times higher dust{sub DINplus} than RCG at nominal and reduced loads, respectively. Not only fuel specific combustion optimization but also operational load specific optimization is essential for efficient use of agro-pellets in this type of boilers. (author)

  10. Physico-Chemical, Functional and Rheological Characterization of Biodegradable Pellets and Composite Sheets

    OpenAIRE

    Jan Kulsum; Jan Shumaila; Riar CS; Saxena DC

    2016-01-01

    Deoiled rice bran, paddy husk, cashew nut shell liquid and glycerol were extruded into pellets and further pressed into composites. Processing and plasticizer type had significant effect on physico-chemical, functional, rheological and morphological properties of pellets and composites. Specific mechanical energy of the pellets containing cashew nut shell liquid as plasticizer was higher than those containing glycerol. The maximum hardness and bulk density were obtained for pellets prepared f...

  11. Fabrication of uranium dioxide ceramic pellets with controlled porosity from oxide microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Remy, E. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Picart, S., E-mail: sebastien.picart@cea.fr [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Delahaye, T. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Jobelin, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Dugne, O. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Bisel, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Blanchart, P. [Heterogeneous Materials Research Group, Centre Européen de la Céramique, F-87068 Limoges (France); Ayral, A. [Institut Européen des Membranes, UMR 5635 CNRS-ENSCM-UM2, University of Montpellier, F-34095 Montpellier cedex 5 (France)

    2014-05-01

    This study concerns the fabrication of uranium oxide pellets using the powder-free process called Calcined Resin Microsphere Pelletization (CRMP). Details are given about oxide microsphere synthesis and particularly about loading operation and heat treatments. The fabrication of ceramic pellets is also described and discussed. Results showed that this process allows the preparation of either dense or porous pellets by mixing U{sub 3}O{sub 8} and UO{sub 2}-like microspheres before pressing and sintering.

  12. Lightning arrestor connector lead magnesium niobate qualification pellet test procedures.

    Energy Technology Data Exchange (ETDEWEB)

    Tuohig, W. (Honeywell FM& T, Kansas City, MO); Mahoney, Patrick A.; Tuttle, Bruce Andrew; Wheeler, Jill Susanne

    2009-02-01

    Enhanced knowledge preservation for DOE DP technical component activities has recently received much attention. As part of this recent knowledge preservation effort, improved documentation of the sample preparation and electrical testing procedures for lead magnesium niobate--lead titanate (PMN/PT) qualification pellets was completed. The qualification pellets are fabricated from the same parent powders used to produce PMN/PT lightning arrestor connector (LAC) granules at HWF&T. In our report, the procedures for fired pellet surface preparation, electrode deposition, electrical testing and data recording are described. The dielectric measurements described in our report are an information only test. Technical reasons for selecting the electrode material, electrode size and geometry are presented. The electrical testing is based on measuring the dielectric constant and dissipation factor of the pellet during cooling from 280 C to 220 C. The most important data are the temperature for which the peak dielectric constant occurs (Curie Point temperature) and the peak dielectric constant magnitude. We determined that the peak dielectric constant for our procedure would be that measured at 1 kHz at the Curie Point. Both the peak dielectric constant and the Curie point parameters provide semi-quantitative information concerning the chemical and microstructural homogeneity of the parent material used for the production of PMN/PT granules for LACs. Finally, we have proposed flag limits for the dielectric data for the pellets. Specifically, if the temperature of the peak dielectric constant falls outside the range of 250 C {+-} 30 C we propose that a flag limit be imposed that will initiate communication between production agency and design agency personnel. If the peak dielectric constant measured falls outside the range 25,000 {+-} 10,000 we also propose that a flag limit be imposed.

  13. Predator-prey interactions and community structure: chironomids, mosquitoes and copepods in Heliconia imbricata (Musaceae).

    Science.gov (United States)

    Naeem, Shahid

    1988-11-01

    Evidence from both field observations and experimental work indicates that predation by larvae of a midge, Pentaneura n. sp. (Chironomidae), causes the low densities of mosquito larvae (Culicidae) found in the water filled bracts of Heliconia imbricata (Musaceae), microhabitats typically colonized by mosquitoes. This predation affects 2 species of mosquitoes, Wyeomyia pseudopecten, a resident species, and Trichoprosopon digitatum, a non-resident species. Predation keeps resident mosquito densities low while completely excluding the nonresident mosquito from the habitat. Both these effects of predation depend on the presence of an abundant alternative prey, an undescribed species of harpacticoid copepod found in the bracts. These copepod prey sustain chironomids when resident mosquito densities are low, permiting predator densities to remain high enough to exclude the non-resident mosquito. I discuss the evolutionary and ecological implications of predation structuring communities.

  14. Unsteady motion: escape jumps in planktonic copepods, their kinematics and energetics

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Andersen, Anders Peter; Langlois, Vincent J.;

    2010-01-01

    estimate the force and power output needed to accelerate and overcome drag. Both are very high compared with those of other organisms, as are the escape velocities in comparison to startle velocities of other aquatic animals. Thus, the maximum weight-specific force, which for muscle motors of other animals...... has been found to be near constant at 57 N (kg muscle)−1, is more than an order of magnitude higher for the escaping copepods. We argue that this is feasible because most copepods have different systems for steady propulsion (feeding appendages) and intensive escapes (swimming legs), with the muscular...... arrangement of the latter probably adapted for high force production during short-lasting bursts. The resulting escape velocities scale with body length to power 0.65, different from the size-scaling of both similar sized and larger animals moving at constant velocity, but similar to that found for startle...

  15. Mating success and sexual selection in a pelagic copepod, Temora longicornis: Evidence from paternity analyses

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte; Eg Nielsen, Einar; Thygesen, Uffe Høgsbro;

    2015-01-01

    Knowledge about mating patterns is essential for understanding and explaining rates of reproduction and genetic potential of copepods populations. The aim of this study was to examine (1) the occurrence of multiple paternity in Temora longicornis, (2) the effect of multiple paternity (if present......) on the females reproductive output, and (3) whether mating is random or some individuals have a higher than average chance of fertilizing or being fertilized (super individuals). We show that multiple paternity is common in this copepod species, that females benefit from multiple matings by increased offspring...... production, and that a relatively small fraction of the males and females in a population account for most of the offspring production. In both males and females, mating is nonrandom. Superior individuals with a higher than average matings success were identified both among females and among males....

  16. Species-specific vulnerability of Arctic copepods to oil contamination and global warming

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    Arctic ecosystems are predicted to have more severe effects from global warming as during the last decades the temperatures have increased in this region at a rate of 2-4 times higher than the global average. In addition, oil exploitation and shipping activities in the Arctic are predicted...... to increase under global warming as the result of the retreat of sea ice, posing the risk of oil contamination. It is poorly known how cold adapted copepods in the Arctic deal with the combined effects of global warming and oil exposure. To address this, we exposed females of two copepods species Calanus...... of temperatures. Notably, exposure to high pyrene resulted in ca. 70% of mortality in C. finmarchicus, the species with North Atlantic Origin, that was two times higher than the mortality observed for C. glacialis, the true Arctic species. These results suggest that extreme temperature under global warming...

  17. Phytoplankton growth rate and nitrogen content: Implications for feeding and fecundity in a herbivorous copepod

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    1989-01-01

    at a concentration of 1.5 ppm. Over more than 2 orders of magnitude increase in algal growth rate, the ingested cell volume increased by less than a factor of 2, ingested carbon remained constant whereas ingested nitrogen as well as rate of egg production increased by a factor of ca 6. Variation in ingested cell......Observations of natural feeding and egg-production rates of planktonic copepods have revealed distinct responses, independent of phytoplankton biomass, to oceanographic processes that fertilize the photic layer. Are such responses caused by changes in phytoplankton growth rate, influencing feeding...... behaviour, and/or by changes in the chemical composition of the phytoplankton, influencing fecundity? The diatom Thalassiosira weissflogii, grown in continuous cultures at different dilution rates and different nitrogen concentrations in the growth medium, was offered to the copepod Acartia tonsa...

  18. Planktivorous feeding in calm and turbulent environments, with emphasis on copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Saiz, E.

    1995-01-01

    feeding copepods, such as Acartidae and many cyclopoids, turbulence has a dominant influence on prey encounter rates. The effect on cruising predators is intermediate. Application of the models to situations examined experimentally demonstrates a high predictive performance. Finally we explore and model...... the potentially negative effects of turbulence on copepod feeding currents, prey perception and capture success. At typical and even high turbulent intensities, none of these is significantly affected....... the levels of turbulence (as dissipation rate) at which ambient fluid motion is important in enhancing prey encounter rates for various types of predators (e.g, ambush and cruise predators, suspension feeders). Generally, turbulence has the largest effect on prey encounters for predators with low motility...

  19. Population dynamic of high latitude copepods - with emphasis on Metridia longa

    DEFF Research Database (Denmark)

    Kjellerup, Sanne

    2014-01-01

    High latitude ecosystems are shaped by seasonality in light, ranging from complete darkness in winter to midnight sun in summer, influencing both temperature and primary production. Copepods are important grazers on phytoplankton in marine systems and occupy a central role in the marine food......, sampling only the upper water column during the day-as is a usual procedure-would underestimate this potential key species. Reproduction patterns of the large calanoids suggested lifecycles adapted to the seasonal and episodic food availability, and consequently had a pulsed reproduction. In contrast......, small copepod species were less dependent on the spring phytoplankton bloom, and their reproduction and population dynamics were less pulsed. Likewise, a large proportion of Oithona similis was ovigerous from March to August. Reproduction of Microsetella norvegica, another of the small key species...

  20. Zooplankton distribution across Fram Strait in autumn: Are small copepods and protozooplankton important?

    Science.gov (United States)

    Svensen, Camilla; Seuthe, Lena; Vasilyeva, Yulia; Pasternak, Anna; Hansen, Edmond

    2011-12-01

    We investigated zooplankton distribution in September 2006/2007 at eight stations across Fram Strait in contrasting water masses ranging from cold Polar water to warm Atlantic water. Our main objectives were: (1) to describe the plankton community in the upper 200 m during autumn, and (2) to investigate the importance of small-sized copepods and protozooplankton in an arctic ecosystem when the majority of the large Calanus species had entered diapause. We sampled both with a WP-2 net and Go-Flo bottle and show that small copepods food. Heterotrophic protozooplankton, on the other hand, were most likely bottom-up regulated by the availability of phytoplankton food and conclude that there was a strong link between the zooplankton community and the microbial food web in Fram Strait.