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1

Venom Proteome of the Box Jellyfish Chironex fleckeri  

PubMed Central

The nematocyst is a complex intracellular structure unique to Cnidaria. When triggered to discharge, the nematocyst explosively releases a long spiny, tubule that delivers an often highly venomous mixture of components. The box jellyfish, Chironex fleckeri, produces exceptionally potent and rapid-acting venom and its stings to humans cause severe localized and systemic effects that are potentially life-threatening. In an effort to identify toxins that could be responsible for the serious health effects caused by C. fleckeri and related species, we used a proteomic approach to profile the protein components of C. fleckeri venom. Collectively, 61 proteins were identified, including toxins and proteins important for nematocyte development and nematocyst formation (nematogenesis). The most abundant toxins identified were isoforms of a taxonomically restricted family of potent cnidarian proteins. These toxins are associated with cytolytic, nociceptive, inflammatory, dermonecrotic and lethal properties and expansion of this important protein family goes some way to explaining the destructive and potentially fatal effects of C. fleckeri venom. Venom proteins and their post-translational modifications (PTMs) were further characterized using toxin-specific antibodies and phosphoprotein/glycoprotein-specific stains. Results indicated that glycosylation is a common PTM of the toxin family while a lack of cross-reactivity by toxin-specific antibodies infers there is significant divergence in structure and possibly function among family members. This study provides insight into the depth and diversity of protein toxins produced by harmful box jellyfish and represents the first description of a cubozoan jellyfish venom proteome.

Brinkman, Diane L.; Aziz, Ammar; Loukas, Alex; Potriquet, Jeremy; Seymour, Jamie; Mulvenna, Jason

2012-01-01

2

An in vivo comparison of the efficacy of CSL box jellyfish antivenom with antibodies raised against nematocyst-derived Chironex fleckeri venom  

Microsoft Academic Search

Although CSL box jellyfish antivenom (AV) remains the primary treatment for Chironex fleckeri envenoming, there has been considerable debate regarding its clinical effectiveness. Animal studies have shown that AV is largely ineffective in preventing C. fleckeri-induced cardiovascular collapse. This study examined the effectiveness of CSL box jellyfish AV (ovine IgG), raised against ‘milked’ venom, and polyclonal rabbit IgG antibodies (Ab)

Kelly L. Winter; Geoffrey K. Isbister; Tamara Jacoby; Jamie E. Seymour; Wayne C. Hodgson

2009-01-01

3

Effects of verapamil and CSL antivenom on Chironex fleckeri (Box-jellyfish) induced mortality  

Microsoft Academic Search

Intravenous verapamil prolonged survival in mice challenged with intravenous Chironex fleckeri venom prepared from clarified nematocyst suspensions. Ovoid antivenom protected mice who had been challenged but only over a limited dose range. Verapamil also enhanced the beneficial effect of ovine antivenom but again was most active only over a restricted dose range. This data suggests that there may be an,

David A Bloom; Jose Burnett

1999-01-01

4

Vinegar and Chironex fleckeri stings - reply.  

PubMed

We thank Drs Gibbs, Corkeron and Blake for their interest in our study. We are delighted to respond to their comments. Firstly, the anecdote that vinegar increases pain and an unpublished case series (into analgesic requirements in Irukandji envenomation) performed at Cairns Hospital concerned us that vinegar may not be the panacea it is thought to be and prompted the study. Interestingly this increased opiate requirement was for systemic pain and not for any pain at the sting site. Our initial suspicion was that the increased opiate requirement was driven by the lack of application of vinegar; however, our findings suggested otherwise; the use of vinegar on an envenomation increased opiate requirements and increased the length of stay at a medical facility. Secondly, the relevance of our stimulated nematocysts model to clinical envenoming has been discussed previously with our in vivo pressure immobilisation bandages (PIB) experiment in 2000. We would expect that by now there would be evidence to support this concern but, to date, we are unaware of any evidence to this effect. Whether this technique is an adequate simulation does not refute the evidence that discharged nematocysts still have residual venom, and that, when vinegar is applied, an average of 60% more venom is released. It has been demonstrated previously that nematocysts have residual venom and that the volume of venom retained within may be equivalent to that which has already been discharged. It has also been demonstrated that this venom can be expressed by pressure and we now add to this knowledge that this residual venom can also be expressed by application of vinegar. Similar to our conclusions with PIB, this has the potential to worsen an envenomation. Thirdly, that vinegar effectively disables undischarged nematocysts is not disputed; however, we are unaware of any data that would support the quoted figure that 80% of nematocysts in contact with skin are undischarged. Consequently, the claim that vinegar protects the victim from these discharging, causing further envenomation, is speculative. It is, however, plausible that some nematocysts may not be in contact with skin, considering that Chironex fleckeri tentacles are ribbon-shaped and may adhere to the victim in a convoluted and contracted state. Without further manipulation these nematocysts are clinically irrelevant to further envenomation. We are unaware of any data that answers the question raised by the authors in relation to the population of discharged versus undischarged nematocysts in direct skin contact, where the relevance of vinegar does actually have a bearing. Finally, vinegar is the one recognised first-aid treatment for tropical marine jellyfish stings. As such, this experiment was performed specifically to examine the effect of vinegar on residual venom held in discharged nematocysts. Further to this, the testing of other common liquids as suggested, which have already been shown to be ineffective in deactivating nematocysts is irrelevant to the experiment and the envenomed victim. We disagree with Gibbs, Corkeron and Blake. Without evidence as to its effectiveness or safety, vinegar was promoted and recommended to specifically reduce further envenomation. Instead we have now demonstrated that it has potential to worsen envenomation. This is not just an interesting finding, it is a genuine concern. Like PIB, where the potential to cause harm has been demonstrated in the absence of effectiveness or safety, it would be prudent to acknowledge the risk in the use of vinegar and to judiciously express this risk in a measured recommendation for its continued use, rather than continuing to recommend its unfettered use. That modified recommendation should continue until the safety and efficacy of vinegar has been established fully by appropriate research. We recognise that vinegar has been introduced and accepted as a core first-aid treatment in marine stings at a time when the requirements for demonstrated safety or efficacy were not as stringent. We now provide a need to re-examine thi

Welfare, Philippa; Little, Mark; Pereira, Peter; Seymour, Jamie

2014-06-01

5

Jellyfish as food  

Microsoft Academic Search

Jellyfish have been exploited commercially by Chinese as an important food for more than a thousand years. Semi-dried jellyfish represent a multi-million dollar seafood business in Asia. Traditional processing methods involve a multi-phase processing procedure using a mixture of salt (NaCl) and alum (AlK[SO4]2c12 H2O) to reduce the water content, decrease the pH, and firm the texture. Processed jellyfish have

Y. H. Peggy Hsieh; Fui-Ming Leong; Jack Rudloe

2001-01-01

6

Jellyfish Stings, First Aid  

MedlinePLUS

... is not actually a jellyfish but rather a colony of small, predatory animals (hydrozoan). However, due to ... treat itching. References/Trusted Links References Handal KA; American Red Cross. Part 2: first aid. In: The ...

7

Dangerous jellyfish blooms are predictable.  

PubMed

The potentially fatal Irukandji syndrome is relatively common in tropical waters throughout the world. It is caused by the sting of the Irukandji jellyfish, a family of box jellyfish that are almost impossible to detect in the water owing to their small size and transparency. Using collated medical records of stings and local weather conditions, we show that the presence of Irukandji blooms in coastal waters can be forecast on the basis of wind conditions. On the Great Barrier Reef, blooms largely coincide with relaxation of the prevailing southeasterly trade winds, with average conditions corresponding to near zero alongshore wind on the day prior to the sting. These conditions are consistent with hypotheses long held by local communities and provide a basis for designing management interventions that have the potential to eliminate the majority of stings. PMID:24829278

Gershwin, Lisa-ann; Condie, Scott A; Mansbridge, Jim V; Richardson, Anthony J

2014-07-01

8

Jellyfish modulate bacterial dynamic and community structure.  

PubMed

Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters. PMID:22745726

Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

2012-01-01

9

Cubozoan venom-induced cardiovascular collapse is caused by hyperkalemia and prevented by zinc gluconate in mice.  

PubMed

Chironex fleckeri (Australian box jellyfish) stings can cause acute cardiovascular collapse and death. We developed methods to recover venom with high specific activity, and evaluated the effects of both total venom and constituent porins at doses equivalent to lethal envenomation. Marked potassium release occurred within 5 min and hemolysis within 20 min in human red blood cells (RBC) exposed to venom or purified venom porin. Electron microscopy revealed abundant ~12-nm transmembrane pores in RBC exposed to purified venom porins. C57BL/6 mice injected with venom showed rapid decline in ejection fraction with progression to electromechanical dissociation and electrocardiographic findings consistent with acute hyperkalemia. Recognizing that porin assembly can be inhibited by zinc, we found that zinc gluconate inhibited potassium efflux from RBC exposed to total venom or purified porin, and prolonged survival time in mice following venom injection. These findings suggest that hyperkalemia is the critical event following Chironex fleckeri envenomation and that rapid administration of zinc could be life saving in human sting victims. PMID:23251508

Yanagihara, Angel A; Shohet, Ralph V

2012-01-01

10

Recurrent jellyfish blooms are a consequence of global oscillations  

PubMed Central

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

Condon, Robert H.; Duarte, Carlos M.; Pitt, Kylie A.; Robinson, Kelly L.; Lucas, Cathy H.; Sutherland, Kelly R.; Mianzan, Hermes W.; Bogeberg, Molly; Purcell, Jennifer E.; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P.; Brodeur, Richard D.; Haddock, Steven H. D.; Malej, Alenka; Parry, Gregory D.; Eriksen, Elena; Quinones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M.; Graham, William M.

2013-01-01

11

Jellyfish Stings and Their Management: A Review  

PubMed Central

Jellyfish (cnidarians) have a worldwide distribution. Despite most being harmless, some species may cause local and also systemic reactions. Treatment of jellyfish envenomation is directed at: alleviating the local effects of venom, preventing further nematocyst discharges and controlling systemic reactions, including shock. In severe cases, the most important step is stabilizing and maintaining vital functions. With some differences between species, there seems to be evidence and consensus on oral/topical analgesics, hot water and ice packs as effective painkillers and on 30 s application of domestic vinegar (4%–6% acetic acid) to prevent further discharge of unfired nematocysts remaining on the skin. Conversely, alcohol, methylated spirits and fresh water should be carefully avoided, since they could massively discharge nematocysts; pressure immobilization bandaging should also be avoided, as laboratory studies show that it stimulates additional venom discharge from nematocysts. Most treatment approaches are presently founded on relatively weak evidence; therefore, further research (especially randomized clinical trials) is strongly recommended. Dissemination of appropriate treatment modalities should be deployed to better inform and educate those at risk. Adequate signage should be placed at beaches to notify tourists of the jellyfish risk. Swimmers in risky areas should wear protective equipment.

Cegolon, Luca; Heymann, William C.; Lange, John H.; Mastrangelo, Giuseppe

2013-01-01

12

Mediterranean Jellyfish Venoms: A Review on Scyphomedusae  

PubMed Central

The production of natural toxins is an interesting aspect, which characterizes the physiology and the ecology of a number of marine species that use them for defence/offence purposes. Cnidarians are of particular concern from this point of view; their venoms are contained in specialized structures–the nematocysts–which, after mechanical or chemical stimulation, inject the venom in the prey or in the attacker. Cnidarian stinging is a serious health problem for humans in the zones where extremely venomous jellyfish or anemones are common, such as in temperate and tropical oceanic waters and particularly along several Pacific coasts, and severe cases of envenomation, including also lethal cases mainly induced by cubomedusae, were reported. On the contrary, in the Mediterranean region the problem of jellyfish stings is quite modest, even though they can have anyhow an impact on public health and be of importance from the ecological and economic point of view owing to the implications on ecosystems and on some human activities such as tourism, bathing and fishing. This paper reviews the knowledge about the various aspects related to the occurrence and the stinging of the Mediterranean scyphozoan jellyfish as well as the activity of their venoms.

Mariottini, Gian Luigi; Pane, Luigi

2010-01-01

13

A fluid mechanical model for current-generating-feeding jellyfish  

NASA Astrophysics Data System (ADS)

Many jellyfish species, e.g. moon jellyfish Aurelia aurita, use body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. In this study, a model was developed to understand the fluid mechanics for this current-generating-feeding mode of jellyfish. The flow generated by free-swimming Aurelia aurita was measured using digital particle image velocimetry. The dynamics of prey (e.g., brine shrimp Artemia) in the flow field were described by a modified Maxey-Riley equation which takes into consideration the inertia of prey and the escape forces, which prey exert in the presence of predator. A Lagrangian analysis was used to identify the region of the flow in which prey can be captured by the jellyfish and the clearance rate was quantified. The study provides a new methodology to study biological current-generating-feeding and the transport and mixing of particles in fluid flow in general.

Peng, Jifeng; Dabiri, John

2008-11-01

14

Jellyfish blooms in China: Dominant species, causes and consequences.  

PubMed

Three jellyfish species, Aurelia aurita, Cyanea nozakii and Nemopilema nomurai, form large blooms in Chinese seas. We report on the distribution and increasing incidence of jellyfish blooms and their consequences in Chinese coastal seas and analyze their relationship to anthropogenically derived changes to the environment in order to determine the possible causes. A. aurita, C. nozakii and N. nomurai form blooms in the temperate Chinese seas including the northern East China Sea, Yellow Sea and Bohai Sea. N. nomurai forms offshore blooms while the other two species bloom mainly in inshore areas. Eutrophication, overfishing, habitat modification for aquaculture and climate change are all possible contributory factors facilitating plausible mechanisms for the proliferation of jellyfish blooms. In the absence of improvement in coastal marine ecosystem health, jellyfish blooms could be sustained and may even spread from the locations in which they now occur. PMID:20553695

Dong, Zhijun; Liu, Dongyan; Keesing, John K

2010-07-01

15

Scyphozoan jellyfish venom metalloproteinases and their role in the cytotoxicity.  

PubMed

The present study, for the first time, comparatively investigated the enzymatic activities (proteases and hyaluronidases) in the venoms of four Scyphozoan jellyfish species, including Nemopilema nomurai, Rhopilema esculenta, Cyanea nozakii, and Aurelia aurita. For this, various zymographic analyses were performed using assay specific substrates. Interestingly, all the four jellyfish venoms showed gelatinolytic, caseinolytic, and fibrinolytic activities, each of which contains a multitude of enzyme components with molecular weights between 17 and 130 kDa. These four jellyfish venoms demonstrated a huge variation in their proteolytic activities in quantitative and qualitative manner depending on the species. Most of these enzymatic activities were disappeared by the treatment of 1,10-phenanthroline, suggesting they might be belonged to metalloproteinases. Toxicological significance of these venom proteases was examined by comparing their proteolytic activity and the cytotoxicity in NIH 3T3 cells. The relative cytotoxic potency was C. nozakii > N. nomurai > A. aurita > R. esculenta. The cytotoxicity of jellyfish venom shows a positive correlation with its overall proteolytic activity. The metalloproteinases appear to play an important role in the induction of jellyfish venom toxicities. In conclusion, the present report proposes a novel finding of Scyphozoan jellyfish venom metalloproteinases and their potential role in the cytotoxicity. PMID:21718715

Lee, Hyunkyoung; Jung, Eun-sun; Kang, Changkeun; Yoon, Won Duk; Kim, Jong-Shu; Kim, Euikyung

2011-09-01

16

Evaluation of the effects of various chemicals on discharge of and pain caused by jellyfish nematocysts  

Microsoft Academic Search

Jellyfish tentacles in contact with human skin can produce pain swelling and redness. The pain is due to discharge of jellyfish nematocysts and associated toxins and discharge can be caused by a variety of mechanical and chemical stimuli. A series of tests were carried out with chemicals traditionally used to treat jellyfish stings e.g. acetic acid ammonia meat tenderizer baking

Laura M. Birsa; Peter G. Verity; Richard F. Lee

2010-01-01

17

Clinical toxicology: a tropical Australian perspective.  

PubMed

Tropical Australia has an amazing diversity of venomous fauna, from "the world's most venomous creature," the multi-tentacled (chirodropid) box jellyfish Chironex fleckeri, to aggressive spiders whose venom remains to be characterized. All genera of highly venomous Australasian elapid snakes are present, except for tiger snakes. Most notable is the taipan (Oxyuranus scutellatus), with the most efficient "snap-release" biting mechanism of any snake and venom components causing the full constellation of clinical envenoming features: coagulopathy from fibrinogen depletion (procoagulant), neurotoxicity (predominantly presynaptic neurotoxin) and rhabdomyolysis (myotoxin). Brown snakes (Pseudonaja textilis and P. nuchalis) now account for most snake bite fatalities in Australia, as a result of severe coagulopathy and a poorly defined early scenario of collapse, postulated to be caused by profound hypotension caused by transient myocardial dysfunction associated with prothrombin activation. Other venomous entities include paralyzing ticks, the blue-ringed octopus, stone fish and other marine animals with venomous spines, paralyzing cone shells, and a wide range of jellyfish including Carukia barnesi and possibly other four-tentacled (carybdeid) box jellyfish causing the Irukandji syndrome. PMID:10688264

Currie, B J

2000-02-01

18

Jellyfish Party: Blowing Soap Bubbles in Mixed Reality Space  

Microsoft Academic Search

This paper describes a mixed reality installation named Jellyfish Party, for enjoying playing with soap bubbles. A special feature of this installation is the use of a spirometer sensor to measure the amount and speed of expelled air used to blow virtual soap bubbles.

Yasuhiro Okuno; Hiroyuki Kakuta; Tomohiko Takayama; Kazuhiro Asai

2003-01-01

19

Anticoagulant activity of Moon jellyfish (Aurelia aurita) tentacle extract.  

PubMed

Moon jellyfish (Aurelia aurita) tentacle extract was studied for its anticoagulant activity in vitro. The Jellyfish Tentacle Extract (JFTE) showed very strong fibrinogenolytic activity by cleaving A? and B? chain of fibrinogen molecule. The fibrinogenolytic activity was found to be stronger than some snake venom derived anticoagulants. JFTE also completely liquefied fibrin clots in 24 h. JFTE was found to contain both high and low molecular weight proteins/peptides. The fibrinogenolysis appears to be caused by high molecular weight fractions of the extract. It has been also noted that PMSF significantly reduced fibrinogenolytic activity and heating totally abolished it. Autolytic degradation of the high molecular weight protein was also noted. Autolysis slowed down, but did not abolish the fibrinogenolytic activity of the extract. PMID:22652129

Rastogi, Akriti; Biswas, Sumit; Sarkar, Angshuman; Chakrabarty, Dibakar

2012-10-01

20

Jellyfish swarms, tourists, and the Christ-child  

Microsoft Academic Search

One of the most remarkable sights in the Western Pacific is a perennial swarm of 1.5 million golden medusae (Mastigias sp.) crowded into a land-locked marine lake in Palau, Micronesia. This 'Jellyfish Lake' became a popular off-gassing stopover for SCUBA divers and a destination in its own right for non-diving tourists in the mid-1980s. Since then, tourism in Palau has

Mike N Dawson; Laura E. Martin; Lolita K. Penland

2001-01-01

21

JELLYFISH AGGREGATIONS AND LEATHERBACK TURTLE FORAGING PATTERNS IN A TEMPERATE COASTAL ENVIRONMENT  

Microsoft Academic Search

Leatherback turtles (Dermochelys coriacea) are obligate predators of gelatinous zooplankton. However, the spatial relationship between predator and prey remains poorly understood beyond sporadic and localized reports. To examine how jellyfish (Phylum Cnidaria: Orders Semaeostomeae and Rhizostomeae) might drive the broad-scale distribution of this wide ranging species, we employed aerial surveys to map jellyfish throughout a temperate coastal shelf area bordering

Jonathan D. R. Houghton; Thomas K. Doyle; Mark W. Wilson; John Davenport; Graeme C. Hays

2006-01-01

22

Evaluation of the effects of various chemicals on discharge of and pain caused by jellyfish nematocysts.  

PubMed

Jellyfish tentacles in contact with human skin can produce pain swelling and redness. The pain is due to discharge of jellyfish nematocysts and associated toxins and discharge can be caused by a variety of mechanical and chemical stimuli. A series of tests were carried out with chemicals traditionally used to treat jellyfish stings e.g. acetic acid ammonia meat tenderizer baking soda and urea to determine if these chemicals stimulated or inhibited nematocyst discharge and if they brought relief to testers who were exposed to jellyfish tentacles. Chrysaora quinquecirrha (sea nettle) Chiropsalmus quadrumanus (sea wasp) and Physalia physalis (Portuguese man-of-war) were used in the study. It was found that many of the chemicals traditionally used to treat jellyfish stings stimulated nematocyst discharge and did not relieve the pain. However there was immediate relief when a common anesthetic lidocaine was sprayed on the skin of testers in contact with jellyfish tentacles. Initial exposure of tentacle suspensions to lidocaine prevented the nematocyst discharge by subsequent exposure to acetic acid ethanol ammonia or bromelain. Thus lidocaine in addition to acting as an anesthetic on skin in contact with jellyfish tentacles inhibited nematocyst discharge possibly by blocking sodium and/or calcium channels of the nematocytes. PMID:20116454

Birsa, Laura M; Verity, Peter G; Lee, Richard F

2010-05-01

23

Impact of Stinging Jellyfish Proliferations along South Italian Coasts: Human Health Hazards, Treatment and Social Costs  

PubMed Central

Stinging jellyfish outbreaks represent a health hazard, causing contact dermatitis and systemic reactions. This study investigated the epidemiology, severity, and treatment protocols of jellyfish stings in a coastal area with high tourist development and frequent stinging jellyfish outbreaks of the central Mediterranean (Salento, Southern Italy), and the associated costs for the Italian National Health Service. In 2007–2011, 1,733 bathers (mostly children and females) sought medical assistance following jellyfish stings, the main cause of human pathologies due to contact with marine organisms. The majority of events were reported in the years 2007–2009, whereas the occurrence of cnidarian jellyfish outbreaks has been increasingly reported in the same area since summer 2010. Most symptoms were limited to local and cutaneous reactions; conversely, 8.7% of cases evoked complications, mainly due to allergic reactions. The main drugs used were corticosteroids, locally applied and systemic (46% and 43%, respectively), and with ammonia (74%) as the main non-pharmacological treatment. The estimated cost of jellyfish-related first-aid services along the Salento coastline over the 5-year period was approximately 400,000 Euros. Therefore the management of jellyfish outbreak phenomena need coordinated research efforts towards a better understanding of underlying ecological mechanisms, together with the adoption of effective prevention policy, mitigation strategies, and appropriate planning of health services at tourist hot spots.

De Donno, Antonella; Idolo, Adele; Bagordo, Francesco; Grassi, Tiziana; Leomanni, Alessandro; Serio, Francesca; Guido, Marcello; Canitano, Mariarita; Zampardi, Serena; Boero, Ferdinando; Piraino, Stefano

2014-01-01

24

A tissue-engineered jellyfish with biomimetic propulsion  

PubMed Central

Reverse engineering of biological form and function requires hierarchical design over several orders of space and time. Recent advances in the mechanistic understanding of biosynthetic compound materials1–3, computer-aided design approaches in molecular synthetic biology4,5 and traditional soft robotics6,7, and increasing aptitude in generating structural and chemical microenvironments that promote cellular self-organization8–10 have enhanced the ability to recapitulate such hierarchical architecture in engineered biological systems. Here we combined these capabilities in a systematic design strategy to reverse engineer a muscular pump. We report the construction of a freely swimming jellyfish from chemically dissociated rat tissue and silicone polymer as a proof of concept. The constructs, termed ‘medusoids’, were designed with computer simulations and experiments to match key determinants of jellyfish propulsion and feeding performance by quantitatively mimicking structural design, stroke kinematics and animal-fluid interactions. The combination of the engineering design algorithm with quantitative benchmarks of physiological performance suggests that our strategy is broadly applicable to reverse engineering of muscular organs or simple life forms that pump to survive.

Nawroth, Janna C; Lee, Hyungsuk; Feinberg, Adam W; Ripplinger, Crystal M; McCain, Megan L; Grosberg, Anna; Dabiri, John O; Parker, Kevin Kit

2014-01-01

25

The improved Jellyfish Valve: durability enhancement with sufficient blood compatibility.  

PubMed

The Jellyfish Valve is one of the most promising polymer valves for artificial hearts. The present problems to be solved are 1) how to prevent a membrane fracture and 2) how to eliminate a calcification, because both of these problems were observed in experiments with goats after 312 days and 414 days of pumping. Finite element analysis demonstrated that mechanical tensile strain induced in the membrane at valve closure was clearly consistent with the fracture location as well as calcification area in in vivo experiments. Based on this finding, a new valve seat with an additional concentric ring 14 mm in diameter and 0.5 mm in width was finally developed. The maximum strain was dramatically reduced to 52% by the design improvement. Moreover, accelerated fatigue tests demonstrated that the improved valve was 10 times more durable as compared with the original valve, which was equivalent to an in vivo duration of 8.3 years. In animal experiments, including 31 days and 46 days use in a total artificial heart (TAH), no thrombus was found despite the lack of anticoagulant or antiplatelet therapies. These results indicate that the improved Jellyfish Valve might be one of the most durable polymer valves, able to perform in artificial hearts for a long period of time. PMID:12296575

Iwasaki, Kiyotaka; Umezu, Mitsuo; Abe, Yusuke; Chinzei, Tsuneo; Isoyama, Takashi; Saito, Itsuro; Ishimaru, Mitsuhiko; Imachi, Kou

2002-01-01

26

J3-crystallin of the jellyfish lens: Similarity to saposins  

PubMed Central

J3-crystallin, one of the three major eye-lens proteins of the cubomedusan jellyfish (Tripedalia cystophora), shows similarity to vertebrate saposins, which are multifunctional proteins that bridge lysosomal hydrolases to lipids and activate enzyme activity. Sequence alignment of deduced J3-crystallin indicates two saposin-like motifs arranged in tandem, each containing six cysteines characteristic of this protein family. The J3-crystallin cDNA encodes a putative precursor analogous to vertebrate prosaposins. The J3-crystallin gene has seven exons, with exons 2–4 encoding the protein. Exon 3 encodes a circularly permutated saposin motif, called a swaposin, found in plant aspartic proteases. J3-crystallin RNA was found in the cubomedusan lens, statocyst, in bands radiating from the pigmented region of the ocellus, in the tentacle tip by in situ hybridization, and in the embryo and larva by reverse transcription–PCR. Our data suggest a crystallin role for the multifunctional saposin protein family in the jellyfish lens. This finding extends the gene sharing evolutionary strategy for lens crystallins to the cnidarians and indicates that the putative primordial saposin/swaposin J3-crystallin reflects both the chaperone and enzyme connections of the vertebrate crystallins.

Piatigorsky, Joram; Norman, Barbara; Dishaw, Larry J.; Kos, Lidia; Horwitz, Joseph; Steinbach, Peter J.; Kozmik, Zbynek

2001-01-01

27

Cell Proliferation in Cubozoan Jellyfish Tripedalia cystophora and Alatina moseri  

PubMed Central

Cubozoans (box jellyfish) undergo remarkable body reorganization throughout their life cycle when, first, they metamorphose from swimming larvae to sessile polyps, and second, through the metamorphosis from sessile polyps to free swimming medusae. In the latter they develop complex structures like the central nervous system (CNS) and visual organs. In the present study several aspects of cell proliferation at different stages of the life cycle of the box jellyfish Tripedalia cystophora and Alatina moseri have been examined through in vivo labeling of cells in the synthetic phase (S phase) of the cell cycle. Proliferation zones were found in metamorphosing polyps, as well as in juvenile medusae, where both the rhopalia and pedalia have enhanced rates of proliferation. The results also indicate a rather fast cell turnover in the rhopalia including the rhopalial nervous system (RNS). Moreover, T. cystophora showed diurnal pattern of cell proliferation in certain body parts of the medusa, with higher proliferation rates at nighttime. This is true for two areas in close connection with the CNS: the stalk base and the rhopalia.

Gurska, Daniela; Garm, Anders

2014-01-01

28

Plasma Calcium Assay, with Use of the Jellyfish Protein, Aequorin, as a Reagent.  

National Technical Information Service (NTIS)

A previously proposed assay for plasma calcium, suitable for routine clinical measurements, has been investigated. The method is based on the calcium-sensitive luminescence of a jellyfish protein, aequorin. Advantages of this method are low cost, simplici...

K. T. Izutsu S. P. Felton

1971-01-01

29

Jellyfish blooms result in a major microbial respiratory sink of carbon in marine systems  

PubMed Central

Jellyfish blooms occur in many estuarine and coastal regions and may be increasing in their magnitude and extent worldwide. Voracious jellyfish predation impacts food webs by converting large quantities of carbon (C), fixed by primary producers and consumed by secondary producers, into gelatinous biomass, which restricts C transfer to higher trophic levels because jellyfish are not readily consumed by other predators. In addition, jellyfish release colloidal and dissolved organic matter (jelly-DOM), and could further influence the functioning of coastal systems by altering microbial nutrient and DOM pathways, yet the links between jellyfish and bacterioplankton metabolism and community structure are unknown. Here we report that jellyfish released substantial quantities of extremely labile C-rich DOM, relative to nitrogen (25.6 ± 31.6 C:1N), which was quickly metabolized by bacterioplankton at uptake rates two to six times that of bulk DOM pools. When jelly-DOM was consumed it was shunted toward bacterial respiration rather than production, significantly reducing bacterial growth efficiencies by 10% to 15%. Jelly-DOM also favored the rapid growth and dominance of specific bacterial phylogenetic groups (primarily ?-proteobacteria) that were rare in ambient waters, implying that jelly-DOM was channeled through a small component of the in situ microbial assemblage and thus induced large changes in community composition. Our findings suggest major shifts in microbial structure and function associated with jellyfish blooms, and a large detour of C toward bacterial CO2 production and away from higher trophic levels. These results further suggest fundamental transformations in the biogeochemical functioning and biological structure of food webs associated with jellyfish blooms.

Condon, Robert H.; Steinberg, Deborah K.; del Giorgio, Paul A.; Bouvier, Thierry C.; Bronk, Deborah A.; Graham, William M.; Ducklow, Hugh W.

2011-01-01

30

Study on effect of jellyfish collagen hydrolysate on anti-fatigue and anti-oxidation  

Microsoft Academic Search

Many bioactive peptides possess specific biological properties that make potential ingredients of health-promoting foods. Jellyfish, which is rich in collagen, has high nutritious and medicinal value. In this study, jellyfish collagen hydrolysate (JCH) were produced. The in vivo anti-fatigue activity and in vivo antioxidant activity of JCH were determined, respectively. Climbing endurance tests of mice were carried out after 6w

Jin-Feng Ding; Yan-Yan Li; Jia-Jie Xu; Xiu-Rong Su; Xiang Gao; Fu-Peng Yue

2011-01-01

31

Irukandji jellyfish polyps exhibit tolerance to interacting climate change stressors.  

PubMed

Increasing ocean temperatures and strengthening boundary currents have caused the poleward migration of many marine species. Cubozoan jellyfish known to cause Irukandji syndrome have historically been confined to tropical waters but may be expanding into subtropical regions. Here, we examine the interactive effects of warming and acidification on the population dynamics of polyps of an Irukandji jellyfish, Alatina nr mordens, and the formation of statoliths in newly metamorphosed medusae, to determine if this jellyfish could tolerate future conditions predicted for southeast Queensland (SEQ), Australia. Two experiments, examining the orthogonal factors of temperature and pH, were undertaken. Experiment 1 mimicked the current, ca. 2050 and ca. 2100 summer temperature and pH conditions predicted for SEQ using A1F1 scenarios (temperature: 25, 27, 29 °C; pH: 7.9, 7.8, 7.6) and Experiment 2 mimicked current and future winter conditions (18 and 22 °C, pH 7.9, 7.8, 7.6). All polyps in Experiment 1 survived and budded. Fewer polyps budded in the lower pH treatments; however, patterns varied slightly among temperature treatments. Statoliths at pH 7.6 were 24% narrower than those at pH 7.8 and 7.9. Most polyps survived the winter conditions mimicked by Experiment 2 but only polyps in the 22 °C, pH 7.9 treatment increased significantly. The current absence of A. nr mordens medusae in SEQ, despite the polyps' ability to tolerate the current temperature and pH conditions, suggests that ecological, rather than abiotic factors currently limit their distribution. Observations that budding was lower under low pH treatments suggest that rates of asexual reproduction will likely be much slower in the future. We consider that A. nr mordens polyps are likely to tolerate future conditions but are unlikely to thrive in the long term. However, if polyps can overcome potential ecological boundaries and acidification proceeds slowly A. nr mordens could expand polewards in the short term. PMID:24323533

Klein, Shannon G; Pitt, Kylie A; Rathjen, Kristen A; Seymour, Jamie E

2014-01-01

32

Characterization and neutralization of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom using polyclonal antibody.  

PubMed

Jellyfish stings have often caused serious health concerns for sea bathers especially in tropical waters. In the coastal areas of Korea, China and Japan, the blooming and stinging accidents of poisonous jellyfish species have recently increased, including Nemopilema nomurai. We have generated a polyclonal antibody against N. nomurai jellyfish venom (NnV) by the immunization of white rabbits with NnV antigen. In the present study, the antibody has been characterized for its neutralizing effect against NnV. At first, the presence of NnV polyclonal antibody has been confirmed from the immunized rabbit serum by Enzyme linked immunosorbent assay (ELISA). Then, the neutralizing activities of the polyclonal antibody have been investigated using cell-based toxicity test, hemolysis assay, and mice lethality test. When the polyclonal antibody was preincubated with NnV, it shows a high effectiveness in neutralizing the NnV toxicities in a concentration-dependent manner. Moreover, we explored proteomic analyses using 2-D SDS-PAGE and MALDI-TOF mass spectrometry to illustrate the molecular identities of the jellyfish venom. From this, 18 different protein families have been identified as jellyfish venom-derived proteins; the main findings of which are matrix metalloproteinase-14, astacin-like metalloprotease toxin 3 precursor. It is expected that the present results would have contributed to our understandings of the envenomation by N. nomurai, their treatment and some valuable knowledge on the pathological processes of the jellyfish stinging. PMID:24751365

Kang, Changkeun; Han, Dae-Yong; Park, Kwang-Il; Pyo, Min-Jung; Heo, Yunwi; Lee, Hyunkyoung; Kim, Gon Sup; Kim, Euikyung

2014-08-01

33

High activity and L?vy searches: jellyfish can search the water column like fish  

PubMed Central

Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d?1, more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean ? = 1.96, range 1.2–2.9) close to the theoretical optimum for searching for sparse prey (?opt ? 2.0). Complex movements in these ‘simple’ animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems.

Hays, Graeme C.; Bastian, Thomas; Doyle, Thomas K.; Fossette, Sabrina; Gleiss, Adrian C.; Gravenor, Michael B.; Hobson, Victoria J.; Humphries, Nicolas E.; Lilley, Martin K. S.; Pade, Nicolas G.; Sims, David W.

2012-01-01

34

High activity and Levy searches: jellyfish can search the water column like fish.  

PubMed

Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d(-1), more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean ?=1.96, range 1.2-2.9) close to the theoretical optimum for searching for sparse prey (?opt?2.0). Complex movements in these 'simple' animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems. PMID:21752825

Hays, Graeme C; Bastian, Thomas; Doyle, Thomas K; Fossette, Sabrina; Gleiss, Adrian C; Gravenor, Michael B; Hobson, Victoria J; Humphries, Nicolas E; Lilley, Martin K S; Pade, Nicolas G; Sims, David W

2012-02-01

35

Isolation, characterization and biological evaluation of jellyfish collagen for use in biomedical applications.  

PubMed

Fibrillar collagens are the more abundant extracellular proteins. They form a metazoan-specific family, and are highly conserved from sponge to human. Their structural and physiological properties have been successfully used in the food, cosmetic, and pharmaceutical industries. On the other hand, the increase of jellyfish has led us to consider this marine animal as a natural product for food and medicine. Here, we have tested different Mediterranean jellyfish species in order to investigate the economic potential of their collagens. We have studied different methods of collagen purification (tissues and experimental procedures). The best collagen yield was obtained using Rhizostoma pulmo oral arms and the pepsin extraction method (2-10 mg collagen/g of wet tissue). Although a significant yield was obtained with Cotylorhiza tuberculata (0.45 mg/g), R. pulmo was used for further experiments, this jellyfish being considered as harmless to humans and being an abundant source of material. Then, we compared the biological properties of R. pulmo collagen with mammalian fibrillar collagens in cell cytotoxicity assays and cell adhesion. There was no statistical difference in cytotoxicity (p > 0.05) between R. pulmo collagen and rat type I collagen. However, since heparin inhibits cell adhesion to jellyfish-native collagen by 55%, the main difference is that heparan sulfate proteoglycans could be preferentially involved in fibroblast and osteoblast adhesion to jellyfish collagens. Our data confirm the broad harmlessness of jellyfish collagens, and their biological effect on human cells that are similar to that of mammalian type I collagen. Given the bioavailability of jellyfish collagen and its biological properties, this marine material is thus a good candidate for replacing bovine or human collagens in selected biomedical applications. PMID:21747742

Addad, Sourour; Exposito, Jean-Yves; Faye, Clément; Ricard-Blum, Sylvie; Lethias, Claire

2011-01-01

36

Role of Thyroxine in Space-Developed Jellyfish  

NASA Technical Reports Server (NTRS)

The Aurelia Metamorphosis Test System was previously used to determine the effects of the space environment on the development and behavior of tiny (1-2 mm) jellyfish ephyrae during the SLS-1 and IML-2 missions. Results from the SLS-1 experiment included the discovery that statolith numbers were significantly reduced in Earth-formed ephyrae flown for nine days in space as compared with ground-based controls. In addition, upon return to Earth, six times more ephyrae which had developed in space than those developed on Earth had pulsing abnormalities, indicating that either these animals did not form their neuromuscular structures normally while in space or they were unable to adapt to the Ig environment upon return to Earth. The metamorphosis process, which enables the formation of ephyrae from polyps is influenced by a hormone, Jf-T4 Oellyfish thyroxine) which is synthesized following iodine administration. Two groups of polyps in space, however, formed ephyrae without iodine administration indicating that Jf-T4 synthesis, utilization, or excretion was different in. the ephyrae. Increased synthesis or build-up in the media of the hormone may also be linked to the increased demineralization of statoliths found in space-exposed ephyrae. In previous experiments, we found that externally administered thyroxine causes increased demineralization of statoliths on Earth. Abnormal pulsina in ephyrae following return to Earth during the SLS-1 mission may also be traced to increased Jf-T4 levels. Thyroxine is known to be important to the normal development and function of the nervous system, heart, and skeletal muscles in higher animals. For this third Jellyfish-in-Space experiment, we proposed to quantitate the levels of Jf- T4 and of T4 receptors in space-developed ephyrae and media and to compare these levels with those of animals developing and at Ig in space and on Earth. We expected to be able to determine whether Jf-T4 synthesis and/or secretion is different in space-flownjellyfish than in controls and to determine which cells (nerve, muscle, lithocytes, etc.)may have enhanced Jf-T4 levels. However, NASA deselected this experiment in August, 1997.

Spangenberg, Dorothy B.

1997-01-01

37

Stable hovering of a jellyfish-like flying machine.  

PubMed

Ornithopters, or flapping-wing aircraft, offer an alternative to helicopters in achieving manoeuvrability at small scales, although stabilizing such aerial vehicles remains a key challenge. Here, we present a hovering machine that achieves self-righting flight using flapping wings alone, without relying on additional aerodynamic surfaces and without feedback control. We design, construct and test-fly a prototype that opens and closes four wings, resembling the motions of swimming jellyfish more so than any insect or bird. Measurements of lift show the benefits of wing flexing and the importance of selecting a wing size appropriate to the motor. Furthermore, we use high-speed video and motion tracking to show that the body orientation is stable during ascending, forward and hovering flight modes. Our experimental measurements are used to inform an aerodynamic model of stability that reveals the importance of centre-of-mass location and the coupling of body translation and rotation. These results show the promise of flapping-flight strategies beyond those that directly mimic the wing motions of flying animals. PMID:24430122

Ristroph, Leif; Childress, Stephen

2014-03-01

38

The jellyfish joyride: causes, consequences and management responses to a more gelatinous future.  

PubMed

Human-induced stresses of overfishing, eutrophication, climate change, translocation and habitat modification appear to be promoting jellyfish (pelagic cnidarian and ctenophore) blooms to the detriment of other marine organisms. Mounting evidence suggests that the structure of pelagic ecosystems can change rapidly from one that is dominated by fish (that keep jellyfish in check through competition or predation) to a less desirable gelatinous state, with lasting ecological, economic and social consequences. Management actions needed to stop such changes require tactical coping strategies and longer-term preventative responses based on fundamental and targeted research on this understudied group. PMID:19324452

Richardson, Anthony J; Bakun, Andrew; Hays, Graeme C; Gibbons, Mark J

2009-06-01

39

Gill Damage to Atlantic Salmon (Salmo salar) Caused by the Common Jellyfish (Aurelia aurita) under Experimental Challenge  

PubMed Central

Background Over recent decades jellyfish have caused fish kill events and recurrent gill problems in marine-farmed salmonids. Common jellyfish (Aurelia spp.) are among the most cosmopolitan jellyfish species in the oceans, with populations increasing in many coastal areas. The negative interaction between jellyfish and fish in aquaculture remains a poorly studied area of science. Thus, a recent fish mortality event in Ireland, involving Aurelia aurita, spurred an investigation into the effects of this jellyfish on marine-farmed salmon. Methodology/Principal Findings To address the in vivo impact of the common jellyfish (A. aurita) on salmonids, we exposed Atlantic salmon (Salmo salar) smolts to macerated A. aurita for 10 hrs under experimental challenge. Gill tissues of control and experimental treatment groups were scored with a system that rated the damage between 0 and 21 using a range of primary and secondary parameters. Our results revealed that A. aurita rapidly and extensively damaged the gills of S. salar, with the pathogenesis of the disorder progressing even after the jellyfish were removed. After only 2 hrs of exposure, significant multi-focal damage to gill tissues was apparent. The nature and extent of the damage increased up to 48 hrs from the start of the challenge. Although the gills remained extensively damaged at 3 wks from the start of the challenge trial, shortening of the gill lamellae and organisation of the cells indicated an attempt to repair the damage suffered. Conclusions Our findings clearly demonstrate that A. aurita can cause severe gill problems in marine-farmed fish. With aquaculture predicted to expand worldwide and evidence suggesting that jellyfish populations are increasing in some areas, this threat to aquaculture is of rising concern as significant losses due to jellyfish could be expected to increase in the future.

Baxter, Emily J.; Sturt, Michael M.; Ruane, Neil M.; Doyle, Thomas K.; McAllen, Rob; Harman, Luke; Rodger, Hamish D.

2011-01-01

40

The jellyfish green fluorescent protein: A new tool for studying ion channel expression and function  

Microsoft Academic Search

Two methods are described for using the jellyfish green fluorescent protein (GFP) as a reporter gene for ion channel expression. GFP fluorescence can be used to identify the transfected cells, and to estimate the relative levels of ion channel expression, in cotransfection experiments. A GFP-NMDAR1 chimera can be constructed that produces a functional, fluorescent receptor subunit. These methods should facilitate

John Marshall; Raymond Molloy; Guy W. J Moss; James R Howe; Thomas E Hughes

1995-01-01

41

Flow patterns generated by oblate medusan jellyfish: field measurements and laboratory analyses  

Microsoft Academic Search

Flow patterns generated by medusan swimmers such as jellyfish are known to differ according the morphology of the various animal species. Oblate medusae have been previously observed to generate vortex ring structures during the propulsive cycle. Owing to the inherent physical coupling between locomotor and feeding structures in these animals, the dynamics of vortex ring formation must be robustly tuned

John O. Dabiri; Sean P. Colin; John H. Costello; Morteza Gharib

2005-01-01

42

In vitro determination of antioxidant activity of proteins from jellyfish Rhopilema esculentum  

Microsoft Academic Search

In this study, the antioxidant activity of proteins isolated from jellyfish, Rhopilema esculentum Kishinouye (R. esculentum), was determined by various antioxidant assays, including superoxide anion radical-scavenging, hydroxyl radical-scavenging, total antioxidant activity, reducing power and metal chelating activity. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), ?-tocopherol, vitamin C and mannitol were used as standards in those various antioxidant activities. The crude protein

Hua-hua Yu; Xi-guang Liu; Rong-e Xing; Song Liu; Zhan-yong Guo; Pi-bo Wang; Cui-ping Li; Peng-cheng Li

2006-01-01

43

Passive energy recapture in jellyfish contributes to propulsive advantage over other metazoans  

PubMed Central

Gelatinous zooplankton populations are well known for their ability to take over perturbed ecosystems. The ability of these animals to outcompete and functionally replace fish that exhibit an effective visual predatory mode is counterintuitive because jellyfish are described as inefficient swimmers that must rely on direct contact with prey to feed. We show that jellyfish exhibit a unique mechanism of passive energy recapture, which is exploited to allow them to travel 30% further each swimming cycle, thereby reducing metabolic energy demand by swimming muscles. By accounting for large interspecific differences in net metabolic rates, we demonstrate, contrary to prevailing views, that the jellyfish (Aurelia aurita) is one of the most energetically efficient propulsors on the planet, exhibiting a cost of transport (joules per kilogram per meter) lower than other metazoans. We estimate that reduced metabolic demand by passive energy recapture improves the cost of transport by 48%, allowing jellyfish to achieve the large sizes required for sufficient prey encounters. Pressure calculations, using both computational fluid dynamics and a newly developed method from empirical velocity field measurements, demonstrate that this extra thrust results from positive pressure created by a vortex ring underneath the bell during the refilling phase of swimming. These results demonstrate a physical basis for the ecological success of medusan swimmers despite their simple body plan. Results from this study also have implications for bioinspired design, where low-energy propulsion is required.

Gemmell, Brad J.; Costello, John H.; Colin, Sean P.; Stewart, Colin J.; Dabiri, John O.; Tafti, Danesh; Priya, Shashank

2013-01-01

44

Two Aberrant Forms of the Moon Jellyfish, 'Aurelia aurita' (Linne), in the Northeastern Gulf of Mexico.  

National Technical Information Service (NTIS)

The moon jellyfish, Aurelia aurita (Linne), is common in the coastal waters of the northeastern Gulf of Mexico from September through December, with infrequent occurrences in March and April. From April, 1971 to June, 1973 over 1500 normal specimens of Au...

K. A. McGraw

1974-01-01

45

Atypical Mouth Shape of Polyps of the Jellyfish, 'Aurelia aurita', from Chesapeake Bay, Delaware Bay, and Gulf of Mexico.  

National Technical Information Service (NTIS)

Fully developed polyps of the Chesapeake Bay jellyfish, Aurelia aurita, reared in the laboratory from known medusae were found to have circular mouths instead of the typical cruciform shape. This characteristic distinguishes them from those of Chrysaora q...

R. Morales-Alamo D. S. Haven

1974-01-01

46

Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea  

NASA Astrophysics Data System (ADS)

The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33°N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 ?g C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii (4.61-15.04 ?g C/L vs. 0.34-0.89 ?g C/L). Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ?g C/(L·d) in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence of N. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.

Wang, Lu; Xu, Kuidong

2013-11-01

47

Reynolds number limits for jet propulsion: a numerical study of simplified jellyfish.  

PubMed

The Scallop theorem states that reciprocal methods of locomotion, such as jet propulsion or paddling, will not work in Stokes flow (Reynolds number=0). In nature the effective limit of jet propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use jet propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. Juvenile jellyfish, or ephyrae, break off from polyps swimming at Re greater than 5. Many other organisms, such as scallops, rarely swim at Re less than 100. The limitations of jet propulsion at intermediate Re is explored here using the immersed boundary method to solve the 2D Navier-Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using jet propulsion. Average forward velocities and work put into the system are calculated for Re between 1 and 320. The results show that forward velocities rapidly decay with decreasing Re for all bell shapes when Re<10. Similarly, the work required to generate the pulsing motion increases significantly for Re<10. When compared to actual organisms, the swimming velocities and vortex separation patterns for the model prolate agree with those observed in Nemopsis bachei. The forward swimming velocities of the model oblate jellyfish after two pulse cycles are comparable to those reported for Aurelia aurita, but discrepancies are observed in the vortex dynamics between when the 2D model oblate jellyfish and the organism. This discrepancy is likely due to a combination of the differences between the 3D reality of the jellyfish and the 2D simplification, as well as the rigidity of the time varying geometry imposed by the idealized model. PMID:21669208

Herschlag, Gregory; Miller, Laura

2011-09-21

48

Jellyfish aggregations and leatherback turtle foraging patterns in a temperate coastal environment.  

PubMed

Leatherback turtles (Dermochelys coriacea) are obligate predators of gelatinous zooplankton. However, the spatial relationship between predator and prey remains poorly understood beyond sporadic and localized reports. To examine how jellyfish (Phylum Cnidaria: Orders Semaeostomeae and Rhizostomeae) might drive the broad-scale distribution of this wide ranging species, we employed aerial surveys to map jellyfish throughout a temperate coastal shelf area bordering the northeast Atlantic. Previously unknown, consistent aggregations of Rhizostoma octopus extending over tens of square kilometers were identified in distinct coastal "hotspots" during consecutive years (2003-2005). Examination of retrospective sightings data (>50 yr) suggested that 22.5% of leatherback distribution could be explained by these hotspots, with the inference that these coastal features may be sufficiently consistent in space and time to drive long-term foraging associations. PMID:16937635

Houghton, Jonathan D R; Doyle, Thomas K; Wilson, Mark W; Davenport, John; Hays, Graeme C

2006-08-01

49

Dynamics of tethered versus free-swimming animals: A wake structure comparison in jellyfish  

NASA Astrophysics Data System (ADS)

Previous research has shown that jellyfish utilize the formation and shedding of vortices to help feed and move the animal. Laboratory experiments often require restricting the motion of an animal by tethering/fluming to allow for repeatable results. However, past research has not addressed the differences that arise when the motion of an animal is restricted/confined. This presentation will attend to this issue by comparing the wake structure of a tethered and free-swimming Aurelia aurita. Digital Particle Image Velocimetry is used to collect measurements of the velocity field surrounding an animal that is either tethered or swimming freely. Dynamical systems methods are used to compute Lagrangian coherent structures (LCS), which is used to identify the geometries of structures in the wake of the animal. Using LCS, a comparison between the wake of a tethered and free-swimming animal can be made. This research provides a quantitative measure of the differences between a tethered and freely moving jellyfish.

Katija, Kakani; Dabiri, John O.

2006-11-01

50

Jellyfish Lake, Palau: Early diagenesis of organic matter in sediments of an anoxic marine lake  

Microsoft Academic Search

Jellyfish Lake, a meromictic, marine lake in the Palau Islands, western Pacific Ocean, is accu- mulating organic matter-rich sediments (46% wt\\/wt) below anoxic, highly sulfidic bottom water. Elemental and stable isotope (#C) data indicate that the sedimentary organic matter is primarily derived from vascular plant remains (65-90%) and would form a type 2 kerogen. A bacterial layer at the oxic-anoxic

W. H. OREM; W. C. BURNETT; W. M. LANDING; W. B. LYONS; W. SHOWERS

1991-01-01

51

Spatial overlap and trophic interactions between pelagic fish and large jellyfish in the northern California Current  

Microsoft Academic Search

Recent studies have indicated that populations of gelatinous zooplankton may be increasing and expanding in geographic coverage,\\u000a and these increases may in turn affect coastal fish populations. We conducted trawl surveys in the northern California Current\\u000a and documented a substantial biomass of scyphomedusae consisting primarily of two species (Chrysaora fuscescens and Aurelia labiata). Spatial overlap of these jellyfish with most

R. D. Brodeur; C. L. Suchman; D. C. Reese; T. W. Miller; E. A. Daly

2008-01-01

52

Nutrient cycling and the biogeochemistry of manganese, iron. and zinc in Jellyfish Lake, Palau  

Microsoft Academic Search

The oxic waters in Jellyfish Lake, a stagnant marine lake in Palau, are depleted in N03-, POd3-, dissolved Si, Mn, Fe, and Zn, while the underlying anoxic waters are significantly enriched in these species and NH,. NH, and Pod3 regeneration and dissolved sulfide production in the anoxic zone yield a stoichiometry of C,,,N,,P for organic matter undergoing recycling in the

WILLIAM M. LANDING; WILLIAM C. BURNETT; W. BERRY LYONS; WILLIAM H. OREM

1991-01-01

53

Biomimetic jellyfish-inspired underwater vehicle actuated by ionic polymer metal composite actuators  

NASA Astrophysics Data System (ADS)

This paper presents the design, fabrication, and characterization of a biomimetic jellyfish robot that uses ionic polymer metal composites (IPMCs) as flexible actuators for propulsion. The shape and swimming style of this underwater vehicle are based on the Aequorea victoria jellyfish, which has an average swimming speed of 20 mm s-1 and which is known for its high swimming efficiency. The Aequorea victoria is chosen as a model system because both its bell morphology and kinematic properties match the mechanical properties of IPMC actuators. This medusa is characterized by its low swimming frequency, small bell deformation during the contraction phase, and high Froude efficiency. The critical components of the robot include the flexible bell that provides the overall shape and dimensions of the jellyfish, a central hub and a stage used to provide electrical connections and mechanical support to the actuators, eight distinct spars meant to keep the upper part of the bell stationary, and flexible IPMC actuators that extend radially from the central stage. The bell is fabricated from a commercially available heat-shrinkable polymer film to provide increased shape-holding ability and reduced weight. The IPMC actuators constructed for this study demonstrated peak-to-peak strains of ˜0.7% in water across a frequency range of 0.1-1.0 Hz. By tailoring the applied voltage waveform and the flexibility of the bell, the completed robotic jellyfish with four actuators swam at an average speed 0.77 mm s-1 and consumed 0.7 W. When eight actuators were used the average speed increased to 1.5 mm s-1 with a power consumption of 1.14 W.

Najem, Joseph; Sarles, Stephen A.; Akle, Barbar; Leo, Donald J.

2012-09-01

54

Optimization of antioxidant activity by response surface methodology in hydrolysates of jellyfish (Rhopilema esculentum) umbrella collagen*  

PubMed Central

To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 °C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da

Zhuang, Yong-liang; Zhao, Xue; Li, Ba-fang

2009-01-01

55

Lessons learned from the jellyfish: Fluid transport at intermediate Reynolds numbers  

NASA Astrophysics Data System (ADS)

Biologically inspired hydrodynamic propulsion and maneuvering strategies promise the advancement of medical implants and novel robotic tools. We have chosen juvenile jellyfish as a model system for investigating fluid dynamics and morphological properties underlying fluid transport by an elastic system at intermediate Reynolds numbers. Recently we have described how natural variations in viscous forces are balanced by changes in jellyfish body shape (phenotypic plasticity), to the effect of facilitating efficient body-fluid interaction. Complementing these studies in our live model organisms, we are also engaged in engineering a synthetic jellyfish, that is, a rhythmically actuated elastomer capable of generating efficient feeding and propulsion currents. The main challenges here are (1) to derive a body shape and deformation suitable for effective fluid transport under physiological fluid conditions, (2) to understand the mechanical properties of actuator and elastomer to derive a design capable of the desired deformation, (3) to establish adequate 3D kinematics of power and recovery stroke, and (4) to evaluate the performance of the design.

Nawroth, Janna; Dabiri, John

2011-11-01

56

Jellyfish as prey: frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii) on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa).  

PubMed

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops. PMID:24727977

Milisenda, Giacomo; Rosa, Sara; Fuentes, Veronica L; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E; Piraino, Stefano

2014-01-01

57

Jellyfish as Prey: Frequency of Predation and Selective Foraging of Boops boops (Vertebrata, Actinopterygii) on the Mauve Stinger Pelagia noctiluca (Cnidaria, Scyphozoa)  

PubMed Central

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops.

Fuentes, Veronica L.; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E.; Piraino, Stefano

2014-01-01

58

Effects of collagen and collagen hydrolysate from jellyfish umbrella on histological and immunity changes of mice photoaging.  

PubMed

Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources. PMID:23344251

Fan, Jian; Zhuang, Yongliang; Li, Bafang

2013-01-01

59

Effects of Collagen and Collagen Hydrolysate from Jellyfish Umbrella on Histological and Immunity Changes of Mice Photoaging  

PubMed Central

Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources.

Fan, Jian; Zhuang, Yongliang; Li, Bafang

2013-01-01

60

Production of the Angiotensin-I-Converting Enzyme (ACE)Inhibitory Peptide from Hydrolysates of Jellyfish ( Rhopilema esculentum ) Collagen  

Microsoft Academic Search

Collagen extracted from jellyfish (Rhopilema esculentum) was hydrolyzed with alcalase to prepare the ACE-inhibitory peptide. The optimal hydrolyzing conditions were determined using\\u000a response surface methodology. The results showed that the optimal conditions were temperature of 52.7 °C, pH of 8.63 and enzyme-to-substrate\\u000a ratio (E\\/S) of 3.46%, and the ACE-inhibitory activity of the obtained hydrolysates could reach 81.7%. Jellyfish collagen peptide, UF3-B2,

Yongliang Zhuang; Liping Sun; Bafang Li

61

Jellyfish life histories: role of polyps in forming and maintaining scyphomedusa populations.  

PubMed

Large population fluctuations of jellyfish occur over a variety of temporal scales, from weekly to seasonal, inter-annual and even decadal, with some regions of the world reported to be experiencing persistent seasonal bloom events. Recent jellyfish research has focussed on understanding the causes and consequences of these population changes, with the vast majority of studies considering the effect of changing environmental variables only on the pelagic medusa. But many of the bloom-forming species are members of the Scyphozoa with complex metagenic life cycles consisting of a sexually reproducing pelagic medusa and asexually reproducing benthic polyp. Recruitment success during the juvenile (planula, polyp and ephyrae) stages of the life cycle can have a major effect on the abundance of the adult (medusa) population, but until very recently, little was known about the ecology of the polyp or scyphistoma phase of the scyphozoan life cycle. The aim of this review is to synthesise the current state of knowledge of polyp ecology by examining (1) the recruitment and metamorphosis of planulae larvae into polyps, (2) survival and longevity of polyps, (3) expansion of polyp populations via asexual propagation and (4) strobilation and recruitment of ephyrae (juvenile medusae). Where possible, comparisons are made with the life histories of other bentho-pelagic marine invertebrates so that further inferences can be made. Differences between tropical and temperate species are highlighted and related to climate change, and populations of the same species (in particular Aurelia aurita) inhabiting different habitats within its geographic range are compared. The roles that polyps play in ensuring the long-term survival of jellyfish populations as well as in the formation of bloom populations are considered, and recommendations for future research are presented. PMID:22877612

Lucas, Cathy H; Graham, William M; Widmer, Chad

2012-01-01

62

Development studies of Aurelia (jellyfish) ephyrae which developed during the SLS-1 mission  

NASA Technical Reports Server (NTRS)

Aurelia polyps (scyphistomae) and ephyrae were exposed to microgravity for nine days aboard the space shuttle during the SLS-1 mission. During strobilation, polyps segment transversely and each segment develops into an ephyra. Polyps were induced to strobilate at 28 C, using iodine or thyroxine, at L(Launch)-48h, L-24h, and L+8h. Ephyrae developed in the groups tested in space and on Earth. The number of ephyrae formed per polyp was slightly higher in the L+8h groups as compared with those induced at L-24h and L-48h. On Earth, iodine is used by jellyfish to synthesize jellyfish-thyroxine (Jf T(sub 4)), needed for ephyra production. Since iodine-treated polyps strobilated and formed ephyrae in space, it appears that jellyfish can synthesize Jf-T(sub 4) in space. Indeed, two groups of polyps not given inducer formed ephryae in space, presumably due to enhanced Jf-T(sub 4) synthesis, utilization or accumulation. Some ephyrae that formed in space were also fixed in space on Mission Day (MD) 8; others were fixed post-flight. Examination of living ephyrae with the light microscope and fixed ones with the Scanning and Transmission Electron Microscopes revealed that those which developed in space were morphologically very similar to those which developed on Earth. Quantitation of arm numbers determined that there were no significant differences between space and Earth-developed ephyrae. Pulsing abnormalities, however, were found in greater number (18.3%) in space-developed ephyrae than in Earth-developed controls (2.9%). These abnormalities suggest abnormal development of the graviceptors, the neuromuscular system, or a defect in the integration between these systems in apparently microgravity-sensitive animals.

Spangenberg, D. B.; Jernigan, T.; Mccombs, R.; Lowe, B. T.; Sampson, M.; Slusser, J.

1994-01-01

63

Synthesis of hierarchical tree-like and jellyfish-like silicon oxide nanostructures.  

PubMed

Hierarchical tree-like and jellyfish-like SiOx nanostructures have been synthesized by annealing a mixture of carbon coated Ni nanoparticles (Ni@C) and SiO2 powers under argon atmosphere at 1400 degrees C. The synthesized products were characterized by electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The tree-like SiOx nanostructures consisting of the trunks and many branches and subbranches with diminishing diameters have been observed for the first time. The diameters of the trunks are about 150-1000 nm, and the branches become more slender for each branching, ultimately to 20-40 nm in diameter for the ends. The jellyfish-like SiOx nanostructures are constructed by the catalyst heads with sizes of about 1-10 microm and many connected quasi-aligned SiOx nanowires with diameters about 20-40 nm. The Ni species of the Ni@C nanoparticles acts as the catalyst and the surface carbon as the reducing agent for carbothermal reduction of SiO2. The experimental results suggest that the formation of different SiOx nanostructures mainly depend on the dimensions of the congregated Ni catalyst droplets during the reaction process and the growth mechanism is reasonably discussed. PMID:19504941

Huo, Kaifu; Fu, Jijiang; Lu, Bin; Ni, Hongwei; Hu, Yemin; Chu, Paul K; Hu, Zheng

2009-06-01

64

NMR study on a novel mucin from jellyfish in natural abundance, Qniumucin from Aurelia aurita.  

PubMed

A novel mucin (qniumucin), which we recently discovered in jellyfish, was investigated by several NMR techniques. Almost all the peaks in the (13)C and proton NMR spectra were satisfactorily assigned to the amino acids in the main chain and to the bridging GalNAc, the major sugar in the saccharide branches. The amino acid sequence in the tandem repeat part (-VVETTAAP-) was reconfirmed by the cross-peaks between alpha protons and carbonyl carbons in the HMBC spectrum. A connectivity analysis around the O-glycoside bond (GalNAc-Thr) was also performed, and detailed information on the local configuration was obtained by the DPFGSE-NOE-HSD technique. The strategy and the results described in this paper can be extended to the structural analysis of general O-glycan chains, which are more complex than the present mucin. NMR analyses reveal the simple structure of qniumucin extracted by the present protocol, and the homogeneity and purity of qniumucin are probably the result of it being extracted from jellyfish, a primitive animal. PMID:19371080

Uzawa, Jun; Urai, Makoto; Baba, Takayuki; Seki, Hiroko; Taniguchi, Kayoko; Ushida, Kiminori

2009-05-22

65

Optimal stroke patterns for a model jellyfish swimmer with thin, flexible body  

NASA Astrophysics Data System (ADS)

In this study, a numerical model is built to simulate swimming of oblate jellyfish (e.g. Aurelia aurita). The model swimmer is a thin, axisymmetric circular plate which is flexible and is able to deform, mimicking contraction and relaxation of a jellyfish. Using body deformation, the swimmer is able to swim by shedding vortices into fluid wake. A prescribed body motion extracted from a free-swimming Aurelia aurita is applied to the swimmer. The induced vortex wake is solved by a vortex sheet method and is compared with the wake of the free-swimming Aurelia aurita measured by PIV. The stoke pattern of the swimmer is optimized for minimal cost of locomotion. The body kinematics are parameterized and cost of locomotion is calculated from simulation using the vortex sheet method. A surrogate management framework is used as the optimization scheme. The vortex wake induced by the optimal stroke pattern is investigated to identify the characteristics of the wake which enhance swimming performance.

Peng, Jifeng; Dabiri, John

2007-11-01

66

Characterisation of acid-soluble and pepsin-solubilised collagen from jellyfish (Cyanea nozakii Kishinouye).  

PubMed

Annual outbreaks of the Jellyfish (Cyanea nozakii Kishinouye) in the waters of the Yellow Sea and the East China Sea are regarded as a nuisance. Thus, utilizing this jellyfish species is of great significance to reduce harm to fisheries and marine environments. The yield of the acid-soluble collagens (ASCs) from the C. nozakii umbrella was 13.0% (dry weight) and that of the pepsin-solubilised collagens (PSCs) was 5.5% (dry weight). The SDS-PAGE patterns of the ASCs and PSCs differed from that of type I collagen, which indicate the presence of (?1)3. The denaturation temperature (Td) of the collagens was approximately 23.8°C. Fourier transform infrared spectroscopy proved that the ASCs and PSCs retained their helical structures and the As, Pb, and Hg content of the collagens, detected by ICP-MS, were considerably lower than the national standards. The results suggest that collagens isolated from C. nozakii can potentially be used as an alternative source of collagen for use in various applications. PMID:24360414

Zhang, Junjie; Duan, Rui; Huang, Lei; Song, Yujie; Regenstein, Joe M

2014-05-01

67

Indomethacin induction of metamorphosis from the asexual stage to sexual stage in the moon jellyfish, Aurelia aurita.  

PubMed

We found while screening a chemical library that indomethacin, an inhibitor of prostaglandin biosynthesis, induced strobilation (metamorphosis from the asexual to sexual stage) in the moon jellyfish, Aurelia aurita. Indomethacin initiated strobilation in a dose-dependent manner, but was not involved in the progression of strobilation. Pharmacological experiments suggested that indomethacin could induce strobilation independently of prostaglandin biosynthesis. PMID:22785488

Kuniyoshi, Hisato; Okumura, Izumi; Kuroda, Rie; Tsujita, Natsumi; Arakawa, Kenji; Shoji, Jun; Saito, Tamio; Osada, Hiroyuki

2012-01-01

68

Polyspermy block in jellyfish eggs: Collaborative controls by Ca(2+) and MAPK.  

PubMed

Jellyfish eggs neither undergo apparent cortical reaction nor show any significant change in the membrane potential at fertilization, but nevertheless show monospermy. Utilizing the perfectly transparent eggs of the hydrozoan jellyfish Cytaeis uchidae, here we show that the polyspermy block is accomplished via a novel mechanism: a collaboration between Ca(2+) and mitogen-activated protein kinase (MAPK). In Cytaeis, adhesion of a sperm to the animal pole surface of an egg was immediately followed by sperm-egg fusion and initiation of an intracellular Ca(2+) rise from this site. The elevated Ca(2+) levels lasted for several minutes following the sperm-egg fusion. The Ca(2+) rise proved to be necessary and sufficient for a polyspermy block, as inhibiting a Ca(2+) rise with EGTA promoted polyspermy, and conversely, triggering a Ca(2+) rise by inositol 1,4,5-trisphosphate (IP3) or excess K(+) immediately abolished the egg's capacity for sperm-egg fusion. A Ca(2+) rise at fertilization or by artificial stimulations evoked dephosphorylation of MAPK in eggs. The eggs in which phosphorylated MAPK was maintained by injection of mRNA for MAPK kinase kinase (Mos), like intact eggs, exhibited a Ca(2+) rise at fertilization or by IP3 injection, and shut down the subsequent sperm-egg fusion. However, the Mos-expressing eggs became capable of accepting sperm following the arrest of Ca(2+) rise. In contrast, addition of inhibitors of MAPK kinase (MEK) to unfertilized eggs caused MAPK dephosphorylation without elevating Ca(2+) levels, and prevented sperm-egg fusion. Rephosphorylation of MAPK by injecting Mos mRNA after fertilization recovered sperm attraction, which is known to be another MAPK-dependent event, but did not permit subsequent sperm-egg fusion. Thus, it is possible that MAPK dephosphorylation irreversibly blocks sperm-egg fusion and reversibly suppresses sperm attraction. Collectively, our data suggest that both the fast and late mechanisms dependent on Ca(2+) and MAPK, respectively, ensure a polyspermy block in jellyfish eggs. PMID:24809798

Arakawa, Mio; Takeda, Noriyo; Tachibana, Kazunori; Deguchi, Ryusaku

2014-08-01

69

Long-Term Fluctuations in Circalunar Beach Aggregations of the Box Jellyfish Alatina moseri in Hawaii, with Links to Environmental Variability  

PubMed Central

The box jellyfish Alatina moseri forms monthly aggregations at Waikiki Beach 8–12 days after each full moon, posing a recurrent hazard to swimmers due to painful stings. We present an analysis of long-term (14 years: Jan 1998– Dec 2011) changes in box jellyfish abundance at Waikiki Beach. We tested the relationship of beach counts to climate and biogeochemical variables over time in the North Pacific Sub-tropical Gyre (NPSG). Generalized Additive Models (GAM), Change-Point Analysis (CPA), and General Regression Models (GRM) were used to characterize patterns in box jellyfish arrival at Waikiki Beach 8–12 days following 173 consecutive full moons. Variation in box jellyfish abundance lacked seasonality, but exhibited dramatic differences among months and among years, and followed an oscillating pattern with significant periods of increase (1998–2001; 2006–2011) and decrease (2001–2006). Of three climatic and 12 biogeochemical variables examined, box jellyfish showed a strong, positive relationship with primary production, >2 mm zooplankton biomass, and the North Pacific Gyre Oscillation (NPGO) index. It is clear that that the moon cycle plays a key role in synchronizing timing of the arrival of Alatina moseri medusae to shore. We propose that bottom-up processes, likely initiated by inter-annual regional climatic fluctuations influence primary production, secondary production, and ultimately regulate food availability, and are therefore important in controlling the inter-annual changes in box jellyfish abundance observed at Waikiki Beach.

Chiaverano, Luciano M.; Holland, Brenden S.; Crow, Gerald L.; Blair, Landy; Yanagihara, Angel A.

2013-01-01

70

Multiple photoreceptor systems control the swim pacemaker activity in box jellyfish.  

PubMed

Like all other cnidarian medusae, box jellyfish propel themselves through the water by contracting their bell-shaped body in discrete swim pulses. These pulses are controlled by a swim pacemaker system situated in their sensory structures, the rhopalia. Each medusa has four rhopalia each with a similar set of six eyes of four morphologically different types. We have examined how each of the four eye types influences the swim pacemaker. Multiple photoreceptor systems, three of the four eye types, plus the rhopalial neuropil, affect the swim pacemaker. The lower lens eye inhibits the pacemaker when stimulated and provokes a strong increase in the pacemaker frequency upon light-off. The upper lens eye, the pit eyes and the rhopalial neuropil all have close to the opposite effect. When these responses are compared with all-eye stimulations it is seen that some advanced integration must take place. PMID:19946073

Garm, A; Mori, S

2009-12-01

71

Pelagia benovici sp. nov. (Cnidaria, Scyphozoa): a new jellyfish in the Mediterranean Sea.  

PubMed

A bloom of an unknown semaestome jellyfish species was recorded in the North Adriatic Sea from September 2013 to early 2014. Morphological analysis of several specimens showed distinct differences from other known semaestome species in the Mediterranean Sea and unquestionably identified them as belonging to a new pelagiid species within genus Pelagia. The new species is morphologically distinct from P. noctiluca, currently the only recognized valid species in the genus, and from other doubtful Pelagia species recorded from other areas of the world. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 28S ribosomal DNA genes corroborate its specific distinction from P. noctiluca and other pelagiid taxa, supporting the monophyly of Pelagiidae. Thus, we describe Pelagia benovici sp. nov. Piraino, Aglieri, Scorrano & Boero. PMID:24870334

Piraino, Stefano; Aglieri, Giorgio; Martell, Luis; Mazzoldi, Carlotta; Melli, Valentina; Milisenda, Giacomo; Scorrano, Simonetta; Boero, Ferdinando

2014-01-01

72

Structural analysis of O-glycans of mucin from jellyfish (Aurelia aurita) containing 2-aminoethylphosphonate.  

PubMed

The structure of O-glycan in qniumucin (Q-mucin), which is a novel mucin extracted from jellyfish, was analyzed by a combination of NMR and ESI-MS/MS. A previously unidentified monosaccharide involved in the glycan chains was determined to be N-acetylgalactosamine (GalNAc) substituted by 2-aminoethylphosphonate (AEP) at the C-6. The O-glycans in Q-mucin from Aurelia aurita were proved to be mainly composed of three monosaccharides: GalNAc, AEP-(O-->6)-GalNAc, and P-6-GalNAc. To the best of our knowledge, this is the first example of an O-glycan structure of glycoproteins containing AEP. This exceptionally simple structure of Q-mucin and its potential use in material science and technology are revealed. PMID:19732869

Urai, Makoto; Nakamura, Takemichi; Uzawa, Jun; Baba, Takayuki; Taniguchi, Kayoko; Seki, Hiroko; Ushida, Kiminori

2009-11-01

73

Cytotoxicity and hemolytic activity of jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) venom.  

PubMed

The recent bloom of a giant jellyfish Nemopilema nomurai has caused a danger to sea bathers and fishery damages in the waters of China, Korea, and Japan. The present study investigated the cytotoxic and hemolytic activities of crude venom extract of N. nomurai using a number of in vitro assays. The jellyfish venom showed a much higher cytotoxic activity in H9C2 heart myoblast than in C2C12 skeletal myoblast (LC(50)=2 microg/mL vs. 12 microg/mL, respectively), suggesting its possible in vivo selective toxicity on cardiac tissue. This result is consistent with our previous finding that cardiovascular function is a target of the venom. In order to determine the stability of N. nomurai venom, its cytotoxicity was examined under the various temperature and pH conditions. The activity was relatively well retained at low environmental temperature (or=60 degrees C). In pH stability test, the venom has abruptly lost its activity at low pH environment (pH

Kang, Changkeun; Munawir, Al; Cha, Mijin; Sohn, Eun-Tae; Lee, Hyunkyoung; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Kim, Euikyung

2009-07-01

74

Plastic Jellyfish.  

ERIC Educational Resources Information Center

Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

Moseley, Christine

2000-01-01

75

Relative blood damage index of the jellyfish valve and the Bjork-Shiley tilting-disk valve  

Microsoft Academic Search

Determination of the potential for blood cell damage induced by artificial heart valves is essential in deciding the suitability\\u000a of the valve for clinical use. Both the magnitude and the duration of the shear stress influence the onset and severity of\\u000a the damage to the constitutents of blood. In this study, in vitro shear stress measurements of the mitral jellyfish

Yos Morsi; Masahisa Kogure; Mitsuo Umezu

1999-01-01

76

Flow structure and transport characteristics of feeding and exchange currents generated by upside-down Cassiopea jellyfish.  

PubMed

Quantifying the flows generated by the pulsations of jellyfish bells is crucial for understanding the mechanics and efficiency of their swimming and feeding. Recent experimental and theoretical work has focused on the dynamics of vortices in the wakes of swimming jellyfish with relatively simple oral arms and tentacles. The significance of bell pulsations for generating feeding currents through elaborate oral arms and the consequences for particle capture are not as well understood. To isolate the generation of feeding currents from swimming, the pulsing kinematics and fluid flow around the benthic jellyfish Cassiopea spp. were investigated using a combination of videography, digital particle image velocimetry and direct numerical simulation. During the rapid contraction phase of the bell, fluid is pulled into a starting vortex ring that translates through the oral arms with peak velocities that can be of the order of 10 cm s(-1). Strong shear flows are also generated across the top of the oral arms throughout the entire pulse cycle. A coherent train of vortex rings is not observed, unlike in the case of swimming oblate medusae such as Aurelia aurita. The phase-averaged flow generated by bell pulsations is similar to a vertical jet, with induced flow velocities averaged over the cycle of the order of 1-10 mm s(-1). This introduces a strong near-horizontal entrainment of the fluid along the substrate and towards the oral arms. Continual flow along the substrate towards the jellyfish is reproduced by numerical simulations that model the oral arms as a porous Brinkman layer of finite thickness. This two-dimensional numerical model does not, however, capture the far-field flow above the medusa, suggesting that either the three-dimensionality or the complex structure of the oral arms helps to direct flow towards the central axis and up and away from the animal. PMID:22723475

Santhanakrishnan, Arvind; Dollinger, Makani; Hamlet, Christina L; Colin, Sean P; Miller, Laura A

2012-07-15

77

A method for eradicating amphipod parasites (hyperiidae) from host jellyfish, Chrysaora fuscescens (Brandt, 1835), in a closed recirculating system.  

PubMed

On 2 December 2006, a heavy infestation of the parasitic hyperiid amphipods Hyperia medusarum and Lestrigonus shoemakeri was discovered in the sea nettles (Chrysaora fuscescens) exhibit at the Tennessee Aquarium. Pretreatment trials that exposed moon jellyfish (Aurelia aurita) and sea nettles to therapeutic levels of diflubenzuron confirmed that the treatment would be tolerated by these species of jellyfish. The exhibit tank was dosed with a 0.03 mg/L concentration of diflubenzuron for 7 days, after which the medication was removed by filtration. An arbitrarily chosen subset from the sea nettle exhibit was sampled regularly over the next 8 wk to monitor the parasite population. The average number of amphipods per jellyfish sampled decreased throughout the treatment and sampling period. No live amphipods were observed 6 wk after the start of treatment, and no negative side effects were observed in the sea nettles. The use of diflubenzuron to eradicate hyperiid parasites from scyphomedusae is a safe and useful option when properly applied in a controlled environment. PMID:19368258

Crossley, Sharyl M G; George, Anna L; Keller, Christian J

2009-03-01

78

Jellyfish: Special Tools for Biological Research on Earth and in Space  

NASA Technical Reports Server (NTRS)

The most intriguing nature of the jellyfish polyps is their ability to metamorphose, giving rise to tiny immature medusae called ephyrae which have a different form or shape from the polyps. The Aurelia Metamorphosis Test System was used to determine the subtle effects of hydrocarbons found in oil spills and the effects of X-irradiation on developing ephyrae. Currently, this test system is used to determine the effects of the gravity-less environment of outer space on the development and behavior of ephyrae. For this purpose, the effects of clinostat rotation on development of the ephyrae and their gravity receptor are being studied. The behavior of the ephyrae during 0 gravity achieved for short intervals of 30 seconds in parabolic flight is examined. The developing ephyrae and the mature ephyrae are exposed to gravity-less environment of outer space via a six or seven day shuttle experiment. If gravity receptors do form in outer space, they will be studied in detail using various types of microscopes, including the electron microscope, to determin whether they developed normally in space as compared with control on Earth.

Spangenberg, Dorothy B.

1991-01-01

79

The state of water in living systems: from the liquid to the jellyfish.  

PubMed

The status of water in living systems is reviewed both from philosophical and scientific viewpoints. Starting from antique Mediterranean civilizations (Sumerian, Egyptian, Hebrew, Greek), a world trip is proposed through Norse myths, Siberian Shamanism, Hinduism, Taoism, Buddhism, Shinto, Mayan, Aztec, Inca, Aboriginal and African philosophies in order to convince that all humans share the same qualitative idea that water was a pre-requisite for life apparition. The quantitative aspect of the problem is further analyzed at the light of the scientific contributions from two leading scientists: R.A. Gortner and E.T. Jaynes. With Gortner's work it is demonstrated using the concrete example of the Jellyfish submitted at a Faraday discussion held in London in 1930, how a paradigm shift has occurred in the thirties concerning the status of bound water in the living cell. With Jaynes' work, the disastrous consequences of the entrenchment of diffusion theory in biology are critically examined and the exact meaning of the second law of thermodynamics for biological systems is given using the concrete example of muscle contraction. In conclusion, the importance of distinguishing between an ontological and epistemological level of knowledge is stressed and suggestions for reconciling scientific and philosophical approaches are given. PMID:16359619

Henry, M

2005-12-14

80

Recombinant expression and solution structure of antimicrobial peptide aurelin from jellyfish Aurelia aurita.  

PubMed

Aurelin is a 40-residue cationic antimicrobial peptide isolated from the mezoglea of a scyphoid jellyfish Aurelia aurita. Aurelin and its (15)N-labeled analogue were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant peptide was examined, and its spatial structure was studied by NMR spectroscopy. Aurelin represents a compact globule, enclosing one 3(10)-helix and two ?-helical regions cross-linked by three disulfide bonds. The peptide binds to anionic lipid (POPC/DOPG, 3:1) vesicles even at physiological salt concentration, it does not interact with zwitterionic (POPC) vesicles and interacts with the DPC micelle surface with moderate affinity via two ?-helical regions. Although aurelin shows structural homology to the BgK and ShK toxins of sea anemones, its surface does not possess the "functional dyad" required for the high-affinity interaction with the K(+)-channels. The obtained data permit to correlate the modest antibacterial properties and membrane activity of aurelin. PMID:23137541

Shenkarev, Zakhar O; Panteleev, Pavel V; Balandin, Sergey V; Gizatullina, Albina K; Altukhov, Dmitry A; Finkina, Ekaterina I; Kokryakov, Vladimir N; Arseniev, Alexander S; Ovchinnikova, Tatiana V

2012-12-01

81

Heavy metals affect regulatory volume decrease (RVD) in nematocytes isolated from the jellyfish Pelagia noctiluca.  

PubMed

The environmental contamination caused by heavy metals raises the question of their effect on biological systems. Among bio-indicators useful to monitor the toxicological effects of these chemicals, Cnidarians offer a unique model. Cnidarians possess highly specialized stinging cells, termed nematocytes, which respond to hyposmotic solution with well established homeostatic parameters as an acute osmotic phase (OP), leading to cell swelling, and then a slower regulatory volume decrease (RVD) phase, causing cell shrinkage. Here we report the effect of 65% artificial sea water (ASW) containing heavy metals, such as Cd, La, Co, Cu and Zn (concentrations comprised between 100 and 0.1 ?M) on both OP and RVD in nematocytes isolated from the jellyfish Pelagia noctiluca by 605 mM NaSCN plus 0.01 mM Ca(2+). The exposure of the cells to Co and La inhibited RVD but not OP. However, Cu, Cd and Zn prevented the OP in a dose-dependent manner and, hence, also the detection of RVD. These results suggest that, in isolated nematocytes, heavy metal pollutants impair RVD either directly or indirectly through interference with the OP, thus negating RVD. Although further studies need to clarify the exact mechanisms whereby heavy metals exert their toxicity, it is evident that nematocytes of Cnidarians could serve as a model for ecotoxicological investigations. PMID:23499922

Morabito, R; Marino, A; La Spada, G

2013-06-01

82

Pharmacological Studies of Tentacle Extract from the Jellyfish Cyanea capillata in Isolated Rat Aorta  

PubMed Central

Our previous studies demonstrated that tentacle extract (TE) from the jellyfish, Cyanea capillata, could cause a dose-dependent increase of systolic blood pressure, which seemed to be the result of direct constriction of vascular smooth muscle (VSM). The aim of this study is to investigate whether TE could induce vasoconstriction in vitro and to explore its potential mechanism. Using isolated aorta rings, a direct contractile response of TE was verified, which showed that TE could induce concentration-dependent contractile responses in both endothelium-intact and -denuded aortas. Interestingly, the amplitude of contraction in the endothelium-denuded aorta was much stronger than that in the endothelium-intact one, implying that TE might also bring a weak functional relaxation in addition to vasoconstriction. Further drug intervention experiments indicated that the functional vasodilation might be mediated by nitric oxide, and that TE-induced vasoconstriction could be attributed to calcium influx via voltage-operated calcium channels (VOCCs) from the extracellular space, as well as sarcoplasmic reticulum (SR) Ca2+ release via the inositol 1,4,5-trisphosphate receptor (IP3R), leading to an increase in [Ca2+]c, instead of activation of the PLC/DAG/PKC pathway or the sympathetic nerve system.

Wang, Beilei; Zhang, Bo; Wang, Qianqian; Zhang, Zhi; Nie, Fei; Liu, Guoyan; Zheng, Jiemin; Xiao, Liang; Zhang, Liming

2013-01-01

83

Flexibly deployed Pax genes in eye development at the early evolution of animals demonstrated by studies on a hydrozoan jellyfish  

PubMed Central

Pax transcription factors are involved in a variety of developmental processes in bilaterians, including eye development, a role typically assigned to Pax-6. Although no true Pax-6 gene has been found in nonbilateral animals, some jellyfish have eyes with complex structures. In the cubozoan jellyfish Tripedalia, Pax-B, an ortholog of vertebrate Pax-2/5/8, had been proposed as a regulator of eye development. Here we have isolated three Pax genes (Pax-A, Pax-B, and Pax-E) from Cladonema radiatum, a hydrozoan jellyfish with elaborate eyes. Cladonema Pax-A is strongly expressed in the retina, whereas Pax-B and Pax-E are highly expressed in the manubrium, the feeding and reproductive organ. Misexpression of Cladonema Pax-A induces ectopic eyes in Drosophila imaginal discs, whereas Pax-B and Pax-E do not. Furthermore, Cladonema Pax-A paired domain protein directly binds to the 5? upstream region of eye-specific Cladonema opsin genes, whereas Pax-B does not. Our data suggest that Pax-A, but not Pax-B or Pax-E, is involved in eye development and/or maintenance in Cladonema. Phylogenetic analysis indicates that Pax-6, Pax-B, and Pax-A belong to different Pax subfamilies, which diverged at the latest before the Cnidaria–Bilateria separation. We argue that our data, showing the involvement of Pax genes in hydrozoan eye development as in bilaterians, supports the monophyletic evolutionary origin of all animal eyes. We then propose that during the early evolution of animals, distinct classes of Pax genes, which may have played redundant roles at that time, were flexibly deployed for eye development in different animal lineages.

Suga, Hiroshi; Tschopp, Patrick; Graziussi, Daria F.; Stierwald, Michael; Schmid, Volker; Gehring, Walter J.

2010-01-01

84

Jellyfish support high energy intake of leatherback sea turtles (Dermochelys coriacea): video evidence from animal-borne cameras.  

PubMed

The endangered leatherback turtle is a large, highly migratory marine predator that inexplicably relies upon a diet of low-energy gelatinous zooplankton. The location of these prey may be predictable at large oceanographic scales, given that leatherback turtles perform long distance migrations (1000s of km) from nesting beaches to high latitude foraging grounds. However, little is known about the profitability of this migration and foraging strategy. We used GPS location data and video from animal-borne cameras to examine how prey characteristics (i.e., prey size, prey type, prey encounter rate) correlate with the daytime foraging behavior of leatherbacks (n = 19) in shelf waters off Cape Breton Island, NS, Canada, during August and September. Video was recorded continuously, averaged 1:53 h per turtle (range 0:08-3:38 h), and documented a total of 601 prey captures. Lion's mane jellyfish (Cyanea capillata) was the dominant prey (83-100%), but moon jellyfish (Aurelia aurita) were also consumed. Turtles approached and attacked most jellyfish within the camera's field of view and appeared to consume prey completely. There was no significant relationship between encounter rate and dive duration (p = 0.74, linear mixed-effects models). Handling time increased with prey size regardless of prey species (p = 0.0001). Estimates of energy intake averaged 66,018 kJ • d(-1) but were as high as 167,797 kJ • d(-1) corresponding to turtles consuming an average of 330 kg wet mass • d(-1) (up to 840 kg • d(-1)) or approximately 261 (up to 664) jellyfish • d(-1). Assuming our turtles averaged 455 kg body mass, they consumed an average of 73% of their body mass • d(-1) equating to an average energy intake of 3-7 times their daily metabolic requirements, depending on estimates used. This study provides evidence that feeding tactics used by leatherbacks in Atlantic Canadian waters are highly profitable and our results are consistent with estimates of mass gain prior to southward migration. PMID:22438906

Heaslip, Susan G; Iverson, Sara J; Bowen, W Don; James, Michael C

2012-01-01

85

Jellyfish Lake, Palau: Regeneration of C, N, Si, and P in anoxic marine lake sediments  

USGS Publications Warehouse

Sediment cores from Jellyfish Lake were processed under an inert atmosphere and the pore waters extracted and analyzed for the following parameters: pH, titration alkalinity (TA), Cl-, H4SiO4, PO43-, NH4+, Ca2-, Mg2+, SO42-, and H2S. Additionally, in one set of pore-water samples (core 10), the ??13C of the ??CO2 was also determined. The TA, H4SiO4, PO43-, NH4+, and H2S increased with depth in the pore waters above anoxic bottom-water values. H2S values increased to 3.8 ??M. In one case, both H4SiO4 and PO43- concentrations increased to a maximum value and then decreased with depth, suggesting removal into solid phases. The H4SiO4 concentrations are equal to or greater than pore-water values observed in sediments underlying upwelling areas. PO43- concentrations are, in general, lower than pore-water values from terrigenous nearshore areas but higher than nearshore carbonate pore-water values from Florida Bay or Bermuda. The Ca2+, Cl-, and Mg2+: Cl- ratios show slight decreases in the top 15-20 cm, suggesting that authigenic carbonate may be forming. This suggestion is supported by the fact that the pore waters are saturated with respect to CaCO3 due to the very high TAs. The ??13C measurements of the pore-water ??CO2 are from a shorter core. These measurements reach their most negative concentration at 72 cm and then become slightly heavier. This change is accompanied by a decrease in TA, suggesting the onset of methanogenesis at this location in this core.

Lyons, W. B.; Lent, R. M.; Burnett, W. C.; Chin, P.; Landing, W. M.; Orem, W. H.; McArthur, J. M.

1996-01-01

86

Recombinant expression and solution structure of antimicrobial peptide aurelin from jellyfish Aurelia aurita  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Aurelin was overexpressed in Escherichia coli, and its spatial structure was studied by NMR. Black-Right-Pointing-Pointer Aurelin compact structure encloses helical regions cross-linked by three disulfide bonds. Black-Right-Pointing-Pointer Aurelin shows structural homology to the BgK and ShK toxins of sea anemones. Black-Right-Pointing-Pointer Aurelin binds to the anionic lipid vesicles, but does not interact with zwitterionic ones. Black-Right-Pointing-Pointer Aurelin binds to DPC micelle surface with moderate affinity via two helical regions. -- Abstract: Aurelin is a 40-residue cationic antimicrobial peptide isolated from the mezoglea of a scyphoid jellyfish Aurelia aurita. Aurelin and its {sup 15}N-labeled analogue were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant peptide was examined, and its spatial structure was studied by NMR spectroscopy. Aurelin represents a compact globule, enclosing one 3{sub 10}-helix and two {alpha}-helical regions cross-linked by three disulfide bonds. The peptide binds to anionic lipid (POPC/DOPG, 3:1) vesicles even at physiological salt concentration, it does not interact with zwitterionic (POPC) vesicles and interacts with the DPC micelle surface with moderate affinity via two {alpha}-helical regions. Although aurelin shows structural homology to the BgK and ShK toxins of sea anemones, its surface does not possess the 'functional dyad' required for the high-affinity interaction with the K{sup +}-channels. The obtained data permit to correlate the modest antibacterial properties and membrane activity of aurelin.

Shenkarev, Zakhar O.; Panteleev, Pavel V.; Balandin, Sergey V. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation)] [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Gizatullina, Albina K.; Altukhov, Dmitry A. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation) [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700 Dolgoprudny, Moscow Region (Russian Federation); Finkina, Ekaterina I. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation)] [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Kokryakov, Vladimir N. [Institute of Experimental Medicine, Russian Academy of Medical Sciences, Academica Pavlova str., 12, 197376 Saint-Petersburg (Russian Federation)] [Institute of Experimental Medicine, Russian Academy of Medical Sciences, Academica Pavlova str., 12, 197376 Saint-Petersburg (Russian Federation); Arseniev, Alexander S. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation) [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700 Dolgoprudny, Moscow Region (Russian Federation); Ovchinnikova, Tatiana V., E-mail: ovch@ibch.ru [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700 Dolgoprudny, Moscow Region (Russian Federation)

2012-12-07

87

Cardiovascular effect is independent of hemolytic toxicity of tentacle-only extract from the jellyfish Cyanea capillata.  

PubMed

Our previous studies have confirmed that the crude tentacle-only extract (cTOE) from the jellyfish Cyanea capillata (Cyaneidae) exhibits hemolytic and cardiovascular toxicities simultaneously. So, it is quite difficult to discern the underlying active component responsible for heart injury caused by cTOE. The inactivation of the hemolytic toxicity from cTOE accompanied with a removal of plenty of precipitates would facilitate the separation of cardiovascular component and the investigation of its cardiovascular injury mechanism. In our research, after the treatment of one-step alkaline denaturation followed by twice dialysis, the protein concentration of the treated tentacle-only extract (tTOE) was about 1/3 of cTOE, and SDS-PAGE showed smaller numbers and lower density of protein bands in tTOE. The hemolytic toxicity of tTOE was completely lost while its cardiovascular toxicity was well retained. The observations of cardiac function, histopathology and ultrastructural pathology all support tTOE with significant cardiovascular toxicity. Blood gas indexes and electrolytes changed far less by tTOE than those by cTOE, though still with significant difference from normal. In summary, the cardiovascular toxicity of cTOE can exist independently of the hemolytic toxicity and tTOE can be employed as a better venom sample for further purification and mechanism research on the jellyfish cardiovascular toxic proteins. PMID:22905209

Liang, Xiao; Beilei, Wang; Ying, Li; Qianqian, Wang; Sihua, Liu; Yang, Wang; Guoyan, Liu; Jia, Lu; Xuting, Ye; Liming, Zhang

2012-01-01

88

Nitrogen and phosphorus budget of a polyculture system of sea cucumber ( Apostichopus japonicus), jellyfish ( Rhopilema esculenta) and shrimp ( Fenneropenaeus chinensis)  

NASA Astrophysics Data System (ADS)

The nitrogen (N) and phosphorus (P) budget and the ecological efficiency of a polyculture system of sea cucumber ( Apostichopus japonicus), jellyfish ( Rhopilema esculenta) and shrimp ( Fenneropenaeus chinensis) were studied in a cofferdam, 120.2 ha in size. The nutrients were supplied by spring tide inflow. In total, 139600 kg N yr-1 and 9730 kg P yr-1 input to the system; while 118900 kg N yr-1 and 2840 kg P yr-1 outflowed from the system concurrently, thus the outflow was 85.7% (N) and 29.2% (P) of inflow. The production of N and P was 889.5 kg yr-1 and 49.28 kg yr-1 (sea cucumber) and 204 kg yr-1 and 18.03 kg yr-1 (jellyfish and shrimp), respectively. The utilization rate of N and P by polycultured animals was 7.8‰ and 6.9‰, respectively, 21.9% and 38% higher than that of monocultured sea cucumber. Our results indicated that the polyculture system was an efficient culture system of animals and a remediation system of coastal environment as well; it scavenged 14.3% and 70.8% of N and P, respectively. Such an ecological efficiency may be improved further by increasing either the stocking density or the size of sea cucumber or both.

Li, Junwei; Dong, Shuanglin; Gao, Qinfeng; Zhu, Changbo

2014-06-01

89

Lipid peroxidation is another potential mechanism besides pore-formation underlying hemolysis of tentacle extract from the jellyfish Cyanea capillata.  

PubMed

This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG) significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA), an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid-Vitamin C (Vc)-and reduced glutathione (GSH). Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca2+ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms. PMID:23303301

Wang, Tao; Wen, Xiao-Juan; Mei, Xiao-Bin; Wang, Qian-Qian; He, Qian; Zheng, Jie-Min; Zhao, Jie; Xiao, Liang; Zhang, Li-Ming

2013-01-01

90

Macrobenthic community structure and species composition in the Yellow Sea and East China Sea in jellyfish bloom  

NASA Astrophysics Data System (ADS)

To understand the characteristics of macrobenthic structures and the relationship between environment and benthic assemblages in jellyfish bloom, we studied the macrobenthos and related environmental factors in the coastal waters of the Yellow Sea and East China Sea. Data were collected during two seasonal cruises in April and August of 2011, and analyzed with multivariate statistical methods. Up to 306 macrobenthic species were registered from the research areas, including 115 species of Polychaeta, 78 of Crustacea, 61 of Mollusca, 30 of Echinodermata, and 22 of other groups. Nine polychaete species occurred at frequencies higher than 25% from the sampling stations: Lumbrineris longifolia, Notomastus latericeus, Ninöe palmata, Ophelina acuminata, Nephtys oligobranchia, Onuphis geophiliformis, Glycera chirori, Terebellides stroemii, and Aricidea fragilis. Both the average biomass and abundance of macrobenthos are higher in August (23.8 g/m2 and 237.7 ind./m2) than those in April (11.3 g/m2 and 128 ind./m2); the dissimilarity of macrobenthic structures among stations is as high as 70%. In terms of the dissimilarity values, we divided the stations into four clusters in spring and eight in summer. The ABC curve shows that the macrofauna communities in high jellyfish abundance were not changed. Canonical correspondence analysis showed that depth, temperature, median grain size, total organic carbon of sediment and total nitrogen in sediment were important factors affecting the macrozoobenthic community in the study area.

Peng, Songyao; Li, Xinzheng; Wang, Hongfa; Zhang, Baolin

2014-05-01

91

Observations on the Trophic Significance of Jellyfishes in Mississippi Sound with Quantitative Data on the Associative Behavior of Small Fishes with Medusae  

Microsoft Academic Search

The trophic interrelationships of jellyfishes to other organisms in Mississippi Sound were investigated from March 1968 to March 1969. Ctenophores and, to a lesser extent, hydromedusae constitute the most important group of predators affecting zooplankton populations in this estuary due to: (1) extreme local abundance, and (2) voracious feeding habits. Evidence is presented that ctenophores and medusae constitute important food

Philip J. Phillips; W. David Burke; Elizabeth J. Keener

1969-01-01

92

In vitro laser Doppler anemometry of pulsatile flow velocity and shear stress measurements downstream from a jellyfish valve in the mitral position of a ventricular assist device  

Microsoft Academic Search

Thrombus formation and hemolysis have both been linked to the dynamic flow characteristics of heart valve prostheses. To enhance our understanding of the flow characteristics past the mitral position of a jellyfish (JF) valve in the left ventricle under physiological pulsatile flow conditions, in vitro laser Doppler anemometry (LDA) measurements were carried out. The hydrodynamic performance of the JF valve

Yos Morsi; Masahisa Kogure; Mitsuo Umezu

1999-01-01

93

Noninvasive laser therapy in the treatment of keloid scar after injury caused by a jellyfish: a case report  

NASA Astrophysics Data System (ADS)

Keloid scars trouble the patients particularly for aesthetical reasons. They also frequency result in various functional disturbances, they are painful and the patient suffers for dysesthesia on touch. Low level laser is able to provide three principal effects: biostimulating, analgesic and antiinflammatory. Particularly thanks to the first two effects we are able, when adhering to the proper therapeutic procedure, to moderate or even remove the above mentioned problems. We complement the low level laser treatment by applications of ointments, cremes or silicone strips. Our communication is aimed at a case report concerning the treatment of keloid scars resulting from an injury by a jellyfish with the aim to familiarize the reader with wide therapeutic possibilities of non-invasive laser, even in indications which are not frequently encountered in central Europe.

Kymplova, Jaroslava; Navratil, Leos; Skopek, Jiri

2001-10-01

94

Effects of collagen and collagen hydrolysate from jellyfish (Rhopilema esculentum) on mice skin photoaging induced by UV irradiation.  

PubMed

Collagen (JC) was extracted from jellyfish (Rhopilema esculentum) and hydrolyzed to prepare collagen hydrolysate (JCH). The protective effects of JC and JCH against UV-induced damages to mice skin were evaluated and compared in this article. JC and JCH could alleviate the UV-induced abnormal changes of antioxidative indicators, including the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities and the contents of glutathione (GSH) and malondiaidehyde (MDA). JC and JCH could protect skin lipid and collagen from the UV radiation damages. Furthermore, the changes of total ceramide and glycosaminoglycan in skin were recovered significantly by JC and JCH. The action mechanisms mainly involved the antioxidative properties and the repairing to endogenous collagen synthesis of JC and JCH in vivo. JCH with the lower molecular weight showed much higher effects than JC. The results indicated that JCH was a novel antiphotoaging agent from natural resources. PMID:19723203

Zhuang, Yongliang; Hou, Hu; Zhao, Xue; Zhang, Zhaohui; Li, Bafang

2009-08-01

95

Antihypertensive Effect of Long-Term Oral Administration of Jellyfish (Rhopilema esculentum) Collagen Peptides on Renovascular Hypertension  

PubMed Central

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides (JCP) on renovascular hypertension rats (RVHs) was evaluated. The systolic blood pressure and diastolic blood pressure of the RVHs were significantly reduced with administration of JCP (p < 0.05), compared with model control group. However, the arterial blood pressure of normal rats showed no significant changes during long-term oral treatment with high dose JCP (p > 0.05). Furthermore, effect of JCP on angiotensin II (Ang II) concentration of plasma had no significance (p > 0.05), but JCP significantly inhibited the Ang II concentration in RVHs’ kidney (p < 0.05). The kidney should be the target site of JCP.

Zhuang, Yongliang; Sun, Liping; Zhang, Yufeng; Liu, Gaoxiang

2012-01-01

96

First Evidence of Inbreeding, Relatedness and Chaotic Genetic Patchiness in the Holoplanktonic Jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria)  

PubMed Central

Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments.

Aglieri, Giorgio; Papetti, Chiara; Zane, Lorenzo; Milisenda, Giacomo; Boero, Ferdinando; Piraino, Stefano

2014-01-01

97

Preliminary Results of the in Vivo and in Vitro Characterization of a Tentacle Venom Fraction from the Jellyfish Aurelia aurita  

PubMed Central

The neurotoxic effects produced by a tentacle venom extract and a fraction were analyzed and correlated by in vivo and in vitro approaches. The tentacle venom extract exhibited a wide range of protein components (from 24 to >225 kDa) and produced tetanic reactions, flaccid paralysis, and death when injected into crabs. Two chromatography fractions also produced uncontrolled appendix movements and leg stretching. Further electrophysiological characterization demonstrated that one of these fractions potently inhibited ACh-elicited currents mediated by both vertebrate fetal and adult muscle nicotinic acetylcholine receptors (nAChR) subtypes. Receptor inhibition was concentration-dependent and completely reversible. The calculated IC50 values were 1.77 ?g/?L for fetal and 2.28 ?g/?L for adult muscle nAChRs. The bioactive fraction was composed of a major protein component at ~90 kDa and lacked phospholipase A activity. This work represents the first insight into the interaction of jellyfish venom components and muscle nicotinic receptors.

Ponce, Dalia; Lopez-Vera, Estuardo; Aguilar, Manuel B.; Sanchez-Rodriguez, Judith

2013-01-01

98

First Report of a Thioredoxin Homologue in Jellyfish: Molecular Cloning, Expression and Antioxidant Activity of CcTrx1 from Cyanea capillata  

PubMed Central

Thioredoxins (Trx proteins) are a family of small, highly-conserved and ubiquitous proteins that play significant roles in the resistance of oxidative damage. In this study, a homologue of Trx was identified from the cDNA library of tentacle of the jellyfish Cyanea capillata and named CcTrx1. The full-length cDNA of CcTrx1 was 479 bp with a 312 bp open reading frame encoding 104 amino acids. Bioinformatics analysis revealed that the putative CcTrx1 protein harbored the evolutionarily-conserved Trx active site 31CGPC34 and shared a high similarity with Trx1 proteins from other organisms analyzed, indicating that CcTrx1 is a new member of Trx1 sub-family. CcTrx1 mRNA was found to be constitutively expressed in tentacle, umbrella, oral arm and gonad, indicating a general role of CcTrx1 protein in various physiological processes. The recombinant CcTrx1 (rCcTrx1) protein was expressed in Escherichia coli BL21 (DE3), and then purified by affinity chromatography. The rCcTrx1 protein was demonstrated to possess the expected redox activity in enzymatic analysis and protection against oxidative damage of supercoiled DNA. These results indicate that CcTrx1 may function as an important antioxidant in C. capillata. To our knowledge, this is the first Trx protein characterized from jellyfish species.

Zhou, Yonghong; Wang, Qianqian; Chang, Yinlong; Wang, Beilei; Zheng, Jiemin; Zhang, Liming

2014-01-01

99

Evolution of paired domains: isolation and sequencing of jellyfish and hydra Pax genes related to Pax-5 and Pax-6.  

PubMed

Pax proteins are a family of transcription factors with a highly conserved paired domain; many members also contain a paired-type homeodomain and/or an octapeptide. Nine mammalian Pax genes are known and classified into four subgroups: Pax-1/9, Pax-2/5/8, Pax-3/7, and Pax-4/6. Most of these genes are involved in nervous system development. In particular, Pax-6 is a key regulator that controls eye development in vertebrates and Drosophila. Although the Pax-4/6 subgroup seems to be more closely related to Pax-2/5/8 than to Pax-3/7 or Pax-1/9, its evolutionary origin is unknown. We therefore searched for a Pax-6 homolog and related genes in Cnidaria, which is the lowest phylum of animals that possess a nervous system and eyes. A sea nettle (a jellyfish) genomic library was constructed and two pax genes (Pax-A and -B) were isolated and partially sequenced. Surprisingly, unlike most known Pax genes, the paired box in these two genes contains no intron. In addition, the complete cDNA sequences of hydra Pax-A and -B were obtained. Hydra Pax-B contains both the homeodomain and the octapeptide, whereas hydra Pax-A contains neither. DNA binding assays showed that sea nettle Pax-A and -B and hydra Pax-A paired domains bound to a Pax-5/6 site and a Pax-5 site, although hydra Pax-B paired domain bound neither. An alignment of all available paired domain sequences revealed two highly conserved regions, which cover the DNA binding contact positions. Phylogenetic analysis showed that Pax-A and especially Pax-B were more closely related to Pax-2/5/8 and Pax-4/6 than to Pax-1/9 or Pax-3/7 and that the Pax genes can be classified into two supergroups: Pax-A/Pax-B/Pax-2/5/8/4/6 and Pax-1/9/3/7. From this analysis and the gene structure, we propose that modern Pax-4/6 and Pax-2/5/8 genes evolved from an ancestral gene similar to cnidarian Pax-B, having both the homeodomain and the octapeptide. PMID:9144207

Sun, H; Rodin, A; Zhou, Y; Dickinson, D P; Harper, D E; Hewett-Emmett, D; Li, W H

1997-05-13

100

Impairment of the cell-to-matrix adhesion and cytotoxicity induced by the Mediterranean jellyfish Pelagia noctiluca venom and its fractions in cultured glioblastoma cells  

PubMed Central

Background The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited source of new active substances in the field of the development of bioactive products. In our study, we have investigated the efficiency of the venom from the Mediterranean jellyfish, Pelagia noctiluca and its fractions for anti-proliferative and anti-cell adhesion to cell–extracellular matrix activities. Results Our experiments have indicated that the separation of the Mediterranean jellyfish Pelagia noctiluca crude venom extract by sephadex G-75 chromatography led to four fractions (F1, F2, F3, and F4). Among the four fractions F1 and F3 were cytotoxic against U87 cells with IC50 values of 125 and 179??g/ml respectively. The venom, F1, F2 and F 3 showed significant anti-proliferative activity in time-dependent manner. Our results also suggest that these fractions and the venom are able to inhibit cell adhesion to fibrinogen in dose-dependent manner. This inhibition is reliant on its ability to interact with integrins. Conclusions To conclude, we have demonstrated for the first time that Pelagia noctiluca venom and its fractions especially (F1 and F2) display potent anti-tumoral properties. Separation by sephadex G-75 chromatography give rise to more active fractions than the crude venom extract. The purification and the determination of chemical structures of compounds of these active fractions are under investigation. Overall, Pelagia noctiluca venom may has the potential to serve as a template for future anticancer-drug development.

2012-01-01

101

Snakes, Jellyfish and Spiders  

Microsoft Academic Search

Our knowledge of animal and human physiological processes owes much to over a century of study of natural toxins. The neurotoxins\\u000a of kraits (bungarotoxins from Bungarus spp.) and cobras (Naja spp.) have helped define the acetylcholine receptor and neuromuscular transmission. Axonal trafficking and sodium channels\\u000a have been studied using tetrodotoxin from the blue-ringed octopus (Hapalochlaena spp.) and puffer fish (fugu).

Bart J. Currie

102

Aurelia labiata jellyfish in Roscoe Bay on the West Coast of Canada: Seasonal changes in adult bell diameter and mingling of juvenile and adult populations  

NASA Astrophysics Data System (ADS)

The bell diameter of adult Aurelia labiata in Roscoe Bay increased from spring (April) to early summer (May/June) and decreased over the rest of the year (2009/2010). The increase in bell diameter in the spring would have been supported by the increase in zooplankton that occurs in the northeast Pacific at this time. Over the summer, bell diameter may have decreased because the food available/medusa would have been decreased by the arrival of a large number of juveniles and may have decreased further over the fall and winter when zooplankton levels are known to be low. Adults and juveniles were intermingled during 2010, 2011, and 2012. Correlations between the number of adults and number of juveniles obtained in individual net lifts across the entire bay and in different parts of the bay were all positive and most were statistically significant. In 2012, salinity in the entire water column of the west side of the bay dropped below 20 ppt in July and most medusae migrated to higher salinity in the east side of the bay, a distance of about 0.5 km. The mingling of adults and juveniles supports other evidence that adult Aurelia sp. medusae do not prey upon juveniles. The ability to withstand months with insufficient food and to inhibit preying on juveniles would contribute greatly to the survival of Aurelia sp. jellyfish.

Albert, David J.; Walsh, Michael L.

2014-01-01

103

For the Classroom: "Plastic" Jellyfish.  

ERIC Educational Resources Information Center

Describes an activity in which students monitor the plastic waste production in their households, research its effects on freshwater and marine life, and propose ways to lessen the problem. Provides objectives, background information, materials, procedures, extension activities, and an evaluation for students. (Author/RT)

Current: The Journal of Marine Education, 1989

1989-01-01

104

Graviceptor development in jellyfish ephyrae in space and on Earth  

NASA Technical Reports Server (NTRS)

Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in artificial sea water (ASW) as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalitities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing.

Spangenberg, D. B.; Jernigan, T.; Philput, C.; Lowe, B.

1994-01-01

105

Graviceptor development in jellyfish ephyrae in space and on earth  

NASA Astrophysics Data System (ADS)

Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in ASW as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing.

Spangenberg, D. B.; Jernigan, T.; Philput, C.; Lowe, B.

1994-08-01

106

Jellyfish on the Ceiling and Deer in the Den: The Biology of Interior Decoration  

Microsoft Academic Search

Few homes are without at least one or two representations of living things. The author argues that this penchant for organic decoration is related to what Edward O. Wilson calls biophilia, an innate urge in humans to have contact with other species. As many people now live apart from the natural world, pictures, statues, dried flowers and other reminders of

Maura C. Flannery

2005-01-01

107

Jellyfish and Ctenophore Blooms Coincide with Human Proliferations and Environmental Perturbations  

NASA Astrophysics Data System (ADS)

Human populations have been concentrated along and exploiting the coastal zones for millennia. Of regions with the highest human impacts on the oceans ( Halpern et al. 2008 ), 6 of the top 10 have recently experienced blooms or problems with jellies. I review the time lines of human population growth and their effects on the coastal environment. I explore evidence suggesting that human activities - specifically, seafood harvest, eutrophication, hard substrate additions, transport of nonindigenous species, aquaculture, and climate change - may benefit jelly populations. Direct evidence is lacking for most of these factors; however, numerous correlations show abundant jellies in areas with warm temperatures and low forage fish populations. Jelly populations fluctuate in ˜10- and ˜20-year cycles in concert with solar and climate cycles. Global warming will provide a rising baseline against which climate cycles will cause fluctuations in jelly populations. The probable acceleration of anthropogenic effects may lead to further problems with jellies.

Purcell, Jennifer E.

2012-01-01

108

Evolution of box jellyfish (Cnidaria: Cubozoa), a group of highly toxic invertebrates  

PubMed Central

Cubozoa (Cnidaria: Medusozoa) represents a small clade of approximately 50 described species, some of which cause serious human envenomations. Our understanding of the evolutionary history of Cubozoa has been limited by the lack of a sound phylogenetic hypothesis for the group. Here, we present a comprehensive cubozoan phylogeny based on ribosomal genes coding for near-complete nuclear 18S (small subunit) and 28S (large subunit) and partial mitochondrial 16S. We discuss the implications of this phylogeny for our understanding of cubozoan venom evolution, biogeography and life-history evolution. Our phylogenetic hypothesis suggests that: (i) the last common ancestor of Carybdeida probably possessed the mechanism(s) underlying Irukandji syndrome, (ii) deep divergences between Atlantic and Indo-Pacific clades may be explained by ancient vicariant events, and (iii) sexual dimorphism evolved a single time in concert with complex sexual behaviour. Furthermore, several cubozoan taxa are either para- or polyphyletic, and we address some of these taxonomic issues by designating a new family, Carukiidae, a new genus, Copula, and by redefining the families Tamoyidae and Tripedaliidae. Lastly, cubozoan species identities have long been misunderstood and the data presented here support many of the recent scientific descriptions of cubozoan species. However, the results of a phylogeographic analysis of Alatina moseri from Hawai'i and Alatina mordens from Australia indicate that these two nominal species represent a single species that has maintained metapopulation cohesion by natural or anthropogenic dispersal.

Bentlage, Bastian; Cartwright, Paulyn; Yanagihara, Angel A.; Lewis, Cheryl; Richards, Gemma S.; Collins, Allen G.

2010-01-01

109

Opposite patterns of diurnal activity in the box jellyfish Tripedalia cystophora and Copula sivickisi.  

PubMed

Cubozoan medusae have a stereotypic set of 24 eyes, some of which are structurally similar to vertebrate and cephalopod eyes. Across the approximately 25 described species, this set of eyes varies surprisingly little, suggesting that they are involved in an equally stereotypic set of visual tasks. During the day Tripedalia cystophora is found at the edge of mangrove lagoons where it accumulates close to the surface in sun-lit patches between the prop roots. Copula sivickisi (formerly named Carybdea sivickisi) is associated with coral reefs and has been observed to be active at night. At least superficially, the eyes of the two species are close to identical. We studied the diurnal activity pattern of these two species both in the wild and under controlled conditions in laboratory experiments. Despite the very similar visual systems, we found that they display opposite patterns of diurnal activity. T. cystophora is active exclusively during the day, whereas C. sivickisi is actively swimming at night, when it forages and mates. At night T. cystophora is found on the muddy bottom of the mangrove lagoon. C. sivickisi spends the day attached to structures such as the underside of stones and coral skeletons. This species difference seems to have evolved to optimize foraging, since the patterns of activity follow those of the available prey items in their respective habitats. PMID:22426630

Garm, A; Bielecki, J; Petie, R; Nilsson, D-E

2012-02-01

110

Occurrence of Type S1A Serine Proteases in Sponge and Jellyfish.  

National Technical Information Service (NTIS)

Although serine proteases are found in all kinds of cellular organisms and many viruses, the classic 'chymotrypsin family' (Group S1A by the 1998 Barrett nomenclature) has an unusual phylogenetic distribution, being especially common in animals, entirely ...

A. Rojas R. F. Doolittle

2003-01-01

111

Evolution of Paired Domains: Isolation and Sequencing of Jellyfish and Hydra Pax Genes Related to Pax5 and Pax6  

Microsoft Academic Search

Pax proteins are a family of transcription factors with a highly conserved paired domain; many members also contain a paired-type homeodomain and\\/or an octapeptide. Nine mammalian Pax genes are known and classified into four subgroups: Pax-1\\/9, Pax-2\\/5\\/8, Pax-3\\/7, and Pax-4\\/6. Most of these genes are involved in nervous system development. In particular, Pax-6 is a key regulator that controls eye

Hongmin Sun; Andrei Rodin; Yihong Zhou; Douglas P. Dickinson; Donald E. Harper; David Hewett-Emmett; Wen-Hsiung Li

1997-01-01

112

Agrobacterium tumefaciens-mediated transformation of Leptosphaeria spp. and Oculimacula spp. with the reef coral gene DsRed and the jellyfish gene gfp.  

PubMed

Four filamentous ascomycetes, Leptosphaeria maculans, L. biglobosa, Oculimacula yallundae and O. acuformis, were transformed via Agrobacterium tumefaciens-mediated transformation with the genes encoding DsRed and GFP. Using vectors pCAMDsRed and pCAMBgfp, either germinated conidia of Leptosphaeria spp. and O. yallundae or physically fragmented cultures of Oculimacula spp. were transformed. In vitro, the expression of the two reporter proteins in mycelium of both Oculimacula and both Leptosphaeria species was sufficient to distinguish each species in co-inoculated cultures. In planta, transformants of L. maculans or L. biglobosa expressing DsRed or GFP could be observed together in leaves of Brassica napus. Either reporter protein could be used to view the colonization of leaf petioles by both Leptosphaeria spp. and growth in the xylem vessels could be clearly observed. With the generation of these transformants, further studies on interactions between pathogen species involved in disease complexes on various host species and between opposite mating types of the same species are now possible. PMID:16243451

Eckert, Maria; Maguire, Kerry; Urban, Martin; Foster, Simon; Fitt, Bruce; Lucas, John; Hammond-Kosack, Kim

2005-12-01

113

A new species of Pseudomacrochiron Reddiah, 1969 (Crustacea: Copepoda: Macrochironidae) associated with scyphistomae of the moon jellyfish Aurelia sp. (Cnidaria: Scyphozoa) off Japan.  

PubMed

A new species of the Macrochironidae Humes & Boxshall, 1996 (Copepoda: Cyclopoida), Pseudomacrochiron aureliae n. sp., is described based on adult specimens extracted from the gastrovacular cavity of the scyphistomae of Aurelia sp. (Cnidaria: Scyphozoa) collected in the Seto Inland Sea and Ise Bay off the coast of Japan. The new species differs from its congeners by having the following combination of characters: a caudal ramus with a length to width ratio of 3.1; an accessory flagellum on caudal setae II, III and VI; three apical setae on the maxillule; only setae I and II on the maxillary basis; two short spines on the female maxilliped claw (endopod); an armature of III, I, 4 on the terminal exopodal segment of leg 3; an armature of I, II, 2 on the terminal endopodal segment of leg 3; an armature of II, I, 4 on the terminal exopodal segment of leg 4; and a short free exopodal segment of leg 5 (length to width ratio of 1.4) armed with a long seta and short spine. P. aureliae n. sp. is the first member of the genus reported from off Japan and from the scyphistomae of its scyphozoan host. PMID:22183922

Tang, Danny; Yasuda, Akira; Yamada, Satoshi; Nagasawa, Kazuya

2012-02-01

114

Introduction to the Ctenophora  

NSDL National Science Digital Library

This site provides an introduction to ctenophores, or "comb jellies". Site includes links to information on Cnidarians (jellyfish, etc.), echinoderms, and sponges. Two images of ctenophores are included.

2011-06-30

115

Learning about Carbohydrates  

MedlinePLUS

... Injuries Jellyfish The Pink Locker Society Learning About Carbohydrates KidsHealth > Kids > Staying Healthy > Fabulous Food > Learning About ... of energy for the body. Two Types of Carbohydrates There are two major types of carbohydrates (or ...

116

Handle with Care: Mid-Atlantic Marine Animals That Demand Your Respect.  

National Technical Information Service (NTIS)

Generally speaking, the marine organisms found along middle Atlantic shores are not considered threatening to people. However, some of these animals can cause problems, either upon simple contact with the skin, as in the case of some jellyfish, or through...

J. Lucy

1978-01-01

117

Marine animal stings or bites  

MedlinePLUS

... lifeguard. Observe posted signs that may warn of danger from jellyfish or other hazardous marine life. Do not touch unfamiliar marine life. Even dead animals or severed tentacles may contain poisonous venom.

118

Playing With Fire?  

MedlinePLUS

... Injuries Jellyfish The Pink Locker Society Playing With Fire? KidsHealth > Kids > Staying Safe > Playing It Safe Outdoors ... night, or a professional fireworks display. Continue Why Fire Fascinates Fire is a tool and a fascinating ...

119

Hey! A Fire Ant Stung Me!  

MedlinePLUS

... Injuries Jellyfish The Pink Locker Society Hey! A Fire Ant Stung Me! KidsHealth > Kids > Illnesses & Injuries > Bug ... Do How to Avoid Getting Bitten What's a Fire Ant? There are many different types of fire ...

120

Intermolecular Energy Transfer in the Bioluminescent System of Aequorea.  

National Technical Information Service (NTIS)

The jellyfish Aequorea emits green light whereas the photoprotein aequorin extracted from the same organism emits blue light when calcium ion is added. Because the photogenic cells contain a green fluorescent protein (GFP) in addition to aequorin, an ener...

H. Morise O. Shimomura F. H. Johnson J. Winant

1974-01-01

121

Development of a Novel Ligand Binding Assay for Estrogen Receptor.  

National Technical Information Service (NTIS)

Nuclear receptors undergo conformational changes when they bind ligands. It should be possible to monitor these changes in vivo using energy transfer between fluorophores. The existence of inherently fluorescent proteins such as the variants of jellyfish ...

A. C. Chung

2002-01-01

122

Global phylogeography of Cassiopea (Scyphozoa: Rhizostomeae): molecular evidence for cryptic species and multiple invasions of the Hawaiian Islands  

Microsoft Academic Search

The upside-down jellyfish Cassiopea is a globally distributed, semi-sessile, planktonically dispersed scyphomedusa. Cassiopea occurs in shallow, tropical inshore marine waters on sandy mudflats and is generally associated with mangrove-dominated habitats. Controversy over the taxonomy of upside-down jellyfishes precedes their introduction to the Hawaiian Islands during the Second World War, and persists today. Here we address the global phylogeography and molecular

Brenden S. Holland; Michael N. Dawson; Gerald L. Crow; Dietrich K. Hofmann

2004-01-01

123

Effects of pH on asexual reproduction and statolith formation of the scyphozoan, Aurelia labiata  

Microsoft Academic Search

Although anthropogenic influences such as global warming, overfishing, and eutrophication may contribute to jellyfish blooms,\\u000a little is known about the effects of ocean acidification on jellyfish. Most medusae form statoliths of calcium sulfate hemihydrate\\u000a that are components of their balance organs (statocysts). This study was designed to test the effects of pH (7.9, within the\\u000a average current range, 7.5, expected

Amanda K. WinansJennifer; Jennifer E. Purcell

2010-01-01

124

An experimental study of Aurelia aurita feeding behaviour: Inference of the potential predation impact on a temperate estuarine nursery area  

NASA Astrophysics Data System (ADS)

Temperate estuaries are nursery areas for economically important fisheries resources. The common jellyfish Aurelia aurita is a resident species in many of these areas, where it can reach high abundances. This work aimed to determine the potential for predation of A. aurita on zooplanktonic organisms and early life stages of fishes, measuring feeding rates at concentrations that mimic those occurring for zooplankton, fish eggs and larvae in an estuarine nursery area. A set of experiments was aimed at determining the feeding selectivity of jellyfish when offered a mixture of fish eggs and larvae and wild plankton. Clearance rates varied markedly with prey availability and concentrations. When given mixtures of different prey types, jellyfish preferentially elected some taxa (copepods and fish eggs). Data obtained in the laboratory experiments were used to infer the potential impact of jellyfish predation upon zooplankton and ichthyoplankton in the Guadiana estuary (Southern Iberia). Repeated sampling of zooplankton, fish eggs and medusae was undertaken during the summer season of 2011. Abundance determinations were combined with experimentally estimated clearance rates of individual medusa to infer the potential jellyfish-induced mortality on prey in the area. In June and early August jellyfish-induced mortality rates were very high, and half-life times (t1/2) were consequently short for the zooplankton and ichthyoplankton. Although the potentially overestimation of our feeding rates typical of confined laboratory experiments, the results show high ingestion and clearance rates at high temperatures, typical from summer condition, and results also suggest that either by predation on early life stages of fish, or by competition for food resources, jellyfish may have a significant impact on estuarine communities and its nursery function.

Pereira, Rita; Teodósio, Maria Alexandra; Garrido, Susana

2014-06-01

125

The Mauve Stinger Pelagia noctiluca (Forssk?l, 1775). Distribution, Ecology, Toxicity and Epidemiology of Stings. A Review  

PubMed Central

The toxicity of Cnidaria is a subject of concern due to its influence on humans. In particular, jellyfish blooms can highly affect human economical activities, such as bathing, fishery, tourism, etc., as well as the public health. Stinging structures of Cnidaria (nematocysts) produce remarkable effects on human skin, such as erythema, swelling, burning and vesicles, and at times further severe dermonecrotic, cardio- and neurotoxic effects, which are particularly dangerous in sensitive subjects. In several zones the toxicity of jellyfish is a very important health problem, thus it has stimulated the research on these organisms; to date toxicological research on Cnidarian venoms in the Mediterranean region is not well developed due to the weak poisonousness of venoms of jellyfish and anemones living in this area. In spite of this, during last decades several problems were also caused in the Mediterranean by stinging consequent to Cnidarian blooms mainly caused by Pelagia noctiluca (Forsskål, 1775) which is known to be the most venomous Mediterranean jellyfish. This paper reviews the knowledge on this jellyfish species, particularly considering its occurrence and toxicity.

Mariottini, Gian Luigi; Giacco, Elisabetta; Pane, Luigi

2008-01-01

126

Reconstructing Source-Sink Dynamics in a Population with a Pelagic Dispersal Phase  

PubMed Central

For many organisms, the reconstruction of source-sink dynamics is hampered by limited knowledge of the spatial assemblage of either the source or sink components or lack of information on the strength of the linkage for any source-sink pair. In the case of marine species with a pelagic dispersal phase, these problems may be mitigated through the use of particle drift simulations based on an ocean circulation model. However, when simulated particle trajectories do not intersect sampling sites, the corroboration of model drift simulations with field data is hampered. Here, we apply a new statistical approach for reconstructing source-sink dynamics that overcomes the aforementioned problems. Our research is motivated by the need for understanding observed changes in jellyfish distributions in the eastern Bering Sea since 1990. By contrasting the source-sink dynamics reconstructed with data from the pre-1990 period with that from the post-1990 period, it appears that changes in jellyfish distribution resulted from the combined effects of higher jellyfish productivity and longer dispersal of jellyfish resulting from a shift in the ocean circulation starting in 1991. A sensitivity analysis suggests that the source-sink reconstruction is robust to typical systematic and random errors in the ocean circulation model driving the particle drift simulations. The jellyfish analysis illustrates that new insights can be gained by studying structural changes in source-sink dynamics. The proposed approach is applicable for the spatial source-sink reconstruction of other species and even abiotic processes, such as sediment transport.

Chen, Kun; Ciannelli, Lorenzo; Decker, Mary Beth; Ladd, Carol; Cheng, Wei; Zhou, Ziqian; Chan, Kung-Sik

2014-01-01

127

Calcium phosphate-mediated transfection of primary cultured brain neurons using GFP expression as a marker: application for single neuron electrophysiology  

Microsoft Academic Search

We investigated the efficiency of transfecting primary cultured rat postnatal brain neurons (substantia nigra pars compacta neurons and locus coeruleus neurons) with cDNA encoding GFP (jellyfish green fluorescent protein) using a calcium phosphate method. The proportion of transfected neurons (transfection efficiency) was ?5%, when cultures from the substantia nigra pars compacta were transfected 3 days after plating. The transfection efficiency

Shinju Y Watanabe; Abla M Albsoul-Younes; Takeharu Kawano; Hiroshi Itoh; Yoshito Kaziro; Shigehiro Nakajima; Yasuko Nakajima

1999-01-01

128

A Nuclear GFP That Marks Nuclei in Living Drosophila Embryos; Maternal Supply Overcomes a Delay in the Appearance of Zygotic Fluorescence  

Microsoft Academic Search

The central role of gene expression in regulating development has largely been studied by in situ hybridization and antibody staining techniques in fixed material. However, rapid temporal and spatial changes in gene expression are often difficult to correlate with complex morphogenetic movements. A green fluorescent protein (GFP) from the jellyfish, Aequorea victoria, can be used as a real-time reporter for

Ilan Davis; Charles H. Girdham; Patrick H. O'Farrell

1995-01-01

129

Engineering Cowpea Mosaic Virus RNA2 into a Vector to Express Heterologous Proteins in Plants  

Microsoft Academic Search

A series of new cowpea mosaic virus (CPMV) RNA-2-based expression vectors were designed. The jellyfish green fluorescent protein (GFP) was introduced between the movement protein (MP) and the large (L) coat protein or downstream of the small (S) coat protein. Release of the GFP inserted between the MP and L proteins was achieved by creating artificial processing sites each side

Kodetham Gopinath; Joan Wellink; Claudine Porta; Kathryn M. Taylor; George P. Lomonossoff; Ab van Kammen

2000-01-01

130

Chimeric green fluorescent protein as a tool for visualizing subcellular organelles in living cells  

Microsoft Academic Search

Background: It has recently been demonstrated that the green fluorescent protein (GFP) of the jellyfish Aequorea victoria retains its fluorescent properties when recombinantly expressed in both prokaryotic (Escherichia coli) and eukaryotic (Caenorhabditis elegans and Drosophila melanogaster) living cells; it can therefore be used as a powerful marker of gene expression in vivo. The specific targeting of recombinant GFP within cells

Rosario Rizzuto; Marisa Brini; Paola Pizzo; Marta Murgia; Tullio Pozzan

1995-01-01

131

An Enhanced Green Fluorescent Protein Allows Sensitive Detection of Gene Transfer in Mammalian Cells  

Microsoft Academic Search

The green fluorescent protein (GFP) from the jellyfishAequorea victoriahas become an important marker of gene expression. However, the sensitivity of wild-type GFP has been below that of standard reporter proteins, such as ?-galactosidase, which utilize enzymatic amplification. To improve the detection of GFP in transfected mammalian cells, we have constructed a unique GFP variant which contains chromophore mutations that make

Guohong Zhang; Vanessa Gurtu; Steven R. Kain

1996-01-01

132

Green Fluorescent Protein as a Vital Marker and Reporter of Gene Expression in Drosophila  

Microsoft Academic Search

We have used the green fluorescent protein (GFP) from the jellyfish Aequorea victoria as a vital marker\\/reporter in Drosophila melanogaster. Transgenic flies were generated in which GFP was expressed under the transcriptional control of the yeast upstream activating sequence that is recognized by GAL4. These flies were crossed to several GAL4 enhancer trap lines, and expression of GFP was monitored

Edward Yeh; Kerstin Gustafson; Gabrielle L. Boulianne

1995-01-01

133

Understanding, improving and using green fluorescent proteins  

Microsoft Academic Search

Green fluorescent proteins (GFPs) are presently attracting tremendous interest as the first general method to create strong visible fluorescence by purely molecular biological means. So far, they have been used as reporters of gene expression, tracers of cell lineage, and as fusion tags to monitor protein localization within living cells. However, the GFP originally cloned from the jellyfish Aequorea victoria

Andrew B. Cubitt; Roger Heim; Stephen R. Adams; Aileen E. Boyd; Larry A. Gross; Roger Y. Tsien

1995-01-01

134

Chemical Nature of the Light Emitter of the Aequorea Green Fluorescent Protein  

Microsoft Academic Search

The jellyfish Aequorea victoria possesses in the margin of its umbrella a green fluorescent protein (GFP, 27 kDa) that serves as the ultimate light emitter in the bioluminescence reaction of the animal. The protein is made up of 238 amino acid residues in a single polypeptide chain and produces a greenish fluorescence (lambda max = 508 nm) when irradiated with

Haruki Niwa; Satoshi Inouye; Takashi Hirano; Tatsuki Matsuno; Satoshi Kojima; Masayuki Kubota; Mamoru Ohashi; Frederick I. Tsuji

1996-01-01

135

Enhanced Green Fluorescence by the Expression of an Aequorea victoria Green Fluorescent Protein Mutant in Mono and Dicotyledonous Plant Cells  

Microsoft Academic Search

The expression of the jellyfish green fluorescent protein (GFP) in plants was analyzed by transient expression in protoplasts from Nicotiana tabacum, Arabidopsis thaliana, Hordeum vulgare, and Zea mays. Expression of GFP was only observed with a mutated cDNA, from which a recently described cryptic splice site had been removed. However, detectable levels of green fluorescence were only emitted from a

Christoph Reichel; Jaideep Mathur; Peter Eckes; Kerstin Langenkemper; Csaba Koncz; Jeff Schell; Bernd Reiss; Christoph Maas

1996-01-01

136

Structural basis of spectral shifts in the yellow-emission variants of green fluorescent protein  

Microsoft Academic Search

Background: Because of its ability to spontaneously generate its own fluorophore, the green fluorescent protein (GFP) from the jellyfish Aequorea victoria is used extensively as a fluorescent marker in molecular and cell biology. The yellow fluorescent proteins (YFPs) have the longest wavelength emissions of all GFP variants examined to date. This shift in the spectrum is the result of a

Rebekka M Wachter; Marc-André Elsliger; Karen Kallio; George T Hanson; S James Remington

1998-01-01

137

Seascapes: Glimpses of Our Water World.  

ERIC Educational Resources Information Center

Presented is a collection of newspaper articles prepared by the Delaware Sea Grant Marine Advisory Service during the summer of 1978. Subjects addressed are bioluminescence, beachcomber finds, gulls, beach erosion, marine research activities, barnacles, sand, seaweed, jellyfish, shore restaurants, diving mammals, and tides. (Author/BW)

Hardin, Jan

138

A physical context for gelatinous zooplankton aggregations: a review  

Microsoft Academic Search

The magnitude and extent of jellyfish blooms are influenced not only by the biology and behavior of the animal, but also by the geographic setting and physical environment. Hydrography alone is often thought to cause or favor gelatinous zooplankton aggregations, however, it is clear that interactions between biology of the animal and physics of the water are very important sources

William M. Graham; Fransesc Pagès; William M. Hamner

2001-01-01

139

A formulation for calculating the translational velocity of a vortex ring or pair  

Microsoft Academic Search

Cephalopods, among other marine animals, use jet propulsion for swimming. A simple actuator is designed to loosely mimic pulsatile jet formation in squid and jellyfish. The actuator is comprised of a cavity with an oscillating diaphragm and an exit orifice. Periodic oscillation of the diaphragm results in the formation of an array of vortex rings and eventually could generate a

Kamran Mohseni

2006-01-01

140

What Makes Me Sneeze?  

MedlinePLUS

... Jellyfish The Pink Locker Society What Makes Me Sneeze? KidsHealth > Kids > Q&A > Q & A > What Makes Me Sneeze? Print A A A Text Size AHHH . . . CHOO! ... irritating or tickling the inside of your nose. Sneezing, also called sternutation, is your body's way of ...

141

A variant of yellow fluorescent protein with fast and efficient maturation for cell-biological applications  

Microsoft Academic Search

The green fluorescent protein (GFP) from the jellyfish Aequorea victoria has provided a myriad of applications for biological systems. Over the last several years, mutagenesis studies have improved folding properties of GFP (refs 1,2). However, slow maturation is still a big obstacle to the use of GFP variants for visualization. These problems are exacerbated when GFP variants are expressed at

Takeharu Nagai; Keiji Ibata; Eun Sun Park; Mie Kubota; Katsuhiko Mikoshiba; Atsushi Miyawaki

2002-01-01

142

Black Sea Battle  

NSDL National Science Digital Library

Story of the invasion of jellyfish into the Black Sea and the resulting affects on the native fish population. An excellent introduction into introduced species and their effects on an ecosystem. Site features an abundance of information on alien species and the delicacy that goes into eradicating them. Also links to additional non-traditional science-related news events.

143

Handle with Care! Mid-Atlantic Marine Animals That Demand Your Respect. Educational Series No. 26. Third Printing.  

ERIC Educational Resources Information Center

Generally speaking, marine organisms found along middle Atlantic shores are not considered threatening to people. However, some of these animals can cause problems, either upon simple contact with the skin, as in the case of some jellyfish, or through careless handling. In addition, larger inhabitants of coastal waters (such as sharks) must always…

Lucy, Jon

144

THE GREEN FLUORESCENT PROTEIN  

Microsoft Academic Search

In just three years, the green fluorescent protein (GFP) from the jellyfish Aequorea victoria has vaulted from obscurity to become one of the most widely studied and exploited proteins in biochemistry and cell biology. Its amazing ability to generate a highly visible, efficiently emitting internal fluorophore is both intrin- sically fascinating and tremendously valuable. High-resolution crystal structures of GFP offer

Roger Y. Tsien

1998-01-01

145

`Green mice' as a source of ubiquitous green cells  

Microsoft Academic Search

The green fluorescent protein (GFP) is responsible for the green bioluminescence of the jellyfish Aequorea victoria. Many classes of GFP mutants exist that display modified fluorescence spectra and an increased extinction coefficient. We produced transgenic mouse lines with an `enhanced' GFP (EGFP) cDNA under the control of a chicken beta-actin promoter and cytomegalovirus enhancer. All of the tissues from these

Masaru Okabe; Masahito Ikawa; Katsuya Kominami; Tomoko Nakanishi; Yoshitake Nishimune

1997-01-01

146

New England Aquarium  

NSDL National Science Digital Library

Information includes logistics, news, calendars, involvement options, research and conservation. A science and learning section offers resources for teachers, parents and kids; those for teachers include guides, trip information, enrichment programs, and a brochure from the Teacher Resource Center that can be downloaded. Largest displays include oceanic, jellyfish, and penguin exhibits. Located in Boston, Massachusetts.

147

Investigating the origins of triploblasty: `mesodermal' gene expression in a diploblastic animal, the sea anemone Nematostella vectensis (phylum, Cnidaria; class, Anthozoa)  

Microsoft Academic Search

Mesoderm played a crucial role in the radiation of the triploblastic Bilateria, permitting the evolution of larger and more complex body plans than in the diploblastic, non- bilaterian animals. The sea anemone Nematostella is a non- bilaterian animal, a member of the phylum Cnidaria. The phylum Cnidaria (sea anemones, corals, hydras and jellyfish) is the likely sister group of the

Mark Q. Martindale; Kevin Pang; John R. Finnerty

2004-01-01

148

Sea Anemone Genome Reveals Ancestral Eumetazoan Gene Repertoire and Genomic Organization  

Microsoft Academic Search

Sea anemones are seemingly primitive animals that, along with corals, jellyfish, and hydras, constitute the oldest eumetazoan phylum, the Cnidaria. Here, we report a comparative analysis of the draft genome of an emerging cnidarian model, the starlet sea anemone Nematostella vectensis. The sea anemone genome is complex, with a gene repertoire, exon-intron structure, and large-scale gene linkage more similar to

Nicholas H. Putnam; Mansi Srivastava; Uffe Hellsten; Bill Dirks; Jarrod Chapman; Asaf Salamov; Astrid Terry; Harris Shapiro; Erika Lindquist; Vladimir V. Kapitonov; Jerzy Jurka; Grigory Genikhovich; Igor V. Grigoriev; Susan M. Lucas; Robert E. Steele; John R. Finnerty; Ulrich Technau; Mark Q. Martindale; Daniel S. Rokhsar

2007-01-01

149

Labeling Neural Cells Using Adenoviral Gene Transfer of Membrane-Targeted GFP  

Microsoft Academic Search

We describe an experimental system to visualize the soma and processes of mammalian neurons and glia in living and fixed preparations by using a recombinant adenovirus vector to transfer the jellyfish green fluorescent protein (GFP) into postmitotic neural cells both in vitro and in vivo. We have introduced several modifications of GFP that enhance its fluorescence intensity in mammalian axons

Koki Moriyoshi; Linda J Richards; Chihiro Akazawa; Dennis D. M O'Leary; Shigetada Nakanishi

1996-01-01

150

Engineered GFP as a vital reporter in plants  

Microsoft Academic Search

Background: The green-fluorescent protein (GFP) of the jellyfish Aequorea victoria has recently been used as a universal reporter in a broad range of heterologous living cells and organisms. Although successful in some plant transient expression assays based on strong promoters or high copy number viral vectors, further improvement of expression efficiency and fluorescent intensity are required for GFP to be

Wan-ling Chiu; Yasuo Niwa; Weike Zeng; Takanori Hirano; Hirokazu Kobayashi; Jen Sheen

1996-01-01

151

Evidence of a planktonic food web response to changes in nutrient input dynamics in the Mar Menor coastal lagoon, Spain  

Microsoft Academic Search

Nutrient input dynamics in the Mar Menor coastal lagoon has recently changed as a consequence of changes in agricultural practises. An interannual comparison of the environmental variables and the planktonic biomass size-spectra was performed between 1988 and 1997. While nitrate concentration was low in 1988, the values in 1997 increased considerably. Since 1995, two alloctonous jellyfish species (Rhyzostoma pulmo and

A. Pérez-Ruzafa; J. Gilabert; J. M. Gutiérrez; A. I. Fernández; C. Marcos; S. Sabah

2002-01-01

152

Expression of GFP in tumor cells and fluorescent examination by confocal microscope  

Microsoft Academic Search

The green fluorescent protein (GFP), from the bioluminescent jellyfish Aequorea victoria, yields a bright green fluorescence when expressed in either eukaryotic or prokaryotic cells and illuminated by blue or UV light. The characteristic properties of GFP make this protein a good candidate for use as a molecular reporter to monitor patterns of protein localization, gene expression, and intracellular protein trafficking

Ying Jin; Da Xing; Chaoyang Xu

2002-01-01

153

Green fluorescent protein as a reporter of gene expression in transgenic mice  

Microsoft Academic Search

We used the green fluorescent protein (GFP) from the jellyfish Aequorea victoria as a reporter of gene expression in transgenic mice. The GFP coding sequence was placed under the control of the human hemopexin and the mouse ?1 integrin promoter that were previously studied in transgenic mice using the lacZ reporter gene. We showed that GFP has a higher degree

Annalisa Chiocchetti; Emanuela Tolosano; Emilio Hirsch; Lorenzo Silengo; Fiorella Altruda

1997-01-01

154

An experimental study of voice-coil driven synthetic jet propulsion for underwater vehicles  

Microsoft Academic Search

This paper investigates the thrust and flow structures produced by submerged synthetic jet actuators. Inspired by the propulsion methods of many sea creatures, such as jellyfish, squids, and salps; synthetic jets use vortex rings to create a net thrust. To assess the potential usability of these thrusters for propulsion and maneuvering of small underwater vehicles, a range of synthetic jet

A. M. Polsenberg-Thomas; Joel Burdick; Kamran Mohseni

2005-01-01

155

Synthetic Jet Propulsion for Small Underwater Vehicles  

Microsoft Academic Search

This paper proposes a new synthetic jet actuation concept for small, low speed, highly maneuverable AUVs. Synthetic jet thrusters, which produce jets of vortex rings, are inspired by the pulsatile jet propulsion of salps, jellyfish, and squid. To assess the potential utility of this scheme, we developed synthetic jet actuator prototypes, and verified their function via both force measurement and

Annmarie Polsenberg Thomas; Michele Milano; Maxwell Grazier G'sell; Kathleen Fischer; Joel W. Burdick

2005-01-01

156

Controlling pulsatile jet formation number with variable diameter exit nozzle for maximum impulse generation  

Microsoft Academic Search

Both jellyfish and Squid propel themselves by ejecting high momentum vortex rings. A set of vortex ring generating thrusters were developed and tested for application in underwater vehicle propulsion. Vortex rings generated from a steady piston cylinder mechanism have a universal formation time, known as the formation number (Gharib et al. 1998), associated with reaching maximum circulation, where the vortex

Mike Krieg; Tyler Thomas; Kamran Mohseni

2009-01-01

157

Trophic Structure and Community Stability in an Overfished Ecosystem  

Microsoft Academic Search

Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased predation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and

Anne C. Utne-Palm; Anne G. V. Salvanes; Bronwen Currie; Stein Kaartvedt; Göran E. Nilsson; Victoria A. Braithwaite; Jonathan A. W. Stecyk; Matthias Hundt; Megan van der Bank; Bradley Flynn; Guro K. Sandvik; Thor A. Klevjer; Andrew K. Sweetman; Volker Brüchert; Karin Pittman; Kathleen R. Peard; Ida G. Lunde; Rønnaug A. U. Strandabø; Mark J. Gibbons

2010-01-01

158

Interaction of pressure and momentum driven flows with thin porous media: Experiments and modeling  

Microsoft Academic Search

Flow interaction with thin porous media arise in a variety of natural and man-made settings. Examples include flow through thin grids in electronics cooling, and NOx emissions reduction by means of ammonia injection grids, pulsatile aquatic propulsion with complex trailing anatomy (e.g., jellyfish with tentacles) and microbursts from thunderstorm activity over dense vegetation, unsteady combustion in or near porous materials,

Christian Naaktgeboren

2007-01-01

159

Reconstructing source-sink dynamics in a population with a pelagic dispersal phase.  

PubMed

For many organisms, the reconstruction of source-sink dynamics is hampered by limited knowledge of the spatial assemblage of either the source or sink components or lack of information on the strength of the linkage for any source-sink pair. In the case of marine species with a pelagic dispersal phase, these problems may be mitigated through the use of particle drift simulations based on an ocean circulation model. However, when simulated particle trajectories do not intersect sampling sites, the corroboration of model drift simulations with field data is hampered. Here, we apply a new statistical approach for reconstructing source-sink dynamics that overcomes the aforementioned problems. Our research is motivated by the need for understanding observed changes in jellyfish distributions in the eastern Bering Sea since 1990. By contrasting the source-sink dynamics reconstructed with data from the pre-1990 period with that from the post-1990 period, it appears that changes in jellyfish distribution resulted from the combined effects of higher jellyfish productivity and longer dispersal of jellyfish resulting from a shift in the ocean circulation starting in 1991. A sensitivity analysis suggests that the source-sink reconstruction is robust to typical systematic and random errors in the ocean circulation model driving the particle drift simulations. The jellyfish analysis illustrates that new insights can be gained by studying structural changes in source-sink dynamics. The proposed approach is applicable for the spatial source-sink reconstruction of other species and even abiotic processes, such as sediment transport. PMID:24835251

Chen, Kun; Ciannelli, Lorenzo; Decker, Mary Beth; Ladd, Carol; Cheng, Wei; Zhou, Ziqian; Chan, Kung-Sik

2014-01-01

160

Lagrangian analysis of fluid transport in empirical vortex ring flows  

NASA Astrophysics Data System (ADS)

In this paper we apply dynamical systems analyses and computational tools to fluid transport in empirically measured vortex ring flows. Measurements of quasisteadily propagating vortex rings generated by a mechanical piston-cylinder apparatus reveal lobe dynamics during entrainment and detrainment that are consistent with previous theoretical and numerical studies. In addition, the vortex ring wake of a free-swimming Aurelia aurita jellyfish is measured and analyzed in the framework of dynamical systems to elucidate similar lobe dynamics in a naturally occurring biological flow. For the mechanically generated rings, a comparison of the net entrainment rate based on the present methods with a previous Eulerian analysis shows good correspondence. However, the current Lagrangian framework is more effective than previous analyses in capturing the transport geometry, especially when the flow becomes more unsteady, as in the case of the free-swimming jellyfish. Extensions of these results to more complex flow geometries is suggested.

Shadden, Shawn C.; Dabiri, John O.; Marsden, Jerrold E.

2006-04-01

161

Labeling effects on the isoelectric point of green fluorescent protein  

Microsoft Academic Search

We studied the effects of fluorescent labeling on the isoelectric points (pI values) of proteins using capillary isoelectric focusing with laser-induced fluorescence detection (cIEF–LIF). Specifically, we labeled green fluorescent protein (GFP) from the jellyfish Aequorea victoria with the fluorogenic dye 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ). cIEF–LIF was used to monitor the native fluorescence of GFP and showed pI changes in GFP’s FQ-labeled products.

Dawn P. Richards; Costas Stathakis; Robert Polakowski; Hossein Ahmadzadeh; Norman J. Dovichi

1999-01-01

162

Flexible Margin Kinematics and Vortex Formation of Aurelia aurita and Robojelly  

PubMed Central

The development of a rowing jellyfish biomimetic robot termed as “Robojelly”, has led to the discovery of a passive flexible flap located between the flexion point and bell margin on the Aurelia aurita. A comparative analysis of biomimetic robots showed that the presence of a passive flexible flap results in a significant increase in the swimming performance. In this work we further investigate this concept by developing varying flap geometries and comparing their kinematics with A. aurita. It was shown that the animal flap kinematics can be replicated with high fidelity using a passive structure and a flap with curved and tapered geometry gave the most biomimetic performance. A method for identifying the flap location was established by utilizing the bell curvature and the variation of curvature as a function of time. Flaps of constant cross-section and varying lengths were incorporated on the Robojelly to conduct a systematic study of the starting vortex circulation. Circulation was quantified using velocity field measurements obtained from planar Time Resolved Digital Particle Image Velocimetry (TRDPIV). The starting vortex circulation was scaled using a varying orifice model and a pitching panel model. The varying orifice model which has been traditionally considered as the better representation of jellyfish propulsion did not appear to capture the scaling of the starting vortex. In contrast, the pitching panel representation appeared to better scale the governing flow physics and revealed a strong dependence on the flap kinematics and geometry. The results suggest that an alternative description should be considered for rowing jellyfish propulsion, using a pitching panel method instead of the traditional varying orifice model. Finally, the results show the importance of incorporating the entire bell geometry as a function of time in modeling rowing jellyfish propulsion.

Villanueva, Alex; Vlachos, Pavlos; Priya, Shashank

2014-01-01

163

Green fluorescent protein: an in vivo reporter of plant gene expression  

Microsoft Academic Search

Summary  Protoplasts were isolated from H89, an embryogenic sweet orange (Citrus sinensis (L.) Osbeck cv. Hamlin) suspension culture, and electroporated with p35S-GFP, a plasmid carrying the gene for the green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria. p35S-GFP was constructed by replacing the GUS coding sequence of pBI221 with a functional GFP gene, thereby placing the GFP gene under

Randall P. Niedz; Michael R. Sussman; John S. Satterlee

1995-01-01

164

Bacterial plasmid conjugation on semi-solid surfaces monitored with the green fluorescent protein (GFP) from Aequorea victoria as a marker  

Microsoft Academic Search

Horizontal transfer of the TOL plasmid was examined in Pseudomonas putida (Pp) KT2442 micro-colonies on semi-solid agar surfaces. Horizontal gene transfer is usually studied in large populations where all information is based on average estimates of the transfer events in the entire population. We have used the green fluorescent protein (GFP) from the jellyfish Aequorea victoria as a plasmid marker,

Bjarke Bak Christensen; Claus Sternberg; Soren Molin

1996-01-01

165

Cell-to-Cell and Long-Distance Trafficking of the Green Fluorescent Protein in the Phloem and Symplastic Unloading of the Protein into Sink Tissues  

Microsoft Academic Search

Macromolecular trafficking within the sieve element-companion cell complex, phloem unloading, and post-phloem transport were studied using the jellyfish green fluorescent protein (GFP). The GFP gene was expressed in Arabidopsis and tobacco under the control of the AtSUC2 promoter. In wild-type Arabidopsis plants, this promoter regulates ex- pression of the companion cell-specific AtSUC2 sucrose-H 1 symporter gene. Analyses of the AtSUC2

Astrid Imlau; Elisabeth Truernit; Norbert Sauer

1999-01-01

166

Cruise Speed Characteristics of a Self--Propelled Pulsed-Jet Underwater Vehicle  

Microsoft Academic Search

Steady-jet propulsion has been widely used for air and marine vehicles. This system has a high propulsive efficiency for high vehicle velocities, but it ceases to be efficient as the vehicle velocity or Reynolds number (Re) decreases. One alternative for low Re propulsion is pulsed-jet propulsion similar to that utilized by squid and jellyfish. We have developed a self-propelled pulsed-jet

Ali Moslemi; Justin Nichols; Paul Krueger

2007-01-01

167

Photo-Induced Peptide Cleavage in the Green-to-Red Conversion of a Fluorescent Protein  

Microsoft Academic Search

Green fluorescent protein from the jellyfish (Aequorea GFP) and GFP-like proteins from coral species encode light-absorbing chromophores within their protein sequences. A coral fluorescent protein, Kaede, contains a tripeptide, His62-Tyr63-Gly64, which acts as a green chromophore that is photoconverted to red. Here, we present the structural basis for the green-to-red photoconversion. As in Aequorea GFP, a chromophore, 4-(p-hydroxybenzylidene)-5-imidazolinone, derived from

Hideaki Mizuno; Tapas Kumar Mal; Kit I. Tong; Ryoko Ando; Toshiaki Furuta; Mitsuhiko Ikura; Atsushi Miyawaki

2003-01-01

168

Dietary exposure to aluminium of the Hong Kong population  

Microsoft Academic Search

A total of 256 individual food samples were collected in Hong Kong for aluminium testing. Most of food samples were analysed in ready-to-eat form. High aluminium levels were found in steamed bread\\/bun\\/cake (mean: 100–320 mg kg), some bakery products such as muffin, pancake\\/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg, respectively), and jellyfish (ready-to-eat form)

Waiky W. K. Wong; Stephen W. C. Chung; K. P. Kwong; Yuk Yin Ho; Ying Xiao

2010-01-01

169

Vulnerability of the copepod Acartia tonsa to predation by the scyphomedusa Chrysaora quinquecirrha?: effect of prey size and behavior  

Microsoft Academic Search

Although scyphomedusae have received increased attention in recent years as important predators in coastal and estuarine\\u000a environments, the factors affecting zooplankton prey vulnerability to these jellyfish remain poorly understood. Current models\\u000a predicting feeding patterns of cruising entangling predators, such as Chrysaora quinquecirrha (Desor, 1948), fail to account for the selection of fast-escaping prey such as copepods. Nevertheless, our analysis of

C. L. Suchman; B. K. Sullivan

1998-01-01

170

Biota of a Pennsylvanian muddy coast: habitat within the Mazonian delta complex, northeast Illinois  

SciTech Connect

The Mazon Creek biota (Westphalian D) is composed of plants and animals from terrestrial fresh water and marginal marine habitats. Fossil animals, including jellyfish, worms, crustaceans, holothurians, insects, chordates, and problematica occur in sideritic concretions on spoilpiles of more than 100 abandoned coal mines in a five county region (Mazon Creek area) of northeast Illinois. These fossils record rapid burial and early diagenesis in a muddy, delta-influenced coastal setting submerged during marine transgression.

Baird, G.C.

1985-03-01

171

Flexible margin kinematics and vortex formation of Aurelia aurita and Robojelly.  

PubMed

The development of a rowing jellyfish biomimetic robot termed as "Robojelly", has led to the discovery of a passive flexible flap located between the flexion point and bell margin on the Aurelia aurita. A comparative analysis of biomimetic robots showed that the presence of a passive flexible flap results in a significant increase in the swimming performance. In this work we further investigate this concept by developing varying flap geometries and comparing their kinematics with A. aurita. It was shown that the animal flap kinematics can be replicated with high fidelity using a passive structure and a flap with curved and tapered geometry gave the most biomimetic performance. A method for identifying the flap location was established by utilizing the bell curvature and the variation of curvature as a function of time. Flaps of constant cross-section and varying lengths were incorporated on the Robojelly to conduct a systematic study of the starting vortex circulation. Circulation was quantified using velocity field measurements obtained from planar Time Resolved Digital Particle Image Velocimetry (TRDPIV). The starting vortex circulation was scaled using a varying orifice model and a pitching panel model. The varying orifice model which has been traditionally considered as the better representation of jellyfish propulsion did not appear to capture the scaling of the starting vortex. In contrast, the pitching panel representation appeared to better scale the governing flow physics and revealed a strong dependence on the flap kinematics and geometry. The results suggest that an alternative description should be considered for rowing jellyfish propulsion, using a pitching panel method instead of the traditional varying orifice model. Finally, the results show the importance of incorporating the entire bell geometry as a function of time in modeling rowing jellyfish propulsion. PMID:24905025

Villanueva, Alex; Vlachos, Pavlos; Priya, Shashank

2014-01-01

172

Marine Collagens  

Microsoft Academic Search

\\u000a As a family of proteins with unique structural features, marine invertebrate collagens have been a focus of structure–function\\u000a correlation studies as well as studies interrelating successive levels of structural organization, from the amino acid sequence\\u000a to the anatomically defined fibril. Structural and biochemical peculiarities of marine invertebrates collagens isolated from\\u000a sponges, jellyfishes, molluscs, and echinoderms as well as perspectives of

Hermann Ehrlich

173

Wavelength Mutations and Posttranslational Autoxidation of Green Fluorescent Protein  

Microsoft Academic Search

The green fluorescent protein (GFP) of the jellyfish Aequorea victoria is an unusual protein with strong visible absorbance and fluorescence from a p-hydroxybenzylidene-imidazolidinone chromophore, which is generated by cyclization and oxidation of the protein's own Ser-Tyr-Gly sequence at positions 65-67. Cloning of the cDNA and heterologous expression of fluorescent protein in a wide variety of organisms indicate that this unique

Roger Heim; Douglas C. Prasher; Roger Y. Tsien

1994-01-01

174

Flow cytometric and microscopic analysis of GFP-tagged Pseudomonas fluorescens bacteria  

Microsoft Academic Search

The gene encoding the green fluorescent protein (GFP) from the jellyfish Aequorea victoria was assembled into an expression cassette for bacteria by fusing it to the T7 gene10 ribosome binding site and the strong, constitutive promoter PpsbA from Amaranthus hybridus. By using Tn5-based transposon delivery systems, Pseudomonas fluorescens bacteria were chromosomally tagged with gfp. We demonstrate that expression of a

Riccardo Tombolini; Annika Unge; Mary Ellen Davey; Frans J de Bruijn; Janet K Jansson

1997-01-01

175

Embryonic stem cells and mice expressing different GFP variants for multiple non-invasive reporter usage within a single animal  

Microsoft Academic Search

BACKGROUND: Non-invasive autofluorescent reporters have revolutionized lineage labeling in an array of different organisms. In recent years green fluorescent protein (GFP) from the bioluminescent jellyfish Aequoria Victoria has gained popularity in mouse transgenic and gene targeting regimes 1. It offers several advantages over conventional gene-based reporters, such as lacZ and alkaline phosphatase, in that its visualization does not require a

Anna-Katerina Hadjantonakis; Suzanne Macmaster; Andras Nagy

2002-01-01

176

GFP-Moesin Illuminates Actin Cytoskeleton Dynamics in Living Tissue and Demonstrates Cell Shape Changes during Morphogenesis in Drosophila  

Microsoft Academic Search

Moesin, ezrin, and radixin (MER) are components of the cortical actin cytoskeleton and membrane processes such as filopodia and microvilli. Their C-terminal tails contain an extended region that is predicted to be helical, an actin binding domain, and a region(s) that participates in self-association. We engineered anin vivofluorescent actin binding protein (GFP-moe) by joining sequences that encode the jellyfish green

Kevin A. Edwards; Maddy Demsky; Ruth A. Montague; Nate Weymouth; Daniel P. Kiehart

1997-01-01

177

Acclimation and adaptation to irradiance in symbiotic dinoflagellates. II. Response of chlorophyll–protein complexes to different photon-flux densities  

Microsoft Academic Search

The response of chlorophyll–protein complexes to super- and sub-saturating photon-flux densities, PFD (250??mol quanta m?2?s?1 and 40??mol quanta m?2?s?1, respectively) were analyzed for Symbiodinium microadriaticum Freudenthal, the symbiont of the Caribbean jellyfish Cassiopeia xamachana; S. kawagutii Trench and Blank, the symbiont of the Indo-Pacific scleractinian Montipora verrucosa; and S. pilosum Trench and Blank, the symbiont of the Carribbean zoanthid Zoanthus

R. Iglesias-Prieto; R. K. Trench

1997-01-01

178

Resource requirements of the Pacific leatherback turtle population.  

PubMed

The Pacific population of leatherback sea turtles (Dermochelys coriacea) has drastically declined in the last 25 years. This decline has been linked to incidental capture by fisheries, egg and meat harvesting, and recently, to climate variability and resource limitation. Here we couple growth rates with feeding experiments and food intake functions to estimate daily energy requirements of leatherbacks throughout their development. We then estimate mortality rates from available data, enabling us to raise food intake (energy requirements) of the individual to the population level. We place energy requirements in context of available resources (i.e., gelatinous zooplankton abundance). Estimated consumption rates suggest that a single leatherback will eat upward of 1000 metric tonnes (t) of jellyfish in its lifetime (range 924-1112) with the Pacific population consuming 2.1×10(6) t of jellyfish annually (range 1.0-3.7×10(6)) equivalent to 4.2×10(8) megajoules (MJ) (range 2.0-7.4×10(8)). Model estimates suggest 2-7 yr-old juveniles comprise the majority of the Pacific leatherback population biomass and account for most of the jellyfish consumption (1.1×10(6) t of jellyfish or 2.2×10(8) MJ per year). Leatherbacks are large gelatinous zooplanktivores with consumption to biomass ratios of 96 (up to 192 if feeding strictly on low energy density Cnidarians); they, therefore, have a large capacity to impact gelatinous zooplankton landscapes. Understanding the leatherback's needs for gelatinous zooplankton, versus the availability of these resources, can help us better assess population trends and the influence of climate induced resource limitations to reproductive output. PMID:23071518

Jones, T Todd; Bostrom, Brian L; Hastings, Mervin D; Van Houtan, Kyle S; Pauly, Daniel; Jones, David R

2012-01-01

179

Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil  

Microsoft Academic Search

Retallack, G.J., September, 2007. Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil. Alcheringa 31, 215-240. ISSN 0311-5518.Dickinsonia is a Neoproterozoic, Ediacaran fossil, variously considered a polychaete, turbellarian or annelid worm, jellyfish, polyp, xenophyophoran protist, lichen or mushroom. Its preservation as unskeletonized impressions in quartz sandstones has been attributed to a Neoproterozoic regime of aerobic decay less effective

Gregory J. Retallack

2007-01-01

180

Dynamic Modeling and Control of Biologically Inspired Vortex Ring Thrusters for Underwater Robot Locomotion  

Microsoft Academic Search

A new type of underwater thruster was designed to provide high-accuracy, low-speed maneuvering to underwater robots. Located internal to the vehicle surface, these thrusters have a minimal effect on the forward-drag profile of the vehicle. These thrusters, whose inspiration comes from the natural propulsion of cephalopods and jellyfish, generate control forces by successive ingestion and expulsion of jets of water

Michael Krieg; Kamran Mohseni

2010-01-01

181

Ontogeny of antipredator performance in hatchery-reared Japanese anchovy Engraulis japonicus larvae exposed to visual or tactile predators in relation to turbidity.  

PubMed

Laboratory experiments revealed distinct effects of turbidity on the survival of Japanese anchovy Engraulis japonicus larvae when exposed to either visual (jack mackerel Trachurus japonicus) or tactile (moon jellyfish Aurelia aurita) predators. The experiments were conducted in 30 l tanks with three levels of turbidity obtained by dissolving 0, 50 or 300 mg l(-1) of kaolin. Predators were introduced to experimental tanks followed by larvae of E. japonicus ranging from 5 to 25 mm standard lengths (L(s) ). When exposed to T. japonicus, the mean survival rate of larvae was significantly higher in 300 mg l(-1) treatments compared to the other turbidity levels. When exposed to A. aurita, however, there was no difference in the survival rates among different turbidity treatments. The survival rates when exposed to either predator improved with larval growth. The logistic survivorship models for E. japonicus larvae when exposed to A. aurita had an inflection point at c. 12 mm L(s) , suggesting that their size refuge from A. aurita is close to this value. Comparison to a previous study suggests a high vulnerability of shirasu (long and transparent) fish larvae to jellyfish predation under turbidity. This study indicates that anthropogenic increases of turbidity in coastal waters may increase the relative effect of jellyfish predation on fish larvae. PMID:22141901

Ohata, R; Masuda, R; Yamashita, Y

2011-12-01

182

Reconstruction of the West Pacific ENSO precipitation anomaly using the compound-specific hydrogen isotopic record of marine lake sediments of Palau  

NASA Astrophysics Data System (ADS)

There is still much uncertainty whether the El Niño Southern Oscillation (ENSO) will become stronger or more frequent in a warming global climate. A principal reason for this uncertainty stems from a glaring lack of paleoclimate data in the equatorial Pacific, which hampers model validation. To partly resolve this data deficiency, sediments of three marine anoxic lakes were cored in Palau, an island group that lies in the heart of the West Pacific Warm Pool. The lakes contain seawater that seeps through fissures in the surrounding karst, and they are permanently stratified due to fresh water input provided by the year-round wet climate (map 1970-2000 = 3.7m). During ENSO events, however, the islands suffer from drought. The surface water hydrogen isotopic compositions in the lakes are sensitive to the relative proportions of D-depleted rainwater and D-enriched seawater, and are therefore sensitive to ENSO events. The lake surface water H/D values are recorded by algal and bacterial biomarkers that are preserved well in the highly organic and anoxic sediments, which accumulate relatively fast (mean 1 mm/yr). Ongoing down core measurement will eventually result in a precipitation proxy record of the islands. To obtain endmember D/H values, a comprehensive set of water samples from sea, lakes and rain water was obtained, as well as suspended particulate matter. Higher plant biomarker D/H values derived from the jungle vegetation surrounding the lakes may render supporting climatic proxy data, being influenced by evapotranspiration. Some lakes are inhabited by millions of jellyfish (Mastigias) that live in symbiosis with zooxanthellae. The jellyfish of one of the investigated lakes disappeared completely after the last large ENSO event in 1998 (returning in 2000-01), and a correlation is suggested. To reconstruct the history of jellyfish occurrence, jellyfish and sedimentary lipids were extracted and compared. In addition to a possible ENSO proxy record, this information will contribute to a better understanding of the lake system and ecology of the jellyfish, providing a better basis for conservation efforts.

Smittenberg, R. H.; Sachs, J. P.; Dawson, M. N.

2004-12-01

183

Selective toxin-lipid membrane interactions of natural, haemolytic Scyphozoan toxins analyzed by surface plasmon resonance.  

PubMed

A comparison of the molecular interaction of natural Scyphozoan lysins with their bioactivity in a haemolytic assay was performed by establishing an efficient, automatable and reproducible procedure for the measurement of protein-membrane interactions. The toxin-membrane interactions were analyzed utilising a chip-based technology with immobilized liposomes as artificial cell membranes. The technique was established with streptolysin O as a cholesterol-selective model toxin and its cholesterol-selectivity has been proven. The haemolytic potency of protein fractions derived from the venom of the jellyfish Aurelia aurita and Cyanea capillata was tested and EC50 values of 35.3mug/mL and 43.1mug/mL against sheep and 13.5mug/mL and 8.8mug/mL against rabbit erythrocytes were measured. Cell membrane binding as a first step in the haemolytic process was analyzed using the Biacore((R)) technology. Major cell membrane lipids (cholesterol, sphingomyelin and phosphatidylcholine) were immobilized as pure liposomes and in binary mixtures. A preference for cholesterol and sphingomyelin of both jellyfish species was demonstrated. The specificity of the method was proven with a non-haemolytic A. aurita protein fraction that did not express a lipid binding. Additionally, an inactivated C. capillata lysine with negligible haemolytic activity showed a remaining but reduced adsorption onto lipid layers. The binding level of the lytic venom fraction of these dominant boreal jellyfish species increased as a function of protein concentration. The binding strength was expressed in RU50 values ranging from 12.4mug/mL to 35.4mug/mL, which were in the same order of magnitude as the EC50 values in the haemolytic assay. PMID:20599534

Helmholz, Heike

2010-10-01

184

Effect of Sub-Lethal Exposure to Ultraviolet Radiation on the Escape Performance of Atlantic Cod Larvae (Gadus morhua)  

PubMed Central

The amount of ultraviolet (UV) radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm) that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments): two-spotted goby (Gobiusculus flavescens; a suction predator) and lion's mane jellyfish (Cyanea capillata; a “passive" ambush predator). Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100), escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively) were significantly lower than those of control larvae (75%, 69±4.7 mm respectively). There was a significant difference in survival as well (UV: 35%, Control: 63%). No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%, Control: 74%) in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations.

Fukunishi, Yuichi; Browman, Howard I.; Durif, Caroline M. F.; Bjelland, Reidun M.; Skiftesvik, Anne Berit

2012-01-01

185

Venomous bites, stings, and poisoning.  

PubMed

This article discusses the epidemiology, prevention, clinical features, first aid and medical treatment of venomous bites by snakes, lizards, and spiders; stings by fish, jellyfish, echinoderms, and insects; and poisoning by fish and molluscs, in all parts of the world. Of these envenoming and poisonings, snake bite causes the greatest burden of human suffering, killing 46,000 people each year in India alone and more than 100,000 worldwide and resulting in physical handicap in many survivors. Specific antidotes (antivenoms/antivenins) are available to treat envenoming by many of these taxa but supply and distribution is inadequate in many tropical developing countries. PMID:22632635

Warrell, David A

2012-06-01

186

Bites and stings in travellers  

PubMed Central

As a rule, bites and stings in travellers are merely a nuisance. But it is sensible to be informed about the more serious possibilities which can result. Systemic diseases can be transmitted, the skin lesions from insects can be troublesome and finally, some bites and stings can cause envenoming. Thus, the bather may be harmed by venomous fish stings, sea urchins, jellyfish and in Asian-Pacific waters by sea-snakes. Land hazards include bites or stings by scorpions, spiders, ticks, centipedes, bees, wasps, caterpillars and snakes. The main clinical features of such bites and stings, including treatment and prevention, are outlined.

Reid, H. Alistair

1975-01-01

187

Antarctica Part Two  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet across, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 2 finds Jonathan continuing his exploration of Antarctica including an encounter with a Leopard seal. This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2011-06-06

188

Global Climate Change : The Ross Ice Shelf  

NSDL National Science Digital Library

This video lecture explores the effects of climate change on the Ross Ice Shelf in Antarctica. Slides depict how a large iceberg fell off the Ross Ice Shelf in March 2000. The lecturer describes his expedition to the ice shelf shortly after this event. He describes dives conducted to observe the underwater ecosystems containing krill and jellyfish, and the ocean currents around the icebergs. Facts about the icebergs in Antarctica are presented, and the sensitivity of polar regions to climate is explained. The video is 14 minutes in length.

2007-12-12

189

Leatherback turtles: the menace of plastic.  

PubMed

The leatherback, Dermochelyscoriacea, is a large sea turtle that feeds primarily on jellyfish. Floating plastic garbage could be mistaken for such prey. Autopsy records of 408 leatherback turtles, spanning 123 years (1885-2007), were studied for the presence or absence of plastic in the GI tract. Plastic was reported in 34% of these cases. If only cases from our first report (1968) of plastic were considered, the figure was 37%. Blockage of the gut by plastic was mentioned in some accounts. These findings are discussed in the context of removal of top predators from poorly understood food chains. PMID:19135688

Mrosovsky, N; Ryan, Geraldine D; James, Michael C

2009-02-01

190

Stimulated bacterioplankton growth and selection for certain bacterial taxa in the vicinity of the ctenophore Mnemiopsis leidyi  

PubMed Central

Episodic blooms of voracious gelatinous zooplankton, such as the ctenophore Mnemiopsis leidyi, affect pools of inorganic nutrients and dissolved organic carbon by intensive grazing activities and mucus release. This will potentially influence bacterioplankton activity and community composition, at least at local scales; however, available studies on this are scarce. In the present study we examined effects of M. leidyi on bacterioplankton growth and composition in incubation experiments. Moreover, we examined community composition of bacteria associated with the surface and gut of M. leidyi. High release of ammonium and high bacterial growth was observed in the treatments with M. leidyi relative to controls. Deep 454 pyrosequencing of 16 S rRNA genes showed specific bacterial communities in treatments with M. leidyi as well as specific communities associated with M. leidyi tissue and gut. In particular, members of Flavobacteriaceae were associated with M. leidyi. Our study shows that M. leidyi influences bacterioplankton activity and community composition in the vicinity of the jellyfish. In particular during temporary aggregations of jellyfish, these local zones of high bacterial growth may contribute significantly to the spatial heterogeneity of bacterioplankton activity and community composition in the sea.

Dinasquet, Julie; Granhag, Lena; Riemann, Lasse

2012-01-01

191

Dietary exposure to aluminium of the Hong Kong population.  

PubMed

A total of 256 individual food samples were collected in Hong Kong for aluminium testing. Most of food samples were analysed in ready-to-eat form. High aluminium levels were found in steamed bread/bun/cake (mean: 100-320 mg kg(-1)), some bakery products such as muffin, pancake/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg(-1), respectively), and jellyfish (ready-to-eat form) (mean: 1200 mg kg(-1)). The results demonstrated that aluminium-containing food additives have been widely used in these food products. The average dietary exposure to aluminium for a 60 kg adult was estimated to be 0.60 mg kg(-1) bw week(-1), which amounted to 60% of the new PTWI established by JECFA. The main dietary source was "steamed bread/bun/cake", which contributed to 60% of the total exposure, followed by "bakery products" and "jellyfish", which contributed to 23 and 10% of the total exposure, respectively. However, the estimation did not include the intake of aluminium from natural food sources, food contact materials or other sources (e.g. drinking water). Although the results indicated that aluminium it is unlikely to cause adverse health effect for the general population, the risk to some populations who regularly consume foods with aluminium-containing food additives cannot be ruled out. PMID:20234962

Wong, Waiky W K; Chung, Stephen W C; Kwong, K P; Yin Ho, Yuk; Xiao, Ying

2010-04-01

192

Development of a quantitative real-time PCR for the detection of Tenacibaculum maritimum and its application to field samples.  

PubMed

The development and the application of a quantitative real-time PCR for the detection of Tenacibaculum maritimum are described. A set of primers and probe was designed to amplify a 155-bp fragment specific to the T. maritimum 16S rRNA gene. The test was shown to be very sensitive, able to detect as little as 4.8 DNA copies number ?L(-1) . In addition, the assay was found to have a high degree of repeatability and reproducibility, with a linear dynamic range (R(2) ?=?0.999) extending over 6 log(10) dilutions and a high efficiency (100%). The assay was applied to DNA samples extracted from 48 formalin-fixed paraffin-embedded (FFPE) Atlantic salmon, Salmo salar, gill tissues showing varying degrees of gill pathology (scored 0-3) and from 26 jellyfish samples belonging to the species Phialella quadrata and Muggiaea atlantica. For each sample, the bacterial load was normalised against the level of the salmonid elongation factor alpha 1 (ELF) detected by a second real-time PCR using previously published primers and probe. Tenacibaculum maritimum DNA was detected in 89% of the blocks with no signs of gill disease as well as in 95% of the blocks with mild-to-severe gill pathology. Association between bacterial load and gill pathology severity was investigated. T. maritimum DNA was detected at low level in four of the 26 jellyfish tested. PMID:22724390

Fringuelli, E; Savage, P D; Gordon, A; Baxter, E J; Rodger, H D; Graham, D A

2012-08-01

193

Perfluoroalkyl contaminants in plasma of five sea turtle species: comparisons in concentration and potential health risks.  

PubMed

The authors compared blood plasma concentrations of 13 perfluoroalkyl contaminants (PFCs) in five sea turtle species with differing trophic levels. Wild sea turtles were blood sampled from the southeastern region of the United States, and plasma was analyzed using liquid chromatography tandem mass spectrometry. Mean concentrations of perfluorooctane sulfonate (PFOS), the predominant PFC, increased with trophic level from herbivorous greens (2.41 ng/g), jellyfish-eating leatherbacks (3.95 ng/g), omnivorous loggerheads (6.47 ng/g), to crab-eating Kemp's ridleys (15.7 ng/g). However, spongivorous hawksbills had surprisingly high concentrations of PFOS (11.9 ng/g) and other PFCs based on their trophic level. These baseline concentrations of biomagnifying PFCs demonstrate interesting species and geographical differences. The measured PFOS concentrations were compared with concentrations known to cause toxic effects in laboratory animals, and estimated margins of safety (EMOS) were calculated. Small EMOS (<100), suggestive of potential risk of adverse health effects, were observed for all five sea turtle species for immunosuppression. Estimated margins of safety less than 100 were also observed for liver, thyroid, and neurobehavorial effects for the more highly exposed species. These baseline concentrations and the preliminary EMOS exercise provide a better understanding of the potential health risks of PFCs for conservation managers to protect these threatened and endangered species. PMID:22447337

Keller, Jennifer M; Ngai, Lily; Braun McNeill, Joanne; Wood, Lawrence D; Stewart, Kelly R; O'Connell, Steven G; Kucklick, John R

2012-06-01

194

A new method for the separation of different types of nematocysts from scyphozoa and investigation of proteinaceous toxins utilizing laser catapulting and subsequent mass spectrometry.  

PubMed

Jellyfish have an increasing impact on marine ecology. Cnidocysts bearing stinging cells afford, amongst others, prey capture and defence. Several different types of stinging capsules are found in one species and they are supposed to have specific functions, e.g. paralysing prey or adhering to it. Due to these assumed different roles of the capsules, it is suggested that toxins, which are contained in the capsules, differ in composition. Analysis of distinct types of nematocysts requires an appropriate method for the separation of the different types. Mixtures of types of nematocysts were obtained of two species of jellyfish, Aurelia aurita and Cyanea lamarckii, by maceration of the tissue. These mixtures were treated with a method called laser microdissection and pressure catapulting (LMPC). Optimized maceration methods, which were firstly introduced as a method for this purpose, in conjunction with optimized LMPC parameters lead to sufficient amounts of separated capsules of individual types for subsequent mass-spectrometric analyses. In case of A. aurita, the resulting mass spectra had some constituents in common, whereas in the overall pattern, the two distinct nematocyst types differed. PMID:20336340

Wiebring, Annika; Helmholz, Heike; Sötje, Ilka; Lassen, Stephan; Prange, Andreas; Tiemann, Henry

2010-06-01

195

Recovery of fish stocks in the Seto Inland Sea.  

PubMed

The total amount of fisheries' yield in the Seto Inland Sea in 1999 was 571,000 MT, consisting of 256,000 MT by fishing and 315,000 MT from aquaculture. About 40,000 people engaged in the fishing and aquaculture industries, earned 129 billion yen (1100 million US$) by fishing and 89 billion yen (770 million $US) by aquaculture. The averaged annual catch for the Seto Inland Sea by fishing was 13 MT/km(2). Division into time periods in terms of eutrophication levels can be made: before 1960 when red sea bream were abundant with ecological divergence (before eutrophication), from 1960 to 1990 when the biomass of anchovy was large (during eutrophication), and after 1990 when the jellyfishes were abundant (excessive eutrophication or high N:P ratio). The fish production will decrease in the sea of jellyfishes. Actually, the amount of catch was 462,000 MT in 1982 which decreased 265,000 MT in 1993, corresponding to 43% in twelve years, then keeping the same level. A big reduction was seen in the catches of the spotlined sardine, anchovy, Spanish mackerel, tiger puffer, short-necked clam, sea cucumber and others. The tiger puffer and Spanish mackerel were abundant as predators in the sea of anchovy. The biomass of anchovy was at its maximum in 1986 and decreased to less than one third in 1996. The stocks of tiger puffer and Spanish mackerel greatly decreased because of the higher fishing pressure compared to the anchovy stock. The fishing power of individual fisheries targeting on the tiger puffer and Spanish mackerel increased substantially when fishing vessel and fishing gear improved, resulting in an excessive fishing effort. A large quantity of small immature fishes is usually caught in the Seto Inland Sea, resulting in growth and/or recruitment overfishing for many species. Hence, it is necessary to promote management of the fisheries so as not to reduce the fish stocks, and to allow the Seto Inland Sea to return from being a sea of jellyfishes to a sea of anchovy, with decreased eutrophication levels. PMID:12787608

Nagai, T

2003-01-01

196

Green fluorescent protein: an in vivo reporter of plant gene expression.  

PubMed

Protoplasts were isolated from H89, an embryogenic sweet orange (Citrus sinensis (L.) Osbeck cv. Hamlin) suspension culture, and electroporated with p35S-GFP, a plasmid carrying the gene for the green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria. p35S-GFP was constructed by replacing the GUS coding sequence of pBI221 with a functional GFP gene, thereby placing the GFP gene under the control of the CaMV 35S promoter. Protoplasts were viewed by incident-light fluorescence microscopy twentyfour h after electroporation. 20-60% of the protoplasts emitted an intense green light when illuminated with blue (450-490 nm) light. PMID:24185445

Niedz, R P; Sussman, M R; Satterlee, J S

1995-04-01

197

Integrated trend assessment of ecosystem changes in the Limfjord (Denmark): Evidence of a recent regime shift?  

NASA Astrophysics Data System (ADS)

An integrated ecosystem assessment was carried out for the Limfjord over the period from 1984 to 2008 to describe changes in ecosystem structure and potentially important drivers. The Limfjord is a eutrophic transitional Danish fjord system with the main inflow from the North Sea in the west and main outflow to the Kattegat in the east. We showed that from 1990 to 1995, the ecosystem structure shifted from dominance by demersal fish species (eelpout, whiting, flounder, plaice) to that of pelagic fish species (sprat, herring, sticklebacks), small-bodied fish species (black goby, pipefish), jellyfish, common shore crab, starfish and blue mussels. We interpret this change as a regime shift that showed a similar temporal pattern to regime shifts identified in adjacent seas. The observed changes in trophic interactions and food web reorganisation suggested a non-linear regime shift. The analyses further showed the regime shift to be driven by a combination of anthropogenic pressures and possible interplay with climatic disturbance.

Tomczak, Maciej T.; Dinesen, Grete E.; Hoffmann, Erik; Maar, Marie; Støttrup, Josianne G.

2013-01-01

198

Evaluation of a GFP Report Gene Construct for Environmental Arsenic Detection  

SciTech Connect

Detection of arsenic and other heavy metal contaminants in the environment is critical to ensuring safe drinking water and effective cleanup of historic activities that have led to widespread contamination of soil and groundwater. Biosensors have the potential to significantly reduce the costs associated with site characterization and long term environmental monitoring. By exploiting the highly selective and sensitive natural mechanisms by which bacteria and other living organisms respond to heavy metals, and fusing transcriptionally active components of these mechanisms to reporter genes, such as B-galactosidase, bacterial luciferase (lux), or green fluorescent protein (GFP) from marine jellyfish, it is possible to produce inexpensive, yet effective biosensors. This article describes the response to submicrogram quantities of arsenite and arsenate of a whole cell arsenic biosensor utilizing a GFP reporter gene.

Roberto, F.F.; Barnes, J.M.; Bruhn, D.F.

2002-03-28

199

Portuguese man-of-war envenomation.  

PubMed

Portuguese man-of-war and jellyfish stings are common occurrence in the coastal waters of the southern United States. Signs and symptoms of Portuguese man-of-war envenomation usually appear immediately following a sting but may be delayed for several hours. Reactions are commonly localized and comprise pain, paresthesia, and intense burning with a linear, red, papular eruption or urticaria at the contact site. Systemic signs may include nausea, myalgia, headache, chills, or pallor. Cardiovascular collapse and death have been reported. Venom can be inactivated with dilute acetic acid (vinegar), proteolytic meat tenderizer, or baking soda. Tentacle debris should be removed. Resolution of symptoms usually occurs within 72 hours, without sequelae. PMID:1351283

Kaufman, M B

1992-02-01

200

Variability of satellite derived chlorophyll-a in the southern Caspian Sea following an invasion of ctenophore Mnemiopsis leidyi  

NASA Astrophysics Data System (ADS)

The comb jellyfish Mnemiopsis leidyi invaded vastly the whole Caspian Sea in summer 2001. Sea-viewing wide field-of-view sensor and moderate resolution imaging spectroradiometer (MODIS) satellite data from 1998 to 2006 and bio-optical field measurements along six transects in the southern Caspian Sea from 2001 to 2006 were used to detect the relationships between M. leidyi abundances with satellite driven sea surface temperature (SST) and chlorophyll-a. MODIS chlorophyll-a and SST monthly composite average value showed a positive linear correlation with M. leidyi abundance in the southern Caspian Sea. Spatiotemporal distribution of MODIS chlorophyll-a high-level patches (˜5 mg.m-3) were also confirmed with the highest recorded M. leidyi and the lowest zooplankton abundances. However, there are several other factors that affect the concentration of chlorophyll-a, and it is not clear how much of the chlorophyll-a variation is related to M. leidyi abundances.

Moradi, Masoud

2013-01-01

201

Fluorescence imaging in the last two decades  

PubMed Central

In commemoration of the 20th anniversary of the molecular cloning of the gene for the green fluorescent protein from the jellyfish Aequorea victoria, I would like to reflect on the development of new fluorescence imaging technology in the last two decades. As this technology has become increasingly diversified, it has become more and more of a challenge to come up with a comprehensive and exhaustive review of it. Here I will focus on optogenetics and large-scale, three-dimensional reconstruction. Those two technological innovations have been achieved in the neuroscience community owing to the combined efforts of molecular biologists and light microscopists. In addition, modern fluorescence imaging has indeed improved our understanding of the spatiotemporal regulation of fundamental biological functions at cellular level. As an example, I will introduce some findings we made regarding the movement of biomolecules across the nuclear membrane. The above-mentioned imaging approaches are possible today but were impossible two decades ago.

Miyawaki, Atsushi

2013-01-01

202

Man-induced hydrological changes, metazooplankton communities and invasive species in the Berre Lagoon (Mediterranean Sea, France).  

PubMed

The Berre Lagoon has been under strong anthropogenic pressure since the early 1950s. The opening of the hydroelectric EDF power plant in 1966 led to large salinity drops. The zooplankton community was mainly composed of two common brackish species: Acartia tonsa and Brachionus plicatilis. Since 2006, European litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. A study was performed between 2008 and 2010 to evaluate how these modifications have impacted the zooplankton community. Our results show that the community is more diverse and contains several coastal marine species (i.e., Centropages typicus, Paracalanus parvus and Acartia clausi). A. tonsa is still present but is less abundant, whereas B. plicatilis has completely disappeared. Strong predatory marine species, such as chaetognaths, the large conspicuous autochtonous jellyfish Aurelia aurita and the invasive ctenophore Mnemiopsis leidyi, are now very common as either seasonal or permanent features of the lagoon. PMID:22776776

Delpy, Floriane; Pagano, Marc; Blanchot, Jean; Carlotti, François; Thibault-Botha, Delphine

2012-09-01

203

Impact of secondary hard substrate on the distribution and abundance of Aurelia aurita in the western Baltic Sea.  

PubMed

This study assessed the impact of secondary hard substrate, as being introduced into marine ecosystems by the establishment of wind farm pillars, on the occurrence and distribution of the moon jelly Aurelia aurita in the southwestern Baltic Sea. A two-year data sampling was conducted with removable settlement plates to assess the distribution and population development of the scyphozoan polyps. The data collected from these samples were used to set up a model with Lagrangian particle technique. The results confirm that anthropogenic created hard substrate (e.g. offshore wind farms) has the potential to increase the abundance of the A. aurita population. The distribution of wind farm borne jellyfish along Danish, German and Polish coasts indicates conflicts with further sectors, mainly energy and tourism. PMID:23987093

Janßen, H; Augustin, C B; Hinrichsen, H H; Kube, S

2013-10-15

204

[Accidents with venomous and poisonous animals in Central Europe].  

PubMed

Central Europe is largely safe from accidents with venomous and poisonous animals. The regions where European vipers are regularly found are shrinking. Today accidents with jellyfish and stings of venomous fish afflicted during leisure activities at the sea side play the dominant role. Life threatening accidents in Europe are mainly due to exotic snakes held in captivity. A system useful in daily medical practice is explained to classify and stage accidents due to poisonous and venomous animals. The important poisonous and venomous animals of Central Europe and the specific therapeutics, the antivenoms, are covered. The antivenom depot "Antivenin-CH" of the Swiss Toxicology Information Centre in Zurich and the MRITox in Munich with the antivenom registry Munich AntiVenom INdex (MAVIN) are presented. PMID:19401985

Bodio, Mauro; Junghanss, Thomas

2009-05-01

205

Genetically modified plants for tactical systems applications  

NASA Astrophysics Data System (ADS)

Plants are ubiquitous in the environment and have the ability to respond to their environment physiologically and through altered gene expression profiles (they cannot walk away). In addition, plant genetic transformation techniques and genomic information in plants are becoming increasingly advanced. We have been performing research to express the jellyfish green fluorescent protein (GFP) in plants. GFP emits green light when excited by blue or UV light. In addition, my group and collaborators have developed methods to detect GFP in plants by contact instruments and at a standoff. There are several tactical uses for this technology. Some obvious applications are using plants as sentinels for detecting biological and chemical warfare agents or their derivatives from a remote platform, as well as detecting explosives. Another tactical application is covert monitoring using individual plants. Different methods to detect GFP in transgenic plants will be discussed.

Stewart, C. Neal, Jr.

2002-08-01

206

Spacelab Life Sciences 1 - The stepping stone  

NASA Technical Reports Server (NTRS)

The Spacelab Life Sciences (SLS-1) mission scheduled for launch in March 1990 will study the effects of microgravity on physiological parameters of humans and animals. The data obtained will guide equipment design, performance of activities involving the use of animals, and prediction of human physiological responses during long-term microgravity exposure. The experiments planned for the SLS-1 mission include a particulate-containment demonstration test, integrated rodent experiments, jellyfish experiments, and validation of the small-mass measuring instrument. The design and operation of the Research Animal Holding Facility, General-Purpose Work Station, General-Purpose Transfer Unit, and Animal Enclosure Module are discussed and illustrated with drawings and diagrams.

Dalton, B. P.; Leon, H.; Hogan, R.; Clarke, B.; Tollinger, D.

1988-01-01

207

A genomic view of 500 million years of cnidarian evolution  

PubMed Central

Cnidarians (corals, anemones, jellyfish, and hydras) are a diverse group of animals of interest to evolutionary biologists, ecologists, and developmental biologists. With the publication of the genome sequences of Hydra and Nematostella, whose last common ancestor was the stem cnidarian, we are beginning to see the genomic underpinnings of cnidarian biology. Cnidarians are known for the remarkable plasticity of their morphology and life cycles. This plasticity is reflected in the Hydra and Nematostella genomes, which differ to an exceptional degree in size, base composition, transposable element content, and gene conservation. We now know what cnidarian genomes are capable of doing given 500 million years; the next challenge is to understand how this genomic history has led to the striking diversity we see in cnidarians.

Steele, Robert E.; David, Charles N.; Technau, Ulrich

2010-01-01

208

The alkaloid Ageladine A, originally isolated from marine sponges, used for pH-sensitive imaging of transparent marine animals.  

PubMed

The brominated pyrrole-imidazole Ageladine A was used for live imaging of the jellyfish (jellies) Nausithoe werneri, the sea anemone Metridium senile and the flatworm Macrostomum lignano. The fluorescence properties of Ageladine A allow for estimation of pH values in tissue and organs in living animals. The results showed that Nausithoe werneri had the most acidic areas in the tentacles and close to the mouth (pH 4-6.5), Metridium senile harbours aggregates of high acidity in the tentacles (pH 5) and in Macrostomum lignano, the rhabdoids, the gonads and areas close to the mouth were the most acidic with values down to pH 5. PMID:22363232

Bickmeyer, Ulf

2012-01-01

209

Optical studies of dynamical processes in fluorescent proteins  

NASA Astrophysics Data System (ADS)

Green fluorescent protein (GFP) extracted from the bioluminescent jellyfish Aequorea Victoria[1] and its mutants are novel nanoscale systems, which have been shown to exhibit desirable linear and nonlinear optical properties[2]. In this paper, a combination of both linear and nonlinear optical spectroscopic techniques was used to investigate dynamical processes in fluorescent proteins in both aqueous solution and an organic polymer matrix. Experimental results were analyzed in terms of a Brownian oscillator model[3] and by comparison to computer simulations. [1] M. Chalfie, G. Euskirchen, W. W. Ward and D. C. Prasher, Science 263 (1994) 802. [2] Sean M. Kirkpatrick, Rajesh R. Naik, Morley O. Stone, J. Phys. Chem. B 105 (2001) 2867. [3] S. Mukamel, "Nonlinear Optical Spectroscopy", (Oxford University Press, New York, 1995) pp. 227.

Liebig, Carl; Dennis, William; Kirkpatrick, Sean; Naik, Rajesh; Stone, Morley

2002-03-01

210

Antarctica Part One  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet wide, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 1 finds Jonathan diving in Ushuaia, Patagonia in Argentina before boarding the ship to Antarctica, then he finally gets to Antarctica and meets some penguins! This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2011-05-04

211

Fabrication and observation of nanowire-assemblages of Si-Ge  

NASA Astrophysics Data System (ADS)

A few of the interesting structures made by the assemblage of Si-Ge nanowires fabricated by the floating-zone melting-vapor method have been observed. They reveal shapes that are similar to coral, jellyfish and sea anemones. The pre-sintered substrate bar has some large crystalline particles (1-15 ?m), which produce sites that are energetically predisposed to nucleation. The peculiar structures created by the assemblage of Si-Ge nanowires form on favored nucleation sites that consist of numerous bundles of nanowires with diameters of 20-50 nm. The periodic variation in the diameter of the bundles of nanowires is a common feature of these structures. In addition, a growth mechanism assisted by the coexistence of Ge and Si-Ge oxides is suggested. The growth process of these assemblages opens up new possibilities for the study of the growth mechanism of Si-Ge nanowires.

Hu, Q.; Araki, H.; Suzuki, H.; Ishikawa, N.; Yang, W.; Noda, T.

212

Chesapeake Bay Program: Field Guide  

NSDL National Science Digital Library

This site describes the biota of the Chesapeake Bay, including mammals, fish, reptiles, amphibians, and crabs and shellfish. Lower food web organisms described are plankton, benthos, Shipworm, Bristle Worm, Jellyfish, Red Beard Sponge, Sea Squirt, Comb Jellies, and the Ghost Anemone. The description of the flora is confined to bay grasses, which are also known as submerged aquatic vegetation (SAV). Birds described at this site include Bald Eagle, Bufflehead, Osprey, Great Blue Heron, Eastern Screech-Owl, Gulls, Ruddy Duck, Carolina Chickadee, Ruddy Turnstone, and the large group known as waterfowl. The site also includes a special section on invasive species, and provides links to publications, status and trends, and extensive databases that include water quality, living resources, point sources, modeling, and cross-cutting indicators.

213

Occupational health issues in marine and freshwater research  

PubMed Central

Marine and freshwater scientists are potentially exposed to a wide variety of occupational hazards. Depending on the focus of their research, risks may include animal attacks, physiological stresses, exposure to toxins and carcinogens, and dangerous environmental conditions. Many of these hazards have been investigated amongst the general population in their recreational use of the environment; however, very few studies have specifically related potential hazards to occupational exposure. For example, while the incidence of shark and crocodile attacks may invoke strong emotions and the occupational risk of working with these animals is certainly real, many more people are stung by jellyfish or bitten by snakes or dogs each year. Furthermore, a large proportion of SCUBA-related injuries and deaths are incurred by novice or uncertified divers, rather than professional divers using aquatic environments. Nonetheless, marine and freshwater research remains a potentially risky occupation, and the likelihood of death, injury and long-term health impacts still needs to be seriously considered.

2012-01-01

214

Multispecies impingement in a tropical power plant, Straits of Malacca.  

PubMed

Marine organisms comprised about 70% of the total impinged materials by weight at water intake screens in the Kapar Power Station (KPS), Malaysia. The general groupings of 'fish', 'shrimp', 'crab', 'cephalopod' and 'others' contributed 26% (87 species), 65% (29), 2% (17), 2% (3) and 5% (42) of the total number of impinged organisms, respectively. In general, higher impingement occurred during spring tide, at nighttime and in shallow water. The glass perchlet, anchovies, ponyfishes, mojarra, catfishes, hairtail, scat and young croakers were the most vulnerable fishes. Vulnerable invertebrates included cephalopods, sea urchin, rockshells and jellyfishes, but penaeid shrimps were the most susceptible in terms of both mortality and body injury. Annually, KPS is estimated to kill 8.5 x 10(6) marine organisms (42 tons) by impingement. This amount, however, is minimal compared to commercial fishery harvests. Multispecies impingement at Malaysian power plants poses the problem of finding the best mitigation options for tropical situations. PMID:20338631

Azila, A; Chong, V C

2010-07-01

215

Development of Plant Gene Vectors for Tissue-Specific Expression Using GFP as a Reporter Gene  

NASA Technical Reports Server (NTRS)

Reporter genes are widely employed in plant molecular biology research to analyze gene expression and to identify promoters. Gus (UidA) is currently the most popular reporter gene but its detection requires a destructive assay. The use of jellyfish green fluorescent protein (GFP) gene from Aequorea Victoria holds promise for noninvasive detection of in vivo gene expression. To study how various plant promoters are expressed in sweet potato (Ipomoea batatas), we are transcriptionally fusing the intron-modified (mGFP) or synthetic (modified for codon-usage) GFP coding regions to these promoters: double cauliflower mosaic virus 35S (CaMV 35S) with AMV translational enhancer, ubiquitin7-intron-ubiquitin coding region (ubi7-intron-UQ) and sporaminA. A few of these vectors have been constructed and introduced into E. coli DH5a and Agrobacterium tumefaciens EHA105. Transient expression studies are underway using protoplast-electroporation and particle bombardment of leaf tissues.

Jackson, Jacquelyn; Egnin, Marceline; Xue, Qi-Han; Prakash, C. S.

1997-01-01

216

The Alkaloid Ageladine A, Originally Isolated from Marine Sponges, Used for pH-Sensitive Imaging of Transparent Marine Animals  

PubMed Central

The brominated pyrrole-imidazole Ageladine A was used for live imaging of the jellyfish (jellies) Nausithoe werneri, the sea anemone Metridium senile and the flatworm Macrostomum lignano. The fluorescence properties of Ageladine A allow for estimation of pH values in tissue and organs in living animals. The results showed that Nausithoe werneri had the most acidic areas in the tentacles and close to the mouth (pH 4–6.5), Metridium senile harbours aggregates of high acidity in the tentacles (pH 5) and in Macrostomum lignano, the rhabdoids, the gonads and areas close to the mouth were the most acidic with values down to pH 5.

Bickmeyer, Ulf

2012-01-01

217

Identification of two novel cytolysins from the hydrozoan Olindias sambaquiensis (Cnidaria)  

PubMed Central

Background Although the hydrozoan Olindias sambaquiensis is the most common jellyfish associated with human envenomation in southeastern and southern Brazil, information about the composition of its venom is rare. Thus, the present study aimed to analyze pharmacological aspects of O. sambaquiensis venom as well as clinical manifestations observed in affected patients. Crude protein extracts were prepared from the tentacles of animals; peptides and proteins were sequenced and submitted to circular dichroism spectroscopy. Creatine kinase, cytotoxicity and hemolytic activity were evaluated by specific methods. Results We identified two novel cytolysins denominated oshem 1 and oshem 2 from the tentacles of this jellyfish. The cytolysins presented the amino acid sequences NEGKAKCGNTAGSKLTFKSADECTKTGQK (oshem 1) and NNSKAKCGDLAGWSKLTFKSADECTKTGQKS (oshem 2) with respective molecular masses of 3.013 kDa and 3.375 kDa. Circular dichroism revealed that oshem 1 has random coils and small ?-helix conformation as main secondary structure whereas oshem 2 presents mainly random coils as its main secondary structure probably due to the presence of W (13) in oshem 2. The hemolysis levels induced by oshem 1 and oshem 2 using a peptide concentration of 0.2 mg/mL were, respectively, 51.7 ± 6.5% and 32.9 ± 8.7% (n = 12 and p ? 0.05). Oshem 1 and oshem 2 showed significant myonecrotic activity, evaluated by respective CK level measurements of 1890.4 ± 89 and 1212.5 ± 103 (n = 4 and p ? 0.05). In addition, myonecrosis was also evaluated by cell survival, which was measured at 72.4 ± 8.6% and 83.5 ± 6.7% (n = 12 and p ? 0.05), respectively. The structural analysis showed that both oshem 1 and oshem 2 should be classified as a small basic hemolytic peptide. Conclusion The amino acid sequences of two peptides were highly similar while the primary amino acid sequence analysis revealed W (22th) as the most important mutation. Finally oshem 1 and oshem 2 are the first cytolytic peptides isolated from the Olindias sambaquiensis and should probably represent a novel class of cytolytic peptides.

2014-01-01

218

Modeling and Thrust Optimization of a Bio-Inspired Pulsatile Jet Thruster  

NASA Astrophysics Data System (ADS)

A new type of thruster technology offers promising low speed maneuvering capabilities for underwater vehicles. Similar to the natural locomotion of squid and jellyfish the thruster successively forces fluid jets in and out of a small internal cavity. We investigate several properties of squid and jellyfish locomotion to drive the thruster design including actuation of nozzle geometry and vortex ring thrust augmentation. The thrusters are compact with no extruding components to negatively impact the vehicle's drag. These devices have thrust rise-times orders of magnitude faster than those reported for typical propeller thrusters, making them an attractive option for high accuracy underwater vehicle maneuvering. The dynamics of starting jet circulation, impulse, and kinetic energy are derived in terms of kinematics at the entrance boundary of a semi-infinite domain, specifically identifying the effect of a non-parallel incoming flow. A model for pressure at the nozzle is derived without the typical reliance on a predetermined potential function, making it a powerful tool for modeling any jet flow. Jets are created from multiple nozzle configurations to validate these models, and velocity and vorticity fields are determined using DPIV techniques. A converging starting jet resulted in circulation 90--100%, impulse 70--75%, and energy 105--135% larger than a parallel starting jet with identical volume flux and piston velocity, depending on the stroke ratio. The new model is a much better predictor of the jet properties than the standard 1D slug model. A simplified thrust model, was derived to describe the high frequency thruster characteristics. This model accurately predicts the average thrust, measured directly, for stroke ratios up to a critical value where the leading vortex ring separates from the remainder of the shear flow. A new model predicting the vortex ring pinch-off process is developed based on characteristic centerline velocities. The vortex ring pinch-off is coincides with this velocity criterion, for all cases tested. Piston velocity program and nozzle radius are optimized with respect to average thrust, and a quantity similar to propulsive efficiency. The average thrust is maximized by a critical nozzle radius. An approximate linear time-invariant (LTI) model of the thruster vehicle system was derived which categorizes maneuvers into different characteristic regimes. Initial thruster testing showed that open and closed loop frequency response were sufficiently approximated by the LTI model, and that the thruster is ideally suited for small scale high accuracy maneuvers.

Krieg, Michael W.

219

Proton nuclear magnetic resonance and fluorescence spectroscopic studies of segmental mobility in aequorin and a green fluorescent protein from Aequorea forskalea  

SciTech Connect

Aequorin is a protein of low molecular weight (20,000) isolated from the jellyfish Aequorea forskalea which emits blue light upon the binding of Ca/sup 2 +/ ions. This bioluminescence requires neither exogenous oxygen nor any other cofactors. The light emission occurs from an excited state of a chromophore (an imidazolopyrazinone) which is tightly and noncovalently bound to the protein. Apparently the binding of Ca/sup 2 +/ by the protein induces changes in the protein conformation which allow oxygen, already bound or otherwise held by the protein, to react with and therein oxidize the chromophore. The resulting discharged protein remains intact, with the Ca/sup 2 +/ and the chromophore still bound, but is incapable of further luminescence. The fluorescence spectrum of this discharged protein and the bioluminescence spectrum of the original charged aequorin are identical. A green fluorescent protein (GFP) of approx. 30,000 mol wt isolated from the same organism, functions in vivo as an acceptor of energy from aequorin and subsequently emits green light. We are applying proton nuclear magnetic resonance (NMR) spectroscopy and fluorescence spectroscopy to examine structural details of, and fluctuations associated with the luminescent reaction of aequorin and the in vivo energy transfer from aequorin to the GFP.

Nageswara Rao, B.D. (Indiana Univ. Purdue Univ., Indianapolis); Kemple, M.D.; Prendergast, F.G.

1980-10-01

220

Creatures of Light  

NSDL National Science Digital Library

What exactly are "creatures of light?" As it happens, they are those organisms that employ bioluminescence, the "generation of light by living things." This dramatic online exhibit from the American Museum of Natural History complements an in situ exhibit that explores the world of these creatures. The materials here are divided into four primary sections, including Meet the Curator, Behind the Scenes, and Creatures. In the Creatures area, visitors can learn more about bioluminescence through a series of interactive visual features. This area also includes detailed explorations of the lives of fireflies, glowworms, and jellyfish. Moving on, the Meet the Curator area affords visitors the opportunity to learn about Dr. John Sparks and read some of his blog posts on the exhibit. Finally, the Videos area contains snippets of coverage on the creation of the exhibit, a behind-the-scenes tour with Dr. Melanie Stiassny, and a profile of researchers at the Monterey Bay Aquarium as they search for jellies from the deep.

221

An endogenous green fluorescent protein-photoprotein pair in Clytia hemisphaerica eggs shows co-targeting to mitochondria and efficient bioluminescence energy transfer.  

PubMed

Green fluorescent proteins (GFPs) and calcium-activated photoproteins of the aequorin/clytin family, now widely used as research tools, were originally isolated from the hydrozoan jellyfish Aequora victoria. It is known that bioluminescence resonance energy transfer (BRET) is possible between these proteins to generate flashes of green light, but the native function and significance of this phenomenon is unclear. Using the hydrozoan Clytia hemisphaerica, we characterized differential expression of three clytin and four GFP genes in distinct tissues at larva, medusa and polyp stages, corresponding to the major in vivo sites of bioluminescence (medusa tentacles and eggs) and fluorescence (these sites plus medusa manubrium, gonad and larval ectoderms). Potential physiological functions at these sites include UV protection of stem cells for fluorescence alone, and prey attraction and camouflaging counter-illumination for bioluminescence. Remarkably, the clytin2 and GFP2 proteins, co-expressed in eggs, show particularly efficient BRET and co-localize to mitochondria, owing to parallel acquisition by the two genes of mitochondrial targeting sequences during hydrozoan evolution. Overall, our results indicate that endogenous GFPs and photoproteins can play diverse roles even within one species and provide a striking and novel example of protein coevolution, which could have facilitated efficient or brighter BRET flashes through mitochondrial compartmentalization. PMID:24718596

Fourrage, Cécile; Swann, Karl; Gonzalez Garcia, Jose Raul; Campbell, Anthony K; Houliston, Evelyn

2014-01-01

222

Ecological extinction and evolution in the brave new ocean  

PubMed Central

The great mass extinctions of the fossil record were a major creative force that provided entirely new kinds of opportunities for the subsequent explosive evolution and diversification of surviving clades. Today, the synergistic effects of human impacts are laying the groundwork for a comparably great Anthropocene mass extinction in the oceans with unknown ecological and evolutionary consequences. Synergistic effects of habitat destruction, overfishing, introduced species, warming, acidification, toxins, and massive runoff of nutrients are transforming once complex ecosystems like coral reefs and kelp forests into monotonous level bottoms, transforming clear and productive coastal seas into anoxic dead zones, and transforming complex food webs topped by big animals into simplified, microbially dominated ecosystems with boom and bust cycles of toxic dinoflagellate blooms, jellyfish, and disease. Rates of change are increasingly fast and nonlinear with sudden phase shifts to novel alternative community states. We can only guess at the kinds of organisms that will benefit from this mayhem that is radically altering the selective seascape far beyond the consequences of fishing or warming alone. The prospects are especially bleak for animals and plants compared with metabolically flexible microbes and algae. Halting and ultimately reversing these trends will require rapid and fundamental changes in fisheries, agricultural practice, and the emissions of greenhouse gases on a global scale.

Jackson, Jeremy B. C.

2008-01-01

223

Biomimetic and live medusae reveal the mechanistic advantages of a flexible bell margin.  

PubMed

Flexible bell margins are characteristic components of rowing medusan morphologies and are expected to contribute towards their high propulsive efficiency. However, the mechanistic basis of thrust augmentation by flexible propulsors remained unresolved, so the impact of bell margin flexibility on medusan swimming has also remained unresolved. We used biomimetic robotic jellyfish vehicles to elucidate that propulsive thrust enhancement by flexible medusan bell margins relies upon fluid dynamic interactions between entrained flows at the inflexion point of the exumbrella and flows expelled from under the bell. Coalescence of flows from these two regions resulted in enhanced fluid circulation and, therefore, thrust augmentation for flexible margins of both medusan vehicles and living medusae. Using particle image velocimetry (PIV) data we estimated pressure fields to demonstrate a mechanistic basis of enhanced flows associated with the flexible bell margin. Performance of vehicles with flexible margins was further enhanced by vortex interactions that occur during bell expansion. Hydrodynamic and performance similarities between robotic vehicles and live animals demonstrated that the propulsive advantages of flexible margins found in nature can be emulated by human-engineered propulsors. Although medusae are simple animal models for description of this process, these results may contribute towards understanding the performance of flexible margins among other animal lineages. PMID:23145016

Colin, Sean P; Costello, John H; Dabiri, John O; Villanueva, Alex; Blottman, John B; Gemmell, Brad J; Priya, Shashank

2012-01-01

224

Fluorescence in insects  

NASA Astrophysics Data System (ADS)

Fluorescent molecules are much in demand for biosensors, solar cells, LEDs and VCSEL diodes, therefore, considerable efforts have been expended in designing and tailoring fluorescence to specific technical applications. However, naturally occurring fluorescence of diverse types has been reported from a wide array of living organisms: most famously, the jellyfish Aequorea victoria, but also in over 100 species of coral and in the cuticle of scorpions, where it is the rule, rather than the exception. Despite the plethora of known insect species, comparatively few quantitative studies have been made of insect fluorescence. Because of the potential applications of natural fluorescence, studies in this field have relevance to both physics and biology. Therefore, in this paper, we review the literature on insect fluorescence, before documenting its occurrence in the longhorn beetles Sternotomis virescens, Sternotomis variabilis var. semi rufescens, Anoplophora elegans and Stellognatha maculata, the tiger beetles Cicindela maritima and Cicindela germanica and the weevil Pachyrrhynchus gemmatus purpureus. Optical features of insect fluorescence, including emitted wavelength, molecular ageing and naturally occurring combinations of fluorescence with bioluminescence and colour-producing structures are discussed.

Welch, Victoria L.; Van Hooijdonk, Eloise; Intrater, Nurit; Vigneron, Jean-Pol

2012-10-01

225

Diagnosis and management of injuries from dangerous marine life.  

PubMed

Injuries from marine life encompass a wide spectrum, from mild stings to severe bites. Fortunately most of the injuries are mild, although some may be significant, resulting in death. Most of these injuries can be treated by family physicians with a knowledge of the cause of the pathology. Over the years, there have been many treatment options. Some have actually caused an increase in severity. An important rule in treating these injuries is to inactivate the venom, treat the local reaction or injury, and treat the systemic sequelae. Jellyfish stings are the most common type of marine injury. The tentacles possess nematocysts, which are stinging units that are inactivated by the application of vinegar. Sea urchin and stingray injuries require the removal of the imbedded spines after the wound is soaked in hot water. Coral, sea bathers eruption, and swimmer's itch require thorough scrubbing and irrigation. Sea snakes, cone shells, and venomous fish possess a neurotoxin that requires close monitoring in the event of cardiopulmonary collapse. All of these injuries require tetanus status monitoring and consideration of coverage for infectious sequelae. PMID:16369231

Brown, Thomas P

2005-01-01

226

Tox-Prot, the toxin protein annotation program of the Swiss-Prot protein knowledgebase.  

PubMed

The Tox-Prot program was initiated in order to provide the scientific community a summary of the current knowledge on animal protein toxins. The aim of this program is to systematically annotate all proteins which act as toxins and are produced by venomous and poisonous animals. Venomous animals such as snakes, scorpions, spiders, jellyfish, insects, cone snails, sea anemones, lizards, some fish, and platypus are equipped with a specialized organ to inject venom in their prey. In contrast, poisonous animals such as some fish or worms, lack such organs. Each toxin is annotated according to the quality standards of Swiss-Prot. This means providing a wealth of information that includes the description of the function, domain structure, subcellular location, tissue specificity, variants, similarities to other proteins, keywords, etc. In the framework of this program, particular care has been made to capture what is known on the function and mode of action, posttranslational modifications and 3D structural data which are all relatively abundant in the field of protein toxins. Researchers are welcome to contribute their knowledge to the scientific community by submitting relevant findings to Swiss-Prot concerning toxins at Tox-Prot@isb-sib.ch. More information on Tox-Prot can be found at http://www.expasy.org/sprot/tox-prot. PMID:15683867

Jungo, Florence; Bairoch, Amos

2005-03-01

227

Medically important venomous animals: biology, prevention, first aid, and clinical management.  

PubMed

Venomous animals are a significant health problem for rural populations in many parts of the world. Given the current level of the international mobility of individuals and the inquisitiveness of travelers, clinicians and travel clinics need to be able to give advice on the prevention, first aid, and clinical management of envenoming. Health professionals often feel overwhelmed by the taxonomy of venomous animals; however, venomous animals can be grouped, using a simple set of criteria, into cnidarians, venomous fish, sea snakes, scorpions, spiders, hymenoterans, and venomous terrestrial snakes. Geographic distribution, habitats, and circumstances of accidents further reduce the range of culprits that need to be considered in any single event. Clinical management of envenomed patients relies on supportive therapy and, if available, specific antivenoms. Supplies of life-saving antivenoms are scarce, and this scarcity particularly affects rural populations in resource-poor settings. Travel clinics and hospitals in highly industrialized areas predominantly see patients with injuries caused by accidents involving marine animals: in particular, stings by venomous fish and skin damage caused by jellyfish. However, globally, terrestrial venomous snakes are the most important group of venomous animals. PMID:17051499

Junghanss, Thomas; Bodio, Mauro

2006-11-15

228

Xenopus Nanos1 is required to prevent endoderm gene expression and apoptosis in primordial germ cells  

PubMed Central

Nanos is expressed in multipotent cells, stem cells and primordial germ cells (PGCs) of organisms as diverse as jellyfish and humans. It functions together with Pumilio to translationally repress targeted mRNAs. Here we show by loss-of-function experiments that Xenopus Nanos1 is required to preserve PGC fate. Morpholino knockdown of maternal Nanos1 resulted in a striking decrease in PGCs and a loss of germ cells from the gonads. Lineage tracing and TUNEL staining reveal that Nanos1-deficient PGCs fail to migrate out of the endoderm. They appear to undergo apoptosis rather than convert to normal endoderm. Whereas normal PGCs do not become transcriptionally active until neurula, Nanos1-depleted PGCs prematurely exhibit a hyperphosphorylated RNA polymerase II C-terminal domain at the midblastula transition. Furthermore, they inappropriately express somatic genes characteristic of endoderm regulated by maternal VegT, including Xsox17?, Bix4, Mixer, GATA4 and Edd. We further demonstrate that Pumilio specifically binds VegT RNA in vitro and represses, along with Nanos1, VegT translation within PGCs. Repressed VegT RNA in wild-type PGCs is significantly less stable than VegT in Nanos1-depleted PGCs. Our data indicate that maternal VegT RNA is an authentic target of Nanos1/Pumilio translational repression. We propose that Nanos1 functions to translationally repress RNAs that normally specify endoderm and promote apoptosis, thus preserving the germline.

Lai, Fangfang; Singh, Amar; King, Mary Lou

2012-01-01

229

Colloquium paper: ecological extinction and evolution in the brave new ocean.  

PubMed

The great mass extinctions of the fossil record were a major creative force that provided entirely new kinds of opportunities for the subsequent explosive evolution and diversification of surviving clades. Today, the synergistic effects of human impacts are laying the groundwork for a comparably great Anthropocene mass extinction in the oceans with unknown ecological and evolutionary consequences. Synergistic effects of habitat destruction, overfishing, introduced species, warming, acidification, toxins, and massive runoff of nutrients are transforming once complex ecosystems like coral reefs and kelp forests into monotonous level bottoms, transforming clear and productive coastal seas into anoxic dead zones, and transforming complex food webs topped by big animals into simplified, microbially dominated ecosystems with boom and bust cycles of toxic dinoflagellate blooms, jellyfish, and disease. Rates of change are increasingly fast and nonlinear with sudden phase shifts to novel alternative community states. We can only guess at the kinds of organisms that will benefit from this mayhem that is radically altering the selective seascape far beyond the consequences of fishing or warming alone. The prospects are especially bleak for animals and plants compared with metabolically flexible microbes and algae. Halting and ultimately reversing these trends will require rapid and fundamental changes in fisheries, agricultural practice, and the emissions of greenhouse gases on a global scale. PMID:18695220

Jackson, Jeremy B C

2008-08-12

230

Neurotoxin localization to ectodermal gland cells uncovers an alternative mechanism of venom delivery in sea anemones  

PubMed Central

Jellyfish, hydras, corals and sea anemones (phylum Cnidaria) are known for their venomous stinging cells, nematocytes, used for prey and defence. Here we show, however, that the potent Type I neurotoxin of the sea anemone Nematostella vectensis, Nv1, is confined to ectodermal gland cells rather than nematocytes. We demonstrate massive Nv1 secretion upon encounter with a crustacean prey. Concomitant discharge of nematocysts probably pierces the prey, expediting toxin penetration. Toxin efficiency in sea water is further demonstrated by the rapid paralysis of fish or crustacean larvae upon application of recombinant Nv1 into their medium. Analysis of other anemone species reveals that in Anthopleura elegantissima, Type I neurotoxins also appear in gland cells, whereas in the common species Anemonia viridis, Type I toxins are localized to both nematocytes and ectodermal gland cells. The nematocyte-based and gland cell-based envenomation mechanisms may reflect substantial differences in the ecology and feeding habits of sea anemone species. Overall, the immunolocalization of neurotoxins to gland cells changes the common view in the literature that sea anemone neurotoxins are produced and delivered only by stinging nematocytes, and raises the possibility that this toxin-secretion mechanism is an ancestral evolutionary state of the venom delivery machinery in sea anemones.

Moran, Yehu; Genikhovich, Grigory; Gordon, Dalia; Wienkoop, Stefanie; Zenkert, Claudia; Ozbek, Suat; Technau, Ulrich; Gurevitz, Michael

2012-01-01

231

An indicator-based evaluation of Black Sea food web dynamics during 1960-2000  

NASA Astrophysics Data System (ADS)

Four Ecopath mass-balance models were implemented for evaluating the structure and function of the Black Sea ecosystem using several ecological indicators during four distinctive periods (1960s, 1980-1987, 1988-1994 and 1995-2000). The results exemplify how the Black Sea ecosystem structure started to change after the 1960s as a result of a series of trophic transformations, i.e., shifts in the energy flow pathways through the food web. These transformations were initiated by anthropogenic factors, such as eutrophication and overfishing, that led to the transfer of large quantities of energy to the trophic dead-end species, which had no natural predators in the ecosystem, i.e., jellyfish whose biomass increased from 0.03 g C m- 2 in 1960-1969 to 0.933 g C m- 2 in 1988-1994. Concurrently, an alternative short pathway for energy transfer was formed that converted significant amounts of system production back to detritus. This decreased the transfer efficiency of energy flow from the primary producers to the higher trophic levels from 9% in the 1960s to 3% between 1980 and 1987. We conclude that the anchovy stock collapse and successful establishment of the alien comb-jelly Mnemiopsis in 1989 were rooted in the trophic interactions in the food web, all of which were exacerbated because of the long-term establishment of a combination of anthropogenic stressors.

Akoglu, Ekin; Salihoglu, Baris; Libralato, Simone; Oguz, Temel; Solidoro, Cosimo

2014-06-01

232

NASA Workshop on Animal Gravity-Sensing Systems  

NASA Technical Reports Server (NTRS)

The opportunity for space flight has brought about the need for well-planned research programs that recognize the significance of space flight as a scientific research tool for advancing knowledge of life on Earth, and that utilize each flight opportunity to its fullest. For the first time in history, gravity can be almost completely eliminated. Thus, studies can be undertaken that will help to elucidate the importance of gravity to the normal functioning of living organisms, and to determine the effects microgravity may have on an organism. This workshop was convened to organize a plan for space research on animal gravity-sensing systems and the role that gravity plays in the development and normal functioning of these systems. Scientists working in the field of animal gravity-sensing systems use a wide variety of organisms in their research. The workshop presentations dealt with topics which ranged from the indirect gravity receptor of the water flea, Daphnia (whose antennal setae apparently act as current-sensing receptors as the animal moves up and down in water), through specialized statocyst structures found in jellyfish and gastropods, to the more complex vestibular systems that are characteristic of amphibians, avians, and mammals.

Corcoran, M. L. (editor)

1986-01-01

233

Fluorescent RNA cytochemistry: tracking gene transcripts in living cells  

PubMed Central

The advent of jellyfish green fluorescent protein and its spectral variants, together with promising new fluorescent proteins from other classes of the Cnidarian phylum (coral and anemones), has greatly enhanced and promises to further boost the detection and localization of proteins in cell biology. It has been less widely appreciated that highly sensitive methods have also recently been developed for detecting the movement and localization in living cells of the very molecules that precede proteins in the gene expression pathway, i.e. RNAs. These approaches include the microinjection of fluorescent RNAs into living cells, the in vivo hybridization of fluorescent oligonucleotides to endogenous RNAs and the expression in cells of fluorescent RNA-binding proteins. This new field of ‘fluorescent RNA cytochemistry’ is summarized in this article, with emphasis on the biological insights it has already provided. These new techniques are likely to soon collaborate with other emerging approaches to advance the investigation of RNA birth, RNA–protein assembly and ribonucleoprotein particle transport in systems such as oocytes, embryos, neurons and other somatic cells, and may even permit the observation of viral replication and transcription pathways as they proceed in living cells, ushering in a new era of nucleic acids research in vivo.

Pederson, Thoru

2001-01-01

234

Folding and unfolding of a non-fluorescent mutant of green fluorescent protein  

PubMed Central

Green fluorescent protein (GFP), from the Pacific jellyfish A. victoria, has numerous uses in biotechnology and cell and molecular biology as a protein marker because of its specific chromophore, which is spontaneously created after proper protein folding. After formation, the chromophore is very stable and remains intact during protein unfolding, meaning that the GFP unfolding process is not the reverse of the original folding reaction; i.e., the principles of microscopic reversibility do not apply. We have generated the mutant S65T/G67A-GFP, which is unable to form the cyclic chromophore, with the goal of investigating the folding, unfolding and competing aggregation of GFP under fully reversible conditions. Our studies have been performed in the presence of GdnHCl. The GFP conformation was monitored using intrinsic tryptophan fluorescence, and fluorescence of bis-ANS. Light scattering was used to follow GFP aggregation. We conclude from these fluorescence measurements, that S65T/G67A-GFP folding is largely reversible. During equilibrium folding, the first step is formation of molten globule, prone to aggregation.

Kutrowska, Beata Wielgus; Narczyk, Marta; Buszko, Anna; Bzowska, Agnieszka; Clark, Patricia L.

2009-01-01

235

Interannual variability, growth, reproduction and feeding of Pelagia noctiluca (Cnidaria: Scyphozoa) in the Straits of Messina (Central Mediterranean Sea): Linkages with temperature and diet  

NASA Astrophysics Data System (ADS)

To identify some of the possible environmental factors stimulating the increasingly frequent outbreaks of the scyphomedusa Pelagia noctiluca in the Straits of Messina, we investigated its abundance, growth, reproduction and feeding over a 4-year period, from 2007 to 2011, at two coastal sites. Using either field investigations and manipulative experiments we show that, among the various factors considered, shifts in water temperature (influencing medusae metabolism, growth and reproduction rates) and the size structure of the zooplankton community (their natural preys) can promote the proliferation of P. noctiluca. In particular, we show that increased temperature let jellyfishes to grow more rapidly and reach exceptional sizes. We also report a peculiar opportunistic behavior of P. noctiluca, which makes this species a potentially strong competitor in the pelagic trophic web of the Straits ecosystem. We therefore propose that more frequent P. noctiluca outbreaks stimulated by increasing sea surface temperature and shifts in their prey availability and composition would become, in the near future, a major cause of ecosystem shift.

Rosa, S.; Pansera, M.; Granata, A.; Guglielmo, L.

2013-02-01

236

Olfactory insights into sleep-dependent learning and memory.  

PubMed

Sleep is pervasive throughout most of the animal kingdom-even jellyfish and honeybees do it. Although the precise function of sleep remains elusive, research increasingly suggests that sleep plays a key role in memory consolidation. Newly formed memories are highly labile and susceptible to interference, and the sleep period offers an optimal window in which memories can be strengthened or modified. Interestingly, a small but growing research area has begun to explore the ability of odors to modulate memories during sleep. The unique anatomical organization of the olfactory system, including its intimate overlap with limbic systems mediating emotion and memory, and the lack of a requisite thalamic intermediary between the nasal periphery and olfactory cortex, suggests that odors may have privileged access to the brain during sleep. Indeed, it has become clear that the long-held assumption that odors have no impact on the sleeping brain is no longer tenable. Here, we summarize recent studies in both animal and human models showing that odor stimuli experienced in the waking state modulate olfactory cortical responses in sleep-like states, that delivery of odor contextual cues during sleep can enhance declarative memory and extinguish fear memory, and that olfactory associative learning can even be achieved entirely within sleep. Data reviewed here spotlight the emergence of a new research area that should hold far-reaching implications for future neuroscientific investigations of sleep, learning and memory, and olfactory system function. PMID:24767488

Shanahan, Laura K; Gottfried, Jay A

2014-01-01

237

Neuroglobins, Pivotal Proteins Associated with Emerging Neural Systems and Precursors of Metazoan Globin Diversity  

PubMed Central

Neuroglobins, previously thought to be restricted to vertebrate neurons, were detected in the brain of a photosymbiotic acoel, Symsagittifera roscoffensis, and in neurosensory cells of the jellyfish Clytia hemisphaerica. For the neuroglobin of S. roscoffensis, a member of a lineage that originated either at the base of the bilateria or of the deuterostome clade, we report the ligand binding properties, crystal structure at 2.3 ?, and brain immunocytochemical pattern. We also describe in situ hybridizations of two neuroglobins specifically expressed in differentiating nematocytes (neurosensory cells) and in statocytes (ciliated mechanosensory cells) of C. hemisphaerica, a member of the early branching animal phylum cnidaria. In silico searches using these neuroglobins as queries revealed the presence of previously unidentified neuroglobin-like sequences in most metazoan lineages. Because neural systems are almost ubiquitous in metazoa, the constitutive expression of neuroglobin-like proteins strongly supports the notion of an intimate association of neuroglobins with the evolution of animal neural systems and hints at the preservation of a vitally important function. Neuroglobins were probably recruited in the first protoneurons in early metazoans from globin precursors. Neuroglobins were identified in choanoflagellates, sponges, and placozoans and were conserved during nervous system evolution. Because the origin of neuroglobins predates the other metazoan globins, it is likely that neuroglobin gene duplication followed by co-option and subfunctionalization led to the emergence of globin families in protostomes and deuterostomes (i.e. convergent evolution).

Lechauve, Christophe; Jager, Muriel; Laguerre, Laurent; Kiger, Laurent; Correc, Gaelle; Leroux, Cedric; Vinogradov, Serge; Czjzek, Mirjam; Marden, Michael C.; Bailly, Xavier

2013-01-01

238

A potential-flow, deformable-body model for fluid structure interactions with compact vorticity: application to animal swimming measurements  

NASA Astrophysics Data System (ADS)

This paper presents an approach to quantify the unsteady fluid forces, moments and mass transport generated by swimming animals, based on measurements of the surrounding flow field. These goals are accomplished within a framework that is independent of the vorticity field, making it unnecessary to directly resolve boundary layers on the animal, body vortex interactions, or interactions among vortex lines in the wake. Instead, the method identifies Lagrangian coherent structures in the flow, whose dynamics in flows with compact vorticity are shown to be well approximated by potential flow concepts, especially the Kirchhoff and deformation potentials from deformable body theory. Examples of the application of these methods are given for pectoral fin locomotion of the bluegill sunfish and undulatory swimming of jellyfish, and the methods are validated by analysis of a canonical starting vortex ring flow. The transition to a Lagrangian approach toward animal swimming measurements suggests the possibility of implementing recently developed particle tracking (vis-à-vis DPIV) techniques for fully three-dimensional measurements of animal swimming.

Peng, Jifeng; Dabiri, John O.

2007-11-01

239

Coral Larvae Move toward Reef Sounds  

PubMed Central

Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency.

Vermeij, Mark J. A.; Marhaver, Kristen L.; Huijbers, Chantal M.; Nagelkerken, Ivan; Simpson, Stephen D.

2010-01-01

240

Pelagia noctiluca (Scyphozoa) Crude Venom Injection Elicits Oxidative Stress and Inflammatory Response in Rats  

PubMed Central

Cnidarian toxins represent a rich source of biologically active compounds. Since they may act via oxidative stress events, the aim of the present study was to verify whether crude venom, extracted from the jellyfish Pelagia noctiluca, elicits inflammation and oxidative stress processes, known to be mediated by Reactive Oxygen Species (ROS) production, in rats. In a first set of experiments, the animals were injected with crude venom (at three different doses 6, 30 and 60 µg/kg, suspended in saline solution, i.v.) to test the mortality and possible blood pressure changes. In a second set of experiments, to confirm that Pelagia noctiluca crude venom enhances ROS formation and may contribute to the pathophysiology of inflammation, crude venom-injected animals (30 µg/kg) were also treated with tempol, a powerful antioxidant (100 mg/kg i.p., 30 and 60 min after crude venom). Administration of tempol after crude venom challenge, caused a significant reduction of each parameter related to inflammation. The potential effect of Pelagia noctiluca crude venom in the systemic inflammation process has been here demonstrated, adding novel information about its biological activity.

Bruschetta, Giuseppe; Impellizzeri, Daniela; Morabito, Rossana; Marino, Angela; Ahmad, Akbar; Spano, Nunziacarla; La Spada, Giuseppa; Cuzzocrea, Salvatore; Esposito, Emanuela

2014-01-01

241

Yellow fluorescent protein phiYFPv (Phialidium): structure and structure-based mutagenesis  

PubMed Central

The yellow fluorescent protein phiYFPv (?em max ? 537?nm) with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The latter fluorescent protein is one of only two known cases of naturally occurring proteins that exhibit emission spectra in the yellow–orange range (535–555?nm). Here, the crystal structure of phiYFPv has been determined at 2.05?Å resolution. The ‘yellow’ chromophore formed from the sequence triad Thr65-Tyr66-Gly67 adopts the bicyclic structure typical of fluorophores emitting in the green spectral range. It was demonstrated that perfect antiparallel ?-stacking of chromophore Tyr66 and the proximal Tyr203, as well as Val205, facing the chromophore phenolic ring are chiefly responsible for the observed yellow emission of phiYFPv at 537?nm. Structure-based site-directed mutagenesis has been used to identify the key functional residues in the chromophore environment. The obtained results have been utilized to improve the properties of phiYFPv and its homologous monomeric biomarker tagYFP.

Pletneva, Nadya V.; Pletnev, Vladimir Z.; Souslova, Ekaterina; Chudakov, Dmitry M.; Lukyanov, Sergey; Martynov, Vladimir I.; Arhipova, Svetlena; Artemyev, Igor; Wlodawer, Alexander; Dauter, Zbigniew; Pletnev, Sergei

2013-01-01

242

Isolation of a Nav channel blocking polypeptide from Cyanea capillata medusae - a neurotoxin contained in fishing tentacle isorhizas.  

PubMed

Jellyfish are efficient predators which prey on crabs, fish larvae, and small fish. Their venoms consist of various toxins including neurotoxins that paralyse prey organisms immediately. One possible mode of action of neurotoxins is the blockage of voltage-gated sodium (Na(v)) channels. A novel polypeptide with Na(v) channel blocking activity was isolated from the northern Scyphozoa Cyanea capillata (L., 1758). For that purpose, a bioactivity-guided multidimensional liquid chromatographic purification method has been developed. A neurotoxic activity of resulting chromatographic fractions was demonstrated by a bioassay, which based on the mouse neuroblastoma cell line Neuro2A. The purification process yielded one fraction containing a single polypeptide with proven activity. The molecular weight of 8.22 kDa was determined by matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF MS). Utilising Laser Microdissection and Pressure Catapulting (LMPC) for the separation of different nematocyst types in combination with direct MALDI-ToF MS analysis of the intact capsules, the neurotoxin was found to be present in all types of fishing tentacle isorhizas (A-isorhizas, a-isorhizas, O-isorhizas) of C. capillata medusae. PMID:22402177

Lassen, Stephan; Wiebring, Annika; Helmholz, Heike; Ruhnau, Christiane; Prange, Andreas

2012-05-01

243

NF-?B is required for cnidocyte development in the sea anemone Nematostella vectensis.  

PubMed

The sea anemone Nematostella vectensis (Nv) is a leading model organism for the phylum Cnidaria, which includes anemones, corals, jellyfishes and hydras. A defining trait across this phylum is the cnidocyte, an ectodermal cell type with a variety of functions including defense, prey capture and environmental sensing. Herein, we show that the Nv-NF-?B transcription factor and its inhibitor Nv-I?B are expressed in a subset of cnidocytes in the body column of juvenile and adult anemones. The size and distribution of the Nv-NF-?B-positive cnidocytes suggest that they are in a subtype known as basitrichous haplonema cnidocytes. Nv-NF-?B is primarily cytoplasmic in cnidocytes in juvenile and adult animals, but is nuclear when first detected in the 30-h post-fertilization embryo. Morpholino-mediated knockdown of Nv-NF-?B expression results in greatly reduced cnidocyte formation in the 5 day-old animal. Taken together, these results indicate that NF-?B plays a key role in the development of the phylum-specific cnidocyte cell type in Nematostella, likely by nuclear Nv-NF-?B-dependent activation of genes required for cnidocyte development. PMID:23063796

Wolenski, Francis S; Bradham, Cynthia A; Finnerty, John R; Gilmore, Thomas D

2013-01-01

244

Spatial patterns of zooplankton and nekton in a hydrothermally active axial valley on Juan de Fuca Ridge  

NASA Astrophysics Data System (ADS)

Zooplankton and nekton at 2000 m depth in the axial valley of Endeavour Segment, Juan de Fuca Ridge, show marked variability in abundances in a plane at 20 m above bottom. A remotely operated vehicle flew a gridded rectangle 3.2×0.5 km that included two large high-temperature and two small low-temperature vent fields. Numbers of zooplankton, jellyfish, shrimp and fish were recorded with a video camera, and the abundance patterns were examined with the program SADIE ©. Each organism group displayed a distinctive distribution pattern. Abundance gaps over the high-temperature fields were significant and, for the more abundant copepods, were related to the locations of individual smokers. Pelagic shrimp and macrourid fish abundances were correlated and concentrated around the northern high temperature field. Distinct aggregations of zooplankton and nekton were correlated with the fluid indicators from both the low temperature diffuse effluent and the focused high temperature vents. Patterns were likely established by organism choice that forms aggregations and gaps, and by physical processes that entrain passive particles near vigorous smoker plumes. While enhanced plankton and nekton numbers were not observed over the vent fields, overall abundances in the axial valley may be sustained by production transported from the vent fields on the seafloor.

Skebo, Kristina; Tunnicliffe, Verena; Garcia Berdeal, Irene; Johnson, H. Paul

2006-06-01

245

Rise characteristics of gas bubbles in a 2D rectangular column: VOF simulations vs experiments  

SciTech Connect

About five centuries ago, Leonardo da Vinci described the sinuous motion of gas bubbles rising in water. The authors have attempted to simulate the rise trajectories of bubbles of 4, 5, 7, 8, 9, 12, and 20 mm in diameter rising in a 2D rectangular column filled with water. The simulations were carried out using the volume-of-fluid (VOF) technique developed by Hirt and Nichols (J. Computational Physics, 39, 201--225 (1981)). To solve the Navier-Stokes equations of motion the authors used a commercial solver, CFX 4.1c of AEA Technology, UK. They developed their own bubble-tracking algorithm to capture sinuous bubble motions. The 4 and 5 mm bubbles show large lateral motions observed by Da Vinci. The 7, 8 and 9 mm bubble behave like jellyfish. The 12 mm bubble flaps its wings like a bird. The extent of lateral motion of the bubbles decreases with increasing bubble size. Bubbles larger than 20 mm in size assume a spherical cap form and simulations of the rise characteristics match experiments exactly. VOF simulations are powerful tools for a priori determination of the morphology and rise characteristics of bubbles rising in a liquid. Bubble-bubble interactions are also properly modeled by the VOF technique.

Krishna, R.; Baten, J.M. van

1999-10-01

246

Ocean acidification and its potential effects on marine ecosystems.  

PubMed

Ocean acidification is rapidly changing the carbonate system of the world oceans. Past mass extinction events have been linked to ocean acidification, and the current rate of change in seawater chemistry is unprecedented. Evidence suggests that these changes will have significant consequences for marine taxa, particularly those that build skeletons, shells, and tests of biogenic calcium carbonate. Potential changes in species distributions and abundances could propagate through multiple trophic levels of marine food webs, though research into the long-term ecosystem impacts of ocean acidification is in its infancy. This review attempts to provide a general synthesis of known and/or hypothesized biological and ecosystem responses to increasing ocean acidification. Marine taxa covered in this review include tropical reef-building corals, cold-water corals, crustose coralline algae, Halimeda, benthic mollusks, echinoderms, coccolithophores, foraminifera, pteropods, seagrasses, jellyfishes, and fishes. The risk of irreversible ecosystem changes due to ocean acidification should enlighten the ongoing CO(2) emissions debate and make it clear that the human dependence on fossil fuels must end quickly. Political will and significant large-scale investment in clean-energy technologies are essential if we are to avoid the most damaging effects of human-induced climate change, including ocean acidification. PMID:18566099

Guinotte, John M; Fabry, Victoria J

2008-01-01

247

An endogenous green fluorescent protein-photoprotein pair in Clytia hemisphaerica eggs shows co-targeting to mitochondria and efficient bioluminescence energy transfer  

PubMed Central

Green fluorescent proteins (GFPs) and calcium-activated photoproteins of the aequorin/clytin family, now widely used as research tools, were originally isolated from the hydrozoan jellyfish Aequora victoria. It is known that bioluminescence resonance energy transfer (BRET) is possible between these proteins to generate flashes of green light, but the native function and significance of this phenomenon is unclear. Using the hydrozoan Clytia hemisphaerica, we characterized differential expression of three clytin and four GFP genes in distinct tissues at larva, medusa and polyp stages, corresponding to the major in vivo sites of bioluminescence (medusa tentacles and eggs) and fluorescence (these sites plus medusa manubrium, gonad and larval ectoderms). Potential physiological functions at these sites include UV protection of stem cells for fluorescence alone, and prey attraction and camouflaging counter-illumination for bioluminescence. Remarkably, the clytin2 and GFP2 proteins, co-expressed in eggs, show particularly efficient BRET and co-localize to mitochondria, owing to parallel acquisition by the two genes of mitochondrial targeting sequences during hydrozoan evolution. Overall, our results indicate that endogenous GFPs and photoproteins can play diverse roles even within one species and provide a striking and novel example of protein coevolution, which could have facilitated efficient or brighter BRET flashes through mitochondrial compartmentalization.

Fourrage, Cecile; Swann, Karl; Gonzalez Garcia, Jose Raul; Campbell, Anthony K.; Houliston, Evelyn

2014-01-01

248

KAnalyze: a fast versatile pipelined K-mer toolkit  

PubMed Central

Motivation: Converting nucleotide sequences into short overlapping fragments of uniform length, k-mers, is a common step in many bioinformatics applications. While existing software packages count k-mers, few are optimized for speed, offer an application programming interface (API), a graphical interface or contain features that make it extensible and maintainable. We designed KAnalyze to compete with the fastest k-mer counters, to produce reliable output and to support future development efforts through well-architected, documented and testable code. Currently, KAnalyze can output k-mer counts in a sorted tab-delimited file or stream k-mers as they are read. KAnalyze can process large datasets with 2 GB of memory. This project is implemented in Java 7, and the command line interface (CLI) is designed to integrate into pipelines written in any language. Results: As a k-mer counter, KAnalyze outperforms Jellyfish, DSK and a pipeline built on Perl and Linux utilities. Through extensive unit and system testing, we have verified that KAnalyze produces the correct k-mer counts over multiple datasets and k-mer sizes. Availability and implementation: KAnalyze is available on SourceForge: https://sourceforge.net/projects/kanalyze/ Contact: fredrik.vannberg@biology.gatech.edu Supplementary information: Supplementary data are available at Bioinformatics online.

Audano, Peter; Vannberg, Fredrik

2014-01-01

249

Xenopus Nanos1 is required to prevent endoderm gene expression and apoptosis in primordial germ cells.  

PubMed

Nanos is expressed in multipotent cells, stem cells and primordial germ cells (PGCs) of organisms as diverse as jellyfish and humans. It functions together with Pumilio to translationally repress targeted mRNAs. Here we show by loss-of-function experiments that Xenopus Nanos1 is required to preserve PGC fate. Morpholino knockdown of maternal Nanos1 resulted in a striking decrease in PGCs and a loss of germ cells from the gonads. Lineage tracing and TUNEL staining reveal that Nanos1-deficient PGCs fail to migrate out of the endoderm. They appear to undergo apoptosis rather than convert to normal endoderm. Whereas normal PGCs do not become transcriptionally active until neurula, Nanos1-depleted PGCs prematurely exhibit a hyperphosphorylated RNA polymerase II C-terminal domain at the midblastula transition. Furthermore, they inappropriately express somatic genes characteristic of endoderm regulated by maternal VegT, including Xsox17?, Bix4, Mixer, GATA4 and Edd. We further demonstrate that Pumilio specifically binds VegT RNA in vitro and represses, along with Nanos1, VegT translation within PGCs. Repressed VegT RNA in wild-type PGCs is significantly less stable than VegT in Nanos1-depleted PGCs. Our data indicate that maternal VegT RNA is an authentic target of Nanos1/Pumilio translational repression. We propose that Nanos1 functions to translationally repress RNAs that normally specify endoderm and promote apoptosis, thus preserving the germline. PMID:22399685

Lai, Fangfang; Singh, Amar; King, Mary Lou

2012-04-01

250

Does prey size matter? Novel observations of feeding in the leatherback turtle (Dermochelys coriacea) allow a test of predator-prey size relationships.  

PubMed

Optimal foraging models predict that large predators should concentrate on large prey in order to maximize their net gain of energy intake. Here, we show that the largest species of sea turtle, Dermochelys coriacea, does not strictly adhere to this general pattern. Field observations combined with a theoretical model suggest that a 300 kg leatherback turtle would meet its energetic requirements by feeding for 3-4 h a day on 4 g jellyfish, but only if prey were aggregated in high-density patches. Therefore, prey abundance rather than prey size may, in some cases, be the overriding parameter for foraging leatherbacks. This is a classic example where the presence of small prey in the diet of a large marine predator may reflect profitable foraging decisions if the relatively low energy intake per small individual prey is offset by high encounter rates and minimal capture and handling costs. This study provides, to our knowledge, the first quantitative estimates of intake rate for this species. PMID:22090203

Fossette, Sabrina; Gleiss, Adrian C; Casey, James P; Lewis, Andrew R; Hays, Graeme C

2012-06-23

251

[The plate in the zone of oocyte and germinal epithelium contact in scyphomedusa Aurelia aurita binds antibodies to ZP-domain-containing protein mesoglein].  

PubMed

Cnidaria are lower multicellular animals with the body consisting of two epithelial layers. An extracellular substance--mesoglea--is situated between epidermal and gastrodermal layers of these animals. Mesoglein is one of the major mesogleal proteins of adult medusa of Scyphozoan jellyfish Aurelia aurita. Search for the known domains in mesoglein amino acid sequence reveals prominent zona pellucida (ZP) domain (which was found at first in the mammal oocyte zona pellucida proteins), so the protein belongs to ZP family of extracellular matrix proteins and it is an early metazoan member of ZP-domain-containing protein family. However, nothing is known about oogenesis related ZP-domain proteins in the lower multicellular animals. Oogenesis in Scyphozoa is described poorly. In this work morphological features of the zone in contact area between the oocyte and the germinal epithelium were investigated in semi-fine sections: To make it more convenient we identified seven stages according to the oocyte size and the structure found in this area was named the plate. It was shown that the components of the plate bound specifically the antibodies against mesoglein. So it seems the plate material contains ZP-domain proteins. Electrophoresis and immunoblot results give evidence that the proteins immunologically related to mesoglein have a higher molecular mass. It might be due to either the posttranslational modifications of the precursors or that they represent other proteins of ZP-domain family in Cnidaria. PMID:19566035

Adonin, L S; Podgornaia, O I; Matveev, I V; Shaposhnikova, T G

2009-01-01

252

Postembryonic development of the parasitic amphipod Hyperia galba  

NASA Astrophysics Data System (ADS)

Hyperia galba Montagu is associated with gelatinous zooplankton as are many species of the Hyperiidea. The hosts preferred in the European seas are the large scyphomedusae Aurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, Cyanea capillata and Cyanea lamarckii, which harbour the first developmental stages. The anamorphic development produces young that are incapable of swimming at the time of hatching. They are characterized by an embryonic abdomen without extremities and external segmentation; the eyes are not completely developed and the mouth is primitive lacking bristles, molar and incisor. The postembryonic development, described in detail, is subdivided into two phases: the pantochelis phase and the protopleon phase; the former comprises only one stage; the latter can be subdivided into four stages. In the course of postnatal development the larval organs are reduced and characters typical of the adult are gradually differentiated. H. galba plays an important role as obligatory endoparasite of scyphomedusae at least during the first stages of development; without a host this amphipod cannot survive, neither benthically nor in the plankton. The transition from life in the female's marsupium to endoparasitism in the jellyfish generally occurs during stage of the postembryonic development which is the first stage of the protopleon phase. The specific adaptations of its reproductive biology to a parasitic mode of life such as moult inhibition under starvation, development of larval organs and the behavioural patterns of the females as well as the young are described. Further, the influence of external factors such as temperature and food supply on the course of development is examined.

Dittrich, Birgit

1987-06-01

253

Quantum dots for molecular imaging and cancer medicine.  

PubMed

Extract: The past few decades have witnessed technical advances that have introduced cell biologists and physicians to a new, dynamic, subcellular world where genes and gene products can be visualized to interact in space and time and in health and disease. The accelerating field of molecular imaging has been critically dependent on indicator probes which show when and where genetically or biochemically defined molecules, signals or processes appear, interact and disappear, with high spatial and temporal resolution in living cells and whole organisms. For example, the use of radionuclide tracers combined with 3-dimensional (3-D) imaging systems such as Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are now helping clinicians to characterize the molecular status of tumors deep within patients. Other types of imaging probes rely on the bioluminescence and fluorescence of genetically encoded proteins (originally found in fireflies and jellyfish, respectively) or entirely synthetic fluorochromes, or a combination of both. New powerful biological fluorescence microscopes provide the ability to study single molecules within single cells. Multiphoton confocal microscopy has been developed to allow for the capturing of high-resolution, 3-D images of living tissues that have been tagged with highly specific fluorophores. PMID:20704913

Bentolila, L A; Michalet, X; Pinaud, F F; Tsay, J M; Doose, S; Li, J J; Sundaresan, G; Wu, A M; Gambhir, S S; Weiss, S

2005-04-01

254

Ring of Stellar Death  

NASA Technical Reports Server (NTRS)

This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant ring of material (red) slightly offset from the cloud's core. This clumpy ring consists of material that was expelled from the aging star.

The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space.

In this image, the expelled gases appear green, and the ring of expelled material appears red. Astronomers believe the ring is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars.

This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

2004-01-01

255

Visual wavelength discrimination by the loggerhead turtle, Caretta caretta.  

PubMed

Marine turtles are visual animals, yet we know remarkably little about how they use this sensory capacity. In this study, our purpose was to determine whether loggerhead turtles could discriminate between objects on the basis of color. We used light-adapted hatchlings to determine the minimum intensity of blue (450 nm), green (500 nm), and yellow (580 nm) visual stimuli that evoked a positive phototaxis (the phototaxis "threshold" [pt]). Juvenile turtles were later trained to associate each color (presented at 1 log unit above that color's pt) with food, then to discriminate between two colors (the original rewarded stimulus plus one of the other colors, not rewarded) when both were presented at 1 log unit above their pt. In the crucial test, turtles were trained to choose between the rewarded and unrewarded color when the colors varied in intensity. All turtles learned that task, demonstrating color discrimination. An association between blue and food was acquired in fewer trials than between yellow and food, perhaps because some prey of juvenile loggerheads in oceanic surface waters (jellyfishes, polyps, and pelagic gastropods) are blue or violet in color. PMID:22426631

Young, Morgan; Salmon, Michael; Forward, Richard

2012-02-01

256

Perception of dimethyl sulfide (DMS) by loggerhead sea turtles: a possible mechanism for locating high-productivity oceanic regions for foraging.  

PubMed

During their long-distance migrations, sea turtles of several species feed on jellyfish and other invertebrates that are particularly abundant in ocean regions characterized by high productivity. An ability to distinguish productive oceanic regions from other areas, and to concentrate foraging activities in locations where prey density is highest, might therefore be adaptive. The volatile compound dimethyl sulfide (DMS) accumulates in the air above productive ocean areas such as upwelling and frontal zones. In principle, DMS might therefore serve as an indicator of high prey density for turtles. To determine whether turtles perceive DMS, juvenile loggerhead sea turtles (Caretta caretta) were placed into a water-filled arena in which DMS and other odorants could be introduced to the air above the water surface. Turtles exposed to air that had passed over a cup containing 10 nmol l(-1) DMS spent more time at the surface with their noses out of the water than control turtles, which were exposed to air that had passed over a cup containing distilled water. Odors that do not occur in the sea (cinnamon, jasmine and lemon) did not elicit increased surface time, implying that the response to DMS is unlikely to reflect a generalized response to any novel odor. The results demonstrate for the first time that sea turtles can detect DMS, an ability that might enable the identification of favorable foraging areas. PMID:23014568

Endres, Courtney S; Lohmann, Kenneth J

2012-10-15

257

Mistaken identity? Visual similarities of marine debris to natural prey items of sea turtles  

PubMed Central

Background There are two predominant hypotheses as to why animals ingest plastic: 1) they are opportunistic feeders, eating plastic when they encounter it, and 2) they eat plastic because it resembles prey items. To assess which hypothesis is most likely, we created a model sea turtle visual system and used it to analyse debris samples from beach surveys and from necropsied turtles. We investigated colour, contrast, and luminance of the debris items as they would appear to the turtle. We also incorporated measures of texture and translucency to determine which of the two hypotheses is more plausible as a driver of selectivity in green sea turtles. Results Turtles preferred more flexible and translucent items to what was available in the environment, lending support to the hypothesis that they prefer debris that resembles prey, particularly jellyfish. They also ate fewer blue items, suggesting that such items may be less conspicuous against the background of open water where they forage. Conclusions Using visual modelling we determined the characteristics that drive ingestion of marine debris by sea turtles, from the point of view of the turtles themselves. This technique can be utilized to determine debris preferences of other visual predators, and help to more effectively focus management or remediation actions.

2014-01-01

258

Effects of green fluorescent protein or beta-glucuronidase tagging on the accumulation and pathogenicity of a resistance-breaking Lettuce mosaic virus isolate in susceptible and resistant lettuce cultivars.  

PubMed

The RNA genome of a resistance-breaking isolate of Lettuce mosaic virus (LMV-E) was engineered to express the jellyfish green fluorescent protein (GFP) or beta-glucuronidase (GUS) fused to the helper-component proteinase (HC-Pro) to study LMV invasion and spread in susceptible and resistant lettuce cultivars. Virus accumulation and movement were monitored by either histochemical GUS assays or detection of GFP fluorescence under UV light. The GFP- and GUS-tagged viruses spread systemically in the susceptible lettuce cultivars Trocadero and Vanguard, where they induced attenuated symptoms, compared with the wild-type virus. Accumulation of the GFP-tagged virus was reduced but less affected than in the case of the GUS-tagged virus. Systemic movement of both recombinant viruses was very severely affected in Vanguard 75, a lettuce cultivar nearly isogenic to Vanguard but carrying the resistance gene mo1(2). Accumulation of the recombinant viruses in systemically infected leaves was either undetectable (GUS-tag) or erratic, strongly delayed, and inhibited by as much as 90% (GFP-tag). As a consequence, and contrary to the parental virus, the recombinant viruses were not able to overcome the protection afforded by the mo1(2) gene. Taken together, these results indicate that GUS or GFP tagging of the HC-Pro of LMV has significant negative effects on the biology of the virus, abolishing its resistance-breaking properties and reducing its pathogenicity in susceptible cultivars. PMID:10707357

German-Retana, S; Candresse, T; Alias, E; Delbos, R P; Le Gall, O

2000-03-01

259

[Intoxications specific to the Aquitaine region].  

PubMed

Some intoxications are more specifically linked to the Aquitaine region than to other regions of France, due to environmental circumstances (fauna, flora, climate) or traditional activities (gastronomy). Three types of intoxications are particular in this area. Pine processionary caterpillar envenomations (Thaumetopoea pityocampa), a Southern Europe pinewood parasite, are frequently encountered in the Landes' forest. They are responsible of ocular and/or skin lesions with urticaria or contact dermatitis, seldom associated with immediate IgE hypersensitivity. According to the south Atlantic coastal region geology and the marine streams, venomous marine animals are mainly located in Charente-Maritime for jellyfish, in Gironde and in Landes for weeverfish and in Atlantic Pyrenees for sea anemone. Usually not dangerous, first-aid workers treat most cases of these envenomations. Some endemic mushrooms (Tricholoma auratum) which grow on the dunes of the Atlantic coastal region, are usually considered as very good comestibles, but were recently responsible for serious intoxications: T.auratum was responsible of several cases of rhabdomyolysis, without neurological involvement, nor renal or hepatic lesion. Three deaths were notified. Animal studies confirmed the responsibility of the mushrooms. PMID:19375827

Bédry, R; Gromb, S

2009-07-01

260

Molecular organization of various collagen fragments as revealed by atomic force microscopy and diffusion-ordered NMR spectroscopy.  

PubMed

Heterogeneous mixtures of collagen fragments can be used as nutrition supplement or as key ingredients for ointments with therapeutic relevance in wound healing. Some mixtures of collagen fragments are referred to as collagen hydrolysates owing to the production process with hydrolytic enzymes. Since the precise composition of collagen hydrolysates is generally unknown, it is of interest to analyze samples containing various collagen fragments with appropriate biophysical methods. Any product optimization without a profound knowledge concerning the size and the molecular weight distribution of its components is nearly impossible. It turned out that a combination of AFM methods with NMR techniques is exceptionally suited to examine the size range and the aggregation behavior of the collagen fragments in the hydrolysates of fish, jellyfish, chicken, porcine and bovine collagen. Supported by molecular modeling calculations, the AFM and NMR experiments provide a detailed knowledge about the composition of collagen hydrolysates and collagen ointments. Furthermore, the data allow a correlation between the size of the fragments and their potential bioactivity. PMID:22855352

Stötzel, Sabine; Schurink, Marloes; Wienk, Hans; Siebler, Uschi; Burg-Roderfeld, Monika; Eckert, Thomas; Kulik, Bianca; Wechselberger, Rainer; Sewing, Judith; Steinmeyer, Jürgen; Oesser, Steffen; Boelens, Rolf; Siebert, Hans-Christian

2012-09-17

261

Prolongation of GFP-expressed skin graft after intrathymic injection of GFP positive splenocytes in adult rat  

NASA Astrophysics Data System (ADS)

GFP is a fluorescent product of the jellyfish Aequorea victoria and has been used for a variety of biological experiments as a reporter molecule. While GFP possesses advantages for the non-invasive imaging of viable cells, GFP-positive cells are still considered potential xeno-antigens. It is difficult to observe the precise fate of transplanted cells/organs in recipients without immunological control. The aim of this study was to determine whether intrathymic injection of GFP to recipients and the depletion of peripheral lymphocytes could lead to donor-specific unresponsiveness to GFP-expressed cell. LEW rats were administered intraperitoneally with 0.2 ml of anti-rat lymphocyte serum (ALS) 1 day prior to intrathymic injection of donor splenocytes or adeno-GFP vector. Donor cells and vector were non-invasively inoculated into the thymus under high frequency ultrasound imaging using an echo-guide. All animals subsequently received a 7 days GFP-expressed skin graft from the same genetic background GFP LEW transgenic rat. Skin graft survival was greater in rats injected with donor splenocytes (23.6+/-9.1) compared with adeno-GFP (13.0+/-3.7) or untreated control rats (9.5+/-1.0). Intrathymic injection of donor antigen into adult rats can induce donor-specific unresponsiveness. Donor cells can be observed for a long-term in recipients with normal immunity using this strategy.

Hakamata, Yoji; Igarashi, Yuka; Murakami, Takashi; Kobayashi, Eiji

2006-03-01

262

[Aluminium content in foods with aluminium-containing food additives].  

PubMed

The aluminium (Al) content of 105 samples, including bakery products made with baking powder, agricultural products and seafoods treated with alum, was investigated. The amounts of Al detected were as follows (limit of quantification: 0.01 mg/g): 0.01-0.37 mg/g in 26 of 57 bakery products, 0.22-0.57 mg/g in 3 of 6 powder mixes, 0.01-0.05 mg/g in all three agricultural products examined, 0.03-0.90 mg/g in 4 of 6 seafood samples, 0.01-0.03 mg/g in 3 of 11 samples of instant noodles, 0.04-0.14 mg/g in 3 of 4 samples of vermicelli, 0.01 mg/g in 1 of 16 soybean products, but none in soybeans. Amounts equivalent to the PTWI of a 16 kg infant were detected in two samples of bakery products, two samples of powder mixes and one sample of salted jellyfish, if each sample was taken once a week. These results suggest that certain foods, depending on the product and the intake, might exceed the PTWI of children, especially infants. PMID:22450671

Ogimoto, Mami; Suzuki, Kumi; Kabashima, Junichiro; Nakazato, Mitsuo; Uematsu, Yoko

2012-01-01

263

Aequorin-based functional assays for G-protein-coupled receptors, ion channels, and tyrosine kinase receptors.  

PubMed

Aequorin is a photoprotein originating from jellyfish, whose luminescent activity is dependent on the concentration of calcium ions. Due to the high sensitivity and low background linked to luminescent assays, as well as to its absence of toxicity and its large linear dynamic range, aequorin has been used as an intracellular calcium indicator since its discovery in the early 1960s. The first applications of aequorin involved its microinjection in cells. The cloning of its gene in 1985 opened the way to the stable expression of aequorin in cell lines or even entire organisms. Here we present the validation of aequorin as a functional assay for the screening of G-protein-coupled receptors, ion channels, and tyrosine kinase receptors, as well as for their pharmacological characterization in agonist and antagonist detection assays. We optimized our cell suspension-based assay and determined that the most sensitive assay was performed at room temperature, with mitochondrially expressed aequorin and using coelenterazine derivative h for reconstitution of aequorin. The robustness of the assay and the current availability of luminometers with integrated injectors allow aequorin to fit perfectly with high throughput functional assays requirements. PMID:12690959

Dupriez, Vincent J; Maes, Karlien; Le Poul, Emmanuel; Burgeon, Emmanuel; Detheux, Michel

2002-01-01

264

Aequorea green fluorescent protein analysis by flow cytometry  

SciTech Connect

The isolation and expression of the cDNA for the green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has highlighted its potential use as a marker for gene expression in a variety of cell types. The longer wavelength peak (470 nm) of GFP`s bimodal absorption spectrum better matches standard fluorescein filter sets; however, it has a considerably lower amplitude than the major absorption peak at 395. In an effort to increase the sensitivity of GFP with routinely available instrumentation, Heim et al. have generated a GFP mutant (serine-65 to threonine; S65T-GFP) which possesses a single absorption peak centered at 490 nm. We have constructed this mutant in order to determine whether it or wild-type GFP (wt-GFP) afforded greater sensitivity when excited near their respective absorption maxima. Using the conventionally available 488 nm and ultraviolet (UV) laser lines from the argon ion laser as well as the 407 nm line from a krypton ion laser with enhanced violet emission, we were able to closely match the absorption maxima of both the S65T and wild-type forms of Aequorea GFP and analyze differences in fluorescence intensity of transiently transfected 293 cells with flow cytometry. The highest fluorescence signal was observed with 488 nm excitation of S65T-GFP relative to all other laser line/GFP pairs. The wt-GFP fluorescence intensity, in contrast, was significantly higher at 407 nm relative to either 488 nm or UV. These results were consistent with parallel spectrofluorometric analysis of the emission spectrum for wt-GFP and S65T- GFP. The relative contribution of cellular autofluorescence at each wavelength was also investigated and shown to be significantly reduced at 407 nm relative to either UV or 488 nm. 29 refs., 5 figs.

Ropp, J.D.; Cuthbertson, R.A.; Donahue, C.J.; Wolfgang-Kimball, D. [Genentech, Inc., San Francisco, CA (United States)] [and others

1995-12-01

265

Flow structures and fluid transport for the hydromedusae Sarsia tubulosa and Aequorea victoria.  

PubMed

The flow structures produced by the hydromedusae Sarsia tubulosa and Aequorea victoria are examined using direct numerical simulation and Lagrangian coherent structures (LCS). Body motion of each hydromedusa is digitized and input to a CFD program. Sarsia tubulosa uses a jetting type of propulsion, emitting a single, strong, fast-moving vortex ring during each swimming cycle while a secondary vortex of opposite rotation remains trapped within the subumbrellar region. The ejected vortex is highly energetic and moves away from the hydromedusa very rapidly. Conversely, A. victoria, a paddling type hydromedusa, is found to draw fluid from the upper bell surface and eject this fluid in pairs of counter-rotating, slow-moving vortices near the bell margins. Unlike S. tubulosa, both vortices are ejected during the swimming cycle of A. victoria and linger in the tentacle region. In fact, we find that A. victoria and S. tubulosa swim with Strouhal numbers of 1.1 and 0.1, respectively. This means that vortices produced by A. victoria remain in the tentacle region roughly 10 times as long as those produced by S. tubulosa, which presents an excellent feeding opportunity during swimming for A. victoria. Finally, we examine the pressure on the interior bell surface of both hydromedusae and the velocity profile in the wake. We find that S. tubulosa produces very uniform pressure on the interior of the bell as well as a very uniform jet velocity across the velar opening. This type of swimming can be well approximated by a slug model, but A. victoria creates more complicated pressure and velocity profiles. We are also able to estimate the power output of S. tubulosa and find good agreement with other hydromedusan power outputs. All results are based on numerical simulations of the swimming jellyfish. PMID:19617437

Lipinski, Doug; Mohseni, Kamran

2009-08-01

266

Minimum clinically significant VAS differences for simultaneous (paired) interval serial pain assessments.  

PubMed

We conducted two studies to determine whether the minimum clinically significant difference in the visual analog scale (VAS) for nearly simultaneous and brief-interval serial assessments of pain is less than that for pain assessment at 20- to 30-minute intervals, using a 10-cm VAS. The first study was a blinded, randomized, placebo-controlled paired trial comparing the pain of intravenous cannulation in both hands (20-minute application of a eutectic mixture of local anesthetics v placebo) of study subjects. The second study was a non-blinded, randomized, paired trial of different treatments for jellyfish stings. In the first study, 37 of 40 subjects indicated that one hand experienced more pain than the other. Eleven of these 37 subjects (30%) indicated differences in VAS values of 1.0 cm or less, with a minimum value of 0.5 cm. In the second study, for all the VAS-based pain comparisons, VAS differences of

Yamamoto, Loren G; Nomura, Jason T; Sato, Renee L; Ahern, Reina M; Snow, Joanne L; Kuwaye, Todd T

2003-05-01

267

Cellular monitoring systems for the assessment of space environmental factors  

NASA Astrophysics Data System (ADS)

Harmful environmental factors - namely ionizing radiation - will continue to influence future manned space missions. The Cellular Biodiagnostic group at the German Aerospace Center (DLR) develops cellular monitoring systems, which include bacterial and mammalian cell systems capable of recognizing DNA damage as a consequence of the presence of genotoxic conditions. Such bioassay or biosensor systems will complement the physical detector systems used in space, insofar as they yield intrinsically biologically weighted measures of cellular responses. Furthermore, synergistic mutagenic and cancerogenic impacts of the radiation environment together with other potentially genotoxic constituents of the space habitat can be quantified using such systems, whose signals are especially relevant for the molecular damage to the DNA or the chromosomes. The experiment Cellular Responses to Radiation in Space (CERASP) has been selected by NASA to be performed on the International Space Station. It will supply basic information on the cellular response to radiation applied in microgravity. One of the biological end-points under investigation will be survival reflected by radiation-dependent reduction of constitutive expression of the enhanced variant of green fluorescent protein (EGFP), originally isolated from the bioluminescent jellyfish Aequorea victoria. A second end-point will be gene activation by space flight conditions in mammalian cells, based on fluorescent promoter reporter systems using the destabilized EGFP variant (d2EGFP). The promoter element to be investigated will reflect the activity of the NF-kB stress response pathway as an anti-apoptotic radiation response. DNA damage will be measured by fluorescent analysis of DNA unwinding (FADU). The systems have worked properly for terrestrial applications during the first experiments. Experiments using accelerated particles produced at the French heavy ion accelerator GANIL have given insights into cellular mechanisms relevant for the exceptional radiation field in space. Keywords: space, green fluorescent protein, radiation, gene activation, bioassay, genotoxicity

Hellweg, C. E.; Arenz, A.; Meier, M. M.; Baumstark-Khan, C.

268

Getting ready for the manned mission to Mars: bioassays for space research  

NASA Astrophysics Data System (ADS)

Harmful environmental factors - namely ionizing radiation - will continue to influence future manned space missions. The Cellular Biodiagnostic group at the German Aerospace Center (DLR) develops cellular monitoring systems, which include bacterial and mammalian cell systems capable of recognizing DNA damage as a consequence of the presence of genotoxic conditions. Such bioassay or biosensor systems will complement the physical detector systems used in space, insofar as they yield intrinsically biologically weighted measures of cellular responses. Furthermore, synergistic mutagenic and cancerogenic impacts of the radiation environment together with other potentially genotoxic constituents of the space habitat can be quantified using such systems, whose signals are especially relevant for the molecular damage to the DNA or the chromosomes. The experiment Cellular Responses to Radiation in Space (CERASP) has been selected by NASA to be performed on the International Space Station. It will supply basic information on the cellular response to radiation applied in microgravity. One of the biological end-points under investigation will be survival reflected by radiation-dependent reduction of constitutive expression of the enhanced variant of green fluorescent protein (EGFP), originally isolated from the bioluminescent jellyfish Aequorea victoria. A second end-point will be gene activation by space flight conditions in mammalian cells, based on fluorescent promoter reporter systems using the destabilized EGFP variant (d2EGFP). The promoter element to be investigated will reflect the activity of the NF-kappaB stress response pathway as an anti-apoptotic radiation response. DNA damage will be measured by fluorescent analysis of DNA unwinding (FADU). The systems have worked properly for terrestrial applications during the first experiments. Experiments using accelerated particles produced at the French heavy ion accelerator GANIL have given insights into cellular mechanisms relevant for the exceptional radiation field in space.

Baumstark-Khan, Christa; Hellweg, Christine E.; Arenz, Andrea; Meier, Matthias M.; Horneck, Gerda

2004-06-01

269

Struan Sutherland--Doyen of envenomation in Australia.  

PubMed

Struan Sutherland (1936-2002) was the doyen of medical research in the field of envenomation and the ultimate authority on the medical management of envenomated victims in Australia for almost 3 decades. In 1981 as Head of Immunology Research of Commonwealth Serum Laboratories (CSL), he produced an antivenom against the Sydney Funnel-web Spider (Atrax robustus)-an accomplishment that had defied numerous previous attempts. Struan also invented the pressure-immobilisation technique of first-aid for snake bite. This ingenious, simple but safe and effective technique revolutionised first-aid management of snake bite and of some other types of envenomation. It made redundant the use of tourniquets and other dangerous first-aid treatments. Similarly, he helped to develop a snake venom detection kit, which enables doctors working at a victim's bedside to ascertain which snake was responsible and which antivenom should be administered. He had a very wide range of research interests and was a prodigious researcher publishing over 200 scientific and medical articles, numerous chapters in books and the standard Australian medical textbook on the management of envenomation, Australian Animal Toxins. He made major contributions to the understanding of the venoms of Australia's remarkable range of fauna including snakes, spiders, Blue-ringed octopus, ants, jellyfish and stinging fish. Struan served the medical fraternity and the public selflessly. He was always available to doctors, or to anybody, to give advice at any hour of the day or night, on management of envenomated victims. Members of the Australian Venom Research Unit, which he founded in 1994 at The University of Melbourne, now continue this 24-h advisory service. PMID:16920170

Tibballs, James

2006-12-01

270

Directed evolution of a monomeric, bright and photostable version of Clavularia cyan fluorescent protein: structural characterization and applications in fluorescence imaging  

SciTech Connect

The arsenal of engineered variants of the GFP [green FP (fluorescent protein)] from Aequorea jellyfish provides researchers with a powerful set of tools for use in biochemical and cell biology research. The recent discovery of diverse FPs in Anthozoa coral species has provided protein engineers with an abundance of alternative progenitor FPs from which improved variants that complement or supersede existing Aequorea GFP variants could be derived. Here, we report the engineering of the first monomeric version of the tetrameric CFP (cyan FP) cFP484 from Clavularia coral. Starting from a designed synthetic gene library with mammalian codon preferences, we identified dimeric cFP484 variants with fluorescent brightness significantly greater than the wild-type protein. Following incorporation of dimer-breaking mutations and extensive directed evolution with selection for blue-shifted emission, high fluorescent brightness and photostability, we arrived at an optimized variant that we have named mTFP1 [monomeric TFP1 (teal FP 1)]. The new mTFP1 is one of the brightest and most photostable FPs reported to date. In addition, the fluorescence is insensitive to physiologically relevant pH changes and the fluorescence lifetime decay is best fitted as a single exponential. The 1.19 {angstrom} crystal structure (1 {angstrom}=0.1 nm) of mTFP1 confirms the monomeric structure and reveals an unusually distorted chromophore conformation. As we experimentally demonstrate, the high quantum yield of mTFP1 (0.85) makes it particularly suitable as a replacement for ECFP (enhanced CFP) or Cerulean as a FRET (fluorescence resonance energy transfer) donor to either a yellow or orange FP acceptor.

Al, Hui-wang; Henderson, J. Nathan; Remington, S. James; Campbell, Robert E. (Alberta); (Oregon)

2008-05-07

271

These Are Not the K-mers You Are Looking For: Efficient Online K-mer Counting Using a Probabilistic Data Structure  

PubMed Central

K-mer abundance analysis is widely used for many purposes in nucleotide sequence analysis, including data preprocessing for de novo assembly, repeat detection, and sequencing coverage estimation. We present the khmer software package for fast and memory efficient online counting of k-mers in sequencing data sets. Unlike previous methods based on data structures such as hash tables, suffix arrays, and trie structures, khmer relies entirely on a simple probabilistic data structure, a Count-Min Sketch. The Count-Min Sketch permits online updating and retrieval of k-mer counts in memory which is necessary to support online k-mer analysis algorithms. On sparse data sets this data structure is considerably more memory efficient than any exact data structure. In exchange, the use of a Count-Min Sketch introduces a systematic overcount for k-mers; moreover, only the counts, and not the k-mers, are stored. Here we analyze the speed, the memory usage, and the miscount rate of khmer for generating k-mer frequency distributions and retrieving k-mer counts for individual k-mers. We also compare the performance of khmer to several other k-mer counting packages, including Tallymer, Jellyfish, BFCounter, DSK, KMC, Turtle and KAnalyze. Finally, we examine the effectiveness of profiling sequencing error, k-mer abundance trimming, and digital normalization of reads in the context of high khmer false positive rates. khmer is implemented in C++ wrapped in a Python interface, offers a tested and robust API, and is freely available under the BSD license at github.com/ged-lab/khmer.

Zhang, Qingpeng; Pell, Jason; Canino-Koning, Rosangela; Howe, Adina Chuang; Brown, C. Titus

2014-01-01

272

Management of multicellular senescence and oxidative stress  

PubMed Central

Progressively sophisticated understanding of cellular and molecular processes that contribute to age-related physical deterioration is being gained from ongoing research into cancer, chronic inflammatory syndromes and other serious disorders that increase with age. Particularly valuable insight has resulted from characterization of how senescent cells affect the tissues in which they form in ways that decrease an organism's overall viability. Increasingly, the underlying pathophysiology of ageing is recognized as a consequence of oxidative damage. This leads to hyperactivity of cell growth pathways, prominently including mTOR (mammalian target of rapamycin), that contribute to a build-up in cells of toxic aggregates such as progerin (a mutant nuclear cytoskeletal protein), lipofuscin and other cellular debris, triggering formation of senescent cellular phenotypes, which interact destructively with surrounding tissue. Indeed, senescent cell ablation dramatically inhibits physical deterioration in progeroid (age-accelerated) mice. This review explores ways in which oxidative stress creates ageing-associated cellular damage and triggers induction of the cell death/survival programs’ apoptosis, necrosis, autophagy and ‘necroapoptophagy’. The concept of ‘necroapoptophagy’ is presented here as a strategy for varying tissue oxidative stress intensity in ways that induce differential activation of death versus survival programs, resulting in enhanced and sustained representation of healthy functional cells. These strategies are discussed in the context of specialized mesenchymal stromal cells with the potential to synergize with telocytes in stabilizing engrafted progenitor cells, thereby extending periods of healthy life. Information and concepts are summarized in a hypothetical approach to suppressing whole-organism senescence, with methods drawn from emerging understandings of ageing, gained from Cnidarians (jellyfish, corals and anemones) that undergo a unique form of cellular regeneration, potentially conferring open-ended lifespans.

Haines, David D; Juhasz, Bela; Tosaki, Arpad

2013-01-01

273

Seeing is believing! Imaging Ca2+-signalling events in living cells  

PubMed Central

Ever since it was shown that maintenance of muscle contraction required the presence of extracellular Ca2+, evidence has accumulated that Ca2+ plays a crucial role in excitation–contraction coupling. This culminated in the use of the photoprotein aequorin to demonstrate that [Ca2+]i increased after depolarization but before contraction in barnacle muscle. Green fluorescent protein was extracted from the same jellyfish as aequorin, so this work also has important historical links to the use of fluorescent proteins as markers in living cells. The subsequent development of cell-permeant Ca2+ indicators resulted in a dramatic increase in related research, revealing Ca2+ to be a ubiquitous cell signal. High-speed, confocal Ca2+ imaging has now revealed subcellular detail not previously apparent, with the identification of Ca2+ sparks. These act as building blocks for larger transients during excitation–contraction coupling in cardiac muscle, but their function in smooth muscle appears more diverse, with evidence suggesting both ‘excitatory’ and ‘inhibitory’ roles. Sparks can activate Ca2+-sensitive Cl? and K+ currents, which exert positive and negative feedback, respectively, on global Ca2+ signalling, through changes in membrane potential and activation of voltage-operated Ca2+ channels. Calcium imaging has also demonstrated that agonists that appear to evoke relatively tonic increases in average [Ca2+]i at the whole tissue level often stimulate much higher frequency phasic Ca2+ oscillations at the cellular level. These findings may require re-evaluation of some of our models of Ca2+ signalling to account for newly revealed cellular and subcellular detail. Future research in the field is likely to make increasing use of genetically coded Ca2+ indicators expressed in an organelle- or tissue-specific manner.

McGeown, J Graham

2010-01-01

274

Management of multicellular senescence and oxidative stress.  

PubMed

Progressively sophisticated understanding of cellular and molecular processes that contribute to age-related physical deterioration is being gained from ongoing research into cancer, chronic inflammatory syndromes and other serious disorders that increase with age. Particularly valuable insight has resulted from characterization of how senescent cells affect the tissues in which they form in ways that decrease an organism's overall viability. Increasingly, the underlying pathophysiology of ageing is recognized as a consequence of oxidative damage. This leads to hyperactivity of cell growth pathways, prominently including mTOR (mammalian target of rapamycin), that contribute to a build-up in cells of toxic aggregates such as progerin (a mutant nuclear cytoskeletal protein), lipofuscin and other cellular debris, triggering formation of senescent cellular phenotypes, which interact destructively with surrounding tissue. Indeed, senescent cell ablation dramatically inhibits physical deterioration in progeroid (age-accelerated) mice. This review explores ways in which oxidative stress creates ageing-associated cellular damage and triggers induction of the cell death/survival programs' apoptosis, necrosis, autophagy and 'necroapoptophagy'. The concept of 'necroapoptophagy' is presented here as a strategy for varying tissue oxidative stress intensity in ways that induce differential activation of death versus survival programs, resulting in enhanced and sustained representation of healthy functional cells. These strategies are discussed in the context of specialized mesenchymal stromal cells with the potential to synergize with telocytes in stabilizing engrafted progenitor cells, thereby extending periods of healthy life. Information and concepts are summarized in a hypothetical approach to suppressing whole-organism senescence, with methods drawn from emerging understandings of ageing, gained from Cnidarians (jellyfish, corals and anemones) that undergo a unique form of cellular regeneration, potentially conferring open-ended lifespans. PMID:23789967

Haines, David D; Juhasz, Bela; Tosaki, Arpad

2013-08-01

275

Assessment of CaMV-mediated gene silencing and integration of CaMV into GM plants with a 35S RNA promoter.  

PubMed

Four GM plant species (Arabidopsis thaliana, Brassica napus, Nicotiana benthamiana and N. tabacum), each expressing the gene encoding the jellyfish green fluorescent protein (GFP) regulated by the cauliflower mosaic virus (CaMV) 35S RNA promoter, were assessed for the extent of transgene silencing and viral genome integration following infection by CaMV. The first three species are systemic hosts of CaMV, while N. tabacum is only a local host for a few strains of CaMV. A generalized systemic silencing of the GFP transgene was not observed in a total of 100 plants of each species infected with CaMV, although some localized loss of GFP was observed in CaMV-infected N. benthamiana leaves, and some loss of fluorescence was observed in older leaves of uninfected as well as infected plants. Progeny seedlings obtained from the above infected plants also did not exhibit transgene silencing showing that virus infection did not affect the stability of the transgene. These progeny plants also did not show signs of virus infection, indicating that the presence of the CaMV 35S RNA promoter sequences in the plant genome did not potentiate seed transmission of the virus. Integration of infective CaMV into the CaMV 35S RNA promoter could not be detected in 944 samples taken from leaves of the above infected plant species or in 2912 samples taken from progeny seedlings. Based on a detection limit of one copy per 4000 haploid genomes, we conclude that if integration of virus does occur into the CaMV 35S RNA promoter, then it occurs at such a low frequency as to be insignificant. PMID:18289501

Squires, Julie; Stephens, Jennifer; Shoelz, James E; Palukaitis, Peter

2007-01-01

276

An ecological model of the Northern and Central Adriatic Sea: Analysis of ecosystem structure and fishing impacts  

NASA Astrophysics Data System (ADS)

A trophic mass-balance model was developed to characterise the food web structure and functioning of the Northern and Central Adriatic Sea and to quantify the ecosystem impacts of fishing during the 1990s. Forty functional groups were described, including target and non-target fish and invertebrate groups, and three detritus groups (natural detritus, discards and by-catch of cetaceans and marine turtles). Results highlighted that there was an important coupling between pelagic-benthic production of plankton, benthic invertebrates and detritus. Organisms located at low and medium trophic levels, (i.e. benthic invertebrates, zooplankton and anchovy), as well as dolphins, were identified as keystone groups of the ecosystem. Jellyfish were an important element in terms of consumption and production of trophic flows within the ecosystem. The analysis of trophic flows of zooplankton and detritus groups indirectly underlined the importance of the microbial food web in the Adriatic Sea. Fishing activities inflicted notable impacts on the ecosystem during the 1990s, with a high gross efficiency of the fishery, a high consumption of fishable production, high exploitation rates for various target and non target species, a low trophic level of the catch and medium values of primary production required to sustain the fishery. Moreover, the analysis of Odum's ecological indicators highlighted that the ecosystem was in a low-medium developmental stage. Bottom trawling ( Strascico), mid-water trawling ( Volante) and beam trawling ( Rapido) fleets had the highest impacts on both target and non target ecological groups. On the contrary, purse seining ( Lampara) showed medium to low impacts on the ecosystem; cetaceans, marine turtles and sea birds were not significantly involved in competition with fishing activity.

Coll, Marta; Santojanni, Alberto; Palomera, Isabel; Tudela, Sergi; Arneri, Enrico

2007-08-01

277

The Skp chaperone helps fold soluble proteins in vitro by inhibiting aggregation*  

PubMed Central

The periplasmic seventeen kilodalton protein (Skp) chaperone has been characterized primarily for its role in outer membrane protein (OMP) biogenesis, during which the jellyfish-like trimeric protein encapsulates partially folded OMPs, protecting them from the aqueous environment until delivery to the BAM outer membrane protein insertion complex. However, Skp is increasingly recognized as a chaperone that also assists in folding soluble proteins in the bacterial periplasm. In this capacity, Skp co-expression increases the active yields of many recombinant proteins and bacterial virulence factors. Using a panel of single-chain antibodies and a single-chain T-cell receptor (collectively termed scFvs) possessing varying stabilities and biophysical characteristics, we performed in vivo expression, and in vitro folding and aggregation assays in the presence or absence of Skp. For Skp-sensitive scFvs, the presence of Skp during in vitro refolding assays reduced aggregation but did not alter the observed folding rates, resulting in a higher overall yield of active protein. Of the proteins analyzed, Skp sensitivity in all assays correlated with the presence of folding intermediates, as observed with urea denaturation studies. These results are consistent with Skp acting as a holdase, sequestering partially folded intermediates and thereby preventing aggregation. Because not all soluble proteins are sensitive to Skp co-expression, we hypothesize that the presence of a long-lived protein folding intermediate renders a protein sensitive to Skp. Improved understanding of the bacterial periplasmic protein folding machinery may assist in high-level recombinant protein expression and may help identify novel approaches to block bacterial virulence.

Entzminger, Kevin C.; Chang, Christine; Myhre, Ryan O.; McCallum, Katie C.; Maynard, Jennifer A.

2013-01-01

278

Star formation in the massive cluster merger Abell 2744  

NASA Astrophysics Data System (ADS)

We present a comprehensive study of star-forming (SF) galaxies in the Hubble Space Telescope (HST) Frontier Field recent cluster merger A2744 (z = 0.308). Wide-field, ultraviolet-infrared (UV-IR) imaging enables a direct constraint of the total star formation rate (SFR) for 53 cluster galaxies, with SFRUV+IR = 343 ± 10 M? yr-1. Within the central 4 arcmin (1.1 Mpc) radius, the integrated SFR is complete, yielding a total SFRUV+IR = 201 ± 9 M? yr-1. Focusing on obscured star formation, this core region exhibits a total SFRIR = 138 ± 8 M? yr-1, a mass-normalized SFRIR of ?SFR = 11.2 ± 0.7 M? yr-1 per 1014 M? and a fraction of IR-detected SF galaxies f_SF = 0.080^{+0.010}_{-0.037}. Overall, the cluster population at z ˜ 0.3 exhibits significant intrinsic scatter in IR properties (total SFRIR, Tdust distribution) apparently unrelated to the dynamical state: A2744 is noticeably different to the merging Bullet cluster, but similar to several relaxed clusters. However, in A2744 we identify a trail of SF sources including jellyfish galaxies with substantial unobscured SF due to extreme stripping (SFRUV/SFRIR up to 3.3). The orientation of the trail, and of material stripped from constituent galaxies, indicates that the passing shock front of the cluster merger was the trigger. Constraints on star formation from both IR and UV are crucial for understanding galaxy evolution within the densest environments.

Rawle, T. D.; Altieri, B.; Egami, E.; Pérez-González, P. G.; Richard, J.; Santos, J. S.; Valtchanov, I.; Walth, G.; Bouy, H.; Haines, C. P.; Okabe, N.

2014-07-01

279

Burst Feeding of Pelagia noctiluca ephyrae on Atlantic Bluefin Tuna (Thunnus thynnus) Eggs  

PubMed Central

This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT) eggs under different experimental conditions. The specific factors considered in the experimental design were: a) water mix conditions to explore predation under two-dimensional (2D) and three-dimensional (3D) prey distributions, b) prey density to investigate the ingestion rate capacity, and c) incubation time to inspect gut saturation. The eggs and jellyfish ephyrae were collected during the 2012 ABFT spawning survey off Ibiza (Balearic Isl., Western Mediterranean). The results showed that the proportion of feeding ephyrae increased with size. The mean clearance rate of feeding ephyrae, 4.14 L h-1, was the highest ever recorded for ephyrae. Under calm conditions the eggs floated at the surface (2D spatial arrangement) and the clearance rates, at low prey densities, were at least twice those under mixed conditions (3D spatial arrangement). At high prey density, clearance rate did not differ between mix conditions, probably due to the fast gut saturation, which was reached in c.a. 15 min, as revealed by time series observations of gut contents. The fast saturation of ephyrae and their slow digestion time of approximately 18 h suggest the existence of a diel feeding periodicity. We conclude that in the Western Mediterranean, P. noctiluca ephyrae are capable of predating on ABFT eggs, a highly pulsed and spatially restricted resource that potentially switches from a 3D to a 2D configuration in the absence of wind-generated turbulence. The P. noctiluca and Atlantic Bluefin tuna egg system might represent an example of a general mechanism linking pelagic and neustonic food webs.

Gordoa, Ana; Acuna, Jose Luis; Farres, Roser; Bacher, Kathrin

2013-01-01

280

To Eat or Not to Eat? Debris Selectivity by Marine Turtles  

PubMed Central

Marine debris is a growing problem for wildlife, and has been documented to affect more than 267 species worldwide. We investigated the prevalence of marine debris ingestion in 115 sea turtles stranded in Queensland between 2006–2011, and assessed how the ingestion rates differ between species (Eretmochelys imbricata vs. Chelonia mydas) and by turtle size class (smaller oceanic feeders vs. larger benthic feeders). Concurrently, we conducted 25 beach surveys to estimate the composition of the debris present in the marine environment. Based on this proxy measurement of debris availability, we modeled turtles’ debris preferences (color and type) using a resource selection function, a method traditionally used for habitat and food selection. We found no significant difference in the overall probability of ingesting debris between the two species studied, both of which have similar life histories. Curved carapace length, however, was inversely correlated with the probability of ingesting debris; 54.5% of pelagic sized turtles had ingested debris, whereas only 25% of benthic feeding turtles were found with debris in their gastrointestinal system. Benthic and pelagic sized turtles also exhibited different selectivity ratios for debris ingestion. Benthic phase turtles had a strong selectivity for soft, clear plastic, lending support to the hypothesis that sea turtles ingest debris because it resembles natural prey items such as jellyfish. Pelagic turtles were much less selective in their feeding, though they showed a trend towards selectivity for rubber items such as balloons. Most ingested items were plastic and were positively buoyant. This study highlights the need to address increasing amounts of plastic in the marine environment, and provides evidence for the disproportionate ingestion of balloons by marine turtles.

Schuyler, Qamar; Hardesty, Britta Denise; Wilcox, Chris; Townsend, Kathy

2012-01-01

281

Puncture mechanics of cnidarian cnidocysts: a natural actuator  

PubMed Central

Background Cnidocysts isolated from cnidarian organisms are attractive as a drug-delivery platform due to their fast, efficient delivery of toxins. The cnidocyst could be utilized as the means to deliver therapeutics in a wearable drug-delivery patch. Cnidocysts have been previously shown to discharge upon stimulation via electrical, mechanical, and chemical pathways. Cnidocysts isolated from the Portuguese Man O' War jellyfish (Physalia physalis) are attractive for this purpose because they possess relatively long threads, are capable of puncturing through hard fish scales, and are stable for years. Results As a first step in using cnidocysts as a functional component of a drug delivery system, the puncture mechanics of the thread were characterized. Tentacle-contained cnidocysts were used as a best-case scenario due to physical immobilization of the cnidocysts within the tentacle. Ex vivo tentacle-contained cnidocysts from Physalia possessed an elastic modulus puncture threshold of approximately 1-2 MPa, based on puncture tests of materials with a gamut of hardness. Also, a method for inducing discharge of isolated cnidocysts was found, utilizing water as the stimulant. Preliminary lectin-binding experiments were performed using fluorophore-conjugated lectins as a possible means to immobilize the isolated cnidocyst capsule, and prevent reorientation upon triggering. Lectins bound homogeneously to the surface of the capsule, suggesting the lectins could be used for cnidocyst immobilization but not orientation. Conclusion Cnidocysts were found to puncture materials up to 1 MPa in hardness, can be discharged in a dry state using water as a stimulant, and bind homogeneously to lectins, a potential means of immobilization. The information gained from this preliminary work will aid in determining the materials and design of the patch that could be used for drug delivery.

Oppegard, Shawn C; Anderson, Peter A; Eddington, David T

2009-01-01

282

Energy, ageing, fidelity and sex: oocyte mitochondrial DNA as a protected genetic template  

PubMed Central

Oxidative phosphorylation couples ATP synthesis to respiratory electron transport. In eukaryotes, this coupling occurs in mitochondria, which carry DNA. Respiratory electron transport in the presence of molecular oxygen generates free radicals, reactive oxygen species (ROS), which are mutagenic. In animals, mutational damage to mitochondrial DNA therefore accumulates within the lifespan of the individual. Fertilization generally requires motility of one gamete, and motility requires ATP. It has been proposed that oxidative phosphorylation is nevertheless absent in the special case of quiescent, template mitochondria, that these remain sequestered in oocytes and female germ lines and that oocyte mitochondrial DNA is thus protected from damage, but evidence to support that view has hitherto been lacking. Here we show that female gametes of Aurelia aurita, the common jellyfish, do not transcribe mitochondrial DNA, lack electron transport, and produce no free radicals. In contrast, male gametes actively transcribe mitochondrial genes for respiratory chain components and produce ROS. Electron microscopy shows that this functional division of labour between sperm and egg is accompanied by contrasting mitochondrial morphology. We suggest that mitochondrial anisogamy underlies division of any animal species into two sexes with complementary roles in sexual reproduction. We predict that quiescent oocyte mitochondria contain DNA as an unexpressed template that avoids mutational accumulation by being transmitted through the female germ line. The active descendants of oocyte mitochondria perform oxidative phosphorylation in somatic cells and in male gametes of each new generation, and the mutations that they accumulated are not inherited. We propose that the avoidance of ROS-dependent mutation is the evolutionary pressure underlying maternal mitochondrial inheritance and the developmental origin of the female germ line.

de Paula, Wilson B. M.; Lucas, Cathy H.; Agip, Ahmed-Noor A.; Vizcay-Barrena, Gema; Allen, John F.

2013-01-01

283

Scyphozoa in the Bornholm Basin (central Baltic Sea) The role of advection  

NASA Astrophysics Data System (ADS)

The usual absence of ephyrae and late appearance of medusae of the Scyphozoa Aurelia aurita and Cyanea capillata in the Bornholm Basin (BB; central Baltic Sea) indicate that these species are not strobilating in the region and their presence depends on advection. To study their potential origin we compared drift from historically known strobilation areas derived from a circulation model with spatial distributions observed during 19 cruises in the BB during 2002 and 2003. The model results are in good accordance with the field observations. According to the model results inter-annual differences in the timing of first appearance and life stage at appearance of A. aurita were clearly related to differences in the hydrodynamic regime during the investigation periods. During the stagnation regime in 2002 young medusae occurred first in June in the BB. In contrast, in 2003 fast transport due to several inflow events advected ephyrae released between January and March in the western Baltic already in April to the BB. Although the Gullmar Fjord (western Sweden) is the nearest known strobilation area for C. capillata, the model did not support advection from there in numbers explaining the occurrence of this species in the BB in 2002 and 2003. If the model works adequately in this regions we have to assume that the Gullmar Fjord is not a main source region of C. capillata in the BB, but other strobilation areas in the Kattegat or the North Sea appear more important. Our results imply that advection and inflow events are critical for the occurrence and distribution of early stages of jellyfish in the central Baltic Sea. They demonstrate the potential of circulation models as tools to study the effect of long-range transport on the spatial composition of these organisms.

Barz, Kristina; Hinrichsen, Hans-Harald; Hirche, Hans-Jürgen

2006-04-01

284

Assessing Fishing and Marine Biodiversity Changes Using Fishers' Perceptions: The Spanish Mediterranean and Gulf of Cadiz Case Study  

PubMed Central

Background The expansion of fishing activities has intensively transformed marine ecosystems worldwide. However, available time series do not frequently cover historical periods. Methodology Fishers' perceptions were used to complement data and characterise changes in fishing activity and exploited ecosystems in the Spanish Mediterranean Sea and Gulf of Cadiz. Fishers' interviews were conducted in 27 fishing harbours of the area, and included 64 fishers from ages between 20 to >70 years old to capture the experiences and memories of various generations. Results are discussed in comparison with available independent information using stock assessments and international convention lists. Principal Findings According to fishers, fishing activity substantially evolved in the area with time, expanding towards deeper grounds and towards areas more distant from the coast. The maximum amount of catch ever caught and the weight of the largest species ever captured inversely declined with time. Fishers (70%) cited specific fishing grounds where depletion occurred. They documented ecological changes of marine biodiversity during the last half of the century: 94% reported the decline of commercially important fish and invertebrates and 61% listed species that could have been extirpated, with frequent mentions to cartilaginous fish. Declines and extirpations were in line with available quantitative evaluations from stock assessments and international conventions, and were likely linked to fishing impacts. Conversely, half of interviewed fishers claimed that several species had proliferated, such as cephalopods, jellyfish, and small-sized fish. These changes were likely related to trophic cascades due to fishing and due to climate change effects. The species composition of depletions, local extinctions and proliferations showed differences by region suggesting that regional dynamics are important when analysing biodiversity changes. Conclusions/Significance Using fishers' perceptions, fishing and ecological changes in the study area were documented. The recovery of local ecological knowledge provides valuable information complementing quantitative monitoring and evaluation surveys.

Coll, Marta; Carreras, Marta; Ciercoles, Cristina; Cornax, Maria-Jose; Gorelli, Giulia; Morote, Elvira; Saez, Raquel

2014-01-01

285

CgDN3: an essential pathogenicity gene of colletotrichum gloeosporioides necessary to avert a hypersensitive-like response in the host Stylosanthes guianensis.  

PubMed

A gene of Colletotrichum gloeosporioides that is induced by nitrogen starvation in axenic culture and is expressed at the early stages of infection of the host Stylosanthes guianensis has been identified and its role in pathogenicity tested. The sequence of this gene, named CgDN3, indicated that it encodes a protein of 74 amino acids that contains a predicted 18 amino acid signal sequence for secretion of a basic 54 amino acid mature protein with weak homology to an internal region of plant wall-associated receptor kinases. Mutants of C. gloeosporioides were produced by homologous recombination in which part of the coding sequence and promoter region of the CgDN3 gene was replaced with a hygromycin-resistance gene cassette. Mutations in the CgDN3 gene were confirmed in two independent transformants and Northern (RNA) analysis demonstrated the disrupted CgDN3 gene was not expressed. The mutants had faster mycelial growth rates in vitro but produced spores that germinated to form appressoria normally on the leaf surface. However, the CgDN3 mutants were unable to infect and reproduce on intact host leaves. Microscopic analysis revealed small clusters of necrotic host cells at inoculation sites on leaves, suggesting that these mutants elicited a localized, host hypersensitive-like response. The mutants were able to grow necrotrophically and reproduce on leaves when conidia were inoculated directly onto wound sites. The putative promoter region of the CgDN3 gene was fused to a gene encoding a modified jellyfish green fluorescent protein and introduced into the fungus. Following inoculation, strong expression of green fluorescent protein was observed in primary infection vesicles in infected epidermal cells with weaker expression evident in hyphae growing within infected leaf tissue. These findings indicate that CgDN3 encodes a novel pathogenicity determinant associated with the biotrophic phase of primary infection and required to avert a hypersensitive-like response by a compatible host. PMID:10975650

Stephenson, S A; Hatfield, J; Rusu, A G; Maclean, D J; Manners, J M

2000-09-01

286

Green Fluorescent Protein as a Novel Indicator of Antimicrobial Susceptibility in Aureobasidium pullulans  

PubMed Central

Presently there is no method available that allows noninvasive and real-time monitoring of fungal susceptibility to antimicrobial compounds. The green fluorescent protein (GFP) of the jellyfish Aequoria victoria was tested as a potential reporter molecule for this purpose. Aureobasidium pullulans was transformed to express cytosolic GFP using the vector pTEFEGFP (A. J. Vanden Wymelenberg, D. Cullen, R. N. Spear, B. Schoenike, and J. H. Andrews, BioTechniques 23:686–690, 1997). The transformed strain Ap1 gfp showed bright fluorescence that was amenable to quantification using fluorescence spectrophotometry. Fluorescence levels in Ap1 gfp blastospore suspensions were directly proportional to the number of viable cells determined by CFU plate counts (r2 > 0.99). The relationship between cell viability and GFP fluorescence was investigated by adding a range of concentrations of each of the biocides sodium hypochlorite and 2-n-octylisothiozolin-3-one (OIT) to suspensions of Ap1 gfp blastospores (pH 5 buffer). These biocides each caused a rapid (<25-min) loss of fluorescence of greater than 90% when used at concentrations of 150 ?g of available chlorine ml?1 and 500 ?g ml?1, respectively. Further, loss of GFP fluorescence from A. pullulans cells was highly correlated with a decrease in the number of viable cells (r2 > 0.92). Losses of GFP fluorescence and cell viability were highly dependent on external pH; maximum losses of fluorescence and viability occurred at pH 4, while reduction of GFP fluorescence was absent at pH 8.0 and was associated with a lower reduction in viability. When A. pullulans was attached to the surface of plasticized poly(vinylchloride) containing 500 ppm of OIT, fluorescence decreased more slowly than in cell suspensions, with >95% loss of fluorescence after 27 h. This technique should have broad applications in testing the susceptibility of A. pullulans and other fungal species to antimicrobial compounds.

Webb, Jeremy S.; Barratt, Sarah R.; Sabev, Hristo; Nixon, Marianne; Eastwood, Ian M.; Greenhalgh, Malcolm; Handley, Pauline S.; Robson, Geoffrey D.

2001-01-01

287

North Sea Scyphomedusae; summer distribution, estimated biomass and significance particularly for 0-group Gadoid fish  

NASA Astrophysics Data System (ADS)

Data on the by-catch of Scyphomedusae from pelagic trawls was collected during the routine ICES International 0-group Gadoid Surveys of the North Sea, in June and July of the years 1971-1986 (except 1984). These data are used to describe the distributions, abundances and biomasses of three common North Sea Scyphomedusae: Aurelia aurita (L.), Cyanea capillata (L.) and C. lamarckii (Péron & Lesuer). Information is also presented on inter-annual variability, size (umbrella diameter) frequencies and, for the Cyanea species, umbrella diameter: wet weight relationships. The general role and ecological significance of Scyphomedusae is discussed and, given the well known 'shelter' relationships between Scyphomedusae and certain 0-group fish, whiting ( Merlangius merlangus) and haddock ( Melanogrammus aeglefinus), in particular. The data were examined for evidence of such relationships. Aurelia aurita, although fairly widespread in the northern North Sea was virtually absent from the central North Sea but very abundant in coastal waters. This species was particularly abundant off the Scottish east coast and especially in the Moray Firth. Cyanea lamerckii was most abundant in the southern and eastern North Sea. More widespread than Aurelia, this species was also most abundant in coastal regions, particularly off the Danish west coast. Cyanea capillata, with a more northern distribution was also more widely distributed and abundant offshore. This species was most abundant in the area between the Orkney/Shetland Isles and the Norwegian Deep and in shelf waters of the north west approaches to the North Sea. As with C. lamarckii it was also, in some years, abundant off the Scottish east coast and west of Denmark. The abundance and the size frequency of the jellyfish show considerable inter-annual variability, and variability between regions of the North Sea. It is considered that hydrographic variability and differences in food supply to both medusae and to their sessile benthic polyps, are the major causes of the observed differences between years and areas. The impact of Scyphomedusae on fishing and recreational activities is discussed.

Hay, S. J.; Hislop, J. R. G.; Shanks, A. M.

288

Gelatinous macroplankton in the Black Sea in the autumn of 2010  

NASA Astrophysics Data System (ADS)

In October and November of 2010, the gelatinous macroplankton in the northwestern Black Sea and at the Crimean shelf was represented by the scyphozoan jellyfish Aurelia aurita, three species of ctenophores ( Beroe ovata, Mnemiopsis leidyi, and Pleurobrachia pileus), and three species of hydromedusae. A. aurita was more common at the shelf, M. leidyi and P. pileus prevailed at the deeper sea stations, and B. ovata was almost ubiquitous with a biomass from below 1 to 49 g/m2 A. aurita, which had an average biomass of 82-224 g/m2, was dominant at all the stations. M. leidyi, which had a biomass from below 1 to 115 g/m2, was recorded in October at only 14 of the 52 stations and in November at 20 of the 46 stations. The highest biomass of M. leidyi in October (105 to 116 g/m2) was recorded in the deep sea areas; in November, it was also the highest in these areas, but it reached at most 100 g/m2. The average daily ration of Aurelia ranged from 19.4 to 27.3 mg/m2 in October and from 7.0 to 17.2 mg/m2 in November; in both cases, it was insufficient to provide for the minimal physiological requirements. The average daily ration of the Mnemiopsis population (2.8-20.5 mg of zooplankton per m2) was invariably more than sufficient to provide for the minimal physiological requirements. Both predatory species together consumed less than 5% of the daily zooplankton production of the sea.

Anninsky, B. E.; Finenko, G. A.; Datsyk, N. A.; Ignatyev, S. M.

2013-11-01

289

A new short-term toxicity assay using Aspergillus awamori with recombinant aequorin gene  

PubMed Central

Background Most currently available short-term toxicity assays are based on bacterial cells. Therefore there is a need for novel eukaryotic microbial bioassays that will be relevant to higher eukaryotes such as animals and plants. Ca2+ is a universal intracellular signalling molecule found in all organisms from prokaryotes to highly specialized animal cells. In fungi calcium has been demonstrated to be involved in control of many important processes. The recombinant aequorin gene from the jellyfish Aequorea victoria responsible for the expression of the Ca2+-sensitive aequorin photoprotein has been cloned in the filamentous fungus Aspergillus awamori. This has allowed real life monitoring of [Ca2+]c changes in living fungal cells. When subjected to different physico-chemical stimuli fungal cells respond by transiently changing the concentration of free Ca2+ in the cytosol ([Ca2+]c) and the pattern of these changes (Ca2+ signature) is specific to each particular stimulus. Therefore it was interesting to investigate whether different environmental toxicants would be able to affect the pattern of [Ca2+]c changes in a reproducible and dose dependant manner. Results Toxicity bioassay has been developed to monitor changes [Ca2+]c of the recombinant fungus in the presence of toxicants representing heavy metals – Cr6+ and Zn2+ and a phenolic polar narcotic -3,5-DCP. The fungus responds to toxicants by a decrease in the amplitude of [Ca2+]c response to 5 mM external CaCl2 and an increase in Ca2+ final resting levels and recovery time. Conclusion A novel toxicity bioassay utilizing eukaryotic cells has been developed based on filamentous fungi transformed with the recombinant aequorin gene. A range of parameters characterising changes in [Ca2+]c has been identified, e.g. Amplitude, Length of Transient, Final Resting Level and Recovery Time. These parameters can be used to determine the toxicity of a range of chemicals to eukaryotic cells in a 96-well microtitre plate method.

Kozlova, Olga; Zwinderman, Mark; Christofi, Nick

2005-01-01

290

Identifying Thresholds for Ecosystem-Based Management  

PubMed Central

Background One of the greatest obstacles to moving ecosystem-based management (EBM) from concept to practice is the lack of a systematic approach to defining ecosystem-level decision criteria, or reference points that trigger management action. Methodology/Principal Findings To assist resource managers and policymakers in developing EBM decision criteria, we introduce a quantitative, transferable method for identifying utility thresholds. A utility threshold is the level of human-induced pressure (e.g., pollution) at which small changes produce substantial improvements toward the EBM goal of protecting an ecosystem's structural (e.g., diversity) and functional (e.g., resilience) attributes. The analytical approach is based on the detection of nonlinearities in relationships between ecosystem attributes and pressures. We illustrate the method with a hypothetical case study of (1) fishing and (2) nearshore habitat pressure using an empirically-validated marine ecosystem model for British Columbia, Canada, and derive numerical threshold values in terms of the density of two empirically-tractable indicator groups, sablefish and jellyfish. We also describe how to incorporate uncertainty into the estimation of utility thresholds and highlight their value in the context of understanding EBM trade-offs. Conclusions/Significance For any policy scenario, an understanding of utility thresholds provides insight into the amount and type of management intervention required to make significant progress toward improved ecosystem structure and function. The approach outlined in this paper can be applied in the context of single or multiple human-induced pressures, to any marine, freshwater, or terrestrial ecosystem, and should facilitate more effective management.

Samhouri, Jameal F.; Levin, Phillip S.; Ainsworth, Cameron H.

2010-01-01

291

Imprudent fishing harvests and consequent trophic cascades on the West Florida shelf over the last half century: A harbinger of increased human deaths from paralytic shellfish poisoning along the southeastern United States, in response to oligotrophication?  

NASA Astrophysics Data System (ADS)

Within the context of ubiquitous overfishing of piscivores, recent consequent increments of jellyfish and clupeids have occurred at the zooplanktivore trophic level in the eastern Gulf of Mexico (GOM), after overfishing of one of their predators, i.e. red snapper. Initiation of a local trophic cascade thence led to declines of herbivore stocks, documented here on the West Florida shelf. These exacerbating world-wide trophic cascades have resulted in larger harmful algal blooms (HABs), already present at the base of most coastal food webs. Impacts on human health have thus far been minimal within nutrient-rich coastal regions. To provide a setting for past morbidities, consideration is given to chronologies of other trophic cascades within eutrophic, cold water marine ecosystems of the Scotian Sea, in the Gulf of Alaska, off Southwest Africa, within the Barents, White, and Black Seas, in the Gulf of Maine, and finally in the North Sea. Next, comparison is now made here of recent ten-fold increments within Florida waters of both relatively benign and saxitoxic HABs, some of which are fatal to humans. These events are placed in a perspective of other warm shelf systems of the South China and Caribbean Seas to assess prior and possible future poison toxicities of oligotrophic coastal habitats. Past wide-spread kills of fishes and sea urchins over the Caribbean Sea and the downstream GOM are examined in relation to the potential transmission of dinoflagellate saxitoxin and other epizootic poison vectors by western boundary currents over larger "commons" than local embayments. Furthermore, since some HABs produce more potent saxitoxins upon nutrient depletion, recent decisions to ban seasonal fertilizer applications to Florida lawns may have unintended consequences. In the future, human-killing phytoplankton, rather than relatively benign fish-killing HABs of the past, may be dispersed along the southeastern United States seaboard.

Walsh, J. J.; Tomas, C. R.; Steidinger, K. A.; Lenes, J. M.; Chen, F. R.; Weisberg, R. H.; Zheng, L.; Landsberg, J. H.; Vargo, G. A.; Heil, C. A.

2011-06-01

292

Transuranium radionuclide pollution in the waters of the La Maddalena National Marine Park.  

PubMed

Following the grounding and subsequent explosion, in October 2003, of a nuclear submarine in the waters of the La Maddalena National Marine Park, fears arose of possible radioactive leakages. However, isotopic analyses on algae showed that the gamma-ray emitting artificial radionuclides that one might expect to leak from a damaged nuclear reactor (such as U-235, I-131, Cs-137) were absent, and that U-238/U-234 activities were in equilibrium with values typical of sea water; this excluded any direct anthropogenic contamination as a result of the accident. We used alpha autoradiographic techniques to detect possible traces of transuranium radionuclides; 160 samples of algae, granites, sea urchins, gastropods, limpets, cuttlefish and jellyfish were collected from the area, as well as from other Mediterranean coastlines and the Baltic Sea. All samples were autoradiographed, and selected samples further analysed by alpha spectrometry. There were no alpha track concentrations above background levels in our control Mediterranean specimens. In the samples from the La Maddalena and Baltic areas two different track distributions were observed: --those homogeneously distributed over the surfaces examined; --groups (10 to over 500) of radially distributed alpha tracks (forming "star" bursts, or "hot spots") emanating from point sources. By comparing radionuclide activities measured by alpha spectroscopy with alpha track densities, we extrapolated Pu activities for all samples. About 74% of algae had Pu activities of less than 1 Bq/kg and 0.25 Bq/kg, 16% had accumulated Pu to levels between 1 and 2 Bq/kg, and a very few specimens had concentrations between 2 and 6 Bq/kg. Plots showed that alpha tracks and stars concentrate around the northern and eastern margins of the Rada (Basin) di Santo Stefano, sites facing the nuclear submarine base on the eastern shore of the island of Santo Stefano. What is the source of these nuclides: last century's atmospheric nuclear testing, Chernobyl or a local source? Their concentrated, extremely localised occurrence seems difficult to explain in terms of left-over worldwide nuclear pollution. A local source seems more plausible. PMID:15829338

Aumento, F; Le Donne, K; Eroe, K

2005-01-01

293

Mass and energy transfer to seabirds in the southeastern Bering Sea  

NASA Astrophysics Data System (ADS)

It has been hypothesized that differentiation in food web structure occurs across the Bering Sea continental shelf as a result of seasonal differentiation of water masses. We tested this idea using an apex predator, pelagic birds. Seasonal abundance of birds in central Bristol Bay was estimated from counts made while underway between hydrographic stations. Prey and body mass were determined from birds collected at sea. Daily intake was estimated as an allometric function of body mass. Annual occupancy was estimated as the integral of a normal curve fit to seasonal data. Estimated carbon flux to seabirds in the middle domain was 0.12 gC m -2 y -1 in 1980, 0.18 gC m -2 y -1 in 1981. Carbon flux to seabirds in the adjacent waters of the outer shelf domain was 1.8 times higher than in the middle domain in 1980, 1.6 times higher in 1981. Carbon flux to seabirds in the inner domain was 1.2 times higher than in the middle domain in 1980, and 3.3 times higher in 1981. Carbon flux to seabirds in the outer domain was due primarily to non-diving species, principally northern fulmars ( Fulmarus glacialis) during the summer and autumn, and Larus gulls in the autumn and winter. Flux to seabirds in the inner domain was due to diving birds, principally murres ( Uria sp.) in the spring and shearwaters ( Puffinus sp.) during the summer. The euphausiid Thysanoessa raschii was the primary food source of shearwaters in shallow waters of the inner shelf domain. A more diverse set of prey, including squid, jellyfish, hyperiids, and fish, was taken by shearwaters and fulmars in the deeper waters of the outer and middle shelf domains. This result suggests that prey diversity is higher in seasonally stratified waters of outer Bristol Bay than in mixed waters of inner Bristol Bay. Greater energy flux to diving species in shallow water, and greater energy flux to non-divers in deep water may be a function of topographic control of prey patchiness.

Schneider, David C.; Hunt, George L.; Harrison, Nancy M.

294

A framework and model system to investigate linear system behavior in Escherichia coli  

PubMed Central

Background The ability to compose biological systems from smaller elements that act independently of the other upon assembly may help make the forward engineering of biological systems practical. Engineering biology in this manner is made difficult by the inherent nonlinear response of organisms to genetic devices. Devices are inevitably coupled to one another in the cell because they share the same transcriptional machinery for expression. Thus, new properties can emerge when devices that had been characterized in isolation are expressed concurrently. We show in this report that, similar to physical systems, the Escherichia coli (E. coli) transcriptional system can exhibit linear behavior under "small" perturbation conditions. This, in turn, allows devices to be treated as independent modules. Results We developed a framework and model system consisting of three devices to investigate linear system behavior in E. coli. Our framework employed the transfer curve concept to determine the amount of nonlinearity elicited by the E. coli transcriptional system in response to the devices. To this effect, the model system was quantitatively characterized using real-time quantitative PCR to produce device transfer curves (DTCs). Two of the devices encoded the bacterial neomycin phosphotransferase II (nptII) and chloramphenicol acetyl transferase (cat), while the third encoded the jellyfish-originating green fluorescent protein (gfp). The gfp device was the most nonlinear in our system, with nptII and cat devices eliciting linear responses. Superposition experiments verified these findings, with independence among the three devices having been lost when gfp was present at copy numbers above the lowest one used. Conclusions We show that linear system behavior is possible in E. coli. Elucidation of the mechanism underlying the nonlinearity observed in gfp may lead to design rules that ensure linear system behavior, enabling the accurate prediction of the quantitative behavior of a system assembled from individually characterized devices. Our work suggests that biological systems follow principles similar to physical ones, and that concepts borrowed from the latter (such as DTCs) may be of use in the characterization and design of biological systems.

2011-01-01

295

Dose-dependent Toxicity of Humanized Renilla reniformis GFP (hrGFP) Limits Its Utility as a Reporter Gene in Mouse Muscle  

PubMed Central

Gene therapy has historically focused on delivering protein-coding genes to target cells or tissues using a variety of vectors. In recent years, the field has expanded to include gene-silencing strategies involving delivery of noncoding inhibitory RNAs, such as short hairpin RNAs or microRNAs (miRNAs). Often called RNA interference (RNAi) triggers, these small inhibitory RNAs are difficult or impossible to visualize in living cells or tissues. To circumvent this detection problem and ensure efficient delivery in preclinical studies, vectors can be engineered to coexpress a fluorescent reporter gene to serve as a marker of transduction. In this study, we set out to optimize adeno-associated viral (AAV) vectors capable of delivering engineered miRNAs and green fluorescent protein (GFP) reporter genes to skeletal muscle. Although the more broadly utilized enhanced GFP (eGFP) gene derived from the jellyfish, Aequorea victoria was a conventional choice, we were concerned about some previous studies suggesting this protein was myotoxic. We thus opted to test vectors carrying the humanized Renilla reniformis-derived GFP (hrGFP) gene, which has not seen as extensive usage as eGFP but was purported to be a safer and less cytotoxic alternative. Employing AAV6 vector dosages typically used in preclinical gene transfer studies (3×1010 –1 × 1011 particles), we found that hrGFP caused dose-dependent myopathy when delivered to wild-type (wt) mouse muscle, whereas identical titers of AAV6 carrying eGFP were relatively benign. Dose de-escalation at or below 8 × 109 AAV particles effectively reduced or eliminated hrGFP-associated myotoxicity, but also had dampening effects on green fluorescence and miRNA-mediated gene silencing in whole muscles. We conclude that hrGFP is impractical for use as a transduction marker in preclinical, AAV-based RNA interference therapy studies where adult mouse muscle is the target organ. Moreover, our data support that eGFP is superior to hrGFP as a reporter gene in mouse muscle. These results may impact the design of future preclinical gene therapy studies targeting muscles and non-muscle tissues alike.

Wallace, Lindsay M; Moreo, Andrew; Clark, K Reed; Harper, Scott Q

2013-01-01

296

Hindcast and Forecast of the Black Sea Ecosystem on the Basis of 3D Interdisciplinary Model  

NASA Astrophysics Data System (ADS)

3D interdisciplinary model was used to simulate evolution of the Black Sea ecosystem during the last three decades of the 20th century. The Black Sea marine ecosystem manifested significant changes during this period of time. Healthy ecosystem which was observed in 60-ies, early 70-ies was altered drastically by the impacts of many factors. Such an evident changes in marine biology of the Black Sea were accompanied by modification of the vertical geochemical structure. The most pronounced signature of the geochemical changes was an increase of nitrate concentration in the oxic/suboxic interface zone from 2 to 3 mmol/m3 in the late 1960s to 6-9 mmol/m3 during the 1980s and 90s. The model of the Black Sea ecosystem is one way coupled with physical model and extends from the sea surface to 200m depth with 26 z-levels. The model includes 15 state variables. Phytoplankton is represented by two groups, typifying diatoms and flagellates. Zooplankton is also separated into two dimension parts: microzooplankton and mesozooplankton. The other compartments are carnivorous jelly-fish Aurelia Aurita and the ctenophore Mnemiopsis; omnivorous dinoflagellate Noctiluca; nonphotosynthetic free living bacteriaplankton; detritus and dissolved organic nitrogen. Nitrogen cycling is resolved into three inorganic forms: nitrate, nitrite and ammonium. Nitrogen is considered as the only limiting nutrients for phytoplankton growth. The geochemical part of the model is added also with oxygen and hydrogen sulfide. Fulfilled numerical experiments on modeling of the Black Sea ecosystem dynamics managed to display the main features of the pelagic ecosystem evolution during three decades 1971 - 2001, which are known from numerous measurements. For example, the phytoplankton biomass grew during the time period from early 70s until early 90s, characterized the eutrophication phase of the Black Sea ecosystem. Surface concentration of the phytoplankton in the deep part of the basin increased during this time by about 3 times. The ecosystem model was then used as a part of the Black Sea nowcasting and forecasting system, set up and developed in MHI in the framework of FP6 and FP7 projects. The further development or the Black Sea ecosystem model was its adaptation to the forecast problems, from which the most important one was initialization of the biogeochemical fields. A set of numerical experiments with assimilation of satellite chlorophyll-a data was carried out to elaborate the scheme of the Black Sea ecosystem forecast.

Dorofeyev, V.; Oguz, T.; Korotaev, G.; Sukhikh, L.

2012-04-01

297

A census of marine zooplankton in the tropical/subtropical Atlantic from the surface to 5000 m.  

NASA Astrophysics Data System (ADS)

Zooplankton from tropical/subtropical waters in the Atlantic Ocean were sampled from the surface to 5000 m, with a particular focus on the mesopelagic, bathypelagic, abyssopelagic zones. Sampling, on a cruise sponsored by the NOAA Ocean Exploration Program and the Census of Marine Life, was conducted at five stations from the northern Sargasso Sea to the equatorial waters northeast of Brazil. Environmental data and zooplankton samples were collected using three Multiple Opening/Closing Nets and Environmental Sensing Systems (MOCNESS): a 10-m opening/closing trawl with 335-um mesh nets sampled from 5000 to 1000 m and two smaller MOCNESS with similar or smaller mesh sampled the upper 1000 m. Ring net and water bottle casts, and blue-water SCUBA diving were also carried out. Samples were analyzed at sea using traditional morphological taxonomic approaches by a team of experts, followed by molecular systematic analysis, including determination of a DNA barcode (i.e., short DNA sequence for species recognition) for each species. Over 500 species were identified onboard ship; more than 1000 specimens were placed in a queue for barcoding; 87 species were barcoded at sea. For several taxonomic groups, a significant fraction of the region's species were collected and identified. Sixty-five species of planktonic ostracods were identified at sea out of the 140 known for the North Atlantic Ocean, with at least six undescribed species collected and the first DNA barcode for a planktonic ostracod obtained. At-sea analysis of samples also yielded identified specimens for more than 40 species of molluscs (pteropods, heteropods, etc.), more than 100 species of jellyfish, several hundred species of copepods, and more than 100 species of fish. In all, taxonomists estimated that at least 12 - 15 new species will be described from this effort. The special deployment of trawls to sample large volumes at great depths for small zooplankton yielded preliminary confirmation that species diversity is high (with many more species yet to be captured and studied), but abundance is low.

Wiebe, P. H.; Bucklin, A.; Madin, L.; Angel, M. V.; Sutton, T.; Pages, F.; Hopcroft, R. R.

2006-12-01

298

Reassessing regime shifts in the North Pacific: incremental climate change and commercial fishing are necessary for explaining decadal-scale biological variability.  

PubMed

In areas of the North Pacific that are largely free of overfishing, climate regime shifts - abrupt changes in modes of low-frequency climate variability - are seen as the dominant drivers of decadal-scale ecological variability. We assessed the ability of leading modes of climate variability [Pacific Decadal Oscillation (PDO), North Pacific Gyre Oscillation (NPGO), Arctic Oscillation (AO), Pacific-North American Pattern (PNA), North Pacific Index (NPI), El Niño-Southern Oscillation (ENSO)] to explain decadal-scale (1965-2008) patterns of climatic and biological variability across two North Pacific ecosystems (Gulf of Alaska and Bering Sea). Our response variables were the first principle component (PC1) of four regional climate parameters [sea surface temperature (SST), sea level pressure (SLP), freshwater input, ice cover], and PCs 1-2 of 36 biological time series [production or abundance for populations of salmon (Oncorhynchus spp.), groundfish, herring (Clupea pallasii), shrimp, and jellyfish]. We found that the climate modes alone could not explain ecological variability in the study region. Both linear models (for climate PC1) and generalized additive models (for biology PC1-2) invoking only the climate modes produced residuals with significant temporal trends, indicating that the models failed to capture coherent patterns of ecological variability. However, when the residual climate trend and a time series of commercial fishery catches were used as additional candidate variables, resulting models of biology PC1-2 satisfied assumptions of independent residuals and out-performed models constructed from the climate modes alone in terms of predictive power. As measured by effect size and Akaike weights, the residual climate trend was the most important variable for explaining biology PC1 variability, and commercial catch the most important variable for biology PC2. Patterns of climate sensitivity and exploitation history for taxa strongly associated with biology PC1-2 suggest plausible mechanistic explanations for these modeling results. Our findings suggest that, even in the absence of overfishing and in areas strongly influenced by internal climate variability, climate regime shift effects can only be understood in the context of other ecosystem perturbations. PMID:23996901

Litzow, Michael A; Mueter, Franz J; Hobday, Alistair J

2014-01-01

299

My school voyages with PERSEUS - PERSEUS@SCHOOL  

NASA Astrophysics Data System (ADS)

PERSEUS@SCHOOL is an international environmental education thematic school network which is inspired and supported by the European research project PERSEUS (Policy Oriented Marine Environmental Research in Southern European Seas_http://www.perseus-net.eu) which is funded by EU FP7 Theme "Ocean of Tomorrow" and it is coordinating by the Hellenic Centre for Marine Research (HCMR). The overall scientific objectives of PERSEUS (FP7) research project are to identify the interacting patterns of natural and human-derived pressures on the Mediterranean and Black Seas, assess their impact on marine ecosystems and, using the objectives and principles of the Marine Strategy Framework Directive as a vehicle, to design an effective and innovative research governance framework based on solid scientific knowledge. This research governance framework will engage scientists, policy-makers and the public, thereby reaching a shared understanding and informed decision-making based on sound scientific knowledge. PERSEUS@SCHOOL network is coordinated by the Department of Environmental Education of the 1st Directorate of Secondary Education of Athens and aims to help and enhance environmental education, focusing on clean seas stewardship in schools. Educators along with marine scientists have a role in supporting and inspiring children to acquire the knowledge, skills and inspire their awareness to live and work as responsible and concerned citizens. For this purpose, the network has designed specific pedagogical activities for primary and secondary education - based on PERSEUS key thematic areas i.e. Marine biodiversity, Overfishing, Chemical Marine Pollution - Bioaccumulation - Health, Eutrophication in Marine Waters and Marine Litter. Complementary, two web-monitoring tools will be used by the network; the Jellyfish Spotting campaign and the Marine LitterWatch (MLW) app (Developed by EEA). A special emphasis is given to MLW app, as school students for first time will use it in order to test this new tool and to monitor beach marine litter in selected areas in Greece. The pedagogical activities of the network will give students an opportunity to explore similarities and differences between schools and nationalities, while simultaneously creating awareness of other young people's reality in a captivating way. PERSEUS@SCHOOL will allow students to use their imagination and knowledge provided by PERSEUS scientists, in order to think and act about the marine environment and its protection in an interactive, appealing and imaginative way. Finally, students will participate in a "true" expedition in the Aegean Sea, on the R/V AEGAEO of the Hellenic Centre for Marine Research (HCMR). The aim of this expedition is to involve students in marine scientific research and guide them to recognize the 'value' of the Mediterranean Sea and the threats and challenges it faces in the modern world. During this expedition, students will collaborate with marine scientists creating a powerful interactive learning experience, participate in experiments, interpret research findings, draw conclusions and voice their opinion for the "Oceans of tomorrow".

Fermeli, Georgia; Papathanassiou, Evangelos; Papatheodorou, George; Streftaris, Nikos; Ioakeimidis, Christos

2014-05-01