Smart acquisition EELS

Energy Technology Data Exchange (ETDEWEB)

Sader, Kasim, E-mail: k.sader@leeds.ac.uk [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Schaffer, Bernhard [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Department of Physics and Astronomy, University of Glasgow (United Kingdom); Vaughan, Gareth [Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Brydson, Rik [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Brown, Andy [Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Bleloch, Andrew [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Department of Engineering, University of Liverpool, Liverpool (United Kingdom)

2010-07-15

We have developed a novel acquisition methodology for the recording of electron energy loss spectra (EELS) using a scanning transmission electron microscope (STEM): 'Smart Acquisition'. Smart Acquisition allows the independent control of probe scanning procedures and the simultaneous acquisition of analytical signals such as EELS. The original motivation for this work arose from the need to control the electron dose experienced by beam-sensitive specimens whilst maintaining a sufficiently high signal-to-noise ratio in the EEL signal for the extraction of useful analytical information (such as energy loss near edge spectral features) from relatively undamaged areas. We have developed a flexible acquisition framework which separates beam position data input, beam positioning, and EELS acquisition. In this paper we demonstrate the effectiveness of this technique on beam-sensitive thin films of amorphous aluminium trifluoride. Smart Acquisition has been used to expose lines to the electron beam, followed by analysis of the structures created by line-integrating EELS acquisitions, and the results are compared to those derived from a standard EELS linescan. High angle annular dark-field images show clear reductions in damage for the Smart Acquisition areas compared to the conventional linescan, and the Smart Acquisition low loss EEL spectra are more representative of the undamaged material than those derived using a conventional linescan. Atomically resolved EELS of all four elements of CaNdTiO show the high resolution capabilities of Smart Acquisition.

The eel immune system: present knowledge and the need for research

DEFF Research Database (Denmark)

Nielsen, Michael Engelbrecht; Esteve-Gassent, M. D.

2006-01-01

The European eel, Anguilla anguilla, is one of the most important warm water fish species cultured in southern Europe and the Mediterranean as well as in northern countries including Germany, the Netherlands and Denmark. The Japanese eel, A. japonica, is an important cultured fish in several...... Asiatic countries including Japan, China and Taiwan. During recent decades, research has been performed to elucidate the immune response of these species against different pathogens (viruses, bacteria or parasites). Nevertheless, there is very limited information in terms of both cellular and humoral...

Adoption of radio-frequency identification to establish traceability in Taiwanese eel exported to the Japanese market.

Science.gov (United States)

Jeng, Shu-Ching; Wu, Chun-Lung; Yang, I-Da

2013-01-01

Eel culture and export to the Japanese market is an important industry in Taiwan; however, the average amount produced by each farm is small. Eels from different farms might be mixed before export, making it difficult to determine which farm is responsible for eels containing drug residues. Therefore, the Taiwanese government uses a two-stage procedure of inspection and accreditation for validating the use of good practice in aquaculture farming. Nevertheless, it is still difficult to trace any farm that has produced eels containing drug residues. Radio-frequency identification has the potential to establish traceability in eel products. Here we suggest that Japanese eel importers should insist on the use of radio-frequency identification by Taiwanese eel exporters to enable verification of the safety of eel products being exported to the Japanese market.

Increased temperature tolerance of the air-breathing Asian swamp eel Monopterus albus after high-temperature acclimation is not explained by improved cardiorespiratory performance.

Science.gov (United States)

Lefevre, S; Findorf, I; Bayley, M; Huong, D T T; Wang, T

2016-01-01

This study investigated the hypothesis that in the Asian swamp eel Monopterus albus, an air-breathing fish from south-east Asia that uses the buccopharyngeal cavity for oxygen uptake, the upper critical temperature (TU) is increased by acclimation to higher temperature, and that the increased TU is associated with improved cardiovascular and respiratory function. Monopterus albus were therefore acclimated to 27° C (current average) and 32° C (current maximum temperature as well as projected average within 100-200 years), and both the effect of acclimation and acute temperature increments on cardiovascular and respiratory functions were investigated. Two weeks of heat acclimation increased upper tolerated temperature (TU ) by 2° C from 36·9 ± 0·1° C to 38·9 ± 0·1° C (mean ± s.e.). Oxygen uptake (M˙O2) increased with acclimation temperature, accommodated by increases in both aerial and aquatic respiration. Overall, M˙O2 from air (M˙O2a ) was predominant, representing 85% in 27° C acclimated fish and 80% in 32° C acclimated fish. M˙O2 increased with acute increments in temperature and this increase was entirely accommodated by an increase in air-breathing frequency and M˙O2a . Monopterus albus failed to upregulate stroke volume; rather, cardiac output was maintained through increased heart rate with rising temperature. Overall, acclimation of M. albus to 32° C did not improve its cardiovascular and respiratory performance at higher temperatures, and cardiovascular adaptations, therefore, do not appear to contribute to the observed increase in TU. © 2015 The Fisheries Society of the British Isles.

Draft genome of the American Eel (Anguilla rostrata).

Science.gov (United States)

Pavey, Scott A; Laporte, Martin; Normandeau, Eric; Gaudin, Jérémy; Letourneau, Louis; Boisvert, Sébastien; Corbeil, Jacques; Audet, Céline; Bernatchez, Louis

2017-07-01

Freshwater eels (Anguilla sp.) have large economic, cultural, ecological and aesthetic importance worldwide, but they suffered more than 90% decline in global stocks over the past few decades. Proper genetic resources, such as sequenced, assembled and annotated genomes, are essential to help plan sustainable recoveries by identifying physiological, biochemical and genetic mechanisms that caused the declines or that may lead to recoveries. Here, we present the first sequenced genome of the American eel. This genome contained 305 043 contigs (N50 = 7397) and 79 209 scaffolds (N50 = 86 641) for a total size of 1.41 Gb, which is in the middle of the range of previous estimations for this species. In addition, protein-coding regions, including introns and flanking regions, are very well represented in the genome, as 95.2% of the 458 core eukaryotic genes and 98.8% of the 248 ultra-conserved subset were represented in the assembly and a total of 26 564 genes were annotated for future functional genomics studies. We performed a candidate gene analysis to compare three genes among all three freshwater eel species and, congruent with the phylogenetic relationships, Japanese eel (A. japanica) exhibited the most divergence. Overall, the sequenced genome presented in this study is a crucial addition to the presently available genetic tools to help guide future conservation efforts of freshwater eels. © 2016 John Wiley & Sons Ltd.

Occurrence of Edwardsiella tarda in wild European eels Anguilla anguilla from Mediterranean Spain.

Science.gov (United States)

Alcaide, Elena; Herraiz, Sonia; Esteve, Consuelo

2006-11-21

Pure cultures of Edwarsiella tarda were isolated from body ulcers and internal organs of wild European eels caught in a Mediterranean freshwater coastal lagoon (Albufera Lake, Valencia, Spain) over a 1 yr period. Overall, the E. tarda isolation rate from wild eels was 9%, but this increased to 22.8% in diseased individuals. All 22 E. tarda isolates belonged to the 'wild-type' biogroup of the species and were virulent for eels (lethal dose that kills 50% of exposed individuals [LD50 dose]: 10(4.85) to 10(6.83) CFU ind.(-1)), and therefore represented the aetiological agent of the haemorrhagic disease observed in wild European eels. The E. tarda isolates and E. tarda CECT 894T type strain were biochemically and serologically related and resistant to macrolides, antifolates, and glycopeptides, but only the isolates from wild eels were resistant to clindamicyn. This study is the first description of edwardsiellosis in a wild European eel population, and alerts us to the presence of E. tarda in natural wetland environments in Mediterranean Europe.

Report on the eel stock and eel fishery in the Netherlands in 2011

NARCIS (Netherlands)

Graaf, de M.; Bierman, S.M.

2012-01-01

Eel fisheries in the Netherlands occur in coastal waters, estuaries, larger and smaller lakes, rivers, polders, etc. Management of eel stock and fisheries has been an integral part of the long tradition in manipulating water courses (polder construction, river straightening, ditches and canals,

Eel Kisspeptins: Identification, Functional Activity, and Inhibition on both Pituitary LH and GnRH Receptor Expression

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Jérémy Pasquier

2018-01-01

Full Text Available The European eel (Anguilla anguilla presents a blockade of sexual maturation at a prepubertal stage due to a deficient production of gonadotropins. We previously initiated, in the eel, the investigation of the kisspeptin system, one of the major gatekeepers of puberty in mammals, and we predicted the sequence of two Kiss genes. In the present study, we cloned and sequenced Kiss1 and Kiss2 cDNAs from the eel brain. The tissue distributions of Kiss1 and Kiss2 transcripts, as investigated by quantitative real-time PCR, showed that both genes are primarily expressed in the eel brain and pituitary. The two 10-residue long sequences characteristic of kisspeptin, eel Kp1(10 and Kp2(10, as well as two longer sequences, predicted as mature peptides, eel Kp1(15 and Kp2(12, were synthesized and functionally analyzed. Using rat Kiss1 receptor-transfected Chinese hamster ovary cells, we found that the four synthesized eel peptides were able to induce [Ca2+]i responses, indicating their ability to bind mammalian KissR-1 and to activate second messenger pathways. In primary culture of eel pituitary cells, all four peptides were able to specifically and dose-dependently inhibit lhβ expression, without any effect on fshβ, confirming our previous data with heterologous kisspeptins. Furthermore, in this eel in vitro system, all four peptides inhibited the expression of the type 2 GnRH receptor (gnrh-r2. Our data revealed a dual inhibitory effect of homologous kisspeptins on both pituitary lhβ and gnrh-r2 expression in the European eel.

Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

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Choi, Min Seop; Kwon, Se Ryun; Choi, Seong Hee; Kwon, Hyuk Chu

2012-12-01

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

How fast do eels grow

International Nuclear Information System (INIS)

Hansen, H.J.M.

1988-01-01

Not so very much about the growth pattern of the eel is known yet. Eels move about nearly all the time. They are thus very difficult to follow and we do not, for examble, yet know how long it actually takes for them to grow to maturity in the wild. So far, a macroscopic analysis of the number of bright and dark areas (growth rings) in the 'earstones' has been used to determine eel age, but this method was recently challenged. Use of radioisotopes has been suggested previously for this purpose. For this present study the rare earth elements, europium-152 and europium-155 are used. When incubated in artificial sea water, a satisfactory final radioactive label was achieved. Two experiments were planned in collaboration with the Swedish Environmental Protection Agency. 2000 Elvers were set out in 1982, in the cooling water outlet of the Oskarshamn nuclear power plant, each marked with europium-155. In 1984 another 10 000 elvers labelled with europium-152 were set out under similar conditions. The idea was mainly to see how fast the eels would grow, and to compare their known age with that determined by examining the earstones. Results showed that there was no clear-cut correlation between actual eel age and the biological age determination used so far. During four years, only 10 of the original 1300 eels were recaptured. It is thus hard to say anything definite from our results on the viability of setting out elvers in the environment

Accumulation of persistent organic pollutants in consumers of eel from polluted rivers compared to marketable eel.

Science.gov (United States)

van den Dungen, Myrthe W; Kok, Dieuwertje E; Polder, Anuschka; Hoogenboom, Ron L A P; van Leeuwen, Stefan P J; Steegenga, Wilma T; Kampman, Ellen; Murk, Albertinka J

2016-12-01

Globally, many river sediments are seriously contaminated with persistent organic pollutants (POPs) known to accumulate in aquatic food. In the Netherlands, toxicological risks of human exposure to dioxins and dioxin-like compounds led to a ban on eel fishing in the Rhine-Meuse delta. The aim of this study is to investigate differences in serum POP levels in consumers of eel from high-polluted areas and consumers of eel from low-polluted areas or aquaculture. In total 80 Dutch men were included, aged 40-70 years, with a habitual eel consumption of at least one portion (150 g) per month. Total levels of dioxins and dioxin-like compounds were measured in serum of all participants with the DR CALUX bioassay, validated with GC-MS. For a subgroup of 38 participants extensive POP measurements were performed. We revealed that consumption of eel from polluted rivers resulted in 2.5 and up to 10 times increased levels of dioxins and polychlorinated biphenyls (PCBs) respectively compared to controls. The highest PCB levels were detected for PCB 153, with a median level of 896 ng/g lipid and a maximum level of 5000 ng/g lipid in the high-exposed group. Furthermore, hydroxylated PCB metabolites (OH-PCBs: sum of 4-OH-CB107, 4-OH-CB146, 4'-OH-CB172, and 4-OH-CB187) were 8 times higher in men who consumed eel from polluted areas, and detected at levels (median 4.5 ng/g ww) reported to cause adverse health effects. Also, the majority of the perfluoroalkyl substances (PFASs) were significantly higher in consumers of eel from pullulated areas. In conclusion, this study is the first to reveal that (past) consumption of eel from polluted rivers resulted in high body burdens of dioxins, PCBs, OH-PCBs and PFASs. We confirmed the predictions made in a former risk assessment, and the high levels of dioxins and dioxin-like compounds as well as the OH-PCBs are of health concern. Copyright © 2016 Elsevier Ltd. All rights reserved.

Proceedings of a workshop on American Eel passage technologies

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Haro, Alexander J.

2013-01-01

Recent concerns regarding a decline in recruitment of American eels (Anguilla rostrata) have prompted efforts to restore this species to historic habitats by providing passage for both upstream migrant juveniles and downstream migrant adults at riverine barriers, including low-head and hydroelectric dams (Castonguay et al. 1994, Haro et al. 2000). These efforts include development of management plans and stock assessment reviews in both the US and Canada (COSEWIC 2006, Canadian Eel Working Group 2009, DFO 2010, MacGregor et al. 2010, ASMFC 2000, ASMFC 2006, ASMFC 2008, Williams and Threader 2007), which target improvement of upstream and downstream passage for eels, as well as identification and prioritization of research needs for development of new and more effective passage technologies for American eels. Traditional upstream fish passage structures, such as fishways and fish lifts, are often ineffective passing juvenile eels, and specialized passage structures for this species are needed. Although designs for such passage structures are available and diverse (Knights and White 1998, Porcher 2002, FAO/DVWK 2002, Solomon and Beach 2004a,b, Environment Agency UK 2011), many biologists, managers, and engineers are unfamiliar with eel pass design and operation, or unaware of the technical options available for upstream eel passage, Better coordination is needed to account for eel passage requirements during restoration efforts for other diadromous fish species. Also, appropriately siting eel passes at hydropower projects is critical, and siting can be difficult and complex due to physical restrictions in access to points of natural concentrations of eels, dynamic hydraulics of tailrace areas, and presence of significant competing flows from turbine outfalls or spill. As a result, some constructed eel passes are sited poorly and may pass only a fraction of the number of eels attempting to pass the barrier. When sited and constructed appropriately, however, eel passes

Magnetic compass orientation in the European eel.

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Caroline M F Durif

Full Text Available European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C, their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12-17°C, eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging and the colder fall and winter (during which eels undertake their migrations. These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel's seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier.

Magnetic compass orientation in the European eel.

Science.gov (United States)

Durif, Caroline M F; Browman, Howard I; Phillips, John B; Skiftesvik, Anne Berit; Vøllestad, L Asbjørn; Stockhausen, Hans H

2013-01-01

European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C), their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12-17°C), eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging) and the colder fall and winter (during which eels undertake their migrations). These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel's seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier.

Aspergillus flavus infection on preserved Eel (Thysoidea macrurus)

Digital Repository Service at National Institute of Oceanography (India)

Gupta, R.; Samuel, C.T.

The fungus Aspergillus flavus was observed growing on a 2.1 m long specimen of eel (Thyrsoidea macrurus). Half of the eel was submerged in 5% formalin in a loosely covered specimen jar. The fungus grew on the eel skin as yellowish-green, heavily...

Umur glas eel (Anguilla spp. yang masuk muara Sungai Progo Yogyakarta

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Agung Budiharjo

2017-03-01

Full Text Available The leptocephalus drift with sea currents and moving from spawning area into coastal area near mouth of Progo River. In thecoastal area, leptocephalus metamorfosed into glass eel, after that glass eel migrated to river. The aims of this research were to estimate glass eels age and predict hatching dates. Glass eels sampled on new moon during Februari 2007-Mei 2009 at mouth of Progo River.Glass eel ages estimated using their otolith micro structure. Hatching dates predicted with back calculation of glass eels age. We collected 1.082 glass eels. The ages of glass eel at recruit ranged from 58 to 190 days, and divided into 5 age groups. Glass eels are migrated to river hatched on a "new moon" from July to January. Glass eels are migrated to river during October-January hatched during July-October. Glass eels are migrated to river during February-Juny hatched during November-January.

Functional characterisation of eel dopamine D2 receptors and involvement in the direct inhibition of pituitary gonadotrophins

DEFF Research Database (Denmark)

Jolly, C.; Rousseau, K.; Prézeau, L.

2016-01-01

and antagonists, supporting subtle structure/activity differences. Furthermore, using eel pituitary cell primary cultures, the expression by gonadotroph cells of both native eel D2‐R paralogues was examined by in situ hybridisation of D2A‐R or D2B‐R transcripts, coupled with immunofluorescence of luteinising...... hormone (LH)β or follicle‐stimulating (FSH)β. LH and to a lesser extent, FSH cells expressed both D2‐R transcripts but with a clear predominance of D2B‐R. Notably, D2B‐R transcripts were detected for the majority of LH cells. Accordingly, using these cultures, we showed that DA potently inhibited basal...

Oceanic migration and spawning of anguillid eels.

Science.gov (United States)

Tsukamoto, K

2009-06-01

Many aspects of the life histories of anguillid eels have been revealed in recent decades, but the spawning migrations of their silver eels in the open ocean still remains poorly understood. This paper overviews what is known about the migration and spawning of anguillid species in the ocean. The factors that determine exactly when anguillid eels will begin their migrations are not known, although environmental influences such as lunar cycle, rainfall and river discharge seem to affect their patterns of movement as they migrate towards the ocean. Once in the ocean on their way to the spawning area, silver eels probably migrate in the upper few hundred metres, while reproductive maturation continues. Although involvement of a magnetic sense or olfactory cues seems probable, how they navigate or what routes they take are still a matter of speculation. There are few landmarks in the open ocean to define their spawning areas, other than oceanographic or geological features such as oceanic fronts or seamounts in some cases. Spawning of silver eels in the ocean has never been observed, but artificially matured eels of several species have exhibited similar spawning behaviours in the laboratory. Recent collections of mature adults and newly spawned preleptocephali in the spawning area of the Japanese eel Anguilla japonica have shown that spawning occurs during new moon periods in the North Equatorial Current region near the West Mariana Ridge. These data, however, show that the latitude of the spawning events can change among months and years depending on oceanographic conditions. Changes in spawning location of this and other anguillid species may affect their larval transport and survival, and appear to have the potential to influence recruitment success. A greater understanding of the spawning migration and the choice of spawning locations by silver eels is needed to help conserve declining anguillid species.

Simulating the Oceanic Migration of Silver Japanese Eels.

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Yu-Lin Chang

Full Text Available The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2. Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading, orientation toward the spawning area (fixed heading, and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season. The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

Simulating the Oceanic Migration of Silver Japanese Eels.

Science.gov (United States)

Chang, Yu-Lin; Miyazawa, Yasumasa; Béguer-Pon, Mélanie

2016-01-01

The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels) were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2). Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading), orientation toward the spawning area (fixed heading), and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season). The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

Swamp tours in Louisiana post Hurricane Katrina and Hurricane Rita

Science.gov (United States)

Dawn J. Schaffer; Craig A. Miller

2007-01-01

Hurricanes Katrina and Rita made landfall in southern Louisiana during August and September 2005. Prior to these storms, swamp tours were a growing sector of nature-based tourism that entertained visitors while teaching about local flora, fauna, and culture. This study determined post-hurricane operating status of tours, damage sustained, and repairs made. Differences...

Complete genomic sequence and taxonomic position of Eel virus European X (EVEX), a rhabdovirus of European eel

NARCIS (Netherlands)

Galinier, R.; Beurden, van S.J.; Amilhat, E.; Castric, J.; Schoehn, G.; Verneau, O.; Fazio, G.; Allienne, J.F.; Engelsma, M.Y.; Sasal, P.; Faliex, E.

2012-01-01

Eel virus European X (EVEX) was first isolated from diseased European eel Anguilla anguilla in Japan at the end of seventies. The virus was tentatively classified into the Rhabdoviridae family on the basis of morphology and serological cross reactivity. This family of viruses is organized into six

Presence of viruses in wild eels Anguilla anguilla L, from the Albufera Lake (Spain).

Science.gov (United States)

Bandín, I; Souto, S; Cutrín, J M; López-Vázquez, C; Olveira, J G; Esteve, C; Alcaide, E; Dopazo, C P

2014-07-01

A virological analysis was conducted on wild eels from the Albufera Lake (Spain). A total of 179 individuals at different growth stages were collected in two different surveys (2004 and 2008). Presence of anguillid herpesvirus (AngHV-1), aquabirnavirus and betanodavirus was confirmed by PCR procedures in both surveys, although the number of detections was clearly higher in 2008 (83% of the eels analysed resulted positive for virus presence). AngHV-1 was the viral agent most frequently detected, followed by aquabirnaviruses. Betanodaviruses were detected by the first time in wild eels, and although the detections were only made by nested PCR, high percentage of positives were achieved. In addition, in 2008, seven aquabirnaviruses were isolated. Phylogenetic analysis performed using partial sequences of both genomic segments of aquabirnaviruses indicated that the seven isolates could be typed as WB (genogroup I) on the basis of segment A sequences, but when segment B was used six of them clustered with C1 strain (genogroup V) and one was typed as Ab (genogroup II). These results indicate natural reassortment between different strains of aquabirnaviruses in the eels. Although betanodaviruses were not isolated in cell culture, the analysis of the sequence of the nested PCR product indicated that they clustered with SJNNV genotype. The diversity of viral agents and the high level of viral detections suggest that viral infections may play a more prominent role in the decline of the European eel than initially thought. © 2014 John Wiley & Sons Ltd.

Isolation of vibrio spp. In oysters (crassostrea rhizophorea) caught in the ‘de la virgen’ swamp

OpenAIRE

López Gutiérrez, Lercy; Autor; Manjarrez Pava, Ganiveth; Autor; Herrera Rodríguez, Lilibeth; Autor; Montes Payares, Ana Elena; Autor; Olascuaga Ruíz, Yuranis Paola; Autor; Ortega Quiroz, Rolando José; Autor

2015-01-01

Objective:  To establish contamination by Vibrio in oysters (Crassostrea rhizophorae) caught in De La Virgen Swamp, in order to alert entities in charge or protecting consumer health in Cartagena city. Methods: Between February and April 2006, 67 oysters from 5 strategic sites along De La Virgen Swamp, were analyzed. Insulation and identification of Vibrio was performed through a culture and biochemical tests.Results.  Predominant species were V. alginolyticus (23%),V fluvialis  (20%),V. para...

Karyological characterization and identification of four repetitive element groups (the 18S – 28S rRNA gene, telomeric sequences, microsatellite repeat motifs, Rex retroelements) of the Asian swamp eel (Monopterus albus)

Science.gov (United States)

Suntronpong, Aorarat; Thapana, Watcharaporn; Twilprawat, Panupon; Prakhongcheep, Ornjira; Somyong, Suthasinee; Muangmai, Narongrit; Surin Peyachoknagul; Srikulnath, Kornsorn

2017-01-01

Abstract Among teleost fishes, Asian swamp eel (Monopterus albus Zuiew, 1793) possesses the lowest chromosome number, 2n = 24. To characterize the chromosome constitution and investigate the genome organization of repetitive sequences in M. albus, karyotyping and chromosome mapping were performed with the 18S – 28S rRNA gene, telomeric repeats, microsatellite repeat motifs, and Rex retroelements. The 18S – 28S rRNA genes were observed to the pericentromeric region of chromosome 4 at the same position with large propidium iodide and C-positive bands, suggesting that the molecular structure of the pericentromeric regions of chromosome 4 has evolved in a concerted manner with amplification of the 18S – 28S rRNA genes. (TTAGGG)n sequences were found at the telomeric ends of all chromosomes. Eight of 19 microsatellite repeat motifs were dispersedly mapped on different chromosomes suggesting the independent amplification of microsatellite repeat motifs in M. albus. Monopterus albus Rex1 (MALRex1) was observed at interstitial sites of all chromosomes and in the pericentromeric regions of most chromosomes whereas MALRex3 was scattered and localized to all chromosomes and MALRex6 to several chromosomes. This suggests that these retroelements were independently amplified or lost in M. albus. Among MALRexs (MALRex1, MALRex3, and MALRex6), MALRex6 showed higher interspecific sequence divergences from other teleost species in comparison. This suggests that the divergence of Rex6 sequences of M. albus might have occurred a relatively long time ago. PMID:29093797

Evolution of Microsatellite Loci of Tropical and Temperate Anguilla Eels

Directory of Open Access Journals (Sweden)

Mei-Chen Tseng

2012-04-01

Full Text Available Anguilla eels are divided into temperate and tropical eels, based on their major distributions. The present study collected two temperate eels, Anguilla japonica and Anguilla anguilla, and two tropical eels, Anguilla marmorata and Anguilla bicolor pacifica, to examine two questions: do temperate and tropical Anguilla eels have different genetic polymorphic patterns?; and do temperate Anguilla japonica and Anguilla anguilla have a closer relationship to each other than to tropical eels? In total, 274 sequences were cloned and sequenced from six conserved microsatellite loci to examine polymorphic patterns of these four catadromous eels. Different mutational events, including substitutions, and repeat-unit deletions and insertions, appeared in major regions, while different point mutations were observed in flanking regions. The results implied that parallel patterns of microsatellite sequences occurred within both tropical and temperate freshwater eels. Consensus flanking sequences of six homologous loci from each of the four species were constructed. Genetic distances ranged from 0.044 (Anguilla bicolor pacifica vs. Anguilla marmorata to 0.061 (Anguilla marmorata vs. Anguilla anguilla. The tree topology suggests the hypothesis of Anguilla japonica and Anguilla anguilla being a sister group must be rejected.

Behaviour of stocked and naturally recruited European eels during migration

DEFF Research Database (Denmark)

Westerberg, Håkan; Sjöberg, Niklas; Lagenfelt, Ingvar

2014-01-01

An objection to the stocking of translocated eels as a management measure for the European eel (Anguilla anguilla L.) is that these eels may lack the ability to find their way back to the spawning area in the Sargasso Sea because the translocation will confuse their imprinted navigation. We...... behaviour could be monitored by acoustic tagging, in addition to using archival and satellite tags to track the subsequent marine migration. In the second year, the eels were released on the open coast and only their marine migration was investigated. Eels were tracked more than 2000 km along a route that...

Reproduction of European Eel in Aquaculture (REEL)

DEFF Research Database (Denmark)

Tomkiewicz, Jonna; Tybjerg, Lars; Støttrup, Josianne

for the development of methods to reproduce European eel in aquaculture. Two major projects: Artificial Reproduction of Eels II and III (ROE II and III) succeeded during 2005-2008 to produce viable eggs and larvae that lived up to 12 days. The larvae thereby accomplished the yolk-sac stage and became ready to start...... feeding. The results were in particular promising because they evidenced that methods successfully applied to Japanese eel has a potential for application also to the European eel. ROE II and III were supported by the Ministry of Food, Agriculture and Fisheries and the European Commission through...... the Financial Instrument for Fisheries Guidance (FIFG) and the Danish Food Research Program 2006, respectively. Results: The REEL project accomplished through three series of experiments to consolidate previous results. The longevity of larvae was extended from 12 to 20 days after hatch in first feeding...

On the way to successful European eel larval rearing: Impact of biophysical conditions and gamete quality

DEFF Research Database (Denmark)

Sørensen, Sune Riis

The European eel is a widely distributed fish species of economic and cultural importance. It inhabits both coastal and freshwater systems, and is targeted by fisheries and treasured as food item. Although eels are reared in aquaculture, this industry relies solely of wild‐caught juvenile glass...... the European continent, they are in an immature stage, and they do not start migration and maturation until the silvering stage. This stage is however tightly controlled by brain and pituitary hormones, preventing maturation of gonads remote from their natural breeding area. This hormonal inhibition...... and larval culture. Our fertilisation procedures initially applied spermatocrit as for sperm quantification technique to standardise sperm:egg ratio. Although being a practical method, it featured moderate precision. Spectrophotometry in contrast, showed high precision in addition to being a fast...

Skin disease affecting the conservation of the western swamp tortoise (Pseudemydura umbrina)

Science.gov (United States)

Ladyman, J M; Kuchling, G; Burford, D; Boardman, W; Raidal, S R

1998-11-01

To review the present position of the western swamp tortoise (Pseudemydura umbrina) as an endangered species and significant health issues affecting efforts to save it from extinction. A retrospective analysis of the husbandry, hospital and pathology records of the western swamp tortoise captive breeding program at Perth Zoo. In 1987 a captive breeding project was developed to prevent the extinction of the western swamp tortoise but an outbreak of a necrotising dermatitis in 1989 threatened the survival of the captive bred hatchlings. Less severe outbreaks occurred in 1990 and 1993, with isolated cases in between. Of 283 tortoises that were born in captivity or came into captivity from the wild, 37 (13.1%) were affected, comprising 37% of all males, 26% of all females and 13% of animals of unknown gender. Of the affected animals, 70% were less than 2 years of age and 29% were older. Males were 1.6 times more likely to be infected than females but this difference was not statistically significant (P = 0.27). Culture of the lesions consistently yielded unidentified Pseudomonas sp. Improved husbandry, such as strict maintenance of water quality and temperature conditions similar to that of the animal's natural habitat, and monitoring the health of individual tortoises have successfully controlled skin disease in the captive breeding of the western swamp tortoise.

OptaDOS - a new tool for EELS calculations

Science.gov (United States)

Nicholls, R. J.; Morris, A. J.; Pickard, C. J.; Yates, J. R.

2012-07-01

Many modern (Scanning) Transmission Electron Microscopes ((S)TEMs) are equipped with an energy loss spectrometer. The Electron Energy Loss (EEL) spectra collected provide an experimental method of probing the bonding within a material. With the extra addition of monochromators, the energy resolution obtainable means that even more information is revealed within the fine structure of the spectra. Interpreting the fine structure can often be aided by simulation. Density-functional theory (DFT) is one method of simulating EEL spectra. DFT allows us to simulate DOS and EEL spectra from different structures. This comparison between simulation and experiment enables us to explore how changes in the spectrum are related to changes within the sample. CASTEP is a pseudopotential DFT code which can simulate both low-loss and core-loss EEL spectra. Recent developments have resulted in a separate analysis tool, OptaDOS. This package computes various spectral properties including DOS, projected DOS, joint DOS, core-loss and low-loss EEL spectra and optical spectra. One of the important aspects of the code is the way in which the DOS is calculated. This is done via linear extrapolation or adaptive smearing, methods which are not currently available within CASTEP (or indeed any other code) and which allow detailed analysis of spectral properties. This paper summarises these developments and what they mean for the interpretation of EEL spectra.

Eel-Ernal võidutses sõjakool / Kristo Sinivee

Index Scriptorium Estoniae

Sinivee, Kristo

2011-01-01

Eel-Erna võistlus toimus 6.-7. mail Pärnumaal, sellel osales 21 võistkonda Kaitseliidust, kaitseväest, Kaitseväe Ühendatud Õppeasutustest, Politsei- ja Piirivalveametist ja vanglate relvastatud üksusest. Eel-Erna tulemused

EELS signal enhancement by means of beam precession in the TEM

International Nuclear Information System (INIS)

Estradé, Sonia; Portillo, Joaquim; Yedra, Lluís; Rebled, José Manuel; Peiró, Francesca

2012-01-01

EELS is nowadays a most relevant characterization tool as it provides chemical and electronic information with an extraordinary spatial resolution. When a crystal is viewed in zone axis in the TEM, there is channelling of the electrons along the atom columns, which strongly reduce the EELS signal, so that it is generally advised to work slightly off the zone axis to collect EELS data, which may not always be possible or advantageous. In the present work, we demonstrate the use of precession to compensate for the reduction of EELS signal when in the zone axis. -- Highlights: ► Channelling compromises EELS signal in zone axis. ► Precession can be used to get rid of channelling effects. ► Use of precession to enhance EELS signal in the zone axis is demonstrated.

TEM-EELS: A personal perspective

International Nuclear Information System (INIS)

Egerton, R.F.

2012-01-01

The development of electron energy-loss spectroscopy in a transmission electron microscope (TEM-EELS) is illustrated through personal anecdote, highlighting some of the basic principles, instrumentation and personalities involved. The current state of the art is reviewed, together with some challenges for the future. -- Highlights: ► The history of EELS instrumentation is reviewed in a lighthearted manner. ► The current state of the art is summarized, together with some future possibilities. ► A couple of related mathematical puzzles are offered as a challenge to the reader.

Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA

Science.gov (United States)

Middleton, B.; Devlin, D.; Proffitt, E.; McKee, K.; Cretini, K.F.

2008-01-01

Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround RIM swamps, and water is pumped into the impoundment during the summer, a season when natural swamps have low water levels. In the New World, these mosquito-managed swamps resemble the mixed basin type of mangrove swamp (based on PCA analysis). An assessment was made of RIM, natural (control), and breached-RIM (restored) swamps in eastern Florida to compare their structural complexities, soil development, and resistance to invasion. Regarding structural complexity, dominant species composition differed between these swamps; the red mangrove Rhizophora mangle occurred at a higher relative density in RIM and breached-RIM swamps, and the black mangrove Avicennia germinans had a higher relative density in natural swamps. Tree density and canopy cover were higher and tree height lower in RIM swamps than in natural and breached-RIM swamps. Soil organic matter in RIM swamps was twice that in natural or breached-RIM swamps. RIM swamps had a lower resistance to invasion by the Brazilian pepper tree Schinus terebinthifolius, which is likely attributable to the lower porewater salinity in RIM swamps. These characteristics may reflect differences in important ecosystem processes (primary production, trophic structure, nutrient cycling, decomposition). Comparative assessments of managed wetlands are vital for land managers, so that they can make informed decisions compatible with conservation objectives. ?? Inter-Research 2008.

Assessing patterns of hybridization between North Atlantic eels using diagnostic single-nucleotide polymorphisms

DEFF Research Database (Denmark)

Pujolar, José Martin; Jacobsen, M.W.; Als, Thomas Damm

2014-01-01

The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify...... species-specific diagnostic single-nucleotide polymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N=159) and from the neighboring Faroe Islands (N=29) were genotyped, along with 94 larvae (49 European and 45 American...... eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid × pure European eel) and three individuals identified as second-generation backcrosses originating from American eel × F1 hybrid backcrosses interbreeding with pure European eels. In comparison...

Utilization of Swamp Forages from South Kalimantan on Local Goat Performances

Directory of Open Access Journals (Sweden)

T. Rostini

2014-04-01

Full Text Available Forages in swamp area consist of grass and legumes that have good productivity and nutrient quality. This research was aimed to evaluate the potency of swamp forage on digestibility and performance of goats. There were 24 local male goats aged 10-12 months with initial body weight of 13.10±1.55 kg, allocated into 6 treatments. Those were control (R0: 60% grass and 40% legumes; (R1: 60% swamp forages and 40% concentrate; (R2: 100% swamp forages; (R3: 100% swamp forage hay; (R4: 100% swamp forage silage; (R5: 100% haylage swamp forages. Results showed that silage treatment significantly increased (P<0.05 consumption and digestibility. Swamp forages could be utilized well by preservation (silage, hay, and haylage. Ensilage of swamp forages increased protein content from 13.72% to 14.02%, protein intake (74.62 g/d, dry matter intake (532.11 g/d, nitrogen free extract intake (257.39 g/d, with total body weight gain (3.5 kg in eight weeks and average daily gain (62.60 g/d. It is concluded that ensilage of swamp forages (R4 is very potential to be utilized as forage source for ruminants such as goats.

Properties and expression of Na+/K+-ATPase α-subunit isoforms in the brain of the swamp eel, Monopterus albus, which has unusually high brain ammonia tolerance.

Directory of Open Access Journals (Sweden)

Xiu L Chen

Full Text Available The swamp eel, Monopterus albus, can survive in high concentrations of ammonia (>75 mmol l(-1 and accumulate ammonia to high concentrations in its brain (4.5 µmol g(-1. Na(+/K(+-ATPase (Nka is an essential transporter in brain cells, and since NH4(+ can substitute for K(+ to activate Nka, we hypothesized that the brain of M. albus expressed multiple forms of Nka α-subunits, some of which might have high K(+ specificity. Thus, this study aimed to clone and sequence the nka α-subunits from the brain of M. albus, and to determine the effects of ammonia exposure on their mRNA expression and overall protein abundance. The effectiveness of NH4(+ to activate brain Nka from M. albus and Mus musculus was also examined by comparing their Na(+/K(+-ATPase and Na(+/NH4(+-ATPase activities over a range of K(+/NH4(+ concentrations. The full length cDNA coding sequences of three nkaα (nkaα1, nkaα3a and nkaα3b were identified in the brain of M. albus, but nkaα2 expression was undetectable. Exposure to 50 mmol l(-1 NH4Cl for 1 day or 6 days resulted in significant decreases in the mRNA expression of nkaα1, nkaα3a and nkaα3b. The overall Nka protein abundance also decreased significantly after 6 days of ammonia exposure. For M. albus, brain Na(+/NH4(+-ATPase activities were significantly lower than the Na(+/K(+-ATPase activities assayed at various NH4(+/K(+ concentrations. Furthermore, the effectiveness of NH4(+ to activate Nka from the brain of M. albus was significantly lower than that from the brain of M. musculus, which is ammonia-sensitive. Hence, the (1 lack of nkaα2 expression, (2 high K(+ specificity of K(+ binding sites of Nkaα1, Nkaα3a and Nkaα3b, and (3 down-regulation of mRNA expression of all three nkaα isoforms and the overall Nka protein abundance in response to ammonia exposure might be some of the contributing factors to the high brain ammonia tolerance in M. albus.

Microbial interference with hatch and survival of European eel larvae

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Lauesen; Tomkiewicz, Jonna

Recent research has significantly improved our knowledge and capabilities in the field of in vitro production of yolk sac larvae from European eel (Anguilla anguilla). Female broodstock European eels are matured by weekly administration of pituitary extract and male eels with hCG (human chorionic...... larviculture should not only focus on optimizing physical incubation conditions, but certainly also on the control over microbial interference....

Variation in organotin accumulation in relation to the life history in the Japanese eel Anguilla japonica

Science.gov (United States)

Ohji, Madoka; Harino, Hiroya; Arai, Takaomi

2009-08-01

In order to examine the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwaters, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in the catadromous eel Anguilla japonica, which has sea, estuarine and river life histories, collected in Japanese sea, brackish and freshwaters within the same region. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along the life history transect to discriminate the migration type. There were generally three different patterns, which were categorized as 'sea eels', 'estuarine eels' and 'river eels' according to the otolith Sr:Ca ratio. The concentrations of TBT in silver eels (mature eels) were significantly higher than that in yellow eels (immature eels), and the percentages of TBT were also higher in silver eels than in yellow eels. A positive correlation was found between TBT concentration and the gonad-somatic index (GSI). It is thus considered that silver eels have a higher risk of contamination by TBT than yellow eels. TBT and TPT concentrations in sea eels were significantly higher than those in river eels, while no significant differences were observed in TBT and TPT concentrations in estuarine eels compared to sea and river eels. These results suggest that sea eels have a higher ecological risk of OT contamination than river eels during their life history, and the risk of OTs in estuarine eels is considered to be intermediate between that of sea and river eels. Positive linear relationships were found between Sr:Ca ratios and the concentrations of TBT and TPT. Therefore, these results suggest that the ecological risk of OTs increase as the sea residence period in the eel becomes longer. TBT and TPT concentrations in sea eels were significantly higher than those in river eels even at the same growth stage. Thus, it is clear that migratory type is the most important factor for OT

Surface vibrational spectroscopy (EELS)

International Nuclear Information System (INIS)

Okuyama, Hiroshi

2006-01-01

Adsorbed states of hydrogen on metal surfaces have been studied by means of electron energy loss spectroscopy (EELS). In this article, typical spectra and analysis as well as recent development are introduced. (author)

Are dioxin-like contaminants responsible for the eel ( Anguilla anguilla) drama?

Science.gov (United States)

Palstra, A. P.; van Ginneken, V. J. T.; Murk, A. J.; van den Thillart, G. E. E. J. M.

2006-03-01

Eel populations worldwide are dangerously close to collapsing. Our study is the first to show that current levels of dioxin-like contaminants are strong candidates because of their devastating effects on development and survival of eel embryos. Female and male silver eels were artificially stimulated to maturation and reproduction by treatment with carp pituitary extracts and hCG, respectively. During maturation of female European silver eels, about 60 g fat per kg eel is incorporated in the oocytes. Together with the fat, however, persistent organic pollutants such as dioxin-like polychlorinated biphenyls (PCBs) are incorporated too. The total dioxin-like toxic potency of the individual gonad batches was determined as 2,3,7,8-tetrachlorodibenzo- p-dioxine equivalents (TEQs), using an in vitro reporter gene assay. The observed differences in development and survival showed a significant negative correlation with the TEQ levels in the gonads, already at levels far below the maximal allowable level for fish consumption, i.e., 4 ng TEQ/kg fish. The clear inverse relationship between the TEQ level and the survival period of the fertilised eggs strongly suggests that the current levels of dioxin-like compounds seriously impair the reproduction of the European eel. The peak of the environmental levels of dioxin-like PCBs and the decline of eel coincide worldwide, further suggesting that, in addition to other threats, these contaminants contributed significantly to the current collapse in eel populations.

Hydrographic features of anguillid spawning areas: Potential signposts for migrating eels

DEFF Research Database (Denmark)

Schabetsberger, Robert; Miller, Michael J.; Dall'Olmo, Giorgio

2016-01-01

Catadromous anguillid eels (genus Anguilla) migrate from their freshwater or estuarine habitats to marine spawning areas. Evidence from satellite tagging studies indicates that tropical and temperate eel species exhibit pronounced diel vertical migrations, from between 150-300 m nighttime depths...... to 600-800 m during the day. Collections of eggs and larvae of Japanese eels A. japonica suggest they may spawn at these upper nighttime migration depths. How anguillid eels navigate through the ocean and find their spawning areas remains unknown; thus, this study describes the salinity, temperature...

Retention and effects of miniature transmitters in juvenile American eels

Energy Technology Data Exchange (ETDEWEB)

Mueller, Robert P.; Janak, Jill; Liss, Stephanie A.; Brown, Richard S.; Deng, Zhiqun; Harnish, Ryan A.

2017-11-01

This study was conducted to assess the effects of a non-functional acoustic micro transmitter (tag) on survival, tag loss, and swimming ability of juvenile American eels (Anguilla rostrata). The transmitter was designed for implantation through a < 3 mm opening into the body cavity of anguilliform fishes without the need for sutures. American eels used for the swimming performance study were 113–175 mm (N = 120). There were two treatment groups (tagged and non-tagged), each treatment was split into six size groups of 10 mm for testing. Potential transmitter effects on swimming performance were examined by comparing critical swimming speeds (Ucrit an index of prolonged swimming performance) for tagged and non-tagged eels. There was no significant difference in Ucrit between tagged and non-tagged eels for all of the size groups tested. Median Ucrits for tagged eels ranged from 50.2 cm/s for the smallest group tested (113–119 mm) to 63.9 cm/s for fish 141–150 mm in length. Non-tagged group median Ucrits ranged from 47.2 cm/s for the smallest group to 66.9 cm/s for the 141–150 mm group. An additional 26 eels (115–208 mm) were tagged and held for 38 d (without undergoing swimming performance tests) to determine the effects on survival and tag loss. There was no mortality during the holding period and the majority of the tag loss occurred after 20 days post-tagging, which is the current projected life of the tag. Our results indicate that micro acoustic tags can be successfully implanted in juvenile American eels with no apparent impacts to swimming ability, and would be a viable option for examining eel movement patterns in river systems and near hydroelectric facilities.

Integral handling of the swamps for indigenous communities - Caribbean of Colombia

International Nuclear Information System (INIS)

Sanchez Paez, Heliodoro; Ulloa Delgado Giovanni, Andres; Tavera Escobar, Hector Arsenio

2004-06-01

The book includes topics like the ecosystems of swamps, zonification for its handling, growth of species of swamps, restoration and vegetation, integral plan of handling of swamps and its fauna among other topics

A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

Science.gov (United States)

Welsh, Stuart A.; Aldinger, Joni L.

2014-01-01

Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

Regeneration potential of Taxodium distichum swamps and climate change

Science.gov (United States)

Middleton, B.A.

2009-01-01

Seed bank densities respond to factors across local to landscape scales, and therefore, knowledge of these responses may be necessary in forecasting the effects of climate change on the regeneration of species. This study relates the seed bank densities of species of Taxodium distichum swamps to local water regime and regional climate factors at five latitudes across the Mississippi River Alluvial Valley from southern Illinois to Louisiana. In an outdoor nursery setting, the seed banks of twenty-five swamps were exposed to non-flooded (freely drained) or flooded treatments, and the number and species of seeds germinating were recorded from each swamp during one growing season. Based on ANOVA analysis, the majority of dominant species had a higher rate of germination in non-flooded versus flooded treatments. Similarly, an NMS comparison, which considered the local water regime and regional climate of the swamps, found that the species of seeds germinating, almost completely shifted under non-flooded versus flooded treatments. For example, in wetter northern swamps, seeds of Taxodium distichum germinated in non-flooded conditions, but did not germinate from the same seed banks in flooded conditions. In wetter southern swamps, seeds of Eleocharis cellulosa germinated in flooded conditions, but did not germinate in non-flooded conditions. The strong relationship of seed germination and density relationships with local water regime and regional climate variables suggests that the forecasting of climate change effects on swamps and other wetlands needs to consider a variety of interrelated variables to make adequate projections of the regeneration responses of species to climate change. Because regeneration is an important aspect of species maintenance and restoration, climate drying could influence the species distribution of these swamps in the future. ?? 2008 Springer Science+Business Media B.V.

Tagging the European eel Anguilla anguilla (L.) with coded wire tags

DEFF Research Database (Denmark)

Thomassen, S.; Pedersen, Michael Ingemann; Holdensgaard, G.

2000-01-01

The coded wire tag (CWT) system was examined as a possible tool for tagging European eels (Anguilla anguilla). Two size groups of eels (3.8 and 10.2 g) were tagged with CWTs in the dorsal musculature, Tag loss 28 days after tagging was 3.1% for the small and 0.7% for the large groups of eels...

Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues

Science.gov (United States)

Galbraith, Heather S.; Blakeslee, Carrie J.; Schmucker, Andrew K.; Johnson, Nicholas; Hansen, Michael J.; Li, Weiming

2017-01-01

The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

Do North Atlantic eels show parallel patterns of spatially varying selection?

DEFF Research Database (Denmark)

Ulrik, Malene G.; Pujolar, Jose Martin; Ferchaud, Anne-Laure

2014-01-01

was used to genotype European eel individuals (glass eels) from 8 sampling locations across the species distribution. We tested for single-generation signatures of spatially varying selection in European eel by searching for elevated genetic differentiation using F-ST-based outlier tests and by testing...... for significant associations between allele frequencies and environmental variables. Results: We found signatures of possible selection at a total of 11 coding-gene SNPs. Candidate genes for local selection constituted mainly genes with a major role in metabolism as well as defense genes. Contrary to what has...... been found for American eel, only 2 SNPs in our study correlated with differences in temperature, which suggests that other explanatory variables may play a role. None of the genes found to be associated with explanatory variables in European eel showed any correlations with environmental factors...

Micro-PIXE line-scan measurements of the yellow eel's otolith

International Nuclear Information System (INIS)

Zheng, Y.; Guo, H.; Tang, W.; Wei, K.; Shen, H.; Yang, M.; Mi, Y.

2011-01-01

Anguilla japonica has a high economic value. The abundance had decreased significantly due to excessive fishing and change in the aquatic ecology. Life history patterns of A. japonica have been studied to prevent excessive fishing and make management plans. Strontium (Sr)-calcium (Ca) ratio along a line down the long axis from the core to the edge of the yellow eel's otolith was measured using micro proton induced X-ray emission (micro-PIXE). An efficient and precise method was proposed to locate the core where an otolith begins to grow, based on Sr concentration and distribution. Using this method, life history patterns of the yellow eels collected from Jingjiang River in China were investigated. In general, there are two types, river eels and estuarine eels.

Magnetic Compass Orientation in the European Eel

OpenAIRE

Durif, Caroline M. F.; Browman, Howard I.; Phillips, John B.; Skiftesvik, Anne Berit; V?llestad, L. Asbj?rn; Stockhausen, Hans H.

2013-01-01

European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at ge...

The scientific value and potential of New Zealand swamp kauri

Science.gov (United States)

Lorrey, Andrew M.; Boswijk, Gretel; Hogg, Alan; Palmer, Jonathan G.; Turney, Christian S. M.; Fowler, Anthony M.; Ogden, John; Woolley, John-Mark

2018-03-01

New Zealand swamp kauri (Agathis australis) are relic trees that have been buried and preserved in anoxic bog environments of northern New Zealand for centuries through to hundreds of millennia. Kauri are massive in proportion to other native New Zealand trees and they can attain ages greater than 1000 years. The export market for swamp (subfossil) kauri has recently been driven by demand for a high-value workable timber, but there are concerns about the sustainability of the remaining resource, a situation exacerbated in recent years by the rapid extraction of wood. Economic exploitation of swamp kauri presents several unique opportunities for Quaternary science, however the scientific value of this wood is not well understood by the wider research community and public. Here, we summarise the history of scientific research on swamp kauri, and explore the considerable potential of this unique resource. Swamp kauri tree-ring chronologies are temporally unique, and secondary analyses (such as radiocarbon and isotopic analyses) have value for improving our understanding of Earth's recent geologic history and pre-instrumental climate history. Swamp kauri deposits that span the last interglacial-glacial cycle show potential to yield "ultra-long" multi-millennia tree-ring chronologies, and composite records spanning large parts of MIS3 (and most of the Holocene) may be possible. High-precision radiocarbon dating of swamp kauri chronologies can improve the resolution of the global radiocarbon calibration curve, while testing age modelling and chronologic alignment of other independent long-term high-resolution proxy records. Swamp kauri also has the potential to facilitate absolute dating and verification of cosmogenic events found in long Northern Hemisphere tree-ring chronologies. Future efforts to conserve these identified values requires scientists to work closely with swamp kauri industry operators, resource consent authorities, and export regulators to mitigate

Evolution of the locomotory system in eels (Teleostei: Elopomorpha).

Science.gov (United States)

Pfaff, Cathrin; Zorzin, Roberto; Kriwet, Jürgen

2016-08-11

Living anguilliform eels represent a distinct clade of elongated teleostean fishes inhabiting a wide range of habitats. Locomotion of these fishes is highly influenced by the elongated body shape, the anatomy of the vertebral column, and the corresponding soft tissues represented by the musculotendinous system. Up to now, the evolution of axial elongation in eels has been inferred from living taxa only, whereas the reconstruction of evolutionary patterns and functional ecology in extinct eels still is scarce. Rare but excellently preserved fossil eels from the Late Cretaceous and Cenozoic were investigated here to gain a better understanding of locomotory system evolution in anguilliforms and, consequently, their habitat occupations in deep time. The number of vertebrae in correlation with the body length separates extinct and extant anguilliforms. Even if the phylogenetic signal cannot entirely be excluded, the analyses performed here reveal a continuous shortening of the vertebral column with a simultaneous increase in vertebral numbers in conjunction with short lateral tendons throughout the order. These anatomical changes contradict previous hypotheses based on extant eels solely. The body curvatures of extant anguilliforms are highly flexible and can be clearly distinguished from extinct species. Anatomical changes of the vertebral column and musculotendinous system through time and between extinct and extant anguilliforms correlate with changes of the body plan and swimming performance and reveal significant shifts in habitat adaptation and thus behaviour. Evolutionary changes in the skeletal system of eels established here also imply that environmental shifts were triggered by abiotic rather than biotic factors (e.g., K/P boundary mass extinction event).

Effect of Using the Lemongrass (Cimbopogon Citratus) to Smoked Eel (Monopterus Albus) Processing Quality

OpenAIRE

Satria, Viki Buana; Buchari, Dewita; ', Sumarto

2015-01-01

This study was aimed to determine the effect of using the lemongrass on organoleptic quality of smoked eel. 4 kg of fresh eel and lemongrass obtained from one of market in Pekanbaru processed into smoked eel. The treatment of this study was using the different concentration of lemongrass (0%, 10%, 20% and 30%) from fresh eel to determine the quality of smoked eel. The result showed that the lemongrass with concentration 30% was the best treatment and most favorable by consumer with appearance...

Oceanic fronts in the Sargasso Sea control the early life and drift of Atlantic eels

DEFF Research Database (Denmark)

Munk, Peter; Hansen, Michael Møller; Maas, Gregory E.

2010-01-01

Anguillid freshwater eels show remarkable life histories. In the Atlantic, the European eel (Anguilla anguilla) and American eel (Anguilla rostrata) undertake extensive migrations to spawn in the oceanic Sargasso Sea, and subsequently the offspring drift to foraging areas in Europe and North......, during a field expedition to the eel spawning sites in the Sargasso Sea, we carried out a wide range of dedicated bio-physical studies across areas of eel larval distribution. Our findings suggest a key role of oceanic frontal processes, retaining eel larvae within a zone of enhanced feeding conditions...

Studies on mangrove swamps of Goa 1. Heterotrophic bacterial flora from mangrove swamps

Digital Repository Service at National Institute of Oceanography (India)

Matondkar, S.G.P; Mathani, S; Mavinkurve, S

Heterotrophic bacterial flora from the mangrove swamps of Goa consisted of physiologically active organisms exhibiting cellulolytic, pectinolytic, amylolytic, proteolytic and H2S forming activities, throughout the year. Coryneform and Bacillus were...

Hepatic receptors for homologous growth hormone in the eel

International Nuclear Information System (INIS)

Hirano, T.

1991-01-01

The specific binding of 125I-labeled eel growth hormone (eGH) to liver membranes of the eel was examined. The specific binding to the 10,000g pellet was greater than that to the 600g pellet. The specific binding was linear up to about 100 mg fresh tissue, and was saturable with increasing amounts of membrane. The specific binding was pH-, temperature-, and time-dependent, with the optimum pH at 7.4, and greater specific binding was obtained at 15 and 25 degrees than at 35 degrees. Scatchard analysis of liver binding gave an association constant of 1.1 x 10(9) M-1 and a capacity of 105 fmol/mg protein. The receptor preparation was highly specific for GHs. Natural and recombinant eel GHs as well as recombinant salmon GH competed equally with 125I-eGH for the receptor sites of the 10,000g liver membrane. Ovine GH was more potent in displacing the labeled eGH than the homologous eel hormone. Tilapia GH and ovine prolactin (PRL) were needed in greater amounts (40 times) than eGH to displace the labeled eGH. Salmon and tilapia PRLs were still less potent (500 times) than eGH. There was no displacement with eel PRL. No significant change in the specific binding was seen 1 week after hypophysectomy, whereas injection of eGH into the hypophysectomized eel caused a significant reduction after 24 hr. The binding to the membrane fractions from gills, kidney, muscle, intestine, and brain was low and exclusively nonspecific, indicating the presence of specific GH receptors predominantly in the liver

Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels.

Science.gov (United States)

Chan, Thomas Y K

2017-06-26

Moray eels ( Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels.

Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels

Directory of Open Access Journals (Sweden)

Thomas Y. K. Chan

2017-06-01

Full Text Available Moray eels (Gymnothorax species from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning, characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver can result in severe or fatal ciguatera. Moray eels (particularly when ungutted must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels.

Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels

Science.gov (United States)

Chan, Thomas Y. K.

2017-01-01

Moray eels (Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels. PMID:28672845

Transition radiation in EELS and cathodoluminescence

Energy Technology Data Exchange (ETDEWEB)

Stöger-Pollach, Michael, E-mail: stoeger@ustem.tuwien.ac.at; Kachtík, Lukáš; Miesenberger, Bernhard; Retzl, Philipp

2017-02-15

The excitation probability of transition radiation is measured for varying beam energies in a transmission electron microscope once using optical spectrometry of the emitted light and second using electron energy loss spectrometry. In both cases similar results are found being in good agreement with theory. The knowledge about this probability enables us to judge whether or not transition radiation has to be considered in EELS and CL data interpretation. Additionally it is shown that the emission of transition radiation happens at the sample surfaces only, when the electron passes the vacuum/sample interface and thus feeling the change of its dielectric environment. We demonstrate that in the case of aluminum the influence of transition radiation on the low loss EELS spectrum is only minor and conclude that it might be negligible for many other materials. - Highlights: • We determine the probability for the excitation of transition radiation at a large variety of beam energies in TEM. • We use a GATAN VULCAN system for optical spectrometry in the TEM. • We do angular resolved EELS experiments in a standard TEM with an angular resolution of 7.57 μrad.

Signatures of natural selection between life cycle stages separated by metamorphosis in European eel.

Science.gov (United States)

Pujolar, J M; Jacobsen, M W; Bekkevold, D; Lobón-Cervià, J; Jónsson, B; Bernatchez, L; Hansen, M M

2015-08-13

Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. We used two sets of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome. Using the RAD approach, outlier tests identified a total of 2413 (1.57%) potentially selected SNPs. Functional annotation analysis identified signal transduction pathways as the most over-represented group of genes, including MAPK/Erk signalling, calcium signalling and GnRH (gonadotropin-releasing hormone) signalling. Many of the over-represented pathways were related to growth, while others could result from the different conditions that eels inhabit during their life cycle. The observation of different genes and gene pathways under selection when comparing glass eels vs. silver eels supports the adaptive decoupling hypothesis for the benefits of metamorphosis. Partitioning the life cycle into discrete morphological phases may be overall beneficial since it allows the different life stages to respond independently to their unique selection pressures. This might translate into a more effective use of food and niche resources and/or performance of phase-specific tasks (e.g. feeding in the case of glass eels, migrating and reproducing in the case of silver eels).

Response of tropical peat swamp forest tree species seedlings to macro nutrients

Directory of Open Access Journals (Sweden)

Tri Wira Yuwati

2015-10-01

Full Text Available Abstract Efforts of restoration of degraded tropical peat swamp forest were facing constraints due to the low available nutrient level of peat. The transplanted peat swamp forest species seedlings experienced low survival rate and poor growth performance. This study aimed to demonstrate the response of ten tropical peat swamp forest species seedlings whether climax and pioneer species to macro-nutrients addition in the nursery. The growth performance of climax and pioneer tropical peat swamp species seedlings was recorded following addition of macro nutrients of Nitrogen (N, Phosphorus(P, Potassium(K and Dolomitic limestone (CaMg. The result showed that Alstonia spatulata and Parartocarpus venenosus showed positive growth response following macro nutrients addition. This study concluded that tropical peat swamp pioneer species has lower necessity for macro-nutrients addition than tropical peat swamp climax species.

Passage of downstream migrant American eels through an airlift-assisted deep bypass

Science.gov (United States)

Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

2016-01-01

Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation.

Science.gov (United States)

Baillon, Lucie; Oses, Jennifer; Pierron, Fabien; Bureau du Colombier, Sarah; Caron, Antoine; Normandeau, Eric; Lambert, Patrick; Couture, Patrice; Labadie, Pierre; Budzinski, Hélène; Dufour, Sylvie; Bernatchez, Louis; Baudrimont, Magalie

2015-11-01

Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish. Copyright © 2015 Elsevier Ltd. All rights reserved.

Signatures of natural selection between life cycle stages separated by metamorphosis in European eel

DEFF Research Database (Denmark)

Pujolar, J.M.; Jacobsen, M.W.; Bekkevold, Dorte

2015-01-01

Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae...... into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. Results: We used two sets...... of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome...

Reproduction of European eel jeopardised by high levels of dioxins and dioxin-like PCBs?

Science.gov (United States)

Geeraerts, C; Focant, J-F; Eppe, G; De Pauw, E; Belpaire, C

2011-09-01

Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the dioxins and furans. In the majority of the sites, eel has levels considered to be detrimental for their reproduction. Field levels of dioxin and dioxin-like PCBs are therefore suggested as an additional causal factor contributing to the decline of the European eel. 42% of the sampling sites show especially dioxin-like PCB levels exceeding the European consumption level (with a factor 3 on average). Human consumption of eel, especially in these highly contaminated sites, seems unjustified. Copyright © 2011 Elsevier B.V. All rights reserved.

Biology and control of swamp dodder (Cuscuta gronovii)

International Nuclear Information System (INIS)

Bewick, T.A.

1987-01-01

A simple model predicting swamp dodder (Cuscuta gronovii Willd.) emergence was developed. The model states that 0.1% of the cranberry seedlings will emerge after 150 to 170 GDD have accumulated after the winter ice has melted on the cranberry beds, using 0 C as the low temperature threshold. Experiments in cranberry showed that pronamide [3,5-dichloro-(N-1,1-dimethyl-2-propynyl)benzamide] was effective in controlling swamp dodder when applied preemergence. Rates below 2.4 kg ai/ha appeared to be safe for cranberry plants and fruit. Experiments with 14 C glyphosate showed that the herbicide moved out of carrot leaves to the physiological sinks in the plant. In carrots parasitized by swamp dodder the dodder acted as one of the strongest sinks for photosynthates from the host. In cranberry glyphosate moved out of the leaves, but most remained in the stem to which the treated leaves were attached. The only physiological sinks that accumulated significant amounts of label were the stem apices. The concentration of the herbicide in this sink decreased with time. Swamp dodder stems were able to absorb glyphosate directly from solution

Analysis of Technical Efficiency among Swamp Rice Farmers in ...

African Journals Online (AJOL)

This study was conducted to evaluate the Technical efficiency among swamp rice farmers in Niger State, Nigeria. A multi-stage sampling technique was used to select 159 swamp rice farmers. The data collected were analysed using descriptive statistics, and the stochastic frontier production function. The results showed ...

Increasing Risk Factors for Imported and Domestic Gnathostomiasis in the United States.

Science.gov (United States)

Diaz, James H

2015-01-01

importation of live freshwater species, such as Asian swamp eels (Monopterus spp.).1 Although raw seafood dishes are typically prepared with saltwater species, freshwater species, which harbor more parasites, are also used in these dishes, such as limejuice marinated tilapia or trout ceviche and eel-sashimi and sushi.2 In 2014, biologists from the US Geological Survey detected Gnathostoma species infective-stage larvae in nearly 30 percent of imported Monopterus species Asian swamp eels and in 4.5 percent of locally-caught Monopterus species freshwater swamp eels in three states.1 The investigators concluded that consumption of imported swamp eels from Gnathostoma-endemic regions of Asia could transmit gnathostomiasis to humans in the US.1 In addition, the release of live imported swamp eels or the disposal of their offal after filleting has introduced more Gnathostoma larvae into open and fish-farmed freshwaters infecting more native species.1 Since the US has all of the components to support Gnathostoma's life cycle, a zoonosis of infective Gnathostoma species, such as G. spinigerum and others, has become established in the US and will increase the risks of gnathostomiasis in humans consuming native, wildcaught, or farmed fish in ethnic dishes.1 As a result, the objectives of this review were to describe the biology and life cycle of Gnathostoma nematodes and the behavioral risk factors for gnathostomiasis; and to describe the clinical manifestations, diagnosis, management, and prevention of human gnathostomiasis.

Shark predation on migrating adult American eels (Anguilla rostrata in the Gulf of St. Lawrence.

Directory of Open Access Journals (Sweden)

Mélanie Béguer-Pon

Full Text Available In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C-too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks.

Results of the 2000 Creek Plantation Swamp Survey

International Nuclear Information System (INIS)

Fledderman, P.D.

2000-01-01

This report is a survey of the Creek Plantation located along the Savannah River and borders the southeast portion of the Savannah River Site. The land is primarily undeveloped and agricultural; its purpose is to engage in equestrian-related operations. A portion of Creek Plantation along the Savannah River is a low-lying swamp, known as the Savannah River Swamp, which is uninhabited and not easily accessible

Persistence of herpesvirus of eel (Herpesvirus anguillae) in farmed European ell (Anguilla anguilla L.)

NARCIS (Netherlands)

Nieuwstadt, van A.P.; Dijkstra, S.G.; Haenen, O.L.M.

2001-01-01

Herpesvirus of eel Herpesvirus anguillae (HVA) was isolated repeatedly from farmed eel of an outwardly healthy stock, but virus isolation was much greater in an experimental group of fish that were injected with dexamethasone. The results suggest that HVA can establish a latent infection in eel.

Swamp Buffalo in South Kalimantan : Problem, Disease and Control

Directory of Open Access Journals (Sweden)

Lily Natalia

2006-12-01

Full Text Available In recent years, several studies have been carried out to evaluate and investigate the important diseases of swamp buffaloes (Bubalus carabanensis in Kalimantan . More attention has been focused on the case of acute infectious diseases and sudden death in the buffaloes . Fasciolosis black disease, acute enteritis, especially fatal enterotoxaemia haemorrhagic septicaemia . and trypanosomiasis (Surra, are some of the important diseases found in these animals . Black disease caused by toxigenic Clostridium novyi occurs in the presence of the organism in the liver and the degree of liver fluke Fasciola gigantica infestation . In regions where black disease is enzootic, Cl. novvi can be isolated from livers of normal healthy animals . In Hulu Sungai Utara district, South Kalimantan, the prevalence of fasciolosis caused by Fasciola gigantica in swamp buffalo was 77% in 1991 . A gross sudden change in diet due to seasonal changes could induce rumen and intestinal stasis, which provide a favourable environment for the rapid proliferation of commensal toxigenic Clostridium perfringens in the small intestine . Subsequent absorption of the toxin produced through the gut wall and its generalized dissemination culminated in a fatal enterotoxaemia . Haemorrhagic septicaemia (HS is an acute, fatal disease affecting swamp buffalo, and caused by Pasteurella multocida B : 2 . The swamp buffalo is particularly susceptible for HS, and the reported greatest losses of swamp buffalo in Kalimantan due to HS is recorded in 1980s. The clinical signs of Surra in swamp buffalo were also found in certain areas in Danau Panggang area . Hulu Sungai Utara district . Vaccination is the accepted method for controlling Black disease, enterotoxaemia and HS. Multi component vaccine, alum adjuvant containing at least 5 types of clostridial toxoids and P. multocida B2 bacterin have been used and provide good protection to the animals . Control and treatment of liver fluke infestation

Status of eel fisheries, stocks and their management in England and Wales

Directory of Open Access Journals (Sweden)

Aprahamian M.

2009-05-01

Full Text Available All continental life stages of eel are exploited in England and Wales. The main fisheries for glass eel are by estuarine dip-nets in the southwest. The main fisheries for yellow and silver eel occur in southern and eastern England, with fyke nets being the preferred instrument. Fishing effort is not directly recorded but is inferred from licence sales. Around 1100 glass eel licenses were sold annually from 1980 to 1994, increasing to around 2500 in 1998, but declined to about 800 per annum since 2001. Declared catches of glass eel have been below 1–2 t since 2001, compared to 10–70 t in the 1970s and 1980s. Licence sales for yellow and silver eel fisheries (combined varied from around 1100 to 2900 over the period 1983–2007, peaking in the mid-1980s, mid-1990s and again in 2005–2007. Declared catches peaked in the late 1980s and mid-1990s (peak 280 t, but have been low since 2001 (mean 29 t. Nett export data suggests catches may be 4 times higher. Eel landings are reported as bycatch from various marine fisheries around the UK coasts, with landings from 2001 to 2007 ranging from 0.2 to 13.7 t per annum. Assessment of stock status is based mainly on catch and catch per unit effort data as there has been little fishery independent survey of eels. There has been a general decreasing trend in both glass eel catches reported to the Agency and in nett export data. Comparing maximum catch levels in the late 1970s–early 1980s with minimum levels in the 2000s suggests that the catch has declined by around 75–95%. Trends in CPUE are similar, at least until 1998. It is concluded that current glass eel recruitment to the western coast of the UK is approximately 30% of the pre-1980 level of recruitment. Yellow and silver eel indices derived from HMRC nett exports or reported catches per licence sold, both suggest that the current estimate of stocks derived from these data are 20% those of the late 1980s and mid 1990s. The Reference Condition

Silver eel migration, wind power and alternating current fields; Blankaalsvandring, vindkraft och vaexelstroemsfaelt, 2011

Energy Technology Data Exchange (ETDEWEB)

Lagenfelt, Ingvar; Andersson, Ingemar; Westerberg, Haakan

2012-02-15

How are eels affected by large offshore wind farms? The study follows the silver eels' migration and behavior at Lillgrund wind farm in Oeresund and the passage over an 130 kV AC cable between the mainland and Oeland. The aim is to see if the AC cable precludes or otherwise affects the eel's ability to reach its destination. Eels migrate up to 7500 km from the Baltic Sea to spawn in the Sargasso Sea. Every delay is of importance for the silver eels, which must be able to travel the entire distance on a single energy reserve. Fish, which make use of the earth's magnetic field for navigation or which are sensitive to electromagnetic fields, may be affected by AC cables on the seabed. The study shows that the silver eels swimming speed was reduced when there was more current in the cable and there was an average delay of 40 minutes before they passed it

Swamp Rice Production in Ogun Waterside Local Government Area ...

African Journals Online (AJOL)

This study examined the economics of swamp rice production among peasant farmers in the Waterside Local Government Area of Ogun State for 2001 cropping year. A total of 50 swamp rice farmers were randomly selected from 5 villages using multistage sampling technique. The data collected, with the aid of ...

Micro-PIXE line-scan measurements of the yellow eel's otolith

Energy Technology Data Exchange (ETDEWEB)

Zheng, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Guo, H.; Tang, W.; Wei, K. [Laboratory of Ichthyology, Shanghai Ocean University, Shanghai 201306 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Yang, M.; Mi, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

2011-10-15

Anguilla japonica has a high economic value. The abundance had decreased significantly due to excessive fishing and change in the aquatic ecology. Life history patterns of A. japonica have been studied to prevent excessive fishing and make management plans. Strontium (Sr)-calcium (Ca) ratio along a line down the long axis from the core to the edge of the yellow eel's otolith was measured using micro proton induced X-ray emission (micro-PIXE). An efficient and precise method was proposed to locate the core where an otolith begins to grow, based on Sr concentration and distribution. Using this method, life history patterns of the yellow eels collected from Jingjiang River in China were investigated. In general, there are two types, river eels and estuarine eels.

Economic analysis of swamp rice production in Ebonyi Southern ...

African Journals Online (AJOL)

The aim of the paper is to analyze the determinants and profitability of the output of swamp rice farmers in Ebonyi southern Agricultural zone of Ebonyi State. Primary data were obtained through the use of structured questionnaires. A total of eighty (80) swamp rice farmers were randomly selected from the different blocks ...

Polyancora globosa gen. sp. nov., an aeroaquatic fungus from Malaysian peat swamp forests.

Science.gov (United States)

Voglmayr, Hermann; Yule, Catherine M

2006-10-01

During an investigation of submerged leaves and twigs sampled from tropical peat swamp forests located in Peninsular Malaysia, an anamorphic fungus not attributable to a described genus was detected and isolated in pure culture. Conidial ontogeny was thoroughly studied and illustrated using both light and SEM, which revealed a unique conidial morphology. Analysis of partial nuLSU rDNA and ITS data revealed a phylogenetic position within the Xylariales (Ascomycota), but family affiliation remained unclear.

Prevalence of Anguillicoloides crassus and growth variation in migrant yellow-phase American eels of the upper Potomac River drainage

Science.gov (United States)

Zimmerman, Jennifer L.; Welsh, Stuart A.

2012-01-01

Prevalence of the non-native swim bladder nematode Anguillicoloides crassus has recently increased in American eels from estuaries of the North American Atlantic coast, but little is known about parasite prevalence or conditions of previous infection in upstream migrant eels within upper watersheds. This study is the first to confirm presence of A. crassus in the upper Potomac River watershed. We estimated A. crassus prevalence during 3 time periods: September to October 2006 (5/143 eels, 3.5%), August to October 2007 (0/49 eels), and June 2008 (0/50 eels). All eels were sampled from the Millville Dam eel ladder on the lower Shenandoah River, a Potomac River tributary located approximately 285 km upstream of Chesapeake Bay, USA. Of the 5 infected eels, parasite intensity was 1 for each eel, and mean intensity was also 1.0. A swim bladder degenerative index (SDI) was calculated for the 50 eels from the final sampling period, and 38% of those eels (19 of 50) showed signs of previous infection by A. crassus. We also aged 42 of the 50 eels (mean ± SE = 6.7 ± 0.29 yr, range 4 to 11 yr) from the final sampling period. Based on the range of possible SDI scores (0 to 6), severity of previously infected swim bladders was moderate (SDI = 1 or 2). Previously infected eels, however, had a lower length-at-age than that of uninfected eels. Female yellow-phase eels in upper watersheds develop into large highly fecund silver-phase adults; hence, a parasite-induced effect on growth of yellow-phase eels could ultimately reduce reproductive potential.

Preslaughter electrical stunning of eels

NARCIS (Netherlands)

Robb, D.H.F.; Wotton, S.B.; Vis, van de J.W.

2002-01-01

The current procedures for slaughtering European eels (Anguilla anguilla) for food are very slow and cause suffering. Although there is little legislation for protecting the welfare of fish at slaughter, the legislation covering farmed mammals and birds at slaughter is well defined, requiring that

Data on the characterization of follicle-stimulating hormone monoclonal antibodies and localization in Japanese eel pituitary

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Dae-Jung Kim

2016-09-01

Full Text Available Monoclonal antibodies were generated against recombinant follicle-stimulating hormone (rec-FSH from Japanese eel Anguilla japonica; rec-FSH was produced in Escherichia coli and purified using Ni-NTA Sepharose column chromatography.In support of our recent publication, ''Production and characterization of monoclonal antibodies against recombinant tethered follicle-stimulating hormone from Japanese eel Anguilla japonica'' [1], it was important to characterize the specificity of eel follicle-stimulating hormone antibodies. Here, the production and ELISA system of these monoclonal antibodies are presented. The affinity-purified monoclonal antibodies specifically detected eel rec-FSH in ELISA and on western blots of rec-FSH produced from CHO cells. Immunohistochemical analysis revealed that FSH staining was specifically localized in the eel pituitary. Keywords: Japanese eel, FSH, Monoclonal Antibody

Kaitseliit testis Eel-Ernal väljaõpet ja võimeid / Taive Kuuse

Index Scriptorium Estoniae

Kuuse, Taive

2007-01-01

Kaitseliidu sõjalis-sportliku võistluse Eel-Erna võitsid Tartu maleva kaitseliitlased ja naiskodukaitse koormusmatka Saaremaa naiskodukaitsjad. Tabel: Eel-Erna tulemused; Naiskodukaitse koormusmatka tulemused

Palynology, sedimentology and environmental significance of Holocene swamps at northern Kaitoke, Great Barrier Island, New Zealand

International Nuclear Information System (INIS)

Horrocks, M.; Ogden, J.; Nichol, S.L.; Alloway, B.V.; Sutton, D.G.

2000-01-01

Pollen and sediment analyses of two cores from coastal freshwater swamps at northern Kaitoke (Kaitoke Swamp and Police Station Swamp), Great Barrier Island, show that c. 7300 calibrated yr BP Kaitoke Swamp was an estuary with tidal flats. Avicennia, now absent from the swamp area, was present in the estuary. By c. 4500 yr BP fresh water conditions had developed at the Kaitoke Swamp site as marine influences decreased. Around the same time, fresh water swamp conditions commenced at the Police Station Swamp site on the surface of a low lying area of a Late Pleistocene dune. A sandy layer at Kaitoke may represent rapid infilling followed by a dry soil surface until c. 1000 yr BP. Conifer-hardwood forest on the hills surrounding the sites c. 7300-c. 1800 yr BP was dominated by Dacrydium and Metrosideros. During this period, environmental conditions were relatively stable, with little change in forest composition. Between 1800 yr and 800 yr BP Kaitoke Swamp was reflooded, and the Police Station Swamp extended as a shallow lake over the nearby dune flat. These new shallow swamps were invaded by swamp forest (mainly Dacrycaprus with some Laurelia). The presence of charcoal and Pteridium spores above the Kaharoa Tephra suggests that major Polynesian deforestation at northern Kaitoke began c. 600 calibrated yr BP. (author). 41 refs., 4 figs., 2 tabs

Methyl mercury bioaccumulation in long-finned eels, Anguilla dieffenbachii, from three rivers in Otago, New Zealand.

Science.gov (United States)

Redmayne, A C; Kim, J P; Closs, G P; Hunter, K A

2000-10-30

This research focuses on mercury (Hg) bioaccumulation in New Zealand long-tinned eels (Anguilla dieffenbachii) from the aquatic environment. Total Hg (HgT) and methyl mercury (MeHg) concentrations were determined in muscle tissue from eels living in three South Island rivers dominated respectively by urban, native bush and agricultural land-uses. Most of the Hg in eels was MeHg (> 84%) and the MeHg concentrations increased linearly with both length and eel age for a given river habitat. The annual growth rates for eels from the urban and agricultural streams were greater than for eels from the native bush stream. The average MeHg accumulation rate was significantly higher for the eels in the agricultural stream compared with either the urban or native bush catchments. These results are probably due to a combination of factors and further investigations in the lower food web are necessary to elucidate the exact mechanisms of MeHg bioaccumulation in these creatures.

Benefits of Riverine Water Discharge into the Lorian Swamp, Kenya

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Zipporah Musyimi

2012-12-01

Full Text Available Use and retention of river water in African highlands deprive communities in arid lowlands of their benefits. This paper reviews information on water use in the Ewaso Ng’iro catchment, Kenya, to evaluate the effects of upstream abstraction on the Lorian Swamp, a wetland used by pastoralists downstream. We first assess the abstractions and demands for water upstream and the river water supplies at the upper and the lower end of the Lorian Swamp. Further analysis of 12 years of monthly SPOT-VEGETATION satellite imagery reveals higher NDVI (Normalized Differential Vegetation Index values in the swamp than nearby rainfed areas, with the difference in NDVI between the two positively related to river water discharged into the swamp. The paper next reviews the benefits derived from water entering the swamp and the vulnerability to abstractions for three categories of water: (i the surface water used for drinking and sanitation; (ii the surface water that supports forage production; and (iii the water that recharges the Merti Aquifer. Our results suggest that benefits from surface water for domestic use and forage production are vulnerable to abstractions upstream whereas the benefits from the aquifer, with significant fossil water, are likely to be affected in the long run, but not the short term.

Recovery from transportation by road of farmed European eel (Anguilla anguilla)

NARCIS (Netherlands)

Boerrigter, J.G.J.; Manuel, R.; Bos, van den R.; Roques, J.A.C.; Spanings, T.; Flik, G.; Vis, van de J.W.

2015-01-01

The objective of this study was to assess the effects of transportation of marketable eel (0.15 kg) in the Netherlands with respect to welfare. Eels (Anguilla anguilla) were obtained from a commercial farm and acclimatized for 7 weeks at the laboratory. Fish were transported according to regular

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States.

Science.gov (United States)

Cooksey-Stowers, Kristen; Schwartz, Marlene B; Brownell, Kelly D

2017-11-14

This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA) Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV) strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision). Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity ( p values ranged from 0.00 to 0.16). Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS) estimates. The food swamp effect was stronger in counties with greater income inequality ( p food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity.

A review on broodstock nutrition of marine pelagic spawners: the curious case of the freshwater eels (Anguilla spp.)

DEFF Research Database (Denmark)

Heinsbroek, L.T.N.; Støttrup, J.G.; Jacobsen, C.

2013-01-01

To sustain eel aquaculture, development of reproduction in captivity is vital. The aim of this review is to assess our current knowledge on the nutrition of broodstock eels in order to improve the quality of broodstock under farming conditions, drawing information from wild adult eels and other...... in the eggs of farmed eels were not detrimental. The total free amino acid amount and profile of eel eggs appears much different from other marine pelagic spawners. Nutritional intervention to influence egg composition seems feasible, but responsiveness of farmed eels to induced maturation might also require...

Evaluation of three telemetry transmitter attachment methods for female silver-phase American eels ( Anguilla rostrata Lesueur)

DEFF Research Database (Denmark)

Cottrill, R.A.; Økland, F.; Aarestrup, Kim

2006-01-01

Declines in juvenile American eel (Anguilla rostrata Lesueur) abundance have led to concern about the impacts of anthropogenic structures on eel migration patterns. Telemetry provides an insightful tool for examining the movements of eels around these structures. Although there have been a number...... of studies investigating movements of Anguillid eels, using a variety of transmitter attachment techniques, there are few published evaluations of the effects of various tag attachment procedures. Hence, the effects of three telemetry attachment procedures were evaluated for female silver phase American eels...... of silver-phase American eels is not affected by the presence of telemetry transmitters or the method of transmitter attachment, even though swim performance decreases. However, transmitter retention rates varied considerably after the 12-week experimental period. Three gastric tags were regurgitated...

Phthalate metabolites in the European eel (Anguilla anguilla) from Mediterranean coastal lagoons.

Science.gov (United States)

Fourgous, C; Chevreuil, M; Alliot, F; Amilhat, E; Faliex, E; Paris-Palacios, S; Teil, M J; Goutte, A

2016-11-01

The levels and fate of phthalate metabolites have been poorly evaluated in fish, despite their potential ecotoxicological impacts. The present study aims to characterize the levels of phthalate metabolites in muscle tissue of yellow eels (Anguilla anguilla) from two coastal Mediterranean lagoons, during three sampling periods. Nine phthalate metabolites were detected in >70% of the samples. Slightly higher levels of phthalate metabolites were detected in March and June compared to October, suggesting possible seasonal variations in environmental release and/or phthalate metabolization process by eels. The large sample size (N=117) made it possible to explore correlations between phthalate metabolites' levels and individual parameters, such as body length, age, body condition and hepatic histo-pathologies. Body length and estimated age poorly correlated with phthalate metabolites, suggesting that eels did not accumulate phthalates during growth, contrary to persistent compounds. Eels presented different grades of hepatic fibrosis and lipidosis. A negative correlation was found between the severity of these pathologies in the liver and the sum of phthalate metabolites levels, supporting the hypothesis that eels with damaged liver are less able to metabolize xenobiotics. Copyright © 2016 Elsevier B.V. All rights reserved.

Biophysics environmental conditions of swamp buffalo Bubalus bubalis Pampangan in district Rambutan South Sumatera

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Yuanita Windusari

2015-06-01

Full Text Available Swamp buffalo (Bubalus bubalis is a germ plasm specific of Pampangan and endemic in South Sumatera with low productivity and limited distribution. The aims of this study was to obtain information regarding biophysical conditions in the central areas of swamp buffalo in South Sumatera. The method used is purposive sampling method. Data collected in the form of quantitative and qualitative. Primary data were obtained through direct observation, interviews breeders selected as respondents while secondary data obtained from various related. The data obtained are presented descriptively and data tabulation. Productivity of swamp buffalo Pampangan can be increased by managing and maintaining habitat conditions although traditional maintenance. The results of observations of the biophysical condition of swamp buffalo (B. bubalis Pampangan showed that habitat of swamp buffalo Pampangan consists of dominated by lowland swamp area is overgrown with shrubs and grass. The conclution of the research are productivity and population of swamp buffalo (B. bubalis pampangan as specific plasma nutfah of South Sumatra can be improved by studying the characteristics and preferred habitat of the buffalo, although developed in a traditional farms but is good enough and so need to be developed, grass is most preferred by swamp buffalo Pampangan derived from ‘Kumpai’ grass group, and ‘Kasur’grass and ‘Kumpai’ grass is the dominant grass type found in habitat swamp buffalo Pampangan.

Reproductive potential of silver European eels (Anguilla anguilla migrating from Vistonis Lake (Northern Aegean Sea, Greece

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R. MACNAMARA

2014-06-01

Full Text Available The European eel (Anguilla anguilla, once abundant throughout much of Europe and North Africa, has recently been classified as critically endangered. Information on its biology from the eastern Mediterranean is lacking, especially in relation to spawner quality. Therefore, silver eels were sampled during their seaward spawning migration from Vistonis Lake in Greece. Characteristics linked to reproductive output and success (i.e. body size and condition, sex ratio, silvering, Anguillicola crassus infection, fecundity and oocyte diameter were examined. The lake produced large (687–1138 mm, exclusively female silver eels, 61.7% of which were infected by A. crassus. Silver eel fecundity, the first estimates from the southern part of the species range, was positively related to body length (R2 = 0.693; P < 0.001 and body weight (R2 = 0.731; P < 0.001. Fecundity did not differ between A. crassus infected and uninfected silver eels, but Greek silver eels were significantly more fecund than those in north-west Europe. The reproductive potential of Vistonis Lake silver eels and their contribution to the A. anguilla spawning stock is discussed.

Bypass devices for descent of eels in hydropower plants; Bypasseinrichtungen zum Abstieg von Aalen an Wasserkraftanlagen

Energy Technology Data Exchange (ETDEWEB)

Goehl, C.

2004-07-01

During their downstream migration, as a consequence of passing hydroelectric turbines, eels receive various injuries. Because of declining numbers the European eel has already been declared an endangered species in several German states. In respect to the distinctive situation of the hydroelectric power station Dettelbach in the river Main, as a first step the fluidic prerequisites of eel migration as well as facilities for the downstream passage of eels were examined in a physical experiment. Following behavioral tests with eels were used to verify their acceptance of these installations. Based on the attained results this thesis discusses the basics of the construction of downstream passage facilities for eels, heeding the principle which underlie the principle of no force and limitation on the area of main activity. The gained results suggest a feasible and cost-effective concept for the downstream passage of eels. Although the transferability of instinctive reactions and a basic efficiency is assumed, further wildlife experiments have to be conducted to verify efficiency in a natural environment. (orig.)

The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

Science.gov (United States)

Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

2014-01-01

Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

Eel, cod and seatrout harvest in Danish recreational fishing during 2011

DEFF Research Database (Denmark)

Sparrevohn, Claus Reedtz; Storr-Paulsen, Marie

, it was estimated that 80 t [Relative standard error (RSE)=6%] eel, close to 1,300 t (RSE=5 %) cod and 400 t (RSE=5 %) seatrout (including freshwater catches) was harvested in the recreational fishery. Eel is almost exclusively taken in the passive gear fykenet fishery and seatrout was mainly caught by anglers...

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States

Directory of Open Access Journals (Sweden)

Kristen Cooksey-Stowers

2017-11-01

Full Text Available This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision. Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity (p values ranged from 0.00 to 0.16. Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS estimates. The food swamp effect was stronger in counties with greater income inequality (p < 0.05 and where residents are less mobile (p < 0.01. Based on these findings, local government policies such as zoning laws simultaneously restricting access to unhealthy food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity.

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States

Science.gov (United States)

Cooksey-Stowers, Kristen; Schwartz, Marlene B.; Brownell, Kelly D.

2017-01-01

This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA) Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV) strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision). Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity (p values ranged from 0.00 to 0.16). Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS) estimates. The food swamp effect was stronger in counties with greater income inequality (p < 0.05) and where residents are less mobile (p < 0.01). Based on these findings, local government policies such as zoning laws simultaneously restricting access to unhealthy food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity. PMID:29135909

Gulf-Wide Information System, Environmental Sensitivity Index Swamps, Geographic NAD83, LDWF (2001) [esi_swamp_LDWF_2001

Data.gov (United States)

Louisiana Geographic Information Center — This data set contains Environmental Sensitivity Index (ESI) swamps data of coastal Louisiana. The ESI is a classification and ranking system, which characterizes...

Modelling the recruitment of European eel (Anguilla anguilla) throughout its European range

DEFF Research Database (Denmark)

Bornarel, Virginie; Lambert, Patrick; Briand, Cédric

2018-01-01

phase remains difficult given its widespread distribution among heterogeneous and separate river catchments. Hence, it is currently considered by the International Council for the Exploration of the Sea (ICES) more feasible to use glass eel recruitment data to assess the status of the overall population......European eel (Anguilla anguilla) recruitment has been declining at least since the early 1980s at the scale of its distribution area. Since the population is panmictic, its stock assessment should be carried out on a range-wide basis. However, assessing the overall stock during the continental....... In this study, we used Glass Eel Recruitment Estimation Model (GEREM) to estimate annual recruitment (i) at the river catchment level, a scale for which data are available, (ii) at an intermediate scale (6 European regions), and (iii) at a larger scale (Europe). This study provides an estimate of the glass eel...

Gene cloning and mRNA expression of glutamate dehydrogenase in the liver, brain and intestine of the swamp eel, Monopterus albus, exposed to freshwater, terrestrial conditions, environmental ammonia or salinity stress

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C Y Toh

2011-12-01

Full Text Available The swamp eel, Monopterus albus, is an obligatory air-breathing teleost which can survive long period of emersion, has high environmental and tissue ammonia tolerance, and acclimate from fresh to brackish water. This study was undertaken to clone and sequence gdh expressed in the liver, intestine and brain of M. albus, to verify whether more than one form of gdh were expressed, and to examine the gdh mRNA expressions in these three organs in fish exposed to various adverse conditions using quantitative real-time PCR. Only one gdh gene sequence, consisted of a 133 bp 5’ UTR, a CDS region spanning 1629 bp and a 3’ UTR of approximately 717 bp, was obtained from the liver, intestine and brain of M. albus. The translated Gdh amino acid sequence from the liver of M. albus had 542 residues and was confirmed to be Gdh1a. It had sequence identity of >90% with Oncorhynchus mykiss Gdh1a, Salmo salar Gdh1a1, Bostrychus sinensis Gdh1a and Tribolodon hakonensis Gdh1a, and formed a monophyletic clade with B. sinensis Gdh1a, Tetraodon nigroviridis Gdh1a, Chaenocephalus aceratus Gdh1a, Salmo salar Gdh1a1 and Gdh1a2 and O. mykiss Gdh1a. An increase in mRNA expression of gdh1a could be essential for increased glutamate production in support of increases in glutamine synthesis under certain environmental condition. Indeed, exposure of M. albus to 1 day of terrestrial conditions or 75 mmol l-1 NH4Cl, but not brackish water, resulted in a significant increase in gdh1a mRNA expression in the liver. However, exposure to brackish water, but not terrestrial conditions or 75 mmol l-1 NH4Cl, lead to a significant increase in the intestinal mRNA expression of gdh1a. By contrast, all the three experimental conditions had no significant effects on the mRNA expression of gdh1a in the brain of M. albus. Our results indicate for the first time that gdh mRNA expression was differentially up-regulated in the liver and intestine of M. albus, in responses to ammonia toxicity and

Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis)

DEFF Research Database (Denmark)

Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta

2016-01-01

The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses....

Tidal-Flat Macrobenthos as Diets of the Japanese Eel Anguilla japonica in Western Japan, with a Note on the Occurrence of a Parasitic Nematode Heliconema anguillae in Eel Stomachs.

Science.gov (United States)

Kan, Kotaro; Sato, Masanori; Nagasawa, Kazuya

2016-02-01

Dietary items of the Japanese eel Anguilla japonica inhabiting estuaries were examined by analyses of the gut (stomach and intestine) contents in two areas in Kyushu, western Japan. In a small estuary in Kagoshima Bay, where seven eel guts were examined, almost all of the dietary organisms consisted of Hemigrapsus crabs and Hediste polychaetes, both of which commonly occurred on tidal flats of this site during our survey on the macrobenthic fauna. In another large estuary in the innermost part of the Ariake Sea, where 14 eel guts were examined, 11 macrobenthic species (nine crustaceans, a polychaete, and a gastropod) were found in the gut contents, mostly consisting of mudflat-specific species. The dietary items are almost completely different not only between the two estuaries, but also among three neighboring sites within the large estuary in the Ariake Sea. These results show that Japanese eels feed on various macrobenthic invertebrates inhabiting estuarine tidal flats at each site. The variety of the prey species occupying different habitats indicates that their foraging areas extend to a wide range of estuarine tidal flats from the upper to lower littoral zones. The physalopterid nematode Heliconema anguillae was found parasitic in eel stomachs in both estuaries. The prevalence of the nematode was higher in the estuary in Kagoshima Bay (100%) than that in the Ariake Sea (43%), although the intensity in the former (4-94 nematodes per infected stomach) was comparable to that of the latter (2-96). The relationship between the nematode infection and the dietary items of Japanese eels is discussed.

The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

Directory of Open Access Journals (Sweden)

Feng-Yu Wang

Full Text Available Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2 revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292 and four putative (S124, V189, V286, I290 tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

Long-term disturbance dynamics and resilience of tropical peat swamp forests.

Science.gov (United States)

Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

2015-01-01

1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude

Changes in the role of the thyroid axis during metamorphosis of the Japanese eel, Anguilla japonica.

Science.gov (United States)

Sudo, Ryusuke; Okamura, Akihiro; Kuroki, Mari; Tsukamoto, Katsumi

2014-08-01

To clarify the role of thyroid function during metamorphosis from leptocephalus to glass eel in the Japanese eel, we examined the histology of the thyroid gland and measured whole-body concentrations of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), and thyroid stimulating hormone β-subunit TSH (TSHβ) mRNA expression levels in five stages of artificially hatched eels (leptocephalus, early-metamorphosis, late-metamorphosis, glass eel, and elver). During metamorphosis, the inner colloid of thyroid follicles showed positive immunoreactivity for T4, and both T4 and T3 levels were significantly increased, whereas a small peak of TSHβ mRNA level was observed at the early-metamorphosis stage. Similarly, TSHβ mRNA levels were highest in the glass eel stage, and then decreased markedly in the elver stage. In contrast to TSHβ mRNA expression, thyroid hormones (both T4 and T3) increased further from the glass eel to elver stages. These results indicated that thyroid function in the Japanese eel was active both during and after metamorphosis. Therefore, the thyrotropic axis may play important roles not only in metamorphosis but also in subsequent inshore or upstream migrations. © 2014 Wiley Periodicals, Inc.

Geomorphic controls on fluvial carbon exports and emissions from upland swamps in eastern Australia.

Science.gov (United States)

Cowley, Kirsten; Looman, Arun; Maher, Damien T; Fryirs, Kirstie

2018-03-15

Temperate Highland Peat Swamps on Sandstone (THPSS) are upland wetlands, similar to fens in the Northern Hemisphere and are found at the headwaters of low-order streams on the plateaus of Eastern Australia. They are classified as endangered ecological communities under State and National legislation. Previous works have identified particular geomorphic characteristics that are important to carbon storage in these low energy sediment accumulation zones. Changes in the geomorphic structure of THPSS, such as channelisation, may have profound implications for carbon storage. To assess the effect of channelisation on carbon budgets in these ecosystems it is essential to identify and quantify differences in carbon export, emissions and stocks of carbon of intact swamps and those that have become channelised. We undertook seasonal sampling of the perched swamp aquifers and surface waters of two intact swamps and two channelised fills in the Blue Mountains of New South Wales, Australia, to investigate differences in carbon exports and emissions between the two swamp types. We found that channelised fills' mean CO 2 emissions were almost four times higher than intact swamps with mean CH 4 emissions up to five times higher. Annual fluvial carbon exports for channelised fills were up to 18 times that of intact swamps. Channelised fill exports and emissions can represent up to 2% of the total swamp carbon stocks per annum which is 40 times higher than the intact swamps. This work clearly demonstrates that changes in geomorphic structure brought about by incision and channelisation results in profound changes to the carbon storage function of THPSS. Copyright © 2017 Elsevier B.V. All rights reserved.

137Cs Transfer Factor from Latosol Soil to Swamp Gabbages (Ipomea Reptans Poir)

International Nuclear Information System (INIS)

Leli-Nirwani; Yurfida; Buchori

2001-01-01

A study of 137 Cs transfer factor from Latosol soil to swamp cabbages plant has been conducted using pot treatment system with complete random design. The aim of the research is to determine transfer factor of 137 Cs from latosol soil to swamp cabbages plant. Cs-137 concentration administered was 7.5287 kBq/pot. The number of swamp cabbages planted in 137 Cs treated soil and in cannot soil respectively was 12 pots filled with 1 kg soil/pot. After harvest, the weight of dried plant was measured. Transfer factor was determined according to the accumulation of 137 Cs concentration in swamp cabbages and soil and counted using Spectrometer Gamma. It was found that is a significant difference between 137 Cs concentration in swamp cabbages planted inthe treated soil and that of control soil. Transfer factor ranges between 0.02 and 0.13 with the averageof 0.08. (author)

Coatal salt marshes and mangrove swamps in China

Science.gov (United States)

Yang, Shi-Lun; Chen, Ji-Yu

1995-12-01

Based on plant specimen data, sediment samples, photos, and sketches from 45 coastal crosssections, and materials from two recent countrywide comprehensive investigations on Chinese coasts and islands, this paper deals with China’s vegetative tidal-flats: salt marshes and mangrove swamps. There are now 141700 acres of salt marshes and 51000 acres of mangrove swamps which together cover about 30% of the mud-coast area of the country and distribute between 18°N (Southern Hainan Island) and 41 °N (Liaodong Bay). Over the past 45 years, about 1750000 acres of salt marshes and 49400 acres of mangrove swamps have been reclaimed. The 2.0×109 tons of fine sediments input by rivers into the Chinese seas form extensive tidal flats, the soil basis of coastal helophytes. Different climates result in the diversity of vegetation. The 3˜8 m tidal range favors intertidal zone development. Of over 20 plant species in the salt marshes, native Suaeda salsa, Phragmites australis, Aeluropus littoralis, Zoysia maerostachys, Imperata cylindrica and introduced Spartina anglica are the most extensive in distribution. Of the 41 mangrove swamps species, Kandelia candel, Bruguiera gymnorrhiza, Excoecaria agallocha and Avicennia marina are much wider in latitudinal distribution than the others. Developing stages of marshes originally relevant to the evolution of tidal flats are given out. The roles of pioneer plants in decreasing flood water energy and increasing accretion rate in the Changjiang River delta are discussed.

Linear chemically sensitive electron tomography using DualEELS and dictionary-based compressed sensing

Energy Technology Data Exchange (ETDEWEB)

AlAfeef, Ala, E-mail: a.al-afeef.1@research.gla.ac.uk [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); School of Computing Science, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Bobynko, Joanna [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Cockshott, W. Paul. [School of Computing Science, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Craven, Alan J. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Zuazo, Ian; Barges, Patrick [ArcelorMittal Maizières Research, Maizières-lès-Metz 57283 (France); MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2016-11-15

We have investigated the use of DualEELS in elementally sensitive tilt series tomography in the scanning transmission electron microscope. A procedure is implemented using deconvolution to remove the effects of multiple scattering, followed by normalisation by the zero loss peak intensity. This is performed to produce a signal that is linearly dependent on the projected density of the element in each pixel. This method is compared with one that does not include deconvolution (although normalisation by the zero loss peak intensity is still performed). Additionally, we compare the 3D reconstruction using a new compressed sensing algorithm, DLET, with the well-established SIRT algorithm. VC precipitates, which are extracted from a steel on a carbon replica, are used in this study. It is found that the use of this linear signal results in a very even density throughout the precipitates. However, when deconvolution is omitted, a slight density reduction is observed in the cores of the precipitates (a so-called cupping artefact). Additionally, it is clearly demonstrated that the 3D morphology is much better reproduced using the DLET algorithm, with very little elongation in the missing wedge direction. It is therefore concluded that reliable elementally sensitive tilt tomography using EELS requires the appropriate use of DualEELS together with a suitable reconstruction algorithm, such as the compressed sensing based reconstruction algorithm used here, to make the best use of the limited data volume and signal to noise inherent in core-loss EELS. - Highlights: • DualEELS is essential for chemically sensitive electron tomography using EELS. • A new compressed sensing based algorithm (DLET) gives high fidelity reconstruction. • This combination of DualEELS and DLET will give reliable results from few projections.

Peat swamp forest of Thailand

Energy Technology Data Exchange (ETDEWEB)

Niyomdham, C.; Urapeepatanapong, C.; Pitayakajornwute, P. [Pikoolthong Royal Development Study Center, Bangkok (Thailand). Royal Forest Department

1996-12-31

Peat swamp forest in Thailand occurs extensively along coastal flatlands in the central and southern parts of the country and some small patches of topogenous peatland are present locally on several mountain tops of the northern region. Many have been deteriorated by recent extensive development programs. However, one large area, about 347.04 km{sup 2}, of ombrogenous peatland is still left intact in the Pru Toh Dang area where conservation activities are being strictly enforced under one of the Royal Initiative Projects. Pru Toh Dang peat consists of 5 metres of fibrous organic soil overlying pyritic marine clay. Despite an inhospitable, submerged and unstable forest floor, the floristic composition of the peat swamp forest is extremely complicated, consisting of 124 families and 470 species of which 109 families and 437 species of flowering plants, and 15 families and 33 species of ferns recorded between 1983-1989 by a team from the Forest Herbarium of the Royal Forest Department of Thailand. (orig.) (4 refs.)

Salinity-dependent in vitro effects of homologous natriuretic peptides on the pituitary-interrenal axis in eels.

Science.gov (United States)

Ventura, Albert; Kusakabe, Makoto; Takei, Yoshio

2011-08-01

We examined the effects of atrial, B-type, ventricular and C-type natriuretic peptides (ANP, BNP, VNP and CNP1, 3, 4) on cortisol secretion from interrenal tissue in vitro in both freshwater (FW) and seawater (SW)-acclimated eels. We first localized the interrenal and chromaffin cells in the eel head kidney using cell specific markers (cholesterol side-chain cleavage enzyme (P450ssc) and tyrosine hydroxylase (TH), respectively) and established the in vitro incubation system for eel interrenal tissue. Unexpectedly, none of the NPs given alone to the interrenal tissue of FW and SW eels stimulated cortisol secretion. However, ANP and VNP, but not BNP and three CNPs, enhanced the steroidogenic action of ACTH in SW interrenal preparations, while CNP1 and CNP4, but not ANP, BNP, VNP and CNP3, potentiated the ACTH action in FW preparations. These salinity dependent effects of NPs are consistent with the previous in vivo study in the eel where endogenous ACTH can act with the injected NPs. 8-Br-cGMP also enhanced the ACTH action in both FW and SW eel preparations, suggesting that the NP actions were mediated by the guanylyl cyclase-coupled NP receptors (GC-A and B) that were localized in the eel interrenal. Further, ANP and CNP1 stimulated ACTH secretion from isolated pituitary glands of SW and/or FW eels. In summary, the present study revealed complex mechanisms of NP action on corticosteroidogenesis through the pituitary-interrenal axis in eels, thereby providing a deeper insight into the role of the NP family in the acclimation of this euryhaline teleost to diverse salinity environments. Copyright © 2011 Elsevier Inc. All rights reserved.

Impact of the North Atlantic Oscillation on the trans-Atlantic migrations of the European eel (Anguilla anguilla)

Science.gov (United States)

Kettle, A. James; Bakker, Dorothee C. E.; Haines, Keith

2008-09-01

Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6-8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0-2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.

Loss of European silver eel passing a hydropower station

DEFF Research Database (Denmark)

Pedersen, Michael Ingemann; Jepsen, Niels; Aarestrup, Kim

2012-01-01

The aim of this study was to assess escapement success of silver eels, Anguilla anguilla (L.), in a lowland river while passing a reservoir and a hydropower station. It was hypothesized that passage success would be lowest at the hydropower station and that survival and migration speed would...... that within the study period, only 23% of the tagged eels reached the tidal limit, mainly due to difficulties in passing the hydropower dam. With such high loss-rates, the escapement goals set in the management plan cannot be achieved...

Ichthyodinium identified in the eggs of European eel (Anguilla anguilla) spawned in captivity

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Tomkiewicz, Jonna; Skovgaard, A.

2014-01-01

A presumed parasitic protozoan was found in the eggs of European eel obtained from an experiment on captive breeding of eel, Anguilla anguilla, based on silver eels from a freshwater lake in the northern part of Denmark. Gross morphology of the organism was comparable to that of early stages...... of Ichthyodinium, a syndinian dinoflagellate parasite found in pelagic eggs of various marine fish species. Sequences of genes coding for small subunit ribosomal RNA confirmed that the organism was an Ichthyodinium species, and molecular phylogenetic analysis demonstrated the presence of two Ichthyodinium...

Expression and ontogeny of growth hormone (Gh) in the protogynous hermaphroditic ricefield eel (Monopterus albus).

Science.gov (United States)

Chen, Dong; Liu, Jiang; Chen, Wanping; Shi, Shuxia; Zhang, Weimin; Zhang, Lihong

2015-12-01

Growth hormone (GH) is a single-chain polypeptide hormone mainly secreted by somatotropes of the anterior pituitary gland and is an important regulator of somatic growth in vertebrates including teleosts. In this study, a polyclonal antiserum against ricefield eel Gh was generated and the expression of Gh at the mRNA and protein levels was analyzed. Both RT-PCR and western blot analysis showed that Gh was predominantly expressed in the pituitary glands of ricefield eels. The immunoreactive Gh signals were localized to the multicellular layers of the adenohypophysis adjacent to the neurohypophysis in ricefield eels. Ontogenetic analysis showed that immunoreactive Gh signals could be detected in the pituitary glands of ricefield eel embryos as early as 3 days post-fertilization. During the sex change from female to male, the levels of the immunoreactive Gh signals in the pituitary glands of the ricefield eels peaked at the intersexual stage. These results suggest that Gh in the pituitary glands may be associated with embryonic development before hatching, as well as with the sex change in the adult ricefield eels, possibly via the classical endocrine manner.

Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

Directory of Open Access Journals (Sweden)

Yu-Lin Chang

Full Text Available The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC, the Kuroshio, and the Subtropical Countercurrent (STCC region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO. This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2. Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels" can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

Science.gov (United States)

Chang, Yu-Lin; Sheng, Jinyu; Ohashi, Kyoko; Béguer-Pon, Mélanie; Miyazawa, Yasumasa

2015-01-01

The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC), the Kuroshio, and the Subtropical Countercurrent (STCC) region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO). This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D) particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2). Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels") can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

EEL spectroscopic tomography: Towards a new dimension in nanomaterials analysis

Energy Technology Data Exchange (ETDEWEB)

Yedra, Lluis, E-mail: llyedra@el.ub.es [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); CCiT, Scientific and Technological Centers, Universitat de Barcelona, C/Lluis Sole i Sabaris 1, E-08028 Barcelona (Spain); Eljarrat, Alberto [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); Arenal, Raul [Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza, E-50018 Zaragoza (Spain); Fundacion ARAID, E-50004 Zaragoza (Spain); Pellicer, Eva; Cabo, Moises [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Lopez-Ortega, Alberto; Estrader, Marta [CIN2(CIN-CSIC) and Universitat Autonoma de Barcelona, Catalan Institute of Nanotechnology, Campus de la UAB, E-08193 Bellaterra (Spain); Sort, Jordi [Institucio Catalana de Recerca i Estudis Avancats (ICREA), Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Baro, Maria Dolors [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); and others

2012-11-15

Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe{sub x}Co{sub (3-x)}O{sub 4}@Co{sub 3}O{sub 4} mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. -- Highlights: Black-Right-Pointing-Pointer EELS-SI tomography was performed at low voltage and low acquisition times. Black-Right-Pointing-Pointer MVA has been applied for noise reduction and information extraction. Black-Right-Pointing-Pointer Tomographic reconstruction has been achieved for chemical information. Black-Right-Pointing-Pointer Elemental distribution extraction in 3D has been proved.

PAH Metabolites in Bile of European Eel (Anguilla anguilla) from Morocco.

Science.gov (United States)

Wariaghli, Fatima; Kammann, Ulrike; Hanel, Reinhold; Yahyaoui, Ahmed

2015-12-01

Environmental pollution of fish with organic contaminants is a topic of rising attention in Morocco. Polycyclic aromatic hydrocarbons (PAH) are prominent organic contaminants which are rapidly metabolized in fish. Their metabolites are accumulated in the bile fluid and can be used to assess PAH exposure. The two PAH metabolites 1-hydroxypyrene and 1-hydroxyphenanthrene were quantified in European eels (Anguilla anguilla) from two Moroccan river systems by high-performance liquid chromatography with fluorescence detection. Mean values ranged from 52 to 210 ng/mL 1-hydroxypyrene and from 61 to 73 ng/mL 1-hydroxyphenanthrene. The overall concentrations of PAH metabolites in eel from Morocco appeared moderate compared to eel from European rivers and coastal sites. The present study provides first information on concentrations of PAH metabolites in fish from Morocco.

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States

OpenAIRE

Cooksey-Stowers, Kristen; Schwartz, Marlene B.; Brownell, Kelly D.

2017-01-01

This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data ...

A question of origin: dioxin-like PCBs and their relevance in stock management of European eels.

Science.gov (United States)

Freese, Marko; Sühring, Roxana; Pohlmann, Jan-Dag; Wolschke, Hendrik; Magath, Victoria; Ebinghaus, Ralf; Hanel, Reinhold

2016-01-01

The stock of European Eel (Anguilla anguilla L.) has reached an all-time low in 2011. Spawner quality of mature eels in terms of health status and fitness is considered one of the key elements for successful migration and reproduction. Dioxin-like Polychlorinated Biphenyls (dl-PCBs) are known persistent organic pollutants potentially affecting the reproductive capability and health status of eels throughout their entire lifetime. In this study, muscle tissue samples of 192 European eels of all continental life stages from 6 different water bodies and 13 sampling sites were analyzed for contamination with lipophilic dl-PCBs to investigate the potential relevance of the respective habitat in light of eel stock management. Results of this study reveal habitat-dependent and life history stage-related accumulation of targeted PCBs. Sum concentrations of targeted PCBs differed significantly between life stages and inter-habitat variability in dl-PCB levels and -profiles was observed. Among all investigated life stages, migrant silver eels were found to be the most suitable life history stage to represent their particular water system due to habitat dwell-time and their terminal contamination status. With reference to a possible negative impact of dl-PCBs on health and the reproductive capability of eels, it was hypothesized that those growing up in less polluted habitats have a better chance to produce healthy offspring than those growing up in highly polluted habitats. We suggest that the contamination status of water systems is fundamental for the life cycle of eels and needs to be considered in stock management and restocking programs.

LEUKOCYTE DIFFERENTIAL OF ANGUILLID EEL, Anguilla bicolor McClelland, EXPOSED TO VARIED SALINITIES

Directory of Open Access Journals (Sweden)

Fita Fatimah

2017-06-01

Full Text Available The anguillid eel is a catadromous eel capable of inhabiting freshwater growth habitat and seawater spawning habitat throughout their life cycle. At the juvenile to mature stage, they inhabit freshwater then migrate to marine water to spawn. Changes in salinity, which is one of the stressful environmental factors for the eel, affect their physiological condition by increasing the leukocytes number. This increase is an adaptation method to improve their immune system as a response to salinity change. This study intended to evaluate the leukocyte differential of anguillid eel (Anguilla bicolor McClelland exposed to various salinities. This research applied a Completely Randomized Design. The treatment was three levels of saline media including 4 ppt, 15 ppt, and 30 ppt with five replicates. The independent variable was the different salinity, and the dependent variable was the leukocyte differential. The parameters measured consisted of the different percentage of neutrophils, lymphocytes, monocytes, and eosinophils in which the measurements administered after two months of the eel exposure. We analyzed the data with ANOVA at the confidence level of 95%. The results showed that exposure of salinity significantly affected the percentage of leukocyte differential (P < 0.05. The increase in salinity decreased the neutrophils and monocytes, but increased the lymphocytes, and showed no effect on eosinophils.

Anthropogenic noise compromises antipredator behaviour in European eels.

Science.gov (United States)

Simpson, Stephen D; Purser, Julia; Radford, Andrew N

2015-02-01

Increases in noise-generating human activities since the Industrial Revolution have changed the acoustic landscape of many terrestrial and aquatic ecosystems. Anthropogenic noise is now recognized as a major pollutant of international concern, and recent studies have demonstrated impacts on, for instance, hearing thresholds, communication, movement and foraging in a range of species. However, consequences for survival and reproductive success are difficult to ascertain. Using a series of laboratory-based experiments and an open-water test with the same methodology, we show that acoustic disturbance can compromise antipredator behaviour--which directly affects survival likelihood--and explore potential underlying mechanisms. Juvenile European eels (Anguilla anguilla) exposed to additional noise (playback of recordings of ships passing through harbours), rather than control conditions (playback of recordings from the same harbours without ships), performed less well in two simulated predation paradigms. Eels were 50% less likely and 25% slower to startle to an 'ambush predator' and were caught more than twice as quickly by a 'pursuit predator'. Furthermore, eels experiencing additional noise had diminished spatial performance and elevated ventilation and metabolic rates (indicators of stress) compared with control individuals. Our results suggest that acoustic disturbance could have important physiological and behavioural impacts on animals, compromising life-or-death responses. © 2014 John Wiley & Sons Ltd.

Indole-positive Vibrio vulnificus isolated from disease outbreaks on a Danish eel farm

DEFF Research Database (Denmark)

Dalsgaard, Inger; Høi, L.; Siebeling, R.J.

1999-01-01

Vibrio vulnificus was isolated in 1996 from 2 disease outbreaks on a Danish eel farm which used brackish water. A characteristic clinical sign was extensive, deep muscle necrosis in the head region. V. vulnificus was isolated from kidney, mucus, spleen, gill and intestine of diseased eels. Thirty...

Parteid lubavad valimiste eel pealinlastele toetusi / Urmas Seaver

Index Scriptorium Estoniae

Seaver, Urmas, 1973-

2005-01-01

Erakonnad lubavad valimiste eel pealinlastele uusi soodustusi - alanevat maamaksu, lastehoiuraha, toetusi lastele ja pensionäridele. Näiteks Reformierakond lubab maamaksu alandada kaks korda. Lisa: Erakonnad peibutavad soodustustega

The pituitary gland of the European eel reveals massive expression of genes involved in the melanocortin system.

Directory of Open Access Journals (Sweden)

Eirill Ager-Wick

Full Text Available Hormones secreted from the pituitary gland regulate important processes such as development, growth and metabolism, reproduction, water balance, and body pigmentation. Synthesis and secretion of pituitary hormones are regulated by different factors from the hypothalamus, but also through feedback mechanisms from peripheral organs, and from the pituitary itself. In the European eel extensive attention has been directed towards understanding the different components of the brain-pituitary-gonad axis, but little is known about the regulation of upstream processes in the pituitary gland. In order to gain a broader mechanistic understanding of the eel pituitary gland, we have performed RNA-seq transcriptome profiling of the pituitary of prepubertal female silver eels. RNA-seq reads generated on the Illumina platform were mapped to the recently assembled European eel genome. The most abundant transcript in the eel pituitary codes for pro-opiomelanocortin, the precursor for hormones of the melanocortin system. Several genes putatively involved in downstream processing of pro-opiomelanocortin were manually annotated, and were found to be highly expressed, both by RNA-seq and by qPCR. The melanocortin system, which affects skin color, energy homeostasis and in other teleosts interacts with the reproductive system, has so far received limited attention in eels. However, since up to one third of the silver eel pituitary's mRNA pool encodes pro-opiomelanocortin, our results indicate that control of the melanocortin system is a major function of the eel pituitary.

EELS from organic crystalline materials

International Nuclear Information System (INIS)

Brydson, R; Seabourne, C R; Hondow, N; Eddleston, M D; Jones, W

2014-01-01

We report the use of the electron energy loss spectroscopy (EELS) for providing light element chemical composition information from organic, crystalline pharmaceutical materials including theophylline and paracetamol and discuss how this type of data can complement transmission electron microscopy (TEM) imaging and electron diffraction when investigating polymorphism. We also discuss the potential for the extraction of bonding information using electron loss near-edge structure (ELNES)

Swamp land optimization in supporting food security and enhancing farmers welfare in South Sumatra Indonesia

Science.gov (United States)

Herwenita; Hutapea, Y.

2018-02-01

Swamp land in Indonesia spread in Sumatra, Kalimantan and West Papua. In Sumatra the largest swamp land area is located in South Sumatera Province. Unfortunately only few of the areas have been utilized due to its fragility, in which farmers could only cultivate rice on it once a year. The purpose of this paper is to develop a feasible farming pattern in swamp land to help farmers and practitioners in optimizing it by managing its water level. Shallow and mid swamp land can be cultivated using rotation model of crops (rice, corn, cassava), horticulture (cucumber, long beans, watermelon etc), fish farming (catfish, snake head fish, tilapia), and duck farming, whereas submergence tolerant rice varieties can be cultivated alternating with fish farming in deep swamp land. This study shows that such swamp land management is financially feasible showing by its positive NPV value, BCR value is above 1.00, and IRR value is greater than the interest rate. Therefore, implementation of this farming pattern is expected to increase farmers’ income and household food supply as well as village food supply.

Pen Branch Delta and Savannah River Swamp Hydraulic Model

International Nuclear Information System (INIS)

Chen, K.F.

1999-01-01

The proposed Savannah River Site (SRS) Wetlands Restoration Project area is located in Barnwell County, South Carolina on the southwestern boundary of the SRS Reservation. The swamp covers about 40.5 km2 and is bounded to the west and south by the Savannah River and to the north and east by low bluffs at the edge of the Savannah River floodplain. Water levels within the swamp are determined by stage along the Savannah River, local drainage, groundwater seepage, and inflows from four tributaries, Beaver Dam Creek, Fourmile Branch, Pen Branch, and Steel Creek. Historic discharges of heated process water into these tributaries scoured the streambed, created deltas in the adjacent wetland, and killed native vegetation in the vicinity of the delta deposits. Future releases from these tributaries will be substantially smaller and closer to ambient temperatures. One component of the proposed restoration project will be to reestablish indigenous wetland vegetation on the Pen Branch delta that covers about 1.0 km2. Long-term predictions of water levels within the swamp are required to determine the characteristics of suitable plants. The objective of the study was to predict water levels at various locations within the proposed SRS Wetlands Restoration Project area for a range of Savannah River flows and regulated releases from Pen Branch. TABS-MD, a United States Army Corps of Engineer developed two-dimensional finite element open channel hydraulic computer code, was used to model the SRS swamp area for various flow conditions

Mineral uptake by taro (colocasla esculenta) in swamp agroecosystem following gramoxone paraquat herbicide spraying

International Nuclear Information System (INIS)

Nashriyah Mat; Mazleha Maskin; Abdul Khalik Wood

2006-01-01

Mineral elemental uptake by Colocasia esculenta growing in swamp agroecosystem was studied following 14, 18 or 28 months of field spraying (MAT, months after treatment) with herbicide Gramoxone paraquat. In overall, Al (68226.67 ± 24066.56 μ/g dw) was the major element in riverine alluvial swamp soil, followed by micronutrient Fe (22280.00 ± 6328.87 μ/g dw). Concentration of macronutrient K (20733.33 ± 7371.82, μ/g dw) was the highest in swamp taro leaf followed by macronutrient Ca (7050.00 ± 3767.26 μ/g dw). In overall, the order of importance of the average mineral concentration in swamp taro leaf was K > Ca > Mn > Al > Na > Fe > Zn > Br > Co. However at 14 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Al > Na > Mn > Fe > Zn > Br > Co. At 18 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Al > Fe > Na > Zn > Br > Co. At 28 AMT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Fe > Al > Zn > Na > Br > Co. In overall, the average order of importance of mineral elemental uptake or the soil plant transfer coefficient was Mn > K > Na > Zn > Co > Fe > Al; similar with the order at 28 MAT However, at 14 MAT the order of importance of the soil plant transfer coefficient was different at Mn > K > Na > Co > Zn > Al > Fe. (Author)

Magruder Park Swamp

Science.gov (United States)

Hotchkiss, N.; Uhler, F.M.

1967-01-01

The last Tuesday in August, between five-thirty and seven in the evening, we zigzaged through this glorious jungle, attended by a family of Wood Pewees for whom we seemed to be stirring up a feast of flying insects. There was gentle background music by Mole Crickets. A few steps in from the playing field and we were out of sight in ten-foot-high Cattails. All through, we met -- as high as we, or higher--clumped Cinnamon Ferns, deep-rose Joe Pye Weed, and orange, pendent flowers of Jewelweed (first cousins to Balsam and Sultana). Here and there were soft, white spikes of Canadian Burnet, a rare plant hereabouts, and deep purple Ironweed. Dense-foliaged Hempweed climbed over bushes and up small trees, filling the air with its delicate fragrance. Arrowleaf Tear-thumb snatched at us with tiny prongs on its angled stems. Once in a while we tripped over huge sedge tussocks, half-hidden in the tangle. A few times we steered around a small bush of Poison Sumac. The next day We remembered seeing ninety kinds of plants on this hasty trip. Skunk Cabbage leaves recalled April, when a person, from the edge of the lawn, could see huge clumps of them all the way across the swamp. The sky had been washed by last week's downpours; scattered Gums were reddening; and Maples were getting ready for crimson beauty a month from now. There wasn't a mosquito! (Ed. Note.-The Hyattsville City Council is taking pains to preserve this interesting swamp.)

Ubiquitous distribution of fluorescent protein in muscles of four species and two subspecies of eel (genus Anguilla).

Science.gov (United States)

Funahashi, Aki; Itakura, Takao; Hassanin Abeer, A I; Komatsu, Masaharu; Hayashi, Seiichi; Kaminishi, Yoshio

2017-03-01

In this study, the localization of fluorescent protein (FP) was characterized in the muscles of four species and two subspecies of eels Anguilla anguilla, A. australis, A. bicolor bicolor (b.), A. bicolor pacifica (p.) and A. mossambica in addition to the previously reported A. japonica. The open reading frame of each eel FP was 417 bp encoding 139 amino acid residues. The deduced amino acid sequences among the four species and two subspecies exhibited 91.4-100% identity, and belonged to the fatty-acid-binding protein (FABP) family. The gene structure of eel FPs in A. japonica, A. anguilla, A. australis, A. bicolor b., A. bicolor p. and A. mossambica have four exons and three introns, and were common to that of FABP family. The apo eel FPs expressed by Escherichia coli with recombinant eel FP genes were analysed for the fluorescent properties in the presence of bilirubin. The excitation and emission spectra of holo eel FPs had the maximum wavelengths of 490-496 and 527-530 nm, respectively. The holo eel FPs indicated that the fluorescent intensities were stronger in A. japonica and A. bicolor than in A. mossambica, A. australis and A. anguilla. The comparison of amino acid sequences revealed two common substitutions in A. mossambica, A. australis and A. anguilla with weak fluorescent intensity.

The effect of metals on condition and pathologies of European eel (Anguilla anguilla): in situ and laboratory experiments.

Science.gov (United States)

Esteve, Consuelo; Alcaide, Elena; Ureña, Rocio

2012-03-01

Forty-nine wild eels (Anguilla anguilla) caught in the Albufera Lake (Spain), measuring 24.0-75.0 cm in length and 25.0-637.7 g in weight, were examined for metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn), condition (CI and HSI indices), as well as for diseases (Anguillicola infestation; bacterial infections). Total metal load significantly increased in eel liver tissue parallel to total length and body weight (log), while silvering females (W(B) > 200 g; L ≥ 500 mm) exhibited the highest amounts of Co, Cu, Hg, Se and Zn. Diverse effects may be expected in these big eels due to long-term metal exposure. In fact, IMBI (individual mean (multi-metal) bioaccumulation index) and copper load (Ln) in particular, were significantly related with a decrease in the HSI, reflecting lower eel fitness. In addition, most silvering females (75%) showed a CI below 0.2, and this size group presented the highest prevalence of chronic diseases, at significant levels, that are non-lethal in the short term, but degenerative in the long term. Amounts of hepatic iron were not correlated with eel size; however, a significant, strong negative correlation between this metal (Ln) and HSI and CI was found for wild eels suffering from diseases of any aetiology. This also included small eels (W(B) <67 g; L < 350 mm), as this size group presented a significant prevalence of acute diseases caused by single virulent bacterial pathogens (i.e. Edwardsiella tarda and Vibrio vulnificus biotype 2). To assess the effect of metals on susceptibility to disease, yellow eels were maintained and exposed to iron, copper, and pathogens, in captivity under laboratory conditions. Co-exposure of eels to iron (9 μg of Fe/g of fish) and bacterial pathogens by intraperitoneal injection (IP), yielded a hundred-fold reduction in the LD50 of all bacteria assayed (i.e. E. tarda, V. vulnificus, and motile Aeromonas), and also the time taken to cause eel death. Short-term aqueous exposure of eels to 0.4, 0.7, 1.7 and

In situ EELS and TEM observation of Al implanted with nitrogen ions

International Nuclear Information System (INIS)

Hojou, K.; Furuno, S.; Kushita, K.N.; Otsu, H.; Izui, K.

1995-01-01

Formation processes of Aluminum nitride (AIN) in Aluminum (AI) implanted with nitrogen were examined by in situ EELS and TEM observations during nitrogen ion implantation in an electron microscope at room temperature and 400 deg C. AIN phase was identified both by EDP and EELS after nitrogen ion implantation to 6 x 10 20 (N + )/m 2 . The observed peak (20.8 eV) in EELS spectra was identified as plasmon loss peak of AIN formed in AI. The binding energy of N ls in AI was found to shift by about 4 eV to the lower side with increasing nitrogen-ion fluence. Unreacted AI was also found to remain in the AIN films after high fluence implantation both at room temperature and 400 deg C. (authors). 11 refs., 5 figs., 2 tabs

A new species of Dentiphilometra (Nematoda: Philometridae) from the musculature of the gray snapper Lutjanus griseus (osteichthyes) off the Caribbean coast of Mexico.

Science.gov (United States)

González-Solís, David; Moravec, Frantisek; Paredes, Vielka M Tuz

2007-10-01

A new nematode, Dentiphilometra lutjani n. sp. (Philometridae), is described from gravid females (the male is unknown) collected from the body musculature of the marine perciform fish gray snapper, Lutjanus griseus (Lutjanidae), from the Bay of Chetumal and southern coast of Quintana Roo, off the Caribbean coast of Mexico. The new species differs from the only other congener, Dentiphilometra monopteri, from the swamp eel Monopterus albus in China, mainly in the body length of gravid female (15.40-53.21 mm), the shape of the posterior body end (not markedly narrowed, with low caudal projections), the esophageal gland (maximum width near its posterior end), and the length (344-483 microm) of larvae from the uterus; both species also differ in their host types (marine perciform fish vs. freshwater swamp eel) and geographical distribution (Mexico vs. China).

The Productivity and Natural Increase of Swamp Buffalo in District Malang

Science.gov (United States)

Budiarto, A.; Ciptadi, G.

2018-02-01

The purpose of this research was to collect the basic information needed to develop a sustainable breeding program, which includes the potential for production and reproduction of buffaloes. This research was conducted on swamp buffalo in Malang Regency East Java. The research method used was survey method. Primary data was obtained from direct observation on 323 tails owned by 98 breeders. Variables observed were population growth and reproductive performance. The data obtained were analyzed descriptively. The result showed that the initial population study of swamp Buffaloes in Malang as many as 1155 with male and female ratio 1: 2. The ratios of male and female swamp Buffalo 20 percent male and 80 percent female. Overall, the buffalo reproduction performance was still low. Service per conception 2.06 ± 0.88; Anestrus Postpartum 7.46 ± 3.83 months; calving interval distance 17.82 ± 4.86 months; 20.43 % birth rate and 4.33% mortality rate of Natural Increase (NI) population was about 16,1%. In conclusion, the value of NI of swamp Buffalo in Malang Regency is still low. To increase buffalo productivity, buffalo breeding program is continuously based on reproduction control.

EEL spectroscopic tomography: towards a new dimension in nanomaterials analysis.

Science.gov (United States)

Yedra, Lluís; Eljarrat, Alberto; Arenal, Raúl; Pellicer, Eva; Cabo, Moisés; López-Ortega, Alberto; Estrader, Marta; Sort, Jordi; Baró, Maria Dolors; Estradé, Sònia; Peiró, Francesca

2012-11-01

Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe(x)Co((3-x))O(4)@Co(3)O(4) mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. Copyright © 2012 Elsevier B.V. All rights reserved.

THE CONTRIBUTION OF SPRINGTIME AND AUTUMN GLASS EELS (ANGUILLA ANGUILLA TO STOCK : RESULTS BASED ON OTOLITH MORPHOMETRY.

Directory of Open Access Journals (Sweden)

BRIAND C.

2003-07-01

Full Text Available A double mark, called a transition ring, or elver mark, was identifiable in light microscopy on otoliths of young yellow eels. In the Vilaine watershed, the radius of this mark decreased from 178 μm in yellow eels corresponding to glass eels arriving in autumn 1997 to 163 μm in yellow eels arriving in spring 1998. The mean transition ring radius of the freshwater eel population in the Vilaine river had an intermediate value between spring and autumn recruits. This implies that it consisted of a mixture of spring and autumn recruits. In the Vilaine estuary and the Frémur populations, the mean radius of the transition rings was close to the autumn one. The springtime recruits formed 68 % of freshwater and 15 % of estuarine population in the Vilaine for the 1998 cohort. This result was in sharp contrast with the available assessments of recruitment, which both in estuary and in the fluvial part of the watershed, were dominated by spring recruits. This contrast is possibly the consequence of density-dependent mortality, which would have been particularly important in springtime for glass eels whose migration was inhibited by the dam.

Synergistic and singular effects of river discharge and lunar illumination on dam passage of upstream migrant yellow-phase American eels

Science.gov (United States)

Welsh, Stuart A.; Aldinger, Joni L.; Braham, Melissa A.; Zimmerman, Jennifer L.

2016-01-01

Monitoring of dam passage can be useful for management and conservation assessments of American eel, particularly if passage counts can be examined over multiple years. During a 7-year study (2007–2013) of upstream migration of American eels within the lower Shenandoah River (Potomac River drainage), we counted and measured American eels at the Millville Dam eel pass, where annual study periods were determined by the timing of the eel pass installation during spring or summer and removal during fall. Daily American eel counts were analysed with negative binomial regression models, with and without a year (YR) effect, and with the following time-varying environmental covariates: river discharge of the Shenandoah River at Millville (RDM) and of the Potomac River at Point of Rocks, lunar illumination (LI), water temperature, and cloud cover. A total of 17 161 yellow-phase American eels used the pass during the seven annual periods, and length measurements were obtained from 9213 individuals (mean = 294 mm TL, s.e. = 0.49, range 183–594 mm). Data on passage counts of American eels supported an additive-effects model (YR + LI + RDM) where parameter estimates were positive for river discharge (β = 7.3, s.e. = 0.01) and negative for LI (β = −1.9, s.e. = 0.34). Interestingly, RDM and LI acted synergistically and singularly as correlates of upstream migration of American eels, but the highest daily counts and multiple-day passage events were associated with increased RDM. Annual installation of the eel pass during late spring or summer prevented an early spring assessment, a period with higher RDM relative to those values obtained during sampling periods. Because increases in river discharge are climatically controlled events, upstream migration events of American eels within the Potomac River drainage are likely linked to the influence of climate variability on flow regime.

Logged peat swamp forest supports greater macrofungal biodiversity than large-scale oil palm plantations and smallholdings.

Science.gov (United States)

Shuhada, Siti Noor; Salim, Sabiha; Nobilly, Frisco; Zubaid, Akbar; Azhar, Badrul

2017-09-01

Intensive land expansion of commercial oil palm agricultural lands results in reducing the size of peat swamp forests, particularly in Southeast Asia. The effect of this land conversion on macrofungal biodiversity is, however, understudied. We quantified macrofungal biodiversity by identifying mushroom sporocarps throughout four different habitats; logged peat swamp forest, large-scale oil palm plantation, monoculture, and polyculture smallholdings. We recorded a total of 757 clusters of macrofungi belonging to 127 morphospecies and found that substrates for growing macrofungi were abundant in peat swamp forest; hence, morphospecies richness and macrofungal clusters were significantly greater in logged peat swamp forest than converted oil palm agriculture lands. Environmental factors that influence macrofungi in logged peat swamp forests such as air temperature, humidity, wind speed, soil pH, and soil moisture were different from those in oil palm plantations and smallholdings. We conclude that peat swamp forests are irreplaceable with respect to macrofungal biodiversity. They host much greater macrofungal biodiversity than any of the oil palm agricultural lands. It is imperative that further expansion of oil palm plantation into remaining peat swamp forests should be prohibited in palm oil producing countries. These results imply that macrofungal distribution reflects changes in microclimate between habitats and reduced macrofungal biodiversity may adversely affect decomposition in human-modified landscapes.

Silvering of European eel (Anguilla anguilla L.): seasonal changes of morphological and metabolic parameters

NARCIS (Netherlands)

Ginneken, van V.; Durif, C.; Paul Balm, S.; Boot, R.; Verstegen, M.W.A.; Antonissen, E.; Thillart, van den G.

2007-01-01

The transformation of yellow eel into silver eel is called `silvering¿, and takes place prior to migration. We found the sedentary yellow phase in spring, the migratory silver phase in autumn, while August was a cross-over month. We used principal component analysis (PCA) to characterise the

Addressing the impact of mercury estuarine contamination in the European eel (Anguilla anguilla L., 1758) - An early diagnosis in glass eel stage based on erythrocytic nuclear morphology.

Science.gov (United States)

Castro, D; Mieiro, C L; Coelho, J P; Guilherme, S; Marques, A; Santos, M A; Duarte, A C; Pereira, E; Pacheco, M

2018-02-01

The decline of the European eel (Anguilla anguilla L., 1758) population throughout Europe has been partially attributed to pollution. As glass eel estuarine migration may represent a considerable threat, the impact of mercury (Hg) contamination at this stage was evaluated through an in situ experiment (7days). Total Hg (tHg) bioaccumulation was evaluated concomitantly with erythrocytic nuclear morphology alterations: erythrocytic nuclear abnormalities assay (ENA), frequency of immature erythrocytes (IE) and the erythrocytic maturity index (EMI). The ENA results suggested a genotoxic pressure at the most contaminated sites, in line with the tHg increase. The EMI data, together with IE frequency, showed that fish exposed to high levels of Hg exhibited alterations of haematological dynamics, translated into an erythropoiesis increment. Despite the presence of these compensatory mechanisms, the present findings suggest a harmful impact of Hg on genome integrity at this early development stage, potentially affecting eels' condition and ultimately the population sustainability. Copyright © 2017. Published by Elsevier Ltd.

Performance measures for a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp

Science.gov (United States)

Krauss, Ken W.; Shaffer, Gary P.; Keim, Richard F.; Chambers, Jim L.; Wood, William B.; Hartley, Stephen B.

2017-06-09

The use of freshwater diversions (river reintroductions) from the Mississippi River as a restoration tool to rehabilitate Louisiana coastal wetlands has been promoted widely since the first such diversion at Caernarvon became operational in the early 1990s. To date, aside from the Bonnet Carré Spillway (which is designed and operated for flood control), there are only four operational Mississippi River freshwater diversions (two gated structures and two siphons) in coastal Louisiana, and they all target salinity intrusion, shellfish management, and (or) the enhancement of the integrity of marsh habitat. River reintroductions carry small sediment loads for various design reasons, but they can be effective in delivering fresh­water to combat saltwater intrusion and increase the delivery of nutrients and suspended fine-grained sediments to receiving wetlands. River reintroductions may be an ideal restoration tool for targeting coastal swamp forest habitat; much of the area of swamp forest habitat in coastal Louisiana is undergo­ing saltwater intrusion, high rates of submergence, and lack of riverine flow leading to reduced concentrations of important nutrients and suspended sediments, which sustain growth and regeneration, help to aerate swamp soils, and remove toxic compounds from the rhizosphere.The State of Louisiana Coastal Protection and Restora­tion Authority (CPRA) has made it a priority to establish a small freshwater river diversion into a coastal swamp forest located between Baton Rouge and New Orleans, Louisiana, to reintroduce Mississippi River water to Maurepas Swamp. While a full understanding of how a coastal swamp forest will respond to new freshwater loading through a Mississippi River reintroduction is unknown, this report provides guidance based on the available literature for establishing performance measures that can be used for evaluating the effectiveness of a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp

The European Eel Anguilla anguilla (Pisces, Anguillidae. Native or Alien in the Black Sea?

Directory of Open Access Journals (Sweden)

Apostolos I. Apostolou

2013-12-01

Full Text Available In 2006 the Scientific, Technical and Economic Committee for Fisheries (STEFC of EU suggested the Black Sea region should be excluded from the list of natural areas, where the European eel (Anguilla anguilla is distributed. The basic conception of this idea was that the eels caught in the Black Sea region represent escaped specimens from fish farming in some Danubian countries. This article illustrates an effort to be given an indirect answer on the question if Black Sea is the end of natural distribution of European eel. The species is present but never been abundant in the region and do not represent an object of commercial fishing.

Throughfall and stemflow dynamics in a riparian cedar swamp: possible ecohydrological feedbacks

Science.gov (United States)

Duval, T. P.

2012-12-01

Partitioning of rainfall through forest canopies as throughfall and stemflow have deservedly been the subject of much research in the past; however, very little is known about the fluxes of water and solutes through forested wetland communities. Temperate swamps are characterized by intermittent canopy coverage, with areas that are denser than upland forests of similar species, but also contain canopy gaps of meadow and marsh communities,. Understanding the role of vegetation on the distribution of precipitation in these ecosystems is necessary to effectively constrain water balance estimates and predict possible community responses to shifting climate regimes. This study examines throughfall, stemflow, and interception dynamics in a riparian cedar swamp in Alliston, Ontario, Canada over the 2012 growing season. Throughfall averaged 76 % of above-canopy rainfall; however, there were spatial-magnitude interaction variations within the swamp. For events less than 20 mm, between 17 and 75 % of the measured swamp floor received greater depth of rain than above the canopy, whereas for events greater than 20 mm only between 2 and 23 % of the sampled swamp floor received more water than the actual event. The observed spatial variability in throughfall was not related to leaf area index, suggesting remote sensing modelling efforts may not be an accurate method for quantification of wetland precipitation dynamics. Stemflow along the predominantly cedar trees averaged 5 %; therefore, net precipitation on a seasonal basis in this cedar swamp was 81 % of above canopy rainfall. Throughfall DOC and total nitrogen concentrations averaged 31 and 2.2 mg/L, respectively, with stemflow DOC and TN concentrations averaging 109 and 6.5 mg/L, respectively. These values are much higher than reported for upland forest species. In general, throughfall magnitudes increased and solute concentrations decreased with increasing distance from the existing forest boles. The delivery of high

Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

Energy Technology Data Exchange (ETDEWEB)

Sühring, Roxana, E-mail: roxana.suehring@hzg.de [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Freese, Marko [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Schneider, Mandy [Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Schubert, Sophia; Pohlmann, Jan-Dag [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Alaee, Mehran [Water Science and Technology Directorate, Environment Canada, Burlington, Ontario, L7R4A6 Canada (Canada); Wolschke, Hendrik [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Hanel, Reinhold [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Ebinghaus, Ralf [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Marohn, Lasse [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany)

2015-10-15

The European eel (Anguilla anguilla) is regarded as a critically endangered species. Scientists are in agreement that the “quality of spawners” is a vital factor for the survival of the species. This quality can be impaired by parasites, disease and pollution. Especially endocrine disrupting organic chemicals pose a potential threat to reproduction and development of offspring. To our knowledge, the findings in this publication for the first time describe maternal transfer of contaminants in eels. We analysed the concentrations of in total 53 polybrominated diphenyl ethers (PBDEs) and their halogenated substitutes in muscle, gonads and eggs of artificially matured European eels and in muscle and gonads of untreated European eels that were used for comparison. We found evidence that persistent organic pollutants such as PBDEs, as well as their brominated and chlorinated substitutes are redistributed from muscle tissue to gonads and eggs. Concentrations ranged from 0.001 ng g{sup −1} ww for sum Dechlorane metabolites (DPMA, aCL{sub 10}DP, aCl{sub 11}DP) to 2.1 ng g{sup −1} ww for TBA in eggs, 0.001 ng g{sup −1} ww for Dechlorane metabolites to 9.4 ng g{sup −1} ww for TBA in gonads and 0.002 ng g{sup −1} ww for Dechlorane metabolites to 54 ng g{sup −1} ww for TBA in muscle tissue. Average egg muscle ratios (EMRs) for compounds detectable in artificially matured eels from both Schlei Fjord and Ems River ranged from 0.01 for Dechlorane 602 (DDC-DBF) to 10.4 for PBEB. Strong correlations were found between flame retardant concentrations and lipid content in the analysed tissue types, as well as transfer rates and octanol–water partitioning coefficient, indicating that these parameters were the driving factors for the observed maternal transfer. Furthermore, indications were found, that TBP-DBPE, TBP-AE, BATE and TBA have a significant uptake from the surrounding water, rather than just food and might additionally be formed by metabolism or

Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

International Nuclear Information System (INIS)

Sühring, Roxana; Freese, Marko; Schneider, Mandy; Schubert, Sophia; Pohlmann, Jan-Dag; Alaee, Mehran; Wolschke, Hendrik; Hanel, Reinhold; Ebinghaus, Ralf; Marohn, Lasse

2015-01-01

The European eel (Anguilla anguilla) is regarded as a critically endangered species. Scientists are in agreement that the “quality of spawners” is a vital factor for the survival of the species. This quality can be impaired by parasites, disease and pollution. Especially endocrine disrupting organic chemicals pose a potential threat to reproduction and development of offspring. To our knowledge, the findings in this publication for the first time describe maternal transfer of contaminants in eels. We analysed the concentrations of in total 53 polybrominated diphenyl ethers (PBDEs) and their halogenated substitutes in muscle, gonads and eggs of artificially matured European eels and in muscle and gonads of untreated European eels that were used for comparison. We found evidence that persistent organic pollutants such as PBDEs, as well as their brominated and chlorinated substitutes are redistributed from muscle tissue to gonads and eggs. Concentrations ranged from 0.001 ng g −1 ww for sum Dechlorane metabolites (DPMA, aCL 10 DP, aCl 11 DP) to 2.1 ng g −1 ww for TBA in eggs, 0.001 ng g −1 ww for Dechlorane metabolites to 9.4 ng g −1 ww for TBA in gonads and 0.002 ng g −1 ww for Dechlorane metabolites to 54 ng g −1 ww for TBA in muscle tissue. Average egg muscle ratios (EMRs) for compounds detectable in artificially matured eels from both Schlei Fjord and Ems River ranged from 0.01 for Dechlorane 602 (DDC-DBF) to 10.4 for PBEB. Strong correlations were found between flame retardant concentrations and lipid content in the analysed tissue types, as well as transfer rates and octanol–water partitioning coefficient, indicating that these parameters were the driving factors for the observed maternal transfer. Furthermore, indications were found, that TBP-DBPE, TBP-AE, BATE and TBA have a significant uptake from the surrounding water, rather than just food and might additionally be formed by metabolism or biotransformation processes. Dechloranes seem to be

The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture.

Science.gov (United States)

Kagawa, Hirohiko; Tanaka, Hideki; Ohta, Hiromi; Unuma, Tatsuya; Nomura, Kazuharu

2005-04-01

The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel.

Solvent and extraction methods effects on the quality of eel ( Anguilla bicolor ) oil

International Nuclear Information System (INIS)

Sasongko, H; Efendi, N R; Farida, Y; Amartiwi, T; Rahmawati, A A; Wicaksono, A; Budihardjo, A; Sugiyarto

2017-01-01

Eel ( Anguilla bicolor) is a general fish consumption in many countries, especially Japan, China, Germany, and France. Besides its vitamin rich, eel oil is also known to contain fatty acids that are necessary for pharmaceutical purposes and as food a supplement. This research was aimed to evaluate the quality of eel oil by different solvent and extraction methods. In this study, fresh eels were extracted using maceration and reflux methods.Chloroform was used as the solvent in the maceration while water used in the reflux method. The oil quality was examined based on the Official Methods of Analysis of the Association of Official Analytical Chemist (AOAC).The result showed that the yield of eel oil using maceration method was 5.44% ± 0.64 with a specific gravity of 0.915 g/mL, while reflux method obtained the yield of 5.33 % ± 0.84 and specific gravity of 0.8575 g/mL. The physicochemical parameters of oil quality used in this study were acid, peroxide, saponification, and iodine value. The maceration method obtained the acid value of 17.389 mgKOH/g, the peroxide value of 7.021meqO 2 /kg, the saponification value of 111.16mgKOH/g, and the iodine value of 65.14 WIJS. While the reflux method produced the acid value of 9.116 mgKOH/g, the peroxide value of 6.088 meqO 2 /kg, the saponification value of 70 mgKOH/g, and the iodine value of 87.74 WIJS. (paper)

Biomonitoring of aquatic pollution with feral eel (Anguilla anguilla). II. Biomarkers: pollution-induced biochemical responses.

NARCIS (Netherlands)

van der Oost, R.; Goksøyr, A.; Celander, M.; Heida, H.; Vermeulen, N.P.E.

1996-01-01

The primary aim of this study was to select a set of relevant biomarkers in feral eel for the biological assessment of inland water pollution. A suite of biochemical parameters in eel (hepatic biotransformation enzymes and cofactors, antioxidant enzymes, PAH metabolites, DNA adducts, serum

Direct calorimetry of free-moving eels with manipulated thyroid status

Science.gov (United States)

van Ginneken, Vincent; Ballieux, Bart; Antonissen, Erik; van der Linden, Rob; Gluvers, Ab; van den Thillart, Guido

2007-02-01

In birds and mammals, the thyroid gland secretes the iodothyronine hormones of which tetraiodothyronine (T4) is less active than triiodothyronine (T3). The action of T3 and T4 is calorigenic and is involved in the control of metabolic rate. Across all vertebrates, thyroid hormones also play a major role in differentiation, development and growth. Although the fish thyroidal system has been researched extensively, its role in thermogenesis is unclear. In this study, we measured overall heat production to an accuracy of 0.1 mW by direct calorimetry in a free-moving European eel ( Anguilla anguilla L.) with different thyroid status. Hyperthyroidism was induced by injection of T3 and T4, and hypothyroidism was induced with phenylthiourea. The results show for the first time at the organismal level, using direct calorimetry, that neither overall heat production nor overall oxygen consumption in eels is affected by hyperthyroidism. Therefore, we conclude that the thermogenic metabolism-stimulating effect of thyroid hormones (TH) is not present with a cold-blooded fish species like the European eel. This supports the concept that TH does not stimulate thermogenesis in poikilothermic species.

Genome-wide single-generation signatures of local selection in the panmictic European eel

DEFF Research Database (Denmark)

Pujolar, J. M.; Jacobsen, M. W.; Als, Thomas Damm

2014-01-01

Next-generation sequencing and the collection of genome-wide data allow identifying adaptive variation and footprints of directional selection. Using a large SNP data set from 259 RAD-sequenced European eel individuals (glass eels) from eight locations between 34 and 64oN, we examined the patterns...... of genome-wide genetic diversity across locations. We tested for local selection by searching for increased population differentiation using FST-based outlier tests and by testing for significant associations between allele frequencies and environmental variables. The overall low genetic differentiation...... with single-generation signatures of spatially varying selection acting on glass eels. After screening 50 354 SNPs, a total of 754 potentially locally selected SNPs were identified. Candidate genes for local selection constituted a wide array of functions, including calcium signalling, neuroactive ligand...

Wastewater treatment by a natural wetland: the Nakivubo swamp, Uganda : processes and implications

NARCIS (Netherlands)

Kansiime, F.; Nalubega, M.

1999-01-01

An investigation to assess the capacity of the Nakivubo swamp, Kampala-Uganda (which has been receiving partially treated sewage from the city for more than 30 years now), to remove nutrients and pathogens was carried out. The aim of the study was to evaluate the potential of this swamp to

ESTIMATING THE STOCK OF GLASS EELS IN AN ESTUARY BY MARK-RECAPTURE EXPERIMENTS USING VITAL DYES

Directory of Open Access Journals (Sweden)

BRIAND C.

2005-10-01

Full Text Available Glass eels (Anguilla anguilla arriving after the fishing season in the Vilaine estuary (France were caught by boat and at a trapping ladder located at a blocking dam upstream in the estuary. They were marked with Bismarck brown, rhodamine B or neutral red, and released into the estuary. The effect of marking on behaviour, mortality and recapture differed according to the dye and concentration used. The glass eels also differed in response to marking according to their origin. Estuarine glass eels were clearly desynchronized in their selective tidal stream transport and left the release area after a few tidal cycles. Trapped glass eels were less sensitive to marking. They remained in the release area and were recaptured in larger number both in the trapping ladder and in the estuary. These results supported a model of two behavioral fractions in the estuary: flow-carried migrants and active glass eels with stronger rheotactic behaviour. The proportion of active glass eels in the estuary shifted from none for the two weeks after the fishery closure, to 10% value of the total stock. At the trapping ladder, the migration ended in June each year, while a large stock was still present in the estuary. These observations favour the interpretation of a short duration of the active phase at this site followed by the transition towards a more benthic behavior. The daily efficiency of the trapping ladder was calculated as 4% of the active stock from both stock estimations and average recapture rate. This value was consistent with the low annual efficiency of the trapping ladder, calculated as 30% of the estuarine stock of glass eels that arrived after the fishing season.

Notes on the Moray Eels (Anguilliformes: Muraenidae) of Malaysia with Two New Records

International Nuclear Information System (INIS)

Kar-Hoe, L.; Muhammad Ali Syed Hussein; Ving-Ching, C.; Sasekumar, A.

2015-01-01

Two new records of moray eels (Muraenidae), Gymnothorax margaritophorus Bleeker, 1864 and Strophidon sathete (Hamilton 1822), are reported for Malaysia. They are represented by two specimens each, all collected from Sabah waters. The present study also provides the current taxonomic and distributional information of the Malaysian moray eels. To date, there are 33 species belonging to six genera of the Muraenidae in Malaysian waters based on the published records. (author)

Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

NARCIS (Netherlands)

Palstra, A.P.; Guerrero, M.A.; Klein Breteler, J.G.P.; Thillart, G.E.E.J.M.

2011-01-01

The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was

Changes in Species Composition in Alder Swamp Forest Following Forest Dieback

Directory of Open Access Journals (Sweden)

Remigiusz Pielech

2018-06-01

Full Text Available It is generally hypothesized that forest dieback is a characteristic of alder swamp forests (alder carrs, Alnion glutinosae alliance. Different internal and external factors may trigger this process, including human disturbance, changes in river discharge, unusually severe and prolonged flooding, terminal age of an even-aged alder forest (ca. 100–150 years and others. Although forest dieback in this type of forest may cause major changes in environmental conditions, the influence of this change on the floristic composition has not been well recognized. The study aimed to detect any possible changes in floristic variation in alder swamp forest following forest dieback. Vegetation plots in alder swamp forests affected by forest dieback were resurveyed 20 years after a previous study. PERMANOVA was used to test the significance of the compositional change and nonmetric multidimensional scaling (NMDS with passively fitted means of the Ellenberg’s Indicator Values were used to interpret its ecological meaning. In addition, different structural and diversity indices were compared, including species richness, percentage cover of vegetation layers, Shannon and Simpson diversity and evenness. Finally, we analyzed changes in the frequency of vascular plant species using Chi square tests. We recorded clear and significant compositional changes following alder swamp forest dieback. This change was most related to the gradient of moisture, followed by the gradients of light and temperature. The analysis of the individual species showed that the species of hummocks declined, while the species of hollows increased. Moreover, the current communities are dominated by some hydrophytes that were not recorded 20 years ago. Forest dieback resulted in profound changes in the hydrological regime. The observed changes are consistent with a model of cyclic succession as proposed for alder swamps. In addition, we conclude that the natural forest dynamics have to be

Detection of Herpesvirus anguillae (AngHV-1) in European eel Anguilla anguilla (L.) originating from northern Poland-assessment of suitability of selected diagnostic methods.

Science.gov (United States)

Nguyen, Tuan Thuc; Jin, Yeonhwa; Kiełpińska, Jolanta; Bergmann, Sven M; Lenk, Matthias; Panicz, Remigiusz

2017-11-01

The Community Action Plan requests EU member states to implement measures that ensure the recovery of the severely depleted European eel stocks. One of the main threats is posed by Anguillid herpesvirus 1 (AngHV-1) leading to increased mortality in both wild and farmed eels. Following recommendations of the OIE to minimize the risk of obtaining false-negative results, the main aim of the study was to optimize diagnostic methods for AngHV-1 detection using conventional PCR, nested PCR and in situ hybridization assay. While 53.3% of the individual organ samples were tested positive for AngHV-1 by PCR, the additional virus analysis via nested PCR revealed that the actual prevalence was 93.3%. In the cell cultivation passages, a cytopathic effect was hardly found in the first two rounds. In the third passage onto cell cultures, a lytic CPE was detected. The identification and confirmation of the viruses obtained from cell cultures as well as directly from the organ tissues were proceeded by PCR, nested PCR and sequencing of the PCR products. While no positive signal was detectable in the first round by PCR using samples from the third cell culture passages, the nested PCR provided weak but visible positive signals. © 2017 John Wiley & Sons Ltd.

Producer farmer’s sovereignty in dry land and swamps areas

Science.gov (United States)

Suhaeti, RN; Wahyuni, S.

2018-01-01

Farmers could perform their farming if they have sovereignty on their farming production inputs and marketing. Suboptimal land, such as dry land and swamps areas have good prospect if applying appropriate technologies. A research in 2015, on status of farmers’ sovereignty, had been conducted in Piani and North Candi Laras Subdistricts, Tapin District, South Borneo Province, representing swamp land and dry land respectively. Data and information were obtained through interviewing related agencies at provincial and district levels and 30 units of farmer’s households. The primary and secondary data were analyzed descriptively. The research results showed that farmers in swamps and dry land were categorized as large farmers and had sovereignty over the land and production. Water shortage and excessive in both land types could be overcome by giving access on appropriate technology such as programs making farmers improve their farming techniques and providing levees. In addition, land certification program, farming expansion and constructing new irrigated lowland were also some efforts to improve farmers’ sovereignty. It was crucial to identify and improve farmer’s sovereignty indicators through research in larger sites and samples.

Complete genome sequence and phylogenetic analyses of an aquabirnavirus isolated from a diseased marbled eel culture in Taiwan.

Science.gov (United States)

Wen, Chiu-Ming

2017-08-01

An aquabirnavirus was isolated from diseased marbled eels (Anguilla marmorata; MEIPNV1310) with gill haemorrhages and associated mortality. Its genome segment sequences were obtained through next-generation sequencing and compared with published aquabirnavirus sequences. The results indicated that the genome sequence of MEIPNV1310 contains segment A (3099 nucleotides) and segment B (2789 nucleotides). Phylogenetic analysis showed that MEIPNV1310 is closely related to the infectious pancreatic necrosis Ab strain within genogroup II. This genome sequence is beneficial for studying the geographic distribution and evolution of aquabirnaviruses.

Ontogeny and growth of early life stages of captive-bred European eel

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Tomkiewicz, Jonna; Munk, Peter

2016-01-01

of viable eggs and larvae of European eel, providing the basis for studies on early life stages of this species in captivity. In this study, we describe and illustrate morphological characteristics of eggs, embryos, and larvae from fertilization to termination of the yolk sac stage and provide a comparison...... forms a large perivitelline space, reaching an egg diameter of 1.45 ± 0.12 mm at 3.0 to 3.5 h post fertilization. Embryonic development from fertilization to larval hatch lasted ~46–48 h at 20 °C with the larvae emerging in a relatively undeveloped stage with a protuberant yolk sac. During the period......-sustained aquaculture of this high-value and critically endangered species. Statement of relevance: European eel is a high-value species in aquaculture, however, production is presently hampered by reliance on wild caught fry. Captive production of glass eels will reopen markets in Europe and Asia, benefiting European...

High Brain Ammonia Tolerance and Down-Regulation of Na+:K+:2Cl- Cotransporter 1b mRNA and Protein Expression in the Brain of the Swamp Eel, Monopterus albus, Exposed to Environmental Ammonia or Terrestrial Conditions

Science.gov (United States)

Ip, Yuen K.; Hou, Zhisheng; Chen, Xiu L.; Ong, Jasmine L. Y.; Chng, You R.; Ching, Biyun; Hiong, Kum C.; Chew, Shit F.

2013-01-01

Na+:K+:2Cl- cotransporter 1 (NKCC1) has been implicated in mediating ischemia-, trauma- or ammonia-induced astrocyte swelling/brain edema in mammals. This study aimed to determine the effects of ammonia or terrestrial exposure on ammonia concentrations in the plasma and brain, and the mRNA expression and protein abundance of nkcc/Nkcc in the brain, of the swamp eel Monopterus albus . Ammonia exposure led to a greater increase in the ammonia concentration in the brain of M. albus than terrestrial exposure. The brain ammonia concentration of M. albus reached 4.5 µmol g-1 and 2.7 µmol g-1 after 6 days of exposure to 50 mmol l-1 NH4Cl and terrestrial conditions, respectively. The full cDNA coding sequence of nkcc1b from M. albus brain comprised 3276 bp and coded for 1092 amino acids with an estimated molecular mass of 119.6 kDa. A molecular characterization indicated that it could be activated through phosphorylation and/or glycosylation by osmotic and/or oxidative stresses. Ammonia exposure for 1 day or 6 days led to significant decreases in the nkcc1b mRNA expression and Nkcc1b protein abundance in the brain of M. albus. In comparison, a significant decrease in nkcc1b mRNA expression was observed in the brain of M. albus only after 6 days of terrestrial exposure, but both 1 day and 6 days of terrestrial exposure resulted in significant decreases in the protein abundance of Nkcc1b. These results are novel because it has been established in mammals that ammonia up-regulates NKCC1 expression in astrocytes and NKCC1 plays an important role in ammonia-induced astrocyte swelling and brain edema. By contrast, our results indicate for the first time that M. albus is able to down-regulate the mRNA and protein expression of nkcc1b/Nkcc1b in the brain when confronted with ammonia toxicity, which could be one of the contributing factors to its extraordinarily high brain ammonia tolerance. PMID:24069137

Regional variation in otolith Sr:Ca ratios of African longfinned eel Anguilla mossambica and mottled eel Anguilla marmorata: a challenge to the classic tool for reconstructing migratory histories of fishes.

Science.gov (United States)

Lin, Y-J; Jessop, B M; Weyl, O L F; Iizuka, Y; Lin, S-H; Tzeng, W-N; Sun, C-L

2012-07-01

Otolith Sr:Ca ratios of the African longfinned eel Anguilla mossambica and giant mottled eel Anguilla marmorata from nine freshwater sites in four rivers of South Africa were analysed to reconstruct their migratory life histories between freshwater and saltwater habitats. For A. mossambica, the Sr:Ca ratios in the otolith edge differed significantly among rivers and had large effect sizes, but did not differ among sites within a river. Otolith Sr:Ca ratios did not differ among rivers for A. marmorata. When rivers were pooled, the edge Sr:Ca ratios of A. mossambica were not significantly different from those of A. marmorata. According to the river-specific critical Sr:Ca ratio distinguishing freshwater from saltwater residence, most A. mossambica and A. marmorata had saltwater habitat experience after settlement in fresh water. This was primarily during their elver stage or early in the yellow eel stage. During the middle and late yellow eel stage, freshwater residency was preferred and only sporadic visits were made to saltwater habitats. The data also suggest that regional variations in otolith Sr:Ca ratios affect the critical Sr:Ca value and are a challenge for the reconstruction of migratory life histories that should be explicitly considered to avoid bias and uncertainty. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Floristic and phytosociological analysis of palm swamps in the central part of the Brazilian savanna

Directory of Open Access Journals (Sweden)

Isa Lucia de Morais Resende

2013-03-01

Full Text Available We analyzed the floristics and phytosociology of three palm swamps in the municipality of Bela Vista de Goiás, located in the state of Goiás, Brazil, in the central part of the Brazilian savanna (Cerrado. The floristic surveys were conducted monthly from May 2008 to April 2009, and 310 species were recorded (seven bryophytes, 15 ferns and 288 angiosperms. Bryophytes belonged to five genera and five families; ferns belonged to nine genera and nine families; and angiosperms belonged to 134 genera and 45 families. The angiosperm families with the highest species richness were Poaceae, Cyperaceae, Asteraceae, Eriocaulaceae, Xyridaceae, Lentibulariaceae, Melastomataceae, Rubiaceae and Fabaceae. The palm swamps were divided into three zones of increasing humidity: edge, middle and core. The number of species was higher in the middle than at the edge and the core. The families with the highest cover values were Cyperaceae, Melastomataceae, Arecaceae and Poaceae. Although the palm swamps had been disturbed to varying degrees, those disturbances did not affect the flora in the middle or the core. Floristic similarity was high between these two zones within a given palm swamp and low between the edges of different palm swamps.

Anguillicola crassus (Nematoda, Dracunculoidea) infections of European eel (Anguila anguilla) in the Netherlands : epidemiology, pathogenensis and pathobiology

NARCIS (Netherlands)

Haenen, O.L.M.

1995-01-01

In the 1980s an eel parasitic nematode, Anguillicola crassus (Nematoda, Dracunculoidea), which infects the swimbladder of European eels ( Anguilla anguilla ) and other freshwater fish species, was introduced into The Netherlands. This thesis

TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks; Etude couplee MET-EELS du carbone deutere: application a la retention du combustible dans les tokamaks

Energy Technology Data Exchange (ETDEWEB)

Bernier, N

2007-12-15

We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large ({approx} 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge.

Science.gov (United States)

Aoyama, Jun; Watanabe, Shun; Miller, Michael J; Mochioka, Noritaka; Otake, Tsuguo; Yoshinaga, Tatsuki; Tsukamoto, Katsumi

2014-01-01

The Japanese eel, Anguilla japonica, spawns within the North Equatorial Current that bifurcates into both northward and southward flows in its westward region, so its spawning location and larval transport dynamics seem important for understanding fluctuations in its recruitment to East Asia. Intensive research efforts determined that Japanese eels spawn along the western side of the West Mariana Ridge during new moon periods, where all oceanic life history stages have been collected, including eggs and spawning adults. However, how the eels decide where to form spawning aggregations is unknown because spawning appears to have occurred at various latitudes. A salinity front formed from tropical rainfall was hypothesized to determine the latitude of its spawning locations, but an exact spawning site was only found once by collecting eggs in May 2009. This study reports on the collections of Japanese eel eggs and preleptocephali during three new moon periods in June 2011 and May and June 2012 at locations indicating that the distribution of lower salinity surface water or salinity fronts influence the latitude of spawning sites along the ridge. A distinct salinity front may concentrate spawning south of the front on the western side of the seamount ridge. It was also suggested that eels may spawn at various latitudes within low-salinity water when the salinity fronts appeared unclear. Eel eggs were distributed within the 150-180 m layer near the top of the thermocline, indicating shallow spawning depths. Using these landmarks for latitude (salinity front), longitude (seamount ridge), and depth (top of the thermocline) to guide the formation of spawning aggregations could facilitate finding mates and help synchronize their spawning.

Fishery-induced selection for slow somatic growth in European eel.

Directory of Open Access Journals (Sweden)

Daniele Bevacqua

Full Text Available Both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. We compared body growth rates in European eel (Anguilla anguilla from three Mediterranean stocks subject to different fishing pressure. Results are consistent with the hypotheses that i fast-growing individuals are more likely to survive until sexual maturity than slow-growing ones under natural conditions (no fishing and ii fishing can select for slow-growing individuals by removing fast-growing ones. Although the possibility of human-induced evolution seems remote for a panmictic species like such as the European eel, further research is desirable to assess the implications of the intensive exploitation on this critically endangered fish.

The Effects of Corrosive Chemicals on Corrosion Rate of Steel Reinforcement Bars: I. Swamp Water

Directory of Open Access Journals (Sweden)

Sulistyoweni Widanarko

2010-10-01

Full Text Available Most of infrastructures using steel concrete to reinforce the strength of concrete. Steel concrete is so vulnerable to chemical compounds that can cause corrosion. It can happen due to the presence of chemical compounds in acid environment in low pH level. These chemical compounds are SO42-, Cl-, NO3-. There are many swamp area in Indonesia. The acid contents and the concentration of ion sulphate, chlorides, and nitrate are higher in the swamp water than in the ground water .The objective of this research was to find out the influence of corrosive chemicals in the swamp water to the steel concrete corrosion rate. There were two treatment used: (1 emerging ST 37 and ST 60 within 60 days in the 'polluted' swamp water, (2 moving the ST 37 up and down periodically in the ' polluted' swamp water. Three variation of 'polluted' swamp water were made by increasing the concentration of corrosive chemical up to 1X, 5X and 10X respectively. The corrosion rate was measured by using an Immersion Method. The result of Immersion test showed that chloride had the greatest influence to corrosion rate of ST 37 and ST 60 and followed by sulphate and Nitrate. Corrosion rate value for ST 37 is 24.29 mpy and for ST 60 is 22.76 mpy. By moving the sample up and down, the corrosion rate of ST 37 increase up to 37.59 mpy, and chloride still having the greatest influence, followed by sulphate and nitrate.

Regional variation in energy storage strategies in American glass eels from Eastern Canada.

Science.gov (United States)

Gaillard, Mélanie; Bernatchez, Louis; Tremblay, Réjean; Audet, Céline

2015-10-01

Energy status was analyzed in glass eels captured during two early waves of arrival at the mouths of the Mersey River, Nova Scotia, Canada (MR), and Grande-Rivière-Blanche, Québec, Canada (GRB), and according to their salinity preference (freshwater, brackish, or saltwater). Glass eels captured in the GRB estuary were larger, more pigmented, and exhibited higher whole-body glycogen, phospholipid, and sterol and wax ester contents. Those from MR had a higher condition index and a higher whole-body triacylglycerol content, suggesting different patterns of storage and/or use of energy reserves. Within a river, a delay of two weeks in estuarine arrival was characterized by significantly lower energy reserves. No differences in energy storage were observed according to salinity preference. Thus, the results revealed the occurrence of different energy storage strategies according to glass eel migration distance and duration, but not according to salinity preference. Copyright © 2015 Elsevier Inc. All rights reserved.

Decline of the Maurepas Swamp, Pontchartrain Basin, Louisiana, and Approaches to Restoration

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Gary P. Shaffer

2016-03-01

Full Text Available The Maurepas swamp is the second largest contiguous coastal forest in Louisiana but it is highly degraded due to subsidence, near permanent flooding, nutrient starvation, nutria herbivory, and saltwater intrusion. Observed tree mortality rates at study sites in the Maurepas swamp are very high (up to 100% tree mortality in 11 years and basal area decreased with average salinities of <1 ppt. Habitat classification, vegetation productivity and mortality, and surface elevation changes show a clear trajectory from stagnant, nearly permanently flooded forests with broken canopy to degraded forests with sparse baldcypress and dominated by herbaceous species and open water to open water habitat for most of the Maurepas swamp without introduction of fresh water to combat saltwater intrusion and stimulate productivity and accretion. Healthy forests in the Maurepas are receiving fresh water containing nutrients and sediments from urban areas, high quality river water, or secondarily treated municipal effluent. Currently, two proposed diversions into the swamp are via Hope Canal (57 m3·s−1 and Blind River (142 m3·s−1. These diversions would greatly benefit their immediate area but they are too small to influence the entire Maurepas sub-basin, especially in terms of accretion. A large diversion (>1422 m3·s−1 is needed to deliver the adequate sediments to achieve high accretion rates and stimulate organic soil formation.

Cardio-respiratory Physiology of the European Eel (em>Agunilla anguilla)em> in Extreme Environments

DEFF Research Database (Denmark)

Methling, Caroline

The main objective of this PhD thesis was to study the cardio-respiratory capabilities of the European eel (Anguilla anguilla) under extreme conditions. Three environmental conditions were studied i.e. temperature, dissolved oxygen and carbon dioxide, while a fourth condition was physiological an......), body wave speed (v) and Strouhal number (St). The results demonstrate that energy expenditure, swimming performance and efficiency all are significantly affected in migrating eels fitted with external tags....

Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla

DEFF Research Database (Denmark)

da Silva, Filipa; Støttrup, Josianne Gatt; Kjørsvik, Elin

2016-01-01

Farmed female eels were fed two experimental diets with similar proximate composition but different n-3 polyunsaturated fatty acid (PUFA) levels. Both diets had similar levels of arachidonic acid (ARA), while levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in one diet were...... approximately 4.5 and 2.6 times higher compared to the other diet, respectively. After the feeding period, each diet group was divided into two and each half received one of two hormonal treatments using salmon pituitary extract (SPE) for 13 weeks: i) a constant hormone dose of 18.75mg SPE/kg initial body...

Cultural Resuscitation and Nation-Building: An Examination of ...

African Journals Online (AJOL)

Mrs Afam

The natural vegetation of Ughievwen clan and the sub-groups is rainforest with swamp ... twentieth century appeared to have eroded these cultural values even up to the post- colonial ... fire with logs and as soon as the smoke had reduced and the charcoal burnt brightly, ..... Globalization and cultural management: Between.

The fungal flora of the mangrove swamps of Goa

Digital Repository Service at National Institute of Oceanography (India)

Matondkar, S.G.P.; Mahtani, S.; Mavinkurve, S.

Mangrove swamps of Goa (India) showed the presence of fungi belonging to 14 different genera, predominant ones being Monilia, Mucor, Syncephalastrum, Aspergillus and Trichothecium. Most of the isolates were found to be physiologically active...

Low levels of persistent organic pollutants (POPs) in New Zealand eels reflect isolation from atmospheric sources

International Nuclear Information System (INIS)

Holmqvist, Niklas; Stenroth, Patrik; Berglund, Olof; Nystroem, Per; Olsson, Karin; Jellyman, Don; McIntosh, Angus R.; Larsson, Per

2006-01-01

Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants. - Low levels of PCBs found in New Zealand eels reflect isolation from atmospheric sources while DDTs levels are determined by land use

Heading south or north: novel insights on European silver eel Anguilla anguilla migration in the North Sea

NARCIS (Netherlands)

Huisman, Jeroen; Verhelst, Pieterjan; Verhelst, Pieterjan; Deneudt, K.; Goethals, Peter; Moens, Tom; Nagelkerke, Leopold A.J.; Nolting, Carsten; Reubens, Jan; Schollema, Peter Paul; Winter, Hendrik V.; Mouton, Ans

2016-01-01

The European eel Anguilla anguilla L. is a critically endangered fish species that migrates from coastal and freshwater habitats to the Sargasso Sea to spawn. However, the exact migration routes and destination of European eel are still unknown. We are the first to observe southward migrating

Food swamps and food deserts in Baltimore City, MD, USA: associations with dietary behaviours among urban adolescent girls.

Science.gov (United States)

Hager, Erin R; Cockerham, Alexandra; O'Reilly, Nicole; Harrington, Donna; Harding, James; Hurley, Kristen M; Black, Maureen M

2017-10-01

To determine whether living in a food swamp (≥4 corner stores within 0·40 km (0·25 miles) of home) or a food desert (generally, no supermarket or access to healthy foods) is associated with consumption of snacks/desserts or fruits/vegetables, and if neighbourhood-level socio-economic status (SES) confounds relationships. Cross-sectional. Assessments included diet (Youth/Adolescent FFQ, skewed dietary variables normalized) and measured height/weight (BMI-for-age percentiles/Z-scores calculated). A geographic information system geocoded home addresses and mapped food deserts/food swamps. Associations examined using multiple linear regression (MLR) models adjusting for age and BMI-for-age Z-score. Baltimore City, MD, USA. Early adolescent girls (6th/7th grade, n 634; mean age 12·1 years; 90·7 % African American; 52·4 % overweight/obese), recruited from twenty-two urban, low-income schools. Girls' consumption of fruit, vegetables and snacks/desserts: 1·2, 1·7 and 3·4 servings/d, respectively. Girls' food environment: 10·4 % food desert only, 19·1 % food swamp only, 16·1 % both food desert/swamp and 54·4 % neither food desert/swamp. Average median neighbourhood-level household income: $US 35 298. In MLR models, girls living in both food deserts/swamps consumed additional servings of snacks/desserts v. girls living in neither (β=0·13, P=0·029; 3·8 v. 3·2 servings/d). Specifically, girls living in food swamps consumed more snacks/desserts than girls who did not (β=0·16, P=0·003; 3·7 v. 3·1 servings/d), with no confounding effect of neighbourhood-level SES. No associations were identified with food deserts or consumption of fruits/vegetables. Early adolescent girls living in food swamps consumed more snacks/desserts than girls not living in food swamps. Dietary interventions should consider the built environment/food access when addressing adolescent dietary behaviours.

A century of research on the larval distributions of the Atlantic eels: a re-examination of the data

DEFF Research Database (Denmark)

Miller, Michael J.; Bonhommeau, Sylvain; Munk, Peter

2015-01-01

The spawning areas of the Atlantic freshwater eels were discovered about a century ago by the Danish scientist Johannes Schmidt who after years of searching found newly hatched larvae of the European eel, Anguilla anguilla, and the American eel, Anguilla rostrata, in the southern Sargasso Sea...... comprehensive database that includes 22612 A. anguilla and 9634 A. rostrata leptocephali, which provides a detailed view of the spatial and temporal distributions and size of the larvae across the Atlantic basin and in the Mediterranean Sea. The differences in distributions, maximum sizes, and growth rates...

The impact of the Suwannee River Sill on the surface hydrology of Okefenokee Swamp, USA

Science.gov (United States)

Yin, Zhi-Yong; Brook, George A.

1992-08-01

Okefenokee Swamp, located in southeastern Georgia and northeastern Florida, is one of the largest freshwater wetland complexes and a National Wildlife Refuge in the United States. A low earthen dam, the Suwannee River Sill, was built on the largest outlet stream of Okefenokee Swamp in the early 1960s. The purpose was to raise the water level and thus reduce fire frequency in this National Wildlife Refuge. In this study, hydrologic conditions in the swamp prior to (1937-1962) and after (1963-1986) sill construction were compared by statistical procedures. An average 9 cm increase in swamp water level at the Suwannee Canal Recreation Area was attributed to the sill. Increased precipitation and decreased evapotranspiration during the study period caused another 5 cm increase in water levels. Seasonal changes in climatic factors were also responsible for seasonal changes in water levels and streamflow in the pre- and post-sill periods. Although the effect of the sill on water level was more significant during dry periods, it is doubtful that the Suwannee River Sill actually prevented occurrence of severe fibres in the post-sill period, which was wetter than the period before sill construction. The sill diverted 2.6% of swamp outflow from the Suwannee River to the St. Mary's River. Diversion of flow was more marked during low flow periods. Therefore, the discharge of the St. Mary's River in the post-sill increased more than the discharge of the Suwannee River and its variability became lower that of the Suwannee River. The relationships between swamp water level, streamflow and precipitation were also changed due to construction of the sill.

Direct observations of American eels migrating across the continental shelf to the Sargasso Sea.

Science.gov (United States)

Béguer-Pon, Mélanie; Castonguay, Martin; Shan, Shiliang; Benchetrit, José; Dodson, Julian J

2015-10-27

Since inferring spawning areas from larval distributions in the Sargasso Sea a century ago, the oceanic migration of adult American eels has remained a mystery. No adult eel has ever been observed migrating in the open ocean or in the spawning area. Here, we track movements of maturing eels equipped with pop-up satellite archival tags from the Scotian Shelf (Canada) into the open ocean, with one individual migrating 2,400 km to the northern limit of the spawning site in the Sargasso Sea. The reconstructed routes suggest a migration in two phases: one over the continental shelf and along its edge in shallow waters; the second in deeper waters straight south towards the spawning area. This study is the first direct evidence of adult Anguilla migrating to the Sargasso Sea and represents an important step forward in the understanding of routes and migratory cues.

[Amphibians and reptiles in the swamps dominated by the palm Raphia taedigera (Arecaceae) in northeastern Costa Rica].

Science.gov (United States)

Bonilla-Murillo, Fabian; Beneyto, Davinia; Sasa, Mahmood

2013-09-01

The herpetofauna that inhabits Caribbean Costa Rica has received considerable attention in the last two decades. This assemblage includes a total of 141 species of reptiles and 95 amphibians mostly distributed in tropical wet and moist lowland forests. While most information available came from primary and secondary forest sites, little is known about the amphibians and reptiles that inhabit more open habitats, such as wetlands and swamps. For instances, swaps dominated by the yolillo palm Raphia taedigera extend through much of the northeastern Caribbean coast of Costa Rica and eastern Nicaragua, but information about the herpetological community that uses such environments remains practically unknown. This situation reflects the little research conducted in such inhospitable environments. Here, we report the results of an intensive survey conducted to assess the herpetological community that inhabit R. taedigera palm-swamps. A total of 14 species of amphibians and 17 of reptiles have been recorded from these swamps. Amphibians and reptiles that inhabit yolillo swamps have wide distributions along much of Middle America and are considered common species throughout their range. In general, yolillo swamps are poor environments for herpetofauna: richness of reptiles and amphibians is almost two times higher in the adjacent forest than in the palm dominated swamps. Furthermore, most species observed in this swamps can be considered habitat generalists that are well adapted to the extreme conditions imposed by the changes in hydroperiods, reduce understory cover, low tree diversity and simple forest architecture of these environments. Despite similarities in the herpetofauna, it is clear that not all forest species use yolillo habitat, a characteristic that is discussed in terms of physical stress driven by the prolonged hydroperiod and reduced leaflitter in the ground, as these features drive habitat structure and herpetofaunal complexity. Our list of species using

Gelatinous plankton is central to the diet of European eel (Anguilla anguilla) larvae in the Sargasso Sea

DEFF Research Database (Denmark)

Ayala, Daniel Jiro; Munk, Peter; Lundgreen, Regitze B. C.

2018-01-01

endangered species. Next-generation 18S rRNA gene sequencing data of Sargasso Sea eel larvae gut contents and marine snow aggregates was compared with a reference plankton database to assess the trophic relations of eel larvae. Gut contents of A. anguilla larvae were not well explained by the eukaryotic...

The mechanism for primordial germ-cell migration is conserved between Japanese eel and zebrafish.

Directory of Open Access Journals (Sweden)

Taiju Saito

Full Text Available Primordial germ cells (PGCs are segregated and specified from somatic cells during early development. These cells arise elsewhere and have to migrate across the embryo to reach developing gonadal precursors. Several molecules associated with PGC migration (i.e. dead-end, nanos1, and cxcr4 are highly conserved across phylum boundaries. However, since cell migration is a complicated process that is regulated spatially and temporally by multiple adaptors and signal effectors, the process is unlikely to be explained by these known genes only. Indeed, it has been shown that there are variations in PGC migration pattern during development among teleost species. However, it is still unclear whether the actual mechanism of PGC migration is conserved among species. In this study, we studied the migration of PGCs in Japanese eel (Anguilla japonica embryos and tested the migration mechanism between Japanese eel and zebrafish (Danio rerio for conservation, by transplanting eel PGCs into zebrafish embryos. The experiments showed that eel PGCs can migrate toward the gonadal region of zebrafish embryos along with endogenous PGCs, even though the migration patterns, behaviors, and settlements of PGCs are somewhat different between these species. Our results demonstrate that the migration mechanism of PGCs during embryonic development is highly conserved between these two distantly related species (belonging to different teleost orders.

Performance and optimisation of trickling filters on eel farms

NARCIS (Netherlands)

Kamstra, A.; Heul, van der J.W.; Nijhof, M.

1998-01-01

The design of trickling filters used on commercial eel farms differs considerably with respect to dimensions, hydraulic and substrate loads and filter medium applied. In this paper, a model, developed for ammonium removal in a pilot-scale trickling filter, has been validated for a range of

CORRELATION ANALYSIS OF AGRONOMIC CHARACTERS AND GRAIN YIELD OF RICE FOR TIDAL SWAMP AREAS

Directory of Open Access Journals (Sweden)

Aris Hairmansis

2013-05-01

Full Text Available Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS 2005, wet season (WS 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356, number of filled grains per panicle (p = 0.544, and spikelet fertility (p = 0.215. Plant height had negative direct effect (p = -0.332 on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.

Downstream passage and impact of turbine shutdowns on survival of silver American Eels at five hydroelectric dams on the Shenandoah River

Science.gov (United States)

Eyler, Sheila; Welsh, Stuart A.; Smith, David R.; Rockey, Mary

2016-01-01

Hydroelectric dams impact the downstream migrations of silver American Eels Anguilla rostrata via migratory delays and turbine mortality. A radiotelemetry study of American Eels was conducted to determine the impacts of five run-of-the-river hydroelectric dams located over a 195-km stretch of the Shenandoah River, Virginia–West Virginia, during fall 2007–summer 2010. Overall, 96 radio-tagged individuals (mean TL = 85.4 cm) migrated downstream past at least one dam during the study. Most American Eels passed dams relatively quickly; over half (57.9%) of the dam passage events occurred within 1 h of reaching a dam, and most (81.3%) occurred within 24 h of reaching the dam. Two-thirds of the dam passage events occurred via spill, and the remaining passage events were through turbines. Migratory delays at dams were shorter and American Eels were more likely to pass via spill over the dam during periods of high river discharge than during low river discharge. The extent of delay in migration did not differ between the passage routes (spill versus turbine). Twenty-eight American Eels suffered turbine-related mortality, which occurred at all five dams. Mortality rates for eels passing through turbines ranged from 15.8% to 40.7% at individual dams. Overall project-specific mortality rates (with all passage routes combined) ranged from 3.0% to 14.3%. To protect downstream-migrating American Eels, nighttime turbine shutdowns (1800–0600 hours) were implemented during September 15–December 15. Fifty percent of all downstream passage events in the study occurred during the turbine shutdown period. Implementation of the seasonal turbine shutdown period reduced cumulative mortality from 63.3% to 37.3% for American Eels passing all five dams. Modifying the turbine shutdown period to encompass more dates in the spring and linking the shutdowns to environmental conditions could provide greater protection to downstream-migrating American Eels.

EEL Calculations and Measurements of Graphite and Graphitic-CNx Core-Losses

International Nuclear Information System (INIS)

Seepujak, A; Bangert, U; Harvey, A J; Blank, V D; Kulnitskiy, B A; Batov, D V

2006-01-01

Core EEL spectra of MWCNTs (multi-wall carbon nanotubes) grown in a nitrogen atmosphere were acquired utilising a dedicated STEM equipped with a Gatan Enfina system. Splitting of the carbon K-edge π* resonance into two peaks provided evidence of two nondegenerate carbon bonding states. In order to confirm the presence of a CN x bonding state, a full-potential linearised augmented plane-wave method was utilised to simulate core EEL spectra of graphite and graphitic-CN x compounds. The simulations confirmed splitting of the carbon K-edge π* resonance in graphitic-CN x materials, with the pristine graphite π* resonance remaining unsplit. The simulations also confirmed the increasing degree of amorphicity with higher concentrations (25%) of substitutional nitrogen in graphite

A new method to grade glass eels according to their appetite

Directory of Open Access Journals (Sweden)

ANGELIDIS Panagiotis

2007-10-01

Full Text Available To optimize fish growth grading is strongly recommended. In our experiment the glass eels (450,000, mean individual body weight 0.31+0.22g sd start feeding for 15 and then they were selected according to their appetite. After selection all the fish of the 10 tanks were fed at liberty and they were weighed on the 10th and 30thday after the grade day. No differences were seen in the fish weight of the eels of the two groups on the 10th day (P>0.01 but the selected fish doubled their weight on the 30th day (selected fish 0.71+0.22g sd, unselected 0.39+0.20g sd, P<0.01.

TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks

International Nuclear Information System (INIS)

Bernier, N.

2007-12-01

We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large (∼ 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

Can lagrangian models reproduce the migration time of European eel obtained from otolith analysis?

Science.gov (United States)

Rodríguez-Díaz, L.; Gómez-Gesteira, M.

2017-12-01

European eel can be found at the Bay of Biscay after a long migration across the Atlantic. The duration of migration, which takes place at larval stage, is of primary importance to understand eel ecology and, hence, its survival. This duration is still a controversial matter since it can range from 7 months to > 4 years depending on the method to estimate duration. The minimum migration duration estimated from our lagrangian model is similar to the duration obtained from the microstructure of eel otoliths, which is typically on the order of 7-9 months. The lagrangian model showed to be sensitive to different conditions like spatial and time resolution, release depth, release area and initial distribution. In general, migration showed to be faster when decreasing the depth and increasing the resolution of the model. In average, the fastest migration was obtained when only advective horizontal movement was considered. However, faster migration was even obtained in some cases when locally oriented random migration was taken into account.

Sequence Stratigraphic Appraisal: Coastal Swamp Depobelt In The ...

African Journals Online (AJOL)

Mid-Lower Miocene Agbada sedimentary intercalations of “AB” Field in the coastal swamp depobelt, Western Niger-Delta, were evaluated to determine their sequence stratigraphic character. The analysis was based on a combination of data sets including logs of six wells to describe lithic variations of the Agbada Formation ...

Production Efficiency of Swamp Rice Production in Cross River ...

African Journals Online (AJOL)

This study compares profit maximization, output optimization and resource use efficiency in ... of two varieties of swamp rice by farmers in Cross River State of Nigeria. ... The result of the finding also shows that small-scale farmers were more ...

Reproductive responses to climatic heat induced by management systems in swamp buffaloes

International Nuclear Information System (INIS)

Dollah, M.A.; Ramakrishnan, N.; Nordin, Y.; Abdullah Sani, R.

1990-01-01

Climatic heat is one of the factors influencing the reproductive performance of swamp buffaloes. Any management system that imposes high climatic heat stress tends to reduce reproductive performance. Buffaloes grazing in an open hilly ranch system reached puberty later (at an age of 33 months) and at heavier body weight (365 kg) than animals raised in confinement (26 months and 289 kg). Physiological data (water metabolism and thyroid activity) indicated that grazing animals had to tolerate a higher heat load. High climatic temperatures were found to depress ovarian activity, especially during the dry season. The effect was observed only in cycling buffaloes denied wallow. Buffaloes having access to wallows were able to maintain their heat balance under various levels of heat load by adjusting their water requirements, mobilizing their body water and adjusting their metabolic rate (thyroid activity). It is concluded that stressful climatic temperatures can depress the reproductive performance of young heifers and adult swamp buffaloes, and that climatic heat stress directly depresses ovarian activity in swamp buffaloes. (author). 16 refs, 1 fig., 4 tabs

Shark predation on migrating adult american eels (Anguilla rostrata) in the Gulf of St. Lawrence

DEFF Research Database (Denmark)

Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin

2012-01-01

to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria....... Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C--too cold for marine mammals but within the range of endothermic fish. In order...... generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit...

Effect of earthworm (Lumbricus rubellus) in feed formulation to improve fatty acids profile in eel (Anguilla bicolor) meat

Science.gov (United States)

Farah, K.; Gunawan, I. R.; Putra, G. B.; Agustono; Lokapirnasari, W. P.; Lamid, M.; Masithah, E. D.; Nurhajati, T.; Rozi

2018-04-01

Eel requires unsaturated fatty acids of linolenic acid for growth. Which can be supplied from earthworms. In this study, addition of earthworm in formulation feed aimsed to improve the fatty acid profile eel meat. This research used experimental method and randomized complete design method with five treatments. Each treatment was repeated four times. The use of earthworms in feeding treatment formulation was done for 21 days with different level i.e: 0 % (P0), 25 % (P1), 50 % (P2), 75 % (P3) and 100 % (P4). The result showed that the addition of eartworm significantly influenced the omega 3 contents (EPA & DHA) of eel meat.

Genetic characteristic of swamp buffalo (Bubalus bubalis) from Pampangan, South Sumatra based on blood protein profile

Science.gov (United States)

Windusari, Yuanita; Hanum, Laila; Wahyudi, Rizki

2017-11-01

Swamp buffalo (Bubalus bubalis) is an endemic species and one of the genetic wealth of South Sumatra with a distribution area in the district of Pampangan (OganIlir and OganOganIlir). Suspected inbreeding causes decreased phenotypic properties. Inbreeding among various swamp buffalo is certainly not only lower the qualities but also genotypes and phenotypes. It is of interest to determine kinship variants swamp buffaloes from Pampangan through the analysis of a blood protein profile. Blood protein profile of four variants swamps buffalo was studied by using five electrophoresis system i.e. pre-albumin (Palb), albumin (Alb), ceruloplasmin (Cp), transferrin (Tf) and transferrin post (Ptf). In this paper, it is obtained that there was no significant differences among the four variants of the buffaloes were used as a sample. Prealbumin has two alleles (Palb1 and Palb2), albumin has three alleles (Alba, AlbB, AlbC), ceruloplasmin has one allele (BPA), post-transferrin has one allele (PTFA) with an allele frequency 1.0000 at any time transferrin has two alleles (TFA and TFB) with the allele frequency of 0.7500 and 1.0000. Characteristics prealbumin (Palb), albumin (Alb), ceruloplasmin (Cp), and post-transferrin (P-tf) is monomorphic, while transferrin is polymorphic average heterozygosity values all loci (H) 0.1286. Based on average heterozygosity, the swamp buffalo (Bubalusbubalis) from Pampangan has low genetic variation and closest genetic relationship.

Temperature effects on gene expression and morphological development of European eel, Anguilla anguilla larvae

DEFF Research Database (Denmark)

Politis, Sebastian Nikitas; Mazurais, David; Servili, Arianna

2017-01-01

°C as the optimal temperature for offspring of European eel. Furthermore, our results suggest that the still enigmatic early life history stages of European eel may inhabit the deeper layer of the Sargasso Sea and indicate vulnerability of this critically endangered species to increasing ocean......Temperature is important for optimization of rearing conditions in aquaculture, especially during the critical early life history stages of fish. Here, we experimentally investigated the impact of temperature (16, 18, 20, 22 and 24°C) on thermally induced phenotypic variability, from larval hatch...

Simulated migration of European eel (Anguilla anguilla, Linnaeus 1758)

NARCIS (Netherlands)

Ginneken, van V.J.T.

2006-01-01

The European eel ( Anguillaanguilla L.) is a catadromic fish species with its spawning grounds thousands of kilometers away in the ocean, possibly theSargasso Sea. The objective of this study was to elucidate this oceanic phase of migration

The exploitation of swamp plants for dewatering liquid sewage sludge

Directory of Open Access Journals (Sweden)

Jiří Šálek

2006-01-01

Full Text Available The operators of little rural wastewater treatment plants have been interested in economic exploitation of sewage sludge in local conditions. The chance is searching simply and natural ways of processing and exploitation stabilized sewage sludge in agriculture. Manure substrate have been obtained by composting waterless sewage sludge including rest plant biomass after closing 6–8 years period of filling liquid sewage sludge to the basin. Main attention was focused on exploitation of swamp plants for dewatering liquid sewage sludge and determination of influence sewage sludge on plants, intensity and course of evapotranspiration and design and setting of drying beds. On the base of determined ability of swamp plants evapotranspiration were edited suggestion solutions of design and operation sludge bed facilities in the conditions of small rural wastewater treatment plant.

Ecological study of the migration of eel by synchrotron radiation induced X-ray fluorescence imaging of otoliths

International Nuclear Information System (INIS)

Nakai, I.; Iwata, R.; Tsukamoto, K.

1999-01-01

Synchrotron radiation-induced X-ray fluorescence imaging is suitable for determining the distribution of trace elements in fish otoliths. The Sr/Ca ratio in an otolith is an indicator of salinity changes and can be used to clarify the migration history of the eel, a catadromous fish. The otoliths of eel collected from the Tone and Elbe rivers exhibited a typical catadromous pattern, i.e. birth and breeding occurred in the ocean, but the remainder of their lives was spent in fresh water. In contrast, eels from the East China Sea and North Sea exhibited an unusual sea-locking phenomenon, as they appear to have remained in marine habitats throughout their lives. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Estimating and mitigating post-release mortality of European eel by combining citizen science with a catch-and-release angling experiment

NARCIS (Netherlands)

Weltersbach, Marc Simon; Weltersbach, Marc Simon; Strehlow, Harry Vincent; Ferter, Keno; Klefoth, Thomas; Graaf, de Martin; Graaf, de Martin; Dorow, Malte

2018-01-01

Several anguillid eel species have experienced severe population declines over the past decades, particularly the European eel (Anguilla anguilla), which is listed as critically endangered by the International Union for Conservation of Nature. To reduce fishing mortality, many European countries

Diseases of eels in an international perspective: Workshop on Eel Diseases at the 15th International Conference on Diseases of Fish and Shellfish, Split, Croatia, 2011

NARCIS (Netherlands)

Haenen, O.L.M.; Mladineo, I.; Konecny, R.; Yoshimizu, M.; Groman, D.; Munoz, P.; Saraiva, A.; Bergmann, S.M.; Beurden, van S.J.

2012-01-01

In recent years, significant attention has been assigned to the decline in the wild freshwater eel stocks worldwide. Possible causative factors include fisheries (overfishing), habitat loss, migration barriers, and chemical pollution, and/or a combination of these factors. Infectious diseases

Applications of STEM-EELS to complex oxides

KAUST Repository

Gá zquez, Jaume; Sá nchez-Santolino, Gabriel; Biškup, Neven; Roldá n, Manuel A.; Cabero, M.; Pennycook, Stephen J.; Varela, Marí a

2016-01-01

In this chapter we will review a few examples of applications of atomic resolution aberration corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) to complex oxide materials. These are most challenging systems where subtle changes in structure or chemistry may result in colossal responses in macroscopic physical behavior. Here, we will review how atomic resolution compositional mapping can be achieved in manganite thin films and single crystals, highlighting the importance of considering artifacts during quantification. Besides, minor changes in near edge fine structure may take place when the crystalline environment, and hence nearest neighbor configuration, is modified. These can also be tracked by atomic resolution EELS, as will be shown through the study of binary Fe oxides. Also, examples regarding the study of distributions of point defects such as O vacancies in cobaltite thin films will be discussed. In these materials, a combination of epitaxial strain and defects may promote physical behaviors not present in bulk, such as the stabilization of unexpected spin state superlattices. Last, a study of extended defects such as dislocation lines will be reviewed. In particular, we will show how chemical segregation at dislocation cores in yttria-stabilized zirconia grain boundaries results in the generation of static O vacancies that affect the local electrostatic potential and hence, the macroscopic ionic conduction properties. © 2016.

Applications of STEM-EELS to complex oxides

KAUST Repository

Gázquez, Jaume

2016-06-26

In this chapter we will review a few examples of applications of atomic resolution aberration corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) to complex oxide materials. These are most challenging systems where subtle changes in structure or chemistry may result in colossal responses in macroscopic physical behavior. Here, we will review how atomic resolution compositional mapping can be achieved in manganite thin films and single crystals, highlighting the importance of considering artifacts during quantification. Besides, minor changes in near edge fine structure may take place when the crystalline environment, and hence nearest neighbor configuration, is modified. These can also be tracked by atomic resolution EELS, as will be shown through the study of binary Fe oxides. Also, examples regarding the study of distributions of point defects such as O vacancies in cobaltite thin films will be discussed. In these materials, a combination of epitaxial strain and defects may promote physical behaviors not present in bulk, such as the stabilization of unexpected spin state superlattices. Last, a study of extended defects such as dislocation lines will be reviewed. In particular, we will show how chemical segregation at dislocation cores in yttria-stabilized zirconia grain boundaries results in the generation of static O vacancies that affect the local electrostatic potential and hence, the macroscopic ionic conduction properties. © 2016.

The hydrological function of upland swamps in eastern Australia: The role of geomorphic condition in regulating water storage and discharge

Science.gov (United States)

Cowley, Kirsten L.; Fryirs, Kirstie A.; Hose, Grant C.

2018-06-01

Temperate Highland Peat Swamps on Sandstone (THPSS) are a type of wetland found in low-order streams on the plateaus of eastern Australia. They are sediment and organic matter accumulation zones, which combined with a climate of high rainfall and low evaporation function as water storage systems. Changes to the geomorphic structure of these systems via incision and channelisation can have profound impacts on their hydrological function. The aim of this study was to develop an understanding of how changes to the geomorphic structure of these systems alter their hydrological function, measured as changes and variability in swamp water table levels and discharge. We monitored the water table levels and discharges of three intact and three channelised THPSS in the Blue Mountains between March 2015 and June 2016. We found that water levels in intact swamps were largely stable over the monitoring period. Water levels rose only in high rainfall events, returned quickly to antecedent levels after rain, and drawdown during dry periods was not significant. In contrast, the water table levels in channelised THPSS were highly variable. Water levels rose quickly after almost all rainfall events and declined significantly during dry periods. Discharge also showed marked differences with the channelised THPSS discharging 13 times more water than intact swamps, even during dry periods. Channelised THPSS also had flashier storm hydrographs than intact swamps. These results have profound implications for the capacity of these swamps to act as water storage reservoirs in the headwaters of catchments and for their ability to maintain base flow to downstream catchments during dry times. Changes to geomorphic structure and hydrological function also have important implications for a range of other swamp functions such as carbon storage, emission and exports, contaminant sorption, downstream water quality and biodiversity, as well as the overall fate of these swamps under a changing

SURVEY OF ECONOMIC TREES IN FRESH WATER SWAMP OF

African Journals Online (AJOL)

1

2011-05-16

May 16, 2011 ... availability because it determines the number of surviving individuals. This is true for all species of .... 2010). CRUTECH, Calabar forest is a pseudo forest having characteristics of rain and swamp forests. ... as reflected in the random and contiguous distribution. (clumped or aggregated population) of the ...

Construction of a BAC library and identification of Dmrt1 gene of the rice field eel, Monopterus albus

International Nuclear Information System (INIS)

Jang Songhun; Zhou Fang; Xia Laixin; Zhao Wei; Cheng Hanhua; Zhou Rongjia

2006-01-01

A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA from the rice field eel (Monopterus albus). The BAC library consists of a total of 33,000 clones with an average insert size of 115 kb. Based on the rice field eel haploid genome size of 600 Mb, the BAC library is estimated to contain approximately 6.3 genome equivalents and represents 99.8% of the genome of the rice field eel. This is first BAC library constructed from this species. To estimate the possibility of isolating a specific clone, high-density colony hybridization-based library screening was performed using Dmrt1 cDNA of the rice field eel as a probe. Both library screening and PCR identification results revealed three positive BAC clones which were overlapped, and formed a contig covering the Dmrt1 gene of 195 kb. By sequence comparisons with the Dmrt1 cDNA and sequencing of first four intron-exon junctions, Dmrt1 gene of the rice field eel was predicted to contain four introns and five exons. The sizes of first and second intron are 1.5 and 2.6 kb, respectively, and the sizes of last two introns were predicted to be about 20 kb. The Dmrt1 gene structure was conserved in evolution. These results also indicate that the BAC library is a useful resource for BAC contig construction and molecular isolation of functional genes

Effects of dietary fatty acid composition on metabolic rate and responses to hypoxia in the European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

McKenzie, D.J.; Piraccini, G.; Piccolella, M.

2000-01-01

European eels (Anguilla anguilla, L.) were fed on a commercial diet supplemented either with 15% by dry feed weight of menhaden oil (MO), an oil rich in highly unsaturated fatty acids of the n-3 series (n-3 HUFA), or with 15% by dry feed weight of coconut oil (CO), an oil composed primarily...... of saturated fatty acids (SFA). Following 90 days of feeding, the mean final masses of eels fed the two different oil supplements were similar, and higher than the mean final mass of a group fed the commercial diet alone. The diets created two distinct phenotypes of eels, distinguished by the fatty acid (FA...

Influence of Soil Type and Drainage on Growth of Swamp Chestnut Oak (Quercus Michauxii Nutt.) Seedlings

Science.gov (United States)

Donald D. Hook

1969-01-01

Swamp chestnut oak (Quercus michauxii Nutt.) seedlings were grown for 2 years in five soil types in drained and undrained pots. First-year height growth was related to soil type and pot drainage, but second-year height growth was related only to soil type. Results suggest that swamp chestnut oak is site-sensitive. But slow growth, a maximum of 2...

Influences of deforestation on radiation and heat balances in tropical peat swamp forest in Thailand

International Nuclear Information System (INIS)

Suzuki, S.; Ishida, T.; Nagano, T.; Matsukawa, S.

1997-01-01

The difference of radiation and heat balances between a natural peat swamp forest and a deforested secondary forest has been investigated in Narathiwat Province, Thailand. Micrometeorological measurements were conducted continuously on observation towers 38 m and 4 m in heights in the primary forest and the secondary forest respectively. Results show that the deforestation of peat swamp forest leads to an increase in the sensible heat flux in the secondary forest. The yearly average ratio of the sensible heat flux to the net radiation was 20.9% in the peat swamp forest, and 33.2% in the secondary forest from Aug. 1995 to Jul. 1996. A ratio more than 40% was observed only in the dry season in the secondary forest. The change in sensible heat flux seemed to be influenced by the change in ground water levels. (author)

Anthropogenic spreading of anguillid herpesvirus 1 by stocking of infected farmed European eels, Anguilla anguilla (L.), in the Schlei fjord in northern Germany.

Science.gov (United States)

Kullmann, B; Adamek, M; Steinhagen, D; Thiel, R

2017-11-01

The Schlei fjord in northern Germany is the recipient water of a comprehensive eel, Anguilla anguilla (L.), stocking programme. Since 2015, stocked eels become alizarin red S marked, but to date no control mechanism is implemented in this stock enhancement measure to prevent anthropogenic spreading of diseases. Consequentially, it was possible that farmed stocking cohorts of 2015 and 2016 (in total ca. 1040 kg) were subsequently tested positive for anguillid herpesvirus 1 (AngHV 1). For this study, 100 eels [total length (TL) 24.3-72.9 cm, age ca. 1-6 years] were caught in 2016 and investigated with regard to AngHV 1 infection, parasite load (Anguillicoloides crassus) and body conditions. 68% of the eels were found to be virus positive while larger specimens were more often infected. In addition, a fitted generalized linear model (area under the curve = 0.741) demonstrated that an increase in individual TL is accompanied with an increased risk of clinically relevant virus loads. Anguillicoloides crassus turned out to be an important stressor for eels, because parasite and virus load revealed a significant positive correlation. The results of this study evidently show the urgent need of a disease containment strategy for eel stocking programmes. © 2017 John Wiley & Sons Ltd.

Utilization of Organic Fertilizer on Sweet Corn (Zea mays saccharata Sturt Crop at Shallow Swamp Land

Directory of Open Access Journals (Sweden)

Midranisiah

2017-01-01

Full Text Available Shallow lowland swamp area has significant potential for cultivation of sweet corn crop. This lowland swamp has rich natural resources such as organic fertilizers from chicken dunk, cow dunk, oil palm fresh bunches and legume cover crops (LCC that are not maximally utilized yet by farmers. These organic fertilizers can be utilized to increase the growth and production of sweet corn crop. The research objective was to determine organic fertilizer types that capable to increase the growth and production of sweet corn crop at shallow lowland swamp area. This research had been conducted from January to April 2015 in Pulau Semambu Village, North Indralaya Subdistrict, Ogan Ilir District, South Sumatra Province. The design used in this research was non-factorial Randomized Block Design (RBD with four treatments of organic fertilizer types with six replications for each treatment. The treatments were consisted of organic fertilizers from chicken dunk, cow dunk, oil palm fresh bunches and legume cover crops (LCC. The results showed that treatment of organic fertilizers from chicken dunk could increase the growth and production of sweet corn at shallow lowland swamp area with yield level of 4.37 kg.plot −1.

Age and growth of the longfin eel, Anguilla mossambica Peters ...

African Journals Online (AJOL)

Otoliths were successfully used for age determination and growth-rate calculation of the longfin eel, Anguilla mossambica Peters, 1852. The large opaque nucleus of the otoliths represents the leptocephalid stage and probably lasts from one and a half to two years. Thereafter, one opaque and one hyaline zone is deposited ...

Nematode eel parasite found inside acanthocephalan cysts--a "Trojan horse" strategy?

Science.gov (United States)

Emde, Sebastian; Rueckert, Sonja; Kochmann, Judith; Knopf, Klaus; Sures, Bernd; Klimpel, Sven

2014-11-18

The invasive eel parasite Anguillicoloides crassus (syn. Anguillicola crassus) is considered one of the major causes for the decline of the European eel (Anguilla anguilla) panmictic population. It impairs the swim bladder function and reduces swimming performance of its host. The life cycle of this parasite involves different intermediate and paratenic hosts. Despite an efficient immune system of the paratenic fish hosts acting against infections with A. crassus, levels of parasitized eels remain high in European river systems. Recently, the round goby Neogobius melanostomus (Gobiidae) has become dominant in many rivers in Europe and is still spreading at a rapid pace. This highly invasive species might potentially act as an important, so far neglected paratenic fish host for A. crassus. Based on own observations and earlier single sightings of A. crassus in N. melanostomus, 60 fresh individuals of N. melanostomus were caught in the Rhine River and examined to assess the infection levels with metazoan parasites, especially A. crassus. Glycerin preparations were used for parasite identification. The parasite most frequently found in N. melanostomus was the acanthocephalan Pomphorhynchus sp. (subadult stage) which occurred mainly encysted in the mesenteries and liver. Every third gobiid (P = 31.7%) was infected by A. crassus larvae (L3) which exclusively occurred inside the acanthocephalan cysts. No intact or degenerated larvae of A. crassus were detected elsewhere in the goby, neither in the body cavity and mesenteries nor in other organs. Affected cysts contained the acanthocephalan larvae and 1-12 (mI =3) living A. crassus larvae. Additionally, encysted larvae of the nematode Raphidascaris acus were detected in the gobies, but only in the body cavity and not inside the acanthocephalan cysts. Based on our observations, we suggest that A. crassus might actively bypass the immune response of N. melanostomus by invading the cysts of acanthocephalan parasites of the

Report of mortmorilloniticas clay in the Medina swamp (Cerro Largo district)

International Nuclear Information System (INIS)

Gomez Rifas, C.; Heinzen, W.; Theune, C.

1980-01-01

This report describes the prospect ion work for the montmorillonitics clay in the region of Medina swamp in Cerro Largo district. The existence of new deposits was detected by cartography and geological study.

Hypotonicity induced K+ and anion conductive pathways activation in eel intestinal epithelium

DEFF Research Database (Denmark)

Lionetto, M G; Giordano, M E; De Nuccio, F

2005-01-01

, the activation of 'emergency' systems of rapid cell volume regulation is fundamental in their physiology. The aim of the present work was to study the physiological response to hypotonic stress in a salt-transporting epithelium, the intestine of the euryhaline teleost Anguilla anguilla. Eel intestinal epithelium......, when symmetrically bathed with Ringer solution, develops a net Cl- current giving rise to a negative transepithelial potential at the basolateral side of the epithelium. The eel intestinal epithelium responded to a hypotonic challenge with a biphasic decrease in the transepithelial voltage (V......(te)) and the short circuit current (I(sc)). This electrophysiological response correlated with a regulatory volume decrease (RVD) response, recorded by morphometrical measurement of the epithelium height. Changes in the transepithelial resistance were also observed following the hypotonicity exposure...

Diversity and Antagonistic Activity of Actinomycete Strains From Myristica Swamp Soils Against Human Pathogens

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Varghese Rlnoy

2014-05-01

Full Text Available Under the present investigation Actinomycetes were isolated from the soils of Myristica swamps of southern Western Ghats and the antagonistic activity against different human bacterial pathogens was evaluated. Results of the present study revealed that Actinomycetes population in the soils of Myristica swamp was spatially and seasonally varied. Actinomycetes load was varied from 24×104 to 71×103, from 129×103 to 40×103 and from 31×104 to 84×103 in post monsoon, monsoon and pre monsoon respectively. A total of 23 Actinomycetes strains belonging to six genera were isolated from swamp soils. Identification of the isolates showed that most of the isolates belonged to the genus Streptomyces (11, followed by Nocardia (6, Micromonospora (3, Pseudonocardia (1, Streptosporangium (1, and Nocardiopsis (1. Antagonistic studies revealed that 91.3% of Actinomycete isolates were active against one or more tested pathogens, of that 56.52% exhibited activity against Gram negative and 86.95% showed activity against Gram positive bacteria. 39.13% isolates were active against all the bacterial pathogens selected and its inhibition zone diameter was also high. 69.5% of Actinomycetes were exhibited antibacterial activity against Listeria followed by Bacillus cereus (65.21%, Staphylococcus (60.86%, Vibrio cholera (52.17%, Salmonella (52.17% and E. coli (39.13%. The results indicate that the Myristica swamp soils of Southern Western Ghats might be a remarkable reserve of Actinomycetes with potential antagonistic activity.

Silicone passive equilibrium samplers as ‘chemometers’ in eels and sediments of a Swedish lake

DEFF Research Database (Denmark)

Jahnke, Annika; Mayer, Philipp; McLachlan, Michael S.

2014-01-01

Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemica...... diagenesis and sorption to phytoplankton. The ‘chemometer’ approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments.......Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical...... activities of seven ‘indicator’ polychlorinated biphenyls (PCBs) and hexachlorobenzene in eels and sediments from a Swedish lake. Chemical concentrations in eels and sediments were also measured using exhaustive extraction methods. Lipid-normalized concentrations in eels were higher than organic carbon...

Kennedy Space Center: Swamp Works

Science.gov (United States)

DeFilippo, Anthony Robert

2013-01-01

When I began my internship with the Granular Mechanics and Regolith Operations laboratory (GMRO), also known as Swamp Works, I was given the unique opportunity to shadow many teams working on various projects, and decide what projects I wanted to take part in. Before I go into details of my experiences at Swamp Works, I would like to take a moment to explain what I discovered Swamp Works to be. Swamp Works is a family of hardworking, dedicated, and driven people from various backgrounds and skill sets. These people all work to advance technologies and make science fiction science fact through means of rapid prototyping. They support and encourage failure as an option when learning new things, as long as lesson learned from said failure. In fact, their motto states "Fail, Fast, Forward." What this means is, not if but when one fails he or she must do so quickly and spring forward from the failure so that his or her progress is not delayed. With this acceptance, it provided me the confidence to dive into a multitude of projects working in various fields and with a wide range of skill sets. The first project I joined was Badger. My motivation for taking on this project was the opportunity I would have to obtain valuable experience working with 3D modeling and 3D printing technologies. Badger was a digging apparatus to be used in a highly dusty environment in a material known as Regolith. Regolith is a scientific term for the dirt or top soil found on planetary bodies. Regolith contains a large quantity of sediments less than lOppm and as a result poses a challenge of keeping it out of any cracks and crevices. Furthermore, regolith can create high levels of electrostatic energy, which can prove damaging to sensitive electrical hardware. With these characteristics in mind, I decided to take on the task of designing and manufacturing a dust proof cover for the sensitive electrical hardware. When I began this project, I did not have the slightest idea as to how to use 3D

Utilization of agro-industrial by-products by swamp buffalo

International Nuclear Information System (INIS)

Jelan, Z.A.; Jalaludin, S.; Vijchulata, P.

1987-01-01

A series of studies were conducted to determine the factors affecting the utilization of palm press fibre (PPF) by swamp buffaloes. The nutritive values, fermentation and rumen kinetics, intake and growth responses to a PPF based diet with or without protein and energy supplementation were studied. Palm press fibre was considered a poor quality feed as it is low in crude protein (about 6%) and high in lignin content (about 21%). Dry matter (DM) disappearance from nylon bags at 48 h was low (about 40%) as compared with grass (47%), oaten hay (49%) and lucerne (64%). Sodium hydroxide (8% solution) was most effective as a treating agent as the DM disappearance of PPF from the nylon bags at 48 h was increased by 14%. Dry matter loss from the bags was greater in swamp buffaloes than in cattle. Rumen fluid volume and flow rate were not significantly (P>0.05) increased with fish meal supplementation, but the total dry matter intake (DMI) increased significantly (P<0.05) when 360 g DM/d fish meal was supplemented. Total volatile fatty acid (VFA) concentrations were low in unsupplemented animals and the molar proportions of the VFAs were typical of those seen in the rumen fluid of ruminants fed a fibre based diet. Rumen ammonia-nitrogen was high (40-70 mg/L) in fish meal supplemented animals. When urea treated PPF was supplemented with fish meal and cassava, the animals showed significant increases (P<0.05) in average daily gain and in both total DMI and in the DMI of a basal diet. The study concludes that supplementation with rumen undegradable protein and an energy source are essential to a PPF based diet and that untreated PPF is not a suitable basal diet for swamp buffaloes. (author)

Integrating habitat restoration and fisheries management : A small-scale case-study to support EEL conservation at the global scale

Directory of Open Access Journals (Sweden)

Ciccotti E.

2013-02-01

Full Text Available The aim of this work was to develop a methodological framework for the management of local eel stocks that integrates habitat restoration with optimal fishery management. The Bolsena lake (Viterbo, Italy and its emissary, the river Marta, were taken as a reference system. The river flows in the Mediterranean sea but its course is fragmented by a number of dams built in the past century preventing eel migration from and to the sea. Eel fishery in the Bolsena lake is thus sustained by periodic stocking of glass eels caught at the Marta river estuary. A detailed demographic model was applied to simulate fishery yields and potential spawner escapement under different recruitment and management scenarios. It was estimated that the high exploitation rates occurring in the nineties reduced the potential spawner escapement from the Bolsena lake to less than 1 t; under current harvesting rates, the potential spawner escapement is estimated in about 12 t while in pristine conditions (i.e. high recruitment and no fishing estimated spawner escapement is about 21 t. This analysis thus showed that current fishery management would comply with the 40% spawner escapement requirement of the EU regulation 1100/2007 if the connections between the Bolsena lake emissary and the sea were fully re-established. This confirms the opportunity of an integrated approach to management at the catchment area level scale for eel populations, that shall hopefully contribute to the conservation of the global stock.

Are persistent organic pollutants and metals in eel muscle predictive for the ecological water quality?

International Nuclear Information System (INIS)

Van Ael, Evy; Belpaire, Claude; Breine, Jan; Geeraerts, Caroline; Van Thuyne, Gerlinde; Eulaers, Igor; Blust, Ronny; Bervoets, Lieven

2014-01-01

Relationships between the presence of PCBs, OCPs and metals in aquatic ecosystems and the ecological water quality were investigated by combining datasets of long-term monitoring of chemicals in European eel (Anguilla anguilla, N = 1156) in Flanders (Belgium) and the Ecological Quality Ratio (EQR), based on the assessment of fish assemblages at 185 locations. For most pollutants, EQR scores were lower when pollutant levels were higher. Threshold concentrations for a good quality could be formulated for PCB's, most metals and OCPs. Mixed models suggested that the ecological water quality was significantly correlated with the presence of PCBs. However, the low R 2 indicates that other environmental pressures may significantly influence the biotic integrity of fish communities. Empirical data and their analyses are essential to enable defining threshold values of bioaccumulated levels to allow better protection of the aquatic environment and its biota through associated food webs as demanded by the Water Framework Directive. -- Highlights: • Relation between ecological water quality and pollution load in eel was studied. • Ecological Quality Ratio was lower when concentrations in eel were higher. • Threshold levels for a good quality status were formulated. • EQS possibly too stringent for Hg and too high for Cd and Pb compared to our results. • Mixed models suggest a significant influence of PCBs on ecological water quality. -- The ecological water quality, as reflected in the biotic integrity of fish communities, is lower when concentrations of PCBs, OCPs and metals in locally sampled eels are higher

Present status of fish culture using warm waste water from power plants

International Nuclear Information System (INIS)

1976-01-01

The research of fish culture using warm waste water from power stations in Japan has history of over ten years. It is being gradually commercialized, but still various problems remain. Among the fish culture activities, those related to nuclear power generation are described as follows: Tokai ponds of Warm Water Fish Culture Development Society of Japan (culturing crimson sea bream, ear shell, flatfish, prawn, and eel); Fukui Prefectural Fisheries Experimental Station (culturing sweetfish and young yellowtail); and, Warm Water Utilization Center of Shizuoka Prefecture (culturing ear shell). (Mori, K.)

Residu Gula Glikokonjugat pada Lambung Depan Kerbau Rawa (Bubalus bubalis Kalimantan Selatan (SUGAR RESIDU OF GLYCOCONJUGATES IN FORESTOMACH OF SOUTH KALIMANTAN SWAMP BUFFALO (BUBALUS BUBALIS

Directory of Open Access Journals (Sweden)

Anni Nurliani

2014-08-01

Full Text Available The ability of swamp buffaloes to adapt with swamp environment was suggested to be supported bytheir digestive system efficiency. The research was done to obtain scientific explanation about digestiveefficiency of swamp buffalo by identification on kinds and distribution of glycoconjugates in swamp buffaloforestomach. Six male swamp buffaloes aged more than 2.5 year old and had body weight between 300-400kg were used in this study. Samples were obtained from Regency of Banjar slaughter house, SouthKalimantan. Every parts of the forestomach included rumen, reticulum, and omasum was taken andprocessed for microscopic observation with hematoxyline eosin (HE and alcian blue-periodic acid schiff(AB-PAS stainings. Sugar residues of glycoconjugates were localized with lectin histochemistry wheatgerm agglutinin (WGA, ulex europaeus agglutinin (UEA, ricinus communis agglutinin (RCA, concanavalinagglutinin (Con A, and soybean agglutinin (SBA. Every part of swamp buffalo forestomach had kinds ofspecific glycoconjugates with special distribution pattern which were different with other ruminant, andwere suitable for their functions in that part. The existence of D mannose/D glucose glycoconjugates thatwas dominant in forestomach estimated that had important role in supporting fermentative digestionfunction in swamp buffalo, through its function as receptor bacteria attachment. This is suggested as aspecial characteristic in digestive system of swamp buffalo which causes high digestive efficiency inswamp buffalo.

High-resolution EELS investigation of the electronic structure of ilmenites

NARCIS (Netherlands)

Radtke, G.; Lazar, S.; Botton, G.A.

2006-01-01

The electronic structure of a series of compounds belonging to the ilmenite family is investigated using high resolution electron energy loss spectroscopy (EELS). The energy loss near edge structure (ELNES) of the O-K, Ti-L23 and transition metal L23 edges have been recorded in MnTiO3, FeTiO3,

Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

Science.gov (United States)

Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

2015-01-01

Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

Rich soil carbon and nitrogen but low atmospheric greenhouse gas fluxes from North Sulawesi mangrove swamps in Indonesia.

Science.gov (United States)

Chen, Guang C; Ulumuddin, Yaya I; Pramudji, Sastro; Chen, Shun Y; Chen, Bin; Ye, Yong; Ou, Dan Y; Ma, Zhi Y; Huang, Hao; Wang, Jing K

2014-07-15

The soil to atmosphere fluxes of greenhouse gases N2O, CH4 and CO2 and their relationships with soil characteristics were investigated in three tropical oceanic mangrove swamps (Teremaal, Likupang and Kema) in North Sulawesi, Indonesia. Mangrove soils in North Sulawesi were rich in organic carbon and nitrogen, but the greenhouse gas fluxes were low in these mangroves. The fluxes ranged -6.05-13.14 μmol m(-2)h(-1), -0.35-0.61 μmol m(-2)h(-1) and -1.34-3.88 mmol m(-2)h(-1) for N2O, CH4 and CO2, respectively. The differences in both N2O and CH4 fluxes among different mangrove swamps and among tidal positions in each mangrove swamp were insignificant. CO2 flux was influenced only by mangrove swamps and the value was higher in Kema mangrove. None of the measured soil parameters could explain the variation of CH4 fluxes among the sampling plots. N2O flux was negatively related to porewater salinity, while CO2 flux was negatively correlated with water content and organic carbon. This study suggested that the low gas emissions due to slow metabolisms would lead to the accumulations of organic matters in North Sulawesi mangrove swamps. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of methods to determine sperm density for the european eel, anguilla anguilla

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Gallego, V.; Pérez, L.

2013-01-01

, computer-assisted sperm analysis (CASA) and flow cytometry (FCM), using Neubauer Improved haemocytometer as benchmark. Initially, relationships between spermatocrit, haemocytometer counts and sperm motility were analysed, as well as the effect of sperm dilution on haemocytometer counts. Furthermore......, accuracy and precision of spermatocrit, applying a range of G-forces, were tested and the best G-force used in method comparisons. We found no effect of dilution on haemocytometer sperm density estimates, whereas motility associated positively with haemocytometer counts, but not with spermatocrit. Results......European eel, Anguilla anguilla, is a target species for future captive breeding, yet best methodology to estimate sperm density for application in in vitro fertilization is not established. Thus, our objectives were to evaluate methods to estimate European eel sperm density including spermatocrit...

Reflex bradycardia does not influence oxygen consumption during hypoxia in the European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

Iversen, Nina Kerting; McKenzie, David; Malte, H.

2010-01-01

the bradycardia on oxygen consumption (MO2), standard metabolic rate (SMR) and the critical oxygen partial pressure for regulation of SMR in hypoxia (Pcrit) in European eels Anguilla anguilla (mean ± SEM mass 528 ± 36 g; n = 14). Eels were instrumented with a Transonic flow probe around the ventral aorta......Most teleost fish reduce heart rate when exposed to acute hypoxia. This hypoxic bradycardia has been characterised for many fish species, but it remains uncertain whether this reflex contributes to the maintenance of oxygen uptake in hypoxia. Here we describe the effects of inhibiting...

Study, using stable isotopes, of flow distribution, surface-groundwater relations and evapotranspiration in the Okavango Swamp, Botswana

International Nuclear Information System (INIS)

Dincer, T.; Hutton, L.G.; Kupee, B.B.J.

1979-01-01

Stable isotope data collected in the Okavango Delta have confirmed that the central distributary system is more active at present than the peripheral systems. The data also show that there is no groundwater outflow at the western and southern margins of the delta. A salinity-isotope model of the deltaic swamp has been developed to study the relation between the salinity and isotopic composition of the swamp waters. An attempt has been made to separate the atmospheric losses from the swamp into its evapotranspiration components. The results indicate that in winter, when high water levels prevail, these losses are almost entirely due to evaporation whilst in summer, when the water levels are low, evaporation and transpiration contribute almost equally to the total atmospheric losses. (author)

The Effects of Corrosive Chemicals on Corrosion Rate of Steel Reinforcement Bars: II. Swamp Sludges

Directory of Open Access Journals (Sweden)

Henki Ashadi

2010-10-01

Full Text Available A polluted environment will influence the building age. The objective of this research was to find out the influence of corrosive chemicals within the sludge swamp area with the corrosion rate of steel concrete. Corrosion in steel concrete usually occur in acid area which contain of SO42-, Cl- and NO3-. The research treatment used by emerging ST 37 andST 60 within 60 days in 'polluted' sludge swamp area. Three variation of 'polluted' swamp sludge were made by increasing the concentration a corrosive unsure up to 1X, 5X and 10X. The corrosion rate measured by using an Immersion Method. The result of Immersion test showed that sulphate had a greatest influence to corrosion rate of ST 37 and ST 60 and followed by chloride and nitrate. Corrosion rate value for ST 37 was 17.58 mpy and for ST 60 was 12.47 mpy.

Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

Directory of Open Access Journals (Sweden)

Wei Yang

2018-04-01

Full Text Available The neurohypophyseal hormone oxytocin (Oxt has been shown to stimulate prolactin (Prl synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr, namely isotocin (Ist receptor 1 (Istr1 and 2 (Istr2, were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

Science.gov (United States)

Yang, Wei; Zhang, Ning; Shi, Boyang; Zhang, Shen; Zhang, Lihong; Zhang, Weimin

2018-01-01

The neurohypophyseal hormone oxytocin (Oxt) has been shown to stimulate prolactin (Prl) synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr), namely isotocin (Ist) receptor 1 (Istr1) and 2 (Istr2), were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh) cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

Ammonia stress under high environmental ammonia induces Hsp70 and Hsp90 in the mud eel, Monopterus cuchia.

Science.gov (United States)

Hangzo, Hnunlalliani; Banerjee, Bodhisattwa; Saha, Shrabani; Saha, Nirmalendu

2017-02-01

The obligatory air-breathing mud eel (Monopterus cuchia) is frequently being challenged with high environmental ammonia (HEA) exposure in its natural habitats. The present study investigated the possible induction of heat shock protein 70 and 90 (hsp70, hsc70, hsp90α and hsp90β) genes and more expression of Hsp70 and Hsp90 proteins under ammonia stress in different tissues of the mud eel after exposure to HEA (50 mM NH 4 Cl) for 14 days. HEA resulted in significant accumulation of toxic ammonia in different body tissues and plasma, which was accompanied with the stimulation of oxidative stress in the mud eel as evidenced by more accumulation of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) during exposure to HEA. Further, hyper-ammonia stress led to significant increase in the levels of mRNA transcripts for inducible hsp70 and hsp90α genes and also their translated proteins in different tissues probably as a consequence of induction of hsp70 and hsp90α genes in the mud eel. However, hyper-ammonia stress was neither associated with any significant alterations in the levels of mRNA transcripts for constitutive hsc70 and hsp90β genes nor their translated proteins in any of the tissues studied. More abundance of Hsp70 and Hsp90α proteins might be one of the strategies adopted by the mud eel to defend itself from the ammonia-induced cellular damages under ammonia stress. Further, this is the first report of ammonia-induced induction of hsp70 and hsp90α genes under hyper-ammonia stress in any freshwater air-breathing teleost.

ANGUILLICOLOSIS AMONG SILVER EELS: A 2-YEAR SURVEY IN 4 HABITATS FROM CAMARGUE (RHÔNE DELTA, SOUTH OF FRANCE

Directory of Open Access Journals (Sweden)

LEFEBVRE F.

2003-07-01

Full Text Available We have investigated the spread of the infection by Anguillicola crassus among the silver phase of the European eel Anguilla anguilla in the Rhône delta. We reported values of prevalence, mean intensity and abundance in 4 habitats and we revealed negative relationships between these parasitic parameters and values of salinity (prevalence from 52 % in brackish waters to 77 % in fresh waters. We have also assessed the health state of the infected organ, i.e. the swimbladder. This may be a way to check the parasitic history of individuals throughout their continental phase. In silver eels free from parasites, the proportion of past infected individuals was ranged between 40 % and 78 %. When adding individuals showing worms at the autopsy with those showing signs of past infection(s, we highlighted a great proportion of silver eels really affected by anguillicolosis (from 71 % to 95 %, with a negative relationship in respect to salinity values. So, considering the spread of the infection, and its potential impairments on body condition, gas exchanges, hydrostatic abilities, etc., one may legitimately question about the proportion of silver eels that may get back to the Sargasso sea and reproduce.

Association between trichodiniasis in eel ( Anguilla anguilla ) and water quality in recirculation systems

DEFF Research Database (Denmark)

Madsen, H.C.K.; Buchmann, K.; Mellergaard, Stig

2000-01-01

Association between various water quality parameters and the infection level of Trichodina jadranica in cultured eels were examined in nine recirculation farms in Denmark. Production units suffering from trichodiniasis (n = 4) had relatively high contents of organic dry matter (13-65 mg l(-1)), low...... concentrations of nitrate (150-500 mg NO3 l(-1)) and high pH (6.2-7.4) in the process water compared to farms without Trichodina problems (n = 5), which had a relatively low load of organic dry matter (9-16 mg l(-1)), high nitrate concentration (250-900 mg NO3 l(-1)) and a low pH (5.3-6.9). More detailed studies...... of the effect of water parameters on the infection level were conducted in two production units suffering from frequent outbreaks of trichodiniasis. In one production unit, the high and highly varying content of organic dry matter (21- 83 mg l(-1)) was significantly and positively correlated (r = 0.37, p

Effects of acute and chronic experimental contamination on direct cesium 137 uptake by the eel, Anguilla anguilla L

International Nuclear Information System (INIS)

Foulquier, Luc; Lambrechts, Alain.

1982-03-01

This study covers the effects of different types of contamination on direct cesium 137 uptake by the eel. In the first experiment (acute contamination), simulating a waste discharge, the fish were kept in water with a rapidly decreasing cesium 137 activity. In a second experiment (chronic contamination), the water activity increased constantly, simulating increasing waste frequency and activity levels. Irrespective of the type of contamination, radiocesium retention by eels is low ( [fr

Net ecosystem CO2 exchange of a primary tropical peat swamp forest in Sarawak, Malaysia

Science.gov (United States)

Tang Che Ing, A.; Stoy, P. C.; Melling, L.

2014-12-01

Tropical peat swamp forests are widely recognized as one of the world's most efficient ecosystems for the sequestration and storage of carbon through both their aboveground biomass and underlying thick deposits of peat. As the peat characteristics exhibit high spatial and temporal variability as well as the structural and functional complexity of forests, tropical peat ecosystems can act naturally as both carbon sinks and sources over their life cycles. Nonetheless, few reports of studies on the ecosystem-scale CO2 exchange of tropical peat swamp forests are available to-date and their present roles in the global carbon cycle remain uncertain. To quantify CO2 exchange and unravel the prevailing factors and potential underlying mechanism regulating net CO2 fluxes, an eddy covariance tower was erected in a tropical peat swamp forest in Sarawak, Malaysia. We observed that the diurnal and seasonal patterns of net ecosystem CO2 exchange (NEE) and its components (gross primary productivity (GPP) and ecosystem respiration (RE)) varied between seasons and years. Rates of NEE declined in the wet season relative to the dry season. Conversely, both the gross primary productivity (GPP) and ecosystem respiration (RE) were found to be higher during the wet season than the dry season, in which GPP was strongly negatively correlated with NEE. The average annual NEE was 385 ± 74 g C m-2 yr-1, indicating the primary peat swamp forest functioned as net source of CO2 to the atmosphere over the observation period.

Mapping swamp timothy (Cripsis schenoides) seed productivity using spectral values and vegetation indices in managed wetlands

Energy Technology Data Exchange (ETDEWEB)

Rahilly, P.J.A.; Li, D.; Guo, Q.; Zhu, J.; Ortega, R.; Quinn, N.W.T.; Harmon, T.C.

2010-01-15

This work examines the potential to predict the seed productivity of a key wetland plant species using spectral reflectance values and spectral vegetation indices. Specifically, the seed productivity of swamp timothy (Cripsis schenoides) was investigated in two wetland ponds, managed for waterfowl habitat, in California's San Joaquin Valley. Spectral reflectance values were obtained and associated spectral vegetation indices (SVI) calculated from two sets of high resolution aerial images (May 11, 2006 and June 9, 2006) and were compared to the collected vegetation data. Vegetation data were collected and analyzed from 156 plots for total aboveground biomass, total aboveground swamp timothy biomass, and total swamp timothy seed biomass. The SVI investigated included the Simple Ratio (SR), Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), Transformed Soil Adjusted Vegetation Index (TSAVI), Modified Soil Adjusted Vegetation Index (MSAVI), and Global Environment Monitoring Index (GEMI). We evaluated the correlation of the various SVI with in situ vegetation measurements for linear, quadratic, exponential and power functions. In all cases, the June image provided better predictive capacity relative to May, a result that underscores the importance of timing imagery to coincide with more favorable vegetation maturity. The north pond with the June image using SR and the exponential function (R{sup 2}=0.603) proved to be the best predictor of swamp timothy seed productivity. The June image for the south pond was less predictive, with TSAVI and the exponential function providing the best correlation (R{sup 2}=0.448). This result was attributed to insufficient vegetal cover in the south pond (or a higher percentage of bare soil) due to poor drainage conditions which resulted in a delay in swamp timothy germination. The results of this work suggest that spectral reflectance can be used to estimate seed productivity in managed seasonal

Adaptive Evolution of Eel Fluorescent Proteins from Fatty Acid Binding Proteins Produces Bright Fluorescence in the Marine Environment.

Directory of Open Access Journals (Sweden)

David F Gruber

Full Text Available We report the identification and characterization of two new members of a family of bilirubin-inducible fluorescent proteins (FPs from marine chlopsid eels and demonstrate a key region of the sequence that serves as an evolutionary switch from non-fluorescent to fluorescent fatty acid-binding proteins (FABPs. Using transcriptomic analysis of two species of brightly fluorescent Kaupichthys eels (Kaupichthys hyoproroides and Kaupichthys n. sp., two new FPs were identified, cloned and characterized (Chlopsid FP I and Chlopsid FP II. We then performed phylogenetic analysis on 210 FABPs, spanning 16 vertebrate orders, and including 163 vertebrate taxa. We show that the fluorescent FPs diverged as a protein family and are the sister group to brain FABPs. Our results indicate that the evolution of this family involved at least three gene duplication events. We show that fluorescent FABPs possess a unique, conserved tripeptide Gly-Pro-Pro sequence motif, which is not found in non-fluorescent fatty acid binding proteins. This motif arose from a duplication event of the FABP brain isoforms and was under strong purifying selection, leading to the classification of this new FP family. Residues adjacent to the motif are under strong positive selection, suggesting a further refinement of the eel protein's fluorescent properties. We present a phylogenetic reconstruction of this emerging FP family and describe additional fluorescent FABP members from groups of distantly related eels. The elucidation of this class of fish FPs with diverse properties provides new templates for the development of protein-based fluorescent tools. The evolutionary adaptation from fatty acid-binding proteins to fluorescent fatty acid-binding proteins raises intrigue as to the functional role of bright green fluorescence in this cryptic genus of reclusive eels that inhabit a blue, nearly monochromatic, marine environment.

Aluminum and iron contents in phosphate treated swamp rice farm ...

African Journals Online (AJOL)

In 2006 aluminum and iron contents were determined in phosphate treated swamp rice farm of Mbiabet, Akwa Ibom State. The objectives were to determine the aluminum and iron contents, the effect of drying, phosphate and lime application in an acid sulphate soil grown to rice in Nigeria. The soil samples used were ...

Changes in body weight and eye size in female European eel kept in fresh and salt water

Directory of Open Access Journals (Sweden)

Joanna Nowosad

2014-05-01

Full Text Available The eel is a catadromous fish which spends most of its life in freshwater and adults swim to the Sargasso Sea region to spawn. While preparing for the reproductive process, eels undergo a metamorphosis to become what is called silver eel; a process involving changes in the colour and weight of the body and an increase in the eye size. These are indicators of fish maturity and they facilitate the selection of fish for reproduction under controlled conditions. During this study, changes in the body weight (BW and eye size in female European eel were observed while being given weekly hormonal injections of 20 mg kg–1 carp pituitary homogenate and kept in 15°C freshwater and in 15°C saltwater with a salinity of 32-33‰. Fish kept in saltwater but not subjected to hormonal stimulation were used as a control group. Furthermore, after the experiment was finished, females in the control group were kept for next 5 months, with the same environmental parameters maintained. Differences between the treated groups were observed as early as week 4 of the experiment. An increase in fish BW was observed in fish kept both in salt and freshwater which were subjected to hormonal stimulation. On the other hand, changes in eye size were observed in the fish kept in saltwater, both in those hormonally stimulated and otherwise. The eye diameter in the fish kept in fresh after hormonal stimulation did not change significantly.

Species Turnover across Different Life Stages from Seedlings to Canopy Trees in Swamp Forests of Central Brazil

Directory of Open Access Journals (Sweden)

Clarissa G. Fontes

2015-01-01

Full Text Available Processes driving the assembly of swamp forest communities have been poorly explored. We analyzed natural regeneration and adult tree communities data of a swamp gallery forest in Central Brazil to discuss the role of ecological filters in shaping plant species turnover in a successional gradient. Species data of 120 plots were used to assess species turnover between natural regeneration and adult tree communities. Our analyses were based on 4995 individuals belonging to 72 species. Community patterns were discerned using ordination analyses. A clear floristic turnover among plant life stages was distinguished. Regeneration community of swamp forests was richer in species composition than the adult community. Tree species commonly found in nonflooded gallery forests were present in the regeneration plots but not in the adult community. Differences in the floristic composition of these two strata suggest that not all species in the seedling stage can stand permanent flooding conditions and only a few tolerant species survive to become adult trees. We propose that natural disturbances play an important role by altering limiting resources, allowing seeds of nonflooded forest species to germinate. This paper elucidates the turnover between plant life stages in swamp forests and suggests mechanisms that may shape these communities.

A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata).

Science.gov (United States)

SongLin, Guo; PanPan, Lu; JianJun, Feng; JinPing, Zhao; Peng, Lin; LiHua, Duan

2015-04-01

The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of oestradiol-enriched diet and of feeding with porcine testicular tissue on macroscopic gonadal sex in European eels

DEFF Research Database (Denmark)

Andersen, D.; Boetius, I.; Larsen, L.O.

1996-01-01

days there were 44% with female-gonads, 40% with male+female-gonads and 16% with male-gonads. Oestradiol thus had a feminizing effect, not only on morphologically undifferentiated gonads but also on morphologically differentiated male-gonads. The presence of sex steroid hormones or their precursors...... and 78% of oestradiol-treated eels developed female-gonads. Minced porcine testicular tissue fed to 2-g eels for up to 371 days had effects similar to oestradiol-enriched food (68% with female-gonads), whereas feeding for only 91 days had no effect during the next 8 months. Oestradiol-enriched food...... in porcine testicular tissue may also exert a feminizing influence. In all experiments the hormone-fed groups showed a tendency (not significant) towards increased growth rate. In small eels early rapid growth and differentiation of female-gonads were clearly correlated, both in hormone treated...

Project conservation and handling for the multiple uses and the development of the swamps of Colombia

International Nuclear Information System (INIS)

Sanchez Paez, Heliodoro

1998-01-01

In Colombia the swamps are distributed in the Atlantic and Pacific coasts; they are located in areas with conditions of pluvial precipitation that varies from annual 200 mm in the Guajira department; nine species of mangroves have registered for Colombia, which are related following a zonation starting from the tide line, still when this pattern not always stays and it depends on the influence of diverse factors and local conditions. The project conservation and handling for the multiple use and the development of the swamps of Colombia, had as objectives; to watch and to control the parameters of salinity, level of water and flow to laminate and of strengthening the generation of alternative productive social and environmentally appropriate for the sustainable use, guaranteeing their conservation and preservation of the swamps. The project was developed in two phases, one of diagnostic and planning and the other of dynamics of growth, phenology and natural regeneration

The socio-cultural importance of Mauritia flexuosa palm swamps (aguajales) and implications for multi-use management in two Maijuna communities of the Peruvian Amazon.

Science.gov (United States)

Gilmore, Michael P; Endress, Bryan A; Horn, Christa M

2013-04-22

Fruit from the palm Mauritia flexuosa (aguaje) is harvested throughout the Peruvian Amazon for subsistence and commercial purposes. Recent estimates suggest that residents of Iquitos, the largest city in the region, consume approximately 148.8 metric tons of aguaje fruit per month, the vast majority of which is harvested by felling and killing adult female trees. In this study, we sought to better understand and document the importance of M. flexuosa palm swamps (aguajales) in two Maijuna indigenous communities to inform the sustainable management of this habitat and species. Semi-structured interviews, focus groups, and household surveys were carried out to assess the significance of aguajales and their associated plant and animal resources as well as to determine how the relationship that the Maijuna have with aguajales has changed over time. Aguajales and their associated resources are culturally significant and useful to the Maijuna in a wide variety of ways. In addition to M. flexuosa, the Maijuna use over 60 different species of plants from aguajales. When M. flexuosa is in fruit, aguajales are important hunting areas with a total of 20 different animal species hunted. The Maijuna also have traditional beliefs about aguajales, believing that malevolent supernatural beings reside in them. Notably, the relationship that the Maijuna have with aguajales has changed considerably over the years as aguaje fruit went from a subsistence item collected opportunistically from the ground to a market good destructively harvested beginning in the early 1990s. The Maijuna are concerned not only about how this has affected the future commercial harvest of aguaje but also about its effects on game animals given the importance of hunting to Maijuna cultural identity, subsistence, and income generation. In order to meet the multiple socio-cultural and economic needs of the Maijuna, sustainable management efforts must be expanded to not only focus on the commercial harvest of

Energy-filtered TEM imaging and EELS study of ODS particles and argon-filled cavities in ferritic-martensitic steels.

Science.gov (United States)

Klimiankou, M; Lindau, R; Möslang, A

2005-01-01

Oxide-dispersion-strengthened (ODS) ferritic-martensitic steels with yttrium oxide (Y(2)O(3)) have been produced by mechanical alloying and hot isostatic pressing for use as advanced material in fusion power reactors. Argon gas, usually widely used as inert gas during mechanical alloying, was surprisingly detected in the nanodispersion-strengthened materials. Energy-filtered transmission electron microscopy (EFTEM) and electron energy loss spectroscopy (EELS) led to the following results: (i) chemical composition of ODS particles, (ii) voids with typical diameters of 1-6 nm are formed in the matrix, (iii) these voids are filled with Ar gas, and (iv) the high-density nanosized ODS particles serve as trapping centers for the Ar bubbles. The Ar L(3,2) energy loss edge at 245 eV as well as the absorption features of the ODS particle elements were identified in the EELS spectrum. The energy resolution in the EEL spectrum of about 1.0 eV allows to identify the electronic structure of the ODS particles.

Biocontrol for Rhizoctonia Stem Rot Disease by Using Combination of Specific Endophyte in Paddy Tidal Swamp

OpenAIRE

Budi, Ismed Setya; Mariana, Mariana

2013-01-01

The use of combination of specific endophytic in tidal swamps to control stem root disease as biological control agents has not been done. It is expected that this combination is able to continuously protect plants from pathogen interference. The research was carried out in type C tidal swamp in Banjar regency of South Kalimantan, from March to November 2011, temperature 29-32oC, and pH 4.0-5.5. The method used was Split Plot design. Biocontrol preparation for both types of endophytic was ap...

Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

International Nuclear Information System (INIS)

Nelson, E.A.

2000-01-01

The Savannah River Swamp is a 3020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy's Savannah River Site (SRS) near Aiken, SC. Historically the swamp consisted of approximately 50 percent bald cypress-water tupelo stands, 40 percent mixed bottomland hardwood stands, and 10 percent shrub, marsh, and open water. Creek corridors were typical of Southeastern bottomland hardwood forests. The hydrology was controlled by flooding of the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream dams have caused some alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950's. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. Flow in one of the tributaries, Pen Branch, was typically 0.3 m3 s-1 (10-20) cfs prior to reactor pumping and 11.0 m3 s-1 (400 cfs) during pumping. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 65 degrees C. The nearly continuous flooding of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. In the years since pumping was reduced, early succession has begun in some affected areas. Most of this has been herbs, grasses, and shrubs. Areas that have seedlings are generally willow

Determination of some individual chlorobiphenyls in eel-fat with capillary gaschromatography: collaborative study

NARCIS (Netherlands)

Tuinstra, L.G.M.T.; Roos, A.H.; Werdmuller, G.A.

1984-01-01

A method for the determination of six individual chlorobiphenyls in eel-fat, based on saponification of the sample and determination with capillary gas chromatography, was studied collaboratively. Eleven laboratories submitted analytical results in duplo of six individual chlorbiphenyls on two

Anguilla rostrata glass eel migration and recruitment in the estuary and Gulf of St Lawrence.

Science.gov (United States)

Dutil, J-D; Dumont, P; Cairns, D K; Galbraith, P S; Verreault, G; Castonguay, M; Proulx, S

2009-06-01

This study describes catches of Anguilla rostrata glass eels and associated oceanographic conditions in the St Lawrence Estuary and Gulf. Ichthyoplankton survey data suggest that they enter the Gulf primarily in May, migrate at the surface at night, and disperse broadly once they have passed Cabot Strait. They arrive in estuaries beginning at about mid-June and through the month of July. Migration extends west up to Québec City, in the freshwater zone of the St Lawrence Estuary, 1000 km west of Cabot Strait. Anguilla rostrata glass eels travel between Cabot Strait and receiving estuaries at a straight-line ground speed of c. 10-15 km day(-1). Catches of fish per unit effort in estuaries in the St Lawrence system are much lower than those reported for the Atlantic coast of Canada. Low abundance of A. rostrata glass eels in the St Lawrence system may be due to cold surface temperatures during the migration period which decrease swimming capacity, long distances from the spawning ground to Cabot Strait and from Cabot Strait to the destination waters (especially the St Lawrence River), complex circulation patterns, and hypoxic conditions in bottom waters of the Laurentian Channel and the St Lawrence Estuary.

TEMPORAL VEGETATION DYNAMICS IN PEAT SWAMP AREA USING MODIS TIME-SERIES IMAGERY: A MONITORING APPROACH OF HIGH-SENSITIVE ECOSYSTEM IN REGIONAL SCALE

Directory of Open Access Journals (Sweden)

Yudi Setiawan

2016-10-01

Full Text Available Peat swamp area is an essential ecosystem due to high vulnerability of functions and services. As the change of forest cover in peat swamp area has increased considerably, many studies on peat swamp have focused on forest conversion or forest degradation. Meanwhile, in the context of changes in the forestlands are the sum of several processes such as deforestation, reforestation/afforestation, regeneration of previously deforested areas, and the changing spatial location of the forest boundary. Remote sensing technology seems to be a powerful tool to provide information required following that concerns. A comparison imagery taken at the different dates over the same locations for assessing those changes tends to be limited by the vegetation phenology and land-management practices. Consequently, the simultaneous analysis seems to be a way to deal with the issues above, as a means for better understanding of the dynamics changes in peat swamp area. In this study, we examined the feasibility of using MODIS images during the last 14 years for detecting and monitoring the changes in peat swamp area. We identified several significant patterns that have been assigned as the specific peat swamp ecosystem. The results indicate that a different type of ecosystem and its response to the environmental changes can be portrayed well by the significant patterns. In understanding the complex situations of each pattern, several vegetation dynamics patterns were characterized by physical land characteristics, such as peat depth, land use, concessions and others. Characterizing the pathways of dynamics change in peat swamp area will allow further identification for the range of proximate and underlying factors of the forest cover change that can help to develop useful policy interventions in peatland management.

Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing

DEFF Research Database (Denmark)

Sparrevohn, Claus Reedtz; Storr-Paulsen, Marie

2012-01-01

Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing. – ICES Journal of Marine Science, 69: 323–330.Marine recreational fishing is a popular outdoor activity in Denmark, practised by both anglers and passive gear fishers....... However, the impact on the targeted stocks is unknown, so to estimate the 2009 harvest of cod Gadus morhua and eel Anguilla anguilla, two separate interview-based surveys were initiated and carried out in 2009/2010. The first recall survey exclusively targeted fishers who had been issued......, in certain areas, the recreational harvest of cod accounted for more than 30% of the total yield. The majority (81%) of the recreational cod harvest was taken by anglers. Eels, however, are almost exclusively caught with passive gear (fykenets) and a total of 104 t year−1 was harvested, which corresponds...

Toxicological effect of herbicides (diuron and bentazon) on snake venom and electric eel acetylcholinesterase.

Science.gov (United States)

Ahmed, Mushtaq; Latif, Nadia; Khan, Rehmat Ali; Ahmad, Akhlaq

2012-08-01

The toxicological effects of the active ingredients of the herbicides diuron and bentazon on the activity of acetylcholinesterase (AChE) of krait (Bungarus sindanus) venom and electric eel (Electrophorus electricus) were studied. The diuron and entazon caused non-competitive inhibition of AChE from both species. For the venom AChE, the calculated IC50 for diuron and bentazon were found to be 3.25 and 0.14 μM, while for eel AChE, the respective IC50 values were 3.6 and 0.135 μM. In comparison, bentazon was a more potent inhibitor than diuron of AChE from both species. The insecticide lindane did not have any inhibitory effect on AChE activity in either species, even when tested at high concentrations (200-800 μM).

A physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals in the European eel (Anguilla anguilla)

International Nuclear Information System (INIS)

Brinkmann, Markus; Freese, Marko; Pohlmann, Jan-Dag; Kammann, Ulrike; Preuss, Thomas G.; Buchinger, Sebastian; Reifferscheid, Georg; Beiermeister, Anne; Hanel, Reinhold; Hollert, Henner

2015-01-01

The European eel (Anguilla anguilla) is a facultatively catadromous fish species with a complex life cycle. Its current population status is alarming: recruitment has decreased drastically since the 1980s and its stock is still considered to be outside safe biological limits. Although there is no consensus on the reasons for this situation, it is currently thought to have resulted from a combination of different stressors, including anthropogenic contaminants. To deepen our understanding of the processes leading to the accumulation of lipophilic organic contaminants in yellow eels (i.e. the feeding, continental growth stage), we developed a physiologically based toxicokinetic model using our own data and values from the literature. Such models can predict the uptake and distribution of water-borne organic chemicals in the whole fish and in different tissues at any time during exposure. The predictive power of the model was tested against experimental data for six chemicals with n-octanol-water partitioning coefficient (log K ow ) values ranging from 2.13–4.29. Model performance was excellent, with a root mean squared error of 0.28 log units. This model has the potential to help identify suitable habitats for restocking under eel management plans. - Highlights: • A PBTK model was developed for European eel (Anguilla anguilla). • Own experimental data and data from the literature were used for parameterization. • The predictive power of the model was excellent, with RMSE of 0.28 log units. • The developed model can be amended with sub-models for dietary and dermal exposure

A physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals in the European eel (Anguilla anguilla)

Energy Technology Data Exchange (ETDEWEB)

Brinkmann, Markus [Department of Ecosystem Analysis, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); Freese, Marko; Pohlmann, Jan-Dag; Kammann, Ulrike [Thünen Institute of Fisheries Ecology, Hamburg (Germany); Preuss, Thomas G. [Environmental Biology and Chemodynamics, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); Buchinger, Sebastian; Reifferscheid, Georg [Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Koblenz (Germany); Beiermeister, Anne; Hanel, Reinhold [Thünen Institute of Fisheries Ecology, Hamburg (Germany); Hollert, Henner, E-mail: Henner.hollert@bio5.rwth-aachen.de [Department of Ecosystem Analysis, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing (China); College of Resources and Environmental Science, Chongqing University, Chongqing (China); Key Laboratory of Yangtze Water Environment, Ministry of Education, Tongji University, Shanghai 200092 (China)

2015-12-01

The European eel (Anguilla anguilla) is a facultatively catadromous fish species with a complex life cycle. Its current population status is alarming: recruitment has decreased drastically since the 1980s and its stock is still considered to be outside safe biological limits. Although there is no consensus on the reasons for this situation, it is currently thought to have resulted from a combination of different stressors, including anthropogenic contaminants. To deepen our understanding of the processes leading to the accumulation of lipophilic organic contaminants in yellow eels (i.e. the feeding, continental growth stage), we developed a physiologically based toxicokinetic model using our own data and values from the literature. Such models can predict the uptake and distribution of water-borne organic chemicals in the whole fish and in different tissues at any time during exposure. The predictive power of the model was tested against experimental data for six chemicals with n-octanol-water partitioning coefficient (log K{sub ow}) values ranging from 2.13–4.29. Model performance was excellent, with a root mean squared error of 0.28 log units. This model has the potential to help identify suitable habitats for restocking under eel management plans. - Highlights: • A PBTK model was developed for European eel (Anguilla anguilla). • Own experimental data and data from the literature were used for parameterization. • The predictive power of the model was excellent, with RMSE of 0.28 log units. • The developed model can be amended with sub-models for dietary and dermal exposure.

Approaches for the environmental evaluation of two swamp complexes of the Momposina depression

International Nuclear Information System (INIS)

Caballero, Humberto; Durango, Consuelo

1998-01-01

The swamp complexes of the Momposina depression in the lower Magdalena River have been submitted to irrational exploitation, transformation and contamination mainly since the beginning of the century, process that has be en getting worse in the last decade. The most evident manifestation of the environmental deterioration is expressed by the drastic reduction of fishing, with important socio-economic effects to the population that lives from this source. The most notorious causes of the actual state of the ecosystem were detected, and some preliminary considerations for its management are presented. However, due to the modifications that the complexes have suffered (closure of the natural sewer, construction of jarillones, modifications of the internal water flows and sediments, over exploitation, of fish and herpetofauna), the deterioration of the limnologic conditions is moderated, which allows to begin recuperation plans. The major impacts were observed in the fauna of birds and reptiles associated to the swamps; the decrease of the ictics populations seems to be related to the strong impact generated by the fishing action used and the interruption of the natural cycles of fish. The possibility of rebuilding the communication swamp-river should be studied with care because it seems the system has arrived to new conditions. The re-opening of the sewers could mean a new unbalanced condition represented mainly by the contamination coming from the Magdalena River

XPS and EELS characterization of Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Grosvenor, A.P., E-mail: andrew.grosvenor@usask.ca [Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9 (Canada); Bellhouse, E.M., E-mail: erika.bellhouse@arcelormittal.com [Global R & D—Hamilton, ArcelorMittal Dofasco, 1330 Burlington St. E, Hamilton, ON L8N 3J5 (Canada); Korinek, A., E-mail: korinek@mcmaster.ca [Canadian Centre for Electron Microscopy, Brockhouse Institute for Materials Research, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada); Bugnet, M., E-mail: bugnetm@mcmaster.ca [Canadian Centre for Electron Microscopy, Brockhouse Institute for Materials Research, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada); McDermid, J.R., E-mail: mcdermid@mcmaster.ca [Steel Research Centre, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada)

2016-08-30

Graphical abstract: XPS and EELS spectra were acquired from Mn2Al2O4, MnSiO3 and Mn2SiO4 standards and unique features identified that will allow unambiguous identification of these compounds when studying the selective oxidation of advanced steels. - Highlights: • Mn2Al2O4, MnSiO3 and Mn2SiO4 standards were synthesized and characterized using both XPS and EELS. • Unique features in both the XPS high resolution and EELS spectra were identified for all compounds. • The spectra can be used to identify these compounds when studying the selective oxidation of steels. - Abstract: X-ray Photoelectron Spectroscopy (XPS) and Electron Energy Loss Spectroscopy (EELS) are strong candidate techniques for characterizing steel surfaces and substrate-coating interfaces when investigating the selective oxidation and reactive wetting of advanced high strength steels (AHSS) during the continuous galvanizing process. However, unambiguous identification of ternary oxides such as Mn{sub 2}SiO{sub 4}, MnSiO{sub 3}, and MnAl{sub 2}O{sub 4} by XPS or EELS, which can play a significant role in substrate reactive wetting, is difficult due to the lack of fully characterized standards in the literature. To resolve this issue, samples of Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4} were synthesized and characterized by XPS and EELS. The unique features of the XPS and EELS spectra for the Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4} standards were successfully derived, thereby allowing investigators to fully differentiate and identify these oxides at the surface and subsurface of Mn, Si and Al alloyed AHSS using these techniques.

Tolerance of chronic hypercapnia by the European eel Anguilla anguilla

DEFF Research Database (Denmark)

McKenzie, D J; Piccolella, M; Dalla Valle, A Z

2003-01-01

European eels were exposed for 6 weeks to water CO(2) partial pressures (P(CO)(2)) from ambient (approx. 0.8 mmHg), through 15+/-1 mmHg and 30+/-1 mmHg to 45+/-1 mmHg in water with a total hardness of 240 mg l(-1) as CaCO(3), pH 8.2, at 23+/-1 degrees C. Arterial plasma P(CO)(2) equilibrated at a...

A review of the possible impacts of long-term oceanic and climate changes and fishing mortality on recruitment of anguillid eels of the Northern Hemisphere.

Science.gov (United States)

Knights, B

2003-07-01

Possible causes of declines in recruitment of European, American and Japanese eels to continental waters are reviewed. Negative correlations between the Den Oever glass eel recruitment index (DOI) and the North Atlantic Oscillation Index since 1938 are discussed, together with older anecdotal evidence. Correlations are established between the DOI and sea surface temperature anomalies at 100-250 m between 1952 and 1995 in the Sargasso Sea/Sub-Tropical Gyre (STG) spawning area. It is hypothesised that, associated with global warming trends, STG warming inhibits spring thermocline mixing and nutrient circulation, with negative impacts on productivity and hence food for leptocephalus larvae. Concurrent gyre spin-up also affects major currents and slowing of oceanic migration has probably enhanced starvation and predation losses. Local factors, such as unfavourable wind-driven currents, can also affect recruitment of glass eels on continental shelves. In contrast, evidence is discussed that indicates fishing mortality and continental climate change appear to have had lesser impacts. Similar starvation-advection explanations for declines in Japanese eel recruitment are proposed. Predictions for the future are made and multidisciplinary and integrated monitoring and research are recommended for managing eel stocks and fisheries.

Gelatinous plankton is central to the diet of European eel (Anguilla anguilla) larvae in the Sargasso Sea

DEFF Research Database (Denmark)

Ayala, Daniel Jiro; Munk, Peter; Lundgreen, Regitze B. C.

2018-01-01

endangered species. Next-generation 18S rRNA gene sequencing data of Sargasso Sea eel larvae gut contents and marine snow aggregates was compared with a reference plankton database to assess the trophic relations of eel larvae. Gut contents of A. anguilla larvae were not well explained by the eukaryotic...... composition of marine snow aggregates; gut contents being dominated by gene sequences of Hydrozoa taxa (phylum Cnidaria), while snow aggregates were dominated by Crustacea taxa. Pronounced differences between gut contents and marine snow aggregates were also seen in the prokaryotic 16S rRNA gene composition...

Greenhouse gas efflux from an impacted Malaysian tropical peat swamp (Invited)

Science.gov (United States)

Waldron, S.; Vihermaa, L. E.; Evers, S.; Garnett, M.; Newton, J.; Padfield, R.

2013-12-01

Tropical peatlands constitute ~11% of global peatland area and ~12% of the global peat C pool. Malaysia alone contains 10% of tropical peats. Due to rising global demands for food and biofuels, SE-Asia peat swamp forest ecosystems are threatened by increasing amounts of drainage, fire and conversion to plantation. These processes can change the GHG emissions and thus net ecosystem C balance. However, in comparison to temperate and boreal peatlands, there is a lack of data on terrestrial-aquatic-atmospheric carbon transfer from tropical peatlands, both those that are little disturbed and those facing anthropogenic pressures. Lateral transport of soil-respired carbon, and fluvial respiration or UV-oxidation of terrestrial DOC primes atmospheric carbon dioxide efflux. We now know that DOC lost from disturbed tropical peat swamp forests can be centuries to millennia old and originates deep within the peat column - this carbon may fuel efflux of old carbon dioxide and so anthropogenic land-use change renders the older, slower carbon cycles shorter and faster. Currently we have no knowledge of how significant ';older-slower' terrestrial-aquatic-atmospheric cycles are in disturbed tropical peatlands. Further, in some areas for commercial reasons, or by conservation bodies trying to minimise peat habitat loss, logged peats have been left to regenerate. Consequently, unpicking the legacy of multiple land uses on magnitude, age and source of GHG emissions is challenging but required to support land management decisions and projections of response to a changing climate. Here, we present the results of our first field campaign in July 2013 to the Raja Musa and Sungai Karang Peat Swamp Forest Reserves in North Selangor, Malaysia. This is one of Malaysia's largest oceanic peat swamps, and has been selectively logged and drained for 80 years, but is now subject to a 30 year logging ban to aid forest regeneration and build up wood stocks. From sites subject to different land use

Salinity reduction benefits European eel larvae: Insights at the morphological and molecular level

DEFF Research Database (Denmark)

Politis, Sebastian Nikitas; Mazurais, David; Servili, Arianna

2018-01-01

. Moreover, larvae were able to keep energy metabolism related gene expression (atp6, cox1) at stable levels, irrespective of the salinity reduction. As such, when reducing salinity, an energy surplus associated to reduced osmoregulation demands and stress (lower nkcc, aqp and hsp expression), likely......European eel (Anguilla anguilla) is a euryhaline species, that has adapted to cope with both, hyper- and hypo-osmotic environments. This study investigates the effect of salinity, from a morphological and molecular point of view on European eel larvae reared from 0 to 12 days post hatch (dph......). Offspring reared in 36 practical salinity units (psu; control), were compared with larvae reared in six scenarios, where salinity was decreased on 0 or 3 dph and in rates of 1, 2 or 4 psu/day, towards iso-osmotic conditions. Results showed that several genes relating to osmoregulation (nkcc2α, nkcc2β, aqp1...

Influence of the North Atlantic oceanograghic and climatic parameters on the Spanish European Eel population recruitment: relationships in the past and for a future climate change

Science.gov (United States)

Ribalaygua, Jaime; Pórtoles, Javier; Monjo, Robert; Díaz, Estíbaliz; Korta, María; Chust, Guillem

2016-04-01

The status of the European eel population is critical.; the annual recruitment of glass eel to European waters in 2015 is 1.2% of the 1960-1979 level in the 'North Sea' area, and 8.4% in the rest of Europe (ICES 2015) . There are a number of anthropogenic impacts potentially affecting eel population including commercial exploitation, habitat loss, dam and weir construction, hydropower, pumping stations and surface water abstractions. Furthermore, the first eel stages and larval migration and marine survival are heavily influenced by oceanic and climatic factors since the species breeds in the Sargasso Sea and migrates to the continental shelf of the Atlantic coast of Europe and North Africa. Therefore, the study of the relations between recruitment and oceanic conditions may allow to study the potential effect of climatic change on the future eel recruitment and therefore stock. In the present study, the relation between glass eel recruitment and oceanic and climatic factors has been studied. Historic glass eel catches data beginning in the 50s from two Mediterranean and two Atlantic estuaries have been used as a proxy of recruitment. The relation of catches with the main oceanographic and climatic factors identified in the literature was established using an ocean reanalysis, the Simple Ocean Data Assimilation (SODA) and determined which variables are significantly related to the number of catches. The analysis shows significant relationships between catches and oceanic (Surface Downward Stress, Sea Water Temperature and Sea Water Velocity) and atmospheric (NAO Index, AMO Index) variables. Subsequently, we applied the results of three climate models (GFDL-ESM2M, CanESM2 and CNRM-CM5), associated with the Coupled Model Intercomparison Project Phase 5 (CMIP5) under two simulations of climate change (RCP4.5 and RCP8.5), both associated with the 5th Assessment Report of the IPCC, for possible future influences on the eel. This research was funded by the Spanish

Mapping Upper Amazon Palm Swamps with Spaceborne L-band Synthetic Aperture Radar

Science.gov (United States)

Pinto, N.; McDonald, K. C.; Podest, E.; Schroeder, R.; Zimmermann, R.; Horna, V.

2010-12-01

Palm swamp ecosystems are widespread in the Amazon basin, forming where seasonal flooding is moderate and surface inundation persists. Recent studies suggest that palm swamps have a disproportional role on tropical biogeochemistry: the combination of persistently saturated soils, warm temperatures, and low oxygen soils can support significant land-atmosphere methane flux. Potential impacts of climate change on these ecosystems include changes in temperature and precipitation regimes that influence primary productivity and flood extent significantly, potentially reversing net land-atmosphere carbon exchanges regionally. Data acquired from Earth-orbiting satellites provides the opportunity to characterize vegetation structure and monitor surface inundation independently of cloud cover. Building on efforts under our NASA MEaSUREs project for assembly of a global-scale Earth System Data Record (ESDR) of inundated wetlands, we develop and evaluate a systematic approach to map the distribution and composition of palm swamps in the upper Amazon using data sets from JAXA’s Advanced Land Observing Satellite (ALOS) Phased Array L-Band SAR (PALSAR). Our input dataset consists of HH backscatter images acquired in 2007 and 2009. Ground measurements for training were obtained from a study site near Loreto, Peru (4.43S 75.34W) containing the palm species Mauritia flexuosa. The ALOS PALSAR images are first averaged temporally and spatially. We then develop ancillary data layers of flood extent, distance from open water, and SAR image texture. The PALSAR data and derived ancillary layers are combined with MODIS Vegetation Indices and SRTM elevation and input in a classification framework. Since palm swamps are found in persistently flooded areas, we evaluate the potential of identifying and mapping these ecosystems using multi-temporal SAR-based flood extent maps. We conclude by comparing the performance between a decision-tree supervised vs. unsupervised approach and by

An otolith microchemistry study of possible relationships between the origins of leptocephali of European eels in the Sargasso Sea and the continental destinations and relative migration success of glass eels

DEFF Research Database (Denmark)

Martin, J.; Daverat, F.; Pécheyran, C.

2010-01-01

's core region of Anguilla anguilla leptocephali caught in the Sargasso Sea in 2007 with those of glass eels and elvers sampled in European estuaries during 2006, 2008 and 2009. Using laser ablation inductively coupled plasma mass spectrometry, the same annular ablation trajectory along the first feeding...

Perinatal programming of depressive-like behavior by inflammation in adult offspring mice whose mothers were fed polluted eels: Gender selective effects.

Science.gov (United States)

Soualeh, Nidhal; Dridi, Imen; Eppe, Gauthier; Némos, Christophe; Soulimani, Rachid; Bouayed, Jaouad

2017-07-01

Several lines of evidence indicate that early-life inflammation may predispose to mental illness, including depression, in later-life. We investigated the impact of perinatal exposure to polluted eels on neonatal, postnatal, and adult brain inflammation, and on the resignation behavior of male and female adult offspring mice. The effects of maternal standard diet (laboratory food) were compared to the same diet enriched with low, intermediate, or highly polluted eels. Brain inflammatory markers including cytokines were assessed in offspring mice on the day of birth (i.e., on the postnatal day-PND 1), upon weaning (PND 21) and at adulthood (PND 100). Plasma myeloperoxidase and corticosterone levels were evaluated at PND 100. Immobility behavior of offspring was assessed in adulthood (i.e., at PNDs 95-100), using the tail suspension and forced swimming tests. Chronic brain inflammation was found in male and female offspring mice compared to controls, as assessed at PNDs 1, 21, and 100. The level of myeloperoxidase was found to be significantly higher in both adult males and females vs. control offspring. However, high corticosterone levels were only found in male offspring mice that were perinatally exposed to eels, suggesting a gender-selective dysregulation of the adult hypothalamic-pituitaryadrenal (HPA) axis. Gender-specific differences were also detected in adulthood in regard to offspring resignation behavior. Thus, compared to controls, males, but not females, whose mothers were fed eels during pregnancy and lactation exhibited a depressive-like behavior in adult age in both behavioral models of depression. Depressive symptoms were more pronounced in male mice perinatally exposed to either intermediate or highly polluted eels than those exposed to only lowly polluted eels. Our results indicate that early-life inflammatory insult is a plausible causative factor that induces the depressive phenotype exhibited by male adult offspring mice, most likely through a

Capture of cell culture-derived influenza virus by lectins: strain independent, but host cell dependent.

Science.gov (United States)

Opitz, Lars; Zimmermann, Anke; Lehmann, Sylvia; Genzel, Yvonne; Lübben, Holger; Reichl, Udo; Wolff, Michael W

2008-12-01

Strategies to control influenza outbreaks are focused mainly on prophylactic vaccination. Human influenza vaccines are trivalent blends of different virus subtypes. Therefore and due to frequent antigenic drifts, strain independent manufacturing processes are required for vaccine production. This study verifies the strain independency of a capture method based on Euonymus europaeus lectin-affinity chromatography (EEL-AC) for downstream processing of influenza viruses under various culture conditions propagated in MDCK cells. A comprehensive lectin binding screening was conducted for two influenza virus types from the season 2007/2008 (A/Wisconsin/67/2005, B/Malaysia/2506/2004) including a comparison of virus-lectin interaction by surface plasmon resonance technology. EEL-AC resulted in a reproducible high product recovery rate and a high degree of contaminant removal in the case of both MDCK cell-derived influenza virus types demonstrating clearly the general applicability of EEL-AC. In addition, host cell dependency of EEL-AC was studied with two industrial relevant cell lines: Vero and MDCK cells. However, the choice of the host cell lines is known to lead to different product glycosylation profiles. Hence, altered lectin specificities have been observed between the two cell lines, requiring process adaptations between different influenza vaccine production systems.

Spectrum image analysis tool - A flexible MATLAB solution to analyze EEL and CL spectrum images.

Science.gov (United States)

Schmidt, Franz-Philipp; Hofer, Ferdinand; Krenn, Joachim R

2017-02-01

Spectrum imaging techniques, gaining simultaneously structural (image) and spectroscopic data, require appropriate and careful processing to extract information of the dataset. In this article we introduce a MATLAB based software that uses three dimensional data (EEL/CL spectrum image in dm3 format (Gatan Inc.'s DigitalMicrograph ® )) as input. A graphical user interface enables a fast and easy mapping of spectral dependent images and position dependent spectra. First, data processing such as background subtraction, deconvolution and denoising, second, multiple display options including an EEL/CL moviemaker and, third, the applicability on a large amount of data sets with a small work load makes this program an interesting tool to visualize otherwise hidden details. Copyright © 2016 Elsevier Ltd. All rights reserved.

An electric-eel-inspired soft power source from stacked hydrogels

Science.gov (United States)

Schroeder, Thomas B. H.; Guha, Anirvan; Lamoureux, Aaron; Vanrenterghem, Gloria; Sept, David; Shtein, Max; Yang, Jerry; Mayer, Michael

2017-12-01

Progress towards the integration of technology into living organisms requires electrical power sources that are biocompatible, mechanically flexible, and able to harness the chemical energy available inside biological systems. Conventional batteries were not designed with these criteria in mind. The electric organ of the knifefish Electrophorus electricus (commonly known as the electric eel) is, however, an example of an electrical power source that operates within biological constraints while featuring power characteristics that include peak potential differences of 600 volts and currents of 1 ampere. Here we introduce an electric-eel-inspired power concept that uses gradients of ions between miniature polyacrylamide hydrogel compartments bounded by a repeating sequence of cation- and anion-selective hydrogel membranes. The system uses a scalable stacking or folding geometry that generates 110 volts at open circuit or 27 milliwatts per square metre per gel cell upon simultaneous, self-registered mechanical contact activation of thousands of gel compartments in series while circumventing power dissipation before contact. Unlike typical batteries, these systems are soft, flexible, transparent, and potentially biocompatible. These characteristics suggest that artificial electric organs could be used to power next-generation implant materials such as pacemakers, implantable sensors, or prosthetic devices in hybrids of living and non-living systems.

An electric-eel-inspired soft power source from stacked hydrogels.

Science.gov (United States)

Schroeder, Thomas B H; Guha, Anirvan; Lamoureux, Aaron; VanRenterghem, Gloria; Sept, David; Shtein, Max; Yang, Jerry; Mayer, Michael

2017-12-13

Progress towards the integration of technology into living organisms requires electrical power sources that are biocompatible, mechanically flexible, and able to harness the chemical energy available inside biological systems. Conventional batteries were not designed with these criteria in mind. The electric organ of the knifefish Electrophorus electricus (commonly known as the electric eel) is, however, an example of an electrical power source that operates within biological constraints while featuring power characteristics that include peak potential differences of 600 volts and currents of 1 ampere. Here we introduce an electric-eel-inspired power concept that uses gradients of ions between miniature polyacrylamide hydrogel compartments bounded by a repeating sequence of cation- and anion-selective hydrogel membranes. The system uses a scalable stacking or folding geometry that generates 110 volts at open circuit or 27 milliwatts per square metre per gel cell upon simultaneous, self-registered mechanical contact activation of thousands of gel compartments in series while circumventing power dissipation before contact. Unlike typical batteries, these systems are soft, flexible, transparent, and potentially biocompatible. These characteristics suggest that artificial electric organs could be used to power next-generation implant materials such as pacemakers, implantable sensors, or prosthetic devices in hybrids of living and non-living systems.

Tolerance of hypercapnic acidosis by the European eel, Anguilla anguilla

DEFF Research Database (Denmark)

McKenzie, DJ; Dalla Valle, AZ; Steffensen, JF

2000-01-01

to progressive hypercapnia (20 min at Pw,CO2 values of 10, 20, 40, 60 and 80 mmHg) caused a linear increase in arterial PCO2 (Pa,CO2) from 3.5 ± 0.4 mmHg in normocapnia to 44.9 ± 2.6 at Pw,CO2 = 80 mmHg, coupled to respective declines in arterial pH (pHa) from 7.86 ± 0.02 to 7.16 ± 0.04 and in arterial total O2...... content (ca,O2) from 9.6 ± 0.7 to 2.0 ± 0.5 vol%. There was a significant increase in fG and POP at Pw,CO2 values of 10, 20, 40 mmHg, then a decline in fG but further increase in POP at Pw,CO2 = 60 and 80 mmHg. Despite the severe acidosis and hypoxaemia, there were no significant effects on CO or O2...... uptake. Eels exposed for 3 months to chronic hypercapnia (Pw,CO2 values of control, 15, 30 or 45 mmHg) were anaesthetised, cannulated and recovered as described above, at the appropriate Pw,CO2. In all groups, Pa,CO2 was about 3 mmHg above Pw,CO2, and hypercapnic eels exhibited a marked accumulation...

Poliitkommunikatsioon kohalike valimiste eel / Liisa Past, Tarvo Sarmet, Taavi Pukk ... [jt.] ; intervjueerinud Küllike Heide

Index Scriptorium Estoniae

2013-01-01

Lähenevate kohalike valimiste eel poliitilise kommunikatsioonitegevuse korraldusest praegustes parlamendierakondades. Mõtteid jagavad Liisa Past ja Tarvo Sarmet Sotsiaaldemokraatlikust Erakonnast, Taavi Pukk Keskerakonnast, Gerrit Mäesalu IRL-st ning Silver Pukk Reformierakonnast

The effect of para-nonylphenol on Japanese eel (Anguilla japonica) spermatogenesis in vitro

International Nuclear Information System (INIS)

Miura, C.; Takahashi, N.; Michino, F.; Miura, T.

2005-01-01

Endocrine disrupters have been recognized to interfere with endocrine systems that regulate reproduction, for example, by mimicking or inhibiting the action of endogenous sex steroid hormones including estradiol-17β (E2). In the present study, we examined the effect of an endocrine disrupter, para-nonylphenol (p-NP) on spermatogenesis, and compared it with the action of E2, using an eel testicular organ culture system. p-NP alone stimulated early spermatogonial renewal in the same manner as E2. Neither induced further progress in spermatogenesis. In the presence of 11-ketotestosterone (11-KT), the major androgen in teleosts, p-NP did not prevent the 11-KT-induced progress in spermatogenesis. However, this treatment enlarged the Sertoli cells. Electron microscopic observation revealed that enlarged Sertoli cells contained well-developed organelles. Moreover, the proportion of germ cells appeared to have decreased as a result of Sertoli cell hypertrophy. These results clearly show that p-NP has an effect on Sertoli cells in the presence of an androgen (11-KT), potentially disturbing 11-KT-induced spermatogenesis

Convergent evolution of jaws between spinosaurid dinosaurs and pike conger eels

Directory of Open Access Journals (Sweden)

Romain Vullo

2016-12-01

Full Text Available Spinosaurs represent a group of peculiar theropod dinosaurs that have often been described as “crocodile-mimic”, predominantly fish-eating predators, and recently claimed to have been semi-aquatic animals. Here we report a suite of craniodental characters unexpectedly shared by spinosaurs and pike conger eels. Pike conger eels are predatory, mainly piscivorous bottom-dwelling anguilliform fishes that inhabit marine and brackish environments. These two groups of dinosaurs and fishes show a mediolaterally compressed, elongated rostrum, a terminal “rosette” bearing enlarged teeth in both upper and lower jaws, and a notch posterior to the premaxillary “rosette” characterized by the presence of reduced teeth. The morphological convergence observed in the jaws of these two distantly related groups of vertebrates may result from similar feeding behaviours. This typical jaw morphology likely represents an effective biomechanical adaptation for biting and grabbing elusive prey items in low-light aquatic environments. Associated with this specialized snout morphology, numerous integumentary mechanoreceptors involved in prey detection are present in both spinosaurs and pike congers. Our new observations provide an additional convincing argument regarding the decades-long and widely debated lifestyle of spinosaurs.

Functional Analysis of Promoter Region from Eel Cytochrome P450 1A1 Gene in Transgenic Medaka.

Science.gov (United States)

Ogino; Itakura; Kato; Aoki; Sato

1999-07-01

: Transcription of the CYP1A1 genes in mammals and fish is stimulated by polyaromatic hydrocarbons. DNA sequencing analysis revealed that CYP1A1 gene in eel (Anguilla japonica) contains two kinds of putative cis-acting regulatory elements, XRE (xenobiotic-responsive element) and ERE (estrogen-responsive element). XRE is known as the enhancer that is responsible for the inducibility of the genes of CYP1A1 and some other drug-metabolizing enzymes. In the eel CYP1A1 gene, XRE motifs are distributed as follows: five times in the region from -2136 to -1125 bp, XRE(-6) to (-2); once in the proximal basal promoter region, XRE(-1); and once in the first intron, XRE(+1). The region between XRE(-2) and XRE(-1) contains three ERE motifs. To investigate the function of the cis-acting regulatory elements in the eel CYP1A1 gene, recombinant plasmids prepared with its 5' upstream sequence and the structural gene for luciferase were microinjected into fertilized eggs of medaka at the one-cell stage. Hatched fry were treated with 3-methylcholanthrene, and the transcription efficiency was assayed using competitive polymerase chain reaction analysis. Deletion of the region containing the five XREs, XRE(-6) to XRE(-2), and the point mutation of XRE(-1) reduced the inducible expressions by 75% and 56%, respectively, showing apparent dependency of the drug induction on the XREs. Constitutive expression, however, was not significantly affected by deletion or disruption of the XREs. When the region between XRE(-2) and XRE(-1) containing no XREs but three ERE motifs was internally deleted, the inducible expression and the constitutive expression were reduced by 88% and 75%, respectively. Replacement of this region with a partial fragment of eel CYP1A1 complementary DNA, with slight alteration of the distance between the five XREs and XRE(-1), reduced the inducible expression and the constitutive expression by 91% and 60%, respectively. These results strongly suggest that not only XRE but

EEL bio makers for water pollution monitoring. Vigilancia de la contaminacion acuatica por medio de biomarcadores en la anguila

Energy Technology Data Exchange (ETDEWEB)

Nunez-Delgado, A.; Fenet, H.; Casellas, C.; Stein, X.; Lafaurie, M.; Botoux, J.

1994-01-01

The characteristic of several bio markers capable of being use in water quality monitoring mainly those related to the cytochrome P450 enzymatic system-are reviewed, and their advantages and limitations are analyzed. The usefulness of the European eel as a bio indicator organism in environmental water pollution monitoring is studied. Experimental data support, the use of eel hepatic microsomal ethoxyresorufino-O-deethylase activity determination (EROD) as a bio marker of water pollution caused by organic compounds such as polycyclic aromatic hydrocarbons. (Author) 48 p.

Molecular markers of oocyte differentiation in European eel during hormonally induced oogenesis.

Science.gov (United States)

Rojo-Bartolomé, Iratxe; Martínez-Miguel, Leticia; Lafont, Anne-Gaëlle; Vílchez, M Carmen; Asturiano, Juan F; Pérez, Luz; Cancio, Ibon

2017-09-01

Reproduction in captivity is a key study issue in Anguilla anguilla as a possible solution for its dwindling population. Understanding the mechanisms controlling the production of ribosomal building blocks during artificially induced oocyte maturation could be particularly interesting. Transcription levels of ribosomal biogenesis associated genes could be used as markers to monitor oogenesis. Eels from the Albufera Lagoon were injected with carp pituitary extract for 15weeks and ovaries in previtellogenic (PV) stage (non-injected), in early-, mid-, late-vitellogenesis (EV, MV, LV), as well as in migratory nucleus stage (MN) were analysed. 5S rRNA and related genes were highly transcribed in ovaries with PV oocytes. As oocytes developed, transcriptional levels of genes related to 5S rRNA production (gtf3a), accumulation (gtf3a, 42sp43) and nucleocytoplasmic transport (rpl5, rpl11) and the 5S/18S rRNA index decreased (PV>EV>MV>LV>MN). On the contrary, 18S rRNA was at its highest at MN stage while ubtf1 in charge of activating RNA-polymerase I and synthesising 18S rRNA behaved as 5S related genes. Individuals that did not respond (NR) to the treatment showed 5S/18S index values similar to PV females, while studied genes showed EV/LV-like transcription levels. Therefore, NR females fail to express the largest rRNAs, which could thus be taken as markers of successful vitellogenesis progression. In conclusion, we have proved that the transcriptional dynamics of ribosomal genes provides useful tools to characterize induced ovarian development in European eels. In the future, such markers should be studied as putative indicators of response to hormonal treatments and of the quality of obtained eel oocytes. Copyright © 2017. Published by Elsevier Inc.

Switch in rod opsin gene expression in the European eel, Anguilla anguilla (L.).

Science.gov (United States)

Hope, A J; Partridge, J C; Hayes, P K

1998-01-01

The rod photoreceptors of the European eel, Anguilla anguilla (L.), alter their wavelength of maximum sensitivity (lambda max) from c.a. 523 nm to c.a. 482 nm at maturation, a switch involving the synthesis of a new visual pigment protein (opsin) that is inserted into the outer segments of existing rods. We artificially induced the switch in rod opsin production by the administration of hormones, and monitored the switch at the level of mRNA accumulation using radiolabelled oligonuleotides that hybridized differently to the two forms of eel rod opsin. The production of the deep-sea form of rod opsin was detected 6 h after the first hormone injection, and the switch in rod opsin expression was complete within four weeks, at which time only the mRNA for the deep-sea opsin was detectable in the retinal cells. It is suggested that this system could be used as a tractable model for studying the regulatory control of opsin gene expression. PMID:9633112

Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species.

Science.gov (United States)

Prospere, Kurt; McLaren, Kurt P; Wilson, Byron

2016-10-01

The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

Thirty year monitoring of PCBs, organochlorine pesticides and tetrabromodiphenylether in eel from The Netherlands

NARCIS (Netherlands)

Boer, de J.; Dao, Q.T.; Leeuwen, van P.W.; Kotterman, M.J.J.; Schobben, J.H.M.

2010-01-01

Because of their excellent properties as a biomonitor, yellow eels (Anguilla anguilla) have been used for time-trend monitoring of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and tetrabrominated diphenylether (tetra-BDE). The program has now lasted for thirty years and has

Tolerance of acute hypercapnic acidosis by the European eel ( Anguilla anguilla)

DEFF Research Database (Denmark)

McKenzie, D J; Taylor, E W; Dalla Valle, A Z

2002-01-01

European eels ( Anguilla anguilla) were exposed sequentially to partial pressures of CO(2) in the water ( PwCO(2)) of 5, 10, 20, 40, 60 then 80 mm Hg (equivalent to 0.66-10.5 kPa), for 30 min at each level. This caused a profound drop in arterial plasma pH, from 7.9 to below 7.2, an increase in a...

Mapping Palm Swamp Wetland Ecosystems in the Peruvian Amazon: a Multi-Sensor Remote Sensing Approach

Science.gov (United States)

Podest, E.; McDonald, K. C.; Schroeder, R.; Pinto, N.; Zimmerman, R.; Horna, V.

2012-12-01

Wetland ecosystems are prevalent in the Amazon basin, especially in northern Peru. Of specific interest are palm swamp wetlands because they are characterized by constant surface inundation and moderate seasonal water level variation. This combination of constantly saturated soils and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, it is critical to develop methods to quantify their spatial extent and inundation state in order to assess their carbon dynamics. Spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We developed a remote sensing methodology using multi-sensor remote sensing data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR), Shuttle Radar Topography Mission (SRTM) DEM, and Landsat to derive maps at 100 meter resolution of palm swamp extent and inundation based on ground data collections; and combined active and passive microwave data from AMSR-E and QuikSCAT to derive inundation extent at 25 kilometer resolution on a weekly basis. We then compared information content and accuracy of the coarse resolution products relative to the high-resolution datasets. The synergistic combination of high and low resolution datasets allowed for characterization of palm swamps and assessment of their flooding status. This work has been undertaken partly within the framework of the JAXA ALOS Kyoto & Carbon Initiative. PALSAR data have been provided by JAXA. Portions of this work were carried out at the Jet Propulsion Laboratory

Dexamethasone (DEX induces Osmotic stress transcription factor 1 (Ostf1 through the Akt-GSK3β pathway in freshwater Japanese eel gill cell cultures

Directory of Open Access Journals (Sweden)

S. C. Chow

2013-03-01

Osmosensing and osmoregulatory processes undertaken in gills of euryhaline fish are coordinated by integrative actions of various signaling molecules/transcriptional factors. Considerable numbers of studies report the hyper- and hypo-osmoregulatory functions of fish gills, by illustrating the process of gill cell remodeling and the modulation of the expression of ion channels/transporters. Comparatively mechanistic information relayed from signal integration to transcriptional regulation in mediating gill cell functions has not yet been elucidated. In this study we demonstrate the functional links from cortisol stimulation, to Akt activation, to the expression of the transcriptional factor, Ostf1. Using the synthetic glucocorticoid receptor agonist, dexamethasone (DEX, Ostf1 expression is found to be activated via glucocorticoid receptor (GR and mediated by the Akt-GSK3β signaling pathway. Pharmacological experiments using kinase inhibitors reveal that the expression of Ostf1 is negatively regulated by Akt activation. The inhibition of PI3K or Akt activities, by the specific kinase inhibitors (wortmannin, LY294002 or SH6, stimulates Ostf1 expression, while a reduction of GSK3β activity by LiCl reduces Ostf1 expression. Collectively, our report for the first time indicates that DEX can induce Ostf1 via GR, with the involvement of the Akt-GSK3β signaling pathway in primary eel gill cell cultures. The data also suggest that Ostf1 may play different roles in gill cell survival during seawater acclimation.

Implications of individual growth status on the future sex of the European eel

DEFF Research Database (Denmark)

Holmgren, K.; Mosegaard, Henrik

1996-01-01

than females. Males also had lower length at weight than females, even in the smallest weight groups. Early growth status may influence the future sex of undifferentiated eels, but other approaches are needed for distinction between cause and effect. (C) 1996 The Fisheries Society of the British Isles....

The Eel River, northwestern California; high sediment yields from a dynamic landscape

Science.gov (United States)

Thomas E. Lisle

1990-01-01

The Eel River draining the Coast Range of northwestern California has the highest recorded average suspended sediment yield per drainage area of any river of its size or larger unaffected by volcanic eruptions or active glaciers in the conterminous United States (1,720 t/km 2 yr from 9,390 km 2 ; Brown and Ritter, 1971).

Improved open-sun drying method for local swamp rice in Uganda ...

African Journals Online (AJOL)

“Kaiso” and “Supa” are the main local swamp-rice (Oryza Sativa) varieties currently grown in Uganda mainly by smallholder farmers on small gardens (0.5 – 2ha). Due to lack of mechanized drying equipment and owing to the low volumes of their harvests, these farmers use open-sun drying methods, where the paddy is ...

Tracking anguillid eels: five decades of telemetry-based research

DEFF Research Database (Denmark)

Beguer-Pon, Melanie; Dodson, Julian J.; Castonguay, Martin

2018-01-01

anguillid species have been tracked in three main geographical locations: Western Europe, the north-eastern part of North America and Australasia. Telemetry has proven to be an effective method for determining patterns of yellow eel movements in continental waters. It has also been used extensively...... satellite tags have provided indications of spawning areas, extensive vertical migrations and initial clues about the orientation mechanisms at sea. Telemetry studies have also revealed apparent evidence of predation by marine mammals and fish at sea, suggesting a significant natural source of mortality...

Oceanic migration behaviour of tropical Pacific eels from Vanuatu

DEFF Research Database (Denmark)

Schabetsberger, R; Økland, F; Aarestrup, K

2013-01-01

Information on oceanic migrations and spawning areas of tropical Pacific freshwater eels (genus Anguilla) is very limited. Lake Letas and its single outflowing river, Mbe Solomul on Gaua Island, Vanuatu, were surveyed for large migrating individuals. Twenty-four Anguilla marmorata (87 to 142 cm),...... impact of the lunar cycle on the upper limit of migration depths was found in A. marmorata (full moon: 230 m, new moon: 170 m). These behaviours may be explained as a trade-off between predator avoidance and the necessity to maintain a sufficiently high metabolism for migration....

Weathering of a petroleum spill in a tropical mangrove swamp

Energy Technology Data Exchange (ETDEWEB)

Fisher, S.J.; Alexander, R.; Kagi, R.I. [Curtin Univ., Perth (Australia)

1996-12-31

In August 1987, an indeterminate amount of petroleum condensate was released from a buried pipe leading to contamination of a tropical mangrove swamp surrounding a tidal creek in North Western Australia. Since no bioremediation was attempted at this site, we have monitored the natural weathering of the condensate by detailed analysis of the petroleum hydrocarbons extracted from sediment samples collected on 11 occasions over a 3 year period.

Comparing Avocado, Swamp Bay, and Camphortree as Hosts of Raffaelea lauricola Using a Green Fluorescent Protein (GFP)-Labeled Strain of the Pathogen.

Science.gov (United States)

Campbell, A S; Ploetz, R C; Rollins, J A

2017-01-01

Raffaelea lauricola, a fungal symbiont of the ambrosia beetle Xyleborus glabratus, causes laurel wilt in members of the Lauraceae plant family. North American species in the family, such as avocado (Persea americana) and swamp bay (P. palustris), are particularly susceptible to laurel wilt, whereas the Asian camphortree (Cinnamomum camphora) is relatively tolerant. To determine whether susceptibility is related to pathogen colonization, a green fluorescent protein-labeled strain of R. lauricola was generated and used to inoculate avocado, swamp bay, and camphortree. Trees were harvested 3, 10, and 30 days after inoculation (DAI), and disease severity was rated on a 1-to-10 scale. By 30 DAI, avocado and swamp bay developed significantly more severe disease than camphortree (mean severities of 6.8 and 5.5 versus 1.6, P < 0.003). The extent of xylem colonization was recorded as the percentage of lumena that were colonized by the pathogen. More xylem was colonized in avocado than camphortree (0.9% versus 0.1%, P < 0.03) but colonization in swamp bay (0.4%) did not differ significantly from either host. Although there were significant correlations between xylem colonization and laurel wilt severity in avocado (r = 0.74), swamp bay (r = 0.82), and camphortree (r = 0.87), even severely affected trees of all species were scarcely colonized by the pathogen.

Spatial differences in hydrologic characteristics and water chemistry of a temperate coastal plain peatland: The Great Dismal Swamp, USA

Science.gov (United States)

Speiran, Gary K.; Wurster, Frederick C.

2016-01-01

Spatial differences in hydrologic processes and geochemistry across forested peatlands control the response of the wetland-community species and resiliency to natural and anthropogenic disturbances. Knowing these controls is essential to effectively managing peatlands as resilient wetland habitats. The Great Dismal Swamp is a 45,325 hectare peatland in the Atlantic Coastal Plain of Virginia and North Carolina, USA, managed by the U.S. Fish and Wildlife Service. The existing forest-species distribution is a product of timber harvesting, hydrologic alteration by canal and road construction, and wildfires. Since 2009, studies of hydrologic and geochemical controls have expanded knowledge of groundwater flow paths, water chemistry, response to precipitation events, and characteristics of the peat. Dominant hydrologic and geochemical controls include (1) the gradual slope in land surface, (2) vertical differences in the hydraulic characteristics of the peat, (3) the proximity of lateral groundwater and small stream inflows from uplands, (4) the presence of an extensive canal and road network, and (5) small, adjustable-height dams on the canals. Although upland sources provide some surface water and lateral groundwater inflow to western parts of the swamp, direct groundwater recharge by precipitation is the major source of water throughout the swamp and the only source in many areas. Additionally, the proximity and type of upland water sources affect water levels and nutrient concentrations in canal water and groundwater. Where streams are a dominant upland source, variations in groundwater levels and nutrient concentrations are greater than where recharge by precipitation is the primary water source. Where upland groundwater is a dominant source, water levels are more stable. Because the species distribution of forest communities in the Swamp is strongly influenced by these controls, swamp managers are beginning to incorporate this knowledge into forest, water, and fire

Studi Perbandingan Komposisi Asam Lemak Daging Ikan Sidat (Anguilla marmorata (Q. Gaimard Fase Yellow Eel Dari Sungai Palu Dan Danau Poso

Directory of Open Access Journals (Sweden)

Jamaluddin Jamaluddin

2018-04-01

Full Text Available Ikan sidat (Anguilla marmorata (Q. Gaimard memiliki keunggulan gizi atau nutrisi yang tinggi seperti vitamin A, vitamin B, vitamin C, vitamin D, vitamin E, protein, mineral, dan asam lemak yang baik bagi kesehatan. Penelitian ini bertujuan untuk menentukan kadar asam lemak, dan membandingkan komposisi asam lemak dari ikan sidat fase yellow eel asal sungai Palu dan danau Poso. Penelitian ini menggunakan metode kromatografi gas dengan mengubah ekstrak lemak menjadi metil ester asam lemak. Hasil analisis komposisi asam lemak daging ikan sidat (Anguilla marmorata (Q. Gaimard fase yellow eel asal sungai Palu dan Danau Poso menunjukan kadar asam lemak jenuh masing-masing 2,766g/100g dan 0,275g/100g; asam lemak tak jenuh tunggal 4,029g/100g dan 0,276g/100g; dan asam lemak tak jenuh ganda 0,541g/100g dan 0,102g/100g. Terdapat perbedaan secara statistik (p<0.05 komposisi dan kadar asam lemak antara daging ikan sidat fase yellow eel asal sungai Palu dan danau Poso. Komposisi asam lemak ikan sidat fase yellow eel asal sungai Palu dan danau Poso masing-masing adalah 23 dan 18 jenis. Asam lemak yang ditemukan pada daging ikan sidat sungai Palu dan tidak ditemukan pada ikan sidat danau Poso adalah asam heneikosenoat, asam miristoleat, Cis-10-pentadekanoat, asam gamma linoleat, dan Cis-11,14,17-eikosatrinoat.

75 FR 8107 - Bond Swamp National Wildlife Refuge, Bibb and Twiggs Counties, GA

Science.gov (United States)

2010-02-23

... impact. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce the availability of our final comprehensive Conservation Plan (CCP) and finding of no significant impact (FONSI) for the environmental..., including upland mixed pine/hardwood, bottomland hardwood, and tupelo gum swamp forests. Creeks, beaver...

The palynology and sedimentology of a coastal swamp at Awana, Great Barrier Island, New Zealand, from c. 7000 yr B.P. to present

International Nuclear Information System (INIS)

Horrocks, M.; Ogden, J.; Nichol, S.L.; Alloway, B.V.; Sutton, D.G.

1999-01-01

Pollen and sediment analysis of two Holocene cores from Awana, Great Barrier Island, shows that at 7000 calibrated yr B.P. the local swamp was an estuarine salt marsh dominated by Restionaceae. By c. 6000 yr B.P. the water table was lower, and a fresh water swamp (Gleichenia-Leptospermum) had replaced the salt marsh. Regional conifer-hardwood forest c. 7000 yr B.P. was initially co-dominated by Libocedrus and Dacrydium cupressinum. Libocedrus declined from c. 6000 yr B.P. During the period c. 6000-c. 2500 yr B.P., relatively stable environmental conditions ensued with little change in local or regional vegetation. Around 2500 yr B.P., the swamp surface became drier and was invaded by Dacrycarpus and Laurelia swamp forest. This forest was subsequently repeatedly disturbed (not by fire), indicating climatic change to drier and windier conditions. Ascarina lucida was periodically a major component of swamp forest. Disturbance is also recorded in the clastic (mineral) sediments, where beds of sand within finer-grained sediment and peat are interpreted as wind blown material derived from partly devegetated dunes to seaward. The presence of the Kaharoa Tephra allows the timing of major Polynesian deforestation at Awana to be reliably dated to c. 600 calibrated yr B.P. In contrast, we see no evidence in the clastic sediment record of disturbance at Awana since Kaharoa time. We attribute this to the maintenance of stable dunes by a herb/scrub cover despite nearby fires, or to the presence of scrub or forest buffering the swamp from ablating dunes. (author). 45 refs., 4 figs., 1 tab

Behavioural and hormonal aspects of the oestrous cycle in swamp buffaloes reared under temperate conditions

International Nuclear Information System (INIS)

Kanai, Y.; Ishikawa, N.; Shimizu, H.

1990-01-01

A series of experiments was carried out using a small herd of swamp buffaloes raised in Japan under temperate conditions at 36 deg. N latitude, with a view to determining whether they exhibit peculiar characteristics in their oestrous cycles. The studies on the oestrous behaviour revealed that under adequate feeding and management conditions, buffaloes regularly display oestrous throughout the year, with the cycle length, duration of oestrous and time of ovulation all falling within ranges similar to those reported in cattle. External signs of oestrus were generally less evident, as previously reported. Hormonal analysis showed that there were no remarkable differences between swamp buffaloes and cattle in terms of the secretory patterns of pituitary gonadotrophins and ovarian steroids during the oestrous cycle. (author). 13 refs, 2 figs

Sparse modeling of EELS and EDX spectral imaging data by nonnegative matrix factorization

Energy Technology Data Exchange (ETDEWEB)

Shiga, Motoki, E-mail: shiga_m@gifu-u.ac.jp [Department of Electrical, Electronic and Computer Engineering, Gifu University, 1-1, Yanagido, Gifu 501-1193 (Japan); Tatsumi, Kazuyoshi; Muto, Shunsuke [Advanced Measurement Technology Center, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Tsuda, Koji [Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561 (Japan); Center for Materials Research by Information Integration, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, 2-4-7 Aomi Koto-ku, Tokyo 135-0064 (Japan); Yamamoto, Yuta [High-Voltage Electron Microscope Laboratory, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Mori, Toshiyuki [Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Tanji, Takayoshi [Division of Materials Research, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)

2016-11-15

Advances in scanning transmission electron microscopy (STEM) techniques have enabled us to automatically obtain electron energy-loss (EELS)/energy-dispersive X-ray (EDX) spectral datasets from a specified region of interest (ROI) at an arbitrary step width, called spectral imaging (SI). Instead of manually identifying the potential constituent chemical components from the ROI and determining the chemical state of each spectral component from the SI data stored in a huge three-dimensional matrix, it is more effective and efficient to use a statistical approach for the automatic resolution and extraction of the underlying chemical components. Among many different statistical approaches, we adopt a non-negative matrix factorization (NMF) technique, mainly because of the natural assumption of non-negative values in the spectra and cardinalities of chemical components, which are always positive in actual data. This paper proposes a new NMF model with two penalty terms: (i) an automatic relevance determination (ARD) prior, which optimizes the number of components, and (ii) a soft orthogonal constraint, which clearly resolves each spectrum component. For the factorization, we further propose a fast optimization algorithm based on hierarchical alternating least-squares. Numerical experiments using both phantom and real STEM-EDX/EELS SI datasets demonstrate that the ARD prior successfully identifies the correct number of physically meaningful components. The soft orthogonal constraint is also shown to be effective, particularly for STEM-EELS SI data, where neither the spatial nor spectral entries in the matrices are sparse. - Highlights: • Automatic resolution of chemical components from spectral imaging is considered. • We propose a new non-negative matrix factorization with two new penalties. • The first penalty is sparseness to choose the number of components from data. • Experimental results with real data demonstrate effectiveness of our method.

Imaging Si nanoparticles embedded in SiO2 layers by (S)TEM-EELS

International Nuclear Information System (INIS)

Schamm, S.; Bonafos, C.; Coffin, H.; Cherkashin, N.; Carrada, M.; Ben Assayag, G.; Claverie, A.; Tence, M.; Colliex, C.

2008-01-01

Fabrication of systems in which Si nanoparticles are embedded in a thin silica layer is today mature for non-volatile memory and opto-electronics applications. The control of the different parameters (position, size and density) of the nanoparticles population is a key point to optimize the properties of such systems. A review of dedicated transmission electron microscopy (TEM) methods, which can be used to measure these parameters, is presented with an emphasis on those relying on electron energy-loss spectroscopy (EELS). Defocused bright-field imaging can be used in order to determine topographic information of a whole assembly of nanoparticles, but it is not efficient for looking at individual nanoparticles. High-resolution electron imaging or dark-field imaging can be of help in the case of crystalline particles but they always provide underestimated values of the nanocrystals population. EELS imaging in the low-energy-loss domain around the Si plasmon peak, which gives rise to strong signals, is the only way to visualize all Si nanoparticles within a silica film and to perform reliable size and density measurements. Two complementary types of experiments are investigated and discussed more extensively: direct imaging with a transmission electron microscope equipped with an imaging filter (EFTEM) and indirect imaging from spectrum-imaging data acquired with a scanning transmission electron microscope equipped with a spectrometer (STEM-PEELS). The direct image (EFTEM) and indirect set of spectra (STEM-PEELS) are processed in order to deliver images where the contribution of the silica matrix is minimized. The contrast of the resulting images can be enhanced with adapted numerical filters for further morphometric analysis. The two methods give equivalent results, with an easier access for EFTEM and the possibility of a more detailed study of the EELS signatures in the case of STEM-PEELS. Irradiation damage in such systems is also discussed

Swimming depth of migrating silver eels Anguilla japonica released at seamounts of the West Mariana Ridge, their estimated spawning sites

OpenAIRE

Aoyama, J.; Hissmann, Karen; Yoshinaga, T.; Sasai, S.; Uto, T.; Ueda, H.

1999-01-01

Five hormone-treated female Japanese silver eels Anguilla japonica were tagged with ultrasonic transmitters and released by submersible in the West Pacific at seamounts of the West Mariana Ridge, their supposed spawning grounds. Four eels were tracked for 60 to 423 min in the vicinity of the seamounts. They did not settle at the seamounts but swam at a mean speed of 0.37 m s-1 into open water above deep ground. Their mean swimming depth ranged from 81 to 172 m. Experiments suggest that pre-ma...

Repeated drought alters resistance of seed bank regeneration in baldcypress swamps of North America

Science.gov (United States)

Lei, Ting; Middleton, Beth A.

2018-01-01

Recurring drying and wetting events are likely to increase in frequency and intensity in predicted future droughts in the central USA and alter the regeneration potential of species. We explored the resistance of seed banks to successive droughts in 53 sites across the nine locations in baldcypress swamps in the southeastern USA. Along the Mississippi River Alluvial Valley and northern Gulf of Mexico, we investigated the capacity of seed banks to retain viable seeds after successive periods of drying and wetting in a greenhouse study. Mean differences in species richness and seed density were compared to examine the interactions of successive droughts, geographical location and water regime. The results showed that both species richness and total density of germinating seedlings decreased over repeated drought trials. These responses were more pronounced in geographical areas with higher annual mean temperature. In seed banks across the southeastern swamp region, most species were exhausted after Trial 2 or 3, except for semiaquatic species in Illinois and Tennessee, and aquatic species in Texas. Distinct geographical trends in seed bank resistance to drought demonstrate that climate-induced drying of baldcypress swamps could influence the regeneration of species differently across their ranges. Despite the health of adult individuals, lack of regeneration may push ecosystems into a relict status. Seed bank depletion by germination without replenishment may be a major conservation threat in a future with recurring droughts far less severe than megadrought. Nevertheless, the protection of moist refugia might aid conservation.

Holocene mangrove swamps of West Africa sedimentology and soils

Science.gov (United States)

Marius, C.; Lucas, J.

The mangrove swamps of West African Coast belong to the Atlantic type which is characterized by a small number of species. They colonize tidal environments which are dissected by numerous meandering tidal channels and are presently subject to a low rate of sediment accumulation. The mangrove vegetation exhibits a characteristic zonation pattern that basically reflects the adaptation of the various species to saline conditions. The typical zonation sequence is: Rhizophora racemosa (or Rh. mangle), Rh. mangle + Avicennia africana, Avicennia, flooded tanne, barren tanne, herbaceous tanne. The tannes are generated by aridic climatic conditions, heavy soil and water salt content, and are, in a way a peculiar feature of mangrove swamps in West Africa. The sediment colonized by the mangroves is relatively homogenous. Mineralogically, they are dominated by quartz and clay to which are associated halite, pyrite and jarosite. The clay suite is mainly composed of smectite and kaolinite. Smectite is predominant in the inlet areas and is replaced inland by kaolinite. Chemically, the sediments contain very low amounts of Ca, bases and trace elements. The mangrove swamp floodwaters have a chemical composition similar to that of seawater. It is dominated by sodium and chloride. Morphologically, the ripening of the soils appears with a chestnut mash colour horizon and buttery consistency in relation with the decomposition of fibrous roots of Rhizophora and also with pale yellow jarosite mottles in the top horizons of the tanne profiles due to the oxidation of pyrine. The two main properties of the mangrove soils of West Africa are acidity and salinity; the first is related to the high content of sulphur and the second to the sea influence. The acidity has to be connected mainly to the Rhizophora vegetation whose the root system is a real trap for catching the pyrites resulting from the reduction of the sulphates of sea water by the sulphate reducing bacteria, in a reduced

Relationships between Vacant Homes and Food Swamps: A Longitudinal Study of an Urban Food Environment.

Science.gov (United States)

Mui, Yeeli; Jones-Smith, Jessica C; Thornton, Rachel L J; Pollack Porter, Keshia; Gittelsohn, Joel

2017-11-21

Research indicates that living in neighborhoods with high concentrations of boarded-up vacant homes is associated with premature mortality due to cancer and diabetes, but the mechanism for this relationship is unclear. Boarded-up housing may indirectly impact residents' health by affecting their food environment. We evaluated the association between changes in vacancy rates and changes in the density of unhealthy food outlets as a proportion of all food outlets, termed the food swamp index, in Baltimore, MD (USA) from 2001 to 2012, using neighborhood fixed-effects linear regression models. Over the study period, the average food swamp index increased from 93.5 to 95.3 percentage points across all neighborhoods. Among non-African American neighborhoods, increases in the vacancy rate were associated with statistically significant decreases in the food swamp index (b = -0.38; 90% CI, -0.64 to -0.12; p -value: 0.015), after accounting for changes in neighborhood SES, racial diversity, and population size. A positive association was found among low-SES neighborhoods (b = 0.15; 90% CI, 0.037 to 0.27; p -value: 0.031). Vacant homes may influence the composition of food outlets in urban neighborhoods. Future research should further elucidate the mechanisms by which more distal, contextual factors, such as boarded-up vacant homes, may affect food choices and diet-related health outcomes.

Impact of a short-term exposure to tributyl phosphate on morphology, physiology and migratory behaviour of European eels during the transition from freshwater to the marine environment

DEFF Research Database (Denmark)

Privitera, Lucia; Aarestrup, Kim; Moore, Andy

2013-01-01

Migrating silver European eels were exposed for 5 days in a laboratory to an environmental level of tributyl phosphate (TBP), tagged with acoustic transmitters and released below the Tange hydropower station, on the River Gudenaa, Denmark. The subsequent movements of the eels were monitored as th...

Gemfibrozil modulates cytochrome P450 and peroxisome proliferation-inducible enzymes in the liver of the yellow European eel (Anguilla anguilla).

Science.gov (United States)

Lyssimachou, Angeliki; Thibaut, Rémi; Gisbert, Enric; Porte, Cinta

2014-01-01

The human lipid regulator gemfibrozil (GEM) has been shown to induce peroxisome proliferation in rodents leading to hepatocarcinogenesis. Since GEM is found at biological active concentrations in the aquatic environment, the present study investigates the effects of this drug on the yellow European eel (Anguilla anguilla). Eels were injected with different concentrations of GEM (0.1 to 200 μg/g) and sampled 24- and 96-h post-injection. GEM was shown to inhibit CYP1A, CYP3A and CYP2K-like catalytic activities 24-h post-injection, but at 96-h post-injection, only CYP1A was significantly altered in fish injected with the highest GEM dose. On the contrary, GEM had little effect on the phase II enzymes examined (UDP-glucuronyltransferase and glutathione-S-transferase). Peroxisome proliferation inducible enzymes (liver peroxisomal acyl-CoA oxidase and catalase) were very weakly induced. No evidence of a significant effect on the endocrine system of eels was observed in terms of plasmatic steroid levels or testosterone esterification in the liver.

Pop up satellite tags impair swimming performance and energetics of the European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

Methling, Caroline; Tudorache, Christian; Skov, Peter Vilhelm

2011-01-01

Pop-up satellite archival tags (PSATs) have recently been applied in attempts to follow the oceanic spawning migration of the European eel. PSATs are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does...... the potential implication for successful migration. Silver eels (L(T)=598.6 +/- 29 mm SD, N = 9) were subjected to swimming trials in a Steffensen-type swim tunnel at increasing speeds of 0.3-0.9 body lengths s(-1), first without and subsequently with, a scaled down PSAT dummy attached. The tag significantly...... increased oxygen consumption (MO(2)) during swimming and elevated minimum cost of transport (COT(min)) by 26 Standard (SMR) and active metabolic rate (AMR) as well as metabolic scope remained unaffected, suggesting that the observed effects were caused by increased drag. Optimal swimming speed (U...

Flood inundation maps for the Wabash and Eel Rivers at Logansport, Indiana

Science.gov (United States)

Fowler, Kathleen K.

2014-01-01

Digital flood-inundation maps for an 8.3-mile reach of the Wabash River and a 7.6-mile reach of the Eel River at Logansport, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage Wabash River at Logansport, Ind. (sta. no. 03329000) and USGS streamgage Eel River near Logansport, Ind. (sta. no. 03328500). Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/. In addition, information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system http:/water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often colocated with USGS streamgages. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgages 03329000, Wabash River at Logansport, Ind., and 03328500, Eel River near Logansport, Ind. The calibrated hydraulic model was then used to determine five water-surface profiles for flood stage at 1-foot intervals referenced to the Wabash River streamgage datum, and four water-surface profiles for flood stages at 1-foot intervals referenced to the Eel River streamgage datum. The stages range from bankfull to approximately the highest

Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region.

Science.gov (United States)

Zhang, Yi; Lu, Yongfang; Yindee, Marnoch; Li, Kuan-Yi; Kuo, Hsiao-Yun; Ju, Yu-Ten; Ye, Shaohui; Faruque, Md Omar; Li, Qiang; Wang, Yachun; Cuong, Vu Chi; Pham, Lan Doan; Bouahom, Bounthong; Yang, Bingzhuang; Liang, Xianwei; Cai, Zhihua; Vankan, Dianne; Manatchaiworakul, Wallaya; Kowlim, Nonglid; Duangchantrasiri, Somphot; Wajjwalku, Worawidh; Colenbrander, Ben; Zhang, Yuan; Beerli, Peter; Lenstra, Johannes A; Barker, J Stuart F

2016-04-01

The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal lineage. We carried out a comprehensive sampling of China, Taiwan, Vietnam, Laos, Thailand, Nepal and Bangladesh and sequenced the mtDNA Cytochrome b gene and control region and the Y-chromosomal ZFY, SRY and DBY sequences. Swamp buffalo has a higher diversity of both maternal and paternal lineages than river buffalo, with also a remarkable contrast between a weak phylogeographic structure of river buffalo and a strong geographic differentiation of swamp buffalo. The highest diversity of the swamp buffalo maternal lineages was found in south China and north Indochina on both banks of the Mekong River, while the highest diversity in paternal lineages was in the China/Indochina border region. We propose that domestication in this region was later followed by introgressive capture of wild cows west of the Mekong. Migration to the north followed the Yangtze valley as well as a more eastern route, but also involved translocations of both cows and bulls over large distances with a minor influence of river buffaloes in recent decades. Bayesian analyses of various migration models also supported domestication in the China/Indochina border region. Coalescence analysis yielded consistent estimates for the expansion of the major swamp buffalo haplogroups with a credibility interval of 900 to 3900 years BP. The spatial differentiation of mtDNA and Y-chromosomal haplotype distributions indicates a lack of gene flow between established populations that is unprecedented in livestock. © 2015 John Wiley & Sons Ltd.

Draining the swamp while making America great: senior dissonance in the age of Trump.

Science.gov (United States)

Hudson, Robert B

2018-04-13

In his surprise election as President, Donald Trump enjoyed disproportionate electoral support from older voters, many of whom saw in Trump a person who would work to reverse demographic, economic, and cultural forces that had transformed American life as they had long seen it. Yet, Trump's campaign and incumbency has also been very much about gutting the Washington policy establishment of officials, bureaucrats, and lobbyists (aka, the Swamp) which, for over half a century, has been instrumental in enacting and expanding legislation that has benefitted older Americans, far more than any other social policy constituency in the country. This article contrasts the value-oriented electoral support Trump enjoyed from older Americans with their interest concerns centered on policies such as the Affordable Care Act, Medicaid, and a host of smaller grant-in-aid programs. It then reviews the strong institutional base seniors and their advocates have in Washington, posing whether interest-oriented concerns may outweigh ideological ones as policy options emerge from a Republican-controlled government prior to the 2018 elections.

Sumatran orangutans differ in their cultural knowledge but not in their cognitive abilities.

Science.gov (United States)

Gruber, Thibaud; Singleton, Ian; van Schaik, Carel

2012-12-04

Animal cultures are controversial because the method used to isolate culture in animals aims at excluding genetic and environmental influences rather than demonstrating social learning. Here, we analyzed these factors in parallel in captivity to determine their influences on tool use. We exposed Sumatran orangutan (Pongo abelii) orphans from tool-using and non-tool-using regions (western swamps and eastern Langkat, respectively) that differed in both genetic and cultural backgrounds to a raking task and a honey-dipping task to assess their understanding of stick use. Orangutans from both regions were equally successful in raking; however, swamp orangutans were more successful than Langkat orangutans in honey dipping, where previously acquired knowledge was required. A larger analysis suggested that the Alas River could constitute a geographical barrier to the spread of this cultural trait. Finally, honey-dipping individuals were on average less than 4 years old, but this behavior is not observed in the wild before 6 years of age. Our results suggest first that genetic differences between wild Sumatran populations cannot explain their differences in stick use; however, their performances in honey dipping support a cultural differentiation in stick knowledge. Second, the results suggest that the honey-dippers were too young when arriving at the quarantine center to have possibly mastered the behavior in the wild individually, suggesting that they arrived with preestablished mental representations of stick use or, simply put, "cultural ideas." Copyright © 2012 Elsevier Ltd. All rights reserved.

Fipronil and two of its transformation products in water and European eel from the river Elbe.

Science.gov (United States)

Michel, N; Freese, M; Brinkmann, M; Pohlmann, J-D; Hollert, H; Kammann, U; Haarich, M; Theobald, N; Gerwinski, W; Rotard, W; Hanel, R

2016-10-15

Fipronil is an insecticide which, based on its mode of action, is intended to be predominantly toxic towards insects. Fipronil bioaccumulates and some of its transformation products were reported to be similar or even more stable in the environment and to show an enhanced toxicity against non-target organisms compared to the parent compound. The current study investigated the occurrence of Fipronil and two of its transformation products, Fipronil-desulfinyl and Fipronil-sulfone, in water as well as muscle and liver samples of eels from the river Elbe (Germany). In water samples total concentrations of FIP, FIP-d and FIP-s ranged between 0.5-1.6ngL(-1) with FIP being the main component in all water samples followed by FIP-s and FIP-d. In contrast, FIP-s was the main component in muscle and liver tissues of eels with concentrations of 4.05±3.73ngg(-1) ww and 19.91±9.96ngg(-1) ww, respectively. Using a physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals, the different distributions of FIP, FIP-d and FIP-s in water and related tissue samples could be attributed to metabolic processes of eels. The measured concentrations in water of all analytes and their fractional distribution did not reflect the assumed seasonal application of FIP and it seems that the water was constantly contaminated with FIP, FIP-d and FIP-s. Copyright © 2016 Elsevier B.V. All rights reserved.

Differential recovery of a deepwater swamp forest across a gradient of disturbance intensity

Science.gov (United States)

Diane De Steven; Rebecca R. Sharitz

1997-01-01

On the Savannah River Site, South Carolina, USA, large areas of floodplain swamp forest of baldcypress (Taxodium distichum) and water tupelo (Nyssa aquatica) were destroyed by the cumulative impacts of cooling-water discharges over a 35-year period of nuclear reactor operations. In one floodplain area, four years after thermal...

Kinetics of radiolabelled silver uptake and depuration in the gills of rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

Wood, C.M.; Grosell, M.; Hogstrand, C.

2002-01-01

We examined the influence of speciation on the kinetics of silver uptake and deputation in the gills of two freshwater fish, the rainbow trout (Oncorhynchus mykiss) which has high branchial Na+ and Cl- uptake rates and is relatively sensitive to silver, and the European eel (Anguilla anguilla...... labile than from Ag+ exposures, with 1.6-1.8-fold greater loss rates during the fast phases in both species. Differences in branchial silver uptake between eel and trout correlate well with differences in acute toxicity, but are not as large as differences in ion uptake rates. The complex time...

Comparative palynomorph signals of vegetation change preserved in an adjacent peat swamp and estuary in north-west Nelson, New Zealand

International Nuclear Information System (INIS)

Armour, R.K.; Kennedy, D.M.

2005-01-01

A history of vegetation for the mid-late Holocene was extracted from the southern margins of Whanganui Inlet and Mangarakau Swamp. These two sites represent very different pollen sinks with the estuary being dominated by fluvially transported material and the swamp by in situ pollen rain. They are, however, located very close to each other and therefore provide a unique study area to investigate how differing source environments affect pollen signals. A vegetation change from podocarps to beech forest is recorded in both settings at around 4000 years CalBP which is similar to that recorded at higher altitudes in the region. Robust palynomorphs were found in greater abundance in the inlet while the swamp contained a higher proportion of wetland species. Despite these differences both environments appeared to record a similar regional vegetation signal. This shows that estuarine environments, often characterised by material that has been transported, can provide accurate reconstructions of vegetation change. (author). 31 refs., 8 figs., 1 tab

Bioaccumulation of polychlorinated biphenyls in the eel (Anguilla anguilla) at the Camargue Nature Reserve - France

International Nuclear Information System (INIS)

Oliveira Ribeiro, C.A.; Vollaire, Y.; Coulet, E.; Roche, H.

2008-01-01

Fish consumption is a potential source of human exposure to pollutants. Here, we study residue levels of PCBs in the eel, Anguilla anguilla, from the Nature Camargue Reserve in southern France. Chromatographic analysis (GC-ECD) found seventy identifiable congeners, among which, 10 are considered as dioxin-like PCBs, such as the non-ortho PCB 81 and the mono-ortho chlorobiphenyls PCB105, 114, 118, 123, 156, 157, 167, 170, 180. Toxic Equivalents (TEQ, WHO 2005 TEF-Toxic Equivalent Factors) varied among sites with a maximum in eels from Mornes (29.6 pg g -1 dry weight). Indicator PCBs (28, 52, 101, 118, 138, 153 and 180) were 22% and 29% of the total PCBs in livers and muscles respectively. Greater homogeneous bioaccumulation in muscle than that in liver suggests an increase risk for humans due to fish consumption. - The reserve of Camargue - South of France is impacted by a myriad of pollutant organic persistent like PCBs

Analyses of organochlorine pesticides residues in eels (Anguilla anguilla from Lake Garda using Gas chromatography coupled with Tandem Mass Spectrometry (GC-MS/MS.

Directory of Open Access Journals (Sweden)

Giuseppe Federico Labella

2017-05-01

Full Text Available Lake Garda is located in Insubria region, that is known for being the most populated and industrialized area of Italy (Camusso et al., 2001. Therefore, the Lake water, and also the fish species present, could be affected by environmental contamination.  European eel (Anguilla anguilla are considered as suitable matrix for biomonitoring environmental contaminants in European water (Belpaire et al., 2007, being widespread in many European waters and highly contaminated by lipophilic compounds, due to the high lipid content (up to 40% (Larsson et al., 1991. Moreover, eel is an edible species (its farming currently supplies approximately 45,000 tons/year (Nielsen et al., 2008, so it also represents a public health issue. Based on these considerations, the aim of this study was to evaluate the occurrence of fourteen organochlorine pesticides (OCs in forty-five eels (Anguilla anguilla from Lake Garda, using Accelerated Solvent Extraction (ASE procedure for the analytes extraction and Gas chromatography coupled with Tandem Mass Spectrometry (GC-MS/MS for the analysis of OCs. GC-MS/MS analysis was developed and validated according to the SANTE/11945/2015 guidelines.  Uncontaminated eel sample (previously checked for the presence of OCs and considered blank with a concentration of compounds < Limit of Detection were used for all procedure's optimization steps. For all the OCs analysed, satisfactory results were achieved. Regarding eel samples, several pesticides were detected, but DDTs (DDT and its metabolites were found with the highest prevalence (92 %. The concentration rage was from not detected (n.d. to 19000 ng g-1. Although DDTs levels in the environment are declining (Albaiges et al., 2011, they continue to bioaccumulate in tissues of human and animal and biomagnify in food chains.

Accurate measurement of absolute experimental inelastic mean free paths and EELS differential cross-sections

Energy Technology Data Exchange (ETDEWEB)

Craven, Alan J.; Bobynko, Joanna; Sala, Bianca; MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk

2016-11-15

Methods are described for measuring accurate absolute experimental inelastic mean free paths and differential cross-sections using DualEELS. The methods remove the effects of surface layers and give the results for the bulk materials. The materials used are VC{sub 0.83}, TiC{sub 0.98}, VN{sub 0.97} and TiN{sub 0.88} but the method should be applicable to a wide range of materials. The data was taken at 200 keV using a probe half angle of 29 mrad and a collection angle of 36 mrad. The background can be subtracted from under the ionisation edges, which can then be separated from each other. This is achieved by scaling Hartree-Slater calculated cross-sections to the edges in the atomic regions well above the threshold. The average scaling factors required are 1.00 for the non-metal K-edges and 1.01 for the metal L-edges (with uncertainties of a few percent). If preliminary measurements of the chromatic effects in the post-specimen lenses are correct, both drop to 0.99. The inelastic mean free path for TiC{sub 0.98} was measured as 103.6±0.5 nm compared to the prediction of 126.9 nm based on the widely used Iakoubovskii parameterisation. - Highlights: • We show how to extract absolute cross sections for EELS edges using DualEELS. • The method removes the effects of any surface layers on standards. • We use a needle specimen to determining the mean free path for inelastic scattering. • Constrained background fitting is essential to correct background subtraction. • Absolute cross sections are determined for TiC, TiN, VC and VN.

A multi-locus molecular timescale for the origin and diversification of eels (Order: Anguilliformes).

Science.gov (United States)

Santini, Francesco; Kong, Xianghui; Sorenson, Laurie; Carnevale, Giorgio; Mehta, Rita S; Alfaro, Michael E

2013-12-01

Anguilliformes are an ecologically diverse group of predominantly marine fishes whose members are easily recognized by their extremely elongate bodies, and universal lack of pelvic fins. Recent studies based on mitochondrial loci, including full mitogenomes, have called into question the monophyly of both the Anguilliformes, which appear to be paraphyletic without the inclusion of the Saccopharyngiformes (gulper eels and allies), as well as other more commonly known eel families (e.g., Congridae, Serrivomeridae). However, no study to date has investigated anguilliform interrelationships using nuclear loci. Here we present a new phylogenetic hypothesis for the Anguilliformes based on five markers (the nuclear loci Early Growth Hormone 3, Myosin Heavy Polypeptide 6 and Recombinase Activating Gene 1, as well as the mitochondrial genes Cytochrome b and Cytochrome Oxidase I). Our sampling spans 148 species and includes 19 of the 20 extant families of anguilliforms and saccopharyngiforms. Maximum likelihood analysis reveals that saccopharyngiform eels are deeply nested within the anguilliforms, and supports the non-monophyly of Congridae and Nettastomatidae, as well as that of Derichthyidae and Chlopsidae. Our analyses suggest that Protanguilla may be the sister group of the Synaphobranchidae, though the recent hypothesis that this species is the sister group to all other anguilliforms cannot be rejected. The molecular phylogeny, time-calibrated using a Bayesian relaxed clock approach and seven fossil calibration points, reveals a Late Cretaceous origin of this expanded anguilliform clade (stem age ~116 Ma, crown age ~99 Ma). Most major (family level) lineages originated between the end of the Cretaceous and Early Eocene, suggesting that anguilliform radiation may have been facilitated by the recovery of marine ecosystems following the KP extinction. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of waste drilling fluid on bacterial isolates from a mangrove swamp oilfield location in the Niger delta of Nigeria

Energy Technology Data Exchange (ETDEWEB)

Benka-Coker, M.O.; Olumagin, A. [Benin Univ. (Nigeria). Dept. of Microbiology

1996-03-01

Four bacteria strains isolated from a mangrove swamp oilfield location in the Niger Delta of Nigeria were cultured aerobically in the presence of 1.0% waste drilling fluid, to determine the effect of the waste on their growth. A 2-h lag phase of growth was produced by the waste in cultures of Micrococcus and Pseudomonas species, while the waste increased the lag phases of Alcaligenes and Staphylococcus species to 4 h. The exponential phase of growth of Pseudomonas sp. was depressed by the waste drilling fluid but fluid stimulated the exponential phases of Micrococcus and Alcaligenes spp. There was enhancement of the growth rate of Alcaligenes and Micrococcus spp. while those of Staphylococcus and Pseudonomas spp. were decreased. The depressed growth rates of Staphylococcus and Pseudonomas spp. in the presence of the waste drilling fluid might lead to a decrease in their contribution to the removal of the waste from the environment during spillage or disposal and, therefore, may result in an accumulation of the waste in the environment. (author)

Effects of waste drilling fluid on bacterial isolates from a mangrove swamp oilfield location in the Niger delta of Nigeria

International Nuclear Information System (INIS)

Benka-Coker, M.O.; Olumagin, A.

1996-01-01

Four bacteria strains isolated from a mangrove swamp oilfield location in the Niger Delta of Nigeria were cultured aerobically in the presence of 1.0% waste drilling fluid, to determine the effect of the waste on their growth. A 2-h lag phase of growth was produced by the waste in cultures of Micrococcus and Pseudomonas species, while the waste increased the lag phases of Alcaligenes and Staphylococcus species to 4 h. The exponential phase of growth of Pseudomonas sp. was depressed by the waste drilling fluid but fluid stimulated the exponential phases of Micrococcus and Alcaligenes spp. There was enhancement of the growth rate of Alcaligenes and Micrococcus spp. while those of Staphylococcus and Pseudonomas spp. were decreased. The depressed growth rates of Staphylococcus and Pseudonomas spp. in the presence of the waste drilling fluid might lead to a decrease in their contribution to the removal of the waste from the environment during spillage or disposal and, therefore, may result in an accumulation of the waste in the environment. (author)

Light impacts embryonic and early larval development of the European eel, Anguilla anguilla

DEFF Research Database (Denmark)

Politis, Sebastian Nikitas; Butts, Ian; Tomkiewicz, Jonna

2014-01-01

Little is known about the natural ecology of European eel during early life history. Weextend our understandings on the ecology of this species by studying howearly life stages perform under various light regimes.We assessed the effects of intensity, photoperiod (12:12 and 24:0 h light/dark) and ......Little is known about the natural ecology of European eel during early life history. Weextend our understandings on the ecology of this species by studying howearly life stages perform under various light regimes.We assessed the effects of intensity, photoperiod (12:12 and 24:0 h light...... stages. In particular, for the 12:12 h photoperiod, embryonic survival, until 26 h post-fertilization was significantly higher when reared under low (62 ± 13%) than those reared under high intensity light (42 ± 13%). Furthermore, embryos reared in low light had a higher hatch success (16 ± 7%) than those...... in high intensity light (12 ± 7%). Larval yolk-sac area was significantly affected by photoperiod and body area was significantly affected by the interaction between intensity × photoperiod. The highest incidence of deformities (75%) occurred when embryos were reared in high intensity white light under...

BIOCONTROL FOR RHIZOCTONIA STEM ROT DISEASE BY USING COMBINATION OF SPECIFIC ENDOPHYTE IN PADDY TIDAL SWAMP

Directory of Open Access Journals (Sweden)

Ismed Setya Budi

2013-10-01

Full Text Available The use of combination of specific endophytic in tidal swamps to control stem root disease as biological control agents has not been done. It is expected that this combination is able to continuously protect plants from pathogen interference. The research was carried out in type C tidal swamp in Banjar regency of South Kalimantan, from March to November 2011, temperature 29-32oC, and pH 4.0-5.5. The method used was Split Plot design. Biocontrol preparation for both types of endophytic was applied in seeds in 7 days after planting (DAP. Observation on high intensity and plant diseases of planting stage on tidal swamps (taradak, ampak and lacak was conducted. The results showed that there was a reduction of disease ranging from 58.70 to 87.29%. The application of combination of two biocontrol agents (T. viride PS-2.1 + P. fluorescent PS-4.8, (Fusarium non-pathogenic PS-1.5 + P. fluorescent PS-4.8 and (T. viride PS-2.1+ FNP PS-1.5 isolate gave the best inhibition result, reduced disease intensity, and increased plant height. The result of soil analysis before and after application of endophytic showed that there was an increase in soil fertility with the element addition of N, P, K and pH.

AGRICULTURE PHENOMENA AND PERSPECTIVES OF LEBAK SWAMP IN JAKABARING SOUTH SUMATRA, INDONESIA

Directory of Open Access Journals (Sweden)

Elisa Wildayana

2017-11-01

Full Text Available The research aimed to analyze agriculture phenomena and perspectives of lebak swamp in Jakabaring South Sumatra Indonesia. The research used mix methods of quantitative and qualitative approaches. The description of the research area was assisted with interpretation of Landsat images in 1987 and 2015. The research resulted that farmer’s groups living in Jakabaring are divided into four group, namely indigenous people (people of Ogan, Komering, Musi, Enim, and Palembang, new comers (Javanese, spontaneous migration (Buginese, Banjarnese, Bataknese and outside spontaneous migration (Chinese, Arabic. The total area of Jakabaring is approximately 5,525 ha, around 2,700 ha (48.87 % was already landfilled by the Government in 1990, while the remaining 2,825 ha (51.13 % is still not reclaimed. The landfill materials were directly sucked from mud, sand, silt and stones of the Musi River. Each lebak swamp typology shows specific soil characters, but after landfills all soils became homogenous because of uniform materials of landfills. Patterns of land degradation after landfills are classified into three groups, namely making layers of water impermeability, changing vegetation types of land cover, and decreasing type and density of vegetation.

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

Science.gov (United States)

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

2007-01-01

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

Yellow perch larval survival in the Zekiah Swamp watershed (Wicomico River, Maryland) relative to the potential effects of a coal ash storage facility

International Nuclear Information System (INIS)

Burton, W.H.; Pinkney, A.E.

1994-01-01

A coordinated program of in situ and laboratory bioassays supported by water quality analyses was used to evaluate the potential effect of a coal ash storage facility on a yellow perch (Perca flavescens) spawning area. The facility is located in the Zekiah Swamp watershed, a tributary of the Wicomico River, MD. In situ bioassays were conducted in Zekiah Swamp Run and reference locations in 1989 and 1990. Larval mortality was high in non-tidal areas of Zekiah Swamp Run, both at a site upstream and beyond the influence of the facility, and at a site downstream of the facility. Mortality was significantly less at a nearby reference stream and at a station in the tidal area of Zekiah Swamp Run. Analysis of water samples for metals (including inorganic monomeric aluminum), organic contaminants, and pH, as well as measurements of stream flow, did not identify a specific cause for the mortality. The field and laboratory bioassays showed that, although leachate from the ash facility contributed to local contamination of ground water, the facility does not appear to be responsible for the poor survival of larval yellow perch. 16 refs., 4 figs., 6 tabs

Laboratory Scale Bioremediation of Petroleum Hydrocarbon – Polluted Mangrove Swamps in the Niger Delta Using Cow Dung

Directory of Open Access Journals (Sweden)

Dike, E. N.

2012-01-01

Full Text Available Aims: The aim of the study was to carry-out laboratory–scale bioremediation of petroleum hydrocarbon polluted mangrove swamps using cow dung as source of limiting of nutrients.Methodology and Results: In a 70 days study, the cow dung treated polluted soil had its total culturable hydrocarbon utilising bacterial/fungi, heterotrophic bacterial and fungal counts increased progressively from the 28th day to the 70th day. The control set- up showed very slight increment in its microbial growth. Alkaline pH was observed in all the treatments and control during the study period. The conductivity values of cow dung decreased progressively. In the cow dung treatment option, the nitrate concentration decreased from 35.44 mg/kg to 14.28 mg/kg. Phosphate concentration of cow dung option decreased from 25.41 mg/kg to 9.31mg/kg. The control had the nitrate decreased from 8.42 mg/kg to 6.98 mg/kg. Percentage total organic carbon (% TOC in the cow dung option decreased from 4.06% to 0.96%. Control experiment had the % TOC decreased from 3.32% to 2.99%. Studies using Gas chromatographic analyses showed that 0%, 49.88%, and 69.85% of Total petroleum hydrocarbon (TPH were lost at zero hour, 28th day and 70th day respectively in the cow dung option. In addition, in the control experimental set-up, 0%, 7.14% and 13.42% of TPH were lost at zero hour, 28th day and 70th day respectively.Conclusion, significance and impact of study: The use of organic nutrient sources such as cow dung has shown good promises in bioremediation of crude oil impacted Mangrove Swamps in the Niger Delta. The next line of action is to transfer the technology to pilot scale study.

Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada)

International Nuclear Information System (INIS)

Yankovich, T.L.; King-Sharp, K.J.; Carr, J.; Robertson, E.; Killey, R.W.D.; Beresford, N.A.; Wood, M.D.

2014-01-01

A detailed survey was conducted to quantify the spatial distribution of 14 C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives 14 C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in 14 C specific activities were evaluated with distance from the sampling location with the maximum 14 C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west 14 C gradient was found, due to the influence of the WMA on 14 C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated 14 C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated 14 C transport to the atmosphere, and possibly, 14 C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower 14 C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of 14 C being carried by discharging groundwater into terrestrial and wetland environments. - Highlights: • Groundwater represents an important source of volatile radionuclides to wetlands. • Habitat type influenced 14 C transport from sub-surface to surface environments. • C-14 specific

Composition and species diversity of pine-wiregrass savannas of the Green Swamp, North Carolina

Science.gov (United States)

Joan Walker; Robert K. Peet

1983-01-01

Fire-maintained, species-rich pines wiregrass savannas in the Green Swamp, North Carolina were sampled over their natural range of environmental conditions and fire frequencies. Species composition, species richness, diversity (Exp H', I/ C), and aboveground production were documented and fertilization experiments conducted to assess possible mechanisms for the...

Recycling of phenolic compounds in Borneo's tropical peat swamp forests.

Science.gov (United States)

Yule, Catherine M; Lim, Yau Yan; Lim, Tse Yuen

2018-02-07

Tropical peat swamp forests (TPSF) are globally significant carbon stores, sequestering carbon mainly as phenolic polymers and phenolic compounds (particularly as lignin and its derivatives) in peat layers, in plants, and in the acidic blackwaters. Previous studies show that TPSF plants have particularly high levels of phenolic compounds which inhibit the decomposition of organic matter and thus promote peat accumulation. The studies of phenolic compounds are thus crucial to further understand how TPSF function with respect to carbon sequestration. Here we present a study of cycling of phenolic compounds in five forests in Borneo differing in flooding and acidity, leaching of phenolic compounds from senescent Macaranga pruinosa leaves, and absorption of phenolics by M. pruinosa seedlings. The results of the study show that total phenolic content (TPC) in soil and leaves of three species of Macaranga were highest in TPSF followed by freshwater swamp forest and flooded limestone forest, then dry land sites. Highest TPC values were associated with acidity (in TPSF) and waterlogging (in flooded forests). Moreover, phenolic compounds are rapidly leached from fallen senescent leaves, and could be reabsorbed by tree roots and converted into more complex phenolics within the leaves. Extreme conditions-waterlogging and acidity-may facilitate uptake and synthesis of protective phenolic compounds which are essential for impeded decomposition of organic matter in TPSF. Conversely, the ongoing drainage and degradation of TPSF, particularly for conversion to oil palm plantations, reverses the conditions necessary for peat accretion and carbon sequestration.

Subcellular partitioning of non-essential trace metals (Ag, As, Cd, Ni, Pb, and Tl) in livers of American (Anguilla rostrata) and European (Anguilla anguilla) yellow eels

Energy Technology Data Exchange (ETDEWEB)

Rosabal, Maikel [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Pierron, Fabien [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Couture, Patrice [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Baudrimont, Magalie [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Hare, Landis [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada)

2015-03-15

Highlights: • Handling of hepatic metals consistently involved cytosolic, thermostable ligands. • Granule-like fractions are also involved in the detoxification of Ni, Pb, and Tl. • Despite these sequestration mechanisms, metal detoxification is incomplete. • Along the metal gradient, concentrations increase in metal-sensitive fractions. • This increase could represent a toxicological risk for the yellow eels. - Abstract: We determined the intracellular compartmentalization of the trace metals Ag, As, Cd, Ni, Pb, and Tl in the livers of yellow eels collected from the Saint Lawrence River system in Canada (Anguilla rostrata) and in the area of the Gironde estuary in France (Anguilla anguilla). Differential centrifugation, NaOH digestion and thermal shock were used to separate eel livers into putative “sensitive” fractions (heat-denatured proteins, mitochondria and microsomes + lysosomes) and detoxified metal fractions (heat-stable peptides/proteins and granules). The cytosolic heat-stable fraction (HSP) was consistently involved in the detoxification of all trace metals. In addition, granule-like structures played a complementary role in the detoxification of Ni, Pb, and Tl in both eel species. However, these detoxification mechanisms were not completely effective because increasing trace metal concentrations in whole livers were accompanied by significant increases in the concentrations of most trace metals in “sensitive” subcellular fractions, that is, mitochondria, heat-denatured cytosolic proteins and microsomes + lysosomes. Among these “sensitive” fractions, mitochondria were the major binding sites for As, Cd, Pb, and Tl. This accumulation of non-essential metals in “sensitive” fractions likely represents a health risk for eels inhabiting the Saint Lawrence and Gironde environments.

Speciation and demographic history of Atlantic eels (Anguilla anguilla and A. rostrata) revealed by mitogenome sequencing

DEFF Research Database (Denmark)

Jacobsen, M.W.; Pujolar, J.M.; Gilbert, M.T.P.

2014-01-01

Processes leading to speciation in oceanic environments without obvious physical barriers remain poorly known. European and American eel (Anguilla anguilla and A. rostrata) spawn in partial sympatry in the Sargasso Sea. Larvae are advected by the Gulf Stream and other currents towards the Europea...

Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium

DEFF Research Database (Denmark)

Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E

2008-01-01

Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work...... was to investigate the functional and molecular expression of BK in the eel intestine, which is a useful experimental model for cell volume regulation research. In the present paper using rat BK channel-specific primer, a RT-PCR signal of 696 pb cDNA was detected in eel intestine, whole nucleotide sequence showed...... high similarity (83%) to the alpha subunit of BK channel family. BK channel protein expression was verified by immunoblotting and confocal microscopy, while the functional role of BK channels in epithelial ion transport mechanisms and cell volume regulation was examined by electrophysiological...

Testate amoebae analysis in the peat deposits of the swamp Dolgon’koye in the south of Western Siberia and peatland paleohydrology for last 3100 years

Science.gov (United States)

Kurina, Irina V.; Blyakharchuk, Tatiana A.

2018-03-01

Our research is devoted to paleohydrological reconstruction in the swamp located in the river valley on the piedmont of the Altai Mountains in the south of Western Siberia. The reconstruction was carried out based on rhizopod analysis for the last 3100 cal yr. A large amount of different testate amoebae was found in the peat. Total 64 testate amoebae taxa were recorded in the peat core with the most abundant being: Trinema lineare, Centropyxis aculeata, C. aerophila, Euglypha rotunda, Cryptodifflugia sp. Decrease of surface wetness in the swamp are observed 2280, 2140, 1900–600 cal yr BP and increase – in 2700, 2500–1900, 230–215 cal yr BP. The results of our reconstruction of the swamp paleohydrology agrees well with the paleoclimatic data obtained earlier for the central area of the south of Western Siberia Plain. It indicates a high sensitivity of the swamp to climatic changes in the Holocene. The rhizopod analysis proved to be very effective when used for paleohydrology reconstruction in minerotrophic peat.

Roles of the cytoskeleton and of Protein Phosphorylation Events in the Osmotic Stress Response in EEL Intestinal Epithelium

DEFF Research Database (Denmark)

Lionetto, Maria G; Pedersen, Stine F; Hoffmann, Else K

2002-01-01

The eel intestinal epithelium responds to an acute hypertonic challenge by a biphasic increase of the rate of Cl(-) absorption (measured as short circuit current, Isc, and creating a negative transepithelial potential, V(te), at the basolateral side of the epithelium). While the first, transient...... phase is bumetanide-insensitive, the second, sustained phase is bumetanide-sensitive, reflecting activation of the apically located Na(+)-K(+)-2Cl(-) (NKCC) cotransporter, which correlates with the cellular RVI response. Here, we investigated the involvement of the cytoskeleton and of serine....../threonine phosphorylation events in the osmotic stress-induced ion transport in the eel intestinal epithelium, focusing on the sustained RVI phase, as well as on the previously uncharacterized response to hypotonic stress. The study was carried out using confocal laser scanning microscopy, a quantitative F-actin assay...

Accumulation of metals, polycyclic (halogenated) aromatic hydrocarbons, and biocides in zebra mussel and eel from the Rhine and Meuse rivers

Energy Technology Data Exchange (ETDEWEB)

Hendriks, A.J. [RIZA, Lelystad (Netherlands). Inst. for Inland Water Management and Waste Water Treatment; Pieters, H.; Boer, J. de [DLO-Netherlands Inst. for Fisheries Research, IJmuiden (Netherlands)

1998-10-01

Concentrations of heavy metals and various groups of organic microcontaminants were measured in zebra mussel and eel from the Rhine-Meuse basin. Residues in mussel from the Rhine and Meuse were on average 2.3 and 2.9 times higher than in those from the reference location of IJsselmeer. Total body burdens of organic microcontaminants in mussel and eel varied between 0.05 to 0.07 mmol/kg fat weight in six out of seven samples. The largest contribution in mussels and eel came from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), respectively. Concentrations of bromodiphenyl-ethers, chlorobenzenes, chloronitrobenzenes, chloroterphenyls, and chlorobenzyltoluenes were lower. Total polybrominated biphenyl residues appear lower than total PCB levels. The largest chlorobiocide residues were noted for 4,4{prime}-DDE, toxaphene, trichlorophenylmethane, and {gamma}-hexachlorocyclohexane. An extraordinary high body burden of 1.2 mmol/kg fat weight, largely consisting of acenaphthene, was observed in one sample. Ratios of concentrations in organism fat and dry organic suspended solids varied between 1 and 10 for traditionally monitored organochlorines, independent of the octanol-water partition coefficient. The values did not deviate significantly from a value of about 3.3, expected for equilibrium partitioning of persistent chemicals. Lower values were observed for PAHs and some chloro(nitro)benzenes. Most ratios of concentrations in eel and mussel fat were within the range of 1 to 10, also largely independent of K{sub ow}. Yet, values tended to be higher at K{sub ow} > 10{sup 6}. Ratios below 1 were noted for pentabromodiphenylether, pentachloro(thio)anisol, chlorobenzyltoluenes, and some chloronitrobenzenes, chlorobiphenyls, and chlorobiocides. These field data confirm recent modeling efforts on bioconcentration and biomagnification. For heavy metals, atomic mass explained 67% of the variation in zebra mussel residues.

Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation.

Science.gov (United States)

Kalujnaia, Svetlana; Hazon, Neil; Cramb, Gordon

2016-08-01

A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells. Copyright © 2016 the American Physiological Society.

SWAMP+: multiple subsequence alignment using associative massive parallelism

Energy Technology Data Exchange (ETDEWEB)

Steinfadt, Shannon Irene [Los Alamos National Laboratory; Baker, Johnnie W [KENT STATE UNIV.

2010-10-18

A new parallel algorithm SWAMP+ incorporates the Smith-Waterman sequence alignment on an associative parallel model known as ASC. It is a highly sensitive parallel approach that expands traditional pairwise sequence alignment. This is the first parallel algorithm to provide multiple non-overlapping, non-intersecting subsequence alignments with the accuracy of Smith-Waterman. The efficient algorithm provides multiple alignments similar to BLAST while creating a better workflow for the end users. The parallel portions of the code run in O(m+n) time using m processors. When m = n, the algorithmic analysis becomes O(n) with a coefficient of two, yielding a linear speedup. Implementation of the algorithm on the SIMD ClearSpeed CSX620 confirms this theoretical linear speedup with real timings.

Structure of the tree stratum of three swamp forest communities in southern Brazil under different soil conditions

Directory of Open Access Journals (Sweden)

Luciana Carla Mancino

2015-03-01

Full Text Available Restinga forests are commonly known to be plant communities rather poor in tree species. This study aimed to describe and explain the association between the floristic-structural similarities and the environmental conditions in three Swamp Restinga Forest communities in southern Brazil. In 13 plots of 100 m2 each, we sampled all individual trees (circumference at breast height >12 cm and height ≥3 m. We collected soil samples in each plot for chemical and textural analyses. Phytosociological parameters were calculated and different structural variables were compared between areas. The density of individuals did not differ between areas; however, the maximum height and abundance of species differed between the site with Histosols and the other two sites with Gleysols. Further, a canonical correspondence analysis based on a matrix of vegetation and that of environmental characteristics explained 31.5% of the total variation. The high floristic and environmental heterogeneity indicate that swamp-forests can shelter many species with low frequency. Most species were generalists that were not exclusive to this type of forest. Overall, our study showed that swamp-forests within the same region can show considerable differences in composition and structure and can include species-rich communities, mostly due to the presence of species with a broader distribution in the Atlantic Rainforest domain on sites with less stressful environmental conditions and without waterlogged conditions.

Angiotensin II dependent cardiac remodeling in the eel Anguilla anguilla involves the NOS/NO system

DEFF Research Database (Denmark)

Filice, Mariacristina; Amelio, Daniela; Garofalo, Filippo

2017-01-01

Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System (RAS), plays an important role in controlling mammalian cardiac morpho-functional remodelling. In the eel Anguilla anguilla, one month administration of AngII improves cardiac performance and influences the expression ...

Evaluating the adaptive potential of the European eel: is the immunogenetic status recovering?

Directory of Open Access Journals (Sweden)

Miguel Baltazar-Soares

2016-04-01

Full Text Available The recent increased integration of evolutionary theory into conservation programs has greatly improved our ability to protect endangered species. A common application of such theory links population dynamics and indices of genetic diversity, usually estimated from neutrally evolving markers. However, some studies have suggested that highly polymorphic adaptive genes, such as the immune genes of the Major Histocompatibility Complex (MHC, might be more sensitive to fluctuations in population dynamics. As such, the combination of neutrally- and adaptively-evolving genes may be informative in populations where reductions in abundance have been documented. The European eel (Anguilla anguilla underwent a drastic and well-reported decline in abundance in the late 20th century and still displays low recruitment. Here we compared genetic diversity indices estimated from neutral (mitochondrial DNA and microsatellites and adaptive markers (MHC between two distinct generations of European eels. Our results revealed a clear discrepancy between signatures obtained for each class of markers. Although mtDNA and microsatellites showed no changes in diversity between the older and the younger generations, MHC diversity revealed a contemporary drop followed by a recent increase. Our results suggest ongoing gain of MHC genetic diversity resulting from the interplay between drift and selection and ultimately increasing the adaptive potential of the species.

Collective modes in CuxTiSe2 measured with meV-resolution EELS

Science.gov (United States)

Rak, Melinda; Vig, Sean; Husain, Ali; Mitrano, Matteo; Rubeck, Samantha; Kogar, Anshul; Karapetrov, Goran; Morosan, Emilia; Abbamonte, Peter

The charge density wave (CDW) in 1 T-TiSe2 has been widely thought to be the result of an excitonic insulator transition. We recently observed a soft electronic mode in TiSe2 using a new, momentum-resolved electron energy loss spectroscopy (M-EELS) technique, demonstrating a condensation of electron-hole pairs in this material. As TiSe2 is doped with Cu to produce CuxTiSe2, a superconducting dome emerges above x ˜ 0.04. In this talk, I describe how the electronic collective mode evolves with Cu doping. We find that the temperature dependence of the electronic mode reverses as Cu is introduced and that the mode is much broader at low temperature as compared to the undoped material. Additionally, the electronic mode no longer has a positive dispersion at 300 K as described by the Lindhard function, but has a slightly negative dispersion for small momentum transfers. We will discuss the implications of these results for the excitonic insulator transition in TiSe2. This work was supported by the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant GBMF4542. An early prototype of the M-EELS instrument was supported by the DOE Center for Emergent Superconductivity under Award No. DE-AC02-98CH10886.

Occurrence of perfluorooctanesulfonate and perfluorooctanoic acid and histopathology in eels from north Italian waters.

Science.gov (United States)

Giari, Luisa; Guerranti, Cristiana; Perra, Guido; Lanzoni, Mattia; Fano, Elisa Anna; Castaldelli, Giuseppe

2015-01-01

A perfluorinated alkylated substances (PFAS) biomonitoring study was conducted in European eel (Anguilla anguilla) in Italy for the first time. Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) concentrations were assessed in the organs of 35 wild eels from two locations, the highly impacted Po River and the Comacchio Lagoon along the north-western Adriatic coast. PFAS were extracted by ion-pairing liquid extraction procedure and measured using high performance liquid chromatography with electrospray ionization tandem mass spectrometry. There were no significant differences in mean PFAS concentrations (p>0.05) between samples from the two sites. PFOS and PFOA were detectable (>0.4ngg(-1) wet weight, w.w) in 73% and 31% of the total samples, respectively. PFOS concentrations ranged from PFAS levels were observed in blood and the lowest in muscle. Histology showed macrophage aggregates and hepatocytic vacuolation in some liver samples. No tissue anomalies were seen in the gonads, suggesting no reproductive impairment. The PFAS contamination levels observed were comparable to, or lower than, those reported in fish in other European countries, seeming to indicate that PFAS pollution of the study area is not remarkable. Copyright © 2014 Elsevier Ltd. All rights reserved.

TEM and EELS studies of microwave-irradiation synthesis of bimetallic platinum nanocatalysts

International Nuclear Information System (INIS)

Mathe, N R; Scriba, M R; Coville, N J; Olivier, J E

2014-01-01

Microwave-irradiation (MW) synthesis of nanostructured materials provides for the synthesis of metal nanoparticles, using fast and uniform heating rates. This procedure affords better control of the shape and size of the nanoparticles when compared to conventional methods. In this work, microwave-irradiation was used to produce platinum-cobalt (Pt-Co) and platinum-nickel (Pt-Ni) nanoparticles for use as electrocatalysts in the methanol oxidation reaction. High resolution TEM imaging and EELS studies revealed that these bimetallic nanoparticles form islands or hetero-structures

Assessing pre- and post-zygotic barriers between North Atlantic eels (Anguilla anguilla and A. rostrata)

DEFF Research Database (Denmark)

Jacobsen, M. W.; Smedegaard, L.; Sørensen, Sune Riis

2017-01-01

Elucidating barriers to gene flow is important for understanding the dynamics of speciation. Here we investigate pre- and post-zygotic mechanisms acting between the two hybridizing species of Atlantic eels: Anguilla anguilla and A. rostrata. Temporally varying hybridization was examined by analyz...... in natural hybrids.Heredity advance online publication, 9 November 2016; doi:10.1038/hdy.2016.96....

Bicarbonate secreted from the pancreas contributed to the formation of Ca precipitates in Japanese eel, Anguilla japonica.

Science.gov (United States)

Mekuchi, Miyuki; Watanabe, Soichi; Kaneko, Toyoji

2013-01-01

Marine teleosts produce Ca precipitates in the intestine as a product of osmoregulation. Ca precipitates are formed by a chemical reaction of Mg(2+) and Ca(2+) derived from ingested seawater with bicarbonate (HCO(3)(-)). It has been reported that HCO(3)(-) originates from the intestine; however, the pancreas is predicted to be another organ that may supply HCO(3)(-) to the intestinal tract. In the present study, the pancreas was surgically removed from Japanese eel to confirm its contribution to Ca precipitate formation. Pancreatectomized eel produced significantly less Ca precipitates than control eel in seawater, indicating that HCO(3)(-) from the pancreas contributes substantially to the formation of Ca precipitates. To further examine the molecular mechanisms of HCO(3)(-) secretion, we cloned cDNAs encoding HCO(3)(-) transporters and identified those transporters that elevated their mRNA expression in the intestine and pancreas following seawater transfer. In the intestine, mRNA expression of Slc26a6A was increased shortly after seawater transfer, whereas Slc26a1 mRNA expression increased gradually following seawater transfer. In the pancreas, Slc26a3 mRNA expression was high during the early stage of seawater acclimation, whereas Slc26a1 expression increased gradually after transfer to seawater. In the intestine and pancreas, therefore, both transient and progressively increasing types of HCO(3)(-) transporters are likely to be involved in HCO(3)(-) secretion into the intestinal lumen in a coordinated manner. Copyright © 2012 Wiley Periodicals, Inc.

The Giant Mottled Eel, Anguilla marmorata, Uses Blue-Shifted Rod Photoreceptors during Upstream Migration

OpenAIRE

Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

2014-01-01

Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity ...

Study by AES, EELS Spectroscopy of electron Irradiation on InP and InPO4/InP in comparison with Monte Carlo simulation

International Nuclear Information System (INIS)

Lounis, Z; Bouslama, M; Hamaida, K; Abdellaoui, A; Ouerdane, A; Ghaffour, M; Berrouachedi, N; Jardin, C

2012-01-01

We give the great interest to characterise the InP and InPO 4 /InP submitted to electron beam irradiation owing to the Auger Electron Spectroscopy (AES) associated to both methods Electron Energy Loss Spectroscopy (EELS). The incident electron produces breaking of (In-P) chemical bonds. The electron beam even acts to stimulate oxidation of InP surface involving on the top layers. Other, the oxide InPO 4 developed on InP does appear very sensitive to the irradiation due to electron beam shown by the monitoring of EELS spectra recorded versus the irradiated times of the surface. There appears a new oxide thought to be In 2 O 3 . We give the simulation methods Casino (Carlo simulation of electron trajectory in solids) for determination with accuracy the loss energy of backscattered electrons and compared with reports results have been obtained with EELS Spectroscopy. These techniques of spectroscopy alone do not be able to verify the affected depth during interaction process. So, using this simulation method, we determine the interaction of electrons in the matter.

Nariva Swamp Ramsar Site, Trinidad and Tobago (West Indies) Wetland Habitat Restoration Initiative

Science.gov (United States)

Montserrat Carbonell; Nadra Nathai-Gyan

2005-01-01

Trinidad and Tobago, a twin island nation, is the most southerly of the Caribbean islands and lies just 11 km off the coast of Venezuela, near the Orinoco delta. Trinidad, the larger of the two islands, is approximately 5,000 km² and the Nariva Swamp is located on its eastern coast (fig. 1). In 1993, this site was designated as a wetland of international...

First production of larvae using cryopreserved sperm: Effects of preservation temperature and cryopreservation on European eel sperm fertilization capacity

DEFF Research Database (Denmark)

Asturiano, J.F.; Sørensen, Sune Riis; Perez, L.

2016-01-01

Sperm cryopreservation is a useful tool in captive fish reproduction management, that is to synchronize gamete production, especially in the case of species as the European eel, where the time of female spawning readiness is unpredictable. Several protocols to cryopreserve sperm of this species....... Fertilization of two egg batches was attempted. Diluted sperm caused a similar percentage of fertilized eggs and a similar number of embryos and larvae, independently of storage temperature (4 or 20°C). The cryopreserved sperm resulted in a lower percentage of fertilized eggs, but embryos developed and a few...... larvae ('cryolarvae') were obtained 55 h after fertilization in one of the two egg batches. This result evidences that the tested cryopreservation protocol is applicable for eel reproduction management, although improvements will be required to enhance fertilization success...

Utilising DualEELS to probe the nanoscale mechanisms of the corrosion of Zircaloy-4 in 350 °C pressurised water

Energy Technology Data Exchange (ETDEWEB)

Annand, Kirsty J., E-mail: k.annand.1@research.gla.ac.uk [Materials and Condensed Matter Physics, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); MacLaren, Ian [Materials and Condensed Matter Physics, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Gass, Mhairi [AMEC Foster Wheeler, Clean Energy, Walton House, Birchwood Park, WA3 6GA (United Kingdom)

2015-10-15

Characterisation of materials utilised for fuel cladding in nuclear reactors prior to service is integral in order to understand corrosion mechanisms which would take place in reactor. Zircaloy-4 is one such material of choice for nuclear fuel containment in Pressurised Water Reactors (PWRs). In particular, the metal-oxide interface has been a predominant focus of previous research, however, due to the complex oxidation process of zirconium cladding, there is still no clear understanding of what is present at the interface. Using Scanning Transmission Electron Microscopy (STEM) and Dual Electron Energy Loss Spectroscopy (DualEELS), we have studied the corrosion of this material under conditions similar to those that could be encountered in service. It is shown that under all conditions, whether during faster oxidation in the early stages, slow growth just prior to the transition to a new growth regime, or in the faster growth that happens after this transition, the surface of the metal below the scale is loaded with oxygen up to around 33 at%. Approaching transition, in conditions of slow growth and slow oxygen supply, an additional metastable suboxide is apparent with a thickness of tens of nm. By studying changes in both chemical composition and dielectric function of the material at the oxide scale – metal interface with nanometre resolution, quantitative mapping could be achieved, clearly showing that this is a suboxide composition of ZrO and a Zr oxidation state close to +2. - Highlights: • Metal-oxide interface evolution studied by few-nm resolution EELS mapping. • Low loss EELS is very effective for mapping phase evolution. • ZrO suboxide phase characterised using EELS, which fits theoretical predictions. • ZrO formation found to correlate to local growth rate of oxide scale.

Development of a broodstock diet to improve developmental competence of embryos in European eel, Anguilla anguilla

NARCIS (Netherlands)

Støttrup, J.G.; Tomkiewicz, J.; Jacobsen, C.; Heinsbroek, L.T.N.

2016-01-01

We examined the effect of dietary arachidonic acid (ARA) and eicosapentaenoic acid (EPA) on the production of embryos and hatched larvae in the European eel, Anguilla anguilla. Two diets with high and intermediate levels of ARA and low and intermediate levels of EPA (Feed 1: ARA 1.9%, EPA 4.2%;

Palm Swamp Wetland Ecosystems of the Upper Amazon: Characterizing their Distribution and Inundation State Using Multiple Resolution Microwave Remote Sensing

Science.gov (United States)

Podest, E.; McDonald, K. C.; Schröder, R.; Pinto, N.; Zimmermann, R.; Horna, V.

2011-12-01

Palm swamp wetlands are prevalent in the Amazon basin, including extensive regions in northern Peru. These ecosystems are characterized by constant surface inundation and moderate seasonal water level variation. The combination of constantly saturated soils, giving rise to low oxygen conditions, and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, knowledge of their spatial extent and inundation state is crucial for assessing the associated land-atmosphere carbon exchange. Precise spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We are developing a remote sensing methodology using multiple resolution microwave remote sensing data to determine palm swamp distribution and inundation state over focus regions in the Amazon basin in northern Peru. For this purpose, two types of multi-temporal microwave data are used: 1) high-resolution (100 m) data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR) to derive maps of palm swamp extent and inundation from dual-polarization fine-beam and multi-temporal HH-polarized ScanSAR, and 2) coarse resolution (25 km) combined active and passive microwave data from QuikSCAT and AMSR-E to derive inundated area fraction on a weekly basis. We compare information content and accuracy of the coarse resolution products to the PALSAR-based datasets to ensure information harmonization. The synergistic combination of high and low resolution datasets will allow for characterization of palm swamps and

Yeast communities in Sphagnum phyllosphere along the temperature-moisture ecocline in the boreal forest-swamp ecosystem and description of Candida sphagnicola sp. nov.

Science.gov (United States)

Kachalkin, Aleksey V; Yurkov, Andrey M

2012-06-01

The effects of the temperature-moisture factors on the phylloplane yeast communities inhabiting Sphagnum mosses were studied along the transition from a boreal forest to a swamp biotope at the Central Forest State Biosphere Reserve (Tver region, Russia). We tested the hypothesis that microclimatic parameters affect yeast community composition and structure even on a rather small spatial scale. Using a conventional plating technique we isolated and identified by molecular methods a total of 15 species of yeasts. Total yeast counts and species richness values did not depend on environmental factors, although yeast community composition and structure did. On average, Sphagnum in the swamp biotope supported a more evenly structured yeast community. Relative abundance of ascomycetous yeasts was significantly higher on swamp moss. Rhodotorula mucilaginosa dominated in the spruce forest and Cryptococcus magnus was more abundant in the swamp. Our study confirmed the low occurrence of tremellaceous yeasts in the Sphagnum phyllosphere. Of the few isolated ascomycetous yeast and yeast-like species, some were differentiated from hitherto known species in physiological tests and phylogenetic analyses. We describe one of them as Candida sphagnicola and designate KBP Y-3887(T) (=CBS 11774(T) = VKPM Y-3566(T) = MUCL 53590(T)) as the type strain. The new species was registered in MycoBank under MB 563443.

Galling arthropod diversity in adjacent swamp forests and restinga vegetation in Rio Grande do Sul, Brazil.

Science.gov (United States)

Mendonça, Milton De S; Piccardi, Hosana M F; Jahnke, Simone M; Dalbem, Ricardo V

2010-01-01

Galling arthropods create plant structures inside which they find shelter. Factors acting on galler diversity are still being discussed, with this fauna considered more diverse in xeric than mesic environments (higrothermic stress hypothesis, HSH), and also in more plant diverse sites. Here we compare galler abundance (N), equitability (E), species richness (S) and composition between adjacent restinga (xeric) and swamp forests (mesic) in Parque Estadual de Itapeva (29°21' S, 49°45' W), Rio Grande do Sul, southern Brazil. Five trails, two in swamp forest and three in restingas, were sampled four times each (January/December 2005). After an effort of 60h/person, 621 galled plant individuals belonging to 104 gall morphotypes were recorded. This suggests a high galler diversity for the Park, comparable to the richest places known. No differences were found for N, E or S between restingas and swamp forests. However, faunal composition differs significantly between the vegetation types. The dominant (most abundant) species are different in either vegetation type, and are rare or absent on the other vegetation type. Such species composition analysis is still largely ignored for gallers, and stresses the fact that the HSH cannot explain this pattern, since the latter is based on preferences by the ovipositing galler for xeric sites instead of mesic ones. The two habitats differ in microclimate, but species richness, as would be predicted by the HSH, does not differ. This small scale pattern can perhaps be attributed to biogeographic processes on larger scales, as suggested by the resource synchronisation hypothesis.

EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

International Nuclear Information System (INIS)

Espinosa-Magana, F.; Ochoa-Lara, M.T.; Lovey, F.; Flores-Zuniga, H.; Rios-Jara, D.

2010-01-01

Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L 2,3 white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

Energy Technology Data Exchange (ETDEWEB)

Espinosa-Magana, F., E-mail: francisco.espinosa@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Ochoa-Lara, M.T. [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Lovey, F. [Centro Atomico Bariloche, 8300 S.C. de Bariloche (Argentina); Flores-Zuniga, H. [Universidad Autonoma de Zacatecaa, Av. Lopez Velarde 801, Zacatecas, Zac. 98060 (Mexico); Rios-Jara, D. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, San luis Potosi, S.L.P. 78126 (Mexico)

2010-01-01

Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L{sub 2,3} white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

Application of STEM/EELS to Plasmon-Related Effects in Optical Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Camden, Jon [Univ. of Notre Dame, IN (United States). Dept. of Chemistry and Biochemistry

2017-08-15

In this project we employed EELS/STEM to understand the near-field enhancements that drive current applications of plasmonic nanostructures. In particular, we explore the connection between optical and electron excitation of plasmon modes in metallic nanostructures: (1) Probing the structural parameters and dielectric properties of multimetallic nanoparticles; (2) Characterization of the near-electric-field enhancements obtained upon excitation of the localized surface plasmon resonance and understand the connection between electron- and photon-driven plasmons; (3) Understanding the behavior of molecules in plasmon-enhanced fields which is essential to emerging applications such as plasmon-assisted catalysis and solar energy harvesting.

Role of BK channels in the apoptotic volume decrease in native eel intestinal cells

DEFF Research Database (Denmark)

Lionetto, Maria Giulia; Giordano, Maria Elena; Calisi, Antonio

2010-01-01

High conductance Ca(+)-activated K(+) channels (BK channels) have previously been demonstrated in the eel intestine. They are specifically activated following a hypotonic stress and sustain Regulatory Volume Decrease (RVD). The aim of the present work was to address the possible role...... enterocytes that BK channels, which are involved in RVD in these cells, plays also a crucial role in the AVD process and in the progression of apoptosis....

Qualitative assessment of the diet of European eel larvae in the Sargasso Sea resolved by DNA barcoding

DEFF Research Database (Denmark)

Riemann, L.; Alfredsson, H.; Hansen, Michael Møller

2010-01-01

, the Sargasso Sea is oligotrophic, with generally low plankton biomass, and the feeding biology of eel larvae has so far remained a mystery, hampering understanding of this peculiar life history. DNA barcoding of gut contents of 61 genetically identified A. anguilla larvae caught in the Sargasso Sea showed...

EELS measurements of boron concentration profiles in p-a-Si and nip a-Si solar cells

DEFF Research Database (Denmark)

Van Aken, Bas B.; Duchamp, Martial; Boothroyd, Chris

2012-01-01

The p-type Si layer in a-Si and μc-Si solar cells on foil needs to fulfil several important requirements. The layer is necessary to create the electric field that separates the photo-generated charge carriers; the doping also increases the conductivity to conduct the photocurrent to the front......-3, using core-loss EELS combined with numerical analysis. We control the band gap and activation energy of p-a-SiC by varying the B2H6 and CH4 flow during deposition in the process chamber. We have found a linear relation between the activation energy of the dark conductivity Eact and the optical...... band gap E04. Modelling shows that the optimum efficiency in nip solar cells is obtained when the p-a-SiC band gap is slightly larger than the band gap of the absorber layer. We have assessed the potential of core-loss EELS for detecting B and C concentrations as low as 1020cm-3 in a spatially resolved...

Proteomic responses of peripheral blood mononuclear cells in the European eel (Anguilla anguilla) after perfluorooctane sulfonate exposure

Energy Technology Data Exchange (ETDEWEB)

Roland, Kathleen, E-mail: kathleen.roland@fundp.ac.be [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Kestemont, Patrick; Hénuset, Laurence; Pierrard, Marie-Aline [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Raes, Martine; Dieu, Marc [Research Unit in Cellular Biology (URBC) Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Silvestre, Frédéric [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium)

2013-03-15

Highlights: ► We have evaluating the toxicity of eel peripheral blood mononuclear cells exposed during 48 h to 10 μg and 1 mg perfluoroctane sulfonate/L. ► After in vitro contaminations, the post-nuclear fraction was isolated and a proteomic analysis using 2D-DIGE was performed. ► 48 different proteins were identified and classified into main functional classes which provide clues on the cellular pathways mainly affected by PFOS. -- Abstract: Since the 1980s, the stocks of European eel have been declining in most of their geographical distribution area. Many factors can be attributed to this decline such as pollution by xenobiotics like perfluorooctane sulfonate (PFOS). This study aimed at evaluating the in vitro toxicity of eel peripheral blood mononuclear cells (PBMC) exposed to PFOS. Exposure time and two concentrations were chosen to avoid cell mortality (48 h exposure at 10 μg PFOS/L and 1 mg PFOS/L). After in vitro contaminations, the post-nuclear fraction was isolated and a proteomic analysis using 2D-DIGE was performed to compare PBMC from the control group with cells exposed to the pollutant. On the 158 spots that were significantly affected by PFOS exposure, a total of 48 different proteins were identified using nano-LCESI-MS/MS and the Peptide and Protein Prophet of Scaffold software. These proteins can be categorized into diverse functional classes, related to cytoskeleton, protein folding, cell signaling, proteolytic pathway and carbohydrate and energy metabolism, which provide clues on the cellular pathways mainly affected by PFOS. Some of the identified proteins are rarely found in other ecotoxicological proteomic studies and could constitute potential biomarkers of exposure to PFOS in fish.

Movement patterns of seaward migrating European eel (Anguilla anguilla) at a complex of riverine barriers: implications for conservation

DEFF Research Database (Denmark)

Piper, Adam T.; Svendsen, Jon Christian; Wright, Rosalind M.

2017-01-01

, this is currently lacking for many species. Employing high-resolution positioning telemetry, this study examined movements of downstream migrating adult European eel, Anguilla anguilla, as they encountered a complex of water control structures in one location on the River Stour, southern England. The distribution...

Dialogues of the deaf in Dutch eel management policy. Explaining controversy and deadlock with argumentative discourse analysis

NARCIS (Netherlands)

Herten, M. van; Runhaar, H.A.C.

2013-01-01

Scientists claim the European eel stock is in a state of crisis. Although stakeholders in the Netherlands agree, also upon the need for action, for a long time no concrete measures were decided upon. Drastic protection measures were only taken 70 years after the first warning signs and 11 years

Nitrogen Dynamics Along a Headwater Stream Draining a Fen, Swamp, and Marsh in a Fractured Dolomite Watershed

Science.gov (United States)

Duval, T. P.; Waddington, J. M.

2009-05-01

Stream-wetland interaction has been shown to have a significant effect on nutrient cycling and downstream water quality. Additionally, connection to regional groundwater systems can dilute or enrich stream water with a number of dissolved constituents. This study demonstrates the resultant downstream change in dissolved nitrogen species as a hardwater stream emerges from a calcareous aquifer and traverses a calcareous fen, a cedar swamp, and a cattail marsh over two growing seasons, a very dry 2006 and a very wet 2007. Upon emergence at a number of groundwater seeps, the water contained appreciable nitrate levels averaging 2.72±0.42 mg NO3-N L-1, minimal organic nitrogen, and ammonium below detectable levels. Through the gently sloping calcareous fen, with a stream residence time of ~ 5 hours, NO3-N concentration decreases of 0.35 mg L-1 were observed. Concomitantly, stream recharge into the dolomite bedrock depressed stream discharge values significantly, further removing nitrate from the stream system. This resulted in the fen-bedrock system acting as an estimated net sink of 432 kg of NO3-N in the early summer of 2007, for example. In contrast, the hydrological-biogeochemical systems became decoupled through the swamp during the same period, where concentrations increased from 2.58±0.34 mg L-1 entering the swamp to 2.65±0.58 mg L-1 exiting, but streamflow decreased in general by 5 L s- 1. This resulted in the swamp, with its large depression storage, acting as a small net sink of nitrate (75 kg through the early summer), which would not be detected simply from concentration changes. The concentration-discharge relation realigned through the marsh, where significant groundwater entered the wetland, increasing both concentration and discharge, yielding a small export of 93 kg over the same time period. A series of tracer injections in each wetland type will be presented to compare the streamflow- concentration patterns with the measured nutrient spiralling

A hybrid method using the widely-used WIEN2k and VASP codes to calculate the complete set of XAS/EELS edges in a hundred-atoms system.

Science.gov (United States)

Donval, Gaël; Moreau, Philippe; Danet, Julien; Larbi, Séverine Jouanneau-Si; Bayle-Guillemaud, Pascale; Boucher, Florent

2017-01-04

Most of the recent developments in EELS modelling has been focused on getting a better agreement with measurements. Less work however has been dedicated to bringing EELS calculations to larger structures that can more realistically describe actual systems. The purpose of this paper is to present a hybrid approach well adapted to calculating the whole set of localised EELS core-loss edges (at the XAS level of theory) on larger systems using only standard tools, namely the WIEN2k and VASP codes. We illustrate the usefulness of this method by applying it to a set of amorphous silicon structures in order to explain the flattening of the silicon L 2,3 EELS edge peak at the onset. We show that the peak flattening is actually caused by the collective contribution of each of the atoms to the average spectrum, as opposed to a flattening occurring on each individual spectrum. This method allowed us to reduce the execution time by a factor of 3 compared to a usual-carefully optimised-WIEN2k calculation. It provided even greater speed-ups on more complex systems (interfaces, ∼300 atoms) that will be presented in a future paper. This method is suited to calculate all the localized edges of all the atoms of a structure in a single calculation for light atoms as long as the core-hole effects can be neglected.

Landscape-scale changes in forest canopy structure across a partially logged tropical peat swamp

Science.gov (United States)

Wedeux, B. M. M.; Coomes, D. A.

2015-11-01

Forest canopy structure is strongly influenced by environmental factors and disturbance, and in turn influences key ecosystem processes including productivity, evapotranspiration and habitat availability. In tropical forests increasingly modified by human activities, the interplay between environmental factors and disturbance legacies on forest canopy structure across landscapes is practically unexplored. We used airborne laser scanning (ALS) data to measure the canopy of old-growth and selectively logged peat swamp forest across a peat dome in Central Kalimantan, Indonesia, and quantified how canopy structure metrics varied with peat depth and under logging. Several million canopy gaps in different height cross-sections of the canopy were measured in 100 plots of 1 km2 spanning the peat dome, allowing us to describe canopy structure with seven metrics. Old-growth forest became shorter and had simpler vertical canopy profiles on deeper peat, consistent with previous work linking deep peat to stunted tree growth. Gap size frequency distributions (GSFDs) indicated fewer and smaller canopy gaps on the deeper peat (i.e. the scaling exponent of Pareto functions increased from 1.76 to 3.76 with peat depth). Areas subjected to concessionary logging until 2000, and illegal logging since then, had the same canopy top height as old-growth forest, indicating the persistence of some large trees, but mean canopy height was significantly reduced. With logging, the total area of canopy gaps increased and the GSFD scaling exponent was reduced. Logging effects were most evident on the deepest peat, where nutrient depletion and waterlogged conditions restrain tree growth and recovery. A tight relationship exists between canopy structure and peat depth gradient within the old-growth tropical peat swamp forest. This relationship breaks down after selective logging, with canopy structural recovery, as observed by ALS, modulated by environmental conditions. These findings improve our

Dissolved Oxygen Dynamics in Backwaters of North America's Largest River Swamp

Science.gov (United States)

Bueche, S. M.; Xu, Y. J.; Reiman, J. H.

2017-12-01

The Atchafalaya River (AR) is the largest distributary of the Mississippi River flowing through south-central Louisiana, creating North America's largest river swamp basin - the Atchafalaya River Basin (ARB). Prior to human settlement, the AR's main channel was highly connected to this large wetland ecosystem. However, due to constructed levee systems and other human modifications, much of the ARB is now hydrologically disconnected from the AR's main channel except during high flow events. This lack of regular inputs of fresh, oxygenated water to these wetlands, paired with high levels of organic matter decomposition in wetlands, has caused low oxygen-deprived hypoxic conditions in the ARB's back waters. In addition, due to the incredibly nutrient-rich and warm nature of the ARB, microbial decomposition in backwater areas with limited flow often results in potentially stressful, if not lethal, levels of DO for organisms during and after flood pulses. This study aims to investigate dynamics of dissolved oxygen in backwaters of the Atchafalaya River Basin, intending to answer a crucial question about hydrological and water quality connectivity between the river's mainstem and its floodplain. Specifically, the study will 1) conduct field water quality measurements, 2) collect composite water samples for chemical analysis of nutrients and carbon, 3) investigate DO dynamics over different seasons for one year, and 4) determine the major factors that affect DO dynamics in this unique swamp ecosystem. The study is currently underway; therefore, in this presentation we will share the major findings gained in the past several months and discuss backwater effects on river chemistry.

Diel and seasonal movements by adult Sacramento pikeminnow (Ptychocheilus grandis) in the Eel River, northwestern California

Science.gov (United States)

Bret C. Harvey; Rodney J. Nakamoto

1999-01-01

Abstract - In late summer and fall, radio-tagged adult Sacramento pike-minnow (Ptychocheilus grandis) at three sites in the Eel River of northwestern California moved more at night than during the day. Fish moved up to 535 m at night and returned to their original positions the following morning. Adult Sacramento pikeminnow at all sites occupied only pools during the...

Surface refinement and electronic properties of graphene layers grown on copper substrate: An XPS, UPS and EELS study

Czech Academy of Sciences Publication Activity Database

Siokou, A.; Ravani, F.; Karakalos, S.; Frank, Otakar; Kalbáč, Martin; Galiotis, C.

2011-01-01

Roč. 257, č. 23 (2011), s. 9785-9790 ISSN 0169-4332 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400911 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * XPS * EELS Subject RIV: CG - Electrochemistry Impact factor: 2.103, year: 2011

[Distribution, surface and protected area of palm-swamps in Costa Rica and Nicaragua].

Science.gov (United States)

Serrano-Sandí, Juan; Bonilla-Murillo, Fabian; Sasa, Mahmood

2013-09-01

In Central America, palm swamps are known collectively as yolillales. These wetlands are usually dominated by the raffia palm Raphia taedigera, but also by the royal palm Manicaria saccifera and -in lower extensions- by the American oil palm Elaeis oleifera. The yolillales tend to be poor in woody species and are characteristic of regions with high rainfall and extensive hydroperiods, so they remain flooded most of the year. The dominance of large raffia palm leaves in the canopy, allow these environments to be distinguishable in aerial photographs, which consequently has helped to map them along most of their distribution. However, while maps depicting yolillales are available, the extent of their surface area, perimeter and connectivity remains poorly understood. This is particularly true for yolillales in Costa Rica and Nicaragua, countries that share a good proportion of palm dominated swaps in the Rio San Juan Basin. In addition, it is not known the actual area of these environments that is under any category of protection according to the conservation systems of both countries. As a first step to catalog yolillal wetlands in Costa Rica and Nicaragua, this paper evaluates cartographic maps to delineate yolillales in the region. A subsample of yolillales mapped in this study were visited and we geo-referenced them and evaluate the extent and condition of the swamp. A total of 110 883.2ha are classified as yolillales in Nicaragua, equivalent to 22% of wetland surface area recorded for that country (excluding the Cocibolca and Xolothn Lakes). In Costa Rica, 53 931.3ha are covered by these palm dominated swamps, which represent 16.24% of the total surface area covered by wetlands. About 47% of the area covered by yolillales in Nicaragua is under some category of protection, the largest extensions protected by Cerro Silva, Laguna Tale Sulumas and Indio Maiz Nature Reserves. In Costa Rica, 55.5% of the area covered by yolillal is located within protected areas

Towards atomically resolved EELS elemental and fine structure mapping via multi-frame and energy-offset correction spectroscopy.

Science.gov (United States)

Wang, Yi; Huang, Michael R S; Salzberger, Ute; Hahn, Kersten; Sigle, Wilfried; van Aken, Peter A

2018-01-01

Electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy are two of the most common means for chemical analysis in the scanning transmission electron microscope. The marked progress of the instrumentation hardware has made chemical analysis at atomic resolution readily possible nowadays. However, the acquisition and interpretation of atomically resolved spectra can still be problematic due to image distortions and poor signal-to-noise ratio of the spectra, especially for investigation of energy-loss near-edge fine structures. By combining multi-frame spectrum imaging and automatic energy-offset correction, we developed a spectrum imaging technique implemented into customized DigitalMicrograph scripts for suppressing image distortions and improving the signal-to-noise ratio. With practical examples, i.e. SrTiO 3 bulk material and Sr-doped La 2 CuO 4 superlattices, we demonstrate the improvement of elemental mapping and the EELS spectrum quality, which opens up new possibilities for atomically resolved EELS fine structure mapping. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Swimming physiology of European silver eels (Anguilla anguilla L.): energetic costs and effects on sexual maturation and reproduction.

Science.gov (United States)

Palstra, Arjan P; van den Thillart, Guido E E J M

2010-09-01

The European eel migrates 5,000-6,000 km to the Sargasso Sea to reproduce. Because they venture into the ocean in a pre-pubertal state and reproduce after swimming for months, a strong interaction between swimming and sexual maturation is expected. Many swimming trials have been performed in 22 swim tunnels to elucidate their performance and the impact on maturation. European eels are able to swim long distances at a cost of 10-12 mg fat/km which is 4-6 times more efficient than salmonids. The total energy costs of reproduction correspond to 67% of the fat stores. During long distance swimming, the body composition stays the same showing that energy consumption calculations cannot be based on fat alone but need to be compensated for protein oxidation. The optimal swimming speed is 0.61-0.67 m s(-1), which is approximately 60% higher than the generally assumed cruise speed of 0.4 m s(-1) and implies that female eels may reach the Sargasso Sea within 3.5 months instead of the assumed 6 months. Swimming trials showed lipid deposition and oocyte growth, which are the first steps of sexual maturation. To investigate effects of oceanic migration on maturation, we simulated group-wise migration in a large swim-gutter with seawater. These trials showed suppressed gonadotropin expression and vitellogenesis in females, while in contrast continued sexual maturation was observed in silver males. The induction of lipid deposition in the oocytes and the inhibition of vitellogenesis by swimming in females suggest a natural sequence of events quite different from artificial maturation protocols.

Site-specific electronic structure analysis by channeling EELS and first-principles calculations.

Science.gov (United States)

Tatsumi, Kazuyoshi; Muto, Shunsuke; Yamamoto, Yu; Ikeno, Hirokazu; Yoshioka, Satoru; Tanaka, Isao

2006-01-01

Site-specific electronic structures were investigated by electron energy loss spectroscopy (EELS) under electron channeling conditions. The Al-K and Mn-L(2,3) electron energy loss near-edge structure (ELNES) of, respectively, NiAl2O4 and Mn3O4 were measured. Deconvolution of the raw spectra with the instrumental resolution function restored the blunt and hidden fine features, which allowed us to interpret the experimental spectral features by comparing with theoretical spectra obtained by first-principles calculations. The present method successfully revealed the electronic structures specific to the differently coordinated cationic sites.

Seed germination studies on Gymnacranthera canarica (King Warb. - a Vulnerable tree species of a highly threatened Myristica swamp ecosystem

Directory of Open Access Journals (Sweden)

K. Keshavachandra

2016-07-01

Full Text Available Gymnacranthera canarica (King Warb. is an exclusive Myristica swamp species endemic to the Western Ghats.  The Myristica swamp is a Critically Endangered ecosystem.  Studies were carried out to assess the viability, germination and storage behaviour of Gymnacranthera canarica seeds.  In the present study, it was observed that seeds have shown an initiation of germination after two weeks.  A maximum of 90% germination was recorded when the initial moisture content was 38.04 ± 1.75 %.  A decreased percentage (3% was observed when the moisture content reached 14.26 ± 2.3 after 70 days of storage.  Seeds failed to germinate beyond this moisture level.  A desiccation study showed recalcitrant behaviour and seeds can be stored in lab conditions for up to two and half months.

Old carbon efflux from tropical peat swamp drainage waters

Science.gov (United States)

Vihermaa, Leena; Waldron, Susan; Evers, Stephanie; Garnett, Mark; Newton, Jason

2014-05-01

Tropical peatlands constitute ~12% of the global peatland carbon pool, and of this 10% is in Malaysia1. Due to rising demand for food and biofuels, large areas of peat swamp forest ecosystems have been converted to plantation in Southeast Asia and are being subjected to degradation, drainage and fire, changing their carbon fluxes eg.2,3. Dissolved organic carbon (DOC) lost from disturbed tropical peat can be derived from deep within the peat column and be aged from centuries to millennia4 contributing to aquatic release and cycling of old carbon. Here we present the results of a field campaign to the Raja Musa Peat Swamp Forest Reserve in N. Selangor Malaysia, which has been selectively logged for 80 years before being granted timber reserve status. We measured CO2 and CH4efflux rates from drainage systems with different treatment history, and radiocarbon dated the evasion CO2 and associated [DOC]. We also collected water chemistry and stable isotope data from the sites. During our sampling in the dry season CO2 efflux rates ranged from 0.8 - 13.6 μmol m-2 s-1. Sediments in the channel bottom contained CH4 that appeared to be primarily lost by ebullition, leading to sporadic CH4 efflux. However, dissolved CH4 was also observed in water samples collected from these systems. The CO2 efflux was aged up to 582±37 years BP (0 BP = AD 1950) with the associated DOC aged 495±35 years BP. Both DOC and evasion CO2 were most 14C-enriched (i.e. younger) at the least disturbed site, and implied a substantial component of recently fixed carbon. In contrast, CO2 and DOC from the other sites had older 14C ages, indicating disturbance as the trigger for the loss of old carbon. 1Page et al., 2010 2Hooijer et al., 2010 3Kimberly et al., 2012 4Moore et al., 2013

Weeds optimally grow in peat swamp after burning

Directory of Open Access Journals (Sweden)

P.D. Susanti

2014-07-01

Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning

Identifying food deserts and swamps based on relative healthy food access: a spatio-temporal Bayesian approach.

Science.gov (United States)

Luan, Hui; Law, Jane; Quick, Matthew

2015-12-30

Obesity and other adverse health outcomes are influenced by individual- and neighbourhood-scale risk factors, including the food environment. At the small-area scale, past research has analysed spatial patterns of food environments for one time period, overlooking how food environments change over time. Further, past research has infrequently analysed relative healthy food access (RHFA), a measure that is more representative of food purchasing and consumption behaviours than absolute outlet density. This research applies a Bayesian hierarchical model to analyse the spatio-temporal patterns of RHFA in the Region of Waterloo, Canada, from 2011 to 2014 at the small-area level. RHFA is calculated as the proportion of healthy food outlets (healthy outlets/healthy + unhealthy outlets) within 4-km from each small-area. This model measures spatial autocorrelation of RHFA, temporal trend of RHFA for the study region, and spatio-temporal trends of RHFA for small-areas. For the study region, a significant decreasing trend in RHFA is observed (-0.024), suggesting that food swamps have become more prevalent during the study period. For small-areas, significant decreasing temporal trends in RHFA were observed for all small-areas. Specific small-areas located in south Waterloo, north Kitchener, and southeast Cambridge exhibited the steepest decreasing spatio-temporal trends and are classified as spatio-temporal food swamps. This research demonstrates a Bayesian spatio-temporal modelling approach to analyse RHFA at the small-area scale. Results suggest that food swamps are more prevalent than food deserts in the Region of Waterloo. Analysing spatio-temporal trends of RHFA improves understanding of local food environment, highlighting specific small-areas where policies should be targeted to increase RHFA and reduce risk factors of adverse health outcomes such as obesity.

Ornithological aspects on the swamp Herghelie – Mangalia (Romania

Directory of Open Access Journals (Sweden)

GACHE Carmen

2005-09-01

Full Text Available This ornithological notice present information on the avifauna recorded in the swamp Herghelie – Mangalia beginning with the 1998’s summer. We identified 132 species of birds. The reedbeds cover about 35% of the swamp’s surface, offering good conditions for the breeding season (Ixobrychus minutus, Botaurus stellaris, Cygnus olor, Himantopus himantopus, Recurvirostra avosetta and Sterna hirundo but also for migration period. The breeding population is low due the high level of the human pressure. Due the presence of sulphurous sources and peat bed, the water is not freezing during the winter, transforming this territory in an important wintering site in the southeastern Dobroudja. Interesting is also the presence in this area during the winter of some summer visitors’ species for Romania like: Phalacrocorax pygmeus, Botaurus stellaris and Rallus aquaticus.

Modeling Flood Plain Hydrology and Forest Productivity of Congaree Swamp, South Carolina

Science.gov (United States)

Doyle, Thomas W.

2009-01-01

An ecological field and modeling study was conducted to examine the flood relations of backswamp forests and park trails of the flood plain portion of Congaree National Park, S.C. Continuous water level gages were distributed across the length and width of the flood plain portion - referred to as 'Congaree Swamp' - to facilitate understanding of the lag and peak flood coupling with stage of the Congaree River. A severe and prolonged drought at study start in 2001 extended into late 2002 before backswamp zones circulated floodwaters. Water levels were monitored at 10 gaging stations over a 4-year period from 2002 to 2006. Historical water level stage and discharge data from the Congaree River were digitized from published sources and U.S. Geological Survey (USGS) archives to obtain long-term daily averages for an upstream gage at Columbia, S.C., dating back to 1892. Elevation of ground surface was surveyed for all park trails, water level gages, and additional circuits of roads and boundaries. Rectified elevation data were interpolated into a digital elevation model of the park trail system. Regression models were applied to establish time lags and stage relations between gages at Columbia, S.C., and gages in the upper, middle, and lower reaches of the river and backswamp within the park. Flood relations among backswamp gages exhibited different retention and recession behavior between flood plain reaches with greater hydroperiod in the lower reach than those in the upper and middle reaches of the Congaree Swamp. A flood plain inundation model was developed from gage relations to predict critical river stages and potential inundation of hiking trails on a real-time basis and to forecast the 24-hour flood In addition, tree-ring analysis was used to evaluate the effects of flood events and flooding history on forest resources at Congaree National Park. Tree cores were collected from populations of loblolly pine (Pinus taeda), baldcypress (Taxodium distichum), water

Differences in impacts of Hurricane Sandy on freshwater swamps on the Delmarva Peninsula, Mid−Atlantic Coast, USA

Science.gov (United States)

Middleton, Beth A.

2016-01-01

Hurricane wind and surge may have different influences on the subsequent composition of forests. During Hurricane Sandy, while damaging winds were highest near landfall in New Jersey, inundation occurred along the entire eastern seaboard from Georgia to Maine. In this study, a comparison of damage from salinity intrusion vs. wind/surge was recorded in swamps of the Delmarva Peninsula along the Pocomoke (MD) and Nanticoke (DE) Rivers, south of the most intense wind damage. Hickory Point Cypress Swamp (Hickory) was closest to the Chesapeake Bay and may have been subjected to a salinity surge as evidenced by elevated salinity levels at a gage upstream of this swamp (storm salinity = 13.1 ppt at Nassawango Creek, Snow Hill, Maryland). After Hurricane Sandy, 8% of the standing trees died at Hickory including Acer rubrum, Amelanchier laevis, Ilex spp., and Taxodium distichum. In Plot 2 of Hickory, 25% of the standing trees were dead, and soil salinity levels were the highest recorded in the study. The most important variables related to structural tree damage were soil salinity and proximity to the Atlantic coast as based on Stepwise Regression and NMDS procedures. Wind damage was mostly restricted to broken branches although tipped−up trees were found at Hickory, Whiton and Porter (species: Liquidamabar styraciflua, Pinus taeda, Populus deltoides, Quercus pagoda and Ilex spp.). These trees fell mostly in an east or east−southeast direction (88o−107o) in keeping with the wind direction of Hurricane Sandy on the Delmarva Peninsula. Coastal restoration and management can be informed by the specific differences in hurricane damage to vegetation by salt versus wind.

Gastrointestinal and metabolic effects of feeding schedule on voluntary feed intake and growth of European eel, Anguilla anguilla

NARCIS (Netherlands)

Heinsbroek, L.T.N.; Goedegebuur, B.J.; Bloemhof, G.; Flach, R.B.; Jong, de G.D.C.

2008-01-01

Gastrointestinal and metabolic influences on short- and medium-term control of voluntary feed intake of European eel were investigated for groups of fish fed at different feeding schedules: 1 meal 2 days(-1), 1 meal day(-1), 2 meals day(-1) and continuous feeding for 12 h and 24 h daily. For fish

Variation in flood tolerance of container-grown seedlings of swamp white oak, bur oak, and white oak

Science.gov (United States)

Michael P. Walsh; J.W. Van Sambeek; Mark V. Coggeshall

2008-01-01

How much variation in flood tolerance exists among seedlings within oak species, given the flood frequency of sites from which acorns are collected, has been largely unexplored. Our studies examined initial growth and flood tolerance for seedlings of swamp white oak (Quercus bicolor Willd.), bur oak (Q. macrocarpa L.), and white...

CONSIDERATIONS ON THE ANTHROPIC IMPACT IN THE AREA OF THE ORNITHOLOGIC RESERVATION “THE SWAMPS FROM SATCHINEZ” (TIMIŞ COUNTY

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Rodica Török-Oance

2005-01-01

Full Text Available The estimate of the anthropic impact within the Ornithologic Reservation Swamps from Satchinez is based on the field notes in the period 2003-2005, the air photos taken in 2004 and the reconstitution of past situations (1963-1973 using the photoplans from that period. Within the reservation and the buffer area a series of anthropic activities are taking place, allowed or not, which have a negative impact on the protected area: agricultural works (including agro-chemical treatments, grazing, mowing, hydrotechnical arrangements, illegal tree felling, cutting and burning the reed, poaching, hunting and fishing, collecting biological material, transport, tourism and petrol exploitation. All these lead to the deterioration of the habitat, affect the life of the birds, the water, the clogging of the swamp and cause the disappearance of the clean water spots thus endangering the reservation itself.

Transcript levels of members of the SLC2 and SLC5 families of glucose transport proteins in eel swimbladder tissue: the influence of silvering and the influence of a nematode infection.

Science.gov (United States)

Schneebauer, Gabriel; Mauracher, David; Fiechtner, Birgit; Pelster, Bernd

2018-04-01

The rate of glucose metabolism has been shown to be correlated to glucose uptake in swimbladder gas gland cells. Therefore, it is assumed that in the European eel silvering, i.e., the preparation of the eel for the spawning migration to the Sargasso Sea, coincides with an enhanced capacity for glucose uptake. To test this hypothesis expression of all known glucose transport proteins has been assessed at the transcript level in yellow and in silver eels, and we also included Anguillicola crassus infected swimbladders. Glucose uptake by rete mirabile endothelial cells could be crucial for the countercurrent exchange capacity of the rete. Therefore, this tissue was also included in our analysis. The results revealed expression of ten different members of the slc2 family of glucose transporters, of four slc5 family members, and of kiaa1919 in gas gland tissue. Glucose transporters of the slc2 family were expressed at very high level, and slc2a1b made up about 80% of all slc2 family members, irrespective of the developmental state or the infection status of the eel. Overall, the slc5 family contributed to only about 8% of all detected glucose transport transcripts in gas gland tissue, and the slc2 family to more than 85%. In rete capillaries, the contribution of sodium-dependent glucose transporters was significantly higher, leaving only 66% for the slc2 family of glucose transporters. Neither silvering nor the infection status had a significant effect on the expression of glucose transporters in swimbladder gas gland tissue, suggesting that glucose metabolism of eel gas gland cells may not be related to transcriptional changes of glucose transport proteins.

Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel

International Nuclear Information System (INIS)

Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Jo, Minho; Song, Duseop; Jo, Cheorun

2012-01-01

Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 10 6 and 10 4 CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed. - Highlights: ► Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish but shelf-life is a concern. ► Radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. ► The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. ► Eel fed HF had about 20% higher growth rate than that fed dried feed in feeding trial.

Induced maturation of eel Anguilla bicolor using different hormone combination

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Agus Oman Sudrajat

2015-10-01

Full Text Available ABSTRACT Artificial reproduction of eel Anguilla bicolor is not yet well-established because of insufficient broodstock number. In this research, induction of Indonesian eel gonad maturation was performed by hormonal with a combination of pregnant mare serum gonadotropin (PMSG, human chorionic gonadotropin (HCG antidopamin and recombinant growth hormone (rGH. This research consisted of five treatments namely: control (NaCl 0,9%, PMSG 20 IU/ kg, PMSG 20 IU/kg + antidopamin 10 ppm/kg, PMSG 20 IU/kg + antidopamin 10 ppm/kg + rGH 10 μg/kg dan PMSG 20 IU/kg + HCG 10 IU/kg. Each treatment contained 10 fishes. Hormonal induction was conducted by intramuscular injections, as much as five times at intervals of seven days. Furthermore observations on gonadal development were performed after injection for 21 days. The results showed that the treatment generated pregnancy level of 100%, while control was 0%. The best treatment was PMSG 20 IU/kg + antidopamin 10 ppm/kg+ rGH 10 μg/kg, seen from a more mature phase of the gametes, spermatocytes in male and oocytes with perinukleolar phase in female fish. Eel at the body weight of 120.4 to 207.8 g and at the body length of 40.9 to 43.1 cm was male, at the body weight of 274.8 g and at the body length of 47 cm was in intersexual phase, and at the body weight of 323.4 g and at the body length of 53 cm was female. Keywords: Anguilla bicolor, antidopamin, hormones, PMSG, rGH, HCG  ABSTRAK Pemijahan ikan sidat secara buatan belum dapat dilakukan karena keterbatasan induk matang gonad. Penelitian ini dilakukan untuk mengetahui pengaruh pemberian hormon terhadap percepatan proses perkembangan gonad ikan sidat (Anguilla bicolor. Hormon yang digunakan adalah kombinasi dari pregnant mare serum gonadotropin (PMSG, human chorionic gonadotropin (HCG, antidopamin dan recombinant growth hormone (rGH. Induksi hormonal untuk mempercepat perkembangan gonad ikan sidat dilakukan melalui lima perlakuan yaitu yaitu kontrol

Gill lipid metabolism and unidirectional Na+ flux in the European eel (Anguilla anguilla) after transfer to dilute media

DEFF Research Database (Denmark)

Hansen, H.J.M.; Grosell, M.; Rosenkilde, P.

1999-01-01

The present study investigated the mechanism involved when fish tighten their gill membrane after transfer to dilute media. Ten individually assayed eels adapted to fresh water (EW) and labelled with radioactive Na-22 in the plasma showed mean exchange rates in equilibrium with ambient radioactive...... Na-24 in FW at 70 mu mol kg(-1) h(-1). Just after transfer to demineralized water (DW), the mean Na+ release rate went up to 120 mu molkg(-1) h(-1); after 24 h in DW it came down again and levelled off at 40 mu mol kg(-1) h(-1) during a period of up to 2 weeks. During the same period the mean Na......% of the total C-14-activity incorporated into gill lipids as (C-14) wax alcohols (WA; octadecanol and eicosanol). This percentage went up to 50% shortly after transfer to DW and came down again to about 20% after 2 weeks in DW. Single eels labelled with Na-22 in the plasma showed a statistically significant...

Reliability of non-lethal assessment methods of body composition and energetic status exemplified by applications to eel (Anguilla anguilla) and carp (Cyprinus carpio)

DEFF Research Database (Denmark)

Klefoth, Thomas; Skov, Christian; Aarestrup, Kim

2013-01-01

tNon-lethal assessments of proximate body composition of fish can help unravelling the physiologicaland condition-dependent mechanisms of individual responses to ecological challenges. Common non-lethal methods designed to index nutrient composition in fish include the relative condition factor (Kn......),bioelectric impedance-based assessments of body composition (BIA), and microwave-based “fat” meters(FM). Previous studies have revealed mixed findings as to the reliability of each of these. We compared theperformance of Kn, BIA and FM at different temperatures to predict energetic status of the whole bodiesof live eel...... approach isthe most suitable method to non-lethally estimate energetic status in both, carp and eel, whereas BIA is oflimited use for energetic measurements in the same species, in contrast to other reports in the literature...

POTENCY OF RAMIN (Gonystylus bancanus Kurtz. AND OTHER COMMERCIAL SPECIES IN PEAT SWAMP FOREST MANAGED WITH TPTI SILVICULTURAL SYSTEM IN BAGAN, RIAU

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Hendromono Hendromono

2005-07-01

Full Text Available Ramin  (Gonystylus bancanus Kurtz.  is one  of  the  tree  species in  peat-swamp  forest  that  is endangered due to excessive exploitation. The objective of this research was to assess the potency of rarnin and other commercial tree species in primary and logged over peat-swamp forests at Bagan, Riau. The tree stands were inventoried in primary forest of the 2004 and 2006 Annual Work Plan (RKTs and in  the  1997  and  2001  RKTs  managed  with  Indonesian  Selective Cutting  and  Planting  (TPTI silvicultural system.  The  result  showed  that  rarnin in  Bagan peat-swamp  forest  was not  evenly distributed. The total number of ramin  in tree stage in primary forests was fewer than that in  logged over forests.  The total number of ramin species at tree stage in primary forest was between 4.5  and 5 trees ha·' with the important value index (IVI of 10.3  to 12.0%,  whereas the one at logged over forest were between 2.5 and 15  trees ha·' with theM    indices of 7.9 to 20.4%.  Commercial species of swamp meranti (Shorea uliginosaand S. teysmaniana and balam/ suntai or (Palaqqiumspp. were dominant at tree stage both in the primary and the logged over forests. Enrichment in logged over forests is not needed since the total number of seedlings and saplings  is enough. The total number of potential core trees in logged over forests was enough for the next cutting cycle. The effort that must be done in logged over forests is to protect them from illegal logging.

Effect of different concentration of fish oil in skim milk-egg yolk extenders on post- thawed semen qualities of Kalang swamp buffalo bull

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Abdul Malik

2018-01-01

Full Text Available Objective: To explore the effect of fish oil at different concentrations on post-thawed semen of Kalang swamp buffalo. Methods: A total of 4 Kalang swamp buffalo bulls with 3-5 years of age and weighed about 340-360 kg were slected. Semen was regularly collected from these buffalo bulls once a week by an artificial vagina. Fish oil was supplementary at the dosages of 0 mg (control, 50 mg, 100 mg, 150 mg, and 200 mg to the extender (skim milk-egg yolk. Fresh, pre-freezing and frozen semen were thawed at 37 °C and evaluated for motility, viability, morphology, and plasma integrity of membrane. Results: The study results indicated that before freezing, supplementation of fish oil at the dose of 150 mg in the extender had significantly motility. And a significant (P<0.05 increase was observed in viability and motility of post-thawed semen at the dose of 150 mg fish oil, which was in difference with other treatment groups. Conclusions: Addition of 150 mg fish oil in the extender could be positive for the enhancement of the quality of post-thawed semen of Kalang swamp buffaloes.

Characterization of organochlorine pesticides, brominated flame retardants and dioxin-like compounds in shellfish and eel from Fiji.

Science.gov (United States)

Lal, Vincent; Bridgen, Phil; Votadroka, Waisea; Raju, Rupantri; Aalbersberg, William

2014-09-01

This article gives an overview of a range of persistent organic pollutant chemical levels in shellfish (Batissa violacea and Anadara antiquata) species and eel (Gymnothorax flavimarginatus) from Fiji. As there is limited data in published literature to date, this paper reports first data on a range of persistent organic pollutants and highlights the more prominent POP chemicals present in marine biota in Fiji. A significant number of POP chemicals were detected (e.g. 17 PCDD/PCDF, 12dl-PCBs, organochlorine pesticides and brominated flame retardants), the concentrations found were generally low (e.g. parts per billion level). The low levels of contamination are indicative of a low input from long range and short-range transport as well as few local point sources. Also concentrations of POPs in eel and shellfish from Fiji are low in comparison to wild species in other regions and are within acceptable limits for POP chemicals in fish and fishery products set by the European Union. It describes also results of early studies on basic POPs levels in shellfish in several Pacific Island Countries, which generally show relatively low levels. Copyright © 2014 Elsevier B.V. All rights reserved.

TALL HERB SPRUCE FORESTS AS CLIMAX COMMUNITIES ON LOWLAND SWAMPS OF BRYANSK POLESIE

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O. I. Evstigneev

2017-09-01

Full Text Available Nettle grey alder forests are a dominant forest type on lowland swamps in the Bryansk Polesie. They are formed as a result of repeated cuttings in the place of tall herb spruce forests. Tall herb spruce forests are very rare communities in the vegetation cover in this area due to clear cutting, melioration and peat extraction. An assessment of the succession status of tall herb spruce forests and nettle grey alder forests was carried out in this paper. The criteria of climax state and succession state of communities, developed for Eastern European forests, were used. These criteria are based on the degree of intensity of the following signs in the community: 1 the completeness of species composition of tree synusia; 2 the ontogenetic structure of tree species cenopopulation; 3 the gap-mosaic stand structure; 4 the diversity of microsites in soil cover; 5 the completeness of species composition and ecological-coenotic diversity of vascular species. We showed that tall herb spruce forest, as opposed to black alder forest, is close to communities of the climax type. This is evidenced by the following features of cenosis: firstly, all tree species in the area that covers the Bryansk Polesie and that are able to grow on lowland swamps are represented in the spruce forest (Alnus glutinosa, Betula pubescens, Fraxinus excelsior, Padus avium, Picea abies, Salix pentandra, Sorbus aucuparia, Ulmus glabra. Secondly, a steady turnover of generations is carried out in the cenopopulations of main edificators (Picea abies and Alnus glutinosa. This is evidenced by the complete and left-sided structure of their ontogenetic spectrum. Thirdly, a system of asynchronously developing gaps (parcels, which are formed on the site of old tree falls, is formed in the community. This ensures the continuous renewal of spruce and alder populations and creates conditions for the regeneration of other tree species. Fourthly, the structure of biogenic microsites has been formed

Studies on algea of Da′erbin lake and its surrounding swamps in daxing anling mountain

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LI Xiaofei

2012-08-01

Full Text Available The paper reports 234 taxa of algae (excluding diatomas and desmids in Da′erbin Lake and its surrounding swamps in the Great Xing′an Mountains.They were identified belong to 6 phylums 79 generas 197 species 31 varieties and 6 forms.Among them Characium ornithocephalum var.pringsheimii (A.Br. Kom.,Characium pluricoccum Kor.,Quadrigula korsikovii Kom.,Crucigeniella rectangularis (Ng. Kom.are newly reported in China.

Cryopreservation of green fluorescent protein (GFP)-labeled primordial germ cells with GFP fused to the 3' untranslated region of the nanos gene by vitrification of Japanese eel (Anguilla japonica) somite stage embryos.

Science.gov (United States)

Kawakami, Y; Ishihara, M; Saito, T; Fujimoto, T; Adachi, S; Arai, K; Yamaha, E

2012-12-01

Primordial germ cells (PGC) are the only cell type in developing embryos with the potential to transmit genetic information to the next generation. In this study, PGC of Japanese eel (Anguilla japonica) were visualized by injection of mRNA synthesized from a construct carrying the green fluorescent protein (GFP) gene fused to the 3' untranslated region of the Japanese eel nanos gene. We investigated the feasibility of cryopreserving Japanese eel PGC by vitrification of dechorionated whole somite stage embryos. The GFP-labeled PGC were rapidly cooled using liquid nitrogen after exposure to a pretreatment solution containing 1.5 M cryoprotectant (methanol, dimethyl sulfoxide, and glycerol for 10 min and ethylene glycol for 10, 20, and 30 min) and a vitrification solution containing 3 M cryoprotectant and 0.5 M sucrose for 1, 5, and 10 min. Ethylene glycerol is an effective cryoprotectant for embryonic cells and shows no evidence of ice formation after thawing. Vitrified and thawed PGC were transplanted into blastula stage embryos from zebrafish (Danio rerio). The GFP-labeled PGC migrated toward the host gonadal ridge, suggesting maintenance of their normal migration motility. These techniques may assist in achieving inter- and intraspecies germ-line chimers using donor Japanese eel PGC.

Cultural Resources in the Southern Lake Erie Basin: A Predictive Study.

Science.gov (United States)

1981-01-01

American elm , black ash, and silver maple; also associated were slippery elm , burr oak, swamp white oak, and bitternut hickory. Another type of swamp...American elm -red maple-black ash association dominated the wetter sites. Associated were slippery elm , burr oak, swamp white oak, and bitternut...americana Red elm ( slippery elm ) U. rubra Balsam fir Abies balsanea Hackberry Celtis occidentalis American hazel Corylus americana Eastern hemlock

Proof of U(VI) sorption on Acidovorax facilis by TRLFS and EF-TEM/EELS

Energy Technology Data Exchange (ETDEWEB)

Krawczyk-Baersch, Evelyn; Gerber, Ulrike [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Biogeochemistry; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Surface Processes

2016-07-01

In EF-TEM/EELS studies it was shown that U(VI) is sorbed mainly on the outer membrane of Acidovorax facilis. The results are supported by TRLFS measurements, which were performed on the pellet of the cells. In comparison to reference spectra of some cell membrane components, the measured emission spectra of the A. facilis pellet show the best agreement with those of the Uranyl-lipopolysaccharide-complex. Hence, it can be concluded that phosphoryl groups may be the main binding sites for uranyl, located in the lipopolysaccharide unit in the outer membrane.

Phenolic Lipids Affect the Activity and Conformation of Acetylcholinesterase from Electrophorus electricus (Electric eel)

Science.gov (United States)

Stasiuk, Maria; Janiszewska, Alicja; Kozubek, Arkadiusz

2014-01-01

Phenolic lipids were isolated from rye grains, cashew nutshell liquid (CNSL) from Anacardium occidentale, and fruit bodies of Merrulius tremellosus, and their effects on the electric eel acetylcholinesterase activity and conformation were studied. The observed effect distinctly depended on the chemical structure of the phenolic lipids that were available for interaction with the enzyme. All of the tested compounds reduced the activity of acetylcholinesterase. The degree of inhibition varied, showing a correlation with changes in the conformation of the enzyme tested by the intrinsic fluorescence of the Trp residues of the protein. PMID:24787269

Observations and modeling of wave-supported sediment gravity flows on the Po prodelta and comparison to prior observations from the Eel shelf

Science.gov (United States)

Traykovski, P.; Wiberg, P. L.; Geyer, W. R.

2007-02-01

A mooring and tripod array was deployed from the fall of 2002 through the spring of 2003 on the Po prodelta to measure sediment transport processes associated with sediment delivered from the Po River. Observations on the prodelta revealed wave-supported gravity flows of high concentration mud suspensions that are dynamically and kinematically similar to those observed on the Eel shelf [Traykovski, P., Geyer, W.R., Irish, J.D., Lynch, J.F., 2000. The role of wave-induced density-driven fluid mud flows for cross-shelf transport on the Eel River continental shelf. Continental Shelf Research 20, 2113-2140]. Due to the dynamic similarity between the two sites, a simple one-dimensional (1D) across-shelf model with the appropriate bottom boundary condition was used to examine fluxes associated with this transport mechanism at both locations. To calculate the sediment concentrations associated with the wave-dominated and wave-current resuspension, a bottom boundary condition using a reference concentration was combined with an "active layer" formulation to limit the amount of sediment in suspension. Whereas the wave-supported gravity flow mechanism dominated the transport on the Eel shelf, on the Po prodelta flux due to this mechanism is equal in magnitude to transport due to wave resuspension and wind-forced mean currents in the cross-shore direction. Southward transport due to wave resuspension and wind forced mean currents move an order of magnitude more sediment along-shore than the down-slope flux associated wave-supported gravity flows.

Carcass Characteristics and Meat Quality of Swamp Buffaloes (Bubalus bubalis) Fattened at Different Feeding Intensities.

Science.gov (United States)

Lambertz, C; Panprasert, P; Holtz, W; Moors, E; Jaturasitha, S; Wicke, M; Gauly, M

2014-04-01

Twenty-four male 1-year old swamp buffaloes (Bubalus bubalis) were randomly allocated to 4 groups. One group grazed on guinea grass (GG) and another on guinea grass and the legume Stylosanthes guianensis (GL). The other two groups were kept in pens and fed freshly cut guinea grass and concentrate at an amount of 1.5% (GC1.5) and 2.0% (GC2.0) of body weight, respectively. The effect of the different feeding intensities on carcass characteristics and meat quality were assessed. The mean body weight at slaughter was 398 (±16) kg. Average daily gain was higher in concentrate-supplemented groups (570 and 540 g/d in GC1.5 and GC2.0, respectively) when compared to GG (316 g/d) and GL (354 g/d) (pbuffaloes. Results of the present study showed that the supplementation of pasture with concentrate enhances the growth and carcass characteristics of swamp buffaloes expressed in superior dressing percentage, better muscling, and redder meat with a higher content of protein and fat, whereas animals grazing only on pasture had a more favorable fatty acid profile and water holding capacity. In conclusion, the supplementation of concentrate at a rate of about 1.5% of body weight is recommended to improve the performance and carcass quality of buffaloes.

STRUCTURE OF NATURAL REGENERATION IN RELATION TO SOIL PROPERTIES AND DISTURBANCE IN TWO SWAMP FORESTS

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Marly Antonielle Ávila

2016-03-01

Full Text Available Veredas (palm swamps is a type of vegetation associated with watercourses, characterized by the presence of Mauritia flexuosa palm trees. These systems are not well understood and suffer from high anthropogenic pressure. The aims of this study were to describe the natural regeneration of two swamp forests in vereda systems with different anthropogenic impacts and investigate if the variation in these plant communities are associated to edaphic conditions. The study was performed in preserved and impacted sites located in the Environmental Protection Area of the Pandeiros River in northern Minas Gerais. At each site, one hundred 25 m2 plots were established for surveying regenerating shrubs and trees (≥1 cm diameter at the base of the stem and < 3 cm diameter at breast height. Vegetation structure was evaluated by phytosociological parameters, similarity index, and size distribution of individuals. Regenerating strata was correlated with chemical and physical soil analyses. The vegetation at the preserved site was characterized by a higher number of individuals and a lower diversity but contained species that were typical of flooded areas. The results also showed differences in soil nutrient availability between sites that influenced the distribution of species at the two study sites.

Stable carbon isotope composition of organic material and carbonate in sediment of a swamp and lakes in Honshu island, Japan

International Nuclear Information System (INIS)

Ishizuka, Toshio

1978-01-01

Recent sediments from a swamp and lakes in Honshu were analyzed for organic carbon and carbonate contents, and stable isotope ratios of carbon in the organic materials and carbonate. delta C 13 values of the carbonate tend to be distinctly larger than those of organic carbon in reducing condition as natural gas field, whereas in oxidizing SO 4 -reducing conditions, they are slightly larger than those of organic carbon within the limited range of a few per mil. Carbon isotopic compositions of organic carbon in sediment of the swamp, Obuchi-numa, were analyzed and compared with habitat analysis of associated fossil diatoms. deltaC 13 values of organic carbon in the sediment vary in correlation with the species abundance in habitat of the associated fossil diatoms, ranging from fresh-water (-0.0282) to coastal marine (-0.0236) via brackish. (auth.)

Surviving in a toxic world: transcriptomics and gene expression profiling in response to environmental pollution in the critically endangered European eel

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Pujolar Jose

2012-09-01

Full Text Available Abstract Background Genomic and transcriptomic approaches have the potential for unveiling the genome-wide response to environmental perturbations. The abundance of the catadromous European eel (Anguilla anguilla stock has been declining since the 1980s probably due to a combination of anthropogenic and climatic factors. In this paper, we explore the transcriptomic dynamics between individuals from high (river Tiber, Italy and low pollution (lake Bolsena, Italy environments, which were measured for 36 PCBs, several organochlorine pesticides and brominated flame retardants and nine metals. Results To this end, we first (i updated the European eel transcriptome using deep sequencing data with a total of 640,040 reads assembled into 44,896 contigs (Eeelbase release 2.0, and (ii developed a transcriptomic platform for global gene expression profiling in the critically endangered European eel of about 15,000 annotated contigs, which was applied to detect differentially expressed genes between polluted sites. Several detoxification genes related to metabolism of pollutants were upregulated in the highly polluted site, including genes that take part in phase I of the xenobiotic metabolism (CYP3A, phase II (glutathione-S-transferase and oxidative stress (glutathione peroxidase. In addition, key genes in the mitochondrial respiratory chain and oxidative phosphorylation were down-regulated at the Tiber site relative to the Bolsena site. Conclusions Together with the induced high expression of detoxification genes, the suggested lowered expression of genes supposedly involved in metabolism suggests that pollution may also be associated with decreased respiratory and energy production.

Characterization of Nb Superconducting Radio Frequency Cavities Based On In-Situ STEM And EELS

Science.gov (United States)

Tao, Runzhe

Niobium, a 4d transition metal, has the highest superconducting transition temperature (Tc=9.2K) of any elemental superconductor as type II superconductor with coherent length, sigma approximately that of the penetration length, lambda. Pure niobium is grey in color and very soft, which makes this metal easily fabricable into different shapes for superconducting radio- frequency (SRF) cavities. Such cavities are used in some modern accelerators (SNS, CEBAF, XFEL), and are intended for usage in the next generation of particle accelerators, such as ILC. Since the crucial part of the cavities is top 100 nm of Nb near the inner cavity surface, considering the penetration depth is around 40 nm, it has attracted more and more attention in improving the surface process for optimizing the performance of the cavities. Nowadays, the main treatment of the Nb surface includes electro polishing (EP), buffered chemical polishing (BCP), high temperature baking (800 °C, 1000 °C and 1200 °C) and mild baking (120 °C). Firstly, the two half cells are welded together and the weld line is quite rough; there exists a lot of visible pits and defects on the inner shell of cavities. In this Ph.D. thesis, novel techniques in a scanning transmission electron microscope (STEM) that can be used to analyze the atomic scale structure-property relationship, both at room tem- perature and high/LN 2 temperature, are explored. Specifically, by using correlated Z-contrast imaging and electron energy loss spectrum (EELS), the structure, composition and bonding can be characterized directly on the atomic scale, also, light atoms, like H, O and C, are visible in ABF images. For the examining the defect behavior on the cavity surface, heating and cold stages are involved to simulate the baking treatment and low-temperature environments. These studies will serve as an important reference for qualifying different surface treatments to further improve SRF cavities' performance. The experimental results

Comparative proteomics analysis of degenerative eye lenses of nocturnal rice eel and catfish as compared to diurnal zebrafish

Science.gov (United States)

Lin, Yi-Reng; Mok, Hin-Kiu; Wu, Yuan-Heng; Liang, Shih-Shin; Hsiao, Chang-Chun; Huang, Chun-Hao

2013-01-01

Purpose The aim of this study was to determine the lens crystallin diversity of degenerative eyes from the rice eel (Monopterus albus) and walking catfish (Clarias batrachus) as compared to that of zebrafish (Danio rerio) by using comparative proteomics methodologies. We endeavored to investigate the evolution of vertebrate lenses particularly concerning the functional loss of lenses in degenerative eyes of rice eels and catfishes living under an environment of perpetual darkness. Methods Fish lenses were collected and homogenized to extract total soluble proteins. The protein mixtures were separated by one- and two-dimensional gel electrophoresis (1D or 2D gel), plus the newer gel-free shotgun proteomic strategy, followed by in-gel digestion and subjection of the digested protein bands or spots to liquid chromatography coupled with tandem mass spectrometry. The proteomics data were analyzed and compared based on the proteomics databank of zebrafish. The soluble lens protein solutions of three piscine species were also processed by gel-filtration chromatography and 1D sodium dodecyl sulfate–polyacrylamide gel electrophoresis for the comparison and validation of various crystallin families, e.g., α-, β-, and γ-crystallins. Results In zebrafish eye lenses, γ-crystallin constituted about 71% and α- and β-crystallins comprised 30% of total lens proteins. In rice eel lenses, very little or almost no α-crystallins were detected and β- and γ-crystallins comprised more than 98% of total lens proteins. In catfish lenses, α- and β-crystallins comprised about 40% and γ-crystallin constitutes 60% of total lens proteins. It was of interest to find that α-crystallin was totally absent in the rice eel in contrast to the presence, albeit with very low amounts, of α-crystallin in similarly nocturnal catfish. The ratio of α-crystallin subunits (αA/αB) was found to be about 20:1 for the catfish lens, in great contrast to the ratio of about 3:1 found for most

Checklists, safety, my culture and me.

Science.gov (United States)

Raghunathan, Karthik

2012-07-01

The world is not flat. Hierarchy is a fact of life in society and in healthcare institutions. National, specialty-specific and institutional cultures may play an important role in shaping today's patient-safety climate. The influence of power distance on safety interventions is under-studied. Checklists may make power distance-hampered negotiations easier by providing a standardised aviation-like framework for communications and by democratising the environment. By using surveys and simulation, we might discover patterns of potentially hidden yet problematic interactions that might foster maintenance of the error swamp. We need to understand how people interact as members of a group as this is crucial for the development of generalisable safety interventions.

Improvement of the productivity of the swamp buffalo of S.E. Asia

International Nuclear Information System (INIS)

Frisch, J.E.; Vercoe, J.E.

1984-01-01

The needs of an expanding human population necessitate an increase in numbers and efficiency of output if the swamp buffalo is to remain as a significant component of S.E. Asian agriculture. Biological constraints to an increase in numbers are associated mainly with high calf mortality and low reproductive rate. A combination of vaccination and deworming markedly increases calf survival and provides the simplest means for increasing buffalo numbers. However, methods for improvement of the low inherent fertility of buffaloes remain to be devised. A first step towards a genetic solution is to obtain accurate comparative data for reproductive rates of different buffalo breeds and measures of the magnitude of heterosis for reproductive rate. However, facilities to do this in the near future do not exist. Milk yield or draft power could be most rapidly increased by crossing to river breeds with the optimum proportion of river breed in the cross determined by that level of milk yield and size commensurate with the locally available feed. This is the only method currently available that allows genetic improvement to initially equal or exceed the rate of human population growth. The lack of both large, well-documented herds and efficient AI schemes at present rules against within-breed selection as a method of improvement for any productive trait. It is unrealistic to expect large amounts of high-quality feeds to ever become available for rearing swamp buffaloes and there is a need to develop the facilities and expertise to allow comparative evaluation of buffalo breeds, the exploitation of heterosis in crosses and ultimately, within-breed selection for higher productivity, on straw-based diets. (author)

Invading species in the Eel River, California: Successes, failures, and relationships with resident species

Science.gov (United States)

Brown, L.R.; Moyle, P.B.

1997-01-01

We examined invasions of non-native fishes into the Eel River, California. At least 16 species of fish have been introduced into the drainage which originally supported 12-14 fish species. Our study was prompted by the unauthorized introduction in 1979 of Sacramento squawfish, Ptychocheilus grandis, a large predatory cyprinid. From 1986 to 1990, we conducted growth and diet studies of squaw fish, conducted intensive surveys of the distribution and habitat associations of both native and introduced species, and examined the nature of species-habitat and interspecies relationships. We found no evidence for increased growth or expanded feeding habits, compared to native populations, of Sacramento squawfish as they invaded the Eel River drainage. Ten of the introduced species were well established, with four species limited to a reservoir and six species established in streams. The success or failure of introductions of stream species appeared to be a function of the ability of a species to survive the fluctuating, highly seasonal, flow regime. The present mixture of native and exotic species has not formed stable fish assemblages but it seems likely that four habitat-associated assemblages will develop. The overall effect of the successful species introductions has been to assemble a group of species, with some exceptions, that are native to and occur together in many California streams. The assemblages now forming are similar to those found in other California streams. The assemblage characterized by squawfish and suckers is likely to be resistant to invasion, in the absence of human caused habitat modifications.

Using NASA's Giovanni System to Simulate Time-Series Stations in the Outflow Region of California's Eel River

Science.gov (United States)

Acker, James G.; Shen, Suhung; Leptoukh, Gregory G.; Lee, Zhongping

2012-01-01

Oceanographic time-series stations provide vital data for the monitoring of oceanic processes, particularly those associated with trends over time and interannual variability. There are likely numerous locations where the establishment of a time-series station would be desirable, but for reasons of funding or logistics, such establishment may not be feasible. An alternative to an operational time-series station is monitoring of sites via remote sensing. In this study, the NASA Giovanni data system is employed to simulate the establishment of two time-series stations near the outflow region of California s Eel River, which carries a high sediment load. Previous time-series analysis of this location (Acker et al. 2009) indicated that remotely-sensed chl a exhibits a statistically significant increasing trend during summer (low flow) months, but no apparent trend during winter (high flow) months. Examination of several newly-available ocean data parameters in Giovanni, including 8-day resolution data, demonstrates the differences in ocean parameter trends at the two locations compared to regionally-averaged time-series. The hypothesis that the increased summer chl a values are related to increasing SST is evaluated, and the signature of the Eel River plume is defined with ocean optical parameters.

Substantial improvements not seen in health behaviors following corner store conversions in two Latino food swamps

OpenAIRE

Ortega, Alexander N.; Albert, Stephanie L.; Chan-Golston, Alec M.; Langellier, Brent A.; Glik, Deborah C.; Belin, Thomas R.; Garcia, Rosa Elena; Brookmeyer, Ron; Sharif, Mienah Z.; Prelip, Michael L.

2016-01-01

Background The effectiveness of food retail interventions is largely undetermined, yet substantial investments have been made to improve access to healthy foods in food deserts and swamps via grocery and corner store interventions. This study evaluated the effects of corner store conversions in East Los Angeles and Boyle Heights, California on perceived accessibility of healthy foods, perceptions of corner stores, store patronage, food purchasing, and eating behaviors. Methods Household data ...

The Indo-Pacific striped eel catfish, Plotosus lineatus (Thunberg, 1787, (Osteichtyes: Siluriformes, a new record from the Mediterranean

Directory of Open Access Journals (Sweden)

Daniel Golani

2002-09-01

Full Text Available The striped eel catfish, Plotosus lineatus (Thunberg, 1787, is recorded for the first time from the eastern Mediterranean coast of Israel. Seventeen specimens of this highly-venomous fish were caught by a commercial trawler at depths of 20 m. This species´ occurrence in the Mediterranean is the result of migration from the Red Sea via the Suez Canal (Lessepsian migration.

Do trout swim better than eels? Challenges for estimating performance based on the wake of self-propelled bodies

Science.gov (United States)

Tytell, Eric D.

Engineers and biologists have long desired to compare propulsive performance for fishes and underwater vehicles of different sizes, shapes, and modes of propulsion. Ideally, such a comparison would be made on the basis of either propulsive efficiency, total power output or both. However, estimating the efficiency and power output of self-propelled bodies, and particularly fishes, is methodologically challenging because it requires an estimate of thrust. For such systems traveling at a constant velocity, thrust and drag are equal, and can rarely be separated on the basis of flow measured in the wake. This problem is demonstrated using flow fields from swimming American eels, Anguilla rostrata, measured using particle image velocimetry (PIV) and high-speed video. Eels balance thrust and drag quite evenly, resulting in virtually no wake momentum in the swimming (axial) direction. On average, their wakes resemble those of self-propelled jet propulsors, which have been studied extensively. Theoretical studies of such wakes may provide methods for the estimation of thrust separately from drag. These flow fields are compared with those measured in the wakes of rainbow trout, Oncorhynchus mykiss, and bluegill sunfish, Lepomis macrochirus. In contrast to eels, these fishes produce wakes with axial momentum. Although the net momentum flux must be zero on average, it is neither spatially nor temporally homogeneous; the heterogeneity may provide an alternative route for estimating thrust. This review shows examples of wakes and velocity profiles from the three fishes, indicating challenges in estimating efficiency and power output and suggesting several routes for further experiments. Because these estimates will be complicated, a much simpler method for comparing performance is outlined, using as a point of comparison the power lost producing the wake. This wake power, a component of the efficiency and total power, can be estimated in a straightforward way from the flow

Sustainable management of peat swamp forest of Sarawak with special reference to ramin (Gonystylus bancanus); development of a monitoring system

NARCIS (Netherlands)

Wijdeven, S.M.J.; Meer, van der P.J.; Chai, F.Y.C.; Tan, S.; Mohizah, M.; Liam, D.

2004-01-01

Peat swamp forests in Sarawak are valuable in terms of timber and biodiversity, but heavily degraded. In order to assess the current status, potential developments and possible management interventions, an adequate monitoring system is necessary. In this study a new monitoring system is proposed,

First record of the Indo-Pacific striped eel catfish, Plotosus lineatus (Thunberg, 1787 from Turkish marine waters

Directory of Open Access Journals (Sweden)

Servet Ahmet Doğdu

2016-05-01

Full Text Available Three specimens of striped eel catfish, Plotosus lineatus (Thunberg, 1787 were caught by a spear gun at depths of 20 m on 4 April 2016 from Iskenderun Bay (Çevlik harbour, Northeastern Mediterranean coast of Turkey. With the present study, P. lineatus is the first time reported from Turkish marine waters, in the Iskenderun Bay, the Northeastern Mediterranean and also this is the first Plotosid species recorded from Turkish Seas.

Differential expression of gonadotropin and estrogen receptors and oocyte cytology during follicular maturation associated with egg viability in European eel (Anguilla anguilla)

DEFF Research Database (Denmark)

da Silva, Filipa F. G.; Tveiten, Helge; Maugars, Gersende

2018-01-01

In captivity, oogenesis and ovarian follicle maturation in European eel can be induced experimentally using hormonal therapy. The follicle's ability to respond effectively to the induction of maturation and ovulation, resulting in viable eggs, depends on the oocyte stage at the time of induction....

Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

International Nuclear Information System (INIS)

Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

2009-01-01

Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

Swamp plots for dynamic aperture studies of PEP-II lattices

International Nuclear Information System (INIS)

Yan, Y.T.; Irwin, J.; Cai, Y.; Chen, T.; Ritson, D.

1995-01-01

With a newly developed algorithm using resonance basis Lie generators and their evaluation with action-angle Poisson bracket maps (nPB tracking) the authors have been able to perform fast tracking for dynamic aperture studies of PEP-II lattices as well as incorporate lattice nonlinearities in beam-beam studies. They have been able to better understand the relationship between dynamic apertures and the tune shift and resonance coefficients in the generators of the one-turn maps. To obtain swamp plots (dynamic aperture vs. working point) of the PEP-II lattices, they first compute a one-turn resonance basis map for a nominal working point and then perform nPB tracking by switching the working point while holding fixed all other terms in the map. Results have been spot-checked by comparing with element-by-element tracking

Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region

NARCIS (Netherlands)

Zhang, Yi; Lu, Yongfang; Yindee, Marnoch; Li, Kuan-Yi; Kuo, Hsiao-Yun; Ju, Yu-Ten; Ye, Shaohui; Faruque, Md Omar; Li, Qiang; Wang, Yachun; Cuong, Vu Chi; Pham, Lan Doan; Bouahom, Bounthong; Yang, Bingzhuang; Liang, Xianwei; Cai, Zhihua; Vankan, Dianne; Manatchaiworakul, Wallaya; Kowlim, Nonglid; Duangchantrasiri, Somphot; Wajjwalku, Worawidh; Colenbrander, Ben; Zhang, Yuan; Beerli, Peter; Lenstra, Johannes A; Barker, J Stuart F

The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal

Beyond the angle of repose: A review and synthesis of landslide processes in response to rapid uplift, Eel River, Northern California

Science.gov (United States)

Roering, Joshua J.; Mackey, Benjamin H.; Handwerger, Alexander L.; Booth, Adam M.; Schmidt, David A.; Bennett, Georgina L.; Cerovski-Darriau, Corina

2015-05-01

In mountainous settings, increases in rock uplift are often followed by a commensurate uptick in denudation as rivers incise and steepen hillslopes, making them increasingly prone to landsliding as slope angles approach a limiting value. For decades, the threshold slope model has been invoked to account for landslide-driven increases in sediment flux that limit topographic relief, but the manner by which slope failures organize themselves spatially and temporally in order for erosion to keep pace with rock uplift has not been well documented. Here, we review past work and present new findings from remote sensing, cosmogenic radionuclides, suspended sediment records, and airborne lidar data, to decipher patterns of landslide activity and geomorphic processes related to rapid uplift along the northward-migrating Mendocino Triple Junction in Northern California. From historical air photos and airborne lidar, we estimated the velocity and sediment flux associated with active, slow-moving landslides (or earthflows) in the mélange- and argillite-dominated Eel River watershed using the downslope displacement of surface markers such as trees and shrubs. Although active landslides that directly convey sediment into the channel network account for only 7% of the landscape surface, their sediment flux amounts to more than 50% of the suspended load recorded at downstream sediment gaging stations. These active slides tend to exhibit seasonal variations in velocity as satellite-based interferometry has demonstrated that rapid acceleration commences within 1 to 2 months of the onset of autumn rainfall events before slower deceleration ensues in the spring and summer months. Curiously, this seasonal velocity pattern does not appear to vary with landslide size, suggesting that complex hydrologic-mechanical feedbacks (rather than 1-D pore pressure diffusion) may govern slide dynamics. A new analysis of 14 yrs of discharge and sediment concentration data for the Eel River indicates

Feeding on protists and particulates by the leptocephali of the worm eels Myrophis spp. (Teleostei: Anguilliformes: Ophichthidae, and the potential energy contribution of large aloricate protozoa

Directory of Open Access Journals (Sweden)

John Jeffrey Govoni

2010-06-01

Full Text Available The food sources of the leptocephali of the teleostean superorder Elopomorpha have been controversial, yet observations on the leptocephali of the worm eels, Myrophis spp. (family Ophichthidae collected in the northern Gulf of Mexico indicate active, not passive, feeding. Leptocephali had protists in their alimentary canals. Estimates of the physiological energetics of worm eels indicate that large aloricate protozoa including ciliates could provide substantial energy to these leptocephali toward the end of the premetamorphic and metamorphic stages, given the low energy requirements of metamorphosing leptocephali. Global ocean warming will likely force a shift in oceanic food webs; a shift away from large protozoa toward smaller protists is possible. Such a disruption of the oceanic food webs could further compromise the survival of leptocephali.

Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel

Science.gov (United States)

Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Jo, Minho; Song, Duseop; Jo, Cheorun

2012-08-01

Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 106 and 104 CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed.

Water-use dynamics of a peat swamp forest and a dune forest in Maputaland, South Africa

Directory of Open Access Journals (Sweden)

A. D. Clulow

2013-05-01

Full Text Available Peat swamp forests are the second rarest forest type found in South Africa while dune forests have been under severe threat through mining and agriculture. Both forest types exist in the conservation area, and World Heritage site, known as the iSimangaliso Wetland Park on the East coast of South Africa. The area is prone to severe droughts (Taylor et al., 2006 and recent attempts to understand the local water balance revealed that there was insufficient information on the water use of the indigenous forests of the area. The peat swamp forest and dune forest sites studied in this research were located within close proximity to each other, yet, are characterised by different landscape positions in terms of water availability. The coastal dune forest soil profile was generally dry and sandy and the tree roots did not have access to the water table. In contrast the peat swamp forest is located in an interdunal wetland where the trees have permanent access to water. The climate at both sites is subtropical with a mean annual precipitation of 1200 mm yr−1. However, over 20 months of measurement, the first summer (October 2009 to March 2010 was drier (424 versus 735 mm than the second summer (October 2010 to March 2011 emphasising the variability of the rainfall in the area and providing a wide range of conditions measured. The sap flow of an evergreen, overstory Syzygium cordatum and a semi-deciduous, understory Shirakiopsis elliptica were measured in the peat swamp forest using the heat ratio method. The Syzygium cordatum water use was not highly seasonal and the daily maximum water use ranged from approximately 30 L d−1 in winter to 45 L d−1 in summer whereas the extit{Shirakiopsis elliptica} water use was more seasonal at 2 L d−1 in winter and 12 L d−1 in summer. The water use of the Syzygium cordatum was not influenced by seasonal rainfall variations and was actually higher in the drier summer (October 2009 to March 2010. Three trees of

Effects of feed composition on life history developments in feed intake, metabolism, growth and body composition of European eel, Anguilla anguilla

NARCIS (Netherlands)

Heinsbroek, L.T.N.; Hooff, P.L.A.; Swinkels, W.; Tanck, M.W.T.; Schrama, J.W.; Verreth, J.A.J.

2007-01-01

To examine the effect of feed composition on changes in feed intake and subsequent feed utilization with age, five populations of European eel, with an average initial body weight of 5 g each fed a different diet, were monitored for 302 d. The five feeds differed in their content of crude protein

Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

Science.gov (United States)

Black, Jeffrey M.; Gress, Carol; Byers, Jacob W.; Jennings, Emily; Ely, Craig R.

2010-01-01

Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

Isolation of peat swamp forest foliar endophyte fungi as biofertilizer

Directory of Open Access Journals (Sweden)

Safinah Surya Hakim

2017-01-01

Full Text Available Peatland restoration activity is facing many obstacles, particularly in planting techniques and poor nutrient in peat soil. Naturally, endophytic fungi are abundant and have great potential as biofertilizer. This research investigates the potential endophytic fungi isolated from leaves of peat swamp tree species for biofertilizer. Research activities include: exploration, in vitro test to examine the phosphate solubilization and identification. Result showed that there were 360 leave segments collected from 4 sampling locations. The colonization percentage of 222 isolates ranged from 52.17% - 60.17%. Fifty seven morphospecies were selected from 222 isolates. Twelve isolates demonstrated ability to produce clear zones and ten isolates were selected for identification. It is concluded that twelve isolated demonstrated potential ability to produce clear zone and Penicillum citrinum isolate P3.10 was identified as an isolate that show the highest potential ability as a biofertilizer

Evaluation of surgical implantation of electronic tags in European eel and effects of different suture materials

DEFF Research Database (Denmark)

Thorstad, Eva B.; Økland, Finn; Westerberg, Håkan

2013-01-01

Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire....... Antibacterial treatment had no effect on inflammation or healing rates. After 6 months, the tag started to become expelled through the incision in five fish (12%). The internal reaction appeared stronger around the floats, suggesting that the coating material of the floats created a tissue reaction, which...

IMPROVEMENT OF RICE GROWTH AND PRODUCTIVITY THROUGH BALANCE APPLICATION OF INORGANIC FERTILIZER AND BIOFERTILIZER IN INCEPTISOL SOIL OF LOWLAND SWAMP AREA

Directory of Open Access Journals (Sweden)

Neni Marlina

2014-02-01

Full Text Available The objective of this study was to obtain a proper balance dose between biofertilizer and inorganic fertilizer in order to increase the growth and yield of rice in Inceptisol soil of lowland swamp origin. Biofertilizer was made by enriching straw compost with N2 interceptor bacteria, phosphate solvent bacteria and growth stimulator bacteria isolated from swamp lowland in South Sumatra. This study was conducted from November 2012 to March 2013 in a greenhouse. The design used was completely randomized design (CRD factorial, with two treatment factors consisting of inorganic fertilizer (0,25, 50, 75 and 100% recommended dosage and biofertilizer (0, 100, 200, 300, 400 and 500 kg.ha-1. The results showed that the best treatment in term of plant height at 8 weeks after planting (WAP, the maximum number of tillers, number of productive tillers, number of grains per panicle and weight of milled dry rice were obtained in combination of 75% inorganic fertilizer and 300 - 400 kg.ha-1biofertilizer.

Immunological responses of pregnant swamp and murrah buffalo cows and calves to Toxocara (Neoascaris) vitulorum infection

International Nuclear Information System (INIS)

Amerasinghe, P.; Masoodi, M.A.; Samarasinghe, B.; Sivanathan, S.; Gunawardana, V.K.; Fernando, S.T.

1984-01-01

Swamp buffalo cows from an area where T. vitulorum infection was heavy were examined for serum antibodies. Serum from all cows showed strongly positive precipitin reactions from the 4th to 6th months of pregnancy and after parturition using homologous larval, adult worm and adult excretory and secretory antigens; these precipitins were still being detected in the sera 4-6 months after calving. The sera of calves born to these cows were negative for T. vitulorum precipitins before feeding with colostrum but a precipitin reaction was evident from 24 hours of birth. Nevertheless, patent infections developed from 19-21 days after birth and one calf died with severe diarrhoea; the remainder revealed heavy faecal Toxocara egg counts. In six calves the infection was spontaneously eliminated between 40 and 60 days after birth suggesting a 'self-cure' reaction. In a similar study involving 30 Murrah cows sera precipitins were not observed during the first 4-6 months of pregnancy. In 14 calves born to these animals serum precipitins were never observed, but the animals had T. vitulorum egg counts comparable with those in swamp buffalo calves. After an initial natural infection a strong resistance to reinfection was acquired by most calves of both breeds in that larvae did not generally develop beyond the second stage. (author)

Hydrography - HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS: Lakes, Ponds, Reservoirs, Swamps, and Marshes in Watersheds of Indiana (U. S. Geological Survey, 1:24,000, Polygon Shapefile)

Data.gov (United States)

NSGIC State | GIS Inventory — HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS.SHP is a polygon shapefile that contains features of lakes, ponds, reservoirs, swamps and marshes in watersheds in and...

Effects of oestradiol-enriched diet and of feeding with porcine testicular tissue on macroscopic gonadal sex in European eels

DEFF Research Database (Denmark)

Andersen, D.; Boetius, I.; Larsen, L.O.

1996-01-01

days there were 44% with female-gonads, 40% with male+female-gonads and 16% with male-gonads. Oestradiol thus had a feminizing effect, not only on morphologically undifferentiated gonads but also on morphologically differentiated male-gonads. The presence of sex steroid hormones or their precursors...... and in control eels. Otherwise no correlation was found between growth rate and gonadal sex. (C) 1996 The Fisheries Society of the British Isles...

Sunken wood habitat for thiotrophic symbiosis in mangrove swamps.

Science.gov (United States)

Laurent, Mélina C Z; Gros, Olivier; Brulport, Jean-Pierre; Gaill, Françoise; Bris, Nadine Le

2009-03-01

Large organic falls to the benthic environment, such as dead wood or whale bones, harbour organisms relying on sulfide-oxidizing symbionts. Nothing is known however, concerning sulfide enrichment at the wood surface and its relation to wood colonization by sulfide-oxidizing symbiotic organisms. In this study we combined in situ hydrogen sulfide and pH measurements on sunken wood, with associated fauna microscopy analyses in a tropical mangrove swamp. This shallow environment is known to harbour thiotrophic symbioses and is also abundantly supplied with sunken wood. A significant sulfide enrichment at the wood surface was revealed. A 72h sequence of measurements emphasized the wide fluctuation of sulfide levels (0.1->100muM) over time with both a tidal influence and rapid fluctuations. Protozoans observed on the wood surface were similar to Zoothamnium niveum and to vorticellids. Our SEM observations revealed their association with ectosymbiotic bacteria, which are likely to be sulfide-oxidizers. These results support the idea that sunken wood surfaces constitute an environment suitable for sulfide-oxidizing symbioses.

Phosphorylation states of the (Na+ + K+)-transporting ATPase in preparations from lamb kidney and electric-eel (Electophorus electricus) electric organ.

Science.gov (United States)

Harris, W E; Stahl, W L

1984-01-01

Phosphorylation states of the (Na+ + K+)-transporting ATPase were studied in highly purified preparations isolated from electric-eel electric organ and from lamb kidney. The steady-state level of phosphorylated lamb kidney enzyme, obtained by reaction with [gamma-32P]ATP, was not appreciably reduced in the presence of ADP unless oligomycin was present. The phosphorylated form of the electric-eel electric-organ enzyme was reduced by at least 95% under the same conditions, suggesting that the E1P state in the kidney enzyme is more transitory than that in electric organ. The level of phosphorylation from [32P]Pi was higher in the lamb kidney preparation than in the electric-organ preparation, and the difference in stimulation of phosphorylation by ouabain in the two preparations was striking. Ouabain increased the level of phosphorylation by 35% in the kidney preparation and 734% in the electric-organ preparation. The E2P state seems to be stabilized by ouabain in the latter preparation. These findings, as well as the different reactivities of the thiol groups to blocking reagents in these preparations, suggest that the tertiary structure in the enzyme isolated from these two sources is different. PMID:6324756

Water quality study at the Congaree Swamp National monument of Myers Creek, Reeves Creek and Toms Creek. Technical report

International Nuclear Information System (INIS)

Rikard, M.

1991-11-01

The Congaree Swamp National Monument is one of the last significant near virgin tracts of bottom land hardwood forests in the Southeast United States. The study documents a water quality monitoring program on Myers Creek, Reeves Creek and Toms Creek. Basic water quality parameters were analyzed. High levels of aluminum and iron were found, and recommendations were made for further monitoring

Metabolic adjustments during semi-aestivation of the marble swamp eel (Synbranchus marmoratus, Bloch 1795 - a facultative air breathing fish Ajustes metabólicos do muçum (Synbranchus marmoratus, Bloch 1795 - um peixe de respiração aérea facultativa - durante semi-estivação

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G. Moraes

2005-05-01

Full Text Available Metabolic changes, principally in intermediary metabolism and nitrogen excretion, were investigated in the marble swamp eel (Synbranchus marmoratus after 15 and 45 days of artificially induced semi-aestivation. Glucose, glycogen, lactate, pyruvate, free amino acids, triglycerides, ammonia, urea, and urate contents were determined in liver, kidney, white muscle, heart, brain, and plasma. Lactate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthase, ornithine carbamoyl transferase, and arginase enzymes were assayed. The teleost S. marmoratus maintained initial energetic demands by lipid oxidation. The course of normal oxidative processes was observed through tissue enzyme profiles. After the lipid stores were exhausted, the fish consumed body proteins. Constant values of hematocrit during induced semi-aestivation suggested that the water balance remained normal. Therefore, the surrounding water was probably did not trigger the semi-aestivation in this teleost. Decrease of ammonia and increase of renal urea synthesis after 45 days of semi-aestivation led to the assumption that an alternative form of eliminating ammonia exists. Metabolic changes entailed by starvation were proposed to explain the biosynthesis of small molecules involved in the semi-aestivation of S. marmoratus.Foram investigadas variações metabólicas em muçum (Synbranchus marmoratus após 15 e 45 dias de semi-estivação artificial induzida, com ênfase no metabolismo intermediário e excreção de nitrogênio. Glicose, glicogênio, lactato, piruvato, aminoácidos livres, triglicerídios, amônia, uréia e uratos foram determinados em fígado, rim, músculo branco, coração, cérebro, e plasma. As enzimas lactato desidrogenase, glutamato desidrogenase, malato desidrogenase, aspartato amino transferase, alanina amino transferase, glutamina sintetase, ornitina carbamil transferase e arginase foram

Three approaches to the classification of inland wetlands. [Dismal Swamp, Tennessee, and Florida

Science.gov (United States)

Gammon, P. T.; Malone, D.; Brooks, P. D.; Carter, V.

1977-01-01

In the Dismal Swamp project, seasonal, color-infrared aerial photographs and LANDSAT digital data were interpreted for a detailed analysis of the vegetative communities in a large, highly altered wetland. In Western Tennessee, seasonal high altitude color-infrared aerial photographs provided the hydrologic and vegetative information needed to map inland wetlands, using a classification system developed for the Tennessee Valley Region. In Florida, color-infrared aerial photographs were analyzed to produce wetland maps using three existing classification systems to evaluate the information content and mappability of each system. The methods used in each of the three projects can be extended or modified for use in the mapping of inland wetlands in other parts of the United States.

Scaling of the Surface Plasmon Resonance in Gold and Silver Dimers Probed by EELS

DEFF Research Database (Denmark)

Kadkhodazadeh, Shima; de Lasson, Jakob Rosenkrantz; Beleggia, Marco

2014-01-01

The dependence of surface plasmon coupling on the distance between two nanoparticles (dimer) is the basis of nanometrology tools such as plasmon rulers. Application of these nanometric rulers requires an accurate description of the scaling of the surface plasmon resonance (SPR) wavelength...... with distance. Here, we have applied electron energy-loss spectroscopy (EELS) and scanning transmission electron microscopy (STEM) imaging to investigate the relationship between the SPR wavelength of gold and silver nanosphere dimers (radius R) and interparticle distance (d) in the range 0.1R .... Instead, within the range 0.1R gold and silver dimers. Despite this common power dependence, consistently larger SPR wavelength shifts are registered for silver for a given change in d, implying...

Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

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M. Wanapat

2013-07-01

Full Text Available The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and CC+rice bran at a ratio 3:1 (CR3:1, and factor B was level of cottonseed meal (CM; 109 g CP/kg (LCM and 328 g CP/kg (HCM in isonitrogenous diets (490 g CP/kg. Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05. Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p0.05. Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

Ground survey of red lechwe in the Linyanti swamps and Chobe floodplains, northern Botswana

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Phemelo Gadimang

2017-05-01

Full Text Available A ground survey of red lechwe was carried out in the Linyanti swamps and the Chobe floodplains of northern Botswana in the dry and wet seasons of 2012 and 2013, respectively. We documented numbers, sex ratio and age structure of red lechwe within the linear strips of 25 km × 300 m along the Linyanti swamps and the Chobe floodplains. Results indicated a significant difference in the numbers of red lechwe between sites and seasons. About 66 and 755 red lechwe were estimated for Chobe in the dry and wet season, respectively, with 343 and 261 of them estimated for Linyanti in the dry and wet season, respectively. In Chobe, the red lechwe densities varied widely between seasons (9 red lechwe/km2 – 101 red lechwe/km2 compared with Linyanti, where the densities did not vary much between seasons (35 red lechwe/km2 – 46 red lechwe/km2 . The lower densities of red lechwe in Chobe in the dry season when compared with the wet season suggest a possible seasonal shift in the distribution of red lechwe to the nearby Zambezi floodplains in Namibia. Conservation implications: The higher number of red lechwe in the Chobe floodplains in the wet season indicates the potential of the floodplains as a habitat for this species in that season. The dry season shift in the distribution of red lechwe in Chobe presents an opportunity for local communities in Namibia to engage in tourism, whereas the return of the red lechwe to the floodplains in the wet season ensures protection of the animals as well as boosts the tourism potential of the Chobe National Park.

Epiphytic ferns in swamp forest remnants of the coastal plain of southern Brazil: latitudinal effects on the plant community

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Letícia S. Machado

Full Text Available ABSTRACT Community structure and spatial distribution of epiphytic ferns in swamp forest remnants along the coastal plain of the state of Rio Grande do Sul were analyzed. A total of 440 trees were sampled in fifty-seven 10 x 10 m plots. Each phorophyte was divided into five ecological zones (strata, where all species of epiphytic ferns were recorded. A total of 34 species representing 18 genera in six families were recorded. Polypodiaceae was the most represented family with 17 species, and Microgramma vacciniifolia had the highest epiphytic importance value. Characteristic holoepiphyte was the predominant ecological category, representing 70 % of the species. Ordination analysis showed a gradual change in floristic composition between ecological zones with richness differing significantly between strata. We observed that with increasing latitude there was a decrease in mean temperature and total rainfall, but an increase in frosts. These climatic and phytogeography changes result in a reduction in species richness and a change in the structure of epiphytic fern communities in a north-to-south direction. The importance of swamp forest remnants of the coastal plain to the diversity of epiphytic ferns is discussed.

Identifying the best season for mapping evergreen swamp and mangrove species using leaf-level spectra in an estuarine system in KwaZulu-Natal, South Africa

CSIR Research Space (South Africa)

Van Deventer, Heidi

2014-10-01

Full Text Available would provide the best discrimination of six evergreen tree species, associated with swamp (Ficus Trichopoda), mangrove (Avicennia marina, Bruguiera gymnorrhiza, Hibiscus tiliaceus), wetlands in adjacent woodlands (Syzygium cordatum) and coastal...

Behaviour and passage of European silver eels (Anguilla anguilla at a small hydropower plant during their downstream migration Comportement et passage de l’anguille argentée (Anguilla anguilla au niveau d’une petite centrale hydroélectrique lors de sa migration de dévalaison

Directory of Open Access Journals (Sweden)

De-Oliveira E.

2010-09-01

Full Text Available Between 2004 and 2007, 116 downstream migrant silver eels (Anguilla anguilla were monitored at a hydropower plant on the Gave de Pau river in South-West France using radio and PIT telemetry. The objectives of the study were: (i to determine the environmental conditions when eels arrived and passed the facility; (ii to determine the rate of eel escapement (passage other than via the turbines; (iii to describe the behaviour of eels faced with the intake structure and the permeability of the intake trashracks for the different sizes of eel; and (iv to determine whether surface bypasses originally designed for salmon could be effective for eels. Five types of behaviour of silver eels in the forebay and at the plant intakes were identified. The study showed the key factor influencing both eel behaviour and the route taken through the plant was variation in river discharge. Escapement rate was related to eel length and the spill flow to river flow ratio, which could be described by a logistic regression model. The surface bypasses originally designed for salmon were found to aid downstream eel migration significantly. At velocities < 0.40 m·s−1, no eels, even the largest, for which the racks are a physical barrier, were found impinged on the trashracks. De 2004 à 2007, une étude sur la migration de dévalaison de l’anguille argentée européenne (Anguilla anguilla a été menée sur la centrale hydroélectrique de Baigts sur le Gave de Pau dans le Sud-Ouest de la France. Cette étude, au cours de laquelle 116 individus ont été suivis par télémétrie PIT et radio, avait pour objectifs : (i de déterminer les conditions de milieu propices à l’arrivée sur site et au franchissement de l’aménagement; (ii de déterminer les taux d’échappement (passages par des voies autres que les turbines; (iii d’analyser le comportement des anguilles devant les ouvrages et la perméabilité des grilles de la prise d’eau en fonction de la taille

Z-Contrast STEM Imaging and EELS of CdSe Nanocrystals: Towards the Analysis of Individual Nanocrystal Surfaces

International Nuclear Information System (INIS)

Erwin, M.; Kadavanich, A.V.; Kippeny, T.; Pennycook, S.J.; Rosenthal, S.J.

1999-01-01

We have applied Atomic Number Contract Scanning Transmission Electron Microscopy (Z-Contrast STEM) and STEM/EELS (Electron Energy Loss Spectroscopy) towards the study of colloidal CdSe semiconductor nanocrystals embedded in MEH-PPV polymer films. Unlike the case of conventional phase-contrast High Resolution TEM, Z-Contrast images are direct projections of the atomic structure. Hence they can be interpreted without the need for sophisticated image simulation and the image intensity is a direct measure of the thickness of a nanocrystal. Our thickness measurements are in agreement with the predicted faceted shape of these nanocrystals. Our unique 1.3A resolution STEM has successfully resolve3d the sublattice structure of these CdSe nanocrystals. In [010] projection (the polar axis in the image plane) we can distinguish Se atom columns from Cd columns. Consequently we can study the effects of lattice polarity on the nanocrystal morphology. Furthermore, since the STEM technique does not rely on diffraction, it is superbly suited to the study of non-periodic detail, such as the surface structure of the nanocrystals. EELS measurements on individual nanocrystals indicate a significant amount (equivalet to 0.5-1 surface monolayers) of oxygen on the nanocrystals, despite processing in an inert atmosphere. Spatially resolved measurements at 7A resolution suggest a surface oxide layer. However, the uncertainty in the measurement precludes definitive assignment at this time. The source of the oxygen is under investigation as well

Effect of day or night grazing on behaviour of swamp buffalo heifers

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Somparn, P.

2007-03-01

Full Text Available An experiment was conducted to examine the effect of day or night grazing on behaviour by swamp buffaloes. A grazing trial was conducted over 42 days in the late rainy season, during September to November2005 at Surin Livestock Research and Breeding Center, Surin province. The experimental period was divided into two 21-day periods. Twelve 2-year-old swamp buffalo heifers were allocated to four groups, eachcontaining three heifers, with the mean group weights being as similar as possible. Each group was allowed to graze either from 06:20 to 18:00 h (daytime treatment or from 18:20 to 06:00 h (nighttime treatment infour separate paddocks, each of 5 rai, using a cross-over design. When not at pasture the animals in each group were kept in the common corral with free access to fresh drinking water and mineral blocks. Individualanimal activity was recorded by visual observation at 1-min intervals during the period at pasture. Individual groups within each period were treated as replicates. Differences between group means weretested using MIXED procedure of SAS.The buffaloes on daytime treatment spent longer (P<0.05 grazing than those on nighttime treatment (423 vs 332 min. The number of meals differed (P<0.05 between treatments, but overall mean meal durationswere similar (73 min. Buffaloes allowed to graze during daylight had a tendency (P<0.10 toward a higher bite and step rates than those grazing during the night. With the reduction in grazing activity duringthe night on nighttime treatment, the animals ruminated for longer during the period at pasture (327 and 191 min, P<0.001. Live-weight change over periods of 20 days did not differ significantly. The difference intemporal behaviour patterns between treatments indicated that animals have to adapt foraging strategies appropriate for different situations in order to maintain feed intake and subsequently production.

Advantages of low beam energies in a TEM for valence EELS

Science.gov (United States)

Stöger-Pollach, M.; Pongratz, P.

2010-02-01

Since the availability of monochromators in transmission electron microscopes (TEMs), electron energy loss spectrometry (EELS) is widely used to determine band gaps and the dielectric properties of semiconductors on a nano-metre scale. Nevertheless, three physical effects hamper straightforward analysis: (a) relativistic energy losses, (b) the delocalization of the energy loss which is in the 10 nano-metreer range for valence losses, and (c) the presence of interface plasmons. When reducing the operation voltage of the TEM one can kill two birds with one stone: (a) the relativistic losses will disappear as soon as veinvestigated sample) and (b) the delocalization will decrease, because it also depends on the energy of the incident electron probe. The determination of the optical properties of quantum structures is discussed in the case of GaP/GaAs interface at 200 keV and 20 keV beam energy, respectively. Further, the influence of the delocalization of the energy loss signal is discussed theoretically and experimentally.

The Cultural Genogram: An International Cross-Cultural Case Study on Entrepreneurship

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Khasadyahu Zarbabal

2017-11-01

Full Text Available Experiential entrepreneurship has become a significant pedagogy in preparing American students to compete in the dynamic and consolidating global economy. Whereas the model of experiential learning facilitates collaboration between industry experts, entrepreneurs and community stakeholders, it is imperative to look at entrepreneurship from a global perspective. Medgar Evers College has a mission for social justice and socio-economic transformation. Through the Entrepreneurship & Experiential Learning (EEL lab, students are exposed to industry leaders, faculty and other stakeholders to the benefits of global entrepreneurship and experiential learning. This paper is a case study that discusses lessons learned on innovation, culture and entrepreneurship from students and faculty’s exposure to innovation and international entrepreneurs from Kenya, Chile, Costa Rico, Jamaica, Dominican Republic, China, London, Paris, Japan and Thailand. Additionally, the paper addresses the implications on entrepreneurial learning by encouraging diverse perspectives and practice for the student entrepreneurs in the 21st century. The originality of the paper is in its diversity of perspectives – it is a collaboration of faculty and staff on three different continents and three academic institutions.

How does conversion from peat swamp forest to oil palm plantation affect emissions of nitrous oxide from the soil? A case study in Jambi, Indonesia

Science.gov (United States)

Hartill, Jodie; Hergoualc'h, Kristell; Comeau, Louis-Pierre; Jo, Smith; Lou, Verchot

2017-04-01

Half of the peatlands across Peninsular Malaysia, Borneo and Sumatra are 'managed'. Conversion of peat swamp forest to workable oil palm plantation requires a drastic, potentially irreversible, change to the landscape, to which fertilizers are then routinely applied. A combination of these factors is now widely thought to increase soil nitrous oxide (N2O) emissions, although there is high uncertainty due to gaps in the knowledge, both regionally and nationally. Despite the widespread use of fertilizers in plantations on peats, studies observing their effects remain very limited. Therefore, there is a need for in situ studies to evaluate how environmental parameters (edaphic properties, climate, soil moisture and N availability indicators) influence soil emissions. This 18 month study was located in plots local to each other, representing the start, intermediate and end of the land conversion process; namely mixed peat swamp forest, drained and logged forest and industrial oil palm plantation. Spatial variability was taken into account by differentiating the hollows and hummocks in the mixed peat swamp forest, and the fertilized zone and the zone without fertilizer addition in the oil palm plantation. Gas samples were collected each month from static chambers at the same time as key environmental parameters were measured. Intensive sampling was performed during a 35 day period following two fertilizer applications, in which urea was applied to palms at rates of 0.5 and 1 kg urea palm-1. Soil N2O emissions (kg N ha-1 y-1 ± SE) were low overall, but they were greater in the oil palm plantation (0.8 ± 0.1) than in the mixed peat swamp forest (0.3 ± 0.0) and the drained/logged forest (0.2 ± 0.0). In the mixed peat swamp forest, monthly average fluxes of N2O (g N ha-1 d-1 ± SE) were similar in the hollows (0.6 ± 0.2) and the hummocks (0.3 ± 0.1), whereas in the oil palm plantation they were consistently higher in the zone without fertilizer (2.5 ± 0.4) than in

A resource of genome-wide single-nucleotide polymorphisms generated by RAD tag sequencing in the critically endangered European eel

DEFF Research Database (Denmark)

Pujolar, J.M.; Jacobsen, M.W.; Frydenberg, J.

2013-01-01

Reduced representation genome sequencing such as restriction-site-associated DNA (RAD) sequencing is finding increased use to identify and genotype large numbers of single-nucleotide polymorphisms (SNPs) in model and nonmodel species. We generated a unique resource of novel SNP markers for the Eu...... 425 loci and 376 918 associated SNPs provides a valuable tool for future population genetics and genomics studies and allows for targeting specific genes and particularly interesting regions of the eel genome...

Tracking the invasion of the red swamp crayfish Procambarus clarkii (Girard, 1852 (Decapoda Cambaridae in Sicily: a “citizen science” approach

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Francesco Paolo Faraone

2017-11-01

Full Text Available The first record of the red swamp crayfish in Sicily dates back to 2003 and, since then, the species seemed to be confined to a few localities in western Sicily. A small “citizen science” project carried out from November 2016 onwards led to the creation of the “Sicilian Procambarus working group” (SPwg, which aims at monitoring the distribution and impact of the species in Sicily. To date, the SPwg found the red swamp crayfish in five new sites on the island, thus doubling the number of local sites of occurrence. The new Procambarus clarkii sites lie in different river basins, some of them located several hundred kilometres from the invaded areas known to date, suggesting the existence of multiple independent releases of the species in the wild. The need of better informing the local population on the risks exerted by invasive species on biological diversity, and of carefully monitoring the impact of P. clarkii on the Sicilian inland water biota is briefly stressed.

Observations on nematodes from the Indonesian shortfin eel Anguilla bicolor bicolor McClelland in India, including a revalidation of Heliconema ahiri Karve, 1941 (Physalopteridae)

Czech Academy of Sciences Publication Activity Database

Moravec, František; Sheeba, S.; Kumar, A. B.

2013-01-01

Roč. 58, č. 4 (2013), s. 496-503 ISSN 1230-2821 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Heliconema * Procamallanus * Spirocamallanus * freshwater eel * Anguilla bicolor bicolor * Kerala * India Subject RIV: EA - Cell Biology Impact factor: 0.965, year: 2013

PENGEMBANGAN KONSEP AGROINDUSTRI BERBASIS SISTEM USAHATANI TERPADU DI WILAYAH PASANG SURUT BAGIAN I: (KONSEP PEMIKIRAN The Concept Development of Agroindustry Based on Integrated Farming System at Tidal Swamp Land Areas Chapter I: Conceptual Thinkin

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Rustan Massinai

2013-06-01

Full Text Available Integrated farming system was directed in efforts to lengthen biological cycle by optimizing use of agriculture and livestock products. Each chain of cycle resulted new product that have high economic value, so this system was expected to optimize empowerment and use of marginal land in all regions. The problems encountered in agricultural systems in tidal swamp land in general, i.e; (a limitations in the form of land, human resources, technology, and capital owned by farmers, then the potential of local resources need to be managed optimally, directed, integrated and sustainable with a view to improve land productivity and living standards of farmers by way of application of integrated farming systems by integrating crop and livestock based on the potential of local areas, and (b socio-economic problems and constraints in the development of food crops was due to a swamp area. The objective of this research was to produce integrated farming system concept to support agroindustry development in tidal swamp land in Pulang Pisau regency of Central Kalimantan province. This research was conducted with a book study method, which identifies a system consisting of integrated farming and agroindustry systems. In the both identification is performed by the system includes four aspects, i,e; economic aspects, technical aspects, social aspects of cultural and environmental. Integrated farming systems concept in tidal swamp land was generated from the production of integrated farming systems should first be processed through the processing system (agroindustry in the form of home industry, or using a mechanical device. After that, it was carried out the marketing of products, systems concepts was expected to increase the added value of agricultural production (rice, coffee and cow. With the application of agroindustry systems in tidal swamp land Pulang Pisau regency of Central Kalimantan Province is expected to increase the economic income of farmers in

Vesicular-arbuscular mycorrhizal status of plant species in the peat swamp forest of Setia Alam Jaya, Sebangau, Central Kalimantan

OpenAIRE

Suciatmih Suciatmih

2003-01-01

In order to describe the vesicular-arbuscular mycorrhizal (VAM) status of plants growing on peat soil, a study was carried out inthe peat swamp forest of Setia Alam Jaya in Sebangau, Central Kalimantan. Out of 146 plant root samples belonging to 48 plantspecies from 25 families examined, all plants colonized by VAM fungi namely 14 (29.2%) high level, 32 (66.7%) medium level, and 2(4.1%) low level respectively.

Efficiency of peptide nucleic acid-directed PCR clamping and its application in the investigation of natural diets of the Japanese eel leptocephali.

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Takeshi Terahara

Full Text Available Polymerase chain reaction (PCR-clamping using blocking primer and DNA-analogs, such as peptide nucleotide acid (PNA, may be used to selectively amplify target DNA for molecular diet analysis. We investigated PCR-clamping efficiency by studying PNA position and mismatch with complementary DNA by designing PNAs at five different positions on the nuclear rDNA internal transcribed spacer 1 of the Japanese eel Anguilla japonica in association with intra-specific nucleotide substitutions. All five PNAs were observed to efficiently inhibit amplification of a fully complementary DNA template. One mismatch between PNA and template DNA inhibited amplification of the template DNA, while two or more mismatches did not. DNA samples extracted from dorsal muscle and intestine of eight wild-caught leptochephalus larvae were subjected to this analysis, followed by cloning, nucleotide sequence analysis, and database homology search. Among 12 sequence types obtained from the intestine sample, six were identified as fungi. No sequence similarities were found in the database for the remaining six types, which were not related to one another. These results, in conjunction with our laboratory observations on larval feeding, suggest that eel leptocephali may not be dependent upon living plankton for their food source.

Chronological Reorganization of Microtubules, Actin Microfilaments, and Chromatin during the First Cell Cycle in Swamp Buffalo (Bubalus bubalis Embryos

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Vibuntita Chankitisakul

2010-01-01

Full Text Available This paper aimed to study the dynamics of early embryonic development, in terms of redistribution of cytoskeleton (microtubules, actin microfilaments and chromatin configurations during the first cell cycle in swamp buffalo embryos. Oocytes were matured and fertilized in vitro, and they were fixed at various time points after IVF. At 6 h after IVF, 44.4% matured oocytes were penetrated by spermatozoa. Partial ZP digestion, however, did not improve fertilization rate compared to control (P>.05. At 12 h after IVF, the fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the paternal chromatin continued to decondense. A sperm aster was observed radiating from the base of the decondensing sperm head. At 18 h after IVF, most presumptive zygotes had reached the pronuclear stage. The sperm aster was concurrently enlarged to assist the migration and apposition of pronuclei. Cell cleavage was facilitated by microfilaments and firstly observed by 30 h after IVF. In conclusion, the cytoskeleton actively involves with the process of fertilization and cleavage in swamp buffalo oocytes. The centrosomal material is paternally inherited. Fertilization failure is predominantly caused by poor sperm penetration. However, partial digestion of ZP did not improve fertilization rate.

Influence of water temperature and feeding regime on otolith growth in Anguilla japonica glass eels and elvers: does otolith growth cease at low temperatures?

Science.gov (United States)

Fukuda, N; Kuroki, M; Shinoda, A; Yamada, Y; Okamura, A; Aoyama, J; Tsukamoto, K

2009-06-01

The influences of water temperature and feeding regime on otolith growth in Anguilla japonica glass eels and elvers were investigated using individuals reared at 5, 10, 15, 20, 25 and 30 degrees C and in fed or unfed conditions at salinity 32 after their otoliths were marked with alizarin complexone (ALC). To eliminate the difficulty of observing the edges of otoliths with optical (OM) or scanning electron (SEM) microscopes, three to 10 individuals were sampled from each tank at 10, 20 and 30 days during the experiment and reared for an additional 10 days at 25 degrees C after their otoliths were marked a second time. Otolith growth and the number of increments were measured using both OM and SEM. Most A. japonica commenced feeding after 10 days at 20-30 degrees C or after 20 days at 15 degrees C, but no feeding occurred at 5 and 10 degrees C. No otolith growth occurred at 5 and 10 degrees C except in two individuals with minimal increment deposition at 10 degrees C. Otolith growth was proportional to water temperature within 15-25 degrees C and not different between 25 and 30 degrees C. At 15, 25 and 30 degrees C, the mean otolith growth rate in fed conditions was higher than in unfed conditions. The number of increments per day was significantly different among water temperatures (0.00-0.01 day(-1) at 5 and 10 degrees C, 0.43-0.48 day(-1) at 15 degrees C and 0.94-1.07 day(-1) at 20-30 degrees C). These results indicated that otolith growth in A. japonica glass eels and elvers was affected by temperature and ceased at otoliths of wild-caught A. japonica glass eels and elvers need to carefully consider the water temperatures potentially experienced by the juveniles in the wild.

EFTEM-EELS characterization of VC and Cr3C2 doped cemented carbides

International Nuclear Information System (INIS)

Warbichler, P.; Hofer, F.; Grogger, W.; Lackner, A.

2001-01-01

Structure-property correlation plays an important role in the design of advanced materials which are increasingly based on sub-micrometer and sometimes even nanometer grains. In this respect, analytical electron microscopy (AEM) offers a comprehensive range of characterization techniques which are particularly well suited for hard materials: electron diffraction and high resolution electron microscopy for obtaining crystallographic information and especially new emerging techniques such as energy-filtering TEM (EFTEM) and electron energy-loss spectroscopy (EELS) which enable nearly atomic resolution analysis. In this paper we concentrate on EFTEM and HREM investigations of both WC precursor-powders and sintered WC-Co composites doped with vanadium and chromium carbides in order to control the grain growth during the sintering of the ultra fine WC powders. The aim was to locate the distribution of the doping elements in the powders and in the sintered materials. (author)

Vesicular-arbuscular mycorrhizal status of plant species in the peat swamp forest of Setia Alam Jaya, Sebangau, Central Kalimantan

Directory of Open Access Journals (Sweden)

Suciatmih Suciatmih

2003-06-01

Full Text Available In order to describe the vesicular-arbuscular mycorrhizal (VAM status of plants growing on peat soil, a study was carried out inthe peat swamp forest of Setia Alam Jaya in Sebangau, Central Kalimantan. Out of 146 plant root samples belonging to 48 plantspecies from 25 families examined, all plants colonized by VAM fungi namely 14 (29.2% high level, 32 (66.7% medium level, and 2(4.1% low level respectively.

The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel.

NARCIS (Netherlands)

Hoogenboom, Ron; Bovee, Toine; Traag, Win A; Hoogerbrugge, Ronald; Baumann, Bert; Portier, Liza; Weg, Guido van de; Vries, Jaap de

2006-01-01

The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a

American black bears and bee yard depredation at Okefenokee Swamp, Georgia

Science.gov (United States)

Clark, J.D.; Dobey, S.; Masters, D.V.; Scheick, B.K.; Pelton, M.R.; Sunquist, M.E.

2005-01-01

We studied American black bears (Ursus americanus), on the northwest periphery of Okefenokee Swamp in southeast Georgia, to assess landowner attitudes toward bears, estimate the extent of damage to commercial honey bee operations by bears, and evaluate methods to reduce bear depredations to apiaries. We collected 8,351 black bear radiolocations and identified 51 bee yards on our study area. Twenty-seven of 43 home ranges contained ≥1 bee yard, averaging 11.3 and 5.1 bee yards/home range of males (n = 7) and females (n = 20), respectively. From 1996 to 1998, we documented 7 instances of bears raiding bee yards within our study area and 6 instances in adjacent areas. All but 1 of the 13 raided yards were enclosed by electric fencing. In the 12 cases of damage to electrically fenced yards, however, the fences were not active because of depleted batteries. Based on compositional analysis, bear use of areas 800–1,400 m from bee yards was disproportionately greater than use 0–800 m from bee yards. Bears disproportionately used bay (red bay: Persea borbonia, loblolly bay: Gordonia lasianthus, and southern magnolia: Magnolia virginia), gum (water tupelo: Nyssa aquatic and black gum: N. sylvatica), and cypress (Taxodium spp.) and loblolly bay habitats, however, compared with slash pine (Pinus elliottii) or pine–oak (Quercus spp.), where bee yards usually were placed. The distribution of bear radiolocations likely reflected the use of those swamp and riparian areas, rather than avoidance of bee yards. Distances to streams from damaged bee yards (x̄ = 1,750 m) were less than from undamaged yards (x̄ = 4,442 m), and damaged bee yards were closer to unimproved roads (x̄ = 134 m) than were undamaged bee yards (x̄ = 802 m). Our analysis suggests that bee yard placement away from bear travel routes (such as streams and unimproved roads) can reduce bear depredation problems. Our results strongly indicate that working electric fences are effective deterrents to bear

A quick method for species identification of Japanese eel (Anguilla japonica) using real-time PCR: an onboard application for use during sampling surveys.

Science.gov (United States)

Watanabe, Shun; Minegishi, Yuki; Yoshinaga, Tatsuki; Aoyama, Jun; Tsukamoto, Katsumi

2004-01-01

To compensate for the limited number of morphological characteristics of fish eggs and larvae, we established a convenient and robust method of species identification for eggs of the Japanese eel (Anguilla japonica) using a real-time polymerase chain reaction (PCR) that can be performed onboard research ships at sea. A total of about 1.2 kbp of the mitochondrial 16S ribosomal RNA gene sequences from all species of Anguilla and 3 other anguilliform species were compared to design specific primer pairs and a probe for A. japonica. This real-time PCR amplification was conducted for a total of 44 specimens including A. japonica, A. marmorata, A. bicolor pacifica, and 6 other anguilliform species. Immediate PCR amplification was only observed in A. japonica. We then tested this method under onboard conditions and obtained the same result as had been produced in the laboratory. These results suggest that real-time PCR can be a powerful tool for detecting Japanese eel eggs and newly hatched larvae immediately after onboard sampling during research cruises and will allow targeted sampling efforts to occur rapidly in response to any positive onboard identification of the eggs and larvae of this species.

Primary production in a shallow water lake with special reference to a reed swamp

International Nuclear Information System (INIS)

Andersen, F.Oe.

1976-01-01

Phytoplankton gross primary production ( 14 C method) in the shallow, eutrophic Danish Lake Arresoe in 1973 was 980 g C m -2 . Calculated net primary production was near zero. Macrophyte net primary production was measured by harvesting the maximum biomass, and above ground values were between 420 and 1325 g ash free dry wt m -2 , while below ground values were between 2480 and 8570 g ash free dry wt m -2 . The reed swamps were mapped on aerial photographs, and the composition of the macrophyte vegetation was determined. A comparison of macrophyte vegetation in 1944 and 1972 showed a reduction in species diversity, especially of submerged species. The seasonal variations in physical and chemical data indicated strong eutrophication in Arresoe. (author)

EFFECT OF ARBUSCULAR MYCORRHIZAL COLONIZATION ON EARLY GROWTH AND NUTRIENT CONTENT OF TWO PEAT­ SWAMP FOREST TREE SPECIES SEEDLINGS, Calophyllum hosei AND Ploiarium alternifolium

Directory of Open Access Journals (Sweden)

Maman Turjaman

2006-03-01

Full Text Available Tropical peat-swamp forests are one of  the largest near-surface reserves of terrestrial organic carbon,  but rnany peat-swamp forest tree species decreased due over-exploitation, forest fire and conversion of natural forests into agricultural lands. Among those species are slow-growing Calophyllum  hoseiand Ploiarium  alternifolium, two species are good for construction of boats, furniture, house building and considerable attention from pharmacological viewpoint for human healthly. This study was aimed at understanding the effects of arbuscular mycorrhizal (AM fungi on early growth of  C. hosei and P.alternifoliumunder greenhouse condition. Seedlings of C. hosei and P.alternifoliumwere inoculated with AM fungi: Glomus clarum and Glomus aggregatum ,or uninoculated under greenhouse condition during 6 months. AM colonization,   plant growth,  survival rate and  nutrient  content  (P, Zn  and B were measured. The percentage of C. hoseiand P.alternifolium ranged from 27-32% and 18-19%,  respectively. Both inoculated seedling species had greater plant  height, diameter, leaf number, shoot and root dry weight than control  seedlings.   Nutrient  content  of  inoculated  plants  were increased with AM colonization- Survival rates of  inoculated plants were higher (100%  than those of  control plants (67%. The results suggested that inoculation of AM fungi could improve the early growth of C. hoseiand P.alternifolium grown in tropical peat-swamp forest therefore  this finding has greater potential impact if this innovative technology applied in field scales which are socially acceptable, commercially profitable and environmentally friendly.

An EELS sub-nanometer investigation of the dielectric gate stack for the realization of InGaAs based MOSFET devices

International Nuclear Information System (INIS)

Longo, P; Paterson, G W; Craven, A J; Holland, M C; Thayne, I G

2010-01-01

In this paper, a subnanometer investigation of the Ga 2 O 3 /GdGaO dielectric gate stack deposited onto InGaAs is presented. Results regarding the influence of the growth conditions on the interface region from a chemical and morphological point of view are presented. The chemical information reported in this paper has been obtained using electron energy loss spectroscopy (EELS) that was carried out in a scanning transmission electron microscope ((S)TEM) showing both spatial and depth resolution.

Algal-mediated ecosystem exchanges in the Eel River drainage network: towards photogrammetric mapping of color to function

Science.gov (United States)

Power, M. E.; Welter, J.; Furey, P.; Lowe, R.; Finlay, J. C.; Hondzo, M.; Limm, M.; Bode, C.; Dietrich, W. E.

2009-12-01

Seasonal algal proliferations in river networks are typically short-lived (weeks-months) but spatially extensive. They mediate important ecological and biogeochemical exchanges within and between ecosystems. We are investigating correspondence of assemblage color with ecosystem function in the nitrogen-limited Eel River of northern California. During summer base flow following winter floods, Eel algal assemblages are dominated by the green macroalga Cladophora glomerata. New growths are green, but blooms turn yellow as Cladophora filaments are colonized by epiphytic diatoms (Cocconeis spp.). Later, proliferations turn rust colored as epiphytic assemblages became dominated by Epithemia spp., diatoms that contain nitrogen-fixing cyanobacterial endosymbionts. Epithemia-encrusted Cladophora occurs at and downstream of reaches draining > 100 km2 (where summer inundated average channel widths > 25 m), coinciding with a threshold increase in concentration of total dissolved nitrogen. Areal nitrogen fixation rates are 14x higher in rusty algal proliferations than in green, and 3-4x higher than in yellow Cladophora mats. Corresponding increases in insect emergence suggest that nitrogen fixed by cyanobacterial endosymbionts is highly edible. Rates of biomass emergence from rusty Cladophora mats are 12-17 times greater than from green mats, and 8-10 times greater from rusty than from yellow Cladophora mats, because larger taxa emerge from rusty mats (Chironominae versus Ceratopogonidae in yellow mats). Photogrammetric detection of spatial coverage and color changes in algal proliferations may help us track nitrogen fluxes they mediate (riverine loading from the atmosphere via fixation, river to the watershed return via insect emergence) that link riverine to aerial, watershed, and potentially nearshore marine ecosystems at reach to basin scales.

A high resolution EELS study of free-carrier variations in H2+/H+ bombarded (100)GaAs

International Nuclear Information System (INIS)

Dubois, L.H.; Schwartz, G.P.

1984-01-01

High resolution electron energy loss spectroscopy (EELS) has been used to examine whether thermal recovery of the near-surface free-carrier concentration in Te-doped (100) GaAs is accomplished following low energy (250--1500 eV) hydrogen ion bombardment. For hydrogen ion impact energies below 500 eV, the nominal bulk free-carrier density is recovered by annealing at 725 K for 2 h. For comparable ion doses, the net free-carrier concentration decreases monotonically at higher impact energies under similar annealing conditions. The threshold for damage retention occurs close to the value of transmitted energy which is necessary to create either a Ga or an As interstitial point defect

Postpartum anoestrus in the suckled swamp buffalo

International Nuclear Information System (INIS)

Jainudeen, M.R.; Sharifuddin, W.; Yap, K.C.; Bakar Dahari, A.

1984-01-01

Postpartum anoestrus is a serious cause of infertility in the swamp buffalo. Our studies have revealed that it is due to a failure in the resumption of ovarian cyclicity. Parity was inversely related to the calving interval being longer in primiparous than multiparous suckled buffaloes. This effect may be partly due to the higher nutrient demands for growth as well as for lactation in the primiparous animal. The effects of suckling on ovarian and pituitary function of postpartum buffaloes were investigated with the aid of radioimmunoassays for progesterone and luteinizing hormone (LH) as well as rectal palpation and laparoscopic inspection of the ovaries. The incidence of postpartum anoestrus was higher in suckled than non-suckled buffaloes. Weaning buffalo calves at 30 d postpartum resulted in the resumption of normal ovarian cycles within 60 d postpartum. LH release in response to a single injection of a synthetic gonadotropin-releasing hormone (GnRH) indicated that pituitary responsiveness to GnRH was restored by Day 30 postpartum in suckled buffaloes whereas anoestrous buffaloes were able to release levels of LH comparable to that of the preovulatory surge. A progesterone-releasing intra-vaginal device (PRID) induced an anovulatory oestrus in the anoestrous suckled buffalo which was partially overcome by human chorionic gonadotropin (HCG) administered at the induced oestrus. However, a 72 h separation of the calf from its dam combined with PRID was the most effective substitute to weaning in initiating ovarian cycles in the suckled buffalo. Our data suggest that suckling inhibits ovarian function not by an effect on the pituitary gland but rather on GnRH release by the hypothalamus. (author)

Biological impact of polycyclic aromatic hydrocarbons (PAH) on european eel Definition and validation of bio-marker useful in situ; Impact biologique des hydrocarbures aromatiques polycycliques (HAP) sur l'anguille europeenne. Definition et validation de biomarqueurs in situ

Energy Technology Data Exchange (ETDEWEB)

Buet, A.

2002-02-15

In the natural environment, especially in aquatic ecosystems, the presence of polycyclic aromatic hydrocarbons (PAH) can have deleterious effects. The aim of this project was to assess the biological impact of PAH on the European eel (Anguilla anguilla) and to define a series of bio-markers useful in situ. The originality of this field study comes from the variety of the considered factors and the choice of a protected site. Bio-markers validation requires the knowledge of normal variations of the selected parameters. Therefore, the first objective of our study was to assess the effects of natural factors on the eco-physiological characteristics of an eel population collected from the National Reserve of Camargue. Bio-metric and metabolic parameters were measured as well as enzymatic markers of contamination: biotransformation activities (EROD, GST, UDPHT), oxidative stress activities (CAT, SOD, GPx, SeGPx) and membrane activities (ATPases, AChE). The temporal evolutions and the nutritional state influenced significantly the answer of these indicators of contamination in the studied population. On the other hand, the effect of sexual maturity and parasitism by the nematode Anguillicola crassus was reduced. After confirming a local atmospheric contribution in PAH, we tried to understand the accumulation patterns of these compounds within organisms and organs. Therefore, the analysis of PAH were performed on the bile, the liver and the muscle samples of European eels. Whatever the season, the sampling site, the sexual maturity and the sanitary state of eels, the PAH tissue contamination was general but fluctuating. The localization of the contamination gives information about its persistence. Chronologically, bile accumulation reflects a recent intoxication, whereas the liver gives a medium-term contamination image and the muscle impregnation represents a longer-term storage. The PAH concentrated in fat tissues but these concentrations were not systematically

Firing Room Remote Application Software Development & Swamp Works Laboratory Robot Software Development

Science.gov (United States)

Garcia, Janette

2016-01-01

The National Aeronautics and Space Administration (NASA) is creating a way to send humans beyond low Earth orbit, and later to Mars. Kennedy Space Center (KSC) is working to make this possible by developing a Spaceport Command and Control System (SCCS) which will allow the launch of Space Launch System (SLS). This paper's focus is on the work performed by the author in her first and second part of the internship as a remote application software developer. During the first part of her internship, the author worked on the SCCS's software application layer by assisting multiple ground subsystems teams including Launch Accessories (LACC) and Environmental Control System (ECS) on the design, development, integration, and testing of remote control software applications. Then, on the second part of the internship, the author worked on the development of robot software at the Swamp Works Laboratory which is a research and technology development group which focuses on inventing new technology to help future In-Situ Resource Utilization (ISRU) missions.

Food habitats of the Antillean manatees (Trichechus manatus manatus) in the Coswine Swamps (French Guiana, South America)

OpenAIRE

Spiegelberger, Thomas; Ganslosser, Udo

2005-01-01

A study was conducted to analyse the habitat of the Antillean manatee (Trichechus manatus manatus L. 1758) in the Coswine Swamps of northwest French Guiana, South America. Water parameters were similar to those described in other studies: water depth varied from 2.5 m to more than 20 m; water temperature was between 24.5 °C and 30.3 °C and pH varied between 5.5 and 6.9. Salinity was low (0.0‰ to 1.3‰) with 86.9% of all samples taken in fresh water. No submerged aquatic vegetation was found in...

MICRO ALGAE CULTURE FROM RAWA GAMBUT: INTRODUCTION STUDY OF MICRO ALGAE POTENTIAL AS BIO DIESEL RAW MATERIAL

Directory of Open Access Journals (Sweden)

Dewi Jumiarni

2018-01-01

Full Text Available Sustainable production of renewable energy is being a crucial problem, since fuel demand in Indonesia rises annually while the production decreases. Microalgae have been suggested as a potential feedstock for biofuel production. This research was a preliminary study to identified microalgal culture from water of peat swamp, and probe its potential as biodiesel feedstock.  Microalgal identification was conducted by morphological observation using microscope, while potential as biodiesel was probed by detection using Nile Red staining and supported by literature study. This research has identified 19 species of microalgae from culture, which were consisting of 16 species were Chlorophyceae and 3 species were Bacillariophyceae. Microalgae that  potentially to be developed biodiesel feedstock were Cyclotella atomus, Cyclotella sp, Nitzschia sp, Chlorella sp, Desmodesmus sp, Chlorella ellipsoida and Chlorella vulgaris.

Eel calcitonin binding site distribution and antinociceptive activity in rats

International Nuclear Information System (INIS)

Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

1986-01-01

The distribution of binding site for [ 125 I]-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing [ 125 I]-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain

Zoneamento ambiental em Pantanais (Banhados Environmental zoning in swamp regions

Directory of Open Access Journals (Sweden)

Fabio C. Kurtz

2001-05-01

Full Text Available O zoneamento ambiental em pantanais (Banhados permitiu avaliar a deterioração ambiental dos ecossistemas existentes na Estação Ecológica do Taim (ESEC/TAIM municípios de Rio Grande, RS, e Santa Vitória do Palmar, RS. Considerou-se dois tipos distintos de ecossistemas: o do Banhado (ECO1 = Ecossistema Límnico e o da Planície Marítima (ECO2 = Ecossistema Planície Marítima. A ECO TOTAL (ECO1 + ECO2 apresentou 64% da classe APP (Área de Preservação Permanente, 27,6% de ACP (Área de Conservação Permanente, e 5,6% de AUO (Área de Uso e Ocupação, enquanto em menor porcentagem se encontra a classe AR (Área de Restauração com 2,8%. A deterioração ambiental da ESEC/TAIM (ECO TOTAL ficou em 13,65%. Com relação à análise fatorial, conclui-se que esta técnica permitiu conhecer a estrutura dos dados, mostrando as correlações entre cada variável (classes de exuberância e seu respectivo fator; entretanto, não foi possível separar grupos ou quantificar a influência de uma ou mais variáveis sobre outra de interesse (variável resposta. Recomenda-se que o zoneamento ambiental seja elaborado pelos órgãos públicos ambientais, nas demais estações ecológicas e nas unidades de conservação.The environmental zoning in swamp regions allowed the evaluation of the environmental deterioration of the ecosystems in the Ecological Station of Taim (ESEC/TAIM, in Rio Grande and Santa Vitória of Palmar (in the State of Rio Grande do Sul - Brazil. Two different types of ecosystems were considered: swamp regions (ECO1 = Límnico Ecosystem and the Marine Plain (ECO2 = Ecosystem Marine Plain. The ECO TOTAL (ECO1 + ECO2 presented 64% of the class APP (Permanent Preservation Area, 27.6% of ACP (Permanent Conservation Area, 5.6% of AUO (Occupation and Use Area, and in a smaller percentage the class AR (Restoration Area with 2.8%. The environmental deterioration of ESEC/TAIM (ECO TOTAL was 13.65%. The factorial analysis technique permitted

Gastrointestinal motor inhibition by exogenous human, salmon, and eel calcitonin in conscious dogs.

Science.gov (United States)

Nakamura, H; Asano, T; Haruta, K; Takeda, K

1995-01-01

Effects of synthetic eel (E-), salmon (S-), and human (H-) calcitonin (CT) on gastrointestinal motility were studied in conscious beagle dogs, which had been implanted with strain gauge force transducers. Intramuscular administration of E-, S-, or H-CT interrupted gastric migrating motor complexes, digestive pattern, and gastric emptying. The order of potency was E-CT = S-CT > H-CT. Motor inhibition induced by CT occurred independently of plasma immunoreactive motilin levels or hypocalcemia. In addition, E-CT and S-CT induced vomiting without a retrograde giant contraction (RGC) during the postprandial state. Apomorphine or CuSO4 initiated RGC prior to vomiting. RGC induced by apomorphine was inhibited by pretreatment with E-CT as well as hexamethonium, atropine, or surgical vagotomy. E-CT showed no inhibitory effect on nicotine stimulated contraction of isolated guinea-pig ileum. These results suggest that peripherally administered CT inhibits canine gastrointestinal motility at the central nervous system level by lowering vagal activity.

Isolation and characterization of gonadotropin isohormones from the pituitary gland of pike eel (Muraenesox cinereus)

International Nuclear Information System (INIS)

Huang, F.-L.; Huang, C.-J.; Lin, S.-H.; Lo, T.-B.; Papkoff, H.

1981-01-01

Pike eel gonadotropins were isolated from pituitary glands by 40% alcohol-6% ammonium acetate, pH 5.1 extraction and were purified by DEAE-cellulose chromatography and electrophoresis into four electrophoretically homogeneous forms. These four isohormones were biologically identified as gonadotropins by the stimulation of 32 P-uptake in 1-day-old chick testes, by the induction of ovulation in catfish, and by the in vitro production of testosterone from isolated rat Leydig cells and of androgen from carp testes. The amino acid composition of the isohormones were similar to other known piscine gonadotropins (carp and salmon) and were composed of two non-identical subunits with Tyr and Ser as N-terminal amino acid residues. The molecular weights of two subunits were 15000 and 10500, respectively, as estimated by SDS-gel disc electrophoresis. (author)

Spatially-resolved EEL studies of plasmons in silver filled carbon nanotubes using a dedicated STEM

International Nuclear Information System (INIS)

Bangert, U; Harvey, A J; Seepujak, A

2008-01-01

Using a dedicated FEG STEM, we present highly spatially-resolved electron energy-loss (EEL) studies of individual multi-walled carbon nanotubes (MWCNTs), each with the inner cavity possessing regions completely filled with silver. The transmission and attenuation of graphite π-collective mode E-fields through the MWCNT walls are established. Noticeable changes in the graphite π-surface mode are witnessed, concomitant with coupling of the silver Mie mode and the graphite π-surface mode. The resulting collective mode is significantly red-shifted to below 5 eV, with considerable intensity in the visible frequency regime. It appears that silver retains its ability to enhance E-fields when surrounded by a MWCNT. Present observations lead to the possibility of collective modes propagating on graphene monolayers being tuned in frequency by the presence of a metal.

Isolation and characterization of active LINE and SINEs from the eel.

Science.gov (United States)

Kajikawa, Masaki; Ichiyanagi, Kenji; Tanaka, Nozomu; Okada, Norihiro

2005-03-01

Long interspersed elements (LINEs) and short interspersed elements (SINEs) are retrotransposons. These elements can mobilize by the "copy-and-paste" mechanism, in which their own RNA is reverse-transcribed into complementary DNA (cDNA). LINEs and SINEs not only are components of eukaryotic genomes but also drivers of genomic evolution. Thus, studies of the amplification mechanism of LINEs and SINEs are important for understanding eukaryotic genome evolution. Here we report the characterization of one LINE family (UnaL2) and two SINE families (UnaSINE1 and UnaSINE2) from the eel (Anguilla japonica) genome. UnaL2 is approximately 3.6 kilobases (kb) and encodes only one open reading frame (ORF). UnaL2 belongs to the stringent type--thought to be a major group of LINEs--and can mobilize in HeLa cells. We also show that UnaL2 and the two UnaSINEs have similar 3' tails, and that both UnaSINE1 and UnaSINE2 can be mobilized by UnaL2 in HeLa cells. These elements are thus useful for delineating the amplification mechanism of stringent type LINEs as well as that of SINEs.

Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Butts, Ian; Munk, Peter

2016-01-01

sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic...... and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30–40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion...

Clonal growth strategy, diversity and structure: A spatiotemporal response to sedimentation in tropical Cyperus papyrus swamps.

Science.gov (United States)

Geremew, Addisie; Stiers, Iris; Sierens, Tim; Kefalew, Alemayehu; Triest, Ludwig

2018-01-01

Land degradation and soil erosion in the upper catchments of tropical lakes fringed by papyrus vegetation can result in a sediment load gradient from land to lakeward. Understanding the dynamics of clonal modules (ramets and genets) and growth strategies of plants on such a gradient in both space and time is critical for exploring a species adaptation and processes regulating population structure and differentiation. We assessed the spatial and temporal dynamics in clonal growth, diversity, and structure of an emergent macrophyte, Cyperus papyrus (papyrus), in response to two contrasting sedimentation regimes by combining morphological traits and genotype data using 20 microsatellite markers. A total of 636 ramets from six permanent plots (18 x 30 m) in three Ethiopian papyrus swamps, each with discrete sedimentation regimes (high vs. low) were sampled for two years. We found that ramets under the high sedimentation regime (HSR) were significantly clumped and denser than the sparse and spreading ramets under the low sedimentation regime (LSR). The HSR resulted in significantly different ramets with short culm height and girth diameter as compared to the LSR. These results indicated that C. papyrus ameliorates the effect of sedimentation by shifting clonal growth strategy from guerrilla (in LSR) to phalanx (in HSR). Clonal richness, size, dominance, and clonal subrange differed significantly between sediment regimes and studied time periods. Each swamp under HSR revealed a significantly high clonal richness (R = 0.80) as compared to the LSR (R = 0.48). Such discrepancy in clonal richness reflected the occurrence of initial and repeated seedling recruitment strategies as a response to different sedimentation regimes. Overall, our spatial and short-term temporal observations highlighted that HSR enhances clonal richness and decreases clonal subrange owing to repeated seedling recruitment and genets turnover.