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Sample records for macrobrachium carcinus em

  1. [Nutrition of juvenile prawn Macrobrachium carcinus (Crustacea: Decapoda) with diets of vegetable and marine residues].

    PubMed

    Casas-Sánchez, R; Vaillard-Nava, Y; Re-Araujo, A D

    1995-01-01

    Juvenile prawn Macrobrachium carcinus were fed two different diets: restaurant by-products (diet I) and fish and vegetable market by-products (diet II). These diets were evaluated by proximal analysis, assimilation efficiency and the factor conversion rate (FCR). Diet I registered a higher efficiency, but there was no difference in the growth rate. The growth mean (G. L.) for three months was 0.254 +/- 0.13 cm (diet I) and 0.191 +/- 0.1 cm (diet II). The conversion rate was good for both, suggesting that 6 to 7 kg of food are needed to obtain 1 kg of prawn. Survival was 76% and 100% for diets I and II, respectively.

  2. Molecular perspective on the American transisthmian species of Macrobrachium (Caridea, Palaemonidae)

    PubMed Central

    Pileggi, Leonardo G.; Rossi, Natália; Wehrtmann, Ingo S.; Mantelatto, Fernando L.

    2014-01-01

    Abstract The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuous populations and created two groups of extant species, which live now in the Pacific and Atlantic drainage systems. This relatively recent event was a trigger to diversification of various species in the Neotropics, nonetheless there are exemplars that do not show sufficient morphologic variability to separate them by traditional morphological tools. About 60 years ago, some freshwater decapod species with high morphological similarity were separate by previous researchers, based on geographical distribution, in Pacific and Atlantic and considered as “sister species”. However, the complete isolation of these prawns by this geographical barrier is questionable, and it has generated doubts about the status of the following transisthmian pairs of sibling species: Macrobrachium occidentale × Macrobrachium heterochirus, Macrobrachium americanum × Macrobrachium carcinus, Macrobrachium digueti × Macrobrachium olfersii, Macrobrachium hancocki × Macrobrachium crenulatum, Macrobrachium tenellum × Macrobrachium acanthurus and Macrobrachium panamense × Macrobrachium amazonicum. Here we evaluated the relation among these pairs of sibling species in a molecular phylogenetic context. We generated 95 new sequences: 26 sequences of 16S rDNA, 25 of COI mtDNA and 44 of 18S nDNA. In total, 181 sequences were analyzed by maximum likelihood phylogenetic method, including 12 Macrobrachium transisthmian species, as well as seven other American Macrobrachium species, and two other palaemonids. Our analysis corroborated the morphological proximity of the sibling species. Despite the high degree of morphological similarities and considerable genetic diversification encountered among the transisthmian sister species, our data support the conclusion that all species included in sibling groups studied herein are valid taxonomic entities, but not all pairs of siblings form natural

  3. Physiological effects of metal toxicity on the tropical freshwater shrimp Microbrachium carcinus (Linneo, 1758).

    PubMed

    Correa, M

    1987-01-01

    Pilot tests were performed to determine the level at which Zn(++) and Cu(++) ceased to be acutely toxic in Macrobrachium carcinus. The data indicated that the static 96h-LC(50) values for Zn(++) and Cu(++) were 0.2 and 0.1 mg litre(-1) respectively. A differential reduction in respiration and ammonia excretion rates was noted with increasing concentrations of these metals in the water. These levels may in a toxic body burden and a progressive deterioration of gill efficiency. A decrease in respiration and ammonia excretion rates resulted in a decrease in O:N ratios, upon exposure to Zn(++) and Cu(++) concentrations. The ratios obtained indicate that these metals, also increased dependence on carbohydrate or lipid reserves.

  4. Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs

    PubMed Central

    Darling, John A.

    2011-01-01

    Interspecific hybridization plays an important role in facilitating adaptive evolutionary change. More specifically, recent studies have demonstrated that hybridization may dramatically influence the establishment, spread, and impact of invasive populations. In Japan, previous genetic evidence for the presence of two non-native congeners, the European green crab Carcinus maenas and the Mediterranean green crab C. aestuarii, has raised questions regarding the possibility of hybridization between these sister species. Here I present analysis based on both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit I (COI) gene which unambiguously argues for a hybrid origin of Japanese Carcinus. Despite the presence of mitochondrial lineages derived from both C. maenas and C. aestuarii, the Japanese population is panmictic at nuclear loci and has achieved cytonuclear equilibrium throughout the sampled range in Japan. Furthermore, analysis of admixture at nuclear loci indicates dramatic introgression of the C. maenas mitochondrial genome into a predominantly C. aestuarii nuclear background. These patterns, along with inferences drawn from the observational record, argue for a hybridization event pre-dating the arrival of Carcinus in Japan. The clarification of both invasion history and evolutionary history afforded by genetic analysis provides information that may be critically important to future studies aimed at assessing risks posed by invasive Carcinus populations to Japan and the surrounding region. PMID:21423759

  5. More than one way to invade: lessons from genetic studies of Carcinus shore crabs

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most widely recognized marine invaders. The success of this species has provided opportunities to explore genetic patterns associated with establishment and population expansion following independent introduction event...

  6. More than one way to invade: lessons from genetic studies of Carcinus shore crabs

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most widely recognized marine invaders. The success of this species has provided opportunities to explore genetic patterns associated with establishment and population expansion following independent introduction event...

  7. CHARACTERIZATION OF MICROSATELLITE LOCI IN THE EUROPEAN GREEN CRAB (CARCINUS MAENAS)

    EPA Science Inventory

    Carcinus maenas (Decapoda: Portunidae) has proven a highly successful invasive marine species whose potential economic and ecological impacts are of great concern worldwide. Here, we characterize fourteen polymorphic microsatellite loci in C. maenas and its sister species C. Ae...

  8. CHARACTERIZATION OF MICROSATELLITE LOCI IN THE EUROPEAN GREEN CRAB (CARCINUS MAENAS)

    EPA Science Inventory

    Carcinus maenas (Decapoda: Portunidae) has proven a highly successful invasive marine species whose potential economic and ecological impacts are of great concern worldwide. Here, we characterize fourteen polymorphic microsatellite loci in C. maenas and its sister species C. Ae...

  9. Pattern and pathways for mercury lifespan bioaccumulation in Carcinus maenas.

    PubMed

    Coelho, J P; Reis, A T; Ventura, S; Pereira, M E; Duarte, A C; Pardal, M A

    2008-06-01

    Carcinus maenas is an important and exploited natural resource in temperate estuaries, being consumed by local populations and also used as fish bait. Through bioaccumulation and bioamplification processes occurring in polluted estuarine ecosystems, this species may directly or indirectly represent a major pathway for Human contamination. No information is available on the overall lifespan bioaccumulation pattern of mercury for this species, which would be an invaluable tool for assessing the risks associated with C. maenas harvest in contaminated areas. Taking that in mind, the main objectives of this work were to clarify the lifespan bioaccumulation pattern of mercury for this species. A consistent lifespan accumulation pattern was found for this species, both for total and organic mercury, and coherent differences were found between genders, suggesting different physiological responses to contamination. From our results two scenarios emerge: (a) for low mercury contamination areas where the diet is the major pathway for metal uptake, with higher levels in muscle and hepatopancreas (twice as high as in gills) and higher organic mercury fractions (as high as 80-90% in muscle), crabs bioaccumulate with age and (b) on high contaminated areas, environmental exposure is predominant, with higher levels found in gills (reaching 0.8 mg kg(-1)), lower organic fractions and no mercury increment with age. Detoxification strategies, dietary differences and species mobility may account for these two accumulation patterns.

  10. Spectroscopic properties of Carcinus aestuarii hemocyanin and its structural subunits

    NASA Astrophysics Data System (ADS)

    Dolashka-Angelova, Pavlina; Hristova, Rumiyana; Stoeva, Stanka; Voelter, Wolfgang

    1999-12-01

    Hemocyanin (Hc) of Carcinus aestuarii contains three major and one minor electrophoretically separable polypeptide chains which were purified by fast protein liquid chromatography (FPLC) ion exchange chromatography. N-terminal amino acid sequences of four structural subunits (SSs) from C. aestuarii were compared with known N-terminal sequences from other arthropodan hemocyanins. The conformational changes, induced by various treatments, were monitored by far UV, CD and fluorescence spectroscopy. The critical temperatures for the structural subunits, Tc, determined by fluorescence spectroscopy, are in the region of 52-59°C and coincide with the melting temperatures, Tm (49-55°C), determined by CD spectroscopy. The free energy of stabilization in water, Δ GDH 2O , toward guanidinium hydrochloride is about 1.3 times higher for the dodecameric Hc as compared to the isolated subunits and about one time higher for Ca1, comparing with other SSs. The studies reveal that the conformational stability of the native dodecamer towards various denaturants (temperature and guanidinium hydrochloride) indicate that the quaternary structure is stabilized by oligomerization between structural subunits, and the possibility of a structural role of the sugar mojeties cannot be excluded.

  11. Green crab (Carcinus maenas) foraging efficiency reduced by fast flows.

    PubMed

    Robinson, Elizabeth M; Smee, Delbert L; Trussell, Geoffrey C

    2011-01-01

    Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities.

  12. Biological impacts of enhanced alkalinity in Carcinus maenas.

    PubMed

    Cripps, Gemma; Widdicombe, Stephen; Spicer, John I; Findlay, Helen S

    2013-06-15

    Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals' acid-base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid-base balance in this comparatively robust crustacean species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows

    PubMed Central

    Robinson, Elizabeth M.; Smee, Delbert L.; Trussell, Geoffrey C.

    2011-01-01

    Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

  14. Crabs in Labs: The Shore Crab (Carcinus maenas) as Teaching Material.

    ERIC Educational Resources Information Center

    Hogarth, P. J.

    1983-01-01

    The shore crab (Carcinus maenas) is an excellent subject for school study, both in the field and the laboratory. It is easily collected and maintained and can be used for a wide range of investigations. Some background details are given and possible areas of investigation suggested. (Author)

  15. GREEN CRAB (CARCINUS MAENAS LINNAEUS) CONSUMPTION RATES ON AND PREY PREFERENCES AMONG FOUR BIVALVE PREY SPECIES

    EPA Science Inventory

    The European green crab, Carcinus maenas, is a recent invader to Pacific Northwest (PNW) estuaries with a voracious appetite, especially for bivalves. To assess their potential impact, we estimated green crab consumption rates on four PNW bivalve species, Yaquina oyster (Ostrea ...

  16. Genetic patterns across multiple introductions of the globally invasive crab genus Carcinus

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most successful aquatic invaders, having established populations on every continent with temperate shores. Here we describe patterns of genetic diversity across both the native and introduced ranges of C. maenas and it...

  17. Genetic patterns across multiple introductions of the globally invasive crab genus Carcinus

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most successful aquatic invaders, having established populations on every continent with temperate shores. Here we describe patterns of genetic diversity across both the native and introduced ranges of C. maenas and it...

  18. GREEN CRAB (CARCINUS MAENAS LINNAEUS) CONSUMPTION RATES ON AND PREY PREFERENCES AMONG FOUR BIVALVE PREY SPECIES

    EPA Science Inventory

    The European green crab, Carcinus maenas, is a recent invader to Pacific Northwest (PNW) estuaries with a voracious appetite, especially for bivalves. To assess their potential impact, we estimated green crab consumption rates on four PNW bivalve species, Yaquina oyster (Ostrea ...

  19. Overview on the European green crab Carcinus spp. (Portunidae, Decapoda), one of the most famous marine invaders and ecotoxicological models.

    PubMed

    Leignel, V; Stillman, J H; Baringou, S; Thabet, R; Metais, I

    2014-01-01

    Green crabs (Carcinus, Portunidae) include two species native to Europe--Carcinus aestuarii (Mediterranean species) and Carcinus maenas (Atlantic species). These small shore crabs (maximal length carapace, approximately 10 cm) show rapid growth, high fecundity, and long planktonic larval stages that facilitate broad dispersion. Carcinus spp. have a high tolerance to fluctuations of environmental factors including oxygen, salinity, temperature, xenobiotic compounds, and others. Shipping of Carcinus spp. over the past centuries has resulted in its invasions of America, Asia, and Australia. Classified as one of the world's 100 worst invaders by the International Union for Conservation of Nature, Carcinus spp. are the most widely distributed intertidal crabs in the world. Their voracious predatory activity makes them strong interactors in local communities, and they are recognized as a model for invasiveness in marine systems as well as a sentinel species in ecotoxicology. This review shows an exhaustive analysis of the literature on the life cycle, diversity, physiological tolerance, genomic investigations, ecotoxicological use, historical invasion, control programs, and putative economical valorization of shore crabs.

  20. Toxicity of rotenone to giant river freshwater prawn Macrobrachium rosenbergii

    USDA-ARS?s Scientific Manuscript database

    Aquaculturists have often suffered predation losses in the production of freshwater giant river prawn Macrobrachium rosenbergii due to the presence of wild fish species in culture ponds. The piscicide rotenone is widely used to remove undesirable fish species from ponds. Although evidence in the t...

  1. RNA-binding region of Macrobrachium rosenbergii nodavirus capsid protein.

    PubMed

    Goh, Zee Hong; Mohd, Nur Azmina Syakirin; Tan, Soon Guan; Bhassu, Subha; Tan, Wen Siang

    2014-09-01

    White tail disease (WTD) kills prawn larvae and causes drastic losses to the freshwater prawn (Macrobrachium rosenbergii) industry. The main causative agent of WTD is Macrobrachium rosenbergii nodavirus (MrNV). The N-terminal end of the MrNV capsid protein is very rich in positively charged amino acids and is postulated to interact with RNA molecules. N-terminal and internal deletion mutagenesis revealed that the RNA-binding region is located at positions 20-29, where 80 % of amino acids are positively charged. Substitution of all these positively charged residues with alanine abolished the RNA binding. Mutants without the RNA-binding region still assembled into virus-like particles, suggesting that this region is not a part of the capsid assembly domain. This paper is, to the best of our knowledge, the first to report the specific RNA-binding region of MrNV capsid protein. © 2014 The Authors.

  2. Methodical aspects of rearing decapod larvae, Pagurus bernhardus (Paguridae) and Carcinus maenas (Portunidae)

    NASA Astrophysics Data System (ADS)

    Dawirs, R. R.

    1982-12-01

    Improved methods for experimental rearing of Pagurus bernhardus and Carcinus maenas larvae are presented. Isolated maintenance was found essential for reliable statistical evaluation of results obtained from stages older than zoea-1. Only by isolated rearing is it possible to calculate mean values ±95% confidence intervals of stage duration. Mean values (without confidence intervals) can only be given for group-reared larvae if mortality is zero. Compared to group rearing, isolated rearing led to better survival, shorter periods of development and stimulated growth. Due to different swimming behavior P. bernhardus zoeae needed larger water volumes than Carcinus maenas larvae. P. bernhardus zoeae were reared with best results when isolated in Petri dishes (ca. 50 ml). They fed on newly hatched brine shrimp nauplii ( Artemia spp.). P. bernhardus megalopa did not require any gastropod shell or substratum; it developed best in glass vials without any food. C. maenas larvae could be reared most sucessfully in glass vials (ca 20 ml) under a simulated day-night regime (LD 16:8); constant darkness had a detrimental effect on development, leading to prolonged stage-duration times. C. maenas larvae were fed a mixture of newly hatched brine shrimp naupli and rotifers ( Brachionus plicatilis).

  3. Carbonic anhydrase, a respiratory enzyme in the gills of the shore crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Böttcher, K.; Siebers, D.; Sender, S.

    1995-03-01

    This paper summarizes investigations on the enzyme carbonic anhydrase (CA) in the gills of the osmoregulating shore crab Carcinus maenas. Carbonic anhydrase, an enzyme catalyzing the reversible hydration of CO2 to HCO3 - and H+, is localized with highest activities in the posterior salt-transporting gills of the shore crab- and here CA activity is strongly dependent on salinity. Contrary to the earlier hypothesis established for the blue crab Callinectes sapidus that cytoplasmic branchial CA provides the counter ions HCO3 - and H+ for apical exchange against Na+ and Cl-, the involvement of CA in NaCl uptake mechanisms can be excluded in Carcinus. Differential and density gradient centrifugations indicate that branchial CA is a predominantly membrane-associated protein. Branchial CA was greatly inhibited by the sulfonamide acetazolamide (AZ) Ki=2.4·10-8 mol/l). Using the preparation of the isolated perfused gill, application of 10-4 mol/l AZ resulted in an 80% decrease of CO2/HCO3 - excretion. Thus we conclude that CA is localized in plasma membranes, maintaining the CO2 gradient by accelerating adjustment of the pH-dependent CO2/HCO3 - equilibrium.

  4. Acidification of the gill cells of the shore crab Carcinus mediterraneus: Its physiological significance

    NASA Astrophysics Data System (ADS)

    Lucu, Č.; Siebers, D.

    1995-03-01

    In a preparation of isolated gills of the shore crab Carcinus mediterraneus perfused with dilute sea water (pH 8.1, 200 mM Na+) which was identical to the bathing solution of the gill, acidification of the collected perfusate was observed. Acidification was not affected by 10-4 M EIPA (5-[N-ethyl-N-isopropyl]amiloride), a strong inhibitor of Na+/H+ exchange. However, in the presence of 10-4 M acetazolamide, acidification was greatly blocked. The significant decrease of the acid load of the perfusate is considered to be a result of inhibition of the branchial intracellular carbonic anhydrase catalyzing the formation of H+ ions.

  5. Modelling the biological invasion of Carcinus maenas (the European green crab).

    PubMed

    Marculis, Nathan G; Lui, Roger

    2016-01-01

    This paper proposes a system of integro-difference equations to model the spread of Carcinus maenas, commonly called the European green crab, that causes severe damage to coastal ecosystems. A model with juvenile and adult classes is first studied. Here, standard theory of monotone operators for integro-difference equations can be applied and yields explicit formulas for the asymptotic spreading speeds of the juvenile and adult crabs. A second model including an infected class is considered by introducing a castrating parasite Sacculina carcini as a biological control agent. The dynamics are complicated and simulations reveal the occurrence of periodic solutions and stacked fronts. In this case, only conjectures can be made for the asymptotic spreading speeds because of the lack of mathematical theory for non-monotone operators. This paper also emphasizes the need for mathematical studies of non-monotone operators in heterogeneous environments and the existence of stacked front solutions in biological invasion models.

  6. Differences in the neighborhood: Structural variations in the carapace of shore crabs Carcinus maenas (Decapoda: Portunidae)

    NASA Astrophysics Data System (ADS)

    Souza, Allan T.; Ilarri, Martina I.; Campos, Joana; Marques, João C.; Martins, Irene

    2011-12-01

    The present study compared the carapace structure of Carcinus maenas in two nearby sites (2 km apart) within Minho estuary, submitted to different physicochemical and ecological conditions (water temperature, pH, crabs' density and sex ratio). The carapace structure of the carapace and chelae of the crabs presented significant differences between sampling sites ( t-test; p < 0.01). The SIMPER analysis revealed that the Weight/CW and Thickness/CW ratios explained all the dissimilarities found among sites. Overall, the male carapace was proportionally thicker at station 2 ( t-test; p < 0.01), while the female carapace was proportionally thicker at station 1 ( t-test; p < 0.001). A thicker carapace can be advantageous when competing for food or a sexual partner. We hypothetized that, since at station 2, the density of individuals was twice higher than at station 1, it is likely that agonistic encounters are more frequent, thus favouring a thicker carapace.

  7. Joint effects of salinity and the antidepressant sertraline on the estuarine decapod Carcinus maenas.

    PubMed

    Rodrigues, Aurélie P; Santos, Lúcia H M L M; Oliva-Teles, Maria Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2014-11-01

    Concurrent exposure of estuarine organisms to man-made and natural stressors has become a common occurrence. Numerous interactions of multiple stressors causing synergistic or antagonistic effects have been described. However, limited information is available on combined effects of emerging pharmaceuticals and natural stressors. This study investigated the joint effects of the antidepressant sertraline and salinity on Carcinus maenas. To improve knowledge about interactive effects and potential vulnerability, experiments were performed with organisms from two estuaries with differing histories of exposure to environmental contamination. Biomarkers related to mode of action of sertraline were employed to assess effects of environmentally realistic concentrations of sertraline at two salinity levels. Synergism and antagonism were identified for biomarkers of cholinergic neurotransmission, energy production, anti-oxidant defences and oxidative damage. Different interactions were found for the two study sites highlighting the need to account for differences in tolerance of local ecological receptors in risk evaluations.

  8. [Predatory capacity of Macrobrachium tenellum on Aedes aegypti larvae in lab conditions].

    PubMed

    Rojas-Sahagún, Cecilia Catalina; Hernández-Sánchez, Judith Marissa; Vargas-Ceballos, Manuel Alejandro; Ruiz-González, Luis Eduardo; Espinosa-Chaurand, Luis Daniel; Nolasco-Soria, Héctor; Vega-Villasante, Fernando

    2012-01-01

    in the last few years, a lot of importance has been given to natural predators against Aedes aegypti. Several organisms have been studied both in lab and in the field so as to find out their capacity to devour mosquito larvae. High densities of Macrobrachium tenellum are found in natural conditions, it is not aggressive and may stand wide ranges of temperature, rates of salinity and oxygen concentrations. to evaluate the predatory capacity of Macrobrachium tenellum on Aedes aegypti larvae in lab conditions. very young Macrobrachium tenellum prawns measuring A(3.0-3.5cm) and B (4.5-5 cm) were used. The mosquito larvae were obtained after hatching of egss from adult females kept in entomological cages. Five, ten, fifteen and twenty Aedes aegypti larvae were placed per treatment per rank, whereas the second bioassays adjusted the number of larvae to 30, 40, 50 and 80 larvae per treatment per rank. Macrobrachium tenellum showed high rate of larval consumption for the two ranks and treatments. In the highest density (80 larvae), the consumption was 95% of larvae at 24 hours for rank A and 100% for rank B. Macrobrachium tenellum may be considered as a potential biological control agent, due to its abundant presence in natural conditions, its resistance to different environmental conditions and to its voraciousness seen in this study.

  9. Characterization of the Carcinus maenas Neuropeptidome by Mass Spectrometry and Functional Genomics

    PubMed Central

    Ma, Mingming; Bors, Eleanor K.; Dickinson, Evelyn S.; Kwiatkowski, Molly A.; Sousa, Gregory L.; Henry, Raymond P.; Smith, Christine M.; Towle, David W.; Christie, Andrew E.; Li, Lingjun

    2010-01-01

    Carcinus maenas, commonly known as the European green crab, is one of the best-known and most successful marine invasive species. While a variety of natural and anthropogenic mechanisms are responsible for the geographic spread of this crab, its ability to adapt physiologically to a broad range of salinities, temperatures and other environmental factors has enabled successful establishment in these new habitats. To extend our understanding of hormonal control in C. maenas, including factors that allow for its extreme adaptability, we have undertaken a mass spectral/functional genomics investigation of the neuropeptides used by this organism. Via a strategy combining MALDI-based high resolution mass profiling, biochemical derivatization, and nanoscale separation coupled to tandem mass spectrometric sequencing, 122 peptide paracrines/hormones were identified from the C. maenas central nervous system and neuroendocrine organs. These peptides include 31 previously described Carcinus neuropeptides (e.g. NSELINSILGLPKVMNDAamide [β-pigment dispersing hormone] and PFCNAFTGCamide [crustacean cardioactive peptide]), 49 peptides only described in species other than the green crab (e.g. pQTFQYSRGWTNamide [Arg7-corazonin]), and 42 new peptides de novo sequenced here for the first time (e.g. the pyrokinins TSFAFSPRLamide and DTGFAFSPRLamide). Of particular note are a collection of 25 FMRFamide-like peptides (including 9 new isoforms sequenced de novo) and a collection of 25 A-type allatostatin peptides (including 10 new sequences reported for the first time) in this study. Both peptide families are among the most diverse families, each containing a large number of isoforms in arthropod species. Also of interest was the identification of two SIFamide isoforms, GYRKPPFNGSIFamide and VYRKPPFNGSIFamide, the latter peptide known previously only from members of the astacidean genus Homarus. Using transcriptome analyses, 15 additional peptides were characterized, including an isoform

  10. Influence of bilateral eyestalk ablation on gonads of fresh water prawn, Macrobrachium dayanum.

    PubMed

    Pervaiz, Pervaiz Ahmed; Sikdar, Malabika

    2014-09-01

    The study was carried out in laboratory for one month to know the effect of bilateral eyestalk ablation on gonads of Macrobrachium dayanum. Healthy specimens of Macrobrachium dayanum in the size group of (4-6 cm in length) were taken for the experiment. The eyestalk ablation was done by cutting away the eyestalks from their bases with sterilized scissor. The results here obtained indicated positive effects of eyestalk ablation on ovary and testes of Macrobrachium dayanum. The histological details of the female prawns which were ablated showed post-vitellogenic oocytes; where as unablated females prawn never developed beyond pre-vitellogenic oocytes. Similarly in males, testes showed pronounced development of different cells as compared to unablated ones. Fully developed spermatozoa were seen in ablated ones. Gonadosomatic studies also showed that ovarian and testicular cells developed better as compared to control and these findings suggest the fact that the eyestalks of M. dayanum contain ovary and testis inhibiting factors.

  11. White Tail Disease of Freshwater Prawn, Macrobrachium rosenbergii.

    PubMed

    Sahul Hameed, A S; Bonami, Jean-Robert

    2012-09-01

    Macrobrachium rosenbergii is the most important cultured freshwater prawn in the world and it is now farmed on a large scale in many countries. Generally, freshwater prawn is considered to be tolerant to diseases but a disease of viral origin is responsible for severe mortalities in larval, post-larval and juvenile stages of prawn. This viral infection namely white tail disease (WTD) was reported in the island of Guadeloupe in 1995 and later in Martinique (FrenchWest Indies) in Taiwan, the People's Republic of China, India, Thailand, Australia and Malaysia. Two viruses, Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus-like particle (XSV) have been identified as causative agents of WTD. MrNV is a small icosahedral non-enveloped particle, 26-27 nm in diameter, identified in the cytoplasm of connective cells. XSV is also an icosahedral virus and 15 nm in diameter. Clinical signs observed in the infected animals include lethargy, opaqueness of the abdominal muscle, degeneration of the telson and uropods, and up to 100 % within 4 days. The available diagnostic methods to detect WTD include RT-PCR, dot-blot hybridization, in situ hybridization and ELISA. In experimental infection, these viruses caused 100 % mortality in post-larvae but failed to cause mortality in adult prawns. The reported hosts for these viruses include marine shrimp, Artemia and aquatic insects. Experiments were carried out to determine the possibility of vertical transmission of MrNV and XSV in M. rosenbergii. The results indicate that WTD may be transferred from infected brooders to their offspring during spawning. Replication of MrNV and XSV was investigated in apparently healthy C6/36 Aedes albopictus and SSN-1 cell lines. The results revealed that C6/36 and SSN-1cells were susceptible to these viruses. No work has been carried out on control and prevention of WTD and dsRNA against protein B2 produced RNAi that was able to functionally prevent and reduce mortality in WTD

  12. Uptake and retention of microplastics by the shore crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Lewis, Ceri; Goodhead, Rhys M; Beckett, Stephen J; Moger, Julian; Tyler, Charles R; Galloway, Tamara S

    2014-01-01

    Microplastics, plastics particles <5 mm in length, are a widespread pollutant of the marine environment. Oral ingestion of microplastics has been reported for a wide range of marine biota, but uptake into the body by other routes has received less attention. Here, we test the hypothesis that the shore crab (Carcinus maenas) can take up microplastics through inspiration across the gills as well as ingestion of pre-exposed food (common mussel Mytilus edulis). We used fluorescently labeled polystyrene microspheres (8-10 μm) to show that ingested microspheres were retained within the body tissues of the crabs for up to 14 days following ingestion and up to 21 days following inspiration across the gill, with uptake significantly higher into the posterior versus anterior gills. Multiphoton imaging suggested that most microspheres were retained in the foregut after dietary exposure due to adherence to the hairlike setae and were found on the external surface of gills following aqueous exposure. Results were used to construct a simple conceptual model of particle flow for the gills and the gut. These results identify ventilation as a route of uptake of microplastics into a common marine nonfilter feeding species.

  13. Fecampia erythrocephala rediscovered: prevalence and distribution of a parasitoid of the European shore crab, Carcinus maenas

    USGS Publications Warehouse

    Kuris, Armand M.; Torchin, Mark E.; Lafferty, Kevin D.

    2002-01-01

    An ecological assessment of Fecampia erythrocephala, reporting its habitat distribution, abundance, host specificity, size-specific prevalence, frequency distribution among hosts, effect on host growth, and its site specificity within these hosts is presented. At the Isle of Man and near Plymouth, Fecampia erythrocephala cocoons were generally abundant on the undersides of rocks in the Ascophyllum and Fucus serratus zones. Infected crabs were also most common in these habitats. Both Carcinus maenas and Cancer pagurus were parasitized at similar prevalences, although the former species was relatively much more common in the habitats where the worm cocoons were abundant. Fecampia erythrocephala did not infect crabs larger than 11 mm carapace width, and prevalence decreased significantly with crab size. Prevalences reached 11% in areas where cocoons were abundant. Together with the large size of these worms relative to the size of the host crabs and the observations on worm emergence, these life history features indicate that F. erythrocephala is a parasitoid of young shore crabs. Fecampia erythrocephala cocoon abundance is often high in localized areas and size-prevalence information suggests that worms mature rapidly in these crabs. This suggests that F. erythrocephala is an important contributor to crab mortality and to the ecology of shore crabs at these sites.

  14. Effect of nanomaterials on the compound action potential of the shore crab, Carcinus maenas.

    PubMed

    Windeatt, Kirsten M; Handy, Richard D

    2013-06-01

    Little is known about the effects of manufactured nanomaterials on the function of nerves. The experiment aimed to test the effects of three different nanomaterials (1 mg l⁻¹ of TiO₂ NPs, Ag NPs or SWCNT) on the compound action potential of the shore crab (Carcinus maenas) compared with an appropriate bulk powder or metal salt control (bulk TiO₂ powder, AgNO₃ and carbon black respectively). In single action potential recordings, there were no effects of any of the nanomaterials on the peak amplitude, duration, rate of rise (depolarisation), or rate of decrease (repolarisation) of the compound action potential in crab saline, despite settling of each nanomaterial directly onto the nerve preparation. The ability of the crab nerve to be stimulated to tetanus was also unaffected by exposure to the nanomaterials compared with the appropriate bulk powder or metal salt control. Solvent controls with sodium dodecyl sulfate (SDS) also had no effect on action potentials. Overall, the study concludes that there were no effects of the materials at the concentrations tested on the compound action potential of the shore crab in physiological saline.

  15. A Membrane-bound Hemoglobin from Gills of the Green Shore Crab Carcinus maenas*

    PubMed Central

    Ertas, Beyhan; Kiger, Laurent; Blank, Miriam; Marden, Michael C.; Burmester, Thorsten

    2011-01-01

    Most hemoglobins serve for the transport or storage of O2. Although hemoglobins are widespread in “entomostracan” Crustacea, malacostracans harbor the copper-containing hemocyanin in their hemolymph. Usually, only one type of respiratory protein occurs within a single species. Here, we report the identification of a hemoglobin of the shore crab Carcinus maenas (Malacostraca, Brachyura). In contrast to the dodecameric hemocyanin of this species, C. maenas hemoglobin does not reside in the hemolymph but is restricted to the gills. Immunofluorescence studies and cell fractioning showed that C. maenas hemoglobin resides in the membrane of the chief cells of the gill. To the best of our knowledge, this is the first time that a membrane-bound hemoglobin has been identified in eukaryotes. Bioinformatic evaluation suggests that C. maenas hemoglobin is anchored in the membrane by N-myristoylation. Recombinant C. maenas hemoglobin has a hexacoordinate binding scheme at the Fe2+ and an oxygen affinity of P50 = 0.5 Torr. A rapid autoxidation rate precludes a function as oxygen carrier. We rather speculate that, analogous to prokaryotic membrane-globins, C. maenas hemoglobin carries out enzymatic functions to protect the lipids in cell membrane from reactive oxygen species. Sequence comparisons and phylogenetic studies suggested that the ancestral arthropod hemoglobin was most likely an N-myristoylated protein that did not have an O2 supply function. True respiratory hemoglobins of arthropods, however, evolved independently in chironomid midges and branchiopod crustaceans. PMID:21118803

  16. Camouflage and Individual Variation in Shore Crabs (Carcinus maenas) from Different Habitats

    PubMed Central

    Stevens, Martin; Lown, Alice E.; Wood, Louisa E.

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this. PMID:25551233

  17. Sex identification of Carcinus maenas by analysis of carapace geometrical morphometry

    NASA Astrophysics Data System (ADS)

    Ledesma, Federico M.; Van der Molen, Silvina; Barón, Pedro J.

    2010-04-01

    The European green crab Carcinus maenas is a widely spread invasive species. Studying the most recently introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of the visceral-cavity detaching from the rest of the exoskeleton after ecdysis) accumulated on the intertidal may be used as a valuable complementary material to analyze the size structure of crabs. However, since growth rate (and consequently size at instar) of crabs differs between males and females, finding a method to distinguish crab sex by observation of carapace morphology was necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes.

  18. Effect of Microplastic on the Gills of the Shore Crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Goodhead, Rhys; Moger, Julian; Lewis, Ceri; Galloway, Tamara S

    2016-05-17

    Microscopic plastic debris (microplastics, <5 mm in diameter) is ubiquitous in the marine environment. Previous work has shown that microplastics may be ingested and inhaled by the shore crab Carcinus maenas, although the biological consequences are unknown. Here, we show that acute aqueous exposure to polystyrene microspheres (8 μm) with different surface coatings had significant but transient effects on branchial function. Microspheres inhaled into the gill chamber had a small but significant dose-dependent effect on oxygen consumption after 1 h of exposure, returning to normal levels after 16 h. Ion exchange was also affected, with a small but significant decrease in hemolymph sodium ions and an increase in calcium ions after 24 h post-exposure. To further asses the effects on osmoregulation, we challenged crabs with reduced salinity after microplastic exposure. Neither microspheres nor natural sediments altered the crab's response to osmotic stress regardless of plastic concentration added. Carboxylated (COOH) and aminated (NH2) polystyrene microspheres were distributed differently across the gill surface, although neither had a significant adverse impact on gill function. These results illustrate the extent of the physiological effects of microplastics compared to the physiological resilience of shore crabs in maintaining osmoregulatory and respiratory function after acute exposure to both anthropogenic plastics and natural particles.

  19. Trophic level transfer of microplastic: Mytilus edulis (L.) to Carcinus maenas (L.).

    PubMed

    Farrell, Paul; Nelson, Kathryn

    2013-06-01

    This study investigated the trophic transfer of microplastic from mussels to crabs. Mussels (Mytilus edulis) were exposed to 0.5 μm fluorescent polystyrene microspheres, then fed to crabs (Carcinus maenas). Tissue samples were then taken at intervals up to 21 days. The number of microspheres in the haemolymph of the crabs was highest at 24 h (15 033 ml(-1) ± SE 3146), and was almost gone after 21 days (267 ml(-1) ± SE 120). The maximum amount of microspheres in the haemolymph was 0.04% of the amount to which the mussels were exposed. Microspheres were also found in the stomach, hepatopancreas, ovary and gills of the crabs, in decreasing numbers over the trial period. This study is the first to show 'natural' trophic transfer of microplastic, and its translocation to haemolymph and tissues of a crab. This has implications for the health of marine organisms, the wider food web and humans.

  20. Sex-specific mediation of foraging in the shore crab, Carcinus maenas.

    PubMed

    Hayden, Dominic; Jennings, Alice; Müller, Carsten; Pascoe, David; Bublitz, Ralf; Webb, Heather; Breithaupt, Thomas; Watkins, Lloyd; Hardege, Jörg

    2007-08-01

    Experiments were conducted to investigate the sex-specific differences to feeding responses of the shore crab Carcinus maenas throughout the year. Results demonstrate that female shore crabs exhibit stronger feeding responses than males throughout the year with a significantly reduced feeding response in males during the summer months' reproductive season. We also studied the possible function(s) of the moulting hormone, 20-hydroxyecdysone (Crustecdysone) that has been described as a potential female-produced sex pheromone to initiate male reproductive behaviour in a number of crustaceans. We recently presented evidence that for shore crabs this is not the case and now show that the steroid is instead functioning as a sex-specific feeding deterrent protecting the moulting 'soft' female crabs. Whilst male shore crabs were deterred from prey (Mytilus edulis) and synthetic feeding stimulants glycine and taurine when these feeding stimulants were spiked with crustecdysone, intermoult female crabs were significantly less affected and rarely deterred from feeding. This sex specificity of the moulting hormone, in combination with the female sex pheromone, which has no anti-feeding properties, ensures that male crabs mate with soft-shelled, moulted females rather than engage in cannibalism, such as found frequently in cases when soft-shelled females are exposed to intermoult females.

  1. Identification of biomarkers responsive to chronic exposure to pharmaceuticals in target tissues of Carcinus maenas.

    PubMed

    Aguirre-Martínez, G V; Del Valls, T A; Martín-Díaz, M L

    2013-01-01

    A 28-day bioassay was performed with Carcinus maenas to evaluate chronic effects caused by exposure to caffeine and ibuprofen (0.1-50 μg L(-1)) in sea water. Lysosomal membrane stability (LMS) was evaluated in hemolymph applying the neutral red retention assay (NRRA); several biomarkers including ethoxyresorufin O-deethylase (EROD), dibenzylfluorescein dealkylase (DBF), glutathione S-transferase (GST), glutathione peroxidase (GPX), lipid peroxidation (LPO) and DNA damage were studied in gill, hepatopancreas, muscle and gonad tissues. In crabs exposed to environmental concentrations of the drugs, retention time was reduced by 50%. EROD and DBFOD activities were induced by caffeine in muscle and hepatopancreas tissues (p < 0.05); GST activity was activated by ibuprofen in gill, hepatopancreas and muscle at the highest concentrations tested (p < 0.05). All tissues showed GPX activity and LPO induction (p < 0.05). Crabs exposed to caffeine and ibuprofen showed evidence of DNA damage mainly in hepatopancreas tissues (p < 0.05). Environmental concentrations of pharmaceuticals induce LMS and the biochemical responses studied in this crab. This methodology is a suitable technique for assessing pharmaceutical toxicity in the marine environment.

  2. Development and Application of Microsatellites in Carcinus maenas: Genetic Differentiation between Northern and Central Portuguese Populations

    PubMed Central

    Pascoal, Sónia; Creer, Simon; Taylor, Martin I.; Queiroga, Henrique; Carvalho, Gary; Mendo, Sónia

    2009-01-01

    Carcinus maenas, the common shore crab of European coastal waters, has recently gained notoriety due to its globally invasive nature associated with drastic ecological and economic effects. The native ubiquity and worldwide importance of C. maenas has resulted in it becoming one of the best-studied estuarine crustacean species globally. Accordingly, there is significant interest in investigating the population genetic structure of this broadly distributed crab along European and invaded coastlines. Here, we developed polymerase chain reaction (PCR) primers for one dinucleotide and two trinucleotide microsatellite loci, resulting from an enrichment process based on Portuguese populations. Combining these three new markers with six existing markers, we examined levels of genetic diversity and population structure of C. maenas in two coastal regions from Northern and Central Portugal. Genotypes showed that locus polymorphism ranged from 10 to 42 alleles (N = 135) and observed heterozygosity per locus ranged from 0.745 to 0.987 with expected heterozygosity ranging from 0.711 to 0.960; values typical of marine decapods. The markers revealed weak, but significant structuring among populations (global FST = 0.004) across a 450 km (over-water distance) spatial scale. Combinations of these and existing markers will be useful for studying population genetic parameters at a range of spatial scales of C. maenas throughout its expanding species range. PMID:19789651

  3. Parasites of the shore crab Carcinus maenas (L.): implications for reproductive potential and invasion success.

    PubMed

    Zetlmeisl, C; Hermann, J; Petney, T; Glenner, H; Griffiths, C; Taraschewski, H

    2011-03-01

    The European shore crab, Carcinus maenas, is one of the most successful marine invasive species. Its success has been in part attributed to the loss of parasites, rekindling an interest in host-parasite interactions and impacts on host fitness in this crab. In the present study, we investigated C. maenas populations from Europe, South Africa and Australia for parasites, and assessed their impact on the fitness of male crabs. For the shore crab, testes weight along with success in mating competition is traded off against other life-history traits. We therefore used this parameter as an indicator both for reproductive fitness and a possible resource trade-off in response to parasite infestation. In the native range, crabs infested with Sacculina carcini showed significantly lower testes weight than uninfected crabs. However, helminth parasites did not generally cause reduced testes weights. Crab populations from South Africa and Australia were either parasitized at very low prevalences, or were completely parasite free. However, no population level effect of this parasite release was reflected in testes weight. These findings do not support a severe fitness impact of helminth parasites on C. maenas, which questions the role of parasites on its population dynamics, both in the native area and for invasive success.

  4. Physiological responses to digestion in low salinity in the crabs Carcinus maenas and Cancer irroratus.

    PubMed

    Penney, Chantelle M; Patton, Richard L; Whiteley, Nia M; Driedzic, William R; McGaw, Iain J

    2016-01-01

    Osmoregulation and digestion are energetically demanding, and crabs that move into low salinity environments to feed must be able to balance the demands of both processes. Achieving this balance may pose greater challenges for weak than for efficient osmoregulators. This study examined the rate of oxygen consumption (MO2) of Carcinus maenas (efficient osmoregulator) and Cancer irroratus (weak osmoregulator) as a function of feeding and hyposaline stress. The MO2 increased 2-fold in both species following feeding. The MO2 increased and remained elevated in fasted crabs during acute hyposaline exposure. When hyposaline stress occurred after feeding, C. maenas responded with an immediate summation of the MO2 associated with feeding and hyposaline stress, whereas C. irroratus reacted with a partial summation of responses in a salinity of 24‰, but were unable to sum responses in 16‰. C. irroratus exhibited longer gut transit times. This may be due to an inability to regulate osmotic water onload as efficiently as C. maenas. Mechanical digestion in crabs can account for a significant portion of SDA, and a short term interruption led to the delay in summation of metabolic demands. Although protein synthesis is reported to account for the majority of SDA, this did not appear to be the case here. Protein synthesis rates were higher in C. irroratus but neither feeding or salinity affected protein synthesis rates of either species which suggests that protein synthesis can continue in low salinity as long as substrates are available. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Feasibility of direct utilization of selected geothermal water for aquaculture of macrobrachium rosenbergii. Technical report

    SciTech Connect

    Spinosa, C.

    1984-05-01

    The feasibility was tested of direct utilization of geothermal water for the aquaculture of Malaysian freshwater prawns (Macrobrachium rosenbergii). A problem with using geothermal water for aquaculture is the chemical composition of the water with high flouride levels being a particular problem. Results show that (1) some geothermal water in Idaho can be used directly for the aquaculture of Macrobrachium rosenbergii, (2) high flouride levels cannot be directly correlated with high mortality rates and (3) low flouride levels do not correlate with high growth rates.

  6. Macrobrachium rosenbergii nodavirus disease (white tail disease) in Australia.

    PubMed

    Owens, Leigh; La Fauce, Kathy; Juntunen, Karen; Hayakijkosol, Orachun; Zeng, Chaoshu

    2009-07-23

    The index case of white tail disease (WTD) is presented in adult broodstock prawns Macrobrachium rosenbergii from the Flinders River in western Queensland, Australia, in mid-2007. Histological examination revealed extensive myonecrosis with massive infiltration of myonuclei and some haemocytes. Juveniles from the same broodstock but not from 3 other families displayed white muscle lesions. Low-grade chronic mortalities approaching 100% over 1 yr occurred. Reverse transcriptase polymerase chain reactions (RT-PCR) were attempted for both M. rosenbergii nodavirus (MrNV) with 2 sets of primers and for the satellite virus, extrasmall virus (XSV). All 3 PCRs generated amplicons of the expected sizes. Basic local alignment search tool (BLAST) analyses of the 3 consensus sequences identified a 91% match with MrNV viral capsid protein gene, 96% match with MrNV RNA-directed RNA polymerase gene, and a 99% match with M. rosenbergii XSV capsid protein gene. The clinical signs, histopathological lesions and RT-PCR amplicons could be reproduced in M. rosenbergii inoculated with cell-free extracts fulfilling River's postulates. We conclude that this is an endemic strain of MrNV as the sequences are dissimilar to strains of MrNV circulating around Asia and the Americas. This case only poorly meets the Office International des Epizooties (OIE) case definition for WTD due to the age of the prawns involved and the nature of the inclusion bodies. Perhaps the OIE case definition needs broadening.

  7. Routine Metabolic Rate and Limiting Oxygen Concentration of Freshwater Prawn Macrobrachium rosenbergii Larvae

    USDA-ARS?s Scientific Manuscript database

    Malaysian prawns, Macrobrachium rosenbergii, are hatched and raised indoors in small tanks. Prawns may be raised and shipped at high densities which could result in low dissolved oxygen (DO) conditions. Because DO may play an important role in prawn development and survival, we measured routine me...

  8. Biochemical and locomotor responses of Carcinus maenas exposed to the serotonin reuptake inhibitor fluoxetine.

    PubMed

    Mesquita, Sofia Raquel; Guilhermino, Lúcia; Guimarães, Laura

    2011-10-01

    The aim of this study was to assess the effects of the widely used anti-depressant fluoxetine on behaviour (locomotion), moulting, neuromuscular transmission, energy production and anti-oxidant defences' efficiency of the epibenthic crab Carcinus maenas. Crabs were individually exposed to fluoxetine concentrations for 7d. Effects on locomotion were assessed at the end of the exposure using an open field test adapted to C. maenas in the present study. Tissue samples were later collected to evaluate fluoxetine effects on physiological functions using the activity of key enzymes and other parameters as biomarkers, namely: N-acetyl-β-glucosaminidase (NAGase) in the epidermis (moulting) and the hepatopancreas; cholinesterases (ChE) in muscle (neuromuscular cholinergic transmission); NADP(+)-dependent isocitrate dehydrogenase (IDH) and lactate dehydrogenease (LDH) in muscle (energy production); glutathione S-transferases (GST) in hepatopancreas (biotransformation and oxidative stress system); glutathione reductase (GR), and glutathione peroxidade (GPx), total glutathione levels (TG) and lipid peroxidation levels in the hepatopancreas (anti-oxidant defences and oxidative damage). Because no information on C. maenas NAGase activity was previously available, its variation during the moult cycle was also investigated. The results showed that locomotion was significantly increased at fluoxetine concentrations equal or above 120 μg L⁻¹, with animals spending more time moving, walking longer distances than controls. Levels of NAGase activity were found to vary in relation to C. maenas moult cycle, but no alterations were observed after exposure to fluoxetine. Significant increases in the activity of ChE, GST and GR enzymes, and the levels of TG were found, with a lowest observed effect concentration (LOEC) of 120 μg L⁻¹. Effects on locomotion were significantly and positively correlated to those induced on ChE activity. The results raise concern when hypothesising

  9. Seed Predation by the Shore Crab Carcinus maenas: A Positive Feedback Preventing Eelgrass Recovery?

    PubMed Central

    2016-01-01

    There is an increasing interest to restore the ecosystem services that eelgrass provides, after their continuous worldwide decline. Most attempts to restore eelgrass using seeds are challenged by very high seed losses and the reasons for these losses are not all clear. We assess the impact of predation on seed loss and eelgrass establishment, and explore methods to decrease seed loss during restoration in the Swedish northwest coast. In a laboratory study we identified three previously undescribed seed predators, the shore crab Carcinus maenas, the hermit crab Pagurus bernhardus and the sea urchin Strongylocentrotus droebachiensis, of which shore crabs consumed 2–7 times more seeds than the other two species. The importance of shore crabs as seed predators was supported in field cage experiments where one enclosed crab caused 73% loss of seeds over a 1-week period on average (~ 21 seeds per day). Seedling establishment was significantly higher (14%) in cages that excluded predators over an 8-month period than in uncaged plots and cages that allowed predators but prevented seed-transport (0.5%), suggesting that seed predation constitutes a major source of seed loss in the study area. Burying the seeds 2 cm below the sediment surface prevented seed predation in the laboratory and decreased predation in the field, constituting a way to decrease seed loss during restoration. Shore crabs may act as a key feedback mechanism that prevent the return of eelgrass both by direct consumption of eelgrass seeds and as a predator of algal mesograzers, allowing algal mats to overgrow eelgrass beds. This shore crab feedback mechanism could become self-generating by promoting the growth of its own nursery habitat (algal mats) and by decreasing the nursery habitat (seagrass meadow) of its dominant predator (cod). This double feedback-loop is supported by a strong increase of shore crab abundance in the last decades and may partly explain the regime shift in vegetation observed

  10. Comparing quality of estuarine and nearshore intertidal habitats for Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Amaral, Valter; Cabral, Henrique N.; Jenkins, Stuart; Hawkins, Stephen; Paula, José

    2009-06-01

    Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different vegetated and nonvegetated estuarine and rocky shore habitats in SW Portugal and SW England was evaluated for intertidal C. maenas populations. We estimated population density, size-structure, and potential growth (RNA/DNA ratios) to investigate habitat quality. Vegetated estuarine habitats supported higher crab densities, than nonvegetated estuarine and rocky shore habitats. Investigation of population size-structure revealed that all habitats seem important recruitment and nursery areas although estuarine habitats in SW Portugal appeared to support higher densities of new recruits than equivalent habitats in SW England. Significant variation was found in RNA/DNA ratios among habitats. Ratios were highest in the rocky shore suggesting a high quality habitat where growth potential is high. We speculate that competition from other top-predators ( Pachygrapsus spp.) rather than low habitat quality may limit the occurrence of C. maenas in intertidal rocky shore habitats in SW Portugal. In estuarine environments RNA/DNA ratios were significantly higher in the vegetated than in the nonvegetated estuarine habitats in SW Portugal but not in SW England, suggesting geographic differences in the extent to which highly structure habitats represent high quality. Our results challenge the current paradigm that structured habitats are necessarily those of higher quality for C. maenas.

  11. Ontogeny of osmoregulatory structures and functions in the green crab Carcinus maenas (Crustacea, Decapoda).

    PubMed

    Cieluch, Ude; Anger, Klaus; Aujoulat, Fabien; Buchholz, Friedrich; Charmantier-Daures, Mireille; Charmantie, Guy

    2004-01-01

    The ontogeny of osmoregulation, the development of branchial transporting epithelia and the expression of the enzyme Na+/K+-ATPase were studied in Carcinus maenas (L.) obtained from the North Sea, Germany. Laboratory-reared zoea larvae, megalopae and young crabs were exposed to a wide range of salinities, and hemolymph osmolality was measured after 24 h exposure time (72 h in juveniles). Zoea I larvae slightly hyper-regulated in dilute media (10.2 per thousand and 17.0 per thousand ) and osmoconformed at >17 per thousand. All later zoeal stages (II-IV) osmoconformed in salinities from 10.2 per thousand to 44.3 per thousand. The megalopa hyper-regulated at salinities from 10.2 to 25.5 per thousand. Young crabs hyperregulated at salinities from 5.3 per thousand to 25.5 per thousand, showing an increase in their osmoregulatory capacity. The development of transporting epithelia and the expression of Na+/K+-ATPase were investigated by means of transmission electron microscopy and immunofluorescence microscopy. In the zoea IV, only a very light fluorescence staining was observed in gill buds. Epithelial cells were rather undifferentiated, without showing any features of ionocytes. Gills were present in the megalopa, where Na+/K+-ATPase was located in basal filaments of the posterior gills. In crab I juveniles and adults, Na+/K+-ATPase was noted in the three most posterior pairs of gills, but lacking in anterior gills. Ionocytes could first be recognized in filaments of megalopal posterior gills, persisting through subsequent stages at the same location. Thus, the development of the gills and the expression of Na+/K+-ATPase are closely correlated with the ontogeny of osmoregulatory abilities. The morphological two-step metamorphosis of C. maenas can also be regarded as an osmo-physiological metamorphosis, (i) from the osmoconforming zoeal stages to the weakly regulating megalopa, and (ii) to the effectively hyper-regulating juvenile and adult crabs.

  12. Effects of temperature on cellular and biochemical parameters in the crab Carcinus aestuarii (Crustacea, Decapoda).

    PubMed

    Matozzo, Valerio; Gallo, Chiara; Marin, Maria Gabriella

    2011-06-01

    The effects of temperature on cellular and biochemical parameters of the crab Carcinus aestuarii were evaluated. Crabs were kept for 7 days at 4, 17 (reference value) and 30 °C (salinity of 35 psu), and total haemocyte count (THC), haemocyte volume, haemocyte proliferation, phenoloxidase (PO) activity in both haemocyte lysate (HL) and cell-free haemolymph (CFH), CFH total protein and glucose levels, superoxide dismutase (SOD) and catalase (CAT) activities in both gills and digestive gland were evaluated. The lowest and the highest temperature significantly decreased THC, whereas haemocyte volume and haemolymph glucose concentration did not differ significantly among experimental conditions. Haemolymph protein concentration significantly reduced in crabs maintained at 30 °C, when compared with that of animals kept at 4 and 17 °C. Haemocyte proliferation increased significantly in crabs kept at 4 and 30 °C, when compared with that of crabs held at 17 °C. Likewise, a significantly higher PO activity was recorded in CFH from crabs kept at 4 and 30 °C, than in control crabs. Conversely, PO activity did not vary significantly in HL. With regard to antioxidant enzyme activities, a significant decrease in CAT activity was observed in gills from crabs kept at 4 °C, when compared to that of crabs kept at 17 °C and 30 °C. Results obtained demonstrated that the highest and lowest temperature tested influenced crab biological responses, and indicated that C. aestuarii modulated its cellular and biochemical parameters (mainly haemocyte proliferation, CFH protein concentrations and CFH PO activity) in order to cope with temperature. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Effects of claw autotomy on green crab (Carcinus maenas) feeding rates

    NASA Astrophysics Data System (ADS)

    Tummon Flynn, Paula S.; Mellish, Cassandra L.; Pickering, Tyler R.; Quijón, Pedro A.

    2015-09-01

    The European green crab (Carcinus maenas) is a voracious non-indigenous predator and a threat to Atlantic Canada's shellfish industry. Its foraging ability, however, may be affected by the occurrence of injuries such as the loss of a cheliped (claw). Given that green crab claws are differentiated into a major crusher and a minor cutter, we argue that autotomy (the reflexive loss of a limb) affects feeding rates, and that this effect depends on which particular claw is lost. We examined the incidence of injuries in two green crab populations of the southern Gulf of St. Lawrence during July-October, 2012. Then we experimentally assessed the influence of the loss of each type of claw upon crab feeding rates over two size-classes of American oysters (Crassostrea virginica) and soft-shell clams (Mya arenaria). Field injury surveys showed that 12.4% of the green crabs collected were missing a claw (the cutter and/or crusher claw). Injury rates increased linearly with crab size, and were found to vary with location. Laboratory experiments showed that, compared to intact crabs, the loss of the crusher claw reduced oyster mortality rates by ~ 93-100%. The loss of the crusher also reduced feeding on small soft-shell clams but only temporarily. The loss of the cutter claw had little impact on green crab feeding rates on oysters and soft-shell clams of either size. Combined, these results suggest that the loss of a claw has an effect on the ability of green crabs to consume commercially important species but this effect depends on which claw is lost and which prey is targeted. It follows that injury rates should be taken into consideration when monitoring and forecasting the potential impacts of green crab populations, particularly on oyster beds.

  14. The ammonium excretion of the shore crab, carcinus maenas, in relation to environmental osmotic conditions

    NASA Astrophysics Data System (ADS)

    Spaargaren, D. H.

    Ammonia concentrations were measured in blood and external media of shore crabs, Carcinus maenas, acclimated to 6 different salinities at high (20° C) and low (4° C) temperatures. It is seen that environmental osmotic conditions (temperature and salinity) have a major influence on NH 4+ formation and thus on protein (amino acid) catabolism. Blood ammonia concentrations appear to be strongly stabilized, independent of environmental osmotic conditions, ranging between 0.25 and 0.55 mmol·l -1. At normal, low environmental NH 4+ concentrations blood NH 4+ is strongly hyper-ionic compared to external concentrations; at high environmental NH 4+ concentrations (even when artificially raised to 2.5 mmol·l -1), blood NH 4+ is strongly hypo-ionic. Regulation of the blood NH 4+ concentrations takes place by a variable efflux of NH 4+; at high environmental NH 4+ concentrations (> 0.28 mmol · l -1), in addition to a high NH 4+ efflux, stabilization of the blood NH 4+ concentrations is effectuated by the formation of urea. Ammonia efflux to the surrounding water is highly dependent to the osmotic conditions of the environment: viz. positively related to temperature and inversely related to external salinity, with relatively stable value near the isosmotic salinity. Related to the strong variations in ammonia efflux, external NH 4+ concentrations in a closed volume of water are highly variable. In the course of time very high values develop in media of low salinity at high temperature. A close connection between NH 4+ excretion and extracellular ion regulation is indicated.

  15. Effects of 4-nonylphenol on the endocrine system of the shore crab, Carcinus maenas.

    PubMed

    Lye, Christina M; Bentley, Matthew G; Galloway, Tamara

    2008-06-01

    There is a considerable body of evidence to suggest that many anthropogenic chemicals, most notably xeno-estrogens, are able to disrupt the endocrine system of vertebrates. There have been few comparable studies on the effects of exposure to these chemicals that may serve as biomarkers of endocrine disruption in aquatic invertebrate species. In addition, the evidence available is complex, conflicting, and far from conclusive. The present study aimed to investigate the impact of the xeno-estrogen 4-nonylphenol (4-NP, nominal concentrations 10-100 microg L(-1)) on the regulation and functioning of the endocrine system of the shore crab Carcinus maenas. It also set out to establish whether 4-NP are causing the effects (i.e., changes of exoskeletons including secondary sexual characteristics, pheromonally mediated behavior and ecdysone levels, and the presence of vt in the male hepatopancreas) found recently in wild shore crabs (Lye et al.,2005). The study utilizes morphological (e.g., gonadosomatic and hepatosomatic indices) and hormonal (ecdysteroid moulting hormone levels and the induction of female specific proteins, vitellins) biomarkers using radioimmunoassay and an indirect enzyme linked immunosorbent assay applied to the soluble protein fraction of adult male hepatopancreatic homogenates. Exposure of C. maenas to an effective concentration as low as 1.5 microg L(-1) 4-NP resulted in a reduced testis weight, increased liver weight, and altered levels of ecdysone equivalents compared to controls. Induction of vitellin-like proteins was absent in all samples tested. The ecological implications and the possible mechanisms for the action of 4-NP on the response of the shore crab to xeno-estrogen exposure are discussed.

  16. Contaminant effects in shore crabs (Carcinus maenas) from Ria Formosa Lagoon.

    PubMed

    Maria, V L; Santos, M A; Bebianno, M J

    2009-08-01

    Defence and damage biomarkers signals were studied in female and male shore crabs Carcinus maenas transplanted between two sites at Ria Formosa Lagoon (South of Portugal). The cross transplantation occurred during 6 days at a hypothetical reference site (Ramalhete), and a contaminated site (Olhão). DNA unwinding technique was used for DNA integrity measurement. General enzymatic antioxidant responses in gills and hepatopancreas (catalase and gills glutathione peroxidase activities increase) showed that cross transplanted crabs (female and male) are suffering from pro-oxidant challenges at the Olhão site. Gills and hepatopancreas glutathione-S-transferase were reduced in both gender crabs transplanted from Ramalhete to Olhão. Metallothioneins induction occurred in crabs transplanted from Ramalhete to Olhão (contaminated by metals and polycyclic aromatic hydrocarbons (PAHs)). However metallothionein differences were also observed towards gender and organ specificities. High gills lipid peroxidation exist in male crabs transplanted from Ramalhete to Olhão, while in females it was the opposite. In both gender crabs from the Olhão site, gills DNA integrity decreased compared to the Ramalhete feral crabs. Moreover, hepatopancreas DNA integrity decreased in male crabs transplanted from Olhão to Ramalhete site which may be related to the environmental conditions (lower contamination levels) revealing the difficulty of selection of reference sites in field studies. Data demonstrated that female and male C. maenas antioxidant defences and damage biomarkers were sensitive to the mixture of contaminants present in these sites as well as good indicators of general stress.

  17. Seed Predation by the Shore Crab Carcinus maenas: A Positive Feedback Preventing Eelgrass Recovery?

    PubMed

    Infantes, Eduardo; Crouzy, Caroline; Moksnes, Per-Olav

    2016-01-01

    There is an increasing interest to restore the ecosystem services that eelgrass provides, after their continuous worldwide decline. Most attempts to restore eelgrass using seeds are challenged by very high seed losses and the reasons for these losses are not all clear. We assess the impact of predation on seed loss and eelgrass establishment, and explore methods to decrease seed loss during restoration in the Swedish northwest coast. In a laboratory study we identified three previously undescribed seed predators, the shore crab Carcinus maenas, the hermit crab Pagurus bernhardus and the sea urchin Strongylocentrotus droebachiensis, of which shore crabs consumed 2-7 times more seeds than the other two species. The importance of shore crabs as seed predators was supported in field cage experiments where one enclosed crab caused 73% loss of seeds over a 1-week period on average (~ 21 seeds per day). Seedling establishment was significantly higher (14%) in cages that excluded predators over an 8-month period than in uncaged plots and cages that allowed predators but prevented seed-transport (0.5%), suggesting that seed predation constitutes a major source of seed loss in the study area. Burying the seeds 2 cm below the sediment surface prevented seed predation in the laboratory and decreased predation in the field, constituting a way to decrease seed loss during restoration. Shore crabs may act as a key feedback mechanism that prevent the return of eelgrass both by direct consumption of eelgrass seeds and as a predator of algal mesograzers, allowing algal mats to overgrow eelgrass beds. This shore crab feedback mechanism could become self-generating by promoting the growth of its own nursery habitat (algal mats) and by decreasing the nursery habitat (seagrass meadow) of its dominant predator (cod). This double feedback-loop is supported by a strong increase of shore crab abundance in the last decades and may partly explain the regime shift in vegetation observed along

  18. Expansion of the neuropeptidome of the globally invasive marine crab Carcinus maenas.

    PubMed

    Christie, Andrew E

    2016-09-01

    Carcinus maenas is widely recognized as one of the world's most successful marine invasive species; its success as an invader is due largely to its ability to thrive under varied environmental conditions. The physiological/behavioral control systems that allow C. maenas to adapt to new environments are undoubtedly under hormonal control, the largest single class of hormones being peptides. While numerous studies have focused on identifying native C. maenas peptides, none has taken advantage of mining transcriptome shotgun assembly (TSA) sequence data, a strategy proven highly successful for peptide discovery in other crustaceans. Here, a C. maenas peptidome was predicted via in silico transcriptome mining. Thirty-seven peptide families were searched for in the extant TSA database, with transcripts encoding precursors for 29 groups identified. The pre/preprohormones deduced from the identified sequences allowed for the prediction of 263 distinct mature peptides, 193 of which are new discoveries for C. maenas. The predicted peptides include isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide, and tachykinin-related peptide. This peptidome is the largest predicted from any single crustacean using the in silico approach, and provides a platform for investigating peptidergic signaling in C. maenas, including control of the processes that allow for its success as a global marine invader. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. De novo assembly of the Carcinus maenas transcriptome and characterization of innate immune system pathways.

    PubMed

    Verbruggen, Bas; Bickley, Lisa K; Santos, Eduarda M; Tyler, Charles R; Stentiford, Grant D; Bateman, Kelly S; van Aerle, Ronny

    2015-06-16

    The European shore crab, Carcinus maenas, is used widely in biomonitoring, ecotoxicology and for studies into host-pathogen interactions. It is also an important invasive species in numerous global locations. However, the genomic resources for this organism are still sparse, limiting research progress in these fields. To address this resource shortfall we produced a C. maenas transcriptome, enabled by the progress in next-generation sequencing technologies, and applied this to assemble information on the innate immune system in this species. We isolated and pooled RNA for twelve different tissues and organs from C. maenas individuals and sequenced the RNA using next generation sequencing on an Illumina HiSeq 2500 platform. After de novo assembly a transcriptome was generated encompassing 212,427 transcripts (153,699 loci). The transcripts were filtered, annotated and characterised using a variety of tools (including BLAST, MEGAN and RSEM) and databases (including NCBI, Gene Ontology and KEGG). There were differential patterns of expression for between 1,223 and 2,741 transcripts across tissues and organs with over-represented Gene Ontology terms relating to their specific function. Based on sequence homology to immune system components in other organisms, we show both the presence of transcripts for a series of known pathogen recognition receptors and response proteins that form part of the innate immune system, and transcripts representing the RNAi, Toll-like receptor signalling, IMD and JAK/STAT pathways. We have produced an assembled transcriptome for C. maenas that provides a significant molecular resource for wide ranging studies in this species. Analysis of the transcriptome has revealed the presence of a series of known targets and functional pathways that form part of their innate immune system and illustrate tissue specific differences in their expression patterns.

  20. Nutritional status of Carcinus maenas (Crustacea: Decapoda) influences susceptibility to contaminant exposure.

    PubMed

    Dissanayake, Awantha; Galloway, Tamara S; Jones, Malcolm B

    2008-08-11

    Using the shore crab Carcinus maenas as a model, this study tested the hypothesis that nutritional status influences susceptibility of adult crabs (>60mm carapace width (CW)) to environmental contamination. In the laboratory, crabs were either starved, given a restricted diet (fed on alternate days) or fully fed (fed each day). In addition, crabs under each feeding regime were exposed to a sublethal concentration (200microgl(-1)) of pyrene (PYR) as a model organic (PAH (polyaromatic hydrocarbon)) contaminant. Various physiological end points were measured after 7 and 14 days. Results indicated that adult shore crab physiology was relatively robust to short-term (7 days) nutritional changes as multivariate analysis (ANOSIM) showed no significant difference in shore crab physiological condition between control and pyrene-exposed crabs, irrespective of dietary feeding regime [Global R=0.018, P (%)=19.2]. After 14 days, however, starved crabs showed significant impacts to physiological condition (as revealed by multivariate analysis) [Global R=0.134, P (%)=0.1], [R=0.209, P (%)=0.1]; starved individuals had significantly lower antioxidant status (F(2,48)=5.35, P<0.01) compared to crabs under both types of feeding regime. Exposure to pyrene resulted in significantly elevated pyrene metabolite concentrations in the urine at 7 and 14 days compared with control individuals (P<0.001), validating contaminant bioavailability, and this was found for all dietary treatments. Also, exposed crabs had significantly increased protein levels (proteinuria) than controls (P<0.001) in their urine after 7 and 14 days, irrespective of dietary regime. After 7 days, pyrene-exposed crabs showed significantly increased antioxidant status (P<0.001) and cellular functioning (increased cellular viability and decreased phagocytosis) (P<0.001) compared to control crabs; however, after 14 days, antioxidant status (P<0.01) and cellular viability (P<0.001) were significantly decreased in pyrene

  1. The crab Carcinus maenas as a suitable experimental model in ecotoxicology.

    PubMed

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo

    2014-09-01

    Aquatic ecotoxicology broadly focuses on how aquatic organisms interact with pollutants in their environment in order to determine environmental hazard and potential risks to humans. Research has produced increasing evidence on the pivotal role of aquatic invertebrates in the assessment of the impact of pollutants on the environment. Its potential use to replace fish bioassays, which offers ethical advantages, has already been widely studied. Nevertheless, the selection of adequate invertebrate experimental models, appropriate experimental designs and bioassays, as well as the control of potential confounding factors in toxicity testing are of major importance to obtain scientifically valid results. Therefore, the present study reviews more than four decades of published research papers in which the Green crab Carcinus maenas was used as an experimental test organism. In general, the surveyed literature indicates that C. maenas is sensitive to a wide range of aquatic pollutants and that its biological responses are linked to exposure concentrations or doses. Current scientific knowledge regarding the biology and ecology of C. maenas and the extensive studies on toxicology found for the present review recognise the Green crab as a reliable estuarine/marine model for routine testing in ecotoxicology research and environmental quality assessment, especially in what concerns the application of the biomarker approach. Data gathered provide valuable information for the selection of adequate and trustworthy bioassays to be used in C. maenas toxicity testing. Since the final expression of high quality testing is a reliable outcome, the present review recommends gender, size and morphotype separation in C. maenas experimental designs and data evaluation. Moreover, the organisms' nutritional status should be taken into account, especially in long-term studies. Studies should also consider the crabs' resilience when facing historical and concurrent contamination. Finally

  2. Effect of meal type on specific dynamic action in the green shore crab, Carcinus maenas.

    PubMed

    McGaw, Iain J; Penney, Chantelle M

    2014-05-01

    The effect of meal type on specific dynamic action was investigated in the green shore crab, Carcinus maenas. When the crabs were offered a meal of fish, shrimp, or mussel of 3 % of their body mass the duration of the SDA response and thus the resultant SDA was lower for the mussel, compared with the shrimp or fish meals. In feeding behaviour experiments the crabs consumed almost twice as much mussel compared with fish or shrimp. When the animals were allowed to feed on each meal until satiated, the differences in the SDA response were abolished. The mussel was much softer (compression test) than the fish or shrimp meal, and meal texture is known to affect the SDA response in amphibians and reptiles. When the crabs were offered a meal of homogenized fish muscle or whole fish muscle, the SDA for the homogenized meal was approximately 35 % lower. This suggested that a significant portion of the SDA budget in decapod crustaceans may be related to mechanical digestion. This is not unexpected since the foregut is supplied by over forty muscles which control the cutting and grinding movements of the gastric mill apparatus. There were slight, but significant differences in protein, lipid, moisture and total energy content of each meal type. Three prepared meals that were high in either protein, lipid or carbohydrate were offered to the crabs to determine if the nutrient content was also a contributing factor to the observed differences in the SDA. The crabs did not eat the prepared meals as readily as the natural food items and as they are messy feeders there was a large variation in the amount of food eaten. The lack of significant differences in the SDA response as a function of nutrient content was likely due to differences in amount of food eaten, which is a major factor determining the SDA response. The differences in SDA when consuming natural food items were likely due to a combination of the costs of mechanical digestion, variation in nutrient content and food

  3. N-Acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium.

    PubMed

    Mesquita, Sofia Raquel; Ergen, Şeyda Fikirdeşici; Rodrigues, Aurélie Pinto; Oliva-Teles, M Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2015-02-01

    Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP(+)-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the epidermis and digestive gland of C. maenas from both estuaries was sensitive to cadmium exposure suggesting its usefulness for inclusion in monitoring programmes. However, in the digestive gland NAGase inhibition was found in crabs from the less impacted site but not in those from the moderately contaminated one. Altered glutathione levels were

  4. Positive feedback fishery: Population consequences of `crab-tiling' on the green crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Sheehan, E. V.; Thompson, R. C.; Coleman, R. A.; Attrill, M. J.

    2008-11-01

    Collection of marine invertebrates for use as fishing bait is a substantial activity in many parts of the world, often with unknown ecological consequences. As new fisheries develop, it is critical for environmental managers to have high quality ecological information regarding the potential impacts, in order to develop sound management strategies. Crab-tiling is a largely unregulated and un-researched fishery, which operates commercially in the south-west UK. The target species is the green crab Carcinus maenas. Those crabs which are pre-ecdysis and have a carapace width greater than 40 mm are collected to be sold to recreational anglers as bait. Collection involves laying artificial structures on intertidal sandflats and mudflats in estuaries. Crabs use these structures as refugia and are collected during low tide. However, the effect that this fishery has on populations of C. maenas is not known. The impact of crab-tiling on C. maenas population structure was determined by sampling crabs from tiled estuaries and non-tiled estuaries using baited drop-nets. A spatially and temporarily replicated, balanced design was used to compare crab abundance, sizes and sex ratios between estuaries. Typically, fisheries are associated with a reduction in the abundance of the target species. Crab-tiling, however, significantly increased C. maenas abundance. This was thought to be a result of the extra habitat in tiled estuaries, which probably provides protection from natural predators, such as birds and fish. Although crabs were more abundant in tiled estuaries than non-tiled estuaries, the overall percentage of reproductively active crabs in non-tiled estuaries was greater than in tiled estuaries. As with most exploited fisheries stocks, crabs in exploited (tiled) estuaries tended to be smaller, with a modal carapace width of 20-29 mm rather than 30-39 mm in non-tiled estuaries. The sex ratio of crabs however; was not significantly different between tiled and non

  5. Microtopography of the eye surface of the crab Carcinus maenas: an atomic force microscope study suggesting a possible antifouling potential.

    PubMed

    Greco, G; Lanero, T Svaldo; Torrassa, S; Young, R; Vassalli, M; Cavaliere, A; Rolandi, R; Pelucchi, E; Faimali, M; Davenport, J

    2013-07-06

    Marine biofouling causes problems for technologies based on the sea, including ships, power plants and marine sensors. Several antifouling techniques have been applied to marine sensors, but most of these methodologies are environmentally unfriendly or ineffective. Bioinspiration, seeking guidance from natural solutions, is a promising approach to antifouling. Here, the eye of the green crab Carcinus maenas was regarded as a marine sensor model and its surface characterized by means of atomic force microscopy. Engineered surface micro- and nanotopography is a new mechanism found to limit biofouling, promising an effective solution with much reduced environmental impact. Besides giving a new insight into the morphology of C. maenas eye and its characterization, our study indicates that the eye surface probably has antifouling/fouling-release potential. Furthermore, the topographical features of the surface may influence the wettability properties of the structure and its interaction with organic molecules. Results indicate that the eye surface micro- and nanotopography may lead to bioinspired solutions to antifouling protection.

  6. Residual analysis in determining the error structure in enzyme kinetic data. Simulation experiments and observations on Carcinus maenas phosphofructokinase.

    PubMed

    Little, D I; Poat, P C; Giles, I G

    1982-06-01

    The nature of the experimental error in the initial velocities of an enzyme-catalysed reaction is required if meaningful least-squares regression is to be applied. When a rate equation more complex that that of Michaelis and Menten is to be solved least-squares techniques are the method of choice and so determination of the error structure becomes mandatory. The use of residual analysis and Tukey's T statistics to determine the weights to use are described. This method has the advantage of requiring no additional experimentation over that required for the primary investigation. Using data obtained for Carcinus maenas phosphofructokinase the variance was found to increase with velocity and was approximated by either an empirical power function, var (vi) alpha vi1.8 or by the function, var (vi) alpha 0.007 + vi2. The latter function is preferred and suggests that the data contains both a constant absolute error and a constant percentage error component.

  7. Sites of release of Putative Sex Pheromone and Sexual Behaviour in Female Carcinus maenas(Crustacea: Decapoda)

    NASA Astrophysics Data System (ADS)

    Bamber, S. D.; Naylor, E.

    1997-02-01

    Pre-moult female Carcinus maenasurine was confirmed as a source of putative sex pheromone. The sexual and temporal specificity of bioactivity in pre-moult female urine was demonstrated when urine samples taken from inter-moult and pre-moult male crabs, and inter-moult females, failed to generate a sexual response from receptive males. Detection sensitivity of male crabs to pre-moult female urine was established at a dilution factor of 1 μl of urine in 10 ml of seawater. Experimental blockage of the site of urine release (the antennal gland opercula) failed to diminish the chemical attractiveness of pre-moult female crabs to test males, implicating at least one further site of putative pheromone release. Observations of female sexual behaviour demonstrated an active role by pre-moult and post-moult female crabs when introduced to male crabs whose locomotor movement had been temporarily restricted.

  8. Grooming as a secondary behavior in the shrimp Macrobrachium rosenbergii (Crustacea, Decapoda, Caridea)

    PubMed Central

    VanMaurik, Lauren N.; Wortham, Jennifer L.

    2014-01-01

    Abstract The giant freshwater prawn, Macrobrachium rosenbergii, is a large shrimp extensively used in aquaculture whose grooming behaviors were analyzed in this study. Macrobrachium rosenbergii exhibits three unique male morphotypes that differ in their behavior, morphology and physiology: small-clawed males (SM), orange-clawed males (OC) and blue-clawed males (BC). The largest and most dominant males, BC males, are predicted to have significantly different grooming behaviors compared to females and the other two male morphotypes. These BC males may be too large and bulky to efficiently groom and may dedicate more time to mating and agonistic interactions than grooming behaviors. Observations were conducted to look at the prevalence of grooming behaviors in the absence and presence of conspecifics and to determine if any differences in grooming behavior exist among the sexes and male morphotypes. Significant differences in the grooming behaviors of all individuals (females and male morphotypes) were found. BC males tended to have the highest grooming time budget (percent of time spent grooming) while SM males had a relatively low grooming time budget. The grooming behaviors of the male morphotypes differed, indicating while these males play distinct, separate roles in the social hierarchy, they also have different grooming priorities. The conditions in which Macrobrachium rosenbergii are cultured may result in increased body fouling, which may vary, depending on the grooming efficiencies and priorities of these male morphotypes. Overall, grooming behaviors were found to be a secondary behavior which only occurred when primary behaviors such as mating, feeding or fighting were not present. PMID:25561831

  9. [Influence of lecithotrofic feeding on growth and development of larvae of freshwater shrimp Macrobrachium rosenbergii].

    PubMed

    Borisov, R R; Kriakhova, N V

    2011-01-01

    In the giant freshwater shrimp Macrobrachium rosenbergii (De Man), lecithotrofic feeding was discovered at the zoea I stage, and facultative lecithotrofic feeding was found at the zoea II stage. Cases of the completion of the first two stages without feeding were detected. However, a delay in feeding at the zoea II stage caused the inhibition of the growth and development of larvae. In this connection, we recommend to introduce food to the aquaculture of the giant freshwater shrimp on the end of the first day after hatching, when the first zoea II larvae emerge.

  10. Clearance of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) and immunological changes in experimentally injected Macrobrachium rosenbergii.

    PubMed

    Ravi, M; Nazeer Basha, A; Taju, G; Ram Kumar, R; Sahul Hameed, A S

    2010-03-01

    Macrobrachium rosenbergii was experimentally challenged with Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) to study the clearance of these viruses and consequent changes in various immunological parameters. The healthy animals were injected MrNV and XSV intramuscularly and various organ samples such as gill tissue, head soft tissue, pleopods and intestine were collected at different time intervals of 3, 5, 10, 15, 25, 50, 75 and 100d post-infection (p.i.) to study the viral clearance. Tissue tropism and clearing of MrNV and XSV were confirmed by RT-PCR, nested RT-PCR and bioassay. These 2 viruses failed to cause mortality or clinical signs of disease in injected adult prawns during the experimental period of 100 days. The result of RT-PCR analysis revealed that all the organs showed positive for both viruses by single step RT-PCR on 3, 5 and 10 d p.i., positive by nested RT-PCR on 15 and 20 d p.i. and all the organs became negative at 25 d p.i. onwards. The viral inoculum prepared from the tissue of MrNV and XSV-injected M. rosenbergii at 3, 5, 10, 15 and 20 d p.i. caused 100% mortality in post-larvae of M. rosenbergii at 9, 8, 7, 10 and 10 d p.i., respectively whereas the inoculum prepared at 25, 50 and 100 d p.i. failed to cause significant mortality in post-larvae of prawn. Immunological parameters such as proPO, superoxide anion, SOD, THC, clotting time and oxyhemocyanin were determined in MrNV and XSV-injected prawns and significant differences in some of the immunological parameters were found in the early days p.i. and became insignificant in the later days p.i.

  11. Lack of adult novel northern lineages of invasive green crab Carcinus maenas along much of the northern US Atlantic coast

    PubMed Central

    Williams, Larissa M.; Nivison, Camilla L.; Ambrose, William G.; Dobbin, Rebecca; Locke, William L.

    2017-01-01

    Introduced over 200 yr ago to the east coast of North America, Carcinus maenas now ranges from New York to Newfoundland. In the 1980s, a secondary invasion of European lineages, termed northern haplotypes, occurred in Nova Scotia. Young-of-the-year sampled in 2007 revealed that northern haplotypes were present in low frequencies at several northwestern Atlantic sites as far south as New York; a model predicted an increase in their range and frequency over time. We collected samples in 2013 and 2014 to determine the haplotypes of adult crabs from New York to Nova Scotia. Six haplotypes, encompassing previously identified northern and southern haplotypes, 1 novel southern haplotype, and 1 Scandinavian haplotype, were identified in 275 crabs sampled at 11 sites. Northern haplotypes were only found in Nova Scotia, Beals Island (Maine), and Mount Desert Island (Maine) at a frequency of 60, 8, and 24%, respectively; remaining sites were predominantly composed of a previously identified southern haplotype. Northern haplotypes are limited in adult crabs to Mount Desert Island and north, indicating that the southern haplotype is selectively favored at some point during their life history, recruitment of northern larvae is limited south of Mount Desert Island, or entire year-classes post-2007 were lost. Our results do not support the predictions of an increase in the range and frequency of northern haplotypes, at least among adults, and indicate that a more complete knowledge of factors affecting C. maenas life stages is necessary to understand the current distribution of haplotypes. PMID:28127110

  12. Competition and niche segregation following the arrival of Hemigrapsus takanoi in the formerly Carcinus maenas dominated Dutch delta

    NASA Astrophysics Data System (ADS)

    van den Brink, A. M.; Wijnhoven, S.; McLay, C. L.

    2012-10-01

    In a combined study including a 20 year monitoring programme of the benthic communities of four Dutch delta waters and a snapshot survey conducted in the Oosterschelde tidal bay in 2011, the populations of the native portunid European shore crab Carcinus maenas and the introduced varunid crabs Hemigrapsus takanoi and Hemigrapsus sanguineus were investigated. Whereas C. maenas was the most common shore crab in these waters, its numbers have declined on the soft sediment substrates during the last 20 years. As the two exotic crab species were first recorded in the Dutch delta in 1999, they could not have initiated the decline of the native C. maenas. However, within a few years H. takanoi completely dominated the intertidal hard substrate environments; the same environments on which juvenile C. maenas depend. On soft sediment substrate the native and exotic shore crab species are presently more or less equally abundant. H. takanoi might initially have taken advantage of the fact that C. maenas numbers were declining. Additionally H. takanoi are thriving in expanding oyster reefs of Crassostrea gigas (Pacific oyster) in the Dutch delta waters, which provide new habitat. Nowadays H. takanoi appears to be a fierce interference competitor or predator for small C. maenas specimens by expelling them from their shelters. These interactions have led to increased mortality of juvenile C. maenas. At present the C. maenas populations seem to be maintained by crabs that survive and reproduce on available soft sediment habitats where H. takanoi densities are low.

  13. On the morphology of the central nervous system in larval stages of Carcinus maenas L. (Decapoda, Brachyura)

    NASA Astrophysics Data System (ADS)

    Harzsch, S.; Dawirs, R. R.

    1993-02-01

    We investigated the morphology of the central nervous system throughout the larval development of Carcinus maenas. For that purpose single larvae were reared in the laboratory from hatching through metamorphosis. Complete series of whole mout semithin sections were obtained from individuals of all successive larval stages and analysed with a light microscope. Morphological feature and spatial arrangement of discernable neural cell clusters, fibre tracts and neuropile are described and compared with the adult pattern. We found that most of the morphological features characterizing the adult nervous system are already present in the zoea-1. Nevertheless, there are marked differences with respect to the arrangement of nerve cell bodies, organization of cerebral neuropile, and disposition of ganglia in the ventral nerve cord. It appears that complexity of the central nervous neuropile is selectively altered during postmetamorphotic development, probably reflecting adaptive changes of sensory-motor integration in response to behavioural maturation. In contrast, during larval development there was little change in the overall structural organization of the central nervous system despite some considerable growth. However, the transition from zoea-4 to megalopa brings about multiple fundamental changes in larval morphology and behavioural pattern. Since central nervous integration should properly adapt to the altered behavioural repertoire of the megalopa, it seems necessary to ask in which respect synaptic rearrangement might characterize development of the central nervous system.

  14. Lack of adult novel northern lineages of invasive green crab Carcinus maenas along much of the northern US Atlantic coast.

    PubMed

    Williams, Larissa M; Nivison, Camilla L; Ambrose, William G; Dobbin, Rebecca; Locke, William L

    2015-01-01

    Introduced over 200 yr ago to the east coast of North America, Carcinus maenas now ranges from New York to Newfoundland. In the 1980s, a secondary invasion of European lineages, termed northern haplotypes, occurred in Nova Scotia. Young-of-the-year sampled in 2007 revealed that northern haplotypes were present in low frequencies at several northwestern Atlantic sites as far south as New York; a model predicted an increase in their range and frequency over time. We collected samples in 2013 and 2014 to determine the haplotypes of adult crabs from New York to Nova Scotia. Six haplotypes, encompassing previously identified northern and southern haplotypes, 1 novel southern haplotype, and 1 Scandinavian haplotype, were identified in 275 crabs sampled at 11 sites. Northern haplotypes were only found in Nova Scotia, Beals Island (Maine), and Mount Desert Island (Maine) at a frequency of 60, 8, and 24%, respectively; remaining sites were predominantly composed of a previously identified southern haplotype. Northern haplotypes are limited in adult crabs to Mount Desert Island and north, indicating that the southern haplotype is selectively favored at some point during their life history, recruitment of northern larvae is limited south of Mount Desert Island, or entire year-classes post-2007 were lost. Our results do not support the predictions of an increase in the range and frequency of northern haplotypes, at least among adults, and indicate that a more complete knowledge of factors affecting C. maenas life stages is necessary to understand the current distribution of haplotypes.

  15. Microtopography of the eye surface of the crab Carcinus maenas: an atomic force microscope study suggesting a possible antifouling potential

    PubMed Central

    Greco, G.; Lanero, T. Svaldo; Torrassa, S.; Young, R.; Vassalli, M.; Cavaliere, A.; Rolandi, R.; Pelucchi, E.; Faimali, M.; Davenport, J.

    2013-01-01

    Marine biofouling causes problems for technologies based on the sea, including ships, power plants and marine sensors. Several antifouling techniques have been applied to marine sensors, but most of these methodologies are environmentally unfriendly or ineffective. Bioinspiration, seeking guidance from natural solutions, is a promising approach to antifouling. Here, the eye of the green crab Carcinus maenas was regarded as a marine sensor model and its surface characterized by means of atomic force microscopy. Engineered surface micro- and nanotopography is a new mechanism found to limit biofouling, promising an effective solution with much reduced environmental impact. Besides giving a new insight into the morphology of C. maenas eye and its characterization, our study indicates that the eye surface probably has antifouling/fouling-release potential. Furthermore, the topographical features of the surface may influence the wettability properties of the structure and its interaction with organic molecules. Results indicate that the eye surface micro- and nanotopography may lead to bioinspired solutions to antifouling protection. PMID:23635491

  16. Foraging behaviour and mutual interference in the Mediterranean shore crab, Carcinus aestuarii, preying upon the immigrant mussel Musculista senhousia

    NASA Astrophysics Data System (ADS)

    Mistri, M.

    2003-01-01

    Predator-prey dynamics between the Mediterranean shore crab Carcinus aestuarii and the immigrant mussel Musculista senhousia were examined in laboratory experiments to assess the effects of varying predator and prey densities upon predator foraging rates and prey survival. The factorial design involved three predator and three prey densities, with four trials per treatment combination. Functional responses were differentiated statistically by analysis of the exponent β of a general functional response model. Shore crabs displayed type II (decelerating rise to an upper asymptote) inversely density-dependent functional responses at low and moderate predator densities, while a non-traditional model was probably more appropriate at high predator density. No density-dependent refuge was observed for M. senhousia, whereas, at high predator density, mutual interference among crabs was evident and prey mortality was lowered. Mediterranean shore crab's combined functional and interference response, by affecting foraging rates, was important to the outcome of interactions between predators and the bivalve prey, and might play an important role in determining crab's predatory behaviour and dispersion, and prey persistence, in the field.

  17. Ingestion of Plastic Microfibers by the Crab Carcinus maenas and Its Effect on Food Consumption and Energy Balance.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Corr, Shauna; Lewis, Ceri; Galloway, Tamara S

    2015-12-15

    Microscopic plastic fragments (<5 mm) are a worldwide conservation issue, polluting both coastal and marine environments. Fibers are the most prominent plastic type reported in the guts of marine organisms, but their effects once ingested are unknown. This study investigated the fate of polypropylene rope microfibers (1-5 mm in length) ingested by the crab Carcinus maenas and the consequences for the crab's energy budget. In chronic 4 week feeding studies, crabs that ingested food containing microfibers (0.3-1.0% plastic by weight) showed reduced food consumption (from 0.33 to 0.03 g d(-1)) and a significant reduction in energy available for growth (scope for growth) from 0.59 to -0.31 kJ crab d(-1) in crabs fed with 1% plastic. The polypropylene microfibers were physically altered by their passage through the foregut and were excreted with a smaller overall size and length and amalgamated into distinctive balls. These results support of the emerging paradigm that a key biological impact of microplastic ingestion is a reduction in energy budgets for the affected marine biota. We also provide novel evidence of the biotransformations that can affect the plastics themselves following ingestion and excretion.

  18. Recruitment of shore crabs Carcinus maenas on tidal flats: Mussel clumps as an important refuge for juveniles

    NASA Astrophysics Data System (ADS)

    Thiel, M.; Dernedde, T.

    1994-06-01

    During the late summer and early fall, juvenile shore crabs ( Carcinus maenas L.) occurred in high abundances in mussel clumps scattered on tidal flats of the Wadden Sea. Abundances were much lower on bare tidal flats without mussel clumps and decreased substantially from July to November, whereas numbers in mussel clumps remained high. Large crabs left the tidal flats in early fall, whereas juveniles undertook tidal migrations only in the late fall. In March very few shore crabs were found in the intertidal area. The size of juvenile shore crabs living between mussels did not increase significantly during fall. On the bare tidal flats surrounding the mussels, a size increase was observed. Mussel beds and mussel clumps serve as a spatial refuge for the early benthic phases of juvenile shore crabs. Between mussels they can hide effectively from their epibenthic predators. Juvenile shore crabs do not leave the intertidal area and the mussel habitats before their major predators have left the area. Mussel clumps scattered over the tidal flats may be a critical refuge for juvenile shore crabs settling on tidal flats. Intensified efforts in mussel culturing in the European Wadden Sea during recent decades may have caused an increased abundance of mussel clumps on tidal flats, thus enhancing habitat availability for some mussel-clump inhabitants.

  19. Temporal genetic homogeneity among shore crab (Carcinus maenas) larval events supplied to an estuarine system on the Portuguese northwest coast

    PubMed Central

    Domingues, C P; Creer, S; Taylor, M I; Queiroga, H; Carvalho, G R

    2011-01-01

    Despite the importance of larval biology in the life histories of many marine animals, relatively little information exists on the dynamics and genetic composition of larval cohorts. The supply of megalopae larvae of the shore crab, Carcinus maenas, was measured on a daily basis during 8 months spread along two larval periods (2006 and 2007) at the Ria de Aveiro estuary, on the Portuguese northwest coast. A total of 10 microsatellite DNA loci were employed to explore the genetic structure, variability and relatedness of temporally distinct megalopal events, selected from the major pulses of supply. Larval variation was also compared genetically with that of a previously studied adult crabs sample, at the same loci, collected in 2006 and 2007 along the Iberian Peninsula. Results revealed a lack of genetic differentiation and identical diversity levels among larval events over time. No evidence of reduced genetic diversity between megalopae relative to the diversity assessed from the pooled sample of adults was found. Moreover, there was no evidence of any family relatedness among larvae from temporal events. The results obtained for C. maenas contradict predictions made by the sweepstakes reproduction hypothesis, in which large variance in reproductive success is expected, which is presumably detectable as sharp genetic discontinuities among separate larval events. Data here indicate conversely a high degree of temporal genetic stability among larval supply to a given estuary under variable oceanographic conditions, consistent with the hypothesis that sampled larvae were drawn from a large number of adults that do not differ in reproductive success. PMID:20959862

  20. Unravelling polar lipids dynamics during embryonic development of two sympatric brachyuran crabs (Carcinus maenas and Necora puber) using lipidomics

    PubMed Central

    Rey, Felisa; Alves, Eliana; Melo, Tânia; Domingues, Pedro; Queiroga, Henrique; Rosa, Rui; Domingues, M. Rosário M.; Calado, Ricardo

    2015-01-01

    Embryogenesis is an important stage of marine invertebrates with bi-phasic life cycles, as it conditions their larval and adult life. Throughout embryogenesis, phospholipids (PL) play a key role as an energy source, as well as constituents of biological membranes. However, the dynamics of PL during embryogenesis in marine invertebrates is still poorly studied. The present work used a lipidomic approach to determine how polar lipid profiles shift during embryogenesis in two sympatric estuarine crabs, Carcinus maenas and Necora puber. The combination of thin layer chromatography, liquid chromatography – mass spectrometry and gas chromatography – mass spectrometry allowed us to achieve an unprecedented resolution on PL classes and molecular species present on newly extruded embryos (stage 1) and those near hatching (stage 3). Embryogenesis proved to be a dynamic process, with four PL classes being recorded in stage 1 embryos (68 molecular species in total) and seven PL classes at stage 3 embryos (98 molecular species in total). The low interspecific difference recorded in the lipidomic profiles of stage 1 embryos appears to indicate the existence of similar maternal investment. The same pattern was recorded for stage 3 embryos revealing a similar catabolism of embryonic resources during incubation for both crab species. PMID:26419891

  1. Genomic evidence of hybridization between two independent invasions of European green crab (Carcinus maenas) in the Northwest Atlantic.

    PubMed

    Jeffery, N W; DiBacco, C; Wringe, B F; Stanley, R R E; Hamilton, L C; Ravindran, P N; Bradbury, I R

    2017-09-01

    Invasive species have been associated with significant negative impacts in their introduced range often outcompeting native species, yet the long-term evolutionary dynamics of biological invasions are not well understood. Hybridization, either among waves of invasion or between native and introduced populations, could alter the ecological and evolutionary impacts of invasions yet has rarely been studied in marine invasive species. The European green crab (Carcinus maenas) invaded eastern North America twice from northern and southern locations in its native range. Here we examine the frequency of hybridization among these two distinct invasions at locations from New Jersey, USA to Newfoundland, Canada using restriction-site-associated DNA sequencing (RAD-seq), microsatellite loci and cytochrome c oxidase subunit I mitochondrial DNA (mtDNA) sequences. We used Bayesian clustering and hybrid assignment analyses to investigate hybridization between the northern and southern populations. Of the samples analyzed, six locations contained at least one hybrid individual, while two locations were characterized by extensive hybridization, with 95% of individuals collected from Placentia Bay, Newfoundland being hybrids (mostly F2) and 90% of individuals from Kejimkujik, Nova Scotia being classified as hybrids, mostly backcrosses to the northern ecotype. The presence of both F2 hybrids and backcrossed individuals suggests that these hybrids are viable and introgression is occurring between invasions. Our results provide insight into the demographic and evolutionary consequences of hybridization between independent invasions, and will inform the management of green crabs in eastern North America.

  2. RAD sequencing reveals genomewide divergence between independent invasions of the European green crab (Carcinus maenas) in the Northwest Atlantic.

    PubMed

    Jeffery, Nicholas W; DiBacco, Claudio; Van Wyngaarden, Mallory; Hamilton, Lorraine C; Stanley, Ryan R E; Bernier, Renée; FitzGerald, Jennifer; Matheson, K; McKenzie, C H; Nadukkalam Ravindran, Praveen; Beiko, Robert; Bradbury, Ian R

    2017-04-01

    Genomic studies of invasive species can reveal both invasive pathways and functional differences underpinning patterns of colonization success. The European green crab (Carcinus maenas) was initially introduced to eastern North America nearly 200 years ago where it expanded northwards to eastern Nova Scotia. A subsequent invasion to Nova Scotia from a northern European source allowed further range expansion, providing a unique opportunity to study the invasion genomics of a species with multiple invasions. Here, we use restriction-site-associated DNA sequencing-derived SNPs to explore fine-scale genomewide differentiation between these two invasions. We identified 9137 loci from green crab sampled from 11 locations along eastern North America and compared spatial variation to mitochondrial COI sequence variation used previously to characterize these invasions. Overall spatial divergence among invasions was high (pairwise FST ~0.001 to 0.15) and spread across many loci, with a mean FST ~0.052 and 52% of loci examined characterized by FST values >0.05. The majority of the most divergent loci (i.e., outliers, ~1.2%) displayed latitudinal clines in allele frequency highlighting extensive genomic divergence among the invasions. Discriminant analysis of principal components (both neutral and outlier loci) clearly resolved the two invasions spatially and was highly correlated with mitochondrial divergence. Our results reveal extensive cryptic intraspecific genomic diversity associated with differing patterns of colonization success and demonstrates clear utility for genomic approaches to delineating the distribution and colonization success of aquatic invasive species.

  3. Genetic diversity of cultured and wild populations of the freshwater prawn Macrobrachium rosenbergii based on microsatellite analysis

    USDA-ARS?s Scientific Manuscript database

    Freshwater prawn Macrobrachium rosenbergii culture in the Western Hemisphere is primarily, if not entirely, based on thirty-six individual prawn introduced to Hawaii from Malaysia in 1965 and 1966. Little information is available regarding the genetic background or current population status of cult...

  4. Species composition and gear characteristics of the Macrobrachium fishery of the Cross River Estuary, Nigeria

    NASA Astrophysics Data System (ADS)

    Nwosu, Francis M.

    2010-03-01

    The Cross River Estuary, Nigeria, is an important shrimping area for artisanal fishermen of the coastal communities. The multi-species Macrobrachium fishery is exploited with three main gears, namely beach seine, push net and trap. Studies on species composition of this fishery recorded thirteen shrimp species, one swimming crab ( Callinectes amnicola) and two fish species ( Eleotris sp. and Pellonula leonensis). The shrimp species identified included Macrobrachium macrobrachion (83.39% and 55.69% by number and weight, respectively), M. vollenhovenii (9.66% and 37.18%), M. equidens (3.8% and 2.87%), juveniles-sub-adults of Penaeus notialis (1.11% and 1.3%), M. dux, M. felicinum, Palaemonetes africanus, Palaemon maculatus, Palaemon elegans, Desmocaris sp., Leander sp., Nematopalaemon hastatus and Alpheus pontederiae. While the selectivity index for trap was 0.25, beach seine and push net had a lower index of 0.063. The results present the first comprehensive and representative report for the Estuary shrimp fishery and will assist in the management of the biodiversity of this ecosystem.

  5. Sertraline accumulation and effects in the estuarine decapod Carcinus maenas: importance of the history of exposure to chemical stress.

    PubMed

    Rodrigues, Aurélie P; Santos, Lúcia H M L M; Ramalhosa, Maria João; Delerue-Matos, Cristina; Guimarães, Laura

    2015-01-01

    Sertraline is widely prescribed worldwide and frequently detected in aquatic systems. There is, however, a remarkable gap of information on its potential impact on estuarine and coastal invertebrates. This study investigated sertraline accumulation and effects in Carcinus maenas. Crabs from a moderately contaminated (Lima) and a low-impacted (Minho) estuary were exposed to environmental and high levels of sertraline (0.05, 5, 500 μg L(-1)). A battery of biomarkers related to sertraline mode of action was employed to assess neurotransmission, energy metabolism, biotransformation and oxidative stress pathways. After a seven-day exposure, sertraline accumulation in crabs' soft tissues was found in Lima (5 μg L(-1): 15.3 ng L(-1) ww; 500 μg L(-1): 1010 ng L(-1) ww) and Minho (500 μg L(-1): 605 ng L(-1) ww) animals. Lima crabs were also more sensitive to sertraline than those from Minho, exhibiting decreased acetylcholinesterase activity, indicative of ventilatory and locomotory dysfunction, inhibition of anti-oxidant enzymes and increased oxidative damage at ≥ 0.05 μg L(-1). The Integrated Biomarker Response (IBR) index indicated their low health status. In addition, Minho crabs showed non-monotonic responses of acetylcholinesterase suggestive of hormesis. The results pointed an influence of the exposure history on differential sensitivity to sertraline and the need to perform evaluations with site-specific ecological receptors to increase relevance of risk estimations when extrapolating from laboratory to field conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Seasonal differences in the physiology of Carcinus maenas (Crustacea: Decapoda) from estuaries with varying levels of anthropogenic contamination

    NASA Astrophysics Data System (ADS)

    Dissanayake, Awantha; Galloway, Tamara S.; Jones, Malcolm B.

    2011-07-01

    This study reports the seasonal variability in aspects of the physiology of the shore crab Carcinus maenas from three estuaries in South-west England, each with varying anthropogenic inputs: Avon Estuary ('relatively low' impact), Yealm Estuary ('intermediate' impact) and Plym Estuary ('relatively high' impact). Crabs collected over 12 months from the Avon had a significantly 'lower' physiological condition in winter and spring compared to summer and autumn; in particular, haemocyte phagocytic capability (a general indicator of immune function) was significantly higher in winter and spring compared to summer and autumn, and total haemolymph antioxidant status (an indicator of oxidative stress) was significantly lower in winter compared to the remainder of the year. Potentially, shore crabs may be more susceptible to the effects of contaminant exposure, such as increased immunotoxicity (thus, reduction of immune function) and/or oxyradicals (or reactive oxygen species) exposure) especially in seasons of increased susceptibility i.e. summer/autumn (lower phagocytic capability) and winter (lowest antioxidant function). As the Avon was taken to represent the 'reference' site, this pattern is considered to reflect the 'normal' seasonal variability in shore crab physiology. Shore crab physiological condition from the 'relatively high' impact estuary (Plym) revealed increased cellular viability and antioxidant status in autumn and winter compared with that of the 'standard' pattern (Avon) However, crabs from the intermediate impact estuary (Yealm) only demonstrated significant physiological differences in summer as shown by a lower cellular viability. All crabs had been exposed to PAHs (confirmed by the presence of PAH metabolites in their urine) which may account for the observed differences in shore crab physiology. In conclusion, to aid understanding of the potential contaminant impacts on biota it is imperative that the 'normal' seasonal variability of physiological

  7. Early responses measured in the brachyuran crab Carcinus maenas exposed to carbamazepine and novobiocin: application of a 2-tier approach.

    PubMed

    Aguirre-Martínez, G V; Del Valls, T A; Martín-Díaz, M L

    2013-11-01

    One of the main consequences of the constant input of pharmaceuticals to the aquatic environment is that biota might develop unknown chronic effects, thus affecting their health even at low concentrations. The aim of this study is to evaluate the health status of Carcinus maenas employing a 2-tier approach, after 28 days of exposure to carbamazepine (CBZ) and novobiocin (NOV) at 0.1, 1, 10 and 50µgL(-1). Lysosomal membrane stability (LMS) is employed in tier 1. In tier 2 was applied a battery of biomarkers of exposure and effect (ethoxyresorufin O-deethylase (EROD), dibenzyl flourescein dealkylase (DBF), glutathione S-transferase (GST), glutathione peroxidase (GPx), lipid peroxidation (LPO) and DNA adducts) measured in gill, hepatopancreas, muscle and gonad tissues. Results show a dose-dependent effect. LMS in crabs exposed to environmental concentrations of pharmaceuticals was significantly lower compared to controls (p<0.05), indicating their stressed status. EROD activity was induced significantly (p<0.05) in all tissues by NOV (10-50µgL(-1)). DBF activity was induced significantly (p<0.05) in gill and hepatopancreas tissues by CBZ (10-50µgL(-1)). GST activity was activated in all tissues of crabs exposed to the highest concentrations tested (p<0.05). All tissues showed induction of GPX activity after exposure to selected drugs (p<0.05). LPO was activated in gill and hepatopancreas tissues by the pharmaceuticals at 50µgL(-1) (p<0.05). Crabs exposed to NOV (50µgL(-1)) presented DNA damage in gill and hepatopancreas tissues (p<0.05). Environmental concentrations of these pharmaceuticals have a measurable effect on the biomarkers studied. The 2-tier approach applied might be a suitable tool for the assessment of sublethal responses in crabs exposed to pharmaceuticals in the marine environment.

  8. Effect of temperature on the spoilage rate of whole, unprocessed crabs: Carcinus maenas, Necora puber and Cancer pagurus.

    PubMed

    Robson, Anthony A; Kelly, Maeve S; Latchford, John W

    2007-06-01

    Shelf life of whole, initially live, crabs depended primarily on the storage conditions and the time at which death occurred. Large differences in the time that individual crab species survived particular storage conditions resulted in wide variations in shelf-life. Bacterial spoilage of Carcinus maenas, Necora puber and Cancer pagurus, measured using aerobic plate counts, indicated that on ice at 4 degrees C whole unprocessed crabs had a shelf life approximately 9-11 days, at 4 degrees C approximately 13-29 days, in simulated supermarket conditions of sale approximately 5-7 days and at 20 degrees C approximately 2-16 days. Storage of whole unprocessed crabs chilled at 4 degrees C considerably extended shelf life compared to crabs stored on ice. Live crabs stored on ice died within 24h, most likely due to thermal shock and their early death was responsible for their more rapid increase in bacterial numbers compared to crabs stored at 4 degrees C. No growth of bacteria occurred in the flesh of live crabs stored at 4 degrees C for between 128 and 504 h. Crab flesh quality deteriorated prior to maximum shelf-life (defined as the time at which bacterial load reached log 5 cfu/g crabmeat) in some instances. The best compromise between high crabmeat yield and long shelf-life is likely to be to transport crabs at 4 degrees C live to market where they could be stored live at 4 degrees C without spoilage for 2 weeks before placed on ice at 4 degrees C, with a potential maximum shelf life of approximately 24 days.

  9. Low salinity enhances NI-mediated oxidative stress and sub-lethal toxicity to the green shore crab (Carcinus maenas).

    PubMed

    Blewett, Tamzin A; Wood, Chris M

    2015-12-01

    Nickel (Ni) is a metal of environmental concern, known to cause toxicity to freshwater organisms by impairing ionoregulation and/or respiratory gas exchange, and by inducing oxidative stress. However, little is known regarding how nickel toxicity is influenced by salinity. In the current study we investigated the salinity-dependence and mechanisms of sub-lethal Ni toxicity in a euryhaline crab (Carcinus maenas). Crabs were acclimated to three experimental salinities--20, 60 and 100% seawater (SW)--and exposed to 3mg/L Ni for 24h or 96 h. Tissues were dissected for analysis of Ni accumulation, gills were taken for oxidative stress analysis (catalase activity and protein carbonyl content), haemolymph ions were analysed for ionoregulatory disturbance, and oxygen consumption was determined in exercised crabs after 96 h of Ni exposure. Total Ni accumulation was strongly dependant on salinity, with crabs from 20% SW displaying the highest tissue Ni burdens after both 24 and 96-h exposures. After 96 h of exposure, the highest accumulation of Ni occurred in the posterior (ionoregulatory) gills at the lowest salinity, 20% SW. Posterior gill 8 exhibited elevated protein carbonyl levels and decreased catalase activity after Ni exposure, but only in 20% SW. Similarly, decreased levels of haemolymph Mg and K and an increased level of Ca were recorded but only in crabs exposed to Ni for 96 h in 20% SW. Oxygen consumption after exercise was also inhibited in crabs exposed to Ni in 20% SW. These data show for the first time the simultaneous presence of all three modes of sub-lethal Ni toxicity in exposed animals, and indicate a strong salinity dependence of sub-lethal Ni toxicity to the euryhaline crab, C. maenas, a pattern that corresponded to tissue Ni accumulation.

  10. Artemia as a possible vector for Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus transmission (XSV) to Macrobrachium rosenbergii post-larvae.

    PubMed

    Sudhakaran, R; Yoganandhan, K; Ahmed, V P Ishaq; Hameed, A S Sahul

    2006-06-12

    Five developmental stages of Artemia were exposed to Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) by immersion and oral routes in order to investigate the possibility of Artemia acting as a reservoir or carrier of these viruses. The second objective was to determine if virus-exposed Artemia were capable of transmitting the disease to post-larvae (PL) of M. rosenbergii. There was no significant difference in percent mortality between Artemia control groups and groups challenged with these viruses. On the other hand, all the developmental stages of Artemia were positive for both viruses by nested RT-PCR, regardless of the challenge route. In horizontal transmission experiments, 100% mortality was observed in M. rosenbergii PL fed with Artemia nauplii exposed to MrNV and XSV by either challenge route. However, no mortality was observed in PL fed with virus-free Artemia. RT-PCR analysis of the M. rosenbergii PL confirmed the presence of MrNV and XSV in the challenge group and absence in the control group.

  11. Experimental vertical transmission of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) from brooders to progeny in Macrobrachium rosenbergii and Artemia.

    PubMed

    Sudhakaran, R; Ishaq Ahmed, V P; Haribabu, P; Mukherjee, S C; Sri Widada, J; Bonami, J R; Sahul Hameed, A S

    2007-01-01

    White tail disease (WTD) is a serious problem in hatcheries and nursery ponds of Macrobrachium rosenbergii in India. Experiments were carried out to determine the possibility of vertical transmission of M. rosenbergii nodavirus (MrNV) and extra small virus (XSV) in M. rosenbergii and Artemia. Prawn broodstock inoculated with MrNV and XSV by oral or immersion challenge survived without any clinical signs of WTD. The brooders spawned 5-7 days after inoculation and the eggs hatched. The survival rate of larvae gradually decreased, and 100% mortality was observed at the post-larvae (PL) stage. Whitish muscle, the typical sign of WTD, was seen in advanced larval developmental stages. The ovarian tissue and fertilized eggs were found to be positive for MrNV/XSV by reverse transcriptase-polymerase chain reaction (RT-PCR) whereas the larval stages showed positive by RT nested PCR (nRT-PCR). In Artemia, reproductive cysts and nauplii derived from challenged brooders were normal and survival rates were within the expected range for normal rearing conditions. The reproductive cysts were found to be positive for MrNV/XSV by RT-PCR whereas the nauplii showed MrNV/XSV-positive by nRT-PCR. The PL of M. rosenbergii fed nauplii derived from challenged Artemia brooders died at 9 days post-inoculum with clinical signs of WTD.

  12. Cloning of precursors for two MIH/VIH-related peptides in the prawn, Macrobrachium rosenbergii.

    PubMed

    Yang, W J; Rao, K R

    2001-11-30

    Two cDNA clones (634 and 1366 bp) encoding MIH/VIH (molt-inhibiting hormone/vitellogenesis-inhibiting hormone)-related peptides were isolated and sequenced from a Macrobrachium rosenbergii eyestalk ganglia cDNA library. The clones contain a 360 and 339 bp open-reading frame, and their conceptually translated peptides consist of a 41 and 34 amino acid signal peptide, respectively, and a 78 amino acid residue mature peptide hormone. The amino acid sequences of the peptides exhibit higher identities with other known MIHs and VIH (44-69%) than with CHHs (28-33%). This is the first report describing the cloning and sequencing of two MIH/VIH-related peptides in a single crustacean species. Transcription of these mRNAs was detected in the eyestalk ganglia, but not in the thoracic ganglia, hepatopancreas, gut, gill, heart, or muscle.

  13. First report on vertical transmission of a plasmid DNA in freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Chowdhury, Labrechai Mog; Gireesh-Babu, P; Pavan-Kumar, A; Suresh Babu, P P; Chaudhari, Aparna

    2014-09-01

    Outbreak of WSSV disease is one of the major stumbling blocks in shrimp aquaculture. DNA vaccines have shown potential for mass scale vaccination owing to their stability, cost effectiveness and easy maintenance. Development of economically feasible delivery strategies remains to be a major challenge. This study demonstrates vertical transmission of a plasmid DNA in a decapod Macrobrachium rosenbergii for the first time. Females at three different maturation stages (immature, matured and berried) and mature males were injected with a plasmid DNA and allowed to spawn with untreated counterparts. Using specific primers the plasmid DNA could be amplified from the offspring of all groups except that of berried females. For this confirmation genomic DNA was isolated from 3 pools of 10 post larvae in each group. This presents an ideal strategy to protect young ones at zero stress.

  14. Ultrastructural observation on genesis and morphology of cortical granules in Macrobrachium nipponense (Crustacea, Caridea).

    PubMed

    Zhang, Tian-Ting; Jiang, Ye-Qin; Zhou, Hong; Yang, Wan-Xi

    2010-01-01

    Cortical granules are secretory vesicles in oocytes that develop from the Golgi complex. In the freshwater shrimp, Macrobrachium nipponense, mitochondria participates in the formation of cortical granules. We investigated the structural changes of mitochondria and the distribution cortical granules in different stages of oocyte development. Transmission electron microscopy provided evidence for the involvement of mitochondria and a particular spiral lamellar organization and an electron-lucent area in internal cortical granules. The ooplasm provided material for the cortical granules in early oocyte development. We demonstrated that mitochondria play a role in coalescence and maturation of cortical granules in this species. Additionally, a concept of cortical granules regarded as a functional integration is put forward. The genesis of shrimp cortical granules exhibited a particular pathway of maturation. The outer shape and inner organization considering different taxa suggested general as well as specific features of the development of cortical granules.

  15. Optimal analytical conditions for catalase in fresh water prawn, Macrobrachium malcolmsonii.

    PubMed

    Arun, S; Thirumurugan, R; Visakan, R; Balamurugan, S; Arunachalam, V; Subramanian, P

    2003-02-01

    The cytosol of hepatopancreas was prepared from the freshwater prawn Macrobrachium malcolmsonii, and optimal assay conditions, ie., concentration of substrate, pH, and temperature, were determined to measure basal activities and kinetic constants of catalase activity. The properties of catalase were examined in M. macolmsonii, because quantitative data on catalase are limited in crustacean species. The optimal pH for catalase was 7.0. The activation energy was 3.55 Kcal/mol and energy inhibition value was 5.16 Kcal/mol. The value of energy inhibition is higher than that of energy activation. This may be due to inhibition of catalase by some substrate other than H2O2. A Km of 66.6 mM was also determined from various concentrations of substrate.

  16. Histological alterations in gills of Macrobrachium amazonicum juveniles exposed to ammonia and nitrite.

    PubMed

    Dutra, Fabrício Martins; Rönnau, Milton; Sponchiado, Dircelei; Forneck, Sandra Carla; Freire, Carolina Arruda; Ballester, Eduardo Luis Cupertino

    2017-04-08

    Aquaculture has shown great growth in the last decades. Due to the restrictions on water use, production systems are becoming increasingly more intensive, raising concerns about the production water quality. Macrobrachium amazonicum is among the freshwater prawn species with favorable characteristics for production and possibility of intensification. Nitrogen compounds such as ammonia and nitrite affect the health of aquatic organisms since they quickly reach toxic concentrations. These compounds can also cause damage to the gill structure, leading to hypoxia in tissues, affecting acid-base balance, osmoregulation (salt absorption) and ammonia excretion, decreasing the immune capacity of the animal and, in extreme cases, cause death. The aim of this study was to assess histological changes in the gills of Macrobrachium amazonicum juveniles subjected to different concentrations of total ammonia and nitrite. The prawns were subjected to different concentrations of those compounds and their gills were removed and preserved for histological analysis. The gills were assessed for changes according to the Organ Index (Iorg) and, for each change, an importance factor (w) was attributed according to the degree of reversibility and applied according to the degree of extension or frequency of the damage. The damage to the gills in the treatments with 100% mortality, both for ammonia and nitrite, corresponded to the high occurrence of progressive, regressive, circulatory, and inflammation damages. The other treatments (which caused less mortality) had mainly inflammation and regressive damages, whose occurrence increased according to the increase in ammonia and nitrite concentration. The histological analysis confirmed that the higher the total ammonia and nitrite concentrations, the larger the damages caused to the gill structure and that lower nitrite concentrations caused similar damages to those caused by higher total ammonia concentrations, which reflects the lower

  17. Bioaccumulation and retention kinetics of cadmium in the freshwater decapod Macrobrachium australiense.

    PubMed

    Cresswell, Tom; Simpson, Stuart L; Smith, Ross E W; Nugegoda, Dayanthi; Mazumder, Debashish; Twining, John

    2014-03-01

    The potential sources and mechanisms of cadmium bioaccumulation by the native freshwater decapods Macrobrachium species in the waters of the highly turbid Strickland River in Papua New Guinea were examined using (109)Cd-labelled water and food sources and the Australian species Macrobrachium australiense as a surrogate. Synthetic river water was spiked with environmentally relevant concentrations of cadmium and animals were exposed for 7 days with daily renewal of test solutions. Dietary assimilation of cadmium was assessed through pulse-chase experiments where prawns were fed separately (109)Cd-labelled fine sediment, filamentous algae and carrion (represented by cephalothorax tissue of water-exposed prawns). M. australiense readily accumulated cadmium from the dissolved phase and the uptake rate increased linearly with increasing exposure concentration. A cadmium uptake rate constant of 0.10 ± 0.05 L/g/d was determined in synthetic river water. During depuration following exposure to dissolved cadmium, efflux rates were low (0.9 ± 5%/d) and were not dependent on exposure concentration. Assimilation efficiencies of dietary sources were comparable for sediment and algae (48-51%), but lower for carrion (28 ± 5%) and efflux rates were low (0.2-2.6%/d) demonstrating that cadmium was well retained by M. australiense. A biokinetic model of cadmium accumulation by M. australiense predicted that for exposures to environmentally relevant cadmium concentrations in the Strickland River, uptake from ingestion of fine sediment and carrion would be the predominant sources of cadmium to the organism. The model predicted the total dietary route would represent 70-80% of bioaccumulated cadmium.

  18. Vibrio spp. from Macrobrachium amazonicum prawn farming are inhibited by Moringa oleifera extracts.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Sales, Jamille Alencar; de Souza Sampaio, Celia Maria; Barbosa, Francisco Geraldo; de Araújo Neto Paiva, Manoel; de Melo Guedes, Glaucia Morgana; de Alencar, Lucas Pereira; de Ponte, Yago Brito; de Jesus Pinheiro Gomes Bandeira, Tereza; Moreira, José Luciano Bezerra; de Souza Collares Maia Castelo-Branco, Débora; de Aquino Pereira-Neto, Waldemiro; de Aguiar Cordeiro, Rossana; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2015-11-01

    To investigate the in vitro antimicrobial potential of extracts of stem, leaves, flowers, pods and seeds of Moringa oleifera (M. oleifera) against Vibrio spp. from hatchery water and the prawn Macrobrachium amazonicum. The ethanol extracts of stem, leaves, pods and seeds and chloroform extract of flowers of M. oleifera were tested against Vibrio cholerae (V. cholerae) serogroups non-O1/non-O139 (n = 4), Vibrio vulnificus (n = 1) and Vibrio mimicus (n = 1). Escherichia coli (E. coli) (ATCC(®) 25922) was used as quality control. Vibrio species were obtained from Macrobrachium amazonicum prawns and from hatchery water from prawn farming. The Minimum Inhibitory Concentration (MIC) was determined by broth microdilution method. The best result was obtained with the ethanol extract of pods, which inhibited three strains of the V. cholerae, Vibrio vulnificus, Vibrio mimicus and E. coli (MIC range 0.312-5.000 mg/mL). The chloroform extract of flowers was effective against all V. cholerae strains and E. coli (MIC range 0.625-1.250 mg/mL). However, the ethanol extracts of stem and seeds showed low effectiveness in inhibiting the bacterial growth. The extracts of pods, flowers and leaves of M. oleifera have potential for the control of Vibrio spp. Further studies are necessary to isolate the bioactive compounds responsible for this antimicrobial activity. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  19. Development and functional morphology of the mouthparts and foregut in larvae and post-larvae of Macrobrachium jelskii (Decapoda: Palaemonidae).

    PubMed

    Rocha, Cristina Pantoja; Souza, Adelson Silva de; Maciel, Murilo; Maciel, Cristiana R; Abrunhosa, Fernando Araújo

    2016-05-01

    The morphology of the mouthparts and foregut of the larvae and post-larvae of Macrobrachium jelskii was investigated to determine their functional roles in feeding, in order to understand the larval feeding behaviour and the changes that occur during its development. The mouthparts and foregut of the zoea I and II are morphologically similar, rudimentary and non-functional in feeding. Only in the final larval stage, zoea III, do the external mouthparts and foregut become structurally more complex and thus likely to play a potential role in feeding. Two behavioral trials (point of no return, point of reserve saturation) evaluated the resistance to starvation in zoea I, II, and III. The results indicate that they have sufficient nutritional reserves to permit them to complete metamorphosis without feeding. Overall, our results suggest that the zoea I and II of Macrobrachium jelskii engage in obligate lecithotrophy and zoea III in facultative lecithotrophy.

  20. A molecular approach towards the taxonomy of fresh water prawns Macrobrachium striatum and M. equidens (Decapoda, Palaemonidae) using mitochondrial markers.

    PubMed

    Jose, Deepak; Nidhin, B; Anil Kumar, K P; Pradeep, P J; Harikrishnan, M

    2016-07-01

    Genus Macrobrachium includes freshwater prawns which inhabit most diverse habitats ranging from low saline areas to inland hill streams and impounded water bodies. Being morphologically conserved, this genus has been exposed to severe disputes related to their taxonomy, systematics and phylogeny. Macrobrachium striatum and M. equidens represent two morphologically related congeneric species within this genus. Earlier, M. striatum was considered as a striped form of M. equidens. Though these species are now well-described morphologically and differentiated into two species, no molecular level investigation has been carried out in support of their speciation. We report a study on M. striatum and M. equidens with emphasis to their molecular data through mitochondrial markers (16S ribosomal RNA and cytochrome oxidase subunit I). Results obtained from developed molecular markers of the two species revealed considerable genetic differentiation between them. Phylogram generated using Minimum evolution and Neighbour joining analyses differentiated M. striatum and M. equidens as two independent species. Genetic distance data showed high interspecific divergence (ranging from 3.9% to 17.0% for 16S rRNA sequences and 13.8% to 21.0% for COI sequences) between M. striatum and M. equidens confirming the findings of phylogram. Hence, it could be delineated that M. striatum and M. equidens represent two distinct species within genus Macrobrachium with emphasis to their morphology and genetics.

  1. Monitoring PAH contamination in the field (South west Iberian Peninsula): biomonitoring using fluorescence spectrophotometry and physiological assessments in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda).

    PubMed

    Dissanayake, Awantha; Bamber, Shaw D

    2010-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants of the marine environment, arising predominantly from petrochemical contamination and pyrogenic sources. A biomarker of PAH exposure was employed in a field study (South West, Spain) in both captured (indigenous) and deployed (caged) shore crabs (Carcinus maenas) in the chronic PAH-exposed Bays of Algeciras and Gibraltar (from associated harbour and boating activity) compared to a relatively 'clean' site (Cadiz). Metabolite fluorescence was attributed to the following key priority PAH groups; naphthalenes (NAPs), pyrenes (PYRs) and benzo[a]pyrenes (BAPs). Temporal variability was assessed using deployed populations over an eight week period. Petrogenic and pyrogenic PAH contamination (as an indicator of the PAH type) was demonstrated using a ratio between FF(BAP + PYR)/FF(NAP). Physiological assessments from deployed crabs demonstrated both physiological and cellular alterations as shown by reduced heart rates (at rest) and increased cellular stress in crabs from the PAH contaminated sites.

  2. Biochemical effects in crabs (Carcinus maenas) and contamination levels in the Bizerta Lagoon: an integrated approach in biomonitoring of marine complex pollution.

    PubMed

    Ben-Khedher, Sana; Jebali, Jamel; Kamel, Naouel; Banni, Mohamed; Rameh, Mohamed; Jrad, Amel; Boussetta, Hamadi

    2013-04-01

    The biochemical effects in Carcinus maenas and contamination levels in seawater and sediments of Bizerta Lagoon (northeast of Tunisia) were investigated. The levels of metals and hydrocarbons were higher in seawater and sediments in Menzel Bourguiba and Cimentery in February and July than in the other sampling sites. Differences among sites for glutathione S-transferase, catalase, acetylcholinesterase activities, and the content of lipid peroxidation and metallothioneins in two important organs which accumulated contaminants (the gills and the digestive gland) of the C. maenas were found and possibly related to differences in metal and hydrocarbon levels. The seasonal variation of biomarkers was possibly associated with chemical contamination and also with the high fluctuation of physico-chemical characteristics of the sites. The integrated biomarker response values found in the five sites is in good agreement with hydrocarbon and trace metal concentrations detected in the water and sediments of the stressful places where crabs are living.

  3. Proteomic response of Macrobrachium rosenbergii hepatopancreas exposed to chlordecone: Identification of endocrine disruption biomarkers?

    PubMed

    Lafontaine, Anne; Baiwir, Dominique; Joaquim-Justo, Célia; De Pauw, Edwin; Lemoine, Soazig; Boulangé-Lecomte, Céline; Forget-Leray, Joëlle; Thomé, Jean-Pierre; Gismondi, Eric

    2017-07-01

    The present work is the first study investigating the impacts of chlordecone, an organochlorine insecticide, on the proteome of the decapod crustacean Macrobrachium rosenbergii, by gel-free proteomic analysis. The hepatopancreas protein expression variations were analysed in organisms exposed to three environmental relevant concentrations of chlordecone (i.e. 0.2, 2 and 20µg/L). Results revealed that 62 proteins were significantly up- or down-regulated in exposed prawns compared to controls. Most of these proteins are involved in important physiological processes such as ion transport, defense mechanisms and immune system, cytoskeleton dynamics, or protein synthesis and degradation. Moreover, it appears that 6% of the deregulated protein are involved in the endocrine system and in the hormonal control of reproduction or development processes of M. rosenbergii (e.g. vitellogenin, farnesoic acid o-methyltransferase). These results indicate that chlordecone is potentially an endocrine disruptor compound for decapods, as already observed in vertebrates. These protein modifications could lead to disruptions of M. rosenbergii growth and reproduction, and therefore of the fitness population on the long-term. Besides, these disrupted proteins could be suggested as biomarkers of exposure for endocrine disruptions in invertebrates. However, further investigations are needed to complete understanding of action mechanisms of chlordecone on proteome and endocrine system of crustaceans. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Viral diseases of the giant fresh water prawn Macrobrachium rosenbergii: a review.

    PubMed

    Bonami, Jean-Robert; Sri Widada, Joannes

    2011-01-01

    The giant freshwater prawn Macrobrachium rosenbergii is cultivated essentially in Southern and South-eastern Asian countries such as continental China, India, Thailand and Taiwan. To date, only two viral agents have been reported from this prawn. The first (HPV-type virus) was observed by chance 25 years ago in hypertrophied nuclei of hepatopancreatic epithelial cells and is closely related to members of the Parvoviridae family. The second, a nodavirus named MrNV, is always associated with a non-autonomous satellite-like virus (XSV), and is the origin of so-called white tail disease (WTD) responsible for mass mortalities and important economic losses in hatcheries and farms for over a decade. After isolation and purification of these two particles, they were physico-chemically characterized and their genome sequenced. The MrNV genome is formed with two single linear ss-RNA molecules, 3202 and 1250 nucleotides long, respectively. Each RNA segment contains only one ORF, ORF1 coding for the RNA-dependant RNA polymerase located on the long segment and ORF2 coding for the structural protein CP-43 located on the small one. The XSV genome (linear ss-RNA), 796 nucleotides long, contains a single ORF coding for the XSV coat protein CP-17. The XSV does not contain any RdRp gene and consequently needs the MrNV polymerase to replicate.

  5. The effects of thermal treatments on protein profiles of Macrobrachium rosenbergii (giant river prawn)

    NASA Astrophysics Data System (ADS)

    Sockalingam, Komathi; Misnan, Rosmilah; Yadzir, Zailatul Hani Mohd

    2017-05-01

    Prawn allergy is certainly the most frequent cause of allergic reactions in countries where this crustacean is a popular dish of seafood. The aim of this study was to determine the protein profiles of giant river prawn which scientifically known as Macrobrachium rosenbergii. Raw and cooked extracts (boiled, steamed and fried) of prawn samples were prepared and then resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). 27 protein bands between 6 to 207 kDa were detected in the SDS-PAGE gel of raw extracts while boiled, steamed and fried extracts revealed fewer protein bands. Steamed and boiled prawns presented higher numbers of protein bands compared to fried prawn. A prominent heat-resistant band between 32 to 38 kDa was seen in all extracts, might hypothesized to be tropomyosin. Other prominent bands between 17 to 20 kDa were also seen in all treated prawn extracts while bands of 24 to 27 kDa were seen in steamed and boiled prawn extracts. These positions are consistent with the known shellfish allergens myosin light chain, sacroplasmic calcium binding protein and troponin C respectively. Several other heat-sensitive protein bands at various molecular weights were also not detected in boiled, steamed and fried extracts of this prawn. This study showed that M. rosenbergii contains numerous heat-sensitive and heat-resistant proteins, which may play an important role in prawn allergy.

  6. Vitellogenin and vitellogenin receptor gene expression and 20-hydroxyecdysone concentration in Macrobrachium rosenbergii exposed to chlordecone.

    PubMed

    Lafontaine, Anne; Hanikenne, Marc; Boulangé-Lecomte, Céline; Forget-Leray, Joëlle; Thomé, Jean-Pierre; Gismondi, Eric

    2016-10-01

    Chlordecone is a persistent organochlorine pesticide widely used in Guadeloupe (French West Indies) to control the banana weevil Cosmopolites sordidus. Although it was previously highlighted that chlordecone may affect the reproduction and growth of vertebrate species, little information is available on the chlordecone effects in invertebrates. The present study investigated the effects of chlordecone on a hormone and a protein having key roles in reproduction and growth of the decapod crustacean Macrobrachium rosenbergii, by measuring the 20-hydroxyecdysone concentration, vitellogenin, and vitellogenin receptor gene expression, as well as the bioconcentration of chlordecone in exposed prawns. First, the results revealed that chlordecone was accumulated in M. rosenbergii. Then, it was found that Vg and VgR gene expression were increased in male and female M. rosenbergii exposed to chlordecone for 90 and 240 days, while the 20-hydroxyecdysone concentrations were decreased. This work suggests that chlordecone accumulates in prawn tissues and could affect key molecules involved in the reproduction and the growth of the invertebrate M. rosenbergii. However, many questions remain unresolved regarding the impacts of chlordecone on growth and reproduction and the signaling pathways responsible for these effects, as well as the potential role of confounding factors present in in situ studies.

  7. Assessment of acute toxicity of carbofuran in Macrobrachium olfersii (Wiegmann, 1836) at different temperature levels.

    PubMed

    Barbieri, Edison; Moreira, Priscila; Luchini, Luiz Alberto; Hidalgo, Karla Ruiz; Muñoz, Alejandro

    2016-01-01

    Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate; C12H15NO3) is one of the most toxic carbamate pesticides. For acute toxicity of carbofuran, juveniles of Macrobrachium olfersii were exposed to different concentrations of carbofuran using the static renewal method at different temperature levels (15, 20 and 25°C) at pH 7.0. The main purpose of the present study was to detect the acute toxicity of carbofuran to M. olfersii and investigate its effects on oxygen consumption and ammonium excretion; these tests have not been carried out in this species before. First, the acute toxicity - median lethal concentration - of carbofuran to M. olfersii for 24, 48, 72 and 96 h was examined, which resulted in the following values: 1.64, 1.22, 0.86 and 0.42 mg L(-1), respectively. Furthermore, we also found that carbofuran caused an inhibition in oxygen consumption of 60.6, 65.3 and 66.2% with respect to the control. In addition, after separate exposures to carbofuran, elevations in ammonium excretion were more than 500% with respect to the control.

  8. TBT effects on the development of intersex (ovotestis) in female fresh water prawn Macrobrachium rosenbergii.

    PubMed

    Peranandam, Revathi; Palanisamy, Iyapparaj; Lourdaraj, Arockia Vasanthi; Natesan, Munuswamy; Vimalananthan, Arun Prasanna; Thangaiyan, Suganya; Perumal, Anantharaman; Muthukalingan, Krishnan

    2014-01-01

    The impact of tributyltin (TBT) on the female gonad and the endocrine system in Macrobrachium rosenbergii was studied. Prawns were exposed to environmentally realistic concentrations of 10, 100, and 1000 ng/L of TBT for 6 months. Dose dependent effects were noticed in TBT exposed prawns. At 1000 ng/L TBT caused ovotestis formation (formation of male germ cells in ovary). Presence immature oocytes, fusion of developing oocytes, increase in interstitial connective tissues, and its modification into tubular like structure and abundance of spermatogonia in the ovary of TBT treated prawns. The control prawn ovary showed normal architecture of cellular organelles such as mature oocytes with type 2 yolk globules, lipid droplets, normal appearance of yolk envelop, and uniformly arranged microvilli. On the other hand, type 1 yolk globules, reduced size of microvilli, spermatogonial cells in ovary, spermatogonia with centrally located nucleus, and chromatin distribution throughout the nucleoplasm were present in the TBT treated group. Immunofluorescence staining indicated a reduction in vitellin content in ovary of TBT treated prawn. Moreover, TBT had inhibited the vitellogenesis by causing hormonal imbalance in M. rosenbergii. Thus, the present investigation demonstrates that TBT substantially affects sexual differentiation and gonadal development in M. rosenbergii.

  9. Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

    SciTech Connect

    Law, A.T.; Yeo, M.E.

    1997-03-01

    Literature on the toxicities of phenol on aquatic organisms is very limited. USEPA reported that the acute and chronic toxicities of phenol to freshwater aquatic life occur at concentrations as low as 10.2 mg/L and 2.56 mg/L, respectively. While for the saltwater aquatic life the acute toxicity occurs at concentrations as low as 5.8 mg/L. No data are available for the chronic toxicity of phenol to saltwater aquatic life. Sublethal concentrations of phenol have significant effects on the physiological and histological processes of the aquatic organisms: such as gill necrosis; destruction of erythrocyte cells; inhibition of sexual activities; suppression on growth and reduction of resistance to diseases. Macrobrachium rosenbergii(de Man) is the sole freshwater prawn cultured in Malaysia. Occasionally, the hatcheries are unable to produce the post-larvae because of undefined pollutants present in the water supplies. It has been observed that the use of cracked fiberglass tanks for larvae rearing is correlated with high mortality. This high mortality is probably due to the toxicity of the phenolic compounds which are leached out from the fiber glass tank into the water. This study was undertaken to evaluate the toxicity of phenol on eggs, larvae and post-larvae of M. rosenbergii and to set the water quality criteria of phenol for the said species. 16 refs., 3 tabs.

  10. Study of biochemical biomarkers in freshwater prawn Macrobrachium borellii (Crustacea: Palaemonidae) exposed to organophosphate fenitrothion.

    PubMed

    Lavarías, S; García, C; Crespo, R; Pedrini, N; Heras, H

    2013-10-01

    Several agrochemicals like organophosphates are extensively used to control pests in agricultural practices but they also adversely affect non-target fauna. The effect of organophosphorous fenitrothion on the prawn Macrobrachium borellii was evaluated. The 96-h LC50 was determined. Activity of superoxide dismutase, catalase, glutathione-S-transferase and lipid oxidation levels, were evaluated in the hepatopancreas from adults exposed to sublethal fenitrothion concentrations for 1, 2, 4 and 7 days. In addition, superoxide dismutase mRNA expression, acetylcholinesterase inhibition and haemocyte DNA damage were determined. The 96-h LC50 was 4.24μg/l of fenitrothion. Prawn exposed to sublethal FS concentrations showed an increase of both catalase and superoxide dismutase activities, mainly after 2 and 4 days exposure and an increase of glutathione-S-transferase activity from day 2 to day 7 while lipid oxidation levels increased mainly on day 1. Superoxide dismutase transcripts were significantly higher in fenitrothion -treated prawns, indicating an induction mechanism. Hemolymph analysis showed that while acetylcholinesterase activity decreased after 2 days, haemocytes displayed most DNA damage after 7-day exposure to fenitrothion. These results indicate that prawn enzymes are highly sensitive to fenitrothion exposure, and these biological responses in M. borellii could be valuable biomarkers to monitor organophosphorous contamination in estuarine environments. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. In vitro generation of superoxide anion by the hemocytes of Macrobrachium rosenbergii: possible mechanism and pathways.

    PubMed

    Vidya, Natarajan; Thiagarajan, Raman; Arumugam, Munusamy

    2007-07-01

    The hemocytes from the giant freshwater prawn Macrobrachium rosenbergii were examined for their ability to generate superoxide anion (O(2) (-)) in vitro upon exposure to various components derived from microbial cell wall components. Among the test molecules, laminarin (a polymer of beta-1, 3 glucans), mannan and LPS from five different bacterial species produced a differential response in terms of stimulated O(2) (-) production in prawn hemocytes, suggesting the ability of the hemocytes to differentiate non-self. This response was almost completely inhibited by superoxide dismutase (SOD) suggesting SOD-inhibitable O(2) (-) generation by prawn hemocytes. Phorbol 12-myristate 13-acetate (PMA) and Ca ionophore led to enhanced O(2) (-) generation by the hemocytes and this suggests the possible role of protein kinase C and Ca(2+) ions in such generation. Cytochemical analysis using nitroblue tetrazolium (NBT)-staining revealed the importance of granular hemocytes in O(2) (-) generation in these prawns. Inhibition of O(2) (-) generation by inhibitors of NADPH-oxidase and phenoloxidase pathways clearly reveal the involvement of two different pathways in non-self stimulated O(2) (-) generation by the prawn hemocytes. These findings demonstrate the importance of O(2) (-) generation and role of possible pathways in hemocyte mediated cellular immune response of a crustacean.

  12. Ammonia toxicity as a criterion for the evaluation of larval quality in the prawn Macrobrachium rosenbergii.

    PubMed

    Cavalli, R O; Berghe, E V; Lavens, P; Nguyen, T T; Wille, M; Sorgeloos, P

    2000-03-01

    The feasibility of a short-term ammonia toxicity test as an evaluation criterion for larval quality was assessed in three trials. In each one, Macrobrachium rosenbergii larvae originating from the same spawn were nutritionally differentiated in two groups by feeding them either a nutrient-rich (Artemia nauplii enriched for 24 h with n-3 highly unsaturated fatty acids (HUFA) and ascorbic acid (AA)) or a nutrient-poor diet (Artemia nauplii starved for 24 h). Throughout their development, larvae from both treatments were exposed during 24 h to six concentrations of total ammonia (NH(4)(+)+NH(3)) and a control (no ammonia added). Based on mortality rates, the median lethal concentration for 50% of the population (LC(50)) was estimated. As expected from earlier work, larvae fed the optimal diet presented higher n-3 HUFA and AA contents as well as higher growth and metamorphosis rates. From the moment the effect of diet quality was analytically detectable in the tissues of the larvae, the ammonia test was able to distinguish both groups of larvae. Differences in ammonia tolerance were observed as early as larval stage 4 and remained evident throughout larval development. The short-term ammonia toxicity test proved to be a valuable, sensitive and reproducible criterion for the establishment of larval quality.

  13. Steroids and genes related to steroid biosynthesis in the female giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Thongbuakaew, Tipsuda; Siangcham, Tanapan; Suwansa-ard, Saowaros; Elizur, Abigail; Cummins, Scott F; Sobhon, Prasert; Sretarugsa, Prapee

    2016-03-01

    The giant freshwater prawn, Macrobrachium rosenbergii, is important to many Asian countries due to its high economic value as an aquaculture product. With demand increasing, there is requirement for a better understanding of the biosynthetic components that regulate its growth and reproduction, including steroids, in order to help increase production. Vertebrate-type steroids and their receptors were identified in crustaceans and implicated in reproduction. In this study, we presented the sex steroids estradiol and progesterone by LC-MS/MS in female M. rosenbergii, and reveal steroidogenic-related genes by in silico analysis of de novo assembled transcriptomes. Comparative analysis with other species was performed to confirm their putative role, as well as tissue-specific and quantitative gene expression. We reveal 29 transcripts that encode for steroidogenic-related proteins, including steroidogenic enzymes, a nuclear steroid hormone receptors, and a steroidogenic factor. Moreover, we identified for the first time the presence of steroidogenic factor 1, StAR-related lipid transfer protein, estradiol receptor- and progesterone-like protein in M. rosenbergii. Those targeted for gene expression analysis (3 beta-hydroxysteroid dehydrogenase, 17 beta-hydroxysteroid dehydrogenase, estrogen sulfotransferase and progesterone receptor-like) showed widespread expression within many tissues, and at relatively high levels in the central nervous system (CNS) during ovarian maturation. In summary, we provide further evidence for the existence of steroidogenic pathways in crustaceans, which may be useful for advancing prawn aquaculture.

  14. Parvo-like virus in the hepatopancreas of freshwater prawns Macrobrachium rosenbergii cultivated in Thailand.

    PubMed

    Gangnonngiw, Warachin; Kiatpathomchai, Wansika; Sriurairatana, Siriporn; Laisutisan, Kesinee; Chuchird, Niti; Limsuwan, Chalor; Flegel, Timothy W

    2009-07-23

    A survey of cultivated giant freshwater prawns Macrobrachium rosenbergii from Thailand revealed the presence of unusual spherical to ovoid inclusions in nuclei of hepatopancreas tubule epithelial cells. These began as small eosinophilic inclusions that became more basophilic as they increased in size. They were present in both R-cells and E-cells but were largest and deeply basophilic only in the E-cells. Confocal laser microscopy revealed that stained nucleic acid fluorescence from the inclusions was lost by treatment with DNase I specific for double- and single-stranded DNA and also lost or reduced by treatment with mungbean nuclease specific for single-stranded nucleic acids. Transmission electron microscopy (TEM) revealed that the inclusions contained tightly packed, unenveloped, viral-like particles of approximately 25 to 30 nm diameter, resembling those produced by shrimp parvoviruses. However, PCR, in situ hybridization and immunohistochemical tests for shrimp parvoviruses previously reported from Thailand were all negative. These results suggested that the inclusions contained a parvo-like virus, not previously reported from M. rosenbergii in Thailand.

  15. Sensitivity of the freshwater prawn, Macrobrachium lanchesteri (Crustacea: Decapoda), to heavy metals.

    PubMed

    Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Ramle, Nur-Amalina; Abas, Ahmad

    2011-07-01

    Adult Macrobrachium lanchesteri were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn) and lead (Pb) concentrations. Mortality was assessed and median lethal times (LT₅₀) and concentrations (LC₅₀) were calculated. At the end of the 4-day period, live prawns were used to determine bioconcentration of the metals. LT₅₀ and LC₅₀ increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC₅₀s for 96 hours for Cu, Cd, Zn and Pb were 32.3, 7.0, 525.1 and 35.0 µg/L, respectively. Cu, Cd, Zn and Pb bioconcentration in M. lanchesteri increases with exposure to increasing concentrations and Cd was the most toxic to M. lanchesteri, followed by Pb, Cu and Zn. Comparison of LC₅₀ values for metals for this species with those for other freshwater crustacean organisms reveals that M. lanchesteri is equally or more sensitive to heavy metals than most other tested crustaceans.

  16. Molecular cloning and characterization of FGLamide allatostatin gene from the prawn, Macrobrachium rosenbergii.

    PubMed

    Yin, Guo-Li; Yang, Jin-Shu; Cao, Jun-Xia; Yang, Wei-Jun

    2006-06-01

    Allatostatins are important regulatory neuropeptides that inhibit juvenile hormone (JH) biosynthesis by the corpora allata (CA) in insects. However, to date, the structure and expression of the gene encoding allatostatins have not been reported in any species other than insects. In this study, we used a combination of a semi-nested polymerase chain reaction (PCR) and screening of a central nervous system cDNA library of Macrobrachium rosenbergii to isolate and sequence a cDNA clone (2885 bp) encoding a 701 amino acid FGLamide allatostatin precursor polypeptide. This is the first reported allatostatin gene in crustacean. The deduced precursor was conceptually split into at least 35 FGLamide allatostatins at dibasic cleavage sites (Lys and Lys/Arg), far more than reported for any other known FGLamide allatostatin precursors from insects (13-14 allatostatins). Reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that the gene was expressed in the brain, gut, thoracic and abdominal ganglia, but not in the heart, muscle, ovary, gill, or hepatopancreas. Furthermore, developmentally-dependent expression of the gene was observed in the brain and thoracic ganglia of the prawn by using semi-quantitative RT-PCR analysis.

  17. Structural changes of oviduct of freshwater shrimp, Macrobrachium nipponense (Decapoda, Palaemonidae), during spawning*

    PubMed Central

    Lu, Jian-ping; Zhang, Xiao-hui; Yu, Xiao-yun

    2006-01-01

    The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was examined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV→I→II→III. PMID:16365928

  18. Toll receptor response to white spot syndrome virus challenge in giant freshwater prawns (Macrobrachium rosenbergii).

    PubMed

    Feng, Jinling; Zhao, Lingling; Jin, Min; Li, Tingting; Wu, Lei; Chen, Yihong; Ren, Qian

    2016-10-01

    Toll receptors are evolutionary ancient families of pattern recognition receptors with crucial roles in invertebrate innate immune response. In this study, we identified a Toll receptor (MrToll) from giant freshwater prawns (Macrobrachium rosenbergii). The full-length cDNA of MrToll is 4257 bp, which encodes a putative protein of 1367 amino acids. MrToll contains 17 LRR domains, a transmembrane domain, and a TIR domain. Phylogenetic analysis showed that MrToll was grouped with Drosophila Toll7 and other arthropod Tolls. The transcripts of MrToll are mainly distributed in the heart, hepatopancreas, gills, stomach, and intestine. A low level of MrToll expression can be detected in hemocytes and the lymphoid organ. MrToll expression in gills was gradually upregulated to the highest level from 24 h to 48 h during the white spot syndrome virus (WSSV) challenge. The expression levels of the crustin (Cru) genes Cru3 and Cru7 in gills were relatively lower than those of Cru2 and Cru4. The expression levels of Cru3 and Cru7 were inhibited after the RNA interference of MrToll in gills during the WSSV challenge. The anti-lipopolysaccharide factor (ALF) genes ALF2, ALF3, ALF4, and ALF5 were also regulated by MrToll in gills during the virus challenge. These findings suggest that MrToll may contribute to the innate immune defense of M. rosenbergii against WSSV.

  19. TBT Effects on the Development of Intersex (Ovotestis) in Female Fresh Water Prawn Macrobrachium rosenbergii

    PubMed Central

    Peranandam, Revathi; Palanisamy, Iyapparaj; Lourdaraj, Arockia Vasanthi; Natesan, Munuswamy; Vimalananthan, Arun Prasanna; Thangaiyan, Suganya; Perumal, Anantharaman; Muthukalingan, Krishnan

    2014-01-01

    The impact of tributyltin (TBT) on the female gonad and the endocrine system in Macrobrachium rosenbergii was studied. Prawns were exposed to environmentally realistic concentrations of 10, 100, and 1000 ng/L of TBT for 6 months. Dose dependent effects were noticed in TBT exposed prawns. At 1000 ng/L TBT caused ovotestis formation (formation of male germ cells in ovary). Presence immature oocytes, fusion of developing oocytes, increase in interstitial connective tissues, and its modification into tubular like structure and abundance of spermatogonia in the ovary of TBT treated prawns. The control prawn ovary showed normal architecture of cellular organelles such as mature oocytes with type 2 yolk globules, lipid droplets, normal appearance of yolk envelop, and uniformly arranged microvilli. On the other hand, type 1 yolk globules, reduced size of microvilli, spermatogonial cells in ovary, spermatogonia with centrally located nucleus, and chromatin distribution throughout the nucleoplasm were present in the TBT treated group. Immunofluorescence staining indicated a reduction in vitellin content in ovary of TBT treated prawn. Moreover, TBT had inhibited the vitellogenesis by causing hormonal imbalance in M. rosenbergii. Thus, the present investigation demonstrates that TBT substantially affects sexual differentiation and gonadal development in M. rosenbergii. PMID:25121096

  20. Molecular cloning and expression pattern of oriental river prawn (Macrobrachium nipponense) nitric oxide synthase.

    PubMed

    Rahman, N M A; Fu, H T; Sun, S M; Qiao, H; Jin, S; Bai, H K; Zhang, W Y; Liang, G X; Gong, Y S; Xiong, Y W; Wu, Y

    2016-08-29

    Nitric oxide synthase (NOS) produces nitric oxide (NO) by catalyzing the conversion of l-arginine to l-citrulline, with the concomitant oxidation of nicotinamide adenine dinucleotide phosphate. Recently, various studies have verified the importance of NOS invertebrates and invertebrates. However, the NOS gene family in the oriental river prawn Macrobrachium nipponense is poorly understood. In this study, we cloned the full-length NOS complementary DNA from M. nipponense (MnNOS) and characterized its expression pattern in different tissues and at different developmental stages. Real-time quantitative polymerase chain reaction (RT-qPCR) showed the MnNOS gene to be expressed in all investigated tissues, with the highest levels observed in the androgenic gland (P < 0.05). Our results revealed that the MnNOS gene may play a key role in M. nipponense male sexual differentiation. Moreover, RT-qPCR revealed that MnNOS mRNA expression was significantly increased in post-larvae 10 days after metamorphosis (P < 0.05). The expression of this gene in various tissues indicates that it may perform versatile biological functions in M. nipponense.

  1. Effects of drought and hurricane disturbances on headwater distributions of palaemonid river shrimp (Macrobrachium spp.) in the Luquillo Mountains, Puerto Rico.

    Treesearch

    Alan P. Covich; Todd A. Crowl; Tamara Heartsill Scalley

    2006-01-01

    Extreme events (hurricanes, floods, and droughts) can influence upstream migration of macroinvertebrates and wash out benthic communities, thereby locally altering food webs and species interactions. We sampled palaemonid river shrimp (Macrobrachium spp.), dominant consumers in headwaters of the Luquillo Mountains of northeastern Puerto Rico, to determine their...

  2. Comparative brain architecture of the European shore crab Carcinus maenas (Brachyura) and the common hermit crab Pagurus bernhardus (Anomura) with notes on other marine hermit crabs.

    PubMed

    Krieger, Jakob; Sombke, Andy; Seefluth, Florian; Kenning, Matthes; Hansson, Bill S; Harzsch, Steffen

    2012-04-01

    The European shore crab Carcinus maenas and the common hermit crab Pagurus bernhardus are members of the sister taxa Brachyura and Anomura (together forming the taxon Meiura) respectively. Both species share similar coastal marine habitats and thus are confronted with similar environmental conditions. This study sets out to explore variations of general brain architecture of species that live in seemingly similar habitats but belong to different major malacostracan taxa and to understand possible differences of sensory systems and related brain compartments. We examined the brains of Carcinus maenas, Pagurus bernhardus, and three other hermit crab species with immunohistochemistry against tyrosinated tubulin, f-actin, synaptic proteins, RF-amides and allatostatin. Our comparison showed that their optic neuropils within the eyestalks display strong resemblance in gross morphology as well as in detailed organization, suggesting a rather similar potential of processing visual input. Besides the well-developed visual system, the olfactory neuropils are distinct components in the brain of both C. maenas and P. bernhardus as well as the other hermit crabs, suggesting that close integration of olfactory and visual information may be useful in turbid marine environments with low visibility, as is typical for many habitats such as, e.g., the Baltic and the North Sea. Comparing the shape of the olfactory glomeruli in the anomurans showed some variations, ranging from a wedge shape to an elongate morphology. Furthermore, the tritocerebrum and the organization of the second antennae associated with the tritocerebrum seem to differ markedly in C. maenas and P. bernhardus, indicating better mechanosensory abilities in the latter close to those of other Decapoda with long second antennae, such as Astacida, Homarida, or Achelata. This aspect may also represent an adaptation to the "hermit lifestyle" in which competition for shells is a major aspect of their life history. The shore

  3. Two Kazal-type protease inhibitors from Macrobrachium nipponense and Eriocheir sinensis: comparative analysis of structure and activities.

    PubMed

    Qian, Ye-Qing; Li, Ye; Yang, Fan; Yu, Yan-Qin; Yang, Jin-Shu; Yang, Wei-Jun

    2012-03-01

    Kazal-type inhibitors (KPIs) play important roles in many biological and physiological processes, such as blood clotting, the immune response and reproduction. In the present study, two male reproductive tract KPIs, termed Man-KPI and Ers-KPI, were identified in Macrobrachium nipponense and Eriocheir sinensis, respectively. The inhibitory activities of recombinant Man-KPI and Ers-KPI against chymotrypsin, elastase, trypsin and thrombin were determined. The results showed that both of them strongly inhibit chymotrypsin and elastase. Kinetic studies were performed to elucidate their inhibition mechanism. Furthermore, individual domains were also expressed to learn further which domain contributes to the inhibitory activities of intact KPIs. Only Man-KPI_domain3 is active in the inhibition of chymotrypsin and elastase. Meanwhile, Ers-KPI_domain2 and 3 are responsible for inhibition of chymotrypsin, and Ers-KPI_domains2, 3 and 4 are responsible for the inhibition of elastase. Meanwhile, the inhibitory activities of these two KPIs toward Macrobrachium rosenbergii, M. nipponense and E. sinensis sperm were compared with that of the Kazal-type peptidase inhibitor (MRPINK) characterized from the M. rosenbergii reproductive tract in a previous study. The results demonstrated that KPIs can completely inhibit the gelatinolytic activities of sperm proteases from their own species, while different levels of cross-inhibition were observed between KPI and proteases from different species. These results may provide new perspective to further clarify the mechanism of KPI-proteases interaction in the male reproductive system.

  4. Acute Toxicity of Nitrite to Various Life Stages of the Amazon River Prawn, Macrobrachium amazonicum, Heller, 1862.

    PubMed

    Dutra, Fabrício Martins; Freire, Carolina Arruda; Vaz Dos Santos, André Martins; Forneck, Sandra Carla; Brazão, Claudia Caramelo; Ballester, Eduardo Luis Cupertino

    2016-11-01

    This study determined the effects of nitrite on different life stages of the Amazon river prawn Macrobrachium amazonicum. Prawns of each life stage (postlarvae, juveniles and adults) were stocked in 24 experimental units (n = 10 prawns), under a complete randomized design. Individuals were exposed to nitrite (0, 1, 2, 4, 8 and 16 mg L(-1)). The median lethal concentration after 96 h (96 h LC50) was calculated through the Weibull I. The mortality results showed that M. amazonicum is slightly less tolerant to nitrite than other species of Macrobrachium. The 96 h LC50 for postlarvae, juveniles and adults of M. amazonicum were of 1.49, 2.36 and 2.34 mg nitrite/L, respectively. Nitrite intoxication risk quotient suggest moderated risk to low risk to the species. Usually in production systems nitrite values are lower than safe levels suggested in this study (0.1 mg L(-1) to postlarvae and 0.2 mg L(-1) nitrite to juvenile and adults), which makes our results appropriate for the production of this species.

  5. Isolation and Characterization of a Novel Dicistrovirus Associated with Moralities of the Great Freshwater Prawn, Macrobrachium rosenbergii.

    PubMed

    Pan, Xiaoyi; Cao, Zheng; Yuan, Junfa; Shi, Zhengli; Yuan, Xuemei; Lin, Lingyun; Xu, Yang; Yao, Jiayun; Hao, Guijie; Shen, Jinyu

    2016-02-02

    The giant freshwater prawn, Macrobrachium rosenbergii, is an economically important crustacean and is farmed in many countries. Since 2009, a larval mortality syndrome of M. rosenbergii has broken out and spread widely in the main breeding area, including Zhejiang, Jiangsu, Guangxi, and Guangdong Provinces in mainland China. A novel virus, named Macrobrachium rosenbergii Taihu virus (MrTV), was isolated from the moribund larvae and was determined to be the causative agent of the M. rosenbergii larval mortality syndrome by experimental infection. Further genomic sequencing suggested that the MrTV genome is monopartite, 10,303 nt in length, and dicistronic with two non-overlapping open reading frames (ORFs) separated by an intergenic region (IGR) and flanked by untranslated regions (UTRs). Phylogenetic analysis using the full-length genomic sequence and the putative amino acid sequences of the capsid protein revealed that MrTV was more closely related to the taura syndrome virus (TSV) than to any other viruses. According to these molecular features, we proposed that MrTV is a new species in the genus Aparavirus, family Dicistroviridae. These results may shed light on controlling larval mortality syndrome in M. rosenbergii.

  6. Isolation and Characterization of a Novel Dicistrovirus Associated with Moralities of the Great Freshwater Prawn, Macrobrachium rosenbergii

    PubMed Central

    Pan, Xiaoyi; Cao, Zheng; Yuan, Junfa; Shi, Zhengli; Yuan, Xuemei; Lin, Lingyun; Xu, Yang; Yao, Jiayun; Hao, Guijie; Shen, Jinyu

    2016-01-01

    The giant freshwater prawn, Macrobrachium rosenbergii, is an economically important crustacean and is farmed in many countries. Since 2009, a larval mortality syndrome of M. rosenbergii has broken out and spread widely in the main breeding area, including Zhejiang, Jiangsu, Guangxi, and Guangdong Provinces in mainland China. A novel virus, named Macrobrachium rosenbergii Taihu virus (MrTV), was isolated from the moribund larvae and was determined to be the causative agent of the M. rosenbergii larval mortality syndrome by experimental infection. Further genomic sequencing suggested that the MrTV genome is monopartite, 10,303 nt in length, and dicistronic with two non-overlapping open reading frames (ORFs) separated by an intergenic region (IGR) and flanked by untranslated regions (UTRs). Phylogenetic analysis using the full-length genomic sequence and the putative amino acid sequences of the capsid protein revealed that MrTV was more closely related to the taura syndrome virus (TSV) than to any other viruses. According to these molecular features, we proposed that MrTV is a new species in the genus Aparavirus, family Dicistroviridae. These results may shed light on controlling larval mortality syndrome in M. rosenbergii. PMID:26848659

  7. Effects of Artificial Shelter and Chitosan on Growth Performance of Freshwater Prawn (Macrobrachium lanchesteri de Man, 1911).

    PubMed

    Jongyotha, Suriya; Doolgindachbaporn, Sompong; Suraniranat, Prawit

    2015-04-01

    Two experiments were carried out at the Department of Fisheries, Khon Kaen University, Khon Kaen, Thailand during September 2013 to February 2014 aiming to pursue both the better growth performance and survival rate of the freshwater prawns (Macrobrachium lanchesteri) where a Completely Randomized Design (CRD) with three replications was used for each experiment. For experiment 1, different percentages of grass shelter were used, i.e. 0% (Control, T1), 25% (T2), 50% (T3) and 75% (T4). For experiment 2, different percentages of commercial chitosan were used, i.e. 0% (Control, T1), 25% (T2), 50% (T3) and 75% (T4). Both experiments were carried out at the same time and each of them was lasted for 75 days. The results showed that the added grass shelter gave significantly higher Total Weight (TW) and Survival Rate (SR) than the control treatment. However, there were no significant differences found on TW and SR among the added grass shelter treatments (T2 up to T4). Chitosan gave significantly higher TW, AW and Number of Molting (NM) than the control treatment. There were no significant differences on TW, NM and AW found amongst the chitosan treatments. The results of the experiment 1 showed that the best rate of grass shelter for the culturing of the Macrobrachium lanchesteri was at a rate of 25% (T 2) and the best rate of the chitosan was at a rate of 4% (Diet 3) for the Experiment 2.

  8. Osmoregulation in larvae and juveniles of two recently separated Macrobrachium species: Expression patterns of ion transporter genes.

    PubMed

    Boudour-Boucheker, Nesrine; Boulo, Viviane; Charmantier-Daures, Mireille; Anger, Klaus; Charmantier, Guy; Lorin-Nebel, Catherine

    2016-05-01

    In this comparative study, osmoregulatory mechanisms were analyzed in two closely related species of palaemonid shrimp from Brazil, Macrobrachium pantanalense and Macrobrachium amazonicum. A previous investigation showed that all postembryonic stages of M. pantanalense from inland waters of the Pantanal are able to hyper-osmoregulate in fresh water, while this species was not able to hypo-osmoregulate at high salinities. In M. amazonicum originating from the Amazon estuary, in contrast, all stages are able to hypo-osmoregulate, but only first-stage larvae, late juveniles and adults are able to hyper-osmoregulate in fresh water. The underlying molecular mechanisms of these physiological differences have not been known. We therefore investigated the expression patterns of three ion transporters (NKA α-subunit, VHA B-subunit and NHE3) following differential salinity acclimation in different ontogenetic stages (stage-V larvae, juveniles) of both species. Larval NKAα expression was at both salinities significantly higher in M. pantanalense than in M. amazonicum, whereas no difference was noted in juveniles. VHA was also more expressed in larvae of M. pantanalense than in those of M. amazonicum. When NHE3 expression is compared between the larvae of the two species, further salinity-related differences were observed, with generally higher expression in the inland species. Overall, a high expression of ion pumps in M. pantanalense suggests an evolutionary key role of these transporters in freshwater invasion.

  9. Transcriptomics of a Giant Freshwater Prawn (Macrobrachium rosenbergii): De Novo Assembly, Annotation and Marker Discovery

    PubMed Central

    Jung, Hyungtaek; Lyons, Russell E.; Dinh, Hung; Hurwood, David A.; McWilliam, Sean; Mather, Peter B.

    2011-01-01

    Background Giant freshwater prawn (Macrobrachium rosenbergii or GFP), is the most economically important freshwater crustacean species. However, as little is known about its genome, 454 pyrosequencing of cDNA was undertaken to characterise its transcriptome and identify genes important for growth. Methodology and Principal Findings A collection of 787,731 sequence reads (244.37 Mb) obtained from 454 pyrosequencing analysis of cDNA prepared from muscle, ovary and testis tissues taken from 18 adult prawns was assembled into 123,534 expressed sequence tags (ESTs). Of these, 46% of the 8,411 contigs and 19% of 115,123 singletons possessed high similarity to sequences in the GenBank non-redundant database, with most significant (E value < 1e–5) contig (80%) and singleton (84%) matches occurring with crustacean and insect sequences. KEGG analysis of the contig open reading frames identified putative members of several biological pathways potentially important for growth. The top InterProScan domains detected included RNA recognition motifs, serine/threonine-protein kinase-like domains, actin-like families, and zinc finger domains. Transcripts derived from genes such as actin, myosin heavy and light chain, tropomyosin and troponin with fundamental roles in muscle development and construction were abundant. Amongst the contigs, 834 single nucleotide polymorphisms, 1198 indels and 658 simple sequence repeats motifs were also identified. Conclusions The M. rosenbergii transcriptome data reported here should provide an invaluable resource for improving our understanding of this species' genome structure and biology. The data will also instruct future functional studies to manipulate or select for genes influencing growth that should find practical applications in aquaculture breeding programs. PMID:22174756

  10. Toxicity of cryoprotectants agents in freshwater prawn embryos of Macrobrachium amazonicum.

    PubMed

    Ferreira, Arthur Vinícius Lourenço; Castro, Elias José Teles; Barbosa, Mariana Silva Alves; de Sousa, Míriam Luzia Nogueira Martins; de Araújo Neto, Manoel Paiva; Filho, Aldeney Andrade Soares; de Souza Sampaio, Celia Maria

    2015-12-01

    The process of cooling and cryopreservation of prawn embryos is a viable alternative for a continuous supply of larvae for freshwater prawn farming ponds. However, studies involving the application of those techniques as well as on toxicity of cryoprotectants in freshwater prawn embryos are scarce. Thus, this study aims to test the toxicity of methylic alcohol (MET), dimethyl sulfoxide (DMSO) and ethylene glycol (EG) on Macrobrachium amazonicum embryos. For the present experiment, pools of embryos were taken from 15 M. amazonicum females and were divided into three groups and tested in duplicate at concentrations of 10, 5, 3; 1, 0.5 or 0.1%. Toxicity tests were conducted for 24 h in Falcon® pipes to obtain the lethal concentration for 50% of the larvae (LC50). After the set period for testing, random samples of embryos were removed for morphological analysis under stereoscopic microscopes. Results were analysed using analysis of variance (ANOVA) and Tukey's test at a 5% significance level and Trimmed Spearman-Karber Analysis to determine LC50-24 h. DMSO toxicity tests revealed that 5% and 10% concentrations showed the highest toxicity and differed from the control (P ≤ 0.05), 24h-LC50 was 437.4 ± 14.4 µL. MET was less toxic among the tested cryoprotectants and concentrations did not allow the determination of its LC50-24h. For tests with EG, concentrations of 3, 5 or 10% solutions resulted in a 100% mortality to tested embryos; EG was the tested cryoprotectant with the highest toxicity, with an LC50-24h average of 81.91 ± 35.3 µl.

  11. Effects of ammonia stress in the Amazon river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae).

    PubMed

    Pinto, Marcelo R; Lucena, Malson N; Faleiros, Rogério Oliveira; Almeida, Eduardo Alves; McNamara, John C; Leone, Francisco A

    2016-01-01

    We evaluate the effects of total ammonia nitrogen-N (TAN) exposure for 72h on (Na(+),K(+))- and V(H(+))-ATPase activities and on their subunit expressions in gills of the diadromous freshwater shrimp Macrobrachium amazonicum. Specific (Na(+),K(+))- and V(H(+))-ATPase activities increased roughly 1.5- to 2-fold, respectively, after exposure to 2.0mmolL(-1) TAN. Quantitative RT-PCR analyses revealed a 2.5-fold increase in V(H(+))-ATPase B subunit mRNA expression while (Na(+),K(+))-ATPase α-subunit expression was unchanged. Immunohistochemical analyses of the gill lamellae located the (Na(+),K(+))-ATPase throughout the intralamellar septal cells, independently of TAN concentration, while the V(H(+))-ATPase was located in both the apical pillar cell flanges and pillar cell bodies. Systemic stress parameters like total hemocyte count decreased by 30% after exposure to 2.0mmolL(-1) TAN, accompanied by increased activities of the oxidative stress enzymes superoxide dismutase, glutathione reductase and glucose-6-phosphate dehydrogenase in the gills. The stress responses of M. amazonicum to elevated TAN include increases in gill (Na(+),K(+))- and V(H(+))-ATPase activities that are accompanied by changes in oxidative stress enzyme activities, immune system effects and an increase in gill V(H(+))-ATPase gene expression. These findings likely underpin physiological effects in a crustacean like M. amazonicum that exploits multiple ecosystems during its life cycle, as well as under culture conditions that may significantly impact shrimp production by the aquaculture industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Growth and antioxidant status of oriental river prawn Macrobrachium nipponense fed with diets containing vitamin E

    NASA Astrophysics Data System (ADS)

    Zhao, Weihong; Wang, Zisheng; Yu, Yebing; Qi, Zhitao; Lü, Linlan; Zhang, Yuxia; Lü, Fu

    2016-05-01

    A feeding trial was carried out to investigate the dietary vitamin E requirement of the oriental river prawn Macrobrachium nipponense (weight of 0.3-0.4 g) and its effect role on antioxidant activity. Prawns were fed with seven levels of vitamin E (0, 25, 50, 75, 100, 200, and 400 mg/kg diet) for 60 days. The results show that dietary vitamin E supplementation could significantly increased the prawn weight ( P < 0.05). The activity of superoxide dismutase (SOD) in the hepatopancreas was significantly higher in prawns fed with diets supplemented with ≤75 mg/kg vitamin E than in those fed with diets supplemented with 100-400 mg/kg vitamin E ( P < 0.05). The activity of catalase (CAT) in the hepatopancreas decreased significantly as dietary vitamin E supplementation increased ( P < 0.05), and no significant difference was detected in glutathione peroxidase (GSH-Px) activity between different dietary groups ( P >0.05). The contents of vitamin E in the hepatopancreas and in the muscle increased with increasing dietary vitamin E. There was a linear correlation between the vitamin E level in diet and that in muscle, and between the vitamin E level in diet and that in the hepatopancreas. All the above results indicated that dietary vitamin E can be stored in the hepatopancreas and muscle and lower both the activities of SOD and CAT in the hepatopancreas, suggesting that it is a potential antioxidant in M. nipponense. Broken line analysis conducted on the weight gains of prawns in each diet group showed that the dietary vitamin E requirement for maximum growth is 94.10 mg/kg.

  13. Metschnikowia bicuspidata dominates in Taiwanese cold-weather yeast infections of Macrobrachium rosenbergii.

    PubMed

    Chen, Shih-Chu; Chen, Yu-Chin; Kwang, Jimmy; Manopo, Ivanus; Wang, Pei-Chi; Chaung, Hso-Chi; Liaw, Li-Ling; Chiu, Shih-Hau

    2007-05-09

    At water temperatures below 17 degrees C, yeast infections often occurred in 6 to 11 mo old giant freshwater prawn Macrobrachium rosenbergii (8 to 12 cm) in Taiwan from May 2001 to December 2003, with a cumulative mortality of 20 to 95%. Gross signs of disease included milky hemolymph, a yellow exoskeleton, opaque muscles, and a swollen hepatopancreas (HP). Histopathology included marked edema and extensive necrotic lesions associated with large numbers of yeast aggregates and inflammation within the muscles, HP, and other internal organs such as the heart, ovary, and intestine. Yeast cell numbers isolated from various tissues ranged from 4.5 x 10(8) to 9.0 x 10(9) colony forming units (CFU) per 100 mg. From diseased prawns from 12 affected farms, the presence of Metschnikowia bicuspidata (98.4% prevalence), Saccharomyces cerevisiae (0.8% prevalence), and Candida albicans (0.8% prevalence) was confirmed by biochemical tests and sequencing of PCR products from the D1/D2 domain of 26S rDNA. Experimental infection with these isolates caused gross signs and histopathological changes similar to those observed in naturally infected prawns, and lethal doses (LD50) were 3.8 x 10(3), 2.0 x 10(3), and 4.3 x 10(3) CFU prawn-1, respectively. Although the results of this study revealed that M. bicuspidata may be the major cause of yeast infections in the giant freshwater prawns in Taiwan, this is the first time that S. cerevisiae and C. albicans are also reported as pathogens.

  14. Diversity of lectins in Macrobrachium rosenbergii and their expression patterns under spiroplasma MR-1008 stimulation.

    PubMed

    Zhu, Huanxi; Du, Jie; Hui, Kai-Min; Liu, Peng; Chen, Jing; Xiu, Yunji; Yao, Wei; Wu, Ting; Meng, Qingguo; Gu, Wei; Ren, Qian; Wang, Wen

    2013-08-01

    Lectins play important roles in crustacean innate immunity through recognition of foreign pathogens. In this study, 20 lectins including C-type lectins [dual-carbohydrate recognition domain (CRD) type and single-CRD type], L-type lectin, and lectin with low-density lipoprotein class A (LDLa) domain were identified from the freshwater prawn Macrobrachium rosenbergii. The tissue distribution and expression patterns of these lectins under spiroplasma strain MR-1008 challenge were investigated. Most of the lectins were found to be mainly distributed in the hepatopancreas. Lectin5, Lectin14, Lectin17, and Lectin18 exhibited the highest expression level in the hemocytes, nerve, intestine, and heart, respectively. MrLec1 to MrLec6 (dual-CRD lectins) in the hepatopancreas were up-regulated by spiroplasma challenge. Single-CRD lectins reached the highest level at 72 h after spiroplasma challenge. Lectin9 and Lectin15 both belong to L-type lectins. At post-spiroplasma challenge, Lectin9 expression was up-regulated, whereas Lectin15 expression was down-regulated. Lectin11 with LDLa domain showed the highest level after 12 h Lectin18 and Lectin20, namely, CD209, were also up-regulated by spiroplasma challenge. Lectin14, a C-type lectin, quickly reached the highest level after 2 h Lectin16 showed the highest level after 72 h Lectin5 reached the highest level in cultured hemocytes after 6 h Lectin17 in the intestine and Lectin14 in the nerve were slightly up-regulated after 6 and 2 h, respectively. Our research results indicate that lectins may play important roles in early or late immune responses against spiroplasma challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Genetic Inheritance of Female and Male Morphotypes in Giant Freshwater Prawn Macrobrachium rosenbergii

    PubMed Central

    2014-01-01

    Giant freshwater prawn (GFP) Macrobrachium rosenbergii is unique with males categorized in five different morphotypes (small claw, orange claw, blue claw, old blue claw and no claw males) and females in three reproductive statuses (mature ovary, berried and spawned females). In the present study we examined genetic inheritance of female and male morphotypes, their body weights and genetic associations between morphotypes and body traits. Restricted maximum likelihood fitting a multi-trait animal model was performed on a total of 21,459 body records collected over five generations in a GFP population selected for high growth rate. The estimates of variance components showed that there were substantial differences in additive genetic variance in body weight between male morphotypes. The low and significantly different from one genetic correlations between the expressions of body weight in male morphotypes also suggest that these traits should be treated as genetically different traits in selective breeding programs. By contrast, body weights of female types are essentially the same characters as indicated by the high genetic correlations between homologous trait expressions. In addition to body weight, male morphotypes and female reproductive statuses were treated as traits in themselves and were analysed as binary observations using animal and sire linear mixed models, and logit and probit threshold models. The estimates of heritability back-transformed from the liability scale were in good agreement with those obtained from linear mixed models, ranging from 0.02 to 0.43 for male morphotypes and 0.06 to 0.10 for female types. The genetic correlations among male morphoptypes were generally favourable. Body weight showed negative genetic associations with SM (−0.96), whereas those of body weight with other male morphotypes were positive (0.25 to 0.76). Our results showed that there is existence of heritable (additive genetic) component for male morphotypes, giving

  16. Tracking the virus-like particles of Macrobrachium rosenbergii nodavirus in insect cells

    PubMed Central

    Hanapi, Ummi Fairuz; Yong, Chean Yeah; Goh, Zee Hong; Alitheen, Noorjahan Banu; Yeap, Swee Keong

    2017-01-01

    Macrobrachium rosenbergii nodavirus (MrNv) poses a major threat to the prawn industry. Currently, no effective vaccine and treatment are available to prevent the spread of MrNv. Its infection mechanism and localisation in a host cell are also not well characterised. The MrNv capsid protein (MrNvc) produced in Escherichia coli self-assembled into virus-like particles (VLPs) resembling the native virus. Thus, fluorescein labelled MrNvc VLPs were employed as a model to study the virus entry and localisation in Spodoptera frugiperda, Sf9 cells. Through fluorescence microscopy and sub-cellular fractionation, the MrNvc was shown to enter Sf9 cells, and eventually arrived at the nucleus. The presence of MrNvc within the cytoplasm and nucleus of Sf9 cells was further confirmed by the Z-stack imaging. The presence of ammonium chloride (NH4Cl), genistein, methyl-β-cyclodextrin or chlorpromazine (CPZ) inhibited the entry of MrNvc into Sf9 cells, but cytochalasin D did not inhibit this process. This suggests that the internalisation of MrNvc VLPs is facilitated by caveolae- and clathrin-mediated endocytosis. The whole internalisation process of MrNvc VLPs into a Sf9 cell was recorded with live cell imaging. We have also identified a potential nuclear localisation signal (NLS) of MrNvc through deletion mutagenesis and verified by classical-NLS mapping. Overall, this study provides an insight into the journey of MrNvc VLPs in insect cells. PMID:28194311

  17. Potential use of the Macrobrachium rosenbergii lectin for diagnosis of T-cell acute lymphoblastic leukemia.

    PubMed

    Pérez-Campos-Mayoral, Laura; Ruiz-Argüelles, Alejandro; Pérez-Romano, Beatriz; Zenteno, Edgar; Hernández-Cruz, Pedro; Martínez-Cruz, Ruth; Martínez-Cruz, Margarito; Pina-Canseco, Socorro; Pérez-Campos, Eduardo

    2008-01-01

    T-cell acute lymphoblastic leukemia is the most common form of cancer in children. Lectins are proteins or glycoproteins from plants or animals that recognize oligossacharides on the cell surface and have been used to characterize the structural changes of oligosaccharides in leukemias. In this study, we used the lectin from the freshwater prawn Macrobrachium (M. rosenbergii), specific for acetyl groups in sialylated glycans, because increased sialylation of glycoproteins and glycolipids has been identified in lymphoblastic leukemias. We compared the specificity of the M. rosenbergii lectin for lymphoblastic leukemias with the specificities of the lectins from Triticum vulgaris, Solanum tuberosum, Arachis hipogaea, and Phytolacca americana. By morphologic and phenotype characterization with a panel of monoclonal antibodies, we identified four types of leukemias from 106 leukemia patients: 11 cases of T-cell acute lymphoblastic leukemia, 61 cases of B-cell acute lymphoblastic leukemia, 24 cases of acute myeloblastic leukemia, and 10 cases of acute biphenotypic leukemia. As determined by cytofluorometric assays, nine of the eleven cases with T-cell acute lymphoblastic leukemia (8 +/- 3 years old) were specifically identified with the lectin from M. rosenbergii. In contrast, only six cases of B-cell leukemia, one case of myeloblastic leukemia, and 2 cases of biphenotypic leukemia were identified with this M. rosenbergii lectin. The other lectins tested showed no capacity to differentiate, in a significant manner, any of the four types of leukemias tested. Thus, the lectin from M. rosenbergii could be considered a useful tool for the diagnosis and study of T-cell acute lymphoblastic leukemia.

  18. Population Structure and Historical Demography of the Oriental River Prawn (Macrobrachium nipponense) in Taiwan.

    PubMed

    Chen, Po-Cheng; Shih, Chun-Han; Chu, Ta-Jen; Wang, Daryi; Lee, Ying-Chou; Tzeng, Tzong-Der

    2015-01-01

    The oriental river prawn (Macrobrachium nipponense) is a non-obligatory amphidromous prawn, and it has a wide distribution covering almost the entire Taiwan. Mitochondrial DNA fragment sequences of the cytochrome oxidase subunit I (COI) and 16S rRNA were combined and used to elucidate the population structure and historical demography of oriental river prawn in Taiwan. A total of 202 individuals from six reservoirs and three estuaries were separately collected. Nucleotide diversity (π) of all populations was 0.01217, with values ranging from 0.00188 (Shihmen Reservoir, SMR, northern Taiwan) to 0.01425 (Mingte Reservoir, MTR, west-central Taiwan). All 76 haplotypes were divided into 2 lineages: lineage A included individuals from all sampling areas except SMR, and lineage B included specimens from all sampling locations except Chengching Lake Reservoir (CLR) and Liyu Lake Reservoir (LLR). All FST values among nine populations were significantly different except the one between Jhonggang River Estuary (JGE, west-central Taiwan) and Kaoping River Estuary (KPE, southern Taiwan). UPGMA tree of nine populations showed two main groups: the first group included the SMR and Tamsui River Estuary (TSE) (both located northern Taiwan), and the second one included the other seven populations (west-central, southern and eastern Taiwan). Demographic analyses implied a population expansion occurred during the recent history of the species. The dispersal route of this species might be from China to west-central and west-southern Taiwan, and then the part individuals belonging to lineage A and B dispersed southerly and northerly, respectively. And then part individuals in west-central Taiwan fell back to and stay at estuaries as the sea level rose about 18,000 years ago.

  19. Population Structure and Historical Demography of the Oriental River Prawn (Macrobrachium nipponense) in Taiwan

    PubMed Central

    Chu, Ta-Jen; Wang, Daryi; Lee, Ying-Chou; Tzeng, Tzong-Der

    2015-01-01

    The oriental river prawn (Macrobrachium nipponense) is a non-obligatory amphidromous prawn, and it has a wide distribution covering almost the entire Taiwan. Mitochondrial DNA fragment sequences of the cytochrome oxidase subunit I (COI) and 16S rRNA were combined and used to elucidate the population structure and historical demography of oriental river prawn in Taiwan. A total of 202 individuals from six reservoirs and three estuaries were separately collected. Nucleotide diversity (π) of all populations was 0.01217, with values ranging from 0.00188 (Shihmen Reservoir, SMR, northern Taiwan) to 0.01425 (Mingte Reservoir, MTR, west-central Taiwan). All 76 haplotypes were divided into 2 lineages: lineage A included individuals from all sampling areas except SMR, and lineage B included specimens from all sampling locations except Chengching Lake Reservoir (CLR) and Liyu Lake Reservoir (LLR). All FST values among nine populations were significantly different except the one between Jhonggang River Estuary (JGE, west-central Taiwan) and Kaoping River Estuary (KPE, southern Taiwan). UPGMA tree of nine populations showed two main groups: the first group included the SMR and Tamsui River Estuary (TSE) (both located northern Taiwan), and the second one included the other seven populations (west-central, southern and eastern Taiwan). Demographic analyses implied a population expansion occurred during the recent history of the species. The dispersal route of this species might be from China to west-central and west-southern Taiwan, and then the part individuals belonging to lineage A and B dispersed southerly and northerly, respectively. And then part individuals in west-central Taiwan fell back to and stay at estuaries as the sea level rose about 18,000 years ago. PMID:26716687

  20. Effects of Host Phylogeny and Habitats on Gut Microbiomes of Oriental River Prawn (Macrobrachium nipponense).

    PubMed

    Tzeng, Tzong-Der; Pao, Yueh-Yang; Chen, Po-Cheng; Weng, Francis Cheng-Hsuan; Jean, Wen Dar; Wang, Daryi

    2015-01-01

    The gut microbial community is one of the richest and most complex ecosystems on earth, and the intestinal microbes play an important role in host development and health. Next generation sequencing approaches, which rapidly produce millions of short reads that enable the investigation on a culture independent basis, are now popular for exploring microbial community. Currently, the gut microbiome in fresh water shrimp is unexplored. To explore gut microbiomes of the oriental river prawn (Macrobrachium nipponense) and investigate the effects of host genetics and habitats on the microbial composition, 454 pyrosequencing based on the 16S rRNA gene were performed. We collected six groups of samples, including M. nipponense shrimp from two populations, rivers and lakes, and one sister species (M. asperulum) as an out group. We found that Proteobacteria is the major phylum in oriental river prawn, followed by Firmicutes and Actinobacteria. Compositional analysis showed microbial divergence between the two shrimp species is higher than that between the two populations of one shrimp species collected from river and lake. Hierarchical clustering also showed that host genetics had a greater impact on the divergence of gut microbiome than host habitats. This finding was also congruent with the functional prediction from the metagenomic data implying that the two shrimp species still shared the same type of biological functions, reflecting a similar metabolic profile in their gut environments. In conclusion, this study provides the first investigation of the gut microbiome of fresh water shrimp, and supports the hypothesis of host species-specific signatures of bacterial community composition.

  1. Effects of Host Phylogeny and Habitats on Gut Microbiomes of Oriental River Prawn (Macrobrachium nipponense)

    PubMed Central

    Chen, Po-Cheng; Weng, Francis Cheng-Hsuan; Jean, Wen Dar; Wang, Daryi

    2015-01-01

    The gut microbial community is one of the richest and most complex ecosystems on earth, and the intestinal microbes play an important role in host development and health. Next generation sequencing approaches, which rapidly produce millions of short reads that enable the investigation on a culture independent basis, are now popular for exploring microbial community. Currently, the gut microbiome in fresh water shrimp is unexplored. To explore gut microbiomes of the oriental river prawn (Macrobrachium nipponense) and investigate the effects of host genetics and habitats on the microbial composition, 454 pyrosequencing based on the 16S rRNA gene were performed. We collected six groups of samples, including M. nipponense shrimp from two populations, rivers and lakes, and one sister species (M. asperulum) as an out group. We found that Proteobacteria is the major phylum in oriental river prawn, followed by Firmicutes and Actinobacteria. Compositional analysis showed microbial divergence between the two shrimp species is higher than that between the two populations of one shrimp species collected from river and lake. Hierarchical clustering also showed that host genetics had a greater impact on the divergence of gut microbiome than host habitats. This finding was also congruent with the functional prediction from the metagenomic data implying that the two shrimp species still shared the same type of biological functions, reflecting a similar metabolic profile in their gut environments. In conclusion, this study provides the first investigation of the gut microbiome of fresh water shrimp, and supports the hypothesis of host species-specific signatures of bacterial community composition. PMID:26168244

  2. Genetic inheritance of female and male morphotypes in giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    Dinh, Hung; Nguyen, Nguyen Hong

    2014-01-01

    Giant freshwater prawn (GFP) Macrobrachium rosenbergii is unique with males categorized in five different morphotypes (small claw, orange claw, blue claw, old blue claw and no claw males) and females in three reproductive statuses (mature ovary, berried and spawned females). In the present study we examined genetic inheritance of female and male morphotypes, their body weights and genetic associations between morphotypes and body traits. Restricted maximum likelihood fitting a multi-trait animal model was performed on a total of 21,459 body records collected over five generations in a GFP population selected for high growth rate. The estimates of variance components showed that there were substantial differences in additive genetic variance in body weight between male morphotypes. The low and significantly different from one genetic correlations between the expressions of body weight in male morphotypes also suggest that these traits should be treated as genetically different traits in selective breeding programs. By contrast, body weights of female types are essentially the same characters as indicated by the high genetic correlations between homologous trait expressions. In addition to body weight, male morphotypes and female reproductive statuses were treated as traits in themselves and were analysed as binary observations using animal and sire linear mixed models, and logit and probit threshold models. The estimates of heritability back-transformed from the liability scale were in good agreement with those obtained from linear mixed models, ranging from 0.02 to 0.43 for male morphotypes and 0.06 to 0.10 for female types. The genetic correlations among male morphoptypes were generally favourable. Body weight showed negative genetic associations with SM (-0.96), whereas those of body weight with other male morphotypes were positive (0.25 to 0.76). Our results showed that there is existence of heritable (additive genetic) component for male morphotypes, giving

  3. A transcriptome study on Macrobrachium rosenbergii hepatopancreas experimentally challenged with white spot syndrome virus (WSSV).

    PubMed

    Rao, Rama; Bhassu, Subha; Bing, Robin Zhu Ya; Alinejad, Tahereh; Hassan, Sharifah Syed; Wang, Jun

    2016-05-01

    The world production of shrimp such as the Malaysian giant freshwater prawn, Macrobrachium rosenbergii is seriously affected by the white spot syndrome virus (WSSV). There is an urgent need to understand the host pathogen interaction between M. rosenbergii and WSSV which will be able to provide a solution in controlling the spread of this infectious disease and lastly save the aquaculture industry. Now, using Next Generation Sequencing (NGS), we will be able to capture the response of the M. rosenbergii to the pathogen and have a better understanding of the host defence mechanism. Two cDNA libraries, one of WSSV-challenged M. rosenbergii and a normal control one, were sequenced using the Illumina HiSeq™ 2000 platform. After de novo assembly and clustering of the unigenes from both libraries, 63,584 standard unigenes were generated with a mean size of 698bp and an N50 of 1137bp. We successfully annotated 35.31% of all unigenes by using BLASTX program (E-value <10-5) against NCBI non-redundant (Nr), Swiss-Prot, Kyoto Encyclopedia of Genes and Genome pathway (KEGG) and Orthologous Groups of proteins (COG) databases. Gene Ontology (GO) assessment was conducted using BLAST2GO software. Differentially expressed genes (DEGs) by using the FPKM method showed 8443 host genes were significantly up-regulated whereas 5973 genes were significantly down-regulated. The differentially expressed immune related genes were grouped into 15 animal immune functions. The present study showed that WSSV infection has a significant impact on the transcriptome profile of M. rosenbergii's hepatopancreas, and further enhanced the knowledge of this host-virus interaction. Furthermore, the high number of transcripts generated in this study will provide a platform for future genomic research on freshwater prawns. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Solution structures of 2×6-meric and 4×6-meric hemocyanins of crustaceans Carcinus aestuarii, Squilla mantis and Upogebia pusilla.

    PubMed

    Mičetić, Ivan; Losasso, Carmen; Muro, Paolo Di; Tognon, Giuseppe; Benedetti, Piero; Beltramini, Mariano

    2010-07-01

    Arthropod hemocyanins (Hcs) are a family of large, high molecular mass, extracellular oxygen transport proteins. They form oligomeric quaternary structures based on different arrangements of a basic 6×75 kDa hexameric unit. Their complex quaternary structures present binding sites for allosteric effectors and regulate the oxygen binding process in a cooperative manner. In order to describe the functional regulation of arthropod Hcs, a detailed description of their quaternary structure is necessary. We have utilized small angle X-ray scattering to characterize the structure of three arthropod Hcs in unperturbed conditions. Two different levels of complexity are evaluated: for the 2×6-meric case, we analyzed the Hcs of the portunid crab Carcinus aestuarii and stomatopod Squilla mantis, while in the case of 4×6-meric structures, we studied the Hc of the thalassinid shrimp Upogebia pusilla. While C. aestuarii Hc presented a structure comparable to other 2×6-meric crustacean Hcs, S. mantis Hc shows a peculiar and quite unique arrangement of its building blocks, resembling a substructure of giant Hcs found among cheliceratans. For U. pusilla, the arrangement of its subunits is described as tetrahedral, in contrast to the more common square planar 4×6-meric structure found in other arthropod Hcs. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. A remarkable, precisely timed release of hyperglycemic hormone from endocrine cells in the gut is associated with ecdysis in the crab Carcinus maenas.

    PubMed

    Chung, J S; Dircksen, H; Webster, S G

    1999-11-09

    Molting or ecdysis is the most fundamentally important process in arthropod life history, because shedding of the exoskeleton is an absolute prerequisite for growth and metamorphosis. Although the hormonal mechanisms driving ecdysis in insects have been studied extensively, nothing is known about these processes in crustaceans. During late premolt and during ecdysis in the crab Carcinus maenas, we observed a precise and reproducible surge in hemolymph hyperglycemic hormone (CHH) levels, which was over 100-fold greater than levels seen in intermolt animals. The source of this hormone surge was not from the eyestalk neurosecretory tissues but from previously undescribed endocrine cells (paraneurons), in defined areas of the foregut and hindgut. During premolt (the only time when CHH is expressed by these tissues), the gut is the largest endocrine tissue in the crab. The CHH surge, which is a result of an unusual, almost complete discharge of the contents of the gut endocrine cell, regulates water and ion uptake during molting, thus allowing the swelling necessary for successful ecdysis and the subsequent increase in size during postmolt. This study defines an endocrine brain/gut axis in the arthropods. We propose that the ionoregulatory process controlled by CHH may be common to arthropods, in that, for insects, a similar mechanism seems to be involved in antidiuresis. It also seems likely that a cascade of very precisely coordinated release of (neuro) hormones controls ecdysis.

  6. Effects of an Offshore Wind Farm (OWF) on the Common Shore Crab Carcinus maenas: Tagging Pilot Experiments in the Lillgrund Offshore Wind Farm (Sweden)

    PubMed Central

    Langhamer, Olivia; Holand, Håkon; Rosenqvist, Gunilla

    2016-01-01

    Worldwide growth of offshore renewable energy production will provide marine organisms with new hard substrate for colonization in terms of artificial reefs. The artificial reef effect is important when planning offshore installations since it can create habitat enhancement. Wind power is the most advanced technology within offshore renewable energy sources and there is an urgent need to study its impacts on the marine environment. To test the hypothesis that offshore wind power increases the abundance of reef species relative to a reference area, we conduct an experiment on the model species common shore crab (Carcinus maenas).Overall, 3962 crabs were captured, observed, marked and released in 2011 and 1995 crabs in 2012. Additionally, carapace size, sex distribution, color morphs and body condition was recorded from captured crabs. We observed very low recapture rates at all sites during both years which made evaluating differences in population sizes very difficult. However, we were able to estimate population densities from the capture record for all three sites. There was no obvious artificial reef effect in the Lillgrund wind farm, but a spill-over effect to nearby habitats cannot be excluded. We could not find any effect of the wind farm on either, morphs, sex distribution or condition of the common shore crab. Our study found no evidence that Lillgrund wind farm has a negative effect on populations of the common shore crab. This study provides the first quantitative and experimental data on the common shore crab in relation to offshore wind farms. PMID:27780212

  7. Effects of an Offshore Wind Farm (OWF) on the Common Shore Crab Carcinus maenas: Tagging Pilot Experiments in the Lillgrund Offshore Wind Farm (Sweden).

    PubMed

    Langhamer, Olivia; Holand, Håkon; Rosenqvist, Gunilla

    2016-01-01

    Worldwide growth of offshore renewable energy production will provide marine organisms with new hard substrate for colonization in terms of artificial reefs. The artificial reef effect is important when planning offshore installations since it can create habitat enhancement. Wind power is the most advanced technology within offshore renewable energy sources and there is an urgent need to study its impacts on the marine environment. To test the hypothesis that offshore wind power increases the abundance of reef species relative to a reference area, we conduct an experiment on the model species common shore crab (Carcinus maenas).Overall, 3962 crabs were captured, observed, marked and released in 2011 and 1995 crabs in 2012. Additionally, carapace size, sex distribution, color morphs and body condition was recorded from captured crabs. We observed very low recapture rates at all sites during both years which made evaluating differences in population sizes very difficult. However, we were able to estimate population densities from the capture record for all three sites. There was no obvious artificial reef effect in the Lillgrund wind farm, but a spill-over effect to nearby habitats cannot be excluded. We could not find any effect of the wind farm on either, morphs, sex distribution or condition of the common shore crab. Our study found no evidence that Lillgrund wind farm has a negative effect on populations of the common shore crab. This study provides the first quantitative and experimental data on the common shore crab in relation to offshore wind farms.

  8. Cadmium bioaccumulates after acute exposure but has no effect on locomotion or shelter-seeking behaviour in the invasive green shore crab (Carcinus maenas).

    PubMed

    Blewett, Tamzin A; Newton, Dustin; Flynn, Shannon L; Alessi, Daniel S; Goss, Greg G; Hamilton, Trevor J

    2017-01-01

    Cadmium (Cd(2+)) is a non-essential metal ubiquitous in the environment due to industrial processes. However, little is known regarding the ability of Cd(2+) to impact the behaviour of aquatic animals in receiving environments. Green shore crabs (Carcinus maenas) were exposed to waterborne Cd(2+) [control (no Cd(2+)), low (0.30 μmol/L), medium (3.3 μmol/L) and high (63 μmol/L)], for 24 h, then, crabs were placed in an open field and shelter test to determine potential changes in locomotion and preference for shelter. Tissues (gill, haemolymph, stomatogastric ganglion) were taken for bioaccumulation analysis of Cd(2+) and ion content. Behavioural testing was recorded with a motion-tracking software system and showed no impact of Cd(2+) on any variable in either of the tests used. All three tissues accumulated Cd(2+) in a concentration-dependent manner. Crabs exposed to low Cd(2+) showed a small but significant decrease in haemolymph Ca(2+), however, this effect was not present at higher Cd(2+) exposures. Overall, the results indicate that short-term Cd(2+) exposure, and the resulting Cd(2+) accumulation, had no effect on locomotor and anxiety-related behaviour of green shore crabs.

  9. Inter-population variability in the reproductive morphology of the shore crab (Carcinus maenas): evidence of endocrine disruption in a marine crustacean?

    PubMed

    Brian, Jayne V

    2005-04-01

    Environmental contaminants that are capable of causing endocrine disrupting effects are currently a major cause for concern. These chemicals are known to influence the reproductive development of vertebrates by mimicking or antagonising the actions of endogenous hormones. However, little is known regarding their potential effects on invertebrates. Here we examine variations in the reproductive morphology of the shore crab (Carcinus maenas) for evidence of endocrine disruption. Crabs were collected from a number of sites comprising a putative gradient of exposure to endocrine disrupting chemicals. Patterns of inter-population variability in the expression of sexually dimorphic traits were then examined for evidence of hormone disruption. Extensive variability was detected and patterns of chelal morphology were consistent with the gradient of endocrine disruption. However, overall, the patterns of morphological variability were not consistent with hormonally-mediated effects. This suggests that shore crabs are not susceptible to the same type of endocrine disrupting effects that have been detected in vertebrates, which are most commonly mediated via the oestrogen receptor. However, the potential for androgenic effects on crustacean morphology are discussed.

  10. An unconventional antimicrobial protein histone from freshwater prawn Macrobrachium rosenbergii: analysis of immune properties.

    PubMed

    Arockiaraj, Jesu; Gnanam, Annie J; Kumaresan, Venkatesh; Palanisamy, Rajesh; Bhatt, Prasanth; Thirumalai, Muthukumaresan Kuppusamy; Roy, Arpita; Pasupuleti, Mukesh; Kasi, Marimuthu

    2013-11-01

    In this study, we have reported the first histone characterized at molecular level from freshwater prawn Macrobrachium rosenbergii (MrHis). A full length cDNA of MrHis (751 base pairs) was identified from an established M. rosenbergii cDNA library using GS-FLX technique. It encodes 137 amino acid residues with a calculated molecular mass of 15 kDa and an isoelectric point of 10.5. MrHis peptide contains a histone H2A signature between 21 and 27 amino acids. Homologous analysis showed that MrHis had a significant sequence identity (99%) with other known histone H2A groups especially from Penaeus monodon. Phylogenetic analysis of MrHis showed a strong relationship with other amino acid sequences from histone H2A arthropod groups. Further phylogenetic analysis showed that the MrHis belongs to histone H2A superfamily and H2A1A sub-family. Secondary structure of MrHis showed that the protein contains 50.36% α-helical region and 49.64% coils. The 3D model of MrHis was predicted by I-Tasser program and the model was evaluated for quality analysis including C-score analysis, Ramachandran plot analysis and RMSD analysis. The surface view analysis of MrHis showed the active domain at the N terminal. The antimicrobial property of MrHis protein was confirmed by the helical structure and the total hydrophobic surface along with its net charge. The MFE of the predicted RNA structure of MrHis is -128.62 kcal/mol, shows its mRNA stability. Schiffer-Edmundson helical wheel analysis of the N-terminal of MrHis showed a perfect amphipathic nature of the peptide. Significantly (P < 0.05) highest gene expression was noticed in the hemocyte and is induced with viral (WSBV and MrNV) and bacteria (A eromonas hydrophila and Vibrio harveyi) infections. The coding sequence of recombinant MrHis protein was expressed in a pMAL vector and purified to study the antimicrobial properties. The recombinant product showed antimicrobial activity against both Gram negative and Gram positive bacteria

  11. RNA-seq analysis of Macrobrachium rosenbergii hepatopancreas in response to Vibrio parahaemolyticus infection.

    PubMed

    Rao, Rama; Bing Zhu, Ya; Alinejad, Tahereh; Tiruvayipati, Suma; Lin Thong, Kwai; Wang, Jun; Bhassu, Subha

    2015-01-01

    The Malaysian giant freshwater prawn, Macrobrachium rosenbergii, is an economically important crustacean worldwide. However, production of this prawn is facing a serious threat from Vibriosis disease caused by Vibrio species such as Vibrio parahaemolyticus. Unfortunately, the mechanisms involved in the immune response of this species to bacterial infection are not fully understood. We therefore used a high-throughput deep sequencing technology to investigate the transcriptome and comparative expression profiles of the hepatopancreas from this freshwater prawn infected with V. parahaemolyticus to gain an increased understanding of the molecular mechanisms underlying the species' immune response to this pathogenic bacteria. A total of 59,122,940 raw reads were obtained from the control group, and 58,385,094 reads from the Vibrio-infected group. Via de novo assembly by Trinity assembler, 59,050 control unigenes and 73,946 Vibrio-infected group unigenes were obtained. By clustering unigenes from both libraries, a total of 64,411 standard unigenes were produced. The standard unigenes were annotated against the NCBI non-redundant, Swiss-Prot, Kyoto Encyclopaedia of Genes and Genome pathway (KEGG) and Orthologous Groups of Proteins (COG) databases, with 19,799 (30.73%), 16,832 (26.13%), 14,706 (22.83%) and 7,856 (12.19%) hits respectively, giving a final total of 22,455 significant hits (34.86% of all unigenes). A Gene Ontology (GO) analysis search using the Blast2GO program resulted in 6,007 unigenes (9.32%) being categorized into 55 functional groups. A differential gene expression analysis produced a total of 14,569 unigenes aberrantly expressed, with 11,446 unigenes significantly up-regulated and 3,103 unigenes significantly down-regulated. The differentially expressed immune genes fall under various processes of the animal immune system. This study provided an insight into the antibacterial mechanism in M. rosenbergii and the role of differentially expressed immune

  12. Insights into Sexual Precocity of Female Oriental River Prawn Macrobrachium nipponense through Transcriptome Analysis

    PubMed Central

    Jiang, Hongxia; Li, Xilian; Sun, Yuhang; Hou, Fujun; Zhang, Yufei; Li, Fei; Gu, Zhimin; Liu, Xiaolin

    2016-01-01

    Background The oriental river prawn (Macrobrachium nipponense) is the most prevalent aquaculture species in China. The sexual precocity in this species has received considerable attention in recent years because more and more individuals matured at a small size, which devalues the commercial production. In this study, we developed deep-coverage transcriptomic sequencing data for the ovaries of sexually precocious and normal sexually mature M. nipponense using next-generation RNA sequencing technology and attempted to provide the first insight into the molecular regulatory mechanism of sexual precocity in this species. Results A total of 63,336 unigenes were produced from the ovarian cDNA libraries of sexually precocious and normal sexually mature M. nipponense using Illumina HiSeq 2500 platform. Through BLASTX searches against the NR, STRING, Pfam, Swissprot and KEGG databases, 15,134 unigenes were annotated, accounting for 23.89% of the total unigenes. 5,195 and 3,227 matched unigenes were categorized by GO and COG analysis respectively. 15,908 unigenes were consequently mapped into 332 KEGG pathways, and many reproduction-related pathways and genes were identified. Moreover, 26,008 SSRs were identified from 18,133 unigenes. 80,529 and 80,516 SNPs were yielded from ovarian libraries of sexually precocious and normal sexually mature prawn, respectively, and 29,851 potential SNPs between these two groups were also predicted. After comparing the ovarian libraries of sexually precocious and normal sexually mature prawn, 549 differentially expressed genes (DEGs) and 9 key DEGs that may be related to sexual precocity of M. nipponense were identified. 20 DEGs were selected for validation by quantitative real-time PCR (QPCR) and 19 DEGs show consistent expression between QPCR and RNAseq-based differential expression analysis datasets. Conclusion This is the first report on the large-scale RNA sequencing of ovaries of sexually precocious and normal sexually mature M

  13. Influence of short term exposure of TBT on the male reproductive activity in freshwater prawn Macrobrachium rosenbergii (De Man).

    PubMed

    Revathi, Peranandam; Iyapparaj, Palanisamy; Vasanthi, Lourduraj Arockia; Munuswamy, Natesan; Prasanna, Vimalanathan Arun; Pandiyarajan, Jayaraj; Krishnan, Muthukalingan

    2014-10-01

    In the present study, the effect of tributyltin (TBT) on the histopathological and hormonal changes during spermatogenesis in freshwater prawn Macrobrachium rosenbergii was documented. Three experimental concentrations such as 10, 100 and 1,000 ng/L were selected and exposed to prawns for 45 days. After TBT exposure, the reproductive activities like sperm count and sperm length were decreased when compared with control. Further, abnormal structure of the seminiferous tubule, decrease in spermatozoa concentration, diminution of the seminiferous tubule membrane and the abundance of spermatocytes in the testis were noticed in treated prawns. Interestingly, radioimmunoassay clearly revealed the reduction of testosterone level in TBT exposed groups. Thus, TBT has considerably reduced the level of testosterone and caused the impairment of spermatogenesis in the freshwater male prawn M. rosenbergii.

  14. A new record of the giant freshwater prawn, Macrobrachium spinipes (Schenkel, 1902) (Crustacea: Decapoda: Palaemonidae) from Taiwan, with notes on its taxonomy.

    PubMed

    Shy, Jhy-Yun; Wowor, Daisy; Ng, Peter K L

    2013-11-04

    The giant freshwater prawn Macrobrachium spinipes (Schenkel, 1902) is recorded from Taiwan for the first time and extends the distribution of the species to north of the Tropic of Cancer. The Taiwanese specimens differ slightly from material from Indonesian Papua in the density of the spination of the adult second pereipods, the relative length of the ridge of the posterior submedian plate of thoracite sternite 4, and the color of the carapace, abdomen and pleural condyles.

  15. Physical and Biological Controls on the Invasion Speed of a Marine Invader with Planktonic Larvae, Illustrated with Examples From Carcinus maenas in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Pringle, J. M.; Blakeslee, A. M.; Byers, J. E.; Roman, J.

    2008-12-01

    Existing estimates of the downstream invasion speed of newly introduced species or novel genotypes with planktonic larvae have usually found that they invade much less rapidly downstream than would be expected from the mean alongshore currents in their habitat. For example, a new, genetically-distinct population of Carcinus maenas was introduced at the northern-edge of its range in Cape Breton, Nova Scotia (Roman 2006). Recently, we have found that this newly introduced genotype is being transported south- westward along the coast by the prevailing currents, displacing established populations of C. maenas. However, the rate of southward spread of the northern genotype is much less than what we would expect from the mean currents along the Scotian Shelf and Gulf of Maine. We examine four reasons for errors in the naive estimates of the rate of spread of an introduced species or genotype from mean currents. 1) Cross-shelf shear in the alongshore currents can interact with cross-shelf dispersion of larvae to bias larval settlement towards larvae which have spent more time in the weaker nearshore currents. 2) Weakly retentive embayments and other coastal features, even if unable to retain larvae for more than a small fraction of their planktonic duration, will tend to reduce the alongshelf transports of those larvae and increase the likelihood that they remain close enough to the coast to successfully recruit. This will reduce the mean alongshore transport of the larvae that recruit. 3) Alongshore gradients in the population density of competing species/genotypes will, if the population density increases in the direction of the mean currents, tend to retard the downstream spread of an introduced species/genotype. 4) Greater relative fitness or competitiveness in the downstream genotype/species will retard the spread of the upstream genotype/species. Examples of and evidence for and against these possible explanations will be provide for C. maenas in the Gulf of Maine

  16. Spontaneous alternation and locomotor activity in three species of marine crabs: green crab (Carcinus maenas), blue crab (Callinectes sapidus), and fiddler crab (Uca pugnax).

    PubMed

    Balcı, Fuat; Ramey-Balcı, Patricia A; Ruamps, Perrine

    2014-02-01

    Spontaneous alternation refers to the tendency of organisms to explore places that they have least recently visited. Our previous work showed that alternation performance of Carcinus maenas (invasive European green crab) was significantly higher than Callinectes sapidus (native blue crab), and chance level performance (Ramey, P. A., Teichman, E., Oleksiak, J., & Balcı, F. [2009]. Spontaneous alternation in marine crabs: Invasive versus native species. Behavioural Processes, 82, 51-55.). In the current study, we first tested the robustness of these findings in the absence of visual cues, longer test durations, and wider maze dimensions. These manipulations enabled us to determine whether these two crab species relied on the visual cues provided during the spontaneous alternation task in our prior work, and allowed for better characterization of their exploratory activity in the maze. Our original findings were reproduced in the present study under these new task conditions, suggesting no role for visual cues during alternation, and emphasizing the robustness and generalizability of the corresponding interspecies differences in alternation performance. We also tested whether the lower alternation performance of C. sapidus also applied to another native crab species, Uca pugnax (fiddler crab). Spontaneous alternation performance of U. pugnax was significantly lower than C. maenas but indistinguishable from C. sapidus. Finally, we examined whether the potentially higher inherent risk-sensitivity of C. sapidus could have contributed to their lower alternation performance by testing C. maenas in the presence of a larger natural predator (stressor). Higher risk sensitivity presumably induced by the stressor led to locomotor activity patterns that better resembled those of C. sapidus, however the resultant reduction in alternation performance was not statistically significant.

  17. An x-ray absorption near edge structure spectroscopy study of metal coordination in Co(II)-substituted Carcinus maenas hemocyanin.

    PubMed Central

    Della Longa, S; Bianconi, A; Palladino, L; Simonelli, B; Congiu Castellano, A; Borghi, E; Barteri, M; Beltramini, M; Rocco, G P; Salvato, B

    1993-01-01

    High-resolution x-ray absorption near edge structure spectroscopy was used to characterize the metal sites in three different cobalt-substituted derivatives of Carcinus maenas hemocyanin (Hc), including a mononuclear cobalt, a dinuclear cobalt and a copper-cobalt hybrid derivative. Co(II) model complexes with structures exemplifying octahedral, trigonal bipyramidal, pseudo-tetrahedral, and square planar geometries were also studied. The results provide structural information about the metal binding site(s) in the Co-Hcs that extend earlier results from EPR and optical spectroscopy (Bubacco et al. 1992. Biochemistry. 31: 9294-9303). Experimental spectra were compared to those calculated for atomic clusters of idealized geometry, generated using a multiple scattering approach. The energy of the dipole forbidden 1s-->3d transition and of the absorption edge in the spectra for all cobalt Hc derivatives confirmed the cobaltous oxidation state which rules out the presence of an oxygenated site. Comparisons between data and simulations showed that the mononuclear and dinuclear Co(II) derivatives, as well as the hybrid derivative, contain four-coordinate Co(II) in distorted tetrahedral sites. Although the spectra for Co(II) in dinuclear metal sites more closely resemble the simulated spectrum for a tetrahedral complex than do spectra for the mononuclear derivative, the Co(II) sites in all derivatives are very similar. The Cu K-edge high resolution x-ray absorption near edge structure spectrum of the hybrid Cu-Co-Hc resembles that of deoxy-Hc demonstrating the presence of three-coordinate Cu(I). PMID:8312502

  18. Neuroendocrine disruption in the shore crab Carcinus maenas: Effects of serotonin and fluoxetine on chh- and mih-gene expression, glycaemia and ecdysteroid levels.

    PubMed

    Robert, Alexandrine; Monsinjon, Tiphaine; Delbecque, Jean-Paul; Olivier, Stéphanie; Poret, Agnès; Foll, Frank Le; Durand, Fabrice; Knigge, Thomas

    2016-06-01

    Serotonin, a highly conserved neurotransmitter, controls many biological functions in vertebrates, but also in invertebrates. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are commonly used in human medication to ease depression by affecting serotonin levels. Their residues and metabolites can be detected in the aquatic environment and its biota. They may also alter serotonin levels in aquatic invertebrates, thereby perturbing physiological functions. To investigate whether such perturbations can indeed be expected, shore crabs (Carcinus maenas) were injected either with serotonin, fluoxetine or a combination of both. Dose-dependent effects of fluoxetine ranging from 250 to 750nM were investigated. Gene expression of crustacean hyperglycemic hormone (chh) as well as moult inhibiting hormone (mih) was assessed by RT-qPCR at 2h and 12h after injection. Glucose and ecdysteroid levels in the haemolymph were monitored in regular intervals until 12h. Serotonin led to a rapid increase of chh and mih expression. On the contrary, fluoxetine only affected chh and mih expression after several hours, but kept expression levels significantly elevated. Correspondingly, serotonin rapidly increased glycaemia, which returned to normal or below normal levels after 12h. Fluoxetine, however, resulted in a persistent low-level increase of glycaemia, notably during the period when negative feedback regulation reduced glycaemia in the serotonin treated animals. Ecdysteroid levels were significantly decreased by serotonin and fluoxetine, with the latter showing less pronounced and less rapid, but longer lasting effects. Impacts of fluoxetine on glycaemia and ecdysteroids were mostly observed at higher doses (500 and 750nM) and affected principally the response dynamics, but not the amplitude of glycaemia and ecdysteroid-levels. These results suggest that psychoactive drugs are able to disrupt neuroendocrine control in decapod crustaceans, as they interfere with the

  19. Application of neutral red retention assay to caged clams (Ruditapes decussatus) and crabs (Carcinus maenas) in the assessment of dredged material.

    PubMed

    Buratti, Sara; Ramos-Gómez, Julia; Fabbri, Elena; DelValls, T Angel; Martín-Díaz, M Laura

    2012-01-01

    Dredged material management is a key issue for the protection of aquatic environments. The in situ approach using caged bioindicator species has been chosen lately as a new methodology for the assessment of dredged material. In a tier testing approach, neutral red retention (NRR) assay has been applied as a screening tool to detect adverse changes in health status associated with contamination. Nevertheless, to authors' knowledge, little is known about the application and validation of this technique in sediment bioindicator species and under field conditions. Caged Ruditapes decussatus and Carcinus maenas were exposed during 28 days to potentially contaminated sediments at three sites in Algeciras Bay (SW Spain) and one site in Cádiz Bay (SW Spain). Lysosomal membrane stability was measured over time in haemolymph samples of exposed clams and crabs using the NRR assay. Sediment characterization of the study sites was performed in parallel. NRR time did not vary significantly (p > 0.05) over time in organisms from Cádiz Bay. Conversely, significant differences (p < 0.05) in NRR time were found in clams and crabs exposed to sediments from Algeciras Bay, which exhibited a 30-70% decrease in haemocyte lysosome membrane stability compared to day 0. Statistical analysis showed a strong correlation between the drop of haemocyte lysosome membrane stability, in both crabs and clams, and the presence of metals (p < 0.05) and PAHs (p < 0.01) in the studied sediments. The results obtained confirmed the use of NRR assay as a suitable and sensitive method to be used in the assessment of sediment quality using as bioindicator species the clam R. philippinarum and the crab C. maenas.

  20. Identification and developmental expression of mRNAs encoding putative insect cuticle hardening hormone, bursicon in the green shore crab Carcinus maenas.

    PubMed

    Wilcockson, David C; Webster, Simon G

    2008-03-01

    Bursicon is the ultimate hormone in insect ecdysis, which is involved in cuticle hardening. Here we show that mRNAs encoding the heterodimeric cystine knot protein bursicon (Burs alpha, beta), are present in crustaceans, suggesting ubiquity of this hormone in arthropods. We firstly report the cloning, sequencing of mRNAs encoding subunits from the water flea, Daphnia arenata and the CNS of the crab, Carcinus maenas, in comparison with insect bursicon subunits. Expression patterns of alpha and beta burs mRNAs were examined by in-situ hybridisation (ISH) and quantitative RT-PCR. In the thoracic ganglion, burs alpha and beta mRNAs were completely colocalised in neurones expressing crustacean cardioactive peptide (CCAP). However, in the brain and eyestalk, bursicon transcripts were never observed, despite a complex expression pattern of CCAP interneurones. Patterns of expression of burs alpha and beta mRNAs were constitutive during the moult cycle of adult crabs, in stark contrast to the situation in insects. Whilst copy numbers of burs beta transcripts closely matched those of CCAP, those of burs alpha mRNA were around 3-fold higher than burs beta. This pattern was apparent during embryogenesis, where bursicon transcripts were first observed at around 50% development-the same time as first expression of CCAP mRNA. Transcript ratios (burs alpha: beta) increased during development. Our studies have shown, for the first time, that bursicon mRNAs are expressed in identified neurones in the nervous system of crustaceans. These findings will now promote further investigation into the functions of bursicon during the moult cycle and development of crustaceans.

  1. Elevated seawater levels of CO(2) change the metabolic fingerprint of tissues and hemolymph from the green shore crab Carcinus maenas.

    PubMed

    Hammer, Karen M; Pedersen, Sindre A; Størseth, Trond R

    2012-09-01

    Carbon dioxide (CO(2)) acts as a weak acid in water and the increasing level of CO(2) in the atmosphere leads to ocean acidification. In addition, possible leakage from sub-seabed storage of anthropogenic CO(2) may pose a threat to the marine environment. (1)H NMR spectroscopy was applied to extracts of hemolymph, gills and leg muscle from shore crabs (Carcinus maenas) to examine the metabolic response to elevated levels of CO(2). Crabs were exposed to different levels of CO(2)-acidified seawater with pH(NBS) 7.4, 6.6 and 6.3 (pCO(2)~2600, 16,000 and 30,000 μatm, respectively) for two weeks (level-dependent exposure). In addition, the metabolic response was followed for up to 4 weeks of exposure to seawater pH(NBS) 6.9 (pCO(2)~7600 μatm). Partial least squares regression analysis of data showed an increased differentiation between metabolic fingerprints of controls and exposed groups for all sample types with increasing CO(2) levels. Difference between controls and animals subjected to time-dependent exposure appeared after 4 weeks in the hemolymph and gills, and after 48 h of exposure in the leg muscle. Changes in metabolic profiles were mainly due to a reduced level of important intracellular osmolytes such as amino acids (glycine, proline), while the level of other metabolites varied between the different sample types. The results are similar to what is observed in animals exposed to hypo-osmotic stress and may suggest disturbances in intracellular iso-osmotic regulation. The results may also reflect increased catabolism of amino acids to supply the body fluids with proton-buffering ammonia (NH(3)). Alternatively, the findings may reflect an exhaustive effect of CO(2) exposure.

  2. Oxidized derivatives of Octopus vulgaris and Carcinus aestuarii hemocyanins at pH 7.5 and related models by x-ray absorption spectroscopy.

    PubMed Central

    Borghi, Elena; Solari, Pier Lorenzo; Beltramini, Mariano; Bubacco, Luigi; Di Muro, Paolo; Salvato, Benedetto

    2002-01-01

    The binuclear copper sites of the met and met-azido derivatives of Octopus vulgaris and Carcinus aestuarii hemocyanins at pH 7.5 were characterized by high-resolution x-ray absorption spectroscopy in the low energy region (XANES) and in the higher region (EXAFS). The accuracy of the analysis of the data was tested with two mononuclear and six binuclear copper(II) complexes of the poly(benzimidazole) ligand systems 2-BB, L-5,5 and L-6,6 (Casella et al., 1993, Inorg. Chem. 32:2056-2067; 1996, Inorg. Chem. 35:1101-1113). Their structural and reactivity properties are related to those of the protein's derivatives. The results obtained for those models with resolved x-ray structure (the 2-BB-aquo and azido mononuclear complexes, and the binuclear L-5,5 Cu(II)-bis(hydroxo) (Casella et al., unpublished)), extends the validity of our approach to the other poly(benzimidazole)-containing complexes and to the hemocyanin derivatives. Comparison between the protein's and the complexes' data, support a description of the met-derivatives as a five-coordinated O-bridged binuclear copper(II) center and favors, for both species, a bis(hydroxo) structure with a 3-A Cu-Cu distance. For O. vulgaris met-azido derivative a mu-1,3 bridging mode for the ligand appears the most likely. The structural situation of C. aestuarii met-azido-derivative is less clear: a mu-1,1 mode is favored, but a terminal mode cannot be excluded. PMID:12023249

  3. An x-ray absorption near edge structure spectroscopy study of metal coordination in Co(II)-substituted Carcinus maenas hemocyanin.

    PubMed

    Della Longa, S; Bianconi, A; Palladino, L; Simonelli, B; Congiu Castellano, A; Borghi, E; Barteri, M; Beltramini, M; Rocco, G P; Salvato, B

    1993-12-01

    High-resolution x-ray absorption near edge structure spectroscopy was used to characterize the metal sites in three different cobalt-substituted derivatives of Carcinus maenas hemocyanin (Hc), including a mononuclear cobalt, a dinuclear cobalt and a copper-cobalt hybrid derivative. Co(II) model complexes with structures exemplifying octahedral, trigonal bipyramidal, pseudo-tetrahedral, and square planar geometries were also studied. The results provide structural information about the metal binding site(s) in the Co-Hcs that extend earlier results from EPR and optical spectroscopy (Bubacco et al. 1992. Biochemistry. 31: 9294-9303). Experimental spectra were compared to those calculated for atomic clusters of idealized geometry, generated using a multiple scattering approach. The energy of the dipole forbidden 1s-->3d transition and of the absorption edge in the spectra for all cobalt Hc derivatives confirmed the cobaltous oxidation state which rules out the presence of an oxygenated site. Comparisons between data and simulations showed that the mononuclear and dinuclear Co(II) derivatives, as well as the hybrid derivative, contain four-coordinate Co(II) in distorted tetrahedral sites. Although the spectra for Co(II) in dinuclear metal sites more closely resemble the simulated spectrum for a tetrahedral complex than do spectra for the mononuclear derivative, the Co(II) sites in all derivatives are very similar. The Cu K-edge high resolution x-ray absorption near edge structure spectrum of the hybrid Cu-Co-Hc resembles that of deoxy-Hc demonstrating the presence of three-coordinate Cu(I).

  4. Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

    PubMed

    Tepolt, Carolyn K; Somero, George N

    2014-04-01

    As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world.

  5. Laboratory simulation system, using Carcinus maenas as the model organism, for assessing the impact of CO2 leakage from sub-seabed injection and storage.

    PubMed

    Rodríguez-Romero, Araceli; Jiménez-Tenorio, Natalia; Riba, Inmaculada; Blasco, Julián

    2016-01-01

    The capture and storage of CO2 in sub-seabed geological formations has been proposed as one of the potential options to decrease atmospheric CO2 concentrations in order to mitigate the abrupt and irreversible consequences of climate change. However, it is possible that CO2 leakages could occur during the injection and sequestration procedure, with significant repercussions for the marine environment. We investigate the effects of acidification derived from possible CO2 leakage events on the European green crab, Carcinus maenas. To this end, a lab-scale experiment involving direct release of CO2 was conducted at pH values between 7.7 and 6.15. Female crabs were exposed for 10 days to sediment collected from two different coastal areas, one with relatively uncontaminated sediment (RSP) and the other with known contaminated sediment (MZ and ML), under the pre-established seawater pH conditions. Survival rate, histopathological damage and metal (Fe, Mn, Cu, Zn, Cr, Cd and Pb) and As accumulation in gills and hepatopancreas tissue were employed as endpoints. In addition, the obtained results were compared with the results of the physico-chemical characterization of the sediments, which included the determination of the metals Fe, Mn, Cu, Zn, Cr, Pb and Cd, the metalloid As, certain polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), as well as nonchemical sediment properties (grain size, organic carbon and total organic matter). Significant associations were observed between pH and the histological damage. Concentrations of Fe, Mn, Cr, Pb, Cd and PAHs in sediment, presented significant negative correlations with the damage to gills and hepatopancreas, and positive correlations with metal accumulation in both tissues. The results obtained in this study reveal the importance of sediment properties in the biological effects caused by possible CO2 leakage. However, a clear pattern was not observed between metal accumulation in tissues and p

  6. Effects of elevated seawater pCO2 on gene expression patterns in the gills of the green crab, Carcinus maenas

    PubMed Central

    2011-01-01

    Background The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3- exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill

  7. Effects of salinity on short-term waterborne zinc uptake, accumulation and sub-lethal toxicity in the green shore crab (Carcinus maenas).

    PubMed

    Niyogi, Som; Blewett, Tamzin A; Gallagher, Trevor; Fehsenfeld, Sandra; Wood, Chris M

    2016-09-01

    Waterborne zinc (Zn) is known to cause toxicity to freshwater animals primarily by disrupting calcium (Ca) homeostasis during acute exposure, but its effects in marine and estuarine animals are not well characterized. The present study investigated the effects of salinity on short-term Zn accumulation and sub-lethal toxicity in the euryhaline green shore crab, Carcinus maenas. The kinetic and pharmacological properties of short-term branchial Zn uptake were also examined. Green crabs (n=10) were exposed to control (no added Zn) and 50μM (3.25mgL(-1)) of waterborne Zn (∼25% of 96h LC50 in 100 seawater) for 96h at 3 different salinity regimes (100%, 60% and 20% seawater). Exposure to waterborne Zn increased tissue-specific Zn accumulation across different salinities. However, the maximum accumulation occurred in 20% seawater and no difference was recorded between 60% and 100% seawater. Gills appeared to be the primary site of Zn accumulation, since the accumulation was significantly higher in the gills relative to the hepatopancreas, haemolymph and muscle. Waterborne Zn exposure induced a slight increase in haemolymph osmolality and chloride levels irrespective of salinity. In contrast, Zn exposure elicited marked increases in both haemolymph and gill Ca levels, and these changes were more pronounced in 20% seawater relative to that in 60% or 100% seawater. An in vitro gill perfusion technique was used to examine the characteristics of short-term (1-4h) branchial Zn uptake over an exposure concentration range of 3-12μM (200-800μgL(-1)). The rate of short-term branchial Zn uptake did not change significantly after 2h, and no difference was recorded in the rate of uptake between the anterior (respiratory) and posterior (ion transporting) gills. The in vitro branchial Zn uptake occurred in a concentration-dependent manner across different salinities. However, the rate of uptake was consistently higher in 20% seawater relative to 60% or 100% seawater - similar to

  8. A novel effect of imidazole derivative KK-42 on increasing survival of Aeromonas hydrophila challenged prawn Macrobrachium nipponense.

    PubMed

    Wang, Wen-Feng; Yang, Hong; Liu, Fang; Chen, Xiang-Li; Lv, Yan-Jie; Ning, Qian-Ji

    2013-01-01

    Imidazole derivative KK-42 is well known as the insect growth regulator. Here we find that KK-42 pretreatment could promote the survival of Macrobrachium nipponense infected with Aeromonas hydrophila, which is considered to be possibly related to the prophenoloxidase (proPO), a conserved copper-containing enzyme that plays an important role in defense against pathogens. In this study, a full-length of proPO gene from M. nipponense haemocytes, designated as MnproPO, was firstly cloned and characterized. The full-length cDNA contained 2428 bp with a 2013 bp open reading frame encoding a putative proPO protein of 671 amino acids with a predicted molecular mass of 76.5 kDa and pI of 7.31. It was predicted to possess all the expected features of proPO members, including two putative copper-binding sites with six histidine residues and a thiol ester-like motif. Sequence analysis showed that MnproPO exhibited the highest amino acid sequence similarity (93%) to a proPO of Macrobrachium rosenbergii. The gene was expressed highly in haemocytes and weakly in hepatopancreas. Real-time PCR analysis revealed that the MnproPO expression increased significantly at 3, 12 and 24 h after KK-42 treatment, the PO activity also importantly rose from 6 to 48 h in KK-42-treated prawns and reached the maximum at 24 h with a 2.3-fold higher than that in control group. Injection of A. hydrophila could stimulate the MnproPO transcription and PO activity whether or not the prawns were pretreated by KK-42, the mRNA level increased obviously only at 3 h and 6 h after the bacterium injection (challenged control), but increased constantly during the phase of experiment except at 6 h under the condition of KK-42 pretreatment (challenged treatment group). The change trend of PO activity was basically similar to that of MnproPO expression. Our present results demonstrate that the MnproPO expression as well as PO activity may be induced by KK-42, which is likely one of the molecular mechanisms of KK

  9. A transcriptomic scan for potential candidate genes involved in osmoregulation in an obligate freshwater palaemonid prawn (Macrobrachium australiense)

    PubMed Central

    Rahi, Md. Lifat; Nguyen, Viet Tuan; Mather, Peter B.; Hurwood, David A.

    2016-01-01

    Background Understanding the genomic basis of osmoregulation (candidate genes and/or molecular mechanisms controlling the phenotype) addresses one of the fundamental questions in evolutionary ecology. Species distributions and adaptive radiations are thought to be controlled by environmental salinity levels, and efficient osmoregulatory (ionic balance) ability is the main mechanism to overcome the problems related to environmental salinity gradients. Methods To better understand how osmoregulatory performance in freshwater (FW) crustaceans allow individuals to acclimate and adapt to raised salinity conditions, here we (i), reviewed the literature on genes that have been identified to be associated with osmoregulation in FW crustaceans, and (ii), performed a transcriptomic analysis using cDNA libraries developed from mRNA isolated from three important osmoregulatory tissues (gill, antennal gland, hepatopancreas) and total mRNA from post larvae taken from the freshwater prawn, Macrobrachium australiense using Illumina deep sequencing technology. This species was targeted because it can complete its life cycle totally in freshwater but, like many Macrobrachium sp., can also tolerate brackish water conditions and hence should have genes associated with tolerance of both FW and saline conditions. Results We obtained between 55.4 and 65.2 million Illumina read pairs from four cDNA libraries. Overall, paired end sequences assembled into a total of 125,196 non-redundant contigs (≥200 bp) with an N50 length of 2,282 bp and an average contig length of 968 bp. Transcriptomic analysis of M. australiense identified 32 different gene families that were potentially involved with osmoregulatory capacity. A total of 32,597 transcripts were specified with gene ontology (GO) terms identified on the basis of GO categories. Abundance estimation of expressed genes based on TPM (transcript per million) ≥20 showed 1625 transcripts commonly expressed in all four libraries. Among the

  10. Light-mediated DNA Repair Prevents UVB-induced Cell Cycle Arrest in Embryos of the Crustacean Macrobrachium olfersi.

    PubMed

    Zeni, Eliane Cristina; Ammar, Dib; Leal, Mayana Lacerda; da Silva, Heloisa Schramm; Allodi, Silvana; Müller, Yara Maria Rauh; Nazari, Evelise Maria

    2015-01-01

    High levels of ultraviolet-B (UVB) radiation can negatively affect aquatic animals. Macrobrachium olfersi is a prawn that lives in clear freshwaters and during the breeding season, females carry eggs in an external brood pouch. Therefore, we hypothesize that eggs are also exposed to environmental UVB radiation. The aim of this study was to investigate whether UVB radiation induces DNA damage and compromises cell cycle in embryos of M. olfersi. In laboratory, UVB irradiance (310 mW. cm(-2) ) that embryos receive in the natural environment was simulated. After irradiation, embryos were kept under different light conditions in order to recognize the presence of cell repair. UVB radiation induces DNA damage, specifically thymine dimers. After 48 h of UVB exposure, a significant decrease in the level of these dimers was observed in embryos kept under visible light while it remained constant in the dark. Moreover, under visible light and darkness, a decrease in proliferation was observed after 48 h of irradiation. An increase in PCNA expression and decrease in p53 expression were observed after, respectively, 1 and 48 h of exposure. Our results showed that UVB radiation disturbs the cell cycle and induces DNA damage in M. olfersi embryos. However, under visible light these embryos showed successful DNA repair.

  11. Gene expression profile analysis of testis and ovary of oriental river prawn, Macrobrachium nipponense, reveals candidate reproduction-related genes.

    PubMed

    Qiao, H; Xiong, Y W; Jiang, S F; Fu, H T; Sun, S M; Jin, S B; Gong, Y S; Zhang, W Y

    2015-03-20

    This study utilized high-throughput RNA sequencing technology to identify reproduction- and development-related genes of Macrobrachium nipponense by analyzing gene expression profiles of testis and ovary. More than 20 million 1 x 51-bp reads were obtained by Illumina sequencing, generating more than 7.7 and 11.7 million clean reads in the testis and ovary library, respectively. As a result, 10,018 unitags were supposed to be differentially expressed genes (DEGs) between ovary and testis. Compared to the ovary library, 4563 (45.5%) of these DEGs exhibited at least 6-fold upregulated expression, while 5455 (54.5%) DEGs exhibited at least 2-fold downregulated expression in the testis. The Gene Ontology (GO) enrichment analysis showed that 113 GO terms had potential molecular functions in reproduction. The Kyoto Encyclopedia of Genes and Genomes results revealed that the most important pathways may be relevant to reproduction and included 7 pathways. Forty-two genes were identified as reproduction-, development-, and sex-related genes based on GO classification and sequence comparison with other publications, including male reproductive-related LIM protein, spermatogenesis-associated protein, gametocyte-specific factor 1, VASA-like protein, vitellogenin, sex-determining protein fem-1, and other potential candidates. These results will advance research in the field of molecular genetics in M. nipponense and offer a valuable resource for further research related to reproduction in crustaceans.

  12. The distribution of APGWamide and RFamides in the central nervous system and ovary of the giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Palasoon, Ronnarong; Panasophonkul, Sasiporn; Sretarugsa, Prapee; Hanna, Peter; Sobhon, Prasert; Chavadej, Jittipan

    2011-06-01

    Immunohistochemistry was used to identify the distribution of both APGWamide-like and RFamide-like peptides in the central nervous system (CNS) and ovary of the mature female giant freshwater prawn, Macrobrachium rosenbergii. APGWamide-like immunoreactivity (ALP-ir) was found only within the sinus gland (SG) of the eyestalk, in small- and medium-sized neurons of cluster 4, as well as their varicosed axons. RFamide-like immunoreactivity (RF-ir) was detected in neurons of all neuronal clusters of the eyestalk and CNS, except clusters 1 and 5 of the eyestalk, and dorsal clusters of the subesophageal, thoracic, and abdominal ganglia. The RF-ir was also found in all neuropils of the CNS and SG, except the lamina ganglionaris. These immunohistochemical locations of the APGWamide-like and RF-like peptides in the eyestalk indicate that these neuropeptides could modulate the release of the neurohormones in the sinus gland. The presence of RFamide-like peptides in the thoracic and abdominal ganglia suggests that it may act as a neurotransmitter which controls muscular contractions. In the ovary, RF-ir was found predominantly in late previtellogenic and early vitellogenic oocytes, and to a lesser degree in late vitellogenic oocytes. These RFs may be involved with oocyte development, but may also act with other neurohormones and/or neurotransmitters within the oocyte in an autocrine or paracrine manner.

  13. Antioxidant response and oxidative stress levels in Macrobrachium borellii (Crustacea: Palaemonidae) exposed to the water-soluble fraction of petroleum.

    PubMed

    Lavarías, S; Heras, H; Pedrini, N; Tournier, H; Ansaldo, M

    2011-05-01

    The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarbons (WSF) on the antioxidant status of the freshwater prawn Macrobrachium borellii. First, seasonal variations were studied in a non-polluted area. Hepatopancreas and gills showed season-related fluctuations in catalase (CAT), glutathione-S-transferase (GST) activities and in lipid peroxidation levels (LPO), but not in superoxide dismutase (SOD). Then, adults were exposed semi-statically to sublethal doses for 7days. CAT, SOD, GST, and glutathione peroxidase (GPx) activities and LPO, reduced glutathione (GSH) and protein oxidation (PO) levels were determined. Exposed individuals showed significant increases in CAT, SOD, and GST activities in hepatopancreas and CAT activity in gills. GPx activity did not vary in either tissues. While LPO levels increased, GSH levels decreased significantly in hepatopancreas of exposed animals, but PO levels showed no variation. Induction of SOD was also assessed by Real-time PCR mRNA expression in hepatopancreas. The non-enzymatic antioxidant activity was also tested; ABTS 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) was higher in hemolymph of treated-prawns compared to controls, but ferric reducing activity of plasma assay (FRAP) values did not change. Taken together, the present results indicated that the antioxidant defenses of M. borellii, mainly in hepatopancreas, were significantly affected by aquatic hydrocarbon contamination, regardless of the season.

  14. In silico Neuropeptidome of Female Macrobrachium rosenbergii Based on Transcriptome and Peptide Mining of Eyestalk, Central Nervous System and Ovary

    PubMed Central

    Wang, Tianfang; Zhao, Min; Elizur, Abigail; Sretarugsa, Prapee; Cummins, Scott F.; Sobhon, Prasert

    2015-01-01

    Macrobrachium rosenbergii is the most economically important of the cultured freshwater crustacean species, yet there is currently a deficiency in genomic and transcriptomic information for research requirements. In this study, we present an in silico analysis of neuropeptide genes within the female M. rosenbergii eyestalk, central nervous system, and ovary. We could confidently predict 37 preproneuropeptide transcripts, including those that encode bursicons, crustacean cardioactive peptide, crustacean hyperglycemic hormones, eclosion hormone, pigment-dispersing hormones, diuretic hormones, neuropeptide F, neuroparsins, SIFamide, and sulfakinin. These transcripts are most prominent within the eyestalk and central nervous system. Transcript tissue distribution as determined by reverse transcription-polymerase chain reaction revealed the presence of selected neuropeptide genes of interest mainly in the nervous tissues while others were additionally present in the non-nervous tissues. Liquid chromatography-mass spectrometry analysis of eyestalk peptides confirmed the presence of the crustacean hyperglycemic hormone precursor. This data set provides a strong foundation for further studies into the functional roles of neuropeptides in M. rosenbergii, and will be especially helpful for developing methods to improve crustacean aquaculture. PMID:26023789

  15. Molecular cloning, characterization and gene expression of an antioxidant enzyme catalase (MrCat) from Macrobrachium rosenbergii.

    PubMed

    Arockiaraj, Jesu; Easwvaran, Sarasvathi; Vanaraja, Puganeshwaran; Singh, Arun; Othman, Rofina Yasmin; Bhassu, Subha

    2012-05-01

    In this study, we reported a full length of catalase gene (designated as MrCat), identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrCat is 2504 base pairs in length, and encodes 516 amino acids. The MrCat protein contains three domains such as catalase 1 (catalase proximal heme-ligand signature) at 350-358, catalase 2 (catalase proximal active site signature) at 60-76 and catalase 3 (catalase family profile) at 20-499. The mRNA expressions of MrCat in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). The MrCat is highly expressed in digestive tract and all the other tissues (walking leg, gills, muscle, hemocyte, hepatopancreas, pleopods, brain and eye stalk) of M. rosenbergii taken for analysis. The expression is strongly up-regulated in digestive tract after IHHNV challenge. To understand its biological activity, the recombinant MrCat gene was constructed and expressed in Escherichia coli BL21 (DE3). The recombinant MrCat existed in high thermal stability and broad spectrum of pH, which showed over 95% enzyme activity between pH 5 and 10.5, and was stable from 40 °C to 70 °C, and exhibited 85-100% enzyme activity from 30 °C to 40 °C.

  16. The key molecular events during Macrobrachium rosenbergii nodavirus (MrNV) infection and replication in Sf9 insect cells.

    PubMed

    Somrit, Monsicha; Watthammawut, Atthaboon; Chotwiwatthanakun, Charoonroj; Weerachatyanukul, Wattana

    2016-09-02

    In this study we demonstrated that Macrobrachium rosenbergii nodavirus (MrNV) was able to internalize and replicate in Sf9 insect cells, with levels of infection altered by substances affecting the caveolin-(CAV) mediated endocytosis pathway. The use of Sf9 cells for efficient MrNV replication and propagation was demonstrated by confocal microscopy and PCR amplification, through which early viral binding and internalization were initially detectable at 30min post-infection; whereas at 72h, the distinguishable sign of late-MrNV infection was observable as the gradual accumulation of a cytopathic effect (CPE) in the cells, ultimately resulting in cellular disruption. Moreover, during the early period of infection, the MrNV signals were highly co-localized with CAV1 signals of the CAV-mediated endocytosis pathway. The use of genistein as an inhibitor of the CAV-mediated endocytosis pathway significantly reduced MrNV and CAV1 co-localization, and also reduced the levels of MrNV infection in Sf9 cells as shown by PCR and ELISA. Moreover, the addition of the pathway agonist okadaic acid not only recovered but also augmented both the levels of MrNV co-localization with CAV1 and of Sf9 infection in the presence of genistein inhibition; therefore demonstrating that MrNV infection in Sf9 cells was associated with the CAV-mediated endocytosis pathway machinery.

  17. Regulation of essential heavy metals (Cu, Cr, and Zn) by the freshwater prawn macrobrachium malcolmsonii (Milne Edwards)

    SciTech Connect

    Vijayram, K.; Geraldine, P.

    1996-02-01

    Despite the low concentrations of heavy metals in the surrounding medium, aquatic organisms take them up and accumulate them in their soft tissues to concentrations several fold higher than those of ambient levels. Knowledge of accumulation patterns of a particular trace metal is a prerequisite for understanding the significance of an observed metal concentration in a particular animal, especially from the aspect of biomonitoring. Many marine invertebrates accumulate heavy metals without any regulation and the accumulation necessarily being associated with mechanisms to store the metals in a detoxified form. Two detoxification mechanisms have been described, both of which may occur in one specimen. Heavy metals can either be bound up in insoluble metalliferous {open_quote}granules{close_quote}, or are bound to soluble metal-binding ligands, such as metallothioneins. Some marine decapod crustaceans have an innate ability to regulate the internal concentrations of essential but potentially toxic metals within a constant level, presumably to meet their metabolic demands. However, at present, there is no such information relating to freshwater decapod crustaceans, especially shrimps which occupy a totally different environment. Macrobrachium malcolmsonii, a potential aquaculture species for freshwater is found in abundance in one of the major Indian rivers, the Cauvery. In the present study, an attempt was made to determine whether the freshwater prawn, M. malcolmsonlii, is able to regulate the three essential elements, copper, chromium and zinc, over a wide range of dissolved concentrations. These three metals were chosen because the Cauvery River receives pollutants containing these metals.

  18. Nutrients budget and effluents characteristics in polyculture of scampi (Macrobrachium rosenbergii) and Indian major carps ponds using organic inputs.

    PubMed

    Adhikari, Subhendu; Sahu, Bharat Chandra; Dey, Lambodar

    2012-01-01

    Experiments were conducted for the study of nutrient budget in farmers' ponds (0.4-0.6 ha) in Orissa, India, at stocking densities of 0.30-0.38/m(2) for scampi (Macrobrachium rosenbergii) and 0.60-0.70/m(2) for Indian major carps (Catla catla, Labeo rohita and Cirrhinus mrigala). The average initial body weights of scampi and the major carps were 0.02 and 8-10 g, respectively. The culture period was 272-292 days. Feed was the main input. The FCR (feed conversion ratio) varied from 1.78 to 1.83. Feed and cow dung were applied to these ponds as organic inputs. At harvest time, the average weight of scampi and carps varied from 73 to 92 g and from 718 to 820 g, respectively. Among all the inputs, feed alone accounted for 97.60% total nitrogen (N), 97.90% total phosphorus (P) and 94.72% total organic carbon (OC), respectively. The harvest of scampi and carps accounted for recovery of 52.45% N, 19.43% P and 18.12% OC, respectively. N, P and OC accumulated in sediment were 38.31, 71.40 and 69.50%, respectively. The median nutrient loads in the fish pond effluents were equivalent to 0.58 kg of inorganic N, 0.135 kg of P and 8.83 kg of total OC per ton of Indian major carps and scampi production.

  19. Feeding and larval growth of an exotic freshwater prawn Macrobrachium equidens (Decapoda: Palaemonidae), from Northeastern Pará, Amazon Region.

    PubMed

    Gomes, Jean N; Abrunhosa, Fernando A; Costa, Anne K; Maciel, Cristiana R

    2014-09-01

    In the present study, we carried out experiments on the diet of the freshwater prawn Macrobrachium equidens. We tested which type of food and which density of food is suitable for larval development. For the experiment on the type of food, eight treatments were carried out: (I) starvation, (AL) microalgae, (RO) rotifers, (AN) Artemia, (RO + AN) rotifers + Artemia, (AL + RO) microalgae + rotifers, (AL + AN) microalgae + Artemia, (AL + RO + AN) microalgae + rotifers + Artemia. For the experiment on the density of food, we used the type of food, which had resulted in a high survival rate in the previous experiment. Three treatments were carried out: 4, 8 and 16 Artemia nauplii /mL. The rate of feeding during larval development was observed. The survival, weight and percentage of juveniles of each feeding experiment were determined. We found that larvae are carnivores; however, they have requirements with respect to the type of food, because larvae completed their cycle from the zoeal to the juvenile stage only when Artemia nauplii were available. We also verified that the larvae feed mainly during the day-time, and are opportunistic with respect to the density of food offered.

  20. Molecular characterization of a novel ovary-specific gene fem-1 homolog from the oriental river prawn, Macrobrachium nipponense.

    PubMed

    Ma, Ke-Yi; Liu, Zhi-Qiang; Lin, Jing-Yun; Li, Jia-Le; Qiu, Gao-Feng

    2016-01-10

    The feminization-1 (fem-1) gene is characterized by one of the most common protein-protein interaction motifs, ankyrin repeat motifs, displays many expression patterns in vertebrates and invertebrates, and plays an essential role in the sex-determination/differentiation pathway in Caenorhabditis elegans. In this study, a fem-1 homolog, designated as Mnfem-1, was first cloned from the oriental river prawn Macrobrachium nipponense. The prawn Mnfem-1 gene consists of six exons and five introns. The full-length cDNA (2603bp) of Mnfem-1 contains an open reading frame (ORF) encoding a protein of 622 amino acids. The Mnfem-1 RNA and protein are exclusively expressed in the ovary in adult prawns as revealed by RT-PCR and immunofluorescence analysis, respectively. In situ hybridization results showed that strong positive signals were concentrated at the edge of the previtellogenic and vitellogenic oocyte. During embryogenesis, Mnfem-1 is highly expressed in both unfertilized eggs and embryos at cleavage stage and thereafter dropped to a low level from blastula to zoea, indicating that the Mnfem-1 in early embryos is maternal. After hatching, the Mnfem-1 expression significantly increased in the larvae at length of 2cm, an important stage of sex differentiation. Yeast two hybridization results showed that the Mnfem-1 protein can be potentially interactive with cathepsin L and proteins containing the domains of insulinase, ankyrin or ubiquitin. Our results suggested that Mnfem-1 could have roles in prawn ovarian development and sex determination/differentiation.

  1. Molecular analysis of the freshwater prawn Macrobrachium olfersii (Decapoda, Palaemonidae) supports the existence of a single species throughout its distribution.

    PubMed

    Rossi, Natália; Mantelatto, Fernando Luis

    2013-01-01

    Macrobrachium olfersii is an amphidromous freshwater prawn, widespread along the eastern coasts of the Americas. This species shows great morphological modifications during ontogenesis, and several studies have verified the existence of a wide intraspecific variation. Because of this condition, the species is often misidentified, and several synonyms have been documented. To elucidate these aspects, individuals of M. olfersii from different populations along its range of distribution were investigated. The taxonomic limit was established, and the degree of genetic variability of this species was described. We extracted DNA from 53 specimens of M. olfersii, M. americanum, M. digueti and M. faustinum, which resulted in 84 new sequences (22 of 16S mtDNA, 45 of Cythocrome Oxidase I (COI) mtDNA, and 17 of Histone (H3) nDNA). Sequences of three genes (single and concatenated) from these species were used in the Maximum Likelihood and Bayesian Inference phylogenetic analyses and COI sequences from M. olfersii were used in population analysis. The genetic variation was evaluated through the alignment of 554 bp from the 16S, 638 bp from the COI, and 338 bp from the H3. The rates of genetic divergence among populations were lower at the intraspecific level. This was confirmed by the haplotype net, which showed a continuous gene flow among populations. Although a wide distribution and high morphological intraspecific variation often suggest the existence of more than one species, genetic similarity of Caribbean and Brazilian populations of M. olfersii supported them as a single species.

  2. Molecular Analysis of the Freshwater Prawn Macrobrachium olfersii (Decapoda, Palaemonidae) Supports the Existence of a Single Species throughout Its Distribution

    PubMed Central

    Rossi, Natália; Mantelatto, Fernando Luis

    2013-01-01

    Macrobrachium olfersii is an amphidromous freshwater prawn, widespread along the eastern coasts of the Americas. This species shows great morphological modifications during ontogenesis, and several studies have verified the existence of a wide intraspecific variation. Because of this condition, the species is often misidentified, and several synonyms have been documented. To elucidate these aspects, individuals of M. olfersii from different populations along its range of distribution were investigated. The taxonomic limit was established, and the degree of genetic variability of this species was described. We extracted DNA from 53 specimens of M. olfersii, M. americanum, M. digueti and M. faustinum, which resulted in 84 new sequences (22 of 16S mtDNA, 45 of Cythocrome Oxidase I (COI) mtDNA, and 17 of Histone (H3) nDNA). Sequences of three genes (single and concatenated) from these species were used in the Maximum Likelihood and Bayesian Inference phylogenetic analyses and COI sequences from M. olfersii were used in population analysis. The genetic variation was evaluated through the alignment of 554 bp from the 16S, 638 bp from the COI, and 338 bp from the H3. The rates of genetic divergence among populations were lower at the intraspecific level. This was confirmed by the haplotype net, which showed a continuous gene flow among populations. Although a wide distribution and high morphological intraspecific variation often suggest the existence of more than one species, genetic similarity of Caribbean and Brazilian populations of M. olfersii supported them as a single species. PMID:23382941

  3. Effect of feeding Bacillus sp. as probiotic bacteria on growth of giant freshwater prawn (Macrobrachium rosenbergii de Man).

    PubMed

    Deeseenthum, Sirirat; Leelavatcharamas, Vichai; Brookes, John D

    2007-05-01

    The effects of feeding two Bacillus spp. isolated from the intestine of the giant freshwater prawn on the growth of Giant Freshwater Prawns (Macrobrachium rosenbergii de Man) was examined. The isolated Bacillus KKU02 and Bacillus KKU03 (approximately 10(7) CFU mL(-1)) were mixed into commercial prawn feed (200 mL kg(-1)). After rearing shrimp with the bacteria in four feed treatments, (Bacillus KKU03, Bacillus KKU02, mixed culture and control groups) for 120 days, body length and weight of the prawns in mixed culture tanks were significantly higher (p = 0.05) than in the control tanks (7.48 cm and 3.32 g, vs 6.6 cm and 2.1 g, respectively). Both isolates were found to produce amylase and protease. The stabilities of the single Bacillus sp., mixed culture and commercial probiotic in the feeds were examined during storage at 4 degrees C and room temperature. The percentage viability of Bacillus KKU02, Bacillus KKU03 and mixed culture stored at room temperature declined dramatically to 2.54, 21.88 and 10.92% within 2 weeks, respectively. At 4 degrees C however, the percentage viability of the tested probiotics reduced slowly. The survival of the commercial probiotics was the same at both temperatures about 50% after 70 days' storage.

  4. Effects of (60)Co gamma irradiation on behavior and gill histoarchitecture of giant fresh water prawn Macrobrachium rosenbergii (DE MAN).

    PubMed

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-babu, P

    2013-06-01

    Present study was designed to observe the effects of (60)Co gamma radiation in behavioral and histological changes in the gills of giant fresh water prawn Macrobrachium rosenbergii. The adult prawns were irradiated with four different dose levels (3mGy, 30mGy, 300mGy and 3000mGy) and the control group (without irradiation) was maintained separately. Behavioral changes like hyperactivity, loss of balance, reduced swimming rate, slower rate of food intake and convulsions were observed in higher dose levels of 300mGy and 3000mGy. The histological alterations such as accumulated haemocytes in haemocoelic spaces, abnormal gill tips, lifted lamellar epithelium, swollen and fused lamellae, hyperplasic, necrotic, clavate-globate and complete disorganization of lamellae were observed in (60)Co gamma irradiated prawns. Significantly more considerable histological alterations were observed in the highest dose level of 3000mGy, but no mortality was evidenced. This study serves as biomonitoring tool to assess the radiation pollution in the aquatic environment. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Identification and function analysis of ras-related nuclear protein from Macrobrachium rosenbergii involved in Spiroplasma eriocheiris infection.

    PubMed

    Ning, Mingxiao; Xiu, Yunji; Yuan, Meijun; Bi, Jingxiu; Liu, Min; Wei, Panpan; Yan, Yuye; Gu, Wei; Wang, Wen; Meng, Qingguo

    2017-09-19

    A ras-related nuclear protein (Ran) protein was obtained from Macrobrachium rosenbergii, named MrRan. Phylogenetic analysis results showed that MrRan was clustered in one group together with other crustaceans. Tissue distribution analysis revealed that MrRan was expressed mainly in gill, intestine and stomach, and expressed weakly in muscle. The MrRan expression levels in gill and hemocyte of prawns were significantly up-regulated after challenged by Spiroplasma eriocheiris. The copy number of S. eriocheiris in MrRan dsRNA injection group was significantly less than control groups during infection. Meanwhile, silencing MrRan obviously increased the survival rate of prawns. The subcellular localization experiment suggested that recombinant MrRan was mainly located in the nucleus, and relatively weak in the cytoplasm. Finally, over-expression in Drosophila S2 cell indicated that MrRan could increase copies of S. eriocheiris and decrease of cell viability. The present study suggested that MrRan participated in regulating the phagocytosis of S. eriocheiris in M. rosenbergii. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Candidate genes that have facilitated freshwater adaptation by palaemonid prawns in the genus Macrobrachium: identification and expression validation in a model species (M. koombooloomba)

    PubMed Central

    Amin, Shorash; Mather, Peter B.; Hurwood, David A.

    2017-01-01

    Background The endemic Australian freshwater prawn, Macrobrachium koombooloomba, provides a model for exploring genes involved with freshwater adaptation because it is one of the relatively few Macrobrachium species that can complete its entire life cycle in freshwater. Methods The present study was conducted to identify potential candidate genes that are likely to contribute to effective freshwater adaptation by M. koombooloomba using a transcriptomics approach. De novo assembly of 75 bp paired end 227,564,643 high quality Illumina raw reads from 6 different cDNA libraries revealed 125,917 contigs of variable lengths (200–18,050 bp) with an N50 value of 1597. Results In total, 31,272 (24.83%) of the assembled contigs received significant blast hits, of which 27,686 and 22,560 contigs were mapped and functionally annotated, respectively. CEGMA (Core Eukaryotic Genes Mapping Approach) based transcriptome quality assessment revealed 96.37% completeness. We identified 43 different potential genes that are likely to be involved with freshwater adaptation in M. koombooloomba. Identified candidate genes included: 25 genes for osmoregulation, five for cell volume regulation, seven for stress tolerance, three for body fluid (haemolymph) maintenance, eight for epithelial permeability and water channel regulation, nine for egg size control and three for larval development. RSEM (RNA-Seq Expectation Maximization) based abundance estimation revealed that 6,253, 5,753 and 3,795 transcripts were expressed (at TPM value ≥10) in post larvae, juveniles and adults, respectively. Differential gene expression (DGE) analysis showed that 15 genes were expressed differentially in different individuals but these genes apparently were not involved with freshwater adaptation but rather were involved in growth, development and reproductive maturation. Discussion The genomic resources developed here will be useful for better understanding the molecular basis of freshwater adaptation in

  7. Application of high resolution melt (HRM) analysis for duplex detection of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) in shrimp.

    PubMed

    Senapin, Saengchan; Molthathong, Sudkhate; Phiwsaiya, Kornsunee; Jaengsanong, Chatlada; Chuchird, Niti

    2010-10-01

    In this work, a probe-free, multiplex RT-PCR was combined with high resolution melt (HRM) analysis for the simultaneous detection of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) infection in the freshwater prawn Macrobrachium rosenbergii. This first application of HRM multiplex RT-PCR in shrimp reveals a new potential for rapid and sensitive detection of multiple pathogens. In addition, sequence variation in XSV could be observed from the high resolution melt peaks, as confirmed by sequence analysis. In 19 field samples of the freshwater prawn M. rosenbergii the technique revealed samples negative for both viruses, positive for both viruses or positive for MrNV alone. No sample was found positive for XSV alone. Comparison of these results to those obtained using the same samples in analysis by traditional nested RT-PCR combined with gel electrophoresis revealed that HRM multiplex RT-PCR was more sensitive. Thus, the latter technique allows for rapid and sensitive, simultaneous detection of MrNV and XSV and also has the potential to be adapted for simultaneous detection of other mixed viral infections in shrimp.

  8. Molecular characterization and upregulation of cytosolic manganese superoxide dismutase by imidazole derivative KK-42 in Macrobrachium nipponense.

    PubMed

    Wang, W F; Mu, L M; Wu, X S; Yang, H; Ning, Q J

    2016-08-29

    Imidazole derivative KK-42 is a well-known regulator of insect growth. KK-42 pretreatment has been shown to promote the survival of Macrobrachium nipponense infected with Aeromonas hydrophila, possibly via activation of superoxide dismutase (SOD). In this study, the cytMnSOD gene was cloned from the hepatopancreas of M. nipponense using the rapid amplification of cDNA ends technique. The full-length cDNA of cytMnSOD was 1233 bp long, and the open reading frame was 858 bp long, encoding a 286-aa protein with a 60-aa leader sequence. The calculated molecular mass of the translated cytMnSOD protein was 31.33 kDa, with an estimated isoelectric point of 5.62. cytMnSOD contained two N-glycosylation sites, four conserved amino acids responsible for binding manganese, and a manganese SOD domain (DVWEHAYY). Real-time RT-PCR analysis showed that cytMnSOD was expressed in all tissues examined with the highest expression observed in the hepatopancreas. Levels of the cytMnSOD transcript in the hepatopancreas were highest in stage C of the molting cycle. Real-time PCR analysis revealed that cytMnSOD expression increased significantly 3, 6, and 12 h after KK-42 treatment, with simultaneous increases in SOD activity from 6 to 12 h. Our results demonstrate that cytMnSOD expression and SOD activity may be induced by KK-42, which may represent one of the molecular mechanisms through which KK-42 promotes increased survival of prawns infected with A. hydrophila.

  9. Subcellular localization and kinetic characterization of a gill (Na+, K+)-ATPase from the giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    França, Juliana L; Pinto, Marcelo R; Lucena, Malson N; Garçon, Daniela P; Valenti, Wagner C; McNamara, John C; Leone, Francisco A

    2013-07-01

    The stimulation by Mg(2+), Na(+), K(+), NH4 (+), and ATP of (Na(+), K(+))-ATPase activity in a gill microsomal fraction from the freshwater prawn Macrobrachium rosenbergii was examined. Immunofluorescence labeling revealed that the (Na(+), K(+))-ATPase α-subunit is distributed predominantly within the intralamellar septum, while Western blotting revealed a single α-subunit isoform of about 108 kDa M r. Under saturating Mg(2+), Na(+), and K(+) concentrations, the enzyme hydrolyzed ATP, obeying cooperative kinetics with V(M) = 115.0 ± 2.3 U mg(-1), K(0.5) = 0.10 ± 0.01 mmol L(-1). Stimulation by Na(+) (V(M) = 110.0 ± 3.3 U mg(-1), K(0.5) = 1.30 ± 0.03 mmol L(-1)), Mg(2+) (V(M) = 115.0 ± 4.6 U mg(-1), K(0.5) = 0.96 ± 0.03 mmol L(-1)), NH4 (+) (V(M) = 141.0 ± 5.6 U mg(-1), K(0.5) = 1.90 ± 0.04 mmol L(-1)), and K(+) (V(M) = 120.0 ± 2.4 U mg(-1), K(M) = 2.74 ± 0.08 mmol L(-1)) followed single saturation curves and, except for K(+), exhibited site-site interaction kinetics. Ouabain inhibited ATPase activity by around 73% with K(I) = 12.4 ± 1.3 mol L(-1). Complementary inhibition studies suggest the presence of F0F1-, Na(+)-, or K(+)-ATPases, but not V(H(+))- or Ca(2+)-ATPases, in the gill microsomal preparation. K(+) and NH4(+) synergistically stimulated enzyme activity (≈25%), suggesting that these ions bind to different sites on the molecule. We propose a mechanism for the stimulation by both NH4(+), and K(+) of the gill enzyme.

  10. Comparative transcriptome analysis reveals molecular strategies of oriental river prawn Macrobrachium nipponense in response to acute and chronic nitrite stress.

    PubMed

    Xu, Zhixin; Li, Tongyu; Li, Erchao; Chen, Ke; Ding, Zhili; Qin, Jian G; Chen, Liqiao; Ye, Jinyun

    2016-01-01

    Macrobrachium nipponense is an economically and nutritionally important species threatened by ambient superfluous nitrite. De novo RNA-Seq was used to explore the molecular mechanism in M. nipponense exposed to the acute nitrite stress (26.05 mg/L nitrite-N) for 24 h and the chronic nitrite stress (1.38 mg/L nitrite-N) for 28 d A total of 175.13 million reads were obtained and assembled into 58,871 unigenes with an average length of 1028.7 bp and N50 of 1294 bp. Under the acute and chronic nitrite stress trials, 2824 and 2610 unigenes were significantly expressed. In GO analysis and KEGG pathway analysis, 30 pathways were significantly different between the two treatments while four pathways were in common and the markedly altered pathways were divided into four sections as immunity, metabolism, cell and others. The immunity section revealing the different depth of immunity provoked by nitrite stress contained the most pathways including the important pathways as phagosome, folate biosynthesis, glycerolipid metabolism, glycine, serine and threonine metabolism, amino sugar and nucleotide sugar metabolism under the acute nitrite stress, and lysosome, alanine, aspartate and glutamate metabolism, arginine and proline metabolism under the chronic nitrite stress. This is the first report of responses of M. nipponense under acute and chronic nitrite stress through de novo transcriptome sequencing on the transcriptome level. The results of transcriptome analysis improve our understanding on the underlying molecular mechanisms coping with nitrite stress in crustacean species.

  11. Impact of TBT on the vitellogenesis and sex hormones in freshwater prawn Macrobrachium rosenbergii (De Man, 1879)

    PubMed Central

    2013-01-01

    Background Tributyltin (TBT) is a ubiquitous persistent xenobiotic that can be found in freshwater, estuarine and marine ecosystem. TBT is a strong endocrine disrupting compound (EDC) that can cause toxic threat to aquatic organisms. Imposex, sexual deformities and endocrine dysfunctions are the causes of TBT to most of the aquatic organisms. Effect of TBT on the vitellogenesis and sex hormonal changes in Macrobrachium rosenbergii has never been reported. Hence, the present investigation was undertaken to find out the impact of TBT on histological changes in the different reproductive tissues, sex hormonal alterations and level of biomarkers like vitellogenin and vitellin in M. rosenbergii. Results The present investigation documents the possible impact of tributyltin (TBT) on the vitellogenesis in freshwater female prawn M. rosenbergii. TBT at 10 ng/l, 100 ng/l and 1000 ng/l concentrations were exposed individually to prawns for a period of three months. At higher concentration of 1000 ng/l, the ovarian development was arrested and ovary remained at spent stage. At lower concentration of TBT (10 ng/l), the development proceeded up to early vitellogenic stage. At intermediate concentration of 100 ng/l TBT, the ovary remained at pre vitellogenic stage and thereafter no development was noticed. Histological results indicated the normal ovarian development with vitellogenic oocytes, filled with yolk globules in control prawn. On the other hand, the TBT treated groups showed reduction in yolk globules, fusion of developing oocytes and abundance of immature oocytes. Immunofluorescence staining denoted the remarkable reduction in vitellin content in ovary of TBT treated prawn. Hence, TBT had conspicuously inhibited the vitellogenesis by causing hormonal imbalance in M. rosenbergii. Conclusion TBT had notably inhibited the vitellogenesis due to hormonal imbalance. This endocrine dysfunction ultimately impaired the oogenesis in the freshwater female prawn M

  12. The hot-water extract of leaves of noni, Morinda citrifolia, promotes the immunocompetence of giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Marisa Halim, Atika; Lee, Pai-Po; Chang, Zhong-Wen; Chang, Chin-Chyuan

    2017-05-01

    The hot-water Morinda citrifolia leaf extract (HMLE) was prepared for in vitro assessment on phenoloxidase (PO) activity, respiratory bursts (RBs), and phagocytic activity (PA). Furthermore, the HMLE was administrated in the diet at 0.6, 3, and 6 g (kg diet)(-1) for Macrobrachium rosenbergii, and the potential effects on the immunocompetence of prawns were evaluated. PO activity, RBs, and PA in hemocytes incubated with the HMLE at 140, 20, 20, and 140 mg l(-1) significantly increased. The immune parameters of the total hemocyte count (THC), differential hemocyte count (DHC), RBs, PO activity, superoxide dismutase (SOD) activity, PA, transglutaminase (TG) activity and hemolymph clotting time were evaluated before and after 1, 3, 5, 7, and 9 weeks of the feeding trial. During 9 weeks of the feeding trial, higher THCs, DHCs, RBs, PO, and TG as well as accelerated clotting times were observed in prawns fed HMLE-containing diets at 0.6 g kg(-1). The mRNA expressions of prophenoloxidase, TG, crustin, and lysozyme of prawns fed HMLE-containing diets at 0.6 g kg(-1) for 9 weeks of the feeding trial significantly increased. The susceptibility of prawns fed the HMLE at 0.6 g kg(-1) to Lactococcus garvieae infection significantly decreased, and the relative survival percentage was 23.1%. We therefore found that HMLE administrated through the diet at 0.6 g kg(-1) was capable of enhancing the immunity and resistance against L. garvieae in M. rosenbergii. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Identification of a Macrobrachium nipponense C-type lectin with a close evolutionary relationship to vertebrate lectins.

    PubMed

    Huang, Xin; Li, Tingting; Jin, Min; Yin, Shaowu; Wang, Wen; Ren, Qian

    2017-07-01

    C-type lectins (CTLs) are involved in the innate immune defense of vertebrates and invertebrates against invading pathogens. This study cloned and characterized a novel C-type lectin (MnCTL) of the oriental river prawn, Macrobrachium nipponense. The cloned MnCTL cDNA encompasses an open reading frame of 774 nucleotides and encodes polypeptides of 257 residues. The deduced MnCTL protein contains a single carbohydrate recognition domain (CRD) with an EPN (Glu-Pro-Asn) motif in calcium-binding site 2. Phylogenetic analysis indicated that MnCTL has a closer evolutionary relationship with vertebrate lectins than with invertebrate lectins. Tissue expression analysis showed that high levels of MnCTL are ubiquitously distributed in the gills and stomach of M. nipponense. Quantitative real-time RT-PCR (qRT-PCR) analysis showed that MnCTL expression was up-regulated by bacteria or white spot syndrome virus (WSSV) challenge. Knock-down of the MnCTL gene in WSSV-challenged prawns significantly decreased MnALF1 and MnALF2 transcript levels. The recombinant MnCRD (rMnCRD) agglutinated both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Vibrio parahaemolyticus) in the presence of calcium. Furthermore, rMnCRD could bind to all the tested bacteria with different activities. The sugar-binding assay showed that rMnCRD was able to bind lipopolysaccharide and peptidoglycan in a concentration-dependent manner. In addition, rMnCRD could accelerate bacterial clearance. On the contrary, MnCTL silencing by dsRNA interference could weaken the bacterial clearance ability. All these findings implicated MnCTL were involved in the antiviral and antibacterial innate immunity of M. nipponense. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Molecular cloning, characterization, and expression analysis of two different types of lectins from the oriental river prawn, Macrobrachium nipponense.

    PubMed

    Xiu, Yunji; Wang, Yinghui; Jing, Yunting; Qi, Yakun; Ding, Zhengfeng; Meng, Qingguo; Wang, Wen

    2015-08-01

    Lectins, which are widely expressed in invertebrates, play important roles in many biological processes, including protein trafficking, cell signaling, pathogen recognition, as effector molecules, and so on (Wang and Wang, 2013). This study identified one novel M-type lectin and one L-Type lectin, designated as MnMTL1 and MnLTL1, from the oriental river prawn Macrobrachium nipponense. The full-length cDNA of MnMTL1 was 2064 bp with a 1761 bp ORF encoding a putative protein of 586 deduced amino acids. The full-length cDNA of MnLTL1 was 1744 bp with a 972 bp ORF encoding a 323-amino acid peptide. The deduced MnMTL1 protein contained a putative type II transmembrane region and a 440-aa Glycoside hydrolase family 47 (GH47) domain. One luminal carbohydrate recognition domain and a 23-aa type I transmembrane region were identified from the MnLTL1. MnMTL1 shared 78% identity with Marsupenaeus japonicus M-type lectin and MnLTL1 shared 83% similarity with M. japonicus L-type lectin. RT-PCR analysis showed that MnMTL1 and MnLTL1 were expressed in all tested tissues. Quantitative real-time PCR analysis revealed that MnMTL1 and MnLTL1 are substantially fluctuant during Aeromonas hydrophila and Aeromonas veronii infections. Based on immune responses and previous literature, we assumed that MnMTL1 and MnLTL1 might be functioned as pattern recognition receptors and play important roles in the immune response of M. nipponense. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Phylogeography and genetic structure of the oriental river prawn Macrobrachium nipponense (Crustacea: Decapoda: Palaemonidae) in East Asia

    PubMed Central

    Chu, Ta-Jen; Lee, Ying-Chou

    2017-01-01

    The oriental river prawn (Macrobrachium nipponense) is mainly distributed in East Asia. The phylogeography, population genetic structure and historical demography of this species in the East Asia were examined by using partial sequences of the cytochrome oxidase subunit I (COI) and 16S rRNA in mitochondrial DNA. Ten populations that included 239 individuals were collected from Taiwan (Shihmen Reservoir, SMR, Mingte Reservoir, MTR and Chengching Lake Reservoir, CLR), mainland China (Taihu Lake, TLC, Min River, MRC, Jiulong River, JRC and Shenzhen Reservoir, SRC), Japan (Biwa Lake, BLJ and Kasumigaura Lake, KLJ) and Korea (Han River, HRK). The nucleotide diversity (π) of all individuals was 0.01134, with values ranging from 0.0089 (BLJ, Japan) to 0.01425 (MTR, Taiwan). A total of 83 haplotypes were obtained, and the haplotypes were divided into 2 main lineages: lineage A included the specimens from BLJ, KLJ, CLR, MTR, TLC, MRC and JRC, and lineage B comprised the ones from HRK, SRC, SMR, MTR, TLC, MRC and JRC. Lineage A could be further divided two sub-lineages (A1 and A2). Individuals of lineage A2 were only from TLC. Demographic expansion was observed in each lineage, starting within the second-to-latest interglacial period for lineage A and within the last glacial period for lineage B. All FST values among the ten populations were significantly different, except for the values between MRC and JRC, and SMR and SRC. The phylogeography and genetic structure of M. nipponense in East Asia might be influenced by Pleistocene glacial cycles, lake isolation and human introduction. The possible dispersal routes of M. nipponense in the East Asia were also discussed. PMID:28267807

  16. Molecular Cloning, Characterization, and mRNA Expression of Hemocyanin Subunit in Oriental River Prawn Macrobrachium nipponense

    PubMed Central

    Kong, Youqin; Ding, Zhili; Sun, Shengming; Wang, Ligai; Ye, Jinyun

    2016-01-01

    Hemocyanin is a copper-containing protein with immune function against disease. In this study, a hemocyanin subunit named MnHc-1 was cloned from Macrobrachium nipponense. The full-length cDNA of MnHc-1 was 2,163 bp with a 2,028-bp open reading frame (ORF) encoding a polypeptide of 675 amino acids. The MnHc-1 mRNA was expressed in the hepatopancreas, gill, hemocytes, intestine, ovary, and stomach, with the highest level in the hepatopancreas. In the infection trial, the MnHc-1 mRNA transcripts in the hemocytes were significantly downregulated at 3 h after injection of Aeromonas hydrophila and then upregulated at 6 h and 12 h, followed by a gradual recovery from 24 to 48 h. The MnHc-1 transcriptional expression in the hepatopancreas was measured after M. nipponense were fed seven diets with 2.8, 12.2, 20.9, 29.8, 43.1, 78.9, and 157.1 mg Cu kg−1 for 8 weeks, respectively. The level of MnHc-1 mRNA was significantly higher in the prawns fed 43.1–157.1 mg Cu kg−1 diet than in that fed 2.8–29.8 mg Cu kg−1 diet. This study indicated that the MnHc-1 expression can be affected by dietary copper and the hemocyanin may potentially participate in the antibacterial defense of M. nipponense. PMID:27818993

  17. Transcriptome Analysis of the Oriental River Prawn, Macrobrachium nipponense Using 454 Pyrosequencing for Discovery of Genes and Markers

    PubMed Central

    Ma, Keyi; Qiu, Gaofeng; Feng, Jianbin; Li, Jiale

    2012-01-01

    Background The oriental river prawn, Macrobrachium nipponense, is an economically and nutritionally important species of the Palaemonidae family of decapod crustaceans. To date, the sequencing of its whole genome is unavailable as a non-model organism. Transcriptomic information is also scarce for this species. In this study, we performed de novo transcriptome sequencing to produce the first comprehensive expressed sequence tag (EST) dataset for M. nipponense using high-throughput sequencing technologies. Methodology and Principal Findings Total RNA was isolated from eyestalk, gill, heart, ovary, testis, hepatopancreas, muscle, and embryos at the cleavage, gastrula, nauplius and zoea stages. Equal quantities of RNA from each tissue and stage were pooled to construct a cDNA library. Using 454 pyrosequencing technology, we generated a total of 984,204 high quality reads (338.59Mb) with an average length of 344 bp. Clustering and assembly of these reads produced a non-redundant set of 81,411 unique sequences, comprising 42,551 contigs and 38,860 singletons. All of the unique sequences were involved in the molecular function (30,425), cellular component (44,112) and biological process (67,679) categories by GO analysis. Potential genes and their functions were predicted by KEGG pathway mapping and COG analysis. Based on our sequence analysis and published literature, many putative genes involved in sex determination, including DMRT1, FTZ-F1, FOXL2, FEM1 and other potentially important candidate genes, were identified for the first time in this prawn. Furthermore, 6,689 SSRs and 18,107 high-confidence SNPs were identified in this EST dataset. Conclusions The transcriptome provides an invaluable new data for a functional genomics resource and future biological research in M. nipponense. The molecular markers identified in this study will provide a material basis for future genetic linkage and quantitative trait loci analyses, and will be essential for accelerating

  18. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with (60)Co gamma radiation.

    PubMed

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-Babu, P

    2013-11-15

    This study was framed to investigate the (60)Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of (60)Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3,000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could affect the vital physiological functions such as respiration, osmotic and ionic regulation in gills and muscles; absorption, storage and secretion of the hepatopancreas which in turn could adversely affect the growth and survival of freshwater prawn M. rosenbergii. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Endemic shrimp Macrobrachium pantanalense as a test species to assess potential contamination by pesticides in Pantanal (Brazil).

    PubMed

    Soares, Mayara Pereira; Jesus, Fátima; Almeida, Ana Rita; Zlabek, Vladimir; Grabic, Roman; Domingues, Inês; Hayd, Liliam

    2017-02-01

    Pantanal is a biome characterized by an extraordinary diversity and abundance of wildlife and houses several endemic species such as the freshwater shrimp Macrobrachium pantanalense. However, the increase in agriculture and husbandry activities in the region has contributed with residues of pesticides reaching aquatic systems. The main objective of this study is to assess the sensitivity of the endemic shrimp M. pantanalense compared with other freshwater species: the shrimp M. amazonicum, the crustacean Daphnia similis and the fish Danio rerio. The sensitivity of these organisms was assessed through acute exposure to copper and cypermethrin (through the formulation Barrage(®), widely used in Pantanal). For copper the species sensitivity decreased in the following order: D. similis (48 h-EC50 0.051 mg/L) > M. pantanalense > D. rerio > M. amazonicum (48 h-LC50 26.34 mg/L). Copper caused reduced length of shrimps and zebrafish and reduced heartbeat of zebrafish embryos. For cypermethrin the species sensitivity decreased in the following order: M. pantanalense (96 h-LC50 0.05 μg/L) > M. amazonicum > D. similis > D. rerio (144 h-LC50 1680 μg/L). Major effects of cypermethrin included reduced length of shrimps and zebrafish, as well as early hatching and increased incidence of developmental deformities in zebrafish embryos. This study highlights the importance of using endemic species for risk evaluations in sensitive biomes such as Pantanal. Moreover, it emphasizes the importance of testing pesticides toxicity as commercial formulations. Furthermore, we suggest that the endemic shrimp species M. pantanalense can be successfully used as a test species in ecotoxicology.

  20. Activation of lipid catabolism by the water-soluble fraction of petroleum in the crustacean Macrobrachium borellii.

    PubMed

    Lavarías, S; Pollero, R J; Heras, H

    2006-05-01

    Little is known about the effect of the water-soluble fraction of crude oil (WSF) on lipid metabolism in invertebrates. The effect of the WSF on the triacylglycerol (TAG) mobilization, fatty acid activation and degradation was evaluated in the decapod Macrobrachium borellii, exposing adult and eggs at different stages of development for 7 days to a sublethal concentration of WSF. Using radioactive tracers, mitochondrial palmitoyl-CoA synthetase (ACS), triacylglycerol lipase (TAG-lipase) and fatty acid beta-oxidation system activities were assayed. Before studying the effect of WSF, the kinetic parameters of ACS were determined in purified mitochondria. Its optimal temperature and pH were 32 degrees C and 8.0, respectively, the apparent K(m) 2.48 micromol l(-1), and its V(max) of 1.93 nmol min(-1) mg protein(-1). These kinetic parameters differed significantly from this shrimp's microsomal isoform. After 7 days exposure to a sublethal concentration of WSF (0.6 mg/l), changes were observed in the enzymatic activity of all enzymes or enzymatic system assayed in adult midgut gland as well as in stage 5 eggs, a period of active organogenesis. An increase in the mobilization of energy stores was detected as early as stage 4, where TAG-lipase activity increased by 27% in exposed eggs. The increase was even more marked in exposed eggs at stage 5 where a three-fold rise (154%) was determined. Exposed adult shrimp also showed an augmented lipase activity by 38%. Fatty acid beta-oxidation increased by 51.0 and 35.5% in midgut gland and eggs at stage 5, respectively, but no changes were observed at less-developed stages. Mitochondrial fatty acid activation by ACS also increased in adults and stage 5 eggs by 7.4 and 52.0%, respectively. A similar response of the lipid catabolic pathways to WSF contamination in both adult and eggs, suggests that the exposure to this pollutant causes an increase in the energy needs of this shrimp. When validated by field studies, these catabolic

  1. The effect of astaxanthin on resistance of juvenile prawns Macrobrachium nipponense (Decapoda: Palaemonidae) to physical and chemical stress.

    PubMed

    Tizkar, Babak; Seidavi, Alireza; Ponce-Palafox, Jesús Trinidad; Pourashoori, Parastoo

    2014-12-01

    In recent years, the use of new scientific techniques has effectively improved aquaculture production processes. Astaxanthin has various properties in aquaculture and its antioxidant benefits have been closely related to stress resistance; besides, it is an essential factor for growth in many crustaceans and fish. The objective of this study was to evaluate the resistance of prawn (Macrobrachium nipponense) fed diets containing different amounts of astaxanthin (AX) to the shock and stress of different physicochemical environments. A 70-day trial was conducted to evaluate the effect of supplementation of a source of astaxanthin (Carophyll Pink, 10% astaxanthin, w/w, Hoffman-La Roche, Switzerland) at various levels in the diet of M. nipponense juveniles. Four dry diets were prepared: AX0 without astaxanthin, AX50 with 50 mg/kg, AX100 with 100 mg/kg, and AX150 with 150 mg/kg astaxanthin. The feeding trial was conducted in a recirculation water system consisting of 12 fiberglass tanks (1000L) used for holding prawns. Three replicate aquaria were initially stocked with 36 org/m2 per tank. During the trial, prawns were maintained on a 12:12-h light:dark photoperiod with an ordinary incandescent lamp, and the water quality parameters were maintained as follows: water temperature, 25-26°C; salinity, 1 g/L; pH, 8.5-8.8; dissolved oxygen, 6.0-6.5 mg/L; and ammonia-nitrogen, 0.05 mg/L. Incorporation of AX, production output, and physiological condition were recorded after 10 weeks of feeding. At the end of the growing period, the prawns were exposed to thermal shock (0°C), ammonia (0.75 mg/L), and reduced oxygen (0.5 mg/L). The time to lethargy and the time to complete death of the prawns were recorded. The results showed that control prawns had the shortest time to lethargy and death compared with prawns subjected to the other treatments. The results of this study have shown that the amount of muscle tissue and gill carotenoids in prawn fed with an AX150 diet showed

  2. Development and assays estradiol equivalent concentration from prawn (p-EEQ) in river prawn, Macrobrachium nipponense, in Taiwan.

    PubMed

    Chiu, Yuh-Wen; Yeh, Fang-Ling; Shieh, Bao-Sen; Chen, Chien-Min; Lai, Hong-Thih; Wang, Shu-Yin; Huang, Da-Ji

    2017-03-01

    The present study established a fast and convenient bioassay method for aqueous ecosystems using the prawn estradiol equivalent concentration (p-EEQ) of male Macrobrachium nipponense, which produce vitellogenin (VTG) after exposure to xeno-estrogens. This method was then used to determine the concentrations of xeno-estrogen pollutants in the rivers of Taiwan. To establish the calibration curve for the concentrations based on the p-EEQ, the induced VTG content was determined using the alkali-labile phosphate method after male M. nipponense were exposed to 0, 10, 100, 1,000 and 10,000ng/L of 17β-estradiol for 1, 3, 5, 7, 10 and 14 days, respectively. The results of the experiments showed that the induced VTG content in all of the experimental groups stabilized after 10 days, except for the 10,000ng/L experimental group, in which the induced VTG content decreased after 10 days. A 17β-estradiol-VTG10day response curve was then established based on the induced VTG content in the 0, 10, 100 and 1000ng/L experimental groups at day 10. After establishing the curve, male M. nipponense were captured from the upper, middle and lower reaches of the Chuo-shui River, the Beigang River, the Jishui River, the Agongdian River and the Sichong River in Taiwan, and the VTG content in these prawns was determined. In addition, the p-EEQ in the waters was determined based on the VTG content, and the estradiol equivalent concentration (EEQ) in the waters was also measured immediately after sampling using the solid-phase extraction-enzyme-linked immunosorbent assay (SPE-ELISA) method. The results showed that the p-EEQ in the middle and lower reaches of the rivers in certain parts of Taiwan ranged from 38 to 400ng/L, and the detection rate was 100%. Moreover, the EEQ ranged from 7.9 to 92.9ng/L, and the detection rate was 42.9%, indicating that most of the middle and lower reaches of the rivers in Taiwan were polluted by xeno-estrogens. The 17β-estradiol concentrations determined based

  3. Comparative acute toxicity of gallium(III), antimony(III), indium(III), cadmium(II), and copper(II) on freshwater swamp shrimp (Macrobrachium nipponense).

    PubMed

    Yang, Jen-Lee

    2014-04-01

    Acute toxicity testing were carried out the freshwater swamp shrimp, Macrobrachium nipponense, as the model animal for the semiconductor applied metals (gallium, antimony, indium, cadmium, and copper) to evaluate if the species is an suitable experimental animal of pollution in aquatic ecosystem. The static renewal test method of acute lethal concentrations determination was used, and water temperature was maintained at 24.0 ± 0.5°C. Data of individual metal obtained from acute toxicity tests were determined using probit analysis method. The median lethal concentration (96-h LC50) of gallium, antimony, indium, cadmium, and copper for M. nipponense were estimated as 2.7742, 1.9626, 6.8938, 0.0539, and 0.0313 mg/L, respectively. Comparing the toxicity tolerance of M. nipponense with other species which exposed to these metals, it is obviously that the M. nipponense is more sensitive than that of various other aquatic animals.

  4. The Prawn Macrobrachium vollenhovenii in the Senegal River Basin: Towards Sustainable Restocking of All-Male Populations for Biological Control of Schistosomiasis

    PubMed Central

    Savaya Alkalay, Amit; Rosen, Ohad; Sokolow, Susanne H.; Faye, Yacinthe P. W.; Faye, Djibril S.; Aflalo, Eliahu D.; Jouanard, Nicolas; Zilberg, Dina; Huttinger, Elizabeth; Sagi, Amir

    2014-01-01

    Early malacological literature suggests that the outbreak of schistosomiasis, a parasitic disease transmitted by aquatic snails, in the Senegal River basin occurred due to ecological changes resulting from the construction of the Diama dam. The common treatment, the drug praziquantel, does not protect from the high risk of re-infection due to human contact with infested water on a daily basis. The construction of the dam interfered with the life cycle of the prawn Macrobrachium vollenhovenii by blocking its access to breeding grounds in the estuary. These prawns were demonstrated to be potential biological control agents, being effective predators of Schistosoma-susceptible snails. Here, we propose a responsible restocking strategy using all-male prawn populations which could provide sustainable disease control. Male prawns reach a larger size and have a lower tendency to migrate than females. We, therefore, expect that periodic restocking of all-male juveniles will decrease the prevalence of schistosomiasis and increase villagers' welfare. In this interdisciplinary study, we examined current prawn abundance along the river basin, complemented with a retrospective questionnaire completed by local fishermen. We revealed the current absence of prawns upriver and thus demonstrated the need for restocking. Since male prawns are suggested to be preferable for bio-control, we laid the molecular foundation for production of all-male M. vollenhovenii through a complete sequencing of the insulin-like androgenic gland-encoding gene (IAG), which is responsible for sexual differentiation in crustaceans. We also conducted bioinformatics and immunohistochemistry analyses to demonstrate the similarity of this sequence to the IAG of another Macrobrachium species in which neo-females are produced and their progeny are 100% males. At least 100 million people at risk of schistosomiasis are residents of areas that experienced water management manipulations. Our suggested non

  5. Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method.

    PubMed

    Danyi, S; Widart, J; Douny, C; Dang, P K; Baiwir, D; Wang, N; Tu, H T; Tung, V T; Phuong, N-T; Kestemont, P; Scippo, M-L

    2011-04-01

    Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method. J. vet. Pharmacol. Therap. 34, 142-152. The fluoroquinolones enrofloxacin (EF) and ciprofloxacin (CF) residues were investigated in the edible tissues of two important Asian aquacultured species such as Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry method. Fish and prawn were treated with medicated feed with multiple doses of EF, in field conditions. A validation study of the analytical method was realized in terms of linearity, specificity, precision (repeatability and within-laboratory reproducibility), recovery and decision limit (CCα). The time needed before the antibiotic disappears from animal tissues or reach the maximum residue limit (MRL, 100μg/kg) was assessed. The concentration values of EF detected in Tra catfish tissue were between the MRL and 2×MRL concentrations, according to the fish density, 7days following the end of the enrofloxacin treatment (20mg/kg body weight per day, for seven consecutive days). The concentration value of ER in prawn tissue was lower than the MRL and the limit of quantification (LOQ, 14μg/kg) 5 and 7days after the stop of the EF treatment (50mg/kg body weight per day, for five consecutive days), respectively. The mean detected levels of CF was much lower in comparison with that of EF, indicating that only a small part of EF is metabolized into CF (<5%) in both Tra catfish and prawn. © 2010 Blackwell Publishing Ltd.

  6. Optimizing Hybrid de Novo Transcriptome Assembly and Extending Genomic Resources for Giant Freshwater Prawns (Macrobrachium rosenbergii): The Identification of Genes and Markers Associated with Reproduction

    PubMed Central

    Jung, Hyungtaek; Yoon, Byung-Ha; Kim, Woo-Jin; Kim, Dong-Wook; Hurwood, David A.; Lyons, Russell E.; Salin, Krishna R.; Kim, Heui-Soo; Baek, Ilseon; Chand, Vincent; Mather, Peter B.

    2016-01-01

    The giant freshwater prawn, Macrobrachium rosenbergii, a sexually dimorphic decapod crustacean is currently the world’s most economically important cultured freshwater crustacean species. Despite its economic importance, there is currently a lack of genomic resources available for this species, and this has limited exploration of the molecular mechanisms that control the M. rosenbergii sex-differentiation system more widely in freshwater prawns. Here, we present the first hybrid transcriptome from M. rosenbergii applying RNA-Seq technologies directed at identifying genes that have potential functional roles in reproductive-related traits. A total of 13,733,210 combined raw reads (1720 Mbp) were obtained from Ion-Torrent PGM and 454 FLX. Bioinformatic analyses based on three state-of-the-art assemblers, the CLC Genomic Workbench, Trans-ABySS, and Trinity, that use single and multiple k-mer methods respectively, were used to analyse the data. The influence of multiple k-mers on assembly performance was assessed to gain insight into transcriptome assembly from short reads. After optimisation, de novo assembly resulted in 44,407 contigs with a mean length of 437 bp, and the assembled transcripts were further functionally annotated to detect single nucleotide polymorphisms and simple sequence repeat motifs. Gene expression analysis was also used to compare expression patterns from ovary and testis tissue libraries to identify genes with potential roles in reproduction and sex differentiation. The large transcript set assembled here represents the most comprehensive set of transcriptomic resources ever developed for reproduction traits in M. rosenbergii, and the large number of genetic markers predicted should constitute an invaluable resource for future genetic research studies on M. rosenbergii and can be applied more widely on other freshwater prawn species in the genus Macrobrachium. PMID:27164098

  7. The prawn Macrobrachium vollenhovenii in the Senegal River basin: towards sustainable restocking of all-male populations for biological control of schistosomiasis.

    PubMed

    Savaya Alkalay, Amit; Rosen, Ohad; Sokolow, Susanne H; Faye, Yacinthe P W; Faye, Djibril S; Aflalo, Eliahu D; Jouanard, Nicolas; Zilberg, Dina; Huttinger, Elizabeth; Sagi, Amir

    2014-08-01

    Early malacological literature suggests that the outbreak of schistosomiasis, a parasitic disease transmitted by aquatic snails, in the Senegal River basin occurred due to ecological changes resulting from the construction of the Diama dam. The common treatment, the drug praziquantel, does not protect from the high risk of re-infection due to human contact with infested water on a daily basis. The construction of the dam interfered with the life cycle of the prawn Macrobrachium vollenhovenii by blocking its access to breeding grounds in the estuary. These prawns were demonstrated to be potential biological control agents, being effective predators of Schistosoma-susceptible snails. Here, we propose a responsible restocking strategy using all-male prawn populations which could provide sustainable disease control. Male prawns reach a larger size and have a lower tendency to migrate than females. We, therefore, expect that periodic restocking of all-male juveniles will decrease the prevalence of schistosomiasis and increase villagers' welfare. In this interdisciplinary study, we examined current prawn abundance along the river basin, complemented with a retrospective questionnaire completed by local fishermen. We revealed the current absence of prawns upriver and thus demonstrated the need for restocking. Since male prawns are suggested to be preferable for bio-control, we laid the molecular foundation for production of all-male M. vollenhovenii through a complete sequencing of the insulin-like androgenic gland-encoding gene (IAG), which is responsible for sexual differentiation in crustaceans. We also conducted bioinformatics and immunohistochemistry analyses to demonstrate the similarity of this sequence to the IAG of another Macrobrachium species in which neo-females are produced and their progeny are 100% males. At least 100 million people at risk of schistosomiasis are residents of areas that experienced water management manipulations. Our suggested non

  8. Optimizing Hybrid de Novo Transcriptome Assembly and Extending Genomic Resources for Giant Freshwater Prawns (Macrobrachium rosenbergii): The Identification of Genes and Markers Associated with Reproduction.

    PubMed

    Jung, Hyungtaek; Yoon, Byung-Ha; Kim, Woo-Jin; Kim, Dong-Wook; Hurwood, David A; Lyons, Russell E; Salin, Krishna R; Kim, Heui-Soo; Baek, Ilseon; Chand, Vincent; Mather, Peter B

    2016-05-07

    The giant freshwater prawn, Macrobrachium rosenbergii, a sexually dimorphic decapod crustacean is currently the world's most economically important cultured freshwater crustacean species. Despite its economic importance, there is currently a lack of genomic resources available for this species, and this has limited exploration of the molecular mechanisms that control the M. rosenbergii sex-differentiation system more widely in freshwater prawns. Here, we present the first hybrid transcriptome from M. rosenbergii applying RNA-Seq technologies directed at identifying genes that have potential functional roles in reproductive-related traits. A total of 13,733,210 combined raw reads (1720 Mbp) were obtained from Ion-Torrent PGM and 454 FLX. Bioinformatic analyses based on three state-of-the-art assemblers, the CLC Genomic Workbench, Trans-ABySS, and Trinity, that use single and multiple k-mer methods respectively, were used to analyse the data. The influence of multiple k-mers on assembly performance was assessed to gain insight into transcriptome assembly from short reads. After optimisation, de novo assembly resulted in 44,407 contigs with a mean length of 437 bp, and the assembled transcripts were further functionally annotated to detect single nucleotide polymorphisms and simple sequence repeat motifs. Gene expression analysis was also used to compare expression patterns from ovary and testis tissue libraries to identify genes with potential roles in reproduction and sex differentiation. The large transcript set assembled here represents the most comprehensive set of transcriptomic resources ever developed for reproduction traits in M. rosenbergii, and the large number of genetic markers predicted should constitute an invaluable resource for future genetic research studies on M. rosenbergii and can be applied more widely on other freshwater prawn species in the genus Macrobrachium.

  9. Crustacean hyperglycaemic hormone (CHH)-like peptides and CHH-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, Carcinus maenas, are putatively spliced and modified products of multiple genes.

    PubMed Central

    Dircksen, H; Böcking, D; Heyn, U; Mandel, C; Chung, J S; Baggerman, G; Verhaert, P; Daufeldt, S; Plösch, T; Jaros, P P; Waelkens, E; Keller, R; Webster, S G

    2001-01-01

    About 24 intrinsic neurosecretory neurons within the pericardial organs (POs) of the crab Carcinus maenas produce a novel crustacean hyperglycaemic hormone (CHH)-like peptide (PO-CHH) and two CHH-precursor-related peptides (PO-CPRP I and II) as identified immunochemically and by peptide chemistry. Edman sequencing and MS revealed PO-CHH as a 73 amino acid peptide (8630 Da) with a free C-terminus. PO-CHH and sinus gland CHH (SG-CHH) share an identical N-terminal sequence, positions 1-40, but the remaining sequence, positions 41-73 or 41-72, differs considerably. PO-CHH may have different precursors, as cDNA cloning of PO-derived mRNAs has revealed several similar forms, one exactly encoding the peptide. All PO-CHH cDNAs contain a nucleotide stretch coding for the SG-CHH(41-76) sequence in the 3'-untranslated region (UTR). Cloning of crab testis genomic DNA revealed at least four CHH genes, the structure of which suggest that PO-CHH and SG-CHH arise by alternative splicing of precursors and possibly post-transcriptional modification of PO-CHH. The genes encode four exons, separated by three variable introns, encoding part of a signal peptide (exon I), the remaining signal peptide residues, a CPRP, the PO-CHH(1-40)/SG-CHH(1-40) sequences (exon II), the remaining PO-CHH residues (exon III) and the remaining SG-CHH residues and a 3'-UTR (exon IV). Precursor and gene structures are more closely related to those encoding related insect ion-transport peptides than to penaeid shrimp CHH genes. PO-CHH neither exhibits hyperglycaemic activity in vivo, nor does it inhibit Y-organ ecdysteroid synthesis in vitro. From the morphology of the neurons it seems likely that novel functions remain to be discovered. PMID:11336648

  10. First confirmation of human diarrhoeic poisonings by okadaic acid esters after ingestion of razor clams (Solen marginatus) and green crabs (Carcinus maenas) in Aveiro lagoon, Portugal and detection of okadaic acid esters in phytoplankton.

    PubMed

    Vale, Paulo; de M Sampayo, Maria Antónia

    2002-07-01

    A new outbreak of human diarrhoeic poisonings (DSP) with esters of okadaic acid (OA) was confirmed after ingestion of razor clams (Solen marginatus) harvested at Aveiro lagoon (NW Portugal) in the summer of 2001. Accumulation of marine toxins in second order consumers was investigated in the edible parts of a shellfish predator abundant at Aveiro lagoon, the green crab Carcinus maenas. Okadaic acid was found, also in a predominant esterified form. Levels in edible parts (comprising mainly viscera) surpassed 16microg/100g. We suggest that one patient may have developed profuse diarrhoea after ingestion of a large number of green crabs contaminated with okadaic acid esters. At least 32microg OA/100g were found in a remaining sample of its meal. Domoic acid was also found but under the allowable level in force in USA of 30microg/g crab viscera. In cooked crabs, significant losses of domoic acid were found and it is not suspected to have contributed to the poisoning event, although being a vector for this toxin. The low percentage of free okadaic acid found is in accordance with a predation predominantly on benthonic shellfish (razor clams, clams and common cockle) rather than on rock mussels. These last ones present usually higher percentages of free okadaic acid. Okadaic acid was confirmed with full-scan mass spectra either in plankton and mussel extracts. Okadaic acid esters were also found in plankton extracts. Percentages between 40-60% of esterified OA were found in samples freshly extracted. Ester's percentage diminished drastically if after sonication the extract was kept at room temperature. The major part of the esters was water-soluble.

  11. Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV)

    PubMed Central

    Alinejad, T.; Bin, Kwong Q.; Vejayan, J.; Othman, R.Y.; Bhassu, S.

    2015-01-01

    Epizootic diseases cause huge mortality and economical loses at post larvae stages in freshwater prawn aquaculture industry. These prawns seem less susceptible to viral diseases except for infectious hypodermal and hematopoietic necrosis virus (IHHNV). During viral infection in prawns, hemocytes are the primary organ that shows immunological response within the early stages of infection. We applied proteomic approaches to understand differential expression of the proteins in hemocytes during the viral disease outbreak. To aid the goal, we collected Macrobrachium rosenbergii broodstocks from the local grow out hatchery which reported the first incidence of IHHNV viral outbreak during larvae stage. Primarily, application of the OIE primer targeting 389 bp fragments of IHHNV virus was used in identification of the infected and non-infected samples of the prawn breeding line. Analysis of two-dimensional gel electrophoresis showed specific down-regulation of Arginine kinase and Sarcoplasmic calcium-binding protein and up/down-regulation of Prophenoloxidase1 and hemocyanin isoforms. These proteins were validated using semi quantitative RT-PCR and gene transcripts at mRNA level. These identified proteins can be used as biomarkers, providing a powerful approach to better understanding of the immunity pathway of viral disease with applications in analytic and observational epidemiology diagnosis. Proteomic profiling allows deep insight into the pathogenesis of IHHNV molecular regulation and mechanism of hemocyte in freshwater prawns. PMID:26106581

  12. Female-only sex-linked amplified fragment length polymorphism markers support ZW/ZZ sex determination in the giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    Jiang, Xue-Hui; Qiu, Gao-Feng

    2013-12-01

    Sex determination mechanisms in many crustacean species are complex and poorly documented. In the giant freshwater prawn, Macrobrachium rosenbergii, a ZW/ZZ sex determination system was previously proposed based on sex ratio data obtained by crosses of sex-reversed females (neomales). To provide molecular evidence for the proposed system, novel sex-linked molecular markers were isolated in this species. Amplified fragment length polymorphism (AFLP) using 64 primer combinations was employed to screen prawn genomes for DNA markers linked with sex loci. Approximately 8400 legible fragments were produced, 13 of which were uniquely identified in female prawns with no indication of corresponding male-specific markers. These AFLP fragments were reamplified, cloned and sequenced, producing two reliable female-specific sequence characterized amplified region (SCAR) markers. Additional individuals from two unrelated geographic populations were used to verify these findings, confirming female-specific amplification of single bands. Detection of internal polymorphic sites was conducted by designing new primer pairs based on these internal fragments. The internal SCAR fragments also displayed specificity in females, indicating high levels of variation between female and male specimens. The distinctive feature of female-linked SCAR markers can be applied for rapid detection of prawn gender. These sex-specific SCAR markers and sex-associated AFLP candidates unique to female specimens support a sex determination system consistent with female heterogamety (ZW) and male homogamety (ZZ).

  13. Survey of protozoan, helminth and viral infections in shrimp Litopenaeus setiferus and prawn Macrobrachium acanthurus native to the Jamapa River region, Mexico.

    PubMed

    Domínguez-Machín, Magda E; Hernández-Vergara, Martha P; Jiménez-García, Isabel; Simá-Alvarez, Raúl; Rodríguez-Canul, Rossanna

    2011-09-09

    We surveyed protozoan and metazoan parasites as well as white spot syndrome virus (WSSV) and infectious hypodermal hematopoietic necrosis virus (IHHNV) in white shrimp Litopenaeus setiferus and the palaemonid prawn Macrobrachium acanthurus native to the lower Jamapa River region of Veracruz, Mexico. The presence of parasites and the infection parameters were evaluated in 113 palaemonid prawns collected during the northwind (n = 45), rainy (n = 38) and dry seasons (n = 30) between October 2007 and July 2008, and in 91 shrimp collected in the rainy season between May and June 2008. In L. setiferus, ciliates of the subclass Apostomatia (Ascophrys sp.) were evident in gills, and third-stage larvae of the nematode Physocephalus sexalatus were evident in the stomach. Cestodes of the genus Prochristianella were evident in the hepatopancreas, while some gregarines of the genus Nematopsis, as well as unidentified larval cestodes, were observed in the intestine. Histology identified Ascophrys sp. in association with gill necrosis and tissue melanization. Slight inflammation was observed in intestinal epithelium near cestode larvae. In M. acanthurus, epibionts of the protozoans Epistylis sp., Acineta sp. and Lagenophrys sp. were observed under uropods, periopods and pleopods. An unidentified ciliate of the Apostomatia was also found in the gills, and Nematopsis was identified in the intestine. No histopathology was observed in association with these parasites. Moreover, neither WSSV nor IHHNV were detected by the polymerase chain reaction (PCR) in any of the L. setiferus or M. acanthurus analysed.

  14. Levels of platinum group metals in selected species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa) in some estuaries and lagoons along the coast of Ghana.

    PubMed

    Essumang, D K; Adokoh, C K; Boamponsem, L

    2010-10-12

    The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs) in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA) method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae), brown goby (Chonophorus lateristriga Gobiidae), shrimp (Macrobrachium vollenhovenii Palaemonidae), and mangrove oysters (Crassostrea tulipa Ostreidae) in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μg/g (dry weight) Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF) values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI) conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  15. Ultrastructural changes during spermatogenesis, biochemical and hormonal evidences of testicular toxicity caused by TBT in freshwater prawn Macrobrachium rosenbergii (De Man, 1879).

    PubMed

    Revathi, Peranandam; Iyapparaj, Palanisamy; Vasanthi, Lourduraj Arockia; Munuswamy, Natesan; Krishnan, Muthukalingan

    2014-10-01

    The present investigation documents the impact of tributyltin (TBT) on the ultrastructural variation of spermatogenesis in freshwater prawn Macrobrachium rosenbergii. The environmentally realistic concentration of TBT can cause damages to the endocrine and reproductive physiology of crustaceans. In this context, three concentrations viz. 10, 100, and 1000 ng/L were selected and exposed to prawns for 90 days. The TBT exposed prawn exhibited decrease the reproductive activity as evidenced by sperm count and sperm length compared to control. Histopathological results revealed the retarded testicular development, abnormal structure of seminiferous tubule, decrease in the concentration of spermatozoa, diminution of seminiferous tubule membrane, abundance of spermatocytes and vacuolation in testis of treated prawns. Ultrastructural study also confirmed the impairment of spermatogenesis in treated prawns. Furthermore, radioimmunoassay (RIA) clearly documented the reduction of testosterone level in TBT exposed groups. Thus, TBT substantially reduced the level of male sex hormone as well as biochemical constituents which ultimately led to impairment of spermatogenesis in the freshwater male prawn M. rosenbergii.

  16. Variation of prostaglandin E2 concentrations in ovaries and its effects on ovarian maturation and oocyte proliferation in the giant fresh water prawn, Macrobrachium rosenbergii.

    PubMed

    Sumpownon, Chanudporn; Engsusophon, Attakorn; Siangcham, Tanapan; Sugiyama, Eiji; Soonklang, Nantawan; Meeratana, Prasert; Wanichanon, Chaitip; Hanna, Peter J; Setou, Mitsutoshi; Sobhon, Prasert

    2015-11-01

    Prostaglandins (PGs) are important bioactive mediators for many physiological functions. In some decapod crustaceans, prostaglandin E2 (PGE2) has been detected in reproductive organs, and may play a role in the control of ovarian maturation. However, in the freshwater prawn, Macrobrachium rosenbergii, the presences of PGE2 and key enzymes for PGE2 biosynthesis, as well as its effects on ovarian maturation have not yet been investigated. In this study we reported the presence of PGE2, cyclooxygenase1 (COX1) and prostaglandin E synthase (PGES) in the ovarian tissues of M. rosenbergii, using immunohistochemistry. Intense immunoreactivities of PGE2 (PGE2-ir), COX1 (Cox1-ir) and PGES (PGES-ir) were detected in previtellogenic oocytes (Oc1 and Oc2), while the immunoreactivities were absent in the late vitellogenic oocytes (Oc4). This finding supports the hypothesis that the PGE2 biosynthesis occurs in the ovary of this prawn. To ascertain this finding we used LC-MS/MS to quantitate PGE2 concentrations during ovarian developmental cycle. The levels of PGE2 were significantly higher in the early ovarian stages (St I and II) than in the late stages (St III and IV). Moreover, we found that administration of PGE2 stimulated the ovarian maturation in this species by shortening the length of the ovarian cycle, increasing ovarian-somatic index, oocyte proliferation, and vitellogenin (Vg) level in the hemolymph.

  17. Molecular cloning, characterization, and expression analysis of a Broad-Complex homolog during development in the oriental river prawn Macrobrachium nipponense.

    PubMed

    Jiang, S F; Zhang, Y P; Sun, S M; Gong, Y S; Xiong, Y W; Qiao, H; Zhang, W Y; Jin, S B; Fu, H T

    2015-05-18

    Broad-Complex (BR-C) is an early ecdysone-responsive gene encoding a family of zinc-finger transcription factors. In this study, we isolated the full-length cDNA of a BR-C homolog from the testes of the oriental river prawn (Macrobrachium nipponense), according to established expressed sequence tag information, using the rapid amplification of cDNA ends technique. The homolog was designated as MnBR-C. The full-length cDNA of MnBR-C contained a 1095-bp open reading frame encoding a precursor protein of 365 amino acid residues. Comparative and bioinformatic analyses revealed that MnBR-C exhibited a high degree of homology with BR-C proteins, and contained the BTB and Zf-H2C2-2 domains. Real-time quantitative polymerase chain reaction (qPCR) analysis revealed that the MnBR-C expression level varied significantly in the developing embryo, postembryonic larva, and adult tissue. Real-time qPCR showed that the MnBR-C gene was expressed in all of the tissues investigated, with the highest level of expression in the brain. In addition, MnBR-C was more abundantly expressed in the testes than in the ovaries.

  18. L-( sup 3 H) glutamate binding to a membrane preparation from the optic lobe of the giant freshwater prawn Macrobrachium rosenbergii de Man

    SciTech Connect

    Pratumtan, P.; Govitrapong, P.; Withyachumnarnkul, B.; Poolsanguan, B. Mahidol Univ., Nakorn Pathom )

    1991-01-01

    Membrane preparation from the optic lobe of the giant freshwater prawn, Macrobrachium rosenbergii de Man, was examined for the presence of specific L-({sup 3}H) glutamate binding. The optic lobes were isolated from live animals. The tissue was homogenized and the membrane fraction isolated by differential centrifugation. The membrane suspension was incubated with 10-1,000 nM of L-({sup 3}H) glutamate at 37{degree}C for 60 min. Nonspecific binding was determined by incubating the mixture with 100 {mu}M L-glutamate. L-({sup 3}H) glutamate specifically bound to the membrane fraction with a dissociation equilibrium constant (Kd) of 205 nM and maximum number of binding sites (Bmax) of 2.04 n mol/mg protein. By using LIGAND computerized program, the saturation isotherm binding pattern indicates a single type of binding. To determine the type of glutamate receptors, competitive inhibition and IC{sub 50} of several glutamate agonists and antagonists were determined. The study reveals a metabotropic type of binding site.

  19. Virus-like particle of Macrobrachium rosenbergii nodavirus produced in Spodoptera frugiperda (Sf9) cells is distinctive from that produced in Escherichia coli.

    PubMed

    Kueh, Chare Li; Yong, Chean Yeah; Masoomi Dezfooli, Seyedehsara; Bhassu, Subha; Tan, Soon Guan; Tan, Wen Siang

    2016-11-14

    Macrobrachium rosenbergii nodavirus (MrNV) is a virus native to giant freshwater prawn. Recombinant MrNV capsid protein has been produced in Escherichia coli, which self-assembled into virus-like particles (VLPs). However, this recombinant protein is unstable, degrading and forming heterogenous VLPs. In this study, MrNV capsid protein was produced in insect Spodoptera frugiperda (Sf9) cells through a baculovirus system. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the recombinant protein produced by the insect cells self-assembled into highly stable, homogenous VLPs each of approximately 40 nm in diameter. Enzyme-linked immunosorbent assay (ELISA) showed that the VLPs produced in Sf9 cells were highly antigenic and comparable to those produced in E. coli. In addition, the Sf9 produced VLPs were highly stable across a wide pH range (2-12). Interestingly, the Sf9 produced VLPs contained DNA of approximately 48 kilo base pairs and RNA molecules. This study is the first report on the production and characterization of MrNV VLPs produced in a eukaryotic system. The MrNV VLPs produced in Sf9 cells were about 10 nm bigger and had a uniform morphology compared with the VLPs produced in E. coli. The insect cell production system provides a good source of MrNV VLPs for structural and immunological studies as well as for host-pathogen interaction studies. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 2016.

  20. C-terminal domain on the outer surface of the Macrobrachium rosenbergii nodavirus capsid is required for Sf9 cell binding and internalization.

    PubMed

    Somrit, Monsicha; Watthammawut, Atthaboon; Chotwiwatthanakun, Charoonroj; Ounjai, Puey; Suntimanawong, Wanida; Weerachatyanukul, Wattana

    2017-01-02

    We have shown that Macrobrachium rosenbergii nodavirus (MrNV) was able to infect Sf9 cells and that MrNV virus-like particles (MrNV-VLPs) were capable nanocontainers for delivering nucleic acid-based materials. Here, we demonstrated that chymotryptic removal of a C-terminal peptide and its truncated variant (F344-MrNV-VLPs) exhibited a drastically reduced ability to interact and internalize into Sf9 cells. Electron microscopic observations revealed that the loss of C-terminal domain either from enzyme hydrolysis or genetic truncation did not affect the generated MrNV-VLPs' icosahedral conformation, but did drastically affect the VLPs' internalization ability into Sf9 cells. Homology-based modelling of the MrNV capsid with other icosahedral capsid models revealed that this chymotrypsin-sensitive C-terminal domain was not only exposed on the capsid surface, but also constituted the core of the viral capsid protrusion. These results therefore suggest the importance of the C-terminal domain as a structure for targeted cell interaction which is presumably localized at the protruding domain. This work thus provided the functional insights into the role of the MrNV C-terminal domain in viral entry into Sf9 cells and lead to the development of strategies in combatting MrNV infection in susceptible cells.

  1. Metal Transfer among Organs Following Short- and Long-Term Exposures Using Autoradiography: Cadmium Bioaccumulation by the Freshwater Prawn Macrobrachium australiense.

    PubMed

    Cresswell, Tom; Mazumder, Debashish; Callaghan, Paul D; Nguyen, An; Corry, Michael; Simpson, Stuart L

    2017-04-04

    The uptake, depuration, and organ distribution of the radioisotope (109)Cd were used to explore the internal kinetics of this nonessential metal following accumulation from waterborne cadmium by the freshwater decapod crustacean Macrobrachium australiense. Short- (6 h) and long-term (7 to 14 days) exposures to the radioisotope in solutions of 0.56 μg Cd/L were followed by depuration in metal- and isotope-free water for up to 21 days. The anatomical distribution of the radionuclide was visualized using autoradiography at predefined time points. The gills did not become saturated with cadmium after 14 days of exposure and demonstrated a greater rate of cadmium uptake relative to the hepatopancreas. Cadmium concentrations decreased rapidly during depuration from both gills and hepatopancreas after short exposures but slowly following long-term exposures. This suggests that the duration of cadmium exposure influences the depuration rate for this organism. The study demonstrates the complex behavior of cadmium accumulated by M. australiense and improves our understanding of how exposure duration will influence the internal location and potential toxicity of metals.

  2. Timing sexual differentiation: full functional sex reversal achieved through silencing of a single insulin-like gene in the prawn, Macrobrachium rosenbergii.

    PubMed

    Ventura, Tomer; Manor, Rivka; Aflalo, Eliahu D; Weil, Simy; Rosen, Ohad; Sagi, Amir

    2012-03-01

    In Crustacea, an early evolutionary group (∼50 000 species) inhabiting most ecological niches, sex differentiation is regulated by a male-specific androgenic gland (AG). The identification of AG-specific insulin-like factors (IAGs) and genomic sex markers offers an opportunity for a deeper understanding of the sexual differentiation mechanism in crustaceans and other arthropods. Here, we report, to our knowledge, the first full and functional sex reversal of male freshwater prawns (Macrobrachium rosenbergii) through the silencing of a single IAG-encoding gene. These "neofemales" produced all-male progeny, as proven by sex-specific genomic markers. This finding offers an insight regarding the biology and evolution of sex differentiation regulation, with a novel perspective for the evolution of insulin-like peptides. Our results demonstrate how temporal intervention with a key regulating gene induces a determinative, extreme phenotypic shift. Our results also carry tremendous ecological and commercial implications. Invasive and pest crustacean species represent genuine concerns worldwide without an apparent solution. Such efforts might, therefore, benefit from sexual manipulations, as has been successfully realized with other arthropods. Commercially, such manipulation would be significant in sexually dimorphic cultured species, allowing the use of nonbreeding, monosex populations while dramatically increasing yield and possibly minimizing the invasion of exotic cultured species into the environment.

  3. Scavenger Receptor Class B, Type I, a CD36 Related Protein in Macrobrachium nipponense: Characterization, RNA Interference, and Expression Analysis with Different Dietary Lipid Sources

    PubMed Central

    Ding, Zhili; Luo, Na; Kong, Youqin; Li, Jingfen; Zhang, Yixiang; Cao, Fang

    2016-01-01

    The scavenger receptor class B, type I (SR-BI), is a member of the CD36 superfamily comprising transmembrane proteins involved in mammalian and fish lipid homeostasis regulation. We hypothesize that this receptor plays an important role in Macrobrachium nipponense lipid metabolism. However, little attention has been paid to SR-BI in commercial crustaceans. In the present study, we report a cDNA encoding M. nipponense scavenger receptor class B, type I (designated as MnSR-BI), obtained from a hepatopancreas cDNA library. The complete MnSR-BI coding sequence was 1545 bp, encoding 514 amino acid peptides. The MnSR-BI primary structure consisted of a CD36 domain that contained two transmembrane regions at the N- and C-terminals of the protein. SR-BI mRNA expression was specifically detected in muscle, gill, ovum, intestine, hepatopancreas, stomach, and ovary tissues. Furthermore, its expression in the hepatopancreas was regulated by dietary lipid sources, with prawns fed soybean and linseed oils exhibiting higher expression levels. RNAi-based SR-BI silencing resulted in the suppression of its expression in the hepatopancreas and variation in the expression of lipid metabolism-related genes. This is the first report of SR-BI in freshwater prawns and provides the basis for further studies on SR-BI in crustaceans. PMID:28003996

  4. Regulation of laboratory populations of snails (Biomphalaria and Bulinus spp.) by river prawns, Macrobrachium spp. (Decapoda, Palaemonidae): implications for control of schistosomiasis.

    PubMed

    Sokolow, Susanne H; Lafferty, Kevin D; Kuris, Armand M

    2014-04-01

    Human schistosomiasis is a common parasitic disease endemic in many tropical and subtropical countries. One barrier to achieving long-term control of this disease has been re-infection of treated patients when they swim, bathe, or wade in surface fresh water infested with snails that harbor and release larval parasites. Because some snail species are obligate intermediate hosts of schistosome parasites, removing snails may reduce parasitic larvae in the water, reducing re-infection risk. Here, we evaluate the potential for snail control by predatory freshwater prawns, Macrobrachium rosenbergii and M. vollenhovenii, native to Asia and Africa, respectively. Both prawn species are high value, protein-rich human food commodities, suggesting their cultivation may be beneficial in resource-poor settings where few other disease control options exist. In a series of predation trials in laboratory aquaria, we found both species to be voracious predators of schistosome-susceptible snails, hatchlings, and eggs, even in the presence of alternative food, with sustained average consumption rates of 12% of their body weight per day. Prawns showed a weak preference for Bulinus truncatus over Biomphalaria glabrata snails. Consumption rates were highly predictable based on the ratio of prawn: snail body mass, suggesting satiation-limited predation. Even the smallest prawns tested (0.5-2g) caused snail recruitment failure, despite high snail fecundity. With the World Health Organization turning attention toward schistosomiasis elimination, native prawn cultivation may be a viable snail control strategy that offers a win-win for public health and economic development.

  5. Use of the Multispecies Freshwater Biomonitor to assess behavioral changes of Poecilia reticulata (Cyprinodontiformes: Poeciliidae) and Macrobrachium lanchesteri (Decapoda: Palaemonidae) in response to acid mine drainage: laboratory exposure.

    PubMed

    Mohti, Azmah; Shuhaimi-Othman, Mohammad; Gerhardt, Almut

    2012-09-01

    The behavioral responses of guppy Poecilia reticulata (Poeciliidae) and prawn Macrobrachium lanchesteri (Palaemonidae) individuals exposed to acid mine drainage (AMD) were monitored online in the laboratory with a Multispecies Freshwater Biomonitor™ (MFB). These responses were compared to those to reference water acidified to the respective pH values (ACID). Test animals in the juvenile stage were used for both species and were exposed to AMD and ACID for 24 hours. The stress behaviors of both test animals consisted mainly of decreased activity in AMD and increased activity in ACID, indicating that the metals in the AMD played a role as a stress factor in addition to pH. The locomotor activity levels of guppies and prawns for the ACID treatment were higher than the locomotor activity levels for the AMD treatment with increasing pH value. For guppies, significant differences were observed when specimens were exposed to AMD and ACID at pH 5.0 and 6.0; the percentage activities were only 16% and 12%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 35% and 40%, respectively, similar to the value of 36% for the controls. Similar trends were also observed for prawns, for which the percentage activities were only 6% and 4%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 31% and 38%, respectively, compared to 44% in the controls. This study showed that both species are suitable for use as indicators for ecotoxicity testing with the MFB.

  6. A spring-matrix model for pigment translocation in the red ovarian chromatophores of the freshwater shrimp Macrobrachium olfersi (Crustacea, Decapoda).

    PubMed

    Boyle, Robert Tew; McNamara, John Campbell

    2008-04-01

    A model for intracellular transport of pigment granules in the red ovarian chromatophores of the freshwater shrimp Macrobrachium olfersi is proposed on the basis of shifts in the equilibrium of resting forces acting on an elastic pigment matrix. The model describes a pigment-transport mechanism in which mechanochemical protein motors like kinesin and myosin alternately stretch and compress a structurally unified, elastic pigment matrix. Quantifiable properties of the spring-matrix obey Hooke's Law during the rapid phases of pigment aggregation and dispersion. The spring-like response of the pigment mass is estimated from previous kinetic experiments on pigment translocation induced by red pigment concentrating hormone, or by the calcium ionophore A23187. Both translocation effectors trigger an initial phase of rapid pigment aggregation, and their removal or washout after complete aggregation produces a phase of rapid pigment dispersion, followed by slow pigment translocation. The rapid-phase kinetics of pigment transport are in reasonable agreement with Hooke's Law, suggesting that such phases represent the release of kinetic energy, probably produced by the mechanochemical protein motors and stored in the form of matrix deformation during the slow phases of translocation. This semiquantitative model should aid in analyzing intracellular transport systems that incorporate an elastic component.

  7. The cloning of the cdk2 transcript and the localization of its expression during gametogenesis in the freshwater giant prawn, Macrobrachium rosenbergii.

    PubMed

    Chen, Jie; Liu, Ping; Li, Zhen; Chen, Ying; Qiu, Gao-Feng

    2013-08-01

    Cyclin-dependent kinases (cdks) are key regulators of the cell cycle. In mammals, cdk2 plays an essential role in the meiosis of spermatocytes and oocytes. To investigate the role of cdk2 kinase during gametogenesis in crustaceans, we cloned a complete cDNA sequence of cdk2 from the freshwater giant prawn, Macrobrachium rosenbergii, and examined its localization and expression in the developing gonads. The prawn cdk2 cDNA is 1,745 bp in length and encodes a putative protein of 305 amino acids. The deduced protein contains a conserved cyclin binding motif PSTAIRE and shares high homology with reported cdk2 kinases of other species. RT-PCR analysis showed a wide distribution of the cdk2 mRNA in all tested organs including the testis, ovary, heart, muscles, hepatopancreas and gills, and the highest level of expression in the ovary and testis. Localization by in situ hybridization of cdk2 mRNA in the ovary showed high expression in the ooplasm of previtellogenic and the nuclei of late vitellogenic oocytes. In testicular sections, cdk2 transcript is low in spermatogonia, high in spermatocytes, but reduced in spermatids and sperm. The high expression of the cdk2 transcripts in meiotic spermatocytes and oocytes indicated that the cdk2 gene has the conservative function in the germ cells meiosis during gametogenesis.

  8. Activity and Transcriptional Responses of Hepatopancreatic Biotransformation and Antioxidant Enzymes in the Oriental River Prawn Macrobrachium nipponense Exposed to Microcystin-LR

    PubMed Central

    Yuan, Julin; Wang, Xueqin; Gu, Zhiming; Zhang, Yingying; Wang, Zaizhao

    2015-01-01

    Microcystins (MCs) are a major group of cyanotoxins with side effects in many organisms; thus, compounds in this group are recognized as potent stressors and health hazards in aquatic ecosystems. In order to assess the toxicity of MCs and detoxification mechanism of freshwater shrimp Macrobrachium nipponense, the full-length cDNAs of the glutathione S-transferase (gst) and catalase (cat) genes were isolated from the hepatopancreas. The transcription level and activity changes in the biotransformation enzyme (glutathione S-transferase (GST)) and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) in the hepatopancreas of M. nipponense exposed to MC-LR (0.2, 1, 5, and 25 μg/L) for 12, 24, 72 and 96 h were analyzed. The results showed that the isolated full-length cDNAs of cat and gst genes from M. nipponense displayed a high similarity to other crustaceans, and their mRNAs were mainly expressed in the hepatopancreas. MC-LR caused significant increase of GST activity following 48–96 h (p < 0.05) and an increase in SOD activity especially in 24- and 48-h exposures. CAT activity was activated when exposed to MC-LR in 12-, 24- and 48-h exposures and then it was inhibited at 96-h exposure. There was no significant effect on GPx activity after the 12- and 24-h exposures, whereas it was significantly stimulated after the 72- and 96-h exposures (p < 0.05). The transcription was altered similarly to enzyme activity, but the transcriptional response was generally more immediate and had greater amplitude than enzymatic response, particularly for GST. All of the results suggested that MC-LR can induce antioxidative modulation variations in M. nipponense hepatopancreas in order to eliminate oxidative damage. PMID:26457718

  9. Molecular characterization and developmental expression of vitellogenin in the oriental river prawn Macrobrachium nipponense and the effects of RNA interference and eyestalk ablation on ovarian maturation.

    PubMed

    Bai, Hongkun; Qiao, Hui; Li, Fajun; Fu, Hongtuo; Sun, Shengming; Zhang, Wenyi; Jin, Shubo; Gong, Yongsheng; Jiang, Sufei; Xiong, Yiwei

    2015-05-10

    Vitellogenin (Vg) is the precursor of yolk protein, which functions as a nutritive resource that is important for embryonic growth and gonad development. In this study, the cDNA encoding the Vg gene from the oriental river prawn Macrobrachium nipponense was cloned using expressed sequence tag (EST) analysis and the rapid amplification of cDNA ends (RACE) approach. The transcript encoded 2536 amino acids with an estimated molecular mass of 286.810 kDa. Quantitative real-time PCR indicated high expression of Mn-Vg in the female ovary, hemocytes, and hepatopancreas. As ovaries developed, the expression level of Mn-Vg increased in both the hepatopancreas and ovary. In the hepatopancreas, the expression level rose more slowly at the early stage of vitellogenesis and reached the peak more rapidly compared to the expression pattern in ovary. The observed changes in Mn-Vg expression level at different development stages suggest the role of nutrient source in embryonic and larval development. Eyestalk ablation caused the Mn-Vg expression level to increase significantly compared to eyestalk-intact groups during the ovary development stages. Ablation accelerated ovary maturation by removing hormone inhibition of Mn-Vg in the hepatopancreas and ovary. In adult females, Mn-Vg dsRNA injection resulted in decreased expression of Mn-Vg in both the hepatopancreas and ovary, and two injection treatment dramatically delayed ovary maturation. Vg RNA interference down-regulated the vitellogenin receptor (VgR) expression level in the ovary, which illustrates the close relationship between Vg and VgR in the process of vitellogenesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Identification and comparative analysis of the oriental river prawn (Macrobrachium nipponense) microRNA expression profile during hypoxia using a deep sequencing approach.

    PubMed

    Sun, Shengming; Fu, Hongtuo; Ge, Xianping; Zhu, Jian; Gu, Zhimin; Xuan, Fujun

    2016-03-01

    Hypoxia refers to a state of oxygen deficiency, which is observed frequently in aquaculture ponds. MicroRNAs (miRNAs) are small non-coding RNAs that are important effectors in regulating gene expression through posttranscriptional mechanisms. They are key elements in the response to hypoxia. The oriental river prawn (Macrobrachium nipponense) is an important commercial aquaculture species, and is sensitive to hypoxia. To date, there are no reports describing M. nipponense miRNAs. In this study, Solexa deep sequencing technology was used for high-throughput analysis of miRNAs in a small RNA library isolated from four M. nipponense tissues (gill, hepatopancreas, muscle and hemocytes). In total, 9,227,356 reads were obtained, 4,293,155 of which were related to 267 unique miRNAs, including 203 conserved and 64 prawn-specific miRNAs. Furthermore, miRNA features including length distribution and end variations were characterized. Annotation of targets revealed a broad range of biological processes and signal transduction pathways regulated by M. nipponense miRNAs. In addition, 880 co-expressed and 39 specific (25 normoxia-specific and 14 hypoxia-specific) miRNAs that may be involved in the response to hypoxia were confirmed using miRNA microarray analysis from the four prawn tissues combined. Real-time quantitative PCR (qPCR) analysis of eight miRNAs in the normoxia and hypoxia groups showed good concordance between the sequencing and qPCR data. This study provides the first large-scale identification and characterization of M. nipponense miRNAs and their potential targets, and represents a foundation for further characterization of their roles in the regulation of the diversity of hypoxia processes.

  11. Developmental effects of exposure to ultraviolet B radiation on the freshwater prawn Macrobrachium olfersi: Mitochondria as a target of environmental UVB radiation.

    PubMed

    de Quadros, Thaline; Schramm, Heloísa; Zeni, Eliane C; Simioni, Carmen; Allodi, Silvana; Müller, Yara M R; Ammar, Dib; Nazari, Evelise M

    2016-10-01

    In South America, increased UVB radiation has become an important environmental issue that is potentially threatening aquatic ecosystems. Considering that species exhibit different degrees of sensitivity to UVB radiation and that embryos are more sensitive than organisms at later life stages, the aim of this study was to characterize the effects of UVB radiation on subcellular compartments of embryos of the freshwater prawn Macrobrachium olfersi. This species lives and reproduces in clear and shallow waters, where UV radiation can fully penetrates. Embryos were irradiated with a UVB 6W lamp for 30min and examined after 1h, 12h, 24h and 48h of exposure. The irradiance of the UVB used simulates the UV radiation that embryos receive in the natural environment. The subcellular compartment most affected by the UVB radiation was the mitochondria, which exhibited a circular shape, a decrease in mitochondrial cristae, rupture of membranes and a morphology compatible with fission. These impairments were observed simultaneously with increased ROS production, just after 1h of UVB exposure. Thus, we investigated proteins related to mitochondrial fission (Drp-1) and fusion (Mfn-1), which are essential to cell maintenance. We found a significant increase in Drp-1 expression at all analyzed time-points and a significant decrease in Mfn-1 expression only after 24h of UVB exposure. Additionally, a decrease in embryonic cell viability was verified via the mitochondrial integrity assay. To conclude, we observed important mitochondrial dysfunctions against the environmental stress caused by UVB radiation. Moreover, the cellular responses found are critical and should not be disregarded, because they impact embryos that can potentially compromise the aquatic ecosystems.

  12. Production of recombinant capsid protein of Macrobrachium rosenbergii nodavirus (r-MCP43) of giant freshwater prawn, M. rosenbergii (de Man) for immunological diagnostic methods.

    PubMed

    Farook, M A; Madan, N; Taju, G; Majeed, S Abdul; Nambi, K S N; Raj, N Sundar; Vimal, S; Hameed, A S Sahul

    2014-08-01

    White tail disease (WTD) caused by Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) is a serious problem in prawn hatcheries. The gene for capsid protein of MrNV (MCP43) was cloned into pRSET B expression vector. The MCP43 protein was expressed as a protein with a 6-histidine tag in Escherichia coli GJ1158 with NaCl induction. This recombinant protein, which was used to raise the antiserum in rabbits, recognized capsid protein in different WTD-infected post-larvae and adult prawn. Various immunological methods such as Western blot, dot blot and ELISA techniques were employed to detect MrNV in infected samples using the antiserum raised against recombinant MCP43 of MrNV. The dot blot assay using anti-rMCP43 was found to be capable of detecting MrNV in WTD-infected post-larvae as early as at 24 h post-infection. The antiserum raised against r-MCP43 could detect the MrNV in the infected samples at the level of 100 pg of total protein. The capsid protein of MrNV estimated by ELISA using anti-rMCP43 and pure r-MCP43 as a standard was found to increase gradually during the course of infection from 24 h p.i. to moribund stage. The results of immunological diagnostic methods employed in this study were compared with that of RT-PCR to test the efficiency of antiserum raised against r-MCP43 for the detection of MrNV. The Western blot, dot blot and ELISA detected all MrNV-positive coded samples as detected by RT-PCR.

  13. Cloning and immunoreactivity of the 5-HT1Mac and 5-HT2Mac receptors in the central nervous system of the freshwater prawn Macrobrachium rosenbergii

    PubMed Central

    Vázquez-Acevedo, Nietzell; Reyes-Colón, Dalynés; Ruíz-Rodríguez, Eduardo A.; Rivera, Nilsa M.; Rosenthal, Joshua; Kohn, Andrea B.; Moroz, Leonid L.; Sosa, María A.

    2009-01-01

    Biogenic amines are implicated in several mental disorders, many of which involve social interactions. Simple model systems, such as crustaceans, are often more amenable than vertebrates for studying mechanisms underlying behaviors. Although various cellular responses of biogenic amines have been characterized in crustaceans, the mechanisms linking these molecules to behavior remain largely unknown. Observed effects of serotonin receptor agonists and antagonists in abdomen posture, escape responses, and fighting have led to the suggestion that biogenic amine receptors may play a role in modulating interactive behaviors. As a first step in understanding this potential role of such receptors, we have cloned and fully sequenced two serotonin receptors, 5-HT1Mac and 5-HT2Mac, from the CNS of the freshwater prawn Macrobrachium rosenbergii, and have mapped their CNS immunohistochemical distribution. 5-HT1Mac was found primarily on the membranes of subsets of cells in all CNS ganglia, in fibers that traverse all CNS regions, and in the cytoplasm of a small number of cells in the brain, circum- and subesophageal ganglia (SEG), most of which also appear to contain dopamine. The pattern of 5-HT2Mac immunoreactivity was found to differ significantly, being found mostly in the central neuropil area of all ganglia, in glomeruli of the brain’s olfactory lobes, and in the cytoplasm of a small number of neurons in the SEG, thoracic and some abdominal ganglia. The observed differences in terms of localization, distribution within cells, and intensity of immunoreactive staining throughout the prawn’s CNS suggest that these receptors are likely to play different roles. PMID:19184976

  14. Isolated and combined exposure to ammonia and nitrite in giant freshwater pawn (Macrobrachium rosenbergii): effects on the oxidative stress, antioxidant enzymatic activities and apoptosis in haemocytes.

    PubMed

    Zhang, Yufan; Ye, Chaoxia; Wang, Anli; Zhu, Xuan; Chen, Changhong; Xian, Jianan; Sun, Zhenzhu

    2015-10-01

    The residual contaminators such as ammonia and nitrite are widely considered as relevant sources of aquatic environmental pollutants, posing a great threat to shrimp survival. To study the toxicological effects of ammonia and nitrite exposure on the innate immune response in invertebrates, we investigated the oxidative stress and apoptosis in haemocytes of freshwater prawn (Macrobrachium rosenbergii) under isolated and combined exposure to ammonia and nitrite in order to provide useful information about adult prawn immune responses. M. rosenbergii (13.44 ± 2.75 g) were exposed to 0, 5, and 25 mg/L total ammonia-N (TAN) and 0, 5, and 20 mg/L nitrite-N for 24 h. All ammonia concentrations were combined with all nitrite concentrations, making a total of nine treatments studied. Following the exposure treatment, antioxidant enzyme activity, reactive oxygen species (ROS) generation, nitric oxide (NO) generation, and apoptotic cell ratio of haemocytes were measured using flow cytometry. Results indicated that ROS generation was sensitive to the combined effect of ammonia and nitrite, which subsequently affected the Cu-Zn SOD activity. In addition, CAT showed the highest activity at 5 mg/L TAN while GPx decreased at 5 mg/L TAN and returned towards baseline at 25 mg/L. NO generation synchronized with the apoptotic cell ratio in haemocytes, indicating that NO production was closely associated with programmed cell death. Both NO production and apoptotic ratios significantly decreased following 25 mg/L TAN, which may be due to the antagonistic regulation of NO and GPx. We hypothesized that the toxicological effect of nitrite exhibited less change in physiological changes compared to that of ammonia, because of the high tolerance to nitrite exposure in mature M. rosenbergii and/or the competitive effects of chloride ions. Taken together, these results showed that ammonia and nitrite caused a series of combined oxidative stress and apoptosis in M. rosenbergi, but further

  15. Activity and Transcriptional Responses of Hepatopancreatic Biotransformation and Antioxidant Enzymes in the Oriental River Prawn Macrobrachium nipponense Exposed to Microcystin-LR.

    PubMed

    Yuan, Julin; Wang, Xueqin; Gu, Zhiming; Zhang, Yingying; Wang, Zaizhao

    2015-10-08

    Microcystins (MCs) are a major group of cyanotoxins with side effects in many organisms; thus, compounds in this group are recognized as potent stressors and health hazards in aquatic ecosystems. In order to assess the toxicity of MCs and detoxification mechanism of freshwater shrimp Macrobrachium nipponense, the full-length cDNAs of the glutathione S-transferase (gst) and catalase (cat) genes were isolated from the hepatopancreas. The transcription level and activity changes in the biotransformation enzyme (glutathione S-transferase (GST)) and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) in the hepatopancreas of M. nipponense exposed to MC-LR (0.2, 1, 5, and 25 μg/L) for 12, 24, 72 and 96 h were analyzed. The results showed that the isolated full-length cDNAs of cat and gst genes from M. nipponense displayed a high similarity to other crustaceans, and their mRNAs were mainly expressed in the hepatopancreas. MC-LR caused significant increase of GST activity following 48-96 h (p < 0.05) and an increase in SOD activity especially in 24- and 48-h exposures. CAT activity was activated when exposed to MC-LR in 12-, 24- and 48-h exposures and then it was inhibited at 96-h exposure. There was no significant effect on GPx activity after the 12- and 24-h exposures, whereas it was significantly stimulated after the 72- and 96-h exposures (p < 0.05). The transcription was altered similarly to enzyme activity, but the transcriptional response was generally more immediate and had greater amplitude than enzymatic response, particularly for GST. All of the results suggested that MC-LR can induce antioxidative modulation variations in M. nipponense hepatopancreas in order to eliminate oxidative damage.

  16. Regulation of laboratory populations of snails (Biomphalaria and Bulinus spp.) by river prawns, Macrobrachium spp. (Decapoda, Palaemonidae): implications for control of schistosomiasis

    PubMed Central

    Lafferty, Kevin D.; Kuris, Armand M.

    2014-01-01

    Human schistosomiasis is a common parasitic disease endemic in many tropical and subtropical countries. One barrier to achieving long-term control of this disease has been re-infection of treated patients when they swim, bathe, or wade in surface fresh water infested with snails that harbor and release larval parasites. Because some snail species are obligate intermediate hosts of schistosome parasites, removing snails may reduce parasitic larvae in the water, reducing re-infection risk. Here, we evaluate the potential for snail control by predatory freshwater prawns, Macrobrachium rosenbergii and M. vollenhovenii, native to Asia and Africa, respectively. Both prawn species are high value, protein-rich human food commodities, suggesting their cultivation may be beneficial in resource-poor settings where few other disease control options exist. In a series of predation trials in laboratory aquaria, we found both species to be voracious predators of schistosome-susceptible snails, hatchlings, and eggs, even in the presence of alternative food, with sustained average consumption rates of 12% of their body weight per day. Prawns showed a weak preference for Bulinus truncatus over Biomphalaria glabrata snails. Consumption rates were highly predictable based on the ratio of prawn: snail body mass, suggesting satiation-limited predation. Even the smallest prawns tested (0.5–2g) caused snail recruitment failure, despite high snail fecundity. With the World Health Organization turning attention toward schistosomiasis elimination, native prawn cultivation may be a viable snail control strategy that offers a win-win for public health and economic development. PMID:24388955

  17. The effects of serotonin, dopamine, gonadotropin-releasing hormones, and corazonin, on the androgenic gland of the giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Siangcham, Tanapan; Tinikul, Yotsawan; Poljaroen, Jaruwan; Sroyraya, Morakot; Changklungmoa, Narin; Phoungpetchara, Ittipon; Kankuan, Wilairat; Sumpownon, Chanudporn; Wanichanon, Chaitip; Hanna, Peter J; Sobhon, Prasert

    2013-11-01

    Neurotransmitters and neurohormones are agents that control gonad maturation in decapod crustaceans. Of these, serotonin (5-HT) and dopamine (DA) are neurotransmitters with known antagonist roles in female reproduction, whilst gonadotropin-releasing hormones (GnRHs) and corazonin (Crz) are neurohormones that exercise both positive and negative controls in some invertebrates. However, the effects of these agents on the androgenic gland (AG), which controls testicular maturation and male sex development in decapods, via insulin-like androgenic gland hormone (IAG), are unknown. Therefore, we set out to assay the effects of 5-HT, DA, l-GnRH-III, oct-GnRH and Crz, on the AG of small male Macrobrachium rosenbergii (Mr), using histological studies, a BrdU proliferative cell assay, immunofluorescence of Mr-IAG, and ELISA of Mr-IAG. The results showed stimulatory effects by 5-HT and l-GnRH-III through significant increases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). In contrast, DA and Crz caused inhibitory effects on the AG through significant decreases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). Moreover, the prawns treated with Crz died before day 16 of the experimental period. We propose that 5-HT and certain GnRHs can be now used to stimulate reproduction in male M. rosenbergii, as they induce increases in AG and testicular size, IAG production, and spermatogenesis. The mechanisms by which these occur are part of our on-going research.

  18. Preliminary obervations on use of ethanol distiller's by-products for polyculture of freshwater prawn (Macrobrachium rosenbergii) and golden shiner (Notemigonus crysoleucas)

    SciTech Connect

    Kohler, C.C.; Lewis, W.M.; Krueger, S.P.

    1983-01-01

    Two major by-products of ethanol distillation, corn distiller's solubles and corn distiller's mash, were evaluated for their potential use as a food source for freshwater prawn (Macrobrachium rosenbergii) and golden shiner (Notemigonus crysoleucas) in mid-western United States. Corn distiller's solubles were not found to be highly toxic to aquatic organisms at concentrations ranging up to 10,000 ppM. However, the high biological oxygen demand of the material requires that single applications not exceed 2000 ppM. Yield trials were conducted over a four month period in five 0.1 ha earthen ponds, located in proximity to an ethanol distillery. Each pond was stocked with 2000 postlarval shrimp (0.02 g mean weight). Three of these ponds were also each stocked with 75 adult golden shiner (27.0 g mean weight). One application of corn distiller's solubles (equivalent to approx. 2000 ppM) and three applications of corn distiller's mash (approx. 5 kg/application) were made over the course of the yield trails (approx. 120 days). No other food or fertilizer was added to the ponds. Survival of shrimp ranged from 34 to 75%. Survival of brood fish exceeded 90%. Mean weight of shrimp at harvest was approximately 12 g, and average production was equivalent to approximately 104 kg ha/sup -1/. Golden shiner reared in the same ponds as shrimp had production rates equivalent to approxmately 130 kg ha/sup -1/. The presence of fish did not appear to impede shrimp production. Although production results of fish and shrimp were encouraging, several factors existed which impeded production; these included: (1) little by-product was applied to ponds because the distillery was undergoing its shakedown period; (2) ponds were new and had minimal natural productivity; (3) grass was not fully established on the watershed and ponds became turbid; and (4) lower than normal temperatures prevailed over much of the growing period. 11 references, 2 figures, 8 tables.

  19. Responses of three very large inducible GTPases to bacterial and white spot syndrome virus challenges in the giant fresh water prawn Macrobrachium rosenbergii.

    PubMed

    Huang, Ying; Jin, Min; Yin, Shaowu; Ding, Zhengfeng; Wang, Wen; Ren, Qian

    2016-04-01

    Interferons (IFNs) are cytokines secreted by cells in response to invasion by pathogens, such as viruses, bacteria, parasites, or tumor cells. Very large inducible GTPases (VLIG) are the latest IFN-inducible GTPase family to be discovered and are the largest known GTPases of any species. However, VLIG proteins from invertebrates have yet to be characterized. In this study, three forms of VLIGs designated as MrVLIG1, MrVLIG2, and MrVLIG3 were cloned from the giant fresh water prawn Macrobrachium rosenbergii. MrVLIG1 has a 5445 bp open reading frame (ORF) encoding an 1814-amino acid protein. The complete nucleotide sequence of MrVLIG2 cDNA is 7055 bp long consisting of a 5757 bp ORF encoding a protein with 1918 amino acids. The full length of the MrVLIG3 gene consists of 5511 bp with a 3909 bp ORF encoding a peptide with 1302 amino acids. BLASTP and phylogenetic tree analyses showed that the three MrVLIGs are clustered into one subgroup and, together with other vertebrate VLIGs, into a branch. Tissue distribution analysis indicated that the mRNAs of the three MrVLIGs were widely expressed in almost all detected tissues, including the hemocytes, heart, hepatopancreas, gills, stomach, and intestine, with the highest expression in the hepatopancreas. They were also detected in the intestine but with relatively low expression levels. Quantitative real-time RT-PCR analysis showed that the mRNA transcripts of the MrVLIGs in the hepatopancreas were significantly expressed at various time points after infection with Vibrio parahaemolyticus and white spot syndrome virus. In summary, the three isoforms of VLIG genes participate in the innate immune response of the shrimps to bacterial and viral infections.

  20. Dietary effects of Azolla pinnata combined with exogenous digestive enzyme (Digestin™) on growth and nutrients utilization of freshwater prawn, Macrobrachium rosenbergii (de Man 1879)

    NASA Astrophysics Data System (ADS)

    Goda, Ashraf; Saad, Amal; Hanafy, Mohamed; Sharawy, Zaki; El-Haroun, Ehab

    2017-07-01

    The present study was conducted to evaluate the effect of either individual or combined wheat bran (WB) replacement with Azolla pinnata supplemented with Digestin™ in the diet of freshwater prawn,Macrobrachium rosenbergii Postlarvae (PL) on growth performance, nutrient utilization, chemical body composition and survival (%). Experimental diets were a wheat bran-soybean based diet with no Azolla and Digestin TM (control, T1), and diets containing 17% Azolla supplemented with Digestin TM 0% (T2), 1% (T3), 2% (T4) and 3% (T5). Each experimental diet was allocated into three tanks (6m3/tank) fed for 12 wks. Each tank was subdivided into three equal pens by nets (2m3) and stoked with 84 PL/m2. The experimental diets were readily consumed by prawns PLs where both high growth and good feed efficiency were achieved for all diets. The results showed that the diets containing A. pinnata supplemented with Digestin™ at the level up to 3% have the higher growth and better nutrient utilization than the control diet. No differences were observed for moisture and protein content among the experimental diets. However, the highest protein content was observed on prawns fed on diets T1 and T5 respectively, while the lowest value was recorded for T 4 diet. The results also show that prawn PLs fed the diets contain A. pinnata and supplemented with Digestin TM recorded the highest values of body lipid content compared to the control diet. Feed efficiency and economic conversion rate (ECR) values show that economic performance and the cost-effectiveness of the A. pinnata supplemented with up to 3% Digestin TM recorded the highest net return, and therefore it is recommended for prawn, M. rosenbergii PL's. These results are clearly indicating that A. pinnata have a good potential for use in prawn diets at reasonable levels than other conventional diets.

  1. Identification and evaluation of reference genes for expression studies by RT-qPCR during embryonic development of the emerging model organism, Macrobrachium olfersii.

    PubMed

    Jaramillo, Michael L; Ammar, Dib; Quispe, Ruth L; Guzman, Frank; Margis, Rogerio; Nazari, Evelise M; Müller, Yara M R

    2017-01-20

    RT-qPCR is a sensitive and highly efficient technique that is widely used in gene expression analysis and to provide insight into the molecular mechanisms underlying embryonic development. The freshwater prawn, Macrobrachium olfersii is an emerging model organism, but, the stable reference genes of this species need to be identified and validated for RT-qPCR analysis. Thus, the aim of this study was to evaluate the expression stability of six genes (β-act, GAPDH, EF-1α, RpL8, RpS6, AK) in embryos and in adult tissues (cerebral ganglia, muscle and hepatopancreas) of M. olfersii. The expression stabilities of these genes were evaluated using geNorm, NormFinder, BestKeeper, ΔCt method and integrated tool RefFinder. In the general ranking, RpL8 and RpS6 were the most stable genes in embryos, while RpS6 and RpL8 were the most stable in a combined adult tissue analysis. Analysis of the adult tissues revealed that β-act and AK were the most stable genes in cerebral ganglia, RpL8 and AK in muscle, and RpS6 and β-act in hepatopancreas. EF-1α and GAPDH were the least stable genes and as normalizer genes in RT-qPCR affected expression of the Distal-less gene during M. olfersii development. This study provides suitable reference genes for RT-qPCR analysis and allows future studies of the gene expression in M. olfersii for understanding the molecular mechanisms of their development. To our knowledge, this is the first published study that identifies and evaluates reference genes for RT-qPCR analysis in M. olfersii and could be useful as basis for evaluations of reference genes in other prawns. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effects of dietary administration of water hyacinth (Eichhornia crassipes) extracts on the immune responses and disease resistance of giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Chang, Chin-Chyuan; Tan, Hui-Ching; Cheng, Winton

    2013-07-01

    The hot-water extract of Eichhornia crassipes leaves (ECE) was produced and incorporated into the diet of the prawn, Macrobrachium rosenbergii, as an immunostimulant. Survival rates of prawn against Lactococcus garvieae, and its immune parameters including the total haemocyte count (THC), different haemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, transglutaminase (TG) activity, haemolymph coagulation time, and phagocytic activity and clearance efficiency against L. garvieae by M. rosenbergii were determined when prawn (23.0 ± 2.8 g) were fed ECE-containing diets at 0, 1.0, 2.0 and 3.0 g kg(-1). Prawn fed a diet containing ECE at 2.0 and 3.0 g kg(-1) for 12 days showed significantly increased THC, HC, GC, PO activity, RBs, SOD activity, GPx activity, and TG activity, and a significantly decreased coagulation time. The phagocytic activity and clearance efficiency against L. garvieae of prawn fed the ECE-containing diets at 1.0, 2.0, and 3.0 g kg(-1) were significantly higher than those of prawn fed the control diet at 3-12 days. Survival rates of M. rosenbergii fed the diet containing ECE at concentrations of 2 and 3 g kg(-1) were significantly higher than those fed the control diet after challenge with L. garvieae for 48-144 h. The relative percentage survival of prawn fed the 1.0, 2.0, and 3.0 g kg(-1) ECE-containing diets for 12 days were 17.5%, 39.1%, and 52.2%. It was concluded that the ECE can be used as an immunostimulant for prawn through dietary administration to enhance immune responses and resistance of M. rosenbergii against L. garvieae.

  3. Low pH affects survival, growth, size distribution, and carapace quality of the postlarvae and early juveniles of the freshwater prawn Macrobrachium rosenbergii de Man

    NASA Astrophysics Data System (ADS)

    Kawamura, Gunzo; Bagarinao, Teodora; Yong, Annita Seok Kian; Chen, Chiau Yu; Noor, Siti Norasidah Mat; Lim, Leong Seng

    2015-06-01

    Acidification of rain water caused by air pollutants is now recognized as a serious threat to aquatic ecosystems. We examined the effects of low pH (control pH 7.5, pH 6, pH 5, pH 4) on the survival, growth, and shell quality of Macrobrachium rosenbergii postlarvae and early juveniles in the laboratory. Hatcheryproduced postlarvae (PL 5) were stocked at 250 PL per aquarium, acclimated over 7 d to experimental pH adjusted with hydrochloric acid, and reared for 30 d. Dead specimens were removed and counted twice a day. After 27 d rearing, all specimens were measured for total length and body weight. Carapace quality was assessed by spectrophotometry. Survival of juveniles was highest at pH 6 (binomial 95% confidence interval 79 - 89%) followed by control pH 7.5 (56 - 68%) and pH 5 (50 - 60%) and was lowest for unmetamorphosed postlarvae and juveniles at pH 4 (43 - 49%). The final median total length and body weight of juveniles were similar at control pH 7.5 (18.2 TL, 50.2 mg BW) and pH 6 (17.7 mm TL, 45.0 mg BW) but significantly less at pH 5 (16.7 mm TL, 38.2 mg BW); at pH 4, the postlarvae did not metamorphose and measured only 9.8 mm TL, 29.3 mg BW. Length frequency distribution showed homogeneous growth at pH 6, positive skew at control pH 7.5 and pH 5, and extreme heterogeneity at pH 4. The carapace showed different transmittance spectra and lower total transmittance (i.e. thicker carapace) in juveniles at pH 7.5, pH 6, and pH 5 than in unmetamorphosed postlarvae and juveniles with thinner carapace at pH 4. Thus, survival, growth, size distribution, and carapace quality of M. rosenbergii postlarvae and early juveniles were negatively affected by pH 5 and especially pH 4. The thinner carapace of the survivors at pH 4 was mostly due to their small size and failure to metamorphose. Natural waters affected by acid rain could decimate M. rosenbergii populations in the wild.

  4. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50 nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18 mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18 mg Mn-oxide NPs/kg shows enhanced (P<0.05) growth performance, including final weight and weight gain (WG). Significant differences (P<0.05) in feed conversion ratio (FCR) were observed in prawn fed with different diets. Additionally, prawns fed with 3.0-18 mg/kg Mn-oxide NPs supplemented diets achieved significant (P<0.05) improvement in growth performance, digestive enzyme activities and muscle biochemical compositions, while, the prawns fed with 16 mg/kg of Mn-oxide NPs showed enhanced performance. Prawns fed on diet supplemented with 16 mg/kg Mn-oxide NPs showed significantly (P<0.05) higher total protein level. The antioxidants enzymatic activity (SOD and CAT) metabolic enzymes status in muscle and hepatopancreas showed no significant (P>0.05) alterations in prawns fed with 3.0-18 mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16 mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16 mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Changes of Phosphatidylcholine and Fatty Acids in Germ Cells during Testicular Maturation in Three Developmental Male Morphotypes of Macrobrachium rosenbergii Revealed by Imaging Mass Spectrometry

    PubMed Central

    Siangcham, Tanapan; Chansela, Piyachat; Hayasaka, Takahiro; Masaki, Noritaka; Sroyraya, Morakot; Poljaroen, Jaruwan; Suwansa-ard, Saowaros; Engsusophon, Attakorn; Hanna, Peter J.; Sobhon, Prasert; Setou, Mitsutoshi

    2015-01-01

    Testis maturation, germ cell development and function of sperm, are related to lipid composition. Phosphatidylcholines (PCs) play a key role in the structure and function of testes. As well, increases of polyunsaturated fatty acids (PUFA) and highly unsaturated fatty acids (HUFA), especially arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are essential for male fertility. This study is the first report to show the composition and distribution of PCs and total fatty acids (FAs) in three groups of seminiferous tubules (STs) classified by cellular associations [i.e., A (STs with mostly early germ cells), B (STs with mostly spermatids), and C (STs with spermatozoa)], in three morphotypes of Macrobrachium rosenbergii, [i.e., small male (SM), orange claw male (OC), and blue claw male (BC)]. Thin layer chromatography exhibited levels of PCs reaching maxima in STs of group B. Imaging mass spectrometry showed remarkably high signals corresponding to PC (16:0/18:1), PC (18:0/18:2), PC (18:2/20:5), and PC (16:0/22:6) in STs of groups A and B. Moreover, most signals were detected in the early developing cells and the intertubular area, but not at the area containing spermatozoa. Finally, gas chromatography-mass spectrometry indicated that the major FAs present in the testes were composed of 14:0, 16:0, 17:0, 18:0, 16:1, 18:1, 18:2, 20:1, 20:2, 20:4, 20:5, and 22:6. The testes of OC contained the greatest amounts of these FAs while the testes of BC contained the least amounts of these FAs, and there was more EPA (20:5) in the testes of SM and OC than those in the BC. The increasing amounts of FAs in the SM and OC indicate that they are important for spermatogenesis and spermiogenesis. This knowledge will be useful in formulating diets containing PUFA and HUFA for prawn broodstocks in order to improve testis development, and lead to increased male fecundity. PMID:25781176

  6. Effects of anthraquinone extract from Rheum officinale Bail on the growth performance and physiological responses of Macrobrachium rosenbergii under high temperature stress.

    PubMed

    Liu, Bo; Xie, Jun; Ge, Xianping; Xu, Pao; Wang, Aiming; He, Yijin; Zhou, Qunlan; Pan, Liangkun; Chen, Ruli

    2010-07-01

    In order to study the effects of anthraquinone extract from Rheum officinale Bail on Macrobrachium rosenbergii under high temperature stress, freshwater prawns were randomly divided into five groups: a control group was fed with basal diet, and four treatment groups fed with basal diet supplemented with 0.05%, 0.1%, 0.2%, and 0.4% anthraquinone extracts for 10 weeks, respectively. Then, freshwater prawns were exposed to high temperature stress at 35 degrees C for 48h. The growth, changes in haemolymph total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lysozyme, nitrogen monoxide (NO) and hepatic catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) were investigated. The results showed that compared the control group, the specific growth rates, feed conversion efficiency, haemolymph ALP and lysozyme activities, total protein contents, hepatic CAT and SOD activities increased while haemolymph AST, ALT and hepatic MDA contents decreased in treatment groups before the stress, but their levels did not correlate with the doses of anthraquinone extracts. The specific growth rate (SGR), feed conversion efficiency and haemolymph lysozyme activity significantly increased but haemolymph AST activity decreased in 0.1% dose group; whereas haemolymph ALP activity and feed conversion efficiency increased but ALT activity and hepatic MDA contents significantly decreased in 0.2% dose group before the stress compared with the control. After high temperature stress, 0.1-0.2% anthraquinone extract also could improve the haemolymph total proteins, lysozyme and ALP activities, hepatic catalase, and superoxide dismutase, and reduce haemolymph ALT and AST activities, hepatic malondialdehyde contents. The cumulative mortality in the control was about 100% at 48h after high temperature stress while the cumulative mortality in the treatment groups supplemented with 0.1-0.2% anthraquinone extract were about 48-65%. The

  7. Effects of arachidonic acid supplementation in maturation diet on female reproductive performance and larval quality of giant river prawn (Macrobrachium rosenbergii)

    PubMed Central

    Pratoomyot, Jarunan; Siranonthana, Nisa; Senanan, Wansuk

    2016-01-01

    The giant river prawn (Macrobrachium rosenbergii) is one of the most farmed freshwater crustaceans in the world. Its global production has been stalling in the past decade due to the inconsistent quality of broodstock and hatchery-produced seeds. A better understanding of the role of nutrition in maturation diets will help overcome some of the production challenges. Arachidonic acid (20:4 n-6, ARA) is a fatty acid precursor of signaling molecules important for crustacean reproduction, prostaglandins E and F of the series II (PGE2 and PGF2α), and is often lacking in maturation diets of shrimp and prawns. We examined the effects of ARA in a combination of different fish oil (FO) and soybean oil (SO) blends on females’ reproductive performance and larval quality. Adult females (15.22 ± 0.13 g and 11.12 ± 0.09 cm) were fed six isonitrogenous and isolipidic diets containing one of two different base compositions (A or B), supplemented with one of three levels of Mortierella alpine-derived ARA (containing 40% active ARA): 0, 1 or 2% by ingredient weight. The two base diets differed in the percentages of (FO and SO with diet A containing 2% SO and 2% FO and diet B containing 2.5% SO and 1.5% FO, resulting in differences in proportional contents of dietary linoleic acid (18:2n-6, LOA) and docosahexaenoic acid (22:6n-3, DHA)). After the eight-week experiment, prawns fed diet B with 1 and 2% ARA supplement (B1 and B2) exhibited the highest gonadosomatic index (GSI), hepatosomatic index (HSI), egg clutch weight, fecundity, hatching rate, number of larvae, and reproductive effort compared to those fed other diets (p ≤ 0.05). Larvae from these two dietary treatments also had higher tolerance to low salinity (2 ppt). The maturation period was not significantly different among most treatments (p ≥ 0.05). ARA supplementation, regardless of the base diet, significantly improved GSI, HSI, egg clutch weight and fecundity. However, the diets with an enhanced ARA and LOA

  8. Transciptomic and histological analysis of hepatopancreas, muscle and gill tissues of oriental river prawn (Macrobrachium nipponense) in response to chronic hypoxia.

    PubMed

    Sun, Shengming; Xuan, Fujun; Fu, Hongtuo; Zhu, Jian; Ge, Xianping; Gu, Zhimin

    2015-07-03

    Oriental river prawn, Macrobrachium nipponense, is a commercially important species found in brackish and fresh waters throughout China. Chronic hypoxia is a major physiological challenge for prawns in culture, and the hepatopancreas, muscle and gill tissues play important roles in adaptive processes. However, the effects of dissolved oxygen availability on gene expression and physiological functions of those tissues of prawns are unknown. Adaptation to hypoxia is a complex process, to help us understand stress-sensing mechanism and ultimately permit selection for hypoxia- tolerant prawns, we performed transcriptomic analysis of juvenile M. nipponense hepatopancreas, gill and muscle tissues by RNA-Seq. Approximately 46,472,741; 52,773,612 and 58,195,908 raw sequence reads were generated from hepatopancreas, muscle and gill tissues, respectively. A total of 62,722 unigenes were generated, of the assembled unigenes, we identified 8,892 genes that were significantly up-regulated, while 5,760 genes were significantly down-regulated in response to chronic hypoxia. Genes from well known functional categories and signaling pathways associated with stress responses and adaptation to extreme environments were significantly enriched, including genes in the functional categories "response to stimulus", "transferase activity" and "oxidoreductase activity", and the signaling pathways "oxidative phosphorylation", "glycolysis/gluconeogenesis" and "MAPK signaling". The expression patterns of 18 DEGs involved in hypoxic regulation of M. nipponense were validated by quantitative real-time reverse-transcriptase polymerase chain reactions (qRT-PCR; average correlation coefficient = 0.94). In addition, the hepatopancreas and gills exhibited histological differences between hypoxia and normoxia groups. These structural alterations could affect the vital physiological functions of prawns in response to chronic hypoxia, which could adversely affect growth and survival of M. nipponense

  9. Evaluation of paraprobiotic applicability of Lactobacillus plantarum in improving the immune response and disease protection in giant freshwater prawn, Macrobrachium rosenbergii (de Man, 1879).

    PubMed

    Dash, Gyanaranjan; Raman, Ram Prakash; Pani Prasad, K; Makesh, M; Pradeep, M A; Sen, Swatipriyanka

    2015-03-01

    Paraprobiotics, also known as ghost probiotics, are non-viable microbial cells which, when administered in adequate amounts, confer a benefit on the host. However, the advantage of non-viable microbes over their viable counterparts is a much debated topic in aquaculture. Therefore, the present study was conducted to evaluate paraprobiotic effect of heat-killed Lactobacillus plantarum on giant freshwater prawn Macrobrachium rosenbergii. A 90-day feeding trial was conducted by feeding prawn juveniles (mean weight ± SE: 0.54 ± 0.03 g) with three experimental diets prepared by supplementing basal diet (Crude protein: 38%; Gross energy: 387 kcal 100 g(-1)) with different concentrations of heat-killed probiotics bacteria viz. HKPB1 (10(7) cfu g(-1) diet), HKPB2 (10(8) cfu g(-1) diet), HKPB3 (10(9) cfu g(-1) diet) and control diet (unsupplemented diet). In the present study, growth parameters viz. WG % and SGR and feed utilization parameters viz. FCE, FCR and PER, though improved marginally in all experimental groups, were found to be insignificant (P > 0.05) compared to the control. The immune parameters viz. total hemocyte count (THC), phenol oxidase (PO) activity, respiratory burst (RB) activity and clearance efficiency were significantly improved (P < 0.05) with concurrent decrease (P < 0.05) in cumulative mortality against Aeromonas hydrophila challenge in all the experimental groups except for HKPB1, where PO and RB activity did not improve significantly (P > 0.05) compared to the control. Among the experimental groups, though the improvement in immune parameters was higher (P < 0.05) in HKPB2 and HKPB3 compared to HKPB1 and the control, no significant difference (P > 0.05) was observed between HKPB2 and HKPB3. The results obtained from the present study indicate that the application of heat-killed L. plantarum at a concentration of 10(8) cfu g(-1) diet, though not effective in augmenting the growth and feed utilization parameters, can significantly improve immune

  10. EMS Student Handbook.

    ERIC Educational Resources Information Center

    Ogle, Patrick

    This student guide is one of a series of self-contained materials for students enrolled in an emergency medical services (EMS) training program. Discussed in the individual sections of the guide are the following topics: the purpose and history of EMS professionals; EMS training, certification and examinations (national and state certification and…

  11. Dietary Supplementation of Magnesium Oxide (MgO) Nanoparticles for Better Survival and Growth of the Freshwater Prawn Macrobrachium rosenbergii Post-larvae.

    PubMed

    Srinivasan, Veeran; Bhavan, Periyakali Saravana; Rajkumar, Gopalan; Satgurunathan, Thangavelu; Muralisankar, Thirunavukkarasu

    2016-10-05

    This study was performed to assess the growth-promoting potential of dietary magnesium oxide nanoparticles (MgO NPs) in Macrobrachium rosenbergii post-larvae (PL). MgO NPs were supplemented at 0, 100, 200, 300, 400 and 500 mg kg(-1) with the basal diet (containing 0.95 g Mg kg(-1)); the concentrations of Mg in MgO NP-supplemented diets were increased correspondingly (1.07, 1.15, 1.24, 1.37 and 1.46 g Mg kg(-1) respectively). MgO NP-supplemented diets were fed to M. rosenbergii PL (initial weight 0.11 ± 0.04 g) for a period of 90 days. In the carcasses of experimental prawns, the content of Mg was found to be elevated significantly with respect to the individual diet (102.14, 183.29, 205.46, 221.03, 237.10 and 254.36 μg Mg g(-1) respectively) when compared with that of the control. The contents of Cu, Zn, Fe, Ca, Na and K levels were also found to be elevated in the carcasses of experimental prawns. Significant (P < 0.05) improvements were observed in nutritional indices [survival rate (SR), weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER)], activities of digestive enzymes (protease, amylase and lipase), concentrations of basic biochemical constituents (total protein, amino acid, carbohydrate, lipid, profiles of amino acids and fatty acids) and population of haemocytes [total and differential (hyalinocytes, semigranulocytes and granulocytes)] in all the test PL. Maximum performance was recorded in 500 mg kg(-1) MgO NP-supplemented-feed-fed PL. There were no significant elevations recorded in activities of antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)], lipid peroxidation (LPO) and metabolic enzymes [glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT)] recorded in any of the MgO NP-supplemented-feed-fed PL when compared with the control. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed increases in the staining

  12. EM International. Volume 1

    SciTech Connect

    Not Available

    1993-07-01

    It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.

  13. Leveraging EMS and VPP

    DTIC Science & Technology

    2009-05-01

    Elements of EMS  International Standards Organization ( ISO ) 14001 , Environmental Management Systems  The Key Elements of EMS: - Policy - Planning...wingman-- ON and OFF duty Fully Conforming vs. Fully Implemented  “Fully Conforming”  Meets standards established in ISO 14001  ESOH council...e n c e Every airman looking out for his wingman-- ON and OFF duty EMS & VPP Commonalities Environmental Management System ISO 14001 : 2004 Voluntary

  14. EMS in the pueblos.

    PubMed

    Vigil, M A

    1994-02-01

    Imagine creating a movie by excerpting scenes from "Dances With Wolves," splicing it with footage from "Code 3" or "Emergency Response" and then flavoring the script with the mystery of a Tony Hillerman novel. A film producer would probably find it quite difficult to choreograph a finished product from such a compilation of material. To hundreds of Native American EMS providers, however, such a movie is played out every day in Indian country. And with this movie come some real-life problems, including trauma, which is the number-one cause of premature death among Native Americans. But a high trauma rate is just one of the challenges facing tribal EMS responders. There's also prolonged response and transport, the problems involved in maintaining the unique culture and standard of care, the challenges of tribal EMS administration and EMS education of Native American students, and the unsure future of Native American EMS. Beyond that, there's the fact that EMS is a s unique to each Indian reservation as are the cultures of the native peoples who reside on these lands. Yet while no two systems are alike, most tribal EMS providers face similar challenges.

  15. The effect of banana (Musa acuminata) peels hot-water extract on the immunity and resistance of giant freshwater prawn, Macrobrachium rosenbergii via dietary administration for a long term: Activity and gene transcription.

    PubMed

    Rattanavichai, Wutti; Chen, Ying-Nan; Chang, Chin-Chyuan; Cheng, Winton

    2015-10-01

    The non-specific immune parameters, disease resistance and immune genes expressions in Macrobrachium rosenbergii were evaluated at 120 days of post feeding the diets containing the extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). Results showed that prawns fed with a diet containing BPE at the level of 1.0, 3.0 and 6.0 g kg(-1) for 120 days had a significantly higher survival rate (30.0%, 40.0% and 56.7%, respectively) than those fed with the control diet after challenge with Lactococcus garvieae for 144 h, and the respective relative survival percentages were 22.2%, 33.3%, and 51.9%, respectively. Dietary BPE supplementation at 3.0 and/or 6.0 g kg(-1) for 120 days showed a significant increase total haemocyte count (THC), granular cell (GC), superoxide dismutase (SOD) activity, phenoloxidase (PO) activity, transglutaminase (TG) activity, and phagocytic activity and clearance efficiency to L. garvieae infection, and meanwhile, the significant decrease in haemolymph clotting times and respiratory bursts (RBs) per haemocyte of prawns were revealed. Furthermore, the mRNA expressions of prophenoloxidase (proPO), lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PE), transglutaminase (TG), and crustin (CT) were significantly increased. We therefore recommend that BPE can be used as an immunomodulator for prawns through dietary administration at 6.0 g kg(-1) for a long term (over 120 days) to modify immune responses and genes expression following the enhanced resistance against pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Using occupancy modeling and logistic regression to assess the distribution of shrimp species in lowland streams, Costa Rica: Does regional groundwater create favorable habitat?

    USGS Publications Warehouse

    Snyder, Marcia; Freeman, Mary C.; Purucker, S. Thomas; Pringle, Catherine M.

    2016-01-01

    Freshwater shrimps are an important biotic component of tropical ecosystems. However, they can have a low probability of detection when abundances are low. We sampled 3 of the most common freshwater shrimp species, Macrobrachium olfersii, Macrobrachium carcinus, and Macrobrachium heterochirus, and used occupancy modeling and logistic regression models to improve our limited knowledge of distribution of these cryptic species by investigating both local- and landscape-scale effects at La Selva Biological Station in Costa Rica. Local-scale factors included substrate type and stream size, and landscape-scale factors included presence or absence of regional groundwater inputs. Capture rates for 2 of the sampled species (M. olfersii and M. carcinus) were sufficient to compare the fit of occupancy models. Occupancy models did not converge for M. heterochirus, but M. heterochirus had high enough occupancy rates that logistic regression could be used to model the relationship between occupancy rates and predictors. The best-supported models for M. olfersii and M. carcinus included conductivity, discharge, and substrate parameters. Stream size was positively correlated with occupancy rates of all 3 species. High stream conductivity, which reflects the quantity of regional groundwater input into the stream, was positively correlated with M. olfersii occupancy rates. Boulder substrates increased occupancy rate of M. carcinus and decreased the detection probability of M. olfersii. Our models suggest that shrimp distribution is driven by factors that function at local (substrate and discharge) and landscape (conductivity) scales.

  17. EMS in Mauritius.

    PubMed

    Ramalanjaona, Georges; Brogan, Gerald X

    2009-02-01

    Mauritius lies in the southwest Indian Ocean about 1250 miles from the African coast and 500 miles from Madagascar. Mauritius (estimated population 1,230,602) became independent from the United Kingdom in 1968 and has one of the highest GDP per capita in Africa. Within Mauritius there is a well established EMS system with a single 999 national dispatch system. Ambulances are either publicly or privately owned. Public ambulances are run by the Government (SAMU). Megacare is a private subscriber only ambulance service. The Government has recently invested in new technology such as telemedicine to further enhance the role of EMS on the island. This article describes the current state of EMS in Mauritius and depicts its development in the context of Government effort to decentralise and modernise the healthcare system.

  18. EMS -- Error Message Service

    NASA Astrophysics Data System (ADS)

    Rees, P. C. T.; Chipperfield, A. J.; Draper, P. W.

    This document describes the Error Message Service, EMS, and its use in system software. The purpose of EMS is to provide facilities for constructing and storing error messages for future delivery to the user -- usually via the Starlink Error Reporting System, ERR (see SUN/104). EMS can be regarded as a simplified version of ERR without the binding to any software environment (e.g., for message output or access to the parameter and data systems). The routines in this library conform to the error reporting conventions described in SUN/104. A knowledge of these conventions, and of the ADAM system (see SG/4), is assumed in what follows. This document is intended for Starlink systems programmers and can safely be ignored by applications programmers and users.

  19. National EMS Research Agenda.

    PubMed

    Sayre, M R; White, L J; Brown, L H; McHenry, S D

    2002-01-01

    Now, more than ever before, the spirit of the emergency services professional is recognized by people everywhere. Individuals from every walk of life comprehend the reality of the job these professionals do each day. Placing the safety of others above their own is their acknowledged responsibility. Rescue and treatment of ill and injured patients are their purpose as well as their gratification. The men and women who provide prehospital care are well aware of the unpredictable nature of emergency medical services (EMS). Prehospital care is given when and where it is needed: in urban settings with vertical challenges and gridlock; in rural settings with limited access; in confined spaces; within entrapments; or simply in the street, exposed to the elements. Despite the challenges, EMS professionals rise to the occasion to do their best with the resources available. Despite more than 30 years of dedicated service by thousands of EMS professionals, academic researchers, and public policy makers, the nation's EMS system is treating victims of illness and injury with little or no evidence that the care they provide is optimal. A national investment in the EMS research infrastructure is necessary to overcome obstacles currently impeding the accumulation of essential evidence of the effectiveness of EMS practice. Funding is required to train new researchers and to help them establish their careers. Financial backing is needed to support the development of effective prehospital treatments for the diseases that drive the design of the EMS system, including injury and sudden cardiac arrest. Innovative strategies to make EMS research easier to accomplish in emergency situations must be implemented. Researchers must have access to patient outcome information in order to evaluate and improve prehospital care. New biomedical and technical advances must be evaluated using scientific methodology. Research is the key to maintaining focus on improving the overall health of the

  20. Effect of feeding frequency on growth, body composition, antioxidant status and mRNA expression of immunodependent genes before or after ammonia-N stress in juvenile oriental river prawn, Macrobrachium nipponense.

    PubMed

    Ding, Zhili; Kong, Youqin; Zhang, Yixiang; Li, Jingfen; Cao, Fang; Zhou, Junbo; Ye, Jinyun

    2017-09-01

    Feeding frequency is important for the improvement of growth performance and immunity of aquatic animals. In this study, the effect of feeding frequency on growth, body composition, antioxidant status and mRNA expression of immunodependent genes before or after ammonia-N stress was examined in Macrobrachium nipponense. Prawns were randomly assigned to one of five feeding frequencies (1, 2, 3, 4 and 6 times/day) following the same ration size over an 8-week growth trial. After the feeding trial, prawns were challenged by ammonia-N. The weight gain of prawns fed with 3-6 times/day was significantly higher than that of prawns fed with 1 time/day. The best feed conversion ratio was obtained from prawns fed with 3-6 times/day. Body crude lipid with feeding frequency of 3, 4 or 6 times/day was quite lower than that with 1 time/day. High feeding frequency (6 times/day) induced significantly elevated hepatopancreas super oxide dismutase and catalase activities. The malondialdehyde level in prawns fed with 6 times/day was also significantly increased, which was higher than that of prawns fed with other feeding frequency. mRNA expression of toll like receptor 3 and myeloid differentiation primary response protein MyD88 was promoted by feeding frequency from 3 to 4 time/day but inhibited by high or low feeding frequency. Similar mRNA expression variation trends of the two genes were observed in prawns after ammonia-N stress. After ammonia-N challenge, the highest cumulative mortality was observed in prawns fed with 6 times/day, which was significantly higher than that of prawns fed with 2-4 times/day. These findings demonstrate that (1) too high feeding frequency induced oxidative stress and malondialdehyde accumulation, negatively affecting the health status of prawns and reduced its resistance to ammonia-N stress; (2) the optimal feeding frequency to improve growth and immune response of this species at juvenile stage is 3-4 times/day; (3) considering costs of labour, a

  1. Characterization and expression pattern of KIFC1-like kinesin gene in the testis of the Macrobrachium nipponense with discussion of its relationship with structure lamellar complex (LCx) and acroframosome (AFS).

    PubMed

    Wang, Yan-Ting; Mao, Huan; Hou, Cong-Cong; Sun, Xiao; Wang, Da-Hui; Zhou, Hong; Yang, Wan-Xi

    2012-07-01

    Spermiogenesis is a developmental process undergoing continuous differentiation to drive a diploid spermatogonium towards a haploid sperm cell. This striking transformation from spermatogonium to spermatozoa is made possible by the stage-specific adaption of cytoskeleton and associated molecular motor proteins. KIFC1 is a C-terminal kinesin motor found to boast essential roles in acrosome biogenesis and nuclear reshaping during spermiogenesis in rat. To explore its functions during the same process in Macrobrachium nipponense, we have cloned and sequenced the cDNA of a mammalian KIFC1 homologue (termed mn-KIFC1) from the total RNA of the testis. The 2,296 bp mn-KIFC1 cDNA contained a 87 bp 5' untranslated region, a 211 bp 3' untranslated region and a 1,998 bp open reading frame. Protein alignment demonstrated that mn-KIFC1 had 37.7, 58.7, 38.4, 37.2, 38.9 and 37.8% identity with its homologues in Salmo salar, Eriocheir sinensis, Homo sapiens, Mus musculus, Danio rerio and Xenopus laevis respectively. The phylogenetic tree revealed that mn-KIFC1 is most related to E. Sinensis KIFC1 among the examined species. Tissue expression analysis showed the presence of mn-KIFC1 in the testis, hepatopancreas, gill, muscle and heart. In situ hybridization showed that the mn-KIFC1 mRNA was localized at the periphery of the nuclear membrane and in the proacrosomal vesicle in early and middle spermatids. In late spermatids and spermatozoa, mn-KIFC1 was expressed in the acrosome and in the spike. In situ hybridization also indicated that KIFC1 works together with lamellar complex (LCx) and acroframosome (AFS) to drive acrosome formation and cellular transformation. LCx and AFS have both been previously proved to have essential roles during spermiogenesis in M. nipponense. In conclusion, the expression of mn-kifc1 at specific stages of spermiogenesis suggests a role in cellular transformations in M. nipponense.

  2. Dietary supplement of banana (Musa acuminata) peels hot-water extract to enhance the growth, anti-hypothermal stress, immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Rattanavichai, Wutti; Cheng, Winton

    2015-04-01

    In the present study, Macrobrachium rosenbergii were fed with diets containing extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). The non-specific immune parameters, disease resistance and anti-hypothermal stress were evaluated at 2, 4, 8, 16 and 32 days of post feeding. Also, we demonstrated the percent weight gain (PWG), percent length gain (PLG), feeding efficiency (FE), and survival rate of giant freshwater prawn at 30, 60, 90, and 120 days of post feeding. The PWG, PLG, FE and survival rate of prawns fed at 0, 1.0, 3.0 and 6.0 g kg(-1) BPE-containing diets after 120 days were 69.5%, 75.4%, 77.8% and 83.3%; 21.8%, 23.6%, 27.8% and 33.9%; 0.60, 0.72, 0.75 and 0.90; and 55.4%, 62.2%, 62.3% and 75.3%, respectively. After 32 days of post feeding, a significant increase in total haemocyte count (THC), different haemocyte count (DHC), respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phenoloxidase (PO) activity and transglutaminase (TG) activity, and meanwhile, a decreased haemolymph coagulation time was observed. Furthermore, phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection were significantly increased. Prawns challenged with L. garvieae after 32 days of feeding at 1.0, 3.0 and 6.0 g kg(-1) had a significantly higher survival rate (33.3%, 40.0% and 56.7%) than those fed with the control diet. Subsequently, hypothermal (14 °C) stress was 43.4%, 50.0% and 50.0%, respectively. Altogether, we therefore recommend the dietary BPE administration at 6.0 g kg(-1) promotes growth, anti-hypothermal stress, and enhance immunity and resistance against L. garvieae in M. rosenbergii. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effects of hot-water extract of banana (Musa acuminata) fruit's peel on the antibacterial activity, and anti-hypothermal stress, immune responses and disease resistance of the giant freshwater prawn, Macrobrachium rosenbegii.

    PubMed

    Rattanavichai, Wutti; Cheng, Winton

    2014-08-01

    The hot-extracts isolated from fruit's peel of banana, Musa acuminata, was evaluated on the antibacterial activity to pathogens from aquatic animals, and immunostimulating potential, disease resistance and anti-hypothermal stress in giant freshwater prawn, Macrobrachium rosenbergii through injection administration. The banana peel extract (BPE) showed good activity against 1 Gram-positive and 3 Gram-negative pathogens, including Lactococcus garvieae, Photobacteria damsella, Vibrio alginolyticus and Vibrio parahemolyticus especially in prawn pathogen of L. garvieae strain, which were carried out by a disk diffusion method. Prawn received BPE via injection administration at 1-6 μg (g prawn)(-1) significantly increased total haemocyte count (THC), hyaline cell (HC), granular cell (GC), phenoloxidase (PO) activity and phagocytic activity against L. garvieae from 3 to 6 days, and significantly increased clearance efficiency against L. garvieae and a significantly decreased coagulation time of prawn from 1 to 6 days. Prawn injected with BPE at 6.0 μg (g prawn)(-1) for 6 days showed significantly increased superoxide dismutase (SOD) activity, but significantly decreased respiratory bursts (RBs) of per haemocyte. Survival rates of M. rosenbergii injected with BPE at concentrations of 1, 3 and 6 μg (g prawn)(-1) were significantly higher than those injected with saline control after challenge with L. garvieae for 4-6 days, and the respective relative survival percentages of prawn were 28.6%, 38.1%, and 47.8%, respectively at 6 days. The sublethal time of prawns that had received saline and BPE at 1, 3 and 6 μg (g prawn)(-1) for 6 days and then were transferred from 28 °C to 14 °C were 69.4, 79.8, 83.6, and 90.2 h, respectively. It was concluded that the BPE can be used as the bacteriostat, and immunostimulant and physiological regulator for prawn through injection administration to enhance immunity, physiological responses, and resistance against L. garvieae

  4. The EM Earthquake Precursor

    NASA Astrophysics Data System (ADS)

    Jones, K. B., II; Saxton, P. T.

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  5. EMS & the DEA.

    PubMed

    Beeson, Jeff; Ayres, Chris

    2010-01-01

    It's clear that EMS medical directors and management staff must be vigilant in their oversight of implementation, administration and monitoring of controlled substances within their agencies to best serve the public and avoid running afoul of investigation and incurring significant penalties. Those potentially affected by the need for individual registrations of both emergency vehicles and central inventory systems should carefully monitor upcoming developments in the interpretation od DEA regulations.

  6. Why do Emergency Medical Services (EMS) Professionals Leave EMS?

    PubMed

    Blau, Gary; Chapman, Susan A

    2016-12-01

    The objective was to determine why Emergency Medical Technician (EMT)-Basics and Paramedics leave the Emergency Medical Services (EMS) workforce. Data were collected through annual surveys of nationally registered EMT-Basics and Paramedics from 1999 to 2008. Survey items dealing with satisfaction with the EMS profession, likelihood of leaving the profession, and likelihood of leaving their EMS job were assessed for both EMT-Basics and Paramedics, along with reasons for leaving the profession. Individuals whose responses indicated that they were not working in EMS were mailed a special exit survey to determine the reasons for leaving EMS. The likelihood of leaving the profession in the next year was low for both EMT-Basics and Paramedics. Although overall satisfaction levels with the profession were high, EMT-Basics were significantly more satisfied than Paramedics. The most important reasons for leaving the profession were choosing to pursue further education and moving to a new location. A desire for better pay and benefits was a significantly more important reason for EMT-Paramedics' exit decisions than for EMT-Basics. Given the anticipated increased demand for EMS professionals in the next decade, continued study of issues associated with retention is strongly recommended. Some specific recommendations and suggestions for promoting retention are provided. Blau G , Chapman SA . Why do Emergency Medical Services (EMS) professionals leave EMS? Prehosp Disaster Med. 2016;31(Suppl. 1):s105-s111.

  7. Identified EM Earthquake Precursors

    NASA Astrophysics Data System (ADS)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  8. EPA LABORATORIES IMPLEMENT EMS PROGRAM

    EPA Science Inventory

    This paper highlights the breadth and magnitude of carrying out an effective Environmental Management System (EMS) program at the U.S. EPA's research and development laboratories. Federal research laboratories have unique operating challenges compared to more centralized industr...

  9. Busca de estruturas em grandes escalas em altos redshifts

    NASA Astrophysics Data System (ADS)

    Boris, N. V.; Sodrã©, L., Jr.; Cypriano, E.

    2003-08-01

    A busca por estruturas em grandes escalas (aglomerados de galáxias, por exemplo) é um ativo tópico de pesquisas hoje em dia, pois a detecção de um único aglomerado em altos redshifts pode por vínculos fortes sobre os modelos cosmológicos. Neste projeto estamos fazendo uma busca de estruturas distantes em campos contendo pares de quasares próximos entre si em z Â3 0.9. Os pares de quasares foram extraídos do catálogo de Véron-Cetty & Véron (2001) e estão sendo observados com os telescópios: 2,2m da University of Hawaii (UH), 2,5m do Observatório de Las Campanas e com o GEMINI. Apresentamos aqui a análise preliminar de um par de quasares observado nos filtros i'(7800 Å) e z'(9500 Å) com o GEMINI. A cor (i'-z') mostrou-se útil para detectar objetos "early-type" em redshifts menores que 1.1. No estudo do par 131046+0006/J131055+0008, com redshift ~ 0.9, o uso deste método possibilitou a detecção de sete objetos candidatos a galáxias "early-type". Num mapa da distribuição projetada dos objetos para 22 < i' < 25 observou-se que estas galáxias estão localizadas próximas a um dos quasares e há indícios de que estejam aglomeradas dentro de um área de ~ 6 arcmin2. Se esse for o caso, estes objetos seriam membros de uma estrutura em grande escala. Um outro argumento em favor dessa hipótese é que eles obedecem uma relação do tipo Kormendy (raio equivalente X brilho superficial dentro desse raio), como a apresentada pelas galáxias elípticas em z = 0.

  10. The European Mobile System (EMS)

    NASA Technical Reports Server (NTRS)

    Jongejans, A.; Rogard, R.; Mistretta, I.; Ananasso, F.

    1993-01-01

    The European Space Agency is presently procuring an L band payload in order to promote a regional European L band system coping with the specific needs of the European market. The payload, and the two communications systems to be supported, are described below. The potential market for EMS in Europe is discussed.

  11. Cosmic muon induced EM showers in NO$\

    SciTech Connect

    Yadav, Nitin; Duyang, Hongyue; Shanahan, Peter; Mishra, Sanjib; Bhuyan, Bipul

    2016-11-15

    Here, the NuMI Off-Axis ve Appearance (NOvA) experiment is a ne appearance neutrino oscillation experiment at Fermilab. It identifies the ne signal from the electromagnetic (EM) showers induced by the electrons in the final state of neutrino interactions. Cosmic muon induced EM showers, dominated by bremsstrahlung, are abundant in NOvA far detector. We use the Cosmic Muon- Removal technique to get pure EM shower sample from bremsstrahlung muons in data. We also use Cosmic muon decay in flight EM showers which are highly pure EM showers.The large Cosmic-EM sample can be used, as data driven method, to characterize the EM shower signature and provides valuable checks of the simulation, reconstruction, particle identification algorithm, and calibration across the NOvA detector.

  12. Correlation of the NBME advanced clinical examination in EM and the national EM M4 exams.

    PubMed

    Hiller, Katherine; Miller, Emily S; Lawson, Luan; Wald, David; Beeson, Michael; Heitz, Corey; Morrissey, Thomas; House, Joseph; Poznanski, Stacey

    2015-01-01

    Since 2011 two online, validated exams for fourth-year emergency medicine (EM) students have been available (National EM M4 Exams). In 2013 the National Board of Medical Examiners offered the Advanced Clinical Examination in Emergency Medicine (EM-ACE). All of these exams are now in widespread use; however, there are no data on how they correlate. This study evaluated the correlation between the EM-ACE exam and the National EM M4 Exams. From May 2013 to April 2014 the EM-ACE and one version of the EM M4 exam were administered sequentially to fourth-year EM students at five U.S. medical schools. Data collected included institution, gross and scaled scores and version of the EM M4 exam. We performed Pearson's correlation and random effects linear regression. 305 students took the EM-ACE and versions 1 (V1) or 2 (V2) of the EM M4 exams (281 and 24, respectively) [corrected].The mean percent correct for the exams were as follows: EM-ACE 74.9 (SD-9.82), V1 83.0 (SD-6.39), V2 78.5 (SD-7.70) [corrected]. Pearson's correlation coefficient for the V1/EM-ACE was 0.53 (0.43 scaled) and for the V2/EM-ACE was 0.58 (0.41 scaled) [corrected]. The coefficient of determination for V1/ EM-ACE was 0.73 and for V2/EM-ACE 0.71 (0.65 and .49 for scaled scores) [ERRATUM]. The R-squared values were 0.28 and 0.30 (0.18 and 0.13 scaled), respectively [corrected]. There was significant cluster effect by institution. There was moderate positive correlation of student scores on the EM-ACE exam and the National EM M4 Exams.

  13. Complaints against an EMS system.

    PubMed

    Colwell, Christopher B; Pons, Peter T; Pi, Randy

    2003-11-01

    Complaints against Emergency Medical Services (EMS) agencies represent a concerning and potentially time-consuming problem for all involved in the delivery of prehospital emergency medical care. The objective of this study was to identify the source of complaints against an EMS system to help focus quality and performance improvement and customer service efforts. We conducted a retrospective review of complaints filed against a busy urban EMS agency over a 6-year period. All complaints were included, totaled by season and by year, and categorized by originator and nature of the complaint. A total of 286 complaints were registered during the 6-year period, with an average of 48 per year and 9.3 per 10,000 responses. The most common originators of complaints were patients (53%) followed by medical personnel (19%) and family members or friends (12%). Rude behavior accounted for 23% of the complaints registered, followed by technical skills (20%), transport problems (18%), and loss of belongings (13%). The identification of areas of dissatisfaction will allow focused quality and performance improvement programs directed at customer service and risk management.

  14. Cosmic muon induced EM showers in NO$$\

    DOE PAGES

    Yadav, Nitin; Duyang, Hongyue; Shanahan, Peter; ...

    2016-11-15

    Here, the NuMI Off-Axis ve Appearance (NOvA) experiment is a ne appearance neutrino oscillation experiment at Fermilab. It identifies the ne signal from the electromagnetic (EM) showers induced by the electrons in the final state of neutrino interactions. Cosmic muon induced EM showers, dominated by bremsstrahlung, are abundant in NOvA far detector. We use the Cosmic Muon- Removal technique to get pure EM shower sample from bremsstrahlung muons in data. We also use Cosmic muon decay in flight EM showers which are highly pure EM showers.The large Cosmic-EM sample can be used, as data driven method, to characterize the EMmore » shower signature and provides valuable checks of the simulation, reconstruction, particle identification algorithm, and calibration across the NOvA detector.« less

  15. The Empathic Operating System (emOS)

    DTIC Science & Technology

    2016-06-15

    The Empathic Operating System ( emOS ) Physiological measurements have typically been limited to expensive and cumbersome clinical research equipment...Report: The Empathic Operating System ( emOS ) Report Title Physiological measurements have typically been limited to expensive and cumbersome clinical...C-0043 Proposal number: 62850-LS-DRP Project title: “The Empathic Operating System ( emOS )” Contract performance period: January 1, 2016 – April 7

  16. DOE/EM Criticality Safety Needs Assessment

    SciTech Connect

    Westfall, Robert Michael; Hopper, Calvin Mitchell

    2011-02-01

    The issue of nuclear criticality safety (NCS) in Department of Energy Environmental Management (DOE/EM) fissionable material operations presents challenges because of the large quantities of material present in the facilities and equipment that are committed to storage and/or material conditioning and dispositioning processes. Given the uncertainty associated with the material and conditions for many DOE/EM fissionable material operations, ensuring safety while maintaining operational efficiency requires the application of the most-effective criticality safety practices. In turn, more-efficient implementation of these practices can be achieved if the best NCS technologies are utilized. In 2002, DOE/EM-1 commissioned a survey of criticality safety technical needs at the major EM sites. These needs were documented in the report Analysis of Nuclear Criticality Safety Technology Supporting the Environmental Management Program, issued May 2002. Subsequent to this study, EM safety management personnel made a commitment to applying the best and latest criticality safety technology, as described by the DOE Nuclear Criticality Safety Program (NCSP). Over the past 7 years, this commitment has enabled the transfer of several new technologies to EM operations. In 2008, it was decided to broaden the basis of the EM NCS needs assessment to include not only current needs for technologies but also NCS operational areas with potential for improvements in controls, analysis, and regulations. A series of NCS workshops has been conducted over the past years, and needs have been identified and addressed by EM staff and contractor personnel. These workshops were organized and conducted by the EM Criticality Safety Program Manager with administrative and technical support by staff at Oak Ridge National Laboratory (ORNL). This report records the progress made in identifying the needs, determining the approaches for addressing these needs, and assimilating new NCS technologies into EM

  17. EMS provider determinations of necessity for transport and reimbursement for EMS response, medical care, and transport: combined resource document for the National Association of EMS Physicians position statements.

    PubMed

    Millin, Michael G; Brown, Lawrence H; Schwartz, Brian

    2011-01-01

    With increasing demands for emergency medical services (EMS), many EMS jurisdictions are utilizing EMS provider-initiated nontransport policies as a method to offload potentially nonemergent patients from the EMS system. EMS provider determination of medical necessity, resulting in nontransport of patients, has the potential to avert unnecessary emergency department visits. However, EMS systems that utilize these policies must have additional education for the providers, a quality improvement process, and active physician oversight. In addition, EMS provider determination of nontransport for a specific situation should be supported by evidence in the peer-reviewed literature that the practice is safe. Further, EMS systems that do not utilize these programs should not be financially penalized. Payment for EMS services should be based on the prudent layperson standard. EMS systems that do utilize nontransport policies should be appropriately reimbursed, as this represents potential cost savings to the health care system.

  18. School Budget Hold'em Facilitator's Guide

    ERIC Educational Resources Information Center

    Education Resource Strategies, 2012

    2012-01-01

    "School Budget Hold'em" is a game designed to help school districts rethink their budgeting process. It evolved out of Education Resource Strategies' (ERS) experience working with large urban districts around the country. "School Budget Hold'em" offers a completely new approach--one that can turn the budgeting process into a long-term visioning…

  19. EM Cep: The Be Star

    NASA Astrophysics Data System (ADS)

    Kochiashvili, N.; Kochiashvili, I.; Natsvlishvili, R.; Vardosanidze, M.; Beradze, S.

    2017-07-01

    On the basis of UBVR photometric data, obtained in the Abastumani Observatory during 1991-1999, very interesting and unusual flare of EM Cep has been revealed. Duration of the flare was over two hours. We estimated the percentage of brightness increase during the flare and brightness decrease of the corresponding anti- flare and the minimum amount of the lost mass during this event. We have solved the light curves of the star using the Wilson-Devinney code. But the resulting fraction of calculated brightness of the companion star was not in accordance with spectral data. Then we decided to check the idea of a pulsating single star using new spectral data. Together with our Buyrakan colleagues we obtained and analyzed spectra of the star. We could not find spectral lines of a companion star or any traces of the radial velocities using this data. Hence, we concluded that we need the higher resolution spectra for final resolution of the matter. On the basis of the latest spectral data of Bulgarian astronomers they concluded that EM Cep is a single star. This makes it possible to suggest, that the question of stellar pulsation could be solved using additional photometric observations.

  20. The EM algorithm in medical imaging.

    PubMed

    Kay, J

    1997-03-01

    This article outlines the statistical developments that have taken place in the use of the EM algorithm in emission and transmission tomography during the past decade or so. We discuss the statistical aspects of the modelling of the projection data for both the emission and transmission cases and define the relevant probability models. This leads to the use of the method of maximum likelihood as a means of estimating the relevant unknown parameters within a given region of a patient's body and to the use of the EM algorithm to compute the reconstruction. Various different types of EM algorithm are discussed, including the SAGE algorithms of Fessler and Hero. The limitations of the EM algorithm, per se, are covered and the need for regularization is stressed. A number of different methods for penalizing the likelihood are described and a number of algorithms for the computation of the penalized EM reconstruction are discussed.

  1. Side mounted EMS for aluminium scrap melters

    SciTech Connect

    Eidem, M.; Tallbaeck, G.; Hanley, P.J.

    1996-10-01

    Normally the electromagnetic stirrer (EMS) is placed below the furnace. However it has recently been found that the EMS can also be placed at the side of the furnace, still giving good stirring. This makes it possible to install EMS on most existing furnaces. The side-mounted EMS is compared with the standard bottom-mounted stirrer with respect to installation, melting time and flow pattern in the melt. The major conclusion is that a side-mounted EMS is practical and will give about as good a performance as the bottom-mounted. Melting time estimates are based upon 3-D fluid flow and heat transfer predictions in combination with a simplified scrap melting theory. Predicted melting times are in fair agreement with operational data for mechanically stirred and electromagnetically bottom stirred furnaces.

  2. EM International, July 1994, Volume 2

    SciTech Connect

    Not Available

    1994-10-01

    The Office of Environmental Management (EM) at the Department of Energy (DOE) is seeking out and leveraging foreign technology, data, and resources in keeping with EM`s mandate to protect public health and the environment through the safe and cost-effective remediation of the Department`s nuclear weapons sites. EM works closely with foreign governments, industry, and universities to obtain innovative environmental technologies, scientific and engineering expertise, and operations experience that will support EM`s objectives. Where appropriate, these international resources are used to manage the more urgent risks at our sites, secure a safe workplace, help build consensus on critical issues, and strengthen our technology development program. Through international agreements EM engages in cooperative exchange of information, technology, and individuals. Currently, we are managing agreements with a dozen countries in Europe, Latin America, and Asia. These agreements focus on environmental restoration, waste management, transportation of radioactive wastes, and decontamination and decommissioning. This publication contains the following articles: in situ remediation integrated program; in-situ characterization and inspection of tanks; multimedia environmental pollutant assessment system (MEPAS); LLNL wet oxidation -- AEA technology. Besides these articles, this publication covers: EU activities with Russia; technology transfer activities; and international organization activities.

  3. Project X RFQ EM Design

    SciTech Connect

    Romanov, Gennady; Hoff, Matthew; Li, Derun; Staples, John; Virostek, Steve; /LBNL

    2012-05-09

    Project X is a proposed multi-MW proton facility at Fermi National Accelerator Laboratory (FNAL). The Project X front-end would consist of an H- ion source, a low-energy beam transport (LEBT), a CW 162.5 MHz radio-frequency quadrupole (RFQ) accelerator, and a medium-energy beam transport (MEBT). Lawrence Berkeley National Laboratory (LBNL) and FNAL collaboration is currently developing the designs for various components in the Project X front end. This paper reports the detailed EM design of the CW 162.5 MHz RFQ that provides bunching of the 1-10 mA H- beam with acceleration from 30 keV to 2.1 MeV.

  4. NEIC Environmental Management System (EMS) Policy

    EPA Pesticide Factsheets

    National Enforcement Investigations Center (NEIC) Environmental Management System (EMS) Policy. Identification and management of actual and potential environmental impacts of operations and decisions for the purpose of continual improvement of performance

  5. EMS offshore. A new horizon for paramedics.

    PubMed

    Mallard, A S

    1991-10-01

    The difficulty in getting medical aid to offshore drilling platforms can be a source of life-threatening delays. Recently, some companies have charted new waters by actually stationing EMS crews on their rigs.

  6. How good can cryo-EM become?

    SciTech Connect

    Glaeser, Robert M.

    2015-12-30

    The suddenness with which single-particle cryo-electron microscopy (cryo-EM) has emerged as a method for determining high-resolution structures of biological macromolecules invites the questions, how much better can this technology get, and how fast is that likely to happen? While we can rightly celebrate the maturation of cryo-EM as a high-resolution structure-determination tool, I believe there still are many developments to look forward to.

  7. Reassessing training levels for prehospital EMS personnel.

    PubMed

    Briese, G L

    1983-01-01

    One of the major questions confronting prehospital care services today concerns determining the appropriate level of training for EMS personnel that will provide the most cost effective systems. Unfortunately there are no studies which assess this problem. Various communities have modified or expanded the roles of prehospital personnel beyond the traditional training of EMTs and paramedics. Continuing education and skills maintenance are ongoing problems faced by all EMS systems, which have been addressed in various ways by individual locales.

  8. SOFIS FTS EM test results

    NASA Astrophysics Data System (ADS)

    Soucy, Marc-Andre A.; Levesque, Luc E.; Tanii, Jun; Kawashima, Takahiro; Nakajima, Hideaki

    2003-04-01

    The Solar Occultation FTS for Inclined-orbit Satellite (SOFIS) is a solar occultation Fourier transform spectrometer developed by the Ministry of the Environment (MOE) in Japan for the Global Change Observation Mission-A1 (GCOM-A1) satellite. GCOM-A1 will be placed in a 650 km non-sun-synchronous orbit, with an inclination angle of 69 degrees. ABB-Bomem is a sub-contractor of NTSpace (NEC-Toshiba Space) for the design and manufacturing of the FTS Engineering Model of SOFIS. SOFIS measures the vertical profile of the atmospheric constituents with 0.2 cm-1 spectral resolution for the spectral range covering 3-13 μm. The atmospheric vertical resolution of SOFIS is 1 km. The target of SOFIS measurements is a global distribution of O3, HNO3, NO2, N2O, CH4, H2O, CO2, CFC-11, CFC-12, ClONO2, aerosol extinction, atmospheric pressure and temperature. NTSpace in Japan is the prime contractor of SOFIS. The spectrometer is an adapted version of the classical Michelson interferometer using an optimized optical layout and moving retro-reflectors. A solid-state laser diode operating at 1550 nm is used as metrology source of the interferometer. Its highly folded optical design results in a high performance instrument with a compact size. SOFIS FTS implements high performance control techniques to achieve outstanding speed stability of the moving mechanism. This paper describes the test activities of the SOFIS-FTS Engineering Model (EM) and preliminary results. The performances of the FTS are presented in terms of key parameters like signal-to-noise ratio, modulation efficiency and stability. Spectra acquired are shown and test methodology and analyses are presented. Lessons learned during assembly, integration and testing are described as well as improvements planned to be implemented in the Flight Model.

  9. EMS adaptation for climate change

    NASA Astrophysics Data System (ADS)

    Pan, C.; Chang, Y.; Wen, J.; Tsai, M.

    2010-12-01

    The purpose of this study was to find an appropriate scenario of pre-hospital transportation of an emergency medical service (EMS) system for burdensome casualties resulting from extreme climate events. A case of natural catastrophic events in Taiwan, 88 wind-caused disasters, was reviewed and analyzed. A sequential-conveyance method was designed to shorten the casualty transportation time and to promote the efficiency of ambulance services. A proposed mobile emergency medical center was first constructed in a safe area, but nearby the disaster area. The Center consists of professional medical personnel who process the triage of incoming patients and take care of casualties with minor injuries. Ambulances in the Center were ready to sequentially convey the casualties with severer conditions to an assigned hospital that is distant from the disaster area for further treatment. The study suggests that if we could construct a spacious and well-equipped mobile emergency medical center, only a small portion of casualties would need to be transferred to distant hospitals. This would reduce the over-crowding problem in hospital ERs. First-line ambulances only reciprocated between the mobile emergency medical center and the disaster area, saving time and shortening the working distances. Second-line ambulances were highly regulated between the mobile emergency medical center and requested hospitals. The ambulance service of the sequential-conveyance method was found to be more efficient than the conventional method and was concluded to be more profitable and reasonable on paper in adapting to climate change. Therefore, additional practical work should be launched to collect more precise quantitative data.

  10. Filter banks and the EM algorithm

    SciTech Connect

    Mair, B.A.; Carroll, R.B.; Anderson, J.M.M.

    1996-12-31

    In this paper, we present a wavelet based modification of the ML-EM algorithm for reconstructing positron emission tomography images. By using the filter bank implementation of the wavelet transform, this algorithm has the flexibility to incorporate a priori information, while maintaining the same computational complexity as the standard ML-EM algorithm. Thus, it has a significant computational advantage over usual Bayesian methods. It differs from recent wavelet-based Bayesian methods as it achieves {open_quotes}regularization{close_quotes} by an adaptive, wavelet-based method of thresholding which minimizes Stein`s Unbiased Estimate of Risk. The basic method consists of applying Donoho and Johnstone`s SureShrink wavelet denoising of the Poisson data, and then applying the standard ML-EM algorithm to the denoised data. A more elaborate method is discussed in which a wavelet denoising step is inserted after each EM iteration. This technique differs from previous smoothing techniques applied to the ML-EM algorithm since it is able to recover edges in discontinuous images.

  11. Processing of Cryo-EM Movie Data.

    PubMed

    Ripstein, Z A; Rubinstein, J L

    2016-01-01

    Direct detector device (DDD) cameras dramatically enhance the capabilities of electron cryomicroscopy (cryo-EM) due to their improved detective quantum efficiency (DQE) relative to other detectors. DDDs use semiconductor technology that allows micrographs to be recorded as movies rather than integrated individual exposures. Movies from DDDs improve cryo-EM in another, more surprising, way. DDD movies revealed beam-induced specimen movement as a major source of image degradation and provide a way to partially correct the problem by aligning frames or regions of frames to account for this specimen movement. In this chapter, we use a self-consistent mathematical notation to explain, compare, and contrast several of the most popular existing algorithms for computationally correcting specimen movement in DDD movies. We conclude by discussing future developments in algorithms for processing DDD movies that would extend the capabilities of cryo-EM even further. © 2016 Elsevier Inc. All rights reserved.

  12. 7 CFR 1945.35 - Special EM loan training.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... workshop and a test. (c) Objective. The basic objective of this training program is to keep State and... kit, will be used for the EM loan training meetings, and any subsequent EM loan training...

  13. 7 CFR 1945.35 - Special EM loan training.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... workshop and a test. (c) Objective. The basic objective of this training program is to keep State and... kit, will be used for the EM loan training meetings, and any subsequent EM loan training...

  14. Integrating Green Purchasing Into Your Environmental Management System (EMS)

    EPA Pesticide Factsheets

    The goal of this report is to help Federal facilities integrate green purchasing into their EMS. The intended audience includes those tasked with implementing an EMS, reducing environmental impacts, meeting green purchasing requirements.

  15. 10 CFR Appendixes E-M to Part 52 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...

  16. 10 CFR Appendixes E-M to Part 52 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52 ...

  17. 10 CFR Appendixes E-M to Part 52 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52 ...

  18. 10 CFR Appendixes E-M to Part 52 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52 ...

  19. 10 CFR Appendixes E-M to Part 52 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52 ...

  20. Risk Communication Within the EM Program

    SciTech Connect

    Edelson, M.

    2003-02-26

    The U.S. Department of Energy Environmental Management program (EM) conducts the most extensive environmental remediation effort in the world. The annual EM budgets have exceeded $6,000,000,000 for approximately ten years and EM has assumed responsibility for the cleanup of the largest DOE reservations (i.e., at Hanford, Washington, Aiken, South Carolina, and Idaho Falls, Idaho) as well as the facilities at Rocky Flats, Colorado and in Ohio. Each of these sites has areas of extensive radioactive and chemical contamination, numerous surplus facilities that require decontamination and removal, while some have special nuclear material that requires secure storage. The EM program has been criticized for being ineffective (1) and has been repeatedly reorganized to address perceived shortcomings. The most recent reorganization was announced in 2001 to become effective at the beginning of the 2003 Federal Fiscal Year (i.e., October 2002). It was preceded by a ''top to bottom'' review (TTBR) of the program (2) that identified several deficiencies that were to be corrected as a result of the reorganization. One prominent outcome of the TTBR was the identification of ''risk reduction'' as an organizing principle to prioritize the activities of the new EM program. The new program also sought to accelerate progress by identifying a set of critical activities at each site that could be accelerated and result in more rapid site closure, with attendant risk, cost, and schedule benefits. This paper investigates how the new emphasis on risk reduction in the EM program has been communicated to EM stakeholders and regulators. It focuses on the Rocky Flats Environmental Technology Site (RFETS) as a case study and finds that there is little evidence for a new emphasis on risk reduction in EM communications with RFETS stakeholders. Discussions between DOE and RFETS stakeholders often refer to ''risk,'' but the word serves as a placeholder for other concepts. Thus ''risk'' communication

  1. Structural Composites With Tuned EM Chirality

    DTIC Science & Technology

    2014-12-23

    AFRL-OSR-VA-TR-2015-0018 STRUCTURAL COMPOSITES WITH TUNED EM CHIRALITY Siavouche Nemat Nasser UNIVERSITY OF CALIFORNIA SAN DIEGO Final Report 12/23...REPORT Grant/Contract  Title:        STRUCTURAL  COMPOSITES  WITH  TUNED  EM   CHIRALITY     Grant  No.:  FA9550-­‐09-­‐1...structural   composites  with   tunable   chiral   elements   has   produced   some   impressive   results   in   the

  2. Lessons Learned: Integrating EMS and Environmental Compliance Auditing

    DTIC Science & Technology

    2009-05-06

    audit an EMS against the – ISO 14001 :2004 Standard – Installation’s own commitments and procedures established under their EMS (i.e. are they doing...what they said they would do?) – Army Policy • Findings are documented in a Word report (external audits) • ISO 14001 conformance is determined by...regulatory requirements • EMS Findings – Conformance: management system conforms to ISO 14001 standard – Major Nonconformance: EMS is missing element

  3. Do earthquakes generate EM signals?

    NASA Astrophysics Data System (ADS)

    Walter, Christina; Onacha, Stephen; Malin, Peter; Shalev, Eylon; Lucas, Alan

    2010-05-01

    study areas, large swarms of earthquakes were located very close to the electromagnetic coils. This abstract focuses on the data from the Wairakei area. Preliminary data analysis has been carried out by band pass filtering and removing of the harmonics of the 50 Hz power line frequency. The initial results clearly show that electromagnetic signals accompany the seismic P and S waves (coseismic signal). Further data analysis involves the extraction of the seismoelectric signal generated at the onset of the earthquake and at interfaces from the coseismic signal and other ‘noise' sources. This processing step exhibits a major challenge in seismoelectric data processing. Unlike in other studies we measured the EM field and the seismic field at one location. Therefore the seismoelectric wave travelling at the speed of light cannot be determined as easily in the arrival times as when an array of coils is used. This makes the determination of the origin time much more difficult. Hence other processing techniques need to be explored.

  4. EMS response to an airliner crash.

    PubMed

    Dasgupta, Shuvra; French, Simone; Williams-Johnson, Jean; Hutson, Rhonda; Hart, Nicole; Wong, Mark; Williams, Eric; Espinosa, Kurdell; Maycock, Celeste; Edwards, Romayne; McCartney, Trevor; Cawich, Shamir; Crandon, Ivor

    2012-06-01

    This report of an aircraft crash at a major airport in Kingston, Jamaica examines the response of the local Emergency Medical Services (EMS). Factors that impacted the response are discussed, and the need for more disaster simulation exercises is highlighted. The objective of this case report was to document the response of EMS personnel to the crash of American Airlines Flight 331, and to utilize the information to examine and improve the present protocol. While multiple errors can occur during a mass-casualty event, these can be reduced by frequent simulation exercises during which various personnel practice and learn designated roles. Efficient triage, proper communication, and knowledge of the roles are important in ensuring the best possible outcome. While the triage system and response of the EMS personnel were effective for this magnitude of catastrophe, more work is needed in order to meet predetermined standards. Ways in which this can be overcome include: (1) hosting more disaster simulation exercises; (2) encouraging more involvement with first responders; and (3) strengthening the links in the local EMS system. Vigorous public education must be instituted and maintained.

  5. Navigating 3D electron microscopy maps with EM-SURFER.

    PubMed

    Esquivel-Rodríguez, Juan; Xiong, Yi; Han, Xusi; Guang, Shuomeng; Christoffer, Charles; Kihara, Daisuke

    2015-05-30

    The Electron Microscopy DataBank (EMDB) is growing rapidly, accumulating biological structural data obtained mainly by electron microscopy and tomography, which are emerging techniques for determining large biomolecular complex and subcellular structures. Together with the Protein Data Bank (PDB), EMDB is becoming a fundamental resource of the tertiary structures of biological macromolecules. To take full advantage of this indispensable resource, the ability to search the database by structural similarity is essential. However, unlike high-resolution structures stored in PDB, methods for comparing low-resolution electron microscopy (EM) density maps in EMDB are not well established. We developed a computational method for efficiently searching low-resolution EM maps. The method uses a compact fingerprint representation of EM maps based on the 3D Zernike descriptor, which is derived from a mathematical series expansion for EM maps that are considered as 3D functions. The method is implemented in a web server named EM-SURFER, which allows users to search against the entire EMDB in real-time. EM-SURFER compares the global shapes of EM maps. Examples of search results from different types of query structures are discussed. We developed EM-SURFER, which retrieves structurally relevant matches for query EM maps from EMDB within seconds. The unique capability of EM-SURFER to detect 3D shape similarity of low-resolution EM maps should prove invaluable in structural biology.

  6. [Ecophysiological adaptability of tropical water organisms to salinity changes].

    PubMed

    Chung, K S

    2001-03-01

    Physiological response of tropical organisms to salinity changes was studied for some marine, estuarine and freshwater fishes (Astyanax bimaculatus, Petenia karussii, Cyprinodon dearborni, and Oreochromis mossambicus), marine and freshwater crustaceans (Penaeus brasiliensis, Penaeus schmitti and Macrobrachium carcinus), and marine bivalves (Perna perna, Crassostrea rhizophorae, and Arca zebra) collected from Northeast Venezuela. They were acclimated for four weeks at various salinities, and (1) placed at high salinities to determine mean lethal salinity, (2) tested by increasing salinity 5@1000 per day to define upper lethal salinity tolerance limit, or (3) observed in a saline gradient tank to determine salinity preference. Acclimation level was the most significant factor. This phenomenon is important for tropical aquatic organisms in shallow waters, where they can adapt to high salinity during the dry season and cannot lose their acclimation level at low salinity during abrupt rain. For saline adaptation of tropical organisms, this behavior will contribute to their proliferation and distribution in fluctuating salinity environments.

  7. Immunochemical and immunocytochemical studies of the crustacean vitellogenesis-inhibiting hormone (VIH).

    PubMed

    Meusy, J J; Martin, G; Soyez, D; van Deijnen, J E; Gallo, J M

    1987-09-01

    Immunochemical investigations, using dot immunobinding assay (DIA) and enzyme-linked immunosorbent assay (ELISA), and immunocytochemical studies reveal the following new information about crustacean vitellogenesis-inhibiting hormone (VIH): (1) The structure of VIH is sufficiently different from that of the other sinus gland neuropeptides to allow a selective recognition of VIH by polyclonal antibodies. (2) From immunochemical criteria, VIH does not seem strictly species specific. The antisera raised against VIH of Homarus americanus cross-react with sinus gland extracts of Palaemonetes varians, Palaemon serratus, Macrobrachium rosenbergii, Carcinus maenas, and Porcellio dilatatus. (3) In the sinus gland of H. americanus, VIH immunoreactivity is localized mainly in electron-dense granules of medium size (110-185 nm in diameter) while, in P. dilatatus, the labeling is mostly on the largest granules (200-270 nm in diameter).

  8. The association between EMS workplace safety culture and safety outcomes.

    PubMed

    Weaver, Matthew D; Wang, Henry E; Fairbanks, Rollin J; Patterson, Daniel

    2012-01-01

    Prior studies have highlighted wide variation in emergency medical services (EMS) workplace safety culture across agencies. To determine the association between EMS workplace safety culture scores and patient or provider safety outcomes. We administered a cross-sectional survey to EMS workers affiliated with a convenience sample of agencies. We recruited these agencies from a national EMS management organization. We used the EMS Safety Attitudes Questionnaire (EMS-SAQ) to measure workplace safety culture and the EMS Safety Inventory (EMS-SI), a tool developed to capture self-reported safety outcomes from EMS workers. The EMS-SAQ provides reliable and valid measures of six domains: safety climate, teamwork climate, perceptions of management, working conditions, stress recognition, and job satisfaction. A panel of medical directors, emergency medical technicians and paramedics, and occupational epidemiologists developed the EMS-SI to measure self-reported injury, medical errors and adverse events, and safety-compromising behaviors. We used hierarchical linear models to evaluate the association between EMS-SAQ scores and EMS-SI safety outcome measures. Sixteen percent of all respondents reported experiencing an injury in the past three months, four of every 10 respondents reported an error or adverse event (AE), and 89% reported safety-compromising behaviors. Respondents reporting injury scored lower on five of the six domains of safety culture. Respondents reporting an error or AE scored lower for four of the six domains, while respondents reporting safety-compromising behavior had lower safety culture scores for five of the six domains. Individual EMS worker perceptions of workplace safety culture are associated with composite measures of patient and provider safety outcomes. This study is preliminary evidence of the association between safety culture and patient or provider safety outcomes.

  9. The association between EMS workplace safety culture and safety outcomes

    PubMed Central

    Weaver, Matthew D.; Wang, Henry E.; Fairbanks, Rollin J.; Patterson, Daniel

    2012-01-01

    Objective Prior studies have highlighted wide variation in EMS workplace safety culture across agencies. We sought to determine the association between EMS workplace safety culture scores and patient or provider safety outcomes. Methods We administered a cross-sectional survey to EMS workers affiliated with a convenience sample of agencies. We recruited these agencies from a national EMS management organization. We used the EMS Safety Attitudes Questionnaire (EMS-SAQ) to measure workplace safety culture and the EMS Safety Inventory (EMS-SI), a tool developed to capture self-reported safety outcomes from EMS workers. The EMS-SAQ provides reliable and valid measures of six domains: safety climate, teamwork climate, perceptions of management, perceptions of working conditions, stress recognition, and job satisfaction. A panel of medical directors, paramedics, and occupational epidemiologists developed the EMS-SI to measure self-reported injury, medical errors and adverse events, and safety-compromising behaviors. We used hierarchical linear models to evaluate the association between EMS-SAQ scores and EMS-SI safety outcome measures. Results Sixteen percent of all respondents reported experiencing an injury in the past 3 months, four of every 10 respondents reported an error or adverse event (AE), and 90% reported safety-compromising behaviors. Respondents reporting injury scored lower on 5 of the 6 domains of safety culture. Respondents reporting an error or AE scored lower for 4 of the 6 domains, while respondents reporting safety-compromising behavior had lower safety culture scores for 5 of 6 domains. Conclusions Individual EMS worker perceptions of workplace safety culture are associated with composite measures of patient and provider safety outcomes. This study is preliminary evidence of the association between safety culture and patient or provider safety outcomes. PMID:21950463

  10. Accuracy of EMS Trauma Transport Destination Plans in North Carolina.

    PubMed

    Moss, Chailee; Cowden, Christopher S; Atterton, Laurie Meyer; Arasaratnam, Meredith H; Fernandez, Antonio R; Evarts, Jeff S; Barrier, Brian; Lerner, E Brooke; Mann, N Clay; Lohmeier, Chad; Shofer, Frances S; Brice, Jane H

    2015-01-01

    Abstract Objective. Planning for time-sensitive injury may allow emergency medical services (EMS) systems to more accurately triage patients meeting accepted criteria to facilities most capable of providing life-saving treatment. In 2010, North Carolina (NC) implemented statewide Trauma Triage and Destination Plans (TTDPs) in all 100 of North Carolina's county-defined EMS systems. Each system was responsible for identifying the specific destination hospitals with appropriate resources to treat trauma patients. We sought to characterize the accuracy of their hospital designations. Methods. In this cross-sectional study, we collected TTDPs for each county-defined EMS system, including their assigned hospital capabilities (i.e., trauma center or community hospital). We conducted a survey with each EMS system to determine how their TTDP was constructed and maintained, as well as with each TTDP-designated hospital to verify their capabilities. We determined the accuracy of the EMS assigned hospital designations by comparing them to the hospital's reported capabilities. Results. The 100 NC EMS systems provided 380 designations for 112 hospitals. TTDPs were created by EMS administrators and medical directors, with only 55% of EMS systems engaging a hospital representative in the plan creation. Compared to the actual hospital capabilities, 97% of the EMS TTDP designations were correct. Twelve hospital designations were incorrect and the majority (10) overestimated hospital capabilities. Of the 100 EMS systems, 7 misclassified hospitals in their TTDP. EMS systems that did not verify their local hospitals' capabilities during TTDP development were more likely to incorrectly categorize a hospital's capabilities (p = 0.001). Conclusions. A small number of EMS systems misclassified hospitals in their TTDP, but most plans accurately reflected hospital capabilities. Misclassification occurred more often in systems that did not consult local hospitals prior to developing their

  11. What Do They Want from Us? A Survey of EM Program Directors on EM Application Criteria

    PubMed Central

    King, Kevin; Kass, Dara

    2017-01-01

    Introduction Although a relatively young specialty, emergency medicine (EM) is popular among medical students and is one of the most competitive large specialties. Consequently, students increasingly seek more opportunity to differentiate themselves from their colleagues by pursuing more clerkships at the cost of taking out additional loans: this despite the fact that those who match in EM typically do so in their top three choices. We sought to ascertain what factors EM program directors seek in their typical candidate. Methods We recruited EM program directors via the Council of Emergency Medicine Residency Directors email listserv to participate in an anonymous survey regarding the United States Medical Licensing Examination (USMLE), the number of standardized letters of evaluation (SLOE), and the number of EM rotations during the fourth year. Results 135 respondents completed the anonymous survey: 59% of respondents stated their program did not have a minimum USMLE Step 1 score, but 39% reported a minimum score of 210 or higher; 95% of programs do not require Step 2 to grant an interview, but 46% require it to place the student on the rank list; 80% require only one EM rotation to grant an interview and none require more than two; 95% of programs will accept two SLOEs for both application and rank list placement. Conclusion For the typical EM applicant, there is likely little benefit to performing more than two rotations and obtaining more than two SLOEs. Students can defer USMLE Step 2 but must complete it by the time rank lists are due. Our study was limited by the anonymity of the survey, and comments by the respondents revealed the questions did not account for some nuances programs apply to their application review process. PMID:28116023

  12. The E-MS Algorithm: Model Selection with Incomplete Data.

    PubMed

    Jiang, Jiming; Nguyen, Thuan; Rao, J Sunil

    2015-04-04

    We propose a procedure associated with the idea of the E-M algorithm for model selection in the presence of missing data. The idea extends the concept of parameters to include both the model and the parameters under the model, and thus allows the model to be part of the E-M iterations. We develop the procedure, known as the E-MS algorithm, under the assumption that the class of candidate models is finite. Some special cases of the procedure are considered, including E-MS with the generalized information criteria (GIC), and E-MS with the adaptive fence (AF; Jiang et al. 2008). We prove numerical convergence of the E-MS algorithm as well as consistency in model selection of the limiting model of the E-MS convergence, for E-MS with GIC and E-MS with AF. We study the impact on model selection of different missing data mechanisms. Furthermore, we carry out extensive simulation studies on the finite-sample performance of the E-MS with comparisons to other procedures. The methodology is also illustrated on a real data analysis involving QTL mapping for an agricultural study on barley grains.

  13. The E-MS Algorithm: Model Selection with Incomplete Data

    PubMed Central

    Jiang, Jiming; Nguyen, Thuan; Rao, J. Sunil

    2014-01-01

    We propose a procedure associated with the idea of the E-M algorithm for model selection in the presence of missing data. The idea extends the concept of parameters to include both the model and the parameters under the model, and thus allows the model to be part of the E-M iterations. We develop the procedure, known as the E-MS algorithm, under the assumption that the class of candidate models is finite. Some special cases of the procedure are considered, including E-MS with the generalized information criteria (GIC), and E-MS with the adaptive fence (AF; Jiang et al. 2008). We prove numerical convergence of the E-MS algorithm as well as consistency in model selection of the limiting model of the E-MS convergence, for E-MS with GIC and E-MS with AF. We study the impact on model selection of different missing data mechanisms. Furthermore, we carry out extensive simulation studies on the finite-sample performance of the E-MS with comparisons to other procedures. The methodology is also illustrated on a real data analysis involving QTL mapping for an agricultural study on barley grains. PMID:26783375

  14. Applying Recursive EM to Scene Segmentation

    NASA Astrophysics Data System (ADS)

    Bachmann, Alexander

    In this paper a novel approach for the interdependent task of multiple object tracking and scene segmentation is presented. The method partitions a stereo image sequence of a dynamic 3-dimensional (3D) scene into its most prominent moving groups with similar 3D motion. The unknown set of motion parameters is recursively estimated using an iterated extended Kalman filter (IEKF) which will be derived from the expectation-maximization (EM) algorithm. The EM formulation is used to incorporate a probabilistic data association measure into the tracking process. In a subsequent segregation step, each image point is assigned to the object hypothesis with maximum a posteriori (MAP) probability. Within the association process, which is implemented as labeling problem, a Markov Random Field (MRF) is used to express our expectations on spatial continuity of objects.

  15. Intense EM filamentation in relativistic hot plasmas

    NASA Astrophysics Data System (ADS)

    Hu, Qiang-Lin; Chen, Zhong-Ping; Mahajan, Swadesh M.

    2017-03-01

    Through 2D particle-in-cell (PIC) simulations, we demonstrate that the nature of filamentation of a high intensity electromagnetic (EM) pulse propagating in an underdense plasma, is profoundly affected at relativistically high temperatures. The "relativistic" filaments are sharper, are dramatically extended (along the direction of propagation), and live much longer than their lower temperature counterparts. The thermally boosted electron inertia is invoked to understand this very interesting and powerful phenomenon.

  16. Cryo-EM: Spinning the Micelles Away.

    PubMed

    Singh, Satinder K; Sigworth, Fred J

    2015-09-01

    Structural characterization of integral membrane proteins (MPs) demands that the samples be pure, monodisperse, and stable. Detergents are required to extract MPs from the lipid bilayer in which they reside and to stabilize them for downstream biophysical analyses. Some of the best MP-stabilizing detergents pose problems for cryo-EM studies, but in this issue of Structure, Hauer et al. (2015) now offer a solution called GraDeR.

  17. Leukocyte Recognition Using EM-Algorithm

    NASA Astrophysics Data System (ADS)

    Colunga, Mario Chirinos; Siordia, Oscar Sánchez; Maybank, Stephen J.

    This document describes a method for classifying images of blood cells. Three different classes of cells are used: Band Neutrophils, Eosinophils and Lymphocytes. The image pattern is projected down to a lower dimensional sub space using PCA; the probability density function for each class is modeled with a Gaussian mixture using the EM-Algorithm. A new cell image is classified using the maximum a posteriori decision rule.

  18. TandEM: Titan and Enceladus mission

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Atreya, S. K.; Balint, T.; Brown, R. H.; Dougherty, M. K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R. A.; Griffith, C. A.; Gurvits, L. I.; Jaumann, R.; Langevin, Y.; Leese, M. R.; Lunine, J. I.; McKay, C. P.; Moussas, X.; Müller-Wodarg, I.; Neubauer, F.; Owen, T. C.; Raulin, F.; Sittler, E. C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E. P.; Wahlund, J.-E.; Waite, J. H.; Baines, K. H.; Blamont, J.; Coates, A. J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R. D.; Morse, A.; Porco, C. C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J. C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D. H.; Bénilan, Y.; Bertucci, C.; Bézard, B.; Bjoraker, G. L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M. T.; Chassefière, E.; Coll, P.; Combes, M.; Cooper, J. F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I. A.; de Angelis, E.; de Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F. M.; Fortes, A. D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Küppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le Mouélic, S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T. A.; Lopes, R. M.; Lopez-Moreno, J.-J.; Luz, D.; Mahaffy, P. R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Menor Salvan, C.; Milillo, A.; Mitchell, D. G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C. D.; Nixon, C. A.; Nna Mvondo, D.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F. T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Ruiz Bermejo, M.; Sarris, E. T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L. J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D. F.; Szego, K.; Szopa, C.; Thissen, R.; Tomasko, M. G.; Toublanc, D.; Vali, H.; Vardavas, I.; Vuitton, V.; West, R. A.; Yelle, R.; Young, E. F.

    2009-03-01

    TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfière) and possibly several landing probes to be delivered through the atmosphere.

  19. TandEM: Titan and Enceladus mission

    USGS Publications Warehouse

    Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, Christophe; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, Ji; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, Catherine D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa,

    2009-01-01

    TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfi??re) and possibly several landing probes to be delivered through the atmosphere. ?? Springer Science + Business Media B.V. 2008.

  20. The US DOE EM international program

    SciTech Connect

    Elmetti, Rosa R.; Han, Ana M.; Roach, Jay A.

    2013-07-01

    The U.S. Department of Energy (DOE) Office of Environmental Management (EM) conducts international collaboration activities in support of U.S. policies and objectives regarding the accelerated risk reduction and remediation of environmental legacy of the nations' nuclear weapons program and government sponsored nuclear energy research. The EM International Program supported out of the EM Office of the Associate Principal Deputy Assistant Secretary pursues collaborations with foreign government organizations, educational institutions and private industry to assist in identifying technologies and promote international collaborations that leverage resources and link international experience and expertise. In fiscal year (FY) 2012, the International Program awarded eight international collaborative projects for work scope spanning waste processing, groundwater and soil remediation, deactivation and decommissioning (D and D) and nuclear materials disposition initiatives to seven foreign organizations. Additionally, the International Program's scope and collaboration opportunities were expanded to include technical as well as non-technical areas. This paper will present an overview of the on-going tasks awarded in FY 2012 and an update of upcoming international activities and opportunities for expansion into the remainder of FY 2013 and beyond. (authors)

  1. 2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) BARRACKS WITH RADAR ATTACHED. - Nike Hercules Missile Battery Summit Site, Battery Control Administration & Barracks Building, Anchorage, Anchorage, AK

  2. The State of Emergency Medical Services (EMS) Systems in Africa.

    PubMed

    Mould-Millman, Nee-Kofi; Dixon, Julia M; Sefa, Nana; Yancey, Arthur; Hollong, Bonaventure G; Hagahmed, Mohamed; Ginde, Adit A; Wallis, Lee A

    2017-02-23

    Introduction Little is known about the existence, distribution, and characteristics of Emergency Medical Services (EMS) systems in Africa, or the corresponding epidemiology of prehospital illness and injury.

  3. Recruitment and retention in rural and urban EMS: results from a national survey of local EMS directors.

    PubMed

    Freeman, Victoria A; Slifkin, Rebecca T; Patterson, P Daniel

    2009-01-01

    Maintaining an adequate staff is a challenge for rural emergency medical services (EMS) providers. This national survey of local EMS directors finds that rural EMS are more likely to be freestanding, that is, not affiliated with other public services, to employ only emergency medical technician-basics (EMT-Bs), and to be all volunteer. Rural EMS directors are more likely than urban ones to report that they are not currently fully staffed. The most common barriers to recruitment of EMTs in both urban and rural areas include unwillingness of community members to volunteer and lack of certified EMTs in the area. In rural areas, barriers to EMT training were noted more often than in urban areas as was the lack of employer support for employee volunteers. Similar rural training barriers affected retention of staff. Rural respondents reported that they lose staff to burnout and to difficulty in meeting continuing education requirements. Among rural respondents, those who direct all-volunteer EMS were the most likely to report recruitment and retention problems. The results suggest areas for further study including how volunteer EMS agencies can transition to paid agencies, how to bring EMS education to rural areas, and how EMS can work with other agencies to ensure EMS viability.

  4. Communication - An Effective Tool for Implementing ISO 14001/EMS

    SciTech Connect

    Rachel Damewood; Bowen Huntsman

    2004-04-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) received ISO 14001/EMS certification in June 2002. Communication played an effective role in implementing ISO 14001/EMS at the INEEL. This paper describes communication strategies used during the implementation and certification processes. The INEEL achieved Integrated Safety Management System (ISMS) and Voluntary Protection Program (VPP) Star status in 2001. ISMS implemented a formal process to plan and execute work. VPP facilitated worker involvement by establishing geographic units at various facilities with employee points of contact and management champions. The INEEL Environmental Management System (EMS) was developed to integrate the environmental functional area into its ISMS and VPP. Since the core functions of ISMS, VPP, and EMS are interchangeable, they were easy to integrate. Communication is essential to successfully implement an EMS. (According to ISO 14001 requirements, communication interacts with 12 other elements of the requirements.) We developed communication strategies that integrated ISMS, VPP, and EMS. For example, the ISMS, VPP, and EMS Web sites communicated messages to the work force, such as “VPP emphasizes the people side of doing business, ISMS emphasizes the system side of doing business, and EMS emphasizes the systems to protect the environment; but they all define work, identify and analyze hazards, and mitigate the hazards.” As a result of this integration, the work force supported and implemented the EMS. In addition, the INEEL established a cross-functional communication team to assist with implementing the EMS. The team included members from the Training and Communication organizations, VPP office, Pollution Prevention, Employee and Media Relations, a union representative, facility environmental support, and EMS staff. This crossfunctional team used various communication strategies to promote our EMS to all organization levels and successfully implemented EMS

  5. Improving Emergency Medical Services (EMS) in the United States Through Improved and Centralized Federal Coordination

    DTIC Science & Technology

    2011-03-01

    other emergencies. 4 • Public Awareness of the EMS Discipline. The public at large is not aware of the EMS structure in its community or at a higher...regard for its imperative role in community service. For this reason, placing EMS under the USFA at the federal level would cause EMS to still be...service to include EMS is appropriate, and in some cases, it is not. Not all communities have a dedicated fire service, which can make EMS provision

  6. EM threat analysis for wireless systems.

    SciTech Connect

    Burkholder, R. J. (Ohio State University Electroscience Laboratory); Mariano, Robert J.; Schniter, P. (Ohio State University Electroscience Laboratory); Gupta, I. J. (Ohio State University Electroscience Laboratory)

    2006-06-01

    Modern digital radio systems are complex and must be carefully designed, especially when expected to operate in harsh propagation environments. The ability to accurately predict the effects of propagation on wireless radio performance could lead to more efficient radio designs as well as the ability to perform vulnerability analyses before and after system deployment. In this report, the authors--experts in electromagnetic (EM) modeling and wireless communication theory--describe the construction of a simulation environment that is capable of quantifying the effects of wireless propagation on the performance of digital communication.

  7. Association between EMS Question Bank Completion and Passing Rates on the EMS Certification Examination.

    PubMed

    Clemency, Brian; Martin-Gill, Christian; Rall, Nicole; May, Paul; Lubin, Jeffrey; Cooley, Craig; Van Dillen, Christine; Silvestri, Salvatore; Portela, Roberto; Cooney, Derek; Knutsen, Christian; March, Juan

    2017-01-01

    A board review question bank was created to assist candidates in their preparation for the 2015 EMS certification examination. We aimed to describe the development of this question bank and evaluate its successes in preparing candidates to obtain EMS subspecialty board certification. An online question bank was developed by 13 subject matter experts who participated as item writers, representing eight different EMS fellowship programs. The online question bank consisted of four practice tests, with each of the tests comprised of 100 questions. The number of candidates who participated in and completed the question bank was calculated. The passing rate among candidates who completed the question bank was calculated and compared to the publicly reported statistics for all candidates. The relationship between candidates' performance on the question bank and subspecialty exam pass rates was determined. A total of 252 candidates took at least one practice test and, of those, 225 candidates completed all four 100-question practice tests. The pass rate on the 2015 EMS certification exam was 79% (95%CI 74-85%) among candidates who completed the question bank, which is 12% higher than the overall pass rate (p = 0.003). Candidates' performance on the question bank was positively associated with overall success on the exam (X(2) = 75.8, p < 0.0001). Achieving a score of ≥ 70% on the question bank was associated with a higher likelihood of passing the exam (OR = 17.8; 95% CI: 8.0-39.6). Completing the question bank program was associated with improved pass rates on the EMS certification exam. Strong performance on the question bank correlated with success on the exam.

  8. Light curve analysis of southern eclipsing binary EM Car

    NASA Astrophysics Data System (ADS)

    Ćiçek, C.; Bulut, I.; Bulut, A.

    2017-02-01

    In this study, ASAS light curve of the eclipsing binary EM Car (Sp = O8V, P = 3.4 days) has been analyzed using the Wilson-Devinney method. The light curve analyses have found that EM Car is a detached eclipsing binary system with small eccentric orbit

  9. Genetic-based EM algorithm for learning Gaussian mixture models.

    PubMed

    Pernkopf, Franz; Bouchaffra, Djamel

    2005-08-01

    We propose a genetic-based expectation-maximization (GA-EM) algorithm for learning Gaussian mixture models from multivariate data. This algorithm is capable of selecting the number of components of the model using the minimum description length (MDL) criterion. Our approach benefits from the properties of Genetic algorithms (GA) and the EM algorithm by combination of both into a single procedure. The population-based stochastic search of the GA explores the search space more thoroughly than the EM method. Therefore, our algorithm enables escaping from local optimal solutions since the algorithm becomes less sensitive to its initialization. The GA-EM algorithm is elitist which maintains the monotonic convergence property of the EM algorithm. The experiments on simulated and real data show that the GA-EM outperforms the EM method since: 1) We have obtained a better MDL score while using exactly the same termination condition for both algorithms. 2) Our approach identifies the number of components which were used to generate the underlying data more often than the EM algorithm.

  10. CryoEM at IUCrJ: a new era

    PubMed Central

    Subramaniam, Sriram; Kühlbrandt, Werner; Henderson, Richard

    2016-01-01

    In this overview, we briefly outline recent advances in electron cryomicroscopy (cryoEM) and explain why the journal IUCrJ, published by the International Union of Crystallography, could provide a natural home for publications covering many present and future developments in the cryoEM field. PMID:26870375

  11. 7 CFR 759.6 - EM to be made available.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... natural disaster has occurred in a county, resulting in severe physical losses. If the FSA Administrator determines that such a natural disaster has occurred, then EM can be made available to eligible farmers for... AGRICULTURE SPECIAL PROGRAMS DISASTER DESIGNATIONS AND NOTIFICATIONS § 759.6 EM to be made available. (a)...

  12. 7 CFR 759.6 - EM to be made available.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... natural disaster has occurred in a county, resulting in severe physical losses. If the FSA Administrator determines that such a natural disaster has occurred, then EM can be made available to eligible farmers for... AGRICULTURE SPECIAL PROGRAMS DISASTER DESIGNATIONS AND NOTIFICATIONS § 759.6 EM to be made available. (a)...

  13. The Post-LBV Supernova 2001em

    NASA Astrophysics Data System (ADS)

    Van Dyk, Schuyler D.; Chornock, R.; Filippenko, A. V.; Foley, R. J.; Lewin, W. H. G.; Li, W.; Panagia, N.; Pooley, D.; Stockdale, C. J.; Weiler, K. W.

    2009-12-01

    The supernova (SN) 2001em in UGC 11794 was classified early as Type Ib/c, i.e., as one arising from a hydrogen-stripped star. As part of a radio survey with the Very Large Array of SNe Ib/c at late times (Stockdale et al. 2003, BAAS, 35, 1346), SN 2001em was detected as a highly luminous radio source ˜2 years after explosion. The SN was also subsequently discovered with Chandra to be a very luminous X-ray source. The properties of both the radio and X-ray emission are more characteristic of the Type II-narrow (IIn) SNe, where the SN shock is interacting with dense, massive circumstellar matter, resulting in bright radio synchrotron emission and thermal bremsstrahlung from the interaction region. In fact, SN 2001em has shown to have spectroscopically transformed to a SN IIn. The premise that this might indicate an off-axis gamma-ray burst has been presented (Granot & Ramirez-Ruiz 2004, ApJ, 609, L9) and later, rather convincingly, refuted (e.g., Schinzel et al. 2009, ApJ, 691, 1380). Chugai & Chevalier (2006, ApJ, 641, 1051) have interpreted the spectral transformation and radio/X-ray emission as the SN shock overtaking the detached hydrogen envelope of the progenitor star, which was shed in a superwind episode many years prior to explosion. Chevalier (2007, RMxAC, 30, 41) has further pointed to the required mass-loss rate in the event being equivalent to what would occur in the eruption of a luminous blue variable (LBV). The optical (ground-based and HST) and radio/X-ray data, together with mid-infrared Spitzer observations, tend to support this scenario of a very massive star that experienced a powerful LBV outburst prior to explosion. Such an event may not be unique, with possible parallels in the cases of SNe 2005bf and 2006jc, and may provide valuable new information about massive stellar evolution.

  14. Refinement of atomic models in high resolution EM reconstructions using Flex-EM and local assessment.

    PubMed

    Joseph, Agnel Praveen; Malhotra, Sony; Burnley, Tom; Wood, Chris; Clare, Daniel K; Winn, Martyn; Topf, Maya

    2016-05-01

    As the resolutions of Three Dimensional Electron Microscopic reconstructions of biological macromolecules are being improved, there is a need for better fitting and refinement methods at high resolutions and robust approaches for model assessment. Flex-EM/MODELLER has been used for flexible fitting of atomic models in intermediate-to-low resolution density maps of different biological systems. Here, we demonstrate the suitability of the method to successfully refine structures at higher resolutions (2.5-4.5Å) using both simulated and experimental data, including a newly processed map of Apo-GroEL. A hierarchical refinement protocol was adopted where the rigid body definitions are relaxed and atom displacement steps are reduced progressively at successive stages of refinement. For the assessment of local fit, we used the SMOC (segment-based Manders' overlap coefficient) score, while the model quality was checked using the Qmean score. Comparison of SMOC profiles at different stages of refinement helped in detecting regions that are poorly fitted. We also show how initial model errors can have significant impact on the goodness-of-fit. Finally, we discuss the implementation of Flex-EM in the CCP-EM software suite. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Refinement of atomic models in high resolution EM reconstructions using Flex-EM and local assessment

    PubMed Central

    Joseph, Agnel Praveen; Malhotra, Sony; Burnley, Tom; Wood, Chris; Clare, Daniel K.; Winn, Martyn; Topf, Maya

    2016-01-01

    As the resolutions of Three Dimensional Electron Microscopic reconstructions of biological macromolecules are being improved, there is a need for better fitting and refinement methods at high resolutions and robust approaches for model assessment. Flex-EM/MODELLER has been used for flexible fitting of atomic models in intermediate-to-low resolution density maps of different biological systems. Here, we demonstrate the suitability of the method to successfully refine structures at higher resolutions (2.5–4.5 Å) using both simulated and experimental data, including a newly processed map of Apo-GroEL. A hierarchical refinement protocol was adopted where the rigid body definitions are relaxed and atom displacement steps are reduced progressively at successive stages of refinement. For the assessment of local fit, we used the SMOC (segment-based Manders’ overlap coefficient) score, while the model quality was checked using the Qmean score. Comparison of SMOC profiles at different stages of refinement helped in detecting regions that are poorly fitted. We also show how initial model errors can have significant impact on the goodness-of-fit. Finally, we discuss the implementation of Flex-EM in the CCP-EM software suite. PMID:26988127

  16. EMS incident management: emergency medical logistics.

    PubMed

    Maniscalco, P M; Christen, H T

    1999-01-01

    If you had to get x amount of supplies to point A or point B, or both, in 10 minutes, how would you do it? The answer lies in the following steps: 1. Develop a logistics plan. 2. Use emergency management as a partner agency for developing your logistics plan. 3. Implement a push logistics system by determining what supplies/medications and equipment are important. 4. Place mass casualty/disaster caches at key locations for rapid deployment. Have medication/fluid caches available at local hospitals. 5. Develop and implement command caches for key supervisors and managers. 6. Anticipate the logistics requirements of a terrorism/tactical violence event based on a community threat assessment. 7. Educate the public about preparing a BLS family disaster kit. 8. Test logistics capabilities at disaster exercises. 9. Budget for logistics needs. 10. Never underestimate the importance of logistics. When logistics support fails, the EMS system fails.

  17. A new preparedness policy for EMS logistics.

    PubMed

    Lee, Seokcheon

    2017-03-01

    Response time in emergency medical services (EMS) is defined as the interval for an ambulance to arrive the scene after receipt of a 911 call. When several ambulances are available upon the receipt of a new call, a decision of selecting an ambulance has to be made in an effort to reduce response time. Dispatching the closest unit available is commonly used in practice; however, recently the Preparedness policy was designed that is in a simplistic form yet being capable of securing a long-term efficiency. This research aims to improve the Preparedness policy, resolving several critical issues inherent in the current form of the policy. The new Preparedness policy incorporates a new metric of preparedness based on the notion of centrality and involves a tuning parameter, weight on preparedness, which has to be appropriately chosen according to operational scenario. Computational experiment shows that the new policy significantly improves the former policy robustly in various scenarios.

  18. Online EM with weight-based forgetting.

    PubMed

    Celaya, Enric; Agostini, Alejandro

    2015-05-01

    In the online version of the EM algorithm introduced by Sato and Ishii ( 2000 ), a time-dependent discount factor is introduced for forgetting the effect of the old estimated values obtained with an earlier, inaccurate estimator. In their approach, forgetting is uniformly applied to the estimators of each mixture component depending exclusively on time, irrespective of the weight attributed to each unit for the observed sample. This causes an excessive forgetting in the less frequently sampled regions. To address this problem, we propose a modification of the algorithm that involves a weight-dependent forgetting, different for each mixture component, in which old observations are forgotten according to the actual weight of the new samples used to replace older values. A comparison of the time-dependent versus the weight-dependent approach shows that the latter improves the accuracy of the approximation and exhibits much greater stability.

  19. DOE EM industry programs robotics development

    SciTech Connect

    Staubly, R.; Kothari, V.

    1997-12-01

    The Office of Science and Technology (OST) manages an aggressive program for RD&D, as well as testing and evaluation for the U.S. Department of Energy`s (DOE) Environmental Management (EM) organization. The goal is to develop new and improved environmental restoration and waste management technologies to clean up the inventory of the DOE weapons complex faster, safer, and cheaper than is possible with currently available technologies. OST has organized technology management activities along focus teams for each major problem area. There are currently five focus areas: decontamination and decommissioning, tanks, subsurface contaminants, mixed waste, and plutonium. In addition, OST is pursuing research and development (R&D) that cuts across these focus areas by having applications in two or more focus areas. Currently, there are three cross-cutting programs: the robotics technology development; characterization, monitoring, and sensor technologies; and efficient separations and processing.

  20. Epidemiology of Emergency Medical Services (EMS) Utilization in Four Indian Emergency Departments.

    PubMed

    Wijesekera, Olindi; Reed, Amanda; Chastain, Parker S; Biggs, Shauna; Clark, Elizabeth G; Kole, Tamorish; Chakrapani, Anoop T; Ashish, Nandy; Rajhans, Prasad; Breaud, Alan H; Jacquet, Gabrielle A

    2016-12-01

    Introduction Without a universal Emergency Medical Services (EMS) system in India, data on the epidemiology of patients who utilize EMS are limited. This retrospective chart review aimed to quantify and describe the burden of disease and patient demographics of patients who arrived by EMS to four Indian emergency departments (EDs) in order to inform a national EMS curriculum.

  1. Best Practices for Managing Large CryoEM Facilities

    PubMed Central

    Alewijnse, Bart; Ashton, Alun W.; Chambers, Melissa G.; Chen, Songye; Cheng, Anchi; Ebrahim, Mark; Eng, Edward; Hagen, Wim J. H.; Koster, Abraham J.; López, Claudia S.; Lukoyanova, Natalya; Ortega, Joaquin; Renault, Ludovic; Reyntjens, Steve; Rice, William J.; Scapin, Giovanna; Schrijver, Raymond; Siebert, Alistair; Stagg, Scott M.; Grum-Tokars, Valerie; Wright, Elizabeth R.; Wu, Shenping; Yu, Zhiheng; Zhou, Z. Hong; Carragher, Bridget; Potter, Clinton S.

    2017-01-01

    This paper provides an overview of the discussion and presentations from the Workshop on the Management of Large CryoEM Facilities held at the New York Structural Biology Center, New York, NY on February 6–7, 2017. A major objective of the workshop was to discuss best practices for managing cryoEM facilities. The discussions were largely focused on supporting single-particle methods for cryoEM and topics included: user access, assessing projects, workflow, sample handling, microscopy, data management and processing, and user training. PMID:28827185

  2. Environmental Education and Development Division (EM-522). Annual report, Fiscal year 1993

    SciTech Connect

    Not Available

    1993-12-31

    The Environmental Education and Development Division (EM-522) is one of three divisions within the Office of Technology Integration and Environmental Education and Development (EM-52) in Environmental Restoration and Waste Management`s (EM`s) Office of Technology Development (EM-50). The primary design criterion for EM-522 education activities is directly related to meeting EM`s goal of environmental compliance on an accelerated basis and cleanup of the 1989 inventory of inactive sites and facilities by the year 2019. Therefore, EM-522`s efforts are directed specifically toward stimulating knowledge and capabilities to achieve the goals of EM while contributing to DOE`s overall goal of increasing scientific, mathematical, and technical literacy and competency. This report discusses fiscal year 1993 activities.

  3. Transforming EMS Compliance at the Utah National Guard with an Automated Tool

    DTIC Science & Technology

    2009-05-01

    14001 & EMS 16 ISO 14001 EMS Requirements ISO14001 Requirement Condition WebEMIS™ 4.1 General Requirements None Uploads and stores EO 13423, EO...top level management with metrics and performance measures based on media WebEMIS vs. ISO 14001 & EMS 17 ISO 14001 EMS Requirements ISO14001 ...14001 EMS Requirements ISO14001 Requirement Condition WebEMIS 4.4 Implementation and Operation 4.4.1 Resources, Roles, Responsibility and Authority

  4. Recent developments in the CCP-EM software suite

    PubMed Central

    Burnley, Tom

    2017-01-01

    As part of its remit to provide computational support to the cryo-EM community, the Collaborative Computational Project for Electron cryo-Microscopy (CCP-EM) has produced a software framework which enables easy access to a range of programs and utilities. The resulting software suite incorporates contributions from different collaborators by encapsulating them in Python task wrappers, which are then made accessible via a user-friendly graphical user interface as well as a command-line interface suitable for scripting. The framework includes tools for project and data management. An overview of the design of the framework is given, together with a survey of the functionality at different levels. The current CCP-EM suite has particular strength in the building and refinement of atomic models into cryo-EM reconstructions, which is described in detail. PMID:28580908

  5. E.M. and Hadronic Shower Simulation with FLUKA

    SciTech Connect

    Battistoni, G.; Fasso, A.; Ferrari, A.; Ranft, J.; Rubbia, A.; Sala, P.R.; /INFN, Milan /SLAC /CERN /Siegen U. /Zurich, ETH

    2005-10-03

    A description of the main features of e.m. and hadronic shower simulation models used in the FLUKA code is summarized and some recent applications are discussed. The general status of the FLUKA project is also reported.

  6. Recent developments in the CCP-EM software suite.

    PubMed

    Burnley, Tom; Palmer, Colin M; Winn, Martyn

    2017-06-01

    As part of its remit to provide computational support to the cryo-EM community, the Collaborative Computational Project for Electron cryo-Microscopy (CCP-EM) has produced a software framework which enables easy access to a range of programs and utilities. The resulting software suite incorporates contributions from different collaborators by encapsulating them in Python task wrappers, which are then made accessible via a user-friendly graphical user interface as well as a command-line interface suitable for scripting. The framework includes tools for project and data management. An overview of the design of the framework is given, together with a survey of the functionality at different levels. The current CCP-EM suite has particular strength in the building and refinement of atomic models into cryo-EM reconstructions, which is described in detail.

  7. DOE-EM Science of Safety Robotics Challenge

    SciTech Connect

    Rimando, Rodrigo; Watts, Alex; Bobbitt, John; McLaughlin, Doug; Quigley, Morgan; Gladwell, Scott; McLoughlin, Mike; Kinnamon, Tony; Garcia, Joe; Ansari, Alex; Voyles, Richard; Chambers, David; Pryor, Mitch; Workman, Theresa; Mehling, Joshua; Browning, Kimberly; Deuel, Jake; Profitt, Bryan; Reibold, Marty

    2016-09-20

    During the week of August 22nd, 2016, over 150 technologists, stakeholders, and Department of Energy, Office of Environmental Management workers, met at DOE’s Portsmouth Gaseous Diffusion Plant in Ohio, for the EM Science of Safety Robotics Challenge.

  8. Near-atomic-resolution cryo-EM for molecular virology.

    PubMed

    Hryc, Corey F; Chen, Dong-Hua; Chiu, Wah

    2011-08-01

    Electron cryo-microscopy (cryo-EM) is a technique in structural biology that is widely used to solve the three-dimensional structures of macromolecular assemblies, close to their biological and solution conditions. Recent improvements in cryo-EM and single-particle reconstruction methodologies have led to the determination of several virus structures at near-atomic resolution (3.3 - 4.6 Å). These cryo-EM structures not only resolve the Cα backbones and side-chain densities of viral capsid proteins, but also suggest functional roles that the protein domains and some key amino acid residues play. This paper reviews the recent advances in near-atomic-resolution cryo-EM for probing the mechanisms of virus assembly and morphogenesis.

  9. EMS: A framework for data acquisition and analysis

    NASA Astrophysics Data System (ADS)

    Nogiec, J. M.; Sim, J.; Trombly-Freytag, K.; Walbridge, D.

    2001-08-01

    The Extensible Measurement System (EMS) is a universal Java framework for building data analysis and test systems. The objective of the EMS project is to replace a multitude of different existing systems with a single expandable system, capable of accommodating various test and analysis scenarios and varying algorithms. The EMS framework is based on component technology, graphical assembly of systems, introspection and flexibility to accommodate various data processing and data acquisition components. Core system components, common to many application domains, have been identified and designed together with the domain-specific components for the measurement of accelerator magnets. The EMS employs several modern technologies and the result is a highly portable, configurable, and potentially distributed system, with the capability of parallel signal data processing, parameterized test scripting, and run-time reconfiguration.

  10. EmPOWER Maryland - Leveraging relationships and experience

    EPA Pesticide Factsheets

    DHCD has gained a deep understanding of the needs of Maryland’s low-income residents and therefore was well-positioned to implement the low-income components of the broader EmPOWER Maryland energy efficiency initiative.

  11. Classification of ASASSN-17em/AT2017cts

    NASA Astrophysics Data System (ADS)

    Bersier, David

    2017-04-01

    We obtained a spectrum of the candidate supernova ASASSN-17em/AT2017cts (ATEL #10241), using the SPRAT spectrograph mounted on the robotic 2m Liverpool Telescope at the Roque de los Muchachos observatory (La Palma).

  12. Classification of ASASSN-17em/AT2017cts

    NASA Astrophysics Data System (ADS)

    Bersier, David

    2017-04-01

    We obtained a spectrum of the candidate supernova ASASSN-17em/AT2017cts (ATEL #10241), using the SPRAT spectrograph mounted on the robotic 2m Liverpool Telescope at the Roque de los Muchachos observatory (La Palma).

  13. Analysis of NSWC Ocean EM Observatory Test Data

    DTIC Science & Technology

    2016-09-01

    Analysis of NSWC Ocean EM Observatory test data: final report J. Bradley Nelson Date: September 2016 Contract #: NICOP - N62909-15...From - To) 09/01/2016 Technical Report #2 July 2015 - September 2016 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Analysis of NSWC Ocean EM Observatory...distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT NSWC-Carderock is leading a defense/academia group to instrument the South Florida Ocean

  14. NASA EM Followup of LIGO-Virgo Candidate Events

    NASA Technical Reports Server (NTRS)

    Blackburn, Lindy L.

    2011-01-01

    We present a strategy for a follow-up of LIGO-Virgo candidate events using offline survey data from several NASA high-energy photon instruments aboard RXTE, Swift, and Fermi. Time and sky-location information provided by the GW trigger allows for a targeted search for prompt and afterglow EM signals. In doing so, we expect to be sensitive to signals which are too weak to be publicly reported as astrophysical EM events.

  15. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-31

    The right hand aft skirt for NASA's Space Launch System (SLS) rocket has been refurbished and painted and is in a drying cell in a support building at the Hangar AF facility at Cape Canaveral Air Force Station in Florida. The space shuttle-era aft skirt will be used on the right hand booster of the SLS for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep space missions, and the Journey to Mars.

  16. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-28

    A technician with Orbital ATK, prime contractor for the Space Launch System (SLS) Booster, preps a section of the right hand aft skirt for primer and paint in a support building at the Hangar AF facility at Cape Canaveral Air Force Station in Florida. The space shuttle-era aft skirt will be used on the right hand booster of NASA's SLS rocket for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep space missions, and the Journey to Mars.

  17. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-29

    The right hand aft skirt for NASA's Space Launch System (SLS) rocket has been painted and is in a drying cell in a support building at the Hangar AF facility at Cape Canaveral Air Force Station in Florida. The space shuttle-era aft skirt will be used on the right hand booster of NASA's Space Launch System rocket for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep space missions, and the Journey to Mars.

  18. EM Telemetry Tool for Deep Well Drilling Applications

    SciTech Connect

    Jeffrey M. Gabelmann

    2005-11-15

    This final report discusses the successful development and testing of a deep operational electromagnetic (EM) telemetry system, produced under a cooperative agreement with the United States Department of Energy's National Energy Technology Laboratory. This new electromagnetic telemetry system provides a wireless communication link between sensors deployed deep within oil and gas wells and data acquisition equipment located on the earth's surface. EM based wireless telemetry is a highly appropriate technology for oil and gas exploration in that it avoids the need for thousands of feet of wired connections. In order to achieve the project performance objectives, significant improvements over existing EM telemetry systems were made. These improvements included the development of new technologies that have improved the reliability of the communications link while extending operational depth. A key element of the new design is the incorporation of a data-fusion methodology which enhances the communication receiver's ability to extract very weak signals from large amounts of ambient environmental noise. This innovative data-fusion receiver based system adapts advanced technologies, not normally associated with low-frequency communications, and makes them work within the harsh drilling environments associated with the energy exploration market. Every element of a traditional EM telemetry system design, from power efficiency to reliability, has been addressed. The data fusion based EM telemetry system developed during this project is anticipated to provide an EM tool capability that will impact both onshore and offshore oil and gas exploration operations, for conventional and underbalanced drilling applications.

  19. STEME: efficient EM to find motifs in large data sets.

    PubMed

    Reid, John E; Wernisch, Lorenz

    2011-10-01

    MEME and many other popular motif finders use the expectation-maximization (EM) algorithm to optimize their parameters. Unfortunately, the running time of EM is linear in the length of the input sequences. This can prohibit its application to data sets of the size commonly generated by high-throughput biological techniques. A suffix tree is a data structure that can efficiently index a set of sequences. We describe an algorithm, Suffix Tree EM for Motif Elicitation (STEME), that approximates EM using suffix trees. To the best of our knowledge, this is the first application of suffix trees to EM. We provide an analysis of the expected running time of the algorithm and demonstrate that STEME runs an order of magnitude more quickly than the implementation of EM used by MEME. We give theoretical bounds for the quality of the approximation and show that, in practice, the approximation has a negligible effect on the outcome. We provide an open source implementation of the algorithm that we hope will be used to speed up existing and future motif search algorithms.

  20. STEME: efficient EM to find motifs in large data sets

    PubMed Central

    Reid, John E.; Wernisch, Lorenz

    2011-01-01

    MEME and many other popular motif finders use the expectation–maximization (EM) algorithm to optimize their parameters. Unfortunately, the running time of EM is linear in the length of the input sequences. This can prohibit its application to data sets of the size commonly generated by high-throughput biological techniques. A suffix tree is a data structure that can efficiently index a set of sequences. We describe an algorithm, Suffix Tree EM for Motif Elicitation (STEME), that approximates EM using suffix trees. To the best of our knowledge, this is the first application of suffix trees to EM. We provide an analysis of the expected running time of the algorithm and demonstrate that STEME runs an order of magnitude more quickly than the implementation of EM used by MEME. We give theoretical bounds for the quality of the approximation and show that, in practice, the approximation has a negligible effect on the outcome. We provide an open source implementation of the algorithm that we hope will be used to speed up existing and future motif search algorithms. PMID:21785132

  1. A History and Informal Assessment of the <em>Slacker Astronomyem> Podcast

    NASA Astrophysics Data System (ADS)

    Price, Aaron; Gay, Pamela; Searle, Travis; Brissenden, Gina

    Slacker Astronomyem> is a weekly podcast that covers a recent astronomical news event or discovery. The show has a unique style consisting of irreverent, over-the-top humor combined with a healthy dose of hard science. According to our demographic analysis, the combination of this style and the unique podcasting distribution mechanism allows the show to reach audiences younger and busier than those reached via traditional channels. We report on the successes and challenges of the first year of the show, and provide an informal assessment of its role as a source for astronomical news and concepts for its approximately 15,500 weekly listeners.

  2. A HF EM installation allowing simultaneous whole body and deep local EM hyperthermia.

    PubMed

    Mazokhin, V N; Kolmakov, D N; Lucheyov, N A; Gelvich, E A; Troshin, I I

    1999-01-01

    The structure and main features of a HF EM installation based upon a new approach for creating electromagnetic fields destined for whole body (WBH) and deep local (DLH) hyperthermia are discussed. The HF EM field, at a frequency of 13.56 MHz, is created by a coplanar capacity type applicator positioned under a distilled water filled bolus that the patient is lying on. The EM energy being released directly in the deep tissues ensures effective whole body heating to required therapeutic temperatures of up to 43.5 degrees C, whereas the skin temperature can be maintained as low as 39-40.5 degrees C. For DLH, the installation is equipped with additional applicators and a generator operating at a frequency of 40.68 MHz. High efficiency of the WBH applicator makes it possible to carry out the WBH procedure without any air-conditioning cabin. Due to this, a free access to the patient's body during the WBH treatment is provided and a simultaneous WBH/DLH or WBH/LH procedure by means of additional applicators is possible. Controllable power output in the range of 100-800 W at a frequency of 13.56 MHz and 50-350 W at a frequency of 40.68 MHz allows accurate temperature control during WBH, DLH and WBH/DLH procedures. SAR patterns created by the WBH and DLH applicators in a liquid muscle phantom and measured by means of a non-perturbing E-dipole are investigated. The scattered EM field strength measured in the vicinity of the operating installation during the WBH, DLH and WBH/DLH procedures does not exceed security standards. Examples of temperature versus time graphs in the course of WBH, DLH and WBH/DLH procedures in clinics are presented. The installation is successfully used in leading oncological institutions of Russia and Belarus, though combined WBH/DLH procedures are evidently more complicated and demand thorough planning and temperature measurements to avoid overheating.

  3. Airborne EM for mine infrastructure planning

    NASA Astrophysics Data System (ADS)

    Wijns, Chris

    2016-08-01

    Airborne electromagnetic (AEM) surveys with near-surface vertical resolution provide rapid and comprehensive coverage of a mine site ahead of infrastructure planning. In environments of sufficient electrical conductivity contrast, the data will map variations in the depth to bedrock, providing guidance for expected excavation depths for solid building foundations, or mine pre-strip volumes. Continuous coverage overcomes the severe areal limitation of relying only on drilling and test pits. An AEM survey in northern Finland illustrates the success of this approach for guiding the placement of a mine crusher and related infrastructure. The cost of the EM data collection and interpretation is insignificant in comparison to the US$300 million capital cost of the mine infrastructure. This environment of shallow glacial cover challenges the limits of AEM resolution, yet analysis of subsequently collected three-dimensional (3D) surface seismic data and actual pre-strip excavation depths reinforces the predictive, but qualitative, mapping capability of the AEM. It also highlights the need to tune the modelling via petrophysics for the specific goal of the investigation, and exposes the limitations of visual drill core logging.

  4. Databases and archiving for cryoEM

    PubMed Central

    Patwardhan, Ardan; Lawson, Catherine L.

    2017-01-01

    Cryo-EM in structural biology is currently served by three public archives – EMDB for 3DEM reconstructions, PDB for models built from 3DEM reconstructions and EMPIAR for the raw 2D image data used to obtain the 3DEM reconstructions. These archives play a vital role for both the structural community and the wider biological community in making the data accessible so that results may be reused, reassessed and integrated with other structural and bioinformatics resources. The important role of the archives is underpinned by the fact that many journals mandate the deposition of data to PDB and EMDB on publication. The field is currently undergoing transformative changes where on the one hand high-resolution structures are becoming a routine occurrence while on the other hand electron tomography is enabling the study of macromolecules in the cellular context. Concomitantly the archives are evolving to best serve their stakeholder communities. In this chapter we describe the current state of the archives, resources available for depositing, accessing, searching, visualising and validating data, on-going community-wide initiatives and opportunities and challenges for the future. PMID:27572735

  5. DOE EM industry programs robotics development

    SciTech Connect

    Staubly, R.; Kothari, V.

    1998-12-31

    The Office of Science and Technology (OST) manages an aggressive program for RD and D, as well as testing and evaluation for the Department of Energy`s (DOE`s) Environmental Management (EM) organization. The goal is to develop new and improved environmental restoration and waste management technologies to clean up the inventory of the DOE weapons complex faster, safer, and cheaper than is possible with currently available technologies. Robotic systems reduce worker exposure to the absolute minimum, while providing proven, cost-effective, and, for some applications, the only acceptable technique for addressing challenging problems. Development of robotic systems for remote operations occurs in three main categories: tank waste characterization and retrieval; decontamination and dismantlement; and characterization, mapping, and inspection systems. In addition, the Federal Energy Technology Center (FETC) has some other projects which fall under the heading of supporting R and D. The central objective of all FETC robotic projects is to make robotic systems more attractive by reducing costs and health risks associated with the deployment of robotic technologies in the cleanup of the nuclear weapons complex. This will be accomplished through development of robots that are cheaper, faster, safer, and more reliable, as well as more straightforward to modify/adapt and more intuitive to operate with autonomous capabilities and intelligent controls that prevent accidents and optimize task execution.

  6. Analysis of EM dataset with several sensor configurations obtained by the loop-loop EM survey on magnetic anomalies

    NASA Astrophysics Data System (ADS)

    CHOI, J.; Yi, M. J.; Sasaki, Y.; Son, J.; Nam, M. J.

    2015-12-01

    Most of mineral mines in Korea are located in rugged mountain area embedding small-scale anomalies. Loop-loop EM survey system can be a better choice for exploring those mines because no ground contact is required and portable loops are freely positioned. Survey design is very important for detecting small amount of mineral deposits efficiently and spatial limits of survey lines should be considered. Along a same survey line, surveys with different separations between a transmitter and a receiver are applicable. EM responses are calculated in a layered-earth model embedding magnetic anomalies and analyses considering electric conductivity and magnetic permeability are made for the loop-loop EM survey data. Combining EM dataset with multi-frequency and multi-separation slightly enhanced a reconstructed image. Loop-loop EM survey using PROMOIS system was conducted on a small magnetite mine. Inversion with and without considering magnetic permeability was conducted for EM data with multi-frequency and multi-separation between a transmitter and a receiver.

  7. Image segmentation by EM-based adaptive pulse coupled neural networks in brain magnetic resonance imaging.

    PubMed

    Fu, J C; Chen, C C; Chai, J W; Wong, S T C; Li, I C

    2010-06-01

    We propose an automatic hybrid image segmentation model that integrates the statistical expectation maximization (EM) model and the spatial pulse coupled neural network (PCNN) for brain magnetic resonance imaging (MRI) segmentation. In addition, an adaptive mechanism is developed to fine tune the PCNN parameters. The EM model serves two functions: evaluation of the PCNN image segmentation and adaptive adjustment of the PCNN parameters for optimal segmentation. To evaluate the performance of the adaptive EM-PCNN, we use it to segment MR brain image into gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). The performance of the adaptive EM-PCNN is compared with that of the non-adaptive EM-PCNN, EM, and Bias Corrected Fuzzy C-Means (BCFCM) algorithms. The result is four sets of boundaries for the GM and the brain parenchyma (GM+WM), the two regions of most interest in medical research and clinical applications. Each set of boundaries is compared with the golden standard to evaluate the segmentation performance. The adaptive EM-PCNN significantly outperforms the non-adaptive EM-PCNN, EM, and BCFCM algorithms in gray mater segmentation. In brain parenchyma segmentation, the adaptive EM-PCNN significantly outperforms the BCFCM only. However, the adaptive EM-PCNN is better than the non-adaptive EM-PCNN and EM on average. We conclude that of the three approaches, the adaptive EM-PCNN yields the best results for gray matter and brain parenchyma segmentation.

  8. FitEM2EM--tools for low resolution study of macromolecular assembly and dynamics.

    PubMed

    Frankenstein, Ziv; Sperling, Joseph; Sperling, Ruth; Eisenstein, Miriam

    2008-01-01

    Studies of the structure and dynamics of macromolecular assemblies often involve comparison of low resolution models obtained using different techniques such as electron microscopy or atomic force microscopy. We present new computational tools for comparing (matching) and docking of low resolution structures, based on shape complementarity. The matched or docked objects are represented by three dimensional grids where the value of each grid point depends on its position with regard to the interior, surface or exterior of the object. The grids are correlated using fast Fourier transformations producing either matches of related objects or docking models depending on the details of the grid representations. The procedures incorporate thickening and smoothing of the surfaces of the objects which effectively compensates for differences in the resolution of the matched/docked objects, circumventing the need for resolution modification. The presented matching tool FitEM2EMin successfully fitted electron microscopy structures obtained at different resolutions, different conformers of the same structure and partial structures, ranking correct matches at the top in every case. The differences between the grid representations of the matched objects can be used to study conformation differences or to characterize the size and shape of substructures. The presented low-to-low docking tool FitEM2EMout ranked the expected models at the top.

  9. Colloidal Oatmeal <em>(Avena Sativa)em> Improves Skin Barrier Through Multi-Therapy Activity.

    PubMed

    Ilnytska, Olha; Kaur, Simarna; Chon, Suhyoun; Reynertson, Kurt A; Nebus, Judith; Garay, Michelle; Mahmood, Khalid; Southall, Michael D

    2016-06-01

    Oats (Avena sativa) are a centuries-old topical treatment for a variety of skin barrier conditions, including dry skin, skin rashes, and eczema; however, few studies have investigated the actual mechanism of action for the skin barrier strengthening activity of colloidal oatmeal. Four extracts of colloidal oatmeal were prepared with various solvents and tested in vitro for skin barrier related gene expression and activity. Extracts of colloidal oatmeal were found to induce the expression of genes related to epidermal differentiation, tight junctions and lipid regulation in skin, and provide pH-buffering capacity. Colloidal oatmeal boosted the expression of multiple target genes related to skin barrier, and resulted in recovery of barrier damage in an in vitro model of atopic dermatitis. In addition, an investigator-blinded study was performed with 50 healthy female subjects who exhibited bilateral moderate to severe dry skin on their lower legs. Subjects were treated with a colloidal oatmeal skin protectant lotion. Clinically, the colloidal oatmeal lotion showed significant clinical improvements in skin dryness, moisturization, and barrier. Taken together, these results demonstrate that colloidal oatmeal can provide clinically effective benefits for dry and compromised skin by strengthening skin barrier.

    <em>J Drugs Dermatolem>. 2016;15(6):684-690.

  10. Emergency medical service (EMS): A unique flight environment

    NASA Technical Reports Server (NTRS)

    Shively, R. Jay

    1993-01-01

    The EMS flight environment is unique in today's aviation. The pilots must respond quickly to emergency events and often fly to landing zones where they have never been before . The time from initially receiving a call to being airborne can be as little as two to three minutes. Often the EMS pilot is the only aviation professional on site, they have no operations people or other pilots to aid them in making decisons. Further, since they are often flying to accident scenes, not airports, there is often complete weather and condition information. Therefore, the initial decision that the pilot must make, accepting or declining a flight, can become very difficult. The accident rate of EMS helicopters has been relatively high over the past years. NASA-Ames research center has taken several steps in an attempt to aid EMS pilots in their decision making and situational awareness. A preflight risk assessment system (SAFE) was developed to aid pilots in their decision making, and was tested at an EMS service. The resutls of the study were promising and a second version incorporating the lessons learned is under development. A second line of research was the development of a low cost electronic chart display (ECD). This is a digital map display to help pilots maintain geographical orientation. Another thrust was undertaken in conjunction with the Aviation Safety Reporting System (ASRS). This involved publicizing the ASRS to EMS pilots and personnel, and calling each of the reporters back to gather additional information. This paper will discuss these efforts and how they may positively impact the safety of EMS operations.

  11. Emergency medical service (EMS): A unique flight environment

    NASA Technical Reports Server (NTRS)

    Shively, R. Jay

    1993-01-01

    The EMS flight environment is unique in today's aviation. The pilots must respond quickly to emergency events and often fly to landing zones where they have never been before . The time from initially receiving a call to being airborne can be as little as two to three minutes. Often the EMS pilot is the only aviation professional on site, they have no operations people or other pilots to aid them in making decisons. Further, since they are often flying to accident scenes, not airports, there is often complete weather and condition information. Therefore, the initial decision that the pilot must make, accepting or declining a flight, can become very difficult. The accident rate of EMS helicopters has been relatively high over the past years. NASA-Ames research center has taken several steps in an attempt to aid EMS pilots in their decision making and situational awareness. A preflight risk assessment system (SAFE) was developed to aid pilots in their decision making, and was tested at an EMS service. The resutls of the study were promising and a second version incorporating the lessons learned is under development. A second line of research was the development of a low cost electronic chart display (ECD). This is a digital map display to help pilots maintain geographical orientation. Another thrust was undertaken in conjunction with the Aviation Safety Reporting System (ASRS). This involved publicizing the ASRS to EMS pilots and personnel, and calling each of the reporters back to gather additional information. This paper will discuss these efforts and how they may positively impact the safety of EMS operations.

  12. Degradation of Benzodiazepines after 120 Days of EMS Deployment

    PubMed Central

    McMullan, Jason T.; Jones, Elizabeth; Barnhart, Bruce; Denninghoff, Kurt; Spaite, Daniel; Zaleski, Erin; Silbergleit, Robert

    2014-01-01

    Introduction EMS treatment of status epilepticus improves outcomes, but the benzodiazepine best suited for EMS use is unclear, given potential high environmental temperature exposures. Objective To describe the degradation of diazepam, lorazepam, and midazolam as a function of temperature exposure and time over 120 days of storage on active EMS units. Methods Study boxes containing vials of diazepam, lorazepam, and midazolam were distributed to 4 active EMS units in each of 2 EMS systems in the southwestern United States during May–August 2011. The boxes logged temperature every minute and were stored in EMS units per local agency policy. Two vials of each drug were removed from each box at 30-day intervals and underwent high-performance liquid chromatography to determine drug concentration. Concentration was analyzed as mean (and 95%CI) percent of initial labeled concentration as a function of time and mean kinetic temperature (MKT). Results 192 samples were collected (2 samples of each drug from each of 4 units per city at 4 time-points). After 120 days, the mean relative concentration (95%CI) of diazepam was 97.0% (95.7–98.2%) and of midazolam was 99.0% (97.7–100.2%). Lorazepam experienced modest degradation by 60 days (95.6% [91.6–99.5%]) and substantial degradation at 90 days (90.3% [85.2-95.4%]) and 120 days (86.5% [80.7–92.3%]). Mean MKT was 31.6°C (95%CI 27.1–36.1). Increasing MKT was associated with greater degradation of lorazepam, but not midazolam or diazepam. Conclusions Midazolam and diazepam experienced minimal degradation throughout 120 days of EMS deployment in high-heat environments. Lorazepam experienced significant degradation over 120 days and appeared especially sensitive to higher MKT exposure. PMID:24548058

  13. Resource Document: Coordination of Pediatric Emergency Care in EMS Systems.

    PubMed

    Remick, Katherine; Gross, Toni; Adelgais, Kathleen; Shah, Manish I; Leonard, Julie C; Gausche-Hill, Marianne

    2017-01-01

    Citing numerous pediatric-specific deficiencies within Emergency Medical Services (EMS) systems, the Institute of Medicine (IOM) recommended that EMS systems appoint a pediatric emergency care coordinator (PECC) to provide oversight of EMS activities related to care of children, to promote the integration of pediatric elements into day-to-day services as well as local and/or regional disaster planning, and to promote pediatric education across all levels of EMS providers. A systematic review of the literature was undertaken to describe the evidence for pediatric coordination across the emergency care continuum. The search strategy was developed by the investigators in consultation with a medical librarian and conducted in OVID, Medline, PubMed, Embase, Web of Science, and CINAHL databases from January 1, 1983 to January 1, 2016. All research articles that measured a patient-related or system-related outcome associated with pediatric coordination in the setting of emergency care, trauma, or disaster were included. Opinion articles, commentaries, and letters to the editors were excluded. Three investigators independently screened citations in a hierarchical manner and abstracted data. Of 149 identified titles, nine were included in the systematic review. The nine articles included one interventional study, five surveys, and three consensus documents. All articles favored the presence of pediatric coordination. The interventional study demonstrated improved documentation, clinical management, and staff awareness of high priority pediatric areas. The current literature supports the identification of pediatric coordination to facilitate the optimal care of children within EMS systems. In order for EMS systems to provide high quality care to children, pediatric components must be integrated into all aspects of care including day-to-day operations, policies, protocols, available equipment and medications, quality improvement efforts, and disaster planning. This systematic

  14. The EM-POGO: A simple, absolute velocity profiler

    NASA Astrophysics Data System (ADS)

    Terker, S. R.; Sanford, T. B.; Dunlap, J. H.; Girton, J. B.

    2013-01-01

    Electromagnetic current instrumentation has been added to the Bathy Systems, Inc. POGO transport sondes to produce a free-falling absolute velocity profiler called EM-POGO. The POGO is a free-fall profiler that measures a depth-averaged velocity using GPS fixes at the beginning and end of a round trip to the ocean floor (or a preset depth). The EM-POGO adds a velocity profile determined from measurements of motionally induced electric fields generated by the ocean current moving through the vertical component of the Earth's magnetic field. In addition to providing information about the vertical structure of the velocity, the depth-dependent measurements improve transport measurements by correcting for the non-constant fall-rate. Neglecting the variable fall rate results in errors O (1 cm s-1). The transition from POGO to EM-POGO included electrically isolating the POGO and electric-field-measuring circuits, installing a functional GPS receiver, finding a pressure case that provided an optimal balance among crush-depth, price and size, and incorporating the electrodes, electrode collar, and the circuitry required for the electric field measurement. The first EM-POGO sea-trial was in July 1999. In August 2006 a refurbished EM-POGO collected 15 absolute velocity profiles; relative and absolute velocity uncertainty was ˜1cms-1 and 0.5-5 cm s-1, respectively, at a vertical resolution of 25 m. Absolute velocity from the EM-POGO compared to shipboard ADCP measurements differed by ˜ 1-2 cm s-1, comparable to the uncertainty in absolute velocity from the ADCP. The EM-POGO is thus a low-cost, easy to deploy and recover, and accurate velocity profiler.

  15. International Space Station (ISS) Emergency Mask (EM) Development

    NASA Technical Reports Server (NTRS)

    Toon, Katherine P.; Hahn, Jeffrey; Fowler, Michael; Young, Kevin

    2011-01-01

    The Emergency Mask (EM) is considered a secondary response emergency Personal Protective Equipment (PPE) designed to provide respiratory protection to the International Space Station (ISS) crewmembers in response to a post-fire event or ammonia leak. The EM is planned to be delivered to ISS in 2012 to replace the current air purifying respirator (APR) onboard ISS called the Ammonia Respirator (AR). The EM is a one ]size ]fits ]all model designed to fit any size crewmember, unlike the APR on ISS, and uses either two Fire Cartridges (FCs) or two Commercial Off-the-Shelf (COTS) 3M(Trademark). Ammonia Cartridges (ACs) to provide the crew with a minimum of 8 hours of respiratory protection with appropriate cartridge swap ]out. The EM is designed for a single exposure event, for either post ]fire or ammonia, and is a passive device that cannot help crewmembers who cannot breathe on their own. The EM fs primary and only seal is around the wearer fs neck to prevent a crewmember from inhaling contaminants. During the development of the ISS Emergency Mask, several design challenges were faced that focused around manufacturing a leak free mask. The description of those challenges are broadly discussed but focuses on one key design challenge area: bonding EPDM gasket material to Gore(Registered Trademark) fabric hood.

  16. Breaking Cryo-EM Resolution Barriers to Facilitate Drug Discovery.

    PubMed

    Merk, Alan; Bartesaghi, Alberto; Banerjee, Soojay; Falconieri, Veronica; Rao, Prashant; Davis, Mindy I; Pragani, Rajan; Boxer, Matthew B; Earl, Lesley A; Milne, Jacqueline L S; Subramaniam, Sriram

    2016-06-16

    Recent advances in single-particle cryoelecton microscopy (cryo-EM) are enabling generation of numerous near-atomic resolution structures for well-ordered protein complexes with sizes ≥ ∼200 kDa. Whether cryo-EM methods are equally useful for high-resolution structural analysis of smaller, dynamic protein complexes such as those involved in cellular metabolism remains an important question. Here, we present 3.8 Å resolution cryo-EM structures of the cancer target isocitrate dehydrogenase (93 kDa) and identify the nature of conformational changes induced by binding of the allosteric small-molecule inhibitor ML309. We also report 2.8-Å- and 1.8-Å-resolution structures of lactate dehydrogenase (145 kDa) and glutamate dehydrogenase (334 kDa), respectively. With these results, two perceived barriers in single-particle cryo-EM are overcome: (1) crossing 2 Å resolution and (2) obtaining structures of proteins with sizes < 100 kDa, demonstrating that cryo-EM can be used to investigate a broad spectrum of drug-target interactions and dynamic conformational states.

  17. Refinement of Atomic Structures Against cryo-EM Maps.

    PubMed

    Murshudov, G N

    2016-01-01

    This review describes some of the methods for atomic structure refinement (fitting) against medium/high-resolution single-particle cryo-EM reconstructed maps. Some of the tools developed for macromolecular X-ray crystal structure analysis, especially those encapsulating prior chemical and structural information can be transferred directly for fitting into cryo-EM maps. However, despite the similarities, there are significant differences between data produced by these two techniques; therefore, different likelihood functions linking the data and model must be used in cryo-EM and crystallographic refinement. Although tools described in this review are mostly designed for medium/high-resolution maps, if maps have sufficiently good quality, then these tools can also be used at moderately low resolution, as shown in one example. In addition, the use of several popular crystallographic methods is strongly discouraged in cryo-EM refinement, such as 2Fo-Fc maps, solvent flattening, and feature-enhanced maps (FEMs) for visualization and model (re)building. Two problems in the cryo-EM field are overclaiming resolution and severe map oversharpening. Both of these should be avoided; if data of higher resolution than the signal are used, then overfitting of model parameters into the noise is unavoidable, and if maps are oversharpened, then at least parts of the maps might become very noisy and ultimately uninterpretable. Both of these may result in suboptimal and even misleading atomic models.

  18. Application of the EM algorithm to radiographic images.

    PubMed

    Brailean, J C; Little, D; Giger, M L; Chen, C T; Sullivan, B J

    1992-01-01

    The expectation maximization (EM) algorithm has received considerable attention in the area of positron emitted tomography (PET) as a restoration and reconstruction technique. In this paper, the restoration capabilities of the EM algorithm when applied to radiographic images is investigated. This application does not involve reconstruction. The performance of the EM algorithm is quantitatively evaluated using a "perceived" signal-to-noise ratio (SNR) as the image quality metric. This perceived SNR is based on statistical decision theory and includes both the observer's visual response function and a noise component internal to the eye-brain system. For a variety of processing parameters, the relative SNR (ratio of the processed SNR to the original SNR) is calculated and used as a metric to compare quantitatively the effects of the EM algorithm with two other image enhancement techniques: global contrast enhancement (windowing) and unsharp mask filtering. The results suggest that the EM algorithm's performance is superior when compared to unsharp mask filtering and global contrast enhancement for radiographic images which contain objects smaller than 4 mm.

  19. Topical Treatment With an Agent Disruptive to <em>P. acnesem> Biofilm Provides Positive Therapeutic Response: Results of a Randomized Clinical Trial.

    PubMed

    Bernhardt, Michael J; Myntti, Matthew F

    2016-06-01

    The traditional disease model of acne has been one of follicular plugging due to 'sticky epithelial cells' associated with increased sebum production with deep follicular anaerobic conditions favoring <em>P. acnesem>- generated inflammation. <em>P. acnesem> biofilms have been found more frequently in patients with acne than controls. Biofilms are genetically coded to create adhesion to the pilosebaceous unit followed by production of a mucopolysaccharide coating capable of binding to lipid surfaces. Traditional therapies for acne have involved mixtures of oral and topical antibiotics admixed with topical keratolytics and retinoids, which are aimed at traditional bacterial reduction as well as downregulating the inflammatory cascade. These approaches are limited by side effect and compliance/tolerability issues. As the <em>P. acnesem> biofilm may, in fact, be the instigator of this process, we studied the use of a topical agent designed to reduce the <em>P. acnesem> biofilm to see if reducing the biofilm would be therapeutically efficacious. We present data of a proprietary topical non-prescription agent with a novel pharmaco mechanism designed to attack the biofilm produced by <em>P. acnesem>. Our data shows a decrease of inflammatory lesions by 44% and non-inflammatory lesions by 32% after 12 weeks and also provided for a meaningful improvement in the quality of life of the patients in the study. These improvements were achieved with a product that was not associated with burning, chafing, irritation, or erythema, which can be seen with topical treatments. It is apparent from this study that by addressing the biofilm which protects the <em>P. acnesem> bacteria through the use of the Acne Gel, the incidence of acne symptoms can be greatly reduced, while having no negative impacts on the patients' skin (ClinicalTrials.gov registry number NCT02404285).

    <em>J Drugs Dermatol. em>2016;15(6):677-683.

  20. Where There is No EMS: Lay Providers in Emergency Medical Services Care - EMS as a Public Health Priority.

    PubMed

    Debenham, Sierra; Fuller, Matthew; Stewart, Matthew; Price, Raymond R

    2017-08-11

    By 2030, road traffic accidents are projected to be the fifth leading cause of death worldwide, with 90% of these deaths occurring in low- and middle-income countries (LMICs). While high-quality, prehospital trauma care is crucial to reduce the number of trauma-related deaths, effective Emergency Medical Systems (EMS) are limited or absent in many LMICs. Although lay providers have long been recognized as the front lines of informal trauma care in countries without formal EMS, few efforts have been made to capitalize on these networks. We suggest that lay providers can become a strong foundation for nascent EMS through a four-fold approach: strengthening and expanding existing lay provider training programs; incentivizing lay providers; strengthening locally available first aid supply chains; and using technology to link lay provider networks. Debenham S , Fuller M , Stewart M , Price RR . Where there is no EMS: lay providers in Emergency Medical Services care - EMS as a public health priority. Prehosp Disaster Med. 2017;32(6):1-3.

  1. EMS Stretcher “Misadventures” in a Large, Urban EMS System: A Descriptive Analysis of Contributing Factors and Resultant Injuries

    PubMed Central

    Goodloe, Jeffrey M.; Crowder, Christopher J.; Arthur, Annette O.; Thomas, Stephen H.

    2012-01-01

    Purpose. There is a paucity of data regarding EMS stretcher-operation-related injuries. This study describes and analyzes characteristics associated with undesirable stretcher operations, with or without resultant injury in a large, urban EMS agency. Methods. In the study agency, all stretcher-related “misadventures” are required to be documented, regardless of whether injury results. All stretcher-related reports between July 1, 2009 and June 30, 2010 were queried in retrospective analysis, avoiding Hawthorne effect in stretcher operations. Results. During the year studied, 129,110 patients were transported. 23 stretcher incidents were reported (0.16 per 1,000 transports). No patient injury occurred. Four EMS providers sustained minor injuries. Among contributing aspects, the most common involved operations surrounding the stretcher-ambulance safety latch, 14/23 (60.9%). From a personnel injury prevention perspective, there exists a significant relationship between combative patients and crew injury related to stretcher operation, Fisher's exact test 0.048. Conclusions. In this large, urban EMS system, the incidence of injury related to stretcher operations in the one-year study period is markedly low, with few personnel injuries and no patient injuries incurred. Safety for EMS personnel and patients could be advanced by educational initiatives that highlight specific events and conditions contributing to stretcher-related adverse events. PMID:22606379

  2. EMS-induced cytomictic variability in safflower (Carthamus tinctorius L.).

    PubMed

    Srivastava, P; Kumar, G

    2011-01-01

    Seeds of safflower (Carthamus tinctorius L.) were subjected to three treatment durations (3h, 5h and 7h) of 0.5 % Ethyl Methane Sulphonate (EMS). Microsporogenesis was carried out in the control as well as in the treated materials. EMS treated plants showed interesting feature of partial inter-meiocyte chromatin migration through channel formation, beak formation or direct cell fusion. Another interesting feature noticed during the study was the fusion among tetrads due to wall dissolution. The phenomenon of cytomixis was recorded at nearly all the stages of microsporogenesis connecting from a few to several meiocytes. Other abnormalities such as laggards, precocious movement, bridge and non-disjunction of chromosomes were also recorded but in very low frequencies. The phenomenon of cytomixis increased along with the increase in treatment duration of EMS. Cells with these types of cytomictic disturbances may probably result in uneven formation of gametes or zygote, heterogenous sized pollen grains or even loss of fertility in future.

  3. Pirmasis lietuvi\\vskas Suvalkijos žemėlapis

    NASA Astrophysics Data System (ADS)

    Girkus, Romualdas; Lukoševičius, Viktoras

    2009-01-01

    Po ilgo paie\\vskos laikotarpio, dr. N. Lietuvninkaitei padedant, KTU bibliotekos Retų knygų skyriaus kartografiniame archyve aptiktas 1915 m. JAV išleistas B. K. Balučio M 1:252 000 Suvalkijos žemėlapis. Lietuvių išeivijos instituto B. K. Balučio fonde žemėlapio sudarymo medžiagos nerasta. Paie\\vska atrodė bevilti\\vska dėl tarpukario Lietuvi\\vskosios enciklopedijos klaidinančios informacijos, kad prasidėjus Pirmajam pasauliniam karui žemėlapis nebuvo išleistas, tad aprašomas ir publikuojamas pirmą kartą.

  4. Recent technical advancements enabled atomic resolution CryoEM

    NASA Astrophysics Data System (ADS)

    Xueming, Li

    2016-01-01

    With recent breakthroughs in camera and image processing technologies single-particle electron cryo-microscopy (CryoEM) has suddenly gained the attention of structural biologists as a powerful tool able to solve the atomic structures of biological complexes and assemblies. Compared with x-ray crystallography, CryoEM can be applied to partially flexible structures in solution and without the necessity of crystallization, which is especially important for large complexes and assemblies. This review briefly explains several key bottlenecks for atomic resolution CryoEM, and describes the corresponding solutions for these bottlenecks based on the recent technical advancements. The review also aims to provide an overview about the technical differences between its applications in biology and those in material science. Project supported by Tsinghua-Peking Joint Center for Life Sciences, China.

  5. Analyses of Subnanometer Resolution Cryo-EM Density Maps

    PubMed Central

    Baker, Matthew L.; Baker, Mariah R.; Hryc, Corey F.; DiMaio, Frank

    2011-01-01

    Today, electron cryomicroscopy (cryo-EM) can routinely achieve subnanometer resolutions of complex macromolecular assemblies. From a density map, one can extract key structural and functional information using a variety of computational analysis tools. At subnanometer resolution, these tools make it possible to isolate individual subunits, identify secondary structures, and accurately fit atomic models. With several cryo-EM studies achieving resolutions beyond 5 Å, computational modeling and feature recognition tools have been employed to construct backbone and atomic models of the protein components directly from a density map. In this chapter, we describe several common classes of computational tools that can be used to analyze and model subnanometer resolution reconstructions from cryo-EM. A general protocol for analyzing subnanometer resolution density maps is presented along with a full description of steps used in analyzing the 4.3 Å resolution structure of Mm-cpn. PMID:20888467

  6. Lietuvos Teritorijos Gravimetrinio Žemėlapio Tikslumo Vertinimas

    NASA Astrophysics Data System (ADS)

    Birvydienė, Rosita; Krikštaponis, Boleslovas; Obuchovski, Romuald; Paršeliūnas, Eimuntas; Petroškevičius, Petras; Šlikas, Dominykas

    2010-01-01

    Remiantis matavimų, atliktų Lietuvos gravimetrinio tinklo punktuose, duomenimis, įvertintas Lietuvos teritorijos 1:200 000 mastelio Bouguer anomalijų gravimetrinio žemėlapio tikslumas. Vertinimui naudota 686 gravimetrinių punktų sunkio pagreičio reikšmės, kurių vidutinė kvadratinė paklaida neviršija 9 μGal. Nustatytos teritorijos, kuriose sunkio pagreitis, apskaičiuotas pagal žemėlapį, turi sistemingąsias paklaidas. Gautas vidutinis skirtumas tarp žemėlapyje taikomos Potsdamo sunkio sistemos ir IGSN 71 sistemos, apibrėžtos Lietuvos gravimetriniame tinkle atliktais absoliučiaisiais gravimetriniais matavimais.

  7. Longitudinal information and radiation damage in EM calorimetry

    SciTech Connect

    Green, D.

    1993-02-05

    The SCC radiation field is higher than that encountered by previous hadron collider detectors. In particular, the electromagnetic (EM) calorimeter compartment sees the highest radiation dose. Since an EM calorimeter also makes the most precise energy measurement, special care must be lavished on this part of a calorimeter. Previous studies have concentrated on Monte Carlo examinations of 2 longitudinal compartments within the EM which can alleviate radiation damage. Recently, it was realized that a ``shower maximum`` detector, such as exists in CDF, also contains information of the conversion point of an electromagnetic shower. As such, it can potentially be used in a fashion analogous to the longitudinal compartments, although it is not designed to be optimized for this role.

  8. Geospatial Analysis of Pediatric EMS Run Density and Endotracheal Intubation

    PubMed Central

    Hansen, Matthew; Loker, William; Warden, Craig

    2016-01-01

    Introduction The association between geographic factors, including transport distance, and pediatric emergency medical services (EMS) run clustering on out-of-hospital pediatric endotracheal intubation is unclear. The objective of this study was to determine if endotracheal intubation procedures are more likely to occur at greater distances from the hospital and near clusters of pediatric calls. Methods This was a retrospective observational study including all EMS runs for patients less than 18 years of age from 2008 to 2014 in a geographically large and diverse Oregon county that includes densely populated urban areas near Portland and remote rural areas. We geocoded scene addresses using the automated address locator created in the cloud-based mapping platform ArcGIS, supplemented with manual address geocoding for remaining cases. We then use the Getis-Ord Gi spatial statistic feature in ArcGIS to map statistically significant spatial clusters (hot spots) of pediatric EMS runs throughout the county. We then superimposed all intubation procedures performed during the study period on maps of pediatric EMS-run hot spots, pediatric population density, fire stations, and hospitals. We also performed multivariable logistic regression to determine if distance traveled to the hospital was associated with intubation after controlling for several confounding variables. Results We identified a total of 7,797 pediatric EMS runs during the study period and 38 endotracheal intubations. In univariate analysis we found that patients who were intubated were similar to those who were not in gender and whether or not they were transported to a children’s hospital. Intubated patients tended to be transported shorter distances and were older than non-intubated patients. Increased distance from the hospital was associated with reduced odds of intubation after controlling for age, sex, scene location, and trauma system entry status in a multivariate logistic regression. The

  9. The photon: EM fields, electrical potentials, and AC charge

    NASA Astrophysics Data System (ADS)

    Meulenberg, A.; Hudgins, W. R.; Penland, R. F.

    2015-09-01

    Photons are here considered to be resonant oscillations (solitons) in four dimensions (space/time) of an undefined `field' otherwise generally existing at a local energy minimum. The photons' constituent EM fields result in elevated energy, and therefore potentials, within that field. It is in the context of the standing waves of and between photons that the EM fields and potentials lead to a description of alternating (AC) `currents' (of some form) of unquantized alternating `charge' (of some sort). The main topic of this paper is the alternating charge.

  10. Geospatial Analysis of Pediatric EMS Run Density and Endotracheal Intubation.

    PubMed

    Hansen, Matthew; Loker, William; Warden, Craig

    2016-09-01

    The association between geographic factors, including transport distance, and pediatric emergency medical services (EMS) run clustering on out-of-hospital pediatric endotracheal intubation is unclear. The objective of this study was to determine if endotracheal intubation procedures are more likely to occur at greater distances from the hospital and near clusters of pediatric calls. This was a retrospective observational study including all EMS runs for patients less than 18 years of age from 2008 to 2014 in a geographically large and diverse Oregon county that includes densely populated urban areas near Portland and remote rural areas. We geocoded scene addresses using the automated address locator created in the cloud-based mapping platform ArcGIS, supplemented with manual address geocoding for remaining cases. We then use the Getis-Ord Gi spatial statistic feature in ArcGIS to map statistically significant spatial clusters (hot spots) of pediatric EMS runs throughout the county. We then superimposed all intubation procedures performed during the study period on maps of pediatric EMS-run hot spots, pediatric population density, fire stations, and hospitals. We also performed multivariable logistic regression to determine if distance traveled to the hospital was associated with intubation after controlling for several confounding variables. We identified a total of 7,797 pediatric EMS runs during the study period and 38 endotracheal intubations. In univariate analysis we found that patients who were intubated were similar to those who were not in gender and whether or not they were transported to a children's hospital. Intubated patients tended to be transported shorter distances and were older than non-intubated patients. Increased distance from the hospital was associated with reduced odds of intubation after controlling for age, sex, scene location, and trauma system entry status in a multivariate logistic regression. The locations of intubations were

  11. A constrained EM algorithm for independent component analysis.

    PubMed

    Welling, M; Weber, M

    2001-03-01

    We introduce a novel way of performing independent component analysis using a constrained version of the expectation-maximization (EM) algorithm. The source distributions are modeled as D one-dimensional mixtures of gaussians. The observed data are modeled as linear mixtures of the sources with additive, isotropic noise. This generative model is fit to the data using constrained EM. The simpler "soft-switching" approach is introduced, which uses only one parameter to decide on the sub- or supergaussian nature of the sources. We explain how our approach relates to independent factor analysis.

  12. Low Bandwidth Vocoding using EM Sensor and Acoustic Signal Processing

    SciTech Connect

    Ng, L C; Holzrichter, J F; Larson, P E

    2001-10-25

    Low-power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference [1]. By combining these data with the corresponding acoustic signal, we've demonstrated an almost 10-fold bandwidth reduction in speech compression, compared to a standard 2.4 kbps LPC10 protocol used in the STU-III (Secure Terminal Unit, third generation) telephone. This paper describes a potential EM sensor/acoustic based vocoder implementation.

  13. Speaker verification using combined acoustic and EM sensor signal processing

    SciTech Connect

    Ng, L C; Gable, T J; Holzrichter, J F

    2000-11-10

    Low Power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference. This greatly enhances the quality and quantity of information for many speech related applications. See Holzrichter, Burnett, Ng, and Lea, J. Acoustic. SOC. Am . 103 ( 1) 622 (1998). By combining the Glottal-EM-Sensor (GEMS) with the Acoustic-signals, we've demonstrated an almost 10 fold reduction in error rates from a speaker verification system experiment under a moderate noisy environment (-10dB).

  14. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-28

    A paint technician with Orbital ATK, prime contractor for the Space Launch System (SLS) Booster, uses an air gun to apply paint to the right hand aft skirt for NASA’s SLS rocket inside a support building at the Hangar AF facility at Cape Canaveral Air Force Station. The space shuttle-era aft skirt, was inspected and resurfaced to prepare it for primer and paint. The aft skirt will be used on the right hand booster of the SLS rocket for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep-space missions, and the journey to Mars.

  15. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-28

    Technicians with Orbital ATK, prime contractor for the Space Launch System (SLS) Booster, prepare the right hand aft skirt for NASA’s SLS rocket for primer and painting inside a support building at the Hangar AF facility at Cape Canaveral Air Force Station in Florida. The space shuttle-era aft skirt, was inspected and resurfaced and will be primed and painted for use on the right hand booster of the SLS rocket for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep-space missions, and the journey to Mars.

  16. Orion EM-1 Booster Preps - Aft Skirt Preps/Painting

    NASA Image and Video Library

    2016-10-28

    Technicians with Orbital ATK, prime contractor for the Space Launch System (SLS) Booster, prepare a paint mixture for the right hand aft skirt for NASA’s SLS in a support building at the Hangar AF facility at Cape Canaveral Air Force Station in Florida. The space shuttle-era aft skirt, was inspected and resurfaced, and will be primed and painted for use on the right hand booster of the SLS rocket for Exploration Mission 1 (EM-1). NASA is preparing for EM-1, deep-space missions, and the Journey to Mars.

  17. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, Lockheed Martin technicians secure a protective cover around the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for its move to a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  18. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians move the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) into a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  19. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) is in a clean room with protective walls secured around it. The adapter will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  20. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians move the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) toward a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  1. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, a Lockheed Martin technician secures a protective cover around the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for its move to a clean room The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  2. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) is being moved to a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  3. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, a protective cover is installed around the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for its move to a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  4. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians secure a protective cover around the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for its move to a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  5. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians are preparing the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for the move into a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  6. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, Lockheed Martin technicians secure a protective cover around the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) for its move to a clean. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  7. Orion EM-1 Crew Module Adapter Move to Clean Room

    NASA Image and Video Library

    2016-11-29

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians begin to move the Orion crew module adapter (CMA) for Exploration Mission 1 (EM-1) to a clean room. The CMA will undergo propellant and environmental control and life support system tube installation and welding. The adapter will connect the Orion crew module to the European Space Agency-provided service module. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  8. A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas

    NASA Astrophysics Data System (ADS)

    de Mello, A. B.; Lorenz-Martins, S.

    2003-08-01

    Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase

  9. Item Parameter Estimation via Marginal Maximum Likelihood and an EM Algorithm: A Didactic.

    ERIC Educational Resources Information Center

    Harwell, Michael R.; And Others

    1988-01-01

    The Bock and Aitkin Marginal Maximum Likelihood/EM (MML/EM) approach to item parameter estimation is an alternative to the classical joint maximum likelihood procedure of item response theory. This paper provides the essential mathematical details of a MML/EM solution and shows its use in obtaining consistent item parameter estimates. (TJH)

  10. An EM System with Dynamic Multi-Axis Transmitter and Tensor Gradiometer Receiver

    DTIC Science & Technology

    2011-06-01

    FINAL REPORT An EM System With Dynamic Multi-Axis Transmitter and Tensor Gradiometer Receiver SERDP Project MR-1534 JUNE 2011 David C...2006- 2010 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER An EM System with Dynamic Multi-Axis transmitter and Tensor Gradiometer W91 2HQ-06-C-0050...239.18 EM Tensor Gradiometer SERDP MM-1532 i Contents Contents

  11. Texas Hold 'em Online Poker: A Further Examination

    ERIC Educational Resources Information Center

    Hopley, Anthony A. B.; Dempsey, Kevin; Nicki, Richard

    2012-01-01

    Playing Texas Hold 'em Online Poker (THOP) is on the rise. However, there is relatively little research examining factors that contribute to problem gambling in poker players. The aim of this study was to extend the research findings of Hopley and Nicki (2010). The negative mood states of depression, anxiety and stress were found to be linked to…

  12. Texas Hold 'em Online Poker: A Further Examination

    ERIC Educational Resources Information Center

    Hopley, Anthony A. B.; Dempsey, Kevin; Nicki, Richard

    2012-01-01

    Playing Texas Hold 'em Online Poker (THOP) is on the rise. However, there is relatively little research examining factors that contribute to problem gambling in poker players. The aim of this study was to extend the research findings of Hopley and Nicki (2010). The negative mood states of depression, anxiety and stress were found to be linked to…

  13. Noise properties of the EM algorithm: II. Monte Carlo simulations.

    PubMed

    Wilson, D W; Tsui, B M; Barrett, H H

    1994-05-01

    In an earlier paper we derived a theoretical formulation for estimating the statistical properties of images reconstructed using the iterative ML-EM algorithm. To gain insight into this complex problem, two levels of approximation were considered in the theory. These techniques revealed the dependence of the variance and covariance of the reconstructed image noise on the source distribution, imaging system transfer function, and iteration number. In this paper a Monte Carlo approach was taken to study the noise properties of the ML-EM algorithm and to test the predictions of the theory. The study also served to evaluate the approximations used in the theory. Simulated data from phantoms were used in the Monte Carlo experiments. The ML-EM statistical properties were calculated from sample averages of a large number of images with different noise realizations. The agreement between the more exact form of the theoretical formulation and the Monte Carlo formulation was better than 10% in most cases examined, and for many situations the agreement was within the expected error of the Monte Carlo experiments. Results from the studies provide valuable information about the noise characteristics of ML-EM reconstructed images. Furthermore, the studies demonstrate the power of the theoretical and Monte Carlo approaches for investigating noise properties of statistical reconstruction algorithms.

  14. EMS-generated Rhizoctonia resistance in an adapted wheat

    USDA-ARS?s Scientific Manuscript database

    We report the first genetic resistance in wheat to Rhizoctonia solani AG-8 and R. oryzae, the causal agents of Rhizoctonia root rot and pre-emergence damping-off. Rhizoctonia resistance was generated in the spring wheat cultivar Scarlet using EMS mutagenesis. Resistant plants, named Scarlet-Rz1, d...

  15. Functionalized Anatomical Models for EM-Neuron Interaction Modeling

    PubMed Central

    Neufeld, Esra; Cassará, Antonino Mario; Montanaro, Hazael; Kuster, Niels; Kainz, Wolfgang

    2017-01-01

    The understanding of interactions between electromagnetic (EM) fields and nerves are crucial in contexts ranging from therapeutic neurostimulation to low frequency EM exposure safety. To properly consider the impact of in-vivo induced field inhomogeneity on non-linear neuronal dynamics, coupled EM-neuronal dynamics modeling is required. For that purpose, novel functionalized computable human phantoms have been developed. Their implementation and the systematic verification of the integrated anisotropic quasi-static EM solver and neuronal dynamics modeling functionality, based on the method of manufactured solutions and numerical reference data, is described. Electric and magnetic stimulation of the ulnar and sciatic nerve were modeled to help understanding a range of controversial issues related to the magnitude and optimal determination of strength-duration (SD) time constants. The results indicate the importance of considering the stimulation-specific inhomogeneous field distributions (especially at tissue interfaces), realistic models of non-linear neuronal dynamics, very short pulses, and suitable SD extrapolation models. These results and the functionalized computable phantom will influence and support the development of safe and effective neuroprosthetic devices and novel electroceuticals. Furthermore they will assist the evaluation of existing low frequency exposure standards for the entire population under all exposure conditions. PMID:27224508

  16. Symmetry-restrained flexible fitting for symmetric EM maps

    PubMed Central

    Chan, Kwok-Yan; Gumbart, James; McGreevy, Ryan; Watermeyer, Jean M.; Sewell, B. Trevor; Schulten, Klaus

    2011-01-01

    Summary Many large biological macromolecules have inherent structural symmetry, being composed of a few distinct subunits, repeated in a symmetric array. These complexes are often not amenable to traditional high-resolution structural determination methods, but can be imaged in functionally relevant states using cryo-electron microscopy (cryo-EM). A number of methods for fitting atomic-scale structures into cryo-EM maps have been developed, including the molecular dynamics flexible fitting (MDFF) method. However, quality and resolution of the cryo-EM map are the major determinants of a method’s success. In order to incorporate knowledge of structural symmetry into the fitting procedure, we developed the symmetry-restrained MDFF method. The new method adds to the cryo-EM map-derived potential further restraints on the allowed conformations of a complex during fitting, thereby improving the quality of the resultant structure. The benefit of using symmetry-based restraints during fitting, particularly for medium to low-resolution data, is demonstrated for three different systems. PMID:21893283

  17. Reservoir characterization and steam flood monitoring with crosshole EM

    SciTech Connect

    Wilt, M.; Torres-Verdin, C.

    1995-06-01

    Crosshole electromagnetic (EM) imaging is applied to reservoir characterization and steam flood monitoring in a central California oil field. Steam was injected into three stacked eastward-dipping, unconsolidated oil sands within the upper 200 m. The steam plume is expected to develop as an ellipse aligned with the regional northwest-southeast strike. EM measurements were made from two fiberglass-cased observation wells straddling the steam injector on a northeast-southwest profile using the LLNL frequency domain crosshole EM system. Field data were collected before the initiation of a steam drive to map the distribution of the oil sands and then 6 and 12 months later to monitor the progress of the steam chest. Resistivity images derived from the EM data before steam injection clearly delineate the distribution and dipping structure on the target oil sands. Difference images, from data collected before and after steam flooding, show resistivity changes that indicate that the steam chest has developed only in the deeper oil sands although steam injection occurred in all three sand layers.

  18. Signs and Guides: Wayfinding Alternatives for the EMS Library.

    ERIC Educational Resources Information Center

    Johnson, Johanna H.

    Concerned with increasing the accessibility of the collection of the Engineering/Math Sciences (EMS) Library at the University of California at Los Angeles through the use of self guidance systems, this practical study focused on the problem context, general library guides, and library signage in reviewing the literature, and conducted a survey of…

  19. Functionalized anatomical models for EM-neuron Interaction modeling

    NASA Astrophysics Data System (ADS)

    Neufeld, Esra; Cassará, Antonino Mario; Montanaro, Hazael; Kuster, Niels; Kainz, Wolfgang

    2016-06-01

    The understanding of interactions between electromagnetic (EM) fields and nerves are crucial in contexts ranging from therapeutic neurostimulation to low frequency EM exposure safety. To properly consider the impact of in vivo induced field inhomogeneity on non-linear neuronal dynamics, coupled EM-neuronal dynamics modeling is required. For that purpose, novel functionalized computable human phantoms have been developed. Their implementation and the systematic verification of the integrated anisotropic quasi-static EM solver and neuronal dynamics modeling functionality, based on the method of manufactured solutions and numerical reference data, is described. Electric and magnetic stimulation of the ulnar and sciatic nerve were modeled to help understanding a range of controversial issues related to the magnitude and optimal determination of strength-duration (SD) time constants. The results indicate the importance of considering the stimulation-specific inhomogeneous field distributions (especially at tissue interfaces), realistic models of non-linear neuronal dynamics, very short pulses, and suitable SD extrapolation models. These results and the functionalized computable phantom will influence and support the development of safe and effective neuroprosthetic devices and novel electroceuticals. Furthermore they will assist the evaluation of existing low frequency exposure standards for the entire population under all exposure conditions.

  20. DOE-EM Science of Safety Robotics Challenge

    ScienceCinema

    Rimando, Rodrigo; Watts, Alex; Bobbitt, John; McLaughlin, Doug; Quigley, Morgan; Gladwell, Scott; McLoughlin, Mike; Kinnamon, Tony; Garcia, Joe; Ansari, Alex; Voyles, Richard; Chambers, David; Pryor, Mitch; Workman, Theresa; Mehling, Joshua; Browning, Kimberly; Deuel, Jake; Profitt, Bryan; Reibold, Marty

    2016-10-19

    During the week of August 22nd, 2016, over 150 technologists, stakeholders, and Department of Energy, Office of Environmental Management workers, met at DOE’s Portsmouth Gaseous Diffusion Plant in Ohio, for the EM Science of Safety Robotics Challenge.

  1. <em>An Amphibious Magnetotelluric Investigation of the Cascadian Seismogenic and ETS zones.em>

    NASA Astrophysics Data System (ADS)

    Parris, B. A.; Livelybrooks, D.; Bedrosian, P.; Egbert, G. D.; Key, K.; Schultz, A.; Cook, A.; Kant, M.; Wogan, N.; Zeryck, A.

    2015-12-01

    The amphibious Magnetotelluric Observations of Cascadia using a Huge Array (MOCHA) experiment seeks to address unresolved questions about the seismogenic locked zone and down-dip transition zone where episodic tremor and slip (ETS) originates. The presence of free fluids is thought to be one of the primary controls on ETS behavior within the Cascadia margin. Since the bulk electrical conductivity in the crust and mantle can be greatly increased by fluids, magnetotelluric(MT) observations can offer unique insights on the fluid distribution and its relation to observed ETS behavior. Here we present preliminary results from the 146 MT stations collected for the MOCHA project. MOCHA is unique in that it is the first amphibious array of MT stations occupied to provide for 3-D interpretation of conductivity structure of a subduction zone. The MOCHA data set comprises 75 onshore stations and 71 offshore stations, accumulated over a two-year period, and located on an approximate 25km grid, spanning from the trench to the Eastern Willamette Valley, and from central Oregon into middle Washington. We present the results of a series of east-west (cross-strike) oriented, two-dimensional inversions created using the MARE2DEM software that provide an initial picture of the conductivity structure of the locked and ETS zones and its along strike variations. Our models can be used to identify correlations between ETS occurrence rates and inferred fluid concentrations. Our modeling explores the impact of various parameterizations on 2-D inversion results, including inclusion of a smoothness penalty reduction along the inferred slab interface. This series of 2-D inversions can then be used collectively to help make and guide an a priori 3-D inversion. In addition we will present a preliminary 3-D inversion of the onshore stations created using the ModEM software. We are currently working on modifying ModEM to support inversion of offshore data. The more computationally intensive 3-D

  2. High school allied health students and their exposure to the profession of EMS.

    PubMed

    Holloman, Joshua B; Hubble, Michael W

    2012-06-01

    Ensuring a stable Emergency Medical Services (EMS) workforce is a growing concern, and effective recruiting strategies are needed to expose young adults to the EMS profession. The objective of this study was to assess the exposure of high school allied health students to EMS as a career option, as well as measure their attitudes and beliefs about the EMS profession. Hypothesis Few high school allied health students are exposed to EMS educational and career opportunities. A convenience sample of allied health students in a rural high school system was surveyed about exposure to EMS, career intentions, factors impacting career decisions, and attitudes and beliefs about EMS. Descriptive statistics were calculated, and intention to pursue an EMS career was modeled using logistic regression. Of 171 students enrolled in allied health courses across six high schools, 135 (78.9%) agreed to participate; 85.2% were female. Almost all (92.6%) respondents intended to pursue a health career, but only 43.0% reported that their allied health course exposed them to EMS as a profession. Few participants (37.7%) were knowledgeable about EMS associate degree or baccalaureate degree (27.4%) programs. Only 20.7% of the respondents intended to pursue EMS as a career, although 46.0% wanted to learn more about the profession. Most (68.2%) students expressed interest in an emergency medical technician (EMT) course if one were offered, and 80.0% were interested in a ride-along program. Independent predictors of pursuing an EMS career included exposure to EMS outside of high school (OR = 7.4, 95% CI = 1.7-30.4); media influence on career choice (OR = 9.6, 95% CI = 1.8-50.1); and the belief that EMS was mentally challenging (OR = 15.9, 95% CI = 1.1-216.6). Negative predictors included the beliefs that an EMS career was stimulating (OR = 0.05, 95% CI = 0.00-0.53) and physically challenging (OR = 0.06, 95% CI = 0.00-0.63); as well as prior exposure to an EMS job advertisement (OR = 0.14, 0

  3. GPS computer navigators to shorten EMS response and transport times.

    PubMed

    Ota, F S; Muramatsu, R S; Yoshida, B H; Yamamoto, L G

    2001-05-01

    GPS (global positioning satellite system to determine one's position on earth) units have become inexpensive and compact. The purpose of this study is to assess the effectiveness of a GPS enhanced computer street map navigator to improve the ability of EMS drivers in an urban setting to locate their destination and shorten response times. For part I, residential addresses in the city were randomly selected from a telephone directory. Two driver/navigator teams were assigned to drive to the address adhering to speed limits. One team used a standard street map, whereas the other team used a GPS computer navigator. The travel time and distance of the runs were compared. For part II, the computer GPS navigator was placed on an ambulance to supplement their normal methods of navigation to find the address requesting EMS. After the run was completed, EMS providers were interviewed to determine their opinion of whether the GPS navigator was helpful. For part I the results showed that in the 29 initial test runs, comparing the GPS team versus the standard map team, the mean distances traveled were 8.7 versus 9.0 kilometers (not significant) and the mean travel times were 13.5 versus 14.6 minutes (P=.02), respectively. The GPS team arrived faster in 72% runs. For part II the results showed that most EMS providers surveyed noted that the GPS computer navigator enhanced their ability to find the destination and all EMS providers acknowledged that it would enhance their ability to find a destination in an area in which they were unfamiliar. These results suggest that a portable GPS computer navigator system is helpful and can enhance the ability of prehospital care providers to locate their destination. Because these units are accurate and inexpensive, GPS computer navigators may be a valuable tool in reducing pre-hospital transport times.

  4. The B and Be States of the Star EM Cepheus

    NASA Astrophysics Data System (ADS)

    Kjurkchieva, Diana; Marchev, Dragomir; Sigut, T. A. A.; Dimitrov, Dinko

    2016-09-01

    We present 11 yr of high-resolution, spectroscopic observations for the star EM Cep. EM Cep switches between B and Be star states, as revealed by the level of Hα emission, but spends most of its time in the B star state. EM Cep has been considered to be an eclipsing, near-contact binary of nearly equal-mass B stars in order to reproduce regular photometric variations; however, this model is problematic due to the lack of any observed Doppler shift in the spectrum. Our observations confirm that there are no apparent Doppler shifts in the wide spectral lines Hα and He i λ6678 in either the B or Be star states. The profiles of He i λ6678 typically exhibited a filled-in absorption core, but we detected weak emission in this line during the highest Be state. Given the lack of observed Doppler shifts, we model EM Cep as an isolated Be star with a variable circumstellar disk. We can reproduce the observed Hα emission profiles over the 11 yr period reasonably well with disk masses on the order of 3{--}10× {10}-11 {M}* in the Be state with the circumstellar disk seen at an inclination of 78° to the line of sight. From a disk ejection episode in 2014, we estimate a mass-loss rate of ≈ 3× {10}-9 {M}⊙ {{yr}}-1. The derived disk density parameters are typical of those found for the classical Be stars. We therefore suggest that the EM Cep is a classical Be star and that its photometric variations are the result of β Cep or nonradial pulsations.

  5. Correlates of suicidality in firefighter/EMS personnel.

    PubMed

    Martin, Colleen E; Tran, Jana K; Buser, Sam J

    2017-01-15

    Firefighter and Emergency Medical Services (EMS) personnel experience higher rates of lifetime suicidal ideation and attempts than the general population and other protective service professions. Several correlates of suicidality (alcohol use, depression, posttraumatic stress) have been identified in the literature as applicable to firefighter/EMS populations; however, few studies to date have examined the specific correlates of suicidality (lifetime suicidal ideation and/or attempts) in a firefighter/EMS sample. Participants (N=3036) from a large, urban fire department completed demographic and self-report measures of alcohol dependence, depression, posttraumatic stress disorder (PTSD) symptom severity, and lifetime suicidal ideation and attempts. Participants in this sample performed both firefighter and EMS duties, were predominately male (97%), White (61.6%), and 25-34 years old (32.1%). Through hierarchical linear regressions, depression (β=.22, p<.05) and PTSD symptom severity (β=.21, p<.05) were significantly associated with lifetime suicidal ideation (R(2) =17.5). Depression (β=.15, p<.001), and PTSD symptom severity (β=.07, p<.01) were significantly associated with lifetime suicide attempts (R(2)=5.1). Several limitations are addressed in the current study. The survey was a self-report pre-existing dataset and lifetime suicidal ideation and attempts were measured using sum scores. Additionally, the disproportionately large sample of males and large, urban setting, may not generalize to female firefighters and members of rural community fire departments. The current study highlights the importance of targeting depression and PTSD symptom severity in efforts to reduce suicidality in firefighter/EMS personnel. Published by Elsevier B.V.

  6. ATTRACT-EM: A New Method for the Computational Assembly of Large Molecular Machines Using Cryo-EM Maps

    PubMed Central

    de Vries, Sjoerd J.; Zacharias, Martin

    2012-01-01

    Many of the most important functions in the cell are carried out by proteins organized in large molecular machines. Cryo-electron microscopy (cryo-EM) is increasingly being used to obtain low resolution density maps of these large assemblies. A new method, ATTRACT-EM, for the computational assembly of molecular assemblies from their components has been developed. Based on concepts from the protein-protein docking field, it utilizes cryo-EM density maps to assemble molecular subunits at near atomic detail, starting from millions of initial subunit configurations. The search efficiency was further enhanced by recombining partial solutions, the inclusion of symmetry information, and refinement using a molecular force field. The approach was tested on the GroES-GroEL system, using an experimental cryo-EM map at 23.5 Å resolution, and on several smaller complexes. Inclusion of experimental information on the symmetry of the systems and the application of a new gradient vector matching algorithm allowed the efficient identification of docked assemblies in close agreement with experiment. Application to the GroES-GroEL complex resulted in a top ranked model with a deviation of 4.6 Å (and a 2.8 Å model within the top 10) from the GroES-GroEL crystal structure, a significant improvement over existing methods. PMID:23251350

  7. DeepEM3D: approaching human-level performance on 3D anisotropic EM image segmentation.

    PubMed

    Zeng, Tao; Wu, Bian; Ji, Shuiwang

    2017-08-15

    Progress in 3D electron microscopy (EM) imaging has greatly facilitated neuroscience research in high-throughput data acquisition. Correspondingly, high-throughput automated image analysis methods are necessary to work on par with the speed of data being produced. One such example is the need for automated EM image segmentation for neurite reconstruction. However, the efficiency and reliability of current methods are still lagging far behind human performance. Here, we propose DeepEM3D, a deep learning method for segmenting 3D anisotropic brain electron microscopy images. In this method, the deep learning model can efficiently build feature representation and incorporate sufficient multi-scale contextual information. We propose employing a combination of novel boundary map generation methods with optimized model ensembles to address the inherent challenges of segmenting anisotropic images. We evaluated our method by participating in the 3D segmentation of neurites in EM images (SNEMI3D) challenge. Our submission is ranked #1 on the current leaderboard as of Oct 15, 2016. More importantly, our result was very close to human-level performance in terms of the challenge evaluation metric: namely, a Rand error of 0.06015 versus the human value of 0.05998. The code is available at https://github.com/divelab/deepem3d/. sji@eecs.wsu.edu. Supplementary data are available at Bioinformatics online.

  8. Effects of caffeine or EDTA post-treatment on EMS mutagenesis in soybean.

    PubMed

    Zhu, B; Gu, A; Deng, X; Geng, Y; Lu, Z

    1995-04-01

    Seeds of soybean cultivar LD4 were mutagenically treated with EMS (0.3, 0.5, 0.6, 0.9, 1.5 and 1.8%) for 3 h only or plus caffeine (50 mM) or EDTA (1 mM) post-treatment for 5 h. The experimental results indicated that: (1) of the different concentrations of EMS treatment, the M2 mutation frequency induced with 0.6% EMS was the highest (9.7%). When the EMS concentration was over 0.9%, the mutation frequency decreased rapidly. (2) Of the EMS treatments plus caffeine or EDTA post-treatment, the mutagenic effect of 0.6% EMS was the best for inducing morphological variations. Caffeine post-treatment decreased notably the mutation frequency of EMS treatment; when concentrations of EMS were very high (1.5% and 1.8%), mutation frequencies of EDTA post-treatment were still 5.0% and 4.88%, but no mutants were found in EMS treatment or plus caffeine post-treatment. (3) In the M2 mutation spectrum, 11 kinds of mutant types were observed in EMS treatment or plus caffeine or EDTA post-treatment. Relative frequencies of some mutant types (growth period, plant height, grain size, leaf shape and sterility, etc.) were similar among the three treatments, but EDTA post-treatment could change the relative frequencies of yield characteristics (number of pods and grains, grain weight/plant) induced by EMS treatment only.

  9. Composting of rice straw with effective microorganisms (EM) and its influence on compost quality

    PubMed Central

    2013-01-01

    This study aims to assess the effect of EM application on the composting process of rice straw with goat manure and green waste and to evaluate the quality of both compost treatments. There are two treatment piles in this study, in which one pile was applied with EM and another pile without EM. Each treatment was replicated three times with 90 days of composting duration. The parameters for the temperature, pH, TOC and C/N ratio, show that decomposition of organic matter occurs during the 90-day period. The t-test conducted shows that there is a significant difference between compost with EM and compost without EM. The application of EM in compost increases the macro and micronutrient content. The following parameters support this conclusion: compost applied with EM has more N, P and K content (P < 0.05) compared to compost without EM. Although the Fe in compost with EM is much higher (P < 0.05) than in the compost without EM, for Zn and Cu, there is no significant difference between treatments. This study suggests that the application of EM is suitable to increase the mineralization in the composting process. The final resultant compost indicated that it was in the range of the matured level and can be used without any restriction. PMID:23390930

  10. Application of Electromagnetic (EM) Separation Technology to Metal Refining Processes: A Review

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Wang, Shengqian; Dong, Anping; Gao, Jianwei; Damoah, Lucas Nana Wiredu

    2014-12-01

    Application of electromagnetic (EM) force to metal processing has been considered as an emerging technology for the production of clean metals and other advanced materials. In the current paper, the principle of EM separation was introduced and several schemes of imposing EM field, such as DC electric field with a crossed steady magnetic field, AC electric field, AC magnetic field, and traveling magnetic field were reviewed. The force around a single particle or multi-particles and their trajectories in the conductive liquid under EM field were discussed. Applications of EM technique to the purification of different liquid metals such as aluminum, zinc, magnesium, silicon, copper, and steel were summarized. Effects of EM processing parameters, such as the frequency of imposed field, imposed magnetic flux density, processing time, particle size, and the EM unit size on the EM purification efficiency were discussed. Experimental and theoretical investigations have showed that the separation efficiency of inclusions from the molten aluminum using EM purification could as high as over 90 pct. Meanwhile, the EM purification was also applied to separate intermetallic compounds from metal melt, such as α-AlFeMnSi-phase from the molten aluminum. And then the potential industrial application of EM technique was proposed.

  11. Development of the Emergency Medical Services Role Identity Scale (EMS-RIS).

    PubMed

    Donnelly, Elizabeth A; Siebert, Darcy; Siebert, Carl

    2015-01-01

    This article describes the development and validation of the theoretically grounded Emergency Medical Services Role Identity Scale (EMS-RIS), which measures four domains of EMS role identity. The EMS-RIS was developed using a mixed methods approach. Key informants informed item development and the scale was validated using a representative probability sample of EMS personnel. Factor analyses revealed a conceptually consistent, four-factor solution with sound psychometric properties as well as evidence of convergent and discriminant validities. Social workers work with EMS professionals in crisis settings and as their counselors when they are distressed. The EMS-RIS provides useful information for the assessment of and intervention with distressed EMS professionals, as well as how role identity may influence occupational stress.

  12. Nonlinear Smoothing and the EM Algorithm for Positive Integral Equations of the First Kind

    SciTech Connect

    Eggermont, P. P. B.

    1999-01-15

    We study a modification of the EMS algorithm in which each step of the EMS algorithm is preceded by a nonlinear smoothing step of the form Nf-exp(S*log f) , where S is the smoothing operator of the EMS algorithm. In the context of positive integral equations (a la positron emission tomography) the resulting algorithm is related to a convex minimization problem which always admits a unique smooth solution, in contrast to the unmodified maximum likelihood setup. The new algorithm has slightly stronger monotonicity properties than the original EM algorithm. This suggests that the modified EMS algorithm is actually an EM algorithm for the modified problem. The existence of a smooth solution to the modified maximum likelihood problem and the monotonicity together imply the strong convergence of the new algorithm. We also present some simulation results for the integral equation of stereology, which suggests that the new algorithm behaves roughly like the EMS algorithm.

  13. Similarity-regulation of OS-EM for accelerated SPECT reconstruction

    NASA Astrophysics Data System (ADS)

    Vaissier, P. E. B.; Beekman, F. J.; Goorden, M. C.

    2016-06-01

    Ordered subsets expectation maximization (OS-EM) is widely used to accelerate image reconstruction in single photon emission computed tomography (SPECT). Speedup of OS-EM over maximum likelihood expectation maximization (ML-EM) is close to the number of subsets used. Although a high number of subsets can shorten reconstruction times significantly, it can also cause severe image artifacts such as improper erasure of reconstructed activity if projections contain few counts. We recently showed that such artifacts can be prevented by using a count-regulated OS-EM (CR-OS-EM) algorithm which automatically adapts the number of subsets for each voxel based on the estimated number of counts that the voxel contributed to the projections. While CR-OS-EM reached high speed-up over ML-EM in high-activity regions of images, speed in low-activity regions could still be very slow. In this work we propose similarity-regulated OS-EM (SR-OS-EM) as a much faster alternative to CR-OS-EM. SR-OS-EM also automatically and locally adapts the number of subsets, but it uses a different criterion for subset regulation: the number of subsets that is used for updating an individual voxel depends on how similar the reconstruction algorithm would update the estimated activity in that voxel with different subsets. Reconstructions of an image quality phantom and in vivo scans show that SR-OS-EM retains all of the favorable properties of CR-OS-EM, while reconstruction speed can be up to an order of magnitude higher in low-activity regions. Moreover our results suggest that SR-OS-EM can be operated with identical reconstruction parameters (including the number of iterations) for a wide range of count levels, which can be an additional advantage from a user perspective since users would only have to post-filter an image to present it at an appropriate noise level.

  14. An economic toolkit for identifying the cost of emergency medical services (EMS) systems: detailed methodology of the EMS Cost Analysis Project (EMSCAP).

    PubMed

    Lerner, E Brooke; Garrison, Herbert G; Nichol, Graham; Maio, Ronald F; Lookman, Hunaid A; Sheahan, William D; Franz, Timothy R; Austad, James D; Ginster, Aaron M; Spaite, Daniel W

    2012-02-01

    Calculating the cost of an emergency medical services (EMS) system using a standardized method is important for determining the value of EMS. This article describes the development of a methodology for calculating the cost of an EMS system to its community. This includes a tool for calculating the cost of EMS (the "cost workbook") and detailed directions for determining cost (the "cost guide"). The 12-step process that was developed is consistent with current theories of health economics, applicable to prehospital care, flexible enough to be used in varying sizes and types of EMS systems, and comprehensive enough to provide meaningful conclusions. It was developed by an expert panel (the EMS Cost Analysis Project [EMSCAP] investigator team) in an iterative process that included pilot testing the process in three diverse communities. The iterative process allowed ongoing modification of the toolkit during the development phase, based upon direct, practical, ongoing interaction with the EMS systems that were using the toolkit. The resulting methodology estimates EMS system costs within a user-defined community, allowing either the number of patients treated or the estimated number of lives saved by EMS to be assessed in light of the cost of those efforts. Much controversy exists about the cost of EMS and whether the resources spent for this purpose are justified. However, the existence of a validated toolkit that provides a standardized process will allow meaningful assessments and comparisons to be made and will supply objective information to inform EMS and community officials who are tasked with determining the utilization of scarce societal resources.

  15. Compassionate Options for Pediatric EMS (COPE): Addressing Communication Skills.

    PubMed

    Calhoun, Aaron W; Sutton, Erica R H; Barbee, Anita P; McClure, Beth; Bohnert, Carrie; Forest, Richard; Taillac, Peter; Fallat, Mary E

    2017-01-01

    Each year, 16,000 children suffer cardiopulmonary arrest, and in one urban study, 2% of pediatric EMS calls were attributed to pediatric arrests. This indicates a need for enhanced educational options for prehospital providers that address how to communicate to families in these difficult situations. In response, our team developed a cellular phone digital application (app) designed to assist EMS providers in self-debriefing these events, thereby improving their communication skills. The goal of this study was to pilot the app using a simulation-based investigative methodology. Video and didactic app content was generated using themes developed from a series of EMS focus groups and evaluated using volunteer EMS providers assessed during two identical nonaccidental trauma simulations. Intervention groups interacted with the app as a team between assessments, and control groups debriefed during that period as they normally would. Communication performance and gap analyses were measured using the Gap-Kalamazoo Consensus Statement Assessment Form. A total of 148 subjects divided into 38 subject groups (18 intervention groups and 20 control groups) were assessed. Comparison of initial intervention group and control group scores showed no statistically significant difference in performance (2.9/5 vs. 3.0/5; p = 0.33). Comparisons made during the second assessment revealed a statistically significant improvement in the intervention group scores, with a moderate to large effect size (3.1/5 control vs. 4.0/5 intervention; p < 0.001, r = 0.69, absolute value). Gap analysis data showed a similar pattern, with gaps of -0.6 and -0.5 (values suggesting team self-over-appraisal of communication abilities) present in both control and intervention groups (p = 0.515) at the initial assessment. This gap persisted in the control group at the time of the second assessment (-0.8), but was significantly reduced (0.04) in the intervention group (p = 0.013, r = 0.41, absolute value

  16. Portable suction unit failure in a rural EMS system.

    PubMed

    Risavi, Brian L; Sabotchick, K J; Heile, Christopher J

    2013-08-01

    Portable suction units used by EMS personnel are utilized infrequently and often are powered by batteries. Lack of use and inspection often results in failure of the device when it is needed. The purpose of this study was to examine the incidence of portable suction unit failure in a rural EMS system and to identify the reasons for failures. A convenience sample was obtained through both random inspections by the staff of a regional EMS council and data from twice monthly checks reported by respective EMS agencies following a standard protocol for each unit. A standard protocol was used, including checking the vacuum level on each suction unit and inspecting the tubing, canister, and battery. Each inspector assessed whether the unit was capable of achieving 300 mmHg of suction within four seconds. Also, the unit was inspected for any signs of misalignment or dry rot of the gasket, kinking of suction hose, damage to the suction canister, weak/dead battery, or defective pump. Findings were recorded. Over a two-year period, 9,631 suction unit inspections were completed. There were 233 failures (2.4%) noted. The majority (126, 54.1%) were due to battery failure. Seventy-three units failed due to other reasons (not recorded, switch failure, battery not seated). Ten inspections failed due to incorrect assembly. Nineteen inspections failed due to defects with the suction canister. Five inspections failed due to kinked/disconnected suction tubing. Only a relatively small percentage of inspections of suction units revealed failures (4.6% Advanced Life Support, 8.6% Basic Life Support) using the above-stated criteria. However, given the importance of airway management and potential complications associated with airway compromise, including aspiration pneumonia, hypoxia, and hemodynamic instability, this is of concern relative to the morbidity and mortality that could be related to airway failure. Due to the relative infrequency of use and the nature of portable suction units

  17. Translation of EMS: clinical practice and system oversight from core content study guide to best practices implementation in an Urban EMS system.

    PubMed

    Tataris, Katie; Mercer, Mary; Brown, John

    2015-01-01

    Since 2009, the seminal text in emergency medical services (EMS) medicine has been used to guide the academic development of the new subspecialty but direct application of the material into EMS oversight has not been previously described. The EMS/Disaster Medicine fellowship program at our institution scheduled a monthly meeting to systematically review the text and develop a study guide to assist the fellow and affiliated faculty in preparation for the board examination. In addition to the summary of chapter content, the review included an assessment of areas from each chapter subject where our EMS system did not exhibit recommended characteristics. A matrix was developed in the form of a gap analysis to include specific recommendations based on each perceived gap. Initial review and completion dates for each identified gap enable tracking and a responsible party. This matrix assisted the fellow with development of projects for EMS system improvement in addition to focusing and prioritizing the work of other interested physicians working in the system. By discussing expert recommendations in the setting of an actual EMS system, the faculty can teach the fellow how to approach system improvements based on prior experiences and current stakeholders. This collaborative environment facilitates system-based practice and practice-based learning, aligning with ACGME core competencies. Our educational model has demonstrated the success of translating the text into action items for EMS systems. This model may be useful in other systems and could contribute to the development of EMS system standards nationwide.

  18. Orion EM-1 Heat Shield Offload, Transport, and Lift

    NASA Image and Video Library

    2016-08-26

    Technicians with Jacobs on the Test and Operations Support Contract have positioned a platform close to NASA’s Super Guppy aircraft at the Shuttle Landing Facility, managed and operated by Space Florida, at the agency’s Kennedy Space Center in Florida, for offloading of the shipping container carrying the Orion heat shield for Exploration Mission 1 (EM-1). The heat shield will be offloaded and transported to the Neil Armstrong Operations and Checkout Building high bay for processing. The heat shield arrived from Lockheed Martin’s manufacturing facility near Denver. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, an uncrewed test flight, in 2018.

  19. Event reconstruction in NEXT using the ML-EM algorithm

    NASA Astrophysics Data System (ADS)

    Simón, A.; Ferrario, P.; Izmaylov, A.; NEXT Collaboration

    2016-04-01

    The NEXT collaboration aims to find the neutrinoless double beta decay in 136Xe. The rareness of this decay demands an exceptional background rejection. This can be obtained with an excellent energy resolution, which has been already demonstrated in the NEXT prototypes. In addition to this, the ββ 0 ν decay in gas produces a characteristic topological signal which could be an extremely useful extra handle to avoid background events. The need for a satisfactory topology reconstruction has led the NEXT Collaboration to implement the Maximum Likelihood Expectation Maximization method (ML-EM) in the data processing scheme. ML-EM is a generic iterative algorithm for many kinds of inverse problems. Although this method is well known in medical imaging and has been used widely in Positron Emission Tomography, it has never been applied to a time projection chamber. First results and studies of the performance of the method will be presented in this poster.

  20. EM susceptibility studies and measurements on electro explosive devices

    NASA Astrophysics Data System (ADS)

    Deb, G. K.; Mukherjee, M.

    Electroexplosive devices (EEDs) are susceptible to stray electromagnetic (EM) fields near high-power communications and radar transmitters. Experiments have been carried out to measure the exact susceptibility of EED resistive squibs in pulsed and continuous EM environments, respectively. The susceptibility test procedure consisted of individual measurements of direct current sensitivity (mA); impulse sensitivity; RF impedance measurements; and safety margin calculations. A stray energy monitor was used to evaluate the safe performance of a hybrid weapons system. It is found that the RF sensitivity of the squib was influenced by the transmission characteristics of the transmission line connected to it. RF absorption peaks were observed above the EED sensitivity threshold of 120 MHz. Methods of EMI control are discussed, including: low-pass pin filters; lossy line filters for all dc power line interconnections; and twisting and shielding of the wires.

  1. Environmental Restoration and Waste Management (EM) program: An introduction

    SciTech Connect

    Not Available

    1990-12-01

    This booklet introduces the reader to the mission and functions of a major new unit within the US Department of Energy (DOE): the Office of Environmental Restoration and Waste Management (EM). The Secretary of Energy established EM in November 1989, implementing a central purpose of DOE's first annual Environmental Restoration and Waste Management Five-Year Plan, which had appeared three months earlier. The contents of this booklet, and their arrangement, reflect the annual update of the Five-Year Plan. The Five-Year Plan supports DOE's strategy for meeting its 30-year compliance and cleanup goal. This strategy involves: focusing DOE's activities on eliminating or reducing known or recognized potential risks to worker and public health and the environment, containing or isolating, removing, or detoxifying onsite and offsite contamination, and developing technology to achieve DOE's environmental goals.

  2. Superconducting Electromagnetic Suspension (EMS) system for Grumman Maglev concept

    NASA Technical Reports Server (NTRS)

    Kalsi, Swarn S.

    1994-01-01

    The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low vehicle speeds; low magnetic field at the SC coil--less than 0.35 T; no need to use non-magnetic/non-metallic rebar in the guideway structure; low magnetic field in passenger cabin--approximately 1 G; low forces on the SC coil; employs state-of-the-art NbTi wire; no need for an active magnet quench protection system; and lower weight than a magnet system with copper coils. The EMS Maglev described in this paper does not require development of any new technologies. The system could be built with the existing SC magnet technology.

  3. A constrained EM algorithm for principal component analysis.

    PubMed

    Ahn, Jong-Hoon; Oh, Jong-Hoon

    2003-01-01

    We propose a constrained EM algorithm for principal component analysis (PCA) using a coupled probability model derived from single-standard factor analysis models with isotropic noise structure. The single probabilistic PCA, especially for the case where there is no noise, can find only a vector set that is a linear superposition of principal components and requires postprocessing, such as diagonalization of symmetric matrices. By contrast, the proposed algorithm finds the actual principal components, which are sorted in descending order of eigenvalue size and require no additional calculation or postprocessing. The method is easily applied to kernel PCA. It is also shown that the new EM algorithm is derived from a generalized least-squares formulation.

  4. Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

    NASA Astrophysics Data System (ADS)

    Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

    2017-07-01

    In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

  5. Love 'em or they'll leave: motivating volunteers.

    PubMed

    McDowell, D

    1999-11-01

    Running a successful volunteer-based service does not begin and end with the recruitment of volunteers. You need to first consider what is in it for the prospective volunteer, define why you want volunteers and then decide exactly what you want those volunteers to do. Then you recruit them, face-to-face, ensuring that every prospect is offered something specific to do and is welcomed into your EMS family.

  6. EMS mutagenesis in the pea aphid Acyrthosiphon pisum.

    PubMed

    Tagu, Denis; Le Trionnaire, Gaël; Tanguy, Sylvie; Gauthier, Jean-Pierre; Huynh, Jean-René

    2014-04-16

    In aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. Such phenotypic plasticity cannot be studied with classical genetic model organisms such as Caenorhabditis elegans or Drosophila melanogaster. The genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. Here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (EMS), to generate random mutations within the Acyrthosiphon pisum genome. We found that even low concentrations of EMS were toxic for two genotypes of A. pisum. Mutagenesis efficiency was nevertheless assessed by estimating the occurrence of mutational events on the X chromosome. Indeed, any lethal mutation on the X-chromosome would kill males that are haploid on the X so that we used the proportion of males as an estimation of mutagenesis efficacy. We could assess a putative mutation rate of 0.4 per X-chromosome at 10 mM of EMS. We then applied this protocol to perform a small-scale mutagenesis on parthenogenetic individuals, which were screened for defects in their ability to produce sexual individuals in response to photoperiod shortening. We found one mutant line showing a reproducible altered photoperiodic response with a reduced production of males and the appearance of aberrant winged males (wing atrophy, alteration of legs morphology). This mutation appeared to be stable because it could be transmitted over several generations of parthenogenetic individuals. To our knowledge, this study represents the first example of an EMS-generated aphid mutant.

  7. EMS Mutagenesis in the Pea Aphid Acyrthosiphon pisum

    PubMed Central

    Tagu, Denis; Le Trionnaire, Gaël; Tanguy, Sylvie; Gauthier, Jean-Pierre; Huynh, Jean-René

    2014-01-01

    In aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. Such phenotypic plasticity cannot be studied with classical genetic model organisms such as Caenorhabditis elegans or Drosophila melanogaster. The genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. Here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (EMS), to generate random mutations within the Acyrthosiphon pisum genome. We found that even low concentrations of EMS were toxic for two genotypes of A. pisum. Mutagenesis efficiency was nevertheless assessed by estimating the occurrence of mutational events on the X chromosome. Indeed, any lethal mutation on the X-chromosome would kill males that are haploid on the X so that we used the proportion of males as an estimation of mutagenesis efficacy. We could assess a putative mutation rate of 0.4 per X-chromosome at 10 mM of EMS. We then applied this protocol to perform a small-scale mutagenesis on parthenogenetic individuals, which were screened for defects in their ability to produce sexual individuals in response to photoperiod shortening. We found one mutant line showing a reproducible altered photoperiodic response with a reduced production of males and the appearance of aberrant winged males (wing atrophy, alteration of legs morphology). This mutation appeared to be stable because it could be transmitted over several generations of parthenogenetic individuals. To our knowledge, this study represents the first example of an EMS-generated aphid mutant. PMID:24531730

  8. Range Condition and ML-EM Checkerboard Artifacts

    PubMed Central

    You, Jiangsheng; Wang, Jing; Liang, Zhengrong

    2007-01-01

    The expectation maximization (EM) algorithm for the maximum likelihood (ML) image reconstruction criterion generates severe checkerboard artifacts in the presence of noise. A classical remedy is to impose an a priori constraint for a penalized ML or maximum a posteriori probability solution. The penalty reduces the checkerboard artifacts and also introduces uncertainty because a priori information is usually unknown in clinic. Recent theoretical investigation reveals that the noise can be divided into two components: one is called null-space noise and the other is range-space noise. The null-space noise can be numerically estimated using filtered backprojection (FBP) algorithm. By the FBP algorithm, the null-space noise annihilates in the reconstruction while the range-space noise propagates into the reconstructed image. The aim of this work is to investigate the relation between the null-space noise and the checkerboard artifacts in the ML-EM reconstruction from noisy projection data. Our study suggests that removing the null-space noise from the projection data could improve the signal-to-noise ratio of the projection data and, therefore, reduce the checkerboard artifacts in the ML-EM reconstructed images. This study reveals an in-depth understanding of the different noise propagations in analytical and iterative image reconstructions, which may be useful to single photon emission computed tomography, where the noise has been a major factor for image degradation. The reduction of the ML-EM checkerboard artifacts by removing the null-space noise avoids the uncertainty of using a priori penalty. PMID:18449363

  9. Generalized single-particle cryo-EM--a historical perspective.

    PubMed

    Frank, Joachim

    2016-02-01

    This is a brief account of the earlier history of single-particle cryo-EM of biological molecules lacking internal symmetry, which goes back to the mid-seventies. The emphasis of this review is on the mathematical concepts and computational approaches. It is written as the field experiences a turning point in the wake of the introduction of digital cameras capable of single electron counting, and near-atomic resolution can be reached even for smaller molecules.

  10. Principles of cryo-EM single-particle image processing

    PubMed Central

    Sigworth, Fred J.

    2016-01-01

    Single-particle reconstruction is the process by which 3D density maps are obtained from a set of low-dose cryo-EM images of individual macromolecules. This review considers the fundamental principles of this process and the steps in the overall workflow for single-particle image processing. Also considered are the limits that image signal-to-noise ratio places on resolution and the distinguishing of heterogeneous particle populations. PMID:26705325

  11. Night Vision Goggles in Emergency Medical Service (EMS) Helicopters

    DTIC Science & Technology

    1994-07-01

    participated in a flight test program to assess the use of NVG’s in EMS operations. Information produced by other government agencies with extensive NVG...recommendations of this document. information produced by other government agencies, with extensive experience with NVGs, was reviewed for use in this...as possible without touching eyelashes or spectacles (see figure 35). 5. Evaluate the picture. The NVG should be correctly aligned. There should be no

  12. Color a bright energy picture with EMS controls

    SciTech Connect

    Not Available

    1985-09-01

    After 80 years in the crayon-manufacturing business, Binney and Smith found that more than 50% of their staggering annual utility costs were being generated by non-production loads. To curtail waste, they installed an expandable EMS which controls energy in the company's two separate, multi-building facilities from one central location. The system selected was an AI2100/MAX System manufactured by American Auto-Matrix, Export, PA.

  13. Integrated GW-EM Follow-up Analysis

    NASA Astrophysics Data System (ADS)

    Ackley, Kendall; Eikenberry, Stephen; Klimenko, Sergey; LSC Collaboration

    2015-04-01

    Advanced Gravitational-Wave (GW) detectors such as Advanced LIGO and Advanced Virgo are expected to become operational for observation runs in 2015, with an expected ultimate improvement in sensitivity over previous configurations by a factor of 10 by 2019. There are many potential electromagnetic (EM) counterparts to GWs including short and long gamma-ray bursts (GRBs) and kilonovae. While SGRBs and LGRBs predominantly emit in the X-ray, and the recently-observed kilonova primarily in the infrared, all three sources are expected to have detectable traces in the optical band, albeit requiring very sensitive optical telescopes. In order to aid in the optimization of GW trigger follow-up procedures, we perform an end-to-end analysis feasibility study using synthesized Advanced detector data simulating a GW detection with a theoretical EM counterpart injected into archival optical images. We use images from Robotic Optical Transient Search Experiment (ROTSE) and Palomar Transient Factory (PTF), and inject candidate events following observed lightcurves of SGRBs, LGRBs, and kilonovae. The use of Zernike PSF decomposition on candidate objects offers a fast way to identify point sources, speeding up the automated identification of transient sources in the images. We present our method of transient recovery and the latest results of our feasibility study of a joint GW-EM observation.

  14. Modeling to Optimize Hospital Evacuation Planning in EMS Systems.

    PubMed

    Bish, Douglas R; Tarhini, Hussein; Amara, Roel; Zoraster, Richard; Bosson, Nichole; Gausche-Hill, Marianne

    2017-01-01

    To develop optimal hospital evacuation plans within a large urban EMS system using a novel evacuation planning model and a realistic hospital evacuation scenario, and to illustrate the ways in which a decision support model may be useful in evacuation planning. An optimization model was used to produce detailed evacuation plans given the number and type of patients in the evacuating hospital, resource levels (teams to move patients, vehicles, and beds at other hospitals), and evacuation rules. Optimal evacuation plans under various resource levels and rules were developed and high-level metrics were calculated, including evacuation duration and the utilization of resources. Using this model we were able to determine the limiting resources and demonstrate how strategically augmenting the resource levels can improve the performance of the evacuation plan. The model allowed the planner to test various evacuation conditions and resource levels to demonstrate the effect on performance of the evacuation plan. We present a hospital evacuation planning analysis for a hospital in a large urban EMS system using an optimization model. This model can be used by EMS administrators and medical directors to guide planning decisions and provide a better understanding of various resource allocation decisions and rules that govern a hospital evacuation.

  15. Essential ethics for EMS: cardinal virtues and core principles.

    PubMed

    Larkin, Gregory Luke; Fowler, Raymond Logan

    2002-11-01

    Dutiful attention to virtue, teamwork, beneficence, justice, and respect for patient autonomy provides a coherent approach to addressing many ethical dilemmas in the out-of-hospital setting. Most of the great risks of EMS--abandonment, competence, and safe-driving skills--lie at the ethike or character of those who ply the prehospital art. Proactively fostering the personal and professional virtue of team members may be a kind of moral vaccination against the ethical pitfalls inherent in emergency medical service provision. Future training, education, disaster preparedness drills, and related exercises must include opportunities for character and team building before optimal performance and accountability can be assured. In the steady, almost glacial, maturation of the specialty of EMS medicine, truly the character of those who serve in the "line of fire" of evaluation, management, and transport in the out-of-hospital arena must be girded with more than the armor and shields of technology. Since September 11, 2001, it has become increasingly clear that EMS workers must strengthen their ability to bear the "slings and arrows of outrageous fortune," armed with swords of discipline, virtue, and character to provide the breadth of care that only a well orchestrated team can deliver. Ultimately, humans perform best when they share themselves unselfconsciously, surrendering to an enterprise and cause far greater than themselves. Our citizens, patients, and heroic colleagues deserve no less.

  16. Marine EM: The Past, The Present, and The Future

    NASA Astrophysics Data System (ADS)

    Constable, S.

    2016-12-01

    The high cost of deepwater exploration motivated the development of commercial marine magnetotelluric (MT) exploration in 1995, but it wasn't until marine controlled-source electromagnetic (CSEM) methods burst upon the industry scene with the formation of three new contractors in 2002 that things got really exciting. Now the bubble has burst and the excitement has diminished, but marine EM remains an important tool for offshore exploration. Early mistakes were made as a result of poor instrumentation and a lack of good interpretation tools - unlike seismics, EM relies heavily on inversion to produce useful results - but both equipment and inversion codes have improved significantly. Still, there are mistakes that can be made. Rock anisotropy and seawater conductivity have to be handled appropriately. A strong galvanic response means that there is a resistivity/thickness ambiguity when imaging reservoirs, but the inductive nature of the data means that multi-frequency inversions are very much better than using single frequencies. Resolution will never be as good as for seismic methods, but is much better than for potential field methods and conductivity may often be a more diagnostic property than acoustic impedance. EM images resistivity, not hydrocarbon content, and false positives occasionally occur, but false negatives are rare. That is, without a CSEM signature there is little chance of discovering economical hydrocarbons. This should bode well for the future of the method.

  17. Forward Genetics by Sequencing EMS Variation-Induced Inbred Lines

    PubMed Central

    Addo-Quaye, Charles; Buescher, Elizabeth; Best, Norman; Chaikam, Vijay; Baxter, Ivan; Dilkes, Brian P.

    2016-01-01

    In order to leverage novel sequencing techniques for cloning genes in eukaryotic organisms with complex genomes, the false positive rate of variant discovery must be controlled for by experimental design and informatics. We sequenced five lines from three pedigrees of ethyl methanesulfonate (EMS)-mutagenized Sorghum bicolor, including a pedigree segregating a recessive dwarf mutant. Comparing the sequences of the lines, we were able to identify and eliminate error-prone positions. One genomic region contained EMS mutant alleles in dwarfs that were homozygous reference sequences in wild-type siblings and heterozygous in segregating families. This region contained a single nonsynonymous change that cosegregated with dwarfism in a validation population and caused a premature stop codon in the Sorghum ortholog encoding the gibberellic acid (GA) biosynthetic enzyme ent-kaurene oxidase. Application of exogenous GA rescued the mutant phenotype. Our method for mapping did not require outcrossing and introduced no segregation variance. This enables work when line crossing is complicated by life history, permitting gene discovery outside of genetic models. This inverts the historical approach of first using recombination to define a locus and then sequencing genes. Our formally identical approach first sequences all the genes and then seeks cosegregation with the trait. Mutagenized lines lacking obvious phenotypic alterations are available for an extension of this approach: mapping with a known marker set in a line that is phenotypically identical to starting material for EMS mutant generation. PMID:28040779

  18. A study on characteristics of EM radiation from stripline structure

    NASA Astrophysics Data System (ADS)

    Kayano, Yoshiki; Inoue, Hiroshi

    2011-10-01

    In recent years, effective methods for predicting and suppressing electromagnetic interference over a broad band are required. In this paper, we focus on the prediction of electromagnetic (EM) radiation from a stripline structure with a ground thin wire by an equivalent circuit model. First, frequency responses of common-mode (CM) current on the printed circuit board and EM radiation are studied with finite difference time domain modeling. Secondly, an equivalent circuit model for predicting CM current is proposed. The equivalent circuit model for prediction is based on the concepts of CM antenna impedance, distributed constant circuit, and electric coupling between the power plane and the thin ground wire. Good agreement between the predicted and full-wave analysis results indicates the validity of the proposed equivalent circuit model. The frequency response of EM radiation from the stripline structure can be identified using our proposed model. In addition, the equivalent circuit model provides enough flexibility for different geometric parameters and can be used to develop physical insights and design guidelines.

  19. Improving EM&V for Energy Efficiency Programs (Fact Sheet)

    SciTech Connect

    Not Available

    2012-07-01

    This fact sheet describes the objectives of the U.S. Department of Energy Uniform Methods Project to bring consistency to energy savings calculations in U.S. energy efficiency programs. The U.S. Department of Energy (DOE) is developing a framework and a set of protocols for determining gross energy savings from energy efficiency measures and programs. The protocols represent a refinement of the body of knowledge supporting energy efficiency evaluation, measurement, and verification (EM&V) activities. They have been written by technical experts within the field and reviewed by industry experts. Current EM&V practice allows for multiple methods for calculating energy savings. These methods were developed to meet the needs of energy efficiency program administrators and regulators. Although they served their original objectives well, they have resulted in inconsistent and incomparable savings results - even for identical measures. The goal of the Uniform Methods Project is to strengthen the credibility of energy savings determinations by improving EM&V, increasing the consistency and transparency of how energy savings are determined.

  20. Debris Avalanche Formation at Kick'em Jenny Submarine Volcano

    NASA Astrophysics Data System (ADS)

    Sigurdsson, H.; Carey, S. N.; Wilson, D.

    2005-12-01

    Kick'em Jenny submarine volcano near Grenada is the most active volcanic center in the Lesser Antilles arc. Multibeam surveys of the volcano by NOAA in 2002 revealed an arcuate fault scarp east of the active cone, suggesting flank collapse. More extensive NOAA surveys in 2003 demonstrated the presence of an associated debris avalanche deposit, judging from their surface morphologic expression on the sea floor, extending at least 15 km and possibly as much as 30 km from the volcano, into the Grenada Basin to the west. Seismic air-gun profiles of the region show that these are lobate deposits, that range in thickness from tens to hundreds of meters. The debris avalanche deposit is contained within two marginal levees, that extend symmetrically from the volcano to the west. A conservative estimate of the volume of the smaller debris avalanche deposit is about 10 km3. Age dating of the deposits and the flank failure events is in progress, by analysis of gravity cores collected during the 2003 survey. Reconstruction of the pre-collapse volcanic edifice suggests that the ancestral Kick'em Jenny volcano might have been at or above sea level. Kick'em Jenny is dominantly supplied by basalt to basaltic andesite magmas, that are extruded now as submarine pillow lavas and domes or ejected as tephra in relatively minor phreatomagmatic explosions. Geochemical evolution of this volcano has not, however, reached the stage of generation of volatile-rich silicic magmas that might form highly explosive eruptions.

  1. The US DOE-EM International Program - 13004

    SciTech Connect

    Elmetti, Rosa R.; Han, Ana M.; Williams, Alice C.

    2013-07-01

    The U.S. Department of Energy (DOE) Office of Environmental Management (EM) conducts international collaboration activities in support of U.S. policies and objectives regarding the accelerated risk reduction and remediation of environmental legacy of the nations' nuclear weapons program and government sponsored nuclear energy research. The EM International Program supported out of the EM Office of the Associate Principal Deputy Assistant Secretary pursues collaborations with foreign government organizations, educational institutions and private industry to assist in identifying technologies and promote international collaborations that leverage resources and link international experience and expertise. In fiscal year (FY) 2012, the International Program awarded eight international collaborative projects for work scope spanning waste processing, groundwater and soil remediation, deactivation and decommissioning (D and D) and nuclear materials disposition initiatives to seven foreign organizations. Additionally, the International Program's scope and collaboration opportunities were expanded to include technical as well as non-technical areas. This paper will present an overview of the on-going tasks awarded in FY 2012 and an update of upcoming international activities and opportunities for expansion into FY 2013 and beyond. (authors)

  2. Bayesian Modeling of Biomolecular Assemblies with Cryo-EM Maps

    PubMed Central

    Habeck, Michael

    2017-01-01

    A growing array of experimental techniques allows us to characterize the three-dimensional structure of large biological assemblies at increasingly higher resolution. In addition to X-ray crystallography and nuclear magnetic resonance in solution, new structure determination methods such cryo-electron microscopy (cryo-EM), crosslinking/mass spectrometry and solid-state NMR have emerged. Often it is not sufficient to use a single experimental method, but complementary data need to be collected by using multiple techniques. The integration of all datasets can only be achieved by computational means. This article describes Inferential structure determination, a Bayesian approach to integrative modeling of biomolecular complexes with hybrid structural data. I will introduce probabilistic models for cryo-EM maps and outline Markov chain Monte Carlo algorithms for sampling model structures from the posterior distribution. I will focus on rigid and flexible modeling with cryo-EM data and discuss some of the computational challenges of Bayesian inference in the context of biomolecular modeling. PMID:28382301

  3. Retrospectively exploring the importance of items in the decision to leave the emergency medical services (EMS) profession and their relationships to life satisfaction after leaving EMS and likelihood of returning to EMS.

    PubMed

    Blau, Gary; Chapman, Susan

    2011-01-01

    An exit survey was returned by a sample of 127 respondents in fully compensated positions who left the EMS profession, most within 12 months prior to filling out the exit survey. A very high percentage continued to work after leaving EMS. Respondents were asked to rate the importance of each of 17 items in affecting their decision to leave EMS. A higher than anticipated response to a "not applicable" response choice affected the usability of 8 of these items. Nine of the 17 items had at least 65 useable responses and were used for further analysis. Within these 9, stress/burnout and lack of job challenges had the highest importance in affecting the decision to leave EMS, while desire for better pay and benefits had the lowest importance. Desire for career change was positively related to life satisfaction after leaving EMS and negatively related to likelihood of returning to EMS. Stress/burnout was positively related to life satisfaction after leaving EMS. Study limitations and future research issues are briefly discussed.

  4. EMS-STARS: Emergency Medical Services "Superuser" Transport Associations: An Adult Retrospective Study.

    PubMed

    Hall, M Kennedy; Raven, Maria C; Hall, Jane; Yeh, Clement; Allen, Elaine; Rodriguez, Robert M; Tangherlini, Niels L; Sporer, Karl A; Brown, John F

    2015-01-01

    Abstract Objective. Emergency medical services (EMS) "superusers" -those who use EMS services at extremely high rates -have not been well characterized. Recent interest in the small group of individuals who account for a disproportionate share of health-care expenditures has led to research on frequent users of emergency departments and other health services, but little research has been done regarding those who use EMS services. To inform policy and intervention implementation, we undertook a descriptive analysis of EMS superusers in a large urban community. In this paper we compare EMS superusers to low, moderate, and high users to characterize factors contributing to EMS use. We also estimate the financial impact of EMS superusers. Methods. We conducted a retrospective cross-sectional study based on 1 year of data from an urban EMS system. Data for all EMS encounters with patients age ≥18 years were extracted from electronic records generated on scene by paramedics. We identified demographic and clinical variables associated with levels of EMS use. EMS users were characterized by the annual number of EMS encounters: low (1), moderate (2-4), high (5-14), and superusers (≥15). In addition, we performed a financial analysis using San Francisco Fire Department (SFFD) 2009 charge and reimbursement data. Results. A total of 31,462 adults generated 43,559 EMS ambulance encounters, which resulted in 39,107 transports (a 90% transport rate). Encounters for general medical reasons were common among moderate and high users and less frequent among superusers and low users, while alcohol use was exponentially correlated with encounter frequency. Superusers were significantly younger than moderate EMS users, and more likely to be male. The superuser group created a significantly higher financial burden/person than any other group, comprising 0.3% of the study population, but over 6% of annual EMS charges and reimbursements. Conclusions. In this retrospective study, adult

  5. Investigation of Electromagnetic Signatures of a FPGA Using an APREL EM-ISIGHT System

    DTIC Science & Technology

    2015-12-01

    INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM THESIS...States. AFIT-ENV-MS-15-D-035 INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM THESIS Presented...ENV-MS-15-D-035 INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM Karynn A. Sutherlin, Civilian, DAF

  6. An EM System With Dramatic Multi-Axis Transmitter and Tensor Gradiometer Receiver

    DTIC Science & Technology

    2011-06-01

    FINAL REPORT An EM System With Dramatic Multi-Axis Transmitter and Tensor Gradiometer Receiver SERDP Project MR-1534 JUNE 2011 David C...Technical 2006-20 10 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER An EM System with Dynamic Multi-Axis transmitter and Tensor Gradiometer W912HQ-06-C-0050...ANSI Std. Z39. 18 EM Tensor Gradiometer SERDP MM-1532 i Contents Contents

  7. Measuring Turbulence Mixing in Indonesian Seas using Microstructure EM APEX Floats

    DTIC Science & Technology

    2015-09-30

    Research and Technology). Our engineers have updated the EM-APEX float software and prepared test floats . Monsoon wind forcing, and thereby upper ocean...Microstructure EM-APEX Floats Ren-Chieh Lien Applied Physics Laboratory University of Washington 1013 NE 40th Street Seattle, Washington 98105...modulation of sea surface temperature and air–sea fluxes. APPROACH Two microstructure EM-APEX floats will be deployed in Indonesian Seas. The

  8. EM absorption reduction in wireless mobile antenna using printed paper-based metamaterial

    NASA Astrophysics Data System (ADS)

    Alam, Touhidul; Islam, Mohammad Tariqul; Kibria, Salehin; Cho, Mengu; Faruque, Mohammad Rashed Iqbal

    2017-01-01

    This paper presents a printed negative index metamaterial for electromagnetic (EM) absorption reduction in portable wireless antenna. The perceptible novelty exhibited in this paper is that EM absorption reduction toward the human head with paper-based metamaterial attachment. This research has been performed using human head phantom integrated in the commercially available CST Microwave Studio software package. The EM absorption has been reduced by 13.2 and 6% at 900 and 1800 MHz, respectively.

  9. An EM-IMM based abrupt change detector for landmine detection

    NASA Astrophysics Data System (ADS)

    Venkatasubramanian, Vijayaraghavan; Leung, Henry

    2006-05-01

    In this paper, we propose an expectation maximization (EM) trained interacting multiple model (IMM) abrupt change detector for land mine detection applications. The proposed EM algorithm learns the parameters of the different models in real time without requiring a priori information on either the number of models or the model parameters. Using the real ground penetrating radar (GPR) data, the learning performance of the EM-IMM technique is analyzed and commented upon. Numerical receiver operating characteristics (ROC) analysis and detected images indicate that the proposed EM-IMM based abrupt change detector has a better detection and imaging performance than the conventional Kalman filter for land mine detection applications.

  10. USMC’s Environmental Management Portal for EMS Implementation Service-wide Rollout and Future Plans

    DTIC Science & Technology

    2010-06-16

    at MCB Camp Lejeune in 2004 – EMS implementation efforts resulted in the need for a web -based system for: communicating with EMS stakeholders Up AND...Si:e m Edit Page EM flortal HOMC Fnwnnm1~nt. Welcome to the E~l : xecJtive Order (:O) 13148, m~lemented at all aplicable Le9dership h Ewironmnt91...sharing environmental information • managing EMS-related data and documentation – Additional linkage to other USMC web -based applications – Migration to

  11. Multi-frequency electromagnetic sounding tool EMS. Archaeological discoveries. Case stories.

    NASA Astrophysics Data System (ADS)

    Abu Zeid, N.; Balkov, E.; Chemyakina, M.; Manstein, A.; Manstein, Y.; Morelli, G.; Santarato, G.

    2003-04-01

    EMS is the new patented tool for shallow-depth (up to 7 m) induction frequency sounding. The tool is developed in Institute of Geophysics, Siberian Branch of Russian Academy, Novosibirsk, RUSSIA. Few years of application of EMS prototypes in archaeological prospection gave us the well described picture of possibilities and limitations of EM sounding for archaeological purpose. We would like to present several archaeological case stories including paleolitic, bronze and iron ages, antique and medieval targets discovery. The cases include complex geophysical works using GPR, Vertical DC sounding and magnetometry together with EM sounding. Archaeological proofs of geophysical prospection will be presented. The last September in Italy we have done the comparative work at few Italian archaeological sites. The second EMS prototype has been compared with commercially available tools for EM prospection such as EM mappers, georadars and DC electrical resistivity tomography. In the comparison EMS feature good noise immunity, high sensibility and resolution. In some cases only EMS data shows the buried targets and it was proved immediately by excavation. The researches were done with financial support of RFBR grant # 00-06-80421

  12. Modeling of MHD edge containment in strip casting with ELEKTRA and CaPS-EM codes

    SciTech Connect

    Chang, F. C.

    2000-01-12

    This paper presents modeling studies of magnetohydrodynamics analysis in twin-roll casting. Argonne National Laboratory (ANL) and ISPAT Inland Inc. (Inland), formerly Inland Steel Co., have worked together to develop a three-dimensional (3-D) computer model that can predict eddy currents, fluid flows, and liquid metal containment of an electromagnetic (EM) edge containment device. The model was verified by comparing predictions with experimental results of liquid metal containment and fluid flow in EM edge dams (EMDs) that were designed at Inland for twin-roll casting. This mathematical model can significantly shorten casting research on the use of EM fields for liquid metal containment and control. The model can optimize the EMD design so it is suitable for application, and minimize expensive time-consuming full-scale testing. Numerical simulation was performed by coupling a 3-D finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA can predict the eddy-current distribution and the EM forces in complex geometries. CaPS-EM can model fluid flows with free surfaces. The computed 3-D magnetic fields and induced eddy currents in ELEKTRA are used as input to temperature- and flow-field computations in CaPS-EM. Results of the numerical simulation compared well with measurements obtained from both static and dynamic tests.

  13. Volta phase plate cryo-EM of the small protein complex Prx3

    NASA Astrophysics Data System (ADS)

    Khoshouei, Maryam; Radjainia, Mazdak; Phillips, Amy J.; Gerrard, Juliet A.; Mitra, Alok K.; Plitzko, Jürgen M.; Baumeister, Wolfgang; Danev, Radostin

    2016-01-01

    Cryo-EM of large, macromolecular assemblies has seen a significant increase in the numbers of high-resolution structures since the arrival of direct electron detectors. However, sub-nanometre resolution cryo-EM structures are rare compared with crystal structure depositions, particularly for relatively small particles (<400 kDa). Here we demonstrate the benefits of Volta phase plates for single-particle analysis by time-efficient cryo-EM structure determination of 257 kDa human peroxiredoxin-3 dodecamers at 4.4 Å resolution. The Volta phase plate improves the applicability of cryo-EM for small molecules and accelerates structure determination.

  14. Emergency medical services and "psych calls": Examining the work of urban EMS providers.

    PubMed

    Prener, Christopher; Lincoln, Alisa K

    2015-11-01

    Emergency medical technicians and paramedics form the backbone of the United States' Emergency Medical Service (EMS) system. Despite the frequent involvement of EMS with people with mental health and substance abuse problems, the nature and content of this work, as well as how EMS providers think about this work, have not been fully explored. Using data obtained through observations and interviews with providers at an urban American EMS agency, this paper provides an analysis of the ways in which EMS providers interact with people with mental illness and substance abuse problems, as well as providers' experiences with the mental health care system. Results demonstrate that EMS providers share common beliefs and frustrations about "psych calls" and the types of calls that involve people with behavioral health problems. In addition, providers described their understandings of the ways in which people with mental health and substance use problems "abuse the system" and the consequences of this abuse. Finally, EMS providers discuss the system-level factors that impact their work and specific barriers and challenges to care. These results suggest that additional work is needed to expand our understanding of the role of EMS providers in the care of people with behavioral health problems and that mental health practitioners and policy makers should include consideration of the important role of EMS and prehospital care in providing community-based supports for people with behavioral health needs. (PsycINFO Database Record

  15. On the relative importance of pool morphology and woody debris to distributions of shrimp in a Puerto Rican headwater stream

    USGS Publications Warehouse

    Pyron, M.; Covich, A.P.; Black, R.W.

    1999-01-01

    In this paper, we report the sizes and distributional orientation of woody debris in a headwater rainforest stream in the Luquillo Experimental Forest (LEF), Puerto Rico. We also provide results of a 4-month study of a wood addition experiment designed to increase cover for benthic macroinvertebrates (freshwater shrimp). We added branch-sized woody debris to 20 pools in three streams. We trapped four species of freshwater shrimp (two species of benthic detritivores and two predatory shrimp species) during each of the 4 months following wood additions. An analysis of pool morphology (maximum depth, surface area and volume) provided a useful predictor of shrimp abundances. In general, numbers of shrimps increased with sizes of stream pools. A repeated measures ANOVA demonstrated no effect of woody debris additions on total numbers of shrimp per pool area. Two detritivore species (Atya lanipes, a filter feeder and Xiphocaris elongata, a shredder) decreased in abundance with increased woody debris and there was no statistical relationship between woody debris additions and predators (Macrobrachium carcinus and M. crenulatum). Small woody debris additions may have altered flow velocities that were important to filter-feeding Atya at the microhabitat scale, although the overall velocities within pools were not altered by wood additions. Lower numbers of Atya and Xiphocaris in two of the three streams may result from the occurrence of two predaceous fishes (American eel and mountain mullet) and more predatory Macrobrachium in these streams. One likely interpretation of the results of this study is that the stream pools in these study reaches had sufficient habitat structure provided by numerous rock crevices (among large rocks and boulders) to provide refuge from predators. Addition of woody debris did not add significantly to the existing structure. These results may not apply to stream channels with sand and gravel substrata where crevices and undercut banks are lacking

  16. Decapod crustaceans in fresh waters of southeastern Bahia, Brazil.

    PubMed

    de Almeida, Alexandre Oliveira; Coelho, Petrônio Alves; Luz, Joaldo Rocha; dos Santos, José Tiago Almeida; Ferraz, Neyva Ribeiro

    2008-09-01

    A total of 117 species of freshwater decapod crustaceans are known from Brazil. Knowledge regarding the fauna of Decapoda from inland waters in the state of Bahia, northeast Brazil, is incipient. In spite of its wide territory and rich hydrographic net, only 13 species of limnetic decapods have been reported from that state. The objective of this contribution was to survey decapod crustaceans of some hydrographic basins in southeastern Bahia. The material described herein was obtained in samplings conducted between 1997 and 2005. Voucher specimens were deposited in the carcinological collections of the Museu de Zoologia, Universidade Estadual de Santa Cruz, Ilhéus, Brazil, and Departamento de Oceanografia, Universidade Federal de Pernambuco, Recife, Brazil. A total of 13 species was collected. The carideans were represented by the atyids Atya scabra (Leach, 1815) and Potimirim potimirim (Müller, 1881) and the palaemonids Macrobrachium acanthurus (Wiegmann, 1836), M. amazonicum (Heller, 1862), M. carcinus (Linnaeus, 1758), M. heterochirus (Wiegmann, 1836), M. jelskii (Miers, 1877), M. olfersi (Wiegmann, 1836), and Palaemon (Palaemon) pandaliformis (Stimpson, 1871). The brachyurans were represented by the portunids Callinectes bocourti A. Milne-Edwards, 1879 and C. sapidus Rathbun, 1895, the trichodactylid Trichodactylus fluviatilis Latreille, 1828 and the panopeid Panopeus rugosus A. Milne-Edwards, 1881. Macrobrachium heterochirus represents a new record from Bahia, and M. amazonicum is reported for the first time in southeast Bahia. The occurrence of two extreme different forms of T. fluviatilis was observed. Form A is characterized by the frontal margin of carapace bordered by conspicuous granules, the anterolateral margin provided with developed teeth plus granules, and the posterolateral margin provided with granulation similar to that found on the front. In form B the frontal margin is smooth or has an inconspicuous granulation; the anterolateral margin is

  17. The HOME Team: Evaluating the Effect of an EMS-based Outreach Team to Decrease the Frequency of 911 Use Among High Utilizers of EMS.

    PubMed

    Tangherlini, Niels; Villar, Julian; Brown, John; Rodriguez, Robert M; Yeh, Clement; Friedman, Benjamin T; Wada, Paul

    2016-12-01

    The San Francisco Fire Department's (SFFD; San Francisco, California USA) Homeless Outreach and Medical Emergency (HOME) Team is the United States' first Emergency Medical Services (EMS)-based outreach effort using a specially trained paramedic to redirect frequent users of EMS to other types of services. The effectiveness of this program at reducing repeat use of emergency services during the first seven months of the team's existence was examined. A retrospective analysis of EMS use frequency and demographic characteristics of frequent users was conducted. Clients that used emergency services at least four times per month from March 2004 through May 2005 were contacted for intervention. Patterns for each frequent user before and after intervention were analyzed. Changes in EMS use during the 15-month study interval was the primary outcome measurement. A total of 59 clients were included. The target population had a median age of 55.1 years and was 68% male. Additionally, 38.0% of the target population was homeless, 43.4% had no primary care, 88.9% had a substance abuse disorder at time of contact, and 83.0% had a history of psychiatric disorder. The HOME Team undertook 320 distinct contacts with 65 frequent users during the study period. The average EMS use prior to HOME Team contact was 18.72 responses per month (SD=19.40), and after the first contact with the HOME Team, use dropped to 8.61 (SD=10.84), P<.001. Frequent users of EMS suffer from disproportionate comorbidities, particularly substance abuse and psychiatric disorders. This population responds well to the intervention of a specially trained paramedic as measured by EMS usage. Tangherlini N , Villar J , Brown J , Rodriguez RM , Yeh C , Friedman BT , Wada P . The HOME Team: evaluating the effect of an EMS-based outreach team to decrease the frequency of 911 use among high utilizers of EMS. Prehosp Disaster Med. 2016;31(6):603-607.

  18. Emergency Medical Services Utilization in EMS Priority Conditions in Beirut, Lebanon.

    PubMed

    El Sayed, Mazen; Tamim, Hani; Chehadeh, Ahel Al-Hajj; Kazzi, Amin A

    2016-12-01

    Early activation and use of Emergency Medical Services (EMS) are associated with improved patient outcomes in EMS priority conditions in developed EMS systems. This study describes patterns of EMS use and identifies predictors of EMS utilization in EMS priority conditions in Lebanon METHODS: This was a cross-sectional study of a random sample of adult patients presenting to the emergency department (ED) of a tertiary care center in Beirut with the following EMS priority conditions: chest pain, major trauma, respiratory distress, cardiac arrest, respiratory arrest, and airway obstruction. Patient/proxy survey (20 questions) and chart review were completed. The responses to survey questions were "disagree," "neutral," or "agree" and were scored as one, two, or three with three corresponding to higher likelihood of EMS use. A total scale score ranging from 20 to 60 was created and transformed from 0% to 100%. Data were analyzed based on mode of presentation (EMS vs other). Among the 481 patients enrolled, only 112 (23.3%) used EMS. Mean age for study population was 63.7 years (SD=18.8 years) with 56.5% males. Mean clinical severity score (Emergency Severity Index [ESI]) was 2.5 (SD=0.7) and mean pain score was 3.1 (SD=3.5) at ED presentation. Over one-half (58.8%) needed admission to hospital with 21.8% to an intensive care unit care level and with a mortality rate of 7.3%. Significant associations were found between EMS use and the following variables: severity of illness, degree of pain, familiarity with EMS activation, previous EMS use, perceived EMS benefit, availability of EMS services, trust in EMS response times and treatment, advice from family, and unavailability of immediate private mode of transport (P≤.05). Functional screening, or requiring full assistance (OR=4.77; 95% CI, 1.85-12.29); acute symptoms onset ≤ one hour (OR=2.14; 95% CI, 1.08-4.26); and higher scale scores (OR=2.99; 95% CI, 2.20-4.07) were significant predictors of EMS use. Patients

  19. EM-21 Retrieval Knowledge Center: Waste Retrieval Challenges

    SciTech Connect

    Fellinger, Andrew P.; Rinker, Michael W.; Berglin, Eric J.; Minichan, Richard L.; Poirier, Micheal R.; Gauglitz, Phillip A.; Martin, Bruce A.; Hatchell, Brian K.; Saldivar, Eloy; Mullen, O Dennis; Chapman, Noel F.; Wells, Beric E.; Gibbons, Peter W.

    2009-04-10

    EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energy’s (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge and expertise that will be used to address retrieval challenges across the DOE complex. The RKC is also designed to facilitate information sharing across the DOE Waste Site Complex through workshops, and a searchable database of waste retrieval technology information. The database may be used to research effective technology approaches for specific retrieval tasks and to take advantage of the lessons learned from previous operations. It is also expected to be effective for remaining current with state-of-the-art of retrieval technologies and ongoing development within the DOE Complex. To encourage collaboration of DOE sites with waste retrieval issues, the RKC team is co-led by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL). Two RKC workshops were held in the Fall of 2008. The purpose of these workshops was to define top level waste retrieval functional areas, exchange lessons learned, and develop a path forward to support a strategic business plan focused on technology needs for retrieval. The primary participants involved in these workshops included retrieval personnel and laboratory staff that are associated with Hanford and Savannah River Sites since the majority of remaining DOE waste tanks are located at these sites. This report summarizes and documents the results of the initial RKC workshops. Technology challenges identified from these workshops and presented here are expected to be a key component to defining future RKC-directed tasks designed to facilitate tank waste retrieval solutions.

  20. Perda de massa em ventos empoeirados de estrelas supergigantes

    NASA Astrophysics Data System (ADS)

    Vidotto, A. A.; Jatenco-Pereira, V.

    2003-08-01

    Em praticamente todas as regiões do diagrama HR, as estrelas apresentam evidências observacionais de perda de massa. Na literatura, pode-se encontrar trabalhos que tratam tanto do diagnóstico da perda de massa como da construção de modelos que visam explicá-la. O amortecimento de ondas Alfvén tem sido utilizado como mecanismo de aceleração de ventos homogêneos. Entretanto, sabe-se que os envelopes de estrelas frias contêm grãos sólidos e moléculas. Com o intuito de estudar a interação entre as ondas Alfvén e a poeira e a sua conseqüência na aceleração do vento estelar, Falceta-Gonçalves & Jatenco-Pereira (2002) desenvolveram um modelo de perda de massa para estrelas supergigantes. Neste trabalho, apresentamos um estudo do modelo acima proposto para avaliar a dependência da taxa de perda de massa com alguns parâmetros iniciais como, por exemplo, a densidade r0, o campo magnético B0, o comprimento de amortecimento da onda L0, seu fluxo f0, entre outros. Sendo assim, aumentando f0 de 10% a partir de valores de referência, vimos que aumenta consideravelmente, enquanto que um aumento de mesmo valor em r0, B0 e L0 acarreta uma diminuição em .

  1. Timely bystander CPR improves outcomes despite longer EMS times.

    PubMed

    Park, Gwan Jin; Song, Kyoung Jun; Shin, Sang Do; Lee, Kyung Won; Ahn, Ki Ok; Lee, Eui Jung; Hong, Ki Jeong; Ro, Young Sun

    2017-08-01

    This study aimed to determine the impact of bystander CPR on clinical outcomes in patients with increasing response time from collapse to EMS response. A population-based observational study was conducted in patients with witnessed out-of-hospital cardiac arrest (OHCA) of presumed cardiac etiology from 2012 to 2014. The time interval from collapse to CPR by EMS providers was categorized into quartile groups: fastest group (<4min), fast group (4 to <8min), late group (8 to <15min), and latest group (15 to <30min). The primary outcome was hospital discharge and the secondary outcome was survival with good neurological outcome. Multivariable logistic regression analysis was performed to evaluate the interaction between bystander CPR and the time interval from collapse to CPR by EMS providers. A total of 15,354 OHCAs were analyzed. Bystander CPR was performed in 8591 (56.0%). Survival to hospital discharge occurred in 1632 (10.6%) and favorable neurological outcome in 996 (6.5%). In an interaction model of bystander CPR, compared to the fastest group, adjusted odds ratios (AORs) (95% CIs) for survival to discharge were 0.89 (0.66-1.20) in the fast group, 0.76 (0.57-1.02) in the late group, and 0.52 (0.37-0.73) in the latest group. For favorable neurological outcome, AORs were 1.12 (0.77-1.62) in the fast group, 0.90 (0.62-1.30) in the late group, 0.59 (0.38-0.91) in the latest group. The survival from OHCA decreases as the ambulance response time increases. The increase in mortality and worsening neurologic outcomes appear to be mitigated in those patients who receive bystander CPR. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Covariance Matrix Estimation for the Cryo-EM Heterogeneity Problem*

    PubMed Central

    Katsevich, E.; Katsevich, A.; Singer, A.

    2015-01-01

    In cryo-electron microscopy (cryo-EM), a microscope generates a top view of a sample of randomly oriented copies of a molecule. The problem of single particle reconstruction (SPR) from cryo-EM is to use the resulting set of noisy two-dimensional projection images taken at unknown directions to reconstruct the three-dimensional (3D) structure of the molecule. In some situations, the molecule under examination exhibits structural variability, which poses a fundamental challenge in SPR. The heterogeneity problem is the task of mapping the space of conformational states of a molecule. It has been previously suggested that the leading eigenvectors of the covariance matrix of the 3D molecules can be used to solve the heterogeneity problem. Estimating the covariance matrix is challenging, since only projections of the molecules are observed, but not the molecules themselves. In this paper, we formulate a general problem of covariance estimation from noisy projections of samples. This problem has intimate connections with matrix completion problems and high-dimensional principal component analysis. We propose an estimator and prove its consistency. When there are finitely many heterogeneity classes, the spectrum of the estimated covariance matrix reveals the number of classes. The estimator can be found as the solution to a certain linear system. In the cryo-EM case, the linear operator to be inverted, which we term the projection covariance transform, is an important object in covariance estimation for tomographic problems involving structural variation. Inverting it involves applying a filter akin to the ramp filter in tomography. We design a basis in which this linear operator is sparse and thus can be tractably inverted despite its large size. We demonstrate via numerical experiments on synthetic datasets the robustness of our algorithm to high levels of noise. PMID:25699132

  3. Accuracy of EMS-Reported Last Known Normal Times in Suspected Acute Stroke Patients

    PubMed Central

    Curfman, David; Connor, Lisa Tabor; Moy, Hawnwan Philip; Heitsch, Laura; Panagos, Peter; Lee, Jin-Moo; Tan, David K.; Ford, Andria L.

    2014-01-01

    Background and Purpose The last known normal (LKN) time is a critical determinant of IV tPA eligibility; however, the accuracy of EMS-reported LKN times is unknown. We determined the congruence between EMS-reported and neurologist-determined LKN times and identified predictors of incongruent LKN times. Methods We prospectively collected EMS-reported LKN times for patients brought into the ED with suspected acute stroke and calculated the absolute difference between the EMS-reported and neurologist-determined LKN times (|ΔLKN|). We determined the rate of inappropriate IV tPA use if EMS-reported times had been used in place of neurologist-determined times. Univariate and multivariable linear regression assessed for any predictors of prolonged |ΔLKN|. Results Of 251 patients, mean and median |ΔLKN| were 28 and 0 minutes, respectively. |ΔLKN| was <15 min in 91% of the entire cohort and was <15 min in 80% of patients with a diagnosis of stroke (n=86). Of patients who received IV tPA, none would have been incorrectly excluded from IV tPA if the EMS LKN time had been used. Conversely, of patients who did not receive IV tPA, 6% would have been incorrectly included for IV tPA consideration had the EMS time been used. In patients with wake-up stroke symptoms, EMS underestimated LKN times: mean EMS LKN time - neurologist LKN time = −208 minutes. The presence of wake-up stroke symptoms (p<0.0001) and older age (p=0.019) were independent predictors of prolonged |ΔLKN|. Conclusions EMS-reported LKN times were largely congruent with neurologist-determined times. Focused EMS training regarding wake-up stroke symptoms may further improve accuracy. PMID:24643409

  4. Theme park EMS. It's no Mickey Mouse operation.

    PubMed

    Philips, J H

    1995-07-01

    In a single shift, they can rescue someone trapped in a time warp, perform CPR while menacing monsters look over their shoulders or calmly watch as a motorboat chase ends in a huge ball of fire. It's just another routine day for EMS providers in America's theme parks, where getting ready for unusual calls is the norm. JEMS went behind the scenes with theme park responders to explore the unique challenges of their service environment. What we found was a group of super-dedicated professionals who place genuine hospitality right alongside quality patient care.

  5. The White Dwarf in EM Cygni: Beyond the Veil

    DTIC Science & Technology

    2009-07-10

    reserved. Printed in the U.S.A. THE WHITE DWARF IN EM CYGNI: BEYOND THE VEIL∗ Patrick Godon1,4, Edward M. Sion1, Paul E. Barrett2, and Albert P. Linnell3 1...However, more recent full three-dimensional hydrodynami- cal simulations, e.g., (Blondin 1998; Kunze et al. 2001; Bisikalo et al. 2003), have followed...deflection is believed to cause X-ray absorption in CVs (and LMXBs) around orbital phase 0.7, if the inclination is at least 65◦ ( Kunze et al. 2001

  6. EMS Bill of Rights: what every patient deserves.

    PubMed

    Meador, Steven R; Slovis, Corey M; Wrenn, Keith D

    2003-03-01

    Every EMT, paramedic, supervisor and EMS medical director must stress that our job is to treat every patient the way we'd like to be treated or the way we'd want one of our family members treated. Those charged with supervision must ensure that EMTs and paramedics receive the support and training necessary to allow adherence to the 10 objectives outlined in this article. Quality-assurance reviews, quality-improvement programs, provider comments and complaints from the public must all be used to improve the care we deliver. Prehospital care should be constantly improving the delivery of excellent, life-saving care.

  7. A compulsator driven rapid-fire EM-gun

    SciTech Connect

    Pratap, S.B.; Bird, W.L.

    1984-03-01

    A compulsator-driven railgun is an attractive alternative to the homopolar generator-inductor-switch configuration, especially for repetitive duty. A conceptual design of a rapid-fire EM-gun system is presented. The generator is sized to accelerate a 0.08-kg projectile to 2 to 3 km/s at a 60 pulse-per-second repetition rate. Initial design parameters are discussed, and example current and velocity waveforms are given. The generator is discharged at the proper phase angle to provide a current zero just as the projectile exits the muzzle of the railgun.

  8. Unravelling the structures of biological macromolecules by cryo-EM

    PubMed Central

    Fernandez-Leiro, Rafael; Scheres, Sjors H.W.

    2016-01-01

    Preface Understanding how proteins and other biological macromolecules perform their complicated tasks in the living cell is often aided by knowledge of their three-dimensional structures. Because many tasks involve the cleavage or formation of chemical bonds, structural characterisation at the atomic level is most useful. Recent developments in electron microscopy of frozen hydrated samples (cryo-EM) have provided unprecedented opportunities for the structural characterization of biological macromolecules. This is resulting in a wave of new information about biological processes that were impossible to characterize with previously existing techniques in structural biology. PMID:27629640

  9. State of the Art in EM Field Computation

    SciTech Connect

    Ng, C.; Akcelik, V.; Candel, A.; Chen, S.; Folwell, N.; Ge, L.; Guetz, A.; Jiang, H.; Kabel, A.; Lee, L.-Q.; Li, Z.; Prudencio, E.; Schussman, G.; Uplenchwar, R.; Xiao, L.; Ko, K.; /SLAC

    2006-09-25

    This paper presents the advances in electromagnetic (EM) field computation that have been enabled by the US DOE SciDAC Accelerator Science and Technology project which supports the development and application of a suite of electromagnetic codes based on the higher-order finite element method. Implemented on distributed memory supercomputers, this state of the art simulation capability has produced results which are of great interest to accelerator designers and with realism previously not possible with standard codes. Examples from work on the International Linear Collider (ILC) project are described.

  10. EMS response at a hazardous material incident: some basic guidelines.

    PubMed

    Plante, D M; Walker, J S

    1989-01-01

    Emergency medical response to a scene where hazardous materials are potentially involved is becoming more commonplace. Following routine response procedures could result in the incapacitation of the rescue crew. Unique to this paper are some suggestions from the fire fighting literature on how to deal with these incidents. As with any type of potential disaster, it has been found that response is much more effective if potential problems are examined beforehand and protocols developed. Emergency physicians in their role as on-site emergency medical services (EMS) medical controllers should play a leading part in the development and implementation of these protocols.

  11. Single-particle cryo-EM at crystallographic resolution

    PubMed Central

    Cheng, Yifan

    2015-01-01

    Until only a few years ago, single-particle electron cryo-microscopy (cryo-EM) was usually not the first choice for many structural biologists due to its limited resolution in the range of nanometer to subnanometer. Now, this method rivals X-ray crystallography in terms of resolution and can be used to determine atomic structures of macromolecules that are either refractory to crystallization or difficult to crystallize in specific functional states. In this review, I discuss the recent breakthroughs in both hardware and software that transformed cryo-microscopy, enabling understanding of complex biomolecules and their functions at atomic level. PMID:25910205

  12. Demonstrate a Leap-Ahead EM Gun Armament System that Proves the Maturity of the Technology for Future Combat Systems

    DTIC Science & Technology

    2001-03-26

    This report, comprised of viewgraphs, discusses the Army EM program and the challenges it faces. Topics include pulsed power, hypervelocity lethality plans, systems and technology integration , and the army EM gun program.

  13. EMS Attitudes Towards Geriatric Prehospital Care And Continuing Medical Education in Geriatrics

    PubMed Central

    Peterson, Lars-Kristofer N.; Fairbanks, Rollin J.; Hettinger, Aaron Z.; Shah, Manish N.

    2008-01-01

    Objectives To understand the opinions of emergency medical service (EMS) providers regarding their ability to care for older adults, the domains of geriatric medicine in which they need more training, and the modality through which continuing education could be best delivered. Design Qualitative study using key informant interviews. Setting Prehospital EMS system in Rochester, New York. Participants EMS providers, EMS instructors and administrators, emergency physicians, and geriatricians. Outcome Measures Semi-structured interviews were conducted using an interview guide that addressed the following domains: 1)knowledge and skill deficiencies; 2)recommendations for improvement of geriatrics continuing education; 3)delivery methods of education. Results Participant responses were generally congruous despite the diverse backgrounds, and redundancy was achieved rapidly. All participants perceived a deficit in EMS education on the care of older adults, particularly related to communications with patients and skilled nursing facility staff. All desired more geriatric continuing education for EMS providers, especially in communications and psychosocial issues. Education was desired in various modalities. Conclusion Further geriatrics continuing education for EMS providers is needed. Some specific topics relate to medical issues, but a large proportion involve communications and psychosocial issues. Education should be delivered in a variety of modalities to meet the needs of the EMS community. Emerging online video technologies may bridge the gap between learners preferring classroom based modailities and those preferring self-study modules. PMID:19170777

  14. Developing State and National Evaluation Infrastructures- Guidance for the Challenges and Opportunities of EM&V

    SciTech Connect

    Schiller, Steven R.; Goldman, Charles A.

    2011-06-24

    Evaluating the impacts and effectiveness of energy efficiency programs is likely to become increasingly important for state policymakers and program administrators given legislative mandates and regulatory goals and increasing reliance on energy efficiency as a resource. In this paper, we summarize three activities that the authors have conducted that highlight the expanded role of evaluation, measurement and verification (EM&V): a study that identified and analyzed challenges in improving and scaling up EM&V activities; a scoping study that identified issues involved in developing a national efficiency EM&V standard; and lessons learned from providing technical assistance on EM&V issues to states that are ramping up energy efficiency programs. The lessons learned are summarized in 13 EM&V issues that policy makers should address in each jurisdiction and which are listed and briefly described. The paper also discusses how improving the effectiveness and reliability of EM&V will require additional capacity building, better access to existing EM&V resources, new methods to address emerging issues and technologies, and perhaps foundational documents and approaches to improving the credibility and cross jurisdictional comparability of efficiency investments. Two of the potential foundational documents discussed are a national EM&V standard or resource guide and regional deemed savings and algorithm databases.

  15. Broadband EM radiation amplification by means of a monochromatically driven two-level system

    NASA Astrophysics Data System (ADS)

    Soldatov, Andrey V.

    2017-02-01

    It is shown that a t